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ZEEB ROAD, ANN ARBOR, Ml 48106 18 BEDFORD ROW, LONDON WC1R 4EJ, ENGLAND 8106471 e Sil v a , Ju a r e z d e So u s a AN ENGINEERING-ECONOMIC COMPARISON OF FIVE DRYING TECHNIQUES FOR SHELLED CORN ON MICHIGAN FARMS Michigan State University Ph.D. University Microfilms International 300 N. Zeeb Road, Ann Arbor, M I 48106 1980 PLEASE NOTE: In a ll cases this material has been filmed in the best possible way from the available copy. Problems encountered with this document have been id e n tifie d here with a check mark . 1. Glossy photographs ________ 2. Colored illu s tra tio n s ________ 3. Photographs with dark background 4. Illu s tra tio n s are poor copy ________ 5. °r1nt shows through as there 1s text on 6. In d is tin c t, broken or small p rin t onseveral 7. Tightly bound copy with p rin t lost in spine ________ 8. Computer printout pages with in d is tin c t p rin t ________ 9. 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A N N A R 3 0 R M l •18106 '3131 761-4700 AN ENGINEERING-ECONOMIC COMPARISON OF FIVE DRYING TECHNIQUES FOR SHELLED CORN ON MICHIGAN FARMS By Juarez de Sousa e Silva A DISSERTATION Submitted to Michigan State U n iversity in p a r tia l f u lfillm e n t of the requirements fo r the degree o f DOCTOR OF PHILOSOPHY Department o f A g ric u ltu ra l Engineering 1980 ABSTRACT AN ENGINEERING-ECONOMIC COMPARISON OF FIVE DRYING TECHNIQUES FOR SHELLED CORN ON MICHIGAN FARMS By Juarez de Sousa e Silva At least 70% of the to ta l corn production in Michigan was estimated to be dried in automatic batch or in-bin batch-type sys­ tems. At an i n i t i a l moisture content of 26% and an after-d rying value of 15.5%, approximately 3 .6x10^ KJ or 14.4x10® lite r s of liq u id pro­ pane were required to dry the 1979 Michigan corn crop. Previous research in other U.S. Corn Belt states had shown that in-bin counterflow, in-bin dryeration, n a tu ra l-a ir, and lowtemperature combination drying produce high-quality corn and can substantially reduce the drying energy requirement under favorable weather conditions. The objectives o f this thesis were to study the fe a s ib ility o f applying and economically comparing the above tech­ niques with conventional batch drying under Michigan conditions. 3 Five steel bins of 85 m capacity were erected a t a farm in B e lla ire , Michigan. The system was designed to te s t each technique and adequately handle the farm's corn production. Four storage bins were arranged in a rectangular pattern, so that each could be f ille d with an auger from a central point, with an automatic cross-flow Juarez de Sousa e S ilv a batch dryer discharging from th at position. Two o f the storage bins were used to dry corn as a combination system. The f i r s t had a 3 3 c en trifu g al fan with a 3.7 Kw motor d eliverin g 2m /min/m o f natural a i r through a 3.7 m bed. 3 3 A fan deliverin g 1.6 m /min/m with a 2.2 Kw motor and a 10 Kw e le c tr ic a l heater were connected to the lowtemperature system. The th ird bin was f it t e d w ith a fan d eliverin g 3 3 0.8 m /min/m fo r the in -b in dryeration. To the fourth bin an a irflo w 3 3 rate of 0.3 m /min/m was applied to cool hot grain from the in-b1n counterflow dryer. The procedures. q u a lity of the corn was g reatly affected by the drying The batch and in-bin counterflow dryers resulted in dried corn w ith s ig n ific a n tly more stress-cracks and higher breakagete s t numbers than the other drying techniques. The energy e ffic ie n c y and drying capacity of the automatic batch dryer increased s u b s ta n tia lly when the corn was dried in the combination systems to 23% rather than to 15%. The energy e ffic ie n c y improved from 7521 to 5750 KJ/Kg HgO, and the drying capacity (exclud­ ing cooling time) from approximately 2.3 to 3.5 to n /h r. The two combination systems showed the best energy e ffic ie n c y w ith 3227 and 3755 KJ/Kg HgO, res p e c tiv ely , fo r the n a tu r a l-a ir and low-temperature combination drying. The lowest operating energy costs o f $2.76 and $ 2 .8 0 /ton were observed 1n the 1n-bin counterflow and in -b in d ryeration , re s p e c tiv e ly , whereas the low-temperature combination drying showed the highest cost ($ 5 .4 0 /to n ). Juarez de Sousa e Silva A computer program (TELPLAN 03) was used to determine the annual per-ton cost of the fiv e systems. Total drying costs of $13.02, $14.34, $15.09, $15.82, and $16.63/ton were observed fo r the in-bin dryeration, in-bin counterflow, n a tu ra l-a ir, batch, and lowtemperature systems, respectively. H u k ill's analysis fo r deep-bed drying was employed success­ fu lly to simulate the batch and in-bin counterflow dryers. Simula­ tions results indicated that d ryin g -air temperature has a strong e ffe c t on the drying cost and e fficien cy of the batch dryer, whereas drying temperatures higher than 72°C have no sig n ifican t e ffe c t on the cost and efficiency of the in-bin counterflow dryer. However, increasing the drying temperature increases the dryer capacity of the in-bin counterflow substantially. In Michigan, the potential annual energy savings of the a lte r g native drying systems are on the order of 2.0x10 MJ or the equiva­ lent of 7.5x10^ lite r s of liq u id propane. For B razilian conditions, the simulation results indicate that an energy of 3988 and 8243 KJ/Kg HgO w ill be required fo r the in-bin counterflow and batch dryer, respectively. Approved Major Professor Approved Department Chairman ACKNOWLEDGMENTS I wish to thank the members o f my guidance committee, Dr. R. C. Brook (A g ric u ltu ra l Engineering), Dr. L. Copeland (Crop and Soil Science), Dr. L. J. Connor (A g ricu ltu ra l Economics), and the out­ side examiner, S. Kalchik, fo r t h e ir assistance and friendship during th is work. I sincerely appreciate the help of Dr. S. B. Harsh and his graduate student, E. M. R is te r, from the Department of A g ricu ltu ral Economics. I am indebted to S. Kalchik, his s is te r , who not only fa th e r, mother, gave th e ir help but also treated me brother, and as oneof th e ir fam ily. To my guidance committee chairman, Dr. F. W. Bakker-Arkema, who provided not only moral and technical support since 1976 but also his friendship and examples th a t w ill p o s itiv e ly influence my career and my way o f l i f e , sincere thanks from me and from my fam ily. For th e ir moral support, fiv e fe llo w graduate students and th e ir fa m ilie s deserve special mention: Juan Rodrigues, Ricardo Miranda, Mauro Montalvo, Romeu Fustado, and Rafael da S ilv a . E. Mawra and V. Dalpasquale, graduate students in the A gri­ c u ltu ra l Engineering Department, must be thanked fo r th e ir help dur­ ing the experimental phase of th is work. Deepest appreciation goes to my w ife, Sonia, and my sons, Mauro Henrique and V ictor, fo r th e ir patience and tolerance in accepting the separation from th e ir husband and father during much of the time of this work. To them I can only o ffe r myself and my love fo r the constant encouragement and devotion they have provided. iii TABLE OF CONTENTS Page LIST OF TA B LES............................................................................................ v ii LIST OF FIGURES............................................................................................ ix LIST OF SYMBOLS............................................................................................ x ii Chapter 1. INTRODUCTION 1.1 1.2 1.3 2. Michigan Corn Production and EnergyUse . . . . How Corn Is Dried in M ic h ig a n ........................ O b je c tiv e s ................................................................ GRAIN DRYING AND STORAGE IN BRAZIL 1 2 3 6 ...................................... 7 The Need fo r Drying and Storage in B razil . . . The Storage Environment, Education, and Technology ..................................................................... 2.2.1 Grain Storage Situations in B ra z il, From Producer to Consumer..................... 2 .2 .2 Governmental Storage Operation. . . . 8 10 13 LITERATURE REVIEW .......................................................................... 15 2.1 2.2 3. .................................................................................. 3.1 3.2 3.3 3.4 Necessity of Grain Drying ........................................ Drying Procedures fo r D iffe re n t Usesof Corn . . 3.2.1 Drying Grain fo r Animal Feed ................ 3 .2 .2 Drying Corn fo r M i l l i n g ............................ 3 .2 .3 Drying Grain fo r S e e d ................................ Commercial Corn Quality as Affected by Drying Procedures .................................................... 3.3.1 Test W e ig h t.................................................... 3 .3 .2 Broken C o rn .................................................... Drying Systems........................................................ 27 3.4.1 Batch D r y e r s ................................................ 3 .4 .2 Continuous-Flow Dryers ............................ 3 .4 .3 Low-Heat and No-Heat In-Bin Storage D r y i n g ......................................................... iv 8 15 18 19 20 22 22 23 24 28 30 31 Page 3 .4 .4 3 .4 .5 3.5 4. EXPERIMENTAL.................................................. 4.1 4.2 4.3 4.4 5. Combination Systems and Dryeration . . In-B in Counterflow Drying ("Shivvers S y s t e m " ) ................................ Drying-System Evaluation ............................................. 3.5.1 Drying Equations ........................................ 3 .5 .2 Basic Assumptions ........................................ 44 44 48 51 55 59 Test L o c a t i o n .................................................................. Design of A lte rn a tiv e Drying System ..................... Drying Procedures .......................................................... Instrumentation and Measurement ............................. 59 60 61 69 RESULTS AND DISCUSSION............................................................... 72 5.1 5.2 5.3 5.4 5.5 5.6 Ambient and Drying Conditions ................................. 5.1.1 High-Temperature Phase ............................ 5 .1 .2 Low-Temperature Phase ................................ Product Q u a l i t y .............................................................. E ffe c t o f the Weather and Design Parameters on the Drying P r o c e d u r e ......................................... Drying E ffic ien c y and Dryer Performance . . . . 5.4.1 O v e r v ie w ......................................................... 5 .4 .2 Energy Consumption and Operating C o s ts .............................................................. 5 .4 .3 Comparison of the Operational Char­ a c te ris tic s o f the Batch and In-B in Counterflow Dryers ..................... Experimental Versus Predicted Results ................. 5.5.1 Model V alid atio n ........................................ 5 .5 .2 Dryer Parameters Study ............................ Economics of the System s............................................. 5.6.1 General Considerations ............................ 5 .6 .2 Capital Budgeting Analysis .................... 5 .6 .3 Budgeting Analysis of the Systems . . . 72 72 76 77 82 84 84 85 87 99 99 105 118 118 121 122 6. SUMMARY................................................................................................ 129 7. SUGGESTIONS FOR FUTURE RESEARCH ............................................... 132 REFERENCES....................................................................................................... 134 APPENDICES....................................................................................................... 142 A. B. BUDGETING ANALYSIS OF THE 378-TON (15,000 BU) DRYING SYSTEMS .......................................................................... 143 THE FARMER'S POINT OF V I E W ....................................................... 165 v Page C. TELPLAN 03 USER'S GUIDE............................................................ 170 D. DRYING-TIME CALCULATION FOR THE IN-BIN COUNTERFLOW SYSTEM ................................................................ 197 vi LIST OF TABLES Table 1. 2. 3. 4. Page The Percentage of Corn Dried by D iffe re n t Drying Techniques in Michigan and SomeMidwestern States . . Shelled Corn Dried A r t i f i c ia l l y in Michigan, by Dryer Type ..................................................................................... E ffect o f Harvest Date and I n i t i a l Moisture Content on the Minimum Airflow Rate (cu m/min3) Required to Dry Corn With LessThan .5% DryMatter Loss . . . . Dryer Specifications of Farm Fans Dryer Model AB-8B, 1978 M o d e l........................................................................ 4 5 41 62 5. In-Bin Counterflow Dryer Specifications fo r "Shivvers 68 S y s te m " ............................................................................ 6. Ambient and Drying Conditions fo r the Experimental Tests (D aily Averages) in B e lla ire , Michigan, November 1979, fo r the Cross-flow Batch Dryer Without Cooling ......................................................................... 73 Ambient and Drying Conditions fo r the Experimental Tests (In -B in Counterflow) in B e lla ire , Michigan, November 1978 75 Ambient and Drying Conditions fo r the Experimental Tests (In -B in Counterflow) in B e lla ire , Michigan, November 1979 78 Average G rain-Q uality Parameters fo r the Cross-flow Batch Dryer, 1978 Drying S e a s o n ......................................... 79 G rain-Q uality Parameters fo r the In-Bin Counterflow Dryer, 1978 Drying Season ........................................... 80 Actual Energy Consumption, Operating Costs (1979 P ric e s ), and Corn-Quality Parameters fo r Six A lte rn ativ e Corn-Drying Methods at the Kalchik Farms, B e lla ire , Michigan,Fall 1978 ................................... 86 7. 8. 9. 10. 11. Table 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. Page Standardized Energy Consumption and Operating Costs (1979 Prices) fo r Five A lte rn a tiv e Corn-Drying Methods in Michigan, Based on the Results o f the Kalchik Farms Tests, F a ll 1978, in B e lla ire , M ic h ig a n ................................................................................... 88 Average Energy From Liquid Propane Consumption, Drying E ffic ie n c y , Drying Time, and Dryer Capacity as Calculated by the Drying Model and as Measured in the Field Tests With the Batch D r y e r ................. 96 Energy Consumption, Drying E ffic ie n c y , Water Removed, and Dryer Capacity as Calculated by the Drying Model (1978 Data) With the In-Bin Counterflow Dryer . 97 Energy Consumption, Drying E ffic ie n c y , Water Removed, and Dryer Capacity as Calculated by the Drying Model (1979 D ata), With the In-Bin Counterflow Dryer . 98 Regression Analysis Between the Observed and Calculated Drying Times fo r the In-Bin Counterflow D r y e r ....................................................................................... ... Regression Analysis Between the Observed and Calculated Drying Times fo r the Batch Dryer . 101 ................. 101 Estimation/Assumptions fo r Investment Cost, Salvage Value, In te re s t, D irect and In d ire c t Energy Costs, Labor, and Maintenance Costs fo r the Five Drying S y s te m s ................................................................................... 125 Economic Analysis of Five A lte rn a tiv e On-Farm CornDrying and Storage Systems fo r Michigan Weather Conditions (1980 Prices) .......................................................... 126 General Economic Analysis fo r a 1 0 -Year Period fo r the Batch-Drying System .......................................................... 148 General Economic Analysis fo r a 10-Year Period fo r the In-B in Counterflow Drying System ................................. 152 General Economic Analysis fo r a 10-Year Period fo r the Low-Temperature Combination Drying System . . . . 156 General Economic Analysis fo r a 10-Year Period fo r the N a tu ra l-A ir Combination Drying System ..................... 160 General Economic Analysis fo r a 10-Year Period fo r the In-B in Dryeration System .................................................. 164 v iii LIST OF FIGURES Figure Page 1. Grain-Flow Pattern in Brazil ................................................ 11 2. Types of Stress-Cracks in Dried Corn .................................... 25 3. Parallel-Flow or Batch-In-Bin System .................................... 33 4. Internal View of a Radial Recirculating BatchDryer 34 5. Internal View of a Cross-flow Batch Dryer ........................ 35 6. Internal View of a Modified Cross-flow DryerUsing Warm Exhaust A ir From the Cooling Section .................... 36 Illu s tra tio n of the Three Types of Continuous-Flow D ry e rs .......................................................................................... 37 8. Schematic of High-Speed Continuous-FlowDryers ................... 38 9. A ir and Product Temperatures Versus Depth for a Single-Stage Concurrent-Flow Dryer .................................... 39 10. Schematic of a Low-Temperature In-Bin Drying System 40 11. Grain Moisture P ro file From the Top to the Bottom Within a Recirculation In-Bin Dryer With an Airflow Rate of 9.15 m3/min/mz ............................................ 46 Schematic of the Internal View of an In-Bin Counter­ flow Drying “Shivvers System" ............................................ 47 13. Deep-Bed Drying Curves ................................................................ 57 14. Schematic of the In-Bin Counterflow Drying System 58 15. Schematic of the Location of the Various Drying Modes a t the Kalchik Farms at B e lla ire , Michigan 7. 12. 16. General View of the Kalchik In s ta lla tio n . . . . . . . ..................... . 17. Farm-Fans Automatic Batch Model AB-8B (3-ton Capacity) ix . . 63 64 . 65 Figure 18. Page View of the Total In-Bin Counterflow "Shivvers S y s te m " ......................................................................................... 66 19. D etails of the 13 HP Blue Flame "Shivvers System" 67 20. Exhaust-Air R elative Humidity and Temperature Versus Drying Time fo r the Batch Dryer Drying From 26 to 15.5% w b ......................................................................................... 91 Exhaust-Air R elative Humidity and Temperature Versus Drying Time fo r the Batch Dryer Drying From 24 to 20% w b ............................................................................................. 92 Exhaust-Air R elative Humidity and Temperature Versus Drying Time fo r the Batch Dryer Drying From 35.7 to 18.3% w b ................................................................................. 93 Variation in the Final Grain Moisture Content With Regard to the Sampling Time fo r the Batch Dryer Under C o n s id e ra tio n ................................................................. 94 Relationship Between the Observed and Estimated Drying Times fo r the In-Bin Counterflow Dryer (Cycling Time) ............................................................................. 103 Relationship Between the Observed and Estimated Drying Times Using Equation 13 fo r the Crossflow Batch D r y e r ......................................................................... 104 E ffect of Drying Temperature and Desired Final Moisture Content on the Drying Time and Dryer Capacity fo r the "Shivvers" In-Bin Counterflow Dryer a t 34 c fm /ft* (9 .4 cm H20 ) ......................................... 107 E ffect of Drying Temperature and Desired Final Moisture Content on the Drying Time and Dryer Capacity fo r the "Farm Fans" Batch Dryer ........................ 108 E ffect o f Drying Temperature and Average Final Moisture Content on the Energy Cost and Drying Efficiency fo r the "Shivvers" In-Bin Counterflow Dryer Under Consideration ..................................................... 110 E ffect of Drying Temperature and Average Final Moisture Content on the Energy Cost and Drying Efficiency fo r the "Farm Fans" Batch Dryer Under Consideration ............................................................................. Ill 21. 22. 23. 24. 25. 26. 27. 28. 29. x . . . Figure 30. 31. 32. 33. 34. Page E ffe ct o f the Ambient R elative Humidity and DryingA ir Temperature on the Drying E fficien cy of the In-B in Counterflow Dryer ............................................................ 113 E ffe c t o f I n i t i a l and Final Moisture Content on the Drying Time and Drying E fficien cy o f the In-Bin Counterflow DryerUnder Consideration ............................... 115 E ffe c t o f I n i t i a l and Final Moisture Content on the Drying Time and Drying E ffic ien cy o f the Crossflow Batch Dryer Under Consideration .................................. 116 E ffe ct o f A irflo w Rate on Dryer Capacity and Energy Cost fo r the "Shivvers" In-Bin Counterflow Dryer . . . 119 E ffe c t o f A irflo w Rate on Dryer Capacity and Energy Cost fo r the "Farm Fans" Batch Dryer Under Consideration ............................................................................... 120 xi LIST OF SYMBOLS c = Cooling rate of a ir passing through grain of uniform moisture content Cp = Specific heat of dry a i r , BTU/lbm °F (KJ/Kg °C) D = Number of dimensionless depth units to the point where M is computed D' = Number of dimensionless depth units to the point where M is computed (Barre et a l . , 1971 analysis) H = Time of h alf response, hour h = Latent heat of vaporization of moisture in the grain, BTU/lb (KJ/Kg) K = drying constant per hour M = Moisture content (db) of grain at a given time and location in the dryer, decimal Me = Equilibrium moisture content (db), decimal Mq = I n it ia l moisture content (db), decimal MR = Moisture r a tio , (M - Mg)(Mq - M0 ) m = Mass flow ra te , lb /f t^ min. (Kg/m^ min) P = Constant fo r any given set of drying conditions T = Drying a ir temperature, °F (°C) Tabs = Product temperature, °R (°K) T = Temperature at which a ir is in equilibrium with the grain 9 at its in it ia l moisture content a fte r the a ir has cooled along a wet bulb temperature lin e , °F (°C) Tq - A ir temperature entry of the grain, °F (°C) xi i W = Density o f dry m atter, lb f t 3 (Kg/m3) X = Kernel depth in the drying bed, f t . (m) Y = Number o f dimensionless time units Y' = Number of dimensionless time units (Barre e t a l . , 1971 analysis) xi i i 1. INTRODUCTION The United States, the number-one food producer in the world, uses only 3% of the national petroleum consumption at the farm level (Stout et a l . , 1979). Each year, the United States produces approxi­ mately 222 m illio n tons of feed, 66.2 m illio n tons of food grains, and over 45 m illion tons of soybeans (USDA, 1977). To maintain this f i r s t position in food production, American farmers have been making large expenditures in energy from petroleum, e le c tr ic ity , or other sources. Because i t is s t i l l pro fitab le to do so, one United States farmer can produce enough food fo r more than 50 other individuals (CAST, 1977). However, with the continuing fuel supply lim ita tio n s , rapidly increasing prices, and the lack of price projections, the p r o fit margin in agricultural production is continuously decreasing. This dramatic situation urges American farmers to take a new look at production techniques and to consider seriously any operation to reduce costs and the uncertainty of future supplies. The Council for A gricultural Science and Technology (CAST, 1977) suggested the follow ­ ing farm operations to minimize energy costs and consumption in the near future: 1. reduce energy use fo r f e r t i li z e r applications and tilla g e ; 2. substitute enterprises that consume less energy; 1 2 3. invest in altern ate technologies th at (a) substitute energy inputs and (b) reduce energy use ( e .g ., a lte rn a tiv e grain-drying technologies); 4. invest in new technology th at uses such energy sources as the sun, the wind, and biomass; 5. modify farm enterprises to make them more e f f ic ie n t for the natural environmental conditions; and/or 6. cease farming i f the adjustments are too d i f f ic u l t . Since drying accounts fo r more than 60% of the energy required fo r corn production (Bakker-Arkema e t a l . , 1974), there is no sounder reason to consider investment in grain-drying technologies in a very short run, as stated in recommendation 3 above. 1.1 Michigan Corn Production and Energy Use According to Fedewa and Pscodna (1978, 1979), in the produc­ tion of corn fo r grain, Michigan ranked ninth in the United States in 1977 and 1978. The corn produced accounted fo r 3.0% of the total United States production in 1977 and 2.6% of the to ta l in 1978. The shelled corn production in Michigan increased from 2.3 m illio n tons in 1960 to 3.9 m illio n tons in 1975. According to the Michigan Agricul­ tu ra l Crop Reporting Service, the predicted corn production fo r 1979 was about 5.5 m illio n tons. From 1960 to 1975, the energy used for drying increased from 75.2xl0^°KJ to 329.5xlO^KJ (Brook, 1977). This increase in energy consumption apparently resulted from the s h ift from an ear-corn to a shelled-corn harvesting system. There are several reasons fo r harvesting the grain e a rly , when its moisture content is s t i l l high, instead o f le ttin g i t dry in the 3 f ie ld . While 1n the f i e l d , the crop is subjected to stresses due to drying and rew etting by the ambient r e la tiv e humidity and ra in ; i t can also be contaminated by mold or damaged by in sects. At lower moisture contents, harvest losses are higher due to grain sh a tterin g . Hence, i f the crop is harvested a t high moisture content, drying is required fo r safe storage. In some cases, by harvesting the crop e a rly , i t is possible to grow a second crop on the same f i e l d , with an increase in the annual production per acre. As previously s tate d , more than 60% of the energy required to produce corn on the farm is used fo r a r t i f i c i a l drying. In 1972, 65% o f the Michigan corn was dried in some kind o f h e a te d -a ir drying system; the prevalent fu el types were propane and natural gas (BakkerArkema e t a l . , 1974). In 1977, however, 74.9% o f the Michigan corn was a r t i f i c i a l l y d rie d ; the prevalent fu el type was propane, which accounted fo r 90.3% o f the to ta l drying energy. The percentage o f corn dried in Michigan from 1974 to 1977 is shown in Table 1, which also shows the status o f corn drying in four other midwestern states in the United S tates. 1.2 How Corn Is Dried in Michigan A pplication o f energy to lower the moisture content o f har­ vested corn in Michigan is without any doubt a necessary practice because o f the c h a ra c te ris tic weather conditions in the s ta te . For example, the 1977 corn-harvesting season presented Michigan farmers w ith a unique d i f f ic u l t y . Because o f the prolonged wet weather in the f a l l , p art o f the corn was l e f t standing in the f ie l d . This corn was harvested the next spring, and, according to Fedewa and Table 1 .—The percentage of corn dried by d iffe re n t drying techniques in Michigan and some midwestern states. State or Region Off-Farm On-Farm Year 1974 1975 1976 1977 1974 1975 1976 b Michigan Northern0 W. Central Central E. Central Southwest S. Central Southeast Total 40.2 77.9 98.6 51.6 43.3 31.6 42.1 57.7 45.3 Illin o is Indiana Iowa Wisconsin 21.0 12.0 37.5 39.7 33.5 12.2 30.6 45.3 Source: Dried A r t if ic ia lly Dried Naturally in Field or During Storage® 1974 1975 10.7 23.8 16.8 57.0 47.2 47.4 65.7 55.2 38.4 51.0 77.5 86.3 60.2 57.3 65.0 87.2 68.4 52.0 39.5 4.4 78.1 56.7 79.7 72.6 73.5 72.5 85.0 86.6 68.9 52.9 87.4 68.6 Fedewa et a l. (1978) and Keyon et a l. (1976). aDoes not include corn stored in silos as high-moisture corn. ^Survey was not conducted for Michigan in 1976. cUpper Peninsula, northwest, and northeast combined. 1976 1977 b b 50.0 77.3 18.5 35.6 18.7 25.9 25.2 25.1 13.0 11.8 29.3 44.8 1977 2.8 5.3 1.4 1.2 9.3 2.7 2.7 3.9 3.7 1.5 1.7 2.3 3.0 1.5 0.6 1.0 27. 10.4 18.3 2.8 7.7 1.6 1.5 1.3 2.4 2.0 1.6 1.8 2.3 1.9 2.1 s Pscodna (1978), th is might possibly have caused the change in drying technique used, as shown in Table 2. Table 2: Shelled corn dried a r t i f i c i a l l y in Michigan, by dryer type. Year (%) Dryer Type 1974 1975 1977 Batch 38.3 48.1 50.0 Continuous flow 45.7 39.5 40.4 Bin 14.3 9.2 8.4 1.7 3.2 0.5 Natural a ir Source: Fedewa e t a l . (1978). I t is estimated th a t a t lea st 70% of the 5 .5 -m illio n -to n Michigan corn crop is a r t i f i c i a l l y dried (Bakker-Arkema e t a l . , 1979), p rim a rily in automatic batch dryers between 82° and 110°C and in -b in batch-type drying systems between 43° and 60°C. At an average harvest moisture content o f 26% (wb) and an a fte r-d ry in g value of 15.5%, about 140 kg of water per ton of corn are removed in the dry­ ing process (Brooker e t a l . , 1974). Assuming an average energy e ffic ie n c y of 7,000 KJ/Kg in conventional on-farm high-temperature drying systems ( e .g ., batch and continuous-flow d ry e rs ), approximately 3.6x10 12 KJ or 15x10 7 lit e r s of liq u id propane were required to dry the 1979 Michigan corn crop; th is is equivalent to $18,280,000 a t current prices. 6 1.3 Objectives The overall objective of this on-farm-type research is to conduct and compare, at the production le v e l, fiv e techniques for drying shelled corn on Michigan farms. The fiv e drying techniques are (a) batch drying, (b) high/low-temperature drying, (c) hightemperature/natural-air drying, (d) in-bin counterflow drying, and (e) in-bin dryeration. The specific objectives required to achieve the overall objective are as follows: 1. to demonstrate the technical fe a s ib ility of the high/low- temperature, high-temperature/natural a ir , in-bin counterflow, and in-bin dryeration drying systems in Michigan; 2. to demonstrate to the Michigan agricultural community that the present energy requirements fo r corn drying on the farm can be reduced by as much as 40% by applying one of these alternative drying methods instead of conventional high-temperature batch drying; 3. to study the economic aspects of the systems; 4. to study safety implications with respect to operation and product quality; 5. to use the Hukill (1954) analysis to describe in-bin counterflow drying and to predict the time required for drying; and 6. to study the effects that various drying parameters have on the capacity, efficien cy, and energy cost of in-bin counterflow and batch-drying systems. 2. GRAIN DRYING AND STORAGE IN BRAZIL B ra z il, a republic of South America and the f i f t h largest country in the world, occupying 3,287,303 square miles and having more than 100 m illio n inhabitants, is basically an agrarian country. U ntil a few years ago, i t was considered to have one of the lowest production levels of grain/acre in the world, but th is s itu a tio n is rapidly changing. B razil is now one o f the world's foremost countries in a g ric u ltu ra l production. In addition to producing more than 50% of the world's coffee, B razil ranks f i r s t in sugar cane and cocoa produc­ tion and second in soybeans. Ranking th ird in corn production worldwide, B razil achieved in 1980 its record production of approxi­ mately 21 m illio n tons (Veja No. 603, 1980). Unfortunately, even though corn production sub stan tially increased from 16 m illio n tons in 1975 (IBGE, 1978) to an estimated 21 m illio n tons in 1980, provision of the necessary storage and drying f a c ilit ie s has not been well planned. In many regions of Brazil (based on the w rite r's experience), storage f a c ili t ie s under normal conditions are inadequate in quantity and q u a lity . For example, during the 1980 harvesting season the t e r r ito r y of Rondonia faced a serious problem. With an estimated 276,000-ton production, harvested at a high i n i t i a l moisture content and with no trans­ portation a v a ila b le , only a 60,000-ton storage capacity was pro­ vided. Also, in the region o f A lta Floresta in the state of 8 Mato Grosso do S u l, collapse of the fuel supply caused heavy losses in ric e production and an increased transportation cost (Veja No. 601, 1980). Under conditions o f stress, such as dramatic increases in production, the status o f the current grain drying and storage s itu a tio n in B razil is brought into sharp focus. 2.1 The Need fo r Drying and Storage in B razil In 1980, an estimated 46 m illio n tons o f cereal grain (wheat, r ic e , soybeans, and corn) were produced in B razil (Veja No. 603, 1980). This fig u re does not include grain sorghum, beans, and coffee. The fa c t th at these crops are seasonal and harvested a t ce rta in times o f the year necessitates holding them fo r varying lengths o f time to provide consumers with as uniform a grain supply as possible. In the northern and northeastern parts o f B r a z il, where a g ric u ltu re (excluding sugar cane, r ic e , and cocoa) is p rim a rily at the subsis­ tence le v e l, or where the grain is used fo r animal feed, farm drying and/or storage is a necessity. In those regions, only a small por­ tio n of the cereal grain is marketed; however, storage fo r th a t which is marketed must be provided, mainly in urban centers. Storage in urban centers in the northern and northeastern regions is also a necessity because the major source fo r urban-population supplies is from the southern s ta te s , and the commodities must be kept in good condition u n til they are delivered to the consumers. 2.2 The Storage Environment, Education, and Technology I t is not d i f f ic u l t to document the need fo r grain drying and storage in B r a z il, which comprises 60% of the South American continent 9 (approximately the size of the United S tates). However, providing storage and technology capable of preserving the qu ality o f cereal grains in the various regions of the country is a more complex under­ taking. Much of Brazil is characterized by climates that are not conducive to the safe storage of grain. High temperatures and re la ­ tiv e humidities exist over prolonged periods of time, making the poten­ t ia l fo r deterioration due to insects, molds, and rodents extremely high. Even with the best of f a c ili t ie s , storing grain under tro p i­ cal conditions is a d if f ic u lt task. In many situations the individuals responsible fo r storing grain in Brazil are not completely aware of the hazards involved in storing the product. Most of them may be aware of the p o s s ib ility of physical losses due to insects, rodents, and molds. However, only a few are concerned with contamination in the form of urine, excrement, h a ir, and toxins that occurs as a resu lt of insect, rodent, and mold in fe s ta tio n . With only a few exceptions, the biochemical changes that occur, reducing the n u tritio n a l q u ality of the grain as food fo r humans and animals, are completely ignored. The manner in which grain is managed or maintained in storage (mainly a t the farm le v e l) re fle c ts the lack of technological knowledge of the in d i­ viduals responsible for the storage f a c i l i t i e s . Besides the loss in market q u a lity , large quantities of grain are lost yearly because of improper storage techniques and/or f a c il it i e s . Fortunately, the government is concerned about this situ atio n and has invested in grain drying and storage education. The National Center fo r Storage Training (CENTREINAR), located on the campus of the Federal University 10 of Vicosa, has recen tly been established. This in s titu tio n , which has a number o f s p e c ia lis ts on it s s t a f f , has been given the respon­ s i b i l i t y o f developing, adapting, and testin g technology applicable to the B ra zilia n storage sector. CENTREINAR is also responsible fo r tra in in g ind ividu als in grain drying and storage a t d iffe r e n t levels fo r the in d u s tria l, governmental, and p riv a te storage sectors. 2.2.1 Grain Storage Situations in B r a z il, From Producer to Consumer In recent years the B ra zilia n government has been spending a s ig n ific a n t amount o f money in an e f f o r t to elim inate bottlenecks and also to reduce transportation costs and losses in its storage and transportation systems. Because o f the complexity o f the "producer- consumer" path, the bottlenecks are very d i f f ic u l t to determine and are sometimes in e v ita b le . As grain flows from producer to consumer, a m ultitude of paths may be follow ed. Figure 1 illu s tr a te s the complexities that may be encountered in these paths. same m arketing-pattern network. No two states appear to have the Whatever pathway grain takes from producer to consumer, i t is in e v ita b le th a t storage w ill take place at one or more points in th is flow. The simplest s itu a tio n is one in which the producer holds grains on the farm fo r his own consumption. Quantities held on the farm generally range from 60 to 70% o f the to ta l production. Of course, there are many exceptions; fo r instance, a ll of a farm er's production may be sold to m ills a t harvest time and bought back as needed. However, the major portion o f grain produced in B razil is 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Producer Local dealers Merchant truckers Government operation Wholesale d istributor Grain orocessor Trucker d istribu to r Retail d istribu to r Exporter Consumer 12 stored on farms. Since the bulk o f the country's cereal food supply is stored on the farm fo r at least 60 days, i t seems iro nic that improvement of th is level of storage has not yet received the neces­ sary consideration or emphasis. Various types of farm-storage f a c ilit ie s are used in B ra z il. They vary from discarded o il drums to modern s ilo s . With some excep­ tions in the southern states, farm storage in B ra z il, at best, leaves grain supplies vulnerable to insect and bird depredation and, in areas where high temperatures and humidity e x is t, to deterioration due to molds. Fortunately, in recent years the B razilian government has been seeking a way to improve farm storage. Some studies have been conducted, mainly by the Federal University of Vigosa, where an economic and physical study of on-farm storage in various regions of Brazil was undertaken (UREMG, 1968). With some exceptions, most of the f a c il it ie s used at the urban level do not vary s ig n ific a n tly from those used on the farm. The urban-level storage referred to here is th a t maintained by local dealers in small c itie s . Grain is held in bags and stored in various types of structures, usually shops or storage rooms. Security from insect, rodent, and bird attack is usually comparable to that on farms. Cooperative e ffo r t on the part of farmers in the southern states has resulted in the development of improved community-level storage f a c i l i t i e s . ing quite common. Fortunately, th is form of cooperation is becom­ 13 Urban-level storage can form the f i r s t lin k in the movement o f grain o ff the farm in to major marketing channels. Lack o f develop­ ment of these " f i r s t c o lle c tio n points" in the flow o f grain from producer to consumer has been one of the major factors hindering the success o f some g ra in -s ta b iliz a tio n programs. The existence o f inade­ quate storage f a c i l i t i e s a t the urban level is not the main drawback, but rather the lack of an adequately developed marketing system (tra n s ­ portation f a c i l i t i e s , grading systems, and market news). The weakness o f th is lin k in the overall flow o f grain from producer to consumer is p a r t ia lly responsible fo r large storage f a c i l i t i e s being empty or not f u lly used. In most parts o f B r a z il, the urban sector o f the grain trade uses warehouses o f various types o f construction to store bagged grain. Some processors are developing bulk storage a t th e ir f a c i l i ­ tie s ; however, most of the grain at the processor level is stored in bags because grain is handled"in bags throughout the marketing system. The q u a lity o f storage a t p rivate and commercial central storage f a c i l i t i e s ranges from very poor to e xc ellen t and depends, in p a rt, on the level of knowledge possessed by those responsible fo r the grain. 2 .2 .2 Governmental Storage Operation In most governmental operations, storage f a c i l i t i e s are used in support o f grain purchasing, s ta b iliz a tio n , and/or reserve programs. In general, storage f a c i l i t i e s range from sm all, simple 14 warehouses to elaborate, large-bulk-handling silo s. The larger storage f a c ilit ie s are generally located in the major consumption centers and at port locations. Smaller f a c ilit ie s are usually located at minor consumption centers and are used e ith e r fo r c o lle c t­ ing grains or fo r d is trib u tin g them to the population. One of the major problems is determining where storage f a c ilit ie s should be located and what types and how many should be b u ilt. In many parts of B ra z il, large f a c ilit ie s stand id le or are underused; hence planning and implementation of storage programs have not been completely successful. In general, improvement is needed in the movement of grains from the producer to the consumer (farm, urban, commercial, proces­ sor, and government storage). To summarize, problems encountered in storing grains safely in Brazil are of a b io lo g ic al, economical, and p o litic a l nature. There is a lack of knowledge of the factors caus­ ing grain deterioration and proper "management." Note; The w rite r drew from his own experience in w riting this chap­ te r. Therefore, only two references were c ite d . 3. LITERATURE REVIEW Grain and seeds are both exceedingly durable and highly perishable. I f they are harvested soundly and are subsequently kept a t low moisture content and low temperature, they may re ta in th e ir origin al germ inability and other q u a litie s fo r a long period of time. Based on th is information, the following lite r a tu r e review was developed. 3.1 Necessity of Grain Drying The objective of proper grain storage is to maintain through­ out the storage period the b io lo g ic a l, chemical, and physical char­ a c te ris tic s th at the grain possessed Immediately following harvesting. The drying operation, which w ill be of concern in th is study, is an inherent part of the storage process. According to Brooker e t a l . (1974), the q u a lity of grain cannot be improved during storage. Improperly harvested grain w ill remain o f low q u a lity no matter how well i t is stored. High harvest moisture content and improper har­ vesting (high cylinder speed) are the most important factors a ffe c t­ ing the q u a lity of the grain and, of course, its s to r a b ility . The principal causes o f loss in q u a lity and quantity of stored grains and seeds are rodents, insects, m ites, birds, and fungi. Respiration may, to a lesser extent, contribute to a loss o f dry matter during grain storage, although the losses due to respiration are minor 15 16 compared to those re s u ltin g from the causes previously mentioned (Brooker e t a l . , 1974). In 1968, according to studies conducted by the Federal Univer­ s ity o f Vicosa and supported by the National Bank o f the Development, the amount o f grain lo s t by on-farm storage in B r a z il, the th ird larg e s t corn producer in the world (Schmidt, 1978), was estimated a t 35% (UREMG, 1968). In the United S tates, losses from grain pests are not as larg e as in some parts o f B r a z il, where c lim a tic conditions and f a c i l i t i e s fo r handling and storing o f grains are less favorable. Nevertheless, losses do occur in the United S tates, and the cost of prevention and c o n tro l, according to Cotton (1963), was estimated to be about $400 m illio n annually in 1962. The means o f c o n tro llin g rodents, in sects, m ites, and birds are known, and they are being e ffe c tiv e ly ap p lied , as indicated by the low degree o f in fe s ta tio n in grain stored in the United States and Canada. The same is not tru e fo r fun gi-typ e spoilage, which only a few decades ago was recognized as a more important cause o f spoilage. The major types o f losses caused by mold growth in stored grains are: (a ) degrease in g e rm in a b ility , (b) d isco lo ratio n o f p a rt or a l l o f the seed k e rn e l, (c ) various biochemical changes, (d) production o f toxins th a t may be in ju rio u s i f consumed by man or anim als, and (e) loss in weight. The major conditions th a t Influence the development o f storage fungi in stored grain are: (a) grain moisture content, (b) grain tem perature, (c ) storage tim e, (d) degree o f f ie ld fungi in fe s ta tio n , (e ) foreign m aterial present, and ( f ) insect and mite a c t iv it ie s . 17 High moisture content is the single most important contributor to mold growth. In r e a lit y , fungi are not d ire c tly affected by mois­ ture content; they are actuated by re la tiv e humidity (Christensen & Kaufmann, 1974). Warm temperatures are also conducive to mold growth. Molds grow most rapidly a t temperatures between 10° and 35°C and at high re la tiv e humidity (Brooker et a l . , 1974). Prolonged growth of fungi on moist grain a t temperatures in the range of 1.7° to 7.2°C may resu lt in the formation of mycotoxins (USDA, 1968). During harvesting, the kernels are subjected to mechanical impacts, which cause stress-cracks and breakage resulting in "open doors" to organism invasion (Brooker et a l . , 1974). Along with mold development, under unfavorable harvesting and storage conditions the grain moisture content may be high enough to permit heating and other types of damage such as discoloration, loss o f v ia b ilit y , increase in fa tty a c id ity , and deterioration in n u tritiv e q u a litie s (Christensen & Kaufmann, 1969). According to Copeland (1976), the increase in fa tt y a c id ity in seeds is la rg e ly due to invasion by fungi and is a major symptom of seed deterio ratio n a t moisture content about 14%. The respiration process involves release of energy by oxida­ tion of carbohydrates and other organic nu trients. the major substance in seeds and especially in corn. represented by the following equation: C6H2 °6 + 6 °2 * 6 H2 ° + 6 C02 + 677 cal Carbohydrate is Respiration is 18 When res p ira tio n proceeds rap id ly and produces heat more quickly than i t can be dissipated, the temperature of the grain rises and mold growth is more lik e ly . Although ignored in the past as a cause of heating in stored g ra in , microorganism a c tiv itie s are now generally recognized as a major cause fo r heating. According to Christensen and Kaufmann (1969), most or a ll heating up to 21-24°C is caused by microorganisms. The growth of fungi decreases at r e la tiv e humidities below 70% and temperatures below 0°C. Thus i t is essential to dry the product at a safe moisture-content level and maintain the product a t th is mois­ ture level during storage. The 12.5-13.5% moisture-content range is generally accepted to be the ideal range fo r long-term storage of corn (Brooker e t a l . , 1974). 3.2 Drying Procedures fo r D iffe re n t Uses of Corn The amount of moisture content in grain has a d e fin ite e ffe c t on i t s c h a ra c te ris tic s during harvesting, storin g, germinating, and m illin g . For such processes, there is an optimum or c r it ic a l moisture content above or below which the results are not s a tis fa c to ry . A g ric u ltu ra l m aterials must be dried by d iffe re n t procedures because o f the inherent ch ara cte ristic s with respect to the follow ing facto rs: 1. Temperature tolerance. High temperatures may reduce germination, p a r t ia lly cook a product, or change its chemical or physical c h a ra c te ris tic s . 19 2. Humidity response. Grains that undergo physiological or other changes during drying have to be dried with a ir of a specific humidity. For example, i f soybeans are to be used fo r seed, the re la ­ tiv e humidity of the drying a ir must be kept above 40% regardless of the d ryin g -air temperature; below 40% re la tiv e humidity, severe crack­ ing damage can occur i f the a ir temperature is too high (Dalpasquale, 1979). 3.2.1 Drying Grain fo r Animal Feed Even though corn is not the most important human food source, i t is by fa r the most important one fo r animal agriculture. Corn constitutes the largest proportion of most mixed feeds, often making up 50-70% of the to tal formula. q u a lity of the finished feed. This has a great e ffe c t on cost and I t is estimated that the to tal volume used as animal feed both in farm use and in commercial rations in the United States is about 85% of the domestic usage (Stewart, 1978). The e ffe c t of drying temperature on the n u tritio n a l value of corn as an animal feed has received considerable research attention. Hathaway et a l. (1952) found that corn dried a t temperatures above 60°C s ig n ific a n tly decreased as a source of energy and also decreased in p a la ta b ility . Sullivan et a l. (1975) reported that heat has a d e fin ite e ffe c t on the nu tritio nal value of corn but that the decrease in commercial q u a lity due to drying at an elevated temperature may not correspond to a decreased value of corn as animal feed. Jensen et a l. (1960) reported th at drying temperatures of 60°, 8 2 .2 °, and 104°C have no deleterious effects on the n u tritiv e 20 value of corn fo r swine, as measured by growth rate and feed use. Gansmann et a l. (1952) found only minor e ffe c ts on the n ia c in , panto­ thenic acid, rib o fla v in , and pyridoxine content of corn dried at 4 3 .3 °, 4 8 .8 °, and 82.2°C. However, Jensen e t a l . (1960) found that when pigs had fre e access to roller-ground corn, the percentage of selection of the 60°, 8 2 .2 °, and 104°C corn samples was 73.5/15, 25.0%, and 1.5%, respectively. In a more recent study, Jensen (1978) showed th a t by roast­ ing corn at 14% and 23% moisture, lysine a v a ila b ility was reduced at 150°C and at 127°C. He found th at niacin was unaffected by roasting temperature, but pyridoxine a v a ila b ility was s ig n ific a n tly reduced in 14%-moisture corn when i t was dried at 160°C. Although investigators may disagree about n u tritio n a l changes due to high-temperature drying, they do agree th a t physical and chemi­ cal characteristics such as consistency, energy content, p a la ta b ility , harness, color, moisture, and protein and amino acid p r o file are affected by drying temperature (Williamson, 1975). 3 .2 .2 Drying Corn fo r M illin g Although farmers and elevator operators who are drying corn often consider only it s feed c h a ra c teristics , corn m ille rs are seriously concerned about the increased volume of a r t i f i c i a l l y dried corn coming into the market (Freeman, 1978; Rutledge, 1978). In 1974, fo r example, over 7.6 m illio n tons of corn were sold fo r indus­ t r i a l purposes (Anon, 1975). 21 According to MacMasters e t a l . (1 9 5 9 ), improper drying a ffe c ts the grain protein and starch con ten t, thereby creating problems such as: (a ) loss o f starch in by-products because o f incompleteness and d i f f i c u l t y in grind ing , and (b) poor separation o f starch and protein in the c e n trifu g e s , re s u ltin g in a low recovery and poor q u a lity of the recovered starch. Among other problems, d i f f i c u l t y in drying the corn gluten fr a c tio n , poor germ separation, low y ie ld o f o il from germ, and high f a t t y acid content o f the o il are freq u e n tly c ite d . Freeman (1978) reported th a t corn dried from 30% to 15% moisture in a sing le pass had a 25% lower production c a p acity, poor dewatering o f coarse f ib e r , increased starch in gluten w ith a correspondingly lower starch y ie ld per bushel o f corn, higher protein content o f is o la te d starch, and lower starch v is c o s ity . According to MacMasters (1 9 5 9 ), the d if f ic u lt ie s o f process­ ing a r t i f i c i a l l y dried corn are so g re a t th a t some corn w e t-m ille rs refuse to purchase corn known or suspected to have been dried a t high temperatures. Watson and H irata (1962) concluded th a t since kernel v ia ­ b i l i t y is e v id en tly more e a s ily a lte re d by drying conditions than are other properties examined, corn dried to preserve v i a b i l i t y should in v a ria b ly be suited fo r starch manufacture. should not exceed 71°C. The drying temperature 22 3.2.3 Drying Grain fo r Seed In general, the techniques used to dry seeds do not d iffe r greatly from those used to dry grain fo r other purposes such as for feed or m illin g . However, a high degree of germination must be pre­ served, and according to Copeland (1976), extra care must be taken in dryer selection, control, and management. be injurious to seed in d iffe re n t ways. The drying operation can I t has been well estab­ lished that d ry in g -a ir temperatures higher than 38°C are detrimental to seed q u ality. Copeland (1976) stated th at the higher lim it varies with the type of seed; he established 38°C as a safe lim it. Wileman and U llstrup (cited in H u k ill, 1954) showed that drying tem­ peratures up to 49°C can be used with corn of 25% moisture content or less, but above 25% the drying temperature should not exceed the 38°C lim it. The rate of moisture removal is also an important fac­ to r; excessive drying rates may cause stress-cracks. Overdried seeds are also susceptible to mechanical damage, which is also detrimental to seed q u ality (Copeland, 1976). 3.3 Commercial Corn Quality as Affected by Drying Procedures Discussed in the previous section of the lite r a tu re review were some of the effects of a r t i f ic i a l drying of corn on its composi­ tio n , n u tritio n a l value, v ia b ilit y as seed, and industrial-processing characteristics. However, the above q u a litie s are not taken into account in determining the actual market grade. Corn is cla s s ifie d into one o f fiv e o f fic ia l commercial grades in the United States on the basis of te st weight, moisture 23 content, proportion o f broken corn and foreign m a te ria l, and the proportion of damaged kernels. In th is section, these factors and how they are affected by drying are reviewed. 3.3.1 Test Weight The te s t weight o f corn depends on a combination o f true density of the kernel and it s packing c h a ra c te ris tic s . The value of the te s t weight usually changes during the drying process. The amount o f the change is a function o f the i n i t i a l and fin a l moisture content, the drying temperature, grain v a rie ty , type and amount o f im purity, and the degree o f damage. cator of grain q u a lity . Test weight is generally taken as an in d i­ Freeman (1978) stated th a t low te s t weight per se reduces the value o f corn fo r wet m illin g , regardless of the reason fo r low te s t weight. H ill (1975) reported th a t m illin g t r ia ls showed no s ig n ific a n t difference in y ie ld and q u a lity of the fin a l product between corn of high and low te s t weights, and th at no research had been published to in d icate a c o rre la tio n between te s t weight and q u a lity of the product. According to Stewart (1978), te s t weight w ithin normal ranges (over 50 lb ./b u .) has not shown any c o rre la tio n with the energy level or feeding value of corn. Under normal conditions, the lower the moisture content, the higher the te s t weight. Overdrying the corn and using excessive temperature w ill damage the kernels and re s u lt in smaller test-w eight increase. At the same fin a l moisture content range, the higher the i 24 drying temperature, the lower the te s t weight, according to Shove (1978), Gustafson et a l. (1978), and Peplinski et a l. (1975). 3 .3 .2 Broken Corn Despite the fact th at drying per se does not d ire c tly a ffe c t the number of broken kernels, i t is well known that grain is physi­ c a lly and physiologically damaged when dried at excessively high temperatures. This can be expected to increase the grain's suscepti­ b i l i t y to handling damage. One of the apparent types of physical damage due to high temperature is stress-carcking. Thompson and Foster (1963) defined stress-cracks as the fissures in the endosperm, or starchy inside of the kernel, in which the seed coat is not ruptured (see Figure 2). The results of Thompson and Foster (1963), in which they related the drying speed and amount of expected breakage, have been confirmed by various authors. Factors other than d ryin g -air temperature and drying rate th a t are closely related to stress-crack formation are drying systems, i n i t i a l moisture content, and cooling rate (Ross & White, 1972). These researchers also found that there is a general decrease in stress-cracking as the grain is dried to lower moisture contents and as drying is started at lower moisture contents. Gustafson et a l. (1978) concluded that the fin a l moisture content fo r high-temperature drying above 18% does not appear to cause a sig n ific a n t increase in breakage s u s c e p tib ility , but the product of heating time and change of moisture content appears to be the best predictor of change in breakage. 25 Single Stress-Crack M u ltip le Stress-Cracks Figure 2. Double Stress-Crack Crazed Kernel Types o f stress-cracks in dried corn. Chowdhury & K line, 1978.) (From 26 In the same fin a l moisture range, Shove (1978) presented a ta b le th a t c le a rly shows the d ifferen ce in s u s c e p tib ility to breakage (as indicated by the Stein Breakage Test) fo r corn dried w ith high temperatures and w ith natural a ir . Differences in breakage o f up to 11.7% by weight were obtained. Chowdhury and Kline (1978) stated th a t l i t t l e inform ation is a v a ila b le regarding the e ffe c t of harvesting and pre-harvesting con­ d itio n s on the formation o f stress-cracks in the corn kern el. Accord­ ing to these w rite rs , Roberts (1972) reported an average o f 25.8% damaged kernels (before a r t i f i c i a l drying) due to stress-cracks. Paulsen and Nave (1978) found th a t the percentage o f kernels with no stress-cracks in three combine types ranged from 90% to 100%. They concluded th a t there was no s ig n ific a n t v a ria tio n in percentage of stress-cracks between c y lin d e r- or ro to r-ty p e combines or among the various peripheral speeds. Attempts have been made to develop a te s tin g device th a t can predict the s u s c e p tib ility of grain to mechanical damage. The designs are based on subjecting the corn samples to a predetermined loading or impact condition and evaluating the res u lta n t damage. At present, only the Stein Breakage Test is used to provide a standard evalua­ tio n of the mechanical damage done to corn during harvestin g, handling, and drying. The great v a ria tio n in breakage s u s c e p tib ility caused by te s t conditions such as moisture content and grain temperature is pointed out as being a major disadvantage in using the Stein Breakage Test. 27 3.4 Drying Systems There are two basic methods of grain drying: temperature methods. high- and low- In the United States, high-temperature drying has been the primary technique for more than 25 years. Although this method requires only a short drying time, i t also has very low energy e ffic ie n c y , high fo s s il-fu e l consumption, and low product q u a lity . Low-temperature grain drying (with no heat or with low heat from e le c tr ic ity , liq u id propane, solar energy, or any kind of heat source) is an energy-efficient process and results in a high-quality product when proper management is applied. The spoilage risk in warm and humid areas is the main problem encountered with low-temperature drying. Brooker et a l . (1978) subdivided the on-farm high- and lowtemperature drying methods into the following categories: 1. high-speed, high-temperature batch and continuous-flow 2. continuous-flow in-bin drying systems; 3. batch-in-bin drying systems with and without grain dryers; s tirrin g ; 4. low-heat and no-heat in-bin drying systems with and without grain s tirrin g ; and 5. combination systems, in which high-speed batch or continuous-flow systems are combined with low-heat or no-heat in-bin drying systems. The grain-drying techniques w ill be reviewed, based on the preceding c la s s ific a tio n . 28 3.4.1 Batch Dryers A popular method used on sm all- to medium-sized farms in the United States is batch drying. Three common types of batch dryers are: 1. Batch-in-bin dryer, in which the a ir enters the grain through a perforated flo o r or a duct arrangement a t the bottom of the bin and leaves through the top surface o f the grain (Figure 3). 2. Batch dryer (Figure 4 ), in which a ir enters the grain from a c y lin d ric a l perforated central duct and leaves mainly through the perforated external w a ll. 3. Column-batch dryer, in which the a i r moves across or perpendicular to a statio n ary grain column (Figure 5 ). In any batch dryer, the grain a t the a ir intake side dries most ra p id ly ; the grain on the exhaust side takes the longest to dry. The resu ltan t grain-m oisture-content gradient is pointed out as being one of the greatest disadvantages o f batch drying. According to Brooker e t a l . (1974), the problem o f moisture gradient is more accentuated in batch -in -b in dryers because of the p o s s ib ility of in s u ffic ie n t grain mixing when the dryer is unloaded. Among the wide v a rie ty of batch-drying methods (Brooker et a l . , 1974; Sutherland, 1975; Brooker et a l . , 1978), column-batch dryers are p a rtic u la rly popular because o f t h e ir simple construction and operation and because t h e ir i n i t i a l cost is generally lower than that o f continuous-flow-type dryers. According to Bakker-Arkema e t a l . (1978), column-batch dryers d if f e r from batch-in-bin systems in the follow ing ways: (a) the bed 29 thickness is sig n ific a n tly less (.3 0 -.4 6 cm), (b) the airflow is 3 3 higher (greater than 40 m /m1n/m ) , (c) the a ir temperature is higher (up to 112°C), and (d) the moisture gradient across the grain column is less (3-5% wb). Although column dryer designs have changed re la tiv e ly l i t t l e over the past decade, some innovative models are continually being marketed. (See, for example, Figure 6.) The energy efficiency of the design shown in Figure 6 is higher than that of conventional column-batch dryers. However, the fan must overcome the resistance of two columns o f grain. Also, chaff and fines that f i l t e r through the cooling section w ill accumulate in the heating plenum. The sys­ tem can not be used fo r dryeration. The column-batch dryer has a number of design and operational parameters that can be adjusted to optimize dryer performance. Column height, length, and thickness can be varied to achieve the desired capacity. To achieve a particular fin a l moisture content, the res i­ dence time w ill be a function of the in it ia l moisture content, dryinga ir temperature, airflow ra te , and, to a lesser degree, in le t grain temperature. Kirk (1959), working with grain-column thicknesses of 10.2 20.3, 30.5, and 40.6 cm, made the following observations: 1. the 20.3, 30.5, and 40.6 cm columns are very sim ilar in th e ir drying-air requirement; 2. a ir requirements, and thus operating costs, are not m aterially increased with an increase of up to 5.08 cm of water for 20.3, 30.5, and 40.6 cm columns in s ta tic pressure; 30 3. despite the increase in drying capacity with an increase in s ta tic pressure, fo r a given drying-column area the 20 .3, 30.5, and 40.6 cm columns are a ll closely grouped in th e ir drying output, and the increase in capacity remains v ir tu a lly lin e a r with s ta tic pres­ sures in the range of .63 to 5.1 cm of water. In some batch dryers, the drying period can be divided into two parts: Ultra-high-tem perature a ir (102-113°C) is provided during the f i r s t part of the cycle and lower-temperature a ir (79.4-83.3°C ) during the second phase. The following general statements can be made about columnbatch and batch-in-bin dryers (Morey et a l . , 1976): 1. fuel and fan operation costs are reduced by decreasing the a irflo w rate at constant temperature or by increasing the d ry in g -a ir temperature at a constant a irflo w rate; 2. moisture-content and grain-temperature gradients are reduced by increasing the a irflo w rate at constant a ir temperature or by decreasing th e d ry in g -a ir temperature at a constant a irflo w ra te . The capacity o f a batch dryer is decreased by a reduction in a i r temperature or a irflo w rate. The capacity and e ffic ie n c y are increased by increasing the column thickness or bed depth, although th is design increases the grain-temperature and moisture-content gradients across the grain column or grain bed. 3 .4 .2 Continuous-Flow Dryers Continuous-flow dryers are categorized by the r e la tiv e direc­ tio n of grain and a i r movement inside the drying chamber (Figure 7 ). 31 High-speed, high-temperature continuous-flow dryers {Figure 8) are normally used fo r high-volume operations. With the exception of the semi-continuous in -b in counterflow system, such dryers do not function as storage u n its. As stated by Brooker e t a l. (1978), the term "portable" is often applied to farm-type continuous-flow dryers. P o rta b ility in these units is only a fa c to r in moving the u n it from the facto ry or dealer to the farm lo catio n , and does not re fe r to th e ir permanence. When the grain and a irflo w are in the same d irec tio n in the drying chamber, the system is said to be a concurrent-flow dryer. This system has only recently become commercially av a ilab le (Brooker e t a l . , 1978). In concurrent-flow dryers the hottest a ir (149-260°C) encounters the w ettest grain; th is causes the a i r to cool rap id ly because of the high rate o f evaporation (Brook, 1977). The a ir and product temperatures versus grain depth are illu s tr a te d in Figure 9. The advantages of a concurrent-flow over a cross-flow dryer are its lower energy usage, higher grain q u a lity , lower p o llu tio n , and discharge of grain a t a uniform moisture content (Brook, 1977; Brooker et a l . , 1978; Dalpasquale, 1979). The in -b in continuous-flow dryers are c la s s ifie d as counter­ flow dryers and w ill be discussed in d e ta il la te r in the "Shivvers System" section. 3 .4 .3 Low-Heat and No-Heat In-Bin Storage Drying Low-heat and no-heat (natural a ir ) in -b in drying include such processes as la y er drying, e le c tric -h e a t drying, solar drying, 32 and n a tu ra l-a ir drying. According to Brooker et a l . (1978), these techniques may or may not be associated with grain s tirrin g (Figure 10). N a tu ra l-a ir and low-temperature-air drying are sim ilar processes (Bakker-Arkema et a l . , 1978). The difference is that no heat (except the approximately 1°C from the fan) is supplied to the intake a ir in the n a tu ra l-a ir system, whereas low-temperature drying is accomplished with an additional 3 -5 .5°C(Shove, 1978) from propane combustion, e le c tric heat, or another a lte rn a tiv e heat source such as a solar c o lle c to r, cob burner, or heat pump (Zink et a l . , 1978). Liquid propane gas and e le c tric heat are the most widely used heat sources for low-temperature drying; both have the benefit of low capital investment. However, Brooker et a l . (1978) asserted that liq u id propane is usually not used because interval timers or other on-off control systems are needed to lim it the to ta l heat delivered. The a irflo w rate required fo r a drying system design depends on the harvest date, harvest moisture content, and location. When operating at a specified airflo w ra te , drying performance is further dependent upon fan and heater management and on year-to-year varia­ tion in weather conditions (Pierce & Thompson, 1978). Table 3 con­ tains simulated results and illu s tra te s the minimum airflo w depend­ ing on the in itia l-m o is tu re content and harvesting data at d iffe re n t locations in the United States. N a tu ra l-a ir and low-temperature drying do have lim ita tio n s . Because of the low a irflo w rates and small or no amount of supplemental heat, i t may take several weeks to dry a deep bin of grain. Figure 3. Note: P a ra lle l-flo w or batch-in-bin system. A large gradient exists through the grain depth a t comple­ tio n o f drying. The shaded area shows th at a large amount of higher-moisture grain (top of mass) is drawn o ff with the f i r s t portion of grain removed (Brooker et a l . , 1978). 34 Direction of Gram Movement Figure 4. Internal view of a radial recirculating batch dryer. (From Gilmore and Tatge Mfg. Co., In c ., dealer manual.) D iv f \*sic>v; D M **| A T H S H IO lM Figure 5. W14M A V A 'L A M ! L -4 P A C > T > itf> T O « T . Internal view of a cross-flow batch dryer. (From Behlen Manufacturing Co., dealer manual.) Figure 6. Internal view of a modified cross-flow dryer using warm exhaust a ir from the cooling section. (From Butler Manufacturing Co., workshop manual.) lii/j ► Wet corn Dry corn Drying a ir Exhaust a ir \xx/ Cross-flow Figure 7. YX Concurrent flow \ y y Counterflow Illu s tra tio n of the three types of continuous-flow dryers. Thompson et a l . , 1969.) (From 38 WET GRAIN IN / \ /N /N /N / S HOT AIR DUCTS „ GRAIN OEFLEC" 2 / TORS / \ r < 7 DRYING AIR OUT COOLING AIR OUT — DRYING SECTION EXHAUST DUCTS COOL AIR DUCTS METERING rolls DRY GRAIN OUT (a) Concurrent-flow dryer w ith counterflow cooling WET Wettest Hottest HEAT 200* COOL OR HEAT (60° F Intermediate Dryest Coolest (b) M u lti-stag e continuous-flow dryer Figure 8. Schematic of high-speed continuous-flow dryers. (From Brooker e t a l . , 1978.) 39 300 550 500 250 450 TEMPERATURE 200 ^ 400 350 150 AIR 250 100 200 150 50 PRODUCT 100 DEPTH, f e e t 0 .5 1.0 1 .5 2.0 2.5 3 .0 DEPTH, m e te rs Figure 9. A ir and product temperatures versus depth fo r a singlestage concurrent-flow dryer. (From Brooker e t a l . , 1974.) DEEP BIN Figure 10. Schematic of a low-temperature in-bin drying system. Butler Manufacturing. Co., workshop manual.) (From Table 3: Effect o f harvest date and in it ia l Moisture content on the MinlMum a irflo w rate (cu m/min-t) required to dry corn with less than .5% dry Matter loss. These a irflo w rates are for the next to worst year indicated by coMputer simulation tests using 10 years of actual weather data. A 1.1°C temperature rise from the fan motor was assumed. October 15 November 1 In it ia l Moisture Content I n it ia l Moisture Content October 1 Location I n it ia l Moisture Content 20* Bismarck, North Dakota Huron, South Dakota Lincoln, Nebraska Dodge C ity , Kansas St. Cloud, Hinnesota Des Koines, Iowa Columbia, Missouri Madison, Wisconsin Chicago, Illin o is Indianapolis, Indiana Indianapolis, Indiana" Lansing, Michigan Mansfield, Ohio Midland, Texas Fresno, C alifornia Macon, Georgia Cape Hatteras, No. Carolina Sioux C ity . Nebraska Grand Island, Nebraska North P la tte , Nebraska Scottsbluff, Nebraska Source: .32® .51® .04 .57® .62® .91 .89 .8tf* !.61 .01 .11 .91 1.02 .86 1.61 !.U .64* .39* .32* .23* 22* 24* 26* 201 22* 241 26* 20* .61* 1.45 1.99 1.25 1.55 1.88 1.93 1.5 2 2.11 3.21 2.92 2.01 2.07 2.24 1.61 4.27 4.76 1.56 1.02 .75* .48* 1.44 2.68 3.39 2.25 3.38 2.90 3.39 3.59 3.56 6.24 5.07 3.31 3.60 3.95 3.05 7.36 10.35 2.80 2.31 1.41 1.06 2.79 4.57 4.73 3.61 4.76 4.98 5.82 6.67 6.85 10.58 8.24 6.34 5.50 6.73 4.88 13.76 17.89 4.13 3.55 2.61 1.92 .35* .43® .48* .39* .50* .64* .60* .53* .61* 1.29 .59* .83 .67* .71* 1.38 1.13 1.90 .63* .36* .30* .24* .48* .68* 1.29 1.22 .89 1.47 1.58 1.12 1.42 2.30 1.23 1.99 1.37 1.45 2.32 2.88 4.23 1.15 .82* .63* 1.56 2.30 2.47 2.13 2.42 2.76 2.49 3.00 4.56 2.08 3.06 2.84 3.07 4.00 4.92 6.96 2.18 1.71 1.45 3.55 4.32 4.42 3.48 5.44 5.32 4.05 5.17 6.00 3.50 4.33 6.75 5.10 5.86 7.95 16.49 4.05 3.49 1.91 1.46 40* • 46® • 51* •37® .47* •70* • 48® • 46* .49* 1.06 .50* .60* .50* .38* 1.20 .81* 1.82 .54* .38* .34* .27* .39* bn. .71* 22* • 55* 24* ■67* .77* 1.20 .98 1.17 •61a 2.48 • 73® 2.37 •61a 1 1 5 a .63* .81* 1.54 2.62 1.20 .92 3.09 •91. 1.97 1.02 2.16 “ a 2.91 .76* 1.62 2.11 5.35 3.91 3.17 .89 1.85 1.07 1.95 3.40 1.85 3.32 .90 1.89 3.12 .91 6.52 5.29 3.01 6.76 1.85 2.91 8.63 2.67 5.07 .72* 1.03 1.59 •92 1.45 •54J •63® 1.11 • 51® .63* .97 .40* Pierce and Thompson (1978). “Airflow rates below .83 cu m/mln-t are considered aeration not drying. are recommended for drying. 26* Rates larger than .93 cu m/mln-t b1.7"C continuous heat (in addition to the 1.1°C from the fan) was assumed for three simulation runs. 42 In a study of low-temperature grain drying in Wisconsin, Bartsch and Finner (1976) found that 27% moisture corn can be dried at low temperatures when unfavorable weather conditions e xis t i f 3 3 airflow s of 2.6 to 3.7 m /min/m o f grain are provided. According to the authors, grain at a moisture content up to 30% can be success­ f u lly dried i f 75% greater a irflo w is provided. As an a lte rn a tiv e source of heat fo r low-temperature drying systems, solar energy is considered to have p o te n tia l. D irect a p p li­ cation of solar energy has long been practiced in drying crops in the f ie l d , in the stack or windrow, on drying flo o rs , and in v en ti­ lated sheds or crib s. Solar energy is not being used on a large scale to dry crops in the United States, even though much of the basic technology needed to develop solar systems is availab le (Buelow & Boyd, 1957; Lipper & Davis, 1960; Peterson, 1973; McLendon & A llis o n , 1978). According to Peterson and Hellickson (1976), fa ilu re to employ solar energy fo r a g ric u ltu ra l processes over the past decade, when much of the a g ric u ltu ra l research was performed, was due to the a v a ila b ility of conventional energy sources a t reasonable prices. The predominant fa c to r in the adoption of solar energy fo r crop drying is th at only a low temperature rise is needed, and th is can e a s ily be accomplished with low-cost f la t - p la t e solar co llecto rs. E ffic ie n c ie s up to 70% fo r low-cost, low-tem perature-rise solar co l­ lectors were reported by Sobel and Buelow (1963). Two major problems encountered in n a tu ra l-a ir and lowtemperature drying are: (a) overdrying of the bottom la y e r, and 43 (b) the high a irflo w ra te required fo r e a rly harvested high-moisture corn (Pierce & Thompson, 1978; Bartsch & Finner, 1976). o f preventing overdrying o f the bottom la y e r are: Two ways (a) to remove the dry grain from the bottom o f the b in , and (b) to avoid the dryingfro n t formation by using s t ir r in g devices. Roberts and Brooker (1975) determined the moisture p r o file from the top to the bottom o f the grain mass w ith in a re c irc u la tio n dryer a t several stages in the drying process. Figure 11 shows the curves generated by the mathematical model o f the re c irc u la tio n dry­ ing process. Since 1965, s t ir r in g devices have been used to avoid overdrying in n a t u r a l-a ir , low-tem perature, and b a tc h -in -b in drying (W illiam s e t a l . , 1978). I t is d i f f i c u l t to design n a tu r a l-a ir or low-temperature drying systems th a t guarantee successful drying without overdesign­ ing them. I t is c r i t i c a l to determine a minimum a irflo w . In t h e ir "sim ulation o f s tir re d -b in low-temperature corn drying ," W illiams et a l . (1978) concluded: 1. using a larger-than-recommended fan on an u n stirred bin appreciably decreases drying tim e, w ith only a s lig h t increase in operating and fix e d costs; 2. using a s t ir r in g device allows a g rea te r bed depth, w ith per-bushel cost equal to th a t o f an un stirred bin with less depth; 3. the a d d itio n a l cost o f a s t ir r in g device cannot be ju s ­ t i f i e d based on equal f i l l u n stirred bin . depth or equal weight o f grain in an 44 3 .4 .4 Combination Systems and Dryeration A combination drying system is a system in which grain is p a r tia lly dried in a high-temperature batch or continuous-flow dryer to a moisture content range of 18-22% wb and the fin a l drying is completed in a low-temperature in-bin drying system (Shove, 1978; Brooker et a l . , 1978). As a variant of combination drying, the widely practiced dryeration technique developed by Foster (1964) is a process involv­ ing the drying and aeration of the corn. The technique consists in removing the corn from the high-temperature dryer, without cooling, at a moisture content about 2-3% above the desired fin a l value. Before the aeration phase, the corn is kept in a tempering tank fo r 3 3 6 to 10 hours and is f in a lly cooled at low a irflo w (.4 to .8 m /min/m ) (Brooker e t a l . , 1978; Bakker-Arkema et a l . , 1978; McKenzie et a l . , 1972). Studies conducted by Gustafson et a l. (1976) and Shove and White (1977) indicated th at the s u sc ep tib ility to breakage was sub­ s ta n tia lly reduced by elim inating rapid cooling of the high-temperature drying methods and rapid moisture-content decrease in the 18-15% range. According to Brooker et a l . (1978), combination drying also offers the advantages of increased fuel effic ien cy and increased drying capacity. 3.4 .5 In-Bin Counterflow Drying ("Shivvers System") As previously stated, in-bin continuous-flow drying is clas­ s ifie d as a counterflow process because the grain flows downward and 45 the a i r flows in the opposite d ire c tio n . The dried grain is removed from the bottom of the bin by means of a tapered sweep auger, which moves the grain to the center o f the bin flo o r (Figure 12). In th is form of continuous o r, more p re cise ly, semi-continuous counterflow drying, the grain is hot when discharged from the dryer, and drying is completed by aeration in the storage bin or by the dryeration process. The hot drying a ir (approximately 71°C) enters the grain through the fa ls e flo o r and, as i t moves upward, evapora­ tion takes place. The a c tiv a tio n o f the sweep auger is controlled by a temperature-sensing element placed about 46 cm above the fa ls e flo o r. As the drying progresses, the drying r a tio in the region below the sensor decreases (less evaporation takes p la c e ), and the d ry in g -a ir temperature a t th a t point increases. When a preselected temperature is reached, the sweep auger is activated ; i t makes one complete cycle around the bin and removes an even, thin layer o f dry corn. As the auger completes the cycle, damp grain moves into the sensor's region and the temperature at th a t point drops. The auger stops and waits fo r the next cycle. According to Brooker e t a l . (1978), keeping a uniform depth o f grain in the bin is of p a rtic u la r concern since an uneven grain depth causes uneven drying. Counterflow dryers have the potential to remove more moisture per foot o f dryer than any other type o f continuous-flow dryers. Counterflow dryers make less e f f ic ie n t use o f the in te rn a l energy of 46 E Uf) ■ C \J x 3 0 --------- S' 20 *o c to s- o SIMULATED 10 15 20 Moisture content (7 ) 25 {% 30 wb) HRS. oQS3 o * ------ * 5 0 0 “525 50 in CVJ i *_ x -S 20 C3 25 20 Moisture content (% wb) (5 Figure 11. 30 Grain moisture p ro file from the top to the bottom within a recirculation in-bin dryer with an airflow rate of 9.15 nr/m in/m . (From Roberts & Brooker, 1975.) Figure 12. Schematic of the internal view of an in-bin counterflow drying "Shivvers System." (From Shivvers Corporation, dealer manual.) 48 the In le t a ir because more of the a ir 's energy is used to heat the grain and, therefore, less energy is available fo r evaporation (Evans, 1970). However, assuming that the bed depth is s u ffic ie n t to absorb v irtu a lly a ll of the drying potential of the heated a ir , the heat-use efficiency of the continuous-flow in-bin dryer is inherently high (Brooker et a l . , 1978). In the in-bin counterflow system the bed depth can vary from .6 to 5 m although the high pressure drop a t high depths w ill greatly reduce the a ir flow, resulting in a reduction of the dryer capacity. Because of the high grain temperature (approximately 50°C) when the grain is discharged from the dryer, the moisture content can be 1-2% higher than desired. in a low-airflow cooling bin. The fin a l drying can be completed I f dryeration is used, 2-2.5% additional moisture can be removed. Technically, however, the added efficiency should not be attributed to the drying system since dryera­ tion also works in other high-temperature drying systems delivering hot grain (Brooker et a l . , 1978). 3.5 Drying-System Evaluation An evaluation of the factors affecting the economical opera­ tion and design of grain dryers requires that a cost analysis be performed. The costs may be classified as operating costs, fixed costs, timeliness costs, and miscellaneous costs. Operating costs include costs of a ll heat and power sources and of labor. In most heated-air drying systems, the labor required 49 to operate the dryer is assumed to be one-sixth o f the operating time, or about three hours per day (Chang et a l . , 1979). In low- temperature drying systems, labor can be ignored because only periodic Inspections are necessary. Fixed costs constitute the major share o f the to ta l cost of a drying system. In te re s t ra te , depreciation, taxes, and insurance are referred to as fixed costs (Young & Dickens, 1975; Bridges e t a l . , 1979; Skees et a l . , 1979). Most authors do not consider tim eliness costs and costs rep­ resented by reduced value of grain q u a lity because there is no way to measure these costs accurately. According to Hukill (1947) and Young and Dickens (1975), a ll of the aforementioned costs are affected in one way or another by the length of time required to dry the product. Therefore, to pre­ d ic t the costs fo r drying, i t is necessary to predict the required drying time. The manner in which water is removed from grain or other bio­ logical products has been the subject of much research. Brooker et a l. (1974) indicated th a t six modes o f moisture removal are pos­ s ib le : (a) liq u id movement due to surface forces (c a p illa ry flo w ), (b) liq u id diffusion due to moisture-concentration difference (liq u id d iffu s io n ), (c) liq u id movement due to diffusion o f moisture on the pore surfaces (surface d iffu s io n ), (d) vapor movement due to moistureconcentration differences (vapor d iffu s io n ), (e) vapor movement due to temperature differences (thermal d iffu s io n ), and ( f ) water and vapor movement due to total-pressure differences (hydrodynamics flo w ). The 50 manner in which water is removed from the grain is in d ire c tly affected by a ir temperature, a i r v e lo c ity , moisture concentration, and product type and condition (Stevens e t a l . , 1978). In recent years, a number of mathematical models have been proposed to describe the bulk drying of a g ric u ltu ra l products. Hamdy and Barre (1970) c la s s ifie d the drying models in to two categories: 1. Rational models, in which a set o f equations derived from theory is applied. The equation system is normally la rg e , and a num­ ber of sim plifying assumptions must be made to permit solu tio n . 2. Empirical models, in which an attempt is made to analyze experimental data and to formulate an expression, normally based on a s t a t is tic a l so lu tio n , to describe the drying process. According to Brooker e t a l. (1974), the resu ltin g equations can p red ict the drying process only w ithin the temperature and m oisture-content range and fo r the p a rtic u la r grain fo r which the equations have been devel­ oped. Among the ra tio n a l models developed to predict the bulk drying o f grain are those by Boyce (1 965 ), Bakker-Arkema e t a l. (1967), Henderson and Henderson (1968), Thompson e t a l. (1968), and Hamdy and Barre (1970). Although these models are said to provide a b e tte r description of the drying process than the em pirical models, some require extensive and sophisticated computer-programming techniques and sometimes considerable computer time fo r solution. 51 3.5.1 Drying Equations Hukill (1954) analyzed deep-bed drying and derived the f o l­ lowing equation, which is less accurate than the previously mentioned models but useful fo r design purposes: ~ = P— 3t 3x (1) where P = !22jLl!L-£E., a constant for any given set of drying conditions 2 m = mass flow rate (Kg/m min) h = la te n t heat of vaporization of moisture in the grain (KJ/Kg) W = density of dry matter (Kg/m ) cp = specific heat of dry a ir (KJ/Kg °C) For grain f u lly exposed to constant drying conditions (such as grain at the very bottom of a b in ), and fo r a ir moving through grain of uniform moisture content (such as a batch of grain at the begin­ ning of the drying process), the following approximations can be made (H u k ill, 1954): for the moisture: M - Me = (Mo - Me) e**1* fo r the grain temperature: T - Tg = (To - Tg) e (2) and ■in u i h i r h in which r - k(MO - Me) c - p (j - Tg) “CX (3) * H ukill proposed the following solution: * cx M = (Mo - Me) ~cx - iff + Ke e + e - 1 t4) 52 and (5) Expressing moisture content in terms of the moisture ra tio (6) the drying time can be expressed in terms of the period of h a lf response (one period [H] is the time required fo r a f u lly exposed grain layer to reach a moisture ra tio equal to 0.5 under a given set of conditions). Then, e -kH = 0.5 or e kH = 2; and the tim e, in periods of h a lf response, is Y = t/H . (7) The unit of equivalent depth (D' ) , as defined by H ukill (1954), is the depth that contains enough grain to a tta in the heat require­ ment fo r evaporating it s moisture, from an i n i t i a l moisture ra tio of MR = 1.0 to a fin a l moisture ra tio o f MR = 0. The heat requirement must be equal to the sensible heat supplied by a ll a ir in one unit of time i f its temperature is dropped from To to Tg. At any level in the bin, the equivalent depth is: (8) I f these units are used (9 ) Figure 13 is the graphical representation o f Equation 9. 53 The rela tio n s h ip s proposed by H u k ill have been used to describe drying in batch and crossflow drying systems {Young & Dickens, 1975). Barre e t a l . (1971) expressed Equation 9 in terms o f base e ra th e r than base 2 and developed the follow ing expressions: +?■ ! ' - 1) e (io > and t H = In e (11) -1 Equation 10 represents the mean moisture r a tio (MR) and Equation 11 represents the drying time (t^ ) required to obtain a desired moisture r a t io . Based on the same procedure, Young and Dickens (1975) developed s im ila r equations in terms o f base 2: nrr _ M - Me _ 1 MR " Mo - Me “ (In 2)D ,_ /2 D + 2Y - I t ln * £7 * 4H ■ 7 and ¥H ■ W 7 ln ( ^ H u k ill's (1954) and Barre e t a l . ' s F > (,3) (1971) dimensionless depth and time variab les have the follow ing rela tio n s h ip : Y* = Y In 2 (14) D' = D In 2 (15) and Equation 13 is sim pler and can be solved fo r drying time more q u ickly than the more sophisticated models. The time determined by Young and Dickens' (1975) equation (Equation 13) Is an estimation of the time required to dry a batch of grain or the time the grain must remain in the drying section of a continuous cross-flow dryer. The time a thin layer of grain must remain a t the bottom of the bin in an in-bin counterflow system to reach a given fin a l average moisture content can likewise be estimated. To calculate the moisture ra tio at any time during the drying process, the equilibrium moisture content of the product must be c a l­ culated fo r the in le t a ir conditions. A number of th e o re tic a l, semi- th e o re tic a l, and empirical models have been proposed fo r calculating the moistureequilibrium of a cereal grain. the Silva relationships Because of its s im p lic ity , fo r equilibrium moisture werechosen (Kalchik et a l . , 1979): For 0 > RH 5 52.0, Me = M 7 .76 .RH.;.4.5.8.4, ln(|^- + 32) {16) and fo r 52.0 > RH < 99.9, Hc . 21.2198 exp(.Q146 RH) (17) l n ( | l + 32) To solve Equation 13, the time of h a lf response (H) must be known. I t is determined from the exponential drying equation, which is assumed fo r th in -la y e r drying (Equation 18): 55 where the th in -la y e r drying constant (k) is given by Equation 19 (Brooker et a l . , 1974): k = 5.4 x 1 0 '1 e x p (-5 0 2 3 /| Tabs) 3 .5 .2 (19) Basic Assumptions Besides the assumptions made by H u kill (1954), the follow ing additional assumptions must be made in order to apply the H u kill pro­ cedure to predict the drying time of an in -b in counterflow dryer ("Shivvers System"): 1. the dryer is a batch dryer with a deep bed (la rg e r than 2. the c h a ra c te ristic s of the a ir entering the grain bed 1 m). are constant; 3. the i n i t i a l grain moisture content is constant; 4. the bed depth is constant and leveled by means o f a grain spreader located a t the entrance to the dryer; 5. the grain bed is divided in to layers o f equal depth (x ); the d ifferen ce in dry-m atter content between the layer being dried and the next la y e r is n e g lig ib le ; 6. the average moisture content fo r each la y e r, a fte r the lowest layer has been d rie d , is the log-mean between the lower and upper edges of the adjacent layers; 7. the tapered sweep auger removes the dried la ye r o f grain a t the bottom o f the bin a t the desired fin a l moisture content with no e ffe c t on the uniform ity of the drying fro n t; 56 8. the drying progresses as shown schematically in Figure 14. Under the above assumptions, i t w ill be guaranteed that: 1. the exhaust drying a ir is always saturated as i t leaves the upper surface a t a temperature equal to the in le t drying a ir wet-bulb temperature (assumptions 2, 3, and 4); 2. the drying rate is constant (assumptions 2, 3, and 4); 3. the s tatic pressure is constant and, as a consequence, a uniform drying front exists (assumption 4); 4. calculation of the distance of the kernels from the bin flo o r with the average moisture content in the second layer is f a c i l i ­ tated (assumption 6); 5. the drying time or time between two consecutive cycles can be calculated at the beginning or at the end of each cycle (assumption 7 ). Excluding the assumptions (1 , 5, 6, 7, and 8) inherent in the in-bin counterflow system, a ll the other assumptions must be made in order to predict the time required to achieve the desired fin a l average moisture content in a cross-flow batch dryer. w vV \X' sS^ ^ : A \ sHp \V A wav\ v\ vVsV s : wvA vV sV 4^-SV \ w Jv rVk \ \ \\ ^ \ sk \ ■V fifcMm It Sj§ ST* k L ii ^ \ s. r ** it i> t* it <• IV it TUMI U W TI IT ) Figure 13. Deep-bed drying curves. (From H u k ill, 1954.) it H Figure 14. Schematic of the in -b in counterflow drying system. 4. EXPERIMENTAL Described in the following section are the conditions under which the tests were performed at the Kalchik Farms in B e lla ire , Michigan, and how the on-farm drying and storage system was designed. Although products other than corn can be dried and stored in the actual systems, they were designed based on corn. 4.1 Test Location Five alte rn a tiv e corn-drying techniques were tested on a com­ mercial farm in B e lla ire , Michigan, during the 1978 and 1979 f a ll harvest seasons. The region where the farm is located is not con­ sidered a prime corn-growing area. However, high harvest moisture content and unfavorable clim atic conditions were the reasons fo r choosing the experiment location. I t can thus be argued that any drying technique th at operates successfully in B e lla ire , Michigan, w ill work a t any farm in the lower peninsula of Michigan. The fiv e a lte rn a tiv e drying systems include: 1. high temperature/natural a ir combination drying 2. high temperature/low temperature (e le c tric heat) combi­ nation drying 3. in-b1n dryeration 4. in-bin counterflow drying 5. conventional batch drying. 59 60 4.2 Design o f A lte rn a tiv e Drying System 3 Five steel bins o f 84.6 m capacity were arranged in a pat­ tern to allow m u ltip le use and f l e x i b i l i t y . The system was designed to e ffe c tiv e ly te s t each drying technique and to handle the farm 's corn production. Four storage bins were set up in a rectangular pattern so th a t each could be f i l l e d with anauger from the central point (Figure 15). tio n drying systems. Two of the storage bins were set up as combina­ The f i r s t had a ce n trifu g a l fan w ith a 3.7 Kw 3 3 motor deliverin g 2.0 m o f natural a ir per min/m o f grain through a 3.7 m bed. 3 3 A fan d eliv e rin g 1.6 m o f a i r per min/m o f grain with a 2.2 Kw motor and a 20 Kw e le c tr ic a l resistance heater were part o f the low-temperature bin drying system. The th ird bin was f it t e d with 3 3 a fan delivering 0.8 m of a ir per min/m o f grain fo r in -b in dryera3 tio n . To the fourth bin a grain a irflo w rate o f 0.3 m o f a ir per 3 min/m of grain was applied to cool hot grain from the in -b in counter­ flow dryer mounted in the adjacent f i f t h storage bin. Wet corn from the f ie ld entered the in s ta lla tio n through e ith e r the in -b in counterflow system or the wet holding tank fo r the cross-flow system. Figure 16 is a general view of the in s ta lla tio n . A ll o f the storage bins have f u ll perforated flo o rs with steel support legs to insure uniform a irflo w through the e n tire bin. The roofs were in s ta lle d with a 12.7 mm gap over the side walls so th at condensation under the roof would drip outside the bin w a ll. Roof vents were in s ta lle d to reduce the exhau st-air v e lo c ity to less than 0.3 m/sec. 61 Ports were d rille d into the plenum under each bin to check the s tatic pressure of the fans fo r determination of airflow s. Thermocouples (copper-constantan) were suspended from the roofs at 0.3 m intervals on a cable with one cable per bin. A ll thermocouples were connected through an underground network to an instrument shelter for central recording. The conventional cross-flow batch dryer (Figure 17 and Table 4) 3 dried batches of approximately 4.2 m of wet corn; the in it ia l dryinga ir temperature was 104°-115°C, and the fin a l temperature was 82°C. The in-bin counterflow system (Figures 18 and 19 and Table 5) dried at 71°C. Both high-temperature systems used liqu id propane as fu e l. 4.3 Drying Procedures Corn (DeKalb XL-12) was harvested during the 1978-1979 season under favorable weather (sunny, no r a in ), November 1-24. The in it ia l moisture content varied from 30% wb at the s tart to 23% wb at the end of the harvesting season. The daytime temperature varied between 7° and 18°C, and the nighttime temperature between 2° and 6°C. 3 of about 531 m of corn was dried. A total The tests were repeated during the 1979-1980 season under unfavorable conditions (with considerable rain and long periods of high re la tiv e humidity), November 3-25. varied from 31-38% wb. The in it ia l moisture content The daytime temperature varied between 7.2° and 14.5°C, and the nighttime temperature between -1° and 4.5°C. 62 Table 4: Dryer specifications of Farm Fans dryer model AB-8B, 1978 model. Grain column length, f t Total holding capacity, bu 1 120 Less transport: Length, f t Width, f t Height, f t 13.25 6.00 8.75 With transport: Length, f t Width, f t Height, f t 16.16 7.75 10.00 Fan horsepower Fan diameter, in . 10-13 28 A irflow at 3 in . s ta tic pressure 15,000 cfm Heater capacity, BTU/hr 3,000,000 Top auger, HP Top auger capacity, Bu/Hr Bottom auger, HP Bottom auger capacity, Bu/hr 1 1,500 1 900 Max. running amps., 1 ph., 230 V (with 5 HP load and unload conveyor) 90 Max. running amps, 3 ph ., 220 V. (with 6 HP load and unload conveyor) 60 Drying capacity, wet Bu shelled corn per hr Dry and cool, 25% to 15% 110 Dry and cool, 20% to 15% 155 Full heat, 25% to 15% 150 Full heat, 20% to 15% 210 ♦Excluding load and unload time Source: Farm Fans Catalog (B u lle tin AB-03-3, 1979). BIN 1 BIN 4 Natural storage Instrument sh elter temperatu Figure 15. holding d rye ra ti Schematic of the location of the various drying modes at the Kalchlk Farms a t B e lla ire , Michigan. o» •Ck Figure 16. General view of the Kalchik in s ta lla tio n . Figure 17. Farm Fans automatic batch model AB-8B {3-ton capacity) Figure 18. View of the total in-bin counterflow "Shivvers System." 67 8y»«w» f. ¥ LO-FLAIYIE HI-FLAIYIE Figure 19. D etails o f the 13 HP blue flame "Shivvers System." (From Shivvers Corporation, dealer manual.) 68 Table 5. 18 f t . * dlam. bln 21 ft. dlam bin 24 f t. dlam. bln 27 f t. dlam. bin 1A da JU Tv. M 4 rnwm cm a m . Li - D1n 9C l a JO T t. □lam. #44am D IT l In-b1n counterflow dryer specifications for "Shivvers Systems." Humber of Fans Horsepower Description Static Pressure 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 2 1 2 1 2 2 1 2 1 1 1 2 1 2 1 2 1 2 5 HP 7.5 HP 10 HP 13 HP 7.5 HP 10 HP 10 HP 13 HP 7.5 HP 10 HP 10 HP 20 HP 7.5 HP 20 HP 13 HP 13 HP 10 HP 7.5 HP 20 HP 10 HP 10 HP 13 HP 13 HP 10 HP 10 HP 20 HP 7.5 HP 20 HP 10 HP 13 HP 13 HP 20 HP 10 HP 20 HP 20 HP 13 HP 13 HP 22" Vane Axial 22" Vane Axial Centrifugal BLUE FLAME 22" Vane Axial 26" Vane Axial Centrifugal BLUE FLAME 22" Vane Axial 26" Vane Axial Centrifugal Centrifugal 22" Vane Axial 30" Vane Axial BLUE FLAME BLUE FLAME 26" Vane Axial 22" Vane Axial 30" Vane Axial 26" Vane Axial Centrifugal BLUE FLAME BLUE FLAME 26“ Vane Axial Centrifugal Centrifugal 22" Vane Axial 30" Vane Axial 26“ Vane Axial BLUE FLAME BLUE FLAME 30" Vane Axial 26" Vane Axial 30" Vane Axial Centrifugal BLUE FLAME BLUE FLAME 2.90“ 3.40" 4.50" 4.50" 2.45" 3.05" 3.20" 3.70" 1.75” 2.00“ 2.20" 3.40" 3.65" 3.95" 3.00" 4.82" 1.72" 3.05” 3.15" 3.58" 4.00" 2.30" 4.20" 1.40" 1.27" 1.8B" 2.40" 2.50" 3.00" 1.80" 3.65" 1.58" 2.08" 3.53" 2.94" 1.10" 2.60" 2 2 1 2 Air Delivery 8,600 9,500 11,500 11,500 10,500 12,250 12,500 13,750 11,250 12.600 13,250 17,000 17,750 16,500 15,750 20,900 14,500 20,000 20,400 22,200 23,750 16,750 24,700 15,000 13,800 18,000 21,300 21,650 24,500 17,500 27,750 23,500 28,000 39,000 34,750 18,300 32,000 CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM CFM Bushels/ Hour Bushels/ Day 61 68 62 82 75 B7 89 98 80 90 94 121 127 132 112 148 103 143 145 158 169 119 175 107 98 128 152 154 174 124 197 167 199 277 247 130 227 1464 1632 1968 1968 1800 2088 2136 2352 1920 2160 2256 2904 3048 3168 2688 3552 2472 3432 3480 3792 4056 2856 4200 2568 2352 3072 3648 3696 4176 2976 4728 4008 4776 6648 5928 3120 5448 These are realistic estimates. Drying conditions are 50° outside a ir at 70* rh .( drying ai r 160°, In itia l corn temperature 50°, grain depth 6 f t . , 25* com dried to 15)!, Model 1328 Single and Three-Phase Specifications Fan Diameter. . . Blade ................. Motor .................. Motor Protection Magnetic Starter Burner Construction Burner Capacity . . Source: .28-1/4 Inch .6 blade axial .13 HP, open drip proof .Manual reset overload relay .Rugged 60 Amp. magnetic starter standard on single and threephase models .Heavy wall 16-gauge stainless steel ring burner .3,650,000 BTU per hour maxi­ mum capacity. Produces 160°F heat rise Shivvers Corporation, dealer manual. aDryer model used at Kalchlk Farms. Vaporizer .. Gas Strainer Regulator . . Ignition . . Fully adjustable vaporizer with high temperature pro­ tection standard on LP models Vapor strainer on propane and natural gas burners. Llqutd strainer standard on liquid propane models. Pressure regulator and pressure gauge standard on a ll models. Continuous 10,000 volt transformer Ignition with heavy duty Ignition plug 69 The corn was cleaned in a rotary cleaner before dumping 1t 3 in a 44 m wet holding bin or into the in-bin counterflow dryer. From the wet holding tank, the corn was transported in a 15.3-cm auger to the automatic batch dryer and dried to the required moisture content. The grain was conveyed from the dryers into one of the 3 84 m drying-storage bins. The intermediate moisture content of the corn a fte r p a rtia l high-temperature drying in the batch dryer and before dumping i t hot into the n a tu ra l-a ir combination drying bin and the low-temperature combination drying bin was about 23%; in the case of the in-bin dryeration bin, i t was about 20%. The conventional batch-drying technique (control treatment) consisted of drying wet corn d ire c tly to 15.5% wb. For the in-bin counterflow system, the corn was dried to about 18.5% wb and was then fin a lly dried to 15.5% wb in the a u x ilia ry aeration bin. 4.4 Instrumentation and Measurement The parameters required fo r rating the drying capacity and energy efficiency of a dryer are: (a) grain in le t moisture content, (b) drying -air temperature, (c) grain in le t temperature, (d) ambienta ir re la tiv e humidity, (e) fuel (liq u id propane and e le c tr ic ity ) consumption, ( f ) airflow rate, (g) corn test weight, (h) BCFM, ( i ) ambient temperature, ( j ) drying and cooling time, (k) loading time, (1) unloading time, and (m) number of bushels per batch or per cycle in the in-bin counterflow system. The number of bushels per batch or per cycle was determined by d ire c tly weighing the dried grain as i t was delivered to a 70 commercial buyer. Thus, dryer capacity was determined by dividing the to ta l weight of the dried corn by the number of batches or cycles. The approximate grain moisture content of the corn samples was determined during on-farm drying operations with a capacitancetype moisture meter. Samples were collected before and a fte r drying. Each sample was la te r checked with the standard oven method {72 hours a t 103°C). The in le t and exhaust d ryin g -air temperatures were measured by copper-constantan thermocouples in conjunction with a datalogger. A to ta l of six thermocouples monitored the temperatures of the ambi­ ent a ir (dry and wet bulb), the drying a ir , and the exhaust a ir (dry and wet bulb). The d ryin g -air temperatures and the stored-grain temperatures were stored on magnetic tape. Data treatment and manipulation were performed d ire c tly by means of tape and a d ig ita l computer. The airflow s were calculated from measured static-pressure data and from fan curves supplied by the fan and dryer manufacturers. The data were checked against standard ASAE static-pressure data fo r corn. Liquid propane usage was estimated from the liq u id propane tank gauge and la te r checked against the receipts received from the liq u id propane supply company. Differences between the gas company receipts and the tank gauge readings were estimated a t ±7% fo r an approximate 950 lite r s measurement. Liquid propane consumption fo r each individual batch or cycle (in -b in counterflow dryer) was taken as the d a ily average (lite r/m in ) times the drying time. 71 E le c tr ic ity usage was measured with a Kwh-meter supplied by the e le c tric a l power company. Sample evaluation was performed using standard methods o f measuring stress-cracks {Thompson & Foster, 1963). The 2 ,3 ,5 - triph enyltetrazoliu m chloride color te s t (TZ te s t) was used to determine the percentage o f viab le kernels. The TZ te s t distinguishes between viable and dead tissues of the embryo on the basis o f re s p i­ ra tio n rate in the hydrate s ta te . The TZte s t is widely recognized as an accurate means of estimating seed v ia b ilit y (Copeland, 1976). Breakage tests were conducted employing a newly developed USDA method { M ille r et a l . , 1979). 5. 5.1 5.1.1 RESULTS AND DISCUSSION Ambient and Drying Conditions High-Temperature Phase Table 6 and Tables 7 and 8 contain the d a ily average ambient and drying conditions fo r the cross-flow batch dryer ( f a ll 1978 and 1979) and fo r the in-bin counterflow dryer ( f a l l 1978 and 1979), respectively. Only the batches or cycles (in -b in counterflow) for which a complete set of data was collected are described in the tables. The data presented in Table 6 were averaged from the d aily operation. As the drying season progressed from November 3, 1978 (ave. 1) to November 10, 1978 (ave. 7 ), the i n it i a l moisture content was substan­ t i a l l y reduced (from 28.6% to about 24% wb). The high ambient tempera­ ture and the low re la tiv e humidity during those days highly contributed to the e ffic ie n t fie ld drying. By November 10, 1978, the 4.9 min. of drying time for the corn from ave. 7 indicates that before being dumped into the combination drying bin, the corn was only warmed up. The corn from ave. 8 and ave. 9 (control batches) was dried on November 7, 1978, and November 10, 1979, when the in it ia l moisture contents were 26% and 35.7% wb, respectively. Table 6 also indicates the e ffe c t of the in i t i a l and fin a l moisture contents on the drying time and energy consumption fo r the crossflow batch dryer. As a resu lt of schedule pressures and instrumentation fa ilu r e , only one complete batch-drying te st is reported fo r 1979 (Table 6, ave. 9 ). 72 Table 6: Ambient and drying conditions fo r the experimental tests (d a ily averages) in B e lla ire , Michigan, November 1978, fo r the cross-flow batch dryer without cooling. Drying Time Min. Liquid Propane Liters 22.9 18.7 29.6 41.6 6.8 1092136 28.6 22.9 18.0 26.0 49.2 6.2 1310331 99.4 27.9 23.0 8.0 21.3 41.2 5.7 1573667 4.8 86.6 26.9 22.9 8.1 17.2 32.5 5.7 884271 60 12.6 98.1 24.7 22.7 12.5 10.3 19.4 3.6 449749 Ave. 6 (15) 71 11.1 103.8 24.0 20.0 11.6 18.4 34.4 4.6 967750 Ave. 7 (6) 82 9.1 100.0 24.8 23.5 11.0 4.9 9.0 2.4 532765 Ave. 8 (2) 50 6.8 100.5 26.0 15.5 10.0 60.0 104.0 12.0 2712352 Ave. 9 ( l ) b 60 12.5 99.4 35.7 18.3 12.2 95.0 149.8 20.8 3918470 Ambient Rel. Hum. % A ir Temp. C Drying Temp. C Ave. 1 (10) 55 17.2 91.0 28.6 Ave. 2 (10) 68 10.6 94.4 Ave. 3 (4) 81 2.8 Ave. 4 (4) 58 Ave. 5 (9) Moisture Content In le t Outlet % wb % wb aThe value in parentheses is the number of replications. ^November 1979 data. Elect. Energy Kwh Total Energy KJ Grain Temp. C Test Number 74 For the grain to be fin a l-d rie d in the in-b in dryeration, n a tu ra l-a ir, and low-temperature combination drying systems, the cooling cycle of the high-temperature batch dryer was not operated. The in-bin dryeration system requires that the corn be at a high temperature for adequate operation. The two combination drying systems also had the advantage of the high sensible heat carried by the uncooled corn, which improved the drying efficien cy of the dryer. As w ill be shown la te r in th is chapter, by eliminating the cooling operation, the drying capacity of the cross-flow dryer was substan­ t i a l l y increased. Tables 7 and 8 contain the ambient and drying condition data fo r the in-bin counterflow system fo r the 1978-1979 season (cycles 1 to 18) and the 1979-1980 season (cycles 19 to 34). The drying time in Tables 7 and 8 refers to the time between two con­ secutive cycles a fte r cycle (0) or the i n i t i a l cycle had been unloaded. The unusually high in it ia l moisture content fo r the corn in the 1979 season (Table 8, cycles 19 to 27 and ave. 9 in Table 6) was a resu lt of the fro s t that occurred during the f i r s t week of October, which required early harvesting of part of the corn (Table 8, cycles 19 to 27), 15 days before the predicted startin g harvest date. In the in-bin counterflow "Shivvers system" the drying occurs in two steps. In the f i r s t step the corn is dried to a low moisture con­ tent such as 18%, and the drying is completed in the aeration bin. During the 1978-1979 season, the fin a l drying fo r the in-bin counterflow Table 7: Cycle No.a 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Ambient and drying conditions fo r the experimental tests (in -b in counterflow) in B e lla ire , Michigan, November 1978. Ambient Rel. Hum. % 92 93 99 99 99 95 96 97 59 70 55 56 58 60 66 69 73 54 Air Temp. C Drying Temp. C 14.5 13.9 13.1 12.1 11.9 11.1 10.9 10.0 7.7 7.9 8.2 8.1 7.7 6.8 6.5 4.9 3.9 5.2 66.3 69.2 72.0 69.0 71.4 68.5 68.4 70.0 67.8 67.7 67.9 65.7 67.4 65.6 67.6 67.5 65.5 65.5 Moisture Content In le t Outlet % wb % wb 25.4 25.0 25.0 25.0 25.0 27.2 27.2 27.2 27.4 27.4 27.4 27.4 27.4 27.0 27.0 27.0 27.0 27.0 15.3 17.3 18.0 17.9 18.6 18.8 18.6 18.4 18.6 19.6 20.3 19.1 19.8 19.2 18.5 19.6 17.5 18.8 Drying Time Min.b Liquid Propane Liters 25.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 25.0 20.0 20.0 25.0 25.0 25.0 30.0 25.0 25.0 25.0 29.1 23.3 23.3 23.3 23.3 23.3 23.3 23.3 28.8 23.0 23.0 28.8 28.8 28.8 29.9 24.9 24.9 24.9 Elect. Energy Kwh 5.0 4.0 4.0 4.0 4.0 4.0 4.0 4.0 5.0 4.0 4.0 5.0 5.0 5.0 6.0 5.0 5.0 5.0 aRefers to the lay er th a t is dropped from the dryer into the a u x ilia ry bin. ^Time between two consecutive cycles. Total Energy KJ Static Pressure CM H20 765365 612292 612292 612292 612292 612292 612292 612292 758571 606468 606468 758571 758571 758571 790319 658599 658599 658599 7.8 6.3 6.8 7.1 7.3 6.3 5.8 5.0 8.1 8.1 7.3 8.8 9.6 9.6 10.1 10.4 9.3 9.1 76 system had been completed by December 7, 1978, a f t e r 590 hours o f fan operation. Because o f the fro s t th a t occurred on the f i r s t day o f October 1979, the corn from cycles 19 to 27 was harvested and dried e a rly to avoid being spoiled in the f ie l d . The second drying phase (from about 18.5 to 15.5% wb) was completed during the remainder o f October w ith the aeration bin less than h a lf f u l l (approximately 20 to n s). Because o f the low moisture content (14.7% average) when the corn was dumped in to the aeration bin (cycles 28 to 3 4 ), the second drying phase is not considered fo r the 1979-1980 season. 5 .1 .2 Low-Temperature Phase The corn from ave. 1, ave. 5, four batches from ave. 7 (Table 6 ) , and one unreported batch was put in the n a tu r a l-a ir combi­ nation drying b in . The average moisture content was 23.1% wb, with a standard deviation o f SD = 1.31. The low-temperature combination drying bin was loaded w ith corn from ave. 2 , ave. 3 , ave. 4 , two batches from ave. 7 (Table 6 ) , and four unreported batches. The average moisture content o f the corn was 23% wb, w ith a standard deviation o f SD = .76. The i n i t i a l moisture content o f the corn when placed in the dryeratio n bin (1978 season) was higher than planned due to the inaccuracy o f the moisture te s te r . The bin was loaded w ith corn from ave. 6 (Table 6) and four unreported batches; the average moisture content was 20% and the standard deviation S D -.5 3 . For the n a tu r a l-a ir and low-temperature combination drying systems, the fan was turned on as soon as the th ird batch (approxiO mately 11.8 m ) o f the hot corn was placed in the bins. For the 77 1n-bin dryeration system, the fan was turned on a fte r a 10-hour 3 tempering period with approximately 58 m of corn in the bin. Drying in the n a tu ra l-a ir and low-temperature drying bins was interrupted in the second week of December 1978, when the average ambient-air temperature had fa lle n below 2°C. In the middle of April 1979, the fans were restarted for 10 days to complete the dry­ ing process. In the 1978-1979 season, the fan in the n a tu ra l-a ir bin operated 884 hours; the fan in the low-temperature bin operated 794 hours. For the in-bin dryeration drying {1978-1979 season), the fan operated 448 hours and drying was completed by December 15, 1978. 5.2 Product Quality The results of the analysis of the wet corn and dried corn samples, which correspond to the data in Tables 6 and 7 (cycles 1 to 18), are shown in Tables 9 and 10, respectively. Except fo r the breakage te s t fo r the high-temperature drying technique, the qu ality test was not performed fo r the 1979-1980 season. The fin a l grain q u ality fo r each drying technique is presented in Table 11, in which the corn breakage te s t determined according to the new USDA method {M ille r et a l . , 1979) is presented. A careful examination of Tables 9, 10, and 11 cle a rly shows that the q u a lity of the end-product is substantially affected by the drying procedure, as was previously found by Thompson and Foster (1963), Peplinski e t a l. (1975), Shove (1978), and Gustafson et a l . (1978). The in-bin counterflow dryer produced dried corn that was Table 8: Cycle No.a 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 Ambient and drying conditions fo r the experimental tests (in -b in counterflow) in B e lla ire , Michigan, November 1979. Ambient Rel. Hum. % 98 98 90 85 70 70 73 78 85 98 100 100 100 100 100 100 Air Temp. C Dryi ng Temp. C 12.7 12.1 12.1 12.1 14.3 14.3 13.2 12.7 8.8 10.0 8.8 3.2 3.2 3.2 3.2 1.0 66.6 65.5 65.5 65.5 65.5 64.3 65.5 66.6 67.7 71.0 70.0 71.0 72.7 71.0 72.1 71.0 Moisture Content In le t Outlet % wb % wb 37.0 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 34.0 34.0 30.8 30.8 30.8 30.8 30.8 18.6 18.8 16.8 15.7 19.5 18.7 18.7 19.7 18.2 14.9 14.9 13.5 14.2 14.7 14.8 15.9 Drying Time Min.b Liquid Propane Liters Elect. Energy Kwh 87.0 60.0 68.0 91.0 57.0 73.0 60.0 63.0 57.0 60.0 65.0 73.0 67.0 73.0 68.0 67.0 71.3 49.2 55.7 74.6 46.7 59.8 49.2 51.6 46.7 50.2 54.4 59.5 54.6 59.5 55.4 54.6 17.4 12.0 13.6 18.2 11.4 14.6 12.0 12.6 11.4 12.0 13.0 14.6 13.4 14.6 14.6 13.4 aRefers to the layer th a t is dropped from the dryer in to the a u x ilia ry bin. ^Time between two consecutive cycles. Total Energy KJ 1892232 1304987 1478662 1979555 1239737 1588058 1304987 1370237 1239737 1331193 1442531 1479323 1449794 1479323 1474498 1449794 Static Pressure CM H20 11.9 11.4 10.9 10.6 9.9 10.1 9.6 9.6 8.8 10.4 8.8 13.4 12.9 14.4 13.4 12.7 Table 9: Test No. Average grain q u a lity parameters fo r the crossflow batch dryer, 1978 drying season. Moisture %wb In Out StressCracksa I Whole Kernels In Out V ia b ility % In Out In BCFM Out Test Weight In Out Ave. 1 28.4 22.9 4.6 96.5 97.0 77.8 39.0 0.0 0.0 52.0 54.0 Ave. 2 28.6 22.9 4.2 96.9 97.4 82.9 38.4 0.0 0.0 52.0 54.0 Ave. 3 27.9 23.0 3.7 96.5 96.6 74.0 40.0 0.0 0.0 53.0 53.7 Ave. 4 26.9 22.9 4.0 96.5 96.6 85.5 42.0 0.0 0.0 53.6 54.2 Ave. 5 24.7 22.7 1.5 96.9 97.2 92.4 52.0 0.0 0.0 53.3 52.7 Ave. 6 24.0 20.0 8.9 96.7 96.5 96.3 34.3 0.0 0.0 53.5 53.9 Ave. 7 24.8 23.5 2.9 95.7 95.7 89.3 59.0 0.0 0.0 54.3 53.5 Ave. 8 26.0 15.5 87.3 96.8 96.6 86.0 8.0 0.0 0.0 54.0 55.0 Ave. 9 35.7 18.3 76.0 96.3 97.0 1.0 1.0 50.0 55.5 aThe i n i t i a l stress-cracks percentage equals zero. * » • * Table 10: Grain q u a lity parameters fo r the in -b in counterflow dryer, 1978 drying season. Test No. Moisture %wb In Out 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 25.11 25.0 25.0 25.0 25.0 27.2 27.2 27.2 27.4 27.4 27.4 27.4 27.4 27.0 27.0 27.0 27.0 27.0 15.3 17.3 18.0 17.9 18.6 18.8 18.6 18.4 18.6 19.6 20.3 19.1 19.8 19.2 18.5 19.6 17.5 18.8 StressCracks® 36.0 32.0 38.0 50.0 26.0 46.0 34.0 38.0 30.0 52.0 34.0 60.0 38.0 50.0 46.0 32.0 86.0 50.0 % Whole Kernels In Out 95.6 95.6 95.6 95.6 95.6 96.8 96.8 96.8 95.7 95.7 95.7 95.7 95.7 94.6 94.6 94.6 94.6 94.6 96.6 95.0 96.8 95.3 94.9 95.0 95.2 95.0 95.0 96.0 95.6 94.3 95.3 96.2 96.0 96.9 96.3 92.0 V ia b ility % In Out In 90.5 90.5 90.5 90.5 90.5 90.0 90.0 90.0 90.0 90.0 90.0 90.0 90.0 90.0 90.0 90.0 90.0 90.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 aThe i n i t i a l stress-cracks percentage equals zero. 68.0 64.0 72.0 68.0 84.0 60.0 78.0 64.0 68.0 62.0 80.0 44.0 44.0 52.0 52.0 64.0 • • • • BCFM Out 0.4 0.4 0.0 0.0 0.4 0.5 0.6 0.4 0.0 0.4 0.0 0.0 0.0 0.0 0.4 0.6 * * • ■ Test Weight In Out 52.7 52.7 52.7 52.7 52.7 53.0 53.0 53.0 53.7 53.7 53.7 53.7 53.7 54.0 54.0 54.0 54.0 54.0 56.0 56.0 55.0 56.0 56.0 55.0 55.0 55.0 55.0 56.0 56.0 57.0 57.0 56.0 56.0 56.0 56.0 56.0 81 less susceptible to damage than th a t produced by the cross-flow batch dryer. Of the 87.3% kernels w ith stress-cracks dried in the auto­ matic batch dryer (Table 11), 28.5% were checked, whereas only 7.0% of the 64% stress-cracked kernels dried 1n the in -b in counterflow dryer exhibited those c h a ra c te ris tic s . This is re fle c te d in the 46.3% breakage te s t fo r the batch dryer compared to 29.0% fo r the in -b in counterflow dryer. When the batch dryer was used in combination w ith the lowtemperature, n a tu r a l-a ir , and in -b in dryeration drying systems, the number of kernels with stress-cracks and the breakage te s t per­ centages were su b s ta n tially improved. This agrees with Gustafson e t a l . (1978), who stated th a t the fin a l moisture content fo r hightemperature drying above 18% does not appear to cause a s ig n ific a n t increase in breakage s u s c e p tib ility . The average breakage te s t resu lts in 1979 were 28.2% and 33.1% fo r the in -b in counterflow and batch d ryer, resp ectively. The d ifferen ce between the two drying techniques was smaller in the 1979-1980 than in the 1978-1979 te s ts . The fin a l moisture contents, 18.5% and 14.7% wb fo r the batch and in -b in counterflow dryer, resp ectively, are the most probable cause of the smaller difference in 1979-1980. When the batch dryer is p art o f the drying system, the change in v ia b ilit y is s u b s ta n tia lly higher than fo r the in -b in counter­ flow dryer. The high d ry in g -a ir temperature used fo r the batch dryer accounts fo r th is d iffere n c e . Even though the "residence time" fo r in -b in dryeration drying is only s lig h tly lower than th a t fo r the two combination drying techniques (high-temperature phase), the decrease 82 in v ia b ilit y fo r in-bin dryeration was substantially higher (Table 11). The long tempering time at high temperatures during the dryeration pro­ cess might be a reasonable explanation fo r the difference. This explana­ tion agrees with Gustafson et a l. (1978), who found that high "timetemperature drying" has a very high negative e ffe c t on germination. Final te s t weight (Table 11), percentage of whole kernels, and BCFM (Tables 9 and 10) were not affected by the d iffe re n t techniques. Auger adjustment fo r the in-bin counterflow system might account for the si ight variation in BCFM (Table 10) fo r this system fo r the 1978 tests. A ll grain dried with the n a tu ra l-a ir and low-temperature combination drying, in-bin dryeration, in-bin counterflow, and auto­ matic batch drying systems was sold commercially as No. 2 corn. 5.3 Effect of the Weather and Design Parameters on the Drying Procedure Compared to the 1979-1980 season, the 1978-1979 drying tests benefited from excellent weather conditions during the harvesting and subsequent drying season. This p a r tia lly accounts fo r the favorable results of the two combination drying techniques and the in-bin dryeration system in 1978-1979. The high-temperature batch drying and in-b in counterflow drying systems are not affected as much by weather changes. The design values for the airflo w rate in the two combination drying systems were re la tiv e ly high (Bakker-Arkema e t a l . , 1978). Simulation (Bakker-Arkema et a l . , 1976) suggests th at airflow s of 3 about 1.0 and 0.8 m /min/m 3 would have been more energy e ffic ie n t during the 1978-1979 season fo r the n a tu ra l-a ir and low-temperature 83 o bins, res p e c tiv e ly , than the design values of 2 .0 and 1.6 m of a ir per cubic meter o f grain. However, in less favorable weather (fewer drying days, humid, and w ith periods o f high temperature) as occurred during the 1979-1980 drying season, the a irflo w rates were in s u ffic ie n t to prevent mold growth in the top layer of the n a tu r a l-a ir bin. The average moisture content o f the corn a t the end of the 1978-1979 drying season in the two combination drying bins was lower than planned because of the need to lower the moisture content in the top layer in the two bins to a t le as t 16.5%. By the time th is occurred, the bottom layers were overdried. This was especially true fo r the high-temperature/low-temperature (e le c tric heat) combination-drying bin , in which the moisture content of the bottom grain la y e r had reached 11.6% by the time the fan was turned o f f . To elim in ate the overdrying problem, a one-screw s t ir r e r was added to the low-temperature system fo r the 1979-1980 season. The r e la tiv e ly warm ambient conditions th a t prevailed in the 1978-1979 season during the loading, tempering, and fin a l drying o f the grain in the in -b in dryeration bin aided in keeping the con­ densation along the bin walls to a minimum. No v is ib le mold or any kind o f odor was detected on the grain next to the w alls or on the top layer when the bin was unloaded a fte r w inter storage. As pre­ viously stated, weather conditions play a major ro le when natural and low-temperature a ir is used. Extra labor is required fo r weekly inspections since automatic humidistats are not dependable, requiring frequent c a lib ra tio n . Because very l i t t l e drying occurs when the 84 temperature drops below freezing, the fans should be shut o ff when the exhaust-air temperature is below 1.6°C. In-bin counterflow and automatic batch drying systems are much less dependent on the weather conditions and do not require the same level of operator attention and expertise as do n a tu ra l-a ir and low-temperature drying techniques. I f the high-temperature system functions properly and the dryers are sized correctly according to harvesting ra te , grain drying should not create any problems or bottlenecks. The unusually high i n i t i a l moisture content in the 1979 harvesting season did not cause any major problems during the drying operation using the batch dryer or the in-bin counterflow dryer. Because no shelter was provided fo r the automatic batch dryer, drying during periods of heavy rain was not possible. The same problem did not a ffe c t the in-bin counterflow dryer, in which the corn being dried is completely protected. 5.4 5.4.1 Drying Efficiency and Dryer Performance Overview Drying systems are commercially sold with rating tables lis tin g crop dryer capacity. However, knowledge of the energy e ffic ie n c y and operating characteristics is needed i f farmers are to select drying systems in te llig e n tly . Dryer capacities are usually quoted in wet or dry bushels of corn being dried and cooled fo r 10 or 5 points o f moisture removed, 25-15% and 20-15%, respectively. To show more favorable s ta tis tic s fo r th e ir dryers, some manufac­ turers use the wet bushel for rating dryer capacities, and in some 85 Instances the loading and unloading times are not taken Into account in rating batch dryers (see Table 4 ). The bushels are calculated by dividing the wet or dry weight in pounds by 56, regardless of the te s t weight (weight per bushel) or grain moisture content. Rating grain dryers by wet weight per u n it of time ( e .g ., tons per hour) would re s u lt in less confusion (Bakker-Arkema et a l . , 1978). In the past fiv e years, the cost of energy sources such as liq u id pro­ pane, natural gas, and e le c tr ic ity has sub stan tially increased. Thus, the need fo r energy-efficiency information becomes more important as nonrenewable energy sources are running out and as various countries face shortages due to p o litic a l pressures. 5 .4 .2 Energy Consumption and Operating Costs Table 11 contains the general energy-consumption results and drying e ffic ie n c y o f the fiv e drying tests performed during the 1978 harvesting season a t the Kalchik Farms. The table also shows the actual operating costs and q u a lity fo r each technique. Natural- a i r and low-temperature combination drying systems have much lower energy (KJ/Kg o f water removed) requirements than the two hightemperature drying systems. Besides being highly dependent on the ambient conditions, the two combination techniques are more dependent on e le c tric a l energy, which has a sub stan tially higher cost per k ilo jo u le than any other conventional source of energy. The fin a l mois­ ture contents fo r n a tu ra l-a ir and low-temperature combination drying (Table 11) are fa r below the desired 15.5% moisture content (wb). Table 1): Actual energy consuaption, operating costs (1979 prices), and corn quality parameters for six alternative corn-drying Methods at the Kalchik Farms, Bellaire, Michigan, fa ll 1978. Drying Technique Moisture Content InterInitial Final Mediate X.wb X.wb Amount Elec­ Dried tricity Drying Propane Efficiency Tons Kwh Liters KJ/Kg H20 Total BreakEnergy,® Energy StressTest Viability ■9* „ Height Changes*^ Costs® cracks Propane Testsc Equivalent X X lb/bu X 11ter/acre J/ton Natural air 26.2 23.1 14.4 60.2 3415 681 3173 53.7 4.26 2.8 11.9 55.0 34.0 Low-temperature 27.5 23.0 13.8 60.0 5095 1022 4028 81.0 7.44 3.4 13.1 54.5 40.0 In-bln dryeration 24.0 20.0 15.6 •• 595 708 3530 43.1 2.44 9.0 13.8 55.0 76.0 In-b1n counterflow 26.4 18.3 16.3 62.0 818 1419 4699 63.3 3.64 64.0 29.0 56.3 25.0 Automatic batch 26.0 •• 15.5 7.5 36 310 6584 11B.5 5.40 87.3 46.3 55.5 78.0 aBased on 2.8 ton/acre. bBased on 6.2 u> O) ■r o c 44- 4 -- 2- m PO » CO a> >> cn u a c> - --1600 1500 55 60 65 70 75 80 Drying temperature (°C) Figure 28. Effect of drying temperature and average fin a l moisture content on the energy cost and drying efficiency for the "Shivvers" in-bin counterflow dryer under consid­ eration. 111 6000 27.0 ■22.5 18.0 4400 - 13.5 3600 - - (x $ .4 /ton) 5200-- Energy cost Energy efficiency (x 2.33 KJ/Kg H20) 1—-E ffic ie n c y (25-15.5% wb) 2— E fficiency (25-18.5% wb) 3— Energy cost (25-15.5% wb) —Energy cost (25-18.5% wb) • 9.0 2800 ■ 4.5 2000 60 70 + 80 90 + 100 no 0 120 Drying temperature (°C) Figure 29. E ffect o f drying temperature and average fin a l moisture content on the energy cost and drying e ffic ie n c y fo r the "Farm Fans" batch dryer under consideration. 112 e ffe c t on the drying cost and energy e ffic ie n c y o f the batch dryer. Again, the exhaust a i r from the layer being dried in the in -b in counterflow system plays a major ro le in it s good performance. As the warmer and less humid a i r leaves the bottom la y e r, i t heats up the upper la y e rs , re s u ltin g in more rapid water removal. Figure 28 sug­ gests th a t drying a t temperatures higher than presently recommended fo r the in -b in counterflow system (71°C) has no s ig n ific a n t e ffe c t on the energy cost and e ffic ie n c y of the system. This re s u lt re fle c ts the assumptions of the in -b in counterflow simulation model. However, as shown in Figure 26, dryer capacity is highly affected by a i r tem­ perature. In th is case, product q u a lity should be the deciding fa cto r in selecting the ideal drying temperature fo r the in -b in counterflow dryer. Because of the almost lin e a r increase in drying e ffic ie n c y and decrease in energy cost fo r the cross-flow batch dryer (Figure 2 9 ), more d if f ic u lt y is encountered in choosing the most e f f ic ie n t tempera­ tu re . Product q u a lity and moisture-content gradient across the grain column w ill lim it the operating temperature. 5 .5 .2 .3 Ambient r e la tiv e humidity and drying temperature versus dryer e ffic ie n c y . The e ffe c t o f ambient r e la tiv e humidity and d ry in g -a ir temperature on the e ffic ie n c y of the in -b in counterflow dryer is shown in Figure 30. The values are fo r 25.5% to 15.5% 3 2 moisture content (wb), ambient temperature (10°C ), and 3.15 m /min/m o f a irflo w . The fig u re shows th a t ambient r e la tiv e humidity and d ry in g -a ir temperature have opposite e ffe c ts on dryer e ffic ie n c y . The lower the drying temperature and the higher the ambient r e la tiv e humidity, the less e f f ic ie n t ly the system w ill perform. For the 113 2200 ■ - (x 2.33 KJ/Kg H?0) 2100 Energy efficiency 1900 -- 1800 ■ 1700 ■■ 1600 40 50 60 70 80 90 100 Ambient re la tiv e humidity (%) Figure 30. Effect of the ambient re la tiv e humidity and dryinga ir temperature on the drying efficiency of the in-bin counterflow dryer. 114 lower ambient r e la tiv e humidity, the e ffe c t of drying temperature is less pronounced. Figure 30 shows th a t fo r the same ambient re la tiv e humidity, the e ffe c t of drying temperature is decreased as drying temperature increases. This condition suggests th at fo r a specific re la tiv e humidity, there is a temperature lim it above which no sub­ s ta n tia l reduction in dryer e ffic ie n c y w ill take place. This is also shown in Figure 28, in which the energy-cost lin e tends to be p a ra lle l to the abscissa. Because of the in s ig n ific a n t change (less than 2% from 20% to 100% re la tiv e humidity) in drying e ffic ie n c y , a fig ure sim ilar to Figure 28 is not presented fo r the cross-flow batch dryer. 5 .5 .2 .4 and drying tim e. E ffect o f moisture content on energy effic ie n c y The estimated heat energy and drying time required to dry corn from two i n i t i a l moisture contents are shown in Figure 31 (in -b in counterflow dryer) and Figure 32 (cross-flow batch d ryer). 3 2 The operating conditions are 71°C, 3.15 m /min/m , and 102°C and^ 3 2 9.73 m /min/m fo r the in -b in counterflow and batch dryer, respec­ tiv e ly . For both fig u re s , the ambient temperature is 10°C and the r e la tiv e humidity 70%. As in Figure 26, the time shown fo r the in-bin counterflow drying is the cycling time, whereas fo r Figure 31 only the heating time is considered. Figures 31 and 32 c le a rly show that the drying time decreases as a smaller amount of water at low in i t ia l moisture content is removed. On the other hand, Figures 31 and 32 e x h ib it completely d iffe re n t behaviors with respect to heat-energy requirements. 115 2500 1--Drying time (30% wb, IM) 2 -E ffic ie n c y (25% wb, IM) 3--Drying time (25% wb, IM) 4--E fficien cy (30% wb, IM) 50-- -2100 time - Drying -.1900 20 - - ..1700 10- Energy efficiency (min.) 40-- (x 2.33 KJ/Kg H^O) -*2300 - 1500 15 18 21 24 27 30 Final moisture content (% wb) Figure 31. Effect of in it ia l and fin a l moisture content on the drying time and drying efficiency of the in-bin counterflow dryer under consideration. 116 50*- Expected --2900 ■■2600 30" 20 Expected - - --2300 Drying efficiency Drying time (min.) ■■3200 (x 2.33 KJ/Kg H2O) 3500 1--Drying time (30%, IM) ou 2— Efficiency (25%, IM) V 3--Drying time (25%, IM) ^ - - E f fic ie n c y (30%, IM) on-. 10- - 2000 Final moisture content (% wb) Figure 32. E ffect of i n i t i a l and fin a l moisture content on the drying time and drying efficiency of the cross-flow batch dryer under consideration. 117 Despite having the normal c h a ra c te ris tic o f energy-efficiency curves fo r cross-flow dryers, H u k ill's (1954) analysis f a ils to pre­ d ic t drying e ffic ie n c y a t the beginning of the process. The dotted lines shown in Figure 32 represent the expected behavior of a crossflow dryer (Morey e t a l.» 1976). F ailu re to predict drying e f f i ­ ciency fo r a small amount of water removed can be explained by the fa c t th a t H u k ill's (1954) analysis does not account fo r the heat required to warm up the grain. For the normal drying range (above 3 points removal), the w rite r fe els th at the model can s a tis fa c ­ t o r ily be used to predict e ffic ie n c y fo r the cross-flow system. Unlike other types of dryers, such as batch or cross-flow , the in -b in counterflow dryer requires less energy with a decrease in the fin a l moisture content (Figure 31). However, a s u ffic ie n t bed depth (over .9 m) must be maintained to guarantee a saturated exhau st-air condition. Since cooling does not occur in in -b in counter­ flow dryers, grain w ill carry enough sensible heat to remove 1 to 1.5 points of moisture, which w ill re s u lt in additional energy savings since drying can be completed with natural a i r . In B r a z il, corn is harvested from A pril to August, when the average ambient temperature is about 20°C and r e la tiv e humidity 70%. The corn moisture content during the harvesting season varies from 16 to 22% wb. Because of B ra z il's tro p ic a l condition, 13% wb or less is required fo r safe storage. Results o f simulation in d icate th a t to dry corn from 18 to 13% wb under B ra zilia n conditions, 3988 and 8243 KJ/Kg H20 are required fo r drying with in -b in counterflow and cross-flow batch dryers, resp ectively. 118 5.5.2.5 A irflo w rate versus drying cost and dryer capacity. The e ffe c t of a irflo w rate on drying cost and dryer capacity fo r the in-bin counterflow and batch dryer is shown in Figures 33 and 34, respectively. Again, i f s u ffic ie n t bed depth is maintained, the behavior of the energy-cost lin e fo r the in-bin counterflow dryer w ill be d iffe re n t than that fo r the batch dryer. Along with the benefit of decreased operating costs, the in-bin counterflow dryer shows a large increase in capacity when compared to the batch dryer a t the same increment in airflo w . Figure 33 shows that the a irflo w has more e ffe c t on dryer capacity than on the energy cost, whereas in the case of the batch dryer (Figure 3 4 ), both energy cost and dryer capacity are equally affected by the a irflo w rate. 5.6 5.6.1 Economics of the Systems General Considerations In analyzing the cost data presented in Tables 11 and 12 or predicted by the drying model (Figures 28, 29, 33, and 3 4 ), i t should be kept in mind that only the direct e le c tr ic ity and fuel costs (operating costs) were considered. I t would not have been r e a lis tic to include the labor and fixed costs since none of the systems analyzed at the Kalchik Farms are b u ilt at optimum size. The main objective of th is study was not to find the to ta l annual cost of each drying technique, but rather to demonstrate the f e a s ib ility of n a tu ra l-a ir and low-temperature combination drying, in-bin dryeration, and in-bin counterflow drying fo r the Michigan weather conditions. 119 180 Moisture content: 25-15.5% wb Ambient : 10°C and 70% r .h . Drying temperature: 71 °C Capacity 6 . 8- - 140 6 .7 .. 120 6 . 6- - 100 Dryer capacity (x $.4/ton) Energy cost Cost (x .025 ton/hr) 160 6 .9 -? 3 2 Airflow (x .4 m /m /min) Figure 33. E ffect of a irflo w rate on dryer capacity and energy cost fo r the "Shivvers" in -b in counterflow dryer. 120 102 (x .025 ton/hr) {x $ .4/ton) Moisture content: 25-15.5% wb Ambient: 10°C and 70% r .h . Drying temperature: 102°C Dryer capacity Energy cost Capacity Cost 9- 7 - 70 90 110 130 A irflo w (x .03 m^/m^/min) Figure 34. E ffe c t o f a irflo w ra te on dryer capacity and energy cost fo r the "Farm Fans" batch dryer under con­ s id e ra tio n . 121 Although some fanners buy an on-farm drying and storage system solely because the dealer has convinced them to do so, most farmers consider on-farm grain drying only i f i t is lik e ly to be cost competitive with other a lte rn a tiv e s . To help farmers or farm man­ agers make sound comparisons between the techniques studied, a 378-ton drying and storage capacity was designed fo r each technique. The following sections contain the economic comparison of the various techniques studied. 5 .6 .2 Capital Budgeting Analysis Much more is involved with adoption of one of the systems than f u e l, e le c t r ic it y , and labor costs. As with any kind of business en te rp ris e , farmers use systems th at are most p ro fita b le in the long run fo r th e ir p a rtic u la r circumstances. The economic choice among the fiv e drying systems studied can be based e n tire ly on current operating costs or elevator charges only i f i t is assumed th a t the various choices w ill a ll increase in price a t the same ra te . In th is case, an on-farm grain-drying and storage system w ill be competitive or less expensive than off-farm drying and storage i f the savings are greater than the in te re s t pay­ ments required to buy the on-farm grain-drying system. A serious problem w ith th is single comparison in an in fla tio n a ry economy is th a t i t 1s d i f f ic u l t to take In to account ris in g e le c t r ic it y , fu e l, and labor costs, as well as elevator charges. Also, other items such as taxes, insurance, maintenance, and labor costs a ffe c tin g the economics of an on-farm grain-drying system have to be taken into consideration. 122 According to Skees e t a l. (1979), capital budgeting accounts fo r the net present value of a lte rn a tiv e investments, allowing fo r cost comparison o f investments w ith d iffe re n t annual flow o f expenses and/or income. Factors such as in te re s t rate and l i f e o f the loan, depreciation l i f e and schedule chosen, marginal tax ra te , e l i g i ­ b i l i t y fo r investment tax c r e d it, and e ffec ts o f in fla tio n on variab le cost are taken in to account in the net present value ca p ita l budgeting approach. The net present value method provides a means of comparing future costs with current costs by reducing a ll costs to the common basis of present worth, th at is , the amount th at one would have to invest today in order to have enough funds av ailab le in the future to meet a l l o f the anticipated expenses. Although net present value c ap ita l budgeting is considered as a sound approach fo r evaluating investment decisions (Skees e t a l . , 1979), i t has one major problem: predict future costs. the decision maker must be able to Future costs such as fo r fu e l, e le c t r ic it y , labo r, custom operation charges, and the ra te of in fla tio n must be accurately estimated. 5 .6 .3 Budgeting Analysis of the Systems In order to have a sound comparison among the drying systems, a capital-budgeting analysis fo r the fiv e a lte rn a tiv e drying systems was performed. The estimated cost per ton includes both ownership costs and operating costs. basis. I t is calculated on a present-value 123 Each of the 378-ton systems was designed to meet the Kalchik Farms' corn production fo r a 16-day drying season a t 10 hours per day. The 16-day season allows some extra drying days fo r the combinationdrying systems and w ill permit some custom drying. I f custom drying is considered, i t w ill generate extra income and greatly reduce the to ta l annual per-ton cost. However, the p o s s ib ility of custom drying was not taken into account in th is analysis. Although storage bins larger than the size designed (177 tons) are less costly (per-ton storage basis), the smaller bins permit more f le x i b i l it y fo r the conditions on the Kalchik Farms. Appendix A specifies the components of each system and th e ir estimated 1980 investment cost (the costs presented may vary among dealers). To a rriv e at the present-value annual per-ton cost of the systems, a computer program (TELPLAN 03) that estimates costs under d iffe re n t assumptions with respect to economic factors such as in te re st rates, tax rates, in fla tio n , and other costs was employed. The reader is directed to Appendices B and C and fo r further information to the work done by Skees e t a l. (1979), who performed a detailed cost analy­ sis fo r d iffe re n t drying systems fo r m ultiple use. 5.6.3.1 Costs and basic assumptions. One of the most important factors affecting variable costs is the energy requirement. The energy-cost values used in this analysis were calculated based on the drying model and experimental determinations (e le c tr ic ity to run the fans during the second drying phase) in Table 12. For the high-temperature phase, the ambient condition was 10°C and 70% re la ­ tiv e humidity, with d ryin g -air temperatures of 71 and 102°C fo r the 124 1n-bin counterflow and batch dryer, respectively. fo r the d iffe re n t techniques are shown in Table 18. The energy costs Assumptions con­ cerning re p a ir, labor requirements, and salvage value varied among the d iffe re n t systems and were chosen according to the values in Appendix A and in Table 18. A number of other assumptions were made fo r the d iffe re n t systems: (a) a 10-year planning horizon, (b) purchase during August of the f i r s t year, (c) e l i g i b i l i t y fo r the 10% investment tax c re d it, (d) use o f double-declining balance depreciation with additional fir s t-y e a r depreciation (20%), (e) a $ .39/ton fuel cost fo r operating associated equipment, ( f ) a 30% marginal tax rate fo r the producer, (g) a 10% annual compounded increase in fuel cost, (h) an annual insurance charge o f 1% of the inventory value of investment, ( i ) an annual insurance charge of 1% of the inventory value of investment, ( j ) an annual property tax of 1.6% of the inventory value of invest­ ment, and (k) a 6% annual compounded increase in investment costs of a new on-farm grain-drying and storage system. to be repaid over eight years, was assumed. A loan rate o f 7.8%, The discount ra te , which is considered a tool to cover risk of the investment, the time value of money, and opportunity to invest in a more p ro fita b le enter­ p ris e , must be assumed above the rate on borrowed money (7.8%). In th is analysis, an a fte r-ta x rate o f 9% was assumed. The results of the economic analysis of the fiv e on-farm drying systems (378-ton capacity) are shown in Table 19. The values associated with each design are fo r t o t a l, fix e d , and variab le costs and are presented in terms of the annual present value. The annual Table 18: Estimation/assumptions fo r investment cost, salvage value, in te re s t, direct and indirect energy costs, labor, and maintenance costs fo r the fiv e drying systems. Drying Systems Batch— N at.-A ir Comb. Drying 5.8 ton/hr. In-Bin Dryeration Drying 4.3 ton/hr 2.41 ton/hr. 3.81 ton/hr. Batch— Low-Temp. Comb. Drying 5.8 ton/hr. 35,126.00 41,538.00 38,286.00 38,274.00 36,332.00 Salvage value of total investment (%) 15% 14% 14% 15% 15% Annual rate of interest on loan (%) 7.8% 7.8% 7.8% 7.8% 7.8% Direct energy cost ($ /to n )a 4.53 2.72 5.31 4.09 2.76 Indirect energy cost ($/ton) .39 .39 .39 .39 .39 1.80 1.16 .89 .89 1.06 1,914.00 1,948.00 Estimation/Assumption Batch Drying In-Bin Counterflow Investment cost (1980 prices) (% )* % Labor cost ($/ton) Maintenance cost (10 years)($) 1,756.00 2,076.00 aBased on $ .62/kwh and $.127 per l i t e r of propane. 1,816.00 Table 19: Economic analysis of fiv e alternative on-farm corn-drying and storage systems fo r Michigan weather conditions (1980 prices). Fixed Cost Variable Cost Total Cost In it ia l Capital Investment Per Ton $7.23 $8.59 $15.82 $ 92.93 In-bin counterflow (26.0-18.0-15.5% wb) 8.51 5.83 14.34 109.89 In-bin dryeration (26.0-20.0-15.5% wb) 7.31 5.71 13.02 96.12 Natural a ir (26.0-23.0-15.5% wb) 7.85 7.24 15.09 101.25 Low temperature (26.0-23.0-15.5% wb) 7.84 8.78 16.62 101.29 System (378 tons annually) Batch drying (26.0-15.5% wb) Annual Cost Per Tona aNet present value for a 10-year planning horizon. 127 nondiscounted returns, selected cost, and cash flow fo r each system are presented in Tables 20, 21, 22, 23, and 24 (Appendix A) fo r the batch, in -b in counterflow, in -b in dryeration , n a tu r a l-a ir , and lowtemperature combination drying systems, respectively. (See TELPLAN 03 User's Guide in Appendix C fo r a b e tte r understanding o f the ta b le s .) Since the fixed costs were not su b stan tially d iffe re n t fo r the fiv e drying system designs, the to ta l drying costs were more affected by the variab le costs, as shown in Table 19. expensive system per ton is the in -b in dryeration. counterflow ranks second. The least The in-b in Although the low-temperature combination drying system has a fixed cost lower than the n a tu ra l-a ir system, the high to ta l cost fo r the low-temperature system can be explained by it s strong dependence on e le c tric a l energy to run the fan and to heat the a ir . A s im ila r comparison can be made fo r the n a tu ra l-a ir combination drying and in -b in counterflow drying systems. Although the n a tu ra l-a ir dryer is a less expensive investment and more energy e f fic ie n t than the in -b in counterflow system (Table 1 2 ), the naturala ir system requires too much e le c tr ic it y to run the fans during the drying and storage phases. Without question, the less expensive system in terms o f i n i t i a l investment per ton is batch drying. How­ ever, i t ranks la s t among the systems studied because o f the unfavor­ able price projection fo r fo s s il fuel in the near fu tu re. The energy and money savings ($1028 less than batch drying fo r a 378-ton annual capacity) more than o ffs e t the additional time and extra care required fo r the in -b in dryeration system. in terms o f future fuel cost. Natural a ir holds the most promise However, i t is a risky operation, 128 and fu rth e r research must be done with regard to the Michigan weather conditions. To conclude th is sectio n, i t should be kept in mind th a t any decision to invest in a new g rain -d ryin g system should take into account commercial drying and storage p ric e s , adequacy o f local marketing, and grain ele va to rs . No doubt, more r e a lis t ic assumptions can be made fo r each p a rtic u la r case. I t may well be th a t the best a lte r n a tiv e fo r some farmers would be to provide to ta l drying and only p a r tia l or no storage f a c i l i t i e s fo r t h e ir crop. TELPLAN 03, which uses the net present-value c a p ita l budgeting, is "on lin e " and is a v a ila b le fo r routine use by extension, research, education, and agribusiness people to conduct economic analyses w ith ­ out the need o f any programming knowledge (Brook & Bakker-Arkema, 1978). 6. 1. SUMMARY Except fo r the high-temperature drying systems, the results obtained in th is research fo r Michigan are s lig h tly d i f f e r ­ ent than those reported fo r other parts o f the United States, such as Kansas, Minnesota, and Nebraska. The Michigan conditions required higher a irflo w and/or lower i n i t i a l moisture content than in the aforementioned states. 2. procedure. The q u a lity of the end-product was affected by the drying The in-b in counterflow dryer produced dried corn with less s u s c e p tib ility to damage than th at produced by the cross-flow batch dryer. 3. When low-temperature, n a tu ra l-a ir, and in-bin dryeration were used in combination, the number of kernels with stress-cracks and the breakage te s t results were substantially improved compared to both in-b in counterflow and batch drying. 4. The fin a l moisture contents, 18.5 and 14.7% fo r the batch and in -b in counterflow dryers, respectively, were the most probable cause of the smaller difference in the reported breakage suscepti­ b i l i t y fo r the 1979-1980 tests. 5. In any case in which the batch dryer was part of the dry­ ing system, the changes in v ia b ilit y were substantially higher than fo r the in -b in counterflow dryer. The high-temperature a ir used fo r the batch dryer accounts fo r the differences. 129 130 6. On the basis o f operating cost (in drying to the same moisture c o n ten ts), the in -b in counterflow dryer is p referab le to a cross-flow batch dryer. However, on the basis o f i n i t i a l investment, the cross-flow batch dryer has a s ig n ific a n tly lower i n i t i a l cost than any other system. 7. The high drying e ffic ie n c y o f the low-temperature and n a tu r a l-a ir combination drying systems did not reduce the to ta l dry­ ing cost. The v a ria b le costs were highly affe cted by the price of e le c t r ic it y . 8. In times of uncertain or inadequate fo s s il fuel sup plies, the combination drying systems are the best choice fo r drying corn on small and medium-sized Michigan farms. 9. The res u lts o f energy requirements, operating costs, fix e d costs and t h e ir p o ten tia l savings data fo r drying corn in Michigan suggest th a t in -b in dryeration and in -b in counterflow drying hold the most promise. 10. Considering th a t a t le a s t 60% o f the Michigan corn crop is a r t i f i c i a l l y d rie d , the annual energy savings fo r Michigan are on the order o f 2.11x10 g MJ. The d o lla r savings in operating costs are between $3 and $10 m illio n (except fo r the low-temperature combina­ tio n drying technique). 11. H u k ill's (1954) analysis fo r deep-bed drying described drying time as a function o f i n i t i a l moisture content, fin a l mois­ tu re content, position in the grain bed, and ambient and drying conditions w ith reasonable accuracy fo r both batch and in -b in counterflow drying systems. 131 12. Results of simulation indicate that fo r the B razilian conditions (70% re la tiv e humidity and 20°C ambient temperature), the energy e ffic ie n c ie s fo r the in-bin counterflow and cross-flow batch dryer are, respectively, 3988 and 8243 KJ/Kg of water removed. This suggests that in-b in counterflow drying is also the best choice for the average B razilian conditions. 7. SUGGESTIONS FOR FUTURE RESEARCH Based on the findings o f th is study, the follow ing suggestions are made fo r fu tu re research: 1. Conduct experiments to v a lid a te H u k ill's analysis fo r the in -b in counterflow dryer over a wider range of drying temperatures and fin a l moisture contents. 2. Apply other drying models to analyze the in -b in counter­ flow drying system. 3. Perform the tests in d iffe r e n t locations and in d iffe r e n t years in the state o f Michigan. 4. Perform the low-temperature and n a tu r a l-a ir combination drying using the in -b in counterflow or other more e f f ic ie n t dryers in the high-temperature phase. 5. In su late the in -b in counterflow dryer and elim in ate it s p o ten tial heat leakage. 6. Test the in -b in counterflow dryer fo r drying tempera­ tures above 72°C. 7. Study the performance of the bees-wing e lim in a to r o f the “Shivvers" system. 8. The e ffe c t o f the uniform ity o f the grain-bed level should be investigated based on the fin a l m oisture-content v a ria tio n o f the in -b in counterflow dryer. 132 133 9. The adaptation of a lte rn a tiv e burners such as fo r wood chips or corn cobs should be investigated in the "Shivvers" in-bin counterflow system. 10. The causes fo r the high v a r ia b ility in fin a l moisture content fo r the cross-flow batch dryer should be investigated and changes in the design suggested. 11. The potential problems fo r in-bin dryeration and the two combination drying techniques increase as bin size increases. There­ fo re , the optimum bin size fo r each technique in relatio n to farm production and management should be investigated. 12. For the B razilian conditions, corn is harvested between 16 and 22% i n i t i a l moisture content; 13% fin a l moisture is required fo r safe storage. Tests in this moisture range with the in-bin counterflow drying system should be conducted. 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Serv. B u ll. AE-72. McLendon, B. D ., and A llis o n , J. M. 1978. Solar energy u t iliz a t io n 1n a lte rn a te grain drying systems in the Southeast. Paper No. 78-3013. ASAE, S t. Joseph, Michigan. 139 M ille r , B. S ., Hughes, J. W., Rousser, R ., and Pomeranz, Y. 1979. Standard method fo r measuring breakage s u s c e p tib ility o f shelled corn. Paper No. 79-8087. ASAE, St. Joseph, Michigan. Morey, R. V ., Cloud, H. A ., and Lueschen, W. E. 1976. Practices fo r the e f fic ie n t u t iliz a tio n o f energy fo r drying corn. Trans­ action o f the ASAE 19(14): 151. Morey, R. V ., Robert, J. G ., and Cloud, A. H. 1978. Combination drying. l £ Proceedings of the A ltern atives fo r Grain Conditioning and Storage Conference. U niversity o f I l l i n o is , Urbana-Champaign, I l l i n o is . Paulsen, M. R ., and Nave, W. R. 1978. Corn damage from conven­ tio n a l and rotary combines. Paper No. 78-7004. ASAE, St. Joseph, Michigan. P eplinski, A. J. e t a l. 1975. Corn q u a lity as Influenced by harvest and drying conditions. Cereal Food World 19(2):145. Peterson, W. 1973. S o la r-e le c tric crop dryer progress report. EMC 657. South Dakota State U niversity. Peterson, H. W., and Hellickson, M. A. 1976. S o la r-e le c tric drying of corn in South Dakota. Transaction of the ASAE 19(2):349. Pfost, H. B ., Maurer, S. G ., Grosh, L. E ., Chung, D. S ., and Foster, G. H. 1977. Fan management systems fo r natural a ir dryers. Paper No. 77-3526. ASAE, St. Joseph, Michigan. Pierce, R. D ., and Thompson, L. T. 1978. Management o f solar and low-temperature grain drying systems. Paper No. 78-3513. ASAE, St. Joseph, Michigan. Pierce, R. D ., and Thompson, L. T. 1978. Management of solar and low-temperature grain drying systems. Part I: Minimum a irflo w rates: Supplemental heat and fan operation strategies with f u ll bin. Paper No. 78-3515. ASAE, S t. Joseph, Michigan. Ross, I . J . , and White, G. M. 1972. Discoloration and stress cracking of white corn as affected by overdrying. Transaction of the ASAE 15(2):327. Rutledge, J. H. 1978. The value o f corn q u a lity to the dry m ille r. In Proceedings 1977 Corn Q uality Conference. University of T T lin o is , Urbana-Champaign, I l l i n o i s . Schmidt, S. C. 1978. Foreign market prospect fo r corn. In Proceed­ ings 1977 Corn Q uality Conference. U niversity o f IllT n o is , Urbana-Champaign, Ill in o is . 140 Shove, G. C. 1978. Corn q u a lity as affec ted by drying procedures. In Proceedings 1977 Corn Q u ality Conference. U n iversity of T T H n o is , Urbana-Champaign, I l l i n o i s . Shove, G. C. 1978. Corn drying w ith low temperature, high tempera­ tu re combination system. Paper No. 78-305. ASAE, St. Joseph, Michigan. Skees, J. R ., R is te r, M. E ., Brook, R. C -, Harsh, S. B ., and BakkerArkema, P. W. 1979. On-farm grain handling costs— Engineering and economic fa c to rs . Paper No. 79-3525. ASAE, St. Joseph, Michigan. Sobel, A. T . , and Buelow, F. 1963. Galvinized steel roof construc­ tio n fo r s o la r heating. A g ric u ltu ra l Engineering 4 4 (6 ): 312. Stevens, J. B ., B a r re tt, J. R ., and Okos, M. R. 1978. Mathematical sim ulation o f low-temperature wheat drying. Paper No. 78-3004. ASAE, S t. Joseph, Michigan. Stew art, L. D. 1978. The s ig n ifican ce o f corn q u a lity fo r feed manufacturer. In Proceedings 1977 Corn Q u ality Conference. U n iv e rs ity o f iT T in o is , Urbana-Champaign, I l l i n o i s . S tout, B. A. 1979. Energy fo r World A g ric u ltu re . Nations, Rome, I t a ly . FAO, United S u lliv a n , J. E. e t a l . 1975. The e ffe c t o f heat on n u tritio n a l value o f corn. J^n Corn Q u ality in World Markets, ed. by L. D. H i l l . In te rs ta te P rin te rs and Publishers, D a n v ille , Illin o is . Sutherland, J . W. 1975. Batch brain dryer design and performance p re d ic tio n . Journal o f A gric. Engr. Res. 20:423. Thompson, R. A ., and Foster, G. H. 1963. Stress cracks and breakage in a r t i f i c i a l l y dried corn. USDA Marketing Research Report 631. USDA, Washington, D.C. Thompson, T. L ., Foster, G. H ., and P ea rt, R. M. 1969. Comparison o f concurrent-flow , crossflow , and counterflow grain drying methods. USDA Marketing Research Report 841. USDA, Washington, D.C. Thompson, T. L . , P e a rt, R. M ., and Foster, G. H. 1968. Mathematical sim ulation o f corn drying—A new model. Transaction o f the ASAE 1 1 (4 ):5 8 2 . UREMG. 1968. Armazenamento nas Fazendas. Unlversidade Rural do Estado de Minas G erais, Vicosa M .G., B r a z il. 141 USDA. 1968. Preventing microtoxins 1n farm commodities. tural Research Service, ARS 20-16. USDA. 1975. Crop Production, 1975. Annual Summary. Reporting Service, USDA, Washington, D.C. Veja. 1980. Corrida de obstaculo. 12 de Marco. Veja. 1980. 0 campo conta os lucros da supersafra. Editora A b ril, 26 de Marco. Watson, S. A ., and M irata, Y. a r t i f i c i a l l y dried corn. Veja No. 601. Agricul­ S ta tis tic a l Editora A b ril, Veja. No. 603. 1962. Some w et-m illing properties of Cereal Chem. 39:35. Williams, E. E ., Fortes, M., C o lliv e r, D. G., and Okos, M. R. 1978. Simulation o f s tirred bin low temperature corn drying. Paper No. 78-3012. ASAE, St. Joseph, Michigan. Williamson, J. L. 1975. N u tritio nal requirements of livestock as related to corn q u a lity . Iji Corn Quality in World Markets, ed. by L. D. H i l l . In te rs ta te Printers and Publishers, D anville, Illin o is . Woods, D. R. 1975. Financial Decision Making in the Process Industry. P re n tic e-H all, Englewood C U ffs , New Jersey. Zink, H., Brook, R. C ., and Peart, R. M. 1978. Engineering analysis of energy source fo r low temperature drying. Paper No. 78-3517. ASAE, St. Joseph, Michigan. APPENDICES 142 APPENDIX A BUDGETING ANALYSIS OF THE 378-TON (1 5 ,0 0 0 BU) DRYING SYSTEMS 143 144 A l. 1. Batch Drying (15,000 bushels) (120 bu/hr) System operation From f i e l d ------------- > Moisture tester Grain cleaner 1 1 F lig h t auger Wet holding tank I 17 f t . auger v Batch dryer V 42 f t . auger 5,000 bushels bin ------ > 5,000 bushels bin 5,000 bushels bin In i t i a l moisture content 26.0% (wb) Final moisture content 15.5% (wb) 145 2. Estimated 1980 Investment Cost Quantity Item Cost ($) 1 Batch dryer (120 bu/hr) 3 24 f t . diameter bin (12 f t . h t .) 9,552.00 3 Perforated flo o r 4,665.00 3 Concrete 2,520.00 Wet holding tank (35 m^) $ 8,170.00 2,235.00 Grain spreader 400.00 Grain cleaner 600.00 Unloading auger + motor 457.00 Sweep auger + motor 298.00 F lig h t auger + motor fo r loading the wet holding tank 3,500.00 42 f t . transport auger + motor (6") 2,050.00 17 f t . transport auger + motor (6") 750.00 3 Axial fan (5" SP 2500 cfm) 978.00 1 Moisture te s te r 220.00 E le c tric a l 1,000.00 Total investment a t l i s t prices 37,175.00 Less 10% discount 33,457.00 In s ta lla tio n Miscellaneous (2% investment) TOTAL COST OF THE SYSTEM 1,000.00 669.00 $35,126.00 146 3. Estimated salvage value at the end of 10 years According to Brook (1977), a dryer is made prim arily of sheet metal, and although the metal may have some scrap value, the cost of disassembling i t would make the total salvage value negligible; how­ ever, one h a lf of bin, flo o r, in s ta lla tio n , concrete, e le c tric a l, and miscellaneous cost remains at the end of 10 years. For the total system: Bins $ 5,893.00 Perforated flo o r 2,332.00 Concrete 1,260.00 E lectrical 500.00 Miscellaneous 334.00 Installatio n s 500.00 Total $10,819.00 at 50% salvage cost ($5,409.00). % salvage of total investment = $5,409.00 * $35,126.00 * 15%. 4. Estimated annual rate of interest on loan Harsh et a l. (1978) assumed an annual rate of interest on loan equal to 7.8%. 5. Estimated direct energy cost Experimental data at 1980 prices indicate $11.5/100 bushels. 6. The estimated ind irect energy cost is assumed to be $1.00/100 bushels (Harsh et a l . , 1978). 147 7. Estimated labor cost At 2.4 tons per hour drying capacity, 157 hours o f labor ($ 4 .00/hr) are required (loading and management). hour unloading capacity, 13 hours are required. 157 hr + 13 hr = 170 hr. At 30 tons per Total labor time = At $4 .00 /h r, labor cost w ill be equal to $680/378 tons or $1.80/ton. 8. Estimated maintenance cost over 10 years Wood (1975) gave a range in the maintenance fa cto r from 2 to 15% of the investment cost per year. A grain-drying system is made of r e la tiv e ly simple pieces of equipment. A maintenance cost of 5% of investment cost per year, including the bins, is assumed. $35,126 x 5% = $1,756 (in 10 years) To use TELPLAN 03, some basic assumptions must be made. For the batch drying and following designs, see respective TELPLAN forms and TELPLAN 03 User's Manual (Appendix C). Table 20: General economic analysis fo r a 10-year period fo r the batch-drying system. TO TA L DEPREC­ YR RETURNS IA T IO N 1 6266 2 6642 7041 3 4 7463 5 7911 6 8386 7 8889 8 9422 9 9988 10 10587 TO TA LS 82595 P R IN C + IN T . 6594 5706 4565 3652 2922 2337 1870 1496 1197 957 31296 R E P A IR S FUEL+ LUB. LABOR SUP­ P L IE S 2528 5810 5810 5810 5810 5810 5810 5810 3539 0 127 180 217 250 281 311 341 371 402 434 2310 2495 2694 2910 3142 3394 3665 3959 4275 4617 721 764 810 859 911 965 1023 1084 1150 1218 0 0 0 0 0 0 0 0 0 0 4842 -1 6 3 4 -1 8 6 2 -2 0 4 8 -2 2 0 0 -2 3 2 8 -2 4 3 6 -2 5 3 1 -2 6 8 3249 46737 2914 33461 9505 0 -7 2 1 6 1. ECONOMIC S A V IN G S (D IS C O U N T E D I F IN V E S T M E N T I S MADE = $ D O LLA R S ) -1 0 . 2. NUMBER OF U N IT S 3. D E P R E C IA T IO N 4. ANNUAL N O N -D IS C O U N T E D RETURN S. OVER P E R O ID ON W H IC H A N A L Y S IS WAS MADE = METHOD USED IN A N A L Y S IS = A F T E R -T X CASH FLW OF USE 378. A. S E L E C T E D COSTS AND CASH FLOWS 149 A2. 1. In-Bin Counterflow Drying (15,000 bushels) (150 bu/hr) System operation From fie ld ----------------------------^ Moisture tester i Grain cleaner 1 42 f t . auger I Dryer (2,000 bushels) 5,000 bushels bin Transport auger ^ 5,000 bushels bin 5,000 bushels bin In it ia l moisture content 26.0% (from f ie ld ) Intermediate moisture content Final moisture content 18.0% (from dryer) 15.5% (from bin) 150 2. Estimated 1980 investment cost Item Quantity Shivvers performance package Cost ($) 13,921.00 Bee‘ s-wing elim inator 1,406.00 35 f t . horizontal transport auger (4") 1,540.00 18 f t . diameter bin 1,929.00 Perforated flo o r (dryer) 873.00 3 24 f t . diameter bin 9,552.00 3 Perforated flo o r (24 f t . ) 4,665.00 3 Concrete (24 f t . bin) 2,520.00 Concrete (18 f t . bin) 750.00 Grain spreader 400.00 Grain cleaner 600.00 Unloading auger + motor (6") 457.00 Sweep auger + motor 298.00 42 f t . auger + motor 2,050.00 3 Axial fan (.5 " SP & 2,500 cfm) 978.00 1 Moisture te ste r 220.00 E le c tric a l 2,000.00 Total investment at l i s t prices 44,159.00 Less 10% discount 39,743.00 In s ta lla tio n Miscellaneous (2% to ta l investment) TOTAL COST OF THE SYSTEM 1,000.00 975.00 $41,538.00 151 3. Estimated salvage value a t the end o f 10 years Bins $5,740.00 Perforated flo ors 2.769.00 Concrete 1.635.00 E le c tric a l 1 ,000.00 Miscellaneous 397.00 In s ta lla tio n 500.00 Total $12,041.00 a t 50% salvage cost = $6,020.00 % 4. salvage o f to ta l investment = $6,020.00 * $41,538.00 = 14% Estimated annual rate of in te re s t on loan 7.8% per year 5. Estimated d ire c t energy cost $6.90/100 bushels 6. Estimated in d ire c t energy cost $1.00/100 bushels 7. Estimated labor cost $2.67/100 bushels 8. Estimated maintenance cost over 10 years $41,538.00 x 5% = $2,076.00 (in 10 years) Table 21: General economic analysis fo r a 10-year period fo r the in -b in counterflow drying system. TO TA L DEPREC­ YR RETURNS IA T IO N 1 2 3 4 5 6 7 8 9 5701 6043 6406 7128 6882 5506 6790 7198 7630 8087 8573 9087 10 963^ TO TA LS 75147 P R IN C + IN T . R E P A IR S FUEL+ LUB. SUP­ A F T E R -T X CASH FLW LABOR P L IE S 0 0 0 5498 -1 9 0 4 -2 1 6 4 0 0 0 -2 3 6 8 -2 5 3 0 -2 6 5 7 o 0 0 -2 7 5 8 -2 8 3 8 -1 2 6 4404 3524 2819 2255 1804 1443 2989 6871 6871 6871 6871 6871 6871 6871 4185 140 203 246 284 320 356 391 426 462 1839 1986 2145 2317 2502 2702 465 493 522 554 587 622 65* 699 741 1155 0 499 2919 785 0 4075 36920 55271 3327 21150 6127 0 -7 7 7 2 1460 1577 1703 1. ECO NO M IC S A V IN G S (D IS C O U N T E D D O LLA R S ) I F IN V E S T M E N T I S MADE = ♦ -8 . 2. NUMBER OF U N IT S ON W H IC H A N A L Y S IS 3. D E P R E C IA T IO N 4. ANNUAL N O N -D IS C O U N T E D R E TU R N S* METHOD USED I N OVER P E R O ID WAS MADE = A N A L Y S IS = OF USE 378. 4. S E LE C TE D COSTS AND CASH FLOWS 153 A3. Batch-Low Temperature Combination Drying (15,000 bushels) (228 bu /hr) 1. System operation From f ie ld Moisture te s te r Grain cleaner F Iig h t auger Wet holding tank I Batch dryer / 5,000 bu. bin v 5,000 bu. bin Moisture te s te r 5,000 bu. bin I n i t i a l moisture content 26% (from f ie ld ) Interm ediate moisture content 22% (from dryer) Final moisture content 15.5% (from bin) 154 2. Estimated 1980 investment cost Item Quantity Cost ($) 1 Batch dryer (120 bu/hr) 3 24 f t . diameter bin 9,552.00 3 Perforated flo o r 4,655.00 1 Wet holding tank 2,235.00 3 Concrete (24 f t . bin) 2,520.00 1 Grain spreader 400.00 1 Grain cleaner 600.00 1 Unloading auger + motor 457.00 1 Sweep auger + motor 298.00 1 42 f t . auger + motor (6") 2,050.00 1 17 f t . auger + motor (6") 750.00 1 Flig ht auger + motor 3,500.00 3 Tube axial fan (1.5" SP & 7500 cfm) 2,640.00 3 E lectrical heater (20 Kwh) 1,560.00 1 E lectrical (w iring) 1,000.00 1 Moisture tester ^ $ 8,170.00 220.00 Total investment a t l i s t prices 40,617.00 Less 10% discount 36,555.00 In s ta lla tio n Miscellaneous (2% to ta l investment) TOTAL COST OF THE SYSTEM 1,000.00 731.00 $38,286.00 155 3. Estimated salvage value a t the end o f 10 years Bins $ 5,893.00 Perforated flo o r 2,332.00 E le c tric a l 500.00 Concrete 1,260.00 Miscellaneous 365.00 In s ta lla tio n 500.00 Total $10,850.00 a t 50% salvage cost = $5,425.00 % salvage value to ta l investment = $5,425.00 * $38,286.00 ~ 14%. 4. Estimated annual rate of in te re s t on loan 7.8% per year 5. Estimated d ire c t energy cost $13.5/100 bushels 6. Estimated in d ire c t energy cost $1.00/100 bushels 7. Estimated labor cost $1.75/100 bushels 8. Estimated maintenance cost $1,914.00 in 10 years Table 2 2 : General economic analysis fo r a 10-year period fo r the low-temperature combination drying system. 1 6627 7024 2 3 7446 4 7093 5 8366 6 8868 7 9400 9964 8 9 10562 10 11196 TO TALS 87346 SUP­ P L IE S A F T E R -T X CASH FLU P R IN C + IN T * R E P A IR S FU E L+ LUB. LABOR 6857 6286 5029 4023 3218 2575 2060 1648 1318 1055 2755 6333 6333 6333 6333 6333 6333 6333 3B57 0 133 1 91 231 267 300 333 366 398 432 466 2676 2890 3121 3371 3641 3932 4246 4586 4953 5349 357 378 401 425 450 477 506 536 568 602 0 0 0 0 0 0 0 0 0 0 5230 -1 7 1 0 -1 9 6 2 -2 1 6 6 -2 3 3 5 -2 4 7 6 -2 5 9 6 -2 7 0 1 -2 3 6 3595 34069 50943 3117 38765 4700 0 -7 3 5 7 DEPREC­ TO TAL IA T IO N YR RETURNS 1. ECO NO M IC S A V IN G S I F IN V E S T M E N T I S (D IS C O U N T E D MADE = $ 2. NUMBER OF U N IT S 3. D E P R E C IA T IO N 4. ANNUAL N O N -D IS C O U N T E D R E TU R N S, ON W H IC H METHOD USED D O L L A R S ) OVER P E R O ID 3. A N A L Y S IS IN WAS MADE = A N A L Y S IS = 4 OF USE 378. . S E L E C T E D CO STS AND CASH FLOWS 157 A4. Batch-Natural A ir Combination Drying (15,000 bushels) (288 bu/hr) 1. System operation From f i e l d > Moisture tester Grain cleaner v F lig h t auger Wet holding tank Batch d r y e r --------------------- > Moisture tester 5,000 bu. bin 5,000 bu. bin In it ia l moisture content 26% (from fie ld ) Intermediate moisture content Final moisture content 5,000 bu. bin 22% (from dryer) 15.5% (from bin) 158 2. Estimated 1980 investment cost Quantity Item Cost ($) $ 8,170.00 1 Batch dryer {120 bu/hr) 3 24 f t . diameter bin 9,552.00 3 Perforated flo o r 4,665.00 1 Wet holding tank 2,235.00 5 Concrete (24 f t . bin) 2,520.00 1 Grain spreader 400.00 1 Grain cleaner 600.00 1 Unloading auger + motor 457.00 1 42 f t . auger + motor (6M) 1 Sweep auger + motor 298.00 1 17 f t . auger + motor (6") 750.00 1 F lig h t auger + motor 3,500.00 3 Centrifugal fan (2" SP & 10,000 cfm) 4,950.00 E le c tric a l (w iring) 1,000.00 1 Moisture te ste r 2,050.00 220.00 Total investment at l i s t prices 41,367.00 Less 10% discount 37,230.00 In s ta lla tio n Miscellaneous (2% to ta l investment) TOTAL COST OF THE SYSTEM 1,000.00 744.00 $38,274.00 159 3. Estimated salvage value a t th e end o f 10 years Bin $5,893.00 Perforated flo o r 2,332.00 E le c tric a l 500.00 Concrete 1,260.00 Mi seellaneous 346.00 In s ta lla tio n 500.00 Total $10,831.00 a t 50% salvage cost = $5,415.00 % salvage value o f to ta l investment = $5,415.00 * $36,332.00 = 15% 4. Estimated annual rate o f in te re s t on loan 7.8% per year 5. Estimated d ire c t energy cost $10.4/100 bushels 6. Estimated in d ire c t energy cost $1.00/100 bushels 7. Estimated labor cost $1.75/100 bushels 8. Estimated maintenance cost $1,948 in 10 years Table 23: General economic analysis fo r a 10-year period fo r the n a tu ra l-a ir combination drying system. DEPREC­ TO TAL YR RETU R N S IA T IO N 1 6014 2 6375 6757 3 4 7162 7592 5 6 8048 7 8531 8 9043 9 9585 10 10160 TO TALS 79267 SUP­ P L IE S A F T E R -T X CASH FLW P R IN C + IN T . R E P A IR S FUEL+ LUB. LABOR 6914 6412 5130 4104 3283 2626 2101 1681 1345 1076 2804 6447 6447 6447 6447 6447 6447 6447 3926 0 135 194 235 271 305 338 371 404 438 473 2103 2272 2453 2649 2861 3090 3338 3605 3593 4204 357 378 401 425 450 477 506 536 568 602 0 0 0 0 0 0 0 0 0 0 5231 -1 8 0 5 -2 0 5 7 -2 2 6 0 -2 4 2 4 -2 5 5 9 -2 6 7 1 -2 7 6 6 -2 4 4 3672 34672 51B 59 3164 30468 4700 0 -7 8 8 3 1. ECO NO M IC S A V IN G S (D IS C O U N T E D I F IN V E S T M E N T I S MADE = * DO LLARS) -1 . 2. NUMBER OF U N IT S 3. D E P R E C IA T IO N 4. ANNUAL N O N -D IS C O U N T E D R E TU R N S, ON W H IC H A N A L Y S IS METHOD USED IN OVER P E R O ID OF USE WAS MADE = A N A L Y S IS = 378. 4. S E L E C T E D COSTS AND CASH FLOWS 161 A5. 1. In -B in D ryeration Drying (15,000 bushels) (170 b u /h r) System operation I From f i e l d -----------------------------> Moisture te s te r I Grain cleaner I F lig h t auger V Wet holding tank 4' Batch dryer 5,000 bu. bin 5,000 bu. bin 5,000 bu. bin 10 hours tempering I aeration I n i t i a l moisture content 26% (from f ie ld ) Interm ediate moisture content Final moisture content 19% (from dryer) 15.5% (from bin) 162 2. Estim ated 1980 investment cost Item Quantity Cost ($) $ 8,170.00 1 Batch dryer (120 bu/hr) 3 24 f t . diameter b in — 12 f t . h t. 9,552.00 3 Perforated flo o r 4,665.00 1 Wet holding tank (800 bu) 2,235.00 3 Concrete 2,520.00 1 Grain spreader 400.00 1 Grain cleaner 600.00 1 Sweep auger 298.00 1 Unloading auger + motor 457.00 1 42 f t . auger + motor (6") 2,050.00 1 17 f t . auger + motor (6") 750.00 3 Tube a x ia l fan (1" SP & 5,000 cfm) 2,070.00 E le c tric a l 1,000.00 1 Moisture te s te r --------- 1------------ ------- P lig h t auger + motor 222.00 3,500.00 Total investment a t l i s t prices 38,489.00 Less 10% discount 34,640.00 In s ta lla tio n Miscellaneous (2% to ta l investment) TOTAL COST OF THE SYSTEM 1,000.00 692.00 $36,332.00 163 3. Estimated salvage value a t the end o f 10 years Bins $5,893.00 Perforated flo o r 2,332.00 Concrete 1,260.00 E le c tric a l 500.00 Mi seellaneous 346.00 In s ta lla tio n 500.00 Total $12,041.00 at 50% salvage cost = $6,020.00 % salvage value of to ta l investment = $5,415.00 * $35,332.00 ~ 15% 4. Estimated annual rate of in te re s t on loan 7.8% per year 5. Estimated d ire c t energy cost $7.00/100 bushels 6. Estimated in d ire c t energy cost $1.00/100 bushels 7. Estimated labor cost $2.35/100 bushels 8. Estimated maintenance cost $1,816.00 in 10 years Table 24: General economic analysis fo r a 10-year period for the in-bin dryeration system. TO TA L D EPR EC ­ YR RETURNS IA T IO N 1 ' 2 5176 5487 3 4 5 6 7 8 5816 6165 6535 6927 7343 7783 6694 5928 4742 3794 3035 2428 1942 1554 P R IN C + IN T . FUEL* SUP­ A F T E R -T X CASH FLW R E P A IR S LU B * LABOR P L IE S 129 184 907 1479 1597 1725 1863 2012 2173 2347 2534 425 450 477 506 536 568 602 639 0 0 0 0 0 0 0 0 2737 677 0 -1 9 2 2614 6010 6010 6010 6010 4921 -1 7 2 3 -1 9 4 9 -2 1 2 9 -2 2 7 3 -2 3 8 8 -2 4 8 1 -2 5 5 7 9 8250 10 8746 TO TALS 1243 3660 256 288 319 350 382 414 994 0 446 2956 718 0 3474 68228 32354 48344 2991 21423 5598 0 -7 2 9 7 6010 6010 6010 1. ECO NO M IC S A V IN G S (D IS C O U N T E D I F IN V E S T M E N T I S MADE = $ 2. NUMBER OF U N IT S 3* D E P R E C IA T IO N 4. ANNUAL N O N -D IS C O U N T E D DO LLARS) 8. ON W HICH A N A L Y S IS METHOD USED IN WAS MADE = A N A L Y S IS R E TU R N S r OVER P E R O ID = OF USE 378. 4. S E L E C T E D COSTS AND CASH FLOWS APPENDIX B THE FARMER'S POINT OF VIEW 165 166 THE FARMER'S POINT OF VIEW The following statements about the fiv e a lte rn a tiv e drying techniques and related equipment were made by Stephen Kalchik, co­ owner of the Kalchik Farms, B e lla ire , Michigan. Mr. Kalchik's The w rite r feels that experience with the system w ill give important help in the decision to adopt any of the studied drying systems. "Much more is involved with the operation of these systems than fuel costs and depreciation schedules. Farmers should be encour­ aged to use systems that are most p ro fitab le in the long run fo r th e ir p a rtic u la r circumstances. Potential grain spoilage losses and manage­ ment expertise should also be major considerations. Automatic batch dryers were the logical f i r s t choice during the era of inexpensive fo ssil fu els. Much f le x i b i l it y is possible, operation is re la tiv e ly easy, and expansion or replacement of the equipment is not d if f ic u lt . In s ta lla tio n of fuel and e le c tric a l com­ ponents is sim ilar fo r a ll models of comparable size. In it ia l con­ tro l settings are predictable from the operator's manual, and output is f a ir l y consistent. No extra time is required to clean the grain because the cleaner is sized to the transport conveyors. A depend­ able electronic moisture te s te r is required fo r th is system and a ll others lis te d to produce the best results. Overdrying is a major problem. to s e ll as much water as possible. Farmers should be encouraged Fire can be a problem because of 167 the high temperature in automatic batch dryers and dust generated a t grain -h an d lin g s ite s . Storage o f the equipment during the o f f season may be indoors to prolong l i f e . than one hour. Many automatic batch dryers can be moved in less S e rv ic e a b ility is very good. The operator must pay close a tte n tio n to the moisture content o f grain delivered to the bin from the automatic batch dryer, grain temperature, and time the grain 'steeps' before the cooling fans are switched on during each produc­ tio n in te rv a l. Benefits from fuel saved more than o ffs e t the addi­ tio n a l time required. Conversion to in -b in dryeration is r e la tiv e ly simple and can make good use o f an existin g automatic batch-drying system. The operator must have instrumentation fo r r e la tiv e humidity measurements. Automatic humidistats are not dependable and require frequent c a lib ra tio n . Continuous use o f the low-temperature heater w ill re s u lt in severe overdrying of the lower grain in some years. During years o f low r e la tiv e humidity, use of a s tir r in g device w ill reduce the MC gradient in the bin. necessary. Continuous operation is not This system requires d a ily a tte n tio n . Excellent grain q u a lity is possible with low-temperature systems. N a tu ra l-a ir systems are comparable to LT in management. In poor years n a tu r a l-a ir systems may f a i l f i r s t , especially i f warm, humid weather occurs fo r a prolonged period. In -b in counterflow drying o ffers some of the same advantages as automatic batch drying. Operation is dependable and consistent. 168 Grain of any moisture content can be dried. f l e x i b i l it y is allowed during operation. However, very l i t t l e T yp ically, the in s ta lla ­ tion is permanent and an integral part of the storage s ite . Since more e le c tric a l wiring is required on s ite , the operator must have a better understanding of the working d etails of th is system. Fuel consumption compares favorably with the in-bin dryeration using the automatic batch dryer, but the in-bin counterflow is much easier to manage. A vacuum apparatus was in stalle d to remove BCFM from the dried grain moving to storage. When BCFM increased to high levels (such as 25%) because of high in itia l-m o is tu re and combine damage, the vacuum system did not perform s a tis fa c to rily . During wet weather the exhausted material actually blocked the vacuum blower exhaust port due to condensation. However, during normal operation with in le t grain below 30%, the cleaning system performed w ell. Most of the components of an in-bin counterflow system are f ie ld in s ta lle d , so the performance of th is system is d ire c tly related to proper in s ta lla tio n . I t can be a very good system. The author f e l t quite comfortable leaving i t on automatic a ll night. A ll grain should be cleaned p rio r to drying by any system to allow b ette r a irflo w . A grain cleaner can be selected to run at the capacity of the transport equipment. The cleanings should be fed to livestock promptly because of high moisture content. is not a loss when used fo r feed. This material The fr ic tio n drive on the grain cleaner used at this te st s ite did not function e ffe c tiv e ly in snow 169 and ra in . In dry weather conditions i t was 100% e ffe c tiv e on fin e m aterials. Labor requirements are highest fo r the low-temperature and n a tu r a l-a ir systems, lowest fo r the automatic batch and in -b in counter flow , and in -b in dryeration f a lls in the middle." APPENDIX C TELPLAN 03 USER'S GUIDE 170 171 User's Manual 03:1 (F3) CAPITAL INVESTMENT MODEL— INCLUDING BUY OR CUSTOM HIRE A TELPLAN PROGRAM Date: Developed by: January 15, 1972 Stephen B. Harsh Department of A gricultural Economics Michigan State University Number: Form: System: 03 3 Touch-Tone Phone O bjective: To evaluate the investment of capital to reduce or elim inate costs including custom hire and leasing, or to generate new income. Description: This model can be used to evaluate numerous types of investment decisions. I t is p a rtic u la rly useful in evaluating investment of capi­ ta l in buildings and/or equipment to perform an operation previously done on a custom basis. I t can also be used to evaluate investment decisions on such items as a new type of hog system, a new m ilk house— parlo r f a c i l i t y or any other new technology which replaces the existing technology. Furthermore, i t can also be used to evaluate the economics of investing 1n new technology to generate new income or to b e tte r f u l­ f i l l the firm manager's goals. Assumptions of the Model: The v a lid ity of answers derived from th is model depends heavily on the q u a lity of the input information supplied. However, a number of assumptions are made by the model. These assumptions are detailed in la te r sections (Page 03:5 [F3] and Page 03:6 [F 3 ]) and the user has the option of overriding any o f these assumptions i f he feels th a t a more r e a lis tic answer would be obtained i f an assumption was modified. Computational Procedures Used in the Analysis: Budgeting and discounted cash flows. Explanation o f Input Data: Section I . Cost Reducing (Custom Hire or Leasing) or Income Producing Information. This section of the input form relates to those costs th a t w ill be eliminated or reduced (or Income generated) i f the investment is made. In add itio n, th is section indicates the in te n s ity of use of the investment. 172 U ser's Manual 03:2 (F3) la . Enter the savings in costs {or income generated) per u n it fo r a c e rta in class o f expenses {or income). Example A— Buy Versus Custom H ire : A farmer is considering the purchase of a combTne to replace a custom operation. He would enter the custom cost ( e .g ., $9.00 per acre) which is a reduction in costs. Example B— Cost Reducing Investment: A farmer is considering the purchase of a new m ilking p a rlo r which w ill elim in ate labor needed fo r the m ilking operation. He would enter the d o llars labor saved ( e .g ., $60.00 per cow an n u ally). Example C--Income Generating Investment: A farmer is con­ sidering the expansion fo r his swine fin is h in g f a c i l i t y . He would enter the p r o fit ( e .g ., $4.00 per head an n u ally). P r o fit in th is case is defined as returns per head less costs per head (feed cost, labor, feeder pigs, e t c . , but excluding the costs associated with the investment). 2a. Enter the savings in costs (or income generated) per u n it fo r a second class of expenses (o r income). NOTE: I t is not necessary fo r you to use th is input lin e . However, i t is included to allow evaluation o f reduced costs (or generated income) th a t have d if f e r ­ ent c h a ra c te ristic s ( e .g ., d iffe r e n t in fla tio n ra te s ) than those included in input lin e la . Example A— Buy Versus Custom H ire : I t is suggested th a t the user enter the additional annuaTlosses associated w ith custom h ire which in r e a lit y is new income generated. In the combine example, enter the d o lla r value ( e .g ., $4.00 per acre annually) o f lo s t y ie ld s due to poor timing or carelessness o f the custom operator. In some cases, th is value may be negative; i f th is is the case, enter the value as such. A point o f caution, additional losses associated w ith custom h ire are important to the economics o f the investment. I f the farmer is uncer­ ta in of the magnitude o f these losses, you are encouraged to do adjusted analyses which cover the possible range o f these losses. Example B--Cost Reducing Investment: In the m ilking p arlo r example, the farmer fe els th a t he may experience a minor drop in m ilk production. This input lin e can be used to enter th is inform ation. Since a drop in m ilk production is not an in ­ crease in income but a c tu a lly a decline in income, th is value ( e .g ., -$ 6.0 0 per cow annually) would be entered w ith a nega­ tiv e sign. 173 User's Manual 03:3 (F3) Example C— Income Generating Investment: The fanner that has plans to expancf his swine operation has included a ll the income generated in the f i r s t lin e and, therefore, chooses to enter a 2ero in this lin e . 3a. Enter the number of units on which costs w ill be reduced (or Income generated). Example A--Buy Versus Custom H ire : Since the cost savings and income produced fo r the combine as indicated in input lines la and 2a was stated in dollars per acre, you should indicate the number of acres you expect to harvest with the combine (e .g ., 300 acres). Example B—Cost Reducing Investment: In the milking parlor case, you should enter the average number of cows in milk (e .g ., 100 cows) that w ill u t iliz e the parlor annually. Example C~Income Generating Investment: Using the swine f a c i l i t y as an example, you should enter the number o f head (e .g ., 400 head) that w ill pass through the f a c i lit y annually. 3b. Enter the percent of the units indicated in 3a that w ill be absorbed by investment in the f ir s t year of purchase. This input is in ­ cluded to allow you to adjust fo r investments made in d iffe re n t times of the year. For example, i f a machine may have been pur­ chased early in the year and f u ll use made of 1t during the year, enter "100". I f a machine was purchased in the la te r part of the year fo r tax purposes with no opportunity fo r u tiliz a tio n , a value of zero would be entered. I f a machine is purchased midseason, the appropriate percentage should be used. Section I I . Investment Information. This section is used to enter information regarding the investment being considered. 4a. Enter the to ta l d o llar cost including the undepreciated balance of trad e-in items. Be sure to consider a ll costs ( e .g ., in s ta lla tio n costs, shipping costs, e t c .) . 4b. Enter the percent of the undepreciated value of trad e-in items that are of to ta l cost. To compute this value, divide the unde­ preciated value of trade-in items by the value entered in input 4a and m ultiply the result by 100. 5a. I f you are considering a used Item, i t is essential to make an estimate of the cost of th is investment when i t was new. This figure is correlated with the present value and is used to deter­ mine the degree of wear on the machine. This, in turn, w ill a ffe c t 174 User's Manual 03:4 (F3) the rep air costs assumed by the model. I f a new Item is being purchased, enter the same value entered 1n 4a in th is input Item. In add itio n, th is input value indicates whether the investment is a new or used item, which w ill a ffe c t depreciation methods used in the analysis. 5b. Enter the number of years you plan to use the investment. 6a. Enter the number o f years th at the investment would be depreciated over. Years must be less than or equal to number o f years that investment w ill be used (input lin e 5b). I f a non-depreciable item, enter "00". 6b. Enter the salvage percentage to be used. Salvage percent should r e fle c t the estimated market value o f investment at the end of the period o f use. This percentage should be entered even fo r non­ depreciable items. For depreciation purposes, the computer w ill autom atically deduct 10 percent from th is value because th is is allowable under depreciation regulations. 6c. Enter the month purchased. January would be quoted as 01; February 02; March 03; etc. This code indicates to the computer what pro­ portion of the f i r s t year's depreciation should be allocated to the machine and adjusts the f i r s t year's loan and in te re s t payments. 6d. Indicate the type o f depreciation th at w ill be used in the analy­ s is . I f you want the model to choose the best depreciation method, enter zero. However, caution should be expressed a t th is point. The model may select a depreciation method th at is not allowable fo r your p a rtic u la r type of investment. I f th is happens, you should override the method selected by forcing the model to use an approp­ r ia te depreciation method and recompute the answers. 6e. Indicate whether or not the machine is e lig ib le fo r investment tax c re d it, as detailed in the tax regulations. I f e lig ib le , enter a "1", i f not, enter "0". 7a. I f a loan is to be obtained in the purchase o f th is investment, enter the percent the loan is o f the to ta l cost. This fig ure can be computed by dividing the size of the loan by input lin e 4a and m ultiplying the res u lt by 100. 7b. Indicate the loan repayment period in years. Number of years must be less than or equal to the years o f use fo r investment (input lin e 5b). 7c. Enter the annual rate o f in te re s t (percent) payable on the loan. 175 User's Manual 03:5 (F3) 8a. 1 2 Ind icate the per hour fuel cost o f operating the investment. * Be sure to adjust cost to account fo r the gas tax refund. This fig u re should include only the fuel cost o f operating the invest­ ment i t s e l f and not the fuel cost of operating any associated equivalent used in conjunction w ith the investment ( e .g ., the gas needed to operate the tra c to r which is p u llin g a forage chopper, the investment being considered, would not be included in th is fig u re but would be included in the input lin e 8b). To estimate fuel consumption the follow ing equations can be used: Gasoline consumption (G a l/H r.) = .06 X Horsepower o f engine. Diesel consumption (G a l/H r.) = .048 X Horsepower o f engine. L.P. consumption (G a l/H r.) = .072 X Horsepower of engine. To estimate e le c t r ic it y consumption the following equation can be used: (KHR/Hr.) = 0.9 X Horsepower of motor. NOTE: 8b. For input lin e 8a and 8b lu b ric a tio n cost (o il & grease) is autom atically added to the fuel costs (see Page 03: [F 3 ]). Enter the per hour fuel cost o f operating the associated equip­ ment used in conjunction with the investment.3 This fig u re is collected separately from the fuel costs of operating the invest­ ment because an assumption is made regarding the additional repairs incurred on th is equipment. The method used to compute the addi­ tio n a l re p a ir costs is explained in Table 1 of the input form (Page 03: ). In entering these costs, i t 1s important to bear in mind that you should include only those costs th a t are in addition to those previously provided. For example, a fanner who was having his silage custom har­ vested also furnished a tra c to r and a man fo r the operation. He is now considering the purchase o f a new forage harvester. To operate his own harvester, he has to have three trac to rs and two men. For the purpose o f th is an a ly s is , he would only be concerned about the costs o f the addi­ tio n a l man and two tra c to rs . In our m ilking p arlo r example, which was discussed in e a r lie r input lin e s , you would only include those costs th a t w ill be higher than those experienced under the old m ilking system. 2 See preceding page. 3 Refer to footnote 1. 176 User's Manual 03:6 (F3) \ 9a. Enter the per hour labor cost of operating the Investment and associated equipment.1 Labor costs should Include wages paid, social security, workman's compensation, fringe benefits, etc. 9b. Enter the per hour cost of supplies in operating the investment and associated equipment.1 10a. This input lin e is used to indicate repairs costs on the invest­ ment. I f you have l i t t l e knowledge of the level of repairs that might be incurred on the investment, i t is suggested that you select one of the types of machines indicated on the input form and the model w ill estimate the repairs fo r the machine over its l i f e based on its level of usage. Repair costs estimated by this means w ill include both the cost of the repairs and a value fo r the labor used in making the repairs. NOTE: When using the computer to estimate repairs, 1t is essential that input lines 8a, 8b, 9b and 11 be stated on a per hour basis. I f the repairs that are estimated by the model appear to be u n re a lis tic , or you have a good estimate o f what repairs w ill be, or you are unable to match his investment with those lis te d , you can enter the estimated rep air cost over the period in today's do llars. The model w ill use th is amount as a base and make adjustments fo r in fla tio n over time. 11a. This factor is used to correlate per hour usage figures indicated in lines 7a through lines 9b with the units discussed in the f i r s t section of the input. Indicate the number of units that can be handled per hour. For machinery used in fie ld operations, the following formula may be useful in figuring the number of acres per hour that can be handled by the machine. 2 Field Capacity (AC/HR) = Speed (MPH) X Width of Machine ( f t ) X Field E ff. (%) ^Refer to footnote 1 on previous page. 2 The costs in lines 8a, 8b, 9a, 9b and the conversion factor in lin e 11a are expressed on a per hour basis. For some types of invest­ ments, the use o f hours as a common denominator for costs is not lo g i­ c a l. Such a case exists 1n our swine finishing f a c ili t y example which was discussed in e a r lie r input lin es. I t is possible fo r you to use another measure as long as you are consistent. For example, you could express the swine fin ishin g costs on a per year basis ( e .g ., $2,000 labor costs per year) rather than on a per hour basis. In addition, the value in lin e 11 would also be stated on the same per year basis. In th is case, the number of units (head) that can be handled per year 1s 400 which is the same value entered in input value 3a. 177 User's Manual 03:7 (F3) Selected Field E fficien cies (Average Values) T illa g e Operations Plant F e r t iliz e r Crop Combining Chop Silage Section 111. 85% 60% 70% 60% Federal Tax, Rate of Return and Cash Flow Information. Taxes are considered because the tax laws have a s ig n ific a n t e ffe c t on the economics of various investments. The rate of return is also a c r it ic a l value. Cash flow information is collected because some investments may be economically p ro fita b le , but because o f liq u id ity problems of some firm s, they are s t i l l unable to ju s t if y the investment. 12a. Enter the estimated tax bracket faced in the year of purchase. 12b. Enter the estimated tax bracket in the f i r s t one-half year of the investment following the f i r s t year. 12c. Enter the estimated tax bracket fo r the la s t h a lf of the invest­ ment. 13a. Indicate the desired percentage rate of return on the investment fo r the f i r s t one-half years o f investment. When considering the rate of return on investment, i t should be a t least equal to what the money can earn when used in other good investments. I t is important that the rate used be above the a fte r -ta x cost of money (a fte r-ta x cost o f money is equal to in te re s t rate o f loan m u lti­ plied by one minus the tax ra te ) of existin g loans plus some amount to r e fle c t ris k . 13b. Indicate the desired return on investment during the la s t oneh a lf years of the investment. The rate of return information is collected in two parts. This relates to those investments of long length. A s itu a tio n in which a young businessman's liq u id ity problem is high in the early years of the investment, but as time passes money becomes much easier to acquire and the demands upon i t less c r i t i c a l . Therefore, a lower rate o f return should be used in the la te r period. 13c. The user should indicate th a t size of loan (thousands o f d o llars) in annual p rin c ip le and In te re s t payments the current business can withstand. This value is used to determine i f the investment w ill cause liq u id ity problems fo r the business. The investment may be a very good one from an economic viewpoint but because of the loan taken, i t may run into liq u id ity problems which may be disastrous fo r the business. 178 U ser's Manual 03:8 (F3) Section IV: M od ification o f Assumptions: A number o f assumptions are made by the computer model which in most cases re s u lts in a more accurate analysis o f the s itu a tio n . These assumptions are d e ta ile d in Table 1. However, there may be situ atio n s in which d iffe r e n t assumptions would y ie ld a more accurate analysis. In th is case, i t is possible fo r you to override the values assumed by the model and replace them with more appropriate values. Table 1. VALUES ASSUMED BY MODEL Assumption Code Assumed Value _ ... D e fin itio n 01. 0 .0 To determine or not determine break-even u n its —When the value is set to zero the model w ill attempt to fin d the break-even units o f usage, i f usage lev el entered in lin e 3a is not larg e enough to make in v e s t­ ment p r o fita b le . When set to 1 .0 , the model w ill not attempt to fin d break-even and w ill s ta te actual losses or gains fo r usage level entered in lin e 3a. 02. 2 .7 Annual percentage ra te o f in fla tio n on the costs saving (o r income generated) indicated in lin e la . The value assumed (2.7%) is the appropriate in f la tio n ra te fo r custom costs. 03. 0 .0 Annual percentage ra te o f in fla tio n on the cost savings (o r income generated) indicated in lin e 2a. A value o f 0% has been assumed because, in many cases, th is w ill closely approximate the in f la tio n rate fo r add itio nal losses associated w ith custom h ire . 04. 6 .0 Labor cost annual percentage ra te o f i n f l a ­ tio n . 05. 1.9 Fuel and o il costs annual percentage ra te of in f la t io n . 06. 4 .0 Repair costs annual percentage ra te o f in f la t io n . 07. 1.3 Supplies cost annual percentage ra te o f in f la t io n . 179 User's Manual 03:9 (F3) (c o n t'd .) Table 1. Assumption Code Assumed Value 08. 4.0 New machine purchase cost annual percentage rate of in fla tio n (a ffects salvage value). 09 0.7 Insurance cost* as a percentage of the begin­ ning inventory value fo r each year. 10. 0.5 Housing cost* as a percentage of the begin­ ning inventory value fo r each year. 11. 15.0 Oil and lubrication cost as a percentage of fuel cost. 12. 35.0 Associated equipment's repairs cost as a percentage of associated equipments fuel cost 13. 0.0 Annual percentage rate of increase in the use of the investment. *NOTE: D efinition Personal property tax can be included by raising this percentage value upward. For example, you feel that the in fla tio n rate fo r labor costs (Assumption Code 04) in your area w ill be somewhat less than the six percent assumed by the model. I f you desire to override the six percent rate and replace i t with a four percent ra te , you should enter information as indicated below: 14a. b. Assumption Value Desired Assumption Code 14. |0 4 . 0 |0 4| / 15a. b. Assumption Value Desired Assumption Code_______________ 15.__i___ - __ i_0_i 1________ Input lin e 15 was coded zero in above examples to indicate end of assumption changes. 180 User's Manual 03:10 (F3) Error Messages Relating to Erroneous Input Data. Line 3. The value fo r lin e 3a has to be greater than 0. Line 5. I f the number of years (lin e 5b) is greater than 25, an e rro r message w ill be given also i f less than two years. Line 6. The maximum number of years fo r depreciation cannot exceed th a t value entered in lin e 5b. Line 7. The number o f repayment years of the loan cannot exceed the number o f years o f the investment (input lin e 5b). Error messages w ill also be given i f repayment years of loan is zero or the ra te of in te re s t is zero when there is a loan indicated in lin e 7a. Line 10. An e rro r is given i f you tr y to use a nonexistent type o f machine code or the estimated d o llars o f re p a ir costs is less than $25. Lines 14-20. You are given an e rro r message i f you use an assumption code th at does not e x is t. Explanation of Output: Line 1 This value gives the economic evaluation of the invest­ ment in discounted d o lla rs over the e n tire period of use. I f th is value is p o s itiv e , then the investment is an economic one, and serious consideration should be given to making the investment. However, i t should be stressed th a t the answers are dependent upon the input values entered in to the model and, th e refo re , are only as good as the input data. Line 2 Output value 2 indicates the number o f units in which the analysis was made. I f the number of units exceed the values inputted in 3a, and the savings indicated in lin e 1 is zero, then the answer indicates the break­ even point o f the analysis (NOTE: I f th is value is approximately 4 times the size of th at entered in input lin e 3a and re s u lt 1 is a large negative value, th is usually indicates th a t the input data was erroneous or th is is a very uneconomic investment). Line 3 The value given depends on whether you have specified a c e rta in type of depreciation method. I f you ind icate the depreciation method to be used, th is value is given and is the same as entered in the input section. I f 181 User's Guide 03:11 (F3) the model selects the best depreciation value, the results obtained from the model are based on this depre­ ciatio n method and using an a lte rn a tiv e depreciation method w ill decrease the economic advantage of this investment. However, i f the model should select a depreciation method not allowable under the tax regula­ tio n s, you should specify an a lte rn a tiv e depreciation method (see information relatin g to input value 6d, page 03:4 [F 3 ]). Line 4 The f i r s t part of th is answer indicates the to ta l repairs costs (nondiscounted d o llars) o f the investment over its l i f e of use. The rep air cost of the associ­ ated equipment used in conjunction with your equipment is also included in th is value. I f th is repair cost appears to be an u n re a lis tic value, adjustments can be made. The procedure fo r th is is explained in the input section under value 10, page 03:6 (F3). The second part of the answer indicates the fuel and lubrication costs in nondiscounted dollars of using the investment over the e n tire period. The fuel and lub rication costs are fo r both the investment i t s e lf and the equipment used in conjunction with the investment. Line 5 Output lin e 5 indicates the nondiscounted dollars labor costs over the l i f e of investment and the second part of the answer contains the supply costs in nondiscounted dollars over the l i f e investment. Line 6 The f i r s t part of the answer indicates the number of years that cash flow problems w ill be encountered over the l i f e of investment. The second part of the output lin e indicates the magnitude o f the cash flows in the worst year. I f the f i r s t answer is zero and the second answer p o sitive, this indicates that th is investment does not have cash flow problems. However, i f the f ir s t answer is positive and the second answer negative, this indicates that the investment w ill run into cash flow problems and the user must evaluate whether these cash flow problems are s ig n ific a n t enough to discourage him from making an investment. The larger the negative answer, the more d if f ic u lt the cash flow problem. 182 Program W o t 03 F o n Not__________ 3 System: T0UCH-T0NE _________ PHONE CAPITAL INVESTMENT MODEL — INCLUDING BUY OR CUSTOM HIRE A TELPLAN PROGRAM s am e Batch D ryin g __________________ address PHONE_____________________________________ DATE RUN Problem: To evaluate the Investment of capital to reduce or eliminate coats including custom hire and leasing, or to generate new income. INPUT: ADJUSTED “ “ ANALYSIS LINE NO. Section I. la. 2a. 3a. b. Cost savings (or income produced) per unit* for a certain class of expenses (or income). For example, custom rate per unit ($) 01. jO 1 Cost savings (or income produced) per unit* for s second class of expenses (or income). For example, additional per unit annual losses associated with custom hire ($) 02, “|0 0 I Normal number of units* per year on which costs will be reduced (or Income generated). Percent of units* indicated in Line 3a that will be absorbed by Investment in the year of purchase. Section II. 4a. b. 5a. b. * Costs Reducing (Custom Hire Or Leasing) Or Income Producing Information. 03* _5. 8 _______________ 2| I .8 F ~ 71 I / / Investment Information. 5 T_12_2 66|,0 Total dollar cost including un04. |^0^35^ 0 depreciated balance of trade-in items. Percentage undepreciated value ___ of trade-in items is of total cost. ' " “ If a used item enter estimated 05. new cost of item. If new item enter same value entered in Line 4a. Years plan to use the Investment. ___ I 0|01 V — |1P| I 71 J It is very important to be consistent in your units. (For example, if the custom rate is stated on acres all the other units are also to be stated In acres). This conputer progTam was designed by Stephen 1. Harsh, Michigan State University. 183 ADJUSTED LIME WO. 6a> > i. to. e. d. e. 7a. b. c. B a. b. 9a. b. 10a. 11a. D e p redation years S ilvuc n c re ra t Salvage percent Month of purchase (Ql*Jan, 1 2 * D e c .) . Depreciation type (0*Have model choose best depreciation method to use} l*Stralght line; 2*Straight line with additional 20%; 3*Double decline balance; b-Double decline balance vith additional 20%; 5*1.5 decline balance; 6*1.5 decline balance vith additional 20%; T*5u»of-dlglts; 6*Sum-of-digits vith additional 20%). Does investment qualify for investment credit (0*no; l*yes). ANALYSIS 06. | L Q l l _ 5 l 0 8 | 4 j l | '* ^ 1 / ^ / J _ Percent of total cost (input 07. p_ 0 0 | 0 8^|0_7_ . 8 1 line ba) borrowed. “ I I Repayment period of loan-years / Annual rate of interest on loan(%) ________________ 7 P e r h o u r * f u e l c o s t o f o p e r a tin g i n v e s t m e n t * 11 ( $ ) P e r h o u r * f u e l c o s t o f o p e r a tin g a s s o c ia te d e q u ip m e n t** ( $ ) 0 8 . (0 4 . “ Per hour* labor coat of operating investment A associated equipment. Per hour* cost of supplies of operating investment & associated equipment. 09* 10 4 . 8 0 _ |_ 0 _ 0 . I I 9 “ / 0_0| ■ / Repairs costs of investment: Enter 10. [2.2 Z .5 estimated repairs costs over period I or use in today's dollars (amount must exceed $25) 0B enter type*** of machine to have model estimate re­ pairs costs, ^rpes of machines are: l*tractors; 2*Self-P. Combine, SelfP. Forage harvester. Rotary Cutter; 3“Pull type combine. Pull type for­ age harvester. Flail harvester; b* Self-P. swather, Self-U.L. Wagon, Side D. Rake; 5*Fertilizer equip; 6*Potato harvester, Sugar beet harvester, FT0 Bailer; 7*Tillage tools. Mover; 6* Seeding equip; Boom sprayers; 9*truck; 10*Air Blast Sprayer. Number of units* handled per hour* 3 5 3 |_ 0 ^ . “ 11. ' | 0 0 0 T_ . _0 0 | * Refer to Page 1 ** See inatructions for Program 03, Form 3 for suggested guidelines. *** If you cannot find your machine in the list, try to match to a machine that is similar or enter estimate of repairs costs. x Hours are used as a measure for expressing costs in lines 8a,6b,9a,9b and as a conversion factor in line 11. You can use a different measure as long as you are consistent in these lines. 184 ADJUSTED AHALYB1S LIHE HO. Section III, 12a. b. c. 13a. b. c. federal Tti. Rate Of Return And Cash Flow Information. . Tax bracket In year of purchase. Tax bracket for firat 1/2 years of investment. Tax bracket for last 1/2 years of investment. 12 Desired percentage rate of return on Investment for first 1/2 years of Investment. Desired percentage rate of return on Investment for last 1/2 years of Investment. Additional debt load (annual principal & Interest payment in thousands of dollars) that the current business can with­ stand. 13. 1 _ 1/ / tOJ)| 0 9 1 00 0 . 01 ' * “I / _______________ 1 Section IV. Modification Of Assumptions306 (Enter "0" on line following last modification to be made. If none, enter "0" on line l1*) xx lba. b. Assumption value desired Assumption code lb. 15a. b. Assumption value desired Assumption code 15. | 0 J . 0 | 0 2 | 16a. Assumption value desired Assumption code 16. b. 17a. b. Assumption value desired Assumption code 17. 18a. b. Assumption value desired Assumption code 16. (S J . S | a j | 19a. b. Assumption value desired Assumption code 19. 20a. b. Assumption value desired Assumption code 20. See instructions for Program 03 , ,0 8 h- 0,05, -l-H (0 6 . 0 |0 8| |0 6 . 0| 0 3_j Form 3 on how to use this section. 185 Program No: 03 Fora Not 3 System: T0UCH-T0NE _________ PHONE CAPITAL INVESTMENT MODEL — INCLUDING BUT OR CUSTOM HIRE A TELPLAN PROGRAM In-Bin Counterflow ___________ address______________________ name PHONE DATE RUN Problem: To evaluate the Investment of capital to reduce or eliminate coata Including custom hire and leasing, or to generate new income. INPUT: LINE NO. Section I. Coats Reducing (Custom Hire Or Leasing) Or Income Producing Information. la. Cost savings (or income produced) per unit* for a certain class of expenses (or income). For example, custom rate per unit ($) 01. 10 J 2a. Coat savings (or income produced) per unit* for a second class of expanses (or income). For exainple, additional per unit annual losses associated with custom hire ($) 02. |O f l . ^ 3a. Normal number of units* per year on which costs will be reduced (or income generated), Percent of units* indicated in Line 3a that will be absorbed by investment in the year of purchase. 04. |0 42 53 8| 0 Cj b. Section II. 4a. b. 5a. b. * ADJUSTED ANALYSIS 4 , 3_4_j Investment Information. Total dollar cost including un­ depreciated balance of trade-in items. Percentage undepreciated value of trade-in ltams is of total cost. If a used item enter estimated 05. I® ^ 2 ^ 3 ® new cost of item. If new item I enter same value entered in Line 4a. Years plan to use the investment. ___________________ IC is very important to be consistent in your units. (For example, if the custom rate is stated on acres all the other units are also to be stated in acres). 7hTs_computer program wa"s designed- by Stephen B. HarTh” Michigan State University. 186 adjusted LIBE MO. Depreciation years Salvage percent Month of purchase (01-Jan,...., 12"Dec.). d. Depredation type (0-Have aodel choose best depredation method to use; 1-Stralght line; 2-Straight line vith additional 20#; 3-Double decline balance; 1*-Double decline balance vith additional SOSCg 5-1.5 decline balance; 6-1.5 decline balance vith additional 2 OS; 7-Sumof-diglta; 8-Sum-of-diglts vith additional 20%). e. Does investment qualify for investment credit (0-no; l-yea). AHALYSIS 6a. b. c. 06. fl Q|1_4|J?8j4 ll * ~ ' 7a. 07. Percent of total coat (input line !ta) borrowed. b. Repayment period of loan-yeara c. Annual rate of interest on loan(S) 6a. b. Per hour* fuel coat of operating investment** ($) Per hour* fuel cost of operating associated equipment** (8) 9a. Per hour* labor coat of operating investment A associated equipment. b. Per hour* cost of supplies of operating investment A associated equipment. 10a. 11a. / li22|£®|2Z- • §1 » " I / J 08. |0 2 . 1_2j_P_P. ,39j # / 09. |5J •J. 2|2 2 • 2 2j ' ~ ' i / Repairs costs of investment: Enter 10. estimated repairs costs over period or use in today's dollars (amount must exceed $25) OR enter type*** of machine to have model estimate re­ pairs costs. Types of machines are: 1-tractors; 2-Self-P. Combine, SelfP. Forage harvester. Rotary Cutter; 3-Pull type combine. Pull type for­ age harvester. Flail harvester; bSelf-P. svather, Belf-U.L. Wagon, Side D. Rake; 5-Fertlliier equip; 6-Potato harvester, Sugar beet harvester, PTO Bailer; 7-Tillage tools. Mover; 6Seeding equip; Boom sprayers; struck; 10-Air Blast Sprayer. Humber of unlta* handled per hour* J 11. 1^2 2 -Z2| “ ~ ~ ~l |2-P.9_] • * Refer to Page 1 ** See instructions for Program 03, Form 3 for suggested guidelines. *** If you cannot find your machine in the list, try to match to a machine that is similar or enter estimate of repairs costs. x Hours are used as a measure for expressing costs in lines 8a,6b,9a,9b and as a conversion factor in line 11. You can use a different measure as long as you are consistent in these lines. 187 ADJUSTED ANALYSIS LIKE BO, Section III. 12a. b. c. 13a. b. c. Federal Tax. Rata Of Return And Cash Flow Information. Tax bracket in year of purchase. Tax bracket for first 1/2 years of Investment. Tax bracket for last 1/2 years of Investment. Desired percentage rate of re­ turn an investment for first 1/2 years of Investment. Desired percentage rate of re­ turn on Investment for last 1/2 years of Investment. Additional debt load (annual principal A interest payment in thousands of dollars) that the current business can with­ stand. 12. , | 3 0 13 0 j 3 0 1 . in c lu d e s ... S O C ia l/ S e C liri 13. | 0 9 | 0 9 | / / Section IV. Modification Of Assumptions** {Enter "0" on line following last modification to be made. If none, enter ”0" on line 1L) xx lka, b. Assumption value desired Assumption code lb. 15a. b. Assumption value desired Assumption code 15. | Q £ - & | Q 2 | 16a. Assumption value desired Assumption code 16 . g 1 - o I a 5 | b. 17a. b. Assumption value desired Assumption code 17. 18a. Assumption value desired Assumption code 16. b. 19a. b. Assumption value desired Assumption code 19. | S 1 . 6 | l i , 20a. b. Assumption value desired Assumption code 20. | 0 6 . 0 , S 3 , R - ' - ly“ - 1 | S 1 . 2 | 0 | See lnetructione for Program 03, Form 3 on how to use this section. 188 Program Mo: 03 Fora No:__________ 3 System: T0UCH-T0HE _________ PHONE CAPITAL INVESTMENT MODEL — INCLUDING BUY OR CUSTOM HIRE A TELPLAN PROGRAM In-B in Dryeration ____________ address name PHONE DATE RUN Problem: To evaluate the Investment of capital to reduce or eliminate coata Including custom hire and leasing, or to generate new Income. INPUT: ' “ ADJUSTED ANALYSIS LINE NO. Section I. la. Coat aavlnga (or Income produced) per unit* for a certain claaa of expenses (or Income). For example, custom rate per unit ($) 01. 2a. Coat aavlnga (or Income produced) per unit* for a second class of axpenaes (or Income). For example, additional per unit annual loaaea associated with cuatom hire ($) 02.” jO 0 I 3a. Normal number of units* per year 03, 1^ 0 0 3. 7^8. i J_0 Q on which costa will be reduced P I 71 (or Income generated), Percent of unite* Indicated in _______________ Line 3a that will be absorbed by Investment In the year of purchase. b. 4a. b. 5a. b. < • Q 2.J I . £6j ~ J Section II. * Coata Reducing (Cuatom Hire Or Leasing) Or Income Producing Information. Inveatment Information. Total dollar cost Including un04. |0 3 3 6 63 3^332 . depreciated balance of trade-in Items. Percentage undepreciated value ___ of trade-in Items la of total coat. If a used Item enter estimated 05. new cost of Item. If new item enter same value entered In Line 4a. Years plan to use the investment. 00. 0 0[ / |0 3 6 3 3 2 l J.Qj I I ,I J It is very important to be consistent in your units. (For example. If the custom rate la atated on acres all the other units are also to be stated In acres). ThTs~computeT program waT 7eaigned~by Stephen B.**Harsh7 Michigan State University. 189 ADJUSTED ANALYSIS D U E MO. 6a. b. e. d. e. 7a. b. c. 6a. b. 9a. b. Depredation years 06. H 0| 1_5|08_(4jll Salvage percent * */ i i Month of purchase {01*Jan,...., / 12»Dec.). ________________ Depreciation type (O H a v e model choose best depreciation method to use; l<*Stralgbt line; 2*Straight line with additional 20JC; 3“Double decline balance; U>Double decline balance with additional 20$; 5*1.5 decline balance; 6el.5 decline balance with additional 20$; 7»SumOf-dlgits; 8“Sum-of-digits with additional 20$). ________________ Does investment qualify for investment credit (Ono; l*yes). J 07. jJ 0 0|0 8j_0_7 . Percent of total coat (input line 4a) borrowed. Repayment period of loan-years / Annual rate of Interest on loan($) _______________ J Per hour* fuel cost of operating investment** ($) Per hour* fuel cost of operating associated equipment** ($) Per hour* labor cost of operating investment It associated equipment. Per hour* cost of supplies of operating investment & associated equipment. I* ' I 09. |_0J ' “ . (^6|0 “ 0 . 0 0] ” —”1 / Repairs costs of investment! Enter 10. estimated repairs costa over period or use in today's dollars (amount must exceed $23) OR enter type*** of machine to have model estimate re­ pairs costs. T^pes of machines are: l>tractors; 2*Self-P. Combine, SelfP. Forage harvester, Rotary Cutter; 3*Pull type combine. Pull type for­ age harvester, Flail harvester; 4» Self-P. swather, Self-U.L. Wagon, Bide D. Rake; ^Fertilizer equip; 6"Potato harvester, Sugar beet harvester, PTO Bailer; 7*Tillage tools. Mower; 6> Seeding equip; Boom sprayers; 9*truck; l O A i r Blast Sprayer. 11a. Number of units* handled per hour* x |02. 76[00.39) 06. 10a. ■ ** *** 8| |0_1£.1 £| I “ ”> 11. |2 £ 2 L * £ £ | Refer to Page 1 See instructions for Program 03, Form 3 for suggested guidelines. If you cannot find your machine in the list, try to match to a machine that is similar or enter estimate of repairs costs. Hours are used as a measure for expressing costs in lines 6a,6b,9a,9b and as a conversion factor in line 11. You can use a different measure as long as you are consistent in these lines. 190 ADJUSTED ANALYSIS LIME HO. Section III, 12e. b. c. 13a. b. c. federal Tax. Rate Of Return And Cash Floy Information. Tex bracket In year of purchase. Tax bracket for first 1/2 years of investment. Tax bracket for last 1 /2 years of Investment. Desired percentage rate of return cm Investment for first 1/2 years of investment. Desired percentage rate of return on investment for last 1/2 years of Investment. Additional debt load (annual principal A interest payment in thousands of dollars) that the current business can with­ stand. 12, |3 0 ,3.0 ,3 0, .. . , in c lu d e s 13. J0 S O C ia / s e c u r i t y 9_10_9_I 0_(^0_ . (^ 1' “ / __________ 1 Section IV. Modification Of Assumptions** (Enter '*£}'’ on line following last modification to be made. If none, enter "0" on line lh) lba. b. Assumption value desired Assumption code 11*. 15a. b. Assumption value desired Assumption code 15. l6a. b. Assumption value desired Assumption code 16. (0 8 . OjO5j 17a. b. Assumption value desired Assumption code 17. |0 6 . 0 10 8 1 18a. b. Assumption value desired Assumption code 18. 1? i 19a. b. Assumption value desired Assumption code 19. h» J . « | 1 9 | 20a. b. Assumption value desired Assumption code 20. ,0 6 . 0, 03, xx | ° i - 0 )0 2 . _________ ✓ ■ 0| a a i See instructions for Program 03, Form 3 on how to use this section. 191 Program H o i 03 Fora Ho:__________ 3 System: T0UCH-T0NE _________ PHONE CAPITAL INVESTMENT MODEL — INCLUDING BUY OR CUSTOM HIRE A TELPLAN PROGRAM Natural A i r_________________ address NAME PHONE_____________ Problem: DATE RUN To evaluate the investment of capital to reduce or eliminate coata Including cuatom hire and leaaing, or to generate new Income. I n p u t :' adjusted LINE NO. Section I. la. 2a. 3a. b. b. 5a. b. * Coata Reducing (Cuatom Hire Or Leasing) Or Income P r o d u d n e Information. Cost aavlnga (or Income produced) per unit* for a certain claaa of expanses (or income). For example, cuatom rate per unit ($) 01. |Q .! .5 » Q L 9 .t Coat aavlnga (or income produced) per unit* for a second claaa of expenses (or Income). For example, additional per unit annual loaaea aaaociatad with cuatom hire ($) 02. Normal number of unita* per year on which coata will be reduced (or Income generated), Percent of units* indicated in Line 3a that will be absorbed by investment in the year of purchaae. Section II. 4a. ANALYSIS < I |0 0 0_ . 8_9j I \ 03. .0 0 03 7 8. 1 0 0 7 Investment Information. 03 8 9 _Z 7 44 1.00_ Oj 0. Total dollar cost including un04. |_0_3_8^ depreciated balance of trade-in items. Percentage undepreciated value ___ of trade-in items is of total cost. If a used item enter estimated 05. new cost of item. If new item anter same value entered in Line 4a. Years plan to uae the investment. I I L 9j I 71 / I It la very important to be consistent in your units. (For example, if the custom rate la stated on acres all the other unlta are also to be stated in acrea). This compuTeT program waa designed by Stephen B. Harah, Michigan State University. 192 ADJUSTED AHALYSIS U H E HO. 6a. b. e. d. e. 7a. b. c. 8a. b. 9a. b. 10a. 11a. • ** *** x Depredation years 06. jl_ 5|0 Salvage percent ' ~ Month of purchase (01"Jan,. . , / 12*Dec.). Depredation type (0*Have model ________________ choose best depredation method to use} l*Stralght line} 2*Straight line with additional 20*; 3-Double decline balance} ^ D o u b l e decline balance with additional 20*} 5*1.5 decline balance; 6*1.5 decline balance with additional 20*; 7-Sumof-digits; 6-Sum-of-digita with additional 20*). Does investment qualify for investment credit (0*no; 1-yes). 8|4|lj Percent of total cost (input 07. |J line Its) borrowed. ' ~~ ""*!** ~I” Repayment period of loan-years / Annual rate of interest on loan(*) _ _ _ _ _ _ _ _ _ Per hour* fuel cost of operating investment** {$) Per hour* fuel coat of operating associated equipment** ($) 08. Per hour* labor cost of operating investment A associated equipment. Per hour* cost of supplies of operating investment A associated equipment. 09. [ 0 4 . 0 9|_00 . 3 9 I ~~l— “1 / [ 0 0 . 8 9|_0_0 . 0 0| ' I > / Repairs costs of investment: Enter 10. estimated repairs costs over period or use in today's dollars (amount must exceed $25) OR enter type*** of machine to have model estimate re­ pairs costs, types of machines are: l*tractors; 2*Self-P. Combine, SelfF. Forage harvester. Rotary Cutter; 3-Pull type combine. Pull type for­ age harvester. Flail harvester; k* Self-P. swather, Self-U.L. Wagon, Side D. Rake; 5-Fertilizer equip; 6*Potato harvester, Sugar beet harvester, PTO Bailer; 7*Tillage tools. Mover; 8* Seeding equip; Boom sprayers; 9-truck; l O A i r Blast Sprayer. Humber of units* handled per hour* J 11. |0 4 8i ” “1 0 0_]_ . 0_0_J Refer to Page 1 See instructions for Program 03, Form 3 for suggested guidelines. If you cannot find your machine in the list, try to match to a machine that is similar or enter estimate of repairs costs. Hours are used as a measure for expressing costs in lines 8a,8b,9a,9b and as a conversion factor in line 11. You can use a different measure as long as you are consistent in these lines. 193 ADJUSTED AMALYSIS LIME MO. Section III. 12*. b. 13a. b. c. Federal Tax. Rate Of Return And Cash Flow Information. Tax bracket in year of purchase. Tax bracket for flrat 1/2 years of Investment. Tax bracket for last 1/2 years of investment. 12. |3 0 3 0 [£ U |1 J U |i 3i Oi D| includes sociaV security Desired percentage rate of re­ turn on investment for first 1/2 years of investment. Desired percentage rate of re­ turn on Investment for last 1/2 years of investment. Additional debt load (annual principal A interest payment in thousands of dollars) that the current business can with­ stand. 13. |0 9 | 0 9 | 0 0 0 . _| 1 Section IV. Modification Of Assumptions** (Enter ^0 on line following last modificat to be made. If none, enter n0" on line l1*) lka. b. Assumption value desired Assumption code lit. ( O i . e i . o i , 15a. b. Assumption value desired Assumption code 15. 16a. Assumption value desired Assumption code 16 . | 0 8 . 0 | S 3 b. 17a. b. Assumption value desired Assumption code 17. |Dfi- Q | £ i a ) 18a. b. Assumption value desired Assumption code IB. pl-2|23 19a. b. Assumption value desired Assumption code 19. | 0 1 . 6 | l ^ 20a. b. Assumption value desired Assumption code 20. |2 § • 2 | ° 3 j xx |22- 0 1 0 2, See instructions for Program 03* Form 3 on how to use this section. 194 Program Wo; 03 Form Nos__________ 3 System:______ TOUCH-TOSE PHONE CAPITAL INVESTMENT MODEL — INCLUDING BUY OR CUSTOM HIRE A TELFLAN PROGRAM Low Temperature_____________ address_ name PHONE DATE RUN Problem; To evaluate the Investment of capital to reduce or eliminate costs including custom hire and leasing, or to generate new income. In p u t; adjusted LINE NO. Section I. la. Coats Reducing {Custom Hire Or Leasing) Or Income Producing Information. Cost savings (or Income produced) per unit* for a certain class of expenses (or Income). For example, custom rate per unit ($) 01, jjQ J_ £ , fi2-( > I 2s. Cost savings (or Income produced)02. “1.9,2.E • per unit* for a second class of I expenses (or Income). For example, additional per unit annual losses associated with custom hire ($) 3a. Normal number of units* per year 03. 0 0 0_ 3_7 8 I T_ 0 Oj on which costs will be reduced I I (or income generated). Percent of units* indicated in __________________ __ Line 3a that will be absorbed by investment in the year of purchase. b. Section II. 4a. b. 5a. b. * ANALYSIS E El H _ _ _ _ _ _ Investment Information. Total dollar cost including un04. |^0_3_8 2 8 6[ depreciated balance of trade-in I I items. Percentage undepreciated value _________________ of trade-in items is of total cost. If a used item enter estimated 05. new cost of item. If new item enter same value entered in Line 4a. Years plan to use the Investment. __ 00 ,| I h„ . ~ n .0 3 8 22_8_6_ 8 6 . |1l_0j 0. |0 It Is very important to be consistent in your units. (For example, if the cuatom rate is stated on acres all the other units are also to be stated in acres). This*-computer program was designed by Stephen B. Harsh, Michigan State University. 195 ADJUSTED AHALTSIS LIKE NO. 6a. b. e. d. e. 7a. b. c. 8a. b. 9a. b. 10a. 11a. a •• ••• x Depreciation years 06. |T_ Oll_ 4|0_8_l4| 1j Salvage percent ' ~ ' i Month of purchase (01*Jan..... / 12*Dec.). Depreciation type ( O H a v e model _ _ _ _ _ _ _ _ _ _ choose best depreciation method to use; l*Straight line; 2*Straight line vith additional 30%', 3“Double decline balance; U*Double decline balance vith additional 20S; 9*1.5 decline balance; 6*1.5 decline balance vith additional 20%; 7*Sumof-dlgits; 6*Sum-of-digits vith additional 20%). _________________ Does Investment qualify for investment credit (t^no; l*yes}. J Percent of total cost (input 07. p. i? Q[,2 ® |Q. _? • 5 line La) borrowed, •""" * I Repayment period of loan-years / Annual rate of interest on loan(*) ________________ J Per hour* fuel cost of operating investment** ($) Per hour* fuel cost of operating associated equipment** ($} Per hour* labor cost of operating Investment t associated equipment. Per hour* cost of supplies of operating investment & associated equipment. 08. |0 _5 . 3_1 I_0_0 . _3 9[ I/ ______________________ / 09. |0 0 . 8 9 10 0 . 0 Oj / Repairs costs of investment: Enter 10. estimated repairs costs over period or use in today's dollars (amount must exceed $25) OR enter type*** of machine to have model estimate re­ pairs costs. Types of machines are: l*tractors; 2*Self-P. Combine, SelfP, Forage harvester, Rotary Cutter; 3“Pull type combine. Pull type for­ age harvester. Flail harvester; 1»= Self-P. svather, Self-U.L. Wagon, Side D. Rake; 5*Fertiliter equip; 6*Potato harvester, Sugar beet harvester, PT0 Bailer; 7*Tillage tools, Mover; 8* Seeding equip; Boom sprayers; S t r u c k ; l O A i r Blast Sprayer. (0_1_9 _1 4| Number of units* handled per hour* |_0 0 0 1_ . 0, OJ 11. * Refer to Page 1 See instructions for Program 03, Form 3 for suggested guidelines. If you cannot find your machine In the list, try to match to a machine that is similar or enter estimate of repairs costs. Hours are used as a measure for expressing costs in lines 8a,8b,9a,9b and as a conversion factor in line 11. You can use a different measure as long as you are consistent in these lines. 196 ADJUSTED ANALYSIS LIME MO. Section III. 12*. b. c. 13a. b. c. Federal Tax. Bate Of Return And Cash Flov Information. Tax bracket in year of purchase. Tax bracket for first 1/2 years of investment. Tax bracket for last 1/2 years of Investment. Desired percentage rate of re­ turn on investment for first 1/2 yearB of investment, Desired percentage rate of re­ turn on Investment for last 1/2 years of investment, Additional debt load (annual principal A interest payment in thousands of dollars) that the current business can with­ stand. 12. |3 0 1 3 0 I 3 Oi Includes social security 13. f0j>|0 9|0JH)_ . 01 / i Section IV. Modification Of Assumptions** (Enter "0" on line following last modification to be made. If none, enter "0" on line lb) Assumption value desired Assumption code lb. |9 1 . 0 , 0 ^ 13a. b. Assumption value desired Assumption code 15. 10 6 . 0 10 2| 16a. Assumption value desired Assumption code 16 . b. h0-8--0!^ 17a. b. Assumption value desired Assumption code 17. jO 6 . 0 1 0 8j 10a. b. Assumption value desired Assumption code 18. |0 1 . 0 | f l 3 19a. b. Assumption value desired Assumption code 19. ifil.SllH 20a. b. Assumption value desired Assumption code 20. 10 6 . o |^0 3j xx lba. b. See Instructions for Program 03, Form 3 on hov to use this section. APPENDIX D DRYING-TIME CALCULATION FOR THE IN-BIN COUNTERFLOW SYSTEM 197 10PRINT "Dryng time . energy consumption . drying efficiency 2 0 P R IN T 3 0 P R IN T 4 0 P R IN T " c a lc u la t e d by th e d r y in g 3 0 P R IN T "C Y C LE M OISTURE CONTENT m odel (C YC LE NO 5 TABLE water removed • and diner c*|>-itity *»“ 14> S h i v v e r t s y s te m n * ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------“ 60 P R 1 N T " NO IN IT IA L F IN A L PROPANE KJ ELECT. K M -h DRYING PROPANE* T IM E E Q U IV A LE N T DRYING EFF K J /H y H20 M A T E R ** D R Y E R * * * " REMOVED C A P A C IT Y " 70P R 1N T " ----------------------------------------------------------------------------------------------------- T --------------------------------------------------------------------------------------------------- “ 8 0 A 7 -3 9 0 IN P U T " B I N DIAM ETER D - j " , D 1 0 0 IN P U T "L A Y E R DEPTH X I - i X I 1 1 0 IN P U T "A M B IE N T TEMP. DECREE F B - i " . B 1 2 0 IN P U T “ DRYING TEMP. DEGREE F T - i “ ,T 13 0 IN P U T " I N I T I A L M OISTURE 7. WO M ! » i " . M I 1 4 0 IN P U T "D E S IR E D F IN A L MOISTURE CONTENT M 2 - i" .M 2 15 01N P U T “ S T A T IC PRESSURE IN H 2 0 5 1 - i SI I 6 0 IN P U T "WET BULB TEMPERATURE FOR D R YIN G A IR DEGREE F T 1 ~ j " , T 1 1 7 0 IN P U T "R E L A T IV E H U M ID IT Y OF DR YIN G A IR X U » i” .U 1 8 0 IN PU T "DRYNO A IR HUM ID VOLUME C U F T /L B V l« i" .V l 1 9 0 IN P U T "T E S T W EIGTH AT I N I T I A L M OISTURE CONTENT L D /B U D 6 -i 2 0 0 A i ( N P l * D A2 ) / 4 2 1 0 L 1 - X 1 * A * D 6 / 1 . 2 3 : REM POUNDS OF DRY CORN 2 2 0 L 2 * L 1 * < I 0 0 - M 2 ) / 1 0 0 : REM POUNDS OF DRY MATTER 2 3 0 L 3 « 1 0 0 * L 2 / < I O O - M 1 ) :R E M POUNDS OF WET CORN 2 4 0 U 1 - L 3 - L I : REM POUNS OF WATER REMOVED PER C IC L E 06 2 3 0 D 6 * ID 6 1 /1 . 2 5 * ( 1 0 0 -M I 1 /1 0 0 2 6 0 E - T 7 . 4 7 7 6 * U ~ . 4 3 B 4 ) / L 0 0 ( T ) : R E M C A LC U LA T IO N OF THE E Q U IL IB R IU M MOISTURE C O N T E N T -S IL V A R E L A T IO N S H IP 2 7 0 E * E / ( 1 0 0 - E 1 : REM E Q U IL IB R IU M MOISTURE CONTENT DRY B A S IS 2 8 0 K 6 - . 3 4 * 3 6 0 0 * E X P ( - 3 0 2 3 / ( T + 4 6 0 1 ) :R E M C A LC U LA T IO N OF THE DRYING CONSTANT 2 9 0 H « L 0 G ( 2 ) /K 6 : REM C A LC U LA T IO N OF THE T IM E OF H ALF RESPONSE 3 0 0 M ! * N I / ( 1 0 0 - M I ) : REM CHANGE M O ISTURE CONTENT IN T O DRV B A S IS 3 1 0 M 2 » M 2 / t 10 0 - M 2 1 : REM CHANGE M OISTURE CONTENT IN T O DRY O A S IS 3 2 0 Q - U B 3 7 7 2 3 * E X P ( - 2 0 2 * 5 1 > > /A : RFM A IR FLOW FOR THE 13 HP S H 1 W E R S DRYER 3 3 0 F -A *Q REM TOTAL A IR FLOW PF.R M IN U TE 3 4 0 W 3 - ( F * S l> / < 6 3 3 6 * . 6 ) : REH C A L C U L A T IO N OF THE FAN POWER 3 3 0 F - 6 0 * A * 0 / V 1 : REM MASS FLOW RATE PER HOUR 3 6 0 D 1 » T X 1 * D 6 * A * 1 0 8 0 * ( M l - E ) I / I 2 4 * F * H * < T - T I 11: REM C A LC U LA T IO N OF THE F IR S T R IM E N T IO N LE S S DEPTH U N IT (A T . 2 4 F T ABOVE THE FLO OR) 3 7 0 R 0 “ C M 2 - E ) / ( M I - E ) : REM MO ISTURE R A T IO FOR A T THE D E S IR E D MOISTURE CONTfcN 3 BO Y 1 « L 0 C ( ( 2 'D 1 - 1 ) / ( E X P ( . 6 9 * D 1 « R 0 > - 1 > > /. 6 9 ; REM F T R S I D1M ENTIO NLFSS TIM E U N IT 3 9 0 J I * ( H / . 6 9 ) «LOC< < 2 '‘D t - 1 > / ( 2 " ( R 0 * D I ) - ! ) ) : REM CA’ .CUI.AT TON OF THE DRYING 1 1HE TO DRY THE F IR S T LAYER •100 D 2 - ( D 1 * 2 > .R E M C A L C U L A T IO N OF THE SECOND DEHPT1I U N IT (A T 5 FT) 4 1 0 R | - ( 2 ' D I > / ( 2 ' D l » 2 * ‘Y l - l ) ; R E M MOISTURE R A T IO AT . 5 F T FROM THE FLOOR 4 2 0 M 3 « R 1 * ( M I- E » * E : REM MQ1TURE CONTENT AT . 2 5 F I FROM THE FLOOR 4 3 0 R 2 - ( 2 " D 2 ) / ( 2 ' ‘ D 2 * 2 'Y I - ! ) : R E M MO ISTURE R A T IO A1 5 FT 4 4 0 H 4 - R 2 * ( M I - E I * E : REM M01TURE CONTENT AT ,5 F T FROM THE FLOOR 4 5 0 M3“ ( M 3 - M 4 I/L O G ( M 3 /M 4 ) : REM AVERAGE MO ISTURE CONTENT FOR THE SECOND LAYER 4 6 0 R 3 " ( M 2 - E I / ( M 5 - E ) : REM MOISTURE R A I I O FOR 1HE SECOND LAYER 4 7 0 D 3 - m * D 6 * A * I O 0 O * ( M 5 - E ) > / ( . 2 4 * F « H * < T - T m : f i E . . " ,M E N T IU N L E S S DEPTH U N IT FOR THE SECOND LAYER AFTE R THE F IR S T HAD BEEN DROPPED 4 0 0 Y 2 * L 0 C I t a ^ D S - l) / C E X P ( . 6 9 * D 3 * R 3 1* -1 > > /. 6 9 : REM D IM E N T IO N LE S S T IM E U N IT FOR IH E SECOND LAYER AFTER T HE F IR S T HAD BEEN DROPPED 4 9 0 J 2 » Y 2 * H : REM C Y C LIN G T IM E OR T IM E REQUIRED TO DRY THE SECOOND LAYER AFTER THE SECOND HAD BEEN D N IE D 5 0 0 J 2 - J 2 * 6 0 : REM C Y C LIN O T IM E I N M IN U T E S 5 1 0 J I « J 1 * 6 0 : R E M T IM E TO DRY THE F IR S T LAYER I N M IN U TES 5 2 0 E 6 - M F / 6 0 0 » * J 2 » . 2 4 8 * C T - B I > / ( . 7 *W 1 » :R E M CALCULATED DRYING E F F IC IE N C Y 3 3 0 B 1 - ( 6 0 « A * X 1 > / ( J 2 4 1 . 2 3 > :R E M DRYER C A P A C IT Y BUSHEL PER HOUR 3 4 0 E 9 » ( ( U S * . 7 4 3 7 ) / ( A * X 1 / I . 2 5 1 > * ( J 2 / 6 0 l * 6 . 2 / . 9 : REM E LE C T. COST AT 6 . 2 CENTS PER KILO W ATT 5 5 0 C 0 * ( I ( W 1 * E 6 1 / 9 2 0 0 0 1* 4 5 . 7 > / ( A * X t / l . 2 5 ) : REM PROPANE COST (CENTS PER BUSHEL) 5 6 0 C 2 * ( C 0 » X l * A / ( 1. 2 5 * 4 3 . 7 ) ) / 13 2 / 6 0 ) * 9 2 0 0 0 : REM TOTAL BTU FROM PROPANE PER HOUR 3 7 0 P 8 - ( ( £ 9 * 3 0 / 6 . 2 ) / ( J 2 / 6 0 > ) ; REM E L E C T R IC IT Y COST PER 5 0 BUSHELS OR PER CYCLE 3 B 0 P 1 M C 2 * ( P 8 * 3 4 1 3 > 1 / 9 2 0 0 0 : REM PROPANE E Q U IV A LE N T PER HOUR S 9 0 W 1 - W 1 * 6 0 /J 2 : REM LB OF WATER REMOVED PER HOUR 6 0 0 M l“ ( H l / ( 1 + M 1 ) 1 * 1 0 0 6 I0 M 2 -(M 2 /(1 + M 2 > > *1 0 0 6 2 0 C 2 -C 2 » 1 . 0 5 3 6 3 0 P 1 - P i* 3 . 7 8 5 6 4 0 E 6 -E 6 *2 . 3 3 3 6 5 0 U t* W I* . 4 5 3 6 6 6 0 B I-B 1 * . 0 2 3 670P R 1N TU S 1N C 6 9 0 . A 7 . M I . M2. C 2 . P S. J 2 . P t . E 6 . W l. B1 6 8 0 P R IN T J 1 . " T IM E TO DRY THE F IR S T LA Y E R ” 690X 44 44. 44 44. 44 4444444 44. 4 444. 4 44. 4 4444 4444 4 4 4 II “ 7 0 0 P R IN T ” ------------------------------------------------------------------------------------------------------------------------------------------------------- D r y n g tin* • e n e r * i« roi>.,uiH p t i o n > d r y i n g e f f i c i e n c y c a l c u l a t e d b y t h e d r y i n g m o d e l (CYCLE. NO S TAW F 1 " ) CYCLE MO ISTURE CONTENT NO IN IT IA L F IN A L PROPANE KJ ELECT K U -h DRYING T IM E S 25 00 1 8 .6 0 156600B 6 4 IB 6 5 3 4 4 0 7 2 0 7 4 3 3 5 T IM E TO DRY THE F IR S T LAYER THE ABOVE RESULTS ARE FOR : B IN DIAM ETER D - i I B A M B IE N T TEMP. DECREE F B i 53. 4 DR YIN G TEMP. DEGREE F T»i 160 5 I N I T I A L MOISTURE 7. UB M l* i 25 D E S IR E D F IN A L M O ISTURE CONTENT M 2 * i S T A T IC PRESSURE IN H 2 0 S l - i 2 .9 NET BULB TEMP. FOR THE DRYING A IR . DEGREE f R E L A T IV E H U M ID IT Y OF THE DRYIN G A IR 7. U“ i DR YIN G A IR H U M ID VOLUME C U F T /L B V l= l TEST W EIGHT AT I N I T I A L MOISTURE L D /B U D 6 = ; * L ite r s pe r hour * * K j l o s p e r h o u r. T ons p e r h o u r. w a t e r re m o v e d > a n d C , i i i v v * r s s y s te m PROPANE* EQ U IV A LE N T 6 1 .9 DRYING F.FF. Y .J/K ., H 2 0 4745 10 6 T l= ; B5 4. 5 15 6 9 31. B iir tn r ' W n lt R n * m .lin '.T .D X il ji ug as DR YER **-* C APAC ITY 4 0