inters, i 4 Po ut Lloyd §F ork. P a eeia \ ring Term <- 1923. 7 ae - Submitted dy - and ag Steam Conswnption Teat on An 8 x 12 Skinner cngine. Mohigan Agricultural College, George Doan rman pats -_ eae era woe laws RM ey ry eee ehaee ae = gee ow . a oe . re ~— 7 — er ee ern P ro ~ a ee ae ; ” ° a tsar ee oe ai x an ney nae a a ae a ee . . 7 7" eeeneene — ; Si a Ane ra oth! Sd " } aa erp pea, Spit & rn 7 ae nn? rats a ram ape a ek, ao ’ . meee a a aan an Fa s es 4 ue eer ‘ errs ese . . . a ee ae eee eee eae oe ae an oe ie 7 ae in ee ae ra = ae a ~ : " wae. = SS See Se SS TE Sees ee 7 . ran barat e = — = eee oan en ana para " os a Z TSS — ~ eee soe See : te ora a = estes ee ~ : ¥ . . LESS A ren. $5 er Se SUC ee. eee ee PEPTYC hE ee ar eit ied hamid tal Sh plats, heele Tate, eas ~ aR _ rath 4 i -_— ad :’ - ww oo, ated “= Rees s Steam Conswiption Teat on An 8 x 12 Skinner -ngine. - Submitted by - George Doan end Lloyd Kenters, as Theein \ork. iMohigan Agrioultural College, - O-ring Term - 1923. THESIS OBJ::CT:=- The object of this thesis is to determine the steam consumtion per Brake Horse “ower and per Indicated Horse ,ower under different conditiona of beck pressure. Description of A paratus. sngine:- The engine ueed wae an 8” x 12" ensine manu- factured by the Skinner wngine Co. cf “rie, ra. The engine ie automatically governed by ochanginz the point cf ont off, by means of en inertia governor located in one of the fly- wheels. The steam porte are 3/4" x 7 3/4" while the exhaust port fe 1 3/4" x 7 3/4". The lead for the orank end was 13/64" head end was 3/16". The envine ia automsetically lubricated by 4 eplash oiling system. Steam ia tskxon from the college vower house about 450° feet distant. The -ressure in the header is kept at eprroxi- matoly 159 ibe. per equare inch. The enctine is riped so as to exheust either into a condeneer, the heatine systcm of the ungineering 3uilding, or d@irectiy into the air. Dimensions:- Engine. Diameter of oylinder ------------ weconwecee 8". SEPOKG en wn en on oe nnn cm ee wenn ns cence 12" Diameter of ciston rod ------ --------------1 7/16". Diameter of Fly :heel] -<--------------2e--- 48". Diometer of 3Jraeke heel <<---, equals Ka >. B. He >. equals C. C equals ; 1 enuels 2x x 4.256 ecusle .9°08l. od Q Vy Ve B. H. ?. equals Cnhk. The enzine fe rated at 300 Re. PP. We Condenser :- Tie condenser used wes a surface condenser ~anufactured by C. i. iheoler Company, “hiladelphia, ~e. The pump uaed in connection witt the condenser was a sinple Gylinder, double acting, sterm actuated rump, mene ufcotured by Knowles, Warren, ‘Anas. The condensing water wus vumped from the Red Cedar River by a Duolex pucp mannfaocturead by H. &. Varthingten, new York, .Y. The indicator used wes a Crosby manufsectured by the Crosby Indic: tor Connany. A 607 indicator spring waa used throughout the series of teste. soth the indicator and avring were ealibreted and found to be correct. fhe thermometers used were one 200° dairy thermometer and a 400° thermometer. These were calibrabed by comparing with a stanéard, and correction curves rlotted an shown on blue rrint sheets So's 10 and 1i. The steam gauge used wee a 29) 7 Teat Gauge, manufactur- ed by Soheffer % Budenberg Co-peny, New York, T. Y. This was oalibrated and found to be corresct through the range of steam pressures used in the teets. The vacaum gauge registered from 30% vacuum to 40 ; pres- sure. Thie wee iikewise calibrated anid found to be correct. Three nlatform sosles were used, all of which weighed correctly within the renge desired. Two weirhing tances with velve in bottom, were used in connection with the serles, for the purpose of weirhine the condensed etean. pomp 8 €0) 0 Before the actual teats were strrted the engine was test- ef for leakage in the following manner. In teating for leaky piston, two rethods were ueed. One, by teking the cylinder neaé off and turning sateen into the orposite end, the actual leakage eculd ve observed. In the other sethod, the engine was placed on dead cater, civing ea small amount of lead at that ena of the oylinder. The indientor cock at the opposite end of the cylinder was opened end steam turned on. The amount of atesem escaping through the indicator cock showed the amount 4. of leakage. The piston leaked oadly, due to one of the rings veing stuck. The piston wes taken ont and washed in easoline whieh losened the ring. This reduced tne leaRage by a amall amount. To teet the valves, we placed the v-lva in mié-po@ition ené blocked the engine. Steam was then turneé on. The an- ount comping through the indicator cooks showed the leakage. she valves proved to be fairly ticht. The clearance Wolune at each end of the cylinder, in- cluding steam port, drain nipe end incieato# pee was found as follows: The steau cheat cover wes texen off and packing was plac- o4 of rubber over the steam port and bicekeéd, the valve alse being removed, so as to prevent leaBage. The engine was placed on €eed center and water wes poured inte the clearance espace through the indicator pipe until the eame was full and time to fill noted. Then weter wae poured from another source, just fast enovrh to keen the olearanoe spsce full for the sane length of time th:t it took to f112 it first. Te latter amornt wae texen to be the leakage ani waa eubtracted from the origin: 1 smount required to fill. The re- sult cave the required lbs of water from which the ocleerance volume was caloulsted. In running the testes, the enzine and aonéenser were start- ead in the usual manner ent 6llowed to run for ebdonut ten minntes under the desired conditions for the ectusal teat. The engine was run under six different ooncitirna of back nresaure, nimely, 5# above atmospherc, at: oenherio crescure, 5", 19", 15" and 20° of vaouum. The different conditi rs of beck reseure were seaured by throttling the exhaunt before 1t entsred the condenser. The throttling wie ecco plished by “eens of a rete vilve in the exhauat pipe leading from engine to condenser. Undor the firet three conditions of back rreseure, loads of 60, 100, 150, and 29° lobe were laced on the scales. Under the lest three conditions losce of 69, 109, 150, 200, and 259 lbe were veed. Using the 250 lbs load, it wan found imposs- ible to obtain a 2°" yacuws 18” being the highest obtainable. U: ine the 50 und 100 ¢ loads each tent wae run for one hour. For the other louda the teate wore 40 minutes in langth Fron 6 to 10 minutes were left between teats having different brake loads. Ali the tests vueine the sane back nressure wore run conscooutively. cincio: tor oards were token at the begin- nine middle «nd end of cach test. Roadines were teken ce foll- ows Drake load, time, stean rressure, back “reecure, R. >. Me, temperature of condensed steaa, tenvereture in calorinater, berometrisc “reassure. Tie quality of the stcem ured, wen found by means of a throttling calorimeter. Knowing the total amount of steam condensed for any one teat ana the quelity, the amount of dry atoam per 3. 8. P., and I. H. F. Gould be celovleted. Tne results are found tab- ulated on ehcets 12 end 13 of blueprints. The following curves were vlctted. 3. He Pe los of dry cond. steam J 3B. Ff. ?. / hour. I. HR. P. lbs of dry cond. steam / I. 1. 2. / hovr. VYeouws "7 " " /B He? f rv ” ¢ ” ry o / I. ee / W . Ww . 060 ” " " per nour. " naunzines ff o Sample indigetor garde are stcwn on blue vorinte. Saturation curves are chown plotted on bBluerrinte 26 - 3) inolusive. ‘They are rlotted es follows:- Firet an indicator oard woe drawn. The leneth -~ the card war taven es renresenting the Gisplacemont of ;isten. Then the line rorresenting clearance wae driwn to the sene scole. ‘Te lines of 0 lhe pressure ebsolute wee also drawn. ( See bRueprint 25 for examie). At any point ae “D" on the compression curve drop a nerren- aioular to the Cy pressure line and also to the oleerance line. From these nerpendiculars tne vwoluzo of eteam and rressure can be soaled, end from a steam table the weirnt of this volume of eteam onn be cbtained. Then the oylinder feed is obtained by dividing the total lbe of stean condensed per hour by the num- per of atrekes per hour. The sum of the oylinder feed and ons - hion steam which hes been obtained gives the total amonnt of eteam in the oylinder. From steam table, the weirht of eteam in the oylinder by the weicht atves of 1 ou £6. at any given pressure gives the volume of ateam in the cylinder at that pressure ae "A 5°. Using this method the ourve © 3 fe plotted, which is the saturation curve and wuld represent the ex- paneion of the steam in the cylinder rrovidineg no éonden- setion tork lace. Come Tan Icy. From a study of the ourvee, we would conolude that the steam consumption decresser with an inorenee of vacuum. The etean per B. H. FP. and per I. i. PP. per hour, drops up to the rated load cfter which if irersases slightly, the rated load beinr avout 40 H.?. “he clearence volvce in higher than is usually found in high epeed enrines, Kent eivine from 6 - 12 % while thie engs- ne has from 15 - 16 %. From a study of the saturation curves, we wera able te determine the quality of the steam in the cylinder at any point in its expenaton ( i.e. ) at any pressure. By drawing the atmosphere line on each eard, we found that a creat deal of condensation took plroe before the atean entered the cylinder, probably dne te valywee ard turns. This was especially noticable on the light loads. For the heavy loads, the corfensation waa very little as ie shown by the drawings. On many of the light loads the saturation curve te- uched or even intersected the empanasion line at release. Thus gshowirg 100 % ary when it touched or superheated when 1¢ inter- sected. For the heavy loade was not so noticable. The quality at en 80 7 absnlute cressure and 290 7 load wes found from the se:mle @zrds for the virious back pressures. On aecount of the irregularity of the osrde, no definite aiff- enoe could be observed. However the quality seemed to be high- er fer higher yaouun. Thue for H. 5. 290 7 load 802 pressure the quality wes es follows:- 5 Oo # 5 # 10" 10” BO" and for =..le 2™ 5 2 oF 5" 10" 15" 20" Blso covparing same back «recrure, we found th: t the quality was higher for tho 76.2 55 quality. 735. 75.4 78.8 76.9 79.6 j “ 4 " 4 " pS re " a ®e load 60 # vrrecnaure the quelity waa:- 75.8 3 Cuality. 69.5% ” 74.8 5 " 62.6 % " “4.15 #" 69.3% " a light load end 6 heavy load with the heavy load as shown by th: foliowing figures. nO& ad BNd# 1 ” " 4 Beck Peceeurs ‘3 6«Cpality. a 5 10" 15" 20" 76.8 69 .§ 74.8 82.38 74.1 85.3 72. 61. 8 w Her. 692 Pressure. $ Tv . OF a . ~ ~ >» . J gt +t Rey, . . ay * a O™S . —~ 1 bE | sam ear - an a TE A eas rire ‘ye eo. “Hef oigt Pi i . Br » . ! f hl . + ak 1 . a ae ry fren 7 . t a an : - . os F ts f _* ' a . a oe 1 n apr ws A Caled mg ye witli be adults i RM of Sete > Be +e ee Load. 60 100; 100d 100 Back Pressure 4 Cuality. 5” 67.6 " . 10" 76. #7” «6 15" 72. “ -« 20" 64. #* « TOUT “WSs Yor 50 7 load and © } back pressure. Symbols used. H equale” R. P. i. n equale” number of strokes. W equale-weight on scale bean. w equals-unbalanced watght of brake. A equale-are a pieton in square inches. 1.2.2. equale-Indicated Eorne cower. B.H.2?. equale-Constant. K equale-I..”. constant. C equels-B.H.?. sonetent. WeTeve Qualia - clean Effective “reassure. Hebe equale - Head imi. C.5. equals - Orank Ené. x equals - Quality of steam. H equale - total heet corresponding to célorineter tempers ENTS. C., acnele - 5 ecifie ~ressvurée = 48 T. equele - Temper: ture in Calorimeter. To equals - " " “ ® corresponding to pressure. q@ equals - Heat of iiquid at throttle pressure. eet ca —- ~- fy owe ToT 7 _ “6 _ ~ I oe . . I . —— ee | rn 7 a! TT po —-t.. “sa , v B: Ca 5B ane #4 pe ’ Pre - ] = ' 3 ve ~ gee eel’ nye. Ie 10. T ~- Heat of liquid at throttle vressure, e,- Rarkine :ffeoiency. } re- Iatent heat at exhaust pressure. X,- “ulity of steam at release. qy- Heat of liquid at throttle pressure. qi- Heat of liquid st exheust >reseure. yr - Latent heat at ixilet pressure. X,- Quality of steam eat inlet.pressure. 1. I.E.r. equal@e Xx Ue. >. X Me HePe ( HZ. ) equals .091527 x 8.5 x 298.6 equale 3.88. TeHe>.e ( C.U. ) equale .991472 x 9.58 x 298.6 " Pl. Total I...°. equale 8.09. 2. Br.” equals Cxexix(Ve-ew ) B.E.>. 005081 x 298.6 x ( 50 - 27.2 ) equale OOO81l x 298.6 x 22.8 equals 5&.61. 3S. GCuality of steam equals x. x, equals H plus C,, ( T- To) - Q *) equale 1149.96 plus 48 (271.4 bad 211.) - 506.9 equals 872.06 equale 99.0. BEL. g- e 4. Lbs of stoam used oor hour, equele 428 =:. &. Lba of dry steam used per hoer, equale .99 x 428 equale 423.7 =. 7. Lbs of dry steam per I.H.>. / hour. equals, 23.7 equals 52,2 }. Lbe of ary atcam / 3.H.>. / hour equale, peat equile 76.8 #. Renkine uffieiency. C.. for 50 # load at & # back pressure. C= 100 - (_961.8 x .88 ) 109 equals ; 2 = plus o& Xe 100 - { 851) 100 190 - a6. 4 equals 13.6 % ‘ Cle: renéde Volume. ( H.E. ) Cyl Dieplacement equals 6” x .7854 x 12 equale 603.12. ou. vee or .349 ou. ft. Water to f411 head end equels 3.175 plus 204 eee 3.2162 ( temp. of water vsed 65.5° Weter at 65.5° F weighs 62.3575 # / ou. ft. e215 equals .0515 eu. ft or 89.09 ou. in. 20815, omuake 14.78 3. (C.5. ) Weight of water to T1121 clearance space, equals, 3.45 7 plus .04 | equals 3.49 2. ots equals .0559 ou ft. or 96.59 ou. in. C. k. oyl. displace ment 603.12. ( ( 17/16)" x .7854 x 12 equals 683.68 ou. in. 3 -5375 cu. Lt. 20559 equals 16.65 % Clearsnoe. OOTO — ae 12. > Total volume EK. =. equeale .349 plus .0615 ecunle.4005 on §% C. 2. equels .3376 plus .0559 equeale .3935 * - oe - | (Ned? tice on career cet ef, - Boo era ts dean woah oad -* & @ Se eee "shgine Zeste” by Barrue. "Transactions of A. A. ie E. of 1902." "Kent". 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