. American engineer . rom the data thus obtained the curves shown in Fig. 5 weredrawn illustrating the relation between the ratio of work in thetwo cylinders and the cut-off in the high pressure cylinder. Thereare six curves, each of them representing one of the conditionsshown in Fig. 4. Examining these curves with references to the first question,viz., What valve arrangement will give a constant ratio of workat all speeds and cut-offs? it will be noticed that curves A andE rise very rapidly, as the cut-off is shortened and an inspectionof the valve conditions on which these curves are based
. American engineer . rom the data thus obtained the curves shown in Fig. 5 weredrawn illustrating the relation between the ratio of work in thetwo cylinders and the cut-off in the high pressure cylinder. Thereare six curves, each of them representing one of the conditionsshown in Fig. 4. Examining these curves with references to the first question,viz., What valve arrangement will give a constant ratio of workat all speeds and cut-offs? it will be noticed that curves A andE rise very rapidly, as the cut-off is shortened and an inspectionof the valve conditions on which these curves are based shows avery long steam lap in the high pressure cylinders and a veryshort steam lap in the low. Curves B, C and D do not rise as ?x Card Al. 100 A L-PLop /f g ISO I Cufof/ 100 so I \ 0 V \ Card Dl. A ) L^P I Ve Lead if % Cui-o^f ZS7S V ^ \ Card AZ. i^p 4 a . Lead i 1 \ Cuf-cff V V ^\ ----_^ Card OZ \ HP. V ■P i re \ \ 4 1 \ Cut-off I 1 V ^^--,. ^> Card D3.\ HP \ Lpp r fe\ ■^ k fe V ^^^ Fig. 3—Indicator Cards Constructed from the Information Given by the Zeuner Diagrams. nients on the high pressure cybnder showing the reverse leverin three difterent positions for each. A similar diagram for the low pressure cylinders gives thevalve events as shown in the table below. On these cylinders Valve Bvenis for Low Pressure Cyfinders Cui-off inHigh Pressure Cui-affinLotv Pressure Release Compression , zs. is .ZS °(L&Ll^) .S6 (LaL=i§) ZO 06 t .zs (LaL=4) (LaL-Is.) the \alves have a maximum travel of 7 in., a steam lap of 11/16in., a lead of 9/16 in., and an exhaust clearance of 5^ in. Theoretical cards were then constructed for one ratio of cylin-ders and the events shown on the Zeuner diagrams. These areshown in Fig. 3. Fig. 4 shows the figures obtained from thediagrams and cards for these two conditions and for four o
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroa, bookyear1912
