. The street railway review . essure which would flowinto the high-pressure cylinder for one-quarter of the stroke untilcut off may be arbitrarily assumed as I. The steam in the high-pressure cylinder will expand its volume six times in exhaustingto the receiver, but as the flow from the live steam main into thehigh-pressure cylinder was cut off after one-quarter of the stroke,and as the exhaust to the receiver takes place during the fullstroke, the relative areas of the admission and exhaust ports arenot as 1 is to 6, but as 1 is to 6 -=- 4; or the exhaust port shouldhave an area V/2 times th
. The street railway review . essure which would flowinto the high-pressure cylinder for one-quarter of the stroke untilcut off may be arbitrarily assumed as I. The steam in the high-pressure cylinder will expand its volume six times in exhaustingto the receiver, but as the flow from the live steam main into thehigh-pressure cylinder was cut off after one-quarter of the stroke,and as the exhaust to the receiver takes place during the fullstroke, the relative areas of the admission and exhaust ports arenot as 1 is to 6, but as 1 is to 6 -=- 4; or the exhaust port shouldhave an area V/2 times that of the admission port. As the steamin the receiver has expanded to six times its original volume inthe high-pressure cylinder, the admission valves of the low-pres-sure cylinder, in order to prevent any accumulation of steam inthe receiver, should have an area of six times the admission valvesto the high-pressure cylinder since the valves of both cylinders cutoff at one-quarter stroke. If the low-pressure cylinder exhausts. fig. 153—(Bi-13). FIG. 154—1 B4-] I to 26 in. of vacuum the steam in the condenser will occupy 72times the volume it did in the high-pressure cylinder up t thetime of cut-off, but as the exhaust ports of the low-pressure cylin-der are open to the condenser during the full stroke and the admission ports from the receiver to the low-pressure cylinder an 268 STREET RAILWAY REVIEW [Vol. XVI, No. 5 ]i\ii iie-quarter of the stroke, the necessary area to maintain aneven flow will be one-quarter of 72, or 18 times the area of thelive steam ports of the high-pressure cylinder. In case the engineexhausts to atmosphere the relative volume of live steam to steamat atmospheric pressure will be as 1 to 10, but the live steam flowsinto the engine only one-quarter of the time and the exhaust steamflows to atmosphere during the full stroke. Therefore, instead ofthe atmospheric valves having an area 10 times as great as thatof the admission valves, the area need be but
Size: 1472px × 1697px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., book, bookcentury1800, bookdecade1890, booksubjectstreetrailroads
