. Electric railway review . ove the drips. The exciter engine■would in all probability be run to supply current for thelighting system, even though the plant were otherwise shutdown. A live steam connection can otherwise be made tothe exhaust main and used when there is not enough ex-haust steam to maintain the necessary pressure. A reducingvalve can be set to open the live steam connection into theexhaust system whenever the pressure in the exhaust maindrops to three pounds. It may be found that this exhaustsystem can be more economically operated by wasting thedrips to the sewer than by carr
. Electric railway review . ove the drips. The exciter engine■would in all probability be run to supply current for thelighting system, even though the plant were otherwise shutdown. A live steam connection can otherwise be made tothe exhaust main and used when there is not enough ex-haust steam to maintain the necessary pressure. A reducingvalve can be set to open the live steam connection into theexhaust system whenever the pressure in the exhaust maindrops to three pounds. It may be found that this exhaustsystem can be more economically operated by wasting thedrips to the sewer than by carrying the necessary back pres-sure to elevate and return the drips through a considerabledistance to the heater. With drip returns as shown inFigure 178 there would be no heat lost due to wasting con-densation nor by leaving the drain valve open so the steamwill blow through to the atmosphere. In fact, the capacityof the heating system would be very materially increasedby using the returns c and d. The steam which does not. Figure 179—(C20-3). pass through these returns to the heater would be free topass through the valve a. The arrangement of this system as shown with the heat-er under lower pressure than the exhaust system makes thehandling of drips possible in the most extreme cases. Forinstance, Figure 179—(C20-3) may illustrate a coil for carshop pits with the drip main on a higher plane than thebottom of the coil. But very little back pressure on theexhaust main would be required to handle the drips. If theriser, a, is 4 feet in length a 2-pound back pressurewould be required to raise the drips. If the drips are blown to the sewer in starting the coil, then but a fractional partof a pound of back pressure will carry the condensationalong with the steam in the form of vapor if the drainvalve be left open and the steam be allowed to flow throughit back to the heater. If the riser, a, is 10 feet in length andthe difference in pressure of the steam supply and the dripmai
Size: 2953px × 846px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectstreetr, bookyear1906
