. The street railway review . ortant that ample means should be allowed forcleaning, especially upon the outside surface of the tubes. Onesquare foot of tube surface would evaporate half a gallon of waterper hour, so that if the water is only moderately hard the amount ofdeposit in a year would be considerable. The circulating wateritself should be kept clean. One method of removing veryhard scale from the tubes is to stop the water in circula-tion and to pass steam into the condenser, when the differ-ence of expansion between the tube and the scale causes the latterto crack; it can then, as a
. The street railway review . ortant that ample means should be allowed forcleaning, especially upon the outside surface of the tubes. Onesquare foot of tube surface would evaporate half a gallon of waterper hour, so that if the water is only moderately hard the amount ofdeposit in a year would be considerable. The circulating wateritself should be kept clean. One method of removing veryhard scale from the tubes is to stop the water in circula-tion and to pass steam into the condenser, when the differ-ence of expansion between the tube and the scale causes the latterto crack; it can then, as a rule, be easily removed by hand. Theexhaust pipe may enter either at the top or bottom of the con-denser. This pipe is generally made of mild steel plate 3-16 to %in. thick, with substantial faced flanges riveted to each end; andpipes 18 to 24 in. diameter arc often erected in complete lengths40 to 50 ft. long. They should, i: possible, have a fall towards thecondenser, but if circumstances do not permit of this, they can be. so arranged as to drain back into a chamber at the lowest pointin the run from which a pipe is led to the air pump. The outlet pipefrom the bottom of the condenser is led with a fall direct to theair pump. Where the condenser is about 29 or 30 ft. above thehot well, this run of pipe may be dispensed with. The condenserwater then drains through a pipe directly into the hot well. Theair pump then deals with the air from the top of the condenseronly, from which a nmch smaller pipe is led to the air the condenser and the air pump a cooler is fixed, intowhich a spray of water is admitted as in an ordinary jet con-denser, thus reducing the final temperature of the air. All joints should be machined, and made even more carefully thansteam joints. The joint may be made with rubber insertion, as- bestos, or asbestos soaked in boiled oil. When the whole of thepipe work and condenser is erected it should be tested underwater pressure, the pressure from
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Keywords: ., book, bookcentury1800, bookdecade1890, booksubjectstreetrailroads
