File:The Street railway journal (1907) (14736756856).jpg

Identifier: streetrailwayjo301907newy (find matches)
Title: The Street railway journal
Year: 1884 (1880s)
Authors:
Subjects: Street-railroads Electric railroads Transportation
Publisher: New York : McGraw Pub. Co.
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Smithsonian Libraries

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it, although the tur-bine auxiliaries are somewhat crowded in the basement.The two turbine units are of the five-stage Curtis type,mounted on a base condenser; each of them, is direct coupledto a six-pole, delta-connected, three-phase, 35-cycle, 13,-200-voh, alternating-current General Electric generatorproducing 5000 kw at 700 r. p. m.The steam consumption ofthese units, with steam at 175 lbs., 2 ins. absolute backpressure and 100 degs. F. of superheat, is guaranteed to be18.3 lbs. per kw-hour at half load; 17 lbs. at full load;17.5 lbs. at 50 per cent overload and 17.8 lbs. when theload varies between 50 per cent and 150 per cent of thefull load. Each unit is controlled by a centrifugal governor,which mechanically operates a poppet type valve in thesteam, supply line, the variation in speed from no load tofull load being guaranteed not to exceed 2 per cent, exceptthat a sudden change in load may cause 4 per cent mo-mentary variation. 126 STREET RAILWAY JOURNAL. • (Vol. XXX. No. 4.
Text Appearing After Image:
July 27, 1907.) STREET RAILWAY JOURNAL. 127 The step bearing of the turbine is supplied with 12 gals,of oil a minute under a pressure of 550 lbs. per square inch.The piping system which supplies oil to these bearings isfurnished with pressure by two twin Worthington steampumps, which are connected in relay so in case one pumpfails to maintain the required pressure the second will start.A hydraulic accumulator built by R. D. Wood & Companyis connected with this piping system to maintain the pres-sure on the latter. This accumulator has an 8-in. ramwith an 8-ft. stroke, and is weighted to produce a workingpressure of 550 lbs. A motor-driven triplex pump is alsoprovided as an auxiliary to the steam pumps, and is startedautomatically if the accumulator falls below the predeter-mined height. A separate pump and system of piping sup-plies oil at 80 lbs. pressure for the governors, steady bear-ings and general lubrication of the turbines. The dischargefrom the step bearings and governors

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