. Electric traction and transmission engineering . tes. There are various types ofgates, including the so-called cylinder^ register, and wicketgates, the last being the most used. In this type the guidevanes are pivoted so that all may simultaneously approachor recede from their neighbors by the rotation of a singleregulating shaft. In order to neutralize the end thrust due to the axialpressure of the water, as well as to secure higher speedsunder a given head, it is common to place two turbinerunners — of correspondingly reduced diameter for thesame total power output — on a single shaft. Som
. Electric traction and transmission engineering . tes. There are various types ofgates, including the so-called cylinder^ register, and wicketgates, the last being the most used. In this type the guidevanes are pivoted so that all may simultaneously approachor recede from their neighbors by the rotation of a singleregulating shaft. In order to neutralize the end thrust due to the axialpressure of the water, as well as to secure higher speedsunder a given head, it is common to place two turbinerunners — of correspondingly reduced diameter for thesame total power output — on a single shaft. Sometimesfour and even six runners are coupled together to constitutea single unit. Fig. 117 shows a-9000 horsepower AUis-Chalmers horizontal twin turbine with the runners dis-mantled. The water enters through the wicket gates atthe ends and within the bearings, passes through the wheels,and emerges at the bottom. Impulse wheels, suitable for heads above 150 feet, com-prise a number of buckets into which water is directed HYDRAULIC STATIONS. 283. 284 TRACTION AND TRANSMISSION. through one or more nozzles at a velocity equal to V2 gHfeet per second, where g is the acceleration due to gravity= 32 ft. per sec. per sec, and H is the head or height ofwater in feet. Each bucket forms two cups divided by acentral ridge which separates the impinging water into twoparts, each part being deflected backward to one side of the
Size: 1256px × 1989px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, bookidelectrictrac, bookyear1920
