. American hydroelectric practice; a compilation of useful data and information on the design, construction and operation of hydroelectric systems, from the penstocks to distribution lines . —Thedraft tubes leave thebucket wheels as circu-lar discharge openingshaving a diameter of18 ft., but rapidly en-large in section as thetubes assume a hori-zontal direction toempty into the tail-race. At the final pointof discharge the veloc-ity is about 4 ft. persecond, or less than 3miles per hour, assur-ing quiet entry intothe tail-pool. At thetop of the draft tube,in the constrictedcross-section, howev
. American hydroelectric practice; a compilation of useful data and information on the design, construction and operation of hydroelectric systems, from the penstocks to distribution lines . —Thedraft tubes leave thebucket wheels as circu-lar discharge openingshaving a diameter of18 ft., but rapidly en-large in section as thetubes assume a hori-zontal direction toempty into the tail-race. At the final pointof discharge the veloc-ity is about 4 ft. persecond, or less than 3miles per hour, assur-ing quiet entry intothe tail-pool. At thetop of the draft tube,in the constrictedcross-section, however,the water is required to move with a speed of 14 ft. per second, or 9miles per hour The tailrace openings from the draft tubes measure 22 in. by 40 ft. 2 in., being made up in sections by two semicircles joined bystraight lines at top and bottom. The lower edge of these openings, as wellas the bottom of the tailrace, is 25 ft. below the bed of the river. Thetailrace is excavated to this depth for a distance of half a mile down-stream. Single Runner Turbines.—Each of the main 10,000 hp. turbine unitsconsists of a single 15 ft. runner equipped with balanced guide vanes con-. Fig. 20b.—Section through Turbine Setting and Switch-ing Apparatus in Keokuk Station of Mississippi RiverPower Company 42 HYDROELECTRIC PRACTICE
Size: 1368px × 1826px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyorkmcgrawhillb
