. The mastery of water. boss with large curved blades. Waterenters the casing and is directed upon the blades by meansof guides. In order to escape near the boss, the waterpresses upon the blades and causes the axle upon whichthe boss is mounted to spin round. Turbines usually have a horizontal axis just the sameas a Pelton Wheel, but if the fall is very low (and theywill work with a head of three feet) vertical turbines are 144 THE MASTERY OF WATER. used. The runner of a vertical turbine is rather moreeasily illustrated than that of a horizontal one, and theaction of the water will be underst
. The mastery of water. boss with large curved blades. Waterenters the casing and is directed upon the blades by meansof guides. In order to escape near the boss, the waterpresses upon the blades and causes the axle upon whichthe boss is mounted to spin round. Turbines usually have a horizontal axis just the sameas a Pelton Wheel, but if the fall is very low (and theywill work with a head of three feet) vertical turbines are 144 THE MASTERY OF WATER. used. The runner of a vertical turbine is rather moreeasily illustrated than that of a horizontal one, and theaction of the water will be understood from the diagrams also show how both inward flow andoutward flow turbines are fixed in position, and how thewater is led into and away from them. As a rule the turbine should be placed as low aspossible in order to utilise the largest head ; but if thetube leading to the tail-race is properly constructed andproportioned, the pull of the column below the turbine Water at i,™, ^ -V/^/7/Pressure III-•^^^. vanes—^ Water at ^&m/^/mm/mmwmv{Low Pressurp. Revolving WhftelDIAGRAM OF AN OUTWARD FLOW TURBINE. is also effective, because it tends to break away and forma vacuum below the moving blades. In order to get as large a fall as possible, the wateris sometimes led for miles across country in open channelsor flumes, or in steel pipes. It crosses low ground onbridges, and is conveyed through mountains by tunnels,which in many cases add enormously to the cost of theworks. Water power is cheap because the water costsnothing, but the works are generally very expensive. Themost important condition is that there should be a con-stant supply. A number of water-power stations whichtake their water from rivers without any arrangements WATER WHEELS AND TURBINES. 145 for storage have to shut down in dry seasons—^anirregularity which is disastrous in modern industry. So Shaft ofWater
Size: 2486px × 1005px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectwatersupply, bookyear
