Kaplan Turbines of Hydro Power Plant
- The Kaplan turbines are reaction type turbines. They are also low-head turbines and hence for same output as that of Francis turbines they require large quantity of water.
- It has gate and governing mechanism similar to Francis turbine but in Kaplan runner the water strikes the turbine blades axially. Kaplan turbine consists of 3 to 6 blades which reduce the frictional resistance.
- The relative setting of inlet and outlet channels in Kaplan turbines are set in the manner shown in Figure. Due to low head quantity of water required is large in such turbines.
- To feed this uniformly to the runner, the walls of the spiral casing in combination with the guide blades are not adequate and they are supplemented by the two curved guide walls.
- These turbines run at 120-200 r.p.m. and have efficiency of about 90% at all loads.