Francis Turbine

The Francis turbine is a very common type of turbine. It is suitable for medium heads and medium quantities of water. The appropriate difference in height for this type of turbine is in the range of 20m to 200m. The output is between 50kW and 3MW.

Function

In this turbine the water flows through a spiral casing (helical tube, also called spiral) towards the diffuser. By adjustable guide vanes in the diffuser (circle of guide vane) the accelerated water strikes the blades of the wheel. This wheel transfers then the energy.

Depending on the circumstances and water data, we distinguish between:

• Small Francis turbines: Power from 30kW up to 100kW
• Medium Francis turbines: Power from 100kW up to 500kW
• Large Francis turbines: Power from 500kW up to 3MW