Classification of Hydraulic Turbines
Turbines are classified on various basis :
A) Head and Quantity of water available
B) Name of originator
C) Nature of Working of the blades
D) Direction of flow of water
E) Axis of Turbine Shaft
F) Specific Speed
According to Head and Quantity of water available
1. Low Head – ( 2-12m )
Kaplan ot Propeller Turbine
2. Medium Head – ( 16-70m )
Either Kaplan or Francis Turbine
3. High Head ( 71-500m )
Francis or Pelton
4. Very High Head ( >500m)
Invariably Pelton, Deriaz upto 300m
According to Name of originator
1. Pelton Turbine – Named after Laster Allen Pelton, Impulse Turbine used for High Head and Low Discharge.
2. Francis Turbine – Named after James B. Francis, Reaction Turbine for medium head and medium discharge.
3. Kaplan Turbine – Named after Dr. Victor Kaplan, Reaction turbine forlow head and large discharge
4. Deriaz – Reversible Turbine pump used upto head of 300m.
According to Nature of Working of the blades
- Impulse Turbines
- Reaction Turbines
According to Direction of flow of water
- Radial Flow Turbine
- Inward Radial Flow Turbines
- Tangential or Peripheral Flow Turbines
- Axial Flow Turbines
- Mixed Flow Turbines
According to Specific Speed :
- Low Specific Speed Turbine
- Medium Specific Speed Turbine
- High Specific Speed Turbine
