Difference Between Impulse and Reaction Turbines

Impulse Turbine 

• The blades mounted to the rotor are stricken by an impulsive force.
• Once the steam passes through the nozzles, it expands fully and its pressure remains constant.
• The blades are symmetrical in form.
• Speed is high in impulse turbine since the speed of steam is high.
• The number of stages needed for manufacturing same power very less.
• High blade potency curve.

Reaction Turbine 

• The vector of reactive and impulsive force strikes the blades mounted to the rotor.
• The pressure cannot expand totally. only it passes through the nozzles and rests on the rotor blades, it partly expands.
• The blades are asymmetrical in form.
• Because the steam speed is lower in reaction turbines, speed so lower than impulse turbines.
• To develop constant power, it needs additional stages.
• The blade potency curve is lower compared to the impulse turbine.