What is the difference between Kaplan and Francis Turbines?
• In Kaplan turbine water enters axially and leaves axially, while in Francis turbine water enters the runner radially and exits axially.
• The Kaplan turbine runner has 3-8 blades while Francis turbine runner has 15-25 blades in general.
• Kaplan turbine has a higher efficiency than Francis turbine.
• Kaplan turbine is smaller and compact compared to Francis turbine.
• The rotation speed (RPM) is higher than that of the Francis turbine.
• Kaplan turbine has lesser friction loss and higher efficiency.
• Kaplan turbines can operate under a wide range of head conditions, but Francis turbine requires relatively higher head conditions.
• Kaplan turbines are used in small hydro power plants.