Francis turbine

machine

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June 26, 2026

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The Francis turbine is a type of reaction turbine used for hydroelectric power generation. It is characterized by a mixed-flow design, where water enters radially and discharges axially. This design allows Francis turbines to operate efficiently across a wide range of heads, typically from three to 600 meters.1

Key features include a spiral inlet casing with adjustable gates to control water flow and a runner with curved blades designed for smooth water entry and minimal swirl at the exit. Francis turbines are widely used due to their versatility and efficiency, especially in medium-head ranges. They can be configured with either horizontal or vertical shafts, with vertical shafts being common for larger units. The development of the Francis turbine is credited to James B. Francis, who improved upon earlier inward-flowing radial turbine designs.12

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James Bicheno Francis
…inventor of the mixed-flow, or Francis, turbine (a combination of the radial- and axial-flow turbines) that was used for low-pressure installations.
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…inventor of the mixed-flow, or Francis, turbine (a combination of the radial- and axial-flow turbines) that was used for low-pressure installations.
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turbine
Mixed-flow turbines
Francis turbines are probably used most extensively because of their wider range of suitable heads, characteristically from three to 600 metres. At the high-head range, the flow rate and the output must be large; otherwise the runner becomes too small for reasonable fabrication. At the…
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Francis turbines are probably used most extensively because of their wider range of suitable heads, characteristically from three to 600 metres. At the high-head range, the flow rate and the output must be large; otherwise the runner becomes too small for reasonable fabrication. At the…
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Enguri Dam
Specifications
…with the dam has five Francis turbines, in which water enters such that it turns the blades of the turbine but exits through an outlet at the center of the turbine body. The turbines together account for a planned power capacity of 1,300 megawatts.
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…with the dam has five Francis turbines, in which water enters such that it turns the blades of the turbine but exits through an outlet at the center of the turbine body. The turbines together account for a planned power capacity of 1,300 megawatts.
Read More