Screw turbine

Water turbine which uses the principle of the Archimedean screw Reverse action of the "Archimedean screw", the principle of the "screw turbine" gaining energy from water flowing down through the screw. Screw turbines typically have three or four flights (second row) Two parallel screw turbines capable of producing 75:kW each, in Monmouth, Wales Play media Video of a 40:kW screw turbine in Munich, Germany

The screw turbine or Archimedean turbine is a water turbine which uses the principle of the Archimedean screw to convert the potential energy of water on an upstream level into work. It may be compared to the water wheel. The turbine consists of a rotor in the shape of an Archimedean screw which rotates in a semicircular trough. Water flows into the turbine and its weight presses down onto the blades of the turbine, which in turn forces the turbine to turn. Water flows freely off the end of the turbine into the river. The upper end of the screw is connected to a generator through a gearbox.

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History

A screw turbine at a small hydro power plant in Goryn, Poland.

The Archimedean screw is an ancient invention, attributed to Archimedes of Syracuse (287–212 BC.), and commonly used to raise water from a watercourse for irrigation purposes. In 1819 the French engineer Claude Louis Marie Henri Navier (1785–1836) suggested using the Archimedean screw as a type of water wheel. In 1916 William Moerscher applied for a U.S. patent on the hydrodynamic screw turbine.

Application

12:kW screw turbine at the Cragside estate

The Archimedean screw turbine is applied on rivers with a relatively low head (from 0.1:m to 10:m) and on low flows (0.01 m³/s up to around 10 m³/s on one turbine). Due to the construction and slow movement of the blades of the turbine, the tur... ...read more

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