Pelton wheel from Walchensee, Germany hydro power station

Figure from Pelton's original patent (October 1880)

Plan view of a Pelton turbine installation (courtesy Voith Siemens Hydro Power Generation).

A Pelton wheel, also called a Pelton turbine, is one of the most efficient types of water turbines. It was invented by Lester Allan Pelton (1829-1908) in the 1870s, and is an impulse machine, meaning that it uses Newton's second law to extract energy from a jet of fluid. Download high resolution version (587x800, 98 KB) by de:User:Softeis File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Download high resolution version (587x800, 98 KB) by de:User:Softeis File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Hydroelectricity is electricity produced by hydropower. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Image File history File links S_vs_pelton_schnitt_1_zoom. ... Image File history File links S_vs_pelton_schnitt_1_zoom. ... Wikipedia does not have an article with this exact name. ... Lester Allan Pelton (1829 - March 14, 1908), was an American inventor who created the impulse water turbine. ... For other uses, see Impulse (disambiguation). ... This article is about devices that perform tasks. ... Newtons laws of motion are the three scientific laws which Isaac Newton discovered concerning the behaviour of moving bodies. ... A fluid is defined as a substance that continually deforms (flows) under an applied shear stress regardless of the magnitude of the applied stress. ...

Function

The pelton wheel turbine is a tangential flow impulse turbine, water flows along the tangent to the path of the runner. Nozzles direct forceful streams of water against a series of spoon-shaped buckets mounted around the edge of a wheel. Each bucket reverses the flow of water, leaving it with diminished energy. The resulting impulse spins the turbine. The buckets are mounted in pairs, to keep the forces on the wheel balanced, as well as to ensure smooth, efficient momentum transfer of the fluid jet to the wheel. The Pelton wheel is most efficient in high head applications. Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... For other uses, see Impulse (disambiguation). ... In fluid dynamics, head refers to the constant right hand side in the incompressible steady version of Bernoullis equation. ...

Since water does not easily compress, almost all of the available energy is extracted in the first stage of the turbine. Therefore, Pelton wheels have only one wheel, unlike turbines that operate with compressible fluids.

Applications

Peltons are the turbine of choice for high head, low flow sites. However, Pelton wheels are made in all sizes. There are multi-ton Pelton wheels mounted on vertical oil pad bearings in the generator houses of hydroelectric plants. The largest units can be up to 200 megawatts. The smallest Pelton wheels, only a few inches across, are used with household plumbing fixtures to tap power from mountain streams with a few gallons per minute of flow, but these small units must have thirty metres or more of head. Depending on water flow and design, Pelton wheels can operate with heads as small as 15 metres and as high as 1,800 metres. Bearing is the following: Often, bearing is the state of having something as a quality, characteristic, or permanent attribute. ... Hydroelectric dam diagram The waters of Llyn Stwlan, the upper reservoir of the Ffestiniog Pumped-Storage Scheme in north Wales, can just be glimpsed on the right. ... For other uses, see Watt (disambiguation). ... An inch (plural: inches; symbol or abbreviation: in or, sometimes, ″ - a double prime) is the name of a unit of length in a number of different systems, including English units, Imperial units, and United States customary units. ... A plumber wrench for working on pipes and fittings A complex arrangement of rigid steel piping, stop valves regulate flow to various parts of the building. ...

In general, as the height of fall increases, less volume of water can generate a bit more power. Energy can be expressed as W = Fs (where W is the work measured in joules, F is the force and s is the displacement measured in metres). In the instance of fluid, flow power is expressed as P=kρV/t (where k is a constant, ρ is the pressure, V is the volume and t is the time). The power, P, increases in direct proportionality to the flow rate and grows with f(Pressure^3/2.) Thus in the case of Pelton Wheel designs, it is usually better to seek a large pressure using a large head rather than to go for a fast flow rate. In physics, power (symbol: P) is the rate at which work is performed or energy is transmitted, or the amount of energy required or expended for a given unit of time. ...

See also

• Ian Gilmartin

Ian Gilmartin is a British inventor from Kendal in the United Kingdom. ...

External links

Wikimedia Commons has media related to:

Pelton wheel

• Small Hydro - Pelton Wheel example.
• Minituriasation of Pelton Wheel.