Windmills

De onderdelen van een waterpompende windmolen

A windmill is made up of a tower and a top. The rotor, the tail vane and a security system are all attachted to the top. The rotor (a set of blades or sails) catches the wind and converte its energy into mechanical energy. In case of small windmills, the main vane should keep the rotor in the wind. This allows the mill to operate in different directions. Sometimes the security system consists of a vane on the side or an angled vane with an eccentrically placed top. This will turn the rotor out of the wind.

A water pumping windmill typically uses a piston pump. (The operation of this pump is generally explained in the chapter on the hand pump). A crankshaft converts the rotary motion of the rotor in an up and down movement of the piston pump. A mill with this pump can be recognized by the large number of blades, usually somewhere between 8 to 24. This large number of blades is necessary, because the unfolding lot of effort. The angle of the blades against the wind is such that much torque (power) and low speed comes. This rotor turns slowly compared to other types and they speak so fast-running nature of a low. Sometimes a delay mechanism (a kind of transmission) to the output torque further.

A water pumping windmill is often placed on top of a pit or near a river. Besides the mill can be a tank top, where water is stored as buffer stock for when the mill is not running. The ferro cement tank in the WOT site is one example. You can read more about this later. The water from the storage tank can be used for domestic use, drinking water for livestock or irrigation. Also, the water used for fish farming. For drinking water storage tank must be sealed to prevent contamination of the water with diseases.

First and second generation windmills

Around 1900 there were many mill manufacturers. Only a few survive to this day. Their products are robust, because the designs are by bitter reached. There are also many materials used some parts from cast iron (heavy). Many steel mills, the expensive materials, installation and transport. These ‘first generation’ mills are still being sold because of their reliability.

The price of a mill can be reduced by using less material. In half the ’70s generation turbines designed. These castings are replaced by welded constructions of standard materials. These standard materials such as angle and plate, are cheap and of good quality. Early last century, plates and profiles specially cast for the application, there was no standardization. The “Oasis” on the WOT site in an example of half-generation windmill.

Electricity-generating windmills

An electricity-generating wind turbine is also called a wind generator. The generator itself is in the top. The rotor has a high speed by a small number of blades, a more perpendicular position of the blades on the wind and an airfoil.

The speed of a rotortip is high compared to the wind speed (high speed running unit). This is desirable to use a small generator to be. Often a gear mechanism used to control the speed of the generator to further enhance and apply to reduce generator. The rotors used in wind generators have a high return but starting only at relatively high wind speeds.

There are electricity-generating turbines at the power coupled (usually the larger mills), but there are also so-called stand-alone turbines are usually used in remote areas. The windmill is not connected to the grid, but for example a storage battery.