CLASSIFICATION OF TURBINES - By: josephperez7080

Water turbines can be classified according to :

The action of water on moving blades
On this basis water turbines are classified into following two categories :

Impulse turbine: Whole of the pressure energy in this turbine is first converted into kinetic energy. The wheel revolves in open air at atmospheric pressure when water strikes in the series of buckets, i.e. in these there is no difference of pressure at the inlet and outlet of the runner. As these turbines convert the velocity energy into mechanical energy, these are known as Impulse or velocity turbines.

Reaction turbine: These operates on the basis of difference of pressure at the inlet and outlet of the turbine, hence these are known as reaction or pressure turbine. In this case entering water has pressure as well as kinetic energy and when it move over the blades both the kinetic energy and pressure energy provides turning moment of the wheel.

Name of the originator

Turbines can also be classified on the basis of names of their inventor or originator, e.g. Peloton wheel, Turbo, Girard, Jonval, Bankin impulse turbinse and similarly Francis, Kaplan and Thomson reaction turbines.

Head and quantity of water available

High head (above 200m) and small quantity of water requires impulse turbine such as peloton wheel.

Medium head (between 30 to 200m) and medium quantity of water requires reaction turbines as Francis turbines.

Low head (below 30m) and large quantity of water requires reaction turbines such as Kaplan or Propeller turbines.

Disposition of shaft

Turbines may have either horizontal or vertical shafts, Generally Peloton wheels have horizontal and Francis and Kaplan turbines have vertical shafts.

Direction of flow of water in the runner

In radial flow turbines water flows in radial direction. The flow may be inward or outward.

In tangential flow turbines, water strikes the runner in the direction of tangent on the depth of rotation of the runner. Peloton wheel is an example of tangential flow turbine.

In axial flow turbines water enters and leaves the runner in a direction parallel to the axis of the turbines shaft.

In mixed flow turbines water enters radically and leaves the runner axially.

Specific speed

Specific speed of a turbines is the speed of a geometrically similar turbines which would develop one H.P. Under a head of 1 m. On this basis some of the important turbines have following specific speeds:
Peloton wheel has specific speeds varying from 10 to 35 for single jet and up to 50 for double jet.

Francis turbine has specific speeds varying from 50 to 300.

Kaplan turbine has specific speeds varying from 300 to 1000.

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Looking for leading manufacturers and exporters of Thermowells from India we manufacturer threaded Standard Thermowell, Flange Thermowells, Socket Thermowells, Sanitary Wells, Van Stone Wells, Weld in Wells in Stainless Steel 304, 316, 304L, 316L, 310, 321 and 446?

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