Types of Turbines :

Condensing Turbines :

With the condensing turbine, the steam exhausts to the condenser and the latent heat of the steam are transferred to the cooling water the condensed steam is returned to the boiler as feed water.

Condensing – Bleeder Turbines :

The condensing – bleeder turbine reduces the condenser losses as steam is bleed off at several points of the turbine the solid steam is used for feed water heating up to 20% of the total steam flow may be bleed off.

Back pressure Turbine :

Back pressure turbines as reducing station plants the turbines acts as a reducing station between the boiler and process steam header the process steam pressure is kept constant and the generator output depend on the demand for process steam.

The back pressure turbine my be also have bleed points and is then called a back pressure bleeder – turbines.

Extraction Turbine :

Extraction turbines are turbine where steam is extracted at one or more points at constant pressure.

Extraction turbine may be single or double extraction condensing turbines or single or double extraction back pressure turbine the extraction turbine may besides extraction points have bleed points for feed water heating.

Topping Turbines :

Topping turbines have been used when old boilers are replaced with new high-pressure boilers the turbine is a back pressure turbine exhausting to the old boiler header still supplying steam to the old lower pressure turbines.

Mixed pressure Turbines :

Mixed pressure turbines are used where excess steam from the process is available for the low-pressure part of the turbine while steam at boiler pressure may be added to the high-pressure part of the turbine when more load is applied to the turbine.

Cross compound Turbines:

Cross compound turbine is a large turbine with parallel shafts with a generator on each shaft the steam flow through the high-pressure turbine and then is crossed – over to the low-pressure turbine.

Tandem compound Turbines:

Tandem compound turbine is large turbines consisting of two or more turbines in series coupled tighter at one shaft and applied to one generator.