The efficiency of a Steam-turbine is mainly determined by the pressure of the steam at its outlet. The Turbine Surface Condenser is therefore maintained under vacuum. To enable this, the Steam Jet Ejector Vacuum System must be capable of removing all non condensable and associated water vapour from the Surface Condenser to produce the minimum steam condensing pressure consistent with physical dimensions and heat transfer and to provide for deaeration of the condensate.
The sources of non condensables include air leakage through all system components operating below atmospheric pressure, gases released from feedwater drains and vents admitted to the condenser, gases released for make-up admitted to the condenser, condensate surge tank when utilized in a closed cycle and disassociation of feedwater into oxygen, hydrogen and non condensables.

The efficiency of a Steam-turbine is mainly determined by the pressure of the steam at its outlet. The Turbine Surface Condenser is therefore maintained under vacuum. To enable this, the Steam Jet Ejector Vacuum System must be capable of removing all non condensable and associated water vapour from the Surface Condenser to produce the minimum steam condensing pressure consistent with physical dimensions and heat transfer and to provide for deaeration of the condensate.
The sources of non condensables include air leakage through all system components operating below atmospheric pressure, gases released from feedwater drains and vents admitted to the condenser, gases released for make-up admitted to the condenser, condensate surge tank when utilized in a closed cycle and disassociation of feedwater into oxygen, hydrogen and non condensables.