Power Industry

Steam Jet Ejectors

Jet ejectors are the most versatile of all industrial apparatus. They are used in numerous applications to pump, mix, heat, cool and produce vacuum.

Generation of more Megawatts a dream ?


MAZDA build more turbine extraction systems for power plants than anyone else in the country.

In the power production business, power plants are finding value in hidden capacity-additional megawatts of uprating or kilowatt-hours of production that can be squeezed from an existing unit. A local utility plant recently gained stealth capacity by replacing an old vacuum system with MAZDA Vacuum Evactor.

The plant had been derated by approximately 10 MW because of poor air removal from its steam-turbine condenser. Mazda studied the problem and concluded that condenser Vacuum could be improved by at least 15mm Hg using its model no. CR Series 200S.

When CR series was installed and started up, it improved condenser vacuum drastically than the original test condition. The power plant thereby picked up, 5 MW of hidden capacity and the cost of CR Series 200S was recovered in less than a month and the savings will go on as long as the plant remains in services.

Our SJAE Systems supplied for large power plants include the following :

2 x 250 MW Neyvelli Ignite Corporation
1 x 228 MW Jegurupadu
1 x 150 MW Tata Electricity , Trombay
1 x 110 MW TNEB, Ennore
2 x 75 MW Hindalco Industries, Renusagar
1 x 50 MW L & T Cement, Kovaya Amreli

In addition, our SJAE Systems from India are regularly exported to Alstom Brazil, Fluidel Italy, Nuovo Pignone Italy etc.

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 recommended design pressure of the Steam Air Ejector (SJAE) System is as follows:

(1) For electric generation service : The design pressure is 0.035 ata (25.4 mm Hg(a)) or the condenser design pressure whichever is lower.
(2) For pumps, compressors and other : mechanical drives The design pressure is that for which the condenser is designed minus 0.035 ata (25.4 mm Hg(a)).

Usually, the SJAE System is of Twin Element type i.e. of duplex design having two identical Ejectors per stage , one of which, being in operation at any one time and the other as stand-by. The Inter and After condensers are generally Single Element type.

The System also includes a Hogger / Start-up Ejector was Silencer for fast pre evacuation and which is in operation only till the desired vacuum has been achieved. Thereafter, the two stage holding ejectors take over.

In this field of application, combination units with Ejector and Surface Condenser coupled Liquid Ring Vacuum Pump are also becoming popular.

Mazda guarantees that when the system is operating , it will meet all capacity , steam consumption and power limit specifications according to Heat Exchanger Institute Standards and ASME PTC 24.