Chemical Engineering - Heat Transfer - Discussion

An injector, ejector, steam ejector, steam injector, eductor-jet pump or thermocompressor is a type of pump that uses the Venturi effect of a converging-diverging nozzle to convert the pressure energy of a motive fluid to velocity energy which creates a low pressure zone that draws in and entrains a suction fluid. After passing through the throat of the injector, the mixed fluid expands and the velocity is reduced which results in recompressing the mixed fluids by converting velocity energy back into pressure energy. The motive fluid may be a liquid, steam or any other gas. The entrained suction fluid may be a gas, a liquid, a slurry, or a dust-laden gas stream.

Steam ejectors are frequently used in condensing steam turbine systems for creation of vacuum in vacuum condensers thus improving turbine and system performance.

In condensing system, steam ejector has function to extract air and other non-condensing gases from the sealed condenser, and in such way to maintain vacuum which corresponds to ratio of cooling water quantity, cooling water temperature and cooling surface.

Steam ejector is a type of thermo compressor that presses the low pressure steam and convert that low pressure steam into high pressure steam according to the principle of energy conservation.

Many industrial units often vent significant amount of low pressure steam to atmosphere but they with the help of thermo compressors we can use again this low pressure steam and, resulting in energy and fuel saving.

It works on Venturi effect. The same principle used in flying of aeroplane.

Correct answer is create vacuum.

Steam injector creates vacuum.

It's create vacuum.