What is ejector working principle?
An ejector is based upon Bernoulli’s Principle which states: ‘When the speed of a fluid increases its pressure decreases and vice versa’. The ejector uses a converging nozzle to increase the fluid velocity to transform high static pressure into velocity pressure.
What is ejector function?
The purpose of the ejector is to transport and compress a weight of induced fluid from the suction pressure to the exit pressure. By staging ejectors it is possible to obtain a very large range of suction pressures from atmospheric down to as low as one micron of mercury absolute.
What are the main part of an ejector?
Ejector has no moving part and uses the potential of a high pressure flow to suck and compress a low pressure flow. Figure 1 presents the main parts of an ejector including primary nozzle, secondary inlet, suction and mixing chambers, secondary throat, and exit diffuser.
Why steam is used in ejector?
Steam ejectors use steam or gas instead of moving parts to compress a gas. In a jet or ejector, a relatively high-pressure gas, like steam or air, expands through a nozzle. The steam or air converts that pressure or potential energy to velocity or kinetic energy.
Is ejector a compressor?
An ejector refrigeration system can be considered as a modification of a conventional vapor compression cycle (VCC). An ejector takes the place of a compressor to pressurize the refrigerant vapor flowing from an evaporator and discharge it to a condenser.
What is ejector capacity?
The higher the molecular weight of a fluid, the greater the ejector suction capacity, assuming equal motivating quantities. Conversely, an ejector will handle less of lower molecular weight fluids. For example, a steam ejector will handle approximately 23% more free dry air than it will saturated vapor.
Why ejector is used?
The ejector is widely used as a vacuum pump where it is staged when required to achieve deeper vacuum levels. If the motive fluid pressure is sufficiently high, the ejector can compress gas to a slightly positive pressure. Ejectors are used both as subsonic and supersonic devices.
What is water ejector?
Water ejectors are vacuum pumps, driven by a high pressure water (or similar medium) or steam. They use kinetic energy of the driving medium to suck in gases, vapors or other liquids and then discharge the resultant mixture against a counter pressure.
How does ejector create vacuum?
In an ejector, a working fluid (liquid or gaseous) flows through a jet nozzle into a tube that first narrows and then expands in cross-sectional area. The fluid leaving the jet is flowing at a high velocity which due to Bernoulli’s principle results in it having low pressure, thus generating a vacuum.
What is motive fluid in ejector?
Very simply, an ejector is a pumping device. It has no moving parts. Instead, it uses a fluid or gas as a motive force. Very often, the motive fluid is steam and the device is called a “steam jet ejector.” Basic ejector components are the steam chest, nozzle, suction, throat, diffuser and they discharge (Fig.