What is a Supersonic ejector?

Supersonic ejectors are simple mechanical components, which generally perform mixing and recompression of two fluid streams. Ejectors have found many applications in engineering. In aerospace engineering, they are used for high altitude testing (HAT) of a propulsion system by reducing the pressure of a test chamber.

What is the principle of ejector?

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.

How does a steam ejector works?

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.

What is the efficiency of an ejector?

(2012) analyzed the efficiencies of an air-air and a steam-steam ejector and found that the properties of working fluid affect the ejector efficiencies significantly; within the compression ratio from 1 to 1.5, the exergetic efficiency of steam-steam ejector varies from 5% to 40%, while the exergetic efficiency of air- …

How many types of ejectors are there?

Ejectors are generally categorized into one of four basic types: single-stage, multi-stage non-condensing, multi-stage condensing and multi-stage with both condensing and non-condensing stages. Single-stage ejectors are the simplest and most commonly used construction.

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 the function of ejector in power plant?

The main function of the ejector is to maintain the vacuum value in the condensation system of the turbine. According to this, main indicators of the efficiency, which influence the vacuum value in the condenser (pressure of the I stage and the length of the performance curve) are also connected with the reliability.

What is nozzle efficiency in ejector refrigeration cycle?

The efficiencies of the controllable ejector motive nozzle, suction nozzle and mixing section range from 0.50 to 0.93, from 0.37 to 0.90, and 0.50 to 1.00, respectively, in CO2 refrigeration cycles under different operating conditions.

Where in the ejector profile the velocity of steam is maximum?

Venturi throat
Potential energy is converted to kinetic energy; thus, velocity increases and pressure decreases. The mixture reaches its maximum velocity and lowest pressure at the Venturi throat (Fig. 2).

Is are the part’s of 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.

How does a vacuum ejector work?

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.

What is supersonic airjectors 3?

SUPERSONIC AIR EJECTORS 3 A high pressure primary flow (stagnation pressure fi%`, stagnation temperature T*’) supplied to the primary nozzle. The supersonic primary is flow leaves the primary nozzle and enters the mixing tube of larger cross section, on the axis of which this nozzle is placed.

What is supersonic primary and induced secondary flow?

The supersonic primary is flow leaves the primary nozzle and enters the mixing tube of larger cross section, on the axis of which this nozzle is placed. The induced secondary flow (stagnation pressure fi,”, stagnation temperature T,”) comes tangentially into contact with the primary flow, throughout the length of the mixing tube.

How does an air ejector differ from an industrial ejector?

Actually such an ejector differs from the industrial set-ups only in minor points. SUPERSONIC AIR EJECTORS 3 A high pressure primary flow (stagnation pressure fi%`, stagnation temperature T*’) supplied to the primary nozzle.