Vane Compressor – Working, Advantages, Disadvantages, and Applications
Vane Compressor is also known as Rotary Vane Compressor or Sliding Vane compressor.
Vane Compressor was invented by Charles C. Barnes of Canada. He patented it on 16 June 1874.
Vane Compressor are one of the most widely used products in today’s world. They serve a wide range of industries.
Vane Compressor used centrifugal motion to generate compressed air.
Vane compressors are generally used for capacities up to 150 metre cube/min and for pressure ratio up to 8:5. Vane compressors are very popular in automotive and hydraulic applications.
Construction:
Vane Compressor consists of a cylindrical rotor eccentrically placed in the casing.
This casing has intake and delivery openings which are also known as inlet and outlet port. The inlet port of the casing is bigger as compared to the outlet port of the casing. Rotor has a drum in its center.
This drum rotates eccentrically with respect to the casing. This rotor has several radial slots in it. Each radial slot has a vane fitted in it which is spring loaded. These vanes are made of steel or synthetic fibrous material. If the compressor is oil-lubricated, there will be a thin layer of oil in between the vane and housing.
The spaces between adjacent vanes form pockets of decreasing volume from a fixed inlet port to a fixed discharge port.
Larger the number of vanes smaller the leakage of air due to small pressure difference prevailing between the adjacent spaces around the rotor.
High pressure ratio requires large number of vanes ( 20 – 30 ). For a given pressure ratio, cane compressor requires less work input than that for roots blower.
Working:-
When the rotor rotates, vanes of the rotor move outward toward the casing due to centrifugal force experienced by them, until they touch the casing.
The rotor of the vane compressor rotates in the anti-clockwise direction.
When the vanes reaches the position where the distance between the rotor drum and casing is less the spring in the vanes compresses to maintain contact with the casing. As the spring compresses the space between the two adjacent vanes also decreases.
Similarly, when the vanes reach the position where the distance between the rotor drum and casing is more the spring in the vanes expands to maintain contact with the casing. As the spring expands the space between the two adjacent vanes also increases.
When the vanes move downward the space between two adjacent vanes increases also space between rotor drum and casing increases which create vacuum. Thus the gas is drawn in from the suction opening
Near the inlet of the vane compressor, the space between two adjacent vanes increases due to increased distance between rotor drum and casing. As the space increases between two adjacent vanes, vacuum is created near the inlet of vane compressor. Due to the vacuum, the suction starts and the gas is drawn in from the inlet of the compressor.
After that, as the rotor continues to rotate the compression of the entrapped gas starts due to a decrease in the space between adjacent vanes. As the space between vanes decreases, the volume of the gas decreases and the gas gets compressed. After that, the high pressure gas which is compressed gets discharged from the outlet of the vane compressor.
Nearly half of the rise of pressure of the gas is developed during the compression which is reversible compression. The remaining pressure rise occurs when the compressed gas is released from the outlet of the compressor.
Advantages of Vane Compressor:
1) It creates a good vacuum for suction.
2) Vane Compressor works well for continuous air supplied.
3) High pressure and high power compression are possible with vane compressor.
4) Vane compressors have a longer life expectancy.
5) They are ideally suited for moderate pressure using applications.
Disadvantages of Vane Compressor:
1) The vibration happens during the reciprocation of the cylinder.
2) Because of more number of moving parts maintenance cost is high.
Applications of Vane Compressor:
Vane Compressor has many applications. They serve a wide range of industries. Some of the applications of the vane compressor are:-
1) They are used in agriculture for operating farm equipment, material conveying, etc.
2) Used in the auto body paint shop for paint pump operation.
3) Used in tire and wheel shop for tire inflation.
4) Used in Dry Cleaning.
5) Used in the operation of air knives for cutting and peeling.
6) It is used in welding operations and air-operated metal and woodworking tools.
