What are the types of air compressors used in air separation?

In the air separation (air separation) system, the air compressor is one of the core equipment, which is used to compress the air to the required high pressure for subsequent cooling, purification and separation processes. There are various types of air compressors used in air separation. According to the different working principles, structural characteristics and application requirements, they can be divided into the following main types:

1. Centrifugal air compressor

• working principle: The gas is accelerated by a high-speed rotating impeller (the blades are usually on the side), and then the speed of the gas is converted into pressure on the diffuser or reflux baffle.
• Features: Large flow, high pressure, high efficiency, suitable for large air separation devices.
• Application: In the air separation system, the centrifugal air compressor is usually used to provide high flow and high pressure compressed air.

2. Axial flow air compressor

• working principle: The air is compressed by a high-speed rotating axial flow impeller, and the main air flow is axial.
• Features: Large flow, high efficiency, compact structure, suitable for occasions that require a lot of air.
• Application: In the air separation system, the axial flow air compressor can be used in combination with the centrifugal air compressor to improve the overall performance and efficiency of the system.

3. Screw air compressor

• working principle: Through the meshing of two rotors with spiral gears, the volume of the meshing place of the two rotors is reduced from large to small, thereby compressing and discharging the gas.
• Features: Compact structure, small footprint, high efficiency, high reliability, low maintenance cost and long service life.
• Application screw air compressors are also used in air separation systems, especially where medium pressure and flow are required.

4. Reciprocating air compressor

• working principle: Compress air by reciprocating the piston in the cylinder.
• Features: Simple structure, convenient operation, long service life, but large vibration and noise.
• Application: In the air separation system, reciprocating air compressors are usually used to provide compressed air with lower pressure and flow.

5. Sliding air compressor

• working principle: Compress air by sliding the sliding vane radially on the eccentric rotor of the same cylindrical cylinder.
• Features: Compact structure, stable operation and low noise.
• Application: Sliding vane air compressor is also used in some specific air separation systems.

6. Centrifugal axial flow combined air compressor

• working principle: Combining the characteristics of centrifugal and axial air compressors, multi-stage compression and inter-stage cooling are used to improve compression efficiency and reduce energy consumption.
• Features: Large flow, high pressure, high efficiency, suitable for large air separation devices.
• Application: In the air separation system that needs to handle a large amount of air, the centrifugal axial flow combined air compressor is an ideal choice.

In addition, there are some special types of air compressors, such as liquid-piston air compressors, Roots double-rotor air compressors, etc., which are also used in some specific air separation systems.

In general, there are various types of air compressors used in air separation, and the choice of which type of air compressor depends on the specific needs of the system, working conditions, and economy. In practical applications, the appropriate air compressor type is usually selected according to the scale and performance requirements of the air separation system.