Why do air...

Two stages of the compressor are suitable for high pressure and one stage is suitable for large gas production. Sometimes, you need more than two compressions, so why do you need hierarchical compression?

When the working pressure of gas is high, the use of single stage compression is not only uneconomical, sometimes even impossible to achieve, must be used multiple stage compression. Multi - stage compression is the gas from the suction, through several times of pressure to achieve the required working pressure.

Open sealing control sub-equipment

Save power consumption

By means of multi-stage compression, an intercooler can be set between stages to cool the compressed gas at the same pressure after the first stage compression, so as to reduce the temperature, and then enter the next stage cylinder. The lower the temperature and the higher the density, the easier it is to compress further, which can greatly save the energy consumption compared with a single compression. Therefore, the area of work done by the multistage compression under the same pressure is less than that of the single-stage compression. The more series you have, the more power you save, the closer you get to isothermal compression.

Note: the air compressor of the oil injection screw air compressor is very close to the constant temperature process. If the state of saturation continues to compress and continue to cool, there will be condensed water out. If these condensate water and compressed air enter the oil and gas separator (oil tank) together, it will emulsify the cooling oil and affect the lubrication effect. With the continuous increase of condensed water, the oil level will also continue to rise. Finally, the cooling oil will enter the system along with the compressed air, polluting the compressed air and causing serious consequences to the system.

Therefore, in order to prevent the generation of condensed water, the temperature in the compression chamber must not be too low, must be greater than the condensation temperature. For an air compressor with exhaust pressure of 11bar (A), the condensing temperature is 68℃. When the temperature in the compression chamber is lower than 68℃, condensed water will be precipitated out. Therefore, the exhaust temperature of the oil injection screw air compressor cannot be too low, that is, the application of isothermal compression in the oil injection screw compressor due to the condensation of water is limited.

Improve capacity utilization

Due to three reasons, manufacture, installation and operation in cylinder clearance volume is always inevitable, and clearance volume directly not only reduced the effective volume of the cylinder, and that the residual of high pressure gas must also swelled to inspiratory pressure, cylinder can begin breathing in fresh air, this is to further reduce the effective volume of the cylinder.

It is not difficult to understand that if the pressure ratio is greater, the residual gas in the clearance volume will expand more rapidly and the effective volume of the cylinder will be smaller. In the limit case, even if the gas in the clearance volume is fully expanded in the cylinder, the pressure is still not lower than the inspiratory pressure, then the suction and exhaust cannot continue, and the effective volume of the cylinder becomes zero. If multi-stage compression is adopted, the compression ratio of each stage is small, and the residual gas in the clearance volume can reach the inspiratory pressure after a slight expansion. In this way, the effective volume of the cylinder can be increased naturally, so as to improve the utilization rate of the cylinder volume.