Air Seperation Unit(ASU)

Air separation unit is a kind of equipment that takes air as a raw material, turns it into a liquid state by compressing and cooling it to cryogenic temperatures, and then gradually separates oxygen, nitrogen, argon or other liquid products from the liquid air by rectification. According to users' needs, the products of air separation units can be single or multiple products at the same time, which can be gas or liquid.

The specific process (external compression) is: the compressed air from the air compressor, after removing impurities such as moisture, carbon dioxide, hydrocarbons and other impurities through the molecular sieve, is directly sent to the upper distillation column, and the other part enters the expander. After expansion, the cryogenic air is sent to the lower column. By rectification, nitrogen can be obtained at the top of the upper column and oxygen at the bottom of the upper column. The separated oxygen, nitrogen and exhaust gases are reheated by the main heat exchanger and then discharged from the cold box. The oxygen or nitrogen products coming out of the cold box are compressed by the compressors to the specified pressure and sent to the user.