Air separation unit is a kind of equipment which takes air as raw material, turns air into liquid by compression cycle deep freezing method, and then gradually separates and produces inert gases such as oxygen, nitrogen and argon from liquid air by Bai over distillation.
At present, there are many forms and types of air separation equipment produced in China. There are devices for producing gaseous oxygen and nitrogen as well as liquid oxygen and nitrogen. However, there are four basic processes: high pressure, medium pressure, high and low pressure and full low pressure. The production scale of air separation plant in China has developed from the early production of only 20m3 / h oxygen generator to the production capacity of 20000 m3 / h, 30000 m3 / h and 50000 m3 / h (oxygen).
Basic system of air separation plant:
The air separation plant can be divided into five basic systems in terms of process flow
1.impurity purification system: mainly through air filter and Molecular Sieve Absorber and other devices, purify the air mixed with mechanical impurities, moisture, carbon dioxide, acetylene, etc.
2. Air cooling and liquefaction system: it is mainly composed of air compressor, heat exchanger, expander and air throttle valve, which plays a role in deep freezing of air.
3. Air distillation system: the main components are distillation tower (upper tower and lower tower), condensing evaporator, subcooler, liquid air and liquid nitrogen throttle valve. It can separate various components in the air
4.heating and blowing system: regenerate the purification system by heating and purging.
5.Instrument control system: control the whole process through various instruments
Post time: Nov-18-2020