Argon is a rare gas widely used in various fields of industry. It is used as protective gas for arc welding of stainless steel, aluminum and other metals, as well as gas for blowing and smelting steel, aluminum, titanium, zirconium and other metals. Argon is used for lighting technology and filling of fluorescent lamps. Industrial electronic products also use argon as protective gas. The content of argon in the air is 0.932%. In the air separation unit, 30% - 50% of argon in the processing air can be obtained as a product. With the improvement of argon production technology and the improvement of advanced air separation process and operation method, the extraction rate of argon has been increased to more than 80%.
In the air separation equipment, the factors that affect the argon extraction rate are: Main column working condition, argon fraction control system, crude argon column working condition, etc.
The working condition stability of the main column is the precondition of the stability of the argon column, and the stability of the argon fraction is the basis of the operation stability of the crude argon column. All of the above conditions are indispensable. The main reasons that affect the working condition of the main column are the amplitude and frequency of the load change of the air separation plant, the change of the air quantity into the column caused by the switching process of the molecular sieve purifier. In the daily operation, the specified variable load can be adopted to ensure the stability of the working condition of the main column. Through the improvement of the argon fraction control system, on the basis of ensuring the stability of the argon fraction, the control value can be reduced appropriately to reduce the fluctuation range of argon fraction. During the operation, the discharge valve on the top of the crude argon column can be opened 3% - 5% frequently, and the discharge of the crude argon gas can be increased on the basis of stable working conditions, so as to ensure that no nitrogen plug occurs in the crude argon column.
Through the above methods, air separation plant can improve nitrogen extraction rate effectively, and considerable economic benefits would be achieved for the enterprises.
