Molecular sieves are cubic aluminosilicates. Molecular sieves have uniform microporous structure and uniform pore diameter. These pores can adsorb molecules smaller than their diameter into the pores and have preferential adsorption capacity for polar molecules and unsaturated molecules. 

Therefore, they can separate molecules with different polarity, saturation, molecular size and boiling point, that is, they have the function of "screening" molecules, so they are called molecular sieves. Molecular sieves are widely used because of their high adsorption capacity and thermal stability.The function of Molecular Sieve Purifier in small or large air separation plant is to purify air. Molecular sieves can adsorb water, carbon dioxide, acetylene and various hydrocarbons in the air.

The air separation process is mainly divided according to the different air purification methods. From the aluminum belt cooler freezing high and low pressure air separation process, stone cooler freezing full low pressure air separation process, heat exchanger freezing full low pressure air separation process, now basically are normal temperature molecular sieve purification full low pressure air separation process, normal temperature molecular sieve purification pressurization expansion air separation process, normal temperature molecular sieve purification filling The process of producing argon by full distillation on the feed type column.

In other words, the former molecular sieve was replaced by the relevant equipment above.