The molecular sieve purification system of air separation equipment is the core link to ensure the safe operation of the air separation unit. Its principle is based on the physical adsorption characteristics and regeneration cycle mechanism of molecular sieves.
The system achieves continuous air purification by alternating the operation of two adsorbers: during the adsorption stage, saturated air containing moisture flows through the molecular sieve bed from bottom to top. The molecular sieve, with its uniform pore size, preferentially adsorbs water, carbon dioxide, acetylene and other hydrocarbons. At the same time, the active aluminum oxide layer deeply adsorbs water to ensure that the dew point of the outlet air is below -60 ℃ and the carbon dioxide content is below 1ppm; In the regeneration stage, after the adsorption saturated molecular sieve is depressurized, heated contaminated nitrogen gas is introduced to desorb impurities, and then cold nitrogen gas is used to blow and cool down to the adsorption temperature to restore the adsorption capacity.
The function of this system is crucial: firstly, to prevent impurity hazards - if not purified, water and carbon dioxide will freeze in low-temperature equipment, blocking heat exchangers and distillation towers, and acetylene accumulation is more likely to cause liquid oxygen explosions; Secondly, improving separation efficiency - highly purified air can reduce energy consumption in cryogenic distillation, ensuring stable and compliant purity of oxygen and nitrogen products; Thirdly, extend the lifespan of the equipment - by adsorbing corrosive gases such as nitrous oxide, reduce the risk of corrosion on the inner walls of the equipment.
