Briefly describe the working principle of PSA nitrogen generator?

Using compressed air as raw material, it uses an adsorbent called carbon molecular sieve to selectively adsorb nitrogen and oxygen to separate the nitrogen in the air. The separation effect of carbon molecular sieve on nitrogen and oxygen is mainly based on the different diffusion rates of nitrogen and oxygen molecules on the surface of the molecular sieve. Oxygen molecules with a smaller diameter diffuse faster and more enter the solid phase of the molecular sieve; nitrogen molecules with a larger diameter diffuse more Slowly and less enter the solid phase of the molecular sieve, so that nitrogen is enriched in the gas phase.

After a period of time, the molecular sieve can absorb oxygen to a certain level. Through decompression, the gas adsorbed by the carbon molecular sieve is released, and the molecular sieve is also regenerated. This is based on the characteristic that molecular sieves have different adsorption capacities for adsorbed gas under different pressures. Pressure swing adsorption nitrogen production equipment usually uses two parallel adsorbers, alternately performing pressure adsorption and decompression regeneration, and the operation cycle period is about 2 minutes.