Working principle: The main application of pressure swing adsorption principle for oxygen and nitrogen separation. Carbon molecular sieve is a speed separation type of adsorbent, when the adsorption properties are not different, the smaller diameter of the gas molecules diffusion speed is faster, more into the molecular sieve solid phase, while the larger diameter of the gas molecules diffusion speed is slower, less into the molecular sieve solid phase, according to the microporous structure characteristics of carbon molecular sieve, when the air enters the carbon molecular sieve, Oxygen (2.8A), whose molecular diameter is slightly smaller than nitrogen (3A), diffused into the pore of carbon molecular sieve at a faster rate and was preferentially selected for adsorption. In the initial short time of adsorption, oxygen was rapidly enriched inside the carbon molecular sieve particles, while nitrogen was enriched in the gas phase before it could be adsorbed. The required nitrogen was collected in the storage tank. The carbon molecular sieve has the characteristics of increasing the adsorption amount of oxygen under pressure and decreasing the adsorption amount of oxygen under pressure. Therefore, PSA uses two adsorption towers A and B to cycle in turn, and the process is automatically controlled by a PLC programmable controller.