3. Workikng Principle The clean, dried compressed air enters the variable-pressure adsorption nitrogen generator, and the oxygen molecule in the compressed air will be absorbed by a carbon molecular sieve, to obtain the nitrogen in a purity of over 99.999%. The absorption capacity of the carbon molecule sieve for nitrogen and oxygen differs under different pressure. One variable-pressure adsorption nitrogen generator is equipped with two adsorption towers, one begins the adsorption while the other reaches balance and begins regeneration. The two adsorption towers alternatively work to create the continuous nitrogen flow. The switchover of the two adsorption towers is automatically completed with the solenoid and pneumatic valves controlled by PLC. Therefore, the performance of the pressure swing adsorption nitrogen generator depends on the quality of some key components, including the adsorption structure, carbon molecule sieve, electromagnetic pneumatic valve, etc. For our products, we adopt famous brand for the key parts such as PLC, solenoid valves and pneumatic valves.