Principle:
After passing through an air filter to remove dust and mechanical impurities, the air enters the air compressor and is compressed to the required pressure. After strict oil, water, and dust removal purification treatment, clean compressed air is output to ensure the service life of the molecular sieve in the adsorption tower. There are two adsorption towers equipped with carbon molecular sieves. When one tower is working, the other tower is depressurized for desorption. Clean air enters the working adsorption tower, and oxygen, carbon dioxide, and water are adsorbed by molecular sieves. The gas flowing to the outlet end is nitrogen and trace amounts of argon and oxygen. The other tower (desorption tower) separates the adsorbed oxygen, carbon dioxide, and water from the micropores of the molecular sieve and releases them into the atmosphere. In this way, the two towers take turns to complete nitrogen oxygen separation and continuously output nitrogen gas.
The purity of nitrogen produced by pressure swing adsorption is 95% -99.9995%. If higher purity nitrogen (above 99.99%) is needed, it can also be achieved by installing a nitrogen purification device behind the nitrogen production equipment. 95% -99.9% of the nitrogen output from the pressure swing adsorption nitrogen generator enters the nitrogen purification device, and at the same time, an appropriate amount of hydrogen/carbon is added through a flow meter. In the deoxygenation tower of the purification device, hydrogen/carbon [2] and trace oxygen in nitrogen undergo catalytic reaction to remove oxygen. Then, it is cooled by a water condenser, dehydrated by a steam water separator, and deeply dried by a dryer (two adsorption drying towers are alternately used: one for adsorption drying and dehydration, and the other for heating and desorption drainage), obtaining high-purity nitrogen gas with a purity of up to 99.9995%. The high-purity nitrogen obtained by installing a nitrogen purification device will contain trace amounts of hydrogen and ammonia (or trace amounts of carbon dioxide when adding carbon). When selecting a nitrogen purification device, it is necessary to choose according to actual usage requirements. At present, the maximum production capacity of nitrogen by pressure swing adsorption in China is 3000m3n/h.
