What is the difference between PSA oxygen production and VPSA oxygen production?

What is the difference between PSA oxygen production and VPSA oxygen production? VPSA oxygen production equipment ①: Equipment introduction and working principle VPSA (Vacuum Pressure Swing Adsorption) oxygen production device, Chinese called low pressure adsorption vacuum desorption oxygen production equipment. Under low pressure conditions, the nitrogen and oxygen in the air are sucked in. After the adsorption is saturated, the molecular sieve is desorbed under vacuum conditions, and the nitrogen is discharged from the discharge port. The oxygen enters the purification system. The molecular sieve is continuously adsorbed and decompressed to circulate to produce higher purity oxygen ( 90-95%). ③: Equipment composition and technical indicators VPSA oxygen production equipment is mainly composed of blower, vacuum pump, cooler, adsorption system, oxygen buffer tank, and control system. The technical indicators are as follows: ◆Product scale: 100-10000Nm3/h ◆Oxygen purity: ≥90-94%, can be adjusted in the range of 30-95% according to user requirements. ◆Oxygen power consumption: when the oxygen purity is 90%, the power consumption converted to pure oxygen is 0.32-0.37KWh/ Nm3 ◆Oxygen pressure: ≤20kpa (can be pressurized) ◆Annual opening power: ≥95% PSA oxygen production equipment ①: Equipment introduction and working principle PSA (Pressure Swing Absorption) oxygen generation device, the Chinese name is pressure swing adsorption oxygen generation. The principle is to separate the gas mixture by using the difference in the “adsorption” performance of molecular sieves to different gas molecules. It uses air as raw material, and uses a high-efficiency, high-selectivity solid adsorbent to selectively adsorb nitrogen and oxygen to separate nitrogen and oxygen in the air. Under normal temperature and pressure conditions, the PSA special molecular sieve is used to selectively adsorb impurities such as nitrogen, carbon dioxide and water in the air to obtain oxygen with higher purity. ③: Equipment composition and technical indicators PSA oxygen production equipment is mainly composed of air compressor, refrigeration dryer, deoiler, adsorption system, oxygen buffer tank, and control system. The technical indicators are as follows↓↓ Purity: 93%+2% (93% for standard type) Pressure: ≥0.2Mpa Dew point: <-40℃ (normal pressure) Output: 3~200Nm3/h