Strictly speaking, VPSA (low pressure adsorption vacuum desorption) oxygen production is another "variant" of PSA oxygen production. Their oxygen production principles are almost the same, and they all use molecular sieves to "adsorb" different gas molecules to separate gas mixtures, but the PSA oxygen generator separates oxygen through pressure adsorption and atmospheric pressure desorption, while the VPSA oxygen generator desorbs the saturated molecular sieve under vacuum conditions.

Although both use air as raw material, the principle of oxygen production is similar. However, there are still the following differences in comparison:

1. The VPSA oxygen generator uses a blower to obtain raw air and pressurizes it, while the PSA oxygen generator uses an air compressor to supply air.

2. In the selection of the core component - zeolite molecular sieve, the PSA oxygen generator uses zeolite molecular sieve, and the VPSA oxygen generator uses lithium molecular sieve.

3. The adsorption pressure of PSA oxygen generator is usually 0.6~0.8Mpa, and the adsorption pressure of VPSA oxygen generator is 0.05Mpa.

4. The gas output of PSA single machine can reach 200~300Nm³/h, and the gas output of VPSA single machine can reach 7500~9000Nm³/h.

5. Compared with PSA, VPSA has low energy consumption (power consumption per cubic meter of oxygen production is less than or equal to 0.5 kW), which is more environmentally friendly and green.

Although the VPSA oxygen generator has a large amount of oxygen in a single mechanism, its disadvantage is that the system equipment is relatively complex, the equipment volume is also larger (it is smaller than the cryogenic device), and there are many requirements for supporting public works, which will occupy a large amount of space, and can not be made into a container type. It needs on-site installation and debugging, just from this point. PSA still has certain advantages.