1、 How it works

Vacuum pressure swing adsorption (VPSA) air separation is to use high-quality zeolite molecular sieve to adsorb nitrogen. The UN adsorbed oxygen is gathered on the top of the tower and transported to the oxygen storage tank as product gas. When the adsorption tower in the adsorption state is near saturation, the tower automatically desorbs and regenerates under reduced pressure, while the other adsorption tower starts to absorb under pressure to produce oxygen. The two adsorption towers work alternately to complete the process of oxygen production. During desorption and regeneration of adsorption tower, negative pressure is used, which is called VPSA oxygen production.

2、 Equipment technology

The adsorption bed of PSA air separation plant must include two steps: adsorption and desorption. In order to obtain the product gas continuously, more than two adsorption beds are usually installed in the hydrogen production unit, and some necessary auxiliary steps are set up from the perspective of energy consumption and stability. Generally, each adsorption bed has to go through the steps of adsorption, pressure relief, evacuation or decompression regeneration, flushing and pressure equalizing and boosting, and the operation is repeated periodically. At the same time, each adsorption bed is in different operation steps. Under the control of PLC, the adsorption beds can operate in coordination, and the time steps are staggered, so that the PSA device can run smoothly and continuously obtain product gas. For the actual separation process, other trace components in the air must also be considered. The adsorption capacity of carbon dioxide and water on the common adsorbent is generally much greater than that of nitrogen and oxygen, so it can be removed by adding suitable adsorbent (or using oxygen generating adsorbent itself) in the adsorption bed.

3、 Technical features

It has the advantages of small civil engineering quantity, shorter installation cycle than deep cooling unit, less investment, lower power consumption and energy consumption for oxygen generation, lower operation and maintenance costs, higher automation, convenient start-up and shutdown, fewer operators, strong operation stability, high safety, simple operation, and main components selected from international well-known manufacturers, original imported molecular sieve for oxygen production, Excellent performance and long service life.

4、 Technical index

Oxygen production: 100 ~ 10000nm3 / h oxygen purity: 30 ~ 95.0% (adjustable) oxygen pressure: 0.015 ~ 0.05Mpa (supercharged) power consumption: 0.32 ~ 0.37kwh/nm3 (equivalent to pure oxygen power consumption when purity is 90%)

4、 Comparison of oxygen production by VPSA and cryogenic air separation