VPSAO vacuum pressure swing adsorption oxygen production equipment
Working principle
The main components in the air are nitrogen and oxygen, using the ambient temperature, nitrogen and oxygen in the air in zeolite molecular sieve (ZMS) adsorption performance is different (oxygen can pass and nitrogen adsorption), design the appropriate process, and make nitrogen and oxygen separation to get oxygen.Nitrogen on zeolite molecular sieve adsorption ability is better than oxygen (nitrogen ion and molecular sieve surface force strong), when the air pressure in a state with a zeolite molecular sieve adsorbent adsorption bed, nitrogen by molecular sieve adsorption, less oxygen by adsorption, concentration and flow in gas phase adsorption bed, the oxygen and nitrogen separation for oxygen.When the molecular sieve adsorption nitrogen to saturated, stop air and reduce the pressure of the adsorption bed, molecular sieve adsorption nitrogen change resolved, molecular sieve regeneration and can be reused.When two or more adsorption beds switch work in turn, oxygen can be continuously produced.
Oxygen and nitrogen have similar boiling points, which make them difficult to separate, and are enriched together in the atmosphere.Therefore, psa oxygen production equipment can usually only obtain 90-95% oxygen (extreme negative concentration of oxygen is 95.6%, the rest is argon), also known as oxygen rich.Compared with cryogenic air separation units, the latter can produce more than 99.5% oxygen concentration.
Device process
The adsorption bed of psa air separation oxygen plant must consist of two operation steps.Adsorption and resolution.In order to continuously obtain product gas, usually more than two adsorption beds are installed in the oxygen production device, and from the perspective of energy consumption and stability, some necessary auxiliary steps are set up.Each adsorption bed generally has to undergo adsorption, pressure release, evacuation or decompression regeneration, flushing replacement and pressure equalization boost steps, periodic repeated operation.At the same time, each adsorption bed is respectively in different operation steps, under the control of PLC timing switch, so that several adsorption bed coordinated operation, in practice is staggered each other, so that the pressure swing adsorption device can run smoothly, continuous access to product gas.Other trace components in the air must also be considered for the actual separation process.Carbon dioxide and water in the usual adsorbent adsorption capacity is generally much larger than nitrogen and oxygen, can be filled in the adsorption bed with appropriate adsorbent (or use of oxygen adsorbent itself) to make it adsorption and removal.
The number of adsorption towers required by oxygen production device depends on the scale of oxygen production, adsorbent performance and process design ideas. The operation stability of multi-tower operation is relatively better, but the equipment investment is higher.The current trend is to use high-efficiency oxygen sorbents to minimize the number of adsorption towers and to use short operating cycles to increase plant efficiency and minimize investment.
Technical characteristics
1. Simple process flow of the device
2. oxygen production scale below 10000m3/h, oxygen production power consumption is lower, less investment;
3 the amount of civil engineering is small, the installation cycle of the device is shorter than the cryogenic device;
4. Low cost of device operation and maintenance;
5. high degree of automation of device operation, convenient and quick start and stop, fewer operators;
6. the operation of the device is stable and safe;
7. the operation is simple, the main parts are selected international well-known manufacturers;
8. using the original imported oxygen molecular sieve, superior performance and long service life;
9. strong flexibility of operation (superior load line, fast conversion speed).
Technical indicators
| 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 | oxygen purity in 90%, converted to pure oxygen power consumption of 0.32-0.37KWh/ Nm3 |
| Oxygen pressure | ≤20kpa(supercharged |
| Annual power | ≥95% |
