Typical Application of Roots Blower and Vacuum Pump in VPSA

Author:

IBrief Introduction :

Industrial oxygen-generating system-VPSA (Vacuum Pressure Swing Adsorption) is acirculating system to generate high purity oxygen (90~95%) continuously by utilizinga special Molecular sieve to adsorb the impurities (such as N2, CO2 and H2O)selectively from the air under the atmospheric pressure, and then desorb under vacuumcondition.The energy consumption of VPSA is low.

IIProcess Description :

VPSA oxygen-generating system mainly consists of blower, vacuum pump, switch valve,adsorber and oxygen balance tank. After removing dust particles by suction filter,the raw air is compressed by Roots blower to 0.3-0.5barg and enters one of theabsorbers that is filled with adsorbent. H2O, CO2 and a small number of other gascomponents are adsorbed at the entrance of the absorber by activated alumina which isfilled at the bottom, then N2 is adsorbed by a zeolite molecular sieve filled on topof the activated alumina. O2 and Ar (non-adsorbed components) will be discharged fromthe top outlet of the adsorber as product to the oxygen balance tank.
The adsorbent will be saturated when adsorbing process achieves a certain level. Atthis point, vacuum (opposite to the direction of adsorption) is carried out byswitching the valve to get vacuum degree of 0.65-0.75barg. The absorbed H2O, CO2, N2and a small number of other gas components will be exhausted into the atmosphere andthe adsorbent is regenerated.

IIIProcess Flow:

Each adsorber of VPSA performs the following steps alternately:
--- adsorption -- desorption --- compression
The above three basic process steps are controlled automatically by PLC and switchingvalve system.

IVProcess Characteristic:

1. Low specific energy consumption. The higher the oxygen production, the lowerspecific energy consumption，suitable for medium and large production
2. Low maintenance cost, the rotary equipment is Roots blower and Roots vacuum pumpwhose working principle is positive displacement type with no oil and easymaintenance.
3. The whole system has a high degree of automation. The rotary equipment and theoxygen generator are controlled synchronously.

VSZB Product in VPSA:

1. RR series Roots blower and RR-W series Roots Vacuum Pump