VPSA Oxygen Plant
Air from a Blower is first cooled in an After-cooler to reduce its moisture content and condensed moisture is separated in Moisture Separator. The cooled air passes through a Tower containing an a adsorbent which has the property to separate oxygen from the air resulting in a gas contains 93% oxygen (balance being argon & nitrogen) coming out as product gas. To ensure continuous flow of product gas, the other Tower is simultaneously regenerated by extracting the gases adsorbed in the previous cycle by a Vacuum Pump. Automatic operation is achieved by opening & closing the valves in a preset sequence by using a PLC. (20 Sec + 20 Sec Cycle) Cost of producing this oxygen is < 0.5 KWH at 0.2 bar pressure. There is a small increment in this due to power required for boosting pressure to required value, but this never exceeds 0.6 KWH/NM3. Overall cost of VPSA oxygen is Rs.5/- to 6/- per NM3
