PSA (Pressure Swing Adsorption) is an economical alternative for Onsite production of Oxygen for Medical use and is in use for over 30 years in the medical industry. Ambient air entering the compressors is 78% nitrogen, 21% oxygen, less than 1% argon and other gases. As nitrogen is separated, the resulting product gas is up to 95.5% oxygen purity. PSA process comprises of Zeolite filled towers and is based on the fact that different gases have the property to be attracted to different solid surfaces more or less strongly. This happens with nitrogen, which is attracted to the zeolites. As the air is compressed, the nitrogen is forced into the crystalline cages of the zeolite, and the oxygen is less adsorbed and conveyed to the end of the zeolite bed and ultimately recovered in the oxygen buffer tank. Two zeolite beds are used together: One filters air under pressure until it gets saturated with nitrogen while oxygen passes through. The second filter begins to do the same while the first one is regenerated as nitrogen is expulsed (desorbed) by releasing the pressure. The process repeats again, storing the oxygen in a tank.
Working of Medical Oxygen Generator
