Coalescing type Pre-filter (1) of 5μ and Oil filter (2) of 0.01μ removes bulk moisture and liquid oil from the compressed air. This pre-treated air diffuses to the bottom of the Tower (T1) and passes through the desiccant bed. This desiccant bed besides adsorbing moisture and dries the air, it also adsorbs CO2. Dry air leaves the Tower (T1) and passes through OvC + CC unit. OvC stands for Oil vapour capturing unit. CC stands for Catalytic converter. As the name implies, OvC adsorbs Oil vapour and CC converts Carbon monoxide to Carbon dioxide. Dust filter (7) of 1μ removes particulates. Bacteria filter (8) filters the air out of microorganisms, such as bacteria, parasites, fungi down to 0.22 micron at 99.9999% efficiency. Thus, ultra-purified grade air is ready for utilization..
The desiccant can adsorb only certain quantity of moisture and will reach equilibrium after certain time. It can no longer dries the air to the required dew point and should be regenerated to keep the process continuous. To regenerate the Tower (T1), some partial quantity of dry air coming out of Tower (T2) is diverted to Tower (T1). This Dry air expands to atmospheric pressure and become subsaturated. This subsaturated dry air purges out all moisture from the Tower (T1) and makes it ready for next adsorption.Air flow is diverted to each Tower alternatively by valves and controller.
