Parameters of Medium Capacity Plants :-
* Range: 1,000 TO 10,000M3/hr.
* Purity oxygen -99.6% .Nitrogen -99.99% or 3PPM
* Operating Air Pressure- 0.6 TO 0.7Mpa
1. Air Compressor-Low Pressure
Air is compressed at a low pressure of 5-7 bar (0.5-0.7mpa). Air can be compressed at such low pressure by trouble free rotary compressor (Screw / Centrifugal Type advanced technology is employed in lieu of old bulky piston compressor).
2. Pre Cooling System
The second stage of the process uses a low pressure refrigerant for pre-cooling processed air to temperature around 12 deg C before it enters the purifier.
3. Purification of Air by Purifier
The air enters a purifier consisting of twin Molecular Sieve driers, working alternatively. The Molecular Sieves remove the Carbon dioxide & moisture from the process air before the air enters Air Separation Unit.
4. Cryogenic Cooling of Air by Turbo (Expander)
The air has to be cooled to sub zero temperatures for liquification & the cryogenic refrigeration & the cooling is provided by highly efficient turbo expander, which cools the air to temperature almost below -165 to-170 degC.
5. Separation of Liquid Air Into Oxygen and Nitrogen by Air Separation Column Oil free, moisture free and Carbon Dioxide free air enters into low pressure plate fin type Heat exchanger where the air is cooled below sub zero temp, by air expansion process in the turbo expander.