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Pure Nitrogen Gas Plants
1. Air Compressor-Low Pressure
Air is compressed at a very pressure of 5-7 bar (kg/cm2). 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. Pure Cooling System
The second stage of the process uses a low pressure refrigerant for pure-cooling the 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 processed 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 deg C
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 fine type heat exchanger where the air is cooled below sub zero temperatures by air expansion process in the turbo expander.
Air gets liquefied when it enters the air separation column & gets separated into oxygen & nitrogen by the process of rectification.
Nitrogen gas is available at the outlet at purity of 99.99% upto 3ppm (lppm in some models)
Liquid nitrogen is also available along with the pure nitrogen gas products.
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