Medium Capacity Low Pressure Gas Pipeline Oxygen Nitrogen Plants

Medium Capacity Liquid Plants(32 TPD TO 320 TPD)

• Range: 1,000 TO 10,000M3/hr.
• Purity oxygen -99.6% .Nitrogen -99.99% or 3PPM
• Operating Air Pressure- 0.6 TO 0.7Mpa

Process Description

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 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 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. Due to the excellent thermal efficiency we can achieve a temperature difference delta t as low as 2 deg c at the warm end of these exchangers.

Air gets liquefied when it enters the air separation column & gets separated into oxygen & nitrogen by the process of rectification.

Liquid Oxygen is available at the outlet of the ASU at a purity of 99.6%. Liquid Nitrogen is also available at the outlet as a alternate product at purity of 99.99% (upto 3ppm as required). Nitrogen gas will be available as a by product.

6. Compression of Oxygen filling in the Cylinder
The final product in the form compressed Oxygen/Nitrogen goes to the high pressure oxygen cylinders at 1 50 bar or upto higher as required. Or for pipeline supply or captive consumption Or for liquid plants to fill in cryogenic liquid tanks.