High Purity Cryogenic Oxygen Plants

Specifications:
1. Gas or liquid oxygen and nitrogen generating plant
2. Oxygen purity: 99.6% oxygen output: 50-2000Nm3/h
3. Nitrogen purity: 99.7% nitrogen output: 50-2000Nm3/h
4. Certifications: ISO9001: 2008 & GB
STEP 1 - Air Compression by rotary air compressors.
In the first stage air is compressed at a low pressure of 5-7 bar (Gas plants) to 10 Bar (liquid plants). 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 reciprocating compressor).
STEP 2 - Air Pre-Cooling
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.
STEP 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.
STEP 4 - Separation of Liquid Air into Oxygen and Nitrogen in 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 temperatures 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.
The air has to be cooled to sub zero temperatures for liquefaction & 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. Air gets liquefied when it enters the air separation column & gets separated into oxygen & nitrogen by the process of rectification.
Oxygen is available in gas or liquid form (as per requirement) at the outlet of the ASU at a purity of 99.6%. Nitrogen is also available at the outlet as a second product at purity of 99.99% up to 3ppm simultaneously without loss of oxygen product (or as specified).
STEP 5- Product storage
For Gas: The final product in the form compressed Oxygen/Nitrogen goes to the high pressure oxygen cylinders at 150 bar or up to higher UPTO 200 BAR as required. OR for pipeline supply or captive consumption.