Cylinder Filling Oxygen Nitrogen Plants

Main Performance of the plant:

A. Oxygen purity 99.6% at 150-160 Bar(2200PSIG) for Oxygen cylinder filling
B. High purity Nitrogen 99.99%(ppm optional) or cylinder filling.
NOTE: There is no loss of oxygen Production when producing high purity nitrogen.

Air separation is CRYOGENIC TYPE with low-pressure cycle of 7 Kg/cm2 with air separation by liquidfication. This cycle utilize an Expansion TURBINE to give the cold calories at (-)1 80^oC. The cold box is supplied as a complete package unit with control panel and insulation.

Process Description:

Process Description
This air separation plant mainly includes:
air filter system
air compressor system
air pre cooling system

Molecular sieve purifying system
rectifying column system, nitrogen & oxygen compress and storage system, instrument control system, electric control system. Etc.

Air filter and compression
Air enters the self cleaning air suction filter, after being removed of dust and other mechanical contaminants in it, then enters main air compressor, after compression air then enters the after cooler.

Air cooling and purifying
Air is cooled in the Pre-Cooling System before enters mole sieve adsorber, Air which enters the evaporator of the Pre-Cooling System is cooled by the refrigerant.

Mole sieve purifying system includes two mole sieve adsorber and Steam heater or Electric heater. The mole sieve adsorber adsorbs water, CO2 and some hydrocarbon in the air, one mole sieve adsorber is regeneration while another one is work.

Air rectification
Air from adsorber is divided two stream: one stream enter directly main heat exchange, then enter lower column after cooled, the second stream enter main heat exchanger to cool after compressed by booster end of the expander and cooled by after cooler, then enter upper column after expanded by the expander.

The content of nitrogen will increase through rising gas connect with the reflux. Needed reflux liquid nitrogen is from condensate evaporator in the top of lower column, oxygen will be evaporated and nitrogen will be condensed in here.
  Lower column production as following from the top down:
  Pure liquid nitrogen
  Poor oxygen liquid air with 20%O₂
  Rich oxygen liquid air with 36.5%O₂

All production in the lower column after sub cooler enter upper column as its reflux.Production of upper column as following from the top down:
  Waster nitrogen at the top.
  Liquid oxygen at the bottom

Direction which all production of upper column go Waster nitrogen is reheated to design temperature out of the cold box by main heat exchanger and sub cooler after drawn from the top of upper column, one steam is regenerated by molecular sieve absorber, the other is taken in water cool column to cool water.
 It is compressed to 150 BAR for filling oxygen cylinders by a oxygen booster in the cylinder filling manifold

Scope of Supply:

Technical Specification