Gas Nitrogen Plant

STAGE 1 – Compression of Air

The free saturated air is drawn from atmosphere through a highly efficient dry-type Suction Filter into the first stage of the horizontally balanced opposed, lubricated reciprocating air compressor. The air is compressed over a multistage process to the desired air pressure (30-40 bar) and is then sent to the process skid for further use.

STAGE 2- Purification of Air

The compressed air is passed into an after cooler where the temperature is reduced to around 35 degree centigrade after which it is chilled in a Chilling Unit to a temperature of 12 degree centigrade and then passed through a Moisture Separator where the condensed moisture gets removed before entering into Molecular Sieve Battery.

Before sending the air to the Molecular Sieve Battery, air is passed through an Oil Absorber where air becomes oil free. Chilled air passes through the

Molecular Sieve Battery consisting of Twin Towers packed with Molecular Sieves to remove moisture and Carbon dioxide present in the air.

Molecular Sieve Battery operates on Twin Tower System. When one tower is under production the, other tower is regenerated by passing waste Nitrogen gas at 200 degree Centigrade through a Reactivation Heater.

After interval of 8 to 10 hours, the tower under production gets exhausted and is regenerated by similar process before use and thus the cycle continues. Any dust particles gets filtered in the Dust Filter before air enters the Air Separation Column.

STAGE 3- Air Separation

Chilled, Oil-free and moisture free air enters into multi-pass Heat Exchanger No. I where it gets cooled to (-80) Degree Centigrade by cold gained from outgoing waste Nitrogen and Oxygen.

A part of this air enters a multi-pass Heat Exchanger No. II or Liquefied made of special Alloy tubes. This air cools to (-170) Degree Centigrade before passing through an Expansion Valve. Due to Joule Thompson Effect, after the expansion valve, air gets further cooled down and gets liquefied before entering into Bottom Column after which it comes to be known as Rich Liquid.

The Rich Liquid in the Bottom Column enters into the feed tray of the top column. Similarly the liquid nitrogen called Poor Liquid enters into Top

Column as a reflux & it takes away the heat of condensing Oxygen and gets vaporized whereas the liquid Oxygen flows down the trays of the Top Column into the Condenser and then passes through a Sub-Cooler to a Liquid Oxygen Pump.

STAGE 4- Gasified Oxygen

In Gas Plants, the L.O pump pumps liquid oxygen through heat exchanger no. I & II, where liquid oxygen gets gasified before filling in cylinders in the Filling Manifold.

The pure bone dry oxygen gas at ambient temperature and high pressure is filled into Oxygen Cylinders through manifold valves by means of the highly efficient reciprocating Liquid Oxygen Pump.

In Liquid Plants, the liquid oxygen or nitrogen is filled directly into a Cryogenic Liquid Tank (capacity of 200 liters to 50,000 liters) where it is stored and used according to requirement.

STAGE 5- Nitrogen Production

Nitrogen can be produced both in gaseous as well as liquid form simultaneously without additional cost. Both commercial as well as technical grade can be produced.