Nitrogen is made from air using separation technology for separating Nitrogen from other constituents of air. The Nitrogen separation is a cylindrical bundle of hollow fiber fine tubes made from polymer material. Pressurized air enters at one end and flows to the opposite end through the fiber bore. Gas separation takes place through fiber wall. Fast permeating gases such as Oxygen, CO2 and water vapor quickly diffuse through the fiber wall and exit at atmospheric pressure through the vent port on the outer side of the Membrane. Nitrogen being a slower gas does not permeate through the fiber wall as quickly under flowing conditions and is collected as the Nitrogen product gas.
Nitrogen Liquifier (Cryorefrigerator):
This unit is fully imported from our USA-collaborators and we integrate it with our Nitrogen unit and supply complete Liquid Nitrogen plant on Turnkey basis.
The cryorefrigerator consists of a cold head, Helium compressor package and a pair of stainless steel flexible helium lines. The cold head is mounted into the top of the liquid tank (dewar). The cold head extends down into the neck of the liquid tank for the purpose of cooling the nitrogen entering the liquid tank to 77K (-196ºC). The nitrogen gas liquefies on contact with the cold head heat exchanger. The liquefied nitrogen drips off the heat exchanger down into the LN2 inside the liquid tank. The flow rate of the nitrogen gas into the liquid tank is controlled by the rate of liquefaction inside the liquid tank. Therefore, if the cryorefrigerator is turned off by the level indicator, the liquefication stops and the flow of nitrogen into the tank stops.
The liquid tank assembly of our Liquid Nitrogen Plant is made of highly reliable stainless steel and functions not just as a vessel when producing liquid nitrogen, but stores a three day production capacity as well. The liquid tank (dewar) assembly includes a nitrogen regulator, level indicator and vacuum jacketed liquid outlet line.