What is Nitrogen?

Nitrogen (N2) is an odourless, non-flammable and harmless gas that makes up 78% of the Earth’s atmosphere.

What is Liquid Nitrogen?

When Nitrogen is below -196° C or -321° F (77 K) it exists in a liquid state and is referred to as Liquid Nitrogen (LN2). LN2 freezes into a solid at ?210 °C or ?346 °F (63 K).

How is Liquid Nitrogen Formed?

LN2 is formed by compressing air in a compressor which forces the air molecules closer and closer together. This compressed air goes along coils of tubing which are exposed to room temperature air which flows over the coils. As the air in the coil tubes warms it is compressed and then the room temperature air cools it. This process is repeated until the compressed air is lower than -196° C or -321° F (77 K). At this very low temperature Nitrogen condenses into a liquid.

What are the uses of Liquid Nitrogen?

Liquid Nitrogen is used for many different industrial and research applications. Some of which are listed below:

Biomedical, Cryogenics, Cryopreservation, Pipe-freezing, Environmental Chambers, Blanketing, Food freezing,

Modified Atmosphere Packing, Lead Free Soldering, Rubber de-flashing, Shrink fitting, Foundries and Laser cutting.

Where to get Liquid Nitrogen?

Liquid Nitrogen can be readily obtained from companies that supply industrial gases. In the UK companies such as CryoService can supply LN2 from desk flasks and non-pressurised dewars (from 2 litres) up to small bulk vessels of 6000 – 10,000 litres.

LN2 can also be obtained from using generators. Generators provide greater flexibility, cost savings and improved health and safety in the workplace.

How to store Liquid Nitrogen?

Liquid Nitrogen can be stored in small dewars of 0.5 litre up to 10,000 litre high compression bulk storage tanks. Dewars are special flasks with high grade thermal glass which has a vacuum around and provide excellent storage capability.

Is Liquid Nitrogen dangerous?

Due to the very cold temperature of Liquid Nitrogen cold burns or frost damage to exposed skin is a very real hazard.

LN2 is noted for its rapid boiling and converting into a gas. Nitrogen gas has a volume around 700 times that of Liquid Nitrogen so a sudden release of large amounts of LN2 can cause asphyxiation. As Liquid Nitrogen is odourless and colourless people can be caught unaware of Oxygen depletion and are at serious risk of death.

In storage in containers with poor thermal and pressure capabilities are at a high risk of explosion. The rapid boiling point of LN2 and sudden increase of gaseous volume can result in a sudden build up of pressure.