Liquid nitrogen is produced in large quantities at air separation plants which liquefy and distil air into its constituent parts: nitrogen, oxygen and argon
Features
Refrigerated liquefied gas
Boiling point -196°C
Gas/vapour heavier than air
Odourless, colourless and non toxic
Chemically inert at ambient temperatures
Specification
Nitrogen 99.999%
Oxygen <5vpm
Moisture <2vpm
Argon is included in the nitrogen
It is delivered to our customers by cryogenic tankers, into onsite storage, for use in high-volume customer applications. It is stored as a cryogenic liquid in a vacuum-insulated vessel which can provide several days' supply and be used on demand as either a liquid or gas.
Nitrogen is often used for the storage of semen samples for artificial insemination of cattle
Blanketing and inerting
Nitrogen is used to maintain a dry inert atmosphere over chemicals during storage, reaction or processing
Controlled atmospheres
The atmosphere and ambient temperature surrounding naturally respiring products such as fruit is actively controlled to provide optimum conditions for long-term storage
Electronics
Used in the inerting of printed circuit board reflow and wave ovens, to prevent oxidation and facilitate the use of weaker fluxes which decompose more easily without leaving a residue
Food freezing/chilling
Liquid nitrogen freezes food quickly, producing a higher-quality product compared to to conventional refrigeration
Food inerting
Used in brewing, soft drinks and wine-making industries to exclude air from the product and de-aerate water
Food packaging
Used in modified atmosphere packaging, liquid nitrogen can increase the shelf-life without the need for vacuum-packing, artificial preservatives or freezing
Freeze-drying
In the freeze-drying process, materials dissolved in water or organic solvents are frozen into particles or droplets. A vacuum is applied to the freezing chamber along with a controlled amount of heat sufficient to drive off moisture by sublimation
Glass
Nitrogen and hydrogen are used in the float glass process for manufacturing flat glass. In this process perfectly flat glass with a very high quality is achieved by floating liquid glass on a bath of molten tin
Heat treatment
Pure nitrogen is used to protect some of the most reactive metals during heat treatment. These metals readily form a protective oxide surface layer from the small amount of oxygen in the nitrogen and need no further protection
Lasers
Nitrogen is used as an assist gas for laser cutting of stainless steel, aluminium and non-metallic materials
Metals
Nitrogen is used in iron and steelworks applications for degassing and metal-stirring, purging, cooling, slag splashing, gas knives and as a carrier gas for injecting de-sulphurising compounds. It is also used for aluminium-extrusion inerting
Pipe-freezing
Repairs can be made to a pipe containing a liquid by using liquid nitrogen to freeze a plug of liquid on each side of the section of pipe to be opened
Purging
Applications include inerting reactors and storage tanks, purging vessels and pipelines of flammable or toxic gases and vapours, and the sparging and pressure transfer of liquids
Shrink-fitting
Liquid nitrogen is used to shrink components so they are small enough to be inserted into another component
Sample storage
Liquid Nitrogen can be used to store medical or research samples such as blood, plasma and semen – safely
