liquid nitrogen
Chinese name nitrogen (high purity)
English name Nitrogen
CAS 7727-37-9
Under normal pressure, the temperature of liquid nitrogen is - 196 ℃; One cubic meter of liquid nitrogen can expand to 696 cubic meters of pure gaseous nitrogen at 21 ° C. Liquid nitrogen is a colorless, odorless liquid and gas with low temperature under high pressure. Liquid nitrogen (often written as LN2) is the liquid form formed by nitrogen at low temperature. The boiling point of nitrogen is - 196 ° C. Under normal atmospheric pressure, if the temperature is below this, liquid nitrogen will be formed; If pressurized, liquid nitrogen can be obtained at a higher temperature.
Nitrogen - use
It is used as carrier gas for chemical vapor deposition, carrier gas for liquid diffusion source, and protective gas for devices in high-temperature diffusion furnace in the manufacturing of integrated circuits, semiconductors and electric vacuums. Nitrogen purity is required to be 99 More than 99%; The purity of nitrogen used as base gas in integrated circuit manufacturing is 99 999%~99.9999%, even higher. In the production of some metal materials, high-purity nitrogen is required.
Liquid nitrogen - safety
It is non-toxic and an asphyxiating gas. Nitrogen can suffocate people and animals. If people are exposed to an environment with nitrogen content higher than 82% for a long time, there will be a risk of hypoxia. If they are exposed to an environment with nitrogen content higher than 94%, they will suffocate and die due to severe hypoxia. Store in a cool place
To avoid impact.