Liquid nitrogen tank, also known as liquid nitrogen biological container, is a kind of biological storage container, which scientifically solves the problem of large amount of liquid nitrogen evaporation loss caused by heat convection, conduction and radiation during storage. Liquid nitrogen is a colorless, odorless, and extremely low-temperature substance. Its temperature is -196°C under normal pressure. The liquid nitrogen tank is made using this physical property of liquid nitrogen.
 
Liquid nitrogen tanks can generally be divided into transport-type liquid nitrogen tanks and storage liquid nitrogen tanks, which are widely used in the fields of animal husbandry, medical treatment, scientific research, and mechanical processing. Liquid nitrogen is used as a refrigerant to preserve animal semen, organs, bacteria and other biological samples, as well as cryogenic treatment of metal materials and cryogenic assembly of precision parts.
 
The main components of the liquid nitrogen tank include the outer shell, the inner tank, the inter-layer, the neck tube, the cover stopper, the lifting cylinder, and the outer jacket:
1. Outer shell: The outer layer of the liquid nitrogen tank is the shell, and the upper part is the tank mouth.
2. Inner tank: The space in the inner layer of the liquid nitrogen tank is called the inner tank, which is generally made of corrosion-resistant aluminum alloy. The bottom of the inner tank has a base for fixing the cylinder. The liquid nitrogen and samples can be stored in the inner tank.
3. Inter-layer: Inter-layer refers to the gap between the inner and outer layers of the tank, and it is in a vacuum state. The purpose of vacuuming is to improve the thermal insulation performance of the liquid nitrogen tank, and at the same time, there are thermal insulation materials and adsorbents in the inter-layer.
4. Neck tube: The neck tube is usually made of glass fiber reinforced plastics, which connects the inner and outer layers and keeps a certain length. There is adsorbent around the neck tube and the bottom inter-layer. The neck opening at the top has a special design. Its structure requires the pores to discharge the nitrogen vaporized by the liquid nitrogen to ensure safety, and also the thermal insulation performance to minimize the amount of liquid nitrogen vaporization.
5. Cover stopper: The cover stopper is made of plastic with good thermal insulation performance to prevent the evaporation of liquid nitrogen, and at the same time fix the handle of the lifting cylinder.
6. Lifting cylinder: The cylinder is placed in the inner tank, where thin tubes can be stored. The handle of the lifting cylinder is hung on the neck and fixed with a cover stopper.
7. Outer jacket: The medium and small liquid nitrogen tanks are equipped with artificial leather backpacks for the convenience of carrying. It increases the anti-collision protection of the product, and is also convenient for the user to carry it manually.