Liquid-liquid nitrogen tanks, i.e. liquid nitrogen biocontainers as opposed to vapour-phase tanks;
Liquid nitrogen is stored inside, so it has this name!
The early liquid nitrogen tank was designed for storing liquid nitrogen, and it was later used in liquid nitrogen storage and biological cryopreservation. It is an indispensable cryogenic container for laboratory cell cryopreservation and animal husbandry frozen semen.
But no matter what kind of biological sample preservation, the refrigeration medium “liquid nitrogen” is always indispensable!
This -196°C liquid often has some problems caused by cryogenic and container insulation when stored in liquid nitrogen tanks. Icing around the bottom of liquid nitrogen tanks is one of the representative problems! What are the reasons for its freezing?
1.The new tank is filled with liquid nitrogen for the first time, and the temperature difference is too large to freeze
The initial filling of a new tank with liquid nitrogen can basically be equivalent to putting a large amount of ice cubes into a hot container;
The internal temperature of the new liquid liquid nitrogen tank is normal temperature, which is “high temperature” compared with -196°C liquid nitrogen. When filling liquid nitrogen for the first time, if a large amount of liquid nitrogen is injected, in addition to white steam, the water vapor outside the tank will be quickly frozen. condensation on the can.
Because the cold air will sink, and the higher the temperature it is exposed to, the lower the ice will form. This is a normal situation, because there is no pre-cooling in advance, you can observe for several hours to see if the ice fades.
If there is still freezing, contact the manufacturer of the liquid nitrogen tank. If there is no freezing, it can be filled with liquid nitrogen and used!
2. The old tank was normally filled with liquid nitrogen, but the lower wall suddenly froze
The old tank is a liquid nitrogen tank that is normally put into use. It was filled with liquid nitrogen according to its own frequency or when the liquid nitrogen could not cover the sample. It turned out that the lower wall suddenly froze.
If the container is used for the second time without cleaning for a long time, it is likely that the inner liner is damaged, which affects the vacuum;
If you have been using it all the time, check whether there is any bumps in the near future, and if some are identified, contact the manufacturer of the liquid nitrogen tank to help repair it during the warranty period;
If there is no bump and suddenly the lower wall freezes, you can also contact the manufacturer, enter the factory to check the vacuum, and then deal with it according to the actual situation.