The reason why the storage temperature of liquid nitrogen freezer is stable

2023-12-15 09:48:01

We know that conventional liquid nitrogen open tanks are stable because the sample is completely immersed in liquid nitrogen.

The liquid nitrogen freezer is different in that its sample and liquid nitrogen are separated. The liquid nitrogen only serves as a medium to “create” a low-temperature environment and does not directly cool the sample. In other words, its freezing temperature is not constant -196°C, so why is it always said that its storage temperature is stable, suitable for long-term storage of large quantities of biological samples, and can be used in stem cell banks and preservation centers?

What is the reason why the storage temperature of  liquid nitrogen freezer is stable?

The manufacturer tells you: it is the combination of the special vapor phase mode + vacuum insulated stainless steel tank, and the innovative lid offset design + hot gas bypass.

The combination of the special vapor phase mode and the vacuum insulated stainless steel tank firmly “contains” the evaporated nitrogen in the sample storage area. The high vacuum coverage isolates external heat and prevents heat from being transferred in through the outer metal material. It ensures that the low temperature in the inner tank will not dissipate through the connection between the inner and outer tanks, ensuring good thermal insulation and thermal insulation properties.

The innovative small opening design of the lid and neck is offset, so that the mouth of the jar is no longer facing the sample storage area, which greatly reduces the entry of external heat after opening the lid and reduces the volatilization rate of liquid nitrogen. Moreover, actual measurement data shows that when the lid is opened for a long time, the temperature inside the liquid nitrogen freezer can still be maintained at no higher than -150°C for 48 hours.

In addition, with the hot gas bypass, before liquid nitrogen is injected, the room temperature nitrogen in the pipeline is first eliminated to ensure that only liquid nitrogen is injected into the tank, instead of liquid nitrogen carrying external heat, which increases losses and causes temperature fluctuations in the vapor phase sample library. Affects the stable storage of samples.

It is this model combined with the structural design and auxiliary measures that makes the storage temperature in the liquid nitrogen freezer stable!

The reason why the storage temperature of liquid nitrogen freezer is stable