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

2024-02-02 13:59:04

If you want to use liquid nitrogen to freeze samples, you must first have a liquid nitrogen storage container, because liquid nitrogen has a low boiling point and is volatile!

Depending on the freezing method, you can choose a conventional liquid nitrogen tank or a nitrogen freezer. The difference between them is not only the freezing method, the capacity, the material of the inner and outer walls, but also the temperature and temperature stability.

In the use test of the two types of containers, it was found that the temperature of the nitrogen freezer is more stable than that of the conventional liquid nitrogen tank. Why is this?

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

It’s very simple, it’s affected by its storage mode!

Nitrogen freezers are containers that preserve biological samples in a gas phase formed by the liquid nitrogen inside.

The specific method is that the inner container of the container is divided into upper and lower layers, and the upper layer is used to “demarcate” the sample storage space with freezing racks, and the samples are stored in categories based on the serial numbers of the freezing racks. The lower layer is filled with liquid nitrogen. There is an evaporator in the liquid nitrogen area. The evaporator will evaporate the liquid nitrogen within the necessary time to ensure low temperature in the sample storage area.

Therefore, the sample storage area of the nitrogen freezer is filled with nitrogen instead of liquid nitrogen, which is equivalent to all samples being “wrapped” in nitrogen in a low-temperature field. When the temperature rises compared to the preset value, the evaporator automatically works to supply nitrogen. Even if the liquid nitrogen evaporates not in time, because it is nitrogen expanded by liquid nitrogen, the cooling rate is not as fast as that of the liquid phase. Once the sample is not soaked in liquid nitrogen, the temperature difference between the front and back is large. If the liquid is not replenished in time, the activity of the sample may be lost.

Therefore, the storage temperature of nitrogen freezer is relatively stable!

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