Ten matters needing attention in the use of liquid nitrogen tanks

Ten matters needing attention in the use of liquid nitrogen tanks

Liquid nitrogen tanks can generally be divided into liquid nitrogen storage tanks and liquid nitrogen transportation tanks. The storage tank is mainly used for the static storage of indoor liquid nitrogen, and is not suitable for long-distance transportation under working conditions.

　　1. Liquid nitrogen is a kind of ultra-low temperature liquid, which can cause frostbite similar to burns if it is splashed on the skin. Therefore, special attention should be paid when filling and removing liquid nitrogen;

　　2. Due to the high heat of the liquid nitrogen tank, the first time it is filled with liquid, the thermal equilibrium time is longer. It can be filled with a small amount of liquid medium to pre-cool (about), and then slowly filled (so that it is not easy to form an ice block.

　　3. When not in use for a long time, make sure to open the vent valve, so as not to close the valve for a long time and cause the increase of nitrogen pressure and cause damage to the container;

　　4. The room where liquid nitrogen is stored for a long time should open windows for ventilation and ventilation.

　 5. The self-pressurized liquid nitrogen tank is mainly used for transportation and storage of liquid media, and can also be used as a cold source for other refrigeration devices. The container is composed of an inner tank, an outer shell and an instrument valve. The upper part has a pressure gauge, which can easily observe the pressure of the inner tank. , To improve the safety of the container, it is equipped with a safety valve.　　

　　 6. In order to reduce the loss when filling the liquid in the future, please refill the liquid when there is a small amount of liquid in the liquid nitrogen tank. Or fill the liquid within hours after using up the liquid.　

　　7. To ensure the safety and reliability of the liquid nitrogen tank, this container can only be filled with liquid nitrogen.　

　　 8. Water and frost on the outer surface of the liquid nitrogen tank during infusion are normal. When the booster valve is opened for boosting work, because the booster coil is attached to the inner wall of the outer cylinder, the heat of the outer cylinder will be absorbed and vaporized when the liquid passes through the coil to achieve the purpose of boosting. There may be speckled frost on the outer cylinder. After closing the booster valve, the frost spots will slowly dissipate. When the pressure-increasing valve is closed and no infusion work is performed, there is water and frost on the outer surface of the container, which indicates that the vacuum of the container has been broken, and the container can no longer be used. It should be repaired or scrapped by a professional manufacturer.　

　　 9. If the liquid nitrogen tank is not used for a long time, please drain the liquid medium inside the tank and blow it dry, then close all valves and seal it. Before the liquid nitrogen tank is filled with liquid medium, dry air must be used to dry the container liner and all valves and pipes before the liquid medium can be filled. Otherwise, the pipe will freeze and block, which will affect the pressure increase and infusion.

10. The liquid nitrogen tank equipment belongs to the category of instruments and meters. It should be handled with care when using. When opening the valves, the force should be moderate, not too high, and the speed should not be too fast; especially the connection between the metal hose and the inlet and outlet valves. When connecting, do not overtighten it with strong force. It is enough to screw it in place with a little force to seal, so as to avoid twisting the connecting pipe or even breaking it. Hold the valve body with one hand when screwing.