Top ten precautions for the use of liquid nitrogen tanks
2019-05-29 Views()
Liquid nitrogen tanks can generally be divided into liquid nitrogen storage tanks and liquid nitrogen transport tanks. The storage tank is mainly used for the static storage of indoor liquid nitrogen, and it is not suitable for long-distance transportation under working conditions.
1. Liquid nitrogen is a kind of ultra-low temperature liquid (-196 °C). If it splashes on the skin, it will cause frostbite like burn. Therefore, it should pay special attention when filling and taking out liquid nitrogen. 2. Because of the heat of liquid nitrogen tank Large, the first time the liquid is filled, the heat balance time is longer, can be pre-cooled with a small amount of liquid medium (about 20L), and then slowly filled (so that it is not easy to form ice block)
3. When not in use for a long time, ensure that the vent valve is opened to prevent the valve from being damaged due to the long-term closing of the valve and the increase of nitrogen pressure;
4. The room for long-term storage of liquid nitrogen should be ventilated and ventilated.
5. Self-pressurized liquid nitrogen tank is mainly used for transporting and storing liquid medium, and can also be used as a cold source for other refrigeration equipment. The container is composed of inner tank, outer casing and instrument valve. The upper part has pressure gauge, which can conveniently observe the inner pressure of the tank. Safety valve is provided to improve the safety of the container.
6. In order to reduce the loss during filling 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 48 hours after using the liquid.
7. In order to ensure the safety and reliability of the liquid nitrogen tank, the container can only be filled with liquid nitrogen.
8. When infusion, the outer surface of the liquid nitrogen tank is watery and frosted, which is a normal phenomenon. When the boosting valve is opened for the boosting operation, since the boosting coil is attached to the inner wall of the outer cylinder, the heat of the outer cylinder is vaporized by the liquid in the coil to achieve the purpose of boosting. There may be spotted frost on the outer tube. When the booster valve is closed, the frost point will slowly dissipate. When the pressure-increasing valve is closed and the infusion operation is not performed, the outer surface of the container has water and frost, which indicates that the vacuum of the container has been destroyed, and the container cannot be used any more. Should be looking for professional manufacturers to repair or do scrapping.
9. If the liquid nitrogen tank is not used for a long time, please discharge and dry the liquid medium inside the tank, then close all the valves. Before filling the liquid medium, the liquid nitrogen tank must dry the container liner and all the valves and pipes with dry air before loading the liquid medium. Otherwise, the pipeline will be blocked by ice, which will affect the boosting and infusion.
10. This equipment belongs to the instrument and meter category. It should be handled gently when using it. When opening each valve, the force should not be too large and the speed should not be too fast; especially the metal hose and the joint at the inlet/drain valve When connecting, you can't over-tighten it with a strong force. It can be sealed with a little force in place, so as to avoid twisting or even twisting the connecting tube. Hold the valve body with one hand when screwing.