Views:87 Author:Site Editor Publish Time: 2019-10-29 Origin:Site
Usually, the liquid nitrogen should be paid special attention to when it is shipped, because slightly inconvenient will have serious consequences, so what should be paid attention to in the use of the liquid nitrogen tank?
1. Activity Preservation of Animal Semen
Liquid nitrogen tanks are mainly used for long-distance transportation and storage, such as storage of sperm and eggs which are for animal artificial insemination.
2. Activity Preservation of Biological Samples.
Vaccines, bacterial strains, cells, human and animal organs in the biomedical field can be immersed in liquid nitrogen stored in a liquid nitrogen container for long-term active storage. Take out the thawing and rewarming and use it if needed.
3. Cryogenic Treatment of Metal Materials
The cryogenic treatment of the metal material by the liquid nitrogen stored in the liquid nitrogen tank can change the metallographic structure of the metal material and significantly improve the hardness, strength and wear resistance of the metal material.
4. Cryogenic Assembly of Precision Parts
After the precision parts are cryogenically treated with liquid nitrogen, It will improve the assembly quality of the parts, thereby improving the overall performance of the equipment or the instrument.
5. Refrigeration in Medical Industry
Liquid nitrogen tanks can also be used for refrigeration and medical operations in the healthcare industry.
In general, when the liquid nitrogen is used, the evaporation loss will take 40 hours to return to the steady state. The time required for the good liquid nitrogen tank to return to the steady state can be reduced to 12 hours, and the evaporation loss can be reduced by 50%. The main methods of use are summarized as follows:
1. Special personnel should be responsible for management, use and maintenance.The liquid nitrogen tank storage room should be ventilated. If a large number of liquid nitrogen tanks are stored in a closed room, the evaporated nitrogen will stay in the room, causing anoxic state, and a suffocation accident may occur. The liquid nitrogen tank should be handled gently to avoid collision with other objects. If the liquid nitrogen tank is exhausted and becomes a high vacuum state, the pressure of the inner and outer tanks is quite large. Taking DR-10 and DR-30 as examples, the pressure of the outer tank is about 40 kg to 90 kg. It must be paid attention to during operation, and must not fall or collide. Liquid nitrogen tank technicians reminded that the liquid nitrogen tank to maintain vertical, strictly prohibit dumping liquid nitrogen tank in order to avoid accidents.
2. When filling the liquid nitrogen for the first time, or when the inside of the liquid nitrogen tank is in a dry state, first check that if there are any depressions or other abnormal conditions outside the tank. Is there any foreign body in the tank or whether the base is fixed properly? If these conditions are good, liquid nitrogen can be started to be filled and should be carried out in a well ventilated area, usually outdoors. If you are indoors, you must open the doors and windows to maintain good ventilation. The filling of liquid nitrogen is a pressurized injection method, in which a flexible hose is connected from a large liquid nitrogen container opening liquid valve, and liquid nitrogen tank is directly filled with liquid nitrogen. The filling of liquid nitrogen is a pressurized injection method, which opens a liquid valve from a large liquid nitrogen container and connects a flexible hose to fill the liquid nitrogen tank directly.The other is directly using the funnel pouring method. It is especially important to make the end of the funnel slightly away from the neck tube, so that the gas evaporated by the liquid nitrogen can escape smoothly from the gap between the funnel and the container, otherwise the liquid will overflow from the funnel. Not only will it increase liquid nitrogen loss, but also frostbite accidents. Filling liquid nitrogen should be injected slowly, with a small amount first, then stopped for a few minutes to cool it down and then gradually injected to the specified capacity.
3. When handling the liquid nitrogen tank, the handle should be slightly raised so that the bottom of the handle is removed from the base, then the handle is moved to the center of the tank and lifted naturally. The action should be swift, so as to avoid bending or breaking the handle. When releasing the handle, attention should be paid to avoiding rubbing the inner wall of the neck tube, so as to avoid damaging the neck tube. The handle should be placed in the indexing ring, cover the plug to avoid running nitrogen.
4. Generally speaking, liquid nitrogen residue is equal to one third of the total capacity or only enough to use for a week, it is better to supplement. A liter of liquid nitrogen weight of 0.8 kg plus the weight of the tank to get the weight of the full tank, minus the existing weight, is the weight to be supplemented. Or a thin wood stick can be used to insert liquid nitrogen for several seconds. The stick can be quickly removed and shaken in the air for several times. The part inserted into liquid nitrogen forms white frost because of the low temperature. It is easy to detect the liquid nitrogen storage in the tank.
5. When transported and transported by vehicles, liquid nitrogen oscillates with the vibration of vehicles, thus increasing consumption. The ratio of increasing consumption varies with the shape of the container. For example, DR-10 liter liquid nitrogen tank, which takes eight hours a day to transport, consumes about 100g. And increases consumption due to the removal of the handle. For example, DR-10 will consume about 10 g per operation. In order to reduce the activity and safety of the storage, liquid nitrogen tanks to be wooden boxes wrapping during transportation, especially in the way to prevent the liquid nitrogen tank upside down and avoid accidents.
6. Liquid nitrogen is an inert substance, and it will not corrode inside the container. However, during the use of the liquid nitrogen tank, water will accumulate inside. And the bacteria may fall into the handle, and mixed with the semen from the handle. Sometimes, due to the above reasons, a considerable degree of corrosion may occur. If mixed with bacteria, the fertility rate of artificial insemination will also be reduced. Therefore, the inside of the liquid nitrogen tank should be cleaned and dried once or twice a year. The steps are as follows: take out the handle and liquid nitrogen from the container and leave it for about two days. The internal temperature of the container rises to 0°C. Inject the warm water at 40°C to 50°C or with a neutral detergent into the liquid nitrogen tank, then scrub with a cloth and rinse with water. Finally, invert the container to dry. The drying method may be a natural air drying method or a hot air drying method. If the latter is used, the temperature is limited to between 40°C and 50°C. The hot air above 60°C should be avoided, so as to avoid affecting the performance of liquid nitrogen tank and shorten the service life.
7. Liquid nitrogen tanks can only be used to hold liquid nitrogen, not used for other refrigerants.