What is the principle of a laboratory liquid nitrogen machine?

　　Laboratory liquid nitrogen generatorWhat is the principle?

　　The outer compression of the experimental liquid nitrogen generator is compressed with oxygen at room temperature, and the inner compression is compressed with liquid oxygen at low temperature. The inner compression process of the liquid nitrogen generator has higher safety performance, will not cause the phenomenon of hydrocarbon accumulation, and has a small fire hazard. So, what is the principle of the laboratory liquid nitrogen generator?

　　What is the principle of the laboratory liquid nitrogen generator?

　　1. The laboratory liquid nitrogen generator uses the principle of pressure swing adsorption, using carbon molecular sieve as the adsorbent, to produce nitrogen from the air under a certain pressure.

　　2. The purified and dried compressed air in the laboratory liquid nitrogen generator is pressurized and adsorbed in the adsorption tower. Due to the kinetic effect, the diffusion rate of oxygen in the micropores of the carbon molecular sieve is much higher than that of nitrogen. When adsorption cannot reach equilibrium, nitrogen is enriched in the gas phase to form finished nitrogen.

　　3. The pressure is reduced to normal pressure, and the adsorbent desorbs the adsorbed oxygen and other impurities to achieve regeneration. The system generally sets two adsorption towers, one adsorbing nitrogen and the other desorbing and regenerating. Through the automatic control of the machine's own program, the two towers alternately cycle, carrying out oxygen-nitrogen adsorption separation to obtain qualified nitrogen, and then Enter the air-cooled oil-free circulating compressor and liquefaction equipment to change the nitrogen from gaseous to liquid state, obtaining liquid nitrogen.

　　What should be paid attention to when operating a laboratory liquid nitrogen generator?

　　1. Wear cryogenic gloves. Before using cryogenic gloves, be sure to check for any cracks, tears, or holes that may allow entry into the gloves. Because cryogenic gloves are used to handle extremely cold items and to prevent accidental splashes. They cannot be immersed in cryogenic liquids.

　　2. Wear long sleeves and long trousers. All work using cryogenic liquids requires long sleeves and long trousers; shorts and capri pants are not allowed. In addition, trousers/long trousers with cuffs can trap cryogenic liquids in the cuff folds, adhere to the skin, and increase the chance of cryogenic burns. When handling refrigerants, it is recommended to wear loose-fitting trousers so that any spills or splashes will roll off the fabric without transferring a large amount of heat to the skin. Tight jeans offer less protection against cryogenic splashes.

　　3. Wear closed-toe shoes. It is increasingly common to wear athletic shoes in the laboratory. Laboratories are often designed to keep feet cool, and mesh tops are used for ventilation. If the base allows air to flow, shoes used with cryogenic liquids should cover the entire top of the foot and at least temporarily repel liquids. Closed-toe shoes without mesh are necessary. Closed heels and full-coverage uppers are recommended.

　　What are the Applications of a laboratory liquid nitrogen generator?

　　1. Laboratory liquid nitrogen generators are widely used in improved techniques for livestock freezing.

　　2. In embryo transplantation of livestock and various animals, embryo freezers are mostly used for embryo preparation and preservation, and belong to intelligent freezers. This instrument uses microcomputer control technology and special software to control the amount of liquid nitrogen, thus ensuring that the frozen biological products are cooled and frozen at a suitable freezing rate.

　　3. Ultra-low temperature preservation of microbial strains in liquid nitrogen. Long-term preservation at -196°C liquid nitrogen.

　　4. Preservation of agricultural biological genes.

　　5. It is also common to use liquid nitrogen to treat mouth closure and livestock skin tumors.

　　6. Laboratory liquid nitrogen generators can also be used in cryomedicine. The rapid development of clinical cryomedicine has promoted the development of transplantation medicine, especially in the cryopreservation and transplantation of bone marrow, hematopoietic stem cells, cornea, endocrine glands, and blood vessels. Successful hematopoietic stem cell transplantation relies on the preservation of hematopoietic stem cell viability.

　　7. During the cooling and freezing of biological samples, a certain amount of heat is released during the phase transition from liquid to solid state, causing its temperature to rise. If the cooling rate is not controlled, the freezing process will lead to the death of tissue cells.

　　8.Laboratory liquid nitrogen generatorDetermine the phase transition point of the biological sample, use a microcomputer to compile a cooling program, and increase the input of liquid nitrogen when the sample undergoes a phase transition, so that the cells can safely and quickly pass through the phase transition period. This is a key step in improving the survival rate of frozen specimens.