When the liquid nitrogen generator leaks, it should be dealt with in time

　　With the popularization of liquid nitrogen cryogenic knowledge, liquid nitrogen generators have been widely used in improving the performance of metal materials. Practice has proved that cryogenic treatment can effectively improve the hardness, strength and wear resistance of metal materials or workpieces to prevent deformation of workpieces ,Extended service life. Since the effect of the liquid nitrogen generator is good, is its cost high?
　　Regarding the cost of the liquid nitrogen generator, in addition to the cost of equipment, everyone is particularly concerned about the cost of using the equipment. In fact, the cryogenic treatment process mainly consumes liquid nitrogen and consumes very little electricity. Therefore, most of the equipment cost comes from the consumption of liquid nitrogen.
　　In the process of cryogenic treatment of liquid nitrogen, the consumption of liquid nitrogen is actually not standardized. The size of metal parts, the size of cryogenic equipment, the process of cryogenic treatment, etc. are important factors that affect the consumption of liquid nitrogen. Different materials, Different cryogenic space, different cryogenic process, the amount of liquid nitrogen is different.
　　Liquid nitrogen generators use nitrogen as a cold source to cool liquid air or liquid nitrogen. There are two types of subcoolers: tube and plate. When a leak occurs, it will affect the normal operation of the fractionation tower. It has two situations:
　　1. Liquid air and liquid nitrogen leak to the nitrogen side. Because the liquid air leaks to the nitrogen side, the liquid nitrogen generator will be further recovered in the heat exchanger, so the increase in cold loss is not obvious, but the cold end temperature is small. Will drop, the cold end is too cold. If the liquid air leaks, the nitrogen concentration of the liquid air is low, and the leakage of nitrogen into the gas will reduce the purity of the gas nitrogen. After the liquid leaks, the amount of liquid entering the upper tower is reduced, and the reflux liquid is reduced, which will worsen the rectification conditions and reduce the oxygen production. In severe cases, the fractionation tower will not work properly.
　　2. Outside the gas nitrogen leaker. This usually occurs at the weld or flange of the connecting pipe. When gas nitrogen leaks out, the amount of gas nitrogen entering the heat exchanger decreases, the degree of supercooling of the liquid decreases, and the gasification rate increases after throttling. At the same time, because this part of the nitrogen that has not been reheated is leaked through the insulation material, the gas nitrogen output decreases, the cold loss increases, the shell frosts, and the liquid oxygen level of the condensing evaporator drops.
　　In order to further determine whether the liquid nitrogen generator is leaking, the fractionating tower needs to be shut down and heated. Separate the medium-pressure system and the low-pressure system so as not to leak air, and then test the pressure of the medium-pressure system and the low-pressure system separately. If the medium-pressure system rises to working pressure, the low-pressure system has gas or the low-pressure system rises to working pressure, and when the medium-pressure system has gas, remove the medium-low pressure connection valves such as the condensing evaporator, liquid air throttle valve, liquid nitrogen throttle valve, etc. If there is no leakage, it can be further confirmed that the liquid air or liquid nitrogen subcooler is leaking. At this time, the pearlescent sand should be stripped and disassembled.