DEAR Air separation plant.This kind of regulation method is only effective when the on-6 valve is closed very small (within one revolution) and the high pressure air pressure is not equal to the pressure in front of the expander. And each adjustment can only rotate 3-5 degrees, not too large.DEAR Air separation plant.When a large amount of water is found flowing into the air separation tower, the air inlet valve of the air separation unit and the water supply valve of the air cooling tower should be closed while the air compressor is venting. The inlet water of the switching heat exchanger with the cold end at the top and the hot end at the bottom is easy to remove the fault, and it is not easy to cause serious freezing phenomenon. However, the accumulator with the hot end at the top and the cold end at the bottom is very afraid of water inflow. Once the water inflow is easy to cause freezing blockage, the only way is to stop heating and thawing.DEAR Air separation plant.In order to avoid the air at the cold end being liquefied, it is necessary to pay attention to the loop flow in the operation. The size of the circulating flow should be adjusted according to the temperature difference between the hot end, the cold end and the middle part of the accumulator. It can not be fixed mechanically because the air volume and the tower working condition are constantly changing. In addition, we should pay attention to the working condition of subcooler and liquefier, and deal with the problems in time. When the liquid is accumulated during the start-up process, if the expansion is too large, it should be reduced appropriately.
DEAR Air separation plant.The oxygen content of liquid oxygen and liquid air in the air separation unit is high, which will cause the oxygen concentration to increase in local range after evaporation in the air. If there is a fire, there is a risk of combustion and explosion. A large amount of liquid oxygen was discharged into the trench in a chemical fertilizer plant, and the electric welding spark caused an explosion injury accident. Therefore, it is strictly forbidden to discharge the liquid into the trench at will, and it should be discharged into the liquid evaporation tank or special low temperature resistant metal discharge pit through pipeline.DEAR Air separation plant.According to the required heat transfer area. Multiple units can be arranged in parallel, star or multi-layer. Therefore, the height of the plate unit of the condensing evaporator of the air separation unit is still maintained at 1.8 ~ 2.1m. Only a few countries use longer unit height in thermosyphon evaporator.According to the different types of products, it can be divided into single high product unit for pure production of high purity oxygen, double high product unit for simultaneous production of high purity oxygen and high purity nitrogen, argon extraction unit or total extraction unit with rare gas extraction. According to the form of products, it can be divided into the device for producing gaseous products, the device for producing liquid products and the device for producing both gaseous and liquid products.
DEAR Air separation plant.In recent years, there are more and more air separation units using molecular sieve purification process, and the main heat exchanger is non switching plate fin heat exchanger. No matter what process the heat exchanger is used for, the arrangement of cold section and hot section is different from that of switching heat exchanger.The structure of water cooling tower for large air separation plant in China is as follows: packed tower. In the early stage, it was equipped with ceramic lacigo ring, which had good heat transfer effect and little resistance. However, when it is used in the self cleaning low-pressure process, because the switching system is switched every few minutes, the air flow has a great impact on the porcelain ring during the switching venting, which is easy to cause the porcelain ring damage and increase the resistance. There are also plastic rings to increase strength.DEAR Air separation plant.Before shutdown or opening, the operating pressure of the whole oxygen pipe network shall be regulated by oxygen compressor to 1.8MPa (the minimum allowable operating pressure). Try to reduce the pressure difference between the front and back of the oxygen valve, and reduce the discharge volume of the shutdown pipeline or spherical tank.
