DEAR Biogas purification unit.The most likely leakage place of the switching heat exchanger is the weld, especially the joint between the head and the pipe. The causes of leakage are mostly manufacturing and installation quality problems, and also related to maintenance. The working condition of the switching heat exchanger is poor. It is not only impacted by the alternating air flow, but also the air temperature changes greatly. In the long-term operation, the weak part is easy to leak.DEAR Biogas purification unit.The process of extracting neon and helium from air separation unit is generally divided into three steps: the first step is to prepare crude neon and helium; the second step is to prepare pure neon and helium mixture; the third step is to separate neon and helium to obtain pure neon and helium products. The purpose of the preparation of crude neon and helium is to remove nitrogen from the raw material and concentrate it.DEAR Biogas purification unit.Oxygen generator is also called air separation equipment (referred to as air separation equipment), it has many kinds, according to different classification methods, there are many different types. According to the product purity, it can be divided into high purity oxygen production units with oxygen purity above 99.2%, low purity oxygen production units with oxygen purity about 95% (also called process oxygen) and oxygen rich oxygen production units with oxygen purity less than 35% (also called liquefied air).
DEAR Biogas purification unit.The thermal conductivity of copper is about 8 times that of steel, and that of aluminum is more than 4 times that of steel. In the heat exchanger, for a certain heat load, the required heat transfer area can be reduced, so copper or aluminum materials with high thermal conductivity are often used. Most of the heat exchangers in air separation plant work at low temperature, and the general steel will produce brittleness at low temperature.DEAR Biogas purification unit.Air pressure test on site is mainly to check the air tightness of the equipment. Attention should be paid to the following problems during pressure test: it is strictly forbidden to use oxygen as the pressure test gas source; clean and oil-free pressure test gas source should be used for the oil-free equipment which is no longer degreased after pressure test; the pressure gauge used for pressure test should be calibrated and lead sealed before use.Due to the increase of air velocity, pressure, backwater volume and spray volume, a large amount of water will be brought into the air separation tower. When the purifier was switched over, water was carried out due to the impact of air flow due to too fast speed. In order to prevent water carrying accident, careful management and operation of nitrogen water precooler should be strengthened.
DEAR Biogas purification unit.When the external work W is consumed in the steam compressor 1 and the refrigerant is compressed to a certain pressure, the corresponding saturation temperature will be higher than the ambient temperature. When passing through condenser 2, heat Q1 is released to the cooling water, and then it is condensed into liquid. After throttling and depressurizing through throttle valve 3, part of the liquid is gasified, and with the decrease of pressure, the corresponding saturation temperature also decreases.Stop pressure test can be carried out only after external leakage is eliminated. After the heat exchanger is raised to the maximum working pressure and stopped for 1 hour, it is qualified if the pressure does not drop obviously. Pressure test of lower tower system. Close the liquid nitrogen throttle valve, liquid air throttle valve and liquid air to argon tower valve.DEAR Biogas purification unit.The middle temperature difference between the control units is generally not greater than 3 ~ 5 ℃; the middle temperature should not be too low, and the cooling capacity should not be too much concentrated in the main heat exchanger, resulting in the increase of the temperature difference at the hot end. When the temperature of the cold end reaches the air liquefaction temperature, the cooling capacity should be transferred to the distillation system to make the distillation system cool enough, accumulate liquid as soon as possible and establish the distillation system.
