DEAR Air separation plant.The mechanical water is carried out with the air and enters the molecular sieve purifier or the switching heat exchanger, which destroys the normal operation of the device. The causes of this failure are as follows: the screen hole of the sieve plate is partially blocked. The spray water of the air cooling tower flows down through the cross flow sieve plate and constantly contacts with the air.In the production of rare gases krypton and xenon, with the concentration of krypton and xenon, N2O is also concentrated. The content of N2O can reach 100 × 10-6 ~ 150 × 10-6. N2O itself does not burn, but can decompose. This will affect the removal of CH4 from crude krypton and xenon and the adsorption of water and carbon dioxide by molecular sieve.DEAR Air separation plant.Before the liquid appears in the start-up stage of the air separation unit, the lowest temperature is generated by the expander, and the temperature in the distillation column can not be lower than the temperature after expansion. However, liquid appears in the lower tower, and when the saturated liquid throttles to the upper tower, the pressure decreases, part of it gasifies, and the temperature also decreases to the saturation temperature corresponding to the upper tower pressure. For example, when the liquid nitrogen at - 177 ℃ on the top of the lower tower is throttled to the upper tower, the temperature can be reduced to - 193 ℃.
DEAR Air separation plant.Membrane air separation method: it uses the permeation selectivity of some organic polymer membranes. When air passes through the membrane (0.1 μ m) or hollow fiber membrane, the speed of oxygen passing through the membrane is about 4-5 times that of nitrogen, so as to realize the separation of oxygen and nitrogen. The oxygen enrichment concentration of this method is generally suitable for 28% - 35%, and the scale is only suitable for medium and small scale.The underground pipeline of dry oxygen can be laid above the freezing line, but the depth is not less than 0.8m, so as to avoid pipeline fracture caused by ground transportation load. Other regulations can be carried out according to relevant regulations; the oxygen pipeline shall be equipped with static electricity conducting grounding device;DEAR Air separation plant.Close the regulating valves of liquid air, liquid nitrogen and sewage liquid nitrogen. Fully close the oxygen and nitrogen product delivery valve, open the vent valve, and place the waste nitrogen vent three-way valve on the vent side. Fully close the butterfly valve of the expansion air into the upper tower, and open the bypass valve.
In order to reduce the temperature of the process air entering the purifier before the molecular sieve purifier, the nitrogen water precooling system, including air cooling tower and water cooling tower, is usually installed in the low-pressure oxygen generator. In the air cooling tower, the air enters from the bottom, leads out from the top of the tower and enters the molecular sieve purifier.DEAR Air separation plant.Krypton and xenon are mainly used in electric light sources. The lamp filled with krypton, xenon and argon mixture has the advantages of small volume, long service life and high efficiency. Generally, the efficiency is 4-5 times higher than that of incandescent lamp, and the service life can be increased by 2-3 times. Krypton and xenon are used in flash lamp and stroboscope. Because the discharge intensity of xenon lamp is higher than that of sunlight, the long arc argon lamp filled with xenon gas, commonly known as "little sun", has strong fog piercing ability, and can be used for lighting in airports, stations, docks and other places, as well as in the battlefield.
