DEAR Air separation equipment.The liquefying temperature of gas is not only related to the type of gas, but also related to the pressure. The higher the pressure. The closer the molecules are, the easier they are to attract each other and turn into liquid. Therefore, the liquefaction temperature decreases with the increase of pressure. For air, the liquefying temperature is - 149 ℃ when the pressure is 2.45mpa;DEAR Air separation equipment.Start the purification stage ahead of time. When the liquid level reaches 60% of the normal level, there is liquid on the tray, and the distillation process of gas-liquid heat and mass exchange has been carried out. Therefore, according to the previous operation experience, we can enter the purification stage ahead of time. Some plants shorten the cold start-up time to less than 20h, reduce the power consumption and provide oxygen and nitrogen products in time.With the continuous increase of the flow rate of central extraction or circulation, the circulating temperature becomes lower and lower, the cold end of the switching heat exchanger becomes colder and colder, and the temperature in front of the expander still can not be increased. Finally, the adjustment means are lost, resulting in a passive situation. The reasons for this situation are: there is no proper restriction on the flow rate of central suction or circulation before liquid accumulation; the liquefier is connected late, or the liquefying effect of liquefier is poor;
DEAR Air separation equipment.1 g potassium dichromate or 2 g sodium nitrite can be added to each liter of water (not suitable for nonferrous metal degreasing); due to the toxicity or explosion of degreasing agent, attention must be paid to prevent poisoning and formation of explosive mixture. In alkaline cleaning, the pipeline with more oil stains is heated to 60-90 ℃ with 10% sodium hydroxide solution, then neutralized with 15% nitric acid and washed with clean water.DEAR Air separation equipment.The gas-liquid two phase moves vigorously on the sieve plate to form a foam layer, which increases the contact area and disturbance degree of the gas and liquid, and makes the gas and liquid energy transfer well in heat and mass. The effect is better than that of the packed tower. There is neither packing nor sieve plate in the hollow tower. The cooling water is sprayed downward by layers through the spray device, the air flows from bottom to top, and the gas and liquid are mixed directly.DEAR Air separation equipment.Neon filling in the bulb is red. It has been used to fill neon signal devices and various discharge tubes for a long time. It is also widely used in laser technology, infrared detection and other aspects. The gasification latent heat of neon is 40 times higher than that of helium, so it can be used as a refrigerant for ultra-low temperature, and its minimum temperature is - 245.9 ℃. Neon and helium can also be used to measure the true density and surface area of porous materials.
DEAR Air separation equipment.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 Air separation equipment.In the distillation column, because N2O is a high boiling point component relative to N2, O2 and AR components, it will be dissolved in liquid oxygen, resulting in the inability to obtain high purity liquid oxygen and gaseous oxygen products at the bottom of the upper column. According to the determination, when the purity of oxygen product is 99.5%, the average content of N2O is 1.4 × 10-5. Moreover, when the liquid oxygen is not discharged sufficiently, N2O accumulates continuously in the liquid oxygen. When the N2O content in the liquid oxygen is more than 50 × 10-6, it will precipitate as a solid state and block the main condenser evaporator channel.
