Air separation unit.The volume fraction of argon in air is 0.932%, and its boiling point is between oxygen and nitrogen. When it enters the lower column and rises block by block along the tray, because argon and oxygen are relatively nonvolatile components to nitrogen, they condense more into the liquid phase than nitrogen.The position of oxygen generator explosion is related to the type of air separation unit to some extent. In the process of high, medium and double pressure, the possibility of explosion is relatively high; in the device of producing liquid oxygen, the main cooling has not been exploded, while the main cooling of gas oxygen device is the central part of explosion. The degree of explosion damage is related to the explosion force, and the weak explosion may only damage individual pipes, even not be detected by the operator.Air separation unit.If you want to increase the output of liquid products and open one more expander in normal production, it is OK only from the perspective of cold balance, but too much expansion air into the upper tower will destroy the distillation condition of the upper tower and reduce the extraction rate of low oxygen. At the same time, taking more liquid will also affect the working condition of the heat exchanger in the tower and the reflux ratio of the distillation tower, so it is also limited.
Air separation unit.The number of molecules leaving the liquid is in dynamic equilibrium with the number of molecules returning from space, which is also called "saturated state". At this time, the pressure produced by steam is called "saturation pressure". For the same substance, the saturation pressure is related to the temperature.Air separation unit.Adjust the distillation condition of upper column, and strive to improve the average nitrogen purity. The average nitrogen purity indicates the oxygen loss rate. The average nitrogen purity depends on the purity of sewage nitrogen, because the proportion of sewage nitrogen is large. The purity of waste nitrogen is mainly guaranteed by the supply of qualified liquid nitrogen from the lower tower.Because the density of the vapor-liquid mixture formed in the boiling process is relatively small, the longer the tube is, the better the condensation heat release is. Generally, when l > 1.2m, the flow of condensate film has become turbulent.Although the chemical properties of N2O are inactive, neither corrosion nor explosion will occur, its physical properties are harmful to air separation. Its critical temperature is 309.7k, critical pressure is 7.27mpa, and its three-phase point is 182.3k and 0.088mpa. Under the condition of pressure and temperature of air separation device, it has sublimation property. At atmospheric pressure, its boiling point is 185K, which is higher than that of N2, O2 and ar. therefore, it will be concentrated in liquid oxygen during the separation of oxygen and nitrogen.
Air separation unit.The oxygen flow rate in the oxygen pipeline shall be in accordance with the provisions of code for design of oxygen station (GB 50030-91): when the pressure is greater than 10MPa, the oxygen flow rate shall be less than 6m / S; when the pressure is between 3Mpa and 10MPa, the oxygen flow rate shall not be greater than 10m / S; when the pressure is between 0.1MPa and 3Mpa or less, the oxygen flow rate shall not be greater than 15m / S; when the pressure is between 3Mpa and 3Mpa, the oxygen flow rate shall not be greater than;The amount of backflow gas and its temperature into the accumulator (or switching heat exchanger) are basically unchanged, and the heat transfer area is also unchanged, so the heat transfer temperature difference will expand. Therefore, although the temperature of the hot end of the backflow gas increases, it is less than that of the air entering the device.In argon production, part of liquid air and liquid nitrogen in the main tower need to be pumped as cold source. At the same time, due to the increase of equipment, the cold loss increases correspondingly. Therefore, more cooling capacity is required to keep the balance of cooling capacity. For medium pressure device, high pressure should be increased.
