DEAR Liquid air separation unit.The cooling water used in the air compressor cooler is generally the industrial water without softening treatment. When the water temperature is high, the bicarbonates such as calcium and magnesium in the water will decompose into hard deposits on the pipe wall, which is called scale. The amount of scale formation is related to the water temperature, time and water quality.DEAR Liquid air separation unit.Solid regenerator is called filler. There are two commonly used types: stone and aluminum strip, so there are two types: Stone accumulator and aluminum strip accumulator. Because the pure product coil channel can not be set in the aluminum strip accumulator, high purity oxygen and nitrogen products can not be obtained, so it has been eliminated. The accumulator makes the water and carbon dioxide in the air freeze at the same time, which plays the role of purifying the air.DEAR Liquid air separation unit.The cooling water with increased temperature is led out from the lower part and sent to the water cooling tower or discharged (for open system). The cooled air is discharged from the top of the tower and sent to the air separation tower or molecular sieve adsorber. The disadvantage of packed tower is that the packing is easy to be blocked by scale, and the packing forms into large pieces, which is difficult to clean and replace.
The purpose of temperature condition adjustment is to keep the temperature difference between cold end and hot end within the specified range. Then, why should the middle temperature be taken as the criterion? It depends on the relationship between the middle temperature and the temperature difference between the cold end and the hot end, as well as the law of temperature change along the height direction of the accumulator (or switched heat exchanger).DEAR Liquid air separation unit.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.DEAR Liquid air separation unit.After switching, the working condition is normal. If the waste nitrogen automatic valve is damaged, the pressure of the upper tower will rise when the air is flowing, and the pressure will be normal when the waste nitrogen is flowing. When equalizing, the air leaks into the low-pressure system, resulting in the pressure reduction in the channel after equalizing, and the pressure of the low-pressure system increases.
DEAR Liquid air separation unit.In the stage of effusion, the liquid of low pressure oxygen generator is mainly produced by liquefier. It liquefies the low-temperature positive air cooled by heat exchanger by the expanded low-temperature gas (- 185 ～ - 189 ℃). The pressure of positive flow air is 0.5 ～ 0.6MPa, the temperature out of the switching heat exchanger is - 171 ～ - 172 ℃, and the liquefaction temperature is - 172.5 ～ - 176.5 ℃Expander, freezer, air precooling system and argon purification system shall be shut down by interlocking. If there is no shutdown, it should be stopped manually; stop the delivery of oxygen, nitrogen and other products, stop the removal of liquid oxygen, liquid nitrogen and liquid argon; close the water valve connecting the air precooling system with the outside. The rest are operated according to the requirements of normal shutdown. After the above operation, find out the cause of the fault and prepare for restart.DEAR Liquid air separation unit.In order to reduce the moisture brought into the purifier (or dryer) by the heating gas and ensure the service life of the purifier (or dryer), the heating pressure of the purifier should be controlled to the normal working pressure (2MPa). In addition, the gas flow velocity in the purifier is inversely proportional to the pressure.
