The running cycle of small-sized air separation plant is shorter than that of large-sized air separation plant, which is because small-sized air separation plant has no thorough removal of impurities than large-sized air separation plant. Therefore, in order to prolong the running cycle of the air separation Tower, we must start from the problem of removing water, carbon dioxide and grease:
1) most of the moisture in the air is precipitated in the process of air compressor compression and cooling, and is removed in the oil-water separator, and a small amount is adsorbed in the dryer (or purifier. If the amount of water entering the purifier increases, its cleaning load will increase, and the service life will be shortened, and the amount of water brought into the tower will increase. Therefore, it is very important to blow off oil-water separators at all levels correctly regularly. The water content in the compressed air is related to the temperature. Therefore, the cooling effect of the air compressor can not be ignored, and enough cooling water with lower temperature should be guaranteed for all levels of coolers.
The amount of water brought into the tower is finally related to the degree of purification of the purifier. And its effect is related to the working pressure and temperature, the degree of regeneration and perfection, the performance of absorbents and the amount of processing air volume. When the conditions change, the working cycle should be adjusted timely. This can be determined according to the moisture analysis results of the outlet. The dew point after silica gel drier should be-52 ℃; the dew point after molecular sieve purifier should be less than-72 ℃;
2) in the past, alkali washing was used to remove carbon dioxide, but now it has been replaced by molecular sieve absorption. Its operation key points are to ensure the perfection of regeneration and control the use cycle, to ensure that the work cycle is shorter than the molecular sieve adsorption conversion point, and to make the content of carbon dioxide in the purified air less than 2×10-6;
3) There are two sources of Grease: one is the excessive amount of lubricating oil in the air compressor cylinder; the other is the failure of the expansion air filter. For the lubricated compressor, attention should be paid to control the amount of lubricating oil (the amount of oil of type 1-15/50 air compressor equipped with 150 m 3/h oxygen generator is 250 g/h ); for those with expansion air filter, heat and blow them off regularly. Currently, most of the new equipments have adopted non-lubricating air compressor and expansion machine, which can solve the problem of oil thoroughly.
In addition, pay attention to the daily maintenance and maintenance of running machines such as air compressor and expansion machine; clean the air filter regularly; ensure that the normal operation of the purifier regeneration heating furnace will also affect the whole running cycle of the unit.
