Air separation plant maintenance

There are mainly the following factors that affect the output of oxygen: 1) insufficient processing air volume. The reasons for the shortage of air volume include: ① the ambient temperature is too high; ② the atmospheric pressure is too low; ③ the air suction filter is blocked; ④ the low voltage or the frequency of the power grid will reduce the rotating speed; ⑤ the cooling effect of intermediate cooler is not good; ⑥ internal leakage exists between levels; ⑦ air leakage of valve and pipeline, and leakage of automatic valve or switching valve; ⑧ for the purification process of molecular sieve, it may be the air leakage of switching butterfly valve. 2) the average purity of nitrogen is too low. The reasons are: ① the efficiency of the distillation column is reduced; ② the expansion air volume is too large due to too much cold loss; ③ the purity of liquid nitrogen is too low and the liquid nitrogen volume is too large; ④ the liquid nitrogen volume is too small; ⑤ leakage of liquid ai...

Reducing the high pressure of small air separation equipment with medium pressure expansion machine can reduce the energy consumption of air separation equipment. Here is a simple analysis of the influence of the temperature before the expansion machine on the high pressure. Under the condition that the total cooling loss and the gas temperature before expansion are fixed, from the perspective of the heat balance of the total unit, increasing the high pressure can reduce the expansion gas; but from the perspective of ensuring the working condition of the cold section heat exchanger, with the increase of high pressure, it is required to increase the expansion amount and reduce the air flow into the cold section heat exchanger. Therefore, the selection of working pressure and expansion amount of the process should meet both requirements. When the total cooling loss and working pressure of the process remain the same, increasing the temperature of expansion forward gas can increase the...