Problems have occurred in the air separation process
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These past few days, every time the molecular sieve is pressurized, towards the end of the 14-minute pressurization process. Initially, the liquid level in the liquid-air column rose from 600 to around 670; as a result, v1 increased from 48% to 58%, which led to an increase in the liquid flow going downward in the upper tower. The liquid level in the main cooler rose by about 100, and ultimately this caused the concentration of impure nitrogen to drop from 5% to below 1%, while the oxygen purity decreased very rapidly. During that period, many methods were tried: increasing the setting of V2 for liquid nitrogen, collecting liquid nitrogen, raising the value of V2, and manually controlling V1. None of them are that good. Is there any way to get some guidance from an expert?
The graph above shows the decrease in oxygen purity during pressurization; under normal conditions, it does not decline in this way and remains quite stable.
If a change occurs during the switching, it is necessary to check whether the production conditions of the two groups of purified gas are different Analyze it from this perspective first; there’s no need to make adjustments hastily. Whether the production conditions of the two groups are consistent as seen from the air flow trend. Inconsistency indicates a possible internal leak in the switch valve, for reference only.