The load adjustment range of low pressure air separation plant is related to the adjustment performance of raw material air compressor, the adjustment performance of expansion machine, the structural characteristics of distillation column and other factors. At present, the flow regulation range of the turbine air compressor equipped with imported guide blades is 75% ~ 100%; the adjustment range of turbine expansion machine with adjustable nozzle can be 65% ~ 100%. The key is how much room for adjustment of the distillation column is. At present, the load regulation range of the distillation column with regular stuffing can reach 50% ~ 100%, while the best adjustment range of traditional screen tower is 70% ~ 100%, no matter how low the load is, the leakage may be caused by the low speed of steam passing through the sieve hole.
When oxygen is rich and needs to reduce the output of oxygen, the output of oxygen products should be reduced first, then the air flow should be reduced correspondingly, and the inflated air volume should be adjusted according to the main cold liquid level. The liquid air and liquid nitrogen regulating valve sent to the upper tower should also be cut down correspondingly according to the rectification working condition. It should be noted that the whole operation should be completed slowly and step by step to keep the stability of the rectification working condition in the process of reduction.
If there is a liquid oxygen storage system, reducing the output of oxygen can increase the output of liquid oxygen, making it more convenient to store liquid oxygen. We can reduce the output of oxygen first, then increase the expansion air volume, and increase the amount of liquid oxygen extraction under the condition of keeping the main cold liquid level unchanged. In order to keep the stability of the rectification working condition of the upper tower, part of the expansion air can be bypass if necessary.
