The air separation equipment in the molecular sieve purification process mainly focuses on fully utilizing the refrigeration capacity of the expander, reasonably allocating cooling capacity, and comprehensively cooling the equipment during the start-up process. It can be divided into three stages: cooling device, liquid accumulation, and adjusting working conditions.
Precautions during operation:
1. The molecular sieve used for the first time needs to undergo an activation regeneration to remove the adsorbed water and carbon dioxide during transportation and filling processes. The activation temperature is generally above 200 ℃ and below 250 ℃. When the outlet temperature reaches 80 ℃, it can be cold blown. The activation time shall not be less than two cycles;
2. When the molecular sieve is started, the gas delivery process should be slow, and the vent valve should be carefully closed to prevent damage to the molecular sieve in the bed due to pressure fluctuations;
3. When two expanders need to be started, the reflux valve of the booster should be fully opened to reduce the pressure of the first running expander. Then, both expanders should be loaded simultaneously to prevent the later started booster from surging;
4. Pay attention to temperature control in the middle of the heat exchanger;
5. Pay attention to the operation of the air cooling tower to ensure that the pre cooled air meets the design requirements.
