The air separation equipment in the molecular sieve purification process mainly focuses on fully utilizing the refrigeration capacity of the expander, allocating cooling capacity reasonably, and comprehensively cooling the equipment during the start-up process. It can be divided into three stages: cooling equipment, accumulation of liquid, and adjustment of operating conditions.
Precautions during operation:
1. The first use of molecular sieves requires an activation regeneration to remove adsorbed moisture 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 supply process should be slow, and caution should be taken when closing the vent valve to prevent damage to the molecular sieve in the bed due to pressure fluctuations;
3. When two expanders need to be started, the return valve of the booster should be fully opened to reduce the pressure of the first running expander, and then both expanders should be loaded simultaneously to prevent the later starting booster from surging;
4. Pay attention to the control of the temperature 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.
