The molecular sieve purification system is a key part of the air separation equipment, used to adsorb impurities such as water, CO₂ and hydrocarbons. Water intake will lead to molecular sieve failure, equipment corrosion and operational failure.
Preventive measures:
1. Optimize the operation of the pre-cooling system, regularly check the chilled water unit and pump to ensure that the outlet air temperature is ≤15℃. Install high-efficiency air-water separator and set liquid level interlock alarm (automatic drainage when liquid level is too high).
2. Valve and pipeline management, choose switching valves with double sealing structure, and conduct sealing test (such as helium leakage detection) every month. Install on-line dew point meter at the inlet of molecular sieve (the alarm value is set to -40℃). Thoroughly empty the pipeline when shutting down and purge with dry nitrogen gas.
3. Standardize the operation procedure and perform at least 2 hours of low-pressure air purging (flow rate ≥ 0.5m/s) before start-up. Strictly monitor the regeneration temperature curve to ensure that the center temperature of the molecular sieve bed is ≥180℃. 4.
4. Add protective measures to install electric heaters in front of the molecular sieve adsorber (to quickly warm up and remove water in case of emergency). Configure standby adsorber to switch and isolate the faulty unit immediately after water intake.
Molecular sieve purification system water inlet accidents mostly stem from equipment defects or operational negligence, need to be pre-cooling system monitoring, valve sealing check, standardize the operation of the trinity of prevention. Once the water inlet, it should be shut down immediately to avoid the expansion of the accident. Regular maintenance and staff training is the key to guarantee the long cycle operation of the system.
