Standardize the operation of air cooling towers. Air should be introduced into the tower first, and water should be introduced after the pressure has increased and stabilized. Do not suddenly increase or decrease the gas volume to avoid causing severe fluctuations in pressure and water level inside the air cooling tower. Maintain the water level of the air cooling tower within the normal range to avoid water entering the molecular sieve purifier with air due to excessive water level. It is recommended to use a silicone oil sensing level gauge and regularly clean the debris inside the flange of the level gauge to ensure accurate readings. At the same time, the central control DCS control system should be equipped with alarm and interlock signals, and each shift should calibrate the liquid level gauge with the site. In winter, the liquid level gauge should have steam tracing measures to prevent inaccurate readings due to low temperatures. The water quality should meet the requirements, reduce the inlet temperature, and minimize scale buildup. The circulating water system should regularly clean the filter screens in front of the circulating water pump and chilled water pump to prevent impurities from clogging.
Optimize the management of the air separation unit. After the air separation unit is shut down, the liquid inside the air cooling tower must be completely discharged, all inlet and outlet valves of the air cooling tower must be closed, and the discharge valve must be opened to prevent water backflow. Program monitoring ensures that the molecular sieve switching program is normal, avoiding sudden emptying of air through the molecular sieve adsorber due to program disorder, resulting in a sharp increase in airflow velocity in the air cooling tower, and water entering the molecular sieve adsorber with air.
Strengthen daily maintenance and inspection, regularly inspect and clean the air cooling tower, water cooling tower and their distributors to prevent blockages in the distributors that may cause poor heat transfer and mist entrainment. The steam heating adopts a double tube plate type, and the inspection of the discharge pipes between the double tube plates is strengthened to ensure accurate online analysis of the dew point of the nitrogen gas at the outlet of the steam heater. Alarm and interlock devices are set up on the DCS control system.
