Intro
The air separation unit is a supporting project of public works, providing nitrogen, oxygen and argon for construction for each unit, power station and auxiliary facilities. The main product of nitrogen is used for purging, sealing, displacement and security. The air cooling tower is an air pre-cooling system, the main function is to compress the gas into the air cooling tower to be cooled and washed by water. The upper part of the air cooling tower is cooled by the low temperature water cooled by the chiller (RU1101 ~ 1103), and the lower part is cooled by the cooling water of the self-circulating water system. The top of the air cooling tower is provided with a free water separation device and a unique anti-flooding device to prevent the free water in the air from being brought out.
Inspection process
The double-flanged liquid level gauge was checked, and the positive pressure side capsule was inelastic, with rust and scale attached to the surface. After cleaning the rust and scale, it was found that the capsule had pinpointed small holes. The indicator returned to normal after replacing the level gauge.
Cause analysis
The double flange liquid level gauge cartridge is damaged, and the lack of silicone oil causes abnormal fluctuation of liquid level, triggering high interlock and causing air compressor unloading. The air cooling tower cools the air compressed by the air compressor and cleans the dust, the water contains dust and impurities, the positive pressure side flange of the double flange level meter is relatively static, and the dust and impurities will precipitate on the surface of the diaphragm, without considering the scaling problem of the diaphragm. There is no set period to discharge and flush the pressure inlet and capsule on the positive pressure side.
Preventive measures:
1, based on the safety instrument system, according to SIL grading, interlocking grade, device importance, production impact, improve the classification of instrument equipment. Allocate manpower and funds according to instrument grade, and tilt management toward important instrument equipment.
2. Promote the data improvement and application of the instrument failure database, record the failure of the instrument equipment, realize the automatic classification statistics of overhaul and maintenance, establish the whole life cycle management of the instrument equipment, and provide reliable data support for the maintenance and overhaul of the instrument.
3, improve the preventive maintenance program of key units, the interlock instrument of the attached system of key units is included in the inspection content. And explore the air cooling tower level gauge for preventive discharge cycle.
The End
