The main function of the pre-cooling system is to cool the wet air after pressurisation of the air compressor, and further wash the micro-particles of dust, part of the water-soluble substances (NH3, SO2, etc.) and other impurities in the air. The air cooled by the air-cooled tower air approximate saturated wet air, according to the working characteristics of the purification system, wet air out of the air-cooled tower, the lower the temperature of the water content is lower, and the more conducive to reducing the adsorption load of the purification system.
Working principle and process: the air-cooled tower is divided into two sections, the lower section of the cooling water with circulating water, the upper section of the cooling water with chilled water, the direct use of cooling water and chilled water in the bulk packing and wet air contact heat transfer to reduce the temperature of the wet air. Cooling water is introduced from the lower part of the air cooling tower and chilled water from the upper part of the air cooling tower. The cooling water comes from the pool of the cooling water supply pipe network of the plant, and is introduced after being pressurised by the cooling water pump, and then collected at the bottom of the air-cooling tower after heat exchange and returned to the cooling water return pipe network. The chilled water comes from the circulating pool, and contacts with dry dirty nitrogen in the water-cooled tower, using the latent heat of vaporisation of water to achieve cooling, and then further reduces the temperature by the ammonia freezer, and then is introduced under pressure by the chilled water pump. At the top of the air cooling tower, there is a water collector, which can separate the free water entrained in the air.