Air cooling tower and water cooling tower are key cooling and purification units in air separation equipment. They work together to provide qualified low-temperature and clean air for subsequent air compression, rectification and other processes. The core is to achieve cooling and preliminary removal of impurities through heat exchange through medium contact.
The air cooling tower is mainly used to cool the compressed air. High-temperature compressed air (about 80 ℃) from air compressor enters the bottom of air cooling tower and flows from top to bottom; Normal temperature cooling water is sprayed on the top of the tower and reversely contacts with air from bottom to top. Through heat exchange, the high temperature air transfers heat to the cooling water, and the temperature is reduced to about 30 ℃. At the same time, some water, oil and other impurities in the air are settled with the cooling water to achieve preliminary purification and avoid scaling or blocking of subsequent equipment.
The core of the water cooling tower is the circulating water used for cooling the air cooling tower to maintain the stability of the cooling effect. It adopts the "gas-water heat exchange" mode, uses the waste nitrogen (low temperature, dry) discharged from the air separation system as the cooling medium, enters from the bottom of the water cooling tower, and reversely contacts with the return water of the air cooling tower sprayed at the top of the tower. The waste nitrogen absorbs the heat in the circulating water, and is heated and discharged. The circulating water is cooled to normal temperature and then sent to the air cooling tower for recycling.
The two complement each other: the air cooling tower realizes air cooling by relying on the low-temperature cooling water provided by the water cooling tower, and the water cooling tower realizes circulating water cooling by relying on the cooling capacity of the contaminated nitrogen, so as to jointly ensure the stable and efficient operation of the subsequent processes of the air separation equipment.
