The compressed hot air enters the lower part of the air cooling tower, passes through the mass transfer unit in the air cooling tower from bottom to top, and in turn contacts with the lower section of normal temperature cooling water and the upper section of low temperature chilled water countercurrent for heat and mass transfer, so as to achieve the purpose of cooling the air and remove most of the water-soluble harmful substances. The normal temperature cooling water is directly supplied from the outside, and the low temperature chilled water is supplied after being cooled by the water cooling tower. Under the condition of no cooling tower, the low-temperature chilled water is completely provided by the chiller.
The waste nitrogen enters from the bottom of the water cooling tower and fully contacts with the normal temperature cooling water entering from the top of the water cooling tower. After heat and mass exchange, the waste nitrogen is humidified and heated before being discharged into the atmosphere. The normal temperature cooling water from the top of the water cooling tower is discharged from the bottom and becomes the low temperature chilled water at the top of the air cooling tower after being boosted by the chilled water pump.
In the design of the KDONAr-30000/70000/900 air separation unit of Anfeng Iron and Steel Co., Ltd., Kaifeng DEAR Air Separation Co., Ltd. independently developed a multi-layer main condensation evaporator for the equipment. In this multi-layer main condensation evaporator, the heat exchanger core, including multi-layer, has been modified to improve the liquefaction efficiency of nitrogen, which plays a good role in reducing the liquid film, greatly improving the heat exchange efficiency of the heat exchanger, further reducing the condensation and adhesion of liquid nitrogen on the side wall, This equipment not only reduces the pressure of the raw material air compressor, saves energy consumption, but also greatly improves the oxygen extraction rate, with a high cost performance ratio.
