A water cooling tower is a hybrid heat exchanger. The purpose is to lower the water temperature of the cooling water in the cooling tower after cooling the air, in order to provide it for circulation in the air cooling tower. Different types strive to enhance heat transfer, improve cooling efficiency, and minimize flow resistance to prevent water from scaling.
1) Packed tower. In the early days, it was equipped with porcelain made Rasigo rings, which had good heat transfer performance and low resistance. However, when used in the self cleaning low-pressure process, due to the switching system switching every few minutes, the impact of the airflow on the ceramic ring is significant during the switching vent, which can easily cause damage to the ceramic ring and increase resistance. There are also plastic rings to increase strength. At present, a new type of packed tower is used in air separation equipment with a capacity of 6000~0000m3/h, using alpha Bauer rings, conjugate rings, and stepped rings. It has the advantages of high flow rate, low resistance, good heat transfer effect, and good strength. The heat transfer temperature difference at the hot end is around 0.5 ℃, and the negative temperature difference (water temperature lower than nitrogen temperature) of the effluent can reach 4-9 ℃, depending on the gas-liquid ratio.
2) Swirl plate. It is composed of several metal structured vortex trays. This structure has minimal resistance and will not be damaged, and has been used as an improved version for a considerable period of time. But the heat transfer effect is not as good as that of a packed tower.
3) Sieve plate tower. The tray adopts a shower tray with a larger aperture and spacing between holes. Both nitrogen and water pass through the sieve. Due to the fact that the water cooling tower does not operate continuously and stably, the cooling effect is not ideal enough, so it is no longer used.
