Plate heat exchangers are made of thin metal plates pressed into corrugations. The cold and hot fluids flow on both sides of the plate and exchange heat through the metal plates. The four corners of the plate are provided with flow channel holes to form a fluid distribution pipe and a converging pipe. Both ends of the whole equipment are tightly sealed with movable end caps and fixed end caps. The main advantage of the plate heat exchanger is that when the fluid flows through the corrugated surface, the flow direction is changed from time to time to form artificial turbulence, so that the medium can reach turbulent flow at a lower flow rate, and the heat transfer coefficient is large. It is very convenient to disassemble, clean, overhaul, increase or decrease plates to adjust the heat transfer area. But the flow channel of the medium is narrow and easy to be blocked.
The boiling temperature is low, and the vacuum cooling is based on the principle of the relationship between the boiling temperature and pressure of the solution in a closed container. Under low pressure and vacuum conditions, the boiling temperature is lower than the boiling temperature under normal pressure. The higher the vacuum, the lower the boiling temperature. When the high-temperature sodium aluminate liquid enters the vacuum container, its own temperature is higher than the boiling temperature under the vacuum condition. The liquid is self-evaporating while achieving the purpose of cooling down. The evaporated gas is condensed by circulating cooling water and then circulated with circulating cooling water, and the liquid is concentrated and cooled. Part of the self-evaporating heat in the vacuum cooling process is taken away with the circulating cooling water and released to the air in the circulating water tower. The other part is discharged with air with the vacuum pump.