Cooling analysis of plate change

Supersaturated sodium aluminate in a tank of semen before decomposition in alumina production. Semen was essential for cooling, to ensure that in the mixed and refined into a first cell slurry temperature to meet the decomposition process requirements (5663 C), get higher aluminum hydroxide precipitation rate and particle size of coarse, good quality the. The Bayer process was used to produce alumina in a factory, and the design process of sodium aluminate semen was used as the first plate heat exchanger and vacuum cooling. Later, the mother liquid of the opposite plate was recovered, and the plate heat exchanger was modified to form a series of two series of vacuum cooling process. After the use of two plate type heat exchanger with a series of semen cooling can meet the requirements of decomposition process. At the same time, the temperature of the mother liquid of the vertical plate is greatly improved as the cold phase is changed.

At certain intervals. The edge of the plate is sealed by a sealing plate, and the plate type heat exchanger is made of thin metal plates to form special ripples. The cold and hot fluid flows on both sides of the plate, and the heat transfer is carried out through the metal plate. The four corners of the plate are provided with a flow passage hole. The equipment used at both ends of the movable end cap and fixed end cover pressing sealing gap between sheets as the main advantages of the 26mm heat exchanger is in fluid flow through the corrugated surface, and change the flow direction and destroying laminar flow, the formation of artificial turbulence, the medium at low velocity to turbulence, heat transfer coefficient compact structure, large heat transfer area per unit volume, per cubic meter volume with 2501250m2 heat transfer area. Disassembly, cleaning, maintenance, increase or decrease plate to adjust the heat transfer area is very convenient, flexible operation. But the medium flow channel is narrow, easy to scar, easy to plug. The heat emission of the plate heat exchanger is transmitted to the cold phase through the corrugated metal sheet, so that the cold phase absorbs the heat and the energy is effectively utilized, and the energy saving effect is obvious.

                                                            
      The boiling temperature is low, the vacuum cooling is based on the relationship between boiling temperature and pressure in the sealed container. Under the condition of vacuum, the boiling temperature is lower than the boiling temperature under normal pressure, the higher the vacuum degree, the lower the boiling temperature. When the temperature of the sodium aluminate semen into the vacuum container, due to its own temperature higher than the boiling temperature of the vacuum conditions, gas evaporation in semen and achieve the purpose of cooling through evaporation of circulating cooling water cooled with circulating cooling water circulation, the semen is concentrated and cooled. In the vacuum cooling process, part of the heat from the evaporation is taken away from the circulating cooling water and released into the atmosphere in the circulating water tower. The amount of heat from semen evaporation has not been recycled.