Reasonable selection of heat exchange area is the key to procurement. When selecting the heat exchanger, the required flow shall be selected according to the process requirements, the viscosity of the feed liquid, the temperature difference of the heat exchange, etc. Excessive flow will cause waste, and the flow channel is easy to block. If the pressure is too small, it will affect the use, increase the non fermentation time, and cause damage to the deflector due to excessive pressure. Therefore, scientific selection and purchase shall be made according to working conditions.
The plate thickness of plate heat exchanger is only 0.6~0.8mm, and the heat exchange tube thickness of shell and tube heat exchanger is 2.0~2.5mm; The shell of shell and tube heat exchanger is much heavier than the layout of plate heat exchanger. In the case of completing the same heat transfer mission, the required heat transfer area of plate heat exchanger is smaller than that of shell and tube heat exchanger.
The layout of shell and tube heat exchanger is excellent in terms of strength, but it is not ideal from the perspective of heat exchange. As the fluid moves in the shell side, there are baffles shell, baffles heat exchange tubes, and tubes shell bypasses. The fluid passing through these bypasses does not fully participate in heat transfer. In plate heat exchanger, there is no bypass, and the ripple of plate can make the fluid turbulent at a small flow rate. Therefore, the plate heat exchanger has a high heat transfer coefficient, which is usually 3~5 times that of the shell and tube heat exchanger.