1. High heat transferring rate. Because different corrugated plates are inverted to form a disordered channel, the fluid in the channel between corrugated plates can rotate in three dimensions, and turbulent flow can occur at a lower Reynolds number (usually Re = 50 ~ 200), so the heat transfer coefficient is high, which is generally considered to be 3 ~ 5 times of the shell and tube type.
2. In the shell and tube heat exchanger, the two kinds of fluid move in the tube side and shell side respectively, which is generally cross flow activity, and the logarithmic uniform temperature difference coefficient is small, while the plate heat exchanger is mostly parallel flow or counter flow activity, and its coefficient is usually 0.95. In addition, the activities of cold and hot fluid in the plate heat exchanger are parallel to the heat exchange surface, and there is no side flow The temperature difference of plate heat exchanger is small, and the heat transfer of water can be lower than 1℃, while that of shell and tube heat exchanger is usually 5℃.
3. the requirement of building space is more smaller, the structure of plate heat exchanger is compact, the heat exchange area per unit volume is 2 ~ 5 times of that of shell and tube type, and it is not like shell and tube type to reserve the maintenance place for the extraction tube, so as to realize the same heat exchange. The floor area of plate heat exchanger is about 1 / 5 ~ 1 / 8 of that of shell and tube type.
4. Simply changing the heat exchange area or process combination, only adding or reducing a few plates can achieve the purpose of adding or reducing the heat exchange area; changing the plate placement or replacing a few plates can achieve the required process combination and get used to the new heat exchange conditions, but it is impossible to add the heat transfer area of shell and tube heat exchanger.
5. The plate thickness of plate heat exchanger is only 0.4 ~ 0.8mm, while that of shell and tube heat exchanger is 2.0 ~ 2.5mm. The shell and tube structure of shell and tube heat exchanger is much heavier than that of plate heat exchanger, and plate heat exchanger usually only needs 1 / 5 of shell and tube structure.
6. The cost of plate heat exchanger is about 40% ~ 60% lower than that of shell and tube heat exchanger under the same material and heat exchange area.
7. It is convenient to manufacture. The heat transfer plate of plate heat exchanger is made by stamping, which has high standardization and can be produced in large quantities. Shell and tube heat exchanger is usually manufactured by technology.
8. Simple cleaning operation. The structural plate heat exchanger only needs to loosen the pressing bolts to loosen the plate bundle and remove the plates for mechanical cleaning, which is very convenient for the heat exchange process that often needs to clean the equipment.
9. The heat loss is smaller. The plate heat exchanger only needs the shell plate of the heat transfer plate to be exposed to the atmosphere, so the heat loss can be ignored, and the heat preservation method is not required. The heat loss of shell and tube heat exchanger is large, so it needs insulation layer.
10. Smaller middle-process product content, 10% ~ 20% of shell and tube heat exchanger.
11. The pressure loss per unit length is larger than that of the traditional smooth tube because the gap between the heat transfer surfaces is smaller and the height of the heat transfer surface is higher.
12. It is not easy to stick, because the internal turbulence is abundant, and its scaling coefficient is only 1 / 3 ~ 1 / 10 of the shell and tube heat exchanger.
13. The working pressure should not be too high, the medium temperature should not be too high, the plate heat exchanger should be sealed with gasket, the working pressure should not exceed 2.5MPa, and the medium temperature should be below 250℃.14.Take care on blocking for some special products, because the channel between plates is very narrow, usually only 2 ~ 5mm. When the heat exchange medium is rich in larger particles or fibrous materials, the channel between plates are blocked.
14. Take care on blocking for some special products, because the channel between plates is very narrow, usually only 2 ~ 5mm. When the heat exchange medium is rich in larger particles or fibrous materials, the channel between plates are blocked.