urgent! Please help recommend a heat exchanger, urgent!
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It is necessary to add a heat exchanger on site. Its cold and hot sources are water with a large temperature difference. The heat source water temperature can reach 130-140 degrees. The cold source is circulating water. The heat source needs to be exchanged to normal temperature. The heat source water volume is about 5-10m3/h. In order to avoid frequent fouling of the heat exchanger due to excessive temperature differences, what kind of material and structure of the heat exchanger should be selected for better performance?~
Generally, this type of heat exchanger is used!
Reply 1# fzzhouhui It is recommended to choose a heat exchanger with double-grained tubes. The specific material will be combined with your site. If your site is corrosive, it is recommended to choose 316 pipes, but it also depends on the specific corrosiveness. Double-grained tubes have strong anti-fouling performance and high heat exchange efficiency.
Personal opinion, for reference only: 1. U-shaped tube heat exchangers can be used, and the outside of the tubes that are prone to scaling can be easily cleaned when scaling occurs. 2. Tube-type heat exchangers can be used, with dirt running inside the tubes, and the water speed should be relatively high, preferably greater than 2.5m/s, which can reduce the possibility of scaling. 3. Optional spiral baffle heat exchanger
Reply 3# zxf760718 The heat source side is pure water, which has certain requirements for water quality. How about using a glass-lined or graphite heat exchanger in this case?
Reply 2# onefly2009 But isn’t it difficult to clean a heat exchanger with this kind of structure if it becomes fouled? Is there any heat exchanger that can avoid the disadvantages of fouling caused by large temperature differences from the perspective of material selection, structure and ease of cleaning in the future? !
Reply 5# fzzhouhui Glass-lined or graphite materials are used in corrosive conditions. If the heat source is pure water as the poster said, and there are certain requirements for water quality, then 316 can definitely be used. The heat transfer coefficient of glass-lined or graphite materials is not as high as that of metal materials. It is not impossible to choose glass-lined or graphite materials, but the equipment may be larger and occupy a larger area. In addition, the heat transfer condition will be worse.
You can choose a heat exchanger that is less likely to be structurally blocked, but equipment investment and floor space will increase accordingly. You have to consider all factors comprehensively, and scaling can be solved by controlling the cooling circulating water. For example, adding a scale inhibitor and slow-release agent to the circulating water can extend and slow down the scaling cycle of the heat exchanger. Although heat exchangers such as tube and plate cooling are difficult to clean after scaling, they have the advantages of high heat exchange efficiency and small footprint, and are worth recommending. If you use stainless steel when selecting materials, you must pay attention to the control of chlorine.
It adopts 316L, with the easy-to-fouling side going through the shell side and the clean side going through the tube side. It adopts a U-shaped tube heat exchanger to ensure normal use under large temperature differences. It is not easy to deal with the scaling of graphite or enamel glass. The tube bundle adopts the baffle rod type, which is beneficial to prevent scaling.
Using spiral plate heat exchanger is the best choice； reason: 1. Difficult to structure: The fluid has centrifugal force 2. It has good heat exchange effect and large heat conduction times.
Replace the board, the temperature can be lower, and the temperature resistance difference is large.