Why do heat exchangers need to be cleaned?

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First, let’s take a look at heat exchangers: Heat exchangers are compact and efficient devices for heat exchange, and they are widely used in industries such as oil refining, petrochemicals, fertilizer production, pharmaceuticals, papermaking, power generation, printing and dyeing, refrigeration, transportation, and food processing. Since heat exchangers need to operate for long periods of time, scaling can occur in them due to the structure of the heat exchanger itself, as well as the purity of the cooling or heating side and the properties of the process medium itself; moreover, the degree of scaling varies from one case to another. After scaling, the cross-section of the internal channels decreases or even gets blocked, which reduces the heat exchange efficiency of the heat exchanger and thus affects the normal operation of production as well as the safety of the equipment. Therefore, the heat exchanger should be cleaned regularly to reduce dirt, thereby ensuring efficient heat exchange and the smooth progress of production. Heat exchanger cleaning is mainly divided into physical and chemical methods. Physical methods generally include sandblasting and rust removal. The process is briefly described. In cases of severe scaling and complex compositions, it is generally difficult to clean using ordinary physical methods, and the disassembly and cleaning process is time-consuming and labor-intensive; therefore, chemical cleaning becomes a good option. This method is simple, and although the costs may be higher compared to physical cleaning, it saves time and effort and yields relatively better results, which is why it is widely used. The chemical method generally involves degreasing → washing → rust removal (washing) → phosphating → washing → drying