Cleaning of scaling in heat exchangers:

1. Water washing: After alkaline washing, rinse the heat exchanger repeatedly with clean softened water to completely clean the residue inside the heat exchanger.

2. Acid washing: statically soak the heat exchanger filled with acid solution for 2 hours, and then dynamically cycle it continuously for 3-4 hours During this period, clean by replacing and cleaning in both directions. After acid washing, if the pH value of the acid solution is greater than 2, the acid solution can be reused.

3. Washing: Before pickling, the heat exchanger should be washed in an open manner to ensure that there are no impurities such as mud or scale inside the heat exchanger. This can not only improve the pickling effect, but also reduce the acid consumption of pickling. Pour the cleaning solution into the cleaning equipment and then write it into the heat exchanger.

4. Alkali washing: After acid washing, use NaOH, Na2CO3，，Na3PO4， Softened water is produced in a certain proportion, and the heat exchanger is washed with alkali using dynamic circulation to achieve acid-base neutralization, so that the heat exchanger plates are no longer corroded.

The main reason for the formation of scale is due to the presence of calcium and magnesium salts with low solubility in water. These salts have common characteristics, and their solubility decreases with increasing water temperature, becoming difficult to accommodate salts. To maintain stable operation of the heat exchanger, timely cleaning work should be done to prevent blockage.