Problems with cleaning plate heat exchangers
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The plate heat exchanger is ready for pickling; I’m not sure what concentration of sulfuric acid or hydrochloric acid is appropriate The medium is the mother liquor of the double-alkali system
What are the main things to be cleaned—scale, impurities, crystals? Adjust the concentration and flow rate of the cleaning solution based on the chemical properties of the object to be cleaned. However, given that the flow channels in plate heat exchangers are relatively narrow, it is difficult to thoroughly clean the dead corners; therefore, cleaning methods need to be considered. The plates of plate heat exchangers are generally made of austenitic stainless steel; hydrochloric acid is not recommended for pickling.
In fact, plate heat exchangers can be disassembled and cleaned piece by piece, but replacing the gaskets is somewhat costly
I have posted about this before, and there are many published papers in it, totaling around 40. You can take a look. It is necessary to consider the type of scale and dirt that needs to be removed from the heat exchanger, what composition those substances have, as well as the material from which the heat exchanger itself is made.
Reply to 1# Hibernating Bear: If there is no frequent blockage, there is no need to consider chemical cleaning methods, as it is difficult to find a chemical that can dissolve scale without corroding the plates. Moreover, plate heat exchangers have narrow channels and dead zones, which makes chemical cleaning quite challenging. It is best to take it apart for cleaning. Pretty thorough. It’s not necessarily necessary to replace the gasket either.
Neither hydrochloric acid nor sulfuric acid works; they can easily corrode the plates, so a 5% phosphoric acid solution should be used.