How to deal with scaling in the finished alkali cooler
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This post was last edited by sunjl1981 on 2013-1-6 at 20:36. The finished alkali cooler in our company’s ion-exchange membrane caustic soda electrolysis plant is a plate-type heat exchanger made of nickel. Recently, poor heat exchange has occurred due to scaling on the circulating water side; we would like to carry out acid cleaning. Please suggest a feasible solution from those who are familiar with this process. Thank you! ， ， -
It’s difficult to choose the right acid for pickling; mechanical cleaning is the best option.
Agree with the person above… After cleaning the heat exchanger, it started leaking internally after not being in use for long··
According to corrosion data manuals and practical experience, common acids such as hydrochloric acid, sulfuric acid, and nitric acid cause significant corrosion to nickel plates. Even with the use of corrosion inhibitors, inadequate cleaning can lead to subsequent crevice or pitting corrosion. Descaling agents like oxalic acid are time-consuming and not very effective. Based on operational conditions, it is advisable to disassemble the plates every two years and clean them manually using tools such as brushes and PVC sheets; this method is efficient and effective. Additionally, if the gaskets have not aged, they can be reused, thereby saving significant costs.
Plate heat exchangers can be disassembled for manual cleaning. Try not to use acid for cleaning.
We manually disassemble it every time and then soak it in acid (the acid concentration should be low, with more water added); after soaking for a while, it’s easy to clean! The best approach is to address the issue at its root by improving the quality of the circulating water; otherwise, cleaning will be necessary again after some time! Additionally, for the finished alkaline plates, the control temperature should generally not be too high, as high temperatures can lead to scaling (we keep it at 45°C here); this is for reference only!