The plate heat exchanger plate is specially used for the plate heat exchanger to isolate the medium and exchange heat, which is an important part of the plate heat exchanger.What are the process requirements for cleaning plate heat exchanger plates?
1) Pickling temperature: Increasing the pickling temperature is beneficial to improve the descaling effect. If the temperature is too high, the corrosion of the heat exchanger plate will be aggravated by the acid washing liquid. It is found through repeated tests that the pickling temperature is controlled at 60 °C. .
2) Pickling solution concentration: According to repeated tests, the pickling solution should be prepared according to the concentration of formic acid 81.0%, water 17.0%, buffer 1.2%, surfactant 0.8%, and the cleaning effect is excellent.
3) Pickling method and time: The pickling method should be carried out by a combination of static soaking and dynamic circulation. The pickling time is first static soaking for 2 h, then dynamic cycling for 3-4 h. The pickling concentration should be sampled frequently during the pickling process. When the difference between the two adjacent assays is less than 0.2%, the pickling reaction is considered to be complete.
(4) Passivation treatment: After the acid washing is finished, most of the scale and metal oxide on the surface of the plate heat exchanger are dissolved and detached, exposing a new metal, which is highly corrosive, the heat exchanger sheet is passivated after pickling.