The basic principle of removing scale from plate heat exchanger
(2) Peeling action. The acid solution dissolves oxides on the metal surface and destroys the bond with scale. Thereby, the scale adhering to the surface of the metal oxide is peeled off.
(3)Air stagnation. After the acid solution reacts with calcium, magnesium, and carbonate scale, a large amount of carbon dioxide is produced.During the overflow process, carbon dioxide gas has a certain driving force for the scale layer which is difficult to dissolve or dissolve slowly.The scale is removed from the heated surface of the heat exchanger.
(4) Loose effect. For silicate and sulfate mixed scales, since the oxides of calcium, magnesium, carbonate and iron are dissolved in the acid solution, the residual scale becomes loose and is easily washed away by the flowing acid solution.