The plate heat exchanger has the characteristics of light weight, small floor space, low investment, high heat exchange efficiency, flexible assembly, easy scaling and other functions, and its role in heating work. The plate heat exchanger should be cleanied timely if scaling. What is the basic principle of scale removal?
(1) Dissolution: The acid solution easily reacts with calcium, magnesium, and carbonate scale to form a soluble compound, which dissolves the scale.
(2) Peeling action: The acid solution can dissolve the oxide on the surface of the metal and break the bond with the scale, so that the scale adhering to the surface of the metal oxide is peeled off and falls off.
(3) Air enthalpy action: After the acid solution reacts with calcium, magnesium and carbonate scale, a large amount of carbon dioxide is generated.During the overflow process, carbon dioxide gas has a certain driving force for the scale layer which is difficult to dissolve or dissolve slowly, so that the scale falls off from the heated surface of the heat exchanger.
(4) Loose effect: For the mixed scale containing silicate and sulfate, since the oxides of calcium, magnesium, carbonate and iron are dissolved in the acid solution, the residual scale becomes loose and the acid which is easily wash down by lowed solution.