Plate heat exchanger is a kind of heat exchanger formed by pressing thin metal plates into heat exchange plates with a certain corrugated shape, and then fastening them with splints and bolts after stacking. Thin rectangular channels are formed between various plates for heat exchange. The working fluid flows through the narrow and tortuous channel formed between the two plates. The purpose of the plate heat exchanger is very practical, and some dirt will be generated during use, so what is the working principle of the heat exchanger to clear the scale?
(1) Peeling effect. The acid solution can dissolve the oxide on the metal surface of the plate heat exchanger and break the bond with the scale, so that the scale attached to the surface of the metal oxide can peel off and fall off.
(2) Dissolution. The acid solution easily reacts with calcium, magnesium, and carbonate scale to form easily soluble compounds to dissolve the scale.
(3) Porosity. For scale containing mixed silicate and sulfate, since the oxides of calcium, magnesium, carbonate and iron are dissolved in the acid solution, the remaining scale will become loose and easily washed away by the flowing acid solution.
(4) After the acid solution reacts with calcium, magnesium, and carbonate scale, a large amount of carbon dioxide is generated. During the overflow process of the carbon dioxide gas of the plate heat exchanger, it has a certain lifting power for the insoluble or slow-dissolving scale layer, so that the scale will fall off the heated surface of the heat exchanger. When the plate heat exchanger removes the scale, the basic principle is also different when the method is different. The reaction process of scale and its acid solution is also very different.