Maintaining the cleanliness of the plate heat exchanger plates is one of the important conditions for maintaining a high heat transfer coefficient.Between the sheets, the medium moves along a narrow, meandering flow path. Even if the sheet produces a thin scale layer, it will cause a change in the flow path, affecting the movement of the fluid, increasing the pressure drop, and decreasing the heat transfer coefficient.For example, when a sugar mill uses a plate heat exchanger, the secondary water is not well treated, and the flow path is blocked for two months during use, and the operation cannot be continued. Therefore, the plates of the plate heat exchanger need to be cleaned regularly to achieve the heat exchange effect.
(1) Chemical cleaning method
In this method, a chemical solution is circulated through the heat exchanger to dissolve and discharge the dirt on the surface of the sheet. This method does not require disassembling the heat exchanger, which simplifies the cleaning process and reduces the labor level of cleaning.The chemical cleaning method is an ideal method because the corrugation of the sheet can be turbulently turbulent and is beneficial to the dissolution of the scale layer.
(2) Mechanical (physical) cleaning method
In this method, the plate is manually washed with a brush to achieve the purpose of fouling the surface of the plate. Although this method is relatively straightforward, it is not easy to clean the harder and thicker scale layer.
(3) Comprehensive cleaning method
In the case where the dirt layer is relatively hard and thick, it is difficult to clean by simply using one of the above methods. The comprehensive method is to soften the scale layer by chemical cleaning first, and then remove the scale layer by mechanical (physical) cleaning method to keep the sheet clean.