The plate heat exchanger is flexible to assemble, increasing or reducing the number of plates or changing the plate assembly process can meet the requirements of changing the process conditions and output of the plate heat exchanger in the production. Plate heat exchangers have low heat loss, light weight, convenient inspection and maintenance, and are widely used in chemical plants. So what are the methods for cleaning the plate heat exchanger during use?
(1) Chemical cleaning method
Stainless steel plate heat exchangers are strictly prohibited to use hydrochloric acid or hydrochloric acid cleaning agents and cleaning powder for chemical descaling cleaning. Because inadequately dissolved scales (containing residual chlorine) are difficult to clean in a multi-slit structure, alkali neutralization cannot be performed sufficiently. Nitric acid plus corrosion inhibitor or peach crisp cleaning agent can be used for cleaning, and proper heating can improve cleaning efficiency. The chemical cleaning method is generally used for plate heat exchangers that are not easy to disassemble and wash.
(2) Backwash method
When the heat exchange effect of the plate heat exchanger suddenly drops, it is still impossible to eliminate external factors and clean the inlet filters of the cold and hot media. From the opposite direction of the flow channel, use a cold or hot medium 1.2 to 1.5 times higher than the operating pressure to backwash. Since the effect of recoil washing method is not obvious, it is rarely used during inspection and maintenance.
(3) Disassembly and assembly cleaning method
The disassembly and assembly cleaning method is a more commonly used cleaning method for plate heat exchangers. It is not advisable to remove the plate after disassembly, it is better to hang it on the upper guide rod for cleaning. Do not use steel brushes or steel wool brushes to clean the plates to prevent damage to the surface of the plates, causing fouling to remain and corrode the plates. Do not damage the gasket during the brushing process. If the gasket is found to fall off, the plate must be dried and glued directly into the groove.