The plate heat exchanger is a kind of high-efficiency heat exchanger made of a series of metal sheets with a certain corrugated shape. Plate heat exchanger is an ideal equipment for liquid-liquid, liquid-vapor heat exchange. It has the characteristics of high heat exchange efficiency, small heat loss, compact and lightweight structure, small footprint, wide application and long service life.The plate heat exchanger is prone to fouling, which will seriously affect the heat exchange efficiency of the plate heat exchanger. Because plate heat exchangers are mostly heat exchange systems that use water as a heating medium, some salts crystallize out of the water when the temperature rises, and adhere to the surface of the heat exchange tubes to form scale.
Adding polyphosphate buffers to the cooling water can also cause scale precipitation when the pH of the water is high.The scale formed in the initial period is relatively soft. With the formation of the scale layer, the heat transfer conditions are deteriorated, and the crystal water in the scale is gradually lost.When the working conditions of the heat exchanger are suitable for the precipitation of crystals from the solution, a scale layer formed by material crystallization can accumulate on the surface of the heat exchange tube.
When the fluid contains a lot of mechanical impurities and organic matter, and the fluid flow rate is small, some mechanical impurities or organic matter will also be deposited in the heat exchanger to form loose, porous or gel-like dirt.