Plate heat exchanger is a compact, efficient heat transfer equipment, it has a high heat transfer efficiency (its heat transfer coefficient than the tube heat exchanger is 3 to 5 times higher), covers an area of small (for the tube heat exchanger 1/3), long service life, small investment, easy to scale, reliable and durable and so on.
In recent years, it has been widely used in metallurgy, petroleum, pharmaceutical, shipping, textile, chemical, pharmaceutical, food and other industries, is to realize the heating, cooling, heat recovery, rapid sterilization and other uses of excellent equipment. However, due to the plate heat exchanger general heat transfer temperature is higher (especially steam exchange), and its high heat transfer efficiency, so it is very easy to scale. At the same time plate heat exchanger internal circulation aperture is small, after scaling the internal channel cross-section becomes smaller or even blocked, resulting in plate heat exchanger heat transfer efficiency is reduced, thus affecting the normal production and equipment safety. Therefore, the plate heat exchanger should be regularly chemical cleaning, remove the dirt, in order to ensure that the plate heat exchanger efficient heat transfer and normal production.
Plate heat exchanger is a thin metal plate (generally stainless steel) pressed into a certain shape of corrugated heat exchanger plate, and then add a sealant gasket stacked into a heat exchanger. Mainly by the heat transfer plate, sealing gasket, clamping bolts, compression plate, the entire frame and other components. Hot and cold media through the adjacent heat transfer plate flow through their respective channels, the middle through a thin heat transfer plate for heat transfer, so energy efficient, high heat transfer coefficient, safe and reliable, compact structure, small size, occupies an area of less, flexible combination, easy to adjust and maintain.
Plate heat exchanger can be generally divided into: water - water exchange and steam - water exchange in two ways. Water - water exchange mode hot and cold medium are water, and hot and cold water temperature difference is not large, probably between 70 ~ 90 ℃, the two sides of the scaling situation is basically the same; steam - water exchange mode of hot medium for water vapor, generally not easy to scale, cold medium for water, temperature of about 90 ℃, easy to scale. The scale can be roughly divided into scale and dirt, especially scale-based. Scale is mainly dissolved in water by thermal decomposition of a variety of salts solubility reduction and crystallization of deposits in the heat transfer piece, usually carbonate, phosphate, sulfate and silicate, this kind of scale crystallization dense, relatively hard, difficult to remove; dirt is generally made up of fine particles of mud, sand, dust, insoluble salts of mud, colloidal hydroxide, debris debris, corrosion products, oil, especially bacteria and algae and their viscous body Secretion and other components, this scale volume is larger, loose and soft texture, easier to remove.
