1、The precipitation dirt

       Sewage heat exchanger are mostly heating medium in hot water system, the high temperature or concentration, the water soluble Ca (HCO3) 2 and Mg (HCO3) 2 precipitation CaCO3 and MgCO3 slightly soluble in water. Precipitation of salts attached to the surface of heat exchange tube, the formation of scale, tightly attached on the surface of heat exchange tube.

       2、particulate fouling 

       Solid particles suspended in a fluid system, such as sand, dust, carbon black, accumulated on the heat exchange surface.

       3、Chemical reaction dirt

       Between the heating surface and fluid, due to chemical reaction from the oxidation and polymerization of sediment formation.

       4、corrosion fouling

     Because the fluid is corrosive or corrosive impurities and corrosion of heat exchange surface, corrosion products deposit on the heat transfer surface and form the dirt.

       5、Biological fouling

 By microbial community and its waste and chemical pollutants, mud and other components adhesive on the heat exchange tube wall formed by adhesive or hair, said biological type of dirt.

       6、solidification fouling

   In extreme cold, heat transfer surface clean liquid or multicomponent solution of high dissolved components coagulation deposition of dirt.