Evaporator material selection issue

Thread Content

The correct choice of material is directly related to the service life of evaporation, crystallization, and drying equipment. Wastewater can be acidic or alkaline, and it may contain chloride ions, sulfur ions, ammonium ions, as well as salts in varying concentrations; its corrosiveness also varies. Therefore, it is necessary to select appropriate materials to ensure the proper operation of the equipment. Different temperatures require different types of materials. 　　 　　For example, when evaporating and crystallizing wastewater containing chloride ions: at temperatures below 40°C, 2304# duplex stainless steel should be used; at temperatures between 40°C and 90°C, 2205# duplex stainless steel is appropriate; and at temperatures above 90°C, 2507# duplex stainless steel is the suitable material. For wastewater containing both chloride ions and ammonium ions, when evaporating and crystallizing it: at temperatures below 40°C, 2205# duplex stainless steel is used; at temperatures between 40°C and 90°C, 2507# duplex stainless steel is chosen; and at temperatures above 90°C, 254SMo or titanium materials are suitable. 　　 　　For wastewater with acidic or alkaline salts and a pH of 4 to 10, austenitic grades 316L and 304L can be used; the higher the temperature, the better the material required.