Continuous crystallization is aimed at the intermittent type of crystallization, continuous feeding < need to crystallize the solution >, continuous discharge < already crystal material liquid >. Whether it is vacuum evaporation crystallization, vacuum flash cooling crystallization, are continuous. Continuous crystallization of small area, high labor productivity, low energy consumption, good crystal quality, uniform particles, the surface is bright and clean. Crystal particle size design is controlled, is the inevitable process of industrial production to replace the batch type. < > solution vacuum evaporation crystallizer liquid during crystallization crystallization is required to have the same temperature under pressure, side edge evaporation crystallization production, so it has the heating chamber and the evaporation chamber. Vacuum flash crystallization is cooling crystallization, need to flash a part of the heat (the heat into steam flash out) so no need to heat the room, only the flash crystallization room. The crystallization chamber is divided into flash zone, grain growth area, settlement zone, liquor separation zone, the central circular District etc.. The vacuum evaporation crystallization process or the vacuum flash cooling crystallization process is determined according to the solubility curve of the crystalline material. From the point of view of energy conservation, is the use of multi effect or single effect is based on the size of the product, the evaporation of water to determine the. In general, the larger the scale, the greater the amount of evaporation, the vacuum evaporation crystallization process using multi effect. Five, three or four effect is commonly used. Sometimes it is determined according to the technical characteristics of the material. Because the more effective number, the first effect of the higher temperature, the temperature is too high will damage the characteristics and molecular structure of the product. So the energy saving at the same time, but also to the quality of the product as the primary condition. Application of sodium chloride, sodium chloride, ammonium sulfate, ammonium chloride, ammonium chloride, barium chloride, zinc sulfate, calcium chloride, ammonium sulfate, sodium hydroxide and other inorganic salts of organic matter evaporation and crystallization. Mainly used in the food industry, chemical industry, metal mining smelting, large steel mills, pickling waste liquid, power plant, such as the treatment of wet desulfurization waste.