◆The evaporator consists of a coaxial double-tube structure, which is connected by a central downcomer. The bottom structure (retention chamber or growth chamber) provides the necessary space and fluidization characteristics for crystal growth and suppression of supersaturation. Since the growth crystallizer can control the crystal growth, the salt crystals generated can be classified according to the particle size, and the classified salt crystals form a fluidized bed, which prevents the occurrence of supersaturation. The circulation of the material from the growth chamber to the heating chamber is realized by an external pump。
◆The evaporative crystallizer produces larger crystal particles and narrower particle size distribution;
◆The circulation volume of the solution is large, the supersaturation of the solution is small, and it is not easy to produce secondary crystal nuclei, which is beneficial to the crystallization operation;
◆There is no crystal breakage in the circulation of clear liquid, and the uniform supersaturation in the suspended bed creates good conditions for crystal growth.
Evaporation and crystallization of ammonium sulfate, ammonium nitrate and potassium chloride