循环流化结晶过程传质与晶体生长速率模型

MODEL OF MASS TRANSFER AND CRYSTAL GROWTH RATE IN CYCLING-FLUIDIZED CRYSTALLIZATION

依据Whiteman传质膜理论 ,针对循环流化床结晶过程 ,建立了传质和晶体生长速率理论模型 .实验研究表明 ,在较宽的流速范围内 ,晶体生长速率仅与结晶物系的物性、晶种粒度和过饱和度有关 ,其基本规律为 :晶体的平均线生长速率与扩散系数、晶种特征长度、晶体与溶液相对密度差、过饱和度成正比 ;与溶液的黏度、晶体的密度成反比 .仅需结晶物系的物性、过饱和度等数据 。

The models of mass transfer and crystal growth rate in cycling-fluidized crystallization were simulated by means of the theory of Whiteman's mass transfer film. The experiment results show that in some conditions, the crystal growth rate in cycling-fluidized crystallization is only related with the physical and chemical properties, the super-saturation level and the diameter of crystal seeds in crystal system, which regularity is that the crystal growth rate is in direct proportion to the diffusivity of solutes, the diameter of crystal seeds, the relative density between solution and the solute and the super-saturation level, and in inverse proportion to the viscosity of solution, the density of crystal, so with them the crystal growth rate in cycling-fluidized crystallization can be easily predicted among wide flow speed ranges by the models.