The Effect of Morphology of Crystals in Suspension on Scale Formation Dynamics in Cooling Crystallization for Organic Compound

抄録

In cooling melt suspension crystallization, scale formation becomes a problem which seriously reduces the heat transfer coefficient of cooling surfaces, and the scale formation results in low productivity and low energy effectiveness. Scale formation still remains an issue to be discussed in cooling melt suspension crystallization, although some previous studies have been reported. The mechanisms of scale formation have been investigated based on surface interaction between crystal and cooling surface. However, studies on the operation method to prevent the scale formation have been insufficient. In the present study, the effect of the morphology of suspended crystals on scale formation dynamics (especially the transition speed of scale formation process) during start-up operation is investigated experimentally in melt crystallization for organic compounds. Scale formation dynamics are investigated using two kinds of seed crystals of different morphologies. As a result, the scale formation dynamics at the initial stage changed with morphology of seed crystals. Therefore, it is clear that crystal morphology is an important factor to consider scale formation dynamics. Moreover, this result suggests that modification of morphology in suspended crystals can be applied to prevent scale formation.