Mathematical Modeling of Layer Crystallization on a Cold Column with Recirculation

Falling film crystallization is a novel technique used to overcome the challenges of solid and slurry handling used for continuous manufacturing in the pharmaceutical industry. The process and its performance were demonstrated recently. In this study, a dynamic model of falling film crystallization with a recirculation loop was developed in the form of coupled partial differential equations describing the effects of mass transfer, heat transfer, impurity inclusion, and crystallization kinetics. The model described the variation of processing parameters, such as the flow rate and cooling temperature, for three different crystallization solution systems (16 cases). The experimental results confirm the predictions of the model, which will provide further insights into processes in which experimental values do not exist or are difficult to obtain, such as the axial temperature profile of the falling liquid film or the overall purity of the deposited crystal layer at different time intervals.