Numerical Study of Crystallization Process Using CFD Tools

Abstract

Crystallization is the formation of solid particles within a homogenous phase. Crystallization is considered a last stage purification step in pharmaceutical, chemical, agrochemical and food industries. Crystallization is mostly used for separation of a pure product from an impure solution and the product formed is suitable for packing and marketing. Good yield and purity are important for crystallization; apart from it crystal size distribution also plays a vital role in the design of crystallization. The energy required for crystallization is less than distillation. The study is made on crystallization process of sucrose in a continuous rectangular flow chamber. The present work is aimed to compare the simulation results with experimental results and to study the parametric sensitivity on mean crystal diameter of sucrose and total crystal production with variation in inlet velocity of solution, inlet mass fraction of sucrose and wall temperature of crystallizer. The transient simulations are carried out to study the crystallization process. The simulation results when validated against experimental results are found to be consistent.The simulation results show that as the inlet mass fraction of sucrose is increased, then the mean crystal size and total crystal production are observed to be increased. The mean crystal size is increased and total crystal production is decreased with decrease in inlet velocity of solution. The mean crystal size is observed to be invariant with change in wall temperature of the crystallizer but the total crystal production is increased with increase in wall temperature.