R. Guardani et A. Belline, APPLICATION OF MATHEMATICAL-MODELING IN A 2-COMPONENT LAYER CRYSTALLIZATION PROCESS, Chemical engineering & technology, 20(7), 1997, pp. 495-501
An algorithm for the computation of design variables in layer crystall
isation processes is presented, based on an algebraic solution of the
moving boundary equation for heat transfer, as well as on an expressio
n for the concentration profile. The algorithm was applied to the disc
ontinuous crystallisation of a NaCl-H2O solution around the wall of an
internally cooled cylindrical tube. Good agreement between simulation
results and laboratory experiments was observed. After input of exper
imentally measurable values of the distribution coefficient, the algor
ithm enables the prediction of the following process variables along t
he crystallisation time: layer thickness, temperature, and composition
profiles across the layer, as well as the end-values of solid and liq
uid mass and concentrations. Multistage processes can be studied by th
e series association of crystallisation cycles, enabling the determina
tion of the optimal number of stages that meets a specific design crit
erion.