Industrial & Engineering Chemistry Research, Vol.44, No.24, 9244-9263, 2005
Modeling and simulation of vertical continuous cooling crystallizers for the sugar industry
Vertical continuous cooling crystallizers (VCCC) are commonly used in the sugar industry for the economically important final recovery of sucrose from the mother liquor present in the massecuite obtained at the end of the vacuum evaporative crystallization stages. In this work, a steady-state one-dimensional distributed model is formulated to simulate well-designed VCCC in which the massecuite follows approximately an ideal plug-flow pattern. The model consists of seven ordinary differential equations comprising mass, energy, and crystal population balances. The model describes the changes (along the crystallizer height) of the massecuite weight fraction of crystals, mother liquor dry substance content, mother liquor purity, crystal average size, crystal size coefficient of variation, massecuite temperature, and cooling water temperature. Simulation of the model yields a very accurate description of the reported performance of a VCCC [with vertically oscillating horizontal cooling coils (OVCC system)] from a beet sugar factory in Germany.