Optimization of Air Cooling Conditions and Temperature Profiles in a Hard Candy Cooling Tunnel

Abstract

This work presents the optimization of the cooling stage during hard candy production process in order to assure the product quality. A one dimensional (1-D) mathematical model of the transient heat transfer on hard candies has been developed. The resulting PDAEs were converted to a set of non linear algebraic equations using the centered finite difference approximation (CFDM) and were implemented into the optimization environment GAMS (General Algebraic Modeling System). Thus, the temperature profiles in the center and surface of the candy, air cooling temperature and velocity are simultaneously optimized. The model proved to be robust and flexible, achieving convergence for the optimizations made. A study case is presented and discussed in detail. The obtained results show that higher cooling air temperature and lower air velocity increase the product quality considerably.