Applying Multiphysics Modeling and Simulation to Optimize Coating Process in Confectionery

A mathematical method has been developed to model and simulate the candy coating process. The framework of the model has been validated experimentally and further used to conduct DOE to study and identify the optimum process conditions as well as physical phenomena that cannot be detected experimentally. To capture accurately the complex physics of sugar coating we used Discrete Element Modeling (DEM) and Computational Fluid Dynamics (CFD) simulation tools. In this work, we discuss the simulation of factory batch coating process as closely as possible. In the model, the shape of the candy, the coating drum inside structure, process and boundary conditions such as temperature, coater speed, humidity, pressure, air flow, number of spray nozzles, etc. are considered. The coating drum is loaded initially with 1700Kg candy centers and at the end of coating process it will be about 2300Kg. It takes about an average of 5hrs to fully coat candies. The goal of the optimization process is to reduce the total coating cycle time without sacrificing the quality of coating. Based on the DOE simulation we identified the best optimum process parameters, predicted the coating thickness distribution, moisture content distribution in candies and crystal growth rates. The validation of the model in one of factory will be discussed also in this paper.