Numerical Analysis of Thermal Processing of Foods in Continuous Microwave System

ARBALLO J.R; CAMPAÑONE, L.A.; MARCHERONI, R.H.

Congreso; Effost 2017; 2017

Microwaves technology is widespread employed in food technology due to the reduction of process time and the environmental impact. In this sense, continuous microwave systems have a great potential, the products enter the system through hoppers then they are conveyed by belt into a resonant cavity where the transport phenomena associated to the process occurs. In thermal processing of foods, these include energy transfer owing to radiation interaction, mass transfer associated to the dehydration process and electromagnetic distribution inside the cavity and the load. In the case of conveyed belt systems, the electric field behavior is complex and difficult to obtain proper predictions. Therefore, a numerical study is necessary for predictions in the treatment zone. With regard to the electromagnetic field distribution in belt systems, few studies have been found in the literature and are determinant to achieve the uniform heating of the products during the residence time. The uniformity of final temperature profiles is directly associated with the final quality of the food and is the main processing purpose. To study the phenomena described in numerical form several techniques can be used with different degrees of difficulty. These methods include finite differences, finite elements, transmission line methods and others. In this work, the finite element method was used using the COMSOL Multiphysics software, which is very suitable for electromagnetic problems and for radiofrequency simulation. The objective of this work is to analyze numerically the behavior of the electric field inside a microwave applicator with the conveyor system, analyzing different foods, their geometry characteristics and dielectric properties on the thermal uniformity of final product.