Microwave Heating of Oil-Water Emulsions : Theoretical and Simulation Studies Using Galerkin FEM

Processing of oil-water emulsion is very common in food and chemical process industries. Microwaves cause volumetric heating and that could be extensively used for emulsion processing due to advantages such as rapid, controlled and selective heating effects. The present work is aimed on the efficient microwave heating of oil-water emulsions in the shape of 1D slabs and 2D cylinders. Microwave heating of emulsion slabs has been studied for samples with various ceramic (Alumina and SiC), metallic and ceramic-metallic composite plates in suitable combinations. Microwave heating of emulsion cylinders has been studied for samples with lateral and radial irradiations (with or without metallic annulus). For each study, Maxwell's equation for electromagnetic wave propagation (electric field equation) and the non-linear heat conduction equation (energy balance equation) with the appropriate boundary conditions are simultaneously solved using Galerkin's FEM to obtain power absorption and transient temperature profile for the emulsion-support assembly. Further, the trends in numerical results of specific studies have been validated with experimental data available in the literature.