Drying process of apple slices in low frequency electromagnetic field

Abstract

In this study, the heat and mass transfer equations for porous organic materials have been derived by using “two port model” and “pi theorem”, and consistency of the derived equations were analyzed by considering the processes with and without electromagnetic waves. Some theoretical and experimental investigations have been performed to determine the effect of electromagnetic fields on the drying process of porous materials and calculation of concentration profiles. Also the molecular and diffusion coefficients have been analyzed empirically by using experimental results. In the experiments, apple slices were used as porous organic material. The samples were exposed to electromagnetic waves at different frequency values. For better analysis of drying process, the experiments were conducted at different temperatures and periods. It was observed that results obtained by derived semi-empirical equations have been agreed with experimental results. It is seen that the diffusion coefficient has important role in drying process and should be determined experimentally for accurate results.