Analytical study of temperature field during microwave drying of the material

Abstract

Mathematical models of heating wet materials in a microwave field are analyzed. A thermal conductivity model is presented that considers two internal sources of heat, positive and negative. A negative heat source considers moisture output during drying of the material. A formula is obtained for calculating the temperature of a semi-bounded body under the action of internal heat sources for boundary conditions of the first kind. The results of calculations of the temperature of water and a dense layer of wheat grain are presented, depending on the duration of the microwave field and the specific power for the heating period. It is shown that in order to obtain reliable results, it is necessary to correctly set the efficiency of the microwave chamber. The results of calculations of moisture content and temperature of a layer of wheat grain for a period of constant drying speed are presented.

Microwave Drying Characteristics and Drying Quality Analysis of Corn in China

“…Chua [6] and Pratap Singh [18] also obtained similar results. The main reason is that microwaves only act on polar molecules, so the heating efficiency is increased, and the energy loss is lower [33,34]. Figures 8 and 9 show that microwave drying is much faster than electrothermal drying.…”