Microwave Field Distribution in Grain Drying Installations for Different Types of Emissions

Abstract

The microwave field is used for drying and disinfection of grain, during pre-sowing seed treat-ment. The use of a microwave field in these installations leads to an increase in their productivity and a decrease in the energy consumed by them. One of the principal problems of microwave field use for treatment of dense grain layers is to insure sufficient distribution uniformity of the field. In this article, waveguide design options have been discussed that serve to introduce microwave radiation into the grain layer. Mathematical simulation of the electromagnetic field distribution was performed with the use of CST Microwave Studio software in order to evaluate and compare horn-type, rectangular and semicircular waveguides. The data on the standing wave ratio and radiation efficiency for these types of waveguides have been reported. Specific features of the microwave electromagnetic field distribution and radiation power in the output of those wave-guides have been described. Results of mathematical simulations enabled to make out that sem-icircular waveguides with slot-type radiators are preferable for processing dense grain layers.