Model-Informed Microwave Processing of Materials

Abstract

ABSTRACTThis paper reviews the expanding application of microwaves for processing solid materials, both natural and synthetic. The Canadian interest ranges from food processing to forest products, ceramic drying and curing to the preprocessing of rare minerals and ores, with the zeolite family of particular industrial interest.In all cases, across the world, the number of process variables is large and the known physical data are limited. Yet the engineer requires to know only a few specific properties which, in general, involve rate and limit functions. The problem posed here, which has to be considered as a part of the unification of the subject of electromagnetic heating, concerns the careful use of atomistic modelling to achieve a model-informed empiricism for process development. As an example, it is shown in this paper that the majority of solids have the same piecewise linear approximate temperature model for absorbing and reflecting power: more than twenty variables affecting the dielectric properties can then be reduced to five or six which need to be measured. Correctly interpreted, this approach (due, in its broad philosophic format, to M.F. Ashby, 1987) may help solve many electromagnetic engineering problems, including those associated with breakdown and thermal-runaway.