EXPERIMENTAL STUDY OF MICROWAVE SLOW WAVE COMB APPLICATORS FOR TIMBER TREATMENT AT FREQUENCIES 2.45 AND 0.922GHz

Abstract

Slow wave comb applicators for timber (and other materials) treatment at frequencies 2.45GHz (Comb1) and 0.922GHz (Comb2), designed for surface layer heating, modification and sterilization, were experimentally studied. Experiments showed that the Comb1 applicator released 83-88% of applied MW energy in wet wood on the depth up to 30mm, in zones with maximum energy application. In other zones, energy application efficiency is higher. The Comb2 applicator releases about 60% of the applied energy on the depth up to 30mm in the zones of maximum energy release. Energy distribution from the comb applicators, in the wet wood, allows the most significant part of the energy to be released in surface layers and increases efficiency of energy use, compared to other MW radiators. Comb1 and Comb2 are recommended for practical use in wood heating, MW modification and sterilization processes. They can be used for soil, concrete, plaster, bricks, plastics and other materials were required heating of surface layers.