Resonance Phenomena in the Process of Wood Microwave Drying

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UDС

674.047:66.047.354

DOI:

10.17238/issn0536-1036.2015.5.135

Abstract

Currently drying of wood with the use of electromagnetic energy in a camera of resonator type is developed intensively. The most efficient is the range of ultra-high frequency. Re-sults of the study of fundamental properties of wood, the processes occurring in the wood when exposed by electromagnetic field of different frequencies, as well as models of mi-crowave energy absorption by unit assortments and lumber stack are given in various scien-tific sources, where the questions of thermal drying of wood are considered, but are poorly elucidated the control process of drying and electrical phenomena. This does not allow for optimum control and automatic control of the drying process of wood, which may result in such negative effects as an increase in the temperature and electrical breakdown in the tim-ber and the volume of the resonator, deformation and warpage of the drying timber. In difference of wood drying in the convection machine the process of resonator-type with the use of ultrahigh frequency has its own characteristics, which are characterized by resonant electro phenomena, occurred in the cavity, which may be considered on the basis of the basic provisions of electrodynamics. The purpose of this work – is on the basis of the functional dependence of resonator to carry out the measurement and control of the drying process of wood. It is considered the electrical phenomena, peculiar to resonator of ultrahigh frequency drying camera of wood, analytical expressions of power balance of electromagnetic Poynting vector coefficients are given, allowing establish the optimal mode of drying.

Authors

V.I. Melekhov, Doctor of Engineering, Professor 

Affiliation

Northern (Arctic) Federal University named after M.V. Lomonosov, Naberezhnaya Severnoy Dviny, 17, Arkhangelsk, 163002, Russia; e-mail: v.shulgin@agtu.ru

Keywords

microwave drying of wood, resonator, factor of quality of the resonance camera, loss-angle tangent, electromagnetic energy, specific dielectric absorption loss, penciled power.

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