Microwave-Vacuum Drying of Wood: Model Formulation and Verification |
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Authors: | Xian-Jun Li Bi-Guang Zhang Wen-Jun Li |
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Affiliation: | 1. School of Material Science and Technology, Central South University of Forestry and Technology , Changsha, China lxjmu@sohu.com;3. School of Material Science and Technology, Beijing Forestry University , Beijing, China |
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Abstract: | Based on the mechanism of moisture and heat transfer in wood during microwave-vacuum drying (MVD), a one-dimensional mathematical model to describe the process of wood MVD was established and verified by experiments in this research. The results showed that the process of MVD of wood experienced three distinct periods: (1) accelerating rate with rapid warming-up drying period, (2) a constant temperature and constant rate drying period, and (3) a heating-up with falling rate drying period. Compared with conventional hot air drying, the total drying process is almost governed by a constant rate period in vacuum-microwave drying of wood. The predicted temperature and moisture content in wood match well with the experimental data, the square of the relevant coefficient of the values of simulation and test is above 0.9, and the simulation precision of the change rule of the moisture is higher than that of the temperature. |
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Keywords: | Drying Mathematical modeling Microwave-vacuum Wood |
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