Evaluating moisture transfer properties of wood by inverse analysis of moisture content profiles determined during drying by X-ray attenuation

Abstract

An X-ray density analyzer was used to determine the evolution of the moisture content (MC) profiles of a wood board during drying. Tests were performed on quartersawn boards of five wood species (oak, beech, Scotch pine, birch, alder) of two thicknesses (20 and 40 mm) dried at low temperature. The water vapor diffusion coefficient and liquid permeability of each wood species were determined by inverse analysis of the profiles using a computational model of coupled heat and mass transfer. These parameters were also measured by classical methods for validation purposes. The inverse method gives values close to the measured ones when using the evolution of the moisture profile, but also quite remarkably when using only the evolution of moisture at the core of the board. On the contrary, the method is less accurate when using only the average kinetics as experimental information.

Keywords:

• Heat and mass transfer
• diffusivity
• permeability
• computational model
• porous media

Acknowledgments

ADEME is a partner in the project and is co-funding, with FCBA, a grant for a thesis on the use of intermittent energy for wood drying by using an intelligent control system.

Disclosure statement

No potential conflict of interest was reported by the author(s).