Mass transfer in wood: identification of structural parameters from diffusivity and permeability measurements

Abstract

This paper proposes a rapid way to use experimental measurements of mass transfer -mass diffusivity and permeability to air- to compute two global morphological parameters of wood: tortuosity factor and equivalent pore radius. The devices conceived for measuring the two mass transfer properties of wood cited above are described. For mass diffusing in steady state, a specific vaporimeter “PVC-CHA” has been used. For air permeability, another device, “ALU-CHA” has been developed. Using a simple structure modelling of the porous medium to analyse the transport phenomena, the two global morphologic parameters cited above has been fitted. Softwood, hardwood and tropical woods are tested through six samples of each specie, sawn for longitudinal, tangential and radial directions flows. The results obtained for tortuosity and equivalent pore radius have been compared with those found in the anatomical literature and a well concordance has been observed. Keywords