A hgih-temperature drying model for softwood timber

摘要

The high-temperature drying of a softwood board with relatively high permeability was modelled on a one-dimensional basis. The moisture-transport mechanism between fibre saturation and irreducible saturation was elucidated, and moisture flow within the thin layer of damaged cells at the sawn surfaces of the timber board was examined. The predicted temperature and average moisture-content profiles with respect to time were in good agreement with some experimental data from the literature. Comparison between the experimental and predicted within-board moisture-content profiles issustrated the importance of accounting for the orientation of the growth rings with respect to the drying surfaces and effect of density variations on liquid permeability at high core moisture contents.