Simulation of High-Temperature Drying of Wood

Abstract

An existing model of heat and mass transfer in wood at conventional temperatures was adapted to simulate the wood drying process at temperatures above the boiling point by adding a pressure equation. Two drying tests were conducted on white spruce (Picea glauca) sapwood and heartwood in a laboratory kiln at 105 and 115°C to validate the model. The predicted drying curves and the evolution of gas pressure in the board center were found to be in good agreement with the experimental data. Predicted and experimental results for the moisture content profiles were also found to be in fairly good agreement in the heartwood but the model tends to underestimate the moisture content gradients near the surface at high moisture contents.

Keywords:

• Drying model
• Gas pressure
• High-temperature drying
• Moisture content profiles
• White spruce wood

ACKNOWLEDGMENTS

This work was financially supported by Natural Resources Canada, Value to Wood Program, and Canada Economic Development for Quebec Regions.