CONTROL-VOLUME FORMULATION OF SIMULTANEOUS TRANSFERS IN ANISOTROPIC POROUS-MEDIA - SIMULATIONS OF SOFTWOOD DRYING AT LOW AND HIGH-TEMPERATURE

A two-dimensional code is presented which solves heat, mass and momentum transfer in porous media. The set of equations, deduced from Whitaker's theory, is revised in order to take into account the most important properties of softwoods. This medium, strongly anisotropic, needs such a two-dimensional and comprehensive approach, especially in cases where the pressure of the gaseous phase becomes important. Drying results are shown, both below (50-degrees-C) and above the boiling point. At low temperature, the extraction of liquid increases the volume of the gaseous phase and subjects the medium to partial vacuum. Above the boiling point an important overpressure appears and drives the moisture in the longitudinal sense.