Solving a Two-Scale Model for Vacuum Drying by Using COMSOL Multiphysics

S. Sandoval Torres[1]
[1]Instituto Politécnico Nacional, CIIDIR, Oaxaca, Mexico
Published in 2012

Drying of porous materials is characterized by the invasion of a gaseous phase replacing the evaporating liquid phase. Vacuum drying is an advanced method applied to oakwood to diminish discoloration, so understand its physics is a very important task. In this work, a two-scale model is solved to simulate vacuum drying of oakwood. A two scale model describes the physics of wood-water relations and interactions with the vacuum dryer. Results provided important information about liquid and gas phase transport in wood. Water vapor and dry-air dynamics in the chamber were simulated linking large scale (dryer) and macroscale (wood) changes. We analyses results at 60–100 bar and 250–300 mbar both at 70°C. The physics-based one-dimensional model was solved by using the COMSOL’s coefficient form and the global equations tool in COMSOL. The numerical results and experimental measures provide some confidence in the proposed model.