Original scientific paper

Modeling Plain Vacuum Drying by Considering a Dynamic Capillary Pressure

S. Sandoval-Torres ; Instituto Politécnico Nacional, CIIDIR-Oaxaca, Hornos No. 1003, Col. Noche Buena, Santa Cruz Xoxocotlan, Oaxaca, Mexico
J. Rodríguez-Ramírez ; Instituto Politécnico Nacional, CIIDIR-Oaxaca, Hornos No. 1003, Col. Noche Buena, Santa Cruz Xoxocotlan, Oaxaca, Mexico
L. L. Méndez-Lagunas ; Instituto Politécnico Nacional, CIIDIR-Oaxaca, Hornos No. 1003, Col. Noche Buena, Santa Cruz Xoxocotlan, Oaxaca, Mexico

Abstract

A coupled drying model for wood is proposed by introducing a dynamic capillary pressure. The pressures of non-wetting phase, the wetting phase, and the capillary pressure at equilibrium has been considered as non-static; this approach includes a two-scale
model. According to numerical results, liquid, water vapor and air dynamics in the chamber have strong interactions with re-homogenization in the surface, controlled by capillary
forces. The results at 60–100 bar and 70 °C are discussed. The phenomenological one-dimensional drying model is solved by using the COMSOL’s coefficient form and a global equation format. A good description of drying kinetics, moisture redistribution, and mass fluxes is obtained. A comprehensible transition at the fiber saturation point is well simulated.

Keywords

Wood; vacuum drying; dynamic capillary pressure; COMSOL®

Hrčak ID:

71949

URI

https://hrcak.srce.hr/71949

Publication date:

2.10.2011.

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