Abstract

NASCIMENTO, J. J. S; MEDEROS, B. J. T.; BELO, F. A.  and  DE LIMA, A. G. B.. Mass Transport with Shrinkage Inside Parallelepiped Solids. Inf. tecnol. [online]. 2005, vol.16, n.1, pp.35-41. ISSN 0718-0764.  http://dx.doi.org/10.4067/S0718-07642005000100006.

A three-dimensional transitory mathematical model is described as applied to the phenomenon of diffusion of water within parallelepiped solids. The finite volumes method was used , considering thermo-physical properties to be constant, equilibrium at the surface, and shrinkage of the material. The model was applied to study the drying process of a ceramic brick. Results are presented on the drying kinetics, on the humidity content distribution of several layers over a determined period, and using two shrinkage coefficients. The results showed that the phenomenon of volume reduction considerably affected the drying rate of the solid, as did the distribution of humidity content within the interior of the solid. It was also found that the highest gradients of humidity content were located near the vertex of the solid at any instant in time. The knowledge of the moisture gradients and drying kinetics allowed optimization of this process and increasing the quality of the final product.

Keywords : drying of solids; finite-volume; simulation; ceramics; parallelepiped.