TITLE:
On the Influence of Particles Characteristics on Moisture Diffusivity during Drying of Granular Porous Media
AUTHORS:
José Teixeira Freire, Fábio Bentes Freire, Hugo Perazzini
KEYWORDS:
Adsorption; Desorption; Diffusion; Fick; Knudsen; Mass Transfer
JOURNAL NAME:
Advances in Chemical Engineering and Science,
Vol.4 No.1,
January
8,
2014
ABSTRACT: The objective of this work was to study the diffusive
mechanisms of mass transfer predominant in the drying of cylindrical
unconsolidated granular porous media of different diameters of porous spherical
particles. The experimental study was based on determining the drying kinetics
of the porous media evaluated and on obtaining the physical properties
regarding the particles that constitute them. Moisture data as a function of
time were obtained by subjecting the porous media to an upward single-phase
flow of heated air at a specific condition of temperature, velocity and
absolute humidity of the drying air. The theoretical study regarded the
determination of the overall effective diffusion coefficient based on mass
transfer foundations. From the results obtained, it was verified that the
drying kinetics, for a given operational condition applied, is influenced by particle
diameter, and the effective superficial liquid diffusivity is the mechanism
that limits the drying process.