On the Influence of Particles Characteristics on Moisture Diffusivity during Drying of Granular Porous Media

José Teixeira  Freire; Fábio Bentes  Freire; Hugo  Perazzini

doi:10.4236/aces.2014.41002

José Teixeira Freire^*, Fábio Bentes Freire, Hugo Perazzini

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.

Keywords: Adsorption; Desorption; Diffusion; Fick; Knudsen; Mass Transfer

Cite this paper: Freire, J. , Freire, F. and Perazzini, H. (2014) On the Influence of Particles Characteristics on Moisture Diffusivity during Drying of Granular Porous Media. Advances in Chemical Engineering and Science, 4, 7-16. doi: 10.4236/aces.2014.41002.

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