Premium
Tracer dispersion in sintered glass beads with a bidisperse size distribution
Author(s) -
Hulin J. P.,
Charlaix E.,
Plona T. J.,
Oger L.,
Guyon E.
Publication year - 1988
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690340410
Subject(s) - materials science , dispersion (optics) , porosity , tracer , dispersity , sintering , homogeneous , composite material , permeability (electromagnetism) , analytical chemistry (journal) , mineralogy , thermodynamics , optics , chemistry , chromatography , polymer chemistry , biochemistry , physics , membrane , nuclear physics
Abstract An experimental study was made of tracer dispersion in bidisperse sintered glass materials prepared from mixtures of two sizes of beads with mean diameters of 325 and 95 μm. The equivalent dispersion coefficient increases by a factor of 30 when the porosity decreases from 30 to 12%; this variation is similar to that measured in monodisperse samples. The variation of dispersion can be characterized by the ratio R = ℓ d /L 1 where ℓ d is a length scale deduced from the equivalent dispersion coefficient and L 1 is obtained from conductivity and permeability measurements. It is shown that the increase of ℓ d / L 1 correlates with the loss of porosity during the sintering process. Lightly sintered samples with a percentage of small beads around the minimum of porosity display a nearly Gaussian behavior, with a dispersion coefficient close to that obtained in homogeneous equivalent mixtures. This result is in contrast with very large anomalies observed by other authors. These results imply that dispersion in consolidated samples is sensitive to large‐scale inhomogeneities of the materials rather than to their detailed structure.