R. Font et Ja. Caballero, Particulate character, inertial effects and diffusion effects in concentrated suspensions, POWD TECH, 120(3), 2001, pp. 264-272
In the sedimentation of suspensions, the particles modify their settling ve
locity in accordance with the solids concentration, Kynch's theory assumes
that in each layer, the settling velocity only depends on the solids concen
tration, and neglects the acceleration and deceleration processes when the
particles descend with a velocity distinct from that corresponding to the s
olids concentration at this layer. The Kynch theory also assumes that there
are so many small particles that the solid mass can be considered homogene
ously distributed in the suspension, so the particulate character of the su
spension is ignored. Kynch's theory also neglects the diffusion effects. An
analysis of the particulate character of the suspension, the inertial effe
cts and the diffusion effects are discussed in this paper, deducing a criti
cal value for considering the particulate character negligible and a critic
al size for considering the diffusion effect also negligible. Finally, seve
ral data of different flocculated suspensions are satisfactorily analysed i
n view of the conclusions obtained previously. (C) 2001 Elsevier Science B.
V. All rights reserved.