Fluidization of fine and ultrafine particles using nitrogen and neon as fluidizing gases

Authors

Jose Manuel Valverde, Universidad de Sevilla
M. A.S. Quintanilla, Universidad de Sevilla
Antonio Castellanos, Universidad de Sevilla
Daniel Lepek, New Jersey Institute of Technology
Jose Quevedo, New Jersey Institute of Technology
Rajesh N. Dave, New Jersey Institute of Technology
Robert Pfeffer, New Jersey Institute of Technology

Document Type

Article

Publication Date

1-1-2008

Abstract

When fluidized by a gas, some agglomerated fine and ultrafine particles display a regime of uniform, nonbubbling fluidization known as agglomerate particulate fluidization (APF). The agglomeration of micrometric sized particles, or simple pre-existing agglomerates in the case of nanoparticles, is governed by the balance between hydrodynamic shear forces and interparticle attractive forces. From this balance the theoretical scaling law Bog ∼ k^D+2 has been derived, where Bog, the granular Bond number, is the ratio of the interparticle attractive force to particle weight, k is the ratio of agglomerate to particle size, and D is the fractal dimension. In the experimental program the behavior of gas-fluidized beds of fine and ultrafine particles as affected by the use of neon and nitrogen as fluidizing gas is studied. The experimental results indicate that there is no relevant distinction between the sizes of agglomerates fluidized with the different gases as theoretically predicted. However, it is seen that the relatively small increment of gas viscosity opens up a new window of highly expanded agglomerate particulate fluidization (APF) behavior with a delayed onset of bubbling. For a sufficiently high-gas viscosity, and/or smaller particle size, full suppression of the bubbling regime is observed. For nanoparticles exhibiting agglomerate bubbling fluidization (ABF) behavior, where bed expansion is small, and bubbling occurs soon after minimum fluidization we also observe a dplayed onset of bubbling when fluidizing with a gas of higher viscosity. © 2007 American Institute of Chemical Engineers.

Identifier

38149005467 (Scopus)

Publication Title

Aiche Journal

External Full Text Location

https://doi.org/10.1002/aic.11329

e-ISSN

15475905

ISSN

00011541

First Page

86

Last Page

103

Issue

1

Volume

54

Recommended Citation

Valverde, Jose Manuel; Quintanilla, M. A.S.; Castellanos, Antonio; Lepek, Daniel; Quevedo, Jose; Dave, Rajesh N.; and Pfeffer, Robert, "Fluidization of fine and ultrafine particles using nitrogen and neon as fluidizing gases" (2008). Faculty Publications. 12947.
https://digitalcommons.njit.edu/fac_pubs/12947