Flow regimes in wet conical spouted beds using glass bead mixtures--颗粒学报PARTICUOLOGY

Bacelos, M. S., & Freire, J. T. (2008). Flow regimes in wet conical spouted beds using glass bead mixtures. Particuology, 6(2), 72–80. https://doi.org/10.1016/j.partic.2008.01.001

Flow regimes in wet conical spouted beds using glass bead mixtures

Marcelo S. Bacelos, José Teixeira Freire^*

Universidade Federal de São Carlos, Centro de Ciências Exatas e de Tecnologia, Programa de Pós-Graduação em Engenharia Química, Centro de Secagem de Pastas, Suspensões e Sementes, Rod. Washington Luiz, Km 235, 13565-905, CP 676, São Carlos, SP, Brazil

10.1016/j.partic.2008.01.001

Volume 6, Issue 2, April 2008, Pages 72-80

Received 30 July 2007, Accepted 7 January 2008, Available online 19 March 2008.

E-mail: freire@power.ufscar.br

Highlights

Abstract

Using a high-viscosity Newtonian fluid, glycerol, an experimental investigation was carried out to evaluate the stable spouting regime in conical spouted beds using four particle mixtures: a reference (monoparticles), a binary mixture, two ternary mixtures with flat and Gaussian distributions respectively. The mixtures were selected for particle diameters (d_p) ranging from 1.09 to 4.98 mm and particle diameter ratios (d_pL/d_pS) ranging from 1.98 to 4.0. Experimental data show that pressure fluctuation signals of the bed, as indicated by changes in their standard deviations, provide suitable information to identify the range of operational conditions for stable spouting. However, the analysis of skewness of curves of pressure fluctuation as a function of air velocity appears not sufficient to identify a particular flow regime. For glycerol in the spouting regime, the standard deviation is noted to increase with increasing glycerol concentration due to the growth of interparticle forces. The implications of these research findings on the drying of suspensions in conical spouted beds using glass bead mixtures are also discussed.

Graphical abstract

Keywords

CSB, conical spouted bed; PB, packed bed; SS, stable spouting; T, transition; US, unstable spouting

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