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Granular dynamics of cohesive powders in a rotating drum as revealed by speckle visibility spectroscopy and synchronous measurement of forces due to avalanching

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journal contribution
posted on 22.03.2016, 15:02 authored by H. Yang, G.L. Jiang, H.Y. Saw, C. Davies, Mark Biggs, Vladimir Zivkovic
We have used speckle visibility spectroscopy (SVS) and synchronized force measurements to compare the granular dynamics of two cohesive lactose powders, with Sauter mean diameters of ~29 and ~151 μm, in a rotating drum. A load cell (LC) was used to measure forces on the drum mounting frame and enable monitoring of bulk powder motion; SVS is a dynamic light scattering technique particularly suited for studying dynamics in dense, non-ergodic granular systems. Our results reveal that surface slumping and intermittent collisional dynamics in the bulk of the bed are correlated, especially for the fine more cohesive particles (Geldart group C/A boundary), but not as much for the less cohesive larger particles (Geldart group A/B boundary). The specific dissipation energy of the particles in the drum is similar for both powders, and increases linearly with increasing drum speed. However, the dependencies of the load cell and SVS signals on rotation speed have opposing trends for these two powders, indicating different dissipation mechanisms for the different Geldart Groups; collisional dissipation is more important for the Geldart C/A powder, while for the Geldart A/B powder avalanche dissipation is dominant.

Funding

This work has been supported by National Natural Science Foundation of China (11572201), Innovation Program of Shanghai Municipal Education Commission (15ZZ072) and Hujiang Foundation of China (C14002).

History

School

  • Science

Department

  • Chemistry

Published in

Chemical Engineering Science

Volume

146

Pages

1 - 9

Citation

YANG, H. ... et al, 2016. Granular dynamics of cohesive powders in a rotating drum as revealed by speckle visibility spectroscopy and synchronous measurement of forces due to avalanching. Chemical Engineering Science, 146, pp. 1 - 9.

Publisher

Crown Copyright © Elsevier Ltd

Version

AM (Accepted Manuscript)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Publication date

2016

Notes

This paper was accepted for publication in the journal Chemical Engineering Science and the definitive published version is available at http://dx.doi.org/10.1016/j.ces.2016.02.023

ISSN

0009-2509

Language

en