Effect of wall rougheners on cross-sectional flow characteristics for non-spherical particles in a horizontal rotating cylinder--颗粒学报PARTICUOLOGY

Lu, G., Third, J. R., & Müller, C. R. (2014). Effect of wall rougheners on cross-sectional flow characteristics for non-spherical particles in a horizontal rotating cylinder. Particuology, 12, 44–53. https://doi.org/10.1016/j.partic.2013.03.003

Guang Lu ^*, James R. Third, Christoph R. Müller

ETH Zürich, Department of Mechanical and Process Engineering, Institute of Energy Technology, Laboratory of Energy Science and Engineering, 8092 Zürich, Switzerland

10.1016/j.partic.2013.03.003

Volume 12, February 2014, Pages 44-53

Received 29 November 2012, Revised 5 March 2013, Accepted 26 March 2013, Available online 17 June 2013.

E-mail: lugu@student.ethz.ch

Highlights

• Rotating cylinders containing non-spherical particles are modeled using the DEM.

• The influence of wall rougheners on the particle dynamics is investigated.

• Highly angular particles do not benefit from the inclusion of wall rougheners.

• The effect of wall rougheners depends on the operating condition of the granular bed.

Abstract

Discrete-element-method (DEM) simulations have been performed to investigate the cross-sectional flow of non-spherical particles in horizontal rotating cylinders with and without wall rougheners. The non-spherical particles were modeled using the three-dimensional super-quadric equation. The influence of wall rougheners on flow behavior of grains was studied for increasing particle blockiness. Moreover, for approximately cubic particles (squareness parameters [5 5 5]), the rotational speed, gravitational acceleration and particle size were altered to investigate the effect of wall rougheners under a range of operating conditions. For spherical and near-spherical particles (approximately up to the squareness parameters [3 4 4]), wall rougheners are necessary to prevent slippage of the bed against the cylinder wall. For highly cubic particle geometries (squareness parameters larger than [3 4 4]), wall rougheners resulted in a counter-intuitive decrease in the angle of repose of the bed. In addition, wall rougheners employed in this study were demonstrated to have a higher impact on bed dynamics at higher rotational speeds and lower gravitational accelerations. Nevertheless, using wall rougheners had a comparatively small influence on particle-flow characteristics for a bed composed of finer grains.

Graphical abstract

Keywords

Granular flow; Non-spherical particles; Rotating cylinder; Discrete element method (DEM); Kiln

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