Computational simulation of fluid and dilute particulate flows on spiral concentrators

Matthews, B.W.; Fletcher, Christopher W.; Partridge, A. C.

doi:10.1016/s0307-904x(98)10030-6

Cited by 49 publications

(19 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In their analysis, however, the viscosity and density of the mixture are constant, independent of the local particle concentration. Matthews et al [10] conducted full CFD simulations of flow in an industrial separator and then computed the trajectories of individual particles in the flow. In this work, the fluid flow is assumed to be completely undisturbed by the particles, which again removes the coupling between the flow and the particles.…”

Section: Introductionmentioning

confidence: 99%

Behavior of a particle-laden flow in a spiral channel

2014

View full text Add to dashboard Cite

Spiral gravity separators are devices used in mineral processing to separate particles based on their specific gravity or size. The spiral geometry allows for the simultaneous application of gravitational and centripetal forces on the particles, which leads to segregation of particles. However, this segregation mechanism is not fundamentally understood, and the spiral separator literatures does not tell a cohesive story either experimentally or theoretically. While experimental results vary depending on the specific spiral separator used, present theoretical works neglect the significant coupling between the particle dynamics and the flow field. Using work on gravity-driven monodisperse slurries on an incline that empirically accounts for this coupling, we consider a monodisperse particle slurry of small depth flowing down a rectangular channel that is helically wound around a vertical axis. We use a thin-film approximation to derive an equilibrium profile for the particle concentration and fluid depth and find that, in the steady state limit, the particles concentrate towards the vertical axis of the helix, leaving a region of clear fluid.

show abstract

Section: Introductionmentioning

confidence: 99%

Behavior of a particle-laden flow in a spiral channel

2014

View full text Add to dashboard Cite

show abstract

“…Recently Holland-Batt (2009) adapted the model for large-diameter rectangular spiral channels, with the strength of the free vortex primary flow computed using laminar, Manning and Bagnold shear equations; little difference was found in the velocity profiles between the three options. Computational simulations were performed by Wang & Andrews (1994), Matthews et al (1998Matthews et al ( , 1999 and Stokes (2001). Das et al (2007) used the semi-empirical model of Holland-Batt (1989) to investigate the behaviour of particles in such a flow, assuming that the particles do not modify the flow, while acknowledging that this model sometimes predicts larger flow depths than reported in experiments.…”

Section: Introductionmentioning

confidence: 99%

Thin-film flow in helically-wound rectangular channels of arbitrary torsion and curvature

2014

View full text Add to dashboard Cite

Laminar helically-symmetric gravity-driven thin-film flow down a helically-wound channel of rectangular cross-section is considered. We extend the work of Stokes et al. (2013) and Lee et al. (2014) to channels with arbitrary curvature and torsion or, equivalently, arbitrary curvature and slope. We use a non-orthogonal coordinate system and, remarkably, find an exact steady-state solution. We find that the free-surface shape and flow have a complicated dependence on the curvature, slope and flux down the channel. Moderate to large channel slope has a significant effect on the flow in the region of the channel near the inside wall, particularly when the curvature of the channel is large. This work has application to flow in static spiral particle separators used in mineral processing.

show abstract

“…They have been studied in the contexts of river flow and sediment transport, [6][7][8] distillation of petroleum products, 9,10 and, of particular interest here, spiral particle separation. [11][12][13][14][15][16][17][18][19][20][21][22] Spiral particle separators are helically wound channels along which particle-laden slurries flow under gravity. They are used in the coal-and mineral-processing industries to segregate and concentrate particles of different sizes and densities.…”

Section: Introductionmentioning

confidence: 99%

Thin-film flow in helically wound rectangular channels with small torsion

et al. 2013

View full text Add to dashboard Cite

Laminar gravity-driven thin-film flow down a helically wound channel of rectangular cross-section with small torsion in which the fluid depth is small is considered. Neglecting the entrance and exit regions we obtain the steady-state solution that is independent of position along the axis of the channel, so that the flow, which comprises a primary flow in the direction of the axis of the channel and a secondary flow in the cross-sectional plane, depends only on position in the two-dimensional cross-section of the channel. A thin-film approximation yields explicit expressions for the fluid velocity and pressure in terms of the free-surface shape, the latter satisfying a nonlinear ordinary differential equation that has a simple exact solution in the special case of a channel of rectangular cross-section. The predictions of the thin-film model are shown to be in good agreement with much more computationally intensive solutions of the small-helix-torsion Navier–Stokes equations. The present work has particular relevance to spiral particle separators used in the mineral-processing industry. The validity of an assumption commonly used in modelling flow in spiral separators, namely, that the flow in the outer region of the separator cross-section is described by a free vortex, is shown to depend on the problem parameters.

show abstract

Computational simulation of fluid and dilute particulate flows on spiral concentrators

Cited by 49 publications

References 20 publications

Behavior of a particle-laden flow in a spiral channel

Behavior of a particle-laden flow in a spiral channel

Thin-film flow in helically-wound rectangular channels of arbitrary torsion and curvature

Thin-film flow in helically wound rectangular channels with small torsion

Contact Info

Product

Resources

About