- Title
- Novel jamming mechanism for dry separation of particles by density
- Creator
- Kumar, Deepak; Iveson, Simon; Galvin, Kevin
- Relation
- Iron Ore 2019. Iron Ore Conference 2019 (Perth, W.A. 22-24 July, 2019)
- Publisher
- AusIMM
- Resource Type
- conference paper
- Date
- 2019
- Description
- A novel system involving a gas-solid fluidized bed subjected to vibration was investigated, building upon Kumar et al.(2018). A mesh with an aperture of 1 mm, incorporating a large central hole referred to as a Sink-Hole, was located just below the surface of a fluidized granular media. The fluidized granular media, nominally 0.3 mm sand particles, expanded through the large Sink Hole, spilling onto the top of the mesh, and then sifted back into the lower fluidized zone. The effective density of the medium at the mouth of the Sink Hole was determined by examining the probability of a large tracer particle of a given density floating as opposed to sinking. The effective density was deemed to be the condition denoting a 50 % probability of the tracer particle passing through. Interestingly, this density condition greatly exceeded the density of the medium and invariably the density of the granular media itself. Moreover, the effective density was largely independent of the size of the tracer particles covering the range 2.8 to 8.0 mm, a sign of genuine density-based separation. The underlying mechanism was attributed to a self-organised, tenuous, jamming condition that develops at the mouth of the Sink Hole. As the diameter of the Sink Hole increased, the separation density decreased, while the speed at which the sorting of the test particles occurred increased significantly. A 60 mm diameter Sink-Hole achieved a steady state separation within approximately 10 seconds, and a remarkably sharp density-based separation.
- Subject
- sink hole; density based separation; granular materials; interacting dynamical systems
- Identifier
- http://hdl.handle.net/1959.13/1420179
- Identifier
- uon:37547
- Language
- eng
- Full Text
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