Investigation of flow regime transition in a column flotation cell using CFD

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dc.contributor.authorMwandawande, I.en_ZA
dc.contributor.authorAkdogan, G.en_ZA
dc.contributor.authorBradshaw, S. M.en_ZA
dc.contributor.authorKarimi, M.en_ZA
dc.contributor.authorSnyders, N.en_ZA
dc.date.accessioned2021-10-11T08:12:53Z
dc.date.available2021-10-11T08:12:53Z
dc.date.issued2019-02
dc.descriptionCITATION: Mwandawande, I. et al. 2019. Investigation of flow regime transition in a column flotation cell using CFD. Journal of the Southern African Institute of Mining and Metallurgy, 119(2):173-186. doi:10.17159/2411-9717/2019/v119n2a10
dc.descriptionThe original publication is available at https://www.saimm.co.za/publications/journal-papers
dc.description.abstractENGLISH ABSTRACT: Flotation columns are normally operated at optimal superficial gas velocities to maintain bubbly flow conditions. However, with increasing superficial gas velocity, loss of bubbly flow may occur with adverse effects on column performance. It is therefore important to identify the maximum superficial gas velocity above which loss of bubbly flow occurs. The maximum superficial gas velocity is usually obtained from a gas holdup versus superficial gas velocity plot in which the linear portion of the graph represents bubbly flow while deviation from the linear relationship indicates a change from the bubbly flow to the churn-turbulent regime. However, this method is difficult to use when the transition from bubbly flow to churn-turbulent flow is gradual, as happens in the presence of frothers. We present two alternative methods in which the flow regime in the column is distinguished by means of radial gas holdup profiles and gas holdup versus time graphs obtained from CFD simulations. Bubbly flow was characterized by saddle-shaped profiles with three distinct peaks, or saddle-shaped profiles with two near-wall peaks and a central minimum, or flat profiles with intermediate features between saddle and parabolic gas holdup profiles. The transition regime was gradual and characterized by flat to parabolic gas holdup profiles that become steeper with increasing superficial gas velocity. The churn-turbulent flow was distinguished by steep parabolic radial gas holdup profiles. Gas holdup versus time graphs were also used to define flow regimes with a constant gas holdup indicating bubbly flow, while wide gas holdup variations indicate churn-turbulent flow.en_ZA
dc.description.urihttps://www.saimm.co.za/publications/journal-papers
dc.description.versionPublisher’s version
dc.format.extent14 pagesen_ZA
dc.identifier.citationMwandawande, I. et al. 2019. Investigation of flow regime transition in a column flotation cell using CFD. Journal of the Southern African Institute of Mining and Metallurgy, 119(2):173-186. doi:10.17159/2411-9717/2019/v119n2a10
dc.identifier.issn2411-9717 (online)
dc.identifier.issn2225-6253 (print)
dc.identifier.otherdoi:10.17159/2411-9717/2019/v119n2a10
dc.identifier.urihttp://hdl.handle.net/10019.1/123196
dc.language.isoen_ZAen_ZA
dc.publisherSouthern African Institute of Mining and Metallurgyen_ZA
dc.rights.holderThe Southern African Institute of Mining and Metallurgyen_ZA
dc.subjectFlotationen_ZA
dc.subjectMaximum superficial -- Velocityen_ZA
dc.subjectFlow regimeen_ZA
dc.subjectBubbly flowen_ZA
dc.subjectTransitionen_ZA
dc.subjectChurn-turbulent flowen_ZA
dc.titleInvestigation of flow regime transition in a column flotation cell using CFDen_ZA
dc.typeArticleen_ZA
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