Prediction of gas holdup in a column flotation cell using computational fluid dynamics (CFD)

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mwandawande_prediction_2019.pdf(1.15 MB)
Date
2019-01
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The Southern African Institute of Mining and Metallurgy
Abstract
ENGLISH ABSTRACT: Computational fluid dynamics (CFD) was applied to predict the average gas holdup and the axial gas holdup variation in a 13.5 m high cylindrical column 0.91 m diameter. The column was operating in batch mode. A Eulerian-Eulerian multiphase approach with appropriate interphase momentum exchange terms was applied to simulate the gas-liquid flow inside the column. Turbulence in the continuous phase was modelled using the k- realizable turbulence model. The predicted average gas holdup values were in good agreement with experimental data. The axial gas holdup prediction was generally good for the middle and top parts of the column, but was over-predicted for the bottom part of the column. Bubble velocity profiles were observed in which the axial velocity of the air bubbles decreased with height in the column. This may be related to the upward increase in gas holdup in the column. Simulations were also conducted to compare the gas holdup predicted with the universal, the Schiller-Naumann, and the Morsi-Alexander drag models. The gas holdup predictions for the three drag models were not significantly different.
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CITATION: Mwandawande, I. et al. 2019. Prediction of gas holdup in a column flotation cell using computational fluid dynamics (CFD). Journal of the Southern African Institute of Mining and Metallurgy, 119(1):81-95. doi:10.17159/2411-9717/2019/v119n1a10
The original publication is available at https://www.saimm.co.za/publications/journal-papers
Keywords
Column flotation, Computational fluid dynamics (CFD), Gas holdup, Axial flow
Citation
Mwandawande, I. et al. 2019. Prediction of gas holdup in a column flotation cell using computational fluid dynamics (CFD). Journal of the Southern African Institute of Mining and Metallurgy, 119(1):81-95. doi:10.17159/2411-9717/2019/v119n1a10
URI
http://hdl.handle.net/10019.1/123197
Collections
Research Articles (Chemical Engineering)