Prediction of gas holdup in a column flotation cell using computational fluid dynamics (CFD)
Journal article, 2019

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-epsilon 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.

column flotation

gas holdup

computational fluid dynamics (CFD)

Author

I Mwandawande

Stellenbosch University

G. Akdogan

Stellenbosch University

S. M. Bradshaw

Stellenbosch University

Mohsen Karimi

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Chemical Process and Reaction Engineering

N. Snyders

Stellenbosch University

Journal of the Southern African Institute of Mining and Metallurgy

2225-6253 (ISSN)

Vol. 119 1 81-95

Subject Categories

Applied Mechanics

Energy Engineering

Fluid Mechanics and Acoustics

DOI

10.17159/2411-9717/2019/v119n1a10

More information

Latest update

2/8/2021 6