The present study considered the application of a multiphase model with Eulerian approach for the solids phase in dilute-phase conveying, where the results are compared against previously published experimental results based on 42µm nominal diameter glass particles. In particular, the Favre-Averaged Drag turbulent dispersion model is studied where it is found to have greater effects on the particle concentration distribution as compared to the gas phase velocity. While certain discrepancies are observed between simulations and published experimental data, the flow characteristics are adequately captured after addressing the underlying cause of inaccuracies. Inaccuracies in the particle concentration distributions along a vertical pipe section result from the difficulty in capturing the transitional zone where the particle rope starts to disperse. On the other hand, particle diameter variations underpin the mismatches along a horizontal pipe section. Interestingly, increasing particle diameter leads to the successful capturing of the particle concentration distribution along the horizontal pipe section. The accuracy of employing an Eulerian approach for solids phase is demonstrated, provided that the particle diameter is accounted for.

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In this paper, an Eulerian granular numerical model is applied in the modelling of an industrial scale pneumatic-based cement conveying system. Steady-state simulation results are found to match pressure and outlet flowrate values with actual system data. By modifying the inlet pressure and material feed rate, data that predicts the performance of the conveying system have been obtained within the present study. Transient simulations have also been conducted and the results reveal intricate details of the cement flows along the pneumatic pipes and pipe bends. In particular, particle roping behaviour is observed to follow the sides of the wall before, during and after the pipe bends. A sloshinglike cement flow motion is also observed after the cement exits the bend. The concentration distribution of the cement particles is found not only to be partly due to gravitational effects but also the pneumatic pipe configuration. Lastly, close inspection of the secondary flows within the pneumatic pipe shows that their directional changes lead to a corresponding change in the particle roping direction, indicating that particle roping is closely associated with the secondary flow structures induced by the exact pipe configuration.Note: Revisions made to manuscript to address Reviewer #1 comments are highlighted in red.