Modelling of the behaviour of gas–solid two-phase mixtures flowing through packed beds

This work is concerned about gas–solid two-phase mixtures flowing upwards through packed beds. An Eulerian-based two-fluid model coupled with a newly proposed porosity distribution model is used to simulate the flow behaviour. The results are compared with recently published experimental results in terms of both hydrodynamics and solids motion. It is found that the use of the newly proposed porosity model not only gives better agreement with experimental porosity data, but also provides a much better prediction of the pressure drop than other porosity models could do. The results also show that the model predicts very well the dynamic hold-up of suspended particles, and captures the main features of the radial distributions of the suspended solids concentration and the axial solids velocity. A discrepancy occurs, however, at the wall region where the predicted axial solids velocity peak is sharper and higher than the measurements. The work also leads to a new relationship for the pressure drop of dilute gas–solid two-phase mixtures flowing through packed beds, which agrees very well with experiments.