Eulerian simulation of gas–solid flow in a countercurrent downer

•A drag correlation is proposed for considering particle clustering structure.•CFD simulations of gas–solid flow in a countercurrent downer.•Experimental and numerical results show a reasonable agreement.

Countercurrent gas–solid downer reactor has been used in various processes, however, fundamental studies on the hydrodynamics of such reactors are sparse, especially, there is no computational fluid dynamics study available. To this end, an empirical inter-phase drag correlation, based on experimental data available in literature, is proposed to address the key role of meso-scale particle clustering structure in determining effective inter-phase drag force. The proposed drag correlation is then integrated into Eulerian model to study the hydrodynamics of gas–solid flow in a countercurrent downer reactor. It was shown that the measured axial pressure distribution and radial solid concentration profiles can be reproduced reasonably well and the radial particle velocity profile can be qualitatively captured as well. Present study offers a preliminary validation of feasibility of modeling gas–solid in a countercurrent downer using Eulerian model.

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