Investigation of the influence of bubble-bubble interactions on the hydrodynamics of bubbling gas-solid fluidised beds using the discrete bubble model

Abstract

To investigate the hydrodynamic behaviour of industrial scale bubbling fluidised bed reactors, a 3D Discrete Bubble Model (DBM) has been developed. In the DBM, an Euler-Lagrange model, the bubbles are treated as discrete elements and the bubble trajectories are tracked individually, while the emulsion phase is considered as a continuum and is described with the continuity and Navier-Stokes equations. The main advantage of the DBM is that it fully accounts for the two-way coupling, allowing computation of the prevailing macroscopic circulation patterns in large scale gas-fluidised beds. In this paper, we have examined the effect of bubble-bubble (wake) interactions on the macro-scale velocity profiles using the DBM. It has been found that the extent of the macroscopic circulation is significantly increased by the bubble-bubble interaction force