The hydrodynamics and chamber interaction in a three-dimensional spout-fluid bed with two interconnected chambers are investigated via computational fluid dynamics coupled with discrete element method (CFD-DEM), because multiple interconnected chambers are key to scaling up spout-fluid beds. The overall solid motion, spouting evolution, and spoutannulus interface is studied, followed by time-averaged hydrodynamics, particle-scale information, spout-annulus interaction, and inter-chamber interaction. The results show that inter-chamber interactions lead to unique characteristics distinct from that for a single-chamber system, including (1) asymmetry of the hydrodynamics within each chamber, (2) alternative spouting behavior in the two chambers, (3) smaller pressure drop in terms of magnitude and fluctuations, (4) two peaks in the solid residence time (SRT) frequency histogram of the annulus, (5) average SRT in the spout is twice that in a single-chamber, and (6) larger solid dispersion in all three directions. The results provide meaningful understanding for the scale-up of spout-fluid beds.In view of its excellent performance and widespread application, numerous experimental efforts have unsurprisingly focused on various aspects of this apparatus, spanning the hydrodynamics, 11,12 solid circulation, 13,14 particle velocity profile, 15 pressure drop 16 and fluctuation, 17 flow reigme, 18-20 maximum bed height, 21 particle mixing, 22 minimum spouting velocity, 23 effect of draft plates, 24-26 thermal behavior, 27 and so on. In tandem with experimental investigations, the numerical simulation of the dense two-phase flow has progressed too. As is well-acknowledged, two approaches, namely, the twofluid model (TFM) and computational fluid dynamics combined with discrete element method (CFD-DEM), are available to model the dense gas-solid flow. 28,29 The critical difference between these two approaches lies in the resolution of the solid motion: the solid phase is treated as a continuum and tracked individually in the Lagrangian framework in TFM and CFD-DEM, respectively. Zhong et al. 30 numerically explored the gas/solid flow in the three-dimensional (3-D) spout-fluid bed using TFM, wherein the kinetic theory of granular flow provided the closures. The results demonstrated that the simulation results are strongly affected by the restitution