Abstract: Spout–fluid beds are widely applied in the process industry due to their advantages of efficient contact between particles and gas. In this paper, a TFM (two-fluid model) is set up to simulate the hydrodynamics and heat transfer of a 3D spout-fluid bed with single, double and triple chambers. Simulation results show that scale-up by aligning multiple chambers is complex in the regimes with low SF (spout-fluid ratio) due to chamber-chamber interaction. In the regimes with high SF, however, scale-up is simple because chamber-chamber interaction is hardly noticed. With increasing SF, gas and particle fluxes on inter-chamber interfaces prefer to occur in the annulus regions instead of in the fountain region. The kinetic heat flux of the solid phase has a similar preference. The molecular heat flux of the solid phase always prefers to pass through the inter-chamber interface in the annulus region. The preference however weakens with increasing SF.