CFD model prediction of the Two-Section Two-Zone Fluidized Bed Reactor (TS-TZFBR) hydrodynamics

•Gas and solid hydrodynamics in a two-zone fluidized bed reactor.•A two-fluids model was employed to predict the hydrodynamics.•Good agreement in bubble size and velocity with previous experimental results.•Prediction of defluidized zones in some operating conditions.•Good prediction for gas hydrodynamics but not for solid flow in this reactor.

Computational simulations and experiments have been carried out to study the bed hydrodynamics in a Two-Section Two-Zone Fluidized Bed Reactor (TS-TZFBR). An Eulerian–Eulerian two-fluid approach has been used to simulate the reactor bubbling behavior, while cold fluidization measurements have been made in pseudo-2D TS-TZFBR facilities. The characteristic bubble shrinkage within the transition bed section as well as the eventual formation of defluidized bed regions have been well predicted by the CFD model. The effect of TS-TZFBR geometry, i.e. the transition section angle (α), superficial gas velocity in the bed and immersed gas distributor location, on the experimental hydrodynamic behavior has been compared to that in computational simulations, resulting in a reasonably good agreement. Bubble related properties have been analyzed for both simulations and experimental measurements. The experimental results validate the standard Eulerian–Eulerian model for simulating the TS-TZFBR bubble hydrodynamics in a wide range of operational conditions: ugas–umf = [5–20] cm/s, α = [0°–85°].

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