Vertical baffles in a fluidized bed reactor: Hydraulic assessment with a numerical and experimental approach

The hydrodynamics of a mini fluidized bed reactor with and without vertical baffles has been studied with Computational Fluid Dynamics (CFD) and verified experimentally for several selected configurations. The CFD – Lagrangian Multiphase Method (CFD-LMM) approach was adopted. The gas was fed at a flow rate of 18 L min⁻¹ via twelve tangential inlets, creating a vortex flow around a cone in the downstream section, and additionally via a single vertical inlet (2 L min⁻¹) in the top plane of the cone. Relevant parameters on the friction factor, namely baffle height, inclination angle, arrangement of the baffles and the distance between the two baffle sets, have been studied. The results showed that increasing the number of baffles, the particle non-uniformity parameter decreases from 75 to 40 %. Moreover, the aligned arrangement was superior to staggered one by providing more fluid mixing. Finally, the trapezoidal baffles further improved the bed uniformity, allowing a decrease of the experimental particle non-uniformity index by more than four times as compared to the reactor without baffles tested in the same conditions.