Performance evaluation of gas maldistribution mitigation via baffle installation: Computational study using ozone decomposition in low-velocity dense fluidized beds

Abstract

Gas maldistribution is an operational challenge peculiar to all industrial fluidized bed applications, resulting in poor reactor performance. In the present work, the multi-phase particle-in-cell (MP-PIC) method was used to simulate an induced-gas maldistribution condition in a low-velocity batch mode fluidized bed of ozone (O3) decomposition process. The effects of mesh and single-turn Louver baffles on gas maldistribution mitigation were compared with baffle-free condition across different superficial gas velocities (Ugs) under similar reactive conditions. Hydrodynamics of the gas-solid flow and reaction performance were examined. Initial simulations agreed well with the experimental data reported in the literature. Baffles installation resulted in a range of favorable impacts, including obstruction of gas channelling, expansion of the bed, enhanced gas-solids contact efficiency, reduced pressure fluctuation and decreased effluent O3. The single-turn Louver baffle showed the best performance due to its stronger bubble-breaking and gas redistribution effects spurred by the inclined vanes; its simulated superiority agreed strongly with previous experimental results. Present study demonstrates the effectiveness of baffle installation in resolving gas maldistribution and/or intensifying industrial processes.