Effect of perforated ratio of distributor on the fluidization characteristics in a gas-solid fluidized bed

A gas-solid fluidized bed, which is 0.14 m in diameter and 1.6 m in height, was employed to investigate systematically the effects of distributor perforated rate on pressure drop of distributors with air as gas phase and fluidized catalytic cracker (FCC) particles as solid phases. The particle concentration distribution and distributor pressure drop were measured simultaneously by a PV-6A particles velocity measurer and a U-manometer, respectively. The parameters of pressure drop and the radial solid holdups profile of three types of distributors, the instantaneous evolution of bubbles and the gas-solid motion with an appropriate distributor were simulated using computational fluid dynamics (CFD) code Fluent 6.2, which proved that the numerical simulation results agreed well with the experimental data. The results showed that the distributor pressure drop was decreased with increasing the perforated ratio, and the effect of perforated ratio on distributor pressure drop was small when the perforated ratio was larger than 0.86%. The fluctuation of radial solid fraction was increased with increasing perforated rate of distributor, and the fluctuation value was the lowest when perforated rate was 0.46% which indicated the gas-solid distribution was more homogeneous.