Numerical study of spouting pulsation and gas inlet velocity variation in a rectangular spouted fluidized bed

Abstract Gas–particle flow in a spouted fluidized bed with rectangular geometry and pulsed inflow was numerically studied using a coupled CFD–DEM approach. The study investigated pulsed spouting at frequencies of 1, 4, and 10 Hz under different combinations of spout and background gas velocities. When background gas was present, pulsed inlet flow effectively reduced dead zones and improved particle circulation across all frequencies. At 10 Hz, the spouted fluidized bed showed a 12.81% increase in particle travel distance and a 55% reduction in dead zones. On the other hand, the removal of background gas created a poor performance with dead zones increasing from 0.5% to 7.7% of the particles. The effect of varying inlet velocity ratios of gases was also studied and revealed that appropriate gas distribution could improve the bed performance. The results generally demonstrate that pulsed flow in combination with suitable inlet velocity distribution is capable of improving the hydrodynamics of spouted fluidized beds without altering any geometry or total flow rate.