CFD-IBM-DEM simulation for elucidation of PM filtration mechanisms in fluidized bed filter.

Fluidized bed filters exhibit high PM 2.5 collection efficiency, as shown in our previous work. In this study, a CFD-IBM-DEM simulation was conducted to elucidate the filtration mechanisms for the further development of these filters. A preliminary numerical simulation of a small fixed-bed filter was performed to determine the appropriate CFD grid size for computational accuracy and cost, and the grid of bed particles/10 was applied for PM filtration simulation of the fluidized bed. Numerical collection efficiency is high value of 92.06%, with bed particles of 420 μm and a superficial velocity of 0.4 m/s. Fluidization becomes violent at 0.6 m/s, which decreases the collection efficiency to 84.12%. However, gentle fluidization is maintained even at 0.6 m/s using bed particles of 600 μm, and the fluidization is the same as that observed using bed particles of 420 μm and 0.4 m/s. These fluidization states exhibit similar collection efficiency. [Display omitted] • CFD-IBM-DEM simulation was conducted to elucidate fluidized bed filter mechanisms. • Bottom layer is maintained close-to-packed bed state and filtered most of the PM. • Adhesion acting on PM is dominant, and captured PM is stabilized on bed particles. • Captured PM is stirred by fluidization while being maintained on bed particles. • Same fluidization states exhibit similar collection efficiencies. [ABSTRACT FROM AUTHOR]