Entrainment of Geldart C particles in fluidized beds with binary particles

The effects were determined of the mass ratio of Geldart C particles on the total amount of particles (M_fine/ M_total=0–50 wt%), superficial gas velocity (U_g=0.5–1.0 m/s) and coarse particle size distribution (mono, binary, flat, and Gaussian type) on entrainment of Geldart C particles in a bubbling fluidized bed with binary particles (coarse particles: d_p=0.512 mm, ρ_s=2,339 kg/m³and Geldart C particles: d_p=13 μm, ρ_s=4,455 kg/m³). The initial entrainment rate increases with increasing U_g. At U_gof 0.5 and 0.7 m/s, the initial entrainment rate slightly increases initially and then remains almost constant with increasing mass ratio (M_fine/M_total). At higher gas U_gof 0.85 and 1.0 m/s, the initial entrainment rate increases with increasing the mass ratio (M_fine/M_total) up to 30 wt%, after which the increasing slope of the initial entrainment rate decreases with increasing the mass ratio (M_fine/M_total). Also, the decrease in the coefficient of entrainment rate is equal to the increase in (M_fine/M_total) at the corresponding U_g. The average particle size of the entrained particles is about 12–16 μm at U_gof 0.5–1.0 m/s.