Fluidization of nano-modulated Group C particles in a circulating fluidized bed

Through nanoparticle modulation, fast fluidization of Group C particles (d_p < 35 μm) is achieved in a circulating fluidized bed (CFB) with an inner diameter of 0.07 m and a height of 2.5 m. Hydrodynamic behaviors of the CFB riser are investigated. Compared to Group A and unmodified Group C particles, a much lower superficial gas velocity in the range of 0.4–0.7 m/s is sufficient to accomplish circulating operation for nano-modulated Group C powders. The average solids holdup is notably denser than traditional CFBs, reaching 0.10–0.15 and remaining relatively homogeneous up to 1.5 m of the riser. Increasing superficial gas velocity results in reduced solids concentration in the riser. Solids circulation rate and auxiliary gas flowrate both positively impact solids holdup, with higher rates leading to increased average solids concentration. The impact of the quantity of incorporated nanoparticles appears to differ across various powders, as the distinct properties of powders present difficulties in identifying the optimal nanoparticle concentration.