Experimental investigation of electrostatic effect on particle motions in gas-solid fluidized beds

摘要

The excess accumulation of charges in the fluidized bed has a severe impact on hydrodynamics. Due to lack of effective experimental methods, electrostatic effects on hydrodynamics have mostly been studied using numerical simulation. By injecting a trace of liquid antistatic agents into a fluidized bed, charges were controlled and electrostatic influences on particle motions were investigated. The average particle-wall impact angles are acquired by developing multiscale wavelet decomposition of acoustic emission signals. The impact angles are significantly influenced by both charge levels and gas velocities. If the electric force is reduced and/or fluid drag is increased, friction dominates the particle-wall interactions. Under a larger gas velocity where fluid drag dominates, charges elimination causes no significant variation in particle impact angles, but particle velocities increase as well as at lower gas velocities. In addition, existence of electrostatic charges influences the ranges of bubble growing zone and jet impacting zone. (c) 2015 American Institute of Chemical Engineers