Solid Fluctuations and Dispersion in Liquid-Solid Fluidized Beds With Low Surface Tension Media

Fluctuations and dispersion of solid particles were investigated in a liquid-solid fluidized bed of which diameter was 0.102 m and 2.5 m in height. Effects of liquid velocity (0.005 ∼ 0.13 m/s), particle size (0.5 ∼ 3.0 × 10⁻³ m) and surface tension of continuous liquid media (56 ∼ 72 × 10⁻³ N/m) on the fluctuation frequency and dispersion coefficient of fluidized solid particles were determined. The fluctuating frequency and dispersion coefficient of particles were estimated by means of the relaxation model based on the stochastic theory. Both of fluctuating frequency and dispersion coefficient of particles showed maximum values with a variation of liquid velocity and increased with an increase in the particle size or surface tension of liquid media. The values of fluctuating frequency and dispersion coefficient of fluidized solid particles were well correlated in terms of dimensionless groups as well as operating variables.