Particle distributions and dynamics of particle movement in solid—liquid fluidized beds

Abstract The results of experimental and theoretical studies of bed structure and particle motion in a glass particle—methyl benzoate fluidized bed are presented. The angular particle distributions are found to be similar to those in the probability model. The radial distributions of particles and particle-free areas indicate a tendency for particles to group near the column wall with oscillatory distributions away from the wall. The structure of the fluidized bed does not change for porosities of up to 0.7. The maximum void diameter is found to equal five particle diameters, and is four times less than the diameter of a stable bubble from the Davidson and Harrison model. The particle velocity distribution is close to a normal one. At a low mean liquid velocity, particle velocities tend to be higher in an upward direction in the centre of the bed and in a downward direction at the column wall. The vertical particle velocity distribution has an oscillatory form with maxima for conveyed particles and corresponding minima for falling particles. The mean value of the ratio of the absolute vertical and horizontal particle velocities is found to be about 2.0 for E = 0.623 - 0.781.