MEASUREMENTS OF VELOCITIES OF SINGLE PARTICLES FOR STEADY AND OSCILLATORY FLOWS IN PLAIN AND BAFFLED TUBES

Preliminary research shows that velocities of single particles in plai n pipes are dependent on the particle Froude number, and can be modell ed by correlations. When fluid oscillation was applied to a plain pipe , the particle velocities increased, especially for low fluid velociti es. This effect was found to be more pronounced with the increase of t he specific gravity of the particles, which suggests that narrower res idence time distributions can be achieved for particles with a density distribution. A twofold increase in particle velocities in a baffled tube was measured in the absence of fluid oscillation. However a criti cal flow velocity existed for this case, below which a particle will b e obstructed by the presence of baffles. Such a critical velocity can be reduced by superimposing fluid oscillation in a baffled tube.