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 plain pipes are dependent on the particle Froude number, and can be modelled by correlations. When fluid oscillation was applied to a plain pipe, the particle velocities increased, especially for low fluid velocities. This effect was found to be more pronounced with the increase of the specific gravity of the particles, which suggests that narrower residence 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 critical flow velocity existed for this case, below which a particle will be obstructed by the presence of baffles. Such a critical velocity can be reduced by superimposing fluid oscillation in a baffled tube.