Characterization of Mixing and Size Segregation in a Rotating Drum by a Particle Tracking Method

Abstract

The mechanisms of segregation in solids mixing, even in simple rotating drums, are not clearly understood. Although most past studies have focused on binary mixtures, this work investigates the effect of polydispersity on granular flow, mixing, and segregation in a rotating drum operated in rolling regime through particle trajectories obtained from the radioactive particle tracking technique. Velocity profiles, radial segregation, and axial dispersion coefficients for monodisperse and polydisperse systems of glass beads are analyzed with respect to rotational speed and particle size. A model is introduced to predict the residence times along streamlines and evaluate the rate at which the material renews at the free surface and within the inner layers of the bed. Our results reveal similar velocity profiles and residence times for monodisperse and polydisperse systems. They also indicate that the particles distribute along the radial direction of the drum, although not necessarily in a core/shell configuration.

Segregation measurement of powder injection molding feedstock using thermogravimetric analysis, pycnometer density and differential scanning calorimetry techniques

“…Particle segregation of dry powder particles has been studied by die filling, shear blender, rotating blender, vibrated shaker, Hele Shaw cells and fluidized beds using measurement techniques such as optical techniques, particle image velocimetry, radioactive particle tracking and infrared or near-infrared spectroscopy [5][6][7][8][9][10][11][12][13][14]. It is well accepted that size and density are the two main factors responsible for particle segregation.…”

Using the discrete element method to assess the mixing of polydisperse solid particles in a rotary drum

“…They reported that the radial segregation in a longer drum was higher than that in a shorter drum. Alizadeh, Dube, Bertrand, and Chaouki (2013) investigated the mixing and segregation of polydisperse particles inside a rotary drum according to particle trajectories, which were obtained employing radioactive particle tracking. The radial segregation, axial dispersion coefficients, and velocity profiles for mono-and polydisperse systems were studied as functions of the particle size and rotational velocity.…”

Modeling of fracture surface of the quasi solid-body zone of motion of the granular fill in a rotating chamber

“…Article [17] examined dynamics of non-spherical particles in a rotating chamber using the method of radioactive particles. The application of such technique to establish trajectories of particles under the rolling over mode is described in [18].…”