Granular Mixing and Diffusion: a 3D Study

L. BRUNO, A. CALVO, I. IPPOLITO

International Journal of Heat & Technology

Año: 2003 vol. 21 p. 67 - 72

0032-5910

We report an experimental study of the dispersion properties of bidisperse glass beads moving under gravity in a 3-dimensional array of obstacles. The experimental set-up consists in a number N of steel squared grids (lattice separation of2.5 cm) of 1 m2 area, placed parallel to the floor. The separation between grids e can take values of 1.25 cm and 2.5 cm. Thegrids act as rigid obstacles to the flow, spreading the particles in random directions. As a consequence, an initial cluster ofbeads can be dispersed and the motion of the particles decorrelated. Eventually, a diffusive regime can be achieved. At theirexit from the array, the particles accumulate in discrete collectors. Afterwards, the beads final mass distributions arereconstructed. These distributions allow to determine a degree of mixing, as well as the dispersion lengths that characterizethe spreading amplitudes for the different particle diameters.