Experimental observation of particle sedimentation in a horizontal annular pipe

Abstract

The behavior of a suspension sedimenting in a horizontal annular pipe is experimentally studied. The suspension is made of oil and spherical beads with diameter 150-180 µm at concentration 0.5 %, and is placed in an annular cylinder space of inner and outer diameters of 90 and 140 mm, respectively, and a thickness of 20 mm. During the sedimentation process, images are recorded with a camera at 1 fps. The south pole area constitutes an area of particular focus, where a clear fluid layer of constant thickness forms along the internal radius. Various particle tracking and velocimetry techniques are used to generate velocity profiles and monitor individual and collective motion of particles within the cell, enabling the identification of 4 zones of distinct bead behaviors. This analysis gives us important information about particles movement within a suspension sedimenting in a horizontal annular pipe.