A study of the axial and radial competition segregation in a rotating drum with internal diameter changing

Abstract

A binary mixture is mixed in a rotating drum composed by 19 rings with different inner diameters. It is found that the larger particles are concentrated in the rings with smaller inner diameters. The collection of the larger particles in these rings is due to the particle dynamic angle of repose. The transition from the particle segregation core pattern at the end wall to the good radial mixing rings is through a transient turning comet segregation pattern. This transition is closely related to the distance from the ring with the smallest inner diameter to the ring with the largest inner diameter. Having a higher fraction of larger particles in a ring requires both the collection ring having a smaller inner diameter and a smoother inner diameter transition to the neighboring rings.

Experimental and Numerical Study of Computer Vision-Based Real-Time Monitoring of Polymeric Particle Mixing Process in Rotary Drum

“…The particles involved in the mixing simulation consist of 20 mm-diameter red particles and 10 mm-diameter blue particles, both made of polyethylene. These sizes were intentionally varied to induce segregation during the mixing process [ 23 ], which improved the study of particle dynamics under differential motion conditions. The properties of the materials used in the DEM analysis are presented in Table 1 .…”

“…A frontal viewpoint of the circular face of the cylindrical vessel was selected for observation. To observe the early-stage transient response, three images were extracted: the initial-time image and images at 5 and 10 s. In addition, to examine the response after a sufficient process time, three more images were chosen: images at 100, 200, and 300 s. According to published studies [ 23 ], smaller particles tend to migrate toward the center, while larger particles move away due to differences in size, resulting in radial segregation of particles. During the drum-mixing operation, radial segregation occurs as particles of varying sizes or densities are sorted into separate radial layers within the drum.…”