Mixing Enhancement of Mono-Disperse and Bi-Disperse Particles in a Cylindrical Drum Mixer Using Discrete Element Simulations

Abstract

Numerous studies tackled the mixing behaviour of granular materials in a cylindrical drum mixer, however research regarding mixing enhancement by conceiving new designs of drum mixers is insufficient. Also, conducted studies to examine the mixing rate in various processes using the contact-based method rather than the variance-based method is unavailable. In this work, the discrete element method was used to study the mixing of mono-disperse and bi-disperse cohesionless solid particles in an inner-paddled rotating cylindrical drum mixer with different amounts of paddles and mixer rotational speeds. We found satisfactory mixing sates around the mixer periphery when compared with previously conducted real experiments to verify our DEM models. The contact-based methodꞌs so-called nearest neighbor was employed to quantitatively assess the different mixing scenarios. A better mixing rate is obtained when a cylindrical drum mixer has 8 uneven paddles installed along its horizontal axel and the mixer rotational speed is set at 48 rpm.

Keywords

• discrete element method
• drum mixer
• granular material
• homogeneity
• mixing process