Analysis of the mixing of solid particles in the slant cone and ploughshare mixers via Discrete Element Method (DEM)

Seyed-Meysam Seyed-Alian

doi:10.32920/ryerson.14645946.v1

Abstract

Discrete element method (DEM) was employed to characterize the mixing of the solid particles in two different types of the powder blenders. In the first part of this study, DEM was used to investigate the effects of initial loading, drum speed, fill level, and agitator speed on the mixing efficiency of a slant cone mixer. DEM simulation results were in good agreement with the experimentally determined data, both qualitatively and quantitatively. In the second part of this study, DEM was employed to characterize the mixing of the solid particles in a Ploughshare mixer. To validate the model, the simulation results were compared to the positron emission particle tracking (PEPT) data reported in the literature. The validated DEM was then utilized to calculate the mixing index as a function of the initial loading, plough rotational speed, fill level, and particle size for a ploughshare mixer.

Highlights

Various industries benefit from the powder blending in manufacturing of some products such as pharmaceutical tablets, ceramic components, fertilizer blends, metal-matrix composites, plastic parts, and food products
The simulation results were compared to the Positron Emission Particle Tracking (PEPT) data reported in the literature by Laurent and Cleary (2012) for a ploughshare mixer
discrete element method (DEM) results were compared to positron emission particle tracking (PEPT) data reported by Laurent and Cleary (2012) for a ploughshare mixer

Summary

Introduction

Various industries benefit from the powder blending in manufacturing of some products such as pharmaceutical tablets, ceramic components, fertilizer blends, metal-matrix composites, plastic parts, and food products. There are some essential factors that should be considered before any attempt to select a proper powder blender for a specific application These vital aspects are the specifications of the materials to be mixed, process safety, industry regulations, labor availability, single or multiple operations, the way that the material is transmitted to and from the blender, and the procedure that the mixer will be integrated into the plant. A closed vessel rotates around the axis in a tumbling mixer Mixing in this type of the blender is achieved due to the random motions of the particles rolling down from an inclined surface. The mixing of particles is achieved by lifting the solid particles, generating chaotic motion, and shearing in the powder mass through the ploughs installed on the mixer shaft. Ploughshare mixer is well-suited for the free flowing to slightly cohesive powders

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Results

Conclusion