Mixing of granular materials. Part I: Effect of periodic shear

Although the study of mixing of granular particles in the last years has shown notable advances, it continues being moderately understood. In this work, a new low shear mixing device consisting of a box with two moving walls and three static walls was developed to study granular mixing. The goal is to obtain an in depth understanding of the internal behavior of granular materials in three dimensions. Experiments at different wall velocities and wall displacements were run. Results reveal that the best mixing is found near the moving walls and in the superficial layer. A triangular pattern was obtained at the bottom of the mixing chamber, whose size depends on the length of the mixing chamber and the velocity and amplitude of wall displacement. The phenomena of dilation and consolidation played an important role in the mixing performance.

Graphical abstractA new low shear mixing device consisting of a box with two moving walls and three static walls was developed to obtain a more in depth understanding of the internal behavior of granular material in the three dimensions. A triangular pattern was obtained at the bottom of the mixing chamber and a chaotic behavior in the top view images.Figure optionsDownload full-size imageDownload as PowerPoint slide