Comparative study of the mixing of free-flowing particles in a V-blender and a bin-blender

The objective of this work consists of investigating the influence of process parameters such as the fill level (35, 50 and 65%v/v), loading profile (front–back (FB), right–left (RL) and top–bottom (TB)) and rotational speed (15, 30 and 45 RPM) on the mixing performance of a V-blender and a bin-blender, on the basis of RSD curves, granular mixing dynamics, mean granular velocities and granular temperatures. The mixing systems consisted of two 7.5-L lab-scale versions of industrial V-blenders and conical bin-blenders. Spheronized microcrystalline cellulose granules (φ=500μm) were used as free-flowing material. Experimental data were generated by analyzing the concentration of thief samples obtained using core samplers by means of image analysis. As a complement to the experimental work and in order to gain more insight into the flow behavior and mixing dynamics in both blenders, numerical simulations of the flow up to 780 000 monodisperse particles were carried out using the discrete element method (DEM). This study shows in particular that, on the basis of RSD curves, the mixing performance of the bin-blender is comparable to that of the V-blender for FB and TB loading profiles, and that the V-blender clearly outperforms the bin-blender in the case of the RL loading profile.