Using flow perturbations to enhance mixing of dry powders in V-blenders

Experiments were conducted to compare mixing performance in a conventional V-blender and in a V-blender that incorporates perturbations of the particle flow by rocking the mixing vessel during rotation, Mixing was investigated using glass beads with sizes from 40 to 800 mu m in vessels of approximately one liter volume. Mixture uniformity was assessed qualitatively using two different methods. One method used a transparent mixing vessel to visualize particle flow patterns and assess the state of homogeneity at the mixture's surface during the entire experiment, The second method involved solidification of the mixture by infiltration with a binder inside disposable aluminum mixing vessels. Using this method, it was possible to assess the state of the entire mixture, including its interior structure, by slicing the solidified structure after completion of each experiment. Mixture uniformity was also assessed quantitatively using image analysis to determine the composition of the solidified samples. In all cases, mixing was greatly enhanced in the rocking V-blender compared to the conventional V-blender.