Mixing of granular material in a drum mixer undergoing rotational and rocking motions - I. Uniform particles

The effects of flow perturbations on the extent of mixing vs. time are examined in a cylindrical vessel partially filled with uniform-sized powder mixtures. Mixtures produced by pure rotational motion are compared to those undergoing rotational motion supplemented by rocking. Characterization of the mixing experiments is conducted using solidification and image analysis methods, affording visual inspection of the internal mixing patterns and evaluation of the composition distributions. Pure rotational motion causes slow axial mixing. When rotational motion is supplemented by a rocking perturbation, mixing time is greatly accelerated. (C) 1998 Elsevier Science S.A. All rights reserved.