Transverse mixing of polymer powders in a rotary cylinder part I: Active layer characterization

This work reports some observations made on particle motion in the transverse plane of rotating cylinders operated in the rolling regime. In particular, techniques were developed to estimate the transition between the active and stagnant layers. Based on the particle trajectory and velocity obtained, a new theoretical model based on the thin active layer approximation is proposed to estimate the size and shape of the active layer with respect to filling ratio, Froude number (rotational speed) and particle sizes.

Video imaging of particle motion in a rotating cylinder is used to determine the region occupied by the active and stagnant layers. From particle trajectory and velocity, a model based on the thin layer approximation is proposed to estimate the shape of the active layer with respect to filling ratio, rotational speed and particle size.Figure optionsDownload as PowerPoint slideHighlights
► Video imaging is used to follow tracer particles in a rotating cylinder.
► The effect of processing conditions on particle motion is presented.
► The effect of Froude number, filling ratio and particle size is determined.
► A characterization of the stagnant and active layers is presented.
► A model is proposed to maximize mixing.