Modeling of Power Consumption and Mixing in a Horizontally Rotating Cylinder

A horizontally rotating cylinder is a suitable geometry for creating a mixing effect by rotating around the central axis. Potential advantages arise from the large wetted surface used for the power input, which may create a superior homogeneous energy dissipation distribution and allow for gentle mixing. However, the rotating cylinder has been characterized only in terms of mixing, with no information available on the corresponding power input. The objective of the present study is to identify the main influencing parameters on the power input. A set of relevant variables was experimentally varied, including equipment and operational parameters, as well as the liquid viscosity. Additionally, mixing times were determined for elevated viscosities, thereby deriving the mixing efficiency to classify the cylinder as a mixing device. Finally, correlations of dimensionless numbers were established to describe the power input and mixing time, suggesting the presence of different flow regimes within the experimentally investigated range.