Congratulations to Anna-Elisabeth Sommer on her successful PhD defence “The role of turbulence on the bubble-particle collision – An experimental study with particle tracking methods“

The analysis of collisions between particles and bubbles in a turbulent flow is a fundamental problem of high technological relevance, e.g. for the separation of valuable mineral particles by froth flotation. That relevance contrasts with an apparent lack of experimental data and insights into this collision process. A major issue is the limitation of available measurement techniques to directly observe the collisions between particles and bubbles.

In her dissertation, novel methodologies are developed to measure the interaction between bubbles and particles under defined hydrodynamic conditions. These methodologies comprise particle tracking techniques such as 4D PTV and PEPT to triangulate the Lagrangian particle trajectories in the vicinity of a bubble and classify those which are colliding.

Overall, the developed methodologies in this dissertation provide a framework to investigate directly the collision between particles and bubbles in a turbulent flow. The gained experimental validation data allows us to verify existing collision models and to advance our understanding of the role of turbulence in froth flotation.