Congratulations on the defense of Paul Naumann's diploma thesis

On April 24, 2024, Paul Naumann successfully defended his diploma thesis entitled “Height measurements in foam and froth experiments using optical measurement techniques” at our Chair of Transport Processes at Interfaces.

Froth flotation is a process used primarily in ore processing to separate valuable minerals from gangue minerals. For Flotation plants, monitoring froth height is important because it is closely related to product quality and quantity. Camera systems and, more recently, lidar sensors are commonly used for this purpose. Laser triangulation is another promising technology that has been applied to other multiphase systems. However, there is still a lack of characterization and testing of lidar and laser triangulation as optical methods for measuring foam and froth height. The objective of this thesis is to experimentally evaluate their suitability and limitations for foam and froth height measurement in different laboratory set-ups.

All sensors investigated were generally capable of measuring foam and froth height. Due to the bubble-scale structure of foam, an underestimation of the measured height is observed for both lidar and laser triangulation, depending on the foam properties. Based on the experimental results, lidar sensors are well suited for industrial applications, while laser triangulation is a useful technique for very precise measurements with high temporal resolution. Further analysis of systematic errors should be pursued.