Pneumatic sorting of bulk goods using free jets
Research Task/Objectives

Schematic of a pneumatic sorting machine
The sorting of bulk goods - e.g. coffee beans, rice or glass shards - often requires methods to separate single particles from a material stream via free jets. Current studies focus only partly on the fluid dynamics of a fast switching process via valves, the build-up and breakdown of the free jet, and the analysis of the physical phenomena of blow processes of single particles. The goal of this research project is the development of fundamentals for an adequate system design of sorting machines.
Approach/Results

Supersonic free jet of a blowing nozzle
Combining experimental and simulation based methods leads to an analysis of the relevant physical phenomena of the blow process. An experimental flow visualization and a CFD simulation enable an examination of the free jet properties. The force impact on the particles within the jet is analyzed via high speed recording of different blow-out processes. The results are used to build up a simulation model with lumped parameters. The model enables the calculation of blow-out processes of particles with regard to a certain sorting machine configuration.
The presented research activities are part of a cooperation with the company Festo AG & Co. KG. The authors would like to thank this company for the funding and support.