Influence of screw element geometry on particle flow in twin screw granulation: A DEM study

Twin screw granulation (TSG) is a key process in continuous manufacturing, yet the impact of screw element geometry on powder flow remains poorly understood. This study uses a GPU-enhanced discrete element method (DEM) to quantitatively analyse the effects of different screw elements on particle kinematics, residence time distribution, Peclet number, and power consumption. The results reveal that conveying elements lead to shorter mean residence times, narrower residence time distributions, and lower power consumption, while kneading elements result in longer mean residence times, wider residence time distributions, and higher power consumption. Distributive mixing elements exhibit intermediate behaviour. Interestingly, most screw element types have little effect on the Peclet number, which primarily governs axial mixing in TSG. These findings provide valuable insights into the conveying and mixing performance of screw elements, offering guidance for optimising screw design in TSG systems.