Investigation of granular dynamics in a continuous blender using the GPU-enhanced discrete element method

Abstract

Continuous powder blending is an essential operation during continuous pharmaceutical manufacturing. However, the complex granular dynamics in the blender is still poorly understood. This study employs a graphic processor unit (GPU) enhanced discrete element method (DEM) to analyse the granular dynamics in a continuous blender. Numerical results indicate that only a small fraction of powder distributes in the upper region of the blender, while most of that distributes in the middle and lower regions. Besides, a higher impeller speed leads to a smaller hold-up mass and a shorter mean residence time. Interestingly, the maximum number of blade passes is achieved at an intermediate impeller speed. There are two distinct regimes during continuous blending: i) a shearing regime at low impeller speeds; and ii) a dynamic regime at high impeller speeds. This study demonstrates that the GPU-enhanced DEM can be a robust tool for analysing powder flow during continuous pharmaceutical manufacturing. • GPU-enhanced DEM analysis on the full-scale continuous blending is performed. • Impeller speed has a significant impact on the powder flow in the inclined blender. • At steady-state, powder mainly distributes in the middle and bottom zones of blender. • Maximum number of blade passes can be achieved at an intermediate impeller speed.