DEM study of effects of particle size and density on mixing behaviour in a ribbon mixer

Ribbon mixers are used in various industries for the mixing of particle matter. The discrete element method (DEM) is used to investigate the effects of the particle size and density on particle mixing in a laboratory-scale ribbon mixer.The mixer consists of a ribbon impeller with spokes and a horizontal cylindrical vessel. The particle size varies from 5 to 15 mm, and density from 417 to 2500 kg/m(3). A particle-scale index is used to analyse the mixing state, and the impeller torque is used to evaluate the mixer's mechanical performance. The results show that the mixing rate generally becomes slower at a given density when the particle size is reduced with the fill-level fixed. For small particle sizes, the density effect was negligible, and the particle-size effect was described by an empirical equation, which was also extrapolated for much smaller particles. Effects of particle size and density on the impeller torque were also investigated. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study uses the discrete element method to investigate the effects of particle size and density on mixing in ribbon mixers. Results show that mixing rate generally slows down with reduced particle size at a given density. The impeller torque is also influenced by particle size and density.