Mixing behaviour of cohesive and non-cohesive particle mixtures in a ribbon mixer

Musha Halidan, Kejun J Dong, G Rohana Chandratilleke, John Bridgwater, Aibing Yu

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

2 Citations (Scopus)

Abstract

Ribbon mixers are used in a wide range of applications involving pharmaceuticals, ceramics and cosmetics, to name a few. Here, the discrete element method is used to investigate the effect of impeller speed on the mixing behaviours of cohesive as well as non-cohesive particle mixtures in a ribbon mixer, which has a horizontal cylindrical vessel. The mixing behaviours are characterized by particle-scale and macroscopic mixing indexes. Simulations show that the mixing rate increases with the impeller speed for both the cohesive and non-cohesive mixtures up to a certain speed, beyond which it showed a reduction. There is a possibility that the mixture quality becomes poorer at higher impeller speeds for the non-cohesive particles, but it was not the case with the cohesive particles. Inspection of velocity fields shows that many local recirculation regions exist in the case of non-cohesive particle mixing, preventing the overall mixing. By contrast, in the case of the cohesive mixture, there exists a circumferential motion about the shaft and a convective motion in the horizontal axial direction, improving the particle mixing. Force analyses are also carried out, which show that the particle contact forces increase with the impeller speed for non-cohesive particles, but in the case of cohesive particles, they increase initially with the impeller speed, and then show a reduction after a certain speed. The results will be useful in selecting operation conditions of a ribbon mixer.
Original languageEnglish
Title of host publicationPowders and Grains 2013: Proceedings of the 7th International Conference on Micromechanics of Granular Media
EditorsAibing Yu, Kejun Dong, Runyu Yang, Stefan Luding
Place of PublicationMelville NY USA
PublisherAmerican Institute of Physics
Pages731 - 734
Number of pages4
Volume1542
ISBN (Print)9780735411661
DOIs
Publication statusPublished - 2013
Externally publishedYes
EventPowders and Grains 2013 - Sydney, Australia
Duration: 8 Jul 201312 Jul 2013
Conference number: 7th
http://www.pg2013.unsw.edu.au/
http://www.proceedings.com/21017.html

Conference

ConferencePowders and Grains 2013
CountryAustralia
CitySydney
Period8/07/1312/07/13
Internet address

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