TY - GEN
T1 - Mixing behaviour of cohesive and non-cohesive particle mixtures in a ribbon mixer
AU - Musha, H.
AU - Dong, K.
AU - Chandratilleke, G. R.
AU - Bridgwater, J.
AU - Yu, A. B.
PY - 2013
Y1 - 2013
N2 - ![CDATA[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.]]
AB - ![CDATA[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.]]
UR - http://handle.uws.edu.au:8081/1959.7/546260
UR - http://www.pg2013.unsw.edu.au/
U2 - 10.1063/1.4812035
DO - 10.1063/1.4812035
M3 - Conference Paper
SN - 9780735411661
SP - 731
EP - 734
BT - Powders and Grains 2013: Proceedings of the 7th International Conference on Micromechanics of Granular Media, 8-12 July 2013, Sydney, Australia
PB - American Institute of Physics
T2 - International Conference on Micromechanics of Granular Media
Y2 - 8 July 2013
ER -