- Title
- Analysis of interaction forces for predicting the transition from segregation to mixing of binary solids in a miniaturised gas fluidised bed
- Creator
- Peng, Zhengbiao; Alghamdi, Yusif A.; Moghtaderi, Behdad; Doroodchi, Elham
- Relation
- APCChE 2015 Congress incorporating Chemeca 2015. Proceedings of APCCHE 2015/Chemeca 2015 (Melbourne 27 September - 1 October, 2015) p. 1854-1865
- Publisher
- Engineers Australia
- Resource Type
- conference paper
- Date
- 2015
- Description
- Gas-solid fluidised beds are widely used in chemical, petrochemical, pharmaceutical, biochemical and powder industries. Particles used in gas-solid fluidised beds often differ in size and/or density, thus have the tendency to segregate under certain operating conditions. The results of our earlier work show that the fate of segregation or mixing is determined by the combining effects of particle properties (e.g. size and density ratios), particle species composition and superficial gas velocity. For a given binary mixture, the transition from segregation to mixing occurred when the superficial gas velocity was increased over a critical value. In this study, the force analysis at particle scale, including particle-particle and particle-fluid interacting forces, has been carried out to investigate the underlying mechanisms that drive the transition. Specifically, the motion of particles was tracked individually by discrete element method (DEM), whilst the gas flow was modelled by computational fluid dynamics (CFD). Experiments on the segregation and mixing of binary mixtures in gas-solid fluidised beds were conducted for model validation. The results showed that as the superficial gas velocity increased, the turbulence of the gas flow increased which in turn induced the chaotic motion of particles. The particle-particle collision intensity dramatically increased and the collision forces led to an intense diffusion of particles and hence mixing of binary solids. The relationship between the force ratio (i.e. particle-fluid force to particle-particle force) and the transition from segregation to mixing has also been discussed. The simulation results agreed well with experimental measurements.
- Subject
- mixing; segregation; gas-solid fluidised bed; DEM-CFD; particle-particle collison; particle-fluid interactions
- Identifier
- http://hdl.handle.net/1959.13/1315171
- Identifier
- uon:22907
- Identifier
- ISBN:9781922107473
- Language
- eng
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