Analysis of flexible ribbon particle residence time distribution in a fluidised bed riser using three-dimensional CFD-DEM simulation

Fluidised bed technology is a very common industrial process and has a wide range of applications in process engineering. Though indirectly, a common way to infer the end product uniformity is through investigating the solid residence time distribution (RTD) in the system. A good understanding of the particle RTD is crucial for the proper design, optimisation, and scale-up of a fluidisation process. Flexible ribbon particles have a very different flow behaviour in a fluidised bed compared to that of spheres which in turn influences the RTD of the particles. However, this issue is still not very well addressed to date. In this paper, a double chain model is adopted to model cut tobacco strips in a fluidised bed riser. The spring constants of this chain model are calibrated, and the model is validated against experimental datum. Finally, the particle RTD as a function of different process parameters is investigated. [Display omitted] •Spring constants of the double chain model is calibrated.•Residence time distribution of flexible ribbon particles is validated against experimental datum.•Flexible ribbon particle in the riser is shown vividly.•Axial and radial residence time distribution of this special particle is discussed.