Simulation of binary particle segregation for bubbling fluidized beds using polydispersed structure‐based drag model extended from a monodispersed model

Abstract

A bubble structure‐based drag model developed for the monodispersed system has been extended to simulate bi‐dispersed bubbling fluidized beds. Both dense phase and dilute phase are considered to be comprised of two types of particles with different sizes. The derivation of the structure‐based drag coefficient for individual particle based on the force equilibrium principle is proved to be independent of the volume fractions (εsi) of particle i. The multi‐fluid model in the commercial software Ansys Fluent is employed to evaluate the polydispersed drag model for the segregation of binary gas‐particle flows in a bubbling fluidized bed. It is shown that the simulation results predicted by the new structure‐based drag model are in reasonable agreement with experimental data with a 6.34% root mean square error (RMSE). The new structure‐based model can capture the particle distribution at the top region of the fluidized bed well. The bubble behaviour can also be captured by the new model well.

Special issue in honour of Professor Jamal Chaouki

“…We are pleased to report that 30 papers were initially submitted to the journal and after peer review, following the standard journal procedures, 28 papers were accepted. Due to the page limitation of each issue, we have decided to publish a full special issue with 16 papers as Part 1 [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] and a special section in the coming issue (vol. 99, issue 12) with 12 papers as Part II.…”

CFD Simulation of a Fluid–Solid Non-Catalytic Reaction Based on a Structure-Based Mass Transfer Model: Shrinking Spherical Reaction

“…21,42,43 Belonging to the same category, the drag coefficient is also greatly influenced by the heterogeneous flow structure and will be overestimated on the assumption of homogeneous conditions. 4,5,44 Since the solid system of carbochlorination is a mixture of TiO 2 and C, the structurebased drag model applied to the binary gas−solid phase system, also developed by our research team, is adopted and described briefly as below 45…”

“…The detailed solution scheme for the above model can be found in our former report as well. 42,45 3.4. Numerical Solution Method.…”

“…The gas–solid drag force is also a crucial parameter to determine the hydrodynamics prediction, which affects the simulation of fluidized reaction further. ,, Belonging to the same category, the drag coefficient is also greatly influenced by the heterogeneous flow structure and will be overestimated on the assumption of homogeneous conditions. ,, Since the solid system of carbochlorination is a mixture of TiO 2 and C, the structure-based drag model applied to the binary gas–solid phase system, also developed by our research team, is adopted and described briefly as below where C De and C Db are the drag coefficients for the emulsion and bubble phases, and the subscript i identifies the solid phase of TiO 2 or C.…”

Issue Highlights

“…The new structure‐based model can capture the particle distribution well. [ 1 ]…”