Parallel CFD–DEM modeling of the hydrodynamics in a lab-scale double slot-rectangular spouted bed with a partition plate

• 3D modeling of the hydrodynamics in a lab-scale multiple-spouted bed is performed.
• Millions of the particles are tracked individually with the parallel CFD–DEM coupling.
• Two parallel fountains are formed without information exchanging in fountain region.
• Distribution properties of the hydrodynamics show strong dependence on the slot shape.
• Spout–annulus interaction intensity is the strongest in conical region and reduces along axis.

This paper presents a numerical modeling of the gas–solid motion in a 3-D lab-scale double slot-rectangular spouted bed with a partition plate under the parallel framework of CFD–DEM coupling approach. Solid motion is tracked with the discrete element method, while the gas motion is solved by the k–ε turbulence model. The bed has two uniform chambers with the diverging base and two parallel slots lying in the bottoms of these two chambers. A total of 2,590,000 glass particles have been tracked with 112 CPUs in a cluster. The distributions of the gas–solid hydrodynamics are investigated initially. Then, the interaction between the spout and the annulus is explored. Finally, the effect of the plate height on the gas–solid motion of the bed is discussed. The results show that the insertion of the partition plate leads to the formation of two parallel fountains without information exchanging and the enlargement of the pressure drop. A velocity peak of the fluid phase or solid phase appears in the central region of each individual chamber. Furthermore, large vertical solid flux appears in the central region of each chamber and shows a distribution strongly related to the slot shape. The slot shape influences the spout–annulus interaction boundary, whereas this effect diminishes obviously with increasing the bed height. Spout–annulus interaction intensity shows the strongest in the conical region of bed and reduces along the axial direction. Finally, the plate height exerts little effect on the solid velocity and voidage distributions.

(a) 3-D view of the spout–annulus interface; (b) instantaneous snapshot of particle distribution in fountain.Figure optionsDownload as PowerPoint slide