Experimental investigation on gas-solid hydrodynamics of coarse particles in a two-dimensional spouted bed

The gas-solid hydrodynamics of coarse particles in a two-dimensional spouted bed (2DSB) are measured using 6 mm glass beads to obtain quantitative experimental results. A one-dimehsional mathematical model based on gas-solid mass and momentum balance is used to characterize the spout-annulus interaction And to further interpret the experimental results. The superficial velocity and static bed height are in the range of 2.58 to 439 m/s and 8.0 to 13.3 cm, respectively. Pressure fluctuation periodicity of the bed pressure drop is characterized by power spectral density (PSD) analysis. The whole-field particle velocity profiles in 2DSB are obtained by high speed CCD camera and Ply technique. The results show that particle motion in the spout in the present 2DSB experiments is dominated by the balance of drag force, solid stress and gravitation. The existence of obvious solid stress from particle impaction and friction leads to energy dissipation, which limits the increase of Vertical particle velocity along the spout axis (v(yc)) in the spout and results in a flat stage of v(yc) with slight fluctuation near the bottom of the fountain. The solid stress also contributes to the nearly flat peak of lateral profile of downward particle velocity in the annulus. These detailed results are helpful for understandifig the gas hydrodynamics and par tide motion behavior of coarse particles in 2DSB, and for verification of the extended CFD-DEM coupling method for particle size approaching fluid cell size. (C) 2016 Elsevier B.V. All rights reserved.