Orderly arrangement of agricultural biomass particles in designed gas–solid fluidized beds using CFD-DEM and image experiment

A CFD-DEM model is developed to reproduce the orderly arrangement process of agricultural biomass particles in designed fluidized beds, and ordered biomass bundles are obtained. Moreover, the high-speed fluidization image experiment platform is established, and a biomass angle recognition method is proposed. Result shows that the biomass is gradually adjusted from random to vertical attitude and entanglement is eliminated in the adjustment zone. The biomass trajectory is acceleration, collision, deceleration and adsorption. Limited by the height of the fluidized bed, the pressurization holes and deflector optimization designs are proposed to accelerate biomass adjustment. The double-side pressurization model reduces tangles and collisions and has symmetrical airflow distribution; thus, orientation control performance is better than the one-sided pressurization model. For the optimum design of deflectors, large deflector hinders the fluidization of biomass particles. The small deflector with a radian of 38° controls the particle orientation in the adjustment zone and prevents the relative slip between the particles and circulating adsorption belt. Therefore, the average particle longitudinal and cross-sectional orderliness in biomass bundles improved by 31% and 17%, respectively. The predictions on biomass velocity and orientation distribution agree well with the experimental findings. This research solves the shortcomings of biomass disorder, which provides new insights for the industrial application of particle filling and packaging.