Orientation simulation and image experiment for flexible biomass particle in wedge fluidization channel

Abstract

Flexible biomass particles have a large proportion in food production and processing, and particle orientation is related to the quality and efficiency of food production. Thus far, the particle orientation control mechanism has rarely been revealed. In this work, Computational Fluid Dynamics–Discrete Element Method (CFD–DEM) model is presented to study the flow characteristics of tea in a wedge channel. The biomass particles are represented by a double chain bonded-sphere model. The CFD–DEM model for flexible particles is verified by image experiments. The effects of gas velocity, particle length, feeding rate, and wedge outlet diameter on particle orientation distribution are investigated and discussed. Results show that the particle orientation is slightly affected by gas superficial velocity. The proportion of particles oriented at 0–30° increases as the particle length and feeding rate increase and decreases as channel outlet diameter increases. The particles with the orientation angles of 0–10° and 0–30° are about 25% and 80%, respectively, when the channel outlet diameter is 40 mm. These findings provide great significance for the processing, storage, and transportation of tea and other biomass. • A double-chain bonded-sphere model of flexible particles is proposed. • Image experiment is designed to verify the established numerical model. • An orientation control method of flexible biomass particles is proposed. • Particle orientation is influenced by gas velocity gradient and particle length.