Experimental Investigation on the Translational and Rotational Motion of Biomass Particle in a Spout-Fluid Bed

Abstract

Abstract The translational and rotational motions of biomass particle in a spout-fluid bed have been investigated. Two kinds of cylindrical biomass particles with different densities were used as bed solids, which were obtained from the jujube tree. To describe the translational and rotational characteristics, virtual particle concentration and rotation angle were introduced. The former obtained by microwave heating-infrared thermal imaging technique was compared with the actual particle concentration determined by box-counting method. Based on the temperature distribution, the translational position and rotation angle of multiple tracers were distinguished. The results show that the heating characteristic of tracer depends on the tracer material. Compared to the spherical particles, non-spherical biomass particle is more likely to cause dead zone in the bed. In the flow regime of fluidizing, the flow characteristic of biomass particle relies on the jet gas velocity. The high resistance resulting from the interparticle cohesion forces hinders the rise of bubbles and weakens the radial dispersion of particle. In the fountain, homogeneous biomass particle rotates uniformly, while non-homogeneous biomass particle exhibits non-uniform rotation. In the annulus, the rotation characteristic of biomass particle depends on the structure of fountain and particle trajectory in the annulus.