Effect of interparticle forces on the conical spouted bed behavior of wet particles with size distribution

This paper aims to analyze air–solid flow behavior in conical spouted beds composed of glass bead mixtures coated by glycerol. Four mixtures of glass beads are used as the solid phase. Although these mixtures have the same mean Sauter diameter, each one is characterized by a different size distribution function (mono-sized; flat, Gaussian or binary size distribution). When glycerol is added to the bed of these particles, which are spouted by air, the gas–solid flow characteristics are changed due to the growth of interparticle forces; however, the trends of these changes are affected by the glass bead mixture type as well as by the concentration of glycerol. For beds of mono-sized particles, the minimum spouting velocity is maintained almost unchanged as the glycerol concentration rises; while, for beds of inert particle mixtures, this velocity increases, becoming greater for flat and binary size distribution particles. Conversely, the minimum spouting pressure drop decreases as the glycerol concentration rises for all beds of particles used. Based on theoretical prediction of interparticle forces, it is shown that these changes in the minimum spouting conditions can be explained by the magnitude of these forces.

The interaction between inertial and interparticle force components in the wet conical spouted beds composed of inert particles with size distribution was described and analyzed. For a given bed region, an analysis of each interparticle force contribution to the conical spouted bed behavior attained following the diagram was presented. Thus, such interparticle forces were qualitatively correlated to the experimental data.Figure optionsDownload as PowerPoint slide