Mesoscale model of radial hydrodynamics for fluidizing small particles with low solid holdup in gas-liquid-solid circulating fluidized bed

Abstract

Gas-liquid-solid circulating fluidized bed (GLSCFB) is an important reactor. Radial hydrodynamics of GLSCFB are critical for the industrial design and scale-up, but the hydrodynamics have not been well described. To mechanically model the radial flow structures, a mesoscale method based on the energy-minimization multiscale principle is applied. A comparison between experimental data and model calculations shows that the radial mesoscale model can reasonably predict the radial distributions of the flow parameters and analyze the influence of the operating conditions on the radial hydrodynamics in GLSCFB for fluidizing solid particles of small diameters (dp ≤ 1 mm) and low solid holdup (εs ≤ 15%). Additionally, model predictions show that the peak positions of the suspension and transportation energy consumed per unit mass of solid particles and liquid shear stress range from 0.75 to 0.9, which is an obvious indicator of the radial flow structure.