Study on hydrodynamic characteristics of the liquid-solid circulating fluidized bed with a central pulsating nozzle by numerical approach

Abstract

• A novel LSCFB with a central pulsating nozzle is proposed. • Hydrodynamics of the riser was studied by three-dimensional numerical simulation. • With the central pulsating flow, the radial interphase mixing degree is enhanced. • Regression formulas of the axial and radial slip velocities are obtained. Pulsating fluidization is gaining increasing attention due to its superiority in efficiency improvement. A novel type of liquid–solid circulating fluidized bed with a central pulsating nozzle was proposed to improve the reaction efficiency in this work. Based on Eulerian-Eulerian two-fluid model and the kinetic theory of granular flow, the hydrodynamic characteristics in the riser was investigated by three-dimensional numerical simulation. The effects of pulsating liquid flow and particle properties on the distributions of solids holdup, the radial velocity of the particles, the slip velocity and the radial mixing degree were studied. The simulation results showed that with the addition of the central pulsating liquid flow, the particles displayed apparent radial motion, and the interphase mixing degree as well as the interphase mass transfer efficiency were enhanced. Based on the numerical results, the regression formulas of the axial and radial slip velocities were obtained respectively.