Numerical simulations of gas-liquid-particle ows in three-phase slurry reactors under gravity variation

Numerical simulations of three-phase gas-liquid-particle ows under 1 g and 2 g gravitational conditions were performed with an Eulerian-Lagrangian method. In this study, the liquid was treated as a continuous phase and modeled by a volume-averaged system of governing equations. Bubbles and particles were modeled as discrete phases using Lagrangian method. Drag, lift, buoyancy, and virtual mass forces were included in the Lagrangian equation. Bubbles were treated as spherical without shape variations. The two-way coupling between bubble-liquid and particle-liquid was included, and interactions between bubble-bubble and particle-particle were considered with the hard sphere model. Particle-bubble interactions and bubble coalescences were also included in the analysis. The results under 1 g normal gravity condition were compared with the available experimental data in earlier simulation, resulting in good agreement. The transient ow characteristics of the three-phase ow under 1 g and 2 g gravitational conditions were studied, and the effects of gravity were analyzed. The results show that gravity has magnificent effect on the ow characteristics of three-phase gas-liquid-particle ows in bubble columns. The three-phase velocities under higher gravity are larger than those of the ow under normal gravity are. The ow under higher gravity develops fast. Bubbles and bubble volume fraction in the higher gravity ow are smaller.