Three-dimensional CFD-VOF-DPM simulations of effects of low-holdup particles on single-nozzle bubbling behavior in gas-liquid-solid systems

Three-dimensional (3D) computational fluid dynamics (CFD) simulations of effects of low-holdup solid particles on the bubbling behavior in a gas-liquid-solid flow system with single gas nozzle were performed with discrete particle model (DPM) and volume of fluid (VOF) method. Both gas and liquid phases (Eulerian phases) were modeled using a continuity equation and a set of momentum equations and the interface of the gas bubbles were tracked using the VOF model. The Lagrangian particles were linked to the Eulerian phases through the interchange terms such as the drag force in the respective momentum equations. Influences of particle properties including volume fraction, diameter and density, fluid properties including liquid surface tension force and viscosity, operating conditions including nozzle gas velocity, superficial liquid velocity, and wettability of gas nozzle material on the size, detachment time and rise velocity of gas bubbles and particle entrainment in the gas-liquid-solid flow under ambient conditions were numerically investigated and the trends analyses were done using related dimensionless numbers. The work lays a foundation for further explorations on the gas-liquid-solid flows and possible industry applications. (C) 2013 Elsevier B.V. All rights reserved.