Numerical modeling of three-phase slurry bubble column: Study of particle effects

In this study, a numerical investigation has been conducted to describe the pulp zone properties by predicting the local gas holdup and bubble size distribution accounting for the effect of bubble-particle aggregate on the flow dynamic of slurry bubble column. Modelling calculations have been conducted using Eulerian–Eulerian multiphase approach with k-ε turbulence for the liquid phase. This work is carried out considering a finite volume method (FVM) tool using AVL FIRE, v.2014 coupled with the user defined subroutines especially for the change in the concentration number of different bubble sizes due to bubble break-up and coalescence. This code is validated comparing the experimental gas holdup with the numerically predicted data and a reasonable agreement has been found. In the current model, the effect of attachment and detachment process was included into the kinetic equation.by transferring the mass of attached particles to the gas bubble-particle aggregate. The results of this study show that the gas holdup linearly decreases with increasing slurry concentration for different gas velocities which has been attributed to the fact that the increase of slurry concentration promotes bubble coalescence and thus increases the rising velocity of bubbles. Overall, the results of simulations are represented a useful addition for a deep understanding of the dynamics of slurry bubble columns in the presence of solid particles.