Investigation on wet particle flow behavior in a riser using LES-DEM coupling approach

Abstract

Hydrodynamic characteristics of dry particles and wet particles are obviously different in a dense gas-solid two-phase flow system. In this work, a modified LES-DEM (Large Eddy Simulation and Discrete Element Method) coupling approach has been used to investigate the flow behaviors of wet particles in a riser. The model of the simulated riser is similar to the one in Mathiesen et al.'s experiment with binary mixture of particles, and simulated results show good agreement with the experimental data. Different liquid contents of the particles are applied to find out the influence on particle behaviors. By contrast, bigger clusters are formed at the riser inlet and near the walls with increasing the liquid contents for the strong influence of liquid bridge on the cohesion between particles. Meanwhile, the translational axial velocities reduce with increasing the liquid content of the wet particles. Besides, the rotational axial velocity fluctuates in a wider range and distribute more randomly for the wet particles than that in the dry particle system. Moreover, the fluctuation of pressure drop increases with increasing the liquid content. Compared with the dry system, translational and rotational cluster granular temperatures for the wet particles distribute in a much wider range and the peak values increase. However, for both big particles and small particles the diameter distribution and particle volume fraction have a similar trend in both dry particle and wet particle systems.