Experimental and Numerical Study of Grinding Media Flow in a Ball Mill

Abstract

An experimental and numerical study on the grinding media dynamics inside a baffled ball mill under different solid‐flow regimes, namely, cascading, cataracting, and centrifuging, is described. The Eulerian approach was used for all simulations and the boundary condition at the drum wall was investigated by means of the specularity coefficient parameter. This effort is an important approach in representing the particle‐wall interaction in a ball mill. The restitution coefficient of the balls was experimentally measured using a video camera, and its influence was evaluated by comparing the numerical and experimental outcome of flow patterns. The simulations results proved that the specularity and restitution coefficients effects at the drum wall were more evident at high rotational speeds.

Application of hydrodynamic lubrication in discrete element method (DEM) simulations of wet bead milling chambers

“…Dissipation is governed largely by the fluid forces described in the following, so damping in the contact force has negligible effect on the dynamics. We choose a restitution coefficient (𝐶𝑂𝑅) of 0.5 to be consistent with the literature [37]. Given the high bead loading, it is assumed, following insights from previous work [38], that the main contribution to the overall stresses is that arising from direct bead-bead contacts, as opposed to bead-fluid interactions.…”

Improving the efficiency of the coal grinding process in ball drum mills at thermal power plants

“…The degree of grinding in the drum can be improved by knowing the solid particles' pathlines in the drum or their collision with the wall. The performed CFD study with the adopted Eulerian approach mechanism showed that at a high rotational speed of the BDM, the impact of the specularity (specular reflection) and restriction coefficient are the most significant [7]. The results show that the specularity and restitution coefficient mostly affect the wall of the ball drum mill.…”

Modeling a flow pattern of the granular fill in the cross section of a rotating chamber

“…The results of determining a position of the free surface of flow patterns of mono-and two-dispersed granular fill in a slow-rotating chamber, which were obtained by using video recording and calculated by applying the DEM method, are given in [28]. In paper [29], authors compared results of research into flow patterns of the ball fill of a rotating chamber under cascade, cataract, and centrifuge modes, which were received by employing the method of computational fluid dynamics in the Euler's statement and visual analysis of video recording data. Similar methods of numerical and experimental studies were applied in [30].…”