Multiphase flow simulation of a simplified coal pulveriser

In coal-fired power plants, the first major component is pulveriser, whose performance dictates the total power station efficiency. Pulveriser is employed to grind the lumped coal and transport the fine coal powder to furnace chamber for an efficient combustion. In this study, we have simulated motion of air and coal particles inside a commercial-scale pulveriser. Multiphase flow simulation of a simplified pulveriser was carried out using a granular Eulerian-Eulerian approach. Due to inclined air-distributor vanes, the flow field within pulveriser was slightly asymmetric. Regions of exceptionally high velocities were predicted close to the outer walls of the pulveriser, indicating a strong probability of particles carryover within these regions. The 100 μm coal particles qualitatively followed the air path-lines. However, the velocity vectors for 500 μm particle deviated significantly from those of airflow. The results presented in the paper provide impetus for the development of a complex pulveriser model, which further could prove valuable to designers for optimisation of components within the mill.