SmartFill (Coal) - KIMA Echtzeitsysteme Accurate measurements allow you to control the mill, meaning you can maintain an optimum fill-level at all times. Consequently, the mill's operation is stable and regular, resulting in a much more uniform coal output. What is more, setting the optimum fill-level reduces wear to the balls and mill shell. You can avoid overfilling.coal grinder measurement,Solids Volume Measurement in Coal-Fired Power PlantsGeneral Process Information. The coal goes through a moderate grinding process and then is stored in a coal bunker. afterwards the coal is typically delivered to a power plant via rail or conveyor belt. The coal is transported by conveyor and tripper cars to coal hoppers / silos. These hoppers feed ball mills which is turn fedd.