粉砕物の混合粒径がボールミル壁面の振動・放射音に及ぼす影響

抄録

A ball mill is a type of grinding equipment. Hard balls called media and material to be ground are placed into a mill cylinder, and the mill is rotated. The material is ground by collision force of material with hard balls or the mill wall. It is difficult to predict grinding status of materials inside mill during operation. During operations, vibration and sound are generated from mill wall. In addition, vibration and sound of mill wall change depending on the grinding condition of materials. If the relationship between the grinding status of materials and the vibration and sound of the mill wall can be clarified, we are able to estimate grinding status of materials during operation. Authors have shown the characteristics of the vibration response and sound pressure when single size material is put into a mill. In the grinding process, material has distribution of diameter. In this study, an experiment with two different materials in the diameter is performed to exam the influence of distribution of material size. Besides, the vibration and radiated sound of the mill wall are predicted by a simulation model developed in our previous study. The experiment result shows that the vibration displacement and sound pressure decrease as the diameter of material decreases. Therefore, even if the material has the distribution of diameter, the relationship between the material diameter, the displacement and sound pressure of the mill wall does not change. The analysis results show the same tendency as the experiment results. Moreover, the analysis predicts decrease of the kinetic energies of each media and material particle when the diameter of material decreases.