Host: The Japan Society of Mechanical Engineers
Name : Dynamics and Design Conference 2018
Date : August 28, 2018 - August 31, 2018
A ball mill is a type of grinding equipment in the mineral and chemical processing industry. Many balls called media are put into a mill with material to be ground, and the mill is rotated. Material is ground by collision force due to contact between the material and the balls or mill wall. During operation, the collision force cause high level of vibration and sound. The vibration and sound of mills provide information related to inside of the mill and are useful for operation control. If the relationship between the internal status and the measured vibration and sound signals is clarified, we are able to estimate the internal status of material. In this study, a ball mill for experiment is manufactured and experiments are performed. On the other hand, the motion of the balls and material to be ground in the mill is simulated by discrete element method in order to predict vibration and radiated sound of the mill wall. As results, the peek values of frequency response of vibration and sound pressure is increased when the rotation speed of the mill is increased. The peek values of frequency response of its decrease when particle size of material become smaller. Moreover, the analysis results of ball motion, vibration and sound show good agreement with experimental results. The analysis result shows that the difference of the material size influences the kinematic energy of the balls. Also, there is no great difference of the frequency response when change of the kinematic energy of the balls is not large.
