Modal and Harmonic analysis of a small-scale ball mill based on ANSYS

Abstract

Ball mill is a grinding machine used in mineral processing, comprising of a rotating cylindrical shell filled with steel balls and the material to be ground. The ball mill is inevitably accompanied by vibration during operation. This vibration may lead to resonance in the structural components if the natural frequency matches the operating frequency. Therefore, it is important to study the dynamic characteristics of the ball mill. Modal analysis is an essential technique which helps in predicting the possibility of resonance by determining the natural frequencies as well as mode shapes. In this study, modal analysis of a small-scale ball mill developed in JKUAT is carried out in ANSYS Workbench 16.0. The first ten modes of vibration are extracted for two scenarios, one, for the ball mill and frame support (drum, shaft and frame support) and two, for the drum and shaft. Harmonic analysis is done to visualize the response of the ball mill structure under dynamic loading. The results show
that some frequencies fall within the expected operating frequencies.