Vibration Characteristics for Reflecting Level of Coal Powder Filling in an Industrial Tubular Ball Mill

To achieve improvements in the production capacity and energy efficiency of an industrial tubular ball mill, a novel method, reflecting the level of coal powder filling in the ball mill by using vibration characteristics, was proposed. Two accelerometers were installed on bearing housing to pick up the vibration transferred from the mill shaft. A system was designed to record the vibration signals and transfer them into energy amplitudes, by using a wavelet packet approach, based on the KINGVIEW program, as well as Visual C++ environment. Based on these, a series of experiments was conducted in a 250 MW power plant to investigate the vibration characteristics corresponding to different powder filling cases, including the effects of different levels without air particle removal, milling times, and varying levels in practical working conditions. The experimental results show that the cases of powder filling in the mill, such as mill over-load, stable case, etc., can be reflected by vibration characteristics. By mean of these vibration characteristics of ball mill, the performance of ball mill can be improved.