Coal level detection system of coal mill based on Hilbertt transform and spectrum correlation

In order to realize the coal level location and control of the steel ball coal mill to improve the security and economic level of the fire power plant. The paper designs a coal level detection system of the steel ball coal mill by analyzing the acoustic radiation principle of the steel ball coal mill and its signal. The system uses the ripple filter, Hilbert transform, high frequency power method, low frequency power method and spectrum correlation to analyze the acoustic radiation signal, and gets the value of coal level. The calibration experiment data shows that Hilbert transform envelope method can satisfy the usage requirement in generalized case, the frequency spectrum correlation method is equal to the required high precision and its measuring error is less than 2%. Our method and system not only improves the accuracy of measurement, but also has the function of diagnose fault.