Fault diagnosis for supporting rollers of the rotary kiln using the dynamic model and empirical mode decomposition

Rotary kiln is key equipment widely used in the cement, metallurgical and environmental protection industry. The operation state of the rotary kiln was largely determined by the working condition of supporting rollers. This paper models the vibration mechanism of the supporting rollers under the rotary kiln crank caused by the internal thermal process. Based on the numerical analysis, a methodology based on empirical mode decomposition (EMD) for the fault diagnosis of the supporting rollers was proposed. By using EMD, the complicated vibration signal of the kiln can be decomposed into a number of intrinsic mode functions (IMFs). An analysis was made over the energy moment of IMF components to indicate the energy variation of the kiln harmonic and the roller harmonic of the vibration signals. Simulation and in field experiment results proved that the proposed method provided a validity of the approach for the condition monitoring and fault diagnosis of the low-speed machinery like the rotary kiln.