Signal Analysis of Acoustic Emission in Gas-Solid Fluidized Bed Reactor —From Data to Information

摘要

The passive acoustic emission (AE) technique has received more and more attention in recent years as a potentially non-intrusive and real-time process monitoring technique to be used in chemical engineering processes, especially in gas-solid fluidized bed reactors (FBRs). The underlying structure characteristics of AE signals and corresponding FBR were investigated by resorting to wavelet transform and Hurst analysis. It was found that most energy contained in AE signals are mainly originated from particle motion. According to the rigorous mathematical and physical derivation, frequency model was obtained and verified by performing systematic experiments. Moreover, flow regime transition and particle fluidization pattern could be characterized by obtaining the AE energy profiles at one or more specific locations. The attractor S based on attractor comparison as well as the coefficients of malfunction C based on complexity analysis, were both proved to be suitable for early warning of agglomeration monitoring inside the FBR. Finally, future research directions in multiphase flow were provided in order to promote the development of AE technique.