Wavelet based analysis of pressure fluctuation signals measured from a wind cap in bubbling fluidized bed

Analysis of pressure fluctuation signals measured from wind caps which was a new method was proposed to realize the condition monitoring of gas-solid flow in fluidized bed. Pressure fluctuation signals measured from a wind cap in a cold bubbling fluidized bed setup at different superficial gas velocities, static bed heights and bed material particle sizes, were analyzed with wavelet analysis method. After wavelet analysis, the energy of reconstructed signals at different levels and the ratios of energy at different levels to total energy were calculated. Finally, the influence of operating conditions changes on the characteristic pressure fluctuations of the wind cap in bubbling fluidized bed was analyzed. It is found that the variations of low-frequency reconstructed signals are related with the variations of gas-solid flow state at different operating conditions. So the proposed method in the paper is proved to be practical.