Intermittence analysis of pressure fluctuation signal of circulating fluidized bed

The multifractal analysis for pressure fluctuation signal in bottom region and upper region of circulating fluidized bed (CFB) was performed by using the wavelet transform modulus maxima method. The intermittence index of the signals can be calculated with this method. Results show that the gas-solid flow in CFB is shown to possess a multifractal character. A new method is also proposed to identify the regime transition in CFB. The lower turning point of intermittence index curve can be used to determine the transition of flow regimes from fast fluidization to dense pneumatic conveying. The transition of flow regime in CFB is not homogeneous along the axis of riser, the transition in bottom region may be later than in upper region, and the transport velocity based on this method is also compared with that calculated by some empirical equations.