MULTIFRACTAL CHARACTERIZATION OF FLOW IN CIRCULATING FLUIDIZED-BEDS

The intermittent flow in a circulating fluidized bed is shown to posse ss a multifractal character. The voidage signals at different solids c oncentrations and radial positions are characterized by defining an in termittency measure selected from a hierarchy of multifractal exponent s. The intermittency profiles based on the raw measured data are consi stent with the findings of Brereton and Grace (Chem. Eng. Sci., 48 (14 ) (1993) 2565-2572), while the results obtained after removing the con tribution from clusters match those of Jiang et al. ( Circulating Flui dized Bed Technology IV, AIChE Publications, 1994, pp. 111-117). The s uccess of multifractal characterization of CFB Bow suggests that the c luster motion may behave as a multiplicative cascade process.