화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.33, No.8, 1889-1896, 1994
Characterization of the Flow Transition Between Bubbling and Turbulent Fluidization
A lot of controversy exists in the literature on the actual boundaries of the turbulent regime in gas-solid fluidization. This work shows that this disagreement results from the type of experimental techniques used. It is found that the onset of turbulent fluidization is at U(c) and that the velocity U(k), which has often been reported in the literature, is an artifact due to the use of differential pressure transducers. Experiments conducted for sand and fluid cracking catalyst (FCC) particles with differential and absolute pressure transducers and with a capacitance probe show that U(c) is the velocity at which bubbles and slugs reach their maximum size. At gas superficial velocities higher than U(c), the breakup of bubbles increases while the formation and coalescence of these bubbles decrease. The turbulent regime ends at the transport velocity.