May 26, 2013


Allan Issangya, S.B. Reddy Karri, Ted Knowlton, Ray Cocco, FluidizationXIV, The Netherlands.

Differential pressure fluctuations are routinely measured in fluidized beds to delineate fluidization regimes, provide hydrodynamics data, and/or assess fluidization quality.  Tests were conducted in 0.3-, 0.6-, and 0.9-m-diameter cylindrical and 1.52-m-diameter semicircular units, all about 6 m tall using FCC catalyst particles.  At some of the operating conditions gas bypassing, a form of intense gas maldistribution, was detected in the bed.  The objective of this study was to determine if overall differential pressure fluctuations are affected by bed diameter and the various methods used to mitigate gas bypassing in fluidized beds of Group A materials.  Results showed that bed diameter did not have a significant affect on the pressure fluctuations.  However, bed height, superficial gas velocity, fines content, system pressure, and installation of baffles significantly affected the pressure fluctuations.