Characterization of the flow transition between bubbling and turbulent fluidization
- Ecole Polytechnique, Montreal, Quebec (Canada). Dept. of Chemical Engineering
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[sub c] and that the velocity U[sub 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[sub c] is the velocity at which bubbles and slugs reach their maximum size. At gas superficial velocities higher than U[sub c], the breakup of bubbles increases while the formation and coalescence of these bubbles decrease. The turbulent regime ends at the transport velocity.
- OSTI ID:
- 6929388
- Journal Information:
- Industrial and Engineering Chemistry Research; (United States), Journal Name: Industrial and Engineering Chemistry Research; (United States) Vol. 33:8; ISSN IECRED; ISSN 0888-5885
- Country of Publication:
- United States
- Language:
- English
Similar Records
On dense phase voidage and bubble size in high pressure fluidized beds of fine powders
Improved techniques for gasifying coal. Third quarterly report, January 1--March 31, 1977
Related Subjects
020400 -- Petroleum-- Processing
42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
BUBBLES
CATALYTIC CRACKING
CHEMICAL REACTIONS
CRACKING
DECOMPOSITION
ENERGY SOURCES
FLOW MODELS
FLUID FLOW
FLUID MECHANICS
FLUIDIZED BEDS
FOSSIL FUELS
FUELS
MATHEMATICAL MODELS
MECHANICS
PARTICLE SIZE
PETROLEUM
PYROLYSIS
SIZE
THERMOCHEMICAL PROCESSES
TURBULENT FLOW
TWO-PHASE FLOW