Flow structure in a three-dimensional bubble column and three-phase fluidized bed
- Ohio State Univ., Columbus, OH (United States). Dept. of Chemical Engineering
Macroscopic flow structures of 3-D bubble columns and gas-liquid-solid fluidization systems under various operating conditions are studied using particle image velocimetry. Flow visualization is also conducted with the aid of a laser sheeting technique. The refractive index matching technique is used to eliminate the opaqueness of solid particles occurring in the visualization study of gas-liquid-solid fluidization. Three flow regimes (dispersed bubble, vortical-spiral flow, and turbulent flow) are identified. The flow structure is investigated for various operating variables including liquid velocity, gas velocity, and particle holdups. Four flow regions (descending flow, vortical-spiral flow, fast bubble flow, and central plume) can generally be characterized in the vortical-spiral flow regime where the gross circulation pattern occurs. A conceptual model for the flow structure in the vortical-spiral flow regime is discussed. The transition of the flow regimes and structure in the vortical-spiral flow regime is postulated to be related to the Taylor instability for flow between two concentric rotating cylinders. Similarities between the flow structures of 2- and 3-D beds are also discussed.
- OSTI ID:
- 6958562
- Journal Information:
- AIChE Journal (American Institute of Chemical Engineers); (United States), Journal Name: AIChE Journal (American Institute of Chemical Engineers); (United States) Vol. 40:7; ISSN 0001-1541; ISSN AICEAC
- Country of Publication:
- United States
- Language:
- English
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