Hydrodynamics and mass transfer in a draft tube gas-liquid solid spouted bed
Experiments were conducted using various types of solid particles to investigate the hydrodynamic properties of a draft tube gas-liquid-solid spouted bed. The hydrodynamic properties under study include flow modes, pressure profile and pressure drop, bubble penetration, depth, overall gas holdup, apparent liquid circulation rate, and bubble size distribution. Three flow modes were classified: a packed bed mode, a fluidized bed mode, and a circulated bed mode. The bubble penetration depth in the annular region, overall gas holdup, and apparent liquid circulation rate increase with an increase in gas or liquid velocity. A model was proposed to describe the liquid circulation behavior in the draft tube gas-liquid-solid spouted bed. The optimal design of a draft tube gas-liquid-solid spouted bed was evaluated by considering four design variables including draft tube diameter, gas-liquid injector, top (above draft tube) spacing, and bottom (below draft tube) spacing. The effects of these design variables on the overall gas holdup were comprehensively examined for various gas and liquid velocities and solid particle properties. The 7.62 cm ID draft tube has highest overall gas holdup. The overall gas holdup increases with decreasing top spacing. The concentric tube gas-liquid injector with the smallest pore size gas distributor plate placed on the top of the outer tube gives rise to the holdup. Dissolution of benzoic acid pellets into water was used to obtain the solid liquid mass transfer coefficient in a draft tube gas-liquid-solid spouted bed. The in-bed benzoic acid concentration was examined to justify the use of the continuous flow stirred tank reactor (CSTR) model in the evaluation of the mass transfer coefficient.
- Research Organization:
- Ohio State Univ., Columbus (USA)
- OSTI ID:
- 5603237
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
FLUIDIZED BEDS
DESIGN
HYDRODYNAMICS
MASS TRANSFER
BENZOIC ACID
BUBBLES
DISSOLUTION
FLOW MODELS
FLUID FLOW
GAS FLOW
PARTICLE SIZE
PRESSURE DROP
PRESSURE GRADIENTS
CARBOXYLIC ACIDS
FLUID MECHANICS
MATHEMATICAL MODELS
MECHANICS
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
SIZE
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