Packed-bed liquid-phase dispersion in pulsed gas-liquid downflow

Journal Article · Fri Feb 01 04:00:00 EST 1980 · Ind. Eng. Chem. Fundam.; (United States)

DOI:https://doi.org/10.1021/i160073a011· OSTI ID:6317193

Lerou, J J; Glasser, D; Luss, D

A theoretical analysis of a pulsed gas-liquid downward flow through a packed bed showed that the axial dispersion of the liquid-phase observed in such flows is mainly caused by the difference in velocity and rapid mixing between fast-moving liquid slugs and slow-moving liquid films. This chromatographic behavior was described by a model which considers the liquid phase as consisting of two continuous phases flowing cocurrently at different velocities with continuous material exchange between the two streams. The liquid dispersion in the column may be characterized by a single mixing parameter. Impulse response experiments, in good accord with the model, showed that liquid dispersion decreases with increasing liquid flow rate because of improving mixing, attains a constant asymptotic value at high gas velocities, and is generally smaller in pulsed flow than in the gas-continuous (trickle) flow regime. Additional advantages of pulsed flow operation in catalytic reactors are increased wetting of the pellets, enhanced transport coefficients, and improved flow uniformity through the bed.

• Research Organization: Univ. of Houston
• OSTI ID: 6317193
• Journal Information: Ind. Eng. Chem. Fundam.; (United States), Journal Name: Ind. Eng. Chem. Fundam.; (United States) Vol. 19:1; ISSN IECFA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
CATALYSTS
CHEMICAL REACTORS
DISPERSIONS
FLOW MODELS
FLUID FLOW
FLUIDS
LIQUIDS
MATHEMATICAL MODELS
PACKED BED
PHASE STUDIES
TWO-PHASE FLOW