𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Gas holdup and liquid velocity in three-phase internal-loop airlift reactors

✍ Scribed by Shyh-Jye Hwang; Yi-Lung Cheng

Publisher
Elsevier Science
Year
1997
Tongue
English
Weight
565 KB
Volume
52
Category
Article
ISSN
0009-2509

No coin nor oath required. For personal study only.

✦ Synopsis

The liquid velocities and gas holdups in the riser and downcomer of three-phase internal-loop airlift reactors with Newtonian and non-Newtonian fluids were studied. The reactor was constructed of 19 cm ID Plexiglas column and 250cm in height. The inside diameters of the draft tube were 9, 12, and 14 cm [wall thickness is 0.5 cm), which made the ratio of the cross-sectional area of the riser to the downcomer equal to 0.69, 1.33 and 3.22, respectively. The draft tube heights used in this study were 70, 110 and 150cm. Water and various concentrations of carboxymethyl cellulose (CMCI aqueous solutions were employed as the liquid phases. Air and polystyrene particles were used as the gas and solid phases, respectively. The liquid velocities and gas holdups in the riser and downcomer were measured by tracer response and manometric techniques, respectively.

It was found that the gas holdups and the liquid velocities generally decreased with an increase in the concentration of CMC or the solids loading. In addition, the gas holdup in the riser decreased but that in the downcomer increased with increasing draft tube length. The liquid velocities increased with increasing draft tube length. Eurthermore. the gas holdup and the liquid velocity in the riser increased but those in the downcomer decreased with decreasing draft tube diameter. Based on the drift-flux model and energy balance, a hydrodynamic model was developed. It was shown that using a correlation equation for the gas holdup in the downcomer, the proposed model could predict satisfactorily the gas holdup in the riser and the liquid velocities in the riser and downcomer of the internal-loop airlift reactors with Newtonian and non-Newtonian fluids, v 1997 Elsevier Science Ltd I N'IROD[!('I'ION '7

πŸ“œ SIMILAR VOLUMES

Liquid velocity and gas holdup in three-
Liquid velocity and gas holdup in three-phase internal loop airlift reactors with low-density particles
✍ Wen-Jang Lu; Shyh-Jye Hwang; Chun-Min Chang πŸ“‚ Article πŸ“… 1995 πŸ› Elsevier Science 🌐 English βš– 707 KB

Liquid velocity and gas holdup in three-phase internal loop airlift reactors were investigated. Air and water were used as the gas and liquid phase, respectively, and the solid particles used were calcium alginate beads with different particle size. The liquid velocity in the riser and the downcomer

Circulation liquid velocity, gas holdup
Circulation liquid velocity, gas holdup and volumetric oxygen transfer coefficient in external-loop airlift reactors
✍ Keun Ho Choi; Won Kook Lee πŸ“‚ Article πŸ“… 2007 πŸ› Wiley (John Wiley & Sons) 🌐 English βš– 656 KB

## Abstract The effects of the horizontal connection length (0.1 Β± __L~e~__ Β± 0.5 m), the cross‐sectional area ratio of downcomer‐to‐riser (0.11 Β± A~d~/A~r~Β± 0.53), and the superficial gas velocity on gas phase holdups in the riser and downcomer were studied. The circulation liquid velocity, the mi

Critical gas velocity in a three-phase i
Critical gas velocity in a three-phase internal loop airlift reactor with low-density particles
✍ Karuppan Muthukumar; Balakrishnan Naveen Prasad; Manickam Velan πŸ“‚ Article πŸ“… 2004 πŸ› Wiley (John Wiley & Sons) 🌐 English βš– 122 KB

## Abstract In the present investigation the effects of the addition of organic additives (propanol, benzoic acid, iso‐amyl alcohol and carboxymethyl cellulose) on the critical gas velocity, (__U__~sg~)~c~, in an internal airlift loop reactor with low‐density particles (Nylon‐6 and polystyrene) wer