Gas holdup and bubble dynamics in a three-phase internal loop reactor with external slurry circulation

Fuel ◽  
2010 ◽  
Vol 89 (7) ◽  
pp. 1361-1369 ◽  
Author(s):  
Kai Zhang ◽  
Nana Qi ◽  
Jiaqi Jin ◽  
Chunxi Lu ◽  
Hu Zhang
Keyword(s):  
Bubble Dynamics ◽  
Gas Holdup ◽  
Loop Reactor ◽  
Internal Loop ◽  
Three Phase

Experiment and CFD Simulation on Gas Holdup Characteristics in an Internal Loop Reactor with External Liquid Circulation

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Chunxi Lu ◽  
Nana Qi ◽  
Kai Zhang ◽  
Jiaqi Jin ◽  
Hu Zhang
Keyword(s):  
Cfd Simulation ◽  
Gas Holdup ◽  
Gas Velocity ◽  
Loop Reactor ◽  
Internal Loop ◽  
Liquid Circulation ◽  
Liquid Phases ◽  
Ansys Cfx ◽  
Other Information ◽  
Superficial Gas Velocity

An external liquid circulation is introduced into a traditional internal loop reactor in order to improve liquid circulation and increase the interface between gas and liquid phases. The effects of superficial gas velocity and external liquid circulation velocity on local and overall gas holdups are explored experimentally and numerically in the loop section of a combined gas-liquid contactor, which consists of a liquid spray, sieve plates and an internal loop with external liquid circulation. Local gas holdup is measured experimentally by a double-sensor conductivity probe. Numerical simulations are conducted in the platform of a commercial software package, ANSYS CFX 10.0. Gas holdup and other information are obtained by solving the governing equations of mass and momentum balances for gas and liquid phases in a hybrid mesh system. Both measured and simulated results indicate that local, section-averaged, and overall gas holdups increase with an increase of the superficial gas velocity. The downcomer tube for circulating external liquid has a significant influence in the gas-distributor and the downcomer-tube action regions rather than in the upper draft-tube and the gas-liquid separation regions. Good agreement between measured and predicted data suggests that CFD simulation together with experimental investigation can be employed to develop novel gas-liquid contactors with a complex geometrical configuration.

Simultaneous sewage sludge digestion and metal leaching using an internal loop reactor

1997 ◽  
Vol 31 (10) ◽  
pp. 2638-2654 ◽  
Author(s):  
H. Benmoussa ◽  
R.D. Tyagi ◽  
P.G.C. Campbell
Keyword(s):  
Sewage Sludge ◽  
Metal Leaching ◽  
Loop Reactor ◽  
Internal Loop ◽  
Sludge Digestion

Numerical simulation and physical modeling of the hydrodynamics in an air-lift internal loop reactor

1997 ◽  
Vol 52 (21-22) ◽  
pp. 3787-3793 ◽  
Author(s):  
A. Cockx ◽  
A. Liné ◽  
M. Roustan ◽  
Z. Do-Quang ◽  
V. Lazarova
Keyword(s):  
Numerical Simulation ◽  
Physical Modeling ◽  
Loop Reactor ◽  
Internal Loop ◽  
Air Lift

Influence of biomass on hydrodynamics of an internal loop airlift reactor

2006 ◽  
Vol 60 (6) ◽  
Author(s):  
M. Juraščík ◽  
M. Hucík ◽  
I. Sikula ◽  
J. Annus ◽  
J. Markoš
Keyword(s):  
Aspergillus Niger ◽  
Gluconic Acid ◽  
Solid Phase ◽  
Biomass Concentration ◽  
Airlift Reactor ◽  
Phase System ◽  
Two Phase ◽  
Experimental Conditions ◽  
Internal Loop ◽  
Three Phase

AbstractThe effect of the biomass presence on the overall circulation velocity, the linear velocities both in the riser and the downcomer and the overall gas hold-up was studied in a three-phase internal loop airlift reactor (ILALR). The measured data were compared with those obtained using a two-phase system (air—water). All experiments were carried out in a 40 dm3 ILALR at six different biomass concentrations (ranging from 0 g dm−3 to 7.5 g dm−3), at a temperature of 30°C, under atmospheric pressure. Air and water were used as the gas and liquid model media, respectively. Pellets of Aspergillus niger produced during the fermentation of glucose to gluconic acid in the ILALR were considered solid phase. In addition, liquid velocities were measured during the fermentation of glucose to gluconic acid using Aspergillus niger. All measurements were performed in a bubble circulation regime. At given experimental conditions the effect of the biomass on the circulation velocities in the ILALR was negligible. However, increasing of the biomass concentration led to lower values of the total gas hold-up.

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