Dense gas–liquid–solid flow in a slurry bubble column: Measurements of dynamic characteristics, gas volume fraction and bubble size distribution

2017 ◽  
Vol 173 ◽  
pp. 346-362 ◽  
Author(s):  
Parul Tyagi ◽  
Vivek V. Buwa
Keyword(s):  
Size Distribution ◽  
Dynamic Characteristics ◽  
Bubble Size ◽  
Volume Fraction ◽  
Bubble Column ◽  
Bubble Size Distribution ◽  
Dense Gas ◽  
Solid Flow ◽  
Gas Volume Fraction ◽  
Gas Volume

Bubble size distribution and gas–liquid interfacial area in a modified downflow bubble column

2006 ◽  
Vol 122 (1-2) ◽  
pp. 1-10 ◽  
Author(s):  
Subrata Kumar Majumder ◽  
Gautam Kundu ◽  
Dibyendu Mukherjee
Keyword(s):  
Size Distribution ◽  
Bubble Size ◽  
Bubble Column ◽  
Interfacial Area ◽  
Bubble Size Distribution

scholarly journals Measurement of Bubble Size, Gas holdup and Interfacial Area in Bubble Columns using Image Processing Techniques

2019 ◽  
Vol 9 (1) ◽  
pp. 4475-4479
Keyword(s):  
Image Processing ◽  
Size Distribution ◽  
Bubble Size ◽  
Bubble Column ◽  
Rectangular Cross Section ◽  
Bubble Diameter ◽  
Water System ◽  
Interfacial Area ◽  
Gas Holdup ◽  
Bubble Size Distribution

Bubble sizes in bubble column affect transfer processes. Therefore, it’s important to calculate bubble size and interfacial area. Bubble size distribution (BSD) in a bubble column of rectangular cross section with dimensions 0.2m x 0.02m was measured using photographic method (400 fps) for air-water system. Gas holdup, Sauter-mean bubble diameter, aspect ratio and specific interfacial area were estimated from BSD. Effect of superficial gas velocity and static bed height on these parameters was investigated. The bubble size distribution exhibited mono-modal distribution showing the presence of non-uniform homogeneous bubbling regime. The frames of video were analysed using image processing steps to obtain major and minor axis of elliptical bubbles. Values of d32, , and ai were estimated from the data. The value of d32 increased with increasing Ug but is independent of Hs. The values of d32 were somewhat higher than the values reported by other investigators. The value of ai increases with increasing Ug and with decreasing Hs. Present values of compared well with the data reported in literature.

Improved Modeling of Bubble Column Reactors by Considering the Bubble Size Distribution

2012 ◽  
Vol 51 (16) ◽  
pp. 5705-5714 ◽  
Author(s):  
Mohammad Ramezani ◽  
Navid Mostoufi ◽  
Mohammad Reza Mehrnia
Keyword(s):  
Size Distribution ◽  
Bubble Size ◽  
Bubble Column ◽  
Bubble Size Distribution ◽  
Bubble Column Reactors

CFD Simulation of Hydrodynamic of a Bubble Column Reactor Operating in Churn-Turbulent Regime and Effect of Gas Inlet Distribution on System Characteristics

2016 ◽  
Vol 14 (1) ◽  
pp. 213-224 ◽  
Author(s):  
Amir Azimi Yancheshme ◽  
Jamshid Zarkesh ◽  
Davod Rashtchian ◽  
Arezou Anvari
Keyword(s):  
Size Distribution ◽  
Bubble Size ◽  
Cfd Simulation ◽  
Bubble Column ◽  
Continuous Phase ◽  
Bubble Size Distribution ◽  
Bubble Column Reactor ◽  
Turbulent Regime ◽  
Turbulent Flow Regime ◽  
Reactor Operating

AbstractCFD simulation of cylindrical bubble column including air as dispersed phase and water as continuous phase operating in churn-turbulent flow regime with diameter of 0.49 m, height of 3.6 m and gas superficial velocity of 0.14 m/s have been conducted. All simulations have been carried out in a 2D axisymmetric, unsteady and Euler/Euler framework with the aid of commercial software FLUENT v. 14.5. Simulations were validated by our experimental results through residence time distribution (RTD) data. Effect of bubble size distribution at inlet on column hydrodynamic was investigated and results clearly showed that equilibrium bubble size distribution in most parts of column is independent of bubble size distribution at inlet. In addition, liquid axial velocity and gas hold-up profiles results in column center were approximately the same for cases with different inlet distribution and confirmed similarity of their hydrodynamic.

Numerical Simulation With a CFD-PBM Model of Hydrodynamics and Bubble Size Distribution of a Rectangle Bubble Column

2016 ◽  
Author(s):  
Yi-Gang Ding ◽  
Xia Lu ◽  
Fu-Li Deng
Keyword(s):  
Size Distribution ◽  
Gas Phase ◽  
Bubble Size ◽  
Discrete Model ◽  
Bubble Column ◽  
Bubble Size Distribution ◽  
Bubble Coalescence ◽  
Complex Behavior ◽  
Gas Velocity ◽  
Superficial Gas Velocity

A coupled CFD-PBM (population balance mode) model is adopted to investigate complex behavior in a rectangle bubble column. In this work The Euler–Euler (E–E) model was adopted for the liquid phase and gas phase, while accounting for bubble coalescence and breakup a PBM discrete model was employed. The total gas holdup for a range of superficial gas velocities were studied and compared with the literature and modest agreement was found. The simulation result shows that the superficial gas velocity has great effect on bubble size distribution, and a wider bubble size distribution is found at higher superficial gas velocity. This indicates an increasing of the superficial gas velocity increases the bubble coalescence and break-up rate.

scholarly journals Numerical investigation and modelling of the venous injection of sclerosant foam

2019 ◽  
Vol 60 ◽  
pp. C261-C278
Author(s):  
K. C. Wong ◽  
S. W. Armfield ◽  
N. Williamson
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Investigation ◽  
Size Distribution ◽  
Bubble Size ◽  
Bubble Column ◽  
Population Balance ◽  
Bubble Size Distribution ◽  
Ambient Fluid ◽  
Saphenofemoral Junction

Sclerosant foam, a mixture of a surfactant liquid and air, is injected directly into varicose veins as a treatment that causes the vein to collapse. This investigation develops a model that will allow the medical specialist to visualise how the sclerosant foam will interact with the blood and behave within the vein. The process is simulated using a multiphase computational fluid dynamics model with the sclerosant foam considered as a two-phase non-Newtonian power law viscosity liquid. The governing multiphase equations are solved using an Eulerian⁠–⁠Eulerian approach coupled with a population balance model to predict the bubble size distribution within the flow field. The computational results demonstrate similar flow characteristics and flow features to an available set of experimental results. The model predicts the mixing layers between the sclerosant foam and the ambient fluid, and the sclerosant liquid and the ambient fluid, as well as the sclerosant liquid coverage on the vein wall and the bubble size distribution within the vein. These quantities are of interest to medical specialists allowing them to assess the treatment feasibility and safety before treating the patients. References S. Ali Mirjalili, J. C. Muirhead, and M. D. Stringer. Redefining the surface anatomy of the saphenofemoral junction in vivo. Clin. Anat., 27(6):915–919, 2014. doi:10.1002/ca.22386. E. Cameron, T. Chen, D. E. Connor, M. Behnia, and K. Parsi. Sclerosant foam structure is strongly influenced by liquid air fraction. Eur. J. Vasc. Endo. Surg., 46:488–494, 2013. doi:10.1016/j.ejvs.2013.07.013. P. Coleridge-Smith. Saphenous ablation: Sclerosant or sclerofoam? Semin. Vasc. Surg., 18:19–24, 2005. doi:10.1053/j.semvascsurg.2004.12.007. J.-J. Guex. Complications and side-effects of foam sclerotherapy. Phlebology, 24:270–274, 2009. doi:10.1258/phleb.2009.009049. Ansys Inc. ANSYS FLUENT 12.0 population balance module manual. ANSYS, 2010. URL https://www.afs.enea.it/project/neptunius/docs/fluent/html/popbal/main_pre.htm. F. Ren, N. A. Noda, T. Ueda, Y. Sano, Y. Takase, T. Umekage, Y. Yonezawa, and H. Tanaka. CFD-PMB coupled simulation of a nanobubble generator with honeycomb structure. volume 372 of IOP Conference Series: Materials Science and Engineering, page 012012, June 2018. doi:10.1088/1757-899X/372/1/012012. P. Souroullas, R. Barnes, G. Smith, S. Nandhra, D. Carradice, and I. Chetter. The classic saphenofemoral junction and its anatomical variations. Phlebology, 32(3):172–178, 2017. doi:10.1177/0268355516635960. A. H. Syed, M. Boulet, T. Melchiori, and J. M. Lavoie. CFD simulations of an air-water bubble column: Effect of Luo coalescence parameter and breakup kernels. Front. Chem., 5(68):1–16, 2017. doi:10.3389/fchem.2017.00068. T. Wang and J. Wang. Numerical simulation of gas-liquid mass transfer in bubble column with a CFD-PBM coupled model. Chem. Eng. Sci., 62:7107–7118, 2007. doi:10.1016/j.ces.2007.08.033. M. R. Watkins. Deactivation of sodium tetradecyl sulphate injection by blood proteins. Euro. J. Vasc. Endo. Surg., 41(4): 521–525, 2011. doi:10.1016/j.ejvs.2010.12.012. K. Wong. Experimental and numerical investigation and modelling of sclerosant foam. PhD thesis, University of Sydney, 2018. K. Wong, T. Chen, D. E. Connor, M. Behnia, and K. Parsi. Basic physiochemical and rheological properties of detergent sclerosants. Phlebology, 30(5):339–349, 2015. doi:10.1177/0268355514529271. K. C. Wong, T. Chen, D. E. Connor, M. Behnia, and K. Parsi. Computational fluid dynamics of liquid and foam sclerosant injection in a vein model. Appl. Mech. Mater., 553:293–298, 2014. doi:10.4028/www.scientific.net/AMM.553.293.

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