CFD-aided contraction-expansion static mixer design for oil-in-water emulsification
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María del Pilar Balbi
Abstract
Contraction-expansion (CE) static mixers can enable solid-liquid and liquid-liquid dispersion with low energy dissipation, low risk of obstruction, and without moving parts. In this work, the influence of CE elements of different geometries on the imposed turbulence of a flowing liquid has been assessed by a two-dimensional computational fluid dynamic (2D-CFD) simulation. The effect of CE on the dispersion of droplets of an immiscible liquid has also been analysed from simulations, using the volume of fluid (VOF) approach. Direct numerical simulation (DNS) performed by the open-source Gerris Flow Solver software was used to get the velocity fields and turbulence characteristics. Different ratios of CE diameters and lengths were analysed for liquid Reynolds numbers from 500 to 20,000. From simulations, the CE geometry that maximised the average root mean square velocity, as an indicator of turbulence, was determined for different liquid flow rates. It was found that the average RMS had a maximum for a wide range of liquid flow rates when the CE diameter ratio was between 0.55 and 0.59 and the length ratio was between 0.2 and 0.3. Then, a device with seven CE elements with geometrical features within this range was built and used for preparing an oil-in-water emulsion. The test system contained water and sunflower oil (5 % v/v) with the further addition of TritonX100 (0.5 % in volume of the solution) as surfactant. The stability of the emulsions was assessed by measuring the time evolution of turbidity (absorbance at 860 nm), to get the initial separation velocities. The emulsions prepared using the CE device showed initial phase separation rates lower than the one obtained in a stirred flask, evidencing the feasibility of using CE static mixers for preparing emulsions with relatively low energy consumption. Moreover, the emulsions obtained with the CE device, although dependent on the flow rate, showed similar features when obtained with 10, 100 and 250 passes through the CE static mixer.
Funding source: Universidad de Buenos Aires
Award Identifier / Grant number: UBACyT 20020220100154BA
Funding source: Fondo para la Investigación CientÃ-fica y Tecnológica
Award Identifier / Grant number: PICT2019-00955
Acknowledgments
Financial support from the University of Buenos Aires and the Agency for Promotion of Science and Technology are gratefully acknowledged.
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Research ethics: Not applicable.
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Author contributions: M.P Balbi performed simulations, experiments and data analysis. S.N. Fleite supervised simulations and experiments and write the manuscript. M.C. Cassanello get funding, supervise research activities and edit the text. The authors have accepted responsibility for the entire content of this manuscript and approved its submission.
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Competing interests: The authors state no conflict of interest.
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Research funding: FONCyT – ANPCyT [PICT2019-00955]; Universidad de Buenos Aires [UBACyT 20020170100604BA].
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Data availability: The raw data can be obtained on request from the corresponding author.
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Articles in the same Issue
- Frontmatter
- Editorial
- CPPM special issue in honor of Professor Faïçal Larachi
- Research Articles
- Predicting buoyant jet characteristics: a machine learning approach
- Insights into the bubble formation dynamics in converging shape microchannels using CLSVOF method
- Comparison of different CFD approaches for the simulation of developing free surface two-phase flow in straight and bent pipes
- A new approach to model the fluid dynamics in sandwich packings
- Effect of novel mixed impeller on local bubble size and flow regime transition in pilot scale gas-liquid stirred tank reactor
- Quantitative structure-electrochemistry relationship modeling of a series of anticancer agents using MLR and ANN approaches
- Extractive desulfurization of crude petroleum oil and liquid fuels using trihexyl tetradecyl phosphonium bis(2-ethylhexyl) phosphate ionic liquid
- CFD-aided contraction-expansion static mixer design for oil-in-water emulsification
- Liquid-liquid flow pattern and mass transfer in a rotating millimeter channel reactor
- By-product Eucalyptus leaves valorization in the basic dye adsorption: kinetic equilibrium and thermodynamic study
Articles in the same Issue
- Frontmatter
- Editorial
- CPPM special issue in honor of Professor Faïçal Larachi
- Research Articles
- Predicting buoyant jet characteristics: a machine learning approach
- Insights into the bubble formation dynamics in converging shape microchannels using CLSVOF method
- Comparison of different CFD approaches for the simulation of developing free surface two-phase flow in straight and bent pipes
- A new approach to model the fluid dynamics in sandwich packings
- Effect of novel mixed impeller on local bubble size and flow regime transition in pilot scale gas-liquid stirred tank reactor
- Quantitative structure-electrochemistry relationship modeling of a series of anticancer agents using MLR and ANN approaches
- Extractive desulfurization of crude petroleum oil and liquid fuels using trihexyl tetradecyl phosphonium bis(2-ethylhexyl) phosphate ionic liquid
- CFD-aided contraction-expansion static mixer design for oil-in-water emulsification
- Liquid-liquid flow pattern and mass transfer in a rotating millimeter channel reactor
- By-product Eucalyptus leaves valorization in the basic dye adsorption: kinetic equilibrium and thermodynamic study
