Influence of Droplet Size on Exergy Destruction in Flow of Concentrated Non-Newtonian Emulsions
Abstract
:1. Introduction
2. Theoretical Background
Exergy Destruction in a Cone-and-Plate Viscometer
3. Experimental Section
4. Results and Discussion
4.1. Droplet Size Distribution of Emulsions
4.2. Rheology of Emulsions
4.3. Reliability of Rheological Measurements
4.4. Exergy Destruction in Emulsions
5. Simulation of Exergy Destruction in Pipeline Flow of Emulsions
6. Conclusions
- The shear-stress τ versus shear rate behavior of concentrated oil-in-water emulsions (fine, coarse, and their mixtures) investigated in this work can be described satisfactorily by a power-law model . The power-law parameters K and n vary with the droplet size and droplet size distribution of emulsions. When fine emulsion (small droplet size) is mixed with the coarse emulsion (large droplet size), keeping the dispersed-phase concentration fixed, the consistency index K goes through a minimum and the power-law index n goes through a maximum at a certain proportion of fine emulsion content of the mixed fine and coarse emulsion.
- The exergy destruction rate per unit volume of emulsion exhibits a minimum when fine emulsion is mixed with the coarse emulsion. The minimum in exergy destruction rate is observed at low shear rates around the fine emulsion proportion of 35%.
- The thermodynamic efficiency of pumping emulsion through a pipeline increases when fine emulsion is mixed with the coarse emulsion provided that the flow regime is laminar and that the Reynolds number is not high (less than about 100).
- At high Reynolds number in the turbulent regime, the exergy loss in pipeline flow of emulsion increases upon mixing fine emulsion with the coarse emulsion, keeping the dispersed-phase concentration fixed. The increase in exergy loss upon increasing the droplet size distribution is due an increase in the flow behavior index n (a decrease in pseudo-plasticity).
Acknowledgments
Conflicts of Interest
References
- Becher, P. Emulsions: Theory and Practice, 3rd ed.; Oxford University Press: Oxford, UK, 2001. [Google Scholar]
- Walstra, P. Formation of emulsions. In Encyclopedia of Emulsion Technology; Becher, P., Ed.; Dekker: New York, NY, USA, 1983; Chapter 2; Volume 1. [Google Scholar]
- Lucassen-Reynders, E.H. Dynamic interfacial properties in emulsification. In Encyclopedia of Emulsion Technology; Becher, P., Ed.; Dekker: New York, NY, USA, 1996; Chapter 2; Volume 4. [Google Scholar]
- Mason, T.G.; Krall, A.H.; Gang, H.; Bibette, J.; Weitz, D.A. Monodisperse emulsions: Properties and uses. In Encyclopedia of Emulsion Technology; Becher, P., Ed.; Dekker: New York, NY, USA, 1996; Chapter 6; Volume 4. [Google Scholar]
- Davis, S.S.; Hadgraft, J.; Palin, K.J. Medical and Pharmaceutical Applications of Emulsions. In Encyclopedia of Emulsion Technology; Becher, P., Ed.; Dekker: New York, NY, USA, 1985; Chapter 3; Volume 2. [Google Scholar]
- Davis, B.W. Applications in the petroleum industry. In Encyclopedia of Emulsion Technology; Becher, P., Ed.; Dekker: New York, NY, USA, 1988; Chapter 8; Volume 3. [Google Scholar]
- Bampfield, H.A.; Cooper, J. Emulsion explosives. In Encyclopedia of Emulsion Technology; Becher, P., Ed.; Dekker: New York, NY, USA, 1988; Chapter 7; Volume 3. [Google Scholar]
- Pal, R. Rheology of Particulate Dispersions and Composites; CRC Press: Boca Raton, FL, USA, 2007. [Google Scholar]
- Pal, R. Effect of droplet size on the rheology of emulsions. AIChE J. 1996, 42, 3181–3190. [Google Scholar] [CrossRef]
- Pal, R. Pipeline flow of unstable and surfactant-stabilized emulsions. AIChE J. 1993, 39, 1754–1764. [Google Scholar] [CrossRef]
- Pal, R. Rheology of simple and multiple emulsions. Curr. Opin. Colloid Interface Sci. 2011, 16, 41–60. [Google Scholar] [CrossRef]
- Pal, R. Techniques for measuring the composition (oil and water content) of emulsions—A state of the art review. Colloids Surf. A 1994, 84, 141–193. [Google Scholar] [CrossRef]
- Pal, R. Rheology of double emulsions. J. Colloid Interface Sci. 2007, 307, 509–515. [Google Scholar] [CrossRef] [PubMed]
- Cengel, Y.; Boles, M. Thermodynamics: An Engineering Approach, 7th ed.; McGraw-Hill: New York, NY, USA, 2011; Chapter 8. [Google Scholar]
- Doi, M.; Ohta, T. Dynamics and rheology of complex interfaces. J. Chem. Phys. 1991, 95, 1242–1248. [Google Scholar] [CrossRef]
- Mason, T.G. New fundamental concepts in emulsion rheology. Curr. Opin. Colloid Interface Sci. 1999, 4, 231–238. [Google Scholar] [CrossRef]
- Larson, R.G. The Structure and Rheology of Complex Fluids; Oxford University Press: New York, NY, USA, 1999. [Google Scholar]
- Ngan, K.H.; Ioannou, K.; Rhyne, L.D.; Wang, W.; Angeli, P. A methodology for predicting phase inversion during liquid-liquid dispersed pipeline flow. Chem. Eng. Res. Des. 2009, 87, 318–324. [Google Scholar] [CrossRef]
- Liu, L.; Matar, O.K.; Lawrence, C.J.; Hewitt, G.F. Laser-induced fluorescence (LIF) studies of liquid-liquid flows. Part I: Flow structures and phase inversion. Chem. Eng. Sci. 2006, 61, 4007–4021. [Google Scholar] [CrossRef]
- Brauner, N.; Ullmann, A. Modeling of phase inversion phenomenon in two-phase pipe flows. Int. J. Multiph. Flow 2008, 28, 1177–1204. [Google Scholar] [CrossRef]
- Piela, K.; Delfos, R.; Ooms, G.; Westerweel, J.; Oliemans, R.V.A.; Mudde, R.F. Experimental investigation of phase inversion in an oil-water flow through a horizontal pipe loop. Int. J. Multiph. Flow 2006, 32, 1087–1099. [Google Scholar] [CrossRef]
- Piela, K.; Delfos, R.; Ooms, G.; Westerweel, J.; Oliemans, R.V.A. On the phase inversion process in an oil-water flow. Int. J. Multiph. Flow 2008, 34, 665–677. [Google Scholar] [CrossRef]
- Xu, J.Y.; Li, D.H.; Guo, J.; Wu, Y.X. Investigations of phase inversion and frictional pressure gradient in upward and downward oil-water flow in vertical pipes. Int. J. Multiph. Flow 2010, 36, 930–939. [Google Scholar] [CrossRef]
- Simmons, M.J.H.; Azzopardi, B.J. Drop size distribution in dispersed liquid-liquid pipe flow. Int. J. Multiph. Flow 2001, 27, 843–859. [Google Scholar] [CrossRef]
- Angeli, P.; Hewitt, G.F. Drop size distributions in horizontal oil-water dispersed flows. Chem. Eng. Sci. 2000, 55, 3133–3143. [Google Scholar] [CrossRef]
- Wang, W.; Cheng, W.; Duan, J.; Gong, J.; Hu, B.; Angeli, P. Effect of dispersed holdup on drop size distribution in oil-water dispersions: Experimental observations and population balance modeling. Chem. Eng. Sci. 2014, 105, 22–31. [Google Scholar] [CrossRef]
- Liao, Y.; Lucas, D. A literature review of theoretical models for drop and bubble breakup in turbulent dispersions. Chem. Eng. Sci. 2009, 64, 3389–3406. [Google Scholar] [CrossRef]
- Jana, A.K.; Das, G.; Das, P.K. Flow regime identification of two-phase liquid-liquid upflow through vertical pipe. Chem. Eng. Sci. 2006, 61, 1500–1515. [Google Scholar] [CrossRef]
- Angeli, P.; Hewitt, G.F. Flow structure in horizontal oil-water flow. Int. J. Multiph. Flow 2000, 26, 1117–1140. [Google Scholar] [CrossRef]
- Lum, J.Y.L.; Al-Wahaibi, T.; Angeli, P. Upward and downward inclination oil-water flows. Int. J. Multiph. Flow 2006, 32, 413–435. [Google Scholar] [CrossRef]
- Lovick, J.; Angeli, P. Experimental studies on the dual continuous flow pattern in oil-water flows. Int. J. Multiph. Flow 2004, 30, 139–157. [Google Scholar] [CrossRef]
- Lu, Y.; He, L.; He, Z.; Wang, A. A study of pressure gradient characteristics of oil-water dispersed flow in horizontal pipe. Energy Procedia 2012, 16, 1111–1117. [Google Scholar] [CrossRef]
- Al-Wahaibi, T. Pressure gradient correlation for oil-water separated flow in horizontal pipes. Exp. Therm. Fluid Sci. 2012, 42, 196–203. [Google Scholar] [CrossRef]
- Angeli, P.; Hewitt, G.F. Pressure gradient in horizontal liquid-liquid flows. Int. J. Multiph. Flow 1998, 24, 1183–1203. [Google Scholar] [CrossRef]
- Bird, R.B.; Armstrong, R.C.; Hassager, O. Dynamics of Polymeric Liquids; Wiley & Sons: New York, NY, USA, 1987; Volume 1. [Google Scholar]
- Slattery, J.C. Advanced Transport Phenomena; Cambridge University Press: New York, NY, USA, 1999; Chapter 3. [Google Scholar]
- Bird, R.B.; Stewart, W.E.; Lightfoot, E.N. Transport Phenomena; John Wiley & Sons: New York, NY, USA, 1960; Chapter 3. [Google Scholar]
- Pal, R. Entropy generation in flow of highly concentrated non-Newtonian emulsions in smooth tubes. Entropy 2014, 16, 5178–5197. [Google Scholar] [CrossRef]
Emulsion Composition | Regression Correlation Coefficient, R2 | Flow Behavior Index, n | Consistency Index, K (Units of Pa·sn) | 95% Confidence Interval of n | 95% Confidence Interval of K |
---|---|---|---|---|---|
Coarse (0f/100c) | 0.9956 | 0.442 | 1.12 | [0.427, 0.456] | [1.044, 1.199] |
10f/90c | 0.9999 | 0.622 | 0.425 | [0.619, 0.625] | [0.420, 0.430] |
20f/80c | 0.9975 | 0.753 | 0.208 | [0.734, 0.771] | [0.191, 0.227] |
35f/65c | 0.9976 | 0.822 | 0.152 | [0.802, 0.841] | [0.138, 0.167] |
50f/50c | 0.9989 | 0.733 | 0.323 | [0.722, 0.744] | [0.307, 0.340] |
65f/35c | 0.9996 | 0.585 | 0.937 | [0.580, 0.591] | [0.916, 0.959] |
80f/20c | 0.9966 | 0.466 | 2.418 | [0.454, 0.478] | [2.303, 2.539] |
90f/10c | 0.9973 | 0.431 | 3.522 | [0.422, 0.441] | [3.383, 3.667] |
Fine (100f/0c) | 0.9745 | 0.364 | 6.777 | [0.336, 0.392] | [5.927, 7.749] |
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Pal, R. Influence of Droplet Size on Exergy Destruction in Flow of Concentrated Non-Newtonian Emulsions. Energies 2016, 9, 293. https://doi.org/10.3390/en9040293
Pal R. Influence of Droplet Size on Exergy Destruction in Flow of Concentrated Non-Newtonian Emulsions. Energies. 2016; 9(4):293. https://doi.org/10.3390/en9040293
Chicago/Turabian StylePal, Rajinder. 2016. "Influence of Droplet Size on Exergy Destruction in Flow of Concentrated Non-Newtonian Emulsions" Energies 9, no. 4: 293. https://doi.org/10.3390/en9040293