Mapping Bubble Formation and Coalescence in a Tubular Cross-Flow Membrane Foaming System
Membrane foaming is a promising alternative to conventional foaming methods to produce uniform bubbles. In this study, we provide a fundamental study of a cross-flow membrane foaming (CFMF) system to understand and control bubble formation for various process conditions and fluid properties. Observa...
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| Format: | Article |
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MDPI AG
2021-09-01
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| Series: | Membranes |
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| Online Access: | https://www.mdpi.com/2077-0375/11/9/710 |
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| author | Boxin Deng Tessa Neef Karin Schroën Jolet de Ruiter |
| author_facet | Boxin Deng Tessa Neef Karin Schroën Jolet de Ruiter |
| author_sort | Boxin Deng |
| collection | DOAJ |
| description | Membrane foaming is a promising alternative to conventional foaming methods to produce uniform bubbles. In this study, we provide a fundamental study of a cross-flow membrane foaming (CFMF) system to understand and control bubble formation for various process conditions and fluid properties. Observations with high spatial and temporal resolution allowed us to study bubble formation and bubble coalescence processes simultaneously. Bubble formation time and the snap-off bubble size (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>D</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula>) were primarily controlled by the continuous phase flow rate (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>Q</mi><mi>c</mi></msub></mrow></semantics></math></inline-formula>); they decreased as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>Q</mi><mi>c</mi></msub></mrow></semantics></math></inline-formula> increased, from 1.64 to 0.13 ms and from 125 to 49 µm. Coalescence resulted in an increase in bubble size (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>D</mi><mrow><mi>c</mi><mi>o</mi><mi>a</mi><mi>l</mi></mrow></msub><mo>></mo><msub><mi>D</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula>), which can be strongly reduced by increasing either continuous phase viscosity or protein concentration—factors that only slightly influence <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>D</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula>. Particularly, in a 2.5 wt % whey protein system, coalescence could be suppressed with a coefficient of variation below 20%. The stabilizing effect is ascribed to the convective transport of proteins and the intersection of timescales (i.e., μs to ms) of bubble formation and protein adsorption. Our study provides insights into the membrane foaming process at relevant (micro-) length and time scales and paves the way for its further development and application. |
| first_indexed | 2024-03-10T07:27:26Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 2077-0375 |
| language | English |
| last_indexed | 2024-03-10T07:27:26Z |
| publishDate | 2021-09-01 |
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| spelling | doaj.art-d4b0d3292ce24c8dbd19781379f7a9f02023-11-22T14:10:46ZengMDPI AGMembranes2077-03752021-09-0111971010.3390/membranes11090710Mapping Bubble Formation and Coalescence in a Tubular Cross-Flow Membrane Foaming SystemBoxin Deng0Tessa Neef1Karin Schroën2Jolet de Ruiter3Food Process Engineering Group, Department of Agrotechnology & Food Science, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The NetherlandsFood Process Engineering Group, Department of Agrotechnology & Food Science, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The NetherlandsFood Process Engineering Group, Department of Agrotechnology & Food Science, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The NetherlandsFood Process Engineering Group, Department of Agrotechnology & Food Science, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The NetherlandsMembrane foaming is a promising alternative to conventional foaming methods to produce uniform bubbles. In this study, we provide a fundamental study of a cross-flow membrane foaming (CFMF) system to understand and control bubble formation for various process conditions and fluid properties. Observations with high spatial and temporal resolution allowed us to study bubble formation and bubble coalescence processes simultaneously. Bubble formation time and the snap-off bubble size (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>D</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula>) were primarily controlled by the continuous phase flow rate (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>Q</mi><mi>c</mi></msub></mrow></semantics></math></inline-formula>); they decreased as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>Q</mi><mi>c</mi></msub></mrow></semantics></math></inline-formula> increased, from 1.64 to 0.13 ms and from 125 to 49 µm. Coalescence resulted in an increase in bubble size (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>D</mi><mrow><mi>c</mi><mi>o</mi><mi>a</mi><mi>l</mi></mrow></msub><mo>></mo><msub><mi>D</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula>), which can be strongly reduced by increasing either continuous phase viscosity or protein concentration—factors that only slightly influence <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>D</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula>. Particularly, in a 2.5 wt % whey protein system, coalescence could be suppressed with a coefficient of variation below 20%. The stabilizing effect is ascribed to the convective transport of proteins and the intersection of timescales (i.e., μs to ms) of bubble formation and protein adsorption. Our study provides insights into the membrane foaming process at relevant (micro-) length and time scales and paves the way for its further development and application.https://www.mdpi.com/2077-0375/11/9/710cross-flow membrane foaming (CFMF)whey protein(sub)millisecondbubble formationbubble coalescenceconvective transport |
| spellingShingle | Boxin Deng Tessa Neef Karin Schroën Jolet de Ruiter Mapping Bubble Formation and Coalescence in a Tubular Cross-Flow Membrane Foaming System Membranes cross-flow membrane foaming (CFMF) whey protein (sub)millisecond bubble formation bubble coalescence convective transport |
| title | Mapping Bubble Formation and Coalescence in a Tubular Cross-Flow Membrane Foaming System |
| title_full | Mapping Bubble Formation and Coalescence in a Tubular Cross-Flow Membrane Foaming System |
| title_fullStr | Mapping Bubble Formation and Coalescence in a Tubular Cross-Flow Membrane Foaming System |
| title_full_unstemmed | Mapping Bubble Formation and Coalescence in a Tubular Cross-Flow Membrane Foaming System |
| title_short | Mapping Bubble Formation and Coalescence in a Tubular Cross-Flow Membrane Foaming System |
| title_sort | mapping bubble formation and coalescence in a tubular cross flow membrane foaming system |
| topic | cross-flow membrane foaming (CFMF) whey protein (sub)millisecond bubble formation bubble coalescence convective transport |
| url | https://www.mdpi.com/2077-0375/11/9/710 |
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