Airfoil-shaped micro-mixers for reducing fouling on membrane surfaces
AssigneeSandia Corporation
InventorsClifford K. Ho, Susan J. Altman, Paul G. Clem, Michael Hibbs, Adam W. Cook
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Abstract
An array of airfoil-shaped micro-mixers that enhances fluid mixing within permeable membrane channels, such as used in reverse-osmosis filtration units, while minimizing additional pressure drop. The enhanced mixing reduces fouling of the membrane surfaces. The airfoil-shaped micro-mixer can also be coated with or comprised of biofouling-resistant (biocidal/germicidal) ingredients.
Claims23
An array of airfoil-shaped micro-mixers disposed on a surface of a permeable membrane, wherein:
- the airfoil shape has a rounded leading edge and a tapered trailing edge;
- an overall length=A and an overall width=B;
- and the leading edge is oriented upstream and the trailing edge is oriented downstream of fluid flowing along the membrane's surface in a direction of fluid flow;
- wherein the micro-mixers and the permeable membrane comprise a biocidal/germicidal agent that reduces fouling.
An array of airfoil-shaped micro-mixers disposed on a surface of a permeable membrane, wherein:
- the airfoil shape has a rounded leading edge and a tapered trailing edge;
- an overall length=A and an overall width=B;
- and the leading edge is oriented upstream and the trailing edge is oriented downstream of fluid flowing along the membrane's surface in a direction of fluid flow;
- the micro-mixer height is greater than or equal to 0.1 mm and less than or equal to 3 mm;
- the permeable membrane comprises a reverse osmosis membrane;
- the airfoil shape has a “S”-shaped lower surface, consisting of a convex-curved forward section and a concave-curved rear section;
- the array comprises regular rows and columns of micro-mixers;
- and every other column of micro-mixers is offset in a direction perpendicular to the flow direction from the adjacent column by a row offset distance=d;
- and wherein adjacent columns of micro-mixers are spaced apart, along the direction of flow, by a separation distance, S;
- and wherein the orientation of the airfoil shapes in every other column is flipped upside-down from the orientation of the airfoil shapes in adjacent columns;
- the separation distance, S, equals 2 times the length, A, of the airfoil shape;
- and the row offset distance, d, is equal to 1.5 times the width, B, of the airfoil shape;
- and
- the aspect ratio, A/B, of the airfoil shape is between 2 and 4;
- and wherein the micro-mixers and the permeable membrane are coated with a biocidal/germicidal coating that reduces fouling.
An array of airfoil-shaped micro-mixers disposed on a surface of a permeable membrane, wherein:
- the airfoil shape has a rounded leading edge and a tapered trailing edge;
- an overall length=A and an overall width=B;
- and the leading edge is oriented upstream and the trailing edge is oriented downstream of fluid flowing along the membrane's surface in a direction of fluid flow;
- wherein the micro-mixers have a hollow cross-section.
Dependencies are inferred from the claim text.