Method and apparatus for anti-biofouling of a protected surface in liquid environments

• US 8,445,864 B2
• Filed: 08/26/2011
• Issued: 05/21/2013
• Est. Priority Date: 08/26/2011
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Thoren, Matthew D., Piper, Andrew M.
• Primary Examiner(s): Souw, Bernard E
• Application Number:
  US13/218,621
• Publication Number:
  US 20130048877A1
• Time in Patent Office: 634 Days
• Field of Search: 250/432.R, 250436-438, 250/455.1, 250/458.1, 250/459.1, 250/461.1, 250/461.2, 250/492.1, 250/504.R, 250/522.1, 210/748.1, 210/748.11, 210/748.13, 210/764, 422/1, 422/6, 422/24, 422/28, 422/186.3, 435/800
• US Class Current: 250/455.11
• CPC Class Codes: B01J 19/123 Ultraviolet light
• CPC Class Codes: B01J 2219/0877 Liquid
• CPC Class Codes: B08B 17/02 Preventing deposition of fouling or of dust
• CPC Class Codes: B63B 59/04 Preventing hull fouling anti-fouling paints C09D5/16
• CPC Class Codes: B63B 59/08 of underwater surfaces while afloat B63B59/10 takes precedence
• CPC Class Codes: C02F 1/325 Irradiation devices or lamp constructions
• CPC Class Codes: C02F 2303/20 Prevention of biofouling
• CPC Class Codes: G02B 6/001 the light being emitted along at least a portion of the lateral surface of the fibre
• CPC Class Codes: G02B 6/0048 with stepwise taper
• CPC Class Codes: G02B 6/102 for infrared and ultraviolet radiation

Abstract

A system includes a UV light source and an optical medium coupled to receive UV light from the UV light source. The optical medium is configured to emit UV light proximate to a surface to be protected from biofouling. A method corresponds to the system.

Claims

1. System for anti-biofouling a protected surface, comprising:

an ultraviolet light source configured to generate ultraviolet light; and

an optical medium disposed proximate to the protected surface and coupled to receive the ultraviolet light, wherein the optical medium has a thickness direction perpendicular to the protected surface, wherein two orthogonal directions of the optical medium orthogonal to the thickness direction are parallel to the protected surface, wherein the optical medium is configured to provide a propagation path of the ultraviolet light such that the ultraviolet light travels within the optical medium in at least one of the two orthogonal directions orthogonal to the thickness direction, and such that, at points along a surface of the optical medium, respective portions of the ultraviolet light escape the optical medium.

2. The system of claim 1, wherein the optical medium comprises a plurality of optical fibers, each optical fiber configured to carry the ultraviolet light along a length of the optical fiber, wherein a physical characteristic of the plurality of optical fibers changes along lengths of the plurality of optical fibers in a way selected to allow, at any point along the lengths of the plurality of optical fibers, a determined percentage of a total power of the ultraviolet light source to escape the optical fiber.

3. The system of claim 2, wherein the plurality of optical fibers is comprised of one or more of Silica, Ethylene Tetrafluoroethylene (ETFE), Fluorinated ethylene propylene (FEP), Polyether ether ketone (PEEK), or Polymethylpentene (PMP).

4. The system of claim 2, wherein spacings between adjacent ones of the plurality of optical fibers are selected to result in a retardation of biological growth upon a substantial portion of the protected surface.

5. The system of claim 2, wherein the plurality of optical fibers is formed into a mesh.

6. The system of claim 5, wherein the mesh comprised of at least one of a Kevlar mesh, a carbon fiber mesh, a fiberglass mesh, a Vectran mesh, an amorphous Polytetrafluoroethylene (PTFE) mesh, a Fluorinated ethylene propylene (FEP) mesh, a Polyether ether ketone (PEEK) mesh, an Ethylene Tetrafluoroethylene (ETFE) mesh, a Polymethylpentene (PMP) mesh, or a Hexafluoropropylene and Vinylidene Fluoride (THV) mesh, having the plurality of optical fibers disposed therein.

7. The system of claim 5, wherein the physical characteristic that changes comprises a cross sectional shape of selected ones of the plurality of optical fibers, the cross sections taken parallel to a thickness direction of the selected ones of the plurality of optical fibers, the cross sectional shapes changing along lengths of the selected ones of the plurality of optical fibers.

8. The system of claim 2, wherein each one of the plurality of optical fibers comprises a plurality of light scattering objects.

9. The system of claim 8, wherein the physical characteristic that changes comprises a number of the light scattering objects per volume along lengths of selected ones of the plurality of optical fibers.

10. The system of claim 8, wherein the physical characteristic that changes comprises a cross sectional shape of selected ones of the plurality of optical fibers, the cross sections taken parallel to a thickness direction of the selected ones of the plurality of optical fibers, the cross sectional shapes changing along lengths of the selected ones of the plurality of optical fibers.

11. The system of claim 2, wherein each one of the plurality of optical fibers comprises a plurality of microbends.

12. The system of claim 11, wherein the physical characteristic that changes comprises a number of the microbends per unit length.

13. The system of claim 11, wherein the physical characteristic that changes comprises a cross sectional shape of selected ones of the plurality of optical fibers, the cross sections taken parallel to a thickness direction of the selected ones of the plurality of optical fibers, the cross sectional shapes changing along lengths of the selected ones of the plurality of optical fibers.

14. The system of claim 2, wherein each one of the plurality of optical fibers comprises a selected surface roughness.

15. The system of claim 14, wherein physical characteristic that changes comprises a roughness of the surface roughness along lengths of selected ones of the plurality of optical fibers.

16. The system of claim 14, wherein the physical characteristic that changes comprises a cross sectional shape of selected ones of the plurality of optical fibers, the cross sections taken parallel to a thickness direction of the selected ones of the plurality of optical fibers, the cross sectional shapes changing along lengths of the selected ones of the plurality of optical fibers.

17. The system of claim 1, wherein the optical medium comprises an optical coating bonded proximate to the protected surface wherein the optical coating is configured to provide the propagation path of the ultraviolet light.

18. The system of claim 17, wherein a physical characteristic of the optical coating is selected to allow, at any point along a surface of the optical coating, a determined percentage of a total power of the ultraviolet light source to escape the optical layer.

19. The system of claim 18, wherein the optical coating is comprised of at least one of a urethane acrylate, an amorphous Polytetrafluoroethylene (PTFE), a Hexafluoropropylene and Vinylidene Fluoride (THV), a Polyether ether ketone (PEEK), a Fluorinated ethylene propylene (FEP), an Ethylene Tetrafluoroethylene (ETFE), or a Polymethylpentene (PMP).

20. The system of claim 18, wherein the physical characteristic changes about the optical coating, and wherein the physical characteristic comprises a roughness of the surface of the optical coating.

21. The system of claim 18, wherein the physical characteristic changes about the optical coating, and wherein the physical characteristic comprises a density of light scattering objects within or proximate to the optical coating.

22. The system of claim 1, wherein the ultraviolet light source comprises a plurality of light emitting diodes, wherein the plurality of light emitting diodes and the optical medium are conjoined in a composite structure, wherein the composite structure comprises a plurality of strip structures, each strip structure comprising:

a strip backing medium; and

at least a portion of the plurality of light emitting diodes coupled to the strip backing medium, wherein the strip backing medium is coupled proximate to the protected surface.

23. The system of claim 22, wherein ones of the plurality of light emitting diodes have spacings between the ones of the light emitting diodes, and the ones of the plurality of light emitting diodes have beamwidths of the ultraviolet light, wherein the spacings and the beamwidths are selected to result in a retardation of biological growth upon a substantial portion of the protected surface.

24. The system of claim 1, further comprising a penetrating structure configured to penetrate through the protected surface, wherein the penetrating structure comprises:

a seal coupled between the penetrating structure and the protected surface; and

at least one of;

an optical structure configured to generate the ultraviolet light and configured to inject the ultraviolet light into the optical medium, or

an optical structure coupled to receive the ultraviolet light and configured to inject the ultraviolet light into the optical medium.

25. The system of claim 1, wherein the optical medium is disposed under the protected surface or embedded in the protected surface.

26. The system of claim 25, wherein the optical medium comprises a plurality UV LEDS.

27. The system of claim 25, wherein the optical medium comprises a plurality of optical fibers.

28. The system of claim 27, wherein the plurality of optical fibers is formed into a mesh.

29. Method of anti-biofouling a protected surface, comprising:

generating ultraviolet light; and

distributing the ultraviolet light about a protected surface though an optical medium disposed proximate to the protected surface, wherein the optical medium has a thickness direction perpendicular to the protected surface, wherein two orthogonal directions of the optical medium orthogonal to the thickness direction are parallel to the protected surface, wherein the optical medium is configured to provide a propagation path of the ultraviolet light such that the ultraviolet light travels within the optical medium in at least one of the two orthogonal directions orthogonal to the thickness direction, and such that, at points along a surface of the optical medium, respective portions of the ultraviolet light escape the optical medium.