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Title:
ANTI-BIOFOULING IN MARINE APPLICATIONS USING UV LIGHT SOURCE
Document Type and Number:
WIPO Patent Application WO/2021/055500
Kind Code:
A1
Abstract:
The invention provides an apparatus and method for: (i) preventing marine biofouling of a water intake port and associated protective screens or wire grids on stationary structures and/or mobile marine vessels comprising a water intake orifice adapter, at least an UV light source, proximate to or optically coupled to the biofouling surfaces of the intake port, and a power conditioning module that supplies energy to and receives information from the UV light source; (ii) preventing marine biofouling from occurring on downstream biofouling surfaces comprising a water transport structure, at least an UV light source and a power conditioning module that supplies electrical energy to and receives information from the UV light source. The invention also describes a threaded UV adapter fitting that can be installed and positioned integrally in the water intake orifice adapter, said fitting houses either an UV light source or an optical conductor bearing UV light.

Inventors:
HATCH MICHAEL (US)
FISHER JOHN (US)
Application Number:
US2020/051103
Publication Date:
March 25, 2021
Filing Date:
September 16, 2020
Export Citation:
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Assignee:
HATCH TRANSF INC (US)
International Classes:
B63B59/04; B08B17/00; B63B13/00; B63B35/00; B63B59/00; C02F1/00; C02F1/32
Attorney, Agent or Firm:
GRAFE, V., Gerald (Corrales, NM, US)
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Claims:
CLAIMS

What is claimed is:

1. A marine intake port system comprising an intake port configured to communicate water into a water-using system, and one or more UV lights mounted such that they communicate UV light to a region of the intake port through which water flows.

2. The marine intake port system of claim 1, further comprising a screen mounted with the intake port such that water communicated to the water-using system passes through the screen, and wherein the UV lights are further mounted such that they communicate UV light to the screen.

3. A marine vessel, comprising one or more water-using systems, each of which comprises a marine intake port system as in claim 1.

4. The marine intake port system of claim 2, wherein screen is mounted at a first end of the intake port, wherein a water source is adjacent a first side of the input screen, and wherein the one or more UV lights are mounted with the intake port such that they communicate UV light to the screen from a second side of the input screen, opposite the first side.

5. A marine intake port system comprising:

(a) a housing having an end face, the end face configured to be attached to an opening in a hull of a marine vessel hull such that a fluid flowing through the opening flows past the housing;

(b) one or more UV light sources affixed to the housing such that UV light from the one or more UV light sources is directed to water flowing past the housing; and

(c) a power conditioning module coupled to the one or more UV light sources and configured to provide electrical power to each of the one or more UV light sources.

6. The marine intake port system of claim 5, wherein the housing is a hollow tubular housing, and wherein fluid flows through the hollow tubular housing, and wherein the UV lights direct UV light to fluid flowing through the hollow tubular housing.

7. The marine intake port system of claim 5, wherein the one or more UV light sources comprise one or more of: (a) UV light emitting diodes mounted to the housing; (b) UV light generators mounted at a distance from the housing and communicating UV light via fiber optics, light channels, or free space optical transmission.

8. The marine intake port system of claim 5, wherein the hollow tubular housing includes one or more angled openings with threads, and wherein the one or more UV light sources mount in the angled openings.

9. The marine intake port system of claim 9, further comprising one or more threaded UV adapter fittings for each of the one or more UV light sources, wherein each the threaded UV adapter fitting includes a hollow threaded cap bolt, the hollow portion configured to accommodate one of the UV light sources, each of the one or more threaded UV adapter fittings configured to be threaded into one of the one or more angled openings.

10. A marine intake port adapter system comprising:

(a) a hollow tubular housing having an end face, the end face configured to be attached to an opening in a hull of a marine vessel hull such that a fluid flowing through the opening flows through the hollow tubular housing;

(b) one or more UV lights affixed to the hollow tubular housing such that UV light from the one or more UV lights is directed to an interior portion of the hollow tubular housing; and

(c) a power conditioning module coupled to the one or more UV lights and configured to provide electrical power to each of the one or more UV lights.

11. The marine intake port adapter system of claimlO, wherein the hollow tubular housing includes one or more angled openings with threads, and wherein the one or more UV lights mount in the angled openings.

12. The marine intake port adapter system of claim 11, further comprising one or more threaded UV adapter fittings for each of the one or more UV lights, wherein each the threaded UV adapter fitting includes a hollow threaded cap bolt, the hollow portion configured to accommodate one of the UV lights, each of the one or more threaded UV adapter fittings configured to be threaded into one of the one or more angled openings.

13. A method to prevent biofouling using UV light, the method comprising the steps of:

(a) positioning one or more UV light sources at or near a marine intake port; and

(b) directing light from the one or more UV light sources toward fluid entering the marine intake port and toward one or more surfaces in contact with the fluid as it enters the marine intake port.

14. The method of claim 13, further comprising providing electrical power to each of the one or more UV light sources, and receiving data from at least one of the one or more UV light sources.

15. The method of claim 14, wherein the data is representative of biofouling, and further comprising controlling the electrical power to the one or more UV light sources responsive to the data.

Description:
Anti-Biofouling in Marine Applications Using UV Light Source [001] Background

[002] Marine vessels use aqueous intake ports for a number of applications, such as circulating water for engine cooling, other machine cooling applications, and harvesting water for cleaning and purification applications. In many cases these intake ports remain fully submerged at all times, unless the marine vessel is removed from the water (dry-docked). In some stationary structure applications, e.g., marine housing or offshore oil wells, removing the host that contains the intake ports is not possible.

[003] Biofouling can comprise calcareous (hard) fouling organisms such as barnacles and non- calcareous organisms such as seaweeds and algae. Continuous submersion in marine environments results in biofouling of most surfaces, with the possible exception of surfaces that have chemical treatments such as biocides. Biocides have also been used as a water treatment process to dispel biofouling organisms.

[004] Marine intake ports that have been compromised due to biofouling can result in very expensive equipment failure, possibly at risk of health or life, or delay of mission-critical activities. Current post- biofouling maintenance methods have two similar problematic characteristics - access to the port, and remediation methods. Access to the fouled port requires human intervention below the surface of the marine body, or removal of the port from the marine environment, or both. Remediation can include a number of methods of manual or chemical removal of the biofoul, or simply require port replacement. In any case, the combination of the intake-port dependent equipment failure, the potentially dangerous process of accessing the biofouled port(s) and equipment, and the subsequent cost and logistics of repairing/replacing and re-installing the intake ports results in an overall situation that is expensive to fix and risky to implement.

[005] What is needed is a reliable and permanent method of preventing marine biofouling from occurring on stationary marine structure and mobile marine vessel intake ports; protective screens that can be easily retrofitted to existing systems; and systems that can be used to keep downstream piping and systems free from biofoul.

[006] Summary of the Invention

[007] Many systems used in or near marine environments take advantage of the abundance of nearby water. Applications are plentiful. It is common for seawater to be circulated as a coolant in inboard and outboard propulsion systems. Seawater can also be circulated as a coolant for luxury yacht cabin cooling systems. In stationary structures in a marine environment such as oil platforms, seawater is often circulated for machinery or cabin system cooling. [008] Another example is water treatment using reverse osmosis systems. On large stationary structures and mobile vessels, these systems harvest seawater and convert it to potable water. All of the foregoing are "water-using systems" as used herein.

[009] A common aspect that all of these applications have is that the seawater is usually extracted through an orifice installed on an aquatic boundary layer. In many cases this orifice is a through-hull or panel mount fitting. This orifice can also include a protective screen, or wire grid, that excludes ingress of larger bio-organisms and marine life while typically providing little if any impediment to aqueous inflow. The term "intake port" as used herein refer to any port that communicates water from the surrounding environment into a water treatment or usage system, including a simple port, and a port that includes a protective screen or wire grid. Typically the intake port is not designed to be readily removed from the marine environment.

[0010] Intake ports are subject to biofouling, a very common problem with marine system intake ports.

If the intake port is not readily removed from the marine environment to accommodate cleaning or replacement, the port must be protected from biofouling to prevent compromised system performance or system failure.

[0011] In addition to the intake port becoming fouled, downstream systems themselves are at risk as well. Extensive research is conducted on reverse osmosis membranes and how to make them less subject to biofouling. Cabin cooling systems, with extensive piping in many areas of the hull of vessels that are difficult to access are another example of downstream piping and systems that are at risk of compromised performance or failure due to biofouling.

[0012] Example embodiments of the invention provide an apparatus that addresses the problem of marine intake port biofouling using a UV light source system, comprising one or more UV light sources integrated into a fitting that is inserted between a marine intake port and the subsequent tubing, and a power conditioning module that supplies electrical energy and receives information from the UV light source intake port. Example embodiments of the invention provide a process for preventing or reducing biofouling on marine intake ports by using one or more UV light sources integrated into a fitting that is inserted between a marine intake port and the subsequent tubing, in combination with a power conditioning module that supplies electrical energy to and receives information from the UV light source intake port. Example embodiments of the invention provide a UV light source system integrated into a water transport structure to create an anti-biofouling water transport structure that disables biofouling organisms (kills, or otherwise renders less capable of reproducing, growing, or adhering to the system) from an intake volume of water such that downstream biofouling is prevented or reduced. Example embodiments of the invention provide a process whereby water is moved through a volume in a water transport structure that is in close proximity to the intake port and subjected to UV treatment using a UV light source system, removing biofouling organisms. Example embodiments of the invention provide a method of use of a sealed UV light source adapter fitting which is installed and positioned in the adapter fitting in such a manner that it propagates UV light to the interior biofouling surface of the intake port. [0013] Brief Description of the Drawings

[0014] FIG. 1 is a horizontal cross-section of an intake port, or WATER INTAKE ORIFICE (2). The intake port can have any of a variety of cross-sectional shapes, e.g., circular, ellipsoidal, rectangular, or others. The intake orifice includes one or more integral light sources that protrude through the INTAKE ORIFICE OUTER WALL (9) and the INTERIOR BIOFOULING SURFACE (5). The integral light sources emit light in the UV spectrum, and are referred to herein as the UV LIGHT SOURCE(S) (1). The UV LIGHT SOURCE(S) (1) emit UV LIGHT RAYS (7) that impinge upon, propagate through, and reflect off a WATER VOLUME (8) and additionally impinge upon and reflect off the INTERIOR BIOFOULING SURFACE (5). The UV LIGHT SOURCE(S)(l) are electrically connected to a POWER CONDITIONING MODULE (3). The power conditioning module is supplied with electrical energy in the form of INPUT POWER (6).

[0015] FIG. 2 is a vertical cross section of a water intake orifice. The orifice is used to extract water through an AQUATIC BOUNDARY LAYER (11). Attachment of the orifice to the boundary layer can be accomplished using an ORIFICE FLANGE NUT (13). Biofouling surfaces include an EXTERIOR BIOFOULING SURFACE (12), generally parallel to the surface of the aquatic boundary layer, and an INTERIOR BIOFOULING SURFACE (5), circumferential in nature and generally orthogonal to the boundary layer. The UV LIGHT SOURCE(S) (1) are shown protruding through a LIGHT SOURCE APERTURE (14), in such a manner that they are neither orthogonal nor parallel to the boundary layer. Also shown in FIG. 2 is the direction of WATER FLOW (7), and a WATER TRANSPORT HOSE (15) in which the water flow occurs.

[0016] FIG. 3 illustrates an anti-biofouling structure in which a WATER VOLUME (8) flows through a WATER TRANSPORT STRUCTURE (25) and is subjected to a UV LIGHT SOURCE (1) or plurality of UV light sources such that the dwell time in the structure and intensity of the UV light rays render the volume of water void of living biofouling organisms.

[0017] FIG. 4 illustrates a sealed UV LED adapter fitting that either hosts a UV LED or a UV LED light pipe. The fitting shown is threaded such that it can be installed into the body of the adapter. The fitting comprises a THREADED CAP BOLT (16), which includes a HOLLOW CAP BOLT CHANNEL (20). It also includes an O-RING SEAL GROOVE (17) that provides a water-tight seal. The cap bolt channel can include an LED light pipe or a discrete UV LED. It can be connected to the control system by lead wires, or to a UV LED assembly by a light pipe.

[0018] FIG. 5 illustrates an INTAKE ORIFICE ADAPTER (22) that can be attached to a standard intake orifice. The INTAKE ORIFICE ADAPTER (22) includes features for integrating UV LIGHT SOURCE(S) (1), or can include the UV LED adapter fitting described in FIG. 4. The INTAKE ORIFICE ADAPTER (22) comprises a WATER TRANSPORT HOSE MATING FEATURE (26), AN ADAPTER HOSE MATING FEATURE (27) and an INTAKE ORIFICE ADAPTER BODY (28). Protruding into the INTAKE ORIFICE ADAPTER BODY (28) and through the INTAKE ORIFICE INNER WALL (29) is one or more UV LIGHT SOURCE(S) (1).

[0019] FIG. 6 depicts a control system that controls the UV emitter devices based on sensor input information.

[0020] Detailed Description Of Invention

[0021] With the exception of surfaces that are chemically treated with a biocide or anti-biofouling paints, or resident in a body of water that has been treated with biocides, almost all surfaces submerged for extended periods of time in marine environments are subjected to biofouling. Biofouling includes microscopic and macroscopic organisms, in both calcareous and non-calcareous forms.

[0022] Light in the ultraviolet range can prevent and in some circumstances remove organic growth from biofouled surfaces. In US2014/0196745, Whelen, et al, describe a system and method using UV light coupled to an optical medium to remove biofouling that has adhered to a surface. In US2017/0343287, Salters, et al., describe a cooling apparatus and method for preventing biofouling growth on said cooling apparatus using at least one light source, in particular a UV light source. Further, in US2017/0197693, Salters, et al., describe a system for anti-fouling based upon a plurality of UV-LEDs, primarily describing a complete control system including the plurality of UV light sources, whereby large aquatic boundary layers, such as a ship's hull can be protected from biofouling.

[0023] Experienced mariners are well aware of the problems that biofouling causes on ship hulls including loss of nautical velocity and increased fuel consumption. However, the aforementioned systems and methods do not address the problem of biofouling of seawater intake apertures. These apertures take the form of through-hull fittings on vessels, or fixed intake ports on stationary structures and in some cases include protective wire screens or wire grids, which are also subject to biofouling.

[0024] Seawater intake apertures represent ideal habitats for marine biofouling organisms. In most cases a continuous or at least frequent flow of marine water is occurring, bringing nutrients and aerated water into and through the port. The entry area of the intake port is also partially shielded from rough seas and forward travel velocity that can help to slow the growth of biofouling organisms. Further, these favorable conditions can exist well past where the intake port penetrates the aquatic boundary layer, such that marine biofouling can exist at the location where the fluid from the intake port is intended to be applied. Cooling systems, system piping and reverse osmosis membranes are examples of systems that can be harmed by downstream biofouling.

[0025] Studies have shown that marine biofouling can be prevented with certain doses of UV lighting. In US 5,308505, Titus, et al., report that 4000uW/cm 2 with an exposure time of 1 minute can prevent biofouling. Similarly, in US 2017/0343287, Salters indicates that 90% of a certain micro-organism can be killed with a dose as little as 10mW-hours/m 2 .

[0026] Example embodiments of the invention provide a UV light source system that is integral to a marine intake port. The marine intake port includes a singular or plurality of UV light sources (1) that are integral to the intake port. The light sources can be located locally or remotely located but coupled optically, that protrude through the intake orifice outer wall (9) and are angled toward the biofouling surface (5) of the intake orifice. The arrangement of the UV light sources is such that UV light rays (7) propagate through and reflect off both the water volume (8) and the interior biofouling surface. Further, the UV light source(s) can be angled in such a way that the UV light rays propagate through the orifice opening, further reflecting and discouraging or preventing biofouling at the exterior biofouling surface in very near proximity to the orifice opening and protective screen or grid, if present.

[0027] Example embodiments of the invention provide a marine intake port adapter system that is inserted between an existing intake port and subsequent piping or tubing. The adapter comprises an attachment means to the existing intake orifice and also to the downstream piping, a single or plurality of UV light source(s), and a power conditioning module. In some applications, the adapter diameter is preferably between 1" and 6" and constructed of a metal alloy, such as stainless steel or a galvanized alloy to resist corrosion. The adapter can have one or more mating features such as temporary triangular increases in the diameter of the adapter, typically referred to in the art as 'barbs', such that mating hoses can be installed and clamped over the barbs. Mating barbs whose diameter increase is approximately 5% of the original adapter diameter are common, although in some applications, more or less diametric increases can be desired.

[0028] Combined, the system discourages or prevents biofouling at and in near proximity to the mouth of the intake orifice and the protective screen or grid, if present. In one embodiment the UV light source(s) are integrated into a shoulder area of the adapter and can be hosted by a threaded and sealed fitting. The body of the adapter can have one or more angled openings with machined threads. The angled openings facilitate and direct UV light propagation toward the orifice opening. Example embodiments of the invention provide a process for preventing marine biofouling at and in near proximity to a marine intake orifice. Example embodiments of the invention provide a system for discouraging or preventing downstream biofouling comprising a singular or a plurality of UV light sources that use the inherent nature of UV light to render a volume of marine water as it flows through a water transport structure void of living biofouling organisms. Example embodiments of the invention provide a process for removing or substantially reducing the presence of living biofouling organisms from a volume of water that is flowing in through a marine intake port, such that downstream biofouling is substantially reduced or eliminated.

[0029] Example embodiments of the invention provide a marine intake orifice adapter that includes a singular or plurality of UV light sources, located locally or remotely located but coupled optically, that protrude through the intake orifice adapter outer wall (9) and are angled toward the biofouling surface (5) of the intake orifice. The arrangement of the UV light sources is such that UV light rays (7) propagate through and arbitrarily reflect off both the water volume (8) and the interior biofouling surface. Further, the UV light source(s) can be angled in such a way that the UV light rays propagate through the orifice opening, further reflecting and discouraging or preventing biofouling at the exterior biofouling surface in very near proximity to the orifice opening and protective screen or grid, if present. The optimum emission angle range for such LEDs is between 30 degrees and 120 degrees from their central axis, such that reflection and propagation is optimized. In some applications, the radiant power of the individual LEDs is between 0.9 watts and 1.7 watts. In some applications, annular spacing between UV lights around the perimeter is one UV light source every 15°-45° degrees, depending on the power level required.

[0030] Example embodiments of the invention provide a method of discouraging or preventing biofouling on a marine intake port and protective screen or grid, if present. The method uses an intake port adapter that includes a singular or plurality of UV light sources that are used and arranged in such a manner so as to propagate through and arbitrarily reflect off of a body of water. The method also includes using UV light rays produced by the UV light source to impinge upon and reflect off of the interior biofouling surfaces of the intake port. Further, the method includes the use of a power conditioning module to properly control the UV light source(s) such that electrical energy is supplied to, and information is received from, the UV light source(s).

[0031] Example embodiments of the invention provide a circumferential anti-biofouling water transport structure. An example embodiment comprises a water transport structure through which a volume of water flows. A plurality of UV light sources are arranged in a manner where UV light rays propagate through and reflect in the volume of water. A power conditioning module supplies electrical energy to and receives information from the plurality of the UV light sources. The effect is such that the volume of water that flows through the anti-biofouling water transport structure is subjected to UV light rays during transport through the structure and is rendered void of living biofouling organisms. The anti-biofouling water transport structure is configured such that the dwell time in the structure, combined with the UV light source irradiance level meets a specific dose known to reduce biofouling to an acceptable level, e.g., to zero.

[0032] Example embodiments of the invention provide a method wherein an anti-biofouling water transport structure is created by using a plurality of UV light sources in combination with a water transport structure to expose a volume of water flowing through the water transport structure to UV light rays. In this method, the UV light sources are supplied energy by, and supply information to, a power conditioning module such that a controlled dose of UV light rays is delivered to the volume of water that renders the volume of water void of living biofouling organisms.

[0033] Example embodiments of the invention provide a sealed adapter fitting that serves as a host for the UV LED light source. The UV LED light source is integral to and centered in the fitting. The fitting has a sealed channel through which leads for the LED, or the LED light pipe itself, exit from the exterior surface of the fitting. The fitting can be a threaded cap bolt, such that it can be screwed into the adapter. Preferred cap bolt dimensions are between ¼ in and ½", and of such a length that the shaft of the cap bolt can be machined properly and the UV light source secured properly in the intake port or the intake port adapter. The preferred sealed channel diameter in the cap bolt is between 1/8" and 3/16", although channel diameters may vary with different UV light sources and optical fibers.

[0034] Example embodiments of the invention provide an in-line anti-biofouling intake port adapter to discourage or eliminate biofouling. Such an adapter has an adapter hose mating feature, an adapter body and a water transport hose mating feature. One or more UV light sources are affixed in light source apertures that are angled such that the UV light source rays propagate and reflect from the body wall to the intake port opening, with some portion of the UV light source rays impinging upon the orifice protective screen or grid, if present. The hose mating features make it possible to add the intake port to to an existing intake port system. An installer can remove the existing water transport hose from the intake port, install a short piece of adapter hose on the existing intake port, then insert and secure the intake port mating feature into the adapter hose. The water transport hose mating feature can then be inserted into and secured to the existing water transport hose.

[0035] Further, a control system that provides electrical energy to the UV radiation sources can be connected to the array and located either adjacent to, or remote from the array. An example control module is depicted in FIG. 6. The control module (1) includes but is not limited to a power conditioning stage (37), an emitter signal conditioning stage (36), a central control section (35) and a sensory input stage (34).

[0036] The power conditioning stage (37) converts input power (6) that is supplied to the control module to a stable supply voltage for the rest of the module. The input to the power conditioning stage can comprise any of numerous types of electrical levels. As examples, electrical levels contemplated by the invention include 12VAC, 12VDC, 24V AC, 24VDC, 36VAC, 36VDC, 48VAC, 48VDC, 120VAC, 240VAC or 277VAC; the invention and the input power stage can function using one or more of these inputs as well as other electrical input signal levels.

[0037] The emitter signal conditioning stage (36) is configured to convert the output of the power conditioning stage (37) to the appropriate drive signal(s) for the UV emitters (1). For LED UV emitters, drive signals can comprise constant voltage or constant current signals such that forward-biasing of the UV LEDs can be controlled. Typical control system output voltage levels for constant voltage type UV LED loads are 12VDC, 24VDC, 36VDC and 48VDC. The invention is not limited to these specific voltages. Typical rms output current values are 100mA, 350mA, 700mA, 1050mA although the invention is not limited to these specific current values. The example wattage range of the control module for some applications can be between 10W and 100W although the invention is not limited to this output power range.

[0038] Alternately, the signal conditioning stage (36) can be configured to control low pressure mercury UV emitters.

[0039] The sensory input stage (34) receives input from proximal or remote sensors (33). Sensors can include but are not limited to system sensing such as moisture, temperature, timing, biofoul threshold detection, other fluorescence detection and system power on/power off.

[0040] The central control stage (35) assimilates inputs from sensors (33) and based on algorithmic results, controls the output level of the signal conditioning stage (36). Because of the nature of UV LED emitters (1), the control can be ON, OFF, or disabled, or operating in a dimmed condition, such that the rms level of current, or the rms level of output voltage can be controlled, thereby operating the system only in the necessary conditions for biofoul control rather than in a continuous full-on condition.

[0041] In some of the intended applications the UV light source can comprise metal halide or mercury vapor lamps, and can also be implemented, as in the embodiments described above, using UV LEDs. The particular quantity and arrangement of UV light sources can be varied, depending on the diameter of the intake port and the irradiance of the individual UV light sources. Likewise, the proximity to the orifice opening and the angle of the UV light source apertures can be varied. Similarly, the beam angle and radiant output power of the UV LED light sources can be selected based on distance from the intake orifice biofouling surfaces.

[0042] Example embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those example embodiments will be apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.