The present invention relates to the prevention of fouling and/or corrosion on objects in an aquatic environment.
Any references to methods, apparatus or documents of the prior art are not to be taken as constituting any evidence or admission that they formed, or form part of the common general knowledge.
Barnacles, algae, and marine organisms often build up on underwater structures, such as hulls of boats, which process is generally referred to as biological fouling. In the case of boats, the presence of fouling may increase resistance (drag) in the water, which in turn increases fuel consumption. Fouling can, however, also cause damage to the hull or propulsion system. Similar problems exist with other underwater structures, such as subsea machinery.
Anti-fouling coatings are often applied to these underwater structures to prevent, or at least reduce the prevalence of fouling. In many cases paints including biocides are applied to the hull of boats and ships to prevent such fouling. A problem with such anti-fouling coatings is that they are often toxic to the marine environments in which they are used. In particular, the anti-fouling coatings generally wear off, and thus become distributed in waterways where they may cause damage to other types of marine life. A further problem with such anti-fouling coatings is that they are generally difficult to apply, as the boat (or other structure) must come out of water for such application. While it is possible to apply such coatings at time of manufacture, the coatings must generally be re-applied periodically.
Another problem with underwater structures is corrosion. Often paint, or similar anti-corrosion coatings, are provided on underwater structures to prevent corrosion. Similar problems, however, exist in relation to anti-corrosion coatings as are discussed above in relation to anti-fouling coatings.
As such, there is clearly a need for an improved system for preventing fouling and/or corrosion on objects in an aquatic environment.
In an aspect, the invention provides a corrosion or fouling prevention system for preventing the fouling or corrosion of a vessel or an aquatic object having a surface in contact with seawater and/or brackish water in an aquatic environment, the system comprising:
a flexible and non-permeable barrier that extends about a surface of the vessel or aquatic object to avoid direct contact between the surface and the seawater and/or brackish water,
an attachment structure for attachment of the barrier relative to the vessel or aquatic object to position the barrier in a spaced apart arrangement from the surface of the vessel to define an internal volume in between the surface of the vessel of the object and the barrier to receive a fluid that has a composition that is different to the aquatic environment.
In an embodiment, the attachment structure comprises one or more floatation devices adapted for being positioned relative to the vessel or object and wherein during use the barrier is suspended in a generally downward direction relative to the floatation device to position the barrier in said spaced apart arrangement.
In an embodiment, buoyancy of the one or more floatation devices may be variable to allow the lowering or raising of the attachment structure.
In an embodiment, the floatation devices are adapted to be attached to the vessel or object.
In an embodiment, the floatation device comprises walls enclosing a hollow cavity with an inlet for receiving a fluid therein such that supplying fluid into the cavity of the floatation device results in lowering or submerging the attachment structure into the seawater and/or brackish water in a lowered position to allow said vessel or aquatic object to be positioned above the attachment structure; and a fluid removal arrangement to gradually remove fluid from the one or more cavities of the floatation device to raise the attachment structure to the surface of the seawater or brackish water to facilitate attachment of the barrier relative to the vessel or aquatic object.
In an embodiment, the corrosion or fouling prevention system further comprises a flow controller for controlling the flow of fluid into or out of the one or more cavities of the floatation devices thereby effecting movement of the attachment structure.
In an embodiment, the corrosion or fouling prevention system further comprises:
a pumping arrangement adapted to pump out sea water or brackish water from the internal volume in between the surface of the vessel of the object; and
a fluid supply arrangement to supply the fluid that has a composition that is different to the aquatic environment into the internal volume in between the surface of the vessel of the object.
In an embodiment, the corrosion or fouling prevention system further comprises one or more coupling assemblies positioned relative to the barrier and/or the attachment structure, said coupling assemblies being adapted to be coupled to the pumping arrangement and/or the fluid supply arrangement.
In an embodiment, the flotation devices further comprise one or more vents positioned to vent the cavities and release accumulation of air when the floatation devices contain pressurised fluid in the one or more cavities.
In an embodiment, the corrosion or fouling prevention system for preventing the fouling or corrosion of a vessel having a surface in contact with seawater and/or brackish water in an aquatic environment further comprises a marina attachment assembly adapted to be coupled with the attachment structure and/or the barrier to facilitate installation or removal of the corrosion or fouling prevention system relative to the vessel.
In an embodiment, the marina attachment assembly further comprises an extension member extending outwardly from the marina for attachment to the attachment structure at one or more attachment locations wherein the extension member is adapted for movement in an upward or downward to facilitate upward or downward movement of the attachment structure relative to the vessel thereby facilitating installation or removal of the corrosion or fouling prevention system relative to the vessel.
In an embodiment, the marina attachment assembly comprising one or more connectors adapted to be fluidly coupled to the fluid supply arrangement and the pumping arrangement.
In an embodiment, the fluid received in the internal volume in between the surface of the vessel of the object and the barrier is fresh water.
In an embodiment, the corrosion or fouling prevention system further comprises a sealing arrangement for sealing a portion of the barrier relative to the vessel or the marine object to prevent the sea water or brackish water from being received into the internal volume in between the surface of the vessel of the object and the barrier.
In another aspect, the invention provides a method for corrosion or fouling prevention in a vessel or an aquatic object having a surface in contact with seawater and/or brackish water in an aquatic environment, the method comprising:
In an embodiment, the attachment structure comprises one or more floatation devices adapted for attachment to the vessel or object and wherein the attachment step of the method comprises suspending the barrier in a generally downward direction relative to the floatation device to position the barrier in said spaced apart arrangement.
In an embodiment, the method for corrosion or fouling prevention further comprises the steps of:
In an embodiment, the method for corrosion or fouling prevention further comprises an intermediate step of: pumping or removing any sea water or brackish water from the internal volume before the step of supplying the fluid into the internal volume in between the surface of the vessel of the object and the barrier.
In an embodiment, the method further comprises the step of coupling the attachment structure and/or the barrier to a marina attachment assembly to facilitate installation or removal of the corrosion or fouling prevention system relative to the vessel.
In an embodiment, the marina attachment assembly further comprises an extension member extending outwardly from the marina and the method comprising the additional steps of:
Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows:
The system 200 includes a flexible and non-permeable sheet 215 which is positioned near the hull of the vessel 205 to form a barrier and define a protection zone 220 adjacent to the vessel 205. During use, the sheet 215 extends about a surface of the hull 205a of the vessel 205 to avoid direct contact between the surface 205a and the seawater and/or brackish water of the aquatic environment 210.
Floatation devices 225 include attachment structures to allow attachment of the floatation devices 225 to the vessel 205 at a plurality of locations extend around the surface of the hull 205a. The floatation devices 225 allow the non-permeable sheet 215 to be positioned in a spaced apart configuration relative to the surface 205a of the hull to define an internal volume in between the surface of the vessel 205a and the sheet/barrier 215 to receive a fluid that has a composition that is different to the aquatic environment. In an in-use configuration, the internal volume in between the surface of the vessel 205a and the sheet/barrier 215 is filled with a protective fluid (e.g. fresh water) which is different to the seawater or brackish water of the aquatic environment 210.
The system 200 is preferably reusable, in that it can be opened or removed when the boat 205 is underway, and closed or reinstalled when the boat 205 is moored or anchored as will be explained in the foregoing sections.
The floatation device(s) 225 comprise a substantially hollow structure. In the presently described embodiment, the floatation devices(s) 225 take the form of hollow pipes (such as PVC pipes) comprising walls that enclose a hollow cavity for receiving a fluid into the hollow cavity. Referring to
Once the vessel 205 has been positioned substantially above the floatation devices (initial position-
Referring to
The floatation device(s) 225 may be fastened or attached to the hull of the vessel at a plurality of attachment locations. The manner in which the floatation device(s) are fastened to the vessel 205 is not limiting and one or more conventional methods may be used for attachment of the floatation devices 225 to the vessel 205. In some embodiments, the attachment of the floatation device(s) to the vessel 205 may result in forming a sealing arrangement for sealing a portion of the sheet or barrier 215 relative to the vessel 205. Formation of such a seal allows the internal volume defined in between the surface of the vessel 205 and the barrier 215 to be fluidly sealed relative to the aquatic environment 210.
Upon attachment of the floatation devices 225 and formation of the sealing arrangement, the next step involves removal of any sea water or brackish water from the internal volume defined in between the surface of the vessel 205 and the barrier 215. A fluid inlet/outlet 217 is provided for removal of fluid from the substantially sealed internal volume. It must be understood that the location or structural configuration of the inlet/outlet 217 is not limiting. A secondary controller 287 may be actuated to commence a pumping operation that results in the sea water or brackish water being pumped out of the internal volume. Another pumping device 280 may be used for pumping out the sea water and directing the sea water into a reservoir 283. Alternatively, the pumped sea water may also be released into the aquatic environment 210.
Once the sea water has been removed from the internal volume, the protective fluid may be pumped into the internal volume by actuating the controller 287. Actuating the controller 287 results in the protective fluid being pumped from a protective fluid reservoir 285 into the internal volume defined by the barrier sheet 215 by introducing the protective fluid into the internal volume through the inlet/outlet 217 to form the protective zone 220 as shown in
Referring to
The marina attachment assembly 235 may also provide one or more supply lines via a services hub 240 for supplying electricity and for supplying the protective fluid (e.g., fresh water) and other fluids (such as fluids pumped into the floatation devices 225). Additional supply lines may also be provided via a secondary hub 245. By way of example, the secondary hub 245 may be used for pumping out sea water or brackish water out of the internal volume of the barrier 215 (as shown in
Additional fluid couplings or connection points 243 and associated controllers may also be provided for providing additional control over fluid flow into and out of the floatation devices 225.
As shown in
While the system 200 as described in the previous sections relates to marine vessels 205, the skilled addressee will readily appreciate that embodiments of the invention may be particularly useful for use around bridge structures which are partially or fully submerged in bodies of water, such as buoys, pylons and subsurface equipment.
A non-permeable sheet 420 is placed around an underside of the buoy 405 and sealed against the anchor 415 on an underside using attachment 430, and against a periphery of the buoy 405 and an upper side, defining a protection zone 425 against a submerged portion of the buoy 405. The seawater is pumped out from the protection zone 425, and replaced by freshwater in a similar manner as explained in the earlier sections in relation to system 200.
According to certain embodiments, the buoy 405 may be configured to generate freshwater, and thus continuously replenish the freshwater in the protection zone 425. This is particularly advantageous if the protection zone 425 is not entirely sealed or for example if the sheet used is permeable in one direction only, as it enables nutrients or saltwater to be flushed from the protection zone either continuously or periodically.
In particular, the machinery 505 is tethered either to the offshore platform 515 or the vessel 520 by a tether 525. A non-permeable sheet 530 is placed around the machinery 505 and sealed against the tether 525 on one side, and against a periphery of the machinery 505 and an the other side, defining a protection zone 535 around at least part of the machinery 505. The seawater is pumped out from the protection zone, and replaced by freshwater, as outlined above.
Remote Operated Vehicles (ROVs) can be used to install such barriers. The tether 525 may be used to pump the saltwater from the protection zone, and provide the freshwater to the protection zone. The fluid can be displaced via the use of e.g. pumps, pressurized gas cylinders, bottles and compressors. Relevant fluid can be placed, replaced, removed or reinstalled into the protection zone 535, as outlined above. If the fluid required in the protective zone is potable water. In this regard, a desalination plant may be located on the offshore platform 515 and/or the vessel 520, together with pumps and the like, to enable such remote displacement of the saltwater around the machinery 505.
Much like the systems described above, a barrier 4 is provided adjacent to an underside of the object 1, which defines a liquid protection zone 2 around an underside of the object. This protects the object 1 from fouling and/or corrosion that would otherwise occur if placed directly in the aquatic environment 5. Furthermore, one or more devices, switches, valves, pumps and/or electronics 3 exist in the liquid protection zone 2.
An upper side of the object 1 is exposed to atmosphere 7, and thus does not need protection from the aquatic environment 5.
The barrier 4 may be configured to at least partially float in the aquatic environment 5 when in use, with a lower portion spaced from the earth base 6 of the aquatic environment 5. The barrier 4 can also be attached to the object 1 directly (e.g. around a periphery thereof), or to one or more other objects.
The barrier 4 may also transition between a raised and a lowered state. In particular, a portion of the barrier 4 may move or be moved out of the aquatic environment 5 and into the atmosphere 7 (and thus into the raised state), which is particularly useful in case the object 1 is a vessel and is berthed, moored or anchored. The barrier 4 may then be move or be moved back into the aquatic environment 5 (surrounding the object 1) (and thus into the lowered state), which is particularly useful when the vessel is in motion or is about to move.
A barrier 4 is provided surrounding the object 1, which defines a liquid protection zone 2 around the object 1. This protects the object 1 from fouling and/or corrosion that would otherwise occur if placed directly in the aquatic environment 5. In contrast to the system 600, the object 1 is entirely encompassed within the liquid protection zone 2, and is thus not exposed to atmosphere 7 but is still separated from the earth base 6 of the aquatic environment 5.
While the above embodiments describe use of fresh, clean water, the skilled addressee will readily appreciate that other fluids may be used. As an illustrated example, fluid may comprise a gas (e.g. Carbon Dioxide, Argon or Nitrogen) or a mixture thereof. Preferably, the gas is substantially non-corrosive to the object, and may comprise an inert (or substantially inert) gas or a mixture of gases forming a substantially inert mixture.
The use of a gas may enable electrical instruments to be deployed in the area that are unable to function in a liquid, such as an electronic measurement device, relays, switches, sensors and the like.
Similarly, the water may comprise seawater (or water from outside of the protection zone) that has been treated with an additive. As an illustrative example, the additive may comprise a biocide and/or a corrosion inhibitor.
Furthermore, while the above embodiment describe use of a non-permeable sheet, the skilled addressee will readily appreciate that any suitable barrier may be used, and such barrier may, for example, comprise a plurality of sheets, or any other suitable structure that provides the barrier. In some embodiments, the barrier may include a frame.
In some embodiments, the barrier (e.g. a non-permeable sheet) is UV permeable. As such, ultraviolet radiation may penetrate the barrier, which may assist in the prevention of fouling. The barrier is preferably resistant to UV radiation, and as such, does not degrade in the presence of UV radiation.
As outlined above, electrical components may be located within the protection zone, including, for example, when the protection zone is filled with a gas. In such case, the barrier may include isolation properties, such as electronic insulation properties, which may prevent interaction of the electrical components with outside components. Furthermore, such barrier may also be provided for the purpose of safety, to further prevent electrical shock or injury to persons or animals in proximity to the barrier.
In addition to the objects described above that are made for water, embodiments of the present invention may be used to protect emergency devices in the water. In such case, the barrier may be gas filled, to prevent submersion of the emergency device in the water.
Some embodiments of the invention may be specifically configured to prevent cross-contamination between fluid (e.g. fresh water) in the protection zone and fluid (e.g. salt water) outside of the protection zone. As an illustrative example, the water from the protection zone may be retrieved (e.g. by a pump) prior to removal of the protection zone. Similarly, the systems may include the ability to exchange ballast and/or bilge water to prevent cross-contamination between different marine zones.
Embodiments described above enable an environment to be quickly and inexpensively created around an object which is at least partially or fully submerged in an aquatic environment, to prevent or reduce fouling, marine growth and/or corrosion (including oxidisation, rust, galvanic corrosion, and change due to electrolysis). As such, the environment around the object may be quickly and efficiently changed from one where marine growth and/or corrosion is sustained, to one where marine growth is not sustained and corrosion is inhibited.
The embodiments may be used on structures that are already submerged, and as such, there is no need to retrieve the object from the water, as is the case for anti-fouling painting and/or cleaning.
In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. The term “comprises” and its variations, such as “comprising” and “comprised of” is used throughout in an inclusive sense and not to the exclusion of any additional features.
It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect.
The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted by those skilled in the art.
Number | Date | Country | Kind |
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2017904918 | Dec 2017 | AU | national |
This application is a continuation of International patent application No. PCT/AU2018/051307, filed on Dec. 6, 2018 and titled SYSTEM AND METHOD FOR PREVENTING FOULING AND/OR CORROSION ON VESSELS AND MARINE OBJECTS (“the '307 PCT Application”). The '307 PCT Application includes a claim for the benefit of priority to the Dec. 6, 2017 filing date of Australian Provisional Patent Application No. 2017904918, titled SYSTEM AND METHOD FOR PREVENTING FOULING AND/OR CORROSION ON VESSELS AND MARINE OBJECTS (“the '918 Australian Provisional Application”). The entire disclosures of the '307 PCT Application and the '918 Australian Provisional Application are hereby incorporated herein.
Number | Date | Country | |
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Parent | PCT/AU2018/051307 | Dec 2018 | US |
Child | 16894486 | US |