AU2021103818A4 - Underwater cleaning apparatus and system - Google Patents

Abstract

The present disclosure relates to an underwater cleaning apparatus and system. The apparatus and system may be used to clean vessels and other underwater structures. The apparatus and system may also be capable of reclaiming and treating the biofoulings cleaned off an underwater surface. The apparatus includes a housing, a cleaner configured to remove the material from the surface of the underwater structure, a fluid injection system, and an extractor configured to extract the material removed from the surface of the underwater structure. The system may include filtration devices to separate material (e.g. biofouling) from fluid discharged from the apparatus. This may allow for the fluid to then be discharged into the sea. ~~/I D CD0 - 0 0n KC Fig. 5

Description

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Underwater cleaning apparatus and system

Technical field

[0001] The present disclosure relates to an underwater cleaning apparatus and system. The apparatus and system may be used to clean vessels and other underwater structures. The apparatus and system may also be capable of reclaiming and treating the biofoulings cleaned off an underwater surface.

Background art

[0002] The underwater portions of vessels and underwater structures are subject to the accumulation of biofouling, which includes marine growth, barnacles, tubeworms, mussels, etc.

[0003] The gradual increase in a biofouling layer can lead to problems for vessels and/or the environment. For example, biofouling may cause damage to the anti-corrosion coating of a vessel, increase fuel consumption of a vessel due to increased resistance, and reduce manoeuvre performance of a vessel. The accumulation of organisms on vessels may also result in problems associated with carrying an invasive species into a foreign environment, which may present a risk to an ecological environment.

[0004] Various methods and tools have been utilised to decrease the impacts of biofouling. This includes dry docking a vessel for cleaning purposes. Dry docking causes down-time for the vessel, and can be an expensive process. Dry docking is typically utilised for cleaning purposes as it is difficult to simultaneously satisfy the requirements of cleaning while reclaiming captured biofoulings, when conducting underwater cleaning. Uncontained cleaning may aggravate an organism, which may result in the release of noxious contaminants into a local environment.

[0005] In this specification, unless the contrary is expressly stated, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge; or known to be relevant to an attempt to solve any problem with which this specification is concerned.

Summary

[0006] Disclosed herein is an underwater cleaning apparatus for removing material from a surface of an underwater structure. The apparatus may comprise a housing defining a primary chamber, the housing comprising housing side walls that surround the primary chamber, and a housing top wall connected to the housing side walls. The apparatus may comprise a cleaner configured to remove the material from the surface of the underwater structure, the cleaner being disposed within the primary chamber of the housing and comprising a cleaner side wall that surrounds a secondary chamber, a cleaner top wall connected to the cleaner side wall and disposed adjacent the housing top wall. The apparatus may comprise a fluid injection system comprising: a first injector configured to inject fluid into the secondary chamber; and a second injector configured to inject fluid into the secondary chamber, the second injector being spaced from the first injector. The apparatus may also comprise an extractor configured to extract the material removed from the surface of the underwater structure, the extractor being fluidically connected to the secondary chamber of the cleaner.

[0007] In some forms, the secondary chamber comprises a first chamber and a second chamber that is fluidically connected to the first chamber, and wherein the first injector is disposed in the first chamber and the second injector is disposed in the second chamber.

[0008] In some forms, the first injector is disposed centrally within the first chamber and the second injector is disposed centrally within the second chamber.

[0009] In some forms, the cleaner side walls comprise a first side wall that surrounds the first chamber and a second side wall that surrounds the second chamber.

[0010] In some forms, the first side wall is curved to form a circular shape such that the first chamber is circular in shape, the second side wall is curved to form a circular shape such that the second chamber is circular in shape, the first and second side walls being connected such that the first and second chambers are fluidically connected via an opening formed between the first and second chambers.

[0011] In some forms, a first width of the first chamber is the same as a second width of the second chamber, and wherein an opening width of the opening between the first and second chambers is less than the first and second widths.

[0012] In some forms, the first and second chambers are open towards the surface of the underwater structure in use, and the cleaner top wall closes the first and second chambers away from the surface of the underwater structure in use.

[0013] In some forms, the first and second injectors are mounted to the cleaner top wall.

[0014] In some forms, the first injector comprises a first nozzle that extends along a first fluid injector axis, and a second nozzle that extends along a second fluid injector axis and away from the first nozzle.

[0015] In some forms, the first and second nozzles are configured to cause the first injector to rotate in use.

[0016] In some forms, the first and second nozzles extend away from the cleaner top wall and into the first chamber.

[0017] In some forms, the first nozzle is elongate and comprises first and second ends, the first end of the first nozzle being mounted to the cleaner top wall, the second end of the first nozzle being spaced from the cleaner top wall, and wherein the second nozzle is elongate and comprises first and second ends, the first end of the second nozzle being mounted to the cleaner top wall, the second end of the second nozzle being spaced from the cleaner top wall.

[0018] In some forms, the first fluid injector axis forms a first acute angle with the cleaner top wall between the first nozzle and the cleaner top wall, and the second fluid injector axis forms a second acute angle with the cleaner top wall between the second fluid injector and the cleaner top wall, the first acute angle being substantially the same as the second acute angle.

[0019] In some forms, the second injector comprises a third nozzle that extends along a third nozzle axis, and a fourth nozzle that extends along a fourth nozzle axis and away from the third nozzle.

[0020] In some forms, the third and fourth nozzles are configured to cause the second injector to rotate in use.

[0021] In some forms, the third and fourth nozzles extend away from the cleaner top wall and into the second chamber.

[0022] In some forms, the third nozzle is elongate and comprises first and second ends, the first end of the third nozzle being mounted to the cleaner top wall, the second end of the third nozzle being spaced from the cleaner top wall, and wherein the fourth nozzle is elongate and comprises first and second ends, the first end of the fourth nozzle being mounted to the cleaner top wall, the second end of the fourth nozzle being spaced from the cleaner top wall.

[0023] In some forms, the third nozzle axis forms a third acute angle with the cleaner top wall between the third nozzle and the cleaner top wall, and the fourth nozzle axis forms a fourth acute angle with the cleaner top wall between the fourth nozzle and the cleaner top wall, the third acute angle being substantially the same as the fourth acute angle.

[0024] In some forms, the housing comprising a frame structure, the frame structure comprising: a first frame that surrounds the primary chamber and is disposed towards the underwater structure in use; a second frame that surrounds the primary chamber and is spaced from the first frame; and a plurality of spaced struts that connect the first frame to the second frame.

[0025] In some forms, the housing further comprising a plurality of panels disposed between the plurality of struts, each panel extending from the first frame to the second frame, wherein the plurality of panels and struts together form the side walls of the housing.

[0026] In some forms, the plurality of panels are formed from a buoyant material.

[0027] In some forms, the first frame comprises: first and second elongate members that extend parallel to one another and are spaced from one another at a first spacing; third and fourth elongate members that extend parallel to one another and perpendicular to the first and second elongate members, the third and fourth elongate members being spaced from one another at a second spacing; a fifth elongate member that connects the first and third elongate members, the fifth and first elongate members forming an obtuse angle therebetween and the fifth and third elongate members forming an obtuse angle therebetween; a sixth elongate member that connects the second and third elongate members, the second and sixth elongate members forming an obtuse angle therebetween and the sixth and third elongate members forming an obtuse angle therebetween; a seventh elongate member that connects the first and fourth elongate members, the first and seventh elongate members forming an obtuse angle therebetween and the fourth and seventh elongate members forming an obtuse angle therebetween; and an eight elongate member that connects the second and fourth elongate members, the fourth and eighth elongate members forming an obtuse angle therebetween and the second and eighth elongate members forming an obtuse angle therebetween.

[0028] In some forms, second spacing is greater than the first spacing.

[0029] In some forms, the second frame comprises: first and second elongate members that extend parallel to one another and are spaced from one another at the first spacing; third and fourth elongate members that extend parallel to one another and perpendicular to the first and second elongate members, the third and fourth elongate members being spaced from one another at the second spacing; a fifth elongate member that connects the first and third elongate members, the fifth and first elongate members forming an obtuse angle therebetween and the fifth and third elongate members forming an obtuse angle therebetween; a sixth elongate member that connects the second and third elongate members, the second and sixth elongate members forming an obtuse angle therebetween and the sixth and third elongate members forming an obtuse angle therebetween; a seventh elongate member that connects the first and fourth elongate members, the first and seventh elongate members forming an obtuse angle therebetween and the fourth and seventh elongate members forming an obtuse angle therebetween; and an eight elongate member that connects the second and fourth elongate members, the fourth and eighth elongate members forming an obtuse angle therebetween and the second and eighth elongate members forming an obtuse angle therebetween.

[0030] In some forms, the plurality of struts comprises first and second struts that connect the third elongate member of the first frame to the third elongate member of the second frame to form a rectangular front end of the apparatus.

[0031] In some forms, the plurality of struts comprises third and fourth struts that connect the first elongate member of the first frame to the first elongate member of the second frame to form a first side of the apparatus.

[0032] In some forms, the plurality of struts comprises fifth and sixth struts that connect the fourth elongate member of the first frame to the fourth elongate member of the second frame to form a rectangular rear end of the apparatus that is spaced from the front end of the apparatus.

[0033] In some forms, the plurality of struts comprises seventh and eighth struts that connect the second elongate member of the first frame to the second elongate member of the second frame to form a second side of the apparatus that is spaced from the first side.

[0034] In some forms, the plurality of struts comprises ninth, tenth, eleventh and twelfth struts, the ninth and tenth struts being disposed intermediate the third and fourth struts at the first side of the apparatus, the eleventh and twelfth struts being disposed intermediate the seventh and eighth struts at the second side of the apparatus.

[0035] In some forms, the cavity top comprises a panel that extends between the first and second elongate members of the second frame member, and one or more handles mounted to the panel and extending away from the primary chamber.

[0036] In some forms, the cleaner top wall comprises a panel that extends between the first and second elongate members of the second frame member, and one or more handles mounted to the panel and extending away from the primary chamber.

[0037] In some forms, a plane defined by the panel is spaced from and parallel to a plane defined by the cleaner top wall.

[0038] In some forms, the apparatus comprises first and second buoyant structures, the first and second buoyant structures being spaced from one another and disposed between the panel of the cleaner top wall and the fourth elongate member of the second frame.

[0039] In some forms, the extractor comprises a plurality of discharge channels fluidically connected to the secondary chamber.

[0040] In some forms, the plurality of discharge channels comprises a first discharge channel that is connected to and extends from the first chamber of the secondary chamber, a second discharge channel that is connected to and extends from the second chamber of the secondary chamber, and a third discharge channel connected between the first and second chambers.

[0041] In some forms, the extractor comprises a splitter body and a reclaim hose connected to the splitter body for extracting material removed from the underwater structure from the secondary chamber.

[0042] In some forms, the splitter body comprises a plurality of apertures disposed in a front face, an aperture disposed in a rear face, and a plurality of channels that extend from the plurality of apertures in the front face to the aperture disposed in the rear face so as to fluidically connect the plurality of apertures in the front face to the aperture disposed in the rear face.

[0043] In some forms, the splitter body comprises an expanded head towards the front face, and a tapered body between the expanded head and the rear face of the splitter body.

[0044] In some forms, the expanded head of the splitter body is connected to the housing and extends from the housing, and wherein the reclaim hose is connected to the rear face of the splitter body.

[0045] In some forms, the first, second and third discharge channels are connected to three of the plurality of apertures formed in the front face of the splitter so as to fluidically connect the first, second and third discharge channels to the reclaim hose.

[0046] In some forms, three of the plurality of apertures formed in the front face of the splitter body are fluidically connected to the primary chamber so as to fluidically connect the primary chamber to the reclaim hose to extract material removed from the underwater structure that is disposed in the primary chamber.

[0047] In some forms, the apparatus further comprises a secondary cleaning system, the secondary cleaning system comprising a brush that extends within the primary chamber.

[0048] In some forms, the brush is offset from the cleaner.

[0049] In some forms, the brush extends between supports disposed at an underside of the apparatus and is configured to rotate to remove material from the surface of the underwater structure.

[0050] In some forms, the material removed by the brush is substantially extracted from the primary chamber via the three apertures formed in the front face of the splitter body that fluidically connect the primary chamber to the reclaim hose.

[0051] In some forms, the system further comprises a plurality of wheels configured to enable the apparatus to me moved along the surface in use.

[0052] In some forms, the plurality of wheels comprises two fixed castor wheels disposed towards a stem end of the apparatus.

[0053] In some forms, the plurality of wheels comprises two swivel castor wheels disposed at a bow end of the apparatus.

[0054] In some forms, the two swivel caster wheels are connected via a steering strut that is configured to rotate the swivel caster wheels to alter movement of the apparatus along the surface in use.

[0055] In some forms, the fixed castor wheels and the swivel castor wheels are disposed on liftable bases connected via a sliding block that is configured to move vertically in use.

[0056] In some forms, vertical movement of the fixed castor wheels and swivel castor wheels is controlled synchronously via an elongate rod.

[0057] In some forms, vertical movement of the sliding block is actuated by turning supporting arms that are connected to an elevation handle.

[0058] In some forms, the system further comprises a height adjustment mechanism configured to alter a distance between the housing and the underwater surface.

[0059] Also disclosed herein is an underwater cleaning and reclaim system for removing and reclaiming material from a surface of an underwater structure. The system may comprise an underwater cleaning apparatus as described above; a cavitation blaster configured to provide fluid to the cleaner via an inlet hose; and a pump connected to the apparatus via an extraction hose for pumping fluid and material removed from the surface of the underwater structure from the primary and secondary chambers of the apparatus.

[0060] In some forms, the apparatus further comprises a treatment subsystem configured to treat the fluid extracted by the pump, the treatment subsystem comprising a macro filtration system configured to filter out solid material greater than 100pm in diameter.

[0061] In some forms, the treatment subsystem further comprises a micro filtration system configured to filter out solid material greater than 10gm diameter.

[0062] In some forms, the treatment subsystem further comprises a container for storing the material filtered out by the macro and micro filtration systems.

Brief Description of Drawings

[0063] Various embodiments/aspects of the disclosure will now be described with reference to the following figures.

[0064] Fig 1. shows a perspective view of the underside of an underwater cleaning apparatus according to an embodiment of the present disclosure;

[0065] Fig 2. shows a perspective view from the top of the apparatus shown in Fig. 1;

[0066] Fig 3. shows a perspective view of the splitter according to an embodiment of the present disclosure;

[0067] Fig 4. shows a perspective view of a brush reel according to an embodiment of the present disclosure; and

[0068] Fig 5. shows a schematic of an underwater cleaning system according to an embodiment of the present disclosure.

Detailed description

[0069] Disclosed herein is an underwater cleaning apparatus, in the form of an underwater cleaning rover. The apparatus will be described in detail with respect to Fig. 1 and Fig. 2. Fig. 1 shows a perspective view of the underside of the apparatus. Fig. 2 shows a perspective view of the top of the apparatus. The apparatus, shown in the form of rover 100, is configured to remove materials from a surface of an underwater structure. The surface of the underwater structure may be in the form of the hull of a vessel, the niche area of a vessel (including sea-chest and propeller), or other underwater structures (e.g. underwater assets of a harbour). The apparatus includes several features that may be used together, or separately (e.g. in a simplified apparatus), for cleaning purposes.

[0070] The rover 100 includes a housing 101. The housing 101 defines a primary chamber 102. The housing includes side walls that surround the primary chamber 102 and a housing top wall 113 that is connected to the housing side walls. The rover 100 includes a cleaner, in the form of a cavitator 140, that is configured to remove the material from the surface of the underwater structure. The cavitator is disposed within the primary chamber 102. The cavitator 140 is configured to separate the biofoulings from the surface to which the rover 100 is applied. The cavitator 140 defines a secondary chamber 141, which is surrounded by a cavitator side wall 142. The cavitator 140 includes a top wall 145 that is connected to the side wall 142 that is adjacent the housing top wall 113. In other words, the cavitator top wall 145 is located towards the housing top wall 113. In the detailed embodiment, the cavitator top wall 145 is spaced from and parallel to the housing top wall 113 (i.e. the top walls are disposed in close proximity to one another). As will be evident to the skilled addressee, the top wall of the housing and cavitator may be one and the same in an alternative embodiment.

[0071] The cavitator 140 includes a fluid injection system. In the detailed form, the fluid injection system includes first 122L and second 122R injectors. In the detailed embodiment, the first injector 122L includes a first rotatable disk 122 to which first 123 and second 124 nozzles are mounted. The first injector is configured to inject fluid, in the form of water, into the secondary chamber 141. The second injector 122R includes a second rotatable disk 125 to which third 127 and fourth 126 nozzles are mounted. The second injector is also configured to inject fluid, in the form of water, into the secondary chamber 141. The injectors will be discussed in further detail below.

[0072] The rover 100 includes an extractor 103 that is configured to extract the material removed from the surface of the underwater structure. The extractor 103 is fluidically connected to the secondary chamber 141. In the detailed embodiment, the extractor includes a reclaim hose 210 that extracts the separated biofoulings from the cavitator 140 to reduce polluting of the ambient environment.

[0073] Use of the above-mentioned primary chamber 102, combined with the secondary chamber 140, enables the rover 100 to remove the biofoulings from an underwater surface without releasing the removed materials (or at least significantly reduce the release of the removed materials) into the ambient environment in compliance with applicable regulations. This is advantageous to stakeholders of the maritime industry as vessel hull cleaning is able to be conducted without dry docking (e.g. in a harbour or in an anchorage). As such, dry docking may become unnecessary and the associated downtime may be avoided.

[0074] The cavitator 140 will now be described in further detail. The secondary chamber 141 includes a first chamber 146 and a second chamber 147 that are fluidically connected. The first 122R and second 122R injectors are utilised as the main cleaning implement for the rover 100.

[0075] A first nozzle disk 122 of the first injector 122L is disposed within the first chamber 146, while a second nozzle disk 125 of the second injector 122R is disposed within the second chamber 147. In the detailed embodiment, the disks 122 and 125 are disposed centrally within the respective chambers 146, 147. As will be evident to the skilled addressee, other structures may be utilised as an alternative to the rotatable disks, which are shown in the form of cavi blaster rotatable disks that support the nozzles. However, the applicant has determined that this arrangement provides adequate support for the connected nozzles while allowing the nozzles to be rotated in use, as will be described in further detail below.

[0076] The secondary chamber includes a first side wall 148 and a second side wall 149 that surround the first chamber 146 and second chamber 147 respectively. Both the first side wall 148 and second wall 149 are curved such that the first chamber 146 and second chamber 147 each form circular shapes. In addition, the first wall 148 and second wall 149 are fluidically connected through an opening formed between the first 146 and second 147 chambers.

[0077] A first width of the first chamber 146 is the same as a second width of the second chamber 147. In other words, the diameter of each circular chamber is the same. The width of the opening between the first 146 and second 147 chambers is less than the first and second widths. In other words, the circular side walls that surround the first 146 and second 147 chambers curve in towards one other before connecting such that the width of the opening between the chambers is less than the diameter of each chamber. This shape provides functional advantages, which will be discussed below. To fulfil the capture of the removed debris, the first 146 and second 147 chambers are open towards the surface of the underwater structure in use, and the cavitator top wall 145 closes the first 146 and second 147 chambers away from the surface of the underwater structure in use.

[0078] Two reclaim inlets 144a and 144b are disposed at the vertex of the secondary chamber 141. These inlets are configured to reclaim mixed flow during cleaning operations. One middle reclaim inlet 144c is disposed at the joint between the first 146 and second 147 chambers (i.e. between the first chamber wall 148 and second chamber wall 149). This inlet is also arranged to reclaim mixed flow during cleaning operations. Otherwise put, the first chamber 146 and the second chamber 147 form an "oo" (infinity) shape when viewed from the underside of the rover. The structural arrangement (nozzles and suction force generated at the reclaim inlets 144) enables the reclaimed flow to create vortices inside the cavitator chamber 141. The vortices are beneficial, as they cause mixing of the seawater and removed biofoulings while avoiding the sedimentation of larger debris.

[0079] In the detailed embodiment, the first rotatable nozzle disk 122 and second rotatable nozzle disk 125 are mounted to the top wall 145 of the cavitator 140. The first and second fluid injectors extend away from the top wall 145 of the cavitator 140 and into the first chamber 146.

[0080] The cleaning performance of the first 122L and second 122R injectors is facilitated by the inclusion of cavitation jets, shown in the detailed embodiment as nozzles. The first injector includes a first nozzle 123 which extends along a first fluid injector axis A, and a second nozzle 124 which extends along a second fluid injector axis B and away from the first fluid injector 123. This arrangement of nozzles is such that the first injector 11 rotates in use. In other words, the force generated by each nozzle when discharging fluid causes the fluid injector to rotate in use. The first 123 and second 124 nozzles extend away from the cavitator top wall 145 and into the first chamber 146 (i.e. there is a space between the tip of each nozzle and the cavitator top wall).

[0081] The first 123 and second 124 nozzles are elongate and each include first and second ends. The first end of the first nozzle 123 is mounted to the cavitator top wall 145 (via the disc 122 in the detailed embodiment). The second end of the first nozzle is spaced from the cavitator top wall 145 (i.e. extends away from the cavitator top wall 145 from the mounting position). The first end of the second nozzle 124 is mounted to the cavitator top wall 145 (also via the disc 122 in the detailed embodiment). The second end of the second nozzle 124 is spaced from the cavitator top wall 145 (i.e. extends away from the cavitator top wall 145 from the mounting position).

[0082] The axis A of the first nozzle 123 forms a first acute angle with the cavitator top wall 145. In the detailed embodiment, this angle is around 30 degrees. The axis B of the second nozzle 124 forms a second acute angle with the cavitator top wall 145. In the detailed embodiment, this angle is around 30 degrees. As will be evident to the skilled addressee, alternate angles could be employed between around 15-45 degrees (e.g. 15-20 degrees, 20-30 degrees, 30-45 degrees). However, the applicant has determined that the detailed angle of around 30 degrees provides a useful angle for propulsion and cleaning purposes.

[0083] Injection of water generates a moment of force between the first nozzle 123 and the second nozzle 124 of the first nozzle disk 122. Recoil forces generate a rotary force which enables the rotation of the first nozzle disk 122 (and therefore the nozzles that are mounted to the disk).

[0084] The second injector includes a third nozzle 126 that extends along a third fluid injector axis C, and a fourth nozzle 127 that extends along a fourth fluid injector axis D and away from the third nozzle 126. The third nozzle 126 and the fourth nozzle 127 extend away from the cavitator top wall 145 and into the second chamber 147 (i.e. there is a space between the tip of each nozzle and the cavitator top wall).

[0085] The third 126 and fourth 127 nozzles are elongate and each includes first and second ends. The first end of the third nozzle 126 is mounted to the cavitator top wall 145 (via the disc 125 in the detailed embodiment), and the second end of the third nozzle 125 is spaced from the cavitator top wall 145 (i.e. extends away from the cavitator top wall 145 from the mounting position). The first end of the fourth nozzle 127 is mounted to the cavitator top wall 145 (also via the disc 125 in the detailed embodiment). The second end of the fourth nozzle 127 is spaced from the cavitator top wall 145 (i.e. extends away from the cavitator top wall 145 from the mounting position).

[0086] Furthermore, the axis of the third nozzle 126 forms a first acute angle with the cavitator top wall 145. In the detailed embodiment, this angle is around 30 degrees. The axis of the fourth nozzle 127 forms a second acute angle with the cavitator top wall 145. In the detailed embodiment, this angle is around 30 degrees. As will be evident to the skilled addressee, alternate angles could be employed between around 15-45 degrees (e.g. 15-20 degrees, 20-30 degrees, 30-45 degrees,). However, the applicant has determined that the detailed angle of around 30 degrees provides a useful cleaning mechanism.

[0087] Injection of water generates a moment of force between the third nozzle 126 and the fourth nozzle 127 of the second nozzle disk 124. Recoil forces generate a rotary force which enables the rotation of the first nozzle disk 125 (and therefore the nozzles that are mounted to the disk).

[0088] In the detailed embodiment, both the first 122L and second 122R fluid injectors produce a cleaning ring with a diameter of around 450mm. The rover 100 is able to be moved along the surface of the underwater structure, thereby producing a cleaning width of around 900mm in use.

[0089] Use of the above-mentioned cavitator 140, which can provide contactless cleaning of an underwater surface, is beneficial in that it avoids damaging the surface to which the rover 100 is applied. Based on the applicable biosecurity regulations in some regions, the hull of some vessels is painted with a silicon coating. The silicon coating is a challenge as a result of the fragile nature of the material. Advantageously, the cavitator disclosed herein is able to be used for underwater cleaning of such a coating as the system provides contactless a cleaning tool that is capable of avoiding scratching the coating. In addition, the cleaning apparatus is useful in the situation wherein the paint of the submerged surface to which it is applied includes copper materials. It is particularly important to avoid damage of a surface containing copper materials as the release of copper materials into an underwater environment can cause undesired consequences given the toxic nature of the material in this environment.

[0090] The primary housing 101 will now be described in further detail. The primary chamber 102 of the rover 100 includes a skeleton frame 110. The skeleton frame 110 includes a first frame 1110 disposed towards the open underside of the apparatus (i.e. towards the surface of the underwater structure in use), a second frame 1120 spaced from the first frame 1110, and vertical struts 1130 connecting the first frame 1110 and second frame 1120. The spaces between the frame members are enclosed by panels to construct top walls and side walls of the primary housing 101, while leaving the underside of the primary housing open for cleaning purposes.

[0091] The panels of the primary housing includes a side wall buoyancy sheet 112, top wall buoyancy sheet 113, buoyancy cabinet 114, and a sealing strip 114, which is mounted and configured to form a sealed enclosure for the capture and reclaim of material cleaned from the surface of an underwater structure.

[0092] The first frame includes a first elongate member 1111 and a second elongate member 1112 that extends parallel to the first elongate member 1111. The first 1111 and second 1112 elongate members are spaced from one another at a first spacing. The frame also includes a third elongate member 1113 and fourth elongate member 1114, these members being spaced from one another at a second spacing and extending parallel to one another. The third 1113 and fourth 1114 members extend perpendicular to the first 1111 and second 1112 elongate members. The first frame also includes a fifth elongate member 1115 that is connected to the first elongate member 1111 and the third elongate member 1113. The fifth elongate member 1115 and first elongate member 1111 form an obtuse angle therebetween. The fifth elongate member 1115 and third elongate member 1113 form an obtuse angle therebetween. The frame also includes a sixth elongate member 1116 that is connected to the second elongate member 1112 and third elongate member 1113. The second elongate member 1112 and sixth elongate member 1116 form an obtuse angle therebetween. The sixth elongate member 1116 and third elongate member 1113 form an obtuse angle therebetween.

[0093] The frame also includes a seventh elongate member 1117 that is connected to the first elongate member 1111 and the fourth elongate member 1114. The first elongate member 1111 and seventh elongate member 1117 form an obtuse angle therebetween. The fourth elongate member 1114 and seventh elongate member 1117 also form an obtuse angle therebetween. The frame also includes an eight elongate member 1118 that is connected to the second elongate member 1112 and fourth elongate member 1114. The fourth elongate member 1114 and eighth elongate member 1118 form an obtuse angle therebetween. The second elongate member 1112 and eighth elongate member 1118 also form an obtuse angle therebetween. The second spacing between the first elongate member 1111 and the second elongate member 1112 is greater than the first spacing between the third elongate member 1113 and the fourth elongate member 1114

[0094] The second frame includes a first elongate member 1121 and a second elongate member 1122 that extend parallel to one another and are spaced from one another at a first spacing. The second frame includes a third elongate member 1123 and fourth elongate member 1124, these members being spaced from one another at a second spacing and extending parallel to one another and perpendicular to the first and second elongate members. The second frame includes a fifth elongate member 1125 that is connected to the first elongate member 1121 and third elongate member 1123. The fifth elongate member 1125 and first elongate member 1121 form an obtuse angle therebetween. The fifth elongate member 1125 and third elongate member 1123 form an obtuse angle therebetween.

[0095] The second frame includes a sixth elongate member 1126 that is connected to the second elongate member 1122 and third elongate member 1123. The second elongate member 1122 and sixth elongate member 1126 form an obtuse angle therebetween. The sixth elongate member 1126 and third elongate member 1123 form an obtuse angle therebetween. The second frame includes a seventh elongate member 1127 that is connected to the first elongate member 1121 and fourth elongate member 1124. The first elongate member 1121 and seventh elongate member 1127 form an obtuse angle therebetween. The fourth elongate member 1124 and seventh elongate member 1127 form an obtuse angle therebetween. The eight elongate member 1128 is connected to the second elongate member 1122 and fourth elongate member 1124. The fourth elongate member 1124 and eighth elongate member 1128 form an obtuse angle therebetween. The second elongate member 1122 and eighth elongate member 1128 form an obtuse angle therebetween.

[0096] The struts 1130 include a first strut 1131 and second strut 1132 that connect the third elongate member 1113 of the first frame 1110 to the third elongate member 1123 of the second frame 1120 to form a rectangular front end of the apparatus. The struts 1130 also include a third strut 1133 and fourth strut 1134 that connect the first elongate member 1111 of the first frame 1110 to the first elongate member 1121 of the second frame 1120 to form a first side of the apparatus.

[0097] The struts 1130 include a fifth strut 1135 and sixth strut 1136 that connect the fourth elongate member 1114 of the first frame 1110 to the fourth elongate member 1124 of the second frame 1120 to form a rectangular rear end of the apparatus that is spaced from the front end of the apparatus. The struts 1130 include a seventh strut 1137 and eighth strut 1138 that connect the second elongate member 1112 of the first frame 1110 to the second elongate member 1122 of the second frame 1120 to form a second side of the apparatus that is spaced from the first side. The struts 1130 also include a ninth strut 1139, tenth strut 1140, eleventh strut 1141 and twelfth strut 1142, in which the ninth strut 1139 and tenth strut 1140 are disposed intermediate the third strut 1133 and fourth strut 1134 at the first side of the apparatus, and the eleventh strut 1141 and twelfth strut 1142 are disposed intermediate the seventh strut 1137 and eighth strut 1138 at the second side of the apparatus.

[0098] In the detailed embodiment, the skeleton frame 110 of the primary housing 101 includes welded aluminium extrusions (e.g. tube), although other materials with a different cross section shape may be used for the frame. The structural arrangement of the primary housing 101 enables the mounting of inner and outer components.

[0099] Three handles 111 are mounted on the top of the rover 100 covered by the top buoyancy sheet 113. The arrangement of the handles enables the rover to be simply manipulated and controlled by divers when the rover is not automatically controlled. The handles are easily disassembled and able to be changed into a quick-connection socket to suit a rover carrier.

[00100] To facilitate the underwater cleaning operations, the side wall buoyancy panels 112 and top wall buoyancy panels 113 are mounted to the frame 110 to balance the buoyancy and gravity forces, as well as to align the centre of gravity and buoyancy of the rover. The top wall buoyancy panel 113 is spaced from and parallel to a plane defined by the cavitator top wall 145.

[00101] To counter the weight of the heavier components being disposed towards the stern area of the rover in the detailed embodiment, two additional buoyancy cabinets 114 are mounted at the stern of the rover to minimize the in-water torque generated by the gravity force and buoyancy force. The installation of the two buoyancy cabinets also enables the installation of components that require a waterproof enclosure.

[00102] Inside the primary chamber 102, the extractor 103 includes three reclaim channels fluidically connected to the secondary chamber 141 to facilitate the reclaim of the biofoulings removed by the first and second fluid injectors.

[00103] The reclaim channels include a first reclaim channel 143a that extends from the first reclaim inlet 144a of the first chamber 146, a second reclaim channel 143b that extends from the second reclaim inlet 144b of the second chamber 147, and a third reclaim channel 143c that is connected to the third reclaim inlet 144c. The three reclaim channels are in communication with the main reclaim hose 210.

[00104] To increase the capture efficacy and minimize egression of the removed biofoulings, a sealing strip 115 is mounted at the edge of the cleaning rover 100. The sealing strip 115 in the detailed embodiment is formed from a strip brush constructed from nylon fabric. As will be evident to the skilled addressee, similar materials, such as silicon rubber, could also be used for sealing purposes with the surface that is being cleaned.

[00105] The arrangement of the primary housing 101 facilitates the reclaim of removed biofoulings caused by the motions of rover 100 along with biofoulings that escape from the secondary chamber 141. This two stage chamber design with incorporated reclaim inlets and channels provides adequate capture and reclaiming performance that avoids (or at least significantly reduces) the escape of debris, such that the cleaning apparatus is able to comply with regulations (e.g. those relating to underwater cleaning guidance, local port control and other relevant authorities). Advantageously, this allows for underwater cleaning to take place while avoiding (or at least significantly reducing) the consequences of invasion by biofoulings that would otherwise be released into the environment during underwater cleaning, as well as minimizing the release of toxic materials into the environment.

[00106] In addition, the two chambers provide a pressure difference between the inside and outside of the cleaning rover 100. This enables the rover 100 to adhere to the surface to be cleaned as a result of the suction force generated by the cavitation jet. To capture a record of the effects of cleaning, cameras can be mounted at the ends 180 and 181 of the rover 100.

[00107] To enable the reclaim of biofouling removed from the rover 100, the extractor also includes a splitter 150. Fig. 3 shows the details of the splitter 150. The splitter 150 includes a plurality of apertures 156 and 157 that are disposed in the front face 154, and an aperture (not shown) in the opposite face. The apertures 156 and 157 extend from the front face 154 to the aperture in the rear face, which enables reclaimed biofoulings to be discharged from the primary chamber 102 and the secondary chamber 141 via the splitter to the reclaim hose 210.

[00108] The splitter 150 includes an expanded head 159 disposed towards the front face and a tapered body 153 that tapers towards the rear face. The profile design and the surface treatment of the chamber 153 provide optimal fluid flow characteristics to minimize friction and loss of suction head. The expanded head 159 is connected to the front face 154 and screwed to the skeleton frame 110, while the aperture in the rear face is in communication with the main reclaim hose 210. Three relatively large apertures 156 are disposed in the front face 154 and are connected to the reclaim channels 143 so as to fluidically connect the mixed flow from secondary chamber 141 to the main reclaim hose 210. Three relatively small apertures 157 are disposed in the front face 154 and are connected to the primary chamber 102 so as to reclaim the removed biofoulings from the primary chamber 102 via the main reclaim hose 210. In this example, the removed biofoulings in the primary chamber 102 comprise the debris that escapes from the secondary chamber 141 and the debris removed from an underwater surface caused by the motion of the rover 100. The neck 152 is secured by a pair of clamps to the frame 111. As such, the main reclaim hose 210 is mounted to the rover 100.

[00109] To further improve flexibility regarding different types and grades of biofoulings, a secondary cleaning tool, namely brush reel 130, is included in primary chamber 102 of the cleaning rover 100 to remove biofoulings on an underwater surface. The brush will now be described with reference to Fig. 4.

[00110] The brush reel 130, which is manufactured from nylon fabric and a stainless steel axle, is offset from the cavitator 140 and mounted by bearings 136 in holders 131. A suspension mechanism 132 is provided to control the contact strength and distance between the brush reel 130 and the underwater surface desired to be cleaned. One side of the suspension mechanism is fixed to the housing 101 of the rover through the strut mount 133, while the other side, suspension strut 134, is in communication with the holder 131 via a base mount. The coil spring 135 provides the resilience force for the suspension mechanism 132.

[00111] The brush reel 130 extends between the mounting bearing 136 and is disposed toward the underwater portions desired to be cleaned. Opposite the mounting bearing 136, the other end 137 of the holders 131 are mounted to the elongate member in the primary housing 101, which allows for the holders 131 to pivot and rotate. Inside the holders 131, a reduction gearbox is arranged to control the rotation speed of the brush reel 130. In the detailed embodiment, an electrical motor is used and positioned in the buoyancy cabinet 114 to supply power. As will be evident to the skilled addressee, other kinds of actuation devices could be implemented to drive the brush.

[00112] The biofoulings removed by the brush reel 130 are substantially extracted via the plurality of apertures 157 in front face 154 of the splitter 150. Therefore, debris in the primary chamber 102 is reclaimed via the main reclaim hose 210. In the marine environment, the types of biofoulings adhering to the underwater portions include algae, barnacles and other kinds of shells. In the detailed embodiment, the combination of the cavitator 140 and brush reel 130 allows for the cleaning rover 100 to handle different types of biofoulings that may not be removed using just the cavitator, or just the brush.

[00113] The rover 100 includes wheels. The wheels are provided to enable straight-line and turning movements for the rover. The wheels can be driven by divers (e.g. manually), or, for example by an electrical or a hydraulic motor. The castor wheels 160 are arranged at the stern of the cleaning rover 100, which allows for the rover to be simply moved along a scheduled cleaning path.

[00114] Two swivel castor wheels 161 are also provided. A steering strut 162 is arranged to determine direction. The steering strut 162 can slide within the steering slot 163, which is fixed with the bracket of the swivel wheel 163, to change the orientation of the rover 100.

[00115] To improve the trafficability of the rover 100 when moving on the surface to be cleaned, a height adjustment mechanism 170 is provided to accommodate the distance between the first frame 1110 of the primary housing 101 and the underwater surface to be cleaned. The castor wheels 160 and swivel castor wheels 161 are mounted on corresponding liftable bases 172. The four liftable bases 172 connect the sliding block 174 via a rigid mount. The vertical motion of the wheels 160 and 161 in parallel with the vertical struts 1130 are controlled and constrained by the sliding block 174. The vertical motions of the fixed castor wheels 160 and swivel castor wheels 161 are synchronously controlled by way of the elongate rod 175.

[00116] In this embodiment, byturning the elevation handle 173, the supporting arms 171 will be turned to control the distance of sliding blocks 174 from the top wall 112 of the primary housing 101. The trafficability of the cleaning rover 100 over a rough surface and obstacles is enhanced using the height adjustment mechanism 170. The design of the height adjustment mechanism allows the cleaning operation to be adaptive to the curvature of the surface to be cleaned, such as the hull surrounding the bulbous bow of a vessel.

[00117] When the primary housing 101 and cavitator 140 are lifted or descended from the surface by the liftable mechanism 170, the configuration of the suspension mechanism 132 enables the contact strength and distance between the brush reel 130 and the surface to be controlled.

[00118] An underwater cleaning and reclaim system for removing and reclaiming material from a surface of an underwater structure will now be described with reference to Fig 5. Fig. 5 depicts a schematic view a moored ship 10 and an underwater cleaning system 20. Besides deploying the system from the bank of the wharf 30, the disclosed system can also be used for similar underwater cleaning applications, such as off-shore platforms and other submerged structures.

[00119] The systems includes the rover 100 described above. The system also includes a filtration subsystem, which includes macro filtration system 310 and micro filtration system 320 to filter out the material greater than around 100 gm (e.g. 50 to 150im, 150 to 250m, etc) and around 10 gm (e.g. 5 to10gm, 10 to 20m, etc) in diameter respectively.

[00120] The filtration subsystem includes several containers 330 for storing the material filtered out by the macro filtration device 310 and micro filtration device 320. The system 20 includes an underwater cleaning rover 100, which is deployed from the bank of the wharf in this application, to remove the accumulated biofoulings on the underwater portions of the vessel 10, including the mid-ship hull 11, the hull around bulbous bow 12, as well as the conjunction area around the bow thruster tunnel 13.

[00121] The cleaning rover 100 is supplied with fluid by the cavitation device 120 through the cavitation hose 121. The system 20 also includes a subsystem for reclaiming the biofoulings cleaned from the hull of the vessel 10, rather than discharging the removed biofoulings in the ambient environment 40. To reclaim the removed biofoulings, a trash pump 220 is used to generate a suction force. As will be evident to the skilled addressee, other types of pump may be utilised for this purpose. The trash pump 220 in the detailed embodiment includes internal components that are fit for use in the marine environment and provides the necessary suction head for the application.

[00122] The negative pressure generated by the pump 220 draws the mixed flow, including the seawater and removed biofoulings, from the cleaning rover 100 upwardly through the main reclaim hose 210. The rewind reel 211 is used to manage the main reclaim hose 210 during the operations.

[00123] The system 20 also includes a treatment subsystem to ensure the quality of the discharged seawater 300 in accordance with applicable regulations. The macro filtration device 310 is used firstly to filter out the larger debris. In this example, a rotating drum filter is used, although other kinds of macro filtration device with similar capabilities could be utilised.

[00124] The preliminarily treated effluent is discharged into the micro filtration device 320, which filters out the particulate materials in effluent water larger than around 10 pm in diameter, while avoiding increasing the level of suspended solids in the ambient environment 40.

[00125] Flow meters maybe included in the macro filtration device 310 and micro filtration device 320 to optimise the mixed flow of seawater and removed biofoulings. In the detailed embodiment, the biofoulings filtered out by the macro filtration device 310 and micro filtration 320 are transferred into a container 330 for further disposal to comply with relevant regulations.

[00126] The system 20 comprises a power supply converter 400 to supply electrical power as required. The power supply converter 400 may be capable of accessing power from a mains power source, although an electrical generator could also be used.

[00127] During the underwater cleaning operations, the cleaning rover 100 is deployed from the bank of the wharf 30. In the detailed embodiment, the cleaning rover 100 is manually controlled by divers or the remotely operated vehicle whilst underwater. Meanwhile, the cavitation jet hose 121 is released or withdrawn simultaneously with the reclaim hose 210 managed by the rewind reel 211. Again, the reclaim pump 220 is used to reclaim the biofoulings removed by the cleaning rover 100, which uses the cavitation jet from cavitation device 120 as the cleaning medium. The mixed flow that includes seawater and removed biofoulings is treated in the macro filtration device 310 and the micro filtration device 320 sequentially before discharging the seawater into the surrounding sea 40. The separated debris and small particulate materials are conveyed into the container 330 for storage before being disposed in another manner.

[00128] The arrangement of system components provided in Fig. 5 is for example purposes only. As will be evident to the skilled addressee, the precise arrangement of the system will be dependent on the application and the available area to set-up the system.

[00129] An example method of using the system will now be described with reference to Fig. 5. The system components are set-up and may be commissioned prior to use. When the system is confirmed to be operational, the rover 100 is deployed from the setup site 31. The cleaning rover 100 is carried by a diver or the remotely operated vehicle to the scheduled starting point to prepare the underwater cleaning operation. Meanwhile, the hoses 210 for reclaiming and supplying the cavitation jet 121 may be released synchronously. Once arriving the starting point, the reclaim pump 220 and the filtration devices 310 and 320 may be started. By starting the pump 220, a negative pressure differential will result in the cleaning rover 100 adhering to the surface to be cleaned.

[00130] The underwater cleaning is commenced once the cleaning rover 100 is attached firmly. The associated cleaning tools discussed above operate to remove biofoulings from the underwater surface. After capturing and feeding the mixed flow, which includes seawater and biofoulings, into the filtration devices 310 and 320, the debris are separated for storage in 330. At the same time, the seawater 300 is released to the sea in compliance with applicable regulations and requirements of the relevant stakeholders. The cleaning rover 100 may be controlled to follow a pre-planned cleaning path.

[00131] The system is able to be moved to another site. To do so, operation of the rover is paused. The rover is disengaged from the underwater surface which has been cleaned. Power of the reclaim pump 220 may be decreased gradually. After debris that remain in the main reclaim hose 210 are drained, the reclaim pump 210 in communication with the filtration devices 310 and 320 can be shut down. Operators may manage the hoses while retrieving and lifting the cleaning rover 100.

[00132] Underwater cleaning is finalised when all cleaning tasks have been executed. The operators may then pack up the system components into a carrier and dispose the removed biofoulings. Utilising the above described method allows for the underwater cleaning system 20 to clean the biofouling without releasing those biofoulings into the ambient environment 40, which allows for the system to meet applicable regulations and not impact a local environment.

[00133] The word 'comprising' and forms of the word 'comprising' as used in this description and in the claims does not limit the invention claimed to exclude any variants or additions.

[00134] Modifications and improvements to the invention will be readily apparent to those skilled in the art. Such modifications and improvements are intended to be within the scope of this invention.

Claims (4)

1. Claims

   1 An underwater cleaning apparatus for removing material from a surface of an underwater structure, the apparatus comprising;

   a housing defining a primary chamber, the housing comprising housing side walls that surround the primary chamber, and a housing top wall connected to the housing side walls;

   a cleaner configured to remove the material from the surface of the underwater structure, the cleaner being disposed within the primary chamber of the housing and comprising a cleaner side wall that surrounds a secondary chamber, a cleaner top wall connected to the cleaner side wall and disposed adjacent the housing top wall;

   a fluid injection system comprising:

   a first injector configured to inject fluid into the secondary chamber; and

   a second injector configured to inject fluid into the secondary chamber, the second injector being spaced from the first injector; and

   an extractor configured to extract the material removed from the surface of the underwater structure, the extractor being fluidically connected to the secondary chamber of the cleaner.
2. 2 An underwater cleaning apparatus according to claim 1, wherein the secondary chamber comprises a first chamber and a second chamber that is fluidically connected to the first chamber, and wherein the first injector is disposed in the first chamber and the second injector is disposed in the second chamber.
3. 3 An underwater cleaning apparatus according to claim 2, wherein the first injector is disposed centrally within the first chamber and the second injector is disposed centrally within the second chamber.
4. 4 An underwater cleaning apparatus according to any one of the preceding claims, further comprising a secondary cleaning system, the secondary cleaning system comprising a brush that extends within the primary chamber.

   An underwater cleaning and reclaim system for removing and reclaiming material from a surface of an underwater structure, the system comprising:

   an underwater cleaning apparatus according to any one of claims 1 to 4;

   a cavitation blaster configured to provide fluid to the cleaner via an inlet hose; and

   a pump connected to the apparatus via an extraction hose for pumping fluid and material removed from the surface of the underwater structure from the primary and secondary chambers of the apparatus.