WO2012037602A1

WO2012037602A1 - Boom recovery system

Info

Publication number: WO2012037602A1
Application number: PCT/AU2011/001211
Authority: WO
Inventors: Neil Deryck Bray Graham
Original assignee: Z-FILTER Pty Ltd
Current assignee: Z-FILTER Pty Ltd
Priority date: 2010-09-20
Filing date: 2011-09-20
Publication date: 2012-03-29
Anticipated expiration: 2013-03-20

Abstract

Apparatus (1) for recovery of matter from a body of water, particularly for the disposal of contaminants such as oil from the surface of a body of water. The apparatus (1)may, however, have application to the recovery of other matter from a body of water, such as, for example, marine vegetation, including algae and other seaweeds, as well as garbage and other floating materials. The apparatus (1) comprises a boom assembly (10) for the capture, containment and diversion of the oil to a disposal zone at which it is collected and removed from the body of water. The boom assembly (10) comprises two buoyant booms (11, 12) each having a first end (15) and a second end (17). The two booms (11, 12) are interconnected at their respective first ends (15). More particularly, the first ends (15) of the two booms (11, 12) are each connected to a retrieval system (21). The second respective ends (17) are connected to tow lines (23) from a towing vessel (25) such as a tug boat. The two buoyant booms (11, 12) are angularly moveable with respect to each other about the respective first ends (15) between collapsed and extended conditions. In the extended condition, the two booms (11, 12) are disposed in angular relation to each other to define a containment zone (27) having an entry opening (29) defined between the second ends (17) of the two booms (11, 12). Each boom (11, 12) has a longitudinal extent and comprises a plurality of boom sections (31) flexibly connected one to another along the longitudinal extent of the boom. Each boom section (31) comprises a first buoyant portion (33), a reflector portion (35) supported on the first buoyant portion (33), and orientation means (37) for orienting the first buoyant portion (33) in the body of water for maintaining the reflector portion (35) in an operative condition relative to the water surface.

Description

Boom Recovery System Field of the Invention

This invention relates to recovery of matter from a body of water. More particularly, the invention is concerned with booms for intercepting matter at or near the surface of a body of water and directing the matter to a disposal or collection zone.

The term "recovery" as used herein is intended to include collection, harvesting or otherwise disposing of matter from a body of water.

The invention has been devised particularly, although not necessarily solely, for the disposal of contaminants such as oil from the surface of a body of water. The invention may, however, have application to the recovery of other matter from a body of water, such as, for example, marine vegetation, including algae and other seaweeds, as well as garbage and other floating materials. Such applications include harvesting of materials such as bio-algae for bio diesel. Background Art

The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application. It is known to use floating booms to provide a temporary barrier for the containment and diversion of oil spillages. Once the spilt oil has been contained, or contained and diverted to a disposal zone, there is a need to dispose of the oil. This is usually done by dispersing the oil, typically with use of mechanical and chemical dispersal agents, and/or collecting the oil. The collected oil is usually either transferred to another location for processing or burnt.

While known booms are effective in containing or diverting oil spillages in certain circumstances, they are not normally able to be moved relative to an oil spillage to guide the contained oil towards a disposal zone. This is because the booms are prone to collapsing upon themselves when being subjected to loading (such as when being towed) in a direction lateral to their longitudinal extent. Additionally, while known booms have proved to be reasonably effective in calm water conditions, they can be less effective in disturbed water conditions with increasing wave height as oil can wash over the top of the booms in such conditions.

In relation to harvesting of algae in a large expanse of water, the use of large algae harvesters has not proved to be effective in limiting the harvesting to only the band of water containing the algae on the surface, or just below the surface. Further, rigid booms attached to the harvesters are considered to be too cumbersome, heavy and expensive to cover large areas for harvesting. They are also subject to extreme loads in waves and as the booms have no elastic qualities cannot accommodate the cyclic shock loads imposed by the wave front without in some cases permanent deformation or mechanical damage.

It is against this background and the problems and difficulties associated therewith that the present invention has been developed.

Disclosure of the Invention

According to a first aspect of the invention there is provided a boom for intercepting matter at or near the surface of a body of water, the boom comprising a plurality of boom sections connected one to another for limited angular movement therebetween.

The matter being intercepted may comprise target material in the body of water or matter in which target material has been collected. In the latter case, the matter may comprise discrete elements in which target material has been collected, or a mass or bulk quantities of material in which target material has been collected. The target material may comprise contaminant material in the body of water or material to be harvested from the body of water. In one particular application of the boom relating to the disposal of contaminants such as oil from the surface of a body of water, the matter to be intercepted may comprise a plurality of discrete collection elements deployed in the area of contamination of the body of water. The discrete collection elements may collect the contaminant material in any appropriate way, such as for example by absorption of contaminant material or through attachment of contaminant material to the collection elements.

The discrete collection elements, or at least one or some of them, may incorporate a feature which facilitates tracking thereof. The feature may comprise, for example, a radio-frequency identification device for the purpose of identification and tracking by radio waves. Other tracking technologies may, of course, also be used. Alternatively, or additionally, a separate tracking device may be deployed with a group of discrete collection elements for the purposes of providing an indication of the location of the group of elements. Preferably, the boom has a longitudinal extent and further comprises connection means for flexibly connecting the boom sections one to another for limited angular movement therebetween, each connection means comprising first and second flexible connections spaced apart laterally with respect to the longitudinal extent of the boom. Preferably, the first and second flexible connections each comprise a flexible element such as a strap, rope or cable.

Each boom section may be configured to abut an adjacent boom section to limit angular movement therebetween in a generally horizontal plane

There may be two abutting conditions limiting angular movement in opposed directions.

Preferably, the boom sections are configured at their ends for abutting engagement with adjacent boom sections. For this purpose, the ends of the boom sections may be provided with resiliently compressible bumper portions. Typically, each end has two bumper portions for limiting angular movement in opposed directions.

Preferably, the flexible connection and abutting engagement between adjacent boom sections serve to constrain relative movement between the adjacent boom sections. This serves to also constrain the boom sections so that one does not ride over another. Each boom section may comprise a first buoyant portion, a reflector portion supported on the first buoyant portion and orientation means for orienting the first buoyancy portion in the body of water for maintaining the reflector portion in an operative condition relative to the water surface. In one arrangement, the orientation means may comprise an outrigger attached to the first buoyant portion. In an another arrangement, the orientation means may comprise ballast means below the first buoyant portion.

The outrigger may comprise a second buoyant portion and framework extending between the first and second buoyant portions. The first buoyant portion may be of tubular configuration. Similarly, the second buoyant portion may be of tubular configuration. In particular, the first and second buoyant portions may each be constructed of plastic pipe closed at the ends thereof.

The reflector portion may comprise an elongate element presenting a reflector surface. The elongate element may be configured as a blade. The reflector surface may be configured as a concave surface. The concave surface may comprise a generally parabolic surface.

Preferably, the reflector portions of the interconnected boom sections cooperate to provide a modular reflector extending along the length of the boom. The modular portions are configured to reflect impinging wave motion, thereby rendering the wave activity less likely to wash over the top of the boom section.

According to a second aspect of the invention there is provided a boom for intercepting matter at or near the surface of a body of water, the boom having a longitudinal extent and comprising a plurality of boom sections, connection means flexibly connecting the boom sections one to another for limited angular movement therebetween, each connection means comprising first and second flexible connections spaced apart laterally with respect to the longitudinal extent of the boom. According to a third aspect of the invention there is provided a boom for intercepting matter at or near the surface of a body of water, the boom comprising a plurality of boom sections, connection means flexibly connecting the boom sections one to another for limited angular movement therebetween, each boom section comprising a first buoyant portion, a reflector portion supported on the first buoyant portion and orientation means for orienting the first buoyancy potion in the body of water for maintaining the reflector portion in an operative condition relative to the water surface.

The boom according to any one of the first, second or third aspects of the invention may be used for disposal of matter from a body of water, with the boom being used to intercept the matter and direct it to a disposal zone. Typically, the matter is collected at the disposal zone and removed from the body of water

According to a fourth aspect of the invention there is provided a boom section for a boom according to any one of the first, second or third aspects of the invention According to a fifth aspect of the invention there is provided a boom section comprising a first buoyant portion, a reflector portion supported on the first buoyant portion and orientation means for orienting the first buoyancy portion in the body of water for maintaining the reflector portion in an operative condition relative to the water surface. Preferably, the boom section according to the fifth aspect of the invention is adapted to be connected to one or more further boom sections to provide a boom.

According to a sixth aspect of the invention there is provided a boom assembly comprising two booms for intercepting matter on a body of water, the two booms being interconnected at one respective end, each boom being in accordance with any one of the first, second or third aspects of the invention.

According to a seventh aspect of the invention there is provided a boom assembly comprising two booms for intercepting matter on a body of water, the two booms being interconnected at one respective end, each boom comprising a plurality of boom sections connected one to another for limited angular movement therebetween. The boom assembly according to the sixth or seventh aspect of the invention may be used for disposal of matter from a body of water, with the boom assembly being used to intercept the matter and direct it to a disposal zone. Typically, the matter is collected at the disposal zone and removed from the body of water. According to an eighth aspect of the invention there is provided apparatus for disposal of matter from a body of water using a boom according to any one of the preceding aspects of the invention.

According to a ninth aspect of the invention there is provided apparatus for disposal of matter from a body of water using a boom assembly according to any one of the preceding aspects of the invention.

According to a tenth aspect of the invention there is provided a method of disposal of matter from a body of water using apparatus according to the eighth or ninth aspect of the invention.

According to an eleventh aspect of the invention there is provided a method of disposal of matter from a body of water comprising placement of a boom according to any one of the preceding aspects of the invention on the surface of the body of water and moving the boom relative to the body of water to intercept the matter.

According to a twelfth aspect of the invention there is provided a method of disposal of matter from a body of water comprising placement of a boom according to any one of the preceding aspects of the invention on the surface of the body of water and moving the boom relative to the body of water to cause the matter to move towards a disposal zone.

Typically, the boom is moved relative to the body of water by propelling it over the surface of the body of water it. The boom may be so propelled in any appropriate way, such as by hauling or towing the boom.

In circumstances where the body of water is moving, the boom may be deployed in the body of moving water without the need for propulsion. Such an arrangement may be applicable where the body of water is under the influence of tidal conditions or where the body of water a is river or river delta having a flow condition.

Preferably, the boom is held and oriented via tension applied typically through a flexible link such as a rope or cable to the towing vessel or mooring point in a stream. In other words, the rope or cable is used to hold and steer the boom sections through the water to intercept and retrieve the materials.

The flexible link (the rope or cable) provides the flexibility needed to accommodate the movements generated by the wave action and still pull the array through the body of water to collect the materials Preferably, the flexible link (the rope or cable) is coupled to the boom assembly at a location below the central axis of the reflector to counter the tipping force of the reflector moving through the water as the reflector cuts into the water. Typically, the flexible link (the rope or cable) is connected to an arm disposed below the central axis of the reflector acts. With this arrangement, the flexible link functioning as the towing line can provide the tension to hold the boom in shape and hold the boom into the waves in an even curve to evenly bring the materials back to the collection point.

Preferably, the booms can be oriented to the flow by the use of controllable surfaces to steer the booms between extended and collapsed conditions. In the collapsed condition the booms may assume a folded form for transport and in the extended condition the booms may be held in a "V" form for harvesting.

According to a thirteenth aspect of the invention there is provided a boom assembly comprising two booms movable between extended and collapsed conditions with respect to each other, at least one of the booms having a controllable surface to interact with relative water flow to steer the boom and thereby cause movement of the boom assemblies between the extended and collapsed conditions.

According to a fourteenth aspect of the invention there is provided a method of disposal of matter from a body of water comprising placement of two booms according to any one of the preceding aspects of the invention on the surface of the body of water in angular relation to define a containment zone therebetween, and moving the booms relative to the body of water to cause the matter to be collected in the containment zone and moved towards a disposal zone. Brief Description of the Drawings

The invention will be better understood by reference to the following description of several specific embodiments thereof as shown in the accompanying drawings in which:

Figure 1 is a schematic perspective view of a boom assembly according to a first embodiment under tow;

Figure 2 is a schematic view of the trailing end of the boom assembly;

Figure 3 is a fragmentary plan view of one boom forming part of the boom assembly, the boom comprising a plurality of boom sections connected one to another; Figure 4 is a schematic plan view of two of the boom sections connected together, illustrating in particular a flexible connection between the two boom sections;

Figure 5 is a schematic plan view of one boom section;

Figure 6 is a schematic side view of one boom section;

Figure 7 is a view similar to Figure 6 with the exception that the boom section is depicted in relation to the surface of a body of water in which the boom section floats;

Figure 8 is a view similar to Figure 7 illustrating in particular deflection of water in the path of the boom section;

Figure 9 is a view similar to Figure 8 except that a tipping force to which the boom section is exposed in use is depicted;

Figure 10 is a schematic view of a boom assembly according to a second embodiment in an operative condition; Figure 11 is a schematic view of the boom assembly according to the second embodiment in a collapsed condition;

Figure 12 is a schematic plan view of a boom assembly according to a third embodiment under tow; Figure 13 is a schematic view of a boom assembly according to a fourth embodiment under tow;

Figure 14 is a schematic view of a boom assembly according to a fifth embodiment under tow;

Figure 15 is a schematic view of a boom assembly according to a sixth embodiment under tow;

Figure 16 is a schematic view of a boom assembly according to a seventh embodiment;

Figure 17 is a schematic view of a boom assembly according to an eighth embodiment; Figure 18 is a schematic view of a boom assembly according to a ninth embodiment under tow;

Figure 19 is a schematic side view of a support for tow lines used with the boom assembly according to the ninth embodiment;

Figure 20 is a schematic view of a boom assembly according to a tenth embodiment;

Figure 21 is a schematic view of a boom assembly according to an eleventh embodiment in a moored condition in flowing water;

Figure 22 is a schematic view of a boom assembly according to a twelfth embodiment in a moored condition in flowing water; Figure 23 is a schematic perspective view of a recovery system utilising, in combination, a boom assembly according to any one of the embodiments and a recovery apparatus; Figure 24 is a fragmentary view of part of the arrangement shown in Figure 23;

Figure 25 is a schematic plan view of part of the arrangement shown in Figure 23;

Figure 26 is a schematic side view of a coupling between the boom assembly and the recovery apparatus as shown in combination in Figure 23; Figure 27 is a view similar to Figure 26 but depicting also a retrieval system;

Figure 28 is a schematic side view depicting the retrieval system;

Figure 29 is a schematic side view of a scoop forming part of the retrieval system;

Figure 30 is a schematic side view of the upper end of the retrieval system, illustrating retrieved discrete collection elements being discharged into a hopper; Figure 31 is a schematic side view of the hopper;

Figure 32 is a schematic view depicting delivery of the retrieved discrete collection elements from the hopper to a circulating tube structure for processing;

Figure 33 is a schematic side view of the circulating tube structure for processing the retrieved discrete collection elements; and Figure 34 is a fragmentary perspective view of the circulating tube structure.

Best Mode(s) for Carrying Out the Invention

The embodiments are each directed to apparatus 1 for use in the disposal of an oil spillage on a body of water 3 having a water surface 5.

The apparatus 1 comprises a boom assembly 10 for the capture, containment and diversion of the oil to a disposal zone at which it is collected and removed from the body of water 3. More particularly, the oil is collected by absorption in discrete collection elements deployed onto the water surface 5 in the area of the oil spill. The discrete collection elements may be of any appropriate form such as, for example, flakes, powder, particles, balls, discrete pieces of material, pads, and pillows. The discrete collection elements may be of any appropriate material, including wool. It is believed that coarse wool may be particularly appropriate. Alternatively, the oil may be collected by absorption in, or attachment to, a mass or bulk quantities of material, including for example wool fibres.

The boom assembly 10 is used in the retrieval of the collection elements from the body of water 3. While the collection elements may be single use, it is preferable that they are of a form which permits absorbed oil to be extracted after retrieval and then the collection elements returned to the body of water for collection of further oil.

The discrete collection elements may be laid out in a group or area; however, the sea conditions may move the collection elements along with the oil slick in an uncontrolled or chaotic manner dependent upon wind tides and currents. This could mean the loss of the absorbent materials and the contamination of the oceans. To overcome these difficulties, the discrete collection elements, or at least one or some of them, may incorporate a feature which facilitates tracking thereof. In one arrangement, a tracking device, such as an RFID or a radio beacon, is inserted into the body of each of the discrete collection elements concerned. In another arrangement, one or a series of buoyant tracking devices such as radio beacons are be deployed in the ocean with the collection elements, typically within a group of deployed collection elements.

The boom assembly 10 comprises two buoyant booms 11, 12 each having a first end 15 and a second end 17. The two booms 11 , 12 are interconnected at their respective first ends 15. More particularly, the first ends 15 of the two booms 11 , 12 are each connected to a retrieval system 21 , the purpose of which will be explained later. The second respective ends 17 are connected to tow lines 23 from a towing vessel 25 such as a tug boat. While not shown in the drawings, elevation systems (such as ski poles of the type used with a water ski boat) may be required to support the tow lines 23 in an elevated condition above the water surface. For larger installations with longer distances between the towing vessel 25 and the boom 11, 12, floatation devices may be employed to hold the tow line 23 out of the water and move with the tow line. In addition, these flotation devices may be positioned so as to provide another towing point back to the line of each boom 11, 12. In this way the loads can be more evenly distributed along the length of the booms

The two buoyant booms 11, 12 are angularly moveable with respect to each other about the respective first ends 15 between collapsed and extended conditions. In the collapsed condition, the two booms 11 , 12 are disposed alongside each other to extend generally in a common direction to facilitate towing for transportation to and from the site of intended use with minimum resistance to movement. In the extended condition, the two booms 11 , 12 are disposed in angular relation to each other to define a containment zone 27 having an entry opening 29 defined between the second ends 17 of the two booms 11, 12.

Each boom 11 , 12 has a longitudinal extent and comprises a plurality of boom sections 31 flexibly connected one to another along the longitudinal extent of the boom.

Each boom section 31 comprises a first buoyant portion 33, a reflector portion 35 supported on the first buoyant portion 33, and orientation means 37 for orienting the first buoyant portion 33 in the body of water for maintaining the reflector portion 35 in an operative condition relative to the water surface, as will be explained in more detail later and as depicted in Figures 7, 8 and 9. In this embodiment, the orientation means 37 is configured as an outrigger 39 attached to the first buoyant portion 33. The outrigger 39 comprises a second buoyant portion 41 spaced from the first buoyant portion 32 and connected thereto by framework 43.

The first buoyant portion 33 comprises a tubular element 45 closed at the ends thereof, and the second buoyant portion 41 also comprises a tubular element 47 closed at the ends thereof. In this embodiment, the tubular elements 45, 47 comprise plastic pipe, and more particularly PVC pipe. The first and second buoyant portions 33, 41 may, of course, be of any other appropriate construction.

The reflector portion 35 comprises an elongate element 51 presenting an outer reflector surface 53. With this arrangement, the elongate element 51 is configured as a blade 55. The reflector surface 53 is configured as a concave surface and in the arrangement illustrated is generally parabolic. Bracing 57 extends between the framework 43 and the upper edge of the blade 55.

The outrigger 39 may incorporate weight on the framework 43 or second buoyant portion 41 to bias the outrigger into a position in which it is supported on the water surface 5 to counteract upsetting forces that might be imparted by wave motion and also by the effect of the blade 55 biting into the body of water 3 as it advances. In the arrangement shown, the weight is provided by a physical weight 59 (shown only in Figure 9). In other arrangements, the weight could be provided by water contained within specific compartments in the second buoyant portion 41 or by additional elements fitted to the framework 43.

The boom sections 31 are configured at their ends for abutting engagement with adjacent boom sections. In the arrangement illustrated, the ends of the boom section 31 are provided with bumper portions 60. The bumper portions 60 comprise first bumper portions 61 at the ends of the first buoyant portion 33 and second bumper portions 62 at the ends of the second buoyant portion 41. With this arrangement, the first bumper portion 61 and the second bumper portion 62 at each end of a respective boom section 31 are spaced apart in a generally horizontal direction.

The bumper portions 60 are resiliently compressible to accommodate limited angular movement between the boom sections 31.

The boom sections 31 are adapted to be flexibly connected one to another by connection means 70. The connection means 70 are adapted to facilitate limited angular movement between adjacent boom sections 31. In the arrangement illustrated, each connection means 70 comprises a first flexible connection 71 extending between the first buoyant sections 33, and a second flexible connection 72 extending between the second buoyant portions 41. In this embodiment, the first and second flexible connections 71, 72 each comprise a flexible strap 73.

When adjacent boom sections 31 are interconnected, the respective first bumper portions 61 are in abutting relation and the respective second bumper portions 62 are in abutting relation, as shown in Figure 4. The flexible straps 73 and the resiliently compressible bumper portions 60 cooperate to permit angular movement between the boom sections 31 in a generally horizontal plane. In particular, the bumper portions 60 can yieldingly resist the angular movement and the flexible straps 73 can flex to accommodate the angular movement.

With this arrangement, the boom sections 31 can assume a straight condition in which they are aligned axially along the longitudinal extent of the respective boom, and an angular condition in which they establish a buckle or curvature in the longitudinal extent of the boom, as depicted in Figure 1 of the drawings. The flexible connections 71 , 72 together with the bumper portions 60 cooperate to allow the limited angular movement. Because the angular movement is limited, the extent to which each boom 11 , 12 can bend to establish the curvature is limited and thus the respective boom cannot fold inwardly upon itself; that is, the extent to which each boom 11, 12 can bend to establish the curvature is limited. The flexible connections 71, 72 also allow angular movement of the interconnected boom sections 31 in a generally vertical plane, thereby permitting the interconnected boom sections 31 to rise and fall, and to articulate one with respect to another, to accommodate wave motion and like disturbances on the water surface 5. With this arrangement, the articulation between interconnected boom sections 31 is facilitated by the flexible connections 71 , 72 but is not necessarily restrained by the resiliently compressible bumper portions 60. The resiliently compressible bumper portions 60 do not function to resist angular movement of the interconnected boom sections 31 in a generally vertical plane in the same manner as they function to resist angular movement of the interconnected boom sections 31 in a generally horizontal plane. More particularly, the abutting first bumper portions 61 and the abutting second bumper portions 62 of adjacent boom sections 31 can roll on each other as the interconnected boom sections undergo angular movement of in a generally vertical plane. When the boom sections 31 are flexibly connected one to another, the reflector portions 35 cooperate to form a modular reflector 80. When the boom assembly 10 is towed in the manner illustrated in Figure 1 , the flexible connections allow each boom 11, 12 to bend to assume the curvature depicted but prevent the booms from collapsing upon themselves or folding further inwardly under the influence of the towing forces. The flexible connections 71 , 72 also allow adjacent boom sections 31 to articulate one with respect to another to rise and fall with wave action at the surface 5 of the body of water 3.

When the boom sections 31 are connected one to another, the reflector portions 35 cooperate to provide the modular reflector 80 which is presented to oncoming water as the boom assembly 10 is towed.

As the boom assembly 10 is towed through a body of water 3 in which the discrete collection elements have been deployed, the floating discrete collection elements can enter the containment zone 27 through the leading entry opening 29. Once within the containment zone 27, the discrete collection elements are deflected and guided towards the retrieval system 21 at the trailing end of the boom assembly 10. In Figure 2, arrows identified by reference numeral 81 indicate the general path of discrete collection elements within the containment zone 27. The modular reflector 80 provides a barrier confining the discrete collection elements to the containment zone 27. The reflector surfaces 53 of the reflector portions 35 have the effect of reflecting wave motion impinging upon the reflector surfaces 53 at the angle of reflection. This returns the waves, reflecting them back to the centre of the collection area 27, and reduces the likelihood of waves washing over the modular reflector 80 and allowing the discrete collection elements to escape from the containment zone 27. A further particular advantage of the profile of the reflector surface 53 is that it reflects oncoming water as the respective boom 11 , 12 moves through the body of water. This can be best seen with reference to Figures 2, 8 and 9 of the drawings. In Figures 8 and 9, the advancing boom moving in a first direction depicted by arrow 91 produces an apparent water flow in an opposite direction as depicted by arrows 92. The lower portion 55a of the blade 55 is immersed below the water surface 5 and effectively scrapes the upper portion of the water surface such that oncoming water impinging upon the reflector surface 53 is reflected forwardly as depicted by arrows 93. This forward reflection of water is useful for several reasons. One is that it assists the water below the surface to climb and be pushed up the advancing face of the blade 55, flushing and cleaning the face with the deeper fresh water at all times. Secondly, it creates a pressure wave (constituted by an upwelling of water) in front of the reflector face 53 that forces the contaminants forward of the blade 55 and tumbles them back into the containment zone 27, at least in close proximity to the booms 11, 12. Additionally, the reflected water serves to direct any discrete collection elements approaching the booms 1, 12 inwardly in a line off the face as depicted in Figure 2, forming a wave that moves them to a collection zone 22 adjacent the retrieval system 21 , thereby preventing an accumulation of discrete collection elements against the face of the booms. The reflected wave is depicted in Figure 2 by lines identified by reference numeral 96. This line of contaminates is then forced along the length of the booms 11, 12 back to a collection zone 22 or an exit point between the respective ends 15. The oncoming (relatively deeper) water below the blade 55 is unaffected, as depicted by arrows 95 in Figures 8 and 9.

As described earlier, the outrigger 39 incorporate weights 59 on the framework 43 or second buoyant portion 41 to bias the outrigger 39 into a position in which it is supported on the water surface 5 to counteract upsetting forces that might be imparted by wave motion and also by the effect of the lower portion 55a of the blade 55 biting into the body of water as it advances. Such an upsetting force is depicted by arrow 97 in Figure 9, and the counteracting force is delivered downwardly by weight 59. As the boom assembly 10 is towed through the body of water, the discrete collection elements are directed towards the retrieval system 21, at which point they are removed from the body of water and the collected oil extracted. Typically, the retrieval system 21 would comprise a mechanical system for retrieving the discrete collection elements. Other arrangements are, however, also possible, including manual collection arrangements such as scoop nets. Referring now to Figures 10 and 11 , there is shown a boom assembly 100 according to a second embodiment. The boom assembly 100 according to the second embodiment is similar in many respects to the boom assembly 10 according to the first embodiment and so corresponding reference numerals are used to identify similar parts. In this second embodiment, the second end 7 of each boom 11 , 12 is fitted with a directional control device such as a rudder 101 which provides a controllable surface and which can be manipulated to facilitate movement of the boom assemblies between the extended condition defining the containment zone 27 (as depicted in Figure 10) and a collapsed condition (as depicted in Figure 11). In the collapsed condition, the two booms 11 , 12 are disposed alongside each other to extend generally in a common direction to facilitate towing of the boom assembly for transportation to and from the site of intended use. The booms are caused to move between the extended and collapsed conditions by operation of the rudders 101. Referring now to Figure 12, there is shown a boom assembly 105 according to a third embodiment. The boom assembly 105 according to the third embodiment is similar in many respects to the boom assembly according to the second embodiment 100 and so corresponding reference numerals are used to identify similar parts. In the boom assembly 105 according to the third embodiment, not only are there tow lines 23 extending from the towing vessel 25 to the booms 11 , 12 but there is a further tow line 107 extending from the towing vessel 25 to the retrieval system 21. The purpose of the additional tow line 111 is to relieve longitudinal towing forces exerted on the booms 11, 12.

Referring now to Figure 13, there is shown a boom assembly 110 according to a fourth embodiment. The boom assembly 110 accordingly the fourth embodiment is similar in many respects to the boom assembly 105 according to the third embodiment except that there is shown a processing system 120 for processing the discrete collection elements which have been retrieved to extract collected oil therefrom.

In this embodiment, the processing system 120 is accommodated on a vessel 121. The boom assembly 105 is separated from the collection vessel 121 and connected thereto by a flexible connection 123 such as a tow line. In the arrangement illustrated, the flexible connection 123 is an extension of the tow line 1 0. A further collection device 125 attached to the collection vessel 121. The rigid collection device 125 comprises rigid booms 127 defining a further collection zone 129. With this arrangement, discrete collection elements collected by booms 11 and 12 are moved to the collection zone 129 and recaptured by the rigid booms 125 attached to the collection vessel 120. The separation and flexible connection between the boom assembly 10 and the collection vessel 121 provided by the flexible connection 123 accommodates differential in movement between the boom assembly 10 and the collection vessel 123.

Referring now to Figure 14, there is shown a boom assembly 140 according to a fifth embodiment. The boom assembly 140 according to the fifth embodiment is similar in many respects to the boom assembly 10 according to the first embodiment except that there are fewer boom sections 31 assembled to construct the booms 11 , 12.

Referring now to Figure 15, there is shown a boom assembly 150 according to a sixth embodiment. The boom assembly 150 according to the sixth embodiment is similar in many respects to the boom assembly 10 according to the first embodiment. In this sixth embodiment, there are two towing vessels, 25a and 25b, with each boom 11 , 12 being connected to a respective towing vessel. The use of several towing vessels may facilitate operation of a larger boom assembly.

Referring now to Figure 16, there is shown a boom assembly 160 according to a seventh embodiment. The boom assembly 160 according to the seventh embodiment is similar in many respects to the boom assembly 10 according to the first embodiment and corresponding reference numerals are used to identify similar parts. In this seventh embodiment, weight is provided on the framework 43 to bias the outrigger 39 into a position in which it is supported on the water surface 5 to counteract upsetting forces that might be imparted by wave motion and also by the effect of the blade 55 biting into the body of water as it advances. In the arrangement shown, the weight is an additional element 161 fitted to the framework 43. The additional element 161 may be adapted to receive and discharge water in a controlled manner in order to regulate its buoyancy. Other components of the boom sections 31 may also be adapted to receive and discharge water in a controlled manner in order to regulate their buoyancy. This can be advantageous to achieve a reduction in the overall mass of the boom sections 31 for transportation out of the water and towing in the water. Once the boom sections 31 are deployed in the water and additional weight is required, water can be introduced as necessary.

Referring now to Figure 17, there is shown a boom assembly 170 according to an eighth embodiment. The boom assembly 170 according to the eighth embodiment is similar in many respects to the boom assembly 160 according to the seventh embodiment, except that it is provided with a tow arm 171 presenting a tow point 173 below the blade 55. Such a tow configuration may reduce, and possibly even avoid, the need for weight as provided on the framework 43 to bias the outrigger 39 into a position in which it is supported on the water surface 5 to counteract upsetting forces that might be impacted by wave motion.

While the tow ami 171 has been described in relation to the boom assembly 170 according to the eighth embodiment, it may have application to any of the other embodiments, as appropriate.

Referring now to Figures 18 and 19, there is shown a boom assembly 180 according to a ninth embodiment. The boom assembly 180 according to the ninth embodiment is similar in many respects to the boom assembly 105 according to the third embodiment and corresponding reference numerals are used to identify similar parts.

In the boom assembly 180 according to the ninth embodiment, there are two lateral tow lines 23 extending from the towing vessel 25 to the booms 11, 12, as well as a further central tow line 1 0 extending from the towing vessel 25 to the retrieval system 21. Additionally, there are intermediate tow lines 181 extending between each lateral tow line 23 and the respective boom 11, 12. The purpose of the intermediate tow lines 181 is to relieve longitudinal towing forces exerted on the booms 11, 12. In this embodiment, the connections between each additional tow line 181 and the respective tow line 23 is provided by a buoyant support 183 as shown in Figure 19. Each buoyant support 183 comprises a hull 185 and a mast 187 on which are mounted rotatable coupling collars 189 providing attachment points for the respective tow lines 23. The buoyant supports 183 assist in holding the various tow lines out of the water and also assist in maintaining the required alignment of the tow lines.

Referring now to Figure 20, there is shown a boom assembly 190 according to a tenth embodiment. The boom assembly 190 according to the tenth embodiment does not have an outrigger as was used in previous embodiments but rather employs a ballast system 191 for maintaining the orientation of the boom section 31. The ballast system 191 is configured as a keel 193 incorporating a ballast weight 195.

In the previous embodiments, the respective boom assembly was adapted to be drawn through the body of water 3, typically by towing it through the water. Other forms of propulsion may also be possible

There may be circumstances where there is contamination or matter to be removed from a body of moving water. In such circumstances, it may be possible to deploy the boom assembly in the moving water without the need to actually move the boom assembly. In such an arrangement, it may be possible to moor or anchor the boom assembly in the moving water and rely on the flow of water to carry matter into the confinement area of the boom assembly. Several such arrangements are depicted in the next two embodiments.

Referring now to Figure 21 of the drawings, there is shown a boom assembly 200 according to an eleventh embodiment. In this eleventh embodiment, second end 17 of the booms 11 , 12 may be tethered to moored structures 201 by mooring lines 203. With such an arrangement, the boom assembly 200 is able to swing to follow any directional change of water flow.

Referring now to Figure 22, there is shown a boom assembly 205 according to a twelfth embodiment. The boom assembly 205 according to the twelfth embodiment is similar in many respects to the boom assembly 10 according to the first embodiment, with the exception that the towing vessel 23 is not moving but rather is moored or anchored at location 207 in the body of water. As with the previous embodiment, the boom assembly 205 can swing with changes in directional flow of the water.

As previously mentioned, the apparatus 1 is typically used in conjunction with a retrieval system 21 for recovery of the discrete collection elements from the body of water.

Referring now to Figures 23 to 34 of the drawings, there is shown a further recovery apparatus 210 which is used in conjunction with the apparatus 1 and which incorporates the retrieval system 21.

The recovery apparatus 210 is incorporated in a floating structure 211 located at the trailing end of the boom assembly 10.

A coupling 213 is provided between each boom 11, 12 of the boom assembly 10 and the floating structure 211. The coupling 213 is adapted to accommodate relative movement between the respective booms 11 , 12 of the boom assembly 10 and the recovering structure 211.

In particular, the couplings 213 isolates the boom assembly 10 from the floating structure 211, as the boom assembly 10 will float on the surface 5 of the body of water 3 and react with the waves, thereby remaining on or close to the water surface 5 to ensure that the tops of the blades 55 always remain above water, thus trapping the contaminants within the containment area 27.

By contrast, the floating structure 211 will move with the waves and yet be driven by its mass to move up more and down more or less with the passing of each wave front. This may mean that as the floating structure 211 is moving up from the last wave, the booms 11 and 12 may be moving down; accordingly, there is a need to disconnect their movement one from the other. The couplings 213 serve this purpose. Each coupling 213 comprises a track 217 mounted vertically on the recovery structure 151 and a carriage 219 connected to the track 217 for movement therealong. The respective boom 11, 12 of the boom assembly 10 is connected to the carriage 219, the arrangement being that the carriage 219 can move vertically along the track 217 in unison with rise and fall motion of the respective boom 11 , 12 in response to wave activity. With this arrangement, the coupling 213 maintains a connection between the boom assembly 10 and the recovery structure 211 while accommodating relative rise and fall movement therebetween in response to wave action. The retrieval system 21 is adapted to scoop discrete collection elements from the body of water 3 and deliver them to a processing station 230 on the floating structure 211. In Figures 28 to 32, the discrete elements are identified by reference numeral 231.

The retrieval system 21 comprises a plurality of scoops 233 movable along an elevating path from a lower collection location 235 within the body of water 3 to an upper discharge location 237 on the floating structure 151. The scoops 233 are mounted in spaced relation on a cyclically moveable structure 237 incorporated in the coupling 211, as depicted in Figure 27. In the arrangement shown, the cyclically movable structure 237 comprises an endless chain structure 241 following a moving path around a series of sprockets 243, at least one of which is driven in order to drive the endless chain structure 241 through its endless path. The endless path of the endless chain structure 241 incorporates an elevating path section 245 which extends between the lower collection location 235 and the upper discharge location 237. Each scoop 233 is configured as a basket 235 having an open top 237. Each basket 235 is perforated to permit water to drain from it. The baskets 235 may be made of mesh for this purpose.

As the baskets 235 move with the cyclically movable structure 237, they are immersed in the body of water 3 and successively conveyed to the lower collection location 235 at which they encounter discrete collection elements 231 congregating at that location. The baskets 235 move successively through the body of water 3 to scoop congregating discrete collection elements 231 at the collection location 235 and convey them upwardly along the elevating path section 245 towards the discharge location 237. Because of the perforated construction of the baskets 235, water gathered with the discrete collection elements 231 at the collection zone 235 can drain from the baskets as they move upwardly towards the discharge location 237.

Each basket 235 can only accommodate a certain number of discrete collection elements 231. In this way, the baskets 235 can regulate the number of discrete collection elements 231 delivered to the processing station 230. Additionally, the rate of travel of the cyclically movable structure 237 assists in regulating the rate of delivery of discrete collection elements 231 to the processing station 230.

Any discrete collection elements 231 that are lifted by each basket 235 beyond the capacity of the basket merely toppled from the basket back into the body of water 3 prior to arrival of the basket at discharge location 237. This is depicted schematically in Figure 28 where toppling elements are identified by reference numeral 231a. This further assists in regulating the rate of delivery of discrete elements 231 to the processing station 230. At the discharge location 237, the retrieved discrete collection elements 231 are delivered into a hopper 240 at the processing station 230. At the processing station 230, oil captured by the discrete collection elements 231 can be removed and the elements then returned to the body of water 3 for further oil collection if so desired. Any suitable arrangement can be used for removal of the collected oil from the discrete collection elements 231.

In this embodiment, the collected oil is removed by subjecting the discrete collection elements 231 to a separation process involving pressing and filtering actions. In the arrangement shown, the separation process is configured as a process of the type described in International application PCT/AU2007/000820, the contents of which are incorporated herein by way of reference. With this arrangement there is a circulating flexible tube structure 250 which is adapted to open at one location 251 to receive discrete collection elements 231 from the hopper 240. The circulating tube structure 250 thereafter closes and conveys the confined discrete collection elements 231 through one or more pressing stages 255 to remove the collected oil therefrom. The circulating tube structure 250 then conveys the confined collection elements 231 to a discharge zone 252 at which the tube structure again opens to release the confined discrete collection elements 231. This operates on a continuous basis; receiving oil-charged discrete collection elements 231 from the hopper 240 and subjecting them to the treatment process. The tube structure 250 is of permeable construction through which extracted oil and remnant water can pass. The extracted oil and remnant water are collected, and either stored or further processed. Opening and closing of the tube structure 200 is facilitated by an integral zipper 203, as described in aforementioned International application PCT/AU2007/000820.

It should be appreciated that any other appropriate arrangement may be utilized for removal of oil from the oil-charged collection elements. In yet another embodiment, which is not illustrated, the discrete collection elements, or other matter used to collect oil from a body of water, may be gathered and processed without having to be brought onboard the vessel to which the boom assembly according to the invention is connected. With this arrangement, water which is removed from the collection elements or other matter would be separated from the collected oil and returned to the body of water without being brought onboard the vessel. Such an arrangement may be advantageous in that is may avoid the need for compliance with regulations relating to disposal of water from marine vessels.

From the foregoing, it is evident that embodiments described each provide a simple yet highly effective arrangement for collecting matter at or near the surface of a body of water.

It should be appreciated that the scope of the invention is not limited to the scope of the embodiments described. In particular, while the embodiment has been directed to the recovery of contaminant oil from the surface of a body of water, it should be appreciated that the invention is not limited thereto. The invention may have various other applications, including those foreshadowed earlier in relation to recovery of other matter from a body of water, such as, for example, marine vegetation, including algae and other seaweeds, garbage and other floating materials, as well as harvesting of materials such as bio-algae. Throughout the specification and claims, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Claims

The Claims Defining the Invention are as Follows:

1. A boom for intercepting matter at or near the surface of a body of water, the boom comprising a plurality of boom sections connected one to another for limited angular movement therebetween.

2. The boom according to claim 1 having a longitudinal extent and further comprising connection means for flexibly connecting the boom sections one to another for limited angular movement therebetween, each connection means comprising first and second flexible connections spaced apart laterally with respect to the longitudinal extent of the boom.

3. The boom according to claim 2 wherein the first and second flexible connections each comprise a flexible element.

4. The boom according to claim 1, 2 or 3 wherein each boom section is configured to abut an adjacent boom section to limit angular movement therebetween in a generally horizontal plane.

5. The boom according to claim 4 wherein there are two abutting conditions limiting angular movement in opposed directions.

6. The boom according to claim 4 or 5 wherein the boom sections are configured at their ends for abutting engagement with adjacent boom sections.

7. The boom according to claim 6 wherein the ends of the boom sections are provided with resiliently compressible bumper portions.

8. The boom according to claim 8 wherein each end has two bumper portions for limiting angular movement in opposed directions.

9. The boom according to any one of claims 4 to 8 wherein the flexible connection and abutting engagement between adjacent boom sections affords constraint to relative movement between the adjacent boom sections.

10. The boom according to any one of the preceding claims wherein each boom section comprises a first buoyant portion, a reflector portion supported on the first buoyant portion and orientation means for orienting the first buoyancy potion in the body of water for maintaining the reflector portion in an operative condition relative to the water surface.

11. The boom according to claim 10 wherein the orientation means comprises an outrigger attached to the first buoyant portion.

12. The boom according to claim 10 wherein the orientation means comprises ballast means below the first buoyant portion.

13. The boom according to claim 11 wherein the outrigger comprises a second buoyant portion and framework extending between the first and second buoyant portions.

14. The boom according to any one of claims 10 to 13 wherein the first buoyant portion is of tubular configuration.

15. The boom according to any one of claims 10 to 14 wherein the second buoyant portion is of tubular configuration.

16. The boom according to any one of claims 10 to 15 wherein the reflector portion comprises an elongate element presenting a reflector surface.

17. The boom according to claim 16 wherein the elongate element is configured as a blade.

18. The boom according to claim 16 or 17 wherein the reflector surface comprises a concave surface.

19. The boom according to any one of claims 10 to 18 wherein the reflector portions of the interconnected boom sections cooperate to provide a modular reflector extending along the length of the boom.

20. A boom for intercepting matter at or near the surface of a body of water, the boom having a longitudinal extent and comprising a plurality of boom sections, connection means flexibly connecting the boom sections one to another for limited angular movement therebetween, each connection means comprising first and second flexible connections spaced apart laterally with respect to the longitudinal extent of the boom.

21. A boom for intercepting matter at or near the surface of a body of water, the boom comprising a plurality of boom sections, connection means flexibly connecting the boom sections one to another for limited angular movement therebetween, each boom section comprising a first buoyant portion, a reflector portion supported on the first buoyant portion and orientation means for orienting the first buoyancy potion in the body of water for maintaining the reflector portion in an operative condition relative to the water surface.

22. A boom section for a boom according to any one of the preceding claims.

23. A boom section comprising a first buoyant portion, a reflector portion supported on the first buoyant portion and orientation means for orienting the first buoyancy portion in the body of water for maintaining the reflector portion in an operative condition relative to the water surface.

24. A boom section according to claim 23 adapted to be connected to one or more further boom sections to provide a boom.

25. A boom assembly comprising two booms for intercepting matter on a body of water, the two booms being interconnected at one respective end, each boom being in accordance with any one of claims 1 to 21.

26. A boom assembly comprising two booms for intercepting matter on a body of water, the two booms being interconnected at one respective end, each boom comprising a plurality of boom sections connected one to another for limited angular movement therebetween.

27. Apparatus for disposal of matter from a body of water using a boom according to any one of claims 1 to 21.

28. Apparatus for disposal of matter from a body of water using a boom assembly according to claim 25 or 26.

29. A method of disposal of matter from a body of water using apparatus according to claim 27 or 28.

30. A method of disposal of matter from a body of water comprising placement of a boom according to any one claims 1 to 21 on the surface of the body of water and moving the boom relative to the body of water to intercept the matter.

31. A method of disposal of matter from a body of water comprising placement of a boom according to any one claims 1 to 21 on the surface of the body of water and moving the boom relative to the body of water to cause the matter to move towards a disposal zone.

32. A method of disposal of matter from a body of water comprising placement of two booms according to any one claims 1 to 21 on the surface of the body of water in angular relation to define a containment zone therebetween, and moving the booms relative to the body of water to cause the matter to be collected in the containment zone and moved towards a disposal zone.

33. A boom assembly comprising two booms movable between extended and collapsed conditions with resects to each other, at least one of the booms having a controllable surface to interact with relative water flow to steer the boom and thereby cause movement of the boom assemblies between the extended and collapsed conditions

34. A boom substantially as herein described with reference to the accompanying drawings.

35. A boom assembly substantially as herein described with reference to the accompanying drawings.

36. A boom section substantially as herein described with reference to the accompanying drawings.

37. A method of disposal of matter from a body of water substantially as herein described.