WO2021201691A1

WO2021201691A1 - Assembly for handling of aquatic organisms and other water-borne elements

Info

Publication number: WO2021201691A1
Application number: PCT/NO2021/050090
Authority: WO
Inventors: Hans-Petter SELSTAD
Original assignee: Selstad As
Priority date: 2020-03-30
Filing date: 2021-03-29
Publication date: 2021-10-07
Also published as: NO20200376A1

Abstract

An assembly (10a; 10b; 10c) for handling of aquatic organisms, when the assembly is in an at least partially submerged state in a body of water, comprising a flexible barrier element (11) for an aquatic organism and a dilation element (20), which is configured to retain a specific geometrical shape at least in a portion of the flexible blocking element. The dilation element (20) comprises an inner cavity and a supply conduit (21), whereby the dilation element (20) can assume an activated state, wherein the dilation element at least partially is filled with a pressurized fluid, and a non-activated state, wherein the cavity of the dilation element is de-pressurized. The assembly can be a production net (10a) or the like, a dilatable collecting unit (10b) or a dilatable retrieving net (10c). The dilatable retrieving net (10c) comprises a lower portion (26), which by means of a closure device (27) can be switched between an open state, wherein the aquatic organisms can flow into the retrieving net (10c), and a closed state. The invention also comprises a method for retrieving aquatic organisms in a water-filled container (40) by means of the retrieving net (10c).

Description

Assembly for handling of aquatic organisms and other water-borne elements Field of the invention

The invention relates to a floating facility for aquatic organisms and other water-borne elements, more specifically an assembly as indicated in the preamble of claim 1. The invention also relates to a method for retrieving of aquatic organisms as indicated in the preamble of claim 8.

Background of the invention

Flexible fishfarming cages usually comprises a net bag (net) attached to a floating ring on the water surface. The flexible net bag is kept dilated in a desired shape by a lower ring (often referred to as a bottom ring), which is configured in a rigid material such as polymer or metal. The bottom rings are often located in the transition between the cylindrical and conical portions of the net bag and may be provided with ballast elements. There is a need for a bottom ring, which is simpler to handle and easier to adapt to various fields of application. Moreover, there is a need for an improved assembly and method for collecting fish from a breeding cage, for instance in connection with the fish being slaughtered or moved to another cage or collecting tank. Prior art comprises pumping the fish out of the cage, either through a bottom opening in the cage or via a suction hose that is guided down into the cage. There is also a need for assemblies that can be placed in a body of water for collection of aquatic organisms and other water-borne elements.

The prior art includes NO 20170257 Al, which describes a device for catching and/or keeping living marine organisms in water. The device comprises a side made up of a pliable material and defining a part of a container, an elongate pliable fluid conduit extending along and being fixed to the side, and a supply conduit configured for supplying a pressurized fluid to the elongate pliable fluid conduit. The the pliable fluid conduit is configured to dilate the container when supplied with a pressurized fluid.

The prior art also includes GB 2187921 A, which describes a net comprising a netting material connected at an open end to a flexible tube adapted to be pressurised from a fluid source, whereby with the tube pressurised, the periphery of the open end of the net assumes the profile of the pressurised tube. The net may be used in fishing or be a football or like net.

The prior art also includes WO 2005/104832 Al, which describes a self-deployable open ocean aquaculture cage that includes at least one elongate flexible support member having an open interior for receiving a fluid and a net that forms an enclosure capable of retaining fish, wherein the at least one flexible support member is constructed and arranged to hold the net in a substantially extended configuration.

The prior art also includes NO 151976 B, which describes a device for collecting materials, in particular hydrocarbons, that accidentally flows onto a seabed.

Summary of the invention

The invention is disclosed and characterized in the independent claim, whilst the dependent claims describe other characteristics of the invention.

An assembly is thus provided for handling of aquatic organisms and other water-borne elements, when the assembly is in an at least partially submerged state in a body of water, wherein the assembly comprises a flexible barrier element for an aquatic organism and a dilation element which is configured to retain a specific geometrical shape at least in a portion of the flexible barrier element, characterized in that the dilation element comprises an inner cavity and a supply conduit, whereby the dilation element can assume an activated state where the dilation element at least partially is filled with a pressurized fluid, and a non-activated state where the cavity of the dilation element is de-pressurized.

In one embodiment, the dilation element comprises a hose body and is attached to at least a portion of the flexible barrier element. The dilation element can extend around a circumference of the assembly.

In one embodiment, the assembly is a net, such as a production net or the like.

In one embodiment, the assembly is a dilatable collecting unit. In one embodiment, the assembly is a dilatable retrieving net. In one embodiment, the dilatable retrieving net comprises a lower portion, which by means of a closure device can be moved between an open state, wherein the aquatic organisms can flow into the retrieving net, and a closed state. It is also provided a method of retrieving aquatic organisms in a water-filled container by means of the retrieving net according to the invention, characterized by the following steps: a) placing the retrieving net in a non-activated state at an upper portion in the container; b) activating the dilation element by adding a pressurized fluid, until the dilation element is alongside the inner wall of the container, mainly around the entire inner circumference of the container; c) guiding the dilation element and the lower portion of the retrieving net down into the water-filled container, while the dilation element is in contact with the wall of the container, until the lower portion reaches a desired depth in the container; and d) activating the closure device to close the lower portion.

In one embodiment, the method comprises drawing the retrieving net out of the container after step d), and the dilation element can then be in the non-activated or the activated state. The dilatable collecting unit can be used for forming a subsea air reservoir or for removing gases or other particles from a body of water.

Short description of drawings

The aforementioned and other characteristics of the invention will be further explained in the following description of embodiments of the invention, presented as non-limiting examples and with reference to the accompanying drawings, wherein:

Fig. 1 shows a first embodiment of the assembly according to the invention;

Fig. 2 is an enlargement of the section marked «A» in Fig. 1 ;

Fig. 3 is a perspective drawing of a section of the assembly according to the invention, showing a portion of the dilation element according to the invention; Fig. 4 shows a second embodiment of the assembly according to the invention;

Fig. 5 shows the embodiment of the assembly according to the invention as shown in Fig. 4, located in a cage;

Fig. 6 shows a third embodiment of the assembly according to the invention, placed in an open state in a cage;

Fig. 7 corresponds to Fig. 6, but shows the third embodiment of the assembly according to the invention in a closed state;

Fig. 8 shows a fourth embodiment of the invention, installed in a submerged cage for forming a subsea air reservoir; and Fig. 9 shows the fourth embodiment of the invention suspended in a body of water above a seabed for capturing gases and other substances that rise from the seabed.

Detailed description of embodiments of the invention

The following description will use expressions as "horizontal", "vertical", 'lateral", "back and forth", "up and down", "upper", "lower", "inner", "outer", "forward", "rear", etc. These expressions essentially refer to the perspectives and locations shown in the drawings and related to a normal use of the invention. The expressions are used only to facilitate the comprehension of the description and should not be limiting.

A first embodiment of the assembly according to the invention will now be described with reference to Figs 1 to 3. Fig. 1 shows an assembly for handling aquatic organisms, here in the form of a net 10a with a netting 11. The net 10a can be a production net or a net for other use. In an upper portion, the netting 11 can be attached to a floating ring or some other buoyancy element (not shown in Fig. 1) on the water surface via suspension lines or ropes 12, 13, so that the net as shown in Fig. 1 hangs in a submerged state in a body of water W. The netting is dimensioned and adapted so as to function as a suitable barrier to the aquatic organism (e.g. farmed salmon or other fish) that the net has to contain, and can therefore be denoted as a flexible barrier element 11. In the illustrated embodiment, the net 10a comprises a cylindrical portion 18 and a conical portion 19, and an annular dilation element 20 is located in the transition between the two portions. As the net 10a is flexible, the dilation element 20 has an essential function to give the net the desired shape (here: circular). Such dilation elements are usually referred to as bottom rings. In the illustrated embodiment, the dilation element 20 is a flexible, hollow ring, which can be filled with a pressurized fluid (liquid or gas) and thereby be dilated to assume the desired shape. Pressurized fluid is supplied to the flexible ring 20 via a supply conduit, here in the form of a hose, 21, which is coupled to a pump and necessary valves (not shown) and a fluid reservoir. The ring (the dilation element) 20 can thus be switched between a non-activated (not fluid-filled) state and an activated (fluid-filled) state. In a practical use, the fluid is water, for example seawater, which is taken from the body of water W, into which the net is submerged. The dilation element 20 will thus have an approximate neutral buoyancy in water, but ballast elements (not shown) can be attached to the dilation element or to the net as needed. In the shown embodiment (see Fig. 3), the dilation element 20 is suspended in fastening sleeves 14, which again are suspended in the suspension lines 12 (which are fastened e.g. sewn into the netting). A lanyard 22 is also attached to the fastening sleeve 14, so that the position of the dilation element 20 in the body of water can be adjusted. The lanyard 22 travels through rings 23 that are attached to the suspension line 12. It should be understood that the suspension lines can be attached to the dilation element 20 in other ways.

At installation, the entire net 10a can be submerged into the body of water W, while the dilation element 20 is in a non-activated or partially activated state. Subsequently, fluid under a pressure that is sufficient to dilate the dilation element (the ring) 20 can be added to the dilation element 20 to desired rigidity. When the dilation element 20 is to be emptied, e.g. in connection with hoisting of the net, it can be emptied by the fluid being evacuated via the hose 21 or by valves (not shown) being opened on the dilation element 20. A second embodiment of the assembly according to the invention will now be described with reference to Figs 4 and 5 as well as Fig. 3. Fig. 4 shows an assembly for handling aquatic organisms, here in the form of a dilatable collecting unit 10b. In the shown embodiment, the collecting unit 10b has the shape of a funnel with a collecting and emptying unit 15 at the lower end and comprises netting 11 and suspension lines or ropes 13 as described above. The whole or parts of the netting can be replaced by or supplemented with an impermeable or permeable sheet 17. The dilation element 20 is attached and operated as described above with reference to Figs 1-3. Suspension loops 16 (or corresponding suspension means) are attached to the dilation element 20. By means of these suspension loops 16, the collecting unit 10b can be located at a desired location (e.g. depth) in the body of water. An example of such location is shown in Fig. 5, wherein the dilatable collecting unit 10b is located inside a cage 30. The cage 30 can be of the type (e.g. a production cage) that is shown in Fig. 1, or it can be a flexible cage of another type or a cage with rigid walls, and/or an open cage or a closed cage. The reference numeral 31 indicates an upper floating ring or another buoyancy element that floats on the water surface and carries the cage. The dilatable collecting unit 10b is suspended in a plurality of suspension elements (e.g. rope or chain), which extend between the suspension loops 16 and the floating ring 31. In this manner, the collecting unit 10b can be located at a desired depth in the cage 30 and be used for collecting e.g. dead or injured fish, excrements/faeces, sludge and fallen feed. When adding fish to the cage 30, e.g. via a hose (not shown) that is guided down towards the collecting unit 10b, dead, injured or weakened fish will fall down into the collecting unit 10b (as it can be removed via the collecting and emptying unit 15), while fresh fish swim out into the cage 30.

A third embodiment of the assembly according to the invention will now be described with reference to Figs 6 and 7 as well as Fig. 3. Figs 6 and 7 show an assembly for handling aquatic organisms, here in the form of a dilatable retrieving net 10c. The net 10c can be used when fish or other aquatic organisms are to be caught from a container, such as a production cage. The illustrated embodiment of the assembly 10c comprises a flexible barrier (e.g. netting) 11, lanyards and suspension lines 22, 24 as described above with reference to Fig. 3 and a dilation element 20 as described above. The retrieving net 10c comprises an upper portion 25 and a lower portion 26, and the dilation element 20 is mounted to the net at the transition between the two portions. Fig. 6 shows the retrieving net 10c in an open state, i.e. it is open at the upper and lower ends. At the lower end (the lower end of the lower portion 26), a closing mechanism 27 is mounted, which can be operated in an actually known manner to close (shut off) the lower end of the lower portion. The closing mechanism can for example be a rope that can be drawn together to tighten the lower end. Fig. 7 shows the retrieving net 10c in such a closed state. The lower end of the lower portion 26 is preferably provided with ballast elements (not shown), such as lead weights or the like.

Figs 6 and 7 show the retrieving net 10c installed in a container 40 for aquatic organisms, for example a production or storage cage. The container 40 can be an open or a closed cage. Only the wall of the container is shown, in dotted lines, as well as a floating element 41. The container 40 has a cylindrical wall, which can be rigid or have a limited elasticity. The wall can be deformable or non-deformable. In the shown configuration, the retrieving net 10c is used for retrieving e.g. fish that stay in the container 40. Basically, the retrieving net 10c is located on top of the container. In this phase, the dilation element 20 is in a non-activated (not fluid-filled) state and, the retrieving net 10c can be packed as a ring and be attached at the top of the container. The retrieving net 10c is then submerged somewhat (preferably a short distance from the water surface) down into the container 40, and the dilation element 20 is pressurized as described above, until the dilation element 20 presses with a selected force against the wall of the container. In this manner, a barrier is formed between the retrieving net 10c and the wall of the container. The retrieving net 10c is then - in an open state - guided downwards into the container, as indicated by the arrow in Fig. 6. The dilation element 20 can be handled by means of the lanyards 22 as mentioned above. Fish and other organisms in the container 40 will in this manner be directed into the retrieving net 10c without being squeezed between the wall of the container 40 and the retrieving net 10c. The downward movement can be provided by the force of gravity (and the ballast elements mentioned above) and/or by means of other movement means (not shown). When the retrieving net 10c has been moved sufficiently far down into the container 40, and the fish are in place inside the retrieving net 10c, the closing mechanism 27 can be activated to shut off the lower opening (see Fig. 7), and the retrieving net can be lifted out of the container 40. A reversed procedure can be used to place fish in the container 40 in a gentle way.

This assembly 10c is particularly suitable for collection of fish in connection with slaughter or transfer to other containers. A fourth embodiment of the assembly lOd according to the invention will subsequently be described with reference to Figs 8 and 9. This embodiment fundamentally corresponds to the second embodiment, involving a dilatable collecting unit 10b. The dilation element 20 is operated in the same way as described above, e.g. via the hose 21. But in this embodiment lOd, the opening of the unit is facing downwards into the body of water when it is installed and in use, and the collecting and emptying unit (reference numeral 15 in Figs 4 and 5) is replaced by a valve coupling 54 at the top of the unit (i.e. at the bottom of the unit/funnel). The netting is replaced by an impermeable sheet 17 or another impermeable and flexible material.

In Fig. 8, the dilatable collecting unit lOd is suspended inside a cage 60, here a submerged cage, via lines 53 or the like, which are attached in a float 50 on the surface S. A hose travels 51 between the valve coupling 54 and a control module 52 on the float. The control module 52 comprises power input, control systems and an air reservoir (e.g. a compressor; not shown), so that air under pressure can be pumped down into the funnel-shaped space inside the dilatable collecting unit lOd. In this manner, an air reservoir can be formed and maintained inside the collecting unit, which fish in the cage can utilize.

In Fig. 9, the dilatable collecting unit lOd is suspended in a body of water, above a seabed B. Lines 53 or the like attach the unit to a float 50 on the surface S. A hose travels 51 between the valve coupling 54 and a control module 55 on the float. The control module 55 contains power input, control systems and pumping systems (not shown), so it will be possible to capture gas and other substances that rise from the seabed in the funnel-shaped space inside the dilatable collecting unit lOd and direct them to the surface through a hose 51. In this way, gases (such as e.g. methane) that are released from the seabed (e.g. in connection with activities on the seabed) can be captured without leaking out into the environment. Through Fig. 9 shows that the collecting unit lOd is carried by a float 50 on the surface S, it should be understood that the unit lOd can also be carried by other structures and assemblies, on, above or under the water surface, such as an ROV or an installation on a bottom below the body of water.

It is common to the embodiments of the assembly 10a, 10b, 10c; lOd that the dilation element 20 comprises an inner cavity and a supply conduit 21 whereby the dilation element can assume an activated state, wherein the dilation element at least partially is filled with a pressurized fluid, and a non-activated state, wherein the cavity of the dilation element is de-pressurized. The dilation element can have the shape of an annular hose. Though the cavity and necessary valves, couplings, pumps etc. are not shown, the person skilled in the art will know how the dilation element can be filled, pressurized an emptied. The person skilled in the art will also know how the dilation element is to be dimensioned and which fluid pressures are necessary in each individual case.

Though the collecting unit 10b, lOd above is described and illustrated as a funnel- shaped unit, it should be understood that it can also have other shapes. Though the flexible dilation element 20 is shown and described above as a continuous ring, it should be understood that the dilation element can comprise a plurality of ring segments, each of which is attached to the barrier element. The dilation element 20 can also have other shapes than circular, such as for example oval, rectangular, square.

It should be understood that the various embodiments described above can be combined. Unless otherwise specified, the individual embodiments comprises the features described with reference to the other embodiments.

Claims

1. An assembly (10a; 10b; 10c; lOd) for handling of aquatic organisms and other water-borne elements, when the assembly is in an at least partially submerged state in a body of water (W), wherein the assembly comprises a flexible barrier element (11) for an aquatic organism and a dilation element (20), which is configured to retain a specific geometrical shape at least in a portion of the flexible barrier element, characterized in that the dilation element (20) comprises an inner cavity and a supply conduit (21), whereby the dilation element (20) can assume an activated state, wherein the dilation element at least partially is filled with a pressurized fluid, and a non-activated state, wherein the cavity of the dilation element is de-pressurized.

2. An assembly according to claim 1, wherein the dilation element (20) comprises a hose body and is attached to at least a portion of the flexible barrier element.

3. An assembly according to any one of claims 1-2, wherein the dilation element (20) extends around a circumference of the assembly.

4. An assembly according to any one of claims 1-3, wherein the assembly is a net (10a), such as a production net or the like.

5. An assembly according to any one of claims 1-3, wherein the assembly is a dilatable collecting unit (10b).

6. An assembly according to any one of claims 1-3, wherein the assembly is a dilatable retrieving net (10c).

7. An assembly according to claim 6, wherein the dilatable retrieving net (10c) comprises a lower portion (26), which by means of a closure device (27) can be moved between an open state, wherein the aquatic organisms can flow into the retrieving net (10c), and a closed state.

8. A method for retrieving aquatic organisms in a water-filled container (40) by means of the retrieving net (10c) according to claim 7, characterized in the steps of: a) placing the retrieving net (10c) in a non-activated state at an upper portion in the container; b) activating the dilation element (20) by adding a pressurized fluid, until the dilation element (20) lies alongside the inner wall of the container (40), mainly around the entire inner circumference of the container; c) guiding the dilation element (20) and the lower portion (26) of the retrieving net (10c) down into the water-filled container, while the dilation element (20) is in contact with the wall of the container, until the lower portion reaches a desired depth in the container; and d) activating the closure device (27) to close the lower portion;

9. A method according to claim 8, wherein the retrieving net (10c) is drawn out of the container after step d), and the dilation element (20) can then be in the non-activated or the activated state.

10. Use of the assembly as indicated in claim 5, to form a subsea air reservoir or to remove gases or other particles from a body of water.