NO20211114A1 - Fish farming system - Google Patents

Description

FISH FARMING SYSTEM

The present invention relates to a fish farm.

BACKGROUND

The recent years have seen a considerable growth in the fish farming industry in various countries, and it is projected that fish farming will continue to play a key role in the provision of food in the future. A continual focus on safety, fish welfare and the environmental impacts of fish farming, however, drives a demand for improved methods and solutions for fish farming. Various such improvements have been suggested over the recent years.

For conventional fish farming, there exists several types of fish pens, but the most common technology for salmon farming is to use a floating flexible collar with a suspended net. The fish pens are often moored in a grid mooring system. A nearby feed barge may be used for providing the required support systems for the fish pens.

Due to the continuous increasing demand for sea food and the limited number sheltered locations suitable for fish farming, there is a need to develop new solutions that can, for example, be used outside these sheltered areas, where environmental influence may be more severe, or which provide advantages in relation to production efficiency, fish welfare, or other parameters.

Publications which may be useful to understand the field of technology include WO17153417A1.

The objective of the present invention is to provide systems and methods which further improve on conventional solutions and techniques in the above or other areas.

SUMMARY

According to the invention, there is provided a fish farming system comprising a ring- or polygonal shaped floating collar and an enclosure for fish suspended from and supported by the floating collar, wherein the system further comprises a plurality of feed storage silos disposed about the floating collar.

A feed conveyor may be operable to move feed between at least two of the feed storage silos.

The feed conveyor may be operable to move feed between all feed storage silos.

The fish farming system may comprise at least two feed storage silos arranged at opposite sides of the enclosure.

The feed storage silos may be disposed inside respective columns.

A filling receiver may be arranged in communication with at least one of the feed storage silos.

The filling receiver may be in communication with the feed conveyor.

The filling receiver may be in communication with at least one feed storage silo via the feed conveyor.

The filling receiver may be in communication with at least one feed storage silo via a buffer tank.

The conveyor may be arranged substantially horizontally inside the upper buoyancy member.

Each feed storage silo may comprise an elevator mechanism operable to move feed from the feed storage silo to at least one of: a mixing unit, the buffer tank, or the conveyor.

The system may comprise a mixer for mixing feed and water. The mixer may be arranged to receive feed from the buffer tank. The mixer may be arranged at a lower elevation than the buffer tank and arranged to receive feed from the buffer tank by means of gravity.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics will become clear from the following description of illustrative embodiments, given as non-restrictive examples, with reference to the attached drawings, in which:

Fig. 1 shows a perspective view of a fish farming system.

Fig. 2 shows a cross-section of the fish farming system of Fig.1.

Fig. 3 shows a perspective view of a fish farming system.

Fig. 4 shows a top view of the fish farming system of Fig.3.

Fig. 5 shows a side view of the fish farming system of Fig.3.

Fig. 6 shows a cross-sectional perspective view of the fish farming system of Fig.3. Fig. 7 shows a cross-sectional perspective view of another fish farming system. Fig. 8 shows a schematic cross-sectional view of the fish farming system of Fig.7. Fig. 9 shows parts of the fish faring system of Fig.6.

Fig. 10 shows details of a lower buoyancy member according to an embodiment. Figs 11 and 12 illustrate parts of a floating collar according to an embodiment. Figs 13-16 illustrate parts of a floating collar according to embodiments.

Figs 17 and 18 illustrate a double net having spacers.

Figs 19-26 illustrate various steps in a fish crowding operation.

Figs 27 and 28 illustrate details of optional embodiments.

Figs 29-32 illustrate embodiments of systems for feed handling.

DETAILED DESCRIPTION

The following description may use terms such as “horizontal”, “vertical”, “lateral”, “back and forth”, “up and down”, ”upper”, “lower”, “inner”, “outer”, “forward”, “rear”, etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader’s convenience only and shall not be limiting.

Aspects of the present disclosure relate to a fish farming installation with a semisubmersible floating collar for a submersible fish pen. This installation may operate on two or more operational drafts such that the top of the net cage can be in a surface or near-surface position, or completely submerged. The top of the net cage can, for example, be submerged to a depth of 5-10 meters or more below the water surface, in order to reduce the exposure to, for example, sea lice, algae, and jellyfish and also reduce the environmental loads from ocean currents and waves or from impacts from floating objects. The installation may optionally be designed for deeper submergence to further reduce environmental loads.

The fish farming system may be designed with a favourable ratio between water line area and displacement to provide an effective construction for handling bending moments from waves and ocean currents, less movement of the floating collar during bad weather conditions, Since the effect of waves tends to be less in deeper water, less movement will be transferred from the floating collar to the net cage, which in turn reduces the change of damage to the net cage and escape of fish.

A semi-submersible fish-farming system, such as a fish pen, according to aspects described herein may be operable between at least two different semi-submerged positions, a first position and a second position, by ballasting and de-ballasting. The system may comprise a rigid floating collar comprising a ring-shaped or polygonal lower buoyancy member, a ring-shaped or polygonal upper buoyancy member, a plurality of pillars connecting the buoyancy members, a net cage suspended from the floating collar and a net roof closing off the top of the net cage, the net cage with the net roof forming an enclosure for fish.

Fig. 1 is a principle drawing showing some elements of a fish farming system according to an aspect and Fig.2 is a cross-section of the system shown in Fig.1. In a preferred embodiment, the system comprises a fish pen 1 with a floating collar 2 comprising a lower buoyancy member 7, an upper buoyancy member 9 and a plurality of columns 8 which are mounted to the lower buoyancy member 7 and the upper buoyancy member 9. The columns 8 connect the lower and upper buoyancy members 7,9. The upper and lower buoyancy members 7,9 and columns 8 are preferably made of a rigid material, such as steel. For additional stiffness, for example to restrict torsion, bending or shear, tie struts or plates may be placed between some of the pillars. The upper and/or the lower buoyancy members 7,9 can, for example, have a circular or polygonal shape.

The lower buoyancy member 7 is a continuous, closed pontoon encircling the central portion of the fish pen 1 in which a net cage 3 is suspended, the net cage 3 forming an enclosure 3 for the fish and the net cage 3 being supported by the floating collar 2. The enclosure 3 is defined by sides 4 and a bottom 44, either or both of which can be flexible, such as a pliable net, or a stiff or semi-stiff construction. Further, the enclosure 3 can have a closed roof 5, arranged to close a top section of the enclosure 3, thereby preventing fish from leaving the enclosure 3 and/or preventing predators from entering the enclosure 3. The roof 5 may be a net, grid, or other suitable arrangement. The roof 5 may be of the same material as the sides 4 and/or bottom 44. Even if phrased a "net" here, this does not preclude other types of materials used in the roof 5, sides 4 or bottom 44. These elements can be separate elements or an integrated construction. The enclosure 3 may also comprise a bottom ring 26, which may be temporarily or permanently installed and which can be pulled towards the surface using winches and wires or other mechanical means for example for fish crowding. The bottom ring 26 may also provide weight to keep the enclosure 3 in a desired form (e.g. keeping the sides 4 substantially vertical), and it may be arranged semi-stiff or stiff in order to assist keeping the shape and form of the enclosure 3 in the case of water currents or other loads.

The bottom ring 26 may be connected to an outer net, an inner net, or both an outer and an inner net defining the enclosure 3, described in further detail below. In such a case, the bottom ring 26 may be arranged to support either the outer net or the inner net, or both the outer net and the inner net.

The lower buoyancy member 7 can, for example, have a circular, square, hexagonal or octagonal design. The cross-section of the lower buoyancy member can for instance be circular, square or have another form. The interior of the lower buoyancy member 7 can, for example, be divided into one or more sections by means of partition walls. Further, the cross-section area and shape of the lower buoyancy member 7 does not need to be uniform. The upper buoyancy member 9 may have any of the above stated configurations and may also have a different design compared to the lower buoyancy member 7. The upper buoyancy member 9 and/or the lower buoyancy member 7 may be arranged with dedicated space for storage, operational equipment or the like. Such space may, for example, be in one or more partitioned sections in the structure.

The cross-section of the columns 8 can be circular, square or any other shape. Further, the columns 8 can each be identical or have different sizes and crosssections. The distance between the columns 8 can be uniform or varying. The distance from a column 8 to the centre of the fish pen 1 can also be uniform or varying. The interior of at least some of the columns 8 is preferably in fluid communication with the interior of the lower buoyancy member 7. For trimming, water may be supplied or removed from the interior of the lower buoyancy member 7 and possible also the interior of some or all the columns 8. There may, optionally, be not multiple, but only one single column connecting the lower buoyancy member 7 and the upper buoyancy member 9.

The interior of one or more of the columns 8 may be may be arranged with dedicated space for storage, operational equipment or the like. One or more of the columns 8 can, for example, be divided into one or more sections by means of partition walls for this purpose. Such space may, for example, be in one or more partitioned sections in the structure.

To lower the fish pen 1 to an operational or submerged position 16, wherein the water line at the operational or submerged position 16 is indicated, water can be pumped into the interior of the lower buoyancy member 7 and possibly also into whole or parts of some or all of the columns 8, until the desired draft is achieved. The interior of the upper buoyancy member 9 and/or the columns 8 or parts thereof can, if desirable, be closed and filled with air or a foam material that provides buoyancy when the fish pen 1 is submerged. In this position, the roof 5 of the enclosure 3 can be kept at a certain depth to avoid or reduce the exposure to sea lice, jellyfish and algae. By submerging the enclosure 3, also the environmental impact of waves and currents can be reduced, since these impacts in general are more pronounced at or near the water surface and are reduced with increasing depth. By submerging the enclosure 3 a distance below the water surface, the movements transferred to the enclosure 3 from the collar 2 can also be reduced and the risk for damaging the enclosure 3 and escape of fish be reduced, due to less movement of the floating collar 2 and consequently less movement of the enclosure 3.

In order to raise the fish pen to a service position 15, wherein the water line at the service position 15 may be as indicated in Fig.2, water can be pumped out of the lower buoyancy member 7 and/or the columns 8. The service position 15 may be a position wherein the lower buoyancy member 7 is at or near the water surface. In the service position 15, the floating collar 2 may then be floating with the lower buoyancy member 7 on the water surface such that the roof 5 of the enclosure 3 can be at or above the water surface. By removing the roof 5 (or parts thereof) of the enclosure 3 when the floating collar 2 is in service position 15, access to the enclosure 3 can be obtained for inspection, maintenance and different operations such as crowding and delousing. The upper buoyancy member 9 can function as support for travelling cranes, winches, personnel basket to facilitate operations in enclosure 3. All necessary tubes, hoses, cables etc. can be connected to the upper buoyancy member 9, led down the columns 8 to the lower buoyancy member 7 and out into the enclosure 3. Consequently, there is no need to take the enclosure 3 to surface for inspection or connection and the operation is not relying on divers/ROV.

The construction of the fish pen 1 may be so robust and strong that it is possible to utilize a direct-coupled mooring system 22 (see Figs 1-5) and it is not necessary to use a frame mooring, such as used for conventional systems with flexible plastic rings. This involves that each individual fish pen 1 can move independent of each other, if more fish pens 1 are placed in the same area, and the distance between each fish pen can be larger for increased safety and improved water quality.

Illustrated in Figs 3-8 multiple embodiments with a similar structure are disclosed, showing preferable and/or optional implementations.

Referring to Figs 3-5, a fish farming system 1 comprises a ring- or polygonal shaped floating collar 2. Similarly as described above, the floating collar 2 may comprise a lower buoyancy member 7, an upper buoyancy member 9 and a plurality of pillars 8 interconnecting the upper and lower buoyancy members 7,9. Alternatively, the floating collar 2 may be made out of an integrated structure having other configurations.

An enclosure 3 for fish is suspended from and supported by the floating collar 2.

The system 1 further comprises an inner structure 50 fixed to and extending inwardly from the floating collar 2.

In this embodiment, the inner structure 50 is fixed to at least one of the upper buoyancy member 9 or one or more of the plurality of pillars 8. The inner structure 50 may, additionally, also be fixed to the lower buoyancy member 7.

The inner structure 50 comprises a ring- or polygonal shaped first inner structure part 51. In the shown embodiment, the first inner structure part 51 is supported by a plurality of second inner structure parts 52 extending between the first inner structure part 51 to the floating collar 2. The second inner structure parts 52 may extend from the first inner structure part 51 to one or more of the pillars 8, and/or to the upper buoyancy member 9. In the shown embodiment, the second inner structure parts 52 are angular members extending between the first inner structure part 51 and the pillars 8 and between the first inner structure part 51 to utility rooms 70 arranged on or as part of the upper buoyancy member 9. In another embodiment, the second inner structure parts 52 may extend between the first inner structure part 51 and any of the pillars 8, the utility rooms 70, the upper buoyancy member 9.

The roof 5 may be fixed to the inner structure 50. Preferably, the roof 5 is arranged such as to be enclosed by the first inner structure part 51 and arranged to close an opening defined by the first inner structure part 51 as shown in Figs 3-4. More preferably, the inner structure 50 is submerged in an operational or submerged position 16 (shown in Fig 1). In this position, the roof 5 of the enclosure 3 can be kept at a certain depth to avoid or reduce the exposure to e.g. sea lice, jellyfish and algae. By submerging the enclosure 3, also the environmental impact of waves and currents is reduced, since these impacts in general are more pronounced at the water surface and are reduced with increasing depth.

The inner structure 50 may, optionally, comprise beams or another structure extending diagonally or substantially diagonally across the enclosure 3. This can be used as, for example, a gangway for inspection or work operations, supporting equipment such as feeding systems or measurement/monitoring equipment, and/or for supporting the roof 5.

The inner structure 50 may comprise an opening 60,61 into the enclosure 3.

Advantageously, the opening 60,61 extends through the first inner structure part 51. As illustrated in Figs 3 and 4, the first inner structure part 51 may comprise a work deck 51a for an operator and an opening 60. The opening 60 may, for example, be a hatch arranged in the work deck 51a. The work deck 51a can be arranged to be non-submerged when the system 1 is in an upper draft position, such that operators can work on the work deck 51a. Advantageously, the opening 60,61 is arranged on the work deck 51a or is arranged such as to be accessible from the work deck 51a.

The opening 60,61 may, for example, allow an operator to access the enclosure 3 via the opening 60,61.

In any embodiment, the first inner structure part 51 may comprise a work deck 51a also without the opening 60 shown in Figs 3 and 4. This can allow an operator to access the enclosure 3 from above, for example via the area enclosed by the first inner structure part 51, and/or to access the roof 5.

Alternatively, or additionally, the opening 60,61 may be accessible through a second inner structure part 52. Illustrated in Fig.6, an opening 61 may for example allow access to the interior of the enclosure 3 from a utility room 70 on the floating collar 2. Advantageously, the second inner structure part 52 extends through the first inner structure part 51. The second inner structure part 52 may, for this purpose, be arranged hollow or with a feed-through channel or equivalent. There may, for example, be systems associated with feed distribution arranged in the upper buoyancy member 9 and/or the utility rooms 70. One or more feeding pipes may be provided from the utility rooms 70 (or alternatively from the pillars 8), via the second inner structure part 52, and into the enclosure 3. In this manner, direct access for feeding can be provided in a protected manner, and wherein feed can be provided more targeted to a desired region within the enclosure. The feeding pipes may be provided inside the inner structure part 52 or fixed partially or fully on the outside of the inner structure part 52. Advantageously, feed pipes are provided into the enclosure at multiple locations around the circumference of the floating collar, such that feeding can be carried out at multiple locations and/or feeding, for example, may be suspended at selected locations in case of strong water currents or other reasons.

Advantageously, a corresponding outlet can be provided at an outside of the floating collar 2, i.e. outside the outer net 4b. Such an outlet can be provided, for example, from one of the utility rooms 70, from an interior of the upper buoyancy member 9, a column 8 or from/via the lower buoyancy member 7. The outlet can, for example, be provided by means of a shaft, similar to the second inner structure part 52. Such an outlet can be used to launch equipment or tools to an outside of the floating collar 2, for example an inspection robot or a cleaning robot.

The second inner structure part 52 may, additionally or alternatively, be arranged hollow or with a feed-through channel or equivalent for introduction of tools or equipment therethrough. This may include tools or equipment needed for the operation of the fish farm system 1, such as inspection robots (e.g., an ROV), cleaning equipment (e.g. a net cleaner), or other items.

In any of the embodiments described or claimed herein, the second inner structure part 52 may advantageously be fixed to the columns 8, the upper buoyancy member 9 or the utility rooms 70 in a position which is above the waterline in all operational positions of the fish farm system 1.

One or more of the utility rooms 70 may have multiple internal storeys or be arranged higher than other utility rooms 70, as can be seen, for example, in Fig.6. This can provide a higher freeboard on the particular utility room 70, for example in the case of work outside on the roof of the utility room 70 in question.

In any of the embodiments described or claimed herein, the utility rooms 70 may be arranged on the upper buoyancy member 9 and may be arranged to provide reserve buoyancy to the floating collar 2. In other words, the utility rooms 70 are not normally contributing to the buoyancy of the floating collar 2, but are dimensioned to provide reserve buoyancy, for example to meet regulatory requirements for such reserve buoyancy.

In any of the embodiments described or claimed herein, the first inner structure part 51 may be arranged such as to be fully above the waterline in a service position 15 of the fish farming system 1.

Now referring to Figs 5, 6, 7 and 8, the enclosure 3 may comprises a double net 4a,4b, wherein an outer net 4a is fixed to and suspended from the floating collar 2 and an inner net 4b is fixed to and suspended from the inner structure 50.

Optionally, the outer net 4a can be suspended from the second inner structure parts 52 and the inner net 4b suspended from the first inner structure part 51.

Advantageously, this can allow access between the inner and outer nets 4a,b, for example for inspection or maintenance. This access can be done in appropriate openings between the first inner structure part 51 and the floating collar 2. For example, such inspection may be carried out by means of a submersible camera or a remotely controlled vehicle. Optionally, other equipment such as lights or sensors may be permanently or semi-permanently installed in the annulus between the inner and outer nets 4a,b. This can be done by suspending the equipment in the annulus, or, optionally, by having a carrier arrangement permanently or semi-permanently installed in the annulus. Such a carrier arrangement, illustrated schematically in Fig. 8, may for example comprise a carrier 48 for holding the equipment, the carrier 48 being vertically movable along a wire or rod 49. The carrier arrangement may, alternatively or additionally, be arranged for horizontal movement within the annulus between the inner and outer nets 4a,b. For example, the carrier arrangement may be arranged on tracks which allow it to be moved about the inner net 4b.

Advantageously, a gap or an opening between the inner structure 50 and the floating collar 2 is provided at regular intervals about the outer circumference or outer sides of the inner structure 50.

Advantageously, a continuous gap or opening is arranged around the first inner structure part 51 and between the first inner structure part 51 and the floating collar 2.

Illustrated in Fig.6, the lower buoyancy member 7 may comprise an opening 63 opening into an annulus or space between the inner and outer nets 4a,b. The opening 63 may, for example, be used for work operations or for launching tools or equipment into the annulus, such as inspection or cleaning tools.

Optionally, as illustrated in Figs 7 and 8, the inner net 4b comprises a mort collector 53 connected to a mort collection pipe 54 arranged between the inner and outer nets 4a,b and extending from the mort collector 53 to the floating collar 2. The mort collector 53 may be a cone-shaped structure arranged at the bottom of the inner net 4b such as to collect faeces, dead fish, debris or other components. The mort collection pipe 54 may be arranged to receive anything collected by the collector 53. The mort collection pipe 54 may, for example, be connected to a pump for conveying the collected matter, or, as illustrated, an air lift system where an air hose 55 is provided to a lower part of the collection pipe 54. The air hose 55 may be arranged between the inner and outer nets 4a,b. Advantageously, this configuration provides protected positioning of the collection pipe 54 and, if applicable, the air hose 55, as well as the connection between the collection pipe 54 and the mort collector 53. One or both the air hose 55 and collection pipe 54 may be fixed to either the inner or outer net 4a,b for support and for holding the pipe/hose in place. For example, one of the inner or outer nets 4a,b may have hooks or the like to which the pipe and/or hose is connected, or sown-in pockets through which the pipe and/or hose extends.

In some embodiments, the fish farming system 1 may comprise equipment for handling dead fish. This may include an ensilage system for processing such dead fish collected from the enclosure 3. The equipment may also comprise, for example, testing equipment. When dead fish is retrieved from the collector 53, it can be processed for example by counting parasites which may be on the fish, by carrying out other tests on the dead fish, by weighing or otherwise measuring the fish, etc. Data from such processing can be stored and, for example, provided to a shore location. This can provide better knowledge of the state of the fish in the enclosure 3. Equipment to carry out such operations may, for example, be arranged in one of the utility rooms 70.

Additionally or alternatively, a fish pumping arrangement may be arranged in the annulus between the inner and outer nets 4a,b. For example, crowding of fish may be done downwardly or to a side of the inner net 4b and towards an opening with a hose connected to it. The hose may be similar to the collection pipe 54, to collect and pump live fish, for example to a well boat or another fish pen. The opening may be at the bottom, similar to the mort collector 53, or at some other position on the inner net 4b. This may provide a more effective method to collect live fish from the enclosure 3, with enhanced safety.

An UPS system may be provided to enable a controlled shut-down in the case power supply to or on the fish farming system 1 is interrupted.

The inner structure 50 may comprise an air-filled dome 56 accessible from inside the enclosure 3. This allows fish, such as salmon, access to air to trim its swim bladder also when the system 1 is submerged. Compressed air lines may be provided to the air-filled dome 56, for example arranged inside or outside the second inner structure parts 52, and connected to a compressor in a utility room 70 or arranged elsewhere on the floating collar 2.

The air-filled dome 56 may be arranged to be above the waterline in the service position 15. In this manner, access to the air-filled dome 56 can be arranged for cleaning or other purposes.

Alternatively, or additionally, the inner structure 50 may comprise one or more openings, for example hatches, through which access to the air-filled dome 56 can be obtained. Illustrated in Fig.28, a hatch 66 may be provided in a wall of the first inner structure part 51 which defines the air-filled dome 56. The hatch 66 may be provided in a vertical section of the wall of the first inner structure part 51. The hatch 66 may be provided at a vertical elevation which is below a design water level 67 which defines the target water level in the dome 56 during normal operation. This water level may be arranged such that the vertical walls of the first inner structure part 51 which define the dome 56 extend farther down than the target water level in order to prevent wash-out of the air in the dome 56. By providing the hatch 66 below the target water level 67 one can reduce the risk of air leakage from the dome 56 during operation. In the de-ballasted / service position 15, the hatch 66 can be arranged to be above the waterline, along with the rest of the first inner structure part 51, such that access to the interior of the dome 56 can be obtained through the hatch 66.

As can be seen in e.g. Figs 7 and 8, the inner net 4b can be arranged radially outwardly from the air-filled dome 56 and the opening 60, 61, such that the air dome 56 and the opening 60, 61 face the interior volume of the enclosure 3.

This may, for example, be used for access during inspections, for example with a submersible camera or a remotely operated vehicle which can be introduced into the enclosure 3 via the opening 60, 61.

In any of the embodiments described or claimed herein, the upper buoyancy member 9 may be provided with an internal gangway or other type of communication path for an operator along at least a part of it’s length. The internal gangway may, for example, be provided between at least two of the utility rooms 70 and/or at least two of the columns 8, whereby an operator can access the internal space of the utility rooms 70 and/or the columns 8 from the internal gangway.

In any of the embodiments described or claimed herein, the fish farming system 1 may comprise one or more equipment modules 31 (see Fig.3) fixed on the lower buoyancy member 7. The equipment modules 31 may advantageously be fixed on the lower buoyancy member 7 such that in an operational position 16 (see Fig.2) the equipment modules 31 are submerged, while in a service position 15, the equipment modules 31 are above the waterline. The equipment modules 31 may, for example, be positioned on an upward-facing surface of the lower buoyancy member 7, as illustrated.

The equipment modules 31 may, for example, be arranged as water-tight containers which can house operational equipment for the fish farming system 1.

Advantageously, the equipment modules 31 may house batteries.

By arranging equipment modules 31 on the lower buoyancy member 7, one can obtain improved cooling, for example passive cooling or direct access to sea water for active cooling, when the fish farming system 1 is in its operational draft, while securing easy access to the equipment modules 31 when the fish farming system 1 is in its service draft.

In any of the embodiments described or claimed herein, the operational position 16 may be such that the upper buoyancy member 9 is in contact with the water such as to provide buoyancy. Alternatively, the upper buoyancy member 9 may be above the waterline when in the operational position 16, as indicated in Fig.2. In this case, the regular buoyancy for the fish farming system 1 is provided by the lower buoyancy member 7 and the columns 8. Optionally, the fish farming system 1 may be provided with more than two draft positions, whereby the fish farming system 1 can be selectively operated in a service position 15, in a first operational position 16 wherein the upper buoyancy member 9 is above the waterline, and a second operational position wherein the upper buoyancy member 9 is in contact with the waterline. This may add operational flexibility to the system, in that a suitable draft can be used according to the type of operation carried out, for example in order that the motion of the fish farming system structure in the water is suitable. This may be, for example, if carrying out an operation on the structure itself or on the fish, when mooring a ship or boat to the fish farming system 1, or for other reasons during conditions when full submergence is not required.

Illustrated in Fig.9, in any of the embodiments described or claimed herein, the first inner structure part 51 may have an inner flange 57, an outer flange 58, or both an inner and an outer flange 57,58. The inner and/or the outer flange 57,58 may be arranged as a gangway or accessway so as to provide a work platform for an operator. This work platform may be used, for example, for inspections of the roof 5, the net 4a,b, the annulus between an inner and outer net 4a,b (if a double net is used), structural parts of the fish farm system 1, or other things. The gangway/accessway may also be used for inspecting the fish volume in the enclosure 3, or as a platform to carry out operations towards this volume. For this purpose, the gangway/accessway may have a fixation arrangement for tools or equipment, for example to allow tools/equipment to be temporarily fixed to the gangway/accessway while carrying out operations. There may, for example, be equipment or tool holders on or under the flange 57 or 58.

Parts of the inner structure 50, for example flange 57 or 58, can be used as support and/or hang-off for permanent and temporary equipment inside or outside the enclosure 3.

The roof 5 may be fixed to the inner flange 57, or optionally to other parts of the inner structure 50.

In any of the embodiments herein, the roof 5 can be a double net 5a,5b as illustrated in Fig.8. The individual nets 5a,5b of the double net roof net are preferably attached at two elevations on the inner structure 50, as illustrated.

The net, or the inner net 4b, may be suspended from the outer flange 58.

Advantageously, the fish farming system 1 is designed such that the inner and/or outer flange 57,58 are above the waterline when the fish farming system is in the service position 15.

The first inner structure part 51 may also comprise a storage space for equipment, for example for wet storage of equipment. This will described in further detail below.

Illustrated in among other Fig.5, the fish farming system 1 may have a boat access 59a,b at an outer periphery of the floating collar 2. Each boat access 59a,b may be fendered or otherwise prepared for service vessels, transport vessels or other types of vessels to dock at the floating collar 2. An upper boat access 59b may be provided at the upper buoyancy member 9, suitable for use in the operational position 16. A lower boat access 59a may be provided at the lower buoyancy member 7, suitable for use in the service position 15.

As is visible in among other Figs 6 and 9, the outer net 4a may be suspended from an inner periphery of the lower buoyancy member 7. Optionally, the outer net 4a may be suspended from an underside of the lower buoyancy member 7, or from an outer periphery of the lower buoyancy member 7. This may, for example, be desirable to obtain a larger distance between the inner and outer nets 4a,b.

Illustrated in Fig.3, in any of the embodiments described or claimed herein, the utility room or rooms 70 may comprise a top opening 71. The top opening 71 may have a hatch or equivalent for selectively providing access into the respective utility room 70. The top opening 71 may be utilised for example to provide supplies, such as fish feed, fuel, or other necessities for the operation of the fish farming system 1.

Advantageously, the utility room or rooms 70 and/or the upper buoyancy member 9 may be arranged for receiving a container or equivalent landed onto the utility room 70 or upper buoyancy member 9. The container may carry equipment, for example a net for crowding, testing equipment, fish treatment equipment, or other items required for the operation of the fish farming unit 1 but which do not need to be permanently available.

The utility room or rooms 70 may comprise a top opening 71 and be arranged for a container or equivalent to be landed on the top opening 71. For example, by landing a container with an opening or a hatch at its bottom, direct access into the utility room 70 can be provided through the top opening 71 from inside the container after it has been landed on top of the utility room 70.

Alternatively, the top opening 71 may be arranged on the upper buoyancy member 9, equivalently.

A guiding structure (not shown) may be arranged on the upper buoyancy member 9 and/or the utility room or rooms 70 for guiding a container or equivalent which is to be landed thereon.

The utility room or rooms 70 may, additionally or alternatively, be arranged for landing personnel thereon. For example, a vessel with a heave compensated gangway can be used to land on the roof or top of the utility room 70 and a door or opening (which can be the top hatch) can be used for personnel to move inside the utility room 70. In this manner, safer landing of personnel can be achieved in that the utility room 70 may have a higher freeboard than other parts of the collar 2.

In any of the embodiments described or claimed herein, the columns 8 may be arranged on the lower buoyancy member 7 in a position which is shifted radially inwardly compared to a mid-point on the lower buoyancy member 7. (The term “radial” should be understood as a line extending from the horizontal centre point of the floating collar 2, even if the collar is polygonal and not circular.) Fig.8 illustrates an embodiment in which the columns 8 are positioned approximately at a mid-point on the lower buoyancy member 7. Alternatively, as can be seen for example in Fig. 9, the columns 8 may be shifted inwardly so to be positioned closer to the enclosure 3. This may provide structural advantages and improved functionality for the fish farming system 1.

In any of the embodiments described or claimed herein, the columns 8 may be angled inwardly or outwardly. In other words, they do not necessarily need to be arranged vertically. This may be the case if, for example, the upper and lower buoyancy members 7,9 have different diameter, or if the placement of the columns 8 on the buoyancy members 7,9 otherwise dictate an angled orientation of the columns 8.

Illustrated in Figs 3, 9 and 10, in any of the embodiments described or claimed herein the lower buoyancy member 7 may have an elevated deck 72 for an operator. The elevated deck 72 may be arranged in conjunction with the boat access 59a on the lower buoyancy member 7. The elevated deck 72 may be provided for an operator to walk or move from a boat or ship docked at the floating collar 2, and/or for an operator to carry out manual operations such as operating the fish farm system 1, carrying out maintenance, or other required tasks. By providing an elevated deck 72, a required freeboard may be provided between the waterline and the deck at which the operator is present, for example in order to ensure appropriate safety of the operator. Providing an elevated deck 72 may avoid the need to de-ballast the floating collar 2 to a position at which the upper surface of the lower buoyancy member 7 itself has the required freeboard or height above the waterline, as that may not be necessary from an operational point of view.

In any of the embodiments described or claimed herein, the floating collar 2 may be substantially polygonal, having, for example, more than 6 sides, 8 sides, 10 sides, 12 sides, 16 sides, or more than 16 sides. A floating collar 2 according to embodiments described here may, for example, allow for efficient manufacturing and assembly. During construction, individual parts, such as each column 8, may share a common geometry, providing efficient manufacturing and assembly processes.

Advantageously, a horizontal cross-section of at least one of the columns 8 may have a polygonal shape. The polygonal shape may have four, five, six, or more than six sides.

Illustrated in Figs 11 and 12, the column 8 may be positioned at the intersection of two parts 7a,7b making up the polygonal lower buoyancy member 7.

The polygonal shape of the column 8 may comprise at least one side 74a which is perpendicular to a longitudinal direction of the first part 7a.

Alternatively, or in addition, the polygonal shape of the column 8 may comprise at least one side 74b which is parallel with a longitudinal direction of the first part 7a.

Alternatively, or in addition, the polygonal shape of the column 8 may comprise at least one side 75a which is perpendicular to a longitudinal direction of the second part 7b.

Alternatively, or in addition, the polygonal shape of the column 8 may comprise at least one side 75b which is parallel with a longitudinal direction of the second part 7b.

By providing the column 8 as a polygonal structure with at least one side perpendicular to or parallel with the longitudinal direction of the lower buoyancy member 7 provides structural advantages in the interconnection between the column 8 and the lower buoyancy member 7. For example, the parts 7a,b can be provided with strengthening members extending longitudinally and/or transversely on the inside of the lower buoyancy member 7. Providing sides of the column 8 which align with the strengthening members can provide enhanced structural stability and avoid local regions of high stress concentration in the interface between the column 8 and the lower buoyancy member 7.

Illustrated in Figs 13-16, in any of the embodiments described or claimed herein, the upper buoyancy member 7, the lower buoyancy member 9, or both the upper and lower buoyancy members 7,9 may be entirely or partially replaced by a truss structure.

As illustrated in Fig.13, the upper buoyancy member 7 may be replaced by an upper truss structure 80, which may extend between upper parts of the columns 8.

Optionally, or additionally, as illustrated in Fig.14, the lower buoyancy module 9 may be replaced by a lower truss structure 81. Figs 13 and 14 illustrate the truss structures 80,81 as being a predominantly flat, two-dimensional structure, however other designs may also be suitable, such as a truss structure also having a depth / a more three-dimensional, elongate structure. Either of the truss structures 80,81 may be arranged upright (as truss structure 80) or horizontal (as truss structure 81), according to any particular design requirements.

Advantageously, in any of these embodiments, the lower truss structure 81 may be arranged so as to be positioned above the water surface in the service position 15 of the floating collar 2. In such a case, the lower truss structure 81 may, for example, be available for inspection when in the service position 15.

Illustrated in Fig.15, the floating collar 2 may also comprise a combination of truss structure 81 and lower buoyancy module 9, for example alternately or with a portion of the floating collar 2 being made up of a truss structure 81 and part of the floating collar 2 being made up of a truss structure 81. The same may be the case for the upper buoyancy module 7 and upper truss structure 80, as appropriate.

Illustrated in Fig.16, the shape of the columns 8 may be adapted to the overall design, for example the columns 8 may comprise an increased volume 8’ at a lower part thereof in order to provide additional buoyancy, if required.

Optionally, the columns 8 may be arranged as a truss structure, or some of the columns 8 may be arranged as a truss structure. In this manner, some (or all) columns 8 may be arranged to provide structural support but not significantly contribute buoyancy to the collar 2.

In any of the embodiments described or claimed herein, if using a double net 4a,b, the fish farming system 1 may be provided with spacers 83,84 provided between the inner net 4b and the outer net 4a. This is illustrated in Figs 17 and 18. In Fig.17, spacers 83 are provided between the inner and outer nets 4a,b, wherein the spacers 83 are made up of an elongate, pliable water-tight container filled with liquid. The container may advantageously be filled with sea water. Due to the water-tight structure, the container may have enhanced stiffness (even if not completely rigid), such as to provide stability and support to the nets 4a,b. Being positioned between the nets 4a,b, the container prevents the nets 4a,b from contacting each other, for example due to water currents, which may otherwise have led to increased wear and potential damage. The spacers 83 may be fixed to one or both of the nets 4a,b, form a part of one of the nets 4a,b (e.g. be sown into the net), or simply be positioned between the nets 4a,b without being fixed to either of them.

In Fig.18, the spacers 84 are provided by flexible or rigid pipes arranged between the nets 4a,b, for example PE pipes. The pipes may be positioned in holders in one of the nets 4a,b, for example sewn-in pockets in the nets 4a,b. Optionally, the spacers may simply be positioned between the nets 4a,b without being fixed to either of them.

Advantageously, the spacers 83,84 are suspended between the nets from the collar 2, between the lower buoyancy member 7 or from the first or second inner structure parts 51,52.

The spacers 83,84 may extend predominantly vertically between the nets 4a,b, they may be arranged predominantly horizontally between the nets 4a,b, or arranged in another shape or pattern, as appropriate.

Figs 19-26 illustrate further embodiments, wherein a crowding net 85 is provided into the enclosure 3 through one of the second inner structure parts 52. The crowding net 85 can, for example, be provided to the floating collar 2 in temporarily provided container 89 landed on the upper buoyancy member 9 and/or the column 8, or it may be present as regular equipment on the fish farming system 1. Providing a crowding net 85 as shown here is another example of accessing the enclosure 3 via the second inner structure parts 52, as also described above.

In any of the embodiments described or claimed herein, the first inner structure part 51 may comprise an actuator arrangement to handle fish handling equipment and to move fish handling equipment inside the enclosure 3.

In the illustrated embodiment of Fig.19, the fish handling equipment is the crowding net 85, however the fish handling equipment may be other items, such as test equipment, fish treatment equipment, inspection and measurement equipment (e.g. cameras and sensors), cleaning equipment, equipment to prevent disease or parasites, equipment to remove dead fish or debris, or any other item which may be required during the operation of the fish farming system 1.

The actuator arrangement may cooperate with at least one of the second inner structure parts 52 when introducing and handling the equipment into and inside the enclosure 3.

In this embodiment, the actuator arrangement is a movable trolley 86 operable to move along the first inner structure part 51 inside the enclosure 3. The trolley 86 may, for example, be movable on tracks or rails 87 (see e.g. Fig.20) arranged for this purpose, and motorised appropriately. In this manner, the fish handling equipment, in this case the crowding net 85, can be moved around inside the enclosure 3 substantially around the outer perimeter of the enclosure 3 if desired.

Other fish handling equipment may have other requirements, for example a trolley 86 could be used in conjunction with a winch-and-rope system to position particular equipment at a desired position within the enclosure 3, with the trolley 86 holding an end or a loop of the rope, on which the equipment can be moved inside the enclosure 3.

Figs 20-26 illustrate steps in a crowding process, whereby the crowding net 85 is moved about the outer perimeter of the enclosure 3 by the trolley 86, and then retrieved through the second inner structure part 52. The purpose of such crowding is well-known in the art, being employed for example for delivery of fish for slaughtering or treatment, or for moving fish between fish pens.

A transport pipe or tube 88 can be used to remove fish from the enclosure 3. The tube 88 may also extend through the second inner structure part 52 and into the enclosure 3. Alternatively, the crowded fish can be removed from the enclosure 3 via an opening on the side of the enclosure 3 or at the bottom (see Figs 7 and 8 and described in relation to Fig.27 below) wherein the fish is crowded towards this opening.

As can be seen from Figs 20-26, the crowding net 85 is pulled around the enclosure 3 to capture a part of or substantially all the fish therein (Figs.21-22). The front end of the crowding net 85 is then pulled out through the second inner structure part 52 and the upper and lower edges are also pulled in towards the second inner structure part 52 to crowd the capture fish and to provide a closed enclosure by the crowding net 85 (Figs.23-24). As the fish is removed from the crowding net 85, this can be pulled in even further to reduce the size of the enclosure. As the operation is completed with all or the required amount of fish removed from the enclosure, the crowding net 85 is again released into the enclosure 3 by reversing the movement of the trolley 86 and pulling the crowding net 85 out of the enclosure 3 again (Figs 25-26).

Advantageously, by embodiments provided herein, operations such as crowding and other activities may, if desirable, be carried out with the floating collar 2 in an operational or submerged position 16 (see also Fig.2), whereby the enclosure 3 is positioned a distance below the water surface. This may provide advantages in that the fish is not exposed to the higher water regions, which can contain higher concentration of parasites, algae or the like. Also, carrying out such operations inside the enclosure 3 in the submerged position 16 may reduce stress on the fish, thereby improving fish welfare and the efficiency of the operations.

Consequently, in any of the embodiments described or claimed herein a method of removing fish from an enclosure 3 of the fish farming system 1 may include introducing a crowding net 85 into the submerged enclosure 3 via an access channel. The access channel may be a second inner structure part 52 as described above or another channel which provides access from a surface location into the submerged enclosure 3.

The method may include removing fish from the enclosure 3 via the access channel.

The method may include driving or pulling the crowding net 85 inside the enclosure 3 to catch at least a part of the fish in the enclosure 3, and to form a closed net defined by the crowding net 85.

The method may include removing fish from the closed net via a tube 88 which extends through the access channel and into the closed net.

Figure 27 illustrates how the transport pipe or tube 88 may, alternatively, be provided from a lower opening 91 or a side opening 90 of the enclosure 3. In this manner, crowding can be carried out towards one of these openings and fish can be removed through it, for example to a well boat.

Figure 28 illustrate a cut cross-section of the first inner structure part 51 according to an optional embodiment. In addition to the air-filled dome 56, the first inner structure part 51 may comprise a compartment 92 in which a crowding net 85 can be stored. The compartment 92 may extend circumferentially about the entire inner structure part 51 or only partially about the first inner structure part 51. An activation mechanism 93, for example comprising wires or ropes for releasing and positioning the crowding net 85 within the enclosure 3 may be provided. Optionally, other equipment may be stored in the compartment 92 alternatively to or in addition to a crowding net 85.

In other embodiments, the fish farming system 1 may comprise an integrated feed storage and handling system. Fig.29 illustrates the floating collar 2 having four storage silos 100a-d for fish feed (the silos are illustrated only schematically here). The feed may be, for example, dry pellets as is conventionally used in fish farming.

Illustrated in relation to Figs 29-32, embodiments according to the present disclosure may include a plurality of feed storage silos 100a-d disposed about the floating collar 2.

As illustrated in Fig.29, the plurality of feed storage silos 100a-d can be disposed about the floating collar 2. For example, it may be advantageous to arrange pairs of silos 100a-d at opposite sides on the floating collar 2, for access and/or stability reasons, as described in further detail below. A feed conveyor 101a,b is operable to move feed between at least two of the feed storage silos 100a-d.

Fig. 29 illustrates the conveyor 101a,b being arranged to move feed between silos 100a,b, and conveyor 101c,d being arranged to move feed between silos 100c,d. in an advantageous alternative, one conveyor may be arranged to be able to move feed between all feed storage silos 100a-d. This can, for example, be done by arranging the conveyor as a “ring line” or, in the example of Fig.29 having four silos 100a-d, by adding a conveyor which is arranged to move feed between silos 100b and 100c.

Fig. 30 shows a partially cut view of a part of the floating collar 2 of one embodiment. Illustrated in Fig.30, the feed storage silos 100a-d are disposed inside respective columns 8. This can provide advantages in terms of space utilisation and stability. The column 8 may be arranged with a central space to accommodate feed.

A filling receiver 102 can be arranged in communication with at least one of the feed storage silos 100a-d. The filling receiver 102 can be arranged on the upper buoyancy member 9, or, as illustrated in Fig.30, on a utility room 70 arranged on the upper buoyancy member 9.

The filling receiver 102 may be in direct communication with one or more of the silos 100a-d such as to lead the received feed to the silo. This can be done by means of gravity or by active conveyance, e.g. with the conveyor 101a-d. For this purpose the filling receiver 102 can be in communication with the feed conveyor 101a,b and with at least one feed storage silo 100a-d via the feed conveyor 101a,b.

Also illustrated in Fig.30, a buffer tank 103 may be arranged in communication with one or more of the filling receiver, silos 100a-d and conveyor 101a,b. The buffer tank 103 may for example be directly connected to the filling receiver 102 such that feed received from e.g. a supply ship via the filling receiver 102 is first led into the buffer tank 103. The buffer tank 103 may then be in communication with one or more silos 100a-d which receive the feed for storage. This may be done by means of gravity, if the buffer tank 103 is arranged above the silo as in Fig.30, and/or by means of the conveyor 101a-d.

In any of the embodiments herein, the conveyor 101a-d may have a plurality of individual conveyor lines such as to increase capacity, provide redundance, and/or to allow conveyance to or from more than one silo simultaneously. For example when receiving feed from a supply ship, parts of the feed may be led from the buffer tank 103 to different silos simultaneously via different conveyor lines.

The conveyor 101a-d may, as illustrated, be arranged substantially horizontally inside the upper buoyancy member 9. This provides advantages that the conveyor 101a-d is protected inside the column structure.

Each feed storage silo 100a-d may comprise an elevator mechanism 104 operable to move feed from the feed storage silo 100a-d to at least one of: a mixing unit 105, described below, the buffer tank 103, or the conveyor 101a-d. Optionally, each feed storage silo 100a-d may comprise more than one elevator mechanism 104, for example to provide increased capacity and/or redundancy.

Figure 31 illustrates schematically an operational configuration in one embodiment. A silo 100a is arranged to store feed. An elevator 104 is arranged to provide feed from the silo 100a to the buffer tank 103. A mixer 105 is arranged to receive feed from the buffer tank and sea water from a sea water supply 110, such as a sea water pump arrangement, and mix the feed into the sea water. Optionally the mixer 105 may receive water from another source, such as a fresh water source. The mixer 105 makes up part of a feed distribution system and is further arranged to provide the water-feed mixture to a distribution line 111 which extends to feeding outlets in the enclosure 3. In this manner, waterborne feed can be provided to the enclosure 3 via the feeding system.

Also, the conveyor 101a-d can be seen. The conveyor 101a-d can have a discharge 112, such as a hatch which is selectively open or closed, whereby feed transported in the conveyor 101a-d can be led into silo 100a by means of gravity. (Similar discharges 112 can be arranged in the other silos 100b-d, whereby the conveyor 101a-d can discharge feed into the respective silo 100a-d via a top opening and by means of gravity.)

In an alternative, the conveyor 101a-d may be provided at a higher elevation than the buffer tank 103 such as to allow the conveyor 101a-d to discharge feed directly into a top opening of the buffer tank 103. (The mechanism for this can be similar to the discharge 112.) This may allow feed from other silos to be provided directly to the buffer tank 103 for feeding, without first providing it to silo 100a. Additionally or alternatively, the other silos may be provided with dedicated buffer tanks and/or mixers for the same purpose.

Figure 32 illustrates another alternative configuration in which two silos 100a,b can both supply feed to and receive feed from one buffer tank 103. The two silos 100a,b may be arranged in the same column 8 on the floating collar 2 or in different columns 8, or at a different position on the floating collar 2.

In all embodiments described here, one or more of the silos 100a-d may have a receiving line 113 (see Fig.32) from the buffer tank 103, or from more than one buffer tank 103 if applicable. The receiving line 113 may allow the buffer tank 103 to distribute feed to the respective silo 100a-d, for example feed received via the filling receiver 102, or to return unused feed to a silo 100a-d, for example when feeding stops. The receiving line 113 may be a simple pipe and the transfer of feed may be based on gravity, or it may be actively conveyed. The return line 113 may be made up of the conveyor 101a-d and this functionality provided by the conveyor 101a-d. Alternatively a dedicated line may be provided. For silos positioned spaced from the buffer tank 103, active conveyance may be used, indicated by dashed lines in Fig. 32.

As can also be seen in Fig.32, the provision of feed from the buffer tank 103 may be by means of active conveyance via a mixer supply line 114 and not by gravity as in Fig.31.

It may be an advantage to have more than one filling receiver 102 in the system 1. For example, there may be two, three, or more receivers 102 arranged at different position of the floating collar 2. This provides an advantage that the most appropriate receiver 102 can be selected by a feed supply ship based on e.g. weather conditions or other activities being carried out on the system 1. By means of a conveyor 101a-d according to one of the examples described above, feed can be distributed to the desired silo 100a-d independent of which receiver 102 is used.

The feed storage and distribution system may consist of one or more nodes, where each node may contain one or more of the following items: feed silo(s) 100a-d, a filling system for the feed silo(s), e.g. receiving line 113; a feed mixing and distribution system 104, 111, 114; a transport system for bringing feed out of a silo 100a-d, e.g. elevator 104; buffer tank(s) 103 in-between any of the other items.

As described, the nodes (if more than one) can advantageously be connected by an internodal feed transportation system, such as a conveyor 101a-d as described. Each node does not need to be identical in design or capacity. For example, one node may contain the silo and the filling system, while another node contains one or more feed distribution systems.

The internodal feed transportation system or other active conveyance arrangements as described above, e.g. conveyor 101a-d, receiving line 113 or elevator 104, can be a screw type conveyor, a conveyor belt, pressurized air conveyance, or any other suitable type. Particularly suitable conveyance systems may include tube chain conveyors, tubular cable conveyor systems, chain disk systems, drag chain conveyors, cable conveyor systems or tubular drag conveyors.

The internodal feed transportation system can consist of several transportation systems operating in series or parallel to increase transportation length, capacity or redundancy. Different types of transportation systems can be combined and the feed can be transported horizontally, vertically or both. The internodal feed transportation system can be used to transport feed between nodes during feeding operation, to distribute feed to several silos during loading operation from a feed transportation vessel, for emptying the feed system or to move feed from one silo to another for balancing or weigh distribution of the collar 2. Moving feed from one silo to another can be used to balance the trim and heel of the collar 2 or to redistribute feed in case of uneven feeding rates between the nodes (e.g. if one node is less used due to dominant current headings). It can also be used for emptying one silo for inspection, maintenance and repair. The internodal feed transportation system can preferably be equipped with a cleaning and/or disinfectant system that is either operating continuously or in predetermined sequences.

The internodal feed transportation system can be arranged with two or more inlets and two or more outlets such that the same system can transport feed in both directions simultaneously.

Although the silos 100a-d are here presented as being positioned in the columns 8 of the floating collar 2, it should be understood that they can be positioned elsewhere, for example in the upper buoyancy member 9, in the lower buoyancy member 7, or as a separate structure fixed onto one of these elements. Feed silos can be arranged on deck, inside pontoons, inside columns or inside equipment rooms 70. Feed silos can advantageously be integrated into the columns 8 such that the column walls make up the silo walls. Stiffeners may then be shaped suitably in order to avoid traps for feed, for example in a laying trapeze shape. Feed is preferably collected and transported from the bottom of the silo. To avoid the need for penetrations to the hull and need for access below a silo, an internal lifting system, which may make up part of elevator 104, can be used to transport the feed from the bottom of the silo to above the silo. The internal lifting system can be arranged inside a channel (circular or rectangular or any other shape) which typically can be arranged vertically or near vertically inside the silo. The internal lifting system can e.g. be a lifting screw, a conveyor bucket elevator system or a drag chain system. Optionally, the internal lifting system can be retrieved from a above for maintenance and repair.

Feed silos may be connected to a HVAC system to control temperature and humidity in the silo.

The feed distribution system 105,111,114 may consist of a dosing system to control the amount of feed and the feed rate, and a transportation system to transport the feed to the feeding point inside the enclosure 3. Feed distribution could be water borne feeding, air born feeding or a mechanical system for transporting the feed to the feeding point. Feed transportation systems can be continuous or operate intermittently. A separate, dedicated system may be used to inject the feed from the dosing system to transportation system, e.g. if the feed is mixed into the flow of a transportation fluid. This is sometimes called the mixing system, and may be combined with the dosing system. One feed distribution system can serve several feeding outlets in the enclosure 3. In such cases, the system may also include a selection system (e.g. valves) for controlling which feed outlets are being used.

For waterborne systems the feed can e.g. be injected into a water flow after a pump, it can be mixed with water in an atmospheric tank before the mixture pass through the pump, or if the atmospheric mixing tank is placed sufficiently high above the water surface the gravity force can be sufficient to transport the mixture to the feeding outlet without pumping. Suitable pumps may be centrifugal pumps, ejector pumps or any other type of pump.

Buffer tanks 103 can be used to reduce variations in a feed flow between two systems that may not be operating at the same rate or with fluctuations on the flow. For example, a buffer tank 103 can be placed between the filling receiver 102 for feed distribution system and the silo, to provide a more steady flow of feed without clogging the filling system. The loading system on the feed transportation vessel can then control the flow of feed by measuring the level in the buffer tank and stopping the transfer at a predefined max level.

By arranging several inlets and/or outlets to a buffer tank 103 (see e.g. Fig 32), the same buffer tank 103 can function between several subsystems. If the buffer tank 103 is equipped with valves or other means for opening and closing, the buffer tank 103 can function as a focal point inside a node, where every inlet to the node and outlet from the node goes through the buffer tank 103: feed supplied from a feed transportation vessel can be led to the buffer tank 103 before it is directed to the silo 100a-d. Feed from the silo 100a-d can be led to the buffer tank 103 before it is led to the feed distribution system 105,111,114. Both the inlet and outlet of the internodal transportation system can be at the buffer tank 103 in the connected nodes. The flow of feed through the buffer tank 103 can be between two or more systems at the same time. E.g. when receiving feed from a feed transportation vessel, the buffer tank 103 may open valves to drop feed to a silo 100a-d in the same node, but also open a valve to an inlet of the internodal transportation system and the valve to the feed distribution system 105,111,114. For example, as shown in Fig.32, while receiving feed through receiver 102 the system may operate to distribute feed from the buffer tank 103 to one or both silos 100a,b via lines 113 and, if desirable, also supply feed from the buffer tank 102 to the mixer supply line 114. This can allow the feed transportation vessel to offload into two or more silos simultaneously, and without interrupting the feeding of the fish. This can be particularly advantageous if weather or other conditions give constraints on which node the feed transportation vessel can operate at.

If the buffer tank 103 is located at a higher elevation than the silo 100a-d, the inlet of the internodal transportation system and the feed distribution system, it may be possible to arrange for most or all feed transfer internally within the node except for the lifting of feed from the silo 100a-d to be performed by gravity flow.

The nodes can be arranged substantially on the outer circumference the fish cage. If there are four nodes, as illustrated in Fig.29, three internodal systems may be sufficient to transport feed between any two nodes.

While the different components of the systems shown in Figs 29-32 are shown in relative elevated position in relation to each other, it should be understood that such placement is not mandatory and other arrangements may be possible, for example arranging the buffer tank 103 at the same height as the silos 100a-d and/or arranging the mixer 105 at a higher or lower elevation compared to that indicated.

As alternative arrangements for the fish farming system 1 and associated systems, the fish farming system 1 may be provided with supplies such as fish feed from elsewhere, for example a land location or another floating unit. The other floating unit may be a feeding barge, having the relevant feeding equipment, for example those components shown in Figs 31 and 32, thereon. In such a case, the floating collar 2 may not need to carry all such equipment. In another alternative, several fish farming systems 1 may be installed in proximity such that the feeding equipment can be arranged on one fish farming system 1 and serve more than one system 1. One may for example arrange one floating collar 2 with the capacity to serve more than one fish farming system 1 with feed. Hoses or pipes may be arranged between the fish farming systems 1 if there are more than one and feeding is provided from one system to others.

In any of the embodiments described or claimed herein, the fish farming system 1 may optionally comprise a plurality of inner nets 4b or an inner net having several separate compartments, arranged inside the outer net 4a. For example, by providing several inner nets 4b which each define a separate pen for fish, one may optimise production between different groups of fish. The same may be achieved by arranging the inner net 4b with several different compartments, for example by vertical separation nets extending from one side to the other or, for example, in a cross shape to provide four compartments. A cross shape to support the nets can be provided as part of the inner structure 50. A corresponding cross shape for lower support may, optionally, be arranged as part of the bottom ring 26.

By having a common outer net 4a, all the inner nets or inner net compartments can be protected from e.g. predators by the outer net 4a, and the outer net 4a may provide a common barrier in case of fish escaping from the inner nets or inner net compartments.

In any of the embodiments described or claimed herein the system (1) may comprise an inner structure (50) fixed to and extending inwardly from the floating collar (2).

In any of the embodiments described or claimed herein, the floating collar (2) may comprise a lower buoyancy member (7), an upper buoyancy member (9) and a plurality of pillars (8) interconnecting the upper and lower buoyancy members (7,9).

In any of the embodiments described or claimed herein, the inner structure (50) may be fixed to at least one of the upper buoyancy member (9) or one or more of the plurality of pillars (8).

In any of the embodiments described or claimed herein, the inner structure (50) may comprise a ring- or polygonal shaped first inner structure part (51).

In any of the embodiments described or claimed herein, the first inner structure part (51) may be supported by a plurality of second inner structure parts (52) extending between the first inner structure part (51) to the floating collar (2).

In any of the embodiments described or claimed herein, the plurality of second inner structure parts (52) may extend from the first inner structure part (51) to the upper buoyancy member (9) and/or to the plurality of pillars (8).

In any of the embodiments described or claimed herein, the enclosure (3) may comprise a double net (4a,4b), wherein an outer net (4a) is fixed to and suspended from the floating collar (2) and an inner net (4b) is fixed to and suspended from the inner structure (50).

In any of the embodiments described or claimed herein, the inner net (4b) may comprise a mort collector (53) connected to a mort collection pipe (54) arranged between the inner and outer nets (4a,b) and extending from the mort collector (53) to the floating collar (2).

In any of the embodiments described or claimed herein, the inner structure (50) may comprise an air-filled dome (56) accessible from inside the enclosure (3).

In any of the embodiments described or claimed herein, the inner structure (50) may comprise an opening (60,61) into the enclosure (3). The opening (60,61) may extend through the first inner structure part (51).

In any of the embodiments described or claimed herein, the first inner structure part (51) may comprise a work deck (51a) for an operator.

In any of the embodiments described or claimed herein, the opening (60,61) may be arranged on the work deck (51a) or arranged such as to be accessible from the work deck (51a).

In any of the embodiments described or claimed herein, the opening (60,61) may be accessible through a second inner structure part (52).

In any of the embodiments described or claimed herein, a roof (5) may be arranged to close a top section of the enclosure (3). The roof (5) may be fixed to the inner structure (50). The roof (5) may be arranged enclosed by the first inner structure part (51) and arranged to close an opening defined by the first inner structure part (51).

In any of the embodiments described or claimed herein, the fish farming system (1) may have a first operational draft (16) wherein the inner structure (50) is submerged and a second operational draft (15) wherein the inner structure (50) is at least partly above a waterline.

In any of the embodiments described or claimed herein, a gap or an opening between the inner structure (50) and the floating collar (2) may be provided at regular intervals about the outer circumference or outer sides of the inner structure (50).

In any of the embodiments described or claimed herein, a continuous gap or opening between the first inner structure part (51) and the floating collar (2).

The invention is not limited by the embodiments described above; reference should be had to the appended claims.

Claims (14)

1. Fish farming system (1) comprising:

a ring- or polygonal shaped floating collar (2), and

an enclosure (3) for fish suspended from and supported by the floating collar (2), characterized in that

the system (1) further comprises a plurality of feed storage silos (100a-d) disposed about the floating collar (2).

2. A fish farming system according to claim 1, further comprising a feed conveyor (101a,b) operable to move feed between at least two of the feed storage silos (100a-d).

3. A fish farming system according to claim 2, wherein the feed conveyor (101a,b) is operable to move feed between all feed storage silos (100a-d).

4. A fish farming system according to any preceding claim, comprising at least two feed storage silos (100a-d) arranged at opposite sides of the enclosure (3).

5. A fish farming system according to any preceding claim, wherein the feed storage silos (100a-d) is disposed inside respective columns (8).

6. A fish farming system according to any preceding claim, comprising a filling receiver (102) arranged in communication with at least one of the feed storage silos (100a-d).

7. A fish farming system according to the preceding claim, wherein the filling receiver (102) is in communication with the feed conveyor (101a,b).

8. A fish farming system according to any preceding claim, wherein the filling receiver (102) is in communication with at least one feed storage silo (100ad) via the feed conveyor (101a,b).

9. A fish farming system according to any preceding claim, wherein the filling receiver (102) is in communication with at least one feed storage silo (100ad) via a buffer tank (103).

10. A fish farming system according to any preceding claim, wherein the conveyor (101a,b) is arranged substantially horizontally inside the upper buoyancy member (9).

11. A fish farming system according to any preceding claim, wherein each feed storage silo (100a-d) comprises an elevator mechanism (104) operable to move feed from the feed storage silo (100a-d) to at least one of:

a mixing unit (105)

the buffer tank (103), or

the conveyor (101a,b).

12. A fish farming system according to any preceding claim, comprising a mixer (105) for mixing feed and water.

13. A fish farming system according to the preceding claim, wherein the mixer (105) is arranged to receive feed from the buffer tank (103).

14. A fish farming system according to the preceding claim, wherein the mixer (105) is arranged at a lower elevation than the buffer tank (103) and arranged to receive feed from the buffer tank (103) by means of gravity.