A system for farming fish

Abstract

A system (100) for farming fish consisting of one or more floating farming units (10) is described, where each farming unit (10) comprises a floating structure (20) that houses one or more closed and independent farming modules (1) where the farming modules comprise at least one production tank (13), at least one holding tank (11), where the floating structure (20) is fixed to the seabed through a set of legs (14) arranged so that it can move in a vertical direction, but has limited or no mobility in the horizontal direction.

Description

[0001] A SYSTEM FOR FARMING FISH

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a sea-based farming system for fish.

[0004] BACKGROUND

[0005] There are several challenges associated with fish farming and especially farming of salmon. These challenges threaten the salmon industry's foundation for operating, and therefore the basis for growth. This applies to lice infestations of the fish, diseases and escaping of the fish, but also the use of sea and land areas as well as energy use in production and personal injuries coming from work on the facilities. As a result of these challenges, efforts have been made in recent years to develop new technology that reduces or eliminates some of the problems, with a particular focus on lice and escape problems.

[0006] It has also been important to reduce waste in the form of fish sludge and dead fish around aquaculture facilities, which can cause problems both for the operation and for marine life in each area. Fishing waste and sludge can be considered a resource and can, for example, be dried and used as fuel in biogas plants.

[0007] There are major challenges with finding new locations for production of salmon and for the start-up of production of other species such as cod. Part of the reason is biosecurity.

[0008] Other factors that limit new possible locations are available approved area from the municipalities, possible conflicts with competing fisheries interests, or the presence of spawning grounds / spawning areas. Farmers naturally want to have the best possible operating conditions at each location. The prerequisites are defined as how much fish can be produced without affecting the environment below and around the facility. Feces and pellets as residual products may form deposits on the seabed below the fish farms. However, some of these products are spread with the current, and strong currents and great depths give greater dispersion and environmental sustainability.

[0009] Conventional farming is currently struggling with lice infestations. The presence of lice up to limit values for the number of lice per farmed salmon results in a requirement for delousing. During treatment the fish are exposed to mechanical delousing, temperature changes or medical forms of delousing. Common to all is that this results in a directly higher mortality during delousing, but also an indirect mortality in the following days. After delousing, the salmon's appetite is reduced, so it may take several days before the fish returns with the same appetite. Reduction in appetite results in lower growth than would have been the case without delousing.

[0010] In the last couple of years, winter sores have been a major challenge for fish throughout the winter season. Fish with winter sores have a higher mortality rate, at the same time fish slaughtered with winter sores are downgraded, which in turn gives a lower price for farmers. Winter sores is a bacterial infection and can occur via mechanical damage through treatment against lice, encroachment on the cage wall, etc.

[0011] Treatments can lead to further bacterial infection which is spread through the cage. Winter sores are thus a problem for fish health. Exposure in closed constructions with control over the biotic factors will probably result in a reduction in mortality. Farming at sea with floating closed cages, or semi-closed cages is part of the technology that is being tested to a greater extent and is also used and can be considered both a known and available technique in today's market and has been given the term closed cage concepts.

[0012] These concepts are often characterized by the fact that they are used in already existing plant structures and collect water with risers with filtration. This reduces the possibility of cross-contamination between devices, but it cannot be ruled out.

[0013] The concepts also use the same area as conventional farming and thus do not solve one of the industry's biggest challenges, which is available area. In addition, these concepts bring with them new problems relating to wave movements inside the closed cages because of external wave stresses. This is often called resonance waves and mainly arises from horizontal movements of closed tanks which in turn create internal waves in the water at a frequency determined by the shape and dimensions of the tank.

[0014] This can lead to unfortunate tensions in the structures and moorings, worsened growing conditions for the fish in the cage and an HSE problem for personnel working at the cage. Horizontal and vertical accelerations on installations at sea are one of the main causes of falls and crushing injuries on personnel.

[0015] From patent NO345194, a farming system for farming fish is known, consisting of a floating structure equipped with several cages for farming marine organisms, where the floating structure comprises at least one water channel, which water channel is supplied with flowing water arranged to allow said marine organisms to swim through the water channel. The water channel is placed externally on the floating structure and runs horizontally between the cages, said water channel comprising a longitudinal dividing wall to allow water flow both ways in the water channel, and respective cages comprise side water channels that run to the water channel.

[0016] From patent NO332589 a marine facility is known comprising two or more standing tanks for farming fish, with a funnel-shaped bottom, one or more water supply systems and one or more drainage systems where the tanks are arranged as integral parts of a rigid hull, where the hull comprises at least an upper rigid main hull comprising a bow section, a stern section, ship sides and a main deck and where the upper rigid main hull is closed and one or more tanks are arranged with a loose and vertically displaceable raised bed.

[0017] From the commitment for development permits for the Salmon Zero concept, the Directorate of Fisheries' reference 16 / 8836, a completely closed marine facility with full recycling of production water is described. In the facility, food fish will be produced until slaughter. Production will take place in closed cages at sea. The recycling and water treatment systems must mainly be located on land, and parts of the water treatment must be integrated into the production units. In the longer term, it should be possible to move all installations to sea, with recycling facilities on board a suitable fleet. The facility must be modular.

[0018] SUMMARY OF THE INVENTION

[0019] It is an object of the present invention to solve some of the problems with the above-mentioned systems with the main emphasis of reduction of resonance waves in the construction, improving fish health, better use of coastal areas and reducing HSE problems.

[0020] The aforementioned is achieved with a farming system as defined in independent claim 1 where the system consists of one or more floating farming units, and where each farming unit comprises a floating structure that houses one or more closed and independent farming modules, where the floating structure is attached to the seabed through a set of legs arranged so that it can move in a vertical direction, but has limited or no movement in a horizontal direction.

[0021] The invention thus includes a marine construction which mainly consists of closed farming modules, consisting of at least one production tank and at least one holding tank in addition to at least one unit for collecting and processing waste from production and collecting and processing dead fish. In one embodiment, the mentioned production tanks and holding tanks can also be separated from the floating structure by disconnecting the floating structure and being transported away in a horizontal direction. This can be done regardless of whether the tanks are filled with water or are completely or partially empty of water.

[0022] The system as described should reduce the risk that lice and diseases can come from water intake as well as from cross-contamination of the water from one farming module to another.

[0023] The facility will be modular so that it can easily be scaled up in the event of future increased demand or scaled down in the event of reduced demand. Each floating structure is in independent connection with the seabed through a set of legs, where the structure only has a movable degree of freedom in the vertical direction and is locked in the horizontal plane. The legs can be firmly attached to the seabed by, for example, being equipped with suction anchors, or poles, or removable weights that hold the legs in place, or a combination of one or more of the aforementioned attachments.

[0024] This connection to the seabed will prevent wave resonance in both the production tanks and the holding tanks and, in addition, there will be no need for mooring, which normally in floating constructions extends beyond a larger area. As the facility is module-based, it will also make it possible to place the modules optimally in relation to the seabed.

[0025] As the floating structure is locked in a horizontal direction, the risk of injury to personnel working on the system is also reduced.

[0026] The present invention can be placed in places with low current and depths of around 7 meters and deeper and will not be in direct competition for the area used in conventional farming and be the solution to using areas that are not suitable for conventional farming.

[0027] Preferred embodiments will be described in more detail in the subsequent dependent claims.

[0028] Accordingly, in a second embodiment of the above-mentioned system, the floating structure is attached to the seabed through vertical telescopic legs where an upper, outer cylinder is attached to the floating structure and a lower, inner cylinder is fixed to the seabed.

[0029] In a third embodiment of the above-mentioned system, said farming module(s) comprise a production tank for growing fish, where the production tank rests on the floating structure on a horizontal plane flange, and is simultaneously locked to the floating structure in a horizontal direction. And where the production tanks is independently movable in an upward vertical direction in relation to the floating structure.

[0030] In a fourth embodiment of the above-mentioned system, the production tank can be separated from the floating structure by being lifted vertically up and out.

[0031] In a fifth embodiment of the above-mentioned system, said farming module(s) comprise at least one holding tank for preparation of fish for slaughter, where the holding tank rests on the floating structure on a horizontal plane flange. And at the same time is locked to the floating structure in a horizontal direction, and where the holding tank is independent movable in the upward vertical direction in relation to the floating structure.

[0032] In a sixth embodiment of the above-mentioned system, the holding tank can be separated from the floating structure by being lifted vertically up and out.

[0033] In a seventh embodiment of the above-mentioned system, the farming module further comprises:

[0034] - at least one dead fish unit for receiving and processing dead fish coming from at least one production tank and / or at least one holding tank, and

[0035] - at least one water purification unit for filtering water coming from the at least one production tank and / or the at least one holding tank, where the purified water is returned to the at least one production tank and / or the at least one holding tank.

[0036] In an eighth embodiment of the above-mentioned system, said farming module further comprises a bio-waste facility common to all modules for receiving waste coming from purification unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The invention will now be described with reference to the figures 1 to 3 mentioned below. Further properties and advantages appear in the following detailed description. Figure 1 shows a farming facility according to the present invention consisting of five farming units shown in perspective,

[0038] Figure 2 shows the system consisting of a farming unit seen from above in a horizontal section, and

[0039] Figure 3 shows a farming unit in perspective. DETAILED DESCRIPTION OF THE INVENTION

[0040] The following reference numbers are used in the detailed description and in the figures:

[0041] I Farming module

[0042] 10 Farming unit

[0043] 13 Production tank

[0044] II Holding tank

[0045] 17 Fodder tank

[0046] 18A Water purification unit

[0047] 18B Dead fish unit

[0048] 20 Floating structure

[0049] A Biowaste plant

[0050] 14A, 14B Telescopic legs, 14A part of the floating structure and 14B fixed in the bottom

[0051] 1120 Plan horizontal flange for the holding tank 11 and floating structure 20 1320 Plan horizontal flange for the production tank 13 and floating structure 20

[0052] SiT Seawater intake pipe

[0053] 100 Farming system

[0054] Figure 1 is showing the present farming system 100 with several interconnected farming units 10 and where each unit 10 comprises a floating structure 20 with at least one production tank 13 where said production tank(s) 13 further comprises a superstructure at a height from the upper deck of the unit 10, And where the top of the superstructure is covered with solar panels 12 which provide energy to supply the production tanks 13 and / or the holding tanks 11 with electricity for the right amount of light and electricity for pumps for internal air circulation over the pool. A bio-waste plant A that receives waste from all the modules 10 is located on the upper deck of one of the modules 10.

[0055] Figure 2 is showing the present farming system 100 in a horizontal plan view of a farming unit 10 and with two closed farming modules 1. A module on the left side embedded in a dashed outline is showing production tank 13, holding tank 11, water purification unit 18A, dead fish unit 18B, and fodder tank 17, pipe connections between the tanks as well as the structure for the attachment of legs 14 a, b, and intake of sea water SiT. On the right side of the module 10, a corresponding, mirrored farming module 1 is shown which is not embedded.

[0056] Figure 3 is showing a farming unit 10 in perspective where parts of the floating structure 20 are illustrated, and where the production tank 13 is raised vertically above the floating structure 20 and its flat horizontal flange 1320 on which the production tank 13 rests during production. The figure is further showing the holding tank 11 raised vertically above the floating structure 20 and its flat horizontal flange 1120 on which the holding tank 11 rests during production. These tanks 11,13 are both completely sealed and not in communication with the sea and may be lifted vertically up either by water being pumped out of the tanks which results in the tanks gaining greater buoyancy, and / or by the tanks being physically lifted vertically by a mechanical device.

[0057] The figure further shows some of the legs 14a, b which in this embodiment of the invention are illustrated as telescopic legs and where 14a is an upper, outer cylinder which is attached to the floating structure 20 and where 14b is a lower, inner cylinder which is in connection with the seabed and motionless. In the event of tidal variations, the upper, outer cylinders 14a will move together with the floating structure 20 in a vertical direction up and down over each respective lower, inner cylinder 14b.

[0058] Both the tanks 11, 13 are closed units located in cylindrical openings in the floating structure 20. They can move or be moved in the vertical direction but are locked in relation to the floating structure in the horizontal direction. That the tanks are closed means in this context that water is taken out of the tanks and transferred to the water purification unit 18A where the water is treated with, for example, filtration, disinfection and the addition of oxygen before it is pumped back to the tanks 11, 13. In this way, there is control over the quality of the water. Water that is taken in or discharged into the surrounding sea is likewise led through the water purification unit 18A where sludge is taken care of and stored in separate tanks. Dead fish are taken to dead fish unit 18B for processing and stored as silage. Sludge and silage are then transported out of the module(s) into ships and / or in pipes to land. The fish's growth environment is thus safeguarded, and pollution of the environment around the farm is avoided.

[0059] Although the production tank 13 and the holding tank 11 are shown embedded in the floating structure 20, they can also be placed floating outside the floating structure 20, but still attached to it, so that the mentioned tanks 11, 13 can only move vertically in the sea. In this embodiment, the floating structure 20 will only house the other mentioned units and where the floating structure 20 is still in connection with the seabed with legs as mentioned. Here, flexible pipe connections will be used between the floating structure and the tanks.

[0060] By the fact that the closed tanks are locked to the floating structure in a horizontal direction, it will be largely avoided that resonance waves occur in the tanks. Known aquaculture facilities with closed tanks are attached to the seabed by anchoring, i.e. moorings with chains that extend outwards from the facility to anchors in the seabed. Such solutions cause horizontal movements in the form of accelerations that create resonance waves in the tanks. Furthermore, anchorage-based solutions require a large area due to mooring lines that extend outwards from each installation. It can be typically about 1.5 to 2 km in each direction. The present invention thus has a major advantage in that several floating structures can be placed closer to each other and then provides a better utilization of the available area within each license to operate.

Claims

CLAIMS1. A system (100) for farming fish consisting of one or more floating farming units(10), where each farming unit (10) comprises a floating structure (20) that houses one or more closed and independent farming modules (1) where the farming modules comprise at least one production tank (13), at least one holding tank (11), characterized in that the floating structure (20) is attached to the seabed through a set of legs (14) arranged so that it can move in a vertical direction, but has limited or no mobility in the horizontal direction.

2. The system (100) according to claim 1, where the floating structure (20) is attached to the seabed through vertically oriented telescopic legs (14A, B) where an upper, outer cylinder (14A) is attached to the floating structure (20) and a lower, inner cylinder (14B) is locked to the seabed.

3. The system (100) according to claim 1, or 2, where the at least one production tank (13) is connected to the floating structure (20) in a horizontal direction and has limited or no mobility in the horizontal direction and is independently movable in an upward vertical direction in relation to the floating construction (20).

4. The system (100) according to claim 3, where the at least one production tank (13) can be separated from the floating structure (20).

5. The system (100) according to claims 1 to 4, where the at least one holding tank(11) is locked to the floating structure (20) in a horizontal direction, and where the holding tank (11) is independently movable in an upward vertical direction in relation to the floating structure (20).

6. The system (100) according to claim 5, where the at least one holding tank (11) can be separated from the floating structure (20).

7. The system (100) according to the preceding claims where said farming module (1) further comprises:- at least one dead fish unit (18B) for receiving and processing dead fish coming from at least one production tank (13) and / or at least one holding tank (11),and / or- at least one water purification unit (18A) for filtering water coming from the at least one production tank (13) and / or the at least one holding tank (11), where the purified water is then fed back to the at least one production tank (13) and / or the at least one holding tank (11).

8. The system (100) according to claim 7, where said farming module (1) further comprises a biowaste facility (A) common to all modules (1) for receiving waste coming from the water purification unit (18A) and / or the dead fish unit (18B).

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