GB2577454A

GB2577454A - Floating, closed, self-supporting fish-farming cage comprising a tubular membrane made of a polymer with high mechanical strength and low biofouling adhesion

Info

Publication number: GB2577454A
Application number: GB1919209.5A
Authority: GB
Inventors: Octavio Bronstein Garin Guillermo
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-06-21
Filing date: 2018-06-19
Publication date: 2020-03-25
Anticipated expiration: 2038-06-19
Also published as: GB201919209D0; CA3067662A1; GB2577454B; NO20191483A1; CL2017001653A1; WO2018232543A1

Abstract

The invention relates to a closed, self-supporting cage (100) for fish-farming in the sea, aimed mainly at the fish-farming industry and/or storage centres, which adapts to the square, rectangular or circular shapes of the existing meccano-type floating metal structures (90), with perimeter passages, which comprises a tubular membrane (1) such as a bag made of a polymer with high mechanical strength and low biofouling adhesion, that ends in a conical shape at the distal end from the surface thereof, wherein said tubular membrane (1) comprises floats (2, 2') that aid the buoyancy of same in the water and which are incorporated into said actual tubular membrane (1); an upper sleeve (6) such as a sealed continuous pocket containing, on the inside thereof, a steel cable that runs along the entire upper edge of the tubular membrane (1), from which a plurality of couplings start; suction or "lift-up" means (4, 4') located centrally on the bottom and inside the tubular membrane (1); and outer perimeter rings (11) concentric with the liner of the tubular membrane (1) which basically consist of a steel cable covered with high-strength polyethylene, which serve as an exoskeleton for the tubular membrane (1). The invention further relates to a system for fish-farming in the sea, which comprises a plurality of cages and a system for supplying refreshing water to the cages (100), which comprises means for treating and recirculating water.

Description

FLOATING, CLOSED, SELF SUPPORTING FISH FARMING CAGE, COMPRISED OF A TUBULAR MEMBRANE MADE OF HIGH STRENGTH AND LOW BIOFOULING ADHERENCE POLYMER AND FISH FARMING CAGE SYSTEMS.

FIELD OF APPLICATION

The present invention refers to ocean fish farming cages, more specifically to a floating, enclosed, self supporting farming cage, mainly aimed at the aquaculture industry and collection centers, among others, and a fish farming cages system.

DESCRIPTION OF PRIOR ART

Aquaculture consists of breeding different species of fish, mollusks, crustaceans, and algae within a containment enclosure to avoid their escape and the access of predators, under controlled conditions. Said activity may be classified as: fresh water aquaculture and marine aquaculture.

Production of marine species by means of aquaculture cages is a relatively recent practice, since it started with the farming of salmon in Norway during the 70's in the past century.

Increase in the utilization of aquaculture in cages is owed to growing consumption demand and the competition faced by the fishing industry, caused by available natural and human resources, economies of scale, the need to obtain a higher productivity per area unit, and the need to expand to new fish farming areas at open and off-shore seas.

This expansion of "aquaculture farms" towards open seas is given by the interest in reducing the effect of the fishing activity on species and sea beds in highly exploited fishing grounds (since certain fishing methods and arts are not too respectful of the environment as they ought to), ensure product supply trying to maintain its quality, observing rigid international, community, and state norms at each specific area on the protection of the environment and human consumption products, in constant and increasing demand.

Cages usually are fixed or floating structures with circular or polygonal shapes (square, hexagonal, etc.), from which the marine species containment spaces are suspended in the form of a net to allow the flow of water, but not the flow of production or predators. Generally, the material used for cages is steel or plastic materials such as polyethylene.

The size of marine aquaculture cages may vary as a function of containment volume needs, reaching up to 30 meters in diameter, equivalent to a perimeter of up to 94 meters and an up to 700 m2 footprint on the ocean surface. In addition to this large net volume, special nets must be installed against predators, both marine and avian. The net against marine predators is a secondary net placed around the main containment net at a distance of approximately one meter. The protection net against birds is placed at the upper part of the cage, normally in the marine artifact topsides.

There are several challenges to be met in respect of the technology and its resistance to the environment in which it must operate.

One of them is the effect of diverse environmental forces, encompassed in the external forces of waves, currents, and wind. The simple systems of suspended nets are typical of areas near the coast, where environmental conditions are less severe and it is possible to use a simpler system, but problems arise involving space and water contamination (feces, dead fish, contamination coming from inland activity, etc.) due to shallower water depth and a lower water renewal rate with relation to areas located further away from the coast.

The weight increase due to the incrustation and accumulation of different marine organisms (also known as "fouling", formed by algae and mussels among others) is another problem in every marine aquaculture cage, in many cases making it necessary to clean up and repair the cages, a circumstance that, depending on the cage type, may become an important costs and logistics problem for aquaculture park or farm operators. The fouling problem is particularly relevant for some materials such as steel. On the other hand, the existence of this fouling may cause drifting derived from net permeability decrease, which creates a sail effect, representing an increase of the loads to which the anchoring system is subjected.

With reference to the latest studies on diseases affecting farmed fish, stands up the marine louse problem in Norway marine salmon farming processes, a circumstance which is being settled by lowering nets to depths greater than 8 meters or creating physical barriers down to such depths so that said parasites do no harm fish.

Patent application document W02011133045 (Al), dated 10-27-2011, of inventor Kyrkjeboe Martin, entitled "FISH FARM CONSTRUCTION AND METHOD FOR WATER FLOW IN A FISH FARM CONSTRUCTION" describes a fish breeding structure, comprising a closed net cage affixed to a floating collar that is, at least, partially submerged in water that also possesses, at least, an admission tube for the supply of fresh water, where water is supplied to the net cage with the help of one or more water distributors, and also has an outlet at a lower part of the lower section of the net cage for the outflow of water and net cage residues through an outlet pipe. The floating collar is formed by a rigid construction for the enclosed net cage comprising, at least, two separate walls and the floating collar comprises, at least, a water deposit connected to the same, and, at least, one admission pipe to receive and distribute fresh water, and a number of water distributors set mutually spaced around the floating collar and prepared to receive and distribute fresh water at the net cage. It also describes a method for the water flow passage at a fish farm construction.

Patent application document KR20120119501 (A), dated 10-31-2012, of inventors LEE SOO SAING and KIM MI SUK, entitled "SEPARATE COLLECTION APPARATUS FOR ANTIPOLLUTION OF FISH HOLDING FARM WATER AND SEPARATE COLLECTION METHOD THEREOF", describes a device to collect separately foreign materials so as to prevent water contamination at fish cage farms, such as remnant foodstuffs, through an aspiration hose. A hopper-shaped protection net is installed in a cage net. A part of the foreign materials to be sucked is located at the final part of the protection net. A foreign materials collection net is installed alongside the inclined side of the protection net. A foreign materials aspiration hose is installed at a part that is connected with the foreign materials suction part. A suction pump connected to a connection hose discharges into a receptacle, where a purifying unit installed in the receptacle purifies the foreign materials discharged through the connecting hose and drains the purified products.

Patent application document US4798168 (A) dated 01-17-1989, of inventors VADSETH RAGNAR and VADSETH ARNE, entitled "ARRANGEMENT FOR FARMING OF FISH, SHELLFISH AND OTHER MARINE BEINGS", describes an arrangement to improve the farming of fish and other similar species, which comprises an enclosure formed as a bag with a preferably circular transversal section submerged in water, with an upper edge of the bag that defines an opening on the water surface and is fastened to the floats or set on an land-based fixture. The bag fabric is preferably watertight, and a hose and pump arrangement is supplied to suck water from a depth having a favorable water temperature, and to eject the water in the bag through an outlet to the water surface, which outlet being oriented tangentially to the transversal horizontal section of the bag.

Patent document US5660141 (A) dated 08-26-1997, of inventors KJERSEM GEIR; AUBERT KARSTEN; FURNES GUNNAR and FRYDENB FREDDY, entitled "PROCESS AND ARRANGEMENT FOR THE SUPPLY OF WATER TO A POND", describes a fish farming device comprising a pool with an external waterproof annular wall to float in a body of water. A water distributor is located at an upper part of the pool to direct the flow of water in the pool and to adjust the rotating water volume in the pool. An exhaust or outlet is found at the bottom of the pool for the free flow of water pool residues in the surrounding water mass. The water distributor includes a regulation handle to change water flow direction from the distributor in order to regulate the rotation speed of water volume in the pool.

All previously mentioned documents present isolated solutions to different problems with enclosed fish farming net cages, but none in particular meets all the features of this invention.

Therefore, there is a clear challenge in finding a design, a solution, which brings together resistance to environmental conditions, good ocean behavior, allows for a proper and safe operation and maintenance strategy while not increasing costs and also allows the adequate farming of marine species, the central purpose of this kind of devices, preventing the entry of ocean water pathogens and contaminants into fish farms and the attack of predators, and capturing feces and foodstuffs falling to the ocean bottom. Also avoiding the costly maintenance of large spreads of nets. This allows for a cycle with lower production costs and reduces the risk of catastrophic events resulting from Harmful Algal Blooms.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 shows a general outline of one of the modes of the fish farming cage in the present invention.

Figure 2 shows a partial front view and a section of the tubular membrane of the present invention showing floats and lift-up aspirators.

Figure 3A shows a partial view of the upper portion of the tubular membrane of the present invention.

Figure 3B shows a partial view of the upper portion of the tubular membrane and the upper turnbuckles linking it to the floating meccano-style metal structure. Figure 4A shows a partial lateral section of the upper flotation system. Figure 4B shows a partial lateral section view of the lower flotation system. Figure 5 shows the system protection rings of a cage in the present invention and the anchoring means to the meccano-style metal floating structure.

Figure 6 shows the cage bottom anchoring system in the present invention.

DETAILED DESCRIPTION OF THE INVENTION

As shown in Figure 1, the invention provides an enclosed self-supporting floating farming cage (100) comprising a bag-type tubular membrane (1) made of high mechanical strength polymer and low biofouling adherence, with control means against pathogens, caligus, harmful algae, and waste control means. In addition, it comprises structural anchoring means, consisting of steel pipes or steel cables inserted into membrane pockets located at the cage upper edge mouth that link the tubular membrane (1) with the meccano-style floating metal structures (90) or existing rafts; bottom anchoring means maintaining the cage position by means of a system of anchors or weights laid on the ocean floor; floats (2, 2") located in the tubular membrane (1) that help supporting it on the water and incorporated into the tubular membrane (1) proper; a bottom ear, consisting of a shackle located at the bottom of the cage used to connect the cable that lifts the cage for cleaning or product extraction; a guiding cable to raise the bottom of the cage; and a cage bottom net to prevent products from being suctioned during water renewal and treatment processes.

Existing cage systems have a number of rafts (90) consisting of a floating quadrangular, rectangular, or circular meccano-style metal structures, with perimeter passageways (91) having metal handrails (92) on one or both sides of them. Inside these perimeter passageways (91) an opening is created from which the tubular membrane (1) or bag is linked by way of hitches, where the number of hitches adapts the shape of the tubular membrane (1) to the shape of the floating metal structure. This is how the cage (100) in the present invention adapts itself to such floating quadrangular, rectangular, or circular metal structures taking advantage of existing structures.

The tubular membrane (1) in cage (100) has a general tubular shape with a square, hexagonal, octagonal, or circular cross section.

In a preferred embodiment of the invention, the tubular membrane (1) made up of high mechanical strength polymer (with a circular cross section), culminates in a conical section (3) at the side distal to the surface, where the conical section (3) houses lift-up means (4, 4').

In fact, as shown in Figure 2, inside the conical section (3) there is a first lift-up device (4'), named lower lift-up found at the bottom of the tubular membrane (1) that, through pipes towards the surface, collects the excess foodstuffs not consumed by fish, feces, and particles in general reaching the bottom of the tubular membrane (1). In addition, this mean provides weight that helps to maintain the tubular membrane (1) stretched.

On the other hand, and above the lower lift-up (4'), a second lift-up (4) is located, named upper lift-up, comprising an interior net (5) of the same diameter as the tubular membrane (1), where such upper lift-up (4) is lodged and rests. This interior net (5) has a double function: on one hand, it supports the upper lift-up (4) and also separates waste materials such as not consumed foodstuffs, feces, and particles smaller than the diameter of the orifices of this interior net (5) in respect to the larger ones, mainly related to process mortality and allows the collection of dead fish.

As shown in figures 2, 4A, and 4B, the flotation system of the cage (100) comprises at least one upper float (2) and at least one lower float denominated air ring (2'), which are incorporated to the body of the tubular membrane (1) creating a kind of perimeter pocket around the outside mantle of the tubular membrane (1) that is filled with air. The upper float (2) fulfills a double function: it increases flotation in the upper part of the membrane or part proximal to the surface and rigidizes the structure without incorporating unnecessary loads at specific points. The air ring (2') has a smaller dimension relative to the upper float (2) since they only intend to provide rigidity to the structure, but since they are found on the lower part of the tubular membrane (1) or distal part to the surface, it is not required to increase its flotation.

The tubular membrane (1) itself allows caring for the habitat of the controlled fish without relation to the exterior, which leads to avoid environment contamination, and also prevents fish contamination from the environment. In addition, this tubular membrane (1) has a reinforcement in all its upper edge, denominated upper sleeve (6), as shown in Figure 3A, where a kind of continuous sealed pocket is generated containing a steel cable inside (not shown) from which a number of hitches are found for upper metal turnbuckles (7), as shown in Figure 3B, which tie the tubular membrane (1) to the meccano-style floating metal structure (90), where the hitches or anchoring means are arranged at both ends of the upper turnbuckles (7).

In order to further prevent the predatory action of sea wolves, a net or an additional portion of tubular membrane, attached with Velcro, may be added (6') (Figure 4A) above the upper edge of the tubular membrane (1), for example, to isolate with headroom the presence of fish from sea wolves, because it breaks visual contact with fish. The same happens with the submerged zone of the tubular membrane (1), which prevents visual contact and does not allow the ripping of the tubular membrane (1) with the action of their biting, since it has a high mechanical strength.

Immediately under this upper sleeve (6) there is an overflow system consisting of a drainage orifice (8) with one-way routing means, conducting water to the outside of the tubular membrane (1), where these routing means might be a system of folds that close the orifice (8) thus preventing exterior water from flowing into the tubular membrane (1) or it could be a pumping system that performs a similar function, so as to allow the evacuation of water inside the tubular membrane (1) when there are bad weather conditions that bring considerable waves that endanger cage buoyancy (100).

As shown in Figure 5, the invention also provides at least two exterior perimeter rings (11) consisting basically in a steel cable coated with high strength polyethylene that prevents metal cable friction with the tubular membrane (1). These external concentric perimeter rings (11) fulfill the function of a tubular membrane (1) exoskeleton so that all concentrated loads are exerted on these rings and not directly on the tubular membrane (1), since from these external perimeter rings (11) come out most of the anchoring with the different turnbuckles, both towards the floating metal structure (90) and the marine bed. Thus, the tubular membrane (1) will function with the least concentrated stresses so as not to stretch the same directly and allowing a relatively free mobility and, at the same time, attaining adequate containment that prevents these motions from being excessive. Consequently, the external perimeter rings (11) stress some upper turnbuckles (12) linking them to the floating metal structure (90) and stress some vertical turnbuckles (13) that link an external perimeter ring (11) to the immediately following external perimeter ring (11) or the one found immediately further down. The last external perimeter ring (11), found at the distal part of the tubular membrane (1) relative to the surface, has two additional functions: on one hand it contains a series of cables which intersect in order to support the bottom of the tubular membrane (1) and thus avoid the detachment of the tubular membrane (1) from the floating metallic structure (90) (not shown), whereas on the other hand, the bottom anchoring (14) comes out for the fastening of the cage (100) to one point (see Figure 6).

The cage (100) of the present invention possesses all the necessary structures to incorporate diverse control systems, water recirculation, CO2 removal, rotary filtering, fractionating, nitrite filter, UV sterilization, temperature control, buoyancy control, pH control, 02 injection.

In fact, cage water renewal supply means (100) are essential since this is a closed system, where this renewal water must be in a special condition to maximize fish survival in such cages. Renewal water is supplied by a support ship providing the following services to the system: a) Pre-filtering to remove coarse particulate; b) Ultra filtering with a membrane system allowing the disinfection of water through the physical removal of bacteria and viruses, the elimination of organic matter and ammonia, and water quality improvement; c) Raise water pressure by means of a pump; d) Oxygenate water through an oxygenation system utilizing VPSA technology. The VPSA technology allows for the generation of oxygen at the site, with a significantly lower fuel consumption compared to alternative technologies; e) Gas extraction, such as CO2; and Injection of 02 using cones or hydrophilic membrane systems.

These water treatment and recirculation means, whose purpose is to carry out physical and chemical processes to restore water quality to optimal levels, is set up on a naval artifact and comprises: A centrifugal pump to boost water flow at required pressures.

Mechanical coarse filtering with a wire mesh of approximately 100 microns, focused on capturing coarse particulate.

* Ultra filtering, removing particles up to 0.02 microns, whose purpose is to remove organic material macro molecules, disinfect bacteria and viruses through mechanical removal, and eliminate harmful contaminants like ammonia. ;* Degasification that eliminates the CO2 produced by means of a multi-tubular contactor with membranes made of hydrophobic materials and micro-perforations that take away the CO2 to an extraction gas in atmospheric or vacuum conditions.

Injection of oxygen by means of a multi-tubular system with micro-perforations and at pressures above one atmosphere.

Production of oxygen.

Autonomous electrical generation system.

A PLC-based parameters control system that manages variables such as pressure, oxygen and CO2 levels, and flows, among others.

Claims

CLAIMS1. An ocean fish farming cage (100), closed, self-supporting, mainly aimed at the aquaculture industry and/or stocking centers, which adapts to the quadrangular, rectangular, or circular shapes of meccano-type floating metal structures(90), with perimeter passageways, existing, CHARACTERIZED because it comprises a raft-type tubular membrane (1) made of high mechanical strength and low biofouling adherence polymer ending in a conical shape at its distal end to the surface, where said tubular membrane (1) comprises floaters (2, 2') that help its buoyancy in water and incorporated to the tubular membrane (1) itself; a top pocket-type sealed sleeve containing a steel cable that goes across the entire top edge of the tubular membrane (1), wherefrom a plurality of hitches come out; some aspirating means or "lift-ups" (4. 4") centrally located at the bottom and inside the tubular membrane (1); and external perimeter rings (11) concentric with the tubular membrane mantle (1) consisting basically of a steel cable coated with high strength polyethylene, which work as an exoskeleton of the tubular membrane (1).
2. The ocean fish farming cage (100) in claim 1, CHARACTERIZED because in the plurality of hitches come out found in the top sleeve (6) are inserted top turnbuckles (7) tying the tubular membrane (1) to the existing meccano-type floating metal structures, where the number of hitches determines the shape of the top sleeve (6) in respect of the floating metal structure shape (90).
3. The ocean fish farming cage (100) in claim 1, CHARACTERIZED because immediately after said top sleeve (6) the tubular membrane (1) also comprises a drainage orifice (8) with means to circulate water in only one direction.
4. The ocean fish farming cage (100) in claim 1, CHARACTERIZED because said floats comprise at least upper top float (2) located close to the surface and at least one lower float denominated air ring (2') located at the surface distal part.
5. The ocean fish farming cage (100) in claim 4, CHARACTERIZED because said top float (2) increases buoyancy in the top part of the membrane dose to the surface and rigidizes the structure without incorporation concentrated stresses to the tubular membrane (1).
6. The ocean fish farming cage (100) in claim 4, CHARACTERIZED because the dimension of said air ring (2') is smaller in respect of the top float (2), because it only seeks to provide more rigidity to the tubular structure, but, being located at the lower part of the tubular membrane (1) or surface distal part, an increase in its buoyancy is required.
7. The ocean fish farming cage (100) in claim 1, CHARACTERIZED because the aspirator means comprise a lower aspirator (4') found at the bottom of the tubular membrane (1) that collects, through pipes running to the surface, the excess foodstuffs not consumed by fish, feces, and particles in general deposited at the tubular membrane (1) bottom.
8. The ocean fish farming cage (100) in claim 1, CHARACTERIZED because the aspiration means comprise a top aspirator (4) with an internal network (5) with the tubular membrane (1) diameter, where said top aspirator (4) rests, and separates waste materials such as non consumed foodstuffs, feces, and particles with a diameter smaller than the diameter of this internal network orifices (5) from the larger particles mostly related to the process inherent mortality arid collects dead fish.
9. The ocean fish farming cage (100) in claim 1, CHARACTERIZED because said concentric external perimeter rings (11) comprise top turnbuckles (12) that tie them to the floating metal structure (90); vertical tensors (13) tying an external perimeter ring (11) with the immediately following external perimeter ring (11) or the one found immediately below.
10. The ocean fish farming cage (100) in claim 9, CHARACTERIZED because the last external perimeter ring (11) found at the distal location of the tubular membrane (1) relative to the surface, comprises a series of intersecting cables that support the tubular membrane (1) bottom, and bottom anchors (14) to fix the cage (100) to a geographic point.
1. Ocean fish farming system mostly aimed at the aquaculture dus and/or stocking centers CHARACTERIZED because it comprises: a) a number of closed self-supporting cages (100), which adapt to existing quadrangular, rectangular, or circular shapes of floating meccano-type metal structures (90), where each one of said cages comprises a bag-type tubular membrane (1) made a of high mechanical strength and low biofouling adherence polymer, ending with a conical shape at its surface distal section, where said tubular membrane (1) comprises floats (2, 2') helping its water buoyancy and incorporate to said tubular membrane (1) itself; a pocket-type continuously sealed top sleeve (6) containing a steel cable running around the entire top edge of the tubular membrane (1), from which a number of hitches emerge; aspirator or "lift-up" means (4, 4') located at the bottom center and inside the tubular membrane (1), and external perimeter rings (11) concentric with the tubular membrane (1) mantle that basically consist of a steel cable with a high strength polymer, constituting a tubular membrane (1) exoskeleton; b) A cage (100) water renewal supply system comprising water treatment and recirculation means to restore water quality to optimum levels.
12. Ocean fish farming system mostly aimed at the aquaculture industry and/or stocking centers pursuant to claim 11, CHARACTERIZED because said water treatment and recirculation means comprise: a) A centrifugal pump that drives water flows at the required pressures; b) A first coarse mechanical filter with an approximately 100 microns wire mesh, intended to capture coarse particulate; c) A second filter removing particles up to 0.02 microns, whose purpose is to remove organic material macro molecules, disinfect bacteria and viruses through mechanical removal, and eliminate harmful contaminants like ammonia; d) A degasifier that eliminates the CO2 produced by means of a multi-tubular contactor with membranes of hydrophobic materials and micro-perforations which take away the CO2 to an extraction gas in atmospheric or vacuum conditions.e) An oxygen injector by means of a multi-tubular system with micro-perforations and at pressures above one atmosphere.f) Oxygen production means; g) Autonomous electricity generation means; and h) PLC-based parameters control means that manage variables such as pressure, oxygen and CO2 levels, and flows, among others.