GB2507077A

GB2507077A - Aquaculture Raft Adapted to Receive a Y-Junction

Info

Publication number: GB2507077A
Application number: GB1218699.5A
Authority: GB
Inventors: Laim Heffernan
Original assignee: Liftup Akva AS
Current assignee: Liftup Akva AS
Priority date: 2012-10-18
Filing date: 2012-10-18
Publication date: 2014-04-23
Anticipated expiration: 2032-10-18
Also published as: GB201218699D0; GB2507077B

Abstract

A raft (10, Fig. 2) suitable for an aquaculture sea cage (3) comprises a Y-junction 13 for connecting a branch pipe 15 to transport waste from a sea cage onto a common pipe (4), where a one-way valve 14 is connected to the Y-Junction; and where the raft is further adapted to gather pipes, cables and hoses which run to and from the sea cage. The gathering may be in the form of fastening means for attaching said pipes, cables, hoses and tubes. The raft may be shaped as a frame with one or more floatation elements therein. Also disclosed is an aquaculture installation comprising at least one floating sea cage (3A/3B/3C) with their own mooring and anchoring systems; and a central raft (1) comprising feed containers, a feeding installation, an electricity supply, and a mooring system independent of the sea cages, wherein one or more rafts as described above act as connectors between main components.

Description

The field of the invention

The present invention concerns a raft for a aquaculture sea cage, where the sea cage is connected to a system for transport of waste from said sea cage and other sea cages to a collection point, and the raft is adapted for connection to the sea cage.

Prior art

Removal of dead fish, spilled feed, and faeces from sea cages used in fish farming is a necessary operation during the daily running of a fish farming facility. The size of todays sea cages, the need for rationalization and automation, and a growing focus on and requirements for health, environment and safety (HMS) for the animal keepers on fish farming facilities require the aid of systems that can de operated as independently as possible from physical human workforce. In connection with this, there has been developed sea cage pumping systems which remove waste and dead fish from a sea cage, and systems that collect this waste from a plurality of sea cages. The present invention is a further development and additional efficiency improvement of such systems.

A common sea cage (also sometimes referred to as a net pen) consists of a movable, surface located, for example ring shaped collar whereupon a netting or fabric forms a sea cage bag, which is fastened on the collar. A sea cage pumping system may mainly comprise a pump connected to a suction hose extending down to the bottom of the net pen bag in order to suction of dead fish and waste. The suction hose leads the dead fish and waste up to the surface, where it is gathered I a container connected to the sea cage. The dead fish and waste is then removed from the container in a manual manner, from one sea cage at the time. The affectivity improvement of such manual systems have been focused on, in stead of each sea cage having its own container, pumping the waste from a plurality of sea cages in on a shared pipe system, and thus collect and process the waste communally. The collection site may be on land, as is the simplest solution but of the technically difficult because the sea cages are located far out from land, or on a stationary raft, or on a vessel that comes by routinely to collect the waste. But the use of vessels is not very practical, since the collection point itself must be stationary in relation to the sea cages, an the suction could then only lake place when the vessel is connected to the system. The processing on the collection site involve first separating of water from the waste, for example by straining, followed by further waste treatment.

Norwegian patent NO 176741 relaters to an arrangement for collecting waste like dead fish and such from a sea cage. Several sea cages are4 connected together so that the waste is lead inn on a communal pipe, leading to a facility with a separation container. A suction pump for suctioning of the waste is localizes in connection with the communal collection container, US 5762024 relates to collection of solid waste from a plurality of sea cages by the use of a pump and a conduit from the bottom of the sea cages to a collection tank on a central floating service platform servicing several sea cages, which is located between the sea cages. Both these systems use a electric pump on the surface in order to pump the waste. This is the usual way to collect waste, since it is not favorable to use electric pumps under water.

NO 329813, the present applicants earlier Norwegian patent on a sock for wrasse fish, discloses an arrangement for collection of waste like dead fish and such from a sea cage. This is pumped to the surface from a funnel down in the cage by a pressure fluid system connected to the lower part of said hose, in order to create a suction effect. By using pressurized air the pumping effect can be applied down in the water, instead of up on the surface, but without exposing the electrical parts to underwater conditions. The pump type is the same as is preferred for the present invention, but only waste from one sea cage is pumped up. This system was then further developed to comprise a plurality of sea cages, as shown in the applicants patent application NO2O1 10903. According to this, the pipes for waste from a plurality of sea cages are connected, and in order to sufficient pressure a pressurized air pump, also known as a flushing pump, is used as a additional pump rather than using an electric suction pump. This pump is located at the end of the system under the surface, before the conduits from the individual sea cages is connected on to the pipe in the direction towards the collection station, in order for the waste to be pushed upwards in the system.

It is known to use different rafts in connection with aquaculture sea cages. As mentioned above, large rafts are used as central collection points for waste from a plurality of sea cages, and smaller rafts is known for use for feeding the fish These smaller rafts may be placed either up against the sea cage on its outside, or inside the sea cage, and are used as feeding stalions.

It is also known to use a communal floating walkway between sea cages, and thus both gain access to the sea cages for the personnel, and at the same time use this as a load bearing element for conveying hoses and cables for delivery of air, water and electricity to the edge of the sea cage. But in many installations there are no such possibilities of conveying cables and such to and from the sea cages. The sea cages are often spread out over a even larger area without any such communal transport way, and cables, hoses and pipes are often conveyed laying floating in the sea to the individual sea cages, since the operation of the different units for feeding, suctioning and such happens by remote control from a central unit. The disadvantage in connection with this is that the cables and hoses are laying free floating in the sea, and this represents a safety risk when the supervision by the personnel out to the individual sea cage is carried out by boat from land. In addition one risks damage to the cables and hoses due to this traffic with vessels to and from the sea cages, and at the same time the vessels may also be damaged.

Short summary of the invention

The raft of the present invention is thus characterized by that it is adapted with a Y-junction for connecting a branch pipe for transport of waste from the sea cage onto a common pipe for transport of waste from a plurality of sea cages to a collection point, where a one-way valve not allowing passage into the branch pipe is connected to the Y-junction, and the raft is adapted to gather pipes, cables and hoses which run to and from the sea cage.

According to a preferred embodiment of the present invention the raft is shaped as a frame with one or more flotation elements located therein.

According to a preferred embodiment of the present invention the raft is adapted to gather pipes, hoses, cables and tubes running to and from the sea cage by fitting it with a fastening means for attaching said pipes, cables and hoses to said raft.

According to a preferred embodiment of the present invention one or more rafts act as connectors between to main components in an aquaculture installation, where said installation comprise the following two main components: a) a floating sea cage or a group of sea cages with their own mooring and anchorage systems; and b) a central raft comprising feed containers, a feeding installation, waste treatment facilities, an electricity supply, and its own mooring system independent from the sea cages.

Purposes and advantages of the present invention The raft in accordance with the present invention is developed for use with different sea cage systems where a plurality of sea cages are connected together for among other purposes collection of waste. The raft is meant to be additional equipment for existing sea cages in such a system, where each sea cage is connected to such a raft. The raft comprises different units which simultaneously solve several problems related to the sea cages.

The raft disclose a simple connection between the pipe transporting waste from the sea cage and the system receiving said waste from all the sea cages connected thereto. It is much easier to reach the connection on the raft moored outside of the sea cage, than on the sea cage itself. Thus the connecting and disconnecting of the individual sea cages from the system, a well as repairs, are easier to carry out. This is especially important during bad weather conditions with winds and waves, when it can be quite difficult to get next to a large sea cage with a lot of equipment trailing therefrom.

By using a one-way valve in the connection, one also prevents fish and water from the other sea cages from passing the wrong way and down into other sea cages instead of out to the collection point. In addition to that it is of course counterproductive and not desirable to pump the waste the wrong way in this manner, it is also very important to avoid to limit the chances of cross contamination of diseases between the sea cages due to the connection of the sea cages.

In addition, the raft in accordance with the present invention function as a collective point for all pipes, hoses and electrical conduits running to and from the sea cage and the rest of the system. It has long been a problem for sea farmers that there is a mess of different conduits floating in the water, rendering work around the sea cages more difficult, and making it difficult to get around by boat. This problem has become even worse when waste is to be collected centrally as well (as described above), resulting in even more pipes etc. both above and under the surface. The present invention is a solution of this problem as well, since it gathers cables, hoses and pipes in one bundle on one location (the raft), and keep them in place there, and not hindering movement.

At the same time as they are being held in place, the pipes, cables etc. are laying on said raft, and thus they can move with the raft, and thus with the sea cage. This is especially important during bad weather conditions with wind and waves, since this leads to a lot of wear and tear on all movable parts, including said pipes, hoses and cables. When they are laying loose (in the water, not on a raft) they are pulled on fairly independently of each other in different directions, and the different movable parts are pushed against each other, can get pinched, and is wearing on each other.

By gathering these parts in a solid bundle and localizing them safely on a small raft moored to the raft, and thus move therewith, they are protected from such wear and tear.

Even though the raft for sea cages is described herein as a separate component, it is meant to be able to function as an integrated part of the floating aquaculture sea cage installation comprising two main components: a) a floating sea cage or a group of sea cages with their own mooring and anchorage systems; and b) a central raft of up to several hundred tons in dead weight, comprising feed containers, a feeding installation, waste collection, an electricity supply, an office and overnight facilities, that has and its own mooring system independent from the sea cages, where (additional) rafts in accordance with the present invention function as connectors between the two main components. Both a) and b) are acted upon by natural forces such as current speeds, wind speeds and wave height, and will move.

The problem is that they do not move in unison, the sea cages are laying low in the water with net bags hanging deeply into the water column rendering them less susceptible to wind and most susceptible to waves and current speeds, while the central raft float high in the water and is most influenced by wind and waves and less influenced by water flow speeds. In accordance with the lateral pumping concept described by the applicants earlier patent application N0201 10903 the central raft is connected to each of the sea cages in the installation through a lateral floating pipe and allows automated removal of dead fish from the bottoms of the sea cages by gathering dead fish and sludge directly to the storage tanks placed in connection to the central raft. But since a) the cages and b) the central raft are not moving in unison, weak points will appear where lateral pipes are connected to each individual sea cage. The applicant has observed that this is the specific point where breaks appear during storms or high waves. The (additional) raft in accordance with the present invention is developed by the applicant in order to encapsulate a Y-connection from the sea cages to the main pipe and a one-way valve in a weather resistant unit, in order to strengthen this weak point. In addition, the raft in accordance with the present application as described above also contend with other problems experienced by many sea farmers; that feed conduits, electrical cables, air hoses etc. (from the central raft to each individual sea cage) float in the water and is exposed to damage from weather or boat traffic around the installation, by installing a place for fastening or mooring these on said raft. Thus one achieve a less messy installation with reduced maintenance and repair work.

Detailed description of the invention

The present invention will now be described in more detail with reference to the following figures, where: FIG. 1 discloses a side view of sea farm installation at sea. It comprises of a central raft 1 which among other things contains a receiving unit 2 for processing dead fish and waste. The waste is transported from a sea cage 3 in a pipe system 4 that is lead via a raft 10 in accordance with the present invention.

FIG. 2 discloses a view from above of a sea farm installation. It consists of a central raft 1 comprising a receiving unit 2 for processing dead fish and waste. Said waste is transported away from the sea cages 3A, 3B, 30 in a pipe system 4 which is lead via rafts 1 OA, 1 OB in accordance with the present invention.

FIG. 3 discloses a top view of a preferred embodiment of e raft in accordance with the present invention where components hidden under other components are shown with weaker colored lines. The raft is constructed with a frame 1 lA-il E which the other components are held in place by/in. The raft comprises two buoys 1 2A, 1 2B which acts as flotation devices for the raft. Parts of the frame hA, 11 B is lead through said flotation devices 12A, 12B and hold them in place. A branch pipe 13 in the form of a Y-junction is mounted inside the framework. Waste from other sea cages which are not connected directly to this raft will pass through the straight part of the branched pipe (from 13A to 13B), while the Y-branch itself 130 leads waste from the sea cage 3A to the raft 1 OA directly connected thereto. A one-way valve 14 not allowing passage into the branch pipe 1 3C is connected thereto, and a pipe 15 leading waste away form the sea cage 3A is connected to the valve 14.

The raft according to the present invention is meant to be a small and simple construction, that is located in connection with a sea cage. More exactly the raft will be placed on the outside of the sea cage, usually fairly close next to the sea cage, so that it can move in the water along with the sea cage. It can of course be located at some distance from the sea cage, but if this distance becomes too long this will result in more wear and tear on pipes and cables running between the sea cage and the raft. Thus it is advantageous for the raft to be fairly close to the sea cage, usually no more than 10 meters away from the sea cage, and preferably up to 2 meters away form the sea cage. Thus the raft will be moored to the sea cage, and will preferably be equipped with attachment points for moorings.

Viewed in respect to the size of the sea cage the raft will be small. It only needs to be large enough to encompass the pipes, hoses, and cables running to and from the sea cage, and a small size makes it move less independently in the water and instead move with the sea cage, and will be less of a hindrance for boat transport to and from the sea cage. The raft will therefore usually have a surface area of less than 100 square meters, more preferred less than 10 quadrat meters, and most preferred 3-6 quadrat meters.

The raft may be constructed from various known materials for raft construction.

These should of course be able to withstand being kept in sea water. It must contain elements for keeping it afloat, also in high seas. In accordance with a preferred embodiment of the raft, the raft is constructed as a simple frame with one or more flotation devices connected therein. The flotation devices may for example be buoys.

The flotation devices are preferably located inside of the frame, in order for said frame to protect them. In accordance with a preferred embodiment of the present invention, the raft contains two buoys located inside of a frame. Said frame may then be welded in place around the buoys. The frame may alternatively be partly hollow, and be airtight in order to add to the buoyancy, or parts of the frame may be pipes which hoses, cables etc. from the sea cage can be lead through.

In accordance with a preferred embodiment of the present invention the raft is made of HDPE. The HDFE is than preferably used as a combination of pipes and plates. It is preferred to use pipes with the same dimensions as are used for the transport of dead fish out of the sea cages, both for connecting the raft to the sea cages and for obtaining good flow of the dead fish via the rafts. Such pipes usually have a diameter of 200mm or 250mm. The thickness of the plates used for the raft may of course wary, but usually a thickness of from 12mm to 25mm be preferable.

A pipe" as used herein can be a rigid or semi rigid tube used as part of the construction of the rafts, or a conduit to or from sea cages. Such conduits used as part of the present invention also include more flexible hoses, and cables (both for strengthening/anchoring or for leading electricity), as well as any other conduits used for any kind of transport to and from the sea cages where said conduits physically connect the sea cages (to for example land or a large central raft). When expressions like cables, hoses and pipes" is used herein, ft is meanl 10 encompass all such conduits.

There are usually many cables, hoses and pipes running to and from a sea farm cage. Cables are used for the delivery of electricity to various systems like for examples pumps, feed units and control systems. Cables are also used for keeping Ihirigs moored and in place. Hoses and pipes are used for Iransport of wasle, fish, fodder, water and air. Such cables, hoses and pipes can be gathered in a bundle of or on the raft by running through, over, under or on the sides of the raft, and thus be lead onwards gathered together. Often heavier cables, pipes and hoses, such as those which conduct liquids, will be located further down in relation to the sea surface, while lighter cables, hoses and pipes are placed higher up, in order to make the raft as stabile as possible in the water. Thus the pipes remain laying in the correct position, where they are stabile and avoid being twisted and scuffed against each other.

Cables, hoses and pipes are gathered by the raft with a fastening means located thereupon. This could be a simple lock and load system. In accordance to a preferred embodiment of the raft cables, hoses and pipes that run to and from the sea cage are gathered in a pillory, and are kept in place thereby.

Systems for transport of waste from the sea cage and other sea cages to a collection point usually encompass a pump system which pumps up dead fish and waste (sludge) mixed with sea water from the bottom of a sea cage and up to the surface, and then this is pumped onward through a branch pipe and into a system connecting these branch pipes, and leads the waste to a communal collection and draining location. The raft is meant to be part of this system, by being adapted with a Y-junction for connecting a branch pipe for transport of waste from the sea cage it is connected to onto a shared main pipe for transport of waste from a plurality of sea cages to a collection point. Pumping of the waste will occur primarily via a pump in the sea cage, but in order for the waste to be transported effectively through the system to the collection point the system will preferably comprise one or more additional pumps. These will usually be localized on the main pipe, either at the collection point, on the main pipe between the sea cages (and thus between rafts in accordance with the present invention), or most preferably at the beginning of the main pipe. "The beginning" is then defined as furthest out on the sea farm facilities, by the sea cage(s) the furthest away from the "end" of the main pipe at the collection point. Most preferably a additional pump will be an air pressure pump placed underwater at the "beginning" of the main pipe, in accordance with the solution disclosed by N020110903.

The Y-junction in accordance with the system in accordance with the present invention may be constructed by any material suitable to the task, but in accordance with a preferred embodiment FE pipes are used. This may for example be a Y-junction with outtakes for a FE pipe of a somewhat larger dimensions for the main pipe running between the sea cages. The one way valve is connected between the outtake for waste from the sea cage and the main pipe for transport thereof from all the sea cages in the system, in a direction allowing passage of waste from the sea cage and into the main pipe, but not the opposite direction. Dead fish and other waste will then flow to the collection site and not end up in the neighboring sea cages even if the pressure in the pump system should fall, for instance due to pump failure. In other words the valve keeps all the sea cages that are connected in the system closed, except from the sea cage (s) which are being pumped from at a given point in time.

The one way valve is preferably connected in connection with the Y-junction. It can then either be connected directly on the Y-junction on the outtake of the branch pipe, so that the branch pipe is then connected to the one way valve, or the one way valve may be produced as a integrated part of the Y-junction. Thus one achieves fewer connections, while the Y valve becomes more specialized. Both these embodiments have the same function, and are considered to be encompassed by "a one way valve not allowing passage into the branch pipe is connected to the Y-junction".

Thus it is intended that every sea cage in a sea farming facility is equipped with its own raft in accordance with the present invention. The raft will connect pipes, hoses and cables between the sea cage and other sea cages or collection points and main installations for several sea cages placed on large rafts or on land. Alternatively, a raft in accordance with the present invention may be connected to and serve more than one sea cage, but this is not a preferred solution since it will usually lead to problems, since the sea cage than must move in the water with a plurality of sea cages, resulting in increased wear and tear in connection with said movement.

Example

In accordance with the present invention the applicant has developed and tested rafts. The rafts have a surface area of 3-6 square meters, are made of HDFE pipes of 200mm or 250mm and plates of 12-25mm. The up drift of the raft is based on 2 buoys of 120-150 liter each.

The rafts were tested on a sea farm consisting of two man components: a) a floating group of sea cages with their own independent mooring and anchoring systems, and b) a "central" raft of several hundred metric tons of dead weight comprising fodder silos, feeding facilities, waste treatment, electricity supply, and has its own mooring system independent of the sea cages, where the rafts in accordance with the present invention functioned as connection points between the two main components. The results from the tests show that use of the rafts gives a much simpler connection system (of the lateral pipe to each sea cage), and a lot of problems with wear and tear of pipes, hoses, cables and connections are avoided.

Claims

Claims 1. Raft (10) for a aquaculture sea cage (3), where said sea cage is connected to a system for transport of waste from said sea cage and other sea cages to a collection point (2), and the raft (10) is adapted for connection to the sea cage(3), characterIze d bythatsaid raft (10) is adapted with a Y-junction (13) for connecting a branch pipe (15) for transport of waste from the sea cage (3) onto a common pipe (4) for transport of waste from a plurality of sea cages (3A, 3B, 3C) to a collection point (2), where a one-way valve (14) not allowing passage into the branch pipe (15) is connected to the Y-junction (13), and the raft (10) is adapted to gather pipes, cables and hoses which run to and from the sea cage (3).
2. Raftinaccordancewithclaiml, characterized bythatsaidraftis shaped as a frame with one or more flotation elements located therein.
3. Raftinaccordancewithclaiml or2, characterized bythatsaidraft is adapted to gather pipes, hoses, cables and tubes running to and from the sea cage by fitting said raft with a fastening means for attaching said pipes, cables and hoses to said raft.

4 Aquaculture installation comprising two main components: a) a floating sea cage (3) or a group of sea cages (3A, 3B, SC) with their own mooring and anchorage systems; and b) a central raft (1) comprising feed containers, a feeding installation, an electricity supply, and a mooring system independent of said sea cages, character I z e d b ythat one or more rafts (bA, lOB) in accordance with one or more of claims 1-3 act as connectors between to main components.