NO347246B1

NO347246B1 - Fish Transport System

Info

Publication number: NO347246B1
Application number: NO20210828A
Authority: NO
Inventors: Gunnar Hoff
Original assignee: Cflow Fish Handling As
Priority date: 2021-06-28
Filing date: 2021-06-28
Publication date: 2023-07-31
Also published as: NO20210828A1

Description

Fish Transport System

The present invention relates to a transport system for moving fish to, from, and between aquaculture tanks, and in particular to a fish transport system comprising a suspended conduit.

Aquaculture systems have been developed to optimize the efficiency of meat production and to reduce space and cost as far as possible. Systems for intensive farming of fish and shellfish include holding pens, which may be delimited by solid walls or flexible walls formed from netting, and in which the fish are held. Some systems are semi-closed or closed meaning that the walls of the pen are either semipermeable to water or they are not permeable to water, and fresh water is pumped into the tank continuously at the same time as the older water and waste, including sludge and dead fish or “morts”, are removed from the pens.

Land-based fish farms allow farming in areas which are not close to the sea, and can provide a more easily controllable environment which is free of sea lice, for example. Land-based farms include closed tanks, many of which may be situated close to one another within a larger building or facility. In order to keep the water within the tanks oxygenated and to provide good conditions for the fish or other marine animals within the tank, recirculating aquaculture systems can be included to recirculate the water, filtering and cleaning with each pass.

One of the major challenges, particularly with respect to land-based fish farming, is that the fish must be moved relatively often with a limited number of personnel working at the facility itself. The structure of the facilities themselves present further challenges in terms of moving fish between tanks. There is often a small clearance between the top of the tank and the roof of the facility, as well as tank structures and walkways that have a limited load capacity.

Prior art systems to move fish out of tanks or between tanks generally comprise pumping fish through a pipe which is moved between tanks either by hand or using a crane. JPS6015365 describes a system for transporting fish using a pipe carried by crane extending above the tank. The crane swings to bring the end of the pipe over the tank before lowering it down. WO2008156370 and WO2020104431 each describe methods for transporting fish between tanks which aim to prevent damage to the fish. The system described in WO2008156370 uses a specific pumping method including passing fish through a draining chamber. WO2020104431 describes a particular configuration of the pipes. JP3048731 relates to a pumping system for transporting fish between tanks, focusing on the pump itself. A pipe running to the tank is used to transport the fish, and this is simply placed into the tank. None of the prior art methods provides a system which can operate in a situation where space above and beside the tank is limited, and which requires minimal lifting or physical input by personnel at the facility. Use of the same system with more than one tank in a facility is also difficult or impossible.

According to a first aspect of the present invention, there is provided a transport system for fish comprising: a support assembly for fixing in place above at least two aquaculture tanks, wherein the support assembly forms a track; and a coupling mechanism for coupling a conduit to the support assembly such that the conduit is movable along the track, wherein the conduit is arranged to transport fish from and/or to any one of the at least two tanks by moving the conduit along the track of the support assembly to position an open end of the conduit above the one of the at least two tanks.

In embodiments, the track is mounted or fixed in place so that it is stationary with respect to the tank. In embodiments, the coupling mechanism is for coupling an end portion of the conduit adjacent the open end to the support assembly. Movement of the coupling assembly along the track thus moves the end portion of the conduit where the free end is located. The other end of the conduit can remain in one place, coupled to a hose or another duct as described below. What is important is that the open end through which fish can enter and leave the tank can be easily positioned above any of the tanks in the group. In embodiments, the at least two aquaculture tanks comprise a group of between three and six, preferably four aquaculture tanks.

In embodiments, when the conduit is coupled to the support assembly via the coupling mechanism, the conduit is suspended beneath and movable along the track. The end portion of the conduit and the open end may be suspended beneath and movable along the track. In embodiments, the track provides a fixed path above the at least two tanks. In embodiments, the support assembly is configured to be fixed in place by suspending from the ceiling of an aquaculture facility. This way, the transport system takes up the minimum space.

In embodiments, the track comprises at least one rail. In embodiments, the at least one rail is a circular rail. A rail is a convenient way to suspend the free end of the conduit and to provide for movement of the free end along a desired path. A circular rail means that the free end can be caused to move in a circular path. Where tanks are located very close together within a facility, which is desirable with respect to space saving, the free end of the conduit can be swung around in a circle to be positioned over any of the group of tanks, while the opposite end remains in more or less the same position, fluidly connected to another hose via a joint. This works particularly well for a group of between three and six, preferably four tanks located adjacent one another.

In embodiments, the coupling mechanism comprises a trolley for attachment to the at least one rail of the support assembly and a coupler for attaching the conduit to the trolley, and the system is arranged to transport fish from and/or to any one of the at least two tanks by moving the trolley along the rail to position the free end of the conduit above the one of the at least two tanks and passing fish along the conduit from or into that tank. A trolley is a convenient way to movably suspend the free end of the conduit where a rail is used as the support assembly. The trolley takes up little room and can be movable both actively and passively. Active movement means that there is a mechanism within the trolley itself which can be activated to cause the trolley to move along the rail (one or more gears and a motor, for example). Passive movement in this case means that there is no such internal mechanism, and the trolley is moved by pulling or pushing via an external mechanism.

In embodiments, the coupling mechanism comprises a section of cable which can be lengthened or shortened to raise and/or lower the conduit. This may provide at least part of the coupler mentioned above.

In embodiments, the track passes directly above each of the at least two tanks. The end portion of the conduit will usually be located substantially directly beneath the trolley or attachment point to the support mechanism, in which case the track passing directly above the tanks allows the open end of the conduit to be positioned also directly above any of the tanks to transfer fish therefrom and to.

In embodiments, the end of the conduit opposite the open end is attachable to a swivel joint at a first attachment point, and the swivel joint comprises a second attachment point, such that when the conduit is attached to the joint at the first attachment point, the conduit can be rotated while the second attachment point of the joint remains static. In embodiments, the second attachment point is for a first hose. The first hose can be used to carry fish from a holding pen to the conduit, or vice-versa.

In embodiments, the support assembly comprises two support sub-assemblies positioned over a respective group of two or more tanks, each sub-assembly movably supports a conduit, and the two conduits are fluidly connected by a second hose. More than to support sub-assemblies can be provided, depending on the size of the facility and the number, shape, and location of the various tanks.

According to a second aspect of the present invention, there is provided a method for transporting fish, the method comprising: fixing a support assembly in place above at least two aquaculture tanks, wherein the support assembly forms a track; coupling a conduit to the support assembly such that the conduit is movable along the track; positioning an open end of the conduit above one of the at least two tanks by moving the conduit along the track; and passing fish along the conduit through the open end to move them into or from the one of the at least two tanks.

In embodiments, the support assembly comprises suspending the support assembly from the ceiling of an aquaculture facility.

Embodiments of the present invention will now be described, by way of example only, with reference to the following figures wherein:

Figure 1 shows a fish transport system in place above a facility including multiple fish tanks; and

Figure 2 illustrates further detail of a part of the fish transport system of figure 1.

The fish transport system described herein is designed to minimise the requirement for personnel to be present in and around the fish tanks themselves, and to open up the possibility of a more flexible/efficient remote operation. The following description of the exemplary embodiments refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims.

The tank or pen described below will usually be a closed aquaculture tank, but can also comprise open aquaculture tanks or semi-closed tanks where the farmed organisms are kept in a more or less watertight enclosed volume, such as in a bag or solid tank, effectively stopping a direct water exchange with the surrounding water and having an external water supply comprising one or more pumps. It may also include cages made of semi-permeable materials which allow some water to pass through the walls, but where potentially harmful organisms such as parasites e.g. salmon lice or poisonous algae are stopped from passing through (e.g. cloths and nets with apertures suitable in size to prevent these organisms from passing through). The aquaculture system described herein will usually be deployed as part of a land-based aquaculture farm, but can be deployed in water e.g. in the sea, a fjord system or a lake. It may be part of an aquaculture system that is sea or land based.

Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification do not necessarily refer to the same embodiment. In the description relative terms such as front, top, center, bottom, side, lower, upper, downward, upward, outward, sideward, clockwise, counterclockwise, vertical, and horizontal etc. are all related to the tank when in upright position i.e. when moored and deployed in the sea or on land and ready for use. The different components shown in the figures may not be to scale relative to one another.

Although fish are referred to herein, the transport system of the invention can be used in the production of any farmed organism held within a pen or tank containing saline or fresh water. By farmed organisms is meant aquatic organisms which are farmed or kept in the tank or pen. The farmed organisms will typically be finfish, most commonly pelagic fish such as salmonids, codfish, bream, bass, groupers, flatfish, tilapia, and the like, but it may also comprise other aquatic organisms which can be farmed, such as crustaceans e.g. prawns and mollusks.

As shown in figure 1, the transport system comprises a support assembly, which can be fixed in place above a group of two or more tanks 1 to support a transport conduit 5, or an end of the transport conduit adjacent an open end, in a way which allows the conduit to be moved in order to transfer fish between, to, or from different tanks in a facility easily. In the example shown, the support assembly includes one or more rails (7a; 7b) which run above, and extend between, the tanks. The conduit is movably suspended from the support assembly, meaning that it is located below and supported by the support assembly in a way that allows it to be moved from a position above one of the tanks 1 to a position above another of the tanks. The movable suspension can be achieved by way of a trolley supported on the rail(s) of the support assembly, and which is able to travel along the or each rail. The conduit is coupled to and suspended beneath the trolley so that it moves with the trolley as the latter runs along the rail. The trolley can be attached so as to be able to travel in either direction from one end to another or continue to travel continuously if the rail forms a looped path, such as a circular path as shown in the figures.

An aquaculture facility may house at least one group of aquaculture tanks 1 in which fish or other aquatic organisms can be contained. In the figures two groups of four tanks are shown, making eight tanks in total. These are located adjacent one another in a grid format, and may be touching or slightly spaced apart. The tanks shown are cylindrical, but may be of any other shape, such as cuboid. Fish may need to be transported from a holding pen 2, such as a holding pen on a vessel, and into one or more of the tanks 1 within the facility. Alternatively, fish may need to be removed from one or more of the tanks 1 and placed in the holding pen 2, or may need to be moved between any two of the tanks 1. The transport system described herein is flexible in that it allows for each of these possibilities, and is at the same time extremely economical in terms of space.

In a case where fish need to be transferred from the holding pen and into one of the tanks of the facility, the fish will generally first be crowded into a smaller region of the pen to make their removal from the pen easier. Any prior art method for crowding the fish can be applied here, and the possibilities in this regard will be well-known to the skilled person. A hose 4 can be lowered into the reduced volume within the holding tank, or can be coupled to an outlet within the reduced volume, such as on the side or base of the holding tank. The hose is connectable at its opposite end to a joint 9 that is coupled to the support assembly and located between the tanks. The joint 9 connects the hose 4 to the transport conduit 5, which carries the fish that have passed through the hose and the joint to the one of the tanks and/or vice-versa. The joint 9 may be a swivel joint, meaning that the hose and the conduit are each able to rotate relative to one another. This swivel joint may allow relative movement through a full 360 degrees or through just part of the full range (through 180 degrees, or 270 degrees, for example). If the hose 4 and the part of the swivel joint connected thereto remain static during the transport process and the full range of movement is allowed, the conduit 6 is able to rotate through a full circle to extend in any desired direction as a result of a swivelling or turning movement at the joint. The swivel joint may be configured to turn continuously, and in both directions, so that the conduit can be caused to swing around in a circle both clockwise and anti-clockwise, and as many times as desired while the hose remains static.

The turning movement of the conduit 5 may be controlled by a mechanism comprised as part of the support assembly. As mentioned above, the support assembly can include one or more rails (7a; 7b) fixed just above the tanks 1. The rails can be fixed to a ceiling or wall of a building in which the tanks are housed or to an additional support structure, such as a frame, extending above the tanks and supported on the ground. The rails in the examples shown in the figures are circular, and two separate circular rails are provided for each four tanks in the group, an inner rail 7b, and an outer rail 7a. The inner circular rail 7b is provided largely as additional support, and may be dispensed with in some examples.

The conduit 5, at an end opposite the end coupled to the swivel joint and adjacent an open end of the conduit, is suspended from the rail system in a manner which allows it to swing around in a circle by relative movement of the parts of the swivel joint. The rails themselves allow the hose to be guided in this movement. The coupling between the conduit 5 and at least one of the rails may be by way of a trolley which is arranged to travel in one or both directions along the rail. The conduit is coupled to the trolley, meaning that when the trolley follows a circular path along the rail, the end of the conduit opposite the swivel joint is pulled around in a circular path causing the conduit to rotate about the swivel joint. In this way, via movement of the trolley, the conduit 5 can be arranged so that its end is situated over any one of the tanks in the group. The internal circular rail is also coupled to the conduit, this time to a region between the swivel joint and the free end near to the middle of the conduit. A further trolley can be provided, and the coupling actively moved as for the outer circular rail. Alternatively, the coupling may be movable but not actively, so that the coupling is pulled along the inner circular rail 7b by movement of the trolley travelling along the outer circular rail 7a. The inner rail in both cases provides additional support to maintain the conduit above the tank, and in particular to prevent the central region of the conduit from drooping. This can be useful given that the weight of the fish and water within the conduit during the transport process can be large, and a sagging region can increase the work required to pump the fish through the conduit.

The trolley (or trolleys if more than one is present) can be configured to travel along the rail in a manner than is passive, rather than active. The conduit can be pulled around, causing the trolley to slide along the rail, for example. Pulling the conduit can be by way of a separate cable coupled to the conduit, and the pulling can be achieved manually or automatically. Alternatively, the conduit may simply be pushed or pulled manually to swing it around over the desired tank within the group, and no automatic mechanism or additional apparatus may be required. Depending on the weight of the conduit, however, this may be difficult and will require at least one staff member to be present at the facility.

Attachment between the trolley and the conduit 5 can be via an extendable cable or a pulley system, which allows the conduit to be lowered and raised once in place above the tank. In one example, the pulley system includes an upper and a lower wheel. A cable extends around both wheels and sits in a groove extending around periphery of each wheel. The cable can be shortened and lengthened to decrease or increase the distance between the upper and lower wheel, which will in turn raise and lower the end of the conduit, which is coupled to the lower wheel. The pulley system can comprise a single wheel, and a cable can extend from the trolley, around the wheel, and back to the trolley. A drum and motor within the trolley can be used to extend and retract the cable to raise and lower the conduit end, which hangs below the wheel via a second cable. The coupling between the trolley and the conduit can be simpler, and may comprise a simple cable coupled to the conduit at a lower end (i.e. via a hook, a hole in the conduit and a knot or stop on the cable inside the conduit, or simply tied around the conduit).

Whether a more complex pulley system is used or not, the or at least one of the cables attaching the conduit to the trolley can be wound around a drum within the trolley which can be turned to wind the cable off and on the drum. Turning of the drum may be manual, may be by way of a remotely operated motor, or via another mechanism. Winding off the drum by turning the drum in one direction will increase the length of the cable between the drum and the conduit, which causes the end of the conduit coupled to the trolley to drop down over the tank. Winding onto the drum, in contrast, lifts the end of the conduit away from the tank. This possibility to adjust the height of the conduit may be used to compensate for different water depths within the tank, to lower the conduit end down into the water in the tank, or to raise the conduit for transport to a position over a different tank by movement of the trolley along the rails.

The trolley may be moved along the rails using a gear wheel within the trolley which interlocks with projections on the rail, for example by way of two sets of interlocking teeth. The gear wheel may turn to cause the trolley to move along the rail. Turning of the gear wheel may be by way of a motor. The motor may be the same or a different motor to that which causes raising and/or lowering of the conduit. The motor may engage and turn the gear wheel in the trolley when it is desired to move the trolley along the rail, and may engage and turn the drum when it is desired to raise or lower the conduit end.

Figure 2 shows a transport system for transporting fish to, from, or between tanks. The support assembly includes two support sub-assemblies 3a and 3b, each comprising a set of circular rails (7a; 7b) as described above, each forming a support sub-assembly. One sub-assembly (3a; 3b), is located above each group of four tanks and can be used to position the free end of a conduit (5a; 5b) over any one of the four tanks in the group.

Each set of circular rails may in some cases comprise only one, three, or more than three circular rails, however in this case each set comprises two circular rails. One conduit is present and supported by each of the sub-assemblies. The conduits (5a; 5b) are fluidly connected together via a laterally extending hose 11. This allows fish from the holding pen 2 to pass along the first hose 4, through the first swivel joint 9a, along the laterally extending hose 11, through a second swivel joint 9b, and along the second conduit 5b into one of the four tanks located furthest from the holding pen. There may be a valve included in the first swivel joint to prevent fish (and water if present) from travelling through the first conduit 5a in such a case. There may be a valve present for every inlet to the swivel joint. The valve or valves can be switchable to either allow fish to pass between the first conduit 5a and the holding pen, or between the laterally extending hose 11 and the holding pen. The switching of the valve can be achieved manually or automatically. The or a different valve can also be operable to close off the outlet for attachment of hose 4. This may be required if fish are to be moved between tanks 1, rather than to and from a holding pen.

The first swivel joint 9a may therefore comprise three inlets/outlets. One will be couplable to the fist conduit 5a, one to the laterally extending hose 11, and one to the first hose 4 which ends at the holding pen. The system is therefore extremely flexible in that material, such as fish and water, can be transferred from any one of the group including the eight tanks and the holding pen to any other of the group by positioning the conduits over the relevant tank, closing and opening the correct valves, and pumping/sucking the fish in the desired direction.

The pump used to move fish from the holding tank to the aquaculture tanks or from the aquaculture tanks to the holding tanks, or between holding tanks, is shown in figure 2 as component 13. The pump can be located anywhere along the first hose 4 or the laterally extending hose 11, depending on where the fish need to be moved to or from. More than one pump can be located within the system, for example one along hose 4 and one along laterally extending hose 11. If fish are to be transported to one of the nearest four tanks then the laterally extending hose may be closed off using a valve, and the pump in the first hose will be used to move the fish. A pump on one or each of the conduits can be used alternatively or in addition to the other pumps in the system in some embodiments. In any case, the pump or pumps, in combination with valves located in the fluid path comprising the conduits and the hoses, should allow fish to be moved in any direction from any of the tanks or the holding pen to any other of the tanks or the holding pen.

In some examples, the water sucked with the fish out of the holding pen or out of one of the tanks in the facility can be returned to the same tank or to the holding pen as part of the transport process. A filter or grating may be included in the return path to allow water, but not fish and/or larger particulate matter, to pass back to the tank or holding pen.

Clearly, any number or shape of tanks can be included in the facility, and the configuration of the support assembly and the position of the hoses and conduits can be adapted to suit these different configurations. The groups of tanks may each comprise two or three tanks, for example, rather than four. The rail, rather than being a circular rail, could be a linear rail or a curved rail extending above each of the tanks in the group. The conduit can then be swung from a position above the first tank to a position above the second tank, or the third tank by movement of a connecting trolley back and forth along the rail. The tanks may be elongate rather than cylindrical, in which case a looping rail may be provided that is not circular but elliptical, rectangular, or another shape. So long as the rail or support assembly extends above each of the tanks within the group so that the end of the conduit can be positions above any of the tanks in the group by movement of the coupling mechanism connecting the conduit to the support assembly, the system will function as intended.

If a swivel joint is used in connection with a group of tanks that are not cylindrical or are not positioned in a circle, the free end of the conduit may be required to move in a path that is other than circular. The conduit may need to bend slightly to enable the free end to be positioned above one or more of the tanks in the group, and this is ok, particularly if one or more additional rails are provided to support the central region of the conduit.

The rails of the support assembly may comprise grooves within a support plate, and the trolley may travel back and forth within the grooves. The support assembly may comprise structure other than one or more rails from which the free end of the conduit can be suspended. The free end of the conduit, and therefore the rails themselves, may not pass over the middle of the each of the tanks but may pass above the tank in a region closer to the tank’s edge for some or all of the tanks in the group. In some cases, the rails themselves may not pass above the tank at all, provided that the free end of the conduit when suspended from the trolley can pass above the tank. This may depend on the stiffness of the conduit and the position along the conduit at which it is suspended from the rail.

Any number of groups of tanks can be included in the facility, and these can each be provided with a support sub-assembly fixed above the group to allow movement of the free end of a conduit to a position above each of the tanks. The conduits associated with each group can be connected by way of one or more hoses to conduits associated with the other groups of tanks (similarly to the longitudinally extending hose 11 in figures 1 and 2, which connects conduits 5a and 5b). Four conduits serving four groups of tanks with their own support sub-assemblies may be connected via four hoses, for example. Valves can be present to close off or open the hoses and conduits for transport of the fish as desired.

In some embodiments, rather than or as well as an adjustable cable allowing the free end of the conduit to be raised and lowered, the rails themselves may extend in an upwards and downwards or vertical direction as well as extending horizontally to pass above each of the tanks within the group. One example of this might be a rail which extends to form a looped path extending over each of a group of tanks, and which slopes downwards and then upwards again when it passes over or close to the center of the tank. The rail will therefore comprise a low point close to the place where it passes over the center region of the tank. The free end of the conduit is therefore lifted as the trolley travels along the rail and the free end passes over the edge of the tank, and dropped slightly as it passes over the center of the tank where it can be stopped in order to transfer fish to and from the tank. This may make transport of the fish easier, and avoid interference between the various parts of the support assembly and conduit and the tanks themselves.

Claims

1. A transport system for fish, comprising:

a support assembly for fixing in place above at least two aquaculture tanks (1), wherein the support assembly forms a track; and

a coupling mechanism for coupling a conduit (5) to the

support assembly such that the conduit (5) is movable along the track, wherein the conduit (5) is arranged to transport fish from and/or to any one of the at least two aquaculture tanks by moving the conduit (5) along the track to position an open end of the conduit (5) above the one of the at least two aquaculture tanks (1).

2. A transport system according to claim 1, wherein the coupling mechanism is for coupling an end portion of the conduit (5) adjacent the open end to the support assembly.

3. A transport system according to any of claims 1 and 2, wherein when the conduit (5) is coupled to the support assembly via the coupling mechanism, the conduit (5) is suspended beneath and movable along the track.

4. A transport system according to any of claims 1 to 3, wherein the track comprises at least one rail (7a; 7b).

5. A transport system according to claim 4, wherein the at least one rail is a circular rail.

6. A transport system according to any of claims 4 and 5, wherein the coupling mechanism comprises a trolley for attachment to the at least one rail (7a; 7b) of the support assembly and a coupler for attaching the conduit to the trolley, and the system is arranged to transport fish from and/or to any one of the at least two tanks (1) by moving the trolley along the rail (7a; 7b) to position the open end of the conduit (5) above the one of the at least two tanks (1), and passing fish along the conduit (5) from or into that tank.

7. A transport system according to any of claims 1 to 6, wherein the coupling mechanism comprises a section of cable which can be lengthened or shortened to raise and lower the conduit (5).

8. A transport system according to any of claims 1 to 7, wherein the track passes directly above each of the at least two tanks (1).

9. A transport system according to any of claims 1 to 8, wherein the end of the conduit opposite the open end is attached to a swivel joint (9) at a first attachment point, and the swivel joint (9) comprises a second attachment point for a first hose, such that when the conduit (5) and the first hose are fluidly connected by attachment to the swivel joint, the conduit (5) can be rotated while the hose remains static.

10. A transport system according to any of claims 1 to 9, wherein the support assembly is adapted to be suspended from a ceiling of an aquaculture facility.

11. A method for transporting fish, the method comprising:

fixing a support assembly in place above at least two aquaculture tanks (1), wherein the support assembly forms a track;

coupling a conduit (5) to the support assembly such that the conduit is movable along the track;

positioning an open end of the conduit (5) above one of the at least two tanks by moving the conduit along the track; and

passing fish along the conduit (5) through the open end to move them into or from the one of the at least two tanks (1).

12. The method of claim 11, wherein fixing the support assembly comprises suspending the support assembly from the ceiling of an aquaculture facility.