NO20230124A1

NO20230124A1 -

Info

Publication number: NO20230124A1
Application number: NO20230124A
Authority: NO
Priority date: 2023-02-07
Filing date: 2023-02-07
Publication date: 2024-08-08
Also published as: NO348145B1; EP4661662A1; WO2024165637A1

Description

Aquaculture service vessel for providing on-site service of fish nets

The invention is related to an aquaculture service vessel for providing on-site service of a fish net. The service vessel comprises a wash drum for cleaning the fish net, and an inspection arrangement for inspection, drying and repair of the fish net.

BACKGROUND

Fish farms include a fish net for keeping the fish. The fish net may have an upper end attached to floating and/or stretched out bodies to keep the net stretched out at the desired depth in the sea. The lower part of the fish net can also be strung out and anchored to sinking bodies or to the seabed, alternatively the bottom of the fish net can hang freely.

The fish net is typically made of a meshed material that is finely meshed enough to prevent fish from escaping, but which has sufficiently large openings for oxygen-rich water to flow into the fish net.

Plants, such as algae etc, as well as shellfish, will stick to the fish net after some time . This fouling reduces water flow through the fish net and improves the living conditions for salmon lice, shells, among other things. Such fouling is therefore undesirable.

Fish net cleaning is about creating an ideal environment for the fish inside the fish farm. By removing the algae from the fish net, good water flow through the fish net may be obtained, thus ensuring the best possible oxygen conditions for the fish, while also removing a breeding ground for all organisms that can develop in these algae.

The fish net needs therefore be cleaned periodically. There are several devices and methods for doing this. It is known to empty the net of fish (for example, to a well boat) and then take the fish net ashore for washing. Disadvantages of this are that it is costly, and that moving fish is undesirable for reasons of fish welfare. Another solution may be to have a replacement fish net to replace the current fish net while it is on service.

It is also known to use underwater vessels with rotating high-pressure nozzles that flush the fish net clean. The disadvantage of flushing the nets is the great wear on the fish net, negative impact on biology, environment, and costs. After such an operation, the fish net must be inspected to check that there has been no hole in the surface.

One big challenge is to get the net clean without damaging it, and with minimal impact to the impregnation intended to prevent the accumulation of algae going forward.

Another challenge is to reduce the service time for the fish net so that it can be put back in operation as quick as possible.

Wear and tear on fish farm nets poses several different types of sustainability challenges. Undetected holes resulting from excessively hard washing can lead to escaped fish, and nets that are washed too hard will have a shorter lifespan than nets that have been gently washed though a single exposure.

Thus, there is an object of the present invention to provide effectively service to fish nets, reduce the service time, and solve some of the sustainability and environmental issues.

SUMMARY OF THE INVENTION

The inspection arrangement comprises a fish net support, and wherein the fish net support is a floor mounted device protruding upwards and having a surface arranged for receiving and supporting the fish net during drying, inspection and repair.

The terms “net” and “fish net” are used interchangeably throughout the application and is referred to the same object.

On-site is referred to as taking place and/or situated at a place or site adjacent to the fish farms where the fish net is laid out.

The process of replacing the fish net at the site before it begins to foul, has a significant biological gain, environmental benefits, and significant cost savings . The process needs to run as smooth as possible to reduce stress to the fish, reduce environment impact and the overall costs.

The present invention solves the problem by conducting onsite service of the fish net, onboard a service vessel. The arrangement provides effective service to fish net, reduce the service time, and solve some of the sustainability and environmental issues by having full control of the waste.

The service vessel comprises a wash drum for cleaning the fish net, and an inspection arrangement comprising a fish net support for inspection, drying and repair of the fish net. The net support and the wash drum may be located below decks of the vessel. It may be located into the vessel or down to a lower deck. To increase efficiency the number of wash drums and net supports may be increased, and they may preferably locate next to each other.

It may be preferable that the floor mounted device has a large surface, so that it supports as much of the fish net as possible, for visual inspection of the fish net. The net may be inspected by human service personnel or robots.

The floor mounted device may have any shape with a large outer surface, it may have any one of a tubular, circular, spherical, triangular, or square shape, or any combinations thereof. In one embodiment, the floor mounted device may have a cone shaped vertical cross section. Thus, the floor mounted device may be a three-dimensional geometric shape that tapers smoothly from a flat base to a top point called the apex. However, according to an embodiment of the present invention, the flat base may be circular or oval, and the apex may be an imaginary point since the top of the floor mounted device may be cut off to provide a flat surface on top. It is also important that all corners or edges of the floor mounted device are rounded so that the fish net won’t get hooked.

The service vessel may comprise a lift located adjacent the floor mounted device for moving service personnel up and down the floor mounted device for inspection and repair of the fish net.

The service vessel may comprise a ledge, elevated platform or balcony located adjacent the floor mounted device, in a height above the floor/flat base, so that service personal may perform inspection and repair of the fish net.

The vessel may comprise one or more overhead crane for moving in longitudinal direction and/or transverse direction of the ship/vessel. The overhead crane may comprise at least two net rollers for moving the fish net from the wash drum via the at least two net rollers to the net support and wherein the fish net is lowered onto the net support from above.

The at least two net rollers may constitute a first net roller and a second net roller, and wherein the fish net extends from the wash drum via the first net roller, to the second net roller and onto the floor mounted device such that the fish net can be inspected, dried and repaired, section by section, while being lowered onto the net support.

The service vessel may further comprise a dryer/impregnator arrangement for drying and vacuum treating the fish net in an impregnator.

The net may be immersed in an antifouling treatment bath, or the net may be vacuum treated in an impregnator.

Surplus antifouling following the treatment may be fed back into the antifouling bath and used again or fed back into the dryer/impregnator arrangement. Dirt and debris after cleaning may be collected in reservoirs for filtering, cleaning, and controlled disposal.

The vessel may comprise a chemical-free disinfection system based on the use of ozonation of the entire vessel's hull, tanks, and sea chests.

A tarpaulin may be pulled around the hull before pumping ozone. The vessel can then be easily disinfected by moving from farming zone to farming zone without docking.

Increased utilisation of the vessel and reduced risk of infection

Great environmental savings (chemical-free)

The aquaculture service vessel may comprise a plurality of work zones, the work zones may be a washing zone, a repair and drying zone, and a drying and impregnation zone. The one or more cranes may be an overhead crane arranged for moving of the fish net between the work zones.

In operation, the aquaculture service vessel may arrive at the fish farmer's location with all necessary net handling equipment on board.

A new impregnated and certified fish net bag may be installed, surrounding the fish net to be replaced. This may be done with powerful and long reaching cranes located onboard the service vessel.

The new fish net is then secured to the fish cage, and the old fish net may be lifted/hauled straight from the fish cage and on board the service vessel with the powerful cranes. One or more cranes may operate in collaboration.

On board the vessel, the fish net is washed, tested, repaired, dried, impregnated, and certified before it is put back into the fish cage. Content and scope may be adapted to customer needs.

The capacity may be one or more nets per day, or the capacity may be 2 nets a day. The fish farmer may not have to be involved in the service process with neither personnel nor equipment.

The present invention is also related to a method of providing on-site service of a fish net. The service may involve cleaning, disinfection, repair work and antifouling treatment of nets.

The method may comprise the step of:

A new fish net is installed and secured to the fish cage, surrounding the net to be replaced. The old net is hauled into the service vessel with a net winch hauler, with assistance from one or more cranes. From the net winch hauler, the net can be transported to a position over the washing drum, by a moveable overhead crane.

One or more washing drums may be arranged side by side for cleaning of one or more nets. The winch hauler may unwind the net into the was drum while situated above the wash drum.

After washing, a crane may lift the net high in the air to unravel any tangles (clearing the net). The crane may grab one end of the fish net which may be marked with a coloured rope and lift it up through the deck hatch and high up (up to almost 40 meters above the wash drum). The weight of the fish net and the gravity helps to unravel any tangles on the fish net.

After the net is cleared, it is lowered back into to the washing drum, and it is ready to be lifted out with the overhead crane for further transport into the inspection arrangement.

The overhead crane may comprise two net rollers for moving the fish net from the wash drum via the at least two net rollers, to the net support, and wherein the fish net is lowered onto the net support from above, and simultaneously being inspected for any damages. The net may be dried before it is repaired.

After inspection, repair and drying, the fish net may be moved into the dryer/impregnator arrangement for drying and vacuum treating the fish net in an impregnator.

FIGURES

The description above, as well as further objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of the preferred embodiment which should be read in conjunction with the accompanying drawings in which:

Fig. 1 Shows an aquaculture service vessel for providing on-site service of a fish net, the vessel comprises wash drums and fish nest inspection arrangements.

Fig. 2 Shows the washing zone and the repair and drying zone and the net rollers for moving the fish net between the zones.

Fig. 3 Shows a perspective view of the wash drums and the inspection arrangement comprising a floor mounted device.

Fig. 4 Shows the service vessel viewed from the back.

DETAILED DESCRIPTION OF THE FIGURES

The invention is related to an aquaculture service vessel 10 for providing on-site service of a fish net 11.

The invention is related to a fully equipped floating service station or service vessel 10 that streamlines the process of providing fish net 11 service. Thus, the service vessel 10 may arrive at the fish farmer's location with all necessary fish net 11 handling equipment on board for performing on-site service of the fish net 11.

The service vessel 10 may comprise a winch hauler (not shown) located at the aft, for hauling the fish net 11 onboard the service vessel 10 for performing on-site cleaning, disinfection, repair work and antifouling treatment of the fish net 11.

The service vessel is shown in figure 1 and comprises a wash drum 12 for cleaning the fish net 11, and an inspection arrangement 13 for inspection, drying and repair of the fish net 11.

One or more wash drums 12 may be located in a wash drum zone and one or more inspection arrangement 13 may be located in a separate repair and drying zone. The one or more zones may be separated by a wall, or a fence and the zones may be located below decks.

The inspection arrangement 13 comprises a fish net support 14, and wherein the fish net support 14 is a floor mounted device 15 protruding upwards and having a surface arranged for receiving and supporting the fish net 11 during drying, inspection and repair.

The floor mounted device 15 may ha a three-dimensional geometric shape with a cone shaped vertical cross section. The flat base of the three-dimensional geometric shape may have circular or oval shape (shown in figure 3) with a large surface for supporting the fish net 11. As illustrated in the figures the floor mounted device 15 has a shape that tapers smoothly from the flat base to a flat top such so that the fish net 11 can be distributed over the large surface for inspection and repair of the fish net 11.

The service vessel 10 may comprise a lift 16 located adjacent the floor mounted device 15 for moving service personnel up and down the floor mounted device 15 for inspection and repair of the fish net 11.

The service vessel 10 may comprise one or more ledge 16, elevated platform 16 or balcony 16 arranged at a height above the floor for service personnel to operate while performing inspection and repair of the fish net 11. The height above the floor allows for easy handling of the fish net 11 and keeping the personnel away from the stack of fish net 11 when it builds up as the fish net 11 is lowered towards the floor.

As shown in figure 1, the aquaculture service vessel 10 comprises a plurality of work zones, the work zones are: a washing zone 21, a repair and drying zone 22 and a drying and impregnation zone 23. The zones are located next to each other, so that the fish net 11 can move easily from one zone to another. The overhead crane 17 is arranged for transport of the fish net 11 between the work zones (21,22,23).

A third net roller 25 may be arranged in connection with the impregnation zone 23 for moving the fish net 11 into an antifouling treatment bath 26. The impregnation zone 23 comprises a dryer/impregnator arrangement for drying and vacuum treating the fish net 11 in the impregnator. The surplus impregnator may be fed back into the dryer/impregnator arrangement.

Figure 2 and 3 shows that the service vessel 10 may comprise an overhead crane 17 comprising at least two net rollers 18,19 for moving the fish net 11 from the wash drum 12 via the at least two net rollers 18,19, to the net support 14, and wherein the fish net 11 is lowered onto the net support 14 from above.

The at least two net rollers 18,19 may constitute a first net roller 18 and a second net roller 19, and wherein the fish net 11 extends from the wash drum 12 via the first net roller 18, to the second net roller 19 and onto the floor mounted device 15 such that the fish net 11 can be inspected, dried and repaired, section by section, while being lowered onto the net support 14. This is illustrated in figure 3.

Figure 4 shows the service vessel 10 from a back view. The net support 14 has a longitudinal shape, extending in the transverse direction of the service vessel 10. The Shape may be similar to a lower section of a cone, that tapers smoothly from a flat base to a flat top. The flat base may be oval shaped. The corners or edges of the flat top may be rounded so that the fish net won’t get hooked when sliding down the net support 14.

Figure 4 also shows the overhead crane 17 and the net roller 19 situated above the net support 14 for guiding the fish net onto the net support 14.

Claims

1. An aquaculture service vessel (10) for providing on-site service of a fish net (11), wherein the service vessel (10) comprises:

- a wash drum (12) for cleaning the fish net (11), and

- an inspection arrangement (13) for inspection, drying and repair of the fish net (11),

characterized in that the inspection arrangement (13) comprises a fish net support (14), and wherein the fish net support (14) is a floor mounted device (15) protruding upwards and having a surface arranged for receiving and supporting the fish net (11) during drying, inspection and repair.

2. The aquaculture service vessel (10) according to claim 1, wherein floor mounted device (15) has a cone shaped vertical cross section.

3. The aquaculture service vessel (10) according to claim 1 or 2, wherein the service vessel comprises a ledge (16) located adjacent the floor mounted device (15) for service personnel to inspect and repair the fish net (11).

4. The aquaculture service vessel (10) according to any one of the preceding claims, wherein the vessel (10) comprises an overhead crane (17) comprising at least two net rollers (18,19) for moving the fish net (11) from the wash drum (12) via the at least two net rollers (18,19), to the net support (14), and wherein the fish net (11) is lowered onto the net support (14) from above.

5. The aquaculture service vessel (10) according to claim 4, wherein the at least two net rollers (18,19) constitute a first net roller (18) and a second net roller (19), and wherein the fish net (11) extends from the wash drum (12) via the first net roller (18), to the second net roller (19) and onto the floor mounted device (15) such that the fish net (11) can be inspected, dried and repaired, section by section, while being lowered onto the net support (14).

6. The aquaculture service vessel (10) according to any one of the preceding claims, wherein service vessel (10) further comprises a dryer/impregnator arrangement (20) for drying and vacuum treating the fish net (11) in an impregnator.

7. The aquaculture service vessel (10) according to claim 6 wherein surplus impregnator is fed back into the dryer/impregnator arrangement (20).

8. The aquaculture service vessel (10) according to any one of the preceding claims, wherein the service vessel (10) comprises a plurality of work zones, the work zones are:

- a washing zone (21),

- a repair and drying zone (22)

- a drying and impregnation zone (23)

wherein the one or more cranes is an overhead crane (17) arranged for transport of the fish net (11) between the work zones (21,22,23).

9. The aquaculture service vessel (10) according to any one of the preceding claims, wherein the service vessel (10) comprises ozonizing system for disinfect the service vessel (10) before it can move from one location to another location.

10. The aquaculture service vessel (10) according to claim 9, wherein the ozonizing system comprises a tarpaulin adapted to be pulled around the vessel hull before pumping ozone into the service vessel (10) for disinfection of the service vessel (10).

11. A method of performing on-site service of a fish net (11), wherein the method is performed in its entirety onboard a service vessel (10) according to claim 1, wherein the method comprises the step of:

- hauling the fish net (11) onboard the service vessel (10),

- moving the fish net (11) into a wash drum (12) for cleaning of the fish net (11), - clearing the fish net (11) by lifting it high in the air to unravel any tangles, - moving the fish net (11) from the wash drum (12) to the inspection arrangement (13) via net rollers (18,19),

- lowering the fish net (11) onto the floor mounted device (15) for drying, inspection and repair.

12. The method according to claim 11, wherein the method comprises the further step of:

- moving the fish net (11) from the inspection arrangement (13) to an antifouling treatment bath (21), via the net rollers (19,22)