Cage with double mesh wall

Abstract

Cage (1) with double net wall (14, 16, 20, 22) where a lower part of the net walls is attached to a pull-down body (36) with an upper attachment point (28) and a lower attachment point (30) with a certain distance from each other, and where, when the pull-down body (36) is pulled down, the net walls come into tension so that they are spread apart and do not come into contact with each other.

Description

[0001] Field of the invention

[0002] The present invention relates to a cage, more specifically a submersible sea cage with double net wall and roof for use in the aquaculture industry.

[0003]

[0004] Background of the invention

[0005] Escape of fish from cages in a fish farm is a known problem. In addition, the infestation of sea lice in the upper water masses and challenges due to deformation of nets in high seas and currents are known problems.

[0006] It is known to make cages with double net walls. However, known constructions are made so that two layers of nets lie close to each other, possibly mounted on each side of the floating collar. These must be installed separately and will lie close to each other in the current, which can cause chafing and damage to the net wall.

[0007]

[0008] The following can be mentioned from the prior art:

[0009] NO337333, which describes a cage with vertical tension anchorage that is connected to anchors on the seabed.

[0010] WO0165925 which describes a device for raising and lowering a cage.

[0011] US6230646 which describes a deep-water fish farming facility that is anchored firmly to the seabed.

[0012] WO2014032199 which describes a mobile cage for farming. The cage is held underwater by means of weights.

[0013] NO20120807 which describes a cage for delousing and other treatment of fish. The cage comprises a lice skirt which surrounds the cage and which can be raised and lowered according to whether or not a closed cage is required.

[0014] NO333479 which describes a fine-mesh fluid-permeable net that surrounds a cage and isolates the cage from unwanted organisms. The fluid-permeable net extends downwards along the depth direction of the cage and forms a skirt around the cage. The skirt comprises buoyancy elements at the upper edge and weights at the lower edge.

[0015] WO2011133045 which describes a mobile closed cage with two separate walls. The outer wall is not water permeable, while the inner wall is water permeable.

[0016] The publication "New closed cage for postsmolt production", Kyst (http: / / kyst.no / nyheter / ny‐lukketmerd‐for‐postsmolt‐produksjon / ) (02.05.2014) concerns a closed mobile cage with a double wall.

[0017] Purpose of the present invention

[0018]

[0019] []

[0020] It is an object of the invention to provide a cage with a double net wall, where the net walls are kept separate from each other by the net walls being played out from each other by a pull-down, where the lower part of the net walls is attached to each bottom cone, which is connected together at a certain distance. A winch mounted on the seabed, or possibly a weight that pulls down on the bottom cones.

[0021] Another object of the invention is to provide a closed cage with a roof structure that provides easy access to the cage.

[0022]

[0023] Brief summary of invention

[0024] Cages according to the invention include a floating collar in the form of a floating circular structure. According to one aspect, the floating collar is made of welded sections of steel tubing. The floating collar may alternatively be made of plastic material. It may also be constructed of tubes or beams assembled into a framework of either metal or plastic material. The floating collar may have a suitable diameter suitable for the aquaculture industry, e.g. a diameter of 30-100 meters. The floating collar provides buoyancy to the cage. According to one aspect, the floating collar is provided with a walkway around its circumference.

[0025] Two codends with approximately cylindrical intermediate portions are attached at their upper edges to the float collar, concentric to each other, but at different heights. Alternatively, the inner codend may be of shorter length than the outer. At the lower part of the cylindrical intermediate portions, the codends are attached to a bottom ring which holds the intermediate portions in a cylindrical shape.

[0026] Each codend has a lower, conical section with a pointed end. The end of each codend is attached to a separate bottom cone, which is connected at a certain distance, for example 50 to 500 cm. The lower bottom cone has an attachment point for connection to a winch or weight, which pulls the codend down towards the seabed.

[0027] The codends have integral tension ropes extending from the float collar to the bottom cones. The tension ropes transmit forces between the float collar and the bottom cone that arise as a result of the pull-down. According to one aspect, the tension ropes may be fiber ropes with a typical diameter of 30 to 70 mm. Alternatively, the tension ropes may be made of wire or chain. When the bottom cones are pulled down by winch or weight, the codends are put under tension, which causes the net walls to be spread apart by a certain distance determined by the distance between the bottom cones, e.g. 0.5‐3m.

[0028] Mounted on the floating collar is a roof structure comprising a plurality of elongated arms attached at their lower ends to the floating collar and at their upper ends to a circular frame. The arms extend from the floating collar to the circular frame and form a substantially conical top. Net sections, hereinafter referred to as the "roof nets", extend from the bags and are suspended from the arms, thus forming a substantially conical top.

[0029]

[0030] []

[0031] roof of the cage. The roof nets can be a single layer or preferably two layers. The lower part of the roof nets is attached to the floating collar, and the upper part to the circular frame.

[0032] According to one aspect, the arms are mounted so that an open access zone is formed between two arms that provides access to the inside of the cage. According to one aspect, the roof nets in this access zone are provided with zippers so that the roof can be opened, e.g. when pumping fish out of the cage to a well boat. The circular frame forms an air dome at the top of the cage, which gives the fish access to a water surface when the cage is lowered.

[0033] The invention is characterized by features set forth in the characterizing part of the following independent claim 1. The preferred embodiments are set forth in the dependent claims.

[0034] Description of the figures

[0035] The invention is described in more detail with reference to the accompanying drawings, in which:

[0036] Figure 1 shows a perspective view of the cage according to the invention.

[0037] Figure 2 shows a side view of the cage according to the invention.

[0038] Figures 3 and 4 show a detailed perspective view showing the gillnets and the cod-ends attached to the floating collar.

[0039] Figure 5 shows a perspective view of the lower part of the net bags attached to the bottom cones.

[0040] Figure 6 shows a perspective view of the bottom cones.

[0041] Figure 7 shows a side view of the cage, showing the double roof and walkway around the moving collar

[0042] Figure 8 shows a wellboat attached to the cage, e.g. for pumping out fish from the cage, and the zips around the perimeter of the roof in an access zone

[0043] Figure 9 shows a perspective view of the float collar and bottom ring.

[0044]

[0045] Detailed description

[0046] As shown in Figure 1, the cage 1 according to the invention includes a floating collar 10 and a bottom ring 12 arranged a certain distance below the floating collar 10. The floating collar 10 is preferably made of steel tubing, and provides buoyancy to the cage. Arranged between the floating collar 10 and the bottom ring 12 are two approximately cylindrical net bags, an inner net bag 14 and an outer net bag 16, which together form an approximately cylindrical intermediate portion 18. At the lower end of the net bags are arranged two approximately conical bottom grooves, in extension of the cylindrical net bags - an inner bottom groove 20 and outer bottom groove 22, which together form a conical lower portion 24. A roof structure 26 is arranged on top of the floating collar 10.

[0047]

[0048] []

[0049] The lower end of each bottom groove 20, 22 is connected to its respective bottom cone. Inner bottom groove 20 is attached to an upper bottom cone 28 and outer bottom groove 22 is attached to a lower bottom cone 30, as shown in Figure 5. The bottom cones are attached to each other at a certain distance by means of a spacer 32, as shown in Figure 6. According to one aspect, several stiffening arms 34 can be arranged between the bottom cones, as shown in Figure 6. The two bottom cones and the spacer together form a pull-down body 36 with an upper attachment point and a lower attachment point. The pull-down body 36 has an attachment point 38 on its lower part.

[0050] As shown in Figure 1, a winch 40 is mounted on the seabed, arranged below the cage 1. A winch cable 42 extends from the winch 40 to the pull-down body 36. The winch acts against the buoyancy from the floating collar 10, and pulls down the cage 1. When the winch pulls down on the pull-down body 36, the net bags 14,16 and the bottom nets 20, 22 are put under tension. This causes the outer nets 16,22 to be played out from the inner nets 14,20 and kept separate from each other. In an alternative embodiment, the winch 40 can be replaced by a weight 44, as shown in Figure 2. The bottom ring 12 ensures that the intermediate section 18 is kept in an approximately cylindrical shape. The cage can be pulled down so that the floating collar 10 is pulled below the surface, or simply subjected to sufficient pulling down so that the net bags are played apart while the floating collar remains on the surface.

[0051] Due to the size of the cage, the forces from the pull-down are very high, e.g. up to 250 tons. Common net materials cannot withstand such a load. Therefore, the nets are equipped with integrated tension ropes that absorb the load from the pull-down. Several of the tension ropes 46 have an extension 48 with a fastening device 50, which is connected to corresponding fastening devices 52, 54 on the bottom cones and the floating collar, respectively, as shown in figures 3, 4, 5 and 6.

[0052] As shown in Figure 1, cage 1 is anchored in the sea by several anchoring ropes 56, which are preferably arranged with several buoys 58.

[0053] As shown in Figure 1, the cage is provided with a roof structure 26. Roof structure 26 is shown in detail in Figures 8 and 9. Roof structure 26 includes a plurality of elongated arms 60 extending upwardly at an angle from the float collar 10 to a circular frame 62, to form an approximately conical top portion 64. Roof structure 26 further includes a walkway 66 up onto the float collar 10, with a fence 68. One or preferably two roof nets, e.g. an outer roof net 70 and an inner roof net 72, are laid on or suspended from the arms 60 to form a roof on the cage, as shown in Figures 1, 3 and 7, preferably in extension of the net bags 14,16. As shown in Figures 3 and 4, the roof nets can be attached to fence 68. In the case where two roof nets are used, these are kept apart from each other by means of a spacer rope 74. The circular frame 62 is tight at the top, forming an air dome which traps air when the cage is pulled below the surface by the winch.This allows the fish to access air even when the cage is pulled below the surface.

[0054]

[0055] []

[0056] According to one aspect of the invention, the cage 1 provides easy access to the inside of the cage, for example when a well boat docks at the facility for pumping out fish, as shown in Figure 8. The floating collar 10 is thus provided with one or more boat landing areas 76. As shown in Figures 8 and 9, two of the arms 60 are arranged at a distance from each other to form one or more access zones 78. The roof nets in the access zone 78 are provided with zippers 80 around the perimeter of the access zone, as shown in Figure 8. The roof nets can thus be easily opened for access to the inside of the cage.

[0057] As shown in Figure 6, according to one aspect, the spacer post 32 of the downdraft body 36 is a cylindrical tube, with an opening 82 located above the upper bottom cone 28. A hose or pipe 84 is connected to the spacer post 32. Opening 82 functions as a suction inlet for suctioning out dead fish or waste. The downdraft body 36 may further include a supply tube 86 for supplying feed, and power / signal cables 88.

[0058]

[0059] []

Claims

PATENT CLAIMS 1. Cage (1) with double net wall (14, 16, 20, 22), characterized in that a lower part of the net walls is attached to a pull-down body (36) with an upper attachment point (28) and a lower attachment point (30) with a certain distance from each other, and where, when the pull-down body (36) is pulled down, the net walls come into tension so that they are spread apart and do not come into contact with each other.

2. Cage according to claim 1, characterized in that the cage (1) includes a circular floating collar (10), a circular bottom ring (12) arranged below the floating collar (10), an approximately cylindrical inner net bag (14) and an approximately cylindrical outer net bag (16) arranged between the floating collar (10) and the bottom ring (12), an approximately conical lower, inner bottom groove (20) in extension of the inner net bag (14), and an approximately conical lower, outer bottom groove (22) in extension of the outer net bag (16), and where the upper attachment point (28) is attached to the tip end of the bottom groove (20) and the lower attachment point (30) is attached to the tip end of the bottom groove (22).3.Cage according to one of the preceding claims, characterized in that the lowering is carried out by a winch (40) on the seabed.

4. Cage according to one of the preceding claims, characterized in that the lowering is carried out by a weight (44) suspended from the lowering body (36).

5. Cage according to one of the preceding claims, characterized in that the net bags (14,16,20,22) have integrated tension ropes (46) arranged to absorb the tensile forces from the winch (40) or weight (44).

6. Cage according to one of the preceding claims, characterized in that the lowering body (36) includes an upper bottom cone (28) and a lower bottom cone (30) attached at a certain distance to a distance post (32).

7. Cage according to claim 6, characterized in that the spacer (32) is a tube, with an opening (80) above the upper bottom cone (28), which tube is connected to a suction hose (84), which tubes are arranged to suck waste from the cage (1). 8.A cage according to any one of the preceding claims, characterized in that the cage (1) further comprises an approximately conical roof structure (26) comprising a plurality of elongated arms (60) attached at their lower ends to a floating collar (10) and at their upper ends to a circular frame (62), and wherein one or two roof nets (70, 72) are laid on or suspended from the arms (60) to form a roof on the cage (1).

9. A cage according to claim 7, characterized in that the circular frame (62) is tight, and arranged to form an air dome that traps air in the event that the cage (1) is dragged below the surface.

10. A cage according to any one of the preceding claims, characterized in that at least two of the arms (60) are arranged at a distance from each other to form an access zone (78), and wherein the roof nets (70, 72) in the access zone are provided with a zipper (80).

11. Cage according to one of the preceding claims, characterized in that the floating collar (10) includes a walkway (66).