The invention concerns a device for operation and maintenance of a sea pen for fish, as is evident from the preamble of claim 1.

Background Today, the fish farming industry has large challenges with respect to daily operation and not at least treatment and prevention of the salmon lice problem. The prevailing lice treatments are expensive and resource demanding, and results in enormous consequences on loss of growth, and poorer feed factor, on top of increased mortality, bad fish health and reduced deployment. Another challenge is cleaning of net cage walls to remove fouling, algae and crustacean without damaging the net cage. Another challenge is to provide fresh water without lice.

NO 341213 Bl, FI 43365 B and CN 206744294 U describes different examples of supply of feed under water.

GB 2286780 A and NO 337292 Bl show different devices for removing undesired elements in water in sea pens, while JP 2011125262 A describes a net cage cleaner. NO 332589 Bl, NO 338389 Bl, NO 332341 Bl and N0175341B are examples of publications which describe how to pump water from the underside of sea pens.

WO 2010015852 A2 and NO 330863 Bl describe how to move devices located in a sea pen by means of winches.

Object An object of the invention is to provide a device which solves the tasks outlined above in a more effective, compact and cost-effective manner than the prior art. Another object of the invention is to reduce the energy consumption during daily operation and to improve fish health.

The invention

The objects are achieved by a device according to the characterizing part of claim 1. Additional advantageous features appear from the independent claims. Summary

The invention discloses a device which solves several of the tasks which today are solved by separate devices. The device is a combined floating feeding and working device comprising a floating substantially circular housing, anchored movable within the sea pen. A set with positioning winches is preferably arranged on the deck of the housing and connected with a set of wires, preferably four, which in the second end are attached to the sea pen floating ring. In this way the feeding and working device can be mowed around to any location within the sea pen according to the tasks sought to be conducted.

Firstly, the circular housing exhibits a cleaning device, which serves to clean the inside of the net cage wall and collect mud, crustaceans, algae and other solid material into an associated container before water is discharged back to the sea pen again. This cleaning device also serves as a filter for continuous or periodical filtering of lice and parasites while the housing is being mowed around in the sea pen. This lice filter can replace the lice treatment of today, or being used as a supplement.

Den combined feeding and working device according to the invention also exhibits a sea water pump which fetches fresh oxygen-rich water from a depth under the lice belt.

Moreover, the combined feeding and working device according to the invention exhibits a feeding device which distributes feed under water, preferably at a depth under the lice belt. The feed is preferably stored on the deck of the feeding and working device.

In a preferred embodiment, all winches and pumps are operated by electric current stored in accumulators aboard the housing, where the accumulators are charged by means of solar cell panels arranged on deck or in the hand rail on the housing.

Hence, the combined feeding and working device according to the invention solves the objects above in a simpler, more effective, less expensive and gentle way than the prior art.

Detailed description The invention is in the following described in further detail by means of drawings, where

Fig. 1A shows the device according to the invention in perspective from above in a first embodiment, Fig. IB is a drawing similar to Fig. 1A, of a second embodiment,

Fig. 2 is a side view of the device according to the invention, Fig. 3 is a vertical cross-section of the device through line A-A in Fig. 2,

Fig. 4 is a top view of the device according to the invention,

Fig. 5 is a top view of the device according to the invention arranged in a sea pen, and Fig. 6 is a perspective view similar to Fig. 5.

Fig. 1A shows a device according to the present invention illustrated generally at reference number 100, hereafter denoted as the feeding and working device. The feeding and working device 100 is located floating within a sea pen 500 and is anchored movable in the water surface by wires 502a, 502b, 502c, 502d (Fig. 5), preferably four, connected with respective winches 107a, 107b, 107c, 107d (Fig. 4) in floating ring 501 of sea pen 500. The feeding and working device 100 further comprises a substantially cylindrical housing 101 with a deck 103 provided with a first outer hand rail 109 along the periphery of the housing 101 and with an opening 110 in the deck 103 shielded by a second inner hand rail 102. A ladder 104 is arranged in the opening 110 of the deck 103 to allow personnel to enter the internal of the housing 101 for inspection or maintenance. In the lower end of the first outer hand rail 109, a number of drainage ports 106 are arranged along the periphery of the housing 101 to drain water from the deck. The feeding and working device is naturally provided with buoyancy which makes sure that the drainage ports 106 are located above the water surface.

Moreover, the feeding and working device exhibits a cleaning device 200 arranged movable horizontally and vertically along the periphery of the housing 101, and a water supply means 300 arranged along the periphery of the housing 101. In order to create weight balance, the cleaning device 200 and the water supply means 300 are preferably arranged on diametrically opposite sides of each other. A feeding device 400 is located in the opening 110 in center of the feeding and working device 100, arranged to distribute feed in the sea pen down in the sea.

Still with particular reference to Figs. 1A and IB, the cleaning device 200 comprises a nozzle device indicated generally at 204, comprising a nozzle outlet 205, a mud container 206 and a filter bag 208. The filter bag 208 has a mesh width which is sufficiently small to prevent mud from fouling, including crustaceans, lice and parasites, to escape from the filter bag, typically about 150 micrometers. A water pump 207 is arranged between the mud container 206 and the nozzle outlet 205 to pump in water through the nozzle outlet 205, further to the mud container 206 and out through the filter bag 208. The cleaning device 200 is suspended in a crane beam 201 through wires 203 and winch house 202. The crane beam can advantageously be supported pivotal in the horizontal plane. In this way the nozzle outlet, which faces away from the sea pen operation device, can move along the wall of the net cage in a sea pen vertically and horizontally and remove fouling on the same. The cleaning device 200 can also serve as a filter device for removing lice and parasites in the sea by moving the feeding and working device around within the sea pen 500 while the water pump 207 continuously is pumping in water in through the nozzle outlet, filtering out lice and parasites and storing in the mud container 206, before the cleaned water is sent back to the sea pen 400 through the filter bag 208. When the mud container 206 with the filter bag 208 is full, the feeding and working device 100 is hauled into the floating ring 501 where it is hauled up from the sea and emptied for mud, lice and parasites, or replaced by an empty mud container 206 with filter bag 208.

The water supply means 300 illustrated in Fig. 1, is supported movable in a vertical and horizontal manner in a crane beam 301 through a winch house 302 and wires 303 similar to the cleaning device 200. The water supply device comprises an extension pipe 306 with a sea water pump 307, here arranged in the lower end of the pipe, and a nozzle device 304 arranged in the upper end of the extension pipe 306 and exhibits a water nozzle outlet 305. The extension pipe 306 exhibits a length which is sufficient to fetch fresh seawater from a depth under the so-called lice belt, i.e. at least at about 6 meters. In Fig. IB, the crane beam and the winches are omitted, and the water supply means 300 is suspended at a fixed height position by the wires 303 with nozzle outlet 305 located under the water surface. In this way the water supply means 300 also serves as a current producer in cases where the sea pen is located in an area with small through currents.

An arrangement with solar cells 105 is in Fig. 1A shown mounted on the deck 103 of the feeding and working device 100. In an alternative embodiment the solar cells 105 are, as illustrated in Fig. IB, arranged in the first outer hand rail 109. The solar cell arrangement is connected electrically to a set of batteries (not shown), arranged in the bottom of the housing 101 in a battery chamber 108 (Fig. 3). The batteries have sufficient capacity to operate the water pumps, the feed pump and the winches arranged aboard in the feeding and working device 100. The embodiment with batteries in the bottom of the housing 101 provides for a low center of gravity and good stability. Alternatively, the water pumps, the feed pump and the winches can be provided with electric or hydraulic operation from outside through cables, wherein the battery chamber instead is constituted of ballast.

Fig. 2 shows a side view of the feeding and working device 100 with the feeding device 400. Feeding device 400 comprises a substantially vertically extending pipe 401, preferably with a length which is sufficient to locate the outlet in the lower end at a depth under the lice belt. The lower end of the feeding pipe 401 exhibits a distributor 402, here illustrated in the form of a funnel, to distribute the feed around in the sea. The feed is preferably stored on the deck 103 of the feeding and working device 100 and is fed by a feed pump, particularly a screw conveyor, (not shown) through the feeding pipe 401. A subsea camera (not shown) is advantageously arranged at the feeding pipe 401 to monitor fish in the sea pen 500. A LED light is attached near the outlet of the feeding pipe 401 to lighten the sea pen during recording. The feeding pipe 401 is advantageously formed telescopically (not shown) to enable control of the dispensing depth of the feed.

A set of positioning winches 107a, 107b, 107c, 107d (see particularly Fig. 4) is arranged on the deck 103 of the feeding and positioning device 100. A positioning wire 502a, 502b, 502c, 502d is at one end attached to the respective the positioning winches 107a, 107b, 107c, 107d and at a second end to the floating ring 501 of the sea pen 500. Alternatively the positioning winches can be arranged in the floating ring itself. By means of a regulator (not shown), the feeding and working device can be mowed around to any location within the sea pen 500 to perform the work in question. Fig. 5 and 6 shows the housing 100 anchored within a sea pen 500, seen from above and in perspective, respectively, with four wires 502a, 502b, 502c and 502d distanced in the periphery of the sea pen 500 at a mutual equal distance. Technical effect

The invention has several advantages. Lice removal can occur continuously during daily operation in a gentle manner and without use of harmful chemicals. Fresh oxygen-rich water can be fetched from a depth under the lice belt to assist the task of keeping water in the sea pen as much as possible free of lice. The use of accumulators and solar cell panels eliminates the need (for these tasks) for expensive diesel-operated power generators with accompanying fuel costs. A larger quantity of feed can be stored aboard in the feeding and working device and be fed out into the sea, particularly at a depth under the lice belt. The geometrical construction of the housing and the nozzle on the cleaning device exhibits no sharp edges that may damage the wall of the net cage.