WO2017204661A2

WO2017204661A2 - Device for supplying feed under water to a floating sea pen

Info

Publication number: WO2017204661A2
Application number: PCT/NO2017/050134
Authority: WO
Inventors: Einar Brattland
Original assignee: Akvapartner As
Priority date: 2016-05-25
Filing date: 2017-05-24
Publication date: 2017-11-30
Also published as: NO20160890A1; NO341213B1; WO2017204661A3

Abstract

Device for supply of feed to a floating sea pen (600) exhibits a cyclone (200) arranged on a raft (100) provided with a framework (101) and floats (102a, 102b). A conduit (206) provides air-transported feed tangentially to the upper part of the cyclone (200). Numerous air vanes (205) are connected to a shaft (304) and further with water vanes (303). The air vanes (205) are driven by transport air from the feed supply and operates the water vanes (303) to pump water from the sea pen via inlets (301a, 301b, 301c, 301d) and into the internal of the cyclone (200) via water outlets (302a, 302b) to mix feed and water. The cyclone (200) is arranged at least partially submerged under the water surface (w) and exhibits feed outlet conduits (401, 402) extending down into the sea to release feed beneath the lice belt. The device is optionally submerged by a sea pen cover (103) to protect fish from injury when jumping. An underwater camera (500) is optionally arranged liftable between a submerged operational position to a retracted position inside a protecting housing (503) located above the water surface (W) to prevent fouling of the camera lens.

Description

Device for supplying feed under water to a floating sea pen

The invention concerns a device for supplying feed under water to a floating sea pen, according to the preamble of patent claim 1.

Background There are numerous systems for supplying feed to floating sea pens. One example is an underwater feeding system where feed is supplied to the sea pens by pressurized air, wheereupon the feed is mixed with water from deep water and spread in a spreading device to a depth below the lice belt. The advantages of a solution like this is that feeding can be peformed even in strong wing and without requirement for bird net. The feed is supplied at the surface to a cyclone, which is located above the water surface.

A disadvantage of the prior art is that feed having high content of fat will deposit fat in the cone of the cyclone on its way down the cyclone and towards the supply pipe down into the sea pen. Based on experience, this will result in a gradual fouling of the feed supply channel with a gradually decreased feeding capacity as a result. This can result in need for continous feeding to keep up with the feed requirement. In worst case the fish can become underfed, particularly during the winter months with limited daylight, and in the end the whole system can become clogged.

When feeding smolt, personell throw the feed out over the surface of the sea pen to spread the feed out to the smolt, which is relatively stationary and which contrary to larger fish is not going to move towards local feeding locations. This is a relatively labor-demanding operation. Another disadvantage is that the feeding occurs at the surface and within the lice belt. Accordingly, there is a need for an efficient method and a device for feeding smolt and similar with less exposure to lice.

JP H0795832 describes a device for supply of feed under water to a floating sea pen. Feed is being transported by pressurized air to a cyclone. Air supplied by the feed is removed from the cyclone and the feed is guided down into the water. WO 2006/093417 and NO 335720 Bl are examples of devices where feed is supplied under water into a sea pen.

NO 318416 Bl and NO 20053766 describe a feeding device where feed and water is mixed in a container and supplied into a sea pen beneath the water surface. Object

An object of the invention is to provide a device for supplying feed to a floating fish farm, which overcomes the disadvantages of the prior art stated above. Another object of the invention is to provide such a device which in addition can provide substantial saving in energy consumption and in addition provide a substantially noiseless feeding since the cyclone of steel is encircled in the plastic structure.

The invention

These objects are achieved by a device according th the characterizing part of patent claim 1. Additional advantageous features appear from the dependent claims. Device in accordance with the invention for supplying feed under water to a floating sea pen, comprises means for supplying feed from a feed sypply system, a cyclone for receiving feed transported from the feed supply means. Typically, the feed supply system delvers feed to the device by means pf pressurized air, but water-borne transport of feed is also possible since the cyclone is located low in the water and can be connected directly to water feeding without modifications, which is not possible with the prior art since the cyclone is located high above the water. Moreover, the device comprises a pump device for supplying water to the cyclone to be mixed with the feed in the cyclone. The cyclone exhibtis a cylindrical upper part with a closed top provided with an aperture to remove air from the cyclone, and a conica lower part connected to an outlet in flow connection with a feed dispenser in the form of one or more feed outlet conduits arranged to guide a mixture of water and feed down into the sea, which is released at a desired depth in the sea pen.

In accordance with the invention, the device is characterized in that the cyclone is arranged to float partially submerged in the sea with substantially all of the cone-shaped part of the cyclone submerged under the water surface, and that the pump device exhibits a housing provided with numerous water supply conduits extending from outside the cyclone, through the cone-shaped part of the cyclone, and into the internal of the housing, and numerous water outlet conduits in flow connection with the internal of the housing and the internal of the cyclone. A pump means is arranged to pump water from the sea pen in through the water supply conduits, through the water outlet conduits and out to the cyclone by means of power from the pump means. In a preferred embodiment the device comprises numerous vanes arranged rotary about a substantially vertical axis inside the cyclone and in flow connection with said feed supply means, wherein the vanes are connected operationally to the pump means by a shaft and arranged to drive the pump means by means of power from said vanes driven by pressurized air from feed transported from the feed supply system.

In further detail, the means for supplying feed to the cyclone can be a supply conduit which leads into inner and upper part of the cyclone in a direction tangential to the periphery of the cylindrical part of the cyclone.

The pump means can be arranged to be driven by an electric motor, as a supplement to air operation as described above or as an alternative.

The pump means, and optionally the accompanying electric motor, can be arranged releasably in the pump device, thus being able to be lifted out of the pump device and out of the device through the aperture in the top of the cyclone. The pump means, and optionally the accompanying electric motor, is hence preferably arranged loosely in a countersink in the pump device.

Advantageously, the water outlet conduits exhibit a bent outlet arranged to form av circulating outlet flow of water to the internal of the cyclone in a direction substantially tangential to the periphery of the cyclone. The water outlet pipes are also preferably bent downward to prevent floating feed to enter the pump when not in use.

The feed supply conduit and the water outlet pipes can be arranged to direct a flow of feed and water, respectively, in the same direction in the cyclone.

An underwater camera is in a preferred embodiment arranged movable at the device from a lower suberged postion in the sea pen to an upper retracted position protected within a housing or pipe located above the water surface. In further detail, the underwater camera can be suspended in a rope or wire which extends through the housing and further to a winch located above the water surface, which can lift and lower the camera. This will reduce the need for cleaning the camera lens because of fouling. Moreover, the camera is advantageously encircled by tarpaulin or sea pen cover serving as jump protection to prevent injury on fish in risk of hitting hard surfaces of the device.

The feed outlet conduits in the feed dispenser are in a first embodiment preferably arranged with an outlet at least 5 meters under the water surface W and that the outlet end of the feed outlet conduits extends only a short distance out to the edge of the sea pen, so that the device in all essentials is arranged to deliver feed close to the position of the device within the sea pen. This is an embodiment directed to larger fish which itself will seek out feed delivered from the device in accordance with the invention.

In a second embodiment of the feed dispenser, the feed outlet conduits exhibit numerous perforations and are arranged with their outlet and perforations at least 5 meters under the water surface W, wherein the end of the feed outlet conduits extends a substantial distance out towards the edge of the sea pen, at least 50-80% of the distance from the device and the edge of the sea pen, so that the device in all essentials is arranged to deliver feed to substantial parts of the sea pen. This embodiment is directed to smolt and smaller fish which itself will not seek out feed delivered from the device in accodance with the invention.

In a third embodiment, the feed dispenser is realized in the form of at least five rigid feed channels which in their upper end is connected to the feed outlet from the cyclone, and the lower end of which is connected to a stiffening bottom frame. The respective rigid feed channels are open in both ends and serve as transportation channel for feed being guided into the sea pen from the cyclone. The internal diameter of the respective rigid feed conduits is the same from one end to the other. The lower end of the respective rigid feed conduits is guided through the bottom frame, so that the outlet of the feed conduits which opens into the water is substantially in flush with the external surface of the bottom frame. The feed conduits and the bottom frame are preferably hollow tubes, particularly plastic tubes. Moreover, the bottom frame is preferably filled by a weight material, particularly concrete. Close to the lower part of the respective feed conduits, the respective feed conduits can be provided with one or more inclined branch conduits in flow connection with the respective rigid feed conduits to which the branch conduit is connected to. The lower part of the respective branch conduits is connected to the bottom frame and has a lower end which is open to the surrounding water mass in the sea pen and having an outlet opening substantially flush with the external surface of the bottom frame. The respective rigid feed conduits wxtending down from the cyclone is arranged at an angle with the vertical of about 5-60 degrees, particularly about 30 degrees with the vertical. The steep outlet conduit makes the feed to flow down through the rigid feed conduits by means of the gravity, assisted by the open water supply conduits in the top.

In an arrangement like this with numerous rigid feed conuits and branch conduits with inclined feed conduits, the gravity makes the feed to slide out by itself, which results in reduced flow resistance through the conduits in the feed dispenser, and enables feeding even though all or parts of the vanes should become damaged or break, whereby the pump means no longer will be able to force water out through the water outlets in the cyclone. In a preferred embodiment of the feed dispenser described above, the bottom frame is square or rectangular with one rigid feed conduit in every corner, and hence the feed dispenser exhibits totally four feed-conducting rigid feed conduits. Moreover, two branch conduits are provided at the lower end of the respective rigid feed conduit connected to opposing sides of the respective corner. The arrangement with the four rigid feed conduits with constant flow cross-section to the outlet, lowers the risk for clogging substantially. It can be mentioned that prior art feed dispensers have been using numerous small outlets from a large feeding pipe, but this increases the risk of clogging. In the third embodiment of the feed dispenser in accordance with the invention, the feed is guided into 4 main pipes directly from the cyclone, and these are guiding the feed in all of the cross-section of the pipe all the way to free water, where the feed in addition can be guided into the water via additional branch conduits. An arrangement like this provides a robust and twist-resistant feed dispenser which can resist strain from rough sea and currents.

The rigid feed conduits, the bottom frame and the branch conduits are in particular made of a rigid plastic material. Detailed description

The invention is in the following described in further detail in the form of some embodiments by means of drawings, where

Fig. 1A illustrates a vertical cross-section through a peferred first embodiment of the device according to the invention, Fig. IB illustrates a top drawing of the first embodiment of the device of Fig. 1A with a section of the cyclone,

Fig. 2A is a drawing similar to Fig. 1A but which illustrates a second embodiment of the device according to the invention,

Fig. 2B is a top sketch of the second embodiment of the device of Fig. 2A with a section of the cyclone,

Fig. 3A is a top sketch of the device according to the invention which shows a first embodiment of a feed dispenser in a sea pen suitable for larger fish,

Fig. 3B shows the embodiment of the feed dispenser of Fig. 3A viewed from the side, Fig. 4A is a top sketch corresponding to Fig. 3A which shows a second embodiment of a feed dispenser in a sea pen, suitable for smolt and smaller fish,

Fig. 4B shows the feed dispenser of Fig. 4A viewed from the side,

Fig. 5A shows a third embodiment of a feed dispenser in a sea pen viewed from the side, Fig. 5B shows the feed dispenser of Fig. 5A viewed from above, and

Fig. 6 is a side sketch of the lower part of the feed dispenser of Figs. 5A and 5B.

Now referring to Figs. 1A and lb, a device for supplying feed to a sea pen is shown. The device comprises a cyclone indicated in general by reference numeral 200. The cyclone 200 is arranged in a raft 100 which comprises a framework 101 arranged on floats or floats 102a, 102b. Moreover, the device comprises an underwater camera 500 and feed outlet hoses 401, 402 for dispensing feed under water. The underwater camera 500 is attached to a rope or wire or similar 501 connected to a winch 502 mounted in the framework 101. The rope extends through a pipe or similar 503 mounted at the framework 101 over the water surface to protect the camera from fouling in the water when not in use. A jump protection for fish is indicated at 103, and can be a tarpaulin, or in particular a sea pen cover, mounted to the framework 101 to protect fish against injury from impact with the framework or the floats. The lower edge of the tarpaulin or the sea pen cover is preferably provided with weights, particularly leaden weights.

The cyclone 200 exhibits a closed top 201 and a cone-shaped bottom 202 which opens into a feed outlet 203. An aperture 204 in the top of the cyclone is arranged to guide away air supplied to the cyclone. The cyclone is provided with a pump device indicated in general by reference numeral 300. The pump device 300 is arranged centrally in within the cyclone 200 in the area of the conical part of the cyclone 200. The pump device 300 comprises a substantially vertically extending cylinder 301 which in its lower end is provided with water inlets 301a, 301c extending outside the cyclone, preferably from a depth below the lice belt under about 5 meters from the water surface (indicated by reference character W). Water outlets 302a, 302b are arranged a distance further up along the cylinder. Moreover, the cyclone 200 is arranged in relation to the framework 101 and the floats 102a, 102b, so that its conical part 202 is located below the water surface W in the sea pen. Moreover, the pump device 300 is arranged inside the cyclone 200 so that the water outlets 302a, 302b of the pump device 300 are located substantially in the transition between the conical part 202 of the cyclone 200 located below the water surface W, and a vertical cylindrical section 205 of the cyclone. Moreover, the pump device 300 is provided with a pumping means in the form of one or more propellers or vanes 303 arranged rotary on a shaft 304 extending substantially vertically up through the cylinder 301 and out through the top of the cylinder 301 where it is connected to vanes 305.

The device illustrated in Fig. 1A for supply of feed to a sea pen is operated as described in the following. Feed is supplied from a traditional central feeding plant (not shown) which blows the feed tangentially (see reference numeral 206 in Fig. IB) into the top of the cyclone 200. The air flow drives the vanes 305, which again drives the shaft 304 and the propeller 303. The propeller 303 sucks water from the sea pen in through the water inlets 301a, 301c, and drives the water up through the cylinder 301 and finally out from the pump device 300 through the water outlets 302a, 302b in a direction substantially tangential to the periphery of the cyclone 200 and in the same direction as the feed supplied in the top of the cyclone. Feed and water is mixed and is brought to rotate and move downward along the conical part 202 of the cyclone 200. Feed mixed with water is "screwed" down through the outlet 203, down through the feed outlet hoses 401, 402 and out into the sea pen. Air transported with the feed from the central feeding plant leaves the cyclone 200 through an aperture 204 in the top of the cyclone.

The embodiment illustrated in Figs. lA and IB has several advantages. Feed is pressed down through the cyclone and the outlet hoses together with water. This gives the advantage that the feeding can occur faster compared to feeding dry feed down through the outlet hoses. The arrangement with a partially submerged cyclone prevents fat from feed to deposit on the surface of the cone-formed part 202 of the cyclone. In this way, improved operational regularity and improved capacity is achieved compared to prior art solutions arranged above the water surface, which has problems with clogging of feed conduits and need shutdown and cleaning.

With prior art solutions utilizing electric pump, experience has shown that the electric pump breaks down, e.g. as a result of torn-off electric cables from a storm. In situations like this, crew or feeding system is not informed about a broken down pump, and the feeding system continues to supply feed to the feeding device. Then, the cyclone and accompanying conduits can become clogged by feed , whereupon the feeding device as a whole can sink and result in escape, whereupon the feeding device must be lifted and the feed conduits unstopped. This can be a risky operation, particularly in bad weather. The use of pressurized air from the central feeding plant for operation of the pump device via he vanes results in energy savings, since at least a part of the kinetic energy in air blown from the central feeding plant can be utilized, which otherwise would get lost. Pumping of water will start automatically when feed supply is started, and will be maintained as long as feed is supplied to the device. At different solutions, shutdown is often encountered because of fault in pumps or remote start.

The jump protection will reduce injury on fish in the sea pen. Finally, the arrangement with the underwater camera, which can be lifted up and protected against the environments in the container at the framework, gives reduced need for cleaning lens, which otherwise will become fouled in the sea.

Still with reference to Fig. 1A, the pump device 303, and the alternative optional accompanying electric motor 306 (Fig. 2A), arranged releasable in the pump device 300 to be lifted out of the pump device 300 and the feeding device according to the invention through the aperture 204 in the top of the cyclone 200. This ca simply be obtained by arranging pump device and optionally accessories in a recess without further fixation means, since the pump device will be forced down into the recess by its own pumping force. In this way, replacement or maintenance of the pump and accessories can be performed in a convenient manner without having to lift the whole feeding device out of the water.

In case the pump device 303 is driven by an electric motor 306, the power cables (not shown) can be guided through the aperture 204 and down to the electric motor 306. In this embodiment propeller or vanes at the pump device 303 is advantageously provided with a surrounding frame device to prevent the power cables from damage or being entangled in propeller or vanes at the pump device 303.

Now with reference to Figs. 2A and 2B, a second embodiment of the device in accordance with the invention is shown. This second embodiment is equal to the first embodiment illustrated in Figs. 1A and IB, but here the pump device is provided with an electric motor 306 for operating the propeller 303, and the vanes 305 are therefore omitted. Figs. 3A and 3B show a first embodiment of a feed dispenser 700 in accordance with the invention, where Fig. 3A shows a sea pen 600 viewed from above, and Fig. 3B shows the sea pen 600 viewed from the side. Now with reference to Fig. 3A, a number of feed dispenser hoses 701a, 701b, 701c and 701d are arranged in a framework 702. The hoses are in their upper end in flow connection with the cyclone 200, and are in the second (lower) end provided with an aperture for releasing feed at a depth below the lice belt. Here, the feed dispenser hoses only extend a short distance into the sea pen, e.g. 10-15% of the sea pen radius. Fish is indicated by reference character F. This first embodiment is best suited for fish from about 500 grams and to slaughtering size, since this is fish that will swim by itself and seek feed dropped out of the feed dispenser.

A second embodiment of a feed dispenser 700 in accordance with the invention is illustrated in Figs. 4A and 4B, corresponding to Figs. 3A and 3B. In this second embodiment, numerous feed dispenser hoses 701 are arranged along the periphery of the sea pen 600, but here the hoses extend further out toward the outer rim of the sea pen. Moreover, the feed dispenser hoses are in an embodiment provided with apertures along at least parts of the hose length to drop feed over a larger area but at a depth below the lice belt. The second embodiment is suited for feeding smolt and small fish who do not seek feed on their own. Here, the feed dispenser hoses 701 are suspended in the sea by means of a rope 703 attached to the rim of the sea pen.

A third embodiment of a feed dispenser 700 in accordance with the invention is illustrated in Figs. 5A, 5B and 6. The feed dispenser exhibits four inclined rigid feed conduits 702a, 702b, 702c, 702d, which at their upper end are connected to the feed outlet 203 from the cyclone 200 and the lower end of which is connected to a stiffening four-sided bottom frame 705 in the respective corners of the same. The respective rigid feed conduits 702a, 702b, 702c, 702d are open in both ends and serve as transport conduit for feed to be ejected into the sea pen from the cyclone 200. The respective feed conduits have an outlet aperture 706 that is substantially in flush with the external surface of the bottom frame. The bottom frame 705 is preferably filled with a weight material (not illustrated), particularly concrete. At the lower end, the respective rigid feed conduits 702a, 702b, 702c, 702d are provided with two inclined branch conduits 704 in flow connection with the respective rigid feed conduits 702 to which the branch conduit 704 is connected to. The lower end of the respective branch conduits 704 is connected with the bottom frame 705 and has a lower end which is open to the surrounding water mass in the sea pen. The respective rigid feed conduit 702 is provided with two branch conduits 704 which extend inclined down from its rigid feed conduit 702 to the bottom frame 705 and is connected to each side of the corner where the respective rigid feed conduit 702 is attached. It should be mentioned that the bottom frame also will serve as a collision protection for fish, since the bottom frame makes a rounded termination of the rigid feed conduits, so that the fish not get injured on sharp pipe ends.

Modifications The embodiments described above are exemplified as floating arrangement. However, the invention is not limited to this. The cyclone, the pump device and the outlet hoses can be fixedly connected to the sea pen in a framework as well. Moreover, the embodiments are illustrated with a given number of water inlets and water outlets at the pump device. This number can naturally be varied without deviating from the basic idea of the invention. Instead of perforated feed dispenser conduits, pipes or hoses can be used, having outlet in the end for releasing feed. Moreover, the pump device 303 is illustrated in the form of a propeller, but other means having equivalent function for transportation of water from the surrounding water mass and into the cyclone 200 can be used, such as one or more vanes.

Whereas the feed dispenser in the third embodiment is illustrated with four rigid feed conduits 702 connected to a four-sided, substantially rectangular, bottom frame 705, it is also conceivable with a triangular bottom frame with three feed conduits arranged at each corner in the triangle, or a polygonal bottom frame with a feed conduit arranged at each corner of the polygon.

It should also be added that whereas the description has not provided any dimensions, a person skilled in the art with support in the present description will be able to find right dimension for the rigid feed conduits and other components in the feed dispenser to obtain the aimed technical effect.

Claims

1. Device for supplying feed under water to a floating sea pen, said device comprising means (206) for supplying feed from a feed supply system, a cyclone (200) for receiving feed transported from said means (206), particularly transported by pressurized air or pressurized water, a pump device (300) for supplying water to the cyclone (200) to be mixed with the feed in the cyclone (200), wherein the cyclone (200) exhibits a cylindrical upper part (205) with a closed top (201) provided with an aperture (204) to remove air from the cyclone (200), and a conical lower part (202) connected with an outlet (203) in flow connection with a feed dispenser comprising one or more feed outlet conduits (401, 402), arranged to guide a mixture of water and feed down into the sea to be released at a desired depth in the sea pen, characterized in that the cyclone (200) is arranged to float partially submerged in the sea with substantially all of the cone-shaped part (202) of the cyclone (200) submerged below the water surface (W), and that the pump device (300) exhibits a housing (301) provided with numerous water supply conduits (301a, 301b, 301c, 301d) extending from outside the cyclone (200), through the cone- shaped part (202) of the cyclone, and into the internal of the housing (301), numerous water outlet conduits (302a, 302b) in flow connection with the internal of the housing (301) and the internal of the cyclone (200), and a pump device (303) arranged to pump water from the sea pen in through the water supply conduits (301a, 301b, 301c, 301d) and through the water outlet conduits (302a, 302b) by means of force from the pump device (303).

2. The device of claim 1, characterized in that the device further comprises numerous vanes (305) arranged rotary about a substantially vertical axis within the cyclone (200) and in flow connection with said feed supply means (206), wherein the vanes (305) are connected operationally with the pump device (303) via a shaft (304), and arranged to operate the pump device (303) by means of force from said vanes (305) operated by pressurized air from feed transported by pressurised air from the feed supply system.

3. The device of claim 1 or 2, characterized in that the means for supplying feed to the cyclone is a supply conduit (206) which opens out in inner and upper part (205) of the cyclone (200) in a direction tangentially with the periphery of the cylindrical part (205) of the cyclone.

4. The device of claim 1, characterized in that the pump device (303) is arranged to be operated by an electric motor (306).

5. The device of any one of the claims above, characterized in that the pump device (303), and optionally the accompanying electric motor (306), are arranged releasable in the pump device (300) to be able to be lifted out of the pump device (300) and the device (100) through the aperture (204) in the top of the cyclone (200).

6. The device of claim 5, characterized in that the pump device (303), and optionally the accompanying electric motor (306), are arranged loosely in a recess in the pump device (300).

7. The device of any one of claims 1 to 6, characterized in that the water outlet pipes (302a, 302b) exhibit a bent outlet arranged to form an outlet flow of water to the internal of the cyclone (200) in a direction substantially tangential with the periphery of the cyclone (200).

8. The device of any one of the claims above, characterized in that the feed supply conduit (206) and the water outlet pipes (302a, 302b) are arranged to direct a flow of feed and water, respectively, in the same direction into the cyclone (200).

9. The device of claim 1, characterized in that an underwater camera (500) is arranged movable at the device from a lower submerged position in the sea pen to an upper retracted position protected in a housing or pipe (503) located above the water surface (W).

10. The device of claim 9, characterized in that the underwater camera (500) is suspended in a rope or wire (501) extending through the housing (503) and further to a winch (502) located above the water surface (W).

11. The device of claim 1, characterized in that the device is surrounded by a tarpaulin or sea pen cover (103) serving as jump protection to prevent injury on fish in risk of hitting hard surfaces of the device.

12. The device of claim 1, characterized in that it exhibits a framework (101) and floats (102a, 102b) arranged to float anchored in a sea pen.

13. The device of claim 1, characterized in that the feed outlet conduits (401, 402) are arranged with an outlet at least 5 meters below the water surface (W) and that the outlet end of the feed outlet conduits (401, 402) extends only a short distance out towards the rim of the sea pen, so that the device in all essentials is arranged to deliver feed close to the position of the device in the sea pen (600).

14. The device of claim 1, characterized in that the feed outlet conduits (401, 402) exhibit numerous perforations and are arranged with their outlet and perforations at least 5 meters below the water surface (W), wherein the end of the feed outlet conduits (401, 402) extends a substantial distance out towards the rim of the sea pen, at least 50-80% of the distance from the device and the rim of the sea pen, so that the device in all essentials is arranged to deliver feed to substantial parts of the sea pen (600).

15. The device of any one of claims 1 to 12, characterized in that the feed dispenser exhibits at least four rigid feed conduits (702a, 702b, 702c, 702d) with an upper end in flow connection with the feed outlet (203) in the cyclone (200), and a lower open end connected with a rigid four-sided or polygonal bottom frame (705) and which exits the same, whereby the respective feed conduit extends at an angle with the vertical of 5-60 degrees, particularly substantially 30 degrees, and optionally one or more branch conduits (704) are arranged at the lower end of every rigid feed conduit (702a, 702b, 702c, 702d) in flow connection with the internal of every rigid feed conduit (702a, 702b, 702c, 702d) and the surrounding water mass in the sea pen, arranged to serve as additional feed transportation channel.

16. The device of claim 15, characterized in that the feed conduits (702a, 702b, 702c, 702d), the bottom frame (705) and the branch conduits (704) are made of a rigid plastic material.

17. The device of claim 15 or 16, characterized in that the bottom frame (705) is four-sided and exhibits one feed conduit (702a, 702b, 702c, 702d) arranged at every corner in the square.

18. The device of any one of claims 15 to 17, characterized in that the respective rigid feed conduits (702a, 702b, 702c, 702d) extends at an angle with the vertical of about 20-60 degrees, particularly about 30 degrees.

19. The device of any one of claim 15 to 18, characterized in that the bottom frame (705) is filled with a weight material.

20. The device of claim 19, characterized in that the weight material is concrete.

21. The device of claim 15, characterized in that the lower part of the respective feed conduits (702a, 702b, 702c, 702d) and the optional branch conduits (704) have an aperture (706) which is substantially in flush with the external surface of the bottom frame (705).