Crowding Device

Abstract

A crowding device for an aquaculture tank for marine life, the tank having at least one outlet at a bottom of the tank, the crowding device comprising a sheet extending between a hub and an outer ring, the sheet surrounding the hub, the outer ring contacting an inner wall surface of the tank, the hub being centrally located in the tank, the sheet, the hub and the outer ring covering a horizontal cross-sectional area of ​​the tank, a first wiper assembly and a second wiper assembly extending substantially radially between the sheet, the hub and the outer ring, or alternatively, the first wiper assembly and a fixed wall portion. The invention also relates to a method for crowding an aquaculture tank for marine organisms using the crowding device, the invention further ...

Description

[Technical field]

[0001] The present invention relates to a crowding device for an aquaculture tank for marine life and a method for crowding an aquaculture tank prior to emptying using the crowding device. [Background technology]

[0002] Reservoirs or tanks for cultivating fish or other marine organisms, such as aquaculture cages, cages or similar devices, are emptied, for example, when the organisms have to be transferred to a larger tank or enclosure. Handling for these transfers needs to be done gently so as not to harm the marine organisms.

[0003] In other reception or intermediate storage facilities for live fish, it is common to wait for the cages in which the fish will be kept before being slaughtered, however the invention is equally applicable to land-based aquaculture and closed net cages at sea.

[0004] No. 324024 shows a conventional method and device for crowding and emptying tanks for aquaculture or intermediate storage of marine organisms. The crowding device is composed of separate parts. A closing net or lid adapted to be lowered into the tank to limit the area of ​​the tank from above is provided. At the bottom of the tank, opposite the outlet from the tank, a mobile profile and a fixed profile are provided. The profiles are attached to the tank in this conventional solution. A limited area is provided between the profiles to collect and guide the fish from the tank. However, the profiles are not a device but an integrated part of the tank. The closing lid is therefore only used to limit the area from above the tank. The closing lid must be arranged separately from the profiles and formed as a rigid structure to ensure that there are no gaps between the profiles and the closing lid to avoid any escape of marine organisms between the profiles and the closing lid.

[0005] The crowding device according to the invention provides a flexible and lightweight device for the crowding process in a tank and therefore also provides a more efficient and easier handling of the crowding process than conventional solutions.

[0006] In the crowding device according to the invention, the sheet does not need to be constituted by a rigid structure, because the sheet and the wiper assembly are formed as one device, with the sheet fitting into a gap in the wiper assembly, the gap being small enough to ensure that the marine organisms or fish do not move from one side of the gap to the other, and the gap being large enough to allow the wiper assembly to move relative to the sheet.

[0007] The sheet is tensioned between the outer and inner rings and is further mated with the wiper device, which allows the sheet to be more flexible and lightweight.

[0008] Other relevant prior art relating to crowding devices includes U.S. Patent Application Publication No. 2012 / 0167829, which describes a floating circular fish pen with an elongated cylindrical section floating in the middle of the fish pen. The fish pen includes a deployable panel system that deploys from the cylindrical section towards the walls of the fish pen to crowd the fish into a smaller portion of the fish pen.

[0009] Finally, WO 2015 / 099540, similar to U.S. Patent Application Publication No. 2012 / 0167829, also describes a circular fish pen for crowding fish with fixed walls and rotatable walls about a center column for crowding the fish in the fish pen, and also includes a movable section of the floor in the fish pen to further crowd the fish. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] NO324024 [Patent Document 2] US Patent Application Publication No. 2012 / 0167829 [Patent Document 3] International Publication No. 2015 / 099540 Summary of the Invention

[0011] The present invention relates to a crowding device for a marine organism culture tank, the tank having at least one outlet at the bottom of the tank. a seat extending between the inner ring and the outer ring; a first wiper assembly and a second wiper assembly extending substantially radially between a hub and an outer ring, or alternatively, the first wiper assembly and a fixed wall, the first wiper assembly being movably disposed relative to the seat; The first wiper assembly includes a crossbar and a wiper arranged in parallel with a gap therebetween for receiving a sheet, and the wiper and crossbar are fixedly attached to one another at one end.

[0012] The invention further relates to a method for crowding an aquaculture tank for marine organisms using a crowding device according to the crowding device of the invention, the method comprising the steps of rotating a first wiper assembly towards a second wiper assembly or fixed wall for guiding the marine organisms towards an outlet of the tank arranged at the bottom of the tank, the outlet being arranged such that in all positions of the wiper assembly the outlet is located in the area between the second wiper assembly or fixed wall (6) and the first wiper assembly.

[0013] Preferred embodiments of the device are set out in the dependent claims to which reference is made.

[0014] The drive mechanism may include a bar connected to the wiper assembly and adapted to follow a track defined by inner and outer guide walls disposed on the outer ring.

[0015] The method may further include lowering the crowding device by a suspension device (not shown) before crowding the tank, and after crowding the tank, lifting the crowding device away from the bottom of the tank and rotating the wiper device in a reverse direction toward the opposite side of the counterpart to reset the crowding device by the suspension device. [Brief description of the drawings]

[0016] [Figure 1] 1 shows a crowding device according to an embodiment of the invention viewed from different angles; [Figure 2a] 1 shows a crowding device according to an embodiment of the invention viewed from different angles; [Figure 2b] 1 shows a crowding device according to an embodiment of the invention viewed from different angles; [Diagram 3] A detailed side view of a first wiper assembly having a seat positioned between the crossbar and the wiper. [Figure 4a] A detailed partial view of the first wiper assembly and outer ring from above. [Figure 4b] FIG. 1 is a detailed partial view of the first wiper assembly and outer ring in an isometric view. [Diagram 5] A further detailed partial view of the arrangement of the first wiper assembly in the outer ring. [Figure 6] FIG. 2 is a detailed partial view of the outer ring with the guide device and the drive mechanism, seen in perspective. [Figure 7] FIG. 2 is a detailed partial view of the outer ring with the guide device and the drive mechanism, seen in perspective. [Figure 8] FIG. 4 shows a further detailed partial view with the guide device and the drive mechanism seen from the side. [Figure 9] FIG. 2 is a further detailed partial view with the guide device and the drive mechanism seen from above. [Figure 10] FIG. 13 is a detailed view of the hub and the first wiper assembly and the connection of the hub to the second wiper assembly or fixed wall. [Figure 11] FIG. 2 shows a side view of the crowding device showing a first wiper assembly and a second wiper assembly or a fixed wall portion. [Figure 12]FIG. 13 illustrates an exemplary position of the first wiper assembly relative to the counter bar, as viewed from below. [Figure 13] A diagram showing a first wiper assembly having a strut device as viewed from above. [Figure 14] FIG. 13 shows an alternative embodiment of a crowding device where the shape of the outer ring is adapted to fit non-circular tank shapes. [Figure 15] FIG. 13 shows the end of the wiper with the wiper extender retracted in an alternative embodiment of the crowding device. [Figure 16] A diagram showing the end of the wiper with the wiper extender extended in an alternative embodiment of the crowding device. [Figure 17] 13A-13D show an alternative embodiment of a crowding device in perspective and isometric views before being lowered vertically in a tank. [Figure 18] 13A-13D show an alternative embodiment of a crowding device in perspective and oblique views near the bottom of the tank. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The term marine organism may be understood to mean an organism that lives in a marine environment and is suitable for farming. This may be, for example, fish, shrimp, lobsters, crabs.

[0018] The tank may be for aquaculture or intermediate storage of marine organisms. The tank may be located, for example, on a live fish carrier or may be a tank located on land. The tank is preferably circular or substantially circular. However, other shapes or tanks may be possible.

[0019] Figures 1 and 2 show a crowding device 1 for use in a tank containing marine organisms such as fish. The tank has at least one outlet for discharging water and marine organisms. The at least one outlet is arranged in the lower part of the tank, preferably in the bottom of the tank, in an outer side wall near the bottom, or in a side of a central column in the tank. The tank is not shown but is known per se, for example from NO 324024. The device in the exemplary drawings is substantially circular to match the circular side wall of the tank. The crowding device 1 is therefore adapted to be arranged in the tank.

[0020] FIG. 1 shows the crowding device 1 from above. The crowding device 1 comprises an outer ring 3 and a hub 5a. The outer ring 3 is adapted to be in contact with the inner wall surface 30 of the tank. The hub 5a may form a circular ring. This hub 5a may surround a central column 19 or similar device in the middle of the tank as shown in FIG. 3. The hub 5a may also be a ring-like central position of the crowding device 1. In the latter case, the ring forms a central position without having any central column 19 or similar. In the absence of a central column, the inner ring must be closed at the top to avoid that marine organisms such as fish can escape. The hub 5a may also be defined as an end connection in the wiper device 5 as disclosed further below.

[0021] Figures 3 to 9 show in more detail the first wiper assembly 5 and the second wiper assembly or fixed wall 6. The figures also show a guide arrangement 9 and a drive mechanism 10.

[0022] As shown in Figure 3, the seat 2 extends between the outer ring 3 and the inner ring 4. The seat 2 is fixedly attached to the inner ring 4 and the outer ring 3, respectively. The seat 2 is in other words tensioned between the outer ring 3 and the inner ring 4. Alternatively, the seat 2 can be fixedly attached to the hub 5a itself, in which case the seat 2 is tensioned between the hub 5a and the outer ring 3.

[0023] The sheet 2 may be perforated or form an impermeable cover. It may be made of a net, a fabric, a plastic sheet with slits / holes, or a tarpaulin. If the sheet is impermeable there must be other ways in which water can pass to / from the crowding device 1. It is noted that the sheet 2 is formed as a continuously arranged cover or made of connected pieces. There are no openings between the sheet parts as figures 12 and 13 may give the impression.

[0024] The crowding device 1 further comprises a first wiper assembly 5. The first wiper assembly 5 extends between the hub 5a and the outer ring 3 as shown in FIG. 3. The first wiper assembly 5 is adapted to rotate with respect to the sheet 2. The first wiper assembly 5 further comprises a wiper 8 and a crossbar 7 connected to the hub 5a, thereby forming a connection between the crossbar 7 and the wiper 8 at the end with the inner ring 4. The wiper 8 and the crossbar 7 are arranged on the opposite side of the sheet 2. The wiper 8 and the crossbar 7 thus form a slit or small gap in which the sheet 2 can be placed. The slit or gap is small enough to prevent fish from crossing the wiper assembly 5, but large enough to allow the sheet 2 to be placed in the gap.

[0025] The slits or gaps may have a predetermined space or distance between the wiper 8 and the crossbar 7, which may be adapted or varied depending on the size of the fish, or more specifically the diameter of the fish. The slits or gaps may have a fixed or adjustable distance between the wiper 8 and the crossbar 7 to prevent larger fish having a diameter, i.e. thickness across the shortest axis, of 0.5 cm to 5.0 cm from passing through the slits or gaps. Alternatively, the slits or gaps may have an adjustable distance to prevent younger fish, e.g. smolts, having a diameter of 0.2 cm to 2.0 cm from passing through the slits or gaps. Furthermore, the slits or gaps may have an adjustable distance to prevent crustaceans, e.g. shrimps, having a diameter of 0.1 cm to 0.5 cm from passing through the slits or gaps.

[0026] By arranging the sheet 2 and wiper assembly 5 in the same crowding device 1, the sheet can be a more flexible and lightweight material than conventional solutions for preventing fish marine life from passing between the sheet and the wiper.

[0027] As mentioned above, the hub 5a may alternatively be a ring surrounding the central column, if present, or a smaller central ring if the central column is not present, however these alternatives are optional as the hub 5a may be guided by the inner ring 4.

[0028] The first wiper assembly may be hingedly connected to the hub 5a by a hinged connection as shown in Figure 3. The wiper is movable about axis B as shown.

[0029] The crowding device 1 also includes a second wiper assembly 6 or alternatively a fixed wall. Both alternatives are indicated by the reference number 6 in the drawings. If a fixed wall is provided, it may be fixedly arranged between the outer ring 3 and the hub 4. In this embodiment, the fixed wall 6 is therefore held in the same position in the crowding device 1. When the crowding device 1 is placed in a tank, the fixed wall 6 is placed near the outlet of the tank. The fixed wall 6 further extends downwards from the crowding device 1. This is further shown in FIG. 11. The fixed wall 6 thus provides a stop and guide for the collected marine fish collected by the first wiper assembly 5. The fixed wall 6 thus facilitates the movement of the marine organisms towards the outlet. In this embodiment, the fixed wall 6 only needs to be a wall similar to the wiper 8 of the first wiper assembly 5 extending downwards from the sheet 2.

[0030] In a further embodiment, there may be a second wiper assembly 6 replacing the fixed wall portion. The second wiper assembly 6 may be rotatably arranged in a manner similar to the first wiper assembly 5. In this embodiment, the second wiper assembly 6 preferably has the same design as the first wiper assembly 5, with a crossbar 7 in addition to wipers 8. Further embodiments of the invention may have three or more wiper assemblies similar to the first wiper assembly 5.

[0031] The first wiper assembly 5 includes a wiper 8, for example as shown in Fig. 4a, Fig. 4b and Fig. 5. The wiper 8 is arranged on the underside of the seat 2. The wiper 8 has a bracket shape that extends vertically towards the bottom of the tank when the crowding device 1 is installed in the tank. This provides a collection function when the first wiper assembly 5 is rotated, so that all marine organisms contained in the tank can be collected in the space between the wiper 8 and the second wiper assembly or the fixed wall 6. The wiper 8 may further have an opening to allow marine organisms under a certain size, such as cleaner fish, to remain in the tank. The same applies to the second wiper assembly 6.

[0032] The first wiper assembly 5 further comprises a crossbar 7 and may also comprise a crossbar roller 17. The crossbar roller 17 is attached to the free end of the crossbar 7. The crossbar 7 is further arranged on the upper surface of the sheet 2. This means that the sheet 2 is arranged between the crossbar 7 and the wiper 8 as already disclosed in FIG.

[0033] A crossbar roller 17 at the end of the crossbar 7 is further arranged in contact with the outer ring 3 and is adapted to follow a sliding movement along the outer ring 3 as the first wiper assembly 5 rotates.

[0034] The guiding device 9 and the drive mechanism 10 are shown in detail in figures 6 to 9. Both the device and the mechanism are part of the outer ring 3.

[0035] The guiding device 9 includes an inner guide wall 13 and an outer guide wall 14. As shown in FIG. 6, these guide walls are arranged at a predetermined distance apart in the outer ring 3 and form a track 15a for the drive mechanism 10. In addition, the arrangement of the inner guide wall 13 and the outer guide wall 14 forms a slit 15b at the bottom of the track 15a, as shown in FIG. 6. The slit 15b allows the first wiper assembly 5 to be connected to the drive mechanism 10 and to perform the movement of the first wiper assembly 5. This will be further explained below.

[0036] The guiding device 9 may further include multiple bar guides 16 arranged on the inner or outer guide walls 13, 14 to facilitate sliding of the drive mechanism 10 in the track 15a. In the illustrated embodiment, there are multiple bar guides 16 attached to the inner guide wall 13. The multiple bar guides 16 are evenly distributed around the circumference of the inner guide wall 13 in this embodiment.

[0037] The guiding device 9 may also include an outer ring second cover 3b arranged to cover the track 15a.

[0038] An embodiment of the drive mechanism 10 is also shown in detail in Figures 6 to 9. The drive mechanism 10 comprises a bar 11. The bar 11 is adapted to be slidably disposed in a track 15a of the guiding device.

[0039] The drive mechanism 10 further comprises a tensioning device 12. The tensioning device 12 may for example be a rope or wire further attached to an actuator, such as a winch or similar. The movement may also be performed manually, for example in smaller tanks.

[0040] The rope 12 in Fig. 6 is arranged between two parts of the bar 11. The parts are connected, thus enclosing part of the rope 12 within the bar 11. The connection between the bar parts may be performed, for example, by bolts and screws in an otherwise known manner. On the outside of the bar 11, the rope 12 may run along a bar guide 16, as shown. Other arrangements of the bars 11 and their connections to the tensioning device 12 may also be possible.

[0041] 7 and 8 further disclose the wiper block 18. The wiper block 10 provides a connection between the first wiper assembly 5 and the drive mechanism 10. The drawings show that the wiper block 18 is fixedly attached to the wiper 8 on one side and to the bar 11 on the opposite side. As the wiper 8 is positioned below the outer ring 3, the wiper block 18 extends through the slit 15b.

[0042] Figures 10 and 11 show detailed views of the central part of the crowding device 1. The hub 5 may be ring-shaped and may be located outside the central column or silo 19 as disclosed in Figure 3. The silo or central column extends vertically when the crowding device 1 is installed in a tank.

[0043] The first wiper assembly 5 is adapted to rotate relative to the central column or silo 19. The axis of rotation is the central axis A of the crowding device 1, as shown in Figure 10. The wiper assembly 5 is also adapted to rotate relative to the seat 2 and the outer ring 3.

[0044] Figure 11 shows a suitable design of the fixed wall or second wiper assembly 6 and the wiper 8 of the first wiper assembly 5. Both the fixed wall or second wiper assembly 6 and the wiper 8 extend downwards a certain distance to provide a collection unit for the marine organisms when installed in the tank. The distance varies because the bottom of the tank is not flat. Brushes may be provided at the end of the wiper 8 or the fixed wall to ensure that the assemblies 5, 6 reach the bottom of the tank.

[0045] The first wiper assembly 5 may be hingedly connected to the hub 5a, for example by a bracket. This offers the possibility for the first wiper assembly 5 to slightly adjust its position according to the outer shape of the tank. In this case, the tank does not have to be perfectly circular and the wiper assembly does not have to follow an exactly radial path when it is moved.

[0046] The hinged connection also allows for further limiting the area or space between the first wiper assembly 5 and the second wiper assembly 6. As shown in FIG. 12, the first wiper assembly 5 and the second wiper assembly 6 extend radially from the inner ring 4. This leaves a V-shaped gap in the area between the first wiper assembly 5 and the second wiper assembly 6. The hinged connection allows for the first wiper assembly 5 and the second wiper assembly 6 to be closer to each other, thereby limiting the collection area 21.

[0047] 13 shows a first wiper assembly 5 including a strut device 20. The strut device may be a wire or the like that extends between the longitudinal ends of the first wiper assembly 5 to maintain stability of the first wiper assembly 5.

[0048] FIG. 12 shows the crowding device 1 as seen from the side facing the bottom of the tank.

[0049] FIG. 13 shows a section of the crowding assembly 1 including the wiper assembly 5 as viewed from above.

[0050] In use, the crowding device 1 is positioned in reverse such that the fixed wall or second wiper assembly 6 and the first wiper assembly 5 face downwards in the tank.

[0051] The function of the invention is further explained below: The crowding device 1 is installed such that the outer ring 3 of the crowding device 1 is mated with the inner wall surface 30 of the tank, which means that the crowding device 1 fills the cross-sectional area of ​​the tank.

[0052] The crowding device 1, if present, may be lowered vertically into the tank along a central column 19 in the middle of the tank. This may be performed by an external suspension device arranged to lift the crowding device vertically. The entire crowding device 1 is lifted by the suspension device, which is preferably attached to both the hub 5a and the outer ring 3 to avoid any further dimensioning of the device when suspended.

[0053] The crowding device 1 is lowered towards the bottom of the tank prior to collection and crowding of the tank, so that the first wiper assembly 5 and the second wiper assembly 6 together with the bottom of the tank prevent marine life from escaping the collection area between the wiper 8 and the second wiper assembly 6.

[0054] The first wiper assembly 5 is then moved by the drive mechanism 10 towards the second wiper assembly 6 to make the collection area 21 narrower. The outlet is positioned to remain in the collection area at all positions of the first wiper assembly 5. As a result, as the collection area 21 decreases, the number of marine organisms that can be guided out of the collection area 21 increases.

[0055] As shown in FIG. 13, when the first wiper assembly 5 reaches the fixed wall or second wiper assembly 6 arranged on the hub 5a, the outer end of the fixed wall or second wiper assembly 6 may be moved towards the first wiper assembly 5 to further limit the collection area 21. The first wiper assembly 5 and the fixed wall or second wiper assembly 6 are arranged independently. The first wiper assembly 5 is connected to the hub 5a and follows the movement of the hub 5a. On the other hand, the second wiper assembly 6 or the fixed wall may be connected to a horizontally arranged ring or several rings 4, 4b. FIG. 10 shows two rings, the upper one being the same as the inner ring 4 connected to the sheet 2. In addition, a lower ring 4b may be provided. The ring may be arranged in a groove in the hub 5a, which is not further shown in the drawing. The hub 5a and the rings 4, 4a are arranged to slide relative to each other.

[0056] Once the collection area has been emptied of marine organisms, the crowding device may be moved vertically away from the bottom of the tank and the first wiper assembly 5 may be moved in the opposite direction towards the initial position to repeat the crowding of the tank.

[0057] 14-18 show alternative embodiments of crowding device 1 for substantially non-circular tank shapes, such as, but not limited to, tanks having corners, for example, elliptical, square, hexagonal or octagonal tanks, as shown in FIG. 14-18.

[0058] In this alternative embodiment of the crowding device 1, the outer ring 3 is formed to cover all water surface between the inner wall surface 30 of the tank and the sheet 2 between the inner ring 4 and the outer ring 3. This surface area of ​​the outer ring 3 is shown as the outer ring first cover 3a. In this form, the outer ring 3 and its outer ring first cover 3a can cover tanks in other shapes, such as, but not limited to, rectangular or even triangular corners, or any non-circular tank available. Thus, as shown in Figures 14-18, the outer ring 3 and its outer ring first cover 3a are adapted to match the shape of an octagonal tank.

[0059] In the first wiper assembly 5 of this embodiment of the crowding device 1, the wiper 8 rotates about a column 19 and further includes a telescoping extension device 8a that is pushed toward the inner wall surface 30 of the tank. The extension device 8a enables this embodiment of the crowding device 1 to crowd marine life in non-circular tanks.

[0060] The extension device 8a is always in contact with the inner wall surface 30 of the tank. The extension or retraction movement of the extension device 8a is performed in a predetermined manner by any one or a combination of mechanical, pneumatic, hydraulic or electrical means.

[0061] The extension device 8a is an elongated element and may be of a similar structure to the wiper 8 or may be of a simpler structure such as a bar or rod.

[0062] The extension length of the extension device 8a is predefined by the available shape of the tank, the longest length of the extension device 8a is the farthest distance between the end of the wiper 8 and the corner of the tank. This is shown in Figure 16, where the extension device 8a is in contact with the corner of the tank (the tank wall is not shown, but follows the shape of the cover 3a).

[0063] Because the extension device 8a comes into contact with the inner wall surface 30 of the tank, the extension device 8a may include non-friction members, such as wheels or ball bearings, at its ends in order not to damage the tank and its inner wall surface 30.

[0064] As shown in Figure 18, the wiper 8 and extension device 8a provide efficient crowding of marine life in a non-circular tank when the crowding device 1 is positioned near the bottom of the tank. During crowding, the first wiper assembly 5 rotates about the column 19, and the wiper 8 crowds any marine life between the sheet 2 and the bottom of the tank, and the extension device 8a crowds any marine life between the outer ring first cover 3a and the bottom of the tank. [Explanation of symbols]

[0065] 1. Device for crowding of tanks 2 seats 3 Outer Ring 3a Outer ring first cover 3b Outer second ring cover 4 Inner Ring 4b Additional inner ring 5 First Wiper Assembly 5a Hub 5b Hinged connection 6 Second wiper assembly or fixed wall 6b Second Wiper Assembly Opening 7 Crossbar 8 Wiper 8a extension device 8b Wiper opening 9 Guide device 10 Drive mechanism 11. Bar 12 Pulling devices for ropes / wires etc. 13 Inner guide wall 14 Outer guide wall 15a Track 15b Slit 16 Bar Guide 17 Crossbar roller 18 Wiper Block 19 Silo / Central Column 20 Strut device 21 Collection Area / Space 30 Inner wall of tank A Central axis of the crowding device B Central axis of hinged connection

Claims

1. 1. A crowding device for an aquaculture tank for marine life, the tank having at least one outlet at a bottom of the tank, the crowding device comprising: The crowding device comprises: A seat (2) extending between the hub (5a) and the outer ring (3), the seat (2) surrounds the hub (5a) and the outer ring (3) is in contact with the inner wall surface (30) of the tank; The hub (5a) is located in the center of the tank, a seat (2), the hub (5a) and the outer ring (3) covering a horizontal cross-sectional area of ​​the tank; a first wiper assembly (5) and a second wiper assembly (6) extending substantially radially between the hub (5a) and the outer ring (3), or alternatively a first wiper assembly (5) and a fixed wall, the first wiper assembly (5) being arranged movably relative to the seat (2), the first wiper assembly (5) comprises a crossbar (7) and a wiper (8), the crossbar (7) and the wiper (8) being arranged in parallel with a gap therebetween for receiving the sheet (2), the wiper (8) and the crossbar (7) being fixedly attached to each other at one end; 13. A crowding device, comprising: a first wiper and a second crossbar, the first wiper and the second crossbar being disposed in a first position relative to the first wiper and the second crossbar being disposed in a second ...

2. 2. The crowding device of claim 1, wherein the hub (5a) further comprises an inner ring (4), the seat (2) surrounding the inner ring (4) and the seat (2) extending between the inner ring (4) and the outer ring (3).

3. the gap has a predetermined size to prevent marine life from passing through the gap; 3. The crowding device of claim 1 or 2, wherein the gaps have a predetermined size to prevent marine organisms having a diameter of 0.5 cm to 5.0 cm, or smaller marine organisms having a diameter of 0.2 cm to 2.0 cm, such as smolts, or even smaller marine organisms having a diameter of 0.1 cm to 0.5 cm, such as crustaceans such as shrimp.

4. 4. The crowding device according to claim 1, wherein the wiper (8) extends downwards towards the bottom of the tank when installed in the tank.

5. The first wiper assembly (5) further comprises an extension device 8a, 5. The crowding device according to claim 1, wherein the extension device (8a) extends from an end of the wiper (8) towards the inner wall surface (30) of the tank in order to crowd marine organisms between the outer ring (3) and the bottom of the tank.

6. 6. The crowding device according to claim 1, further comprising a drive mechanism (10) adapted to rotate the first wiper assembly (5) about a central axis (A) of the crowding device (1).

7. 7. The crowding device according to claim 6, wherein the drive mechanism (10) is arranged on the outer ring (3) of the crowding device (1).

8. 8. The crowding device according to claim 6 or 7, wherein the drive mechanism (10) further comprises a tensioning device (12) attached to the drive mechanism (10) for facilitating movement of the wiper assembly (5).

9. 9. The crowding device according to claim 7 or 8, wherein the wiper (8) is attached to the bar (11) by a wiper block (18).

10. 10. The crowding device according to claim 9, wherein the wiper block (18) is adapted to be moved along a slit (15) between an outer guide wall (14) and an inner guide wall (13).

11. 11. The crowding device according to any one of the preceding claims, wherein the first wiper assembly (5) is hingedly connected to the hub (5a).

12. A method for crowding an aquaculture tank for marine organisms using a crowding device according to any one of claims 1 to 11, comprising the step of rotating a first wiper assembly (5) towards a second wiper assembly or a fixed wall (6) in order to guide the marine organisms towards an outlet of the tank arranged at the bottom of the tank, characterized in that in all positions of the wiper assembly (5) the outlet is arranged in the area between the second wiper assembly or the fixed wall (6) and the first wiper assembly (5).

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