WO2019035719A1 - Improved closed fish rearing tank - Google Patents

Improved closed fish rearing tank Download PDF

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Publication number
WO2019035719A1
WO2019035719A1 PCT/NO2018/050206 NO2018050206W WO2019035719A1 WO 2019035719 A1 WO2019035719 A1 WO 2019035719A1 NO 2018050206 W NO2018050206 W NO 2018050206W WO 2019035719 A1 WO2019035719 A1 WO 2019035719A1
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WO
WIPO (PCT)
Prior art keywords
water
column
tank according
shell
fish rearing
Prior art date
Application number
PCT/NO2018/050206
Other languages
French (fr)
Inventor
Cato LYNGØY
Original Assignee
Hauge Aqua As
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hauge Aqua As filed Critical Hauge Aqua As
Publication of WO2019035719A1 publication Critical patent/WO2019035719A1/en

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Classifications

    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01K—ANIMAL HUSBANDRY; AVICULTURE; APICULTURE; PISCICULTURE; FISHING; REARING OR BREEDING ANIMALS, NOT OTHERWISE PROVIDED FOR; NEW BREEDS OF ANIMALS
    • A01K61/00—Culture of aquatic animals
    • A01K61/60—Floating cultivation devices, e.g. rafts or floating fish-farms
    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01K—ANIMAL HUSBANDRY; AVICULTURE; APICULTURE; PISCICULTURE; FISHING; REARING OR BREEDING ANIMALS, NOT OTHERWISE PROVIDED FOR; NEW BREEDS OF ANIMALS
    • A01K61/00—Culture of aquatic animals
    • A01K61/10—Culture of aquatic animals of fish
    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01K—ANIMAL HUSBANDRY; AVICULTURE; APICULTURE; PISCICULTURE; FISHING; REARING OR BREEDING ANIMALS, NOT OTHERWISE PROVIDED FOR; NEW BREEDS OF ANIMALS
    • A01K63/00—Receptacles for live fish, e.g. aquaria; Terraria
    • A01K63/04—Arrangements for treating water specially adapted to receptacles for live fish
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
    • Y02A40/80—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in fisheries management
    • Y02A40/81—Aquaculture, e.g. of fish

Definitions

  • the present invention relates to a fish rearing tank comprising an egg-shaped shell (1) with a mainly vertical long axis and a gradually narrowing shape towards it upward pointing tip portion (4). More specifically, it relates to such an egg-shaped tank with an axially directed, mainly vertical, central pipe column which extends from said upper tip portion of said egg shaped shell to a lower, wider end portion of said egg shaped shell.
  • a main water inlet to a rearing volume near the bottom of the lower end portion, in or just above the ballast, and wherein water outlets from the rearing volume is near the upper, inner surface of the water in the rearing volume, and wherein the main water inlets (11) are nearly horizontally, tangentially directed so as for a circular main flow from below and upwardly through the rearing volume.
  • Pumps are arranged preferably near but below the water surface, inside the pipe-shaped vertical column so as for us having near access to those.
  • an integrated cleaning plant for the outlet water from the rearing volume arranged e.g. as rotating drum filters, alternatively as cyclone separators, arranged in the buoyancy ring about the tip portion of the shell of the egg.
  • Salmon rearing is usually conducted with the fish enclosed in cages which comprise a floating ring and a closed net hanging from the floating ring. The fish is fed inside the cage and water flows rather freely through, depending on the natural currents in the sea. Salmon rearing is considerably and increasingly hampered by salmn lice, of several reasons, amongst others due to the increasing amound of available salmon in cages, and the adaptability of the salmon lice, and increasing resistance to medical substances, and transfer of contagious elements between fish cages and rearing plants.
  • the latin name of salmon lice is Lepeophtheirus salmonis.
  • There are further types of lice which may also infect the salmon such as the so-called "skottelus" (Norw) Caligus elongatus. There are moreover several sub-species.
  • JP patent publication JP06276887 iichi filed 25.03.1993 describes a ballon constituting a tight, inflated submerged fish rearing container with a soft shell. It is kept spanned due to its inner air pressure in its top, and the inner sea surface is thus lower than the sea surface. It is drained from below and via an outlet hose and has a floating top, and a separate water treatment plant.
  • WO2017026899 belonging to the applicant himself describes the problems involved with salmon lice in an extensive way and presents a solution to several problems by suggesting a fish rearing tank comprising the following features:
  • the shell has one or more main water inlets and one or more water outlets
  • the egg-shaped shell is arranged for holding water in its lower, wide volume portion and air in its upper volume portion in its tip,
  • main water inlets (11) are nearly horizontally, tangentially directed so as for establishing circular water flow from below and upwardly through said rearing volume (0).
  • main inlet pumps for fresh water are arranged directly as separate sections on deep draft [dyptstikkende] main intake pipes which extend downwardly from a radially arranged bend to each of their horizontal, tangential main water inlet pipes.
  • the main inlet pipes are arranged directly as an integrated section on these vertical main intake pipes.
  • the main intake pipes thus extend out through separate apertures in the shell and are axial parallel, but not arranged axilly.
  • Such an arrangement has some disadvantages: firstly it may incur an increased roll moment of inerita in their attachment through the shell aperture due to the mass of the motors, and may be vulnerable to roll motion, and secondly, it requires additional apertures through the shell for each main intake pipe, and thirdly, there is no access t these pumps from the surface in case of need of repair, maintenance, or replacement of the pumps, and will thus require a docking of the entire shell.
  • the invention is a fish rearing tank comprising the following features: a fish rearing tank comprising the following features:
  • said shell (1) forms a generally rigid, closed tank
  • said shell (1) has one or more main water inlets (11) to a rearing volume (0) and one or more water outlets (16) from said rearing volume (0),
  • said egg-shaped shell (1) is arranged for holding water in its upper tip portion (4) and water in said rearing volume (0) down to a ballast (7) in its lower, butt end portion (5),
  • main water inlets (11) are nearly horizontally, tangentially directed so as for establishing circular water flow from below and upwardly through said rearing volume (0),
  • the invention is a fish rearing tank with a rigid, closed egg shaped shell (1) with a upwardly pointing tip portion (4) and with a butt end portion, and with tangential main water inlets (11) to the rearing volume, wherein the circulation water inlet (10) arranged through the lower portion of an open, axially directed central, hollow column (2) which extends from said upper tip portion (4) to said lower, butt end portion (5), and wherein said egg shaped shell (1) with peripher water outlet (16) from the rearing volume (0) out through said shell (1) by the upper inner surface of the water in said rearing volume (0), so as to establishing a mainly hellical shaped main flow from below and upwardly through said rearing volume (0), wherein pumps (12) arranged inside said central column (2) and arranged for supplying water to said main water inlet (11) to said rearing volume (0), and wherein pumps (12) arranged inside said central column (2) and arranged for supplying water to said main water inlet (11) to said rearing volume (0), and wherein pumps
  • a significant advantage with the invention is that key elements and functions of the fish rearing tank, such as pumps, inlets, pump channels, filters, drainage pipes, mooring lines and desinfection gear, can be arranged in the axially directed central, hollow column, in a way that resembles the way you align in a pertroleum well.
  • access to these elements can be made via the top of the tubular central column (2), either by an external crane, or by internal winch of crane arrangements.
  • the input in the column (2) may consist of single components each mounted to the inner wall of the column (2) or in a casing with the necessary recesses and seats/flanges in the column (2).
  • components such as pumps, inlet filters, inlet pipes, valves, anchor winch etc. be mounted in one or more complementary sleeves which can be locked in place from above through the upper passage (201). Replacement or repairing of parts of the input in the column will, no matter which embodiment, be easy to perform via the column (2) without big interventions in the shell (1). Further you can avoid a large number of gates and implementations in the shell (1), which would otherwise require apertures and reinforcements of the edges of the shell around the apertures, flanges, sockets and sealings.
  • a cleaning robot can operate vertically with mainly the same cross section as the column (2) cleaning the entire height under the water line.
  • a cleaning robot can be aligned to be lowered down through the aperture in the plate (129) for the filter (9) after the filter has been removed, and winched down while cleaning the walls of the column (2) and the channels (121) by flushing and scraping or a combination of the both.
  • Such a cleaning robot can be lowered all the way down to a bottom filter at the lowest point of the column (2) and clean this.
  • Fig. 1 is a view and vertical section through a embodiment of the invention. See placement of the vertical section in BB the horizontal section of Fig. 4.
  • a water inlet (10) for fresh water is shown at the bottom of a vertical, tubular axial column stretching vertically, axially through the whole shell (1) of the fish rearing tank, which is egg shaped.
  • At least pumps (12), inlet water filters (9), and channels (121) are arranged inside the central axial column (2).
  • the channels (121) are connected with the tangentially main water inlet (11) at the bottom of the rearing volume (0) inside the shell (1) and by pumping the water we establish and sustain an hellical circular water flow upwardly around the column (2) in the rearing volume, and with water outlets (16) setting the inner surface of the water inside the shell.
  • the pump pressure helps holding the inner water level above sea level. Hence the water flows out of the shell to a cleaning plant making use of the water fall for the transportation of the water.
  • a problem with large tanks and tubs for rearing is that the water close to the center can become static for a long period of time some time thus accumulating both infectous substances, debris and become oxygen deficient. The water is not replaced to the same extent as the
  • the channels can be arranged with auxiliary inlets at one or more heights out through the wall of the center column (2).
  • the water supply through these auxiliary inlets can for example be up to 10 % of the total water supply to the rearing volume (0) and help prevent the formation of eddes in the circular flow through the rearing volume.
  • Fig. lb is a perspective view and section corresponding to the embodiment in Fig. 1 and shows the flow of the water in through the water inlet (10) through the lower end portion of the tubular column (2), up through the water filter (9), out to the water above the pumps (12), and down through the channels (121) (which are closed in the bottom) and with apertures out to the channels through the ballast to the tangential main water inlets (11) to the rearing volume (0).
  • Fig. 2 is another view and vertical section of an embodiment of the invention, wherein the section is 45 degrees of the section in Fig. 1. See the placement of the vertical section in AA in the horizontal section in Fig. 4.
  • the section shows the water outlets (16) out through the shell to a ring-shaped drain channel (31) to a water cleaning plant (160) placed on a ring-shaped buoyancy column (3).
  • Mud tanks for separated solid material and possibly ballast can be arranged in the buoyancy column (3); cleaned and filtered water is being led to the sea via water outlets (29).
  • Fig. 3 is a view and section through the horizontal plane CC of Fig. 1. It shows the ring and rods in which the inner work deck is hung up in, and gives a top view of a plate (129) below the inner water surface in the tubular column (2) with apertures for the centrally placed inlet water filter (9) and pumps (12).
  • the wing-shaped lobes on the right and left side of the upper tip portion (4) of the egg are gates through the shell (1) from the deck on the buoyancy column (3) to the inner work deck leading to gates in the tubular column (2).
  • the plate (129) and all other objects between the plate (129) and the upper passage (201) in the column's bore is in an embodiment of the invention dismountable to secure free access down through the column (2) at the least down to the pumps.
  • Fig. 4 is a top view of the rearing tank in Fig. 1. This view and section shows the same gates and section of the column (2) and filter (9) and pumps (12), as well as top view of the drum filter (162) in water cleaning plant in the buoyancy ring (3).
  • This view and section shows the same gates and section of the column (2) and filter (9) and pumps (12), as well as top view of the drum filter (162) in water cleaning plant in the buoyancy ring (3).
  • section lines BB in Fig. 1 and AA in Fig. 2 also shown.
  • Fig. 5 is a view and section through the horizontal plane DD in Fig. 1 and just under plane CC in Fig. 3.
  • This view and section shows the same gates and section of the column (2) and the filter (9) and pumps (12), and horizontal section thruogh the drum filters (162) i the water cleaning plant.
  • Hers is also a work deck (40) hung up in rods and stretching between the gates to the deck of the bouyancy ring (3).
  • FIG. 6 is a top view of the upper part of the ballast sections with the ballast and the main water inlets (11) in the section EE in the butt end portion of the egg-shaped shell (1) of an embodiment of the fish rearing tank according according to the invention.
  • the section of the vertical half pipe profiles of the channels (121) stretching from the pumps (12) down to the outlets through the wall of the column (2) to the radial inflow channels (11a) to the tangential water inlets (11) to the rearing volume (0) is also shown.
  • One of the ballast sections (7c) is shown filled with sand or cement.
  • One or more of the sections can also be ballast water tanks possible to regulate when needed according to changing bouyancy conditions.
  • Fig. 7 is a vertical section through a part of the upper portion of the central tubular column (2) in level with the work deck with the motors of the pumps arranged dry in level with the work deck.
  • Fig. 8 shows a vertical section and view corresponding to Fig. 1, and showing an embodiment of the invention equipped with one or more generally vertically running anchor lines (chain, wire, rope, elastic anchor line) stretching from an anchor winch (6), preferably with a heave compensator, down through the central column (2), here through one of the channels (121) among what otherwise are the pump channels (121) and provided with a cleat (121B) for reinforcement at least in the pipe channel's (121) lower end about the exit for said anchor line.
  • the anchor winch (6) shown in this embodiment is the anchor winch arranged inside the column (2), and the channel (121) is extended up above the inner water level in the column (2).
  • Fig. 9 shows a vertical section and view of an embodiment of the invention with anchor lines down through the central column (2); the anchor winch arranged in the upper tip portion (4) outside the column (2).
  • the anchor lines runs down through a separate channel (121A) in addition to the channels (121) belonging to the pumps (12), inside the column (2).
  • Fig. 10 shows a perspective view and section of the same embodiment.
  • Fig. 11 shows an embodiment of the invention as in Fig. 8 wherein in a simple view the cleat (121B) is shown for the anchor line in one of the channels (121). In addition an embodiment is shown of the alternative configuration with a separate channel (121A) for the anchor line as in Fig. 9 and 10.
  • Fig. 12a is a horizontal section and view through the upper tip portion (4) in an embodiment of the invention with the bouyancy ring (3) showing the main arrangement of the water cleaning plant (160).
  • Fig. 12b is a vertical section through one of the drum filters (162) and a ring-shaped drain channel (31) leading between the outlets (16) to the drum filters (162).
  • Fig. 12c shows a more detailed top view and section of the drum filter (162) in a section with outlet for cleaned water.
  • Fig. 12d shows an enlarged section of the mud belt separator (164).
  • Fig. 13a and 13b shows a partially transparent perspective view of an embodiment of the inlet water filter (9).
  • the invention is a fish rearing tank. It comprises: - an egg-shaped shell (1) with a mainly vertical long axis and gradually narrowing shape towards its upwardly pointing tip portion (4);
  • said shell (1) forms a generally rigid, closed tank
  • said shell (1) has one or more main water inlets (11) to a rearing volume (0) and one or more water outlets (16),
  • said egg-shaped shell (1) is arranged for holding water in its upper tip portion (4) and water in said rearing volume (0) down to a ballast (7) at the bottom (51) in its lower, butt end portion (5),
  • main water inlets (11) are nearly horizontally, tangentially directed into the rearing volume (0) so as for establishing circular water flow from below and upwardly through said rearing volume (0), and with
  • the central, hollow column (2) is open and extends axially through both ends of the shell (1) of the egg. There can be arranged a lid which opens over the upper end portion of the column (2).
  • a crane through the upper passage (201) of the column (2) as shown in Fig. 1 but an alternative is inner crane access in addition to the upper passage (201), with the use of a crane on rails stretching through gates in the column's (2) wall as shown in Fig. 7.
  • the rearing volume in the shell (1) is between 4500 m3 and 22000 m3 or more.
  • the height of the shell (1) shown in Fig. 1 is 26 meters. In other embodiments of the invention the height of the shell (1) can be between 8 and 60 meters or more.
  • the shell (1) can be produced in fibre reinforced plastic, steel, rotational hoop winded, or in slide cast concrete.
  • the water inlet (10) via the lower end portion of the tubular column (2), see Fig. lb, Fig. 2 and Fig. 6, will, in an embodiment of the invention, have continuous water access up through the central portion of the column (2) up to a plate (129) with an aperture for the water filter (9) between the pumps (12).
  • a tank which in the invention can have a height from the pointy to the butt end of about 26 meters as shown in the embodiment in Fig. 1, but in larger embodiments can be 46 meters high or more than that.
  • the diameter of the central column is in preferred embodiments of between 2 and 5 meters, and in an even more preferred embodiment between 3 and 3,5 meters, depending on the size of the shell (1).
  • FIG. 1 there is, under the water line, generally only the lower implementation for the column (2) through the shell (1), something which simplifies the prosess and reduces the building time of the shell (1).
  • a significant advantage with the invention is that key elements and functions of the fish rearing tank, such as pumps, inlets, pump channels, filters, drainage pipes, mooring lines and desinfection gear, can be arranged in the axially directed central, hollow column. Implementations for water flow is easier to arrange inn and out through the wall of the column (2) than through the egg-shaped shell (1), that requires more complex shape of each implementation, and also would weaken and weigh down the shell or complicate its production.
  • the input in the column (2) may consist of single components each mounted to the inner wall of the column (2).
  • components such as pumps, inlet filters, inlet pipes, valves, anchor winch be mounted in one or more complementary sleeves which can be locked in place from above through the upper passage (201) and mounted at the desired level inside the colun (2).
  • FIG. 1 there is, under the water line, generally only the lower implementation for the column (2) through the shell (1).
  • the pumps (12) and their respective engines (123) are mounted under the inner surface of the water inside the central tubular column (2).
  • the pumps (12) are powered by engines (123) arranged dry above the water level inside the central column (2).
  • FIG. 7 shows section through pumps and engines by the work deck, motors on dry ground arranged over wells with driving shaft to the pumps down through a well lid.
  • a significant advantage with pump engines on dry ground is that they are in fact above the water surface thus making them directly accessible for inspection; the motors requires a much simpler construction with regard to prevent water instrusion, and there is access with crane from above so that the engines and pumps are accessible for mounting and replacement, either through the upper end of the column (2), see Fig. 1, or with a crane as shown in Fig. 7.
  • the pumps (12) are arranged in the top of pressure channels (121) which extend downwardly through said central column (2) and having apertures out to radial inflow channels (11a) to the tangential main water inlets (11) to the rearing volume (0).
  • This is shown in vertical sections of the tank in Fig. 1 and 2; the sections are shown as AA and BB in Fig. 4 which is a horizontal section and view under deck under line DD from Fig. 1.
  • the vertical channels (121) which extend downwardly along the wall in the central column (2) is in a embodiment channels with a transition (121T) from circular flange at the pump (12) to semicircular outline in the top of pressure channels (121). This gives more space in the central cross-section of the column (2) and less friction for the upwardly water stream in the column (2), as well as fewer narrow corners for fouling inside the column (2).
  • a replaceable inlet water filter (9) between the water inlet (10) and the inlet to the pumps (12), inside the central column (2).
  • the inlet water filter (9) is in an embodiment cylindrical with inlets in its lower end portion and arranged in a central aperture in a plate under the water surface inside the column (2) wherein there are flanges for the pumps (12) around the central aperture.
  • the inlet water filter (9) can have outlets in the cylinder wall towards the water above and around the pumps. It should be a minimum of water above the pumps and the plate, for example 1,5 m.
  • the inlet water filter will be the only passage for water from the surrounding sea to the water in the the rearing volume (0) inside the tank and if this filter is intact and has a filter opening which is low enough one will efficiently prevent intake of parasites such as salmon lice.
  • This is a mayor advantage over prior art which for example uses water permeable lice skirt, with mesh of 350 mu, arranged around cages and which are open in the bottom, i.e. simply reducing the amount of lice, not preventing it. It is also a significant advantage over hemispheric cages which are without roofs, and therefore letting in salmon lice through sea spray.
  • the water inlet (10) comprises an extension pipe (102), see Fig. 1, extending to a desired depth below the lower end of said central tubular column (2) so that one might be able to take in water from an additional desired depth deeper than the depth of the shell (1), if possible further avoid undesired organisms.
  • the water wil be above the pumps (12) to the inner water surface in the column (2), see the water surface outlined in Fig. 1.
  • the pumps (12) are arranged below the inner water surface in the column (2).
  • the motors are in an embodiment arranged above the water surface, above the well hatch with passages for the drive axles to the pumps (12).
  • the motor can also be arranged directly on the pumps (12) as shown in Fig. 1 and 2.
  • the pumps (12) pump water down through the pressure channels (121) and out through apertures in the wall of the column (2) to the radial inflow channes (11a) out to the tangential water inlets (11) to the rearing volume (0);
  • the water running out from the tangential water inlets (11) will therefore establish and maintain a circular water flow, (here shown counter clockwise) around the outside of the central column (2) , and mainly run in a hellical shaped water flow in the whole of the tanks rearing volume if the capacity of the pumps are adjusted sufficiently, rising up to the outlets (16) and out through the shell (1).
  • the pressure of the pumps (12) will establish and maintain a higher water level inside the shell (1) than the surface of the sea (provided that the ballasting is accurate).
  • Fig. 1 which is sufficient to lead a water flow via the outlets (16) via the water cleaning plant with drum filter (162) to the final outlet (29) to the sea.
  • Fig. 11 shows an embodiment of the invention as in Fig. 8 wherein in a simple view the cleat (121B) is shown for the anchor line in one of the channels (121).
  • a separate channel (121A) for the anchor line as in Fig. 9 and 10.
  • Fig. 12a is a horizontal section and view through the upper tip portion (4) in an embodiment of the invention with the bouyancy ring (3) showing the main arrangement of the water cleaning plant (160), comprising drum filter (162) and a mud belt separator (164).
  • Fig. 12b is a vertical section through one of the drum filters (162) and a ring-shaped drain channel (31) leading between the outlets (16) to the drum filters (162).
  • Fig. 12c shows a more detailed top view and section of the drum filter (162) in a section with outlet for cleaned water, and a inflow section from the structure channel (31) with higher water level.
  • Wet separated mud is lead via pipes to the mud belt separator (164) and can temporarily be stored in sludge tanks in the bouyancy ring (3).
  • Such drum filters are commercially available off the shelf.
  • Fig. 12d shows an enlarged section of the mud belt separator (164) receiving wet separated mud via pipes from the drum filter (162).
  • Fig. 13a and 13b shows a partially transparent perspective view of an embodiment of the inlet water filter (9) here divided in two concentric filters (9o, 9i) wherein the inner filter (9i) is threaded inside the outer filter (9o). Both are arranged to be mounted releasably in the plate (129) which can have a center hole with a flange with a diameter less or equal the the inner diameter of the inner filter (9i), wherein the water flows in axial, and wherein the water runs out radially through both filters.
  • the filters (9, 9i, 9o) are arranged so that one is able pull out and change the inner or the outer filter separately and independent of one another, not to risk having a filter free passage through the plate (129).
  • UV-radiation gear which kills parasites
  • micro-organisms such as bacteria, phages, viruses, lice, and Crustacea prior to the passage into the water inlet filter.
  • a separator for bigger particles such as fodder particles, in the channel (31) between the outlets (16) and the drum filter (162).
  • the top of the ballast section is slightly conical and leans in towards the sump (8).
  • the pipe connection between the vertical channels (121) and the main water inlets (11) are arranged inside and through the ballast sections (7,7c) with the orifices for the main water inlets (11) arranged as elliptical apertures in line with the top of the ballast sections (7,7c), see Fig. 1, 9a, 9b.
  • the rearing tank is provided with an anchor winch (6) arranged in the tip portion (4) and with one or more generally vertically running anchor lines (chain, wire, rope, elastic anchor line) which extends downwardly through the central column (2), either in one of the channels (121) among the pump channels (121) or in a separate pipe channel (121A) provided with a cleat (121B) for reinforcement at least in the pipe channel's (121, 121A) lower end about the exit for said anchor line, and with mainly vertical anchoring to the seafloor.
  • anchor winch (6) arranged in the tip portion (4) and with one or more generally vertically running anchor lines (chain, wire, rope, elastic anchor line) which extends downwardly through the central column (2), either in one of the channels (121) among the pump channels (121) or in a separate pipe channel (121A) provided with a cleat (121B) for reinforcement at least in the pipe channel's (121, 121A) lower end about the exit for said anchor line, and with mainly vertical anchoring to the seafloor.
  • An advantage with a vertical anchoring stretching down through the lower end of the column (2) and down to a mooring point in the sea floor is that one might reduce the length of the anchor lines significantly in comparison to having a star-arrangement of anchor lines out from the buoyancy ring, something which could require several kilometres of anchor line all together, and that such a star arrangement also would have tied up large parts of the sea and the sea floor, thus preventing ordinary fishing such as trawling around the rearing tank.
  • anchor one might use bolts fixed to the bedrock, plumb weights or suction anchor.
  • a flexible hose (92) with supply of freswater can be connected from the main land and out to the rearing tank for replacement of the tank's seawater with freshwater, in order to kill salmon lice while the salmon tolerates freshwater.
  • the flexible hose (92), see Fig. 9a can be connected to the space inside the column (2) outside the water filter or through the top of the filter (9) and over the plate (129), with the water having a higher pressure than the water rising up through the inlet (10) in the bottom of the column (2) so that the pumps (12) runs freshwater in to the rearing volume (0). In order to go back to normal seawater circulation the supply of freshwater is simply disconnected.

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  • Life Sciences & Earth Sciences (AREA)
  • Environmental Sciences (AREA)
  • Marine Sciences & Fisheries (AREA)
  • Animal Husbandry (AREA)
  • Biodiversity & Conservation Biology (AREA)
  • Zoology (AREA)
  • Farming Of Fish And Shellfish (AREA)

Abstract

The invention is a fish rearing tank comprising the following features:- an egg shaped shell (1) with a mainly vertical long axis and gradually narrowing shape towards its upwardly pointing tip portion (4); - wherein said shell (1) forms a generally rigid, closed tank; - wherein said shell (1) has one or more main water inlets (11) to a rearing volume (0) and one or more water outlets (16) from said rearing volume (0), - wherein said egg-shaped shell (1) is arranged for holding water in its upper tip portion (4) and water in said rearing volume (0) down to a ballast (7) in its lower, butt end portion (5), - an axially directed central, hollow column (2) which extends from said upper tip portion (4) of said egg shaped shell (1) to said lower, butt end portion (5); - wherein said main water inlet is arranged in near a bottom (51) of said lower end portion (5), and wherein water outlet (16) is by the upper inner surface of said water in said rearing volume ((0), - and wherein said main water inlets (11) are nearly horizontally, tangentially directed so as for establishing circular water flow from below and upwardly through said rearing volume (0), - characterized by - a water inlet (10) arranged through a lower portion of said central column (2); and - pumps (12) arranged inside said central column (2) and arranged for supplying said main water inlet (11) to said rearing volume (0).

Description

Improved closed fish rearing tank Introduction
The present invention relates to a fish rearing tank comprising an egg-shaped shell (1) with a mainly vertical long axis and a gradually narrowing shape towards it upward pointing tip portion (4). More specifically, it relates to such an egg-shaped tank with an axially directed, mainly vertical, central pipe column which extends from said upper tip portion of said egg shaped shell to a lower, wider end portion of said egg shaped shell. There is arranged a main water inlet to a rearing volume near the bottom of the lower end portion, in or just above the ballast, and wherein water outlets from the rearing volume is near the upper, inner surface of the water in the rearing volume, and wherein the main water inlets (11) are nearly horizontally, tangentially directed so as for a circular main flow from below and upwardly through the rearing volume. Pumps are arranged preferably near but below the water surface, inside the pipe-shaped vertical column so as for us having near access to those. In an embodiment of the invention there is arranged an integrated cleaning plant for the outlet water from the rearing volume arranged e.g. as rotating drum filters, alternatively as cyclone separators, arranged in the buoyancy ring about the tip portion of the shell of the egg.
Background art
Fish rearing is usually conducted with the fish enclosed in cages which comprise a floating ring and a closed net hanging from the floating ring. The fish is fed inside the cage and water flows rather freely through, depending on the natural currents in the sea. Salmon rearing is considerably and increasingly hampered by salmn lice, of several reasons, amongst others due to the increasing amound of available salmon in cages, and the adaptability of the salmon lice, and increasing resistance to medical substances, and transfer of contagious elements between fish cages and rearing plants. The latin name of salmon lice is Lepeophtheirus salmonis. There are further types of lice which may also infect the salmon such as the so-called "skottelus" (Norw) Caligus elongatus. There are moreover several sub-species. Typically for Lepeophtheirus is that the infectious stadium of the lice, the lice larvae, are within the upper 20 metres of the sea. Thus a water inlet at below 25 metres eliminate all contagious elements. Despite this, the Caligus elongatus and salmon lice in Chile be situated deeper and may enter below 25 metres. Throughout the lice are a considerable contagious carrier for virae and other pathogenes. Thus it is incredibly important to keep this out.
JP patent publication JP06276887 iichi filed 25.03.1993 describes a ballon constituting a tight, inflated submerged fish rearing container with a soft shell. It is kept spanned due to its inner air pressure in its top, and the inner sea surface is thus lower than the sea surface. It is drained from below and via an outlet hose and has a floating top, and a separate water treatment plant.
WO2017026899 belonging to the applicant himself describes the problems involved with salmon lice in an extensive way and presents a solution to several problems by suggesting a fish rearing tank comprising the following features:
- an egg shaped shell (1) with a mainly vertical long axis and gradually narrowing shape towards its upwardly pointing tip portion (4);
- wherein the shell forms a generally rigid, closed tank;
- wherein the shell has one or more main water inlets and one or more water outlets
- wherein the egg-shaped shell is arranged for holding water in its lower, wide volume portion and air in its upper volume portion in its tip,
- an axially directed central, pipe column which extends from said upper tip portion of said egg shaped shell to said lower, butt end portion, for guiding a vertically running separation grating; - wherein at least one main water inlet to the rearing volume is arranged in near a bottom of said lower end portion directly throug the shell's (1) wall, and wherein water outlets (16) from the rearing volume (0) is by the upper, inner surface of said water in said rearing volume ((0),
- and wherein said main water inlets (11) are nearly horizontally, tangentially directed so as for establishing circular water flow from below and upwardly through said rearing volume (0).
In the described patent the main inlet pumps for fresh water are arranged directly as separate sections on deep draft [dyptstikkende] main intake pipes which extend downwardly from a radially arranged bend to each of their horizontal, tangential main water inlet pipes. The main inlet pipes are arranged directly as an integrated section on these vertical main intake pipes. The main intake pipes thus extend out through separate apertures in the shell and are axial parallel, but not arranged axilly. Such an arrangement has some disadvantages: firstly it may incur an increased roll moment of inerita in their attachment through the shell aperture due to the mass of the motors, and may be vulnerable to roll motion, and secondly, it requires additional apertures through the shell for each main intake pipe, and thirdly, there is no access t these pumps from the surface in case of need of repair, maintenance, or replacement of the pumps, and will thus require a docking of the entire shell.
The same applies for water intake filters on the main intake pipes.
Brief summary of the invention
The invention is a fish rearing tank comprising the following features: a fish rearing tank comprising the following features:
- an egg shaped shell (1) with a mainly vertical long axis and gradually narrowing shape towards its upwardly pointing tip portion (4);
- wherein said shell (1) forms a generally rigid, closed tank;
- wherein said shell (1) has one or more main water inlets (11) to a rearing volume (0) and one or more water outlets (16) from said rearing volume (0),
- wherein said egg-shaped shell (1) is arranged for holding water in its upper tip portion (4) and water in said rearing volume (0) down to a ballast (7) in its lower, butt end portion (5),
- an axially directed central, hollow column (2) which extends from said upper tip portion (4) of said egg shaped shell (1) to said lower, butt end portion (5);
- wherein said main water inlet is arranged in near a bottom (51) of said lower end portion (5), and wherein water outlet (16) is by the upper inner surface of said water in said rearing volume ((0),
- and wherein said main water inlets (11) are nearly horizontally, tangentially directed so as for establishing circular water flow from below and upwardly through said rearing volume (0),
- characterized by
- a water inlet (10) arranged through a lower portion of said central column (2); and
- pumps (12) arranged inside said central column (2) and arranged for supplying water to said main water inlet (11) to said rearing volume (0). In other words, the invention is a fish rearing tank with a rigid, closed egg shaped shell (1) with a upwardly pointing tip portion (4) and with a butt end portion, and with tangential main water inlets (11) to the rearing volume, wherein the circulation water inlet (10) arranged through the lower portion of an open, axially directed central, hollow column (2) which extends from said upper tip portion (4) to said lower, butt end portion (5), and wherein said egg shaped shell (1) with peripher water outlet (16) from the rearing volume (0) out through said shell (1) by the upper inner surface of the water in said rearing volume (0), so as to establishing a mainly hellical shaped main flow from below and upwardly through said rearing volume (0), wherein pumps (12) arranged inside said central column (2) and arranged for supplying water to said main water inlet (11) to said rearing volume (0), and wherein there is access from above through said central, hollow column, at least to said pumps (12) and an inlet water filter (9).
Advantages with the invention
A significant advantage with the invention is that key elements and functions of the fish rearing tank, such as pumps, inlets, pump channels, filters, drainage pipes, mooring lines and desinfection gear, can be arranged in the axially directed central, hollow column, in a way that resembles the way you align in a pertroleum well. Thus, access to these elements can be made via the top of the tubular central column (2), either by an external crane, or by internal winch of crane arrangements. There are several advantanges by gathering key elements and functions inside the column (2) than the access by crane from the above; it is possible to produce the shell (1) and the column (2) separate from the input in the column (2), and assemble the input as a complement at a shipyard. The input in the column (2) may consist of single components each mounted to the inner wall of the column (2) or in a casing with the necessary recesses and seats/flanges in the column (2). In an embodiment of the invention components such as pumps, inlet filters, inlet pipes, valves, anchor winch etc. be mounted in one or more complementary sleeves which can be locked in place from above through the upper passage (201). Replacement or repairing of parts of the input in the column will, no matter which embodiment, be easy to perform via the column (2) without big interventions in the shell (1). Further you can avoid a large number of gates and implementations in the shell (1), which would otherwise require apertures and reinforcements of the edges of the shell around the apertures, flanges, sockets and sealings. An additional advantage by having the water supply gathered through the central column and in vertical pipes inside said column is that the cleaning of fouling of mussels and macro algeas in the water supply becomes much more easy: a cleaning robot can operate vertically with mainly the same cross section as the column (2) cleaning the entire height under the water line. In an embodiment of the invention such a cleaning robot can be aligned to be lowered down through the aperture in the plate (129) for the filter (9) after the filter has been removed, and winched down while cleaning the walls of the column (2) and the channels (121) by flushing and scraping or a combination of the both. Such a cleaning robot can be lowered all the way down to a bottom filter at the lowest point of the column (2) and clean this. Figure captions
The attached figures illustrate some embodiments of the claimed invention.
Fig. 1 is a view and vertical section through a embodiment of the invention. See placement of the vertical section in BB the horizontal section of Fig. 4. A water inlet (10) for fresh water is shown at the bottom of a vertical, tubular axial column stretching vertically, axially through the whole shell (1) of the fish rearing tank, which is egg shaped. At least pumps (12), inlet water filters (9), and channels (121) are arranged inside the central axial column (2). The channels (121) are connected with the tangentially main water inlet (11) at the bottom of the rearing volume (0) inside the shell (1) and by pumping the water we establish and sustain an hellical circular water flow upwardly around the column (2) in the rearing volume, and with water outlets (16) setting the inner surface of the water inside the shell. The pump pressure helps holding the inner water level above sea level. Hence the water flows out of the shell to a cleaning plant making use of the water fall for the transportation of the water. A problem with large tanks and tubs for rearing is that the water close to the center can become static for a long period of time some time thus accumulating both infectous substances, debris and become oxygen deficient. The water is not replaced to the same extent as the
surrounding water. In the present invention the helix shaped flow around the center column prevent water from being static in the center, but rather leading the circulation around the column in a steadier flow rate than without the center column. In an embodiment of the invention the channels can be arranged with auxiliary inlets at one or more heights out through the wall of the center column (2). The water supply through these auxiliary inlets can for example be up to 10 % of the total water supply to the rearing volume (0) and help prevent the formation of eddes in the circular flow through the rearing volume. In an embodiment of the invention there can be an arrangement with a vertically running and adjustable separation grating (not shown) running on the vertical column's (2) outer wall equipped with wings aligned to run along the inner wall of the rearing volume (0).
Fig. lb is a perspective view and section corresponding to the embodiment in Fig. 1 and shows the flow of the water in through the water inlet (10) through the lower end portion of the tubular column (2), up through the water filter (9), out to the water above the pumps (12), and down through the channels (121) (which are closed in the bottom) and with apertures out to the channels through the ballast to the tangential main water inlets (11) to the rearing volume (0). Fig. 2 is another view and vertical section of an embodiment of the invention, wherein the section is 45 degrees of the section in Fig. 1. See the placement of the vertical section in AA in the horizontal section in Fig. 4. The section shows the water outlets (16) out through the shell to a ring-shaped drain channel (31) to a water cleaning plant (160) placed on a ring-shaped buoyancy column (3). Mud tanks for separated solid material and possibly ballast can be arranged in the buoyancy column (3); cleaned and filtered water is being led to the sea via water outlets (29).
Fig. 3 is a view and section through the horizontal plane CC of Fig. 1. It shows the ring and rods in which the inner work deck is hung up in, and gives a top view of a plate (129) below the inner water surface in the tubular column (2) with apertures for the centrally placed inlet water filter (9) and pumps (12). The wing-shaped lobes on the right and left side of the upper tip portion (4) of the egg are gates through the shell (1) from the deck on the buoyancy column (3) to the inner work deck leading to gates in the tubular column (2). The plate (129) and all other objects between the plate (129) and the upper passage (201) in the column's bore is in an embodiment of the invention dismountable to secure free access down through the column (2) at the least down to the pumps.
Fig. 4 is a top view of the rearing tank in Fig. 1. This view and section shows the same gates and section of the column (2) and filter (9) and pumps (12), as well as top view of the drum filter (162) in water cleaning plant in the buoyancy ring (3). Here is free crane access through the upper passage (201) down to the input in the column (2). Here are the section lines BB in Fig. 1 and AA in Fig. 2 also shown.
Fig. 5 is a view and section through the horizontal plane DD in Fig. 1 and just under plane CC in Fig. 3. This view and section shows the same gates and section of the column (2) and the filter (9) and pumps (12), and horizontal section thruogh the drum filters (162) i the water cleaning plant. Hers is also a work deck (40) hung up in rods and stretching between the gates to the deck of the bouyancy ring (3). There is an inner ring of the work deck directly connected around the column (2, a ring- shaped observation opening, an outer ring of the work deck, and a ring-shaped outer observation opening down to the rearing volume (0). Fig. 6 is a top view of the upper part of the ballast sections with the ballast and the main water inlets (11) in the section EE in the butt end portion of the egg-shaped shell (1) of an embodiment of the fish rearing tank according according to the invention. The section of the vertical half pipe profiles of the channels (121) stretching from the pumps (12) down to the outlets through the wall of the column (2) to the radial inflow channels (11a) to the tangential water inlets (11) to the rearing volume (0) is also shown. One of the ballast sections (7c) is shown filled with sand or cement. One or more of the sections can also be ballast water tanks possible to regulate when needed according to changing bouyancy conditions.
Fig. 7 is a vertical section through a part of the upper portion of the central tubular column (2) in level with the work deck with the motors of the pumps arranged dry in level with the work deck.
Fig. 8 shows a vertical section and view corresponding to Fig. 1, and showing an embodiment of the invention equipped with one or more generally vertically running anchor lines (chain, wire, rope, elastic anchor line) stretching from an anchor winch (6), preferably with a heave compensator, down through the central column (2), here through one of the channels (121) among what otherwise are the pump channels (121) and provided with a cleat (121B) for reinforcement at least in the pipe channel's (121) lower end about the exit for said anchor line. The anchor winch (6) shown in this embodiment is the anchor winch arranged inside the column (2), and the channel (121) is extended up above the inner water level in the column (2).
Fig. 9 shows a vertical section and view of an embodiment of the invention with anchor lines down through the central column (2); the anchor winch arranged in the upper tip portion (4) outside the column (2). In this embodiment the anchor lines runs down through a separate channel (121A) in addition to the channels (121) belonging to the pumps (12), inside the column (2).
Fig. 10 shows a perspective view and section of the same embodiment.
Fig. 11 shows an embodiment of the invention as in Fig. 8 wherein in a simple view the cleat (121B) is shown for the anchor line in one of the channels (121). In addition an embodiment is shown of the alternative configuration with a separate channel (121A) for the anchor line as in Fig. 9 and 10.
Fig. 12a is a horizontal section and view through the upper tip portion (4) in an embodiment of the invention with the bouyancy ring (3) showing the main arrangement of the water cleaning plant (160). Fig. 12b is a vertical section through one of the drum filters (162) and a ring-shaped drain channel (31) leading between the outlets (16) to the drum filters (162).
Fig. 12c shows a more detailed top view and section of the drum filter (162) in a section with outlet for cleaned water.
Fig. 12d shows an enlarged section of the mud belt separator (164).
Fig. 13a and 13b shows a partially transparent perspective view of an embodiment of the inlet water filter (9).
Detailed description of the embodiments of the invention
Here follows a description of the invention and embodiments of the invention with reference to the attached figures.
The invention is a fish rearing tank. It comprises: - an egg-shaped shell (1) with a mainly vertical long axis and gradually narrowing shape towards its upwardly pointing tip portion (4);
- wherein said shell (1) forms a generally rigid, closed tank;
- wherein said shell (1) has one or more main water inlets (11) to a rearing volume (0) and one or more water outlets (16),
- wherein said egg-shaped shell (1) is arranged for holding water in its upper tip portion (4) and water in said rearing volume (0) down to a ballast (7) at the bottom (51) in its lower, butt end portion (5),
- an axially directed central, hollow column (2) which extends from said upper tip portion (4) of said egg shaped shell (1) to said lower, butt end portion (5);
- wherein said main water inlet (11) to the rearing volume (0) is arranged in or near the bottom of said lower end portion (5), and wherein water outlet (16) out through the shell (1) from the rearing volume (0) is arranged by the upper inner surface of said water in said rearing volume ((0), and
- wherein said main water inlets (11) are nearly horizontally, tangentially directed into the rearing volume (0) so as for establishing circular water flow from below and upwardly through said rearing volume (0), and with
- a water inlet (10) arranged through a lower portion of said central column (2); and
- pumps (12) arranged inside said central column (2) and arranged for supplying water to said main water inlet (11) to said rearing volume (0). The central, hollow column (2) is open and extends axially through both ends of the shell (1) of the egg. There can be arranged a lid which opens over the upper end portion of the column (2). Thus there will be free access for example for a crane through the upper passage (201) of the column (2) as shown in Fig. 1 but an alternative is inner crane access in addition to the upper passage (201), with the use of a crane on rails stretching through gates in the column's (2) wall as shown in Fig. 7.
In embodiments of the invention the rearing volume in the shell (1) is between 4500 m3 and 22000 m3 or more. The height of the shell (1) shown in Fig. 1 is 26 meters. In other embodiments of the invention the height of the shell (1) can be between 8 and 60 meters or more. The shell (1) can be produced in fibre reinforced plastic, steel, rotational hoop winded, or in slide cast concrete.
The water inlet (10) via the lower end portion of the tubular column (2), see Fig. lb, Fig. 2 and Fig. 6, will, in an embodiment of the invention, have continuous water access up through the central portion of the column (2) up to a plate (129) with an aperture for the water filter (9) between the pumps (12). Thus, making all the water which comes in pass the water filter and out over to the pumps. A tank which in the invention can have a height from the pointy to the butt end of about 26 meters as shown in the embodiment in Fig. 1, but in larger embodiments can be 46 meters high or more than that. The diameter of the central column is in preferred embodiments of between 2 and 5 meters, and in an even more preferred embodiment between 3 and 3,5 meters, depending on the size of the shell (1). In the embodiment shown in Fig. 1 there is, under the water line, generally only the lower implementation for the column (2) through the shell (1), something which simplifies the prosess and reduces the building time of the shell (1). A significant advantage with the invention is that key elements and functions of the fish rearing tank, such as pumps, inlets, pump channels, filters, drainage pipes, mooring lines and desinfection gear, can be arranged in the axially directed central, hollow column. Implementations for water flow is easier to arrange inn and out through the wall of the column (2) than through the egg-shaped shell (1), that requires more complex shape of each implementation, and also would weaken and weigh down the shell or complicate its production. Therefore one may gain access to these elements via the top of the central tubular column (2), either with the use of an external crane or internal winch or lift arrangement. There are numerous advantages by gathering key elements and functions inside the column (2) than the access by crane from the above; it is possible to produce the shell (1) and the column (2) separate from the input in the column (2), and assemble the input as a complement at a shipyard. The input in the column (2) may consist of single components each mounted to the inner wall of the column (2). In an embodiment of the invention components such as pumps, inlet filters, inlet pipes, valves, anchor winch be mounted in one or more complementary sleeves which can be locked in place from above through the upper passage (201) and mounted at the desired level inside the colun (2). Replacement, maintenance or repairing of parts of the input in the column will, no matter which embodiment, be easy to perform via the column (2) without big interventions in the shell (1). Further you can avoid a large number of gates and implementations in the shell (1), which would otherwise require apertures and reinforcements of the edges of the shell around the apertures, flanges, sockets and sealings. In Fig. 1 there is, under the water line, generally only the lower implementation for the column (2) through the shell (1). In the embodiment of the invention shown in Fig. 1 the pumps (12) and their respective engines (123) are mounted under the inner surface of the water inside the central tubular column (2). In another embodiment of the invention shown in Fig. 7 the pumps (12) are powered by engines (123) arranged dry above the water level inside the central column (2). Fig. 7 shows section through pumps and engines by the work deck, motors on dry ground arranged over wells with driving shaft to the pumps down through a well lid. A significant advantage with pump engines on dry ground is that they are in fact above the water surface thus making them directly accessible for inspection; the motors requires a much simpler construction with regard to prevent water instrusion, and there is access with crane from above so that the engines and pumps are accessible for mounting and replacement, either through the upper end of the column (2), see Fig. 1, or with a crane as shown in Fig. 7.
In an embodiment of the invention the pumps (12) are arranged in the top of pressure channels (121) which extend downwardly through said central column (2) and having apertures out to radial inflow channels (11a) to the tangential main water inlets (11) to the rearing volume (0). This is shown in vertical sections of the tank in Fig. 1 and 2; the sections are shown as AA and BB in Fig. 4 which is a horizontal section and view under deck under line DD from Fig. 1. The vertical channels (121) which extend downwardly along the wall in the central column (2) is in a embodiment channels with a transition (121T) from circular flange at the pump (12) to semicircular outline in the top of pressure channels (121). This gives more space in the central cross-section of the column (2) and less friction for the upwardly water stream in the column (2), as well as fewer narrow corners for fouling inside the column (2).
In an embodiment of the invention there is arranged a replaceable inlet water filter (9) between the water inlet (10) and the inlet to the pumps (12), inside the central column (2). The inlet water filter (9) is in an embodiment cylindrical with inlets in its lower end portion and arranged in a central aperture in a plate under the water surface inside the column (2) wherein there are flanges for the pumps (12) around the central aperture. The inlet water filter (9) can have outlets in the cylinder wall towards the water above and around the pumps. It should be a minimum of water above the pumps and the plate, for example 1,5 m. The inlet water filter will be the only passage for water from the surrounding sea to the water in the the rearing volume (0) inside the tank and if this filter is intact and has a filter opening which is low enough one will efficiently prevent intake of parasites such as salmon lice. This is a mayor advantage over prior art which for example uses water permeable lice skirt, with mesh of 350 mu, arranged around cages and which are open in the bottom, i.e. simply reducing the amount of lice, not preventing it. It is also a significant advantage over hemispheric cages which are without roofs, and therefore letting in salmon lice through sea spray.
In an embodiment of the invention the water inlet (10) comprises an extension pipe (102), see Fig. 1, extending to a desired depth below the lower end of said central tubular column (2) so that one might be able to take in water from an additional desired depth deeper than the depth of the shell (1), if possible further avoid undesired organisms. Mode of operation
The circulation of water in the rearing tank will according to the invention be like this:
- the water runs through tha main water inlet (10) in the lower end of said central tubular column (2);
- the water rises up through the central portion of the column (2) and runs through the water filter (9) and out through the cylindrical wall of the water filter;
- an inner water surface is created inside the column (2) after the water has passed through the water filter(9); if the diameter of the tubular column (2) is sufficient, for example here about 3 m, and the filter has little flow resistance, the flow resistance for the rising water will not be of significance, and the water surface inside the column (2) will in a dynamic flow be in almost the same level as the sea surface;
- the water wil be above the pumps (12) to the inner water surface in the column (2), see the water surface outlined in Fig. 1. The pumps (12) are arranged below the inner water surface in the column (2). The motors are in an embodiment arranged above the water surface, above the well hatch with passages for the drive axles to the pumps (12). The motor can also be arranged directly on the pumps (12) as shown in Fig. 1 and 2.
- the pumps (12) pump water down through the pressure channels (121) and out through apertures in the wall of the column (2) to the radial inflow channes (11a) out to the tangential water inlets (11) to the rearing volume (0);
-the water running out from the tangential water inlets (11) will therefore establish and maintain a circular water flow, (here shown counter clockwise) around the outside of the central column (2) , and mainly run in a hellical shaped water flow in the whole of the tanks rearing volume if the capacity of the pumps are adjusted sufficiently, rising up to the outlets (16) and out through the shell (1). The pressure of the pumps (12) will establish and maintain a higher water level inside the shell (1) than the surface of the sea (provided that the ballasting is accurate). Thus achieveing a level drop between the inner water level and the sea surface, see Fig. 1, which is sufficient to lead a water flow via the outlets (16) via the water cleaning plant with drum filter (162) to the final outlet (29) to the sea.
Fig. 11 shows an embodiment of the invention as in Fig. 8 wherein in a simple view the cleat (121B) is shown for the anchor line in one of the channels (121). In addition an embodiment is shown of the alternative configuration with a separate channel (121A) for the anchor line as in Fig. 9 and 10. Fig. 12a is a horizontal section and view through the upper tip portion (4) in an embodiment of the invention with the bouyancy ring (3) showing the main arrangement of the water cleaning plant (160), comprising drum filter (162) and a mud belt separator (164).
Fig. 12b is a vertical section through one of the drum filters (162) and a ring-shaped drain channel (31) leading between the outlets (16) to the drum filters (162). There are overflow pipes as a by-pass from the drain channels (31) water level down to the level for cleaned water after the drum filter, and overflow pipes for cleaned water to the outlet (29) to the sea.
Fig. 12c shows a more detailed top view and section of the drum filter (162) in a section with outlet for cleaned water, and a inflow section from the darin channel (31) with higher water level. Wet separated mud is lead via pipes to the mud belt separator (164) and can temporarily be stored in sludge tanks in the bouyancy ring (3). Such drum filters are commercially available off the shelf. Fig. 12d shows an enlarged section of the mud belt separator (164) receiving wet separated mud via pipes from the drum filter (162).
Fig. 13a and 13b shows a partially transparent perspective view of an embodiment of the inlet water filter (9) here divided in two concentric filters (9o, 9i) wherein the inner filter (9i) is threaded inside the outer filter (9o). Both are arranged to be mounted releasably in the plate (129) which can have a center hole with a flange with a diameter less or equal the the inner diameter of the inner filter (9i), wherein the water flows in axial, and wherein the water runs out radially through both filters. The filters (9, 9i, 9o) are arranged so that one is able pull out and change the inner or the outer filter separately and independent of one another, not to risk having a filter free passage through the plate (129). To lift the filters in and out one can usually use an internal crane. Inside the filter (9) one can lower down disinfecting equipment such as UV-radiation gear which kills parasites; micro-organisms such as bacteria, phages, viruses, lice, and Crustacea prior to the passage into the water inlet filter.
In an embodiment of the invention there is arranged a separator for bigger particles, such as fodder particles, in the channel (31) between the outlets (16) and the drum filter (162).
In an embodiment of the invention shown in Fig. 1, Fig. lb, Fig. 2, Fig. 6, Fig. 8 and Fig. 11, there is arranged a ring shaped sump (8) for dead fish and precipitates around the transition between the tubular column's (2) outer face and the top of the ballast (7), and wherein a J-shaped drain suction pipe (81) extends from the sump (8) in through the wall of the tubular column and up inside the column (2) to the surface. The top of the ballast section is slightly conical and leans in towards the sump (8). In a preferred embodiment of the invention the pipe connection between the vertical channels (121) and the main water inlets (11) are arranged inside and through the ballast sections (7,7c) with the orifices for the main water inlets (11) arranged as elliptical apertures in line with the top of the ballast sections (7,7c), see Fig. 1, 9a, 9b.
In an embodiment of the invention the rearing tank is provided with an anchor winch (6) arranged in the tip portion (4) and with one or more generally vertically running anchor lines (chain, wire, rope, elastic anchor line) which extends downwardly through the central column (2), either in one of the channels (121) among the pump channels (121) or in a separate pipe channel (121A) provided with a cleat (121B) for reinforcement at least in the pipe channel's (121, 121A) lower end about the exit for said anchor line, and with mainly vertical anchoring to the seafloor. An advantage with a vertical anchoring stretching down through the lower end of the column (2) and down to a mooring point in the sea floor is that one might reduce the length of the anchor lines significantly in comparison to having a star-arrangement of anchor lines out from the buoyancy ring, something which could require several kilometres of anchor line all together, and that such a star arrangement also would have tied up large parts of the sea and the sea floor, thus preventing ordinary fishing such as trawling around the rearing tank. As anchor one might use bolts fixed to the bedrock, plumb weights or suction anchor.
System for water replacement with freshwater for delousing
In embodiment of the invention a flexible hose (92) with supply of freswater can be connected from the main land and out to the rearing tank for replacement of the tank's seawater with freshwater, in order to kill salmon lice while the salmon tolerates freshwater. The flexible hose (92), see Fig. 9a, can be connected to the space inside the column (2) outside the water filter or through the top of the filter (9) and over the plate (129), with the water having a higher pressure than the water rising up through the inlet (10) in the bottom of the column (2) so that the pumps (12) runs freshwater in to the rearing volume (0). In order to go back to normal seawater circulation the supply of freshwater is simply disconnected.

Claims

Claims
1. A fish rearing tank comprising the following features:
- an egg shaped shell (1) with a mainly vertical long axis and gradually narrowing shape towards its upwardly pointing tip portion (4);
- wherein said shell (1) forms a generally rigid, closed tank;
- wherein said shell (1) has one or more main water inlets (11) to a rearing volume (0) and one or more water outlets (16) from said rearing volume (0),
- wherein said egg-shaped shell (1) is arranged for holding air in its upper tip portion (4) and water in said rearing volume (0) down to a ballast (7) in its lower, butt end portion (5),
- an axially directed central, hollow column (2) which extends from said upper tip portion (4) of said egg shaped shell (1) to said lower, butt end portion (5);
- wherein said main water inlet is arranged in near a bottom (51) of said lower end portion (5), and wherein water outlet (16) is by the upper inner surface of said water in said rearing volume ((0),
- and wherein said main water inlets (11) are nearly horizontally, tangentially directed so as for establishing circular water flow from below and upwardly through said rearing volume (0),
- characterized by
- a water inlet (10) arranged through a lower portion of said central column (2); and
- pumps (12) arranged inside said central column (2) and arranged for supplying said main water inlet (11) to said rearing volume (0).
2. The fish rearing tank according to any of the preceding claims,
- wherein said pumps (12) are driven by motors (123) arranged dry above said water surface and its level inside said central column (2).
3. The fish rearing tank according to any of the preceding claims,
- wherein said pumps (12) are arranged in the top of pressure channels (121) which extend downwardly through said central column (2) and having apertures out to radial inflow channels (11a) out to the tangential main water inlets (11) to said rearing volume (0).
4. The fish rearing tank according to any of the preceding claims,
- wherein there is arranged a replaceable inlet water filter (9) between said water inlet (10) and the inlet to said pumps (12) inside said central column (2).
5. The fish rearing tank according to any of the preceding claims, - wherein said pumps (12) and said water filter (9) is arranged with its inlets near below said water surface inside said central column (2).
6. The fish rearing tank according to any of the preceding claims,
- that said pipe shaped central column (2) has a passage (201) with generally the same diameter as said column (2) itself, vertically up through said tip portion (4) of said shell (1).
7. The fish rearing tank according to any of the preceding claims,
with a buoyancy ring (3) arranged near and below said shell's tip portion (4) and provided with a ring- shaped drain channel (31) which leads to a water cleaning plant (160) and further to an outlet (29) for the cleaned water to the sea.
8. The fish rearing tank according to the preceding claim,
- wherein said water cleaning plant (160) comprises a rotating drum filter (162).
9. The fish rearing tank according to claim 7 or claim 8, wherein said rotating drum filter (162) is arranged to transport the separated wet solid material further to a mud belt separator (164).
10. The fish rearing tank according to any of the preceding claims,
- wherein said water inlet (10) comprises an extension pipe (102) extending to a desired depth below the lower end of said central pipe-shaped column (2).
11. The fish rearing tank according to any of the preceding claims,
- wherein said pumps (12) below said water surface has drive axles (122) extending from motors (123) placed above the water surface, preferably wherein said drive axle extending through a well hatch below a work deck.
12. The fish rearing tank according to any of the preceding claims,
- wherein there is arranged ballast (7) in the bottom of the butt end (5) of said shell (1) and about said column (2) .
13. The fish rearing tank according to any of the preceding claims,
- wherein there is arranged a ring-shaped buoyancy column (3) about said shell's (3) upper tip portion (4).
14. The fish rearing tank according to any of the preceding claims,
- wherein there is arranged a water cleaning plant (160) in said ring-shaped buoyancy column (3), wherein said water cleaning plant (160) has a supply channel (161) from said outlets (16) to one or more horizontally arranged drum filters' (162) inner face, pickup devices for separated sludge from said inner face of said drum filters' inner face, and with an outlet for cleaned water from said drum filters' (162) outside to said water outlet (29) to the sea.
15. The fish rearing tank according to any of the preceding claims,
- wherein said shell (1) below the outer water line is generally continuous and without pipe sleeves except for said pipe shaped column (2).
16. The fish rearing tank according to any of the preceding claims,
- wherein the fish rearing volume in said shell (1) is between 4500 m3 and 22000 m3 or more.
17. The fish rearing tank according to any of the preceding claims,
- wherein there is arranged a ring shaped sump (8) for dead fish and precipitates around the transition between the pipe shaped column's (2) outer face and the top of said ballast (7), and wherein a J-shaped drain suction pipe (81) extends from said sump (8) in through the wall of said pipe-shaped column (2) and up inside said column (2) to the surface.
18. The fish rearing tank according to any of the preceding claims, provided with an anchor winch (6) arranged in said tip portion (4) and with one or more generally vertically running anchor lines (chain, wire, rope, elastic anchor line) which extends downwardly through said central column (2), either in one of said channels (121) among said pump channels (121) or in a separate pipe channel (121A) and provided with a cleat (121B) for reinforcement at least in the pipe channel's (121, 121A) lower end about the exit for said anchor line, and with mainly vertical anchoring to the seafloor.
19. The fish rearing tank according to claim 18, having said anchor winch (6) arranged in an upper portion of said central column (2).
20. The fish rearing tank according to any of the preceding claims,
wherein an intake water filter (9) is cylindrical and having an inlet in its lower end and arranged in a central aperture in a plate (129) below said water surface internally in said column (2).
21. The fish rearing tank according to claim 20,
wherein said inlet water filter (9) has outlet apertures in its cylinder wall out towards said water above said plate (129) and out towards surrounding inlets for said pumps (12) about said inlet water filter (9).
22. The fish rearing tank according to any of the preceding claims, wherein said inlet water filter (9) is subdivided into two concentric filters (9o, 9i) wherein said inner filter (9i) is thread into said outer filter (9o), and both are arranged to be mounted releasable in said plate (129) in a central hole with flange with diameter smaller or equal to an inner diameter of said inner filter (9i), wherein said water flows in axially, and wherein said water runs out radially through both filters.
23. The fish rearing tank according to any of the preceding claims,
with two or more separate ballast sections (7c) arranged as sectors about said column (2), wherein said ballast is cement, pumpable sand slurry, or water, exchangeable via ballast pumps with supply pipes internally via said column (2).
PCT/NO2018/050206 2017-08-14 2018-08-10 Improved closed fish rearing tank WO2019035719A1 (en)

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NO345758B1 (en) * 2020-01-28 2021-07-12 Hauge Aqua Solutions As Improved breeding tank
EP3850945A1 (en) * 2020-01-17 2021-07-21 Hainan Minde Ocean Development Co., Ltd Semi-submersible offshore aquaculture platform based on liquid cargo ship modification
NO346305B1 (en) * 2020-12-19 2022-05-30 Hauge Aqua Solutions As A liquid, mainly egg-shaped breeding tank with an upper, suction pump outlet.
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FR3141600A1 (en) * 2022-11-09 2024-05-10 Serge Ferrari Sas CLOSED CAGE TYPE AQUACULTURE BREEDING DEVICE, COMPRISING NESTABLE ANNULAR STRUCTURES CONNECTED BY MEMBRANE PORTIONS IN THE SHAPE OF REVOLUTION HYPERBOLOIDS

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WO2017026899A1 (en) * 2015-08-12 2017-02-16 Hauge Aqua As Floating and submersible closed-contained aquaculture farming, and method of rearing fish

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Cited By (12)

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Publication number Priority date Publication date Assignee Title
WO2020231270A1 (en) * 2019-05-16 2020-11-19 Total Betong As Tank provided with a hatch and method for providing access to the tank
NO20190766A1 (en) * 2019-06-20 2020-12-21 Hauge Aqua Solutions As Liquid egg-shaped breeding tank
NO345584B1 (en) * 2019-06-20 2021-04-26 Hauge Aqua Solutions As Liquid egg-shaped breeding tank
EP3850945A1 (en) * 2020-01-17 2021-07-21 Hainan Minde Ocean Development Co., Ltd Semi-submersible offshore aquaculture platform based on liquid cargo ship modification
NO345758B1 (en) * 2020-01-28 2021-07-12 Hauge Aqua Solutions As Improved breeding tank
WO2021154087A1 (en) * 2020-01-28 2021-08-05 Hauge Aqua Solutions As Fish farming tank with an internal buoyancy ballast tank
NO346305B1 (en) * 2020-12-19 2022-05-30 Hauge Aqua Solutions As A liquid, mainly egg-shaped breeding tank with an upper, suction pump outlet.
WO2022131930A1 (en) * 2020-12-19 2022-06-23 Hauge Aqua Solutions As A buoyant rearing tank with upper, suction pumping outlets
WO2022191716A1 (en) * 2021-03-08 2022-09-15 Eide Fjordbruk As Fish farm with a closed submersible unit
GB2618741A (en) * 2021-03-08 2023-11-15 Watermoon AS Fish farm with a closed submersible unit
FR3141600A1 (en) * 2022-11-09 2024-05-10 Serge Ferrari Sas CLOSED CAGE TYPE AQUACULTURE BREEDING DEVICE, COMPRISING NESTABLE ANNULAR STRUCTURES CONNECTED BY MEMBRANE PORTIONS IN THE SHAPE OF REVOLUTION HYPERBOLOIDS
WO2024100358A1 (en) * 2022-11-09 2024-05-16 Serge Ferrari Sas Closed-cage aquaculture farming device comprising nestable annular structures connected by membrane portions in the shape of hyperboloids of revolution

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