WO1996008142A1

WO1996008142A1 - Fish farm

Info

Publication number: WO1996008142A1
Application number: PCT/NO1995/000155
Authority: WO
Inventors: Rolf Engelsen
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-09-16
Filing date: 1995-09-08
Publication date: 1996-03-21
Anticipated expiration: 1997-03-16
Also published as: NO943469D0; AU3579795A

Abstract

A land based or closed sea based fish farm, comprising two longitudinal tanks, each of which having one side wall (1) and a common center wall (2), end walls thereby closing the tanks, all walls being secured to a base (16), each tank being provided with flow deviators (3) secured to the side walls (1) and the center wall (2), preferably with the same distance, thereby defining a number of identical shaped cells in each tank, the flow deviators (3) extending from the base (16) in each corner of each cell, establishing a square with truncated corners, and each cell comprising at least one vertical water supply pipe (4) near the center wall (2), the supply pipes (4) being provided with perforations in one side along the pipe height to direct water in a desired angle along the center wall and in a spiral pattern towards the center of the cell where the water enters an outlet pipe (5).

Description

Fish farm The present invention is related to a land based or closed sea based fish farm. 5 Fish farming of today is often accomplished in closed units such as in containers or tanks on shore or in tanks in water.

The different fish species may be grouped into two main types in connection with fish farming, fish demanding volume and 10 fish demanding area to lay on or rest.

Volume demanding fishes, such as salmon, very often are farmed in open systems (sea cages) as these provide large volumes at low cost. Other fishes demanding volume, such as fresh water trout, are often farmed in land based systems. s Area demanding species to a very high extent, rest on the sea bed or bottom and does not efficiently utilize a large volume, even if accessible. The size of the accessible farming area is however essential. Area demanding fishes are for example ocean catfish and flatfish species as halibut, hirame, turbot, o sole and plaice.

In all farming there exists limits for optimal density i.e. biomass per unit. These units are respectively cubic and square meters for volume and area demanding species. Hence volume available or area accessible determines the production capacity 5 in the case of respectively volume and area demanding species.

Closed systems for farming area demanding fish are costly due to the large area required. Furthermore it is favourable to provide indoor farming systems, in buildings or in tents. Economical analyzes show there is a need for reduction of o investments connected with construction of such farms, whereby investment cost per square meter available farming area is an major key.

Existing closed farms are typically of either the race¬ way type or consist of separate circular (or octagonal) tanks. 5 In raceway systems there is a major problem with sedimentation and consequently bad self-cleaning. Plants consisting of separate circular tanks causes inefficient solutions for the internal transfer of fish and hence problems in securing high average levels of tankutilization in the farm as a total .

The above mentioned disadvantages are overcome with the fish farm according to the present invention. Additionally even other advantages are achieved. The present invention represents s a solution to these major problems by combining the advantages of the two existing systems as well as introducing new features making internal transportation easy in combination with a good self-cleaning system. The rational and compact solution of the present invention reduces operational cost and minimizes the 0 investment involved.

In a specific embodiment the fish farm according to the present invention provides a possibility to farm area demanding fish species on a relatively small ground surface and at relatively low cost, resulting in a substantial increased s production. Simultaneously investments as well as operation cost are reduced.

The plant may be used for farming a number of different fish species. Water supply to the plant may be based on pumping or if available, in the case of farming in fresh water, water may o be supplied by gravity from rivers and/or lakes.

The fish farm according to the present invention is constructed preferably in concrete on site or as prefabricated concrete elements. The farm design, however, is evenly well suited for the use of other materials such as steel, and also a 5 combination of steel and concrete.

The drawing discloses in figure 1 a cross section of a fish farm according to the present invention and figure 2 discloses a smaller ground view of the fish farm disclosed in figure 1. o The basic fish farm comprises two outer walls 1 arranged parallel to and at a distance from one inner wall 2 all of which being secured to a concrete base 16, thereby establishing two elongated tanks being closed at both ends by end walls (not shown). Due to the stability of the walls a roof may 5 cover the entire building, resting on the walls. The base 16 or floor may be horizontal or slightly inclined inwardly to the middle of each tank.

Each longitudinal tank is divided into cells by flow deviators 3, preferably in such a way that one deviator 3 is arranged at each corner of a square. The deviators 3 constrict the corners of the square, each deviator 3 extending along the height of the walls. The deviators 3 provide space for feeding, regulation of the water level 6, instrumentation etc. The deviators 3 may be plane walls extending from the base 16 to the top of the walls and facing the center of the cell. Furthermore the deviators 3 may have a step like surface or even be concave.

In the centre of each cell a vertical outlet pipe 5 is extending, being provided with perforations guiding the water through a pipe 7 below the cell to a collector 8, to which corresponding pipes 7 from all cells is connected.

Water is supplied to the tank through one or possibly more supply pipes 4 in each cell, having equally directed perforations along the height, thereby maintaining a directed water flow along the walls and the deviators 3 creating a spiral ending up in the outlet pipe 5.

The supply pipes 4 direct the water flow in alternating directions in adjacent cells, the water thereby flowing in the same direction between two cells where typically no wall is located but where partition walls 13 may be inserted, in the form of a grid of any kind or even a closed wall. The partition walls 13 may .be inserted or removed between the opposite deviators 3 according to the needs present, thereby closing some of the cells completely or only partially with partition walls 13 in the shape of grids. Closed partition walls 13 also provide a possibility to establish infection bars when sealingly closed.

Further outer walls 17 may be erected parallel with and at a distance from the outer walls 1, thereby establishing a transportation channel 11. In case a further farm building is constructed parallel to the first, the distance between the opposed outer walls establish a channel 11.

Working platforms 18 are extending in the longitudinal direction above the center wall 2 and flow deviators, adapted for inspection, maintenance and transportation, which platforms 18 giving access to gangways extending above the cells, carried by frame work, possibly connected with the outlet pipe 5.

Gates or closures 19 provide connection from each cell through the center wall 2 as well as to the outer channels 11, providing excellent possibilities for grading fish as well as transporting fish between individual cells.

A common water supply channel 15 is arranged above the center wall 2, for water supply to the inlet pipes 4. Valves s control in a known manner the water flow supply from the channel 15 to the inlet pipes 4 as well as downstreams through the water flow circuit. The channel 15 may be connected to a purifying means, thereby recycling water from the channel 8.

Each cell furthermore contains a sludge pot 14 situated o in the centre of the cell in the base 16 around the outlet pipe

5, being connected with sludge outlet pipes 9 from each cell, being interconnected for collection and disposal or recovery of particles according to local regulations.

The length of the cell wall tanks typically may be from s 3 to 20 meters or more, the height of the walls and thereby the water depth may be up to 4 meters.

The fish farm preferably is equipped with a central pneumatic (or otherwise) automatic feeding system comprising external silos and farm integrated components as dosing o equipment, screw conveyors, ejectors, blower and others. The feed is distributed either on the surface in each cell or in the water in each cell.

To a certain extent the fish farm may be monitored and controlled by computer processors to ensure optimum conditions 5 in each individual cell and tank.

Supply of oxygen may be performed by means of diffusors arranged at specific places in the water flow. Emergency supply of oxygen is achieved with pipes or hoses secured to the tank wall near the tank floor, being activated by signals from oxygen sensors at the outlet of each tank.

Plants provided with roof may comprise continuously adjustable light in such a way that light control and light manipulation is possible.

The water supply needed for the farm may be pumped up from the sea, whereby pumps and pump stations being integrated in the farm itself. Additional installations provide the possibility for recirculation of substantial water amount using part of the water flow from the water outlet 8, supply air to this water and recirculate the water by pumping. The farm also may contain installations making use of heated water possible.

Fish grading may be performed by means of the partition walls 13 between cells and/or between the cells and the transpor¬ tation channel 11. Fish to be slaughtered may be taken out s through the same transportation channel 11 from which the fish is guided into a special gutting chamber.

Grading preferably is accomplished also by grid partition walls 13 between the cells or between the cells and the transportation channels. Such grading also may use conveyors in o the transportation channels.

Shelves 10 may be arranged in the cells, extending from the walls 1, the partition walls 13 and the flow deviators 3 inwardly towards the centre of the cell, leaving an opening 12 around the outlet pipe 5, the opening preferably extending to the s middle wall 2. The shelves 10 can be nets or even solid sheets having open or perforated portions. The vertical distance between the shelves 10 shall supply the fish sufficient space. The shelf height will vary depending on the species farmed.

The shelves 10 may be shaped in such a way that an open slot is left along the circumference between the shelf and the walls. Each shelf 10 preferably comprise a number of shelf sections. The surfaces of the shelves (10) may consist of perforated net, may be combinated with solid materials and/or open areas, consisting alternatively of solid materials with open areas.

The shelves 10 may be constructed in stainless steel, seawater resistant aluminium or another material having corre¬ sponding qualities, possibly in reduced qualities if used in fresh water. A framework carries the shelves 10, which framework also is carrying a working platform or platforms extending above each cell. The framework preferably may be interconnected pipes, being used as distributor for feed, oxygen etc. Furthermore the framework may be used for carrying equipment such as propulsion devices and current generators.

The opening 12 may vary up to a sector of 180°. The openings 12 may be arranged directly above each other or in another suitable manner.

The fish farm according to the present invention may be combined with known systems for fish farming, water supply and oxygenating such that one or more of these functions may be performed through the piping system, including the frame work.

With the system according to the present invention a base is provided for substantially intensivated farming of both volume and area demanding fish species.

Claims

P a t e n t C l a i m s

s 1. A land based or closed sea based fish farm, CHARAC¬

TERIZED IN comprising two longitudinal tanks, each of which having one side wall (1) and a common center wall (2), end walls thereby closing the tanks, all walls being secured to a base (16), each tank being provided with flow deviators (3) secured o to the side walls (1) and the center wall (2), preferably with the same distance, thereby defining a number of identical shaped cells in each tank, the flow deviators (3) extending from the base (16) in each corner of each cell, establishing a square with truncated corners, and each cell comprising at least one vertical s water supply pipe (4) near the center wall (2), the supply pipes (4) being provided with perforations in one side along the pipe height to direct water in a desired angle along the center wall and in a spiral pattern towards the center of the cell where the water enters an outlet pipe (5).

2. Fish farm according to previous claim, CHARACTERIZED

IN the flow deviators (3) having plane surfaces facing the cell center.

3. Fish farm according to claim 1, CHARACTERIZED IN the flow deviators (3) having step like surfaces facing the cell center.

4. Fish farm according to claim 1, CHARACTERIZED IN the flow deviators (3) having concave surfaces facing the cell center.

5. Fish farm according to previous claim, CHARACTERIZED IN each cell being provided with gates or closures (19) in the side wall (1) as well as in the center wall (2), enabling grading and transportation of fish between neighbour cells in opposite tanks, to the channels (11) as well as through the partition between neighbour cells in the same tank, the closures being grids, dredges, gates or closed doors, depending on the operation to be performed.

6. Fish farm according to previous claims, CHARAC¬ TERIZED IN two fish farm buildings, both of which comprising two tanks being arranged parallel to each other, thereby utilizing a distance between the side walls ( 1 ) of the two buildings as channels (11) for grading and transportation of fish.

7. Fish farm according to previous claims, CHARAC¬ TERIZED IN single additional side walls (17) being erected outside the tank side walls ( 1), thereby establishing further channels (11) for grading and transportation of fish.

8. Fish farm according to previous claims, CHARAC¬ TERIZED IN at least some of the cells being provided with at least one shelf (10) extending from the side walls (1, 2) and the partition walls (13) between cells, to an open area in the middle of the cell, the opening (12) thereby extending to one side wall, such as to a center side wall (2) of a double tank unit.

9. Fish farm according to claim 8, CHARACTERIZED IN a number of shelves (10) being arranged above each other in a stack system, the open sectors evenly being arranged above each other.

10. Fish farm according to claims 8-9, CHARACTERIZED IN each shelf (10) sloping downwardly from the walls (1, 2, 13) towards the center of the cell at an appropriate angle.

11. Fish farm according to claims 8-10, CHARACTERIZED IN the surfaces of the shelves (10) consisting of perforated net or combinated with solid materials and/or open areas, consisting alternatively of solid materials with open areas.

12. Fish farm according to claims 8-11, CHARACTERIZED IN the shelves (10) being carried by a framework, which framework also carrying a working platform or platforms extending above each cell.

13. Fish farm according to claim 12, CHARACTERIZED IN the framework being interconnected pipes, which framework being used as distributor for feed, oxygen etc., and for carrying equipment such as propulsion devices and current generators.