HK1238085B - Strainer regulator for an outlet in a closed fish pen - Google Patents

Description

Filter regulator for outlets in closed fish pens

This application is a divisional application of the invention patent application whose applicant is AKVA Design Co., Ltd., the application date is February 5, 2014, the application number is 201480007557.6 (PCT international application number is PCT/NO2014/050019), and the invention name is "Exit pool for fish farming fence".

Technical Field

The present invention relates to a filter regulator for a filter in a closed fish pen. More particularly, the present invention relates to a filter regulator for a filter, wherein the filter covers a cross section of an outlet channel in the bottom of the closed fish pen.

Background Art

Fish farming in the sea is usually carried out in so-called open fish pens. Open fish pens consist of a net that forms a closed barrier for the fish, while allowing fluid to pass through. The fish pens float on the water surface with the help of a surrounding buoyancy system.

Open fish pens have several drawbacks. For salmon farming, the drawbacks are that the fish can be infected with crustacean parasites such as salmon lice, as well as other diseases caused by viruses, bacteria, and parasites. Fish can escape, especially if the nets are accidentally torn. Open fish pens release waste, such as uneaten feed and feces, into a receptacle. The water temperature within the fish pens varies with the temperature of the surrounding water. In winter, the water temperature, especially near the surface, may be too low for the fish to grow optimally. In summer, the water temperature may be too high for the fish to grow optimally.

Closed fish pens are an alternative to open fish pens and address some of the issues associated with open fish pens. Closed fish pens are well known in the art. They can be made of a dense fabric material formed into a bag. Patent Publication No. 160752/US4711199 discloses an example of such a fish pen. This fish pen has a substantially flat bottom with a conical sludge collector. Patent Publication No. 4798168 discloses a cylindrical fish pen made of fabric material with a conical bottom. Water is directed tangentially across the surface of the fish pen, and an outlet (with its own inlet) is located at the water surface in the center of the fish pen. Excrement and feed residues are collected at the lowest part of the bottom and pumped upward to the surface via a pipeline. For example, a flexible straw made of corrugated plastic tubing is attached to the inlet of the fish pen. The flexible straw has a rope extending to the water surface at its free end. Since the straw is flexible, the free end can be raised or lowered to the desired water depth. The length of the straw is constant.

Enclosed fish pens made of rigid materials are also known. Patent Publication No. 166511/EPO347489 discloses a semi-submersible floating platform comprising a cylindrical cabin with a tapered lower portion. Patent Publication No. 165783/US4909186 discloses a hull-shaped container for fish farming. Patent Publication WO2010/016769 discloses a fish pen made of a watertight, substantially rigid material, having a substantially hemispherical shape. This patent discloses that the depth of the water inlet can be adjusted to achieve the optimal water temperature. Patent Publication WO2010/099590 discloses a fish pen composed of waterproof fiberglass sheets with an intermediate foam material to provide buoyancy. This fish pen is substantially cylindrical with a flat bottom.

Patent Publication No. 175341/WO9402005 discloses an enclosed fish pen with a cylindrical upper portion and a conical lower portion. This fish pen can be made of steel, concrete, or a flexible reinforced plastic fabric. Water is pumped into the fish pen through a horizontal water supply pipe at the upper portion of the pen. The water supply pipe, located within the pen, is equipped with a rotatable outlet, which can direct the incoming water horizontally and vertically in a specific direction. At the lower end of the pen, the conical lower portion of the pen is equipped with a funnel-shaped outlet. A grid is provided in a portion of the wall of the outlet, which prevents fish from passing through but allows outward water flow. The outlet is also equipped with static guide vanes to prevent the water from moving in a circular motion within the pen and instead convert it into a vertical downward motion.

The buoyancy system used in floating aquaculture fish pens can consist of rectangular steel walkways with floating bodies. These walkways are hinged together, forming a grid of longitudinal and transverse walkways. Such buoyancy systems are often used with open fish pens. The seine net (which provides a barrier to the fish) is arranged in a square shape and secured to the surrounding walkways by hooks protruding from separate poles or brackets. The buoyancy system can also consist of at least one plastic tube welded together to form a ring. Typically, the buoyancy system consists of two concentric rings placed side by side, such as those shown in patent publications WO90/01872 and WO91/17653. Plastic fish pens with three concentric plastic rings are also known. The multiple plastic rings are connected by radially locating clips made of plastic or steel. The walkway can be placed on top of the two concentric rings. In open fish pens, the seine net is placed within the innermost pipe of the buoyancy system and secured with protruding seine net hooks. These seine hooks may be fixed to pipes or rails protruding upwards from the buoyancy system.The circumference of the seine net in a plastic fish pen may be between 90m and 160m, for example, corresponding to a diameter of approximately between 30m and 50m.

Known closed fish pens solve some of the drawbacks associated with open fish pens. However, known closed fish pens also have some drawbacks.

To ensure a sufficient water exchange rate to maintain a good water environment within the fish pen, water is typically pumped in so much that the water level inside the fish pen is higher than the water level outside the pen. Consequently, the pressure inside the fish pen is greater than the surrounding pressure, and water will flow out of the pen through the formed openings. This subjects the buoyancy system of a closed fish pen to greater forces than the buoyancy system of an open fish pen of the same size. In addition to keeping the solid fabric or net of the fish pen afloat, the buoyancy of the buoyancy system must be designed to maintain the volume of water inside the fish pen above the surface of the surrounding water. The water inside a fish pen contains considerable mass. Furthermore, the water inside the fish pen has a moment of inertia, which causes waves to have a greater impact on the buoyancy system than in an open fish pen (where waves pass through the buoyancy system and into the fish pen largely unimpeded). As mentioned above, the walls of a closed fish pen may include fabric materials. Because the volume of water inside the fish pen creates negative buoyancy, fabric materials must possess good tear strength. Fabric materials cannot be attached to the buoyancy system in the same manner as seine nets. Perforations in fabric-like materials can weaken tear strength. A single hole can be reinforced with a grommet, but it's difficult to match the spacing of the holes to the hooks in a way that maintains a smooth fabric. Water pressure inside the fish pen will stretch the fabric, and too short a distance between hooks will cause wrinkling. Hook spacing that's too wide relative to the spacing of the holes can render one or more of the hooks unusable. This weakens the attachment strength of the fish pen fabric to the buoyancy system.

Over time, a thin layer of sludge forms inside closed fish pens. This sludge consists of fecal matter and fine feed particles. The feed particles are fatty. The sludge has poor settling properties. In fish pens with a nearly flat bottom (whether the pen has substantially rounded sides or is spherical), the sludge will settle at the bottom and move only slowly toward the center of the pen. The outlet of the fish pen is typically located in the center of the bottom. The sludge forms a puddling pattern, which traps more fecal matter and feed residue and prevents them from being transported toward the outlet. The velocity of the flowing water can be increased to move the sludge toward the outlet, but experience has shown that this dissolves the sludge and reincorporates it into the water within the fish pen, especially if the water flow is somewhat turbulent and deviates from the desired laminar flow. When an aeration system is used, a certain amount of air bubbles is present near the outlet of the fish pen, and sludge particles can be easily transported all the way to the surface of the water within the pen. Sludge dissolves in the water, causing turbidity and adverse water quality for the fish. Dead fish will sink to the bottom of the fish pen and begin to rot if not removed. Because infection by pathogenic organisms can cause mass mortality, it is important to quickly remove dead fish to reduce any infection pressure on the fish in the fish pen. Patent Publication No. 332341/WO2011133045 discloses an enclosed fish pen with a conical bottom. In one embodiment, all sewage is conveyed to a sludge tank located on a floating collar within the fish pen. In an alternative embodiment, feed residue and excrement are partially separated from the water at the bottom of the fish pen. Sewage is conveyed to the sludge tank, while feed residue and excrement are conveyed to the surface in separate outlet pipes. Patent Publication No. 175082/WO9323994 discloses an outlet for a land-based container. This container is designed for fish farming and has a relatively flat bottom. Primary and secondary water flows transport particles in the water toward the center of the container. At the center of the container, wastewater is removed through a slot and enters a circulating particle trap (formed as an annular space surrounding an outlet pipe). Water flows out through a row of holes in the outlet pipe, while sediment is displaced by the water flowing through the slot openings and downward into the particle outlet. Patent Publication No. 318527/US6443100 discloses an outlet for a closed fish pen. The outlet pipe extends through the bottom of the fish pen and protrudes upward within the pen. Water flows out of the pen through a slot located in the upper portion of the outlet pipe. Sediment sinks along the outside of the outlet pipe and is transported out of the pen through an opening in the pen at the outlet pipe guide opening.

Water must be pumped into closed fish pens because the pressure inside is greater than the pressure outside. Inflowing water causes a surge within the fish pen. This surge should ensure that the entire water volume is regularly replaced. Ideally, the water flow should be laminar and uniform from the inlet to the outlet. Patent publication No. 160753 discloses an inlet for a floating or land-based tank, in which water is delivered to the tank via a pipe extending through the tank wall. Inside the tank, water is delivered via a vertically oriented nozzle assembly with fixed nozzles, which imparts a tangential component to the inflowing water. The vertical nozzle assembly can be positioned at a certain horizontal distance from the tank wall. Patent publication WO2006/000042 also discloses a vertically oriented nozzle assembly located within a floating tank. The inflowing water acquires a tangential component. Water is delivered to the tank via a pipe extending through the tank wall. Patent publication US5762024 also discloses a vertically oriented nozzle assembly located within a floating tank. Water is pumped into the tank from above, with nozzle openings located at the bottom of the nozzle assembly. Water circulates within the tank. The water flow rate is adjusted by varying the pump speed. The nozzle assemblies described in these three patent publications are fixed so that the direction of water flowing out of the nozzle assembly is constant. Patent publication No. 332589 also discloses a floating tank with a vertically oriented nozzle assembly. This nozzle assembly is preferably equipped with slots or nozzles with adjustable direction. No. 332589 does not describe how this is implemented in practice. No. 332589 further discloses that the nozzle assembly may include an outer tube and an inner tube that can be rotated, raised, and lowered relative to each other in a controllable manner. In this way, the amount, direction, and level of inflowing water can be adjusted. No. 332589 does not specifically describe how this is achieved. No. 332589 also discloses telescopically arranged inlet pipes. The length of these pipes, and therefore the depth of the inlet opening, can be adjusted using a wire extending through the pipes and attached to their lower portions. Patent Publication No. 327035 discloses a nozzle assembly for a land-based tank. The nozzle assembly includes a vertically oriented, fixed distribution pipe. The distribution pipe is provided with a plurality of nozzle openings along its longitudinal direction. These nozzle openings extend axially in a slit-like configuration, with their length exceeding their width by a factor of at least two. A damping member having a hole therein is axially displaceable along the distribution pipe. The damping member is provided with a plurality of slit openings that correspond to the slit openings in the distribution pipe.

As described above, the surface of the water inside a closed fish pen can be higher than the surface of the water surrounding the fish pen. Water inside the fish pen can be pumped upward from a depth where the salinity of the water is greater than that of the water outside the fish pen. The water inside the fish pen thus has a greater density than the surrounding water. It has been shown that upon loss of electrical power driving the pumps supplying water to the fish pen, water will initially flow out of the fish pen until the water surface inside the fish pen is at the same level as the water surface outside the fish pen. If the density of the water inside the fish pen is greater than that of the surrounding water, water will continue to flow out of the fish pen. Water outside the fish pen can flow through the fish pen at a relatively high rate. It has been shown that once water flow out of the fish pen is established, it can be maintained by water flowing through the outside. When the pressure inside the fish pen is greater than the pressure outside the fish pen, closed fish pen walls formed of fabric-like material will stretch. When water begins to flow out of such a closed fish pen, the bag-like walls will begin to collapse. This happens especially in the lower part of the fish pen, while the upper part of the fish pen is kept in shape by the fish pen's buoyancy system. As a result, the volume of the fish pen will decrease, and this will have a stressful effect on the fish kept in the fish pen.

Water can be transported out of the closed fish pen through an outlet located at the bottom of the fish pen. The opening at the outlet must be secured with a grating or similar component to prevent fish from escaping through the outlet. Over time, such gratings become covered with sludge. They can also become contaminated by, for example, shells and tunicates. The interior of the closed fish pen will also become contaminated. This contamination can be removed by cleaning. This causes a relatively large amount of material to settle toward the outlet and onto the grating. Consequently, the grating can become partially clogged with sludge, contamination, and material from the fish pen walls. As the grating becomes partially clogged, the resistance to water flowing out of the outlet becomes greater. This is counteracted by the increasing water column above the grating. This means that the water level inside the fish pen rises relative to the surrounding water level. This, in turn, increases the load on the buoyancy system. As an illustrative measure, a 1 cm increase in the water level inside the closed fish pen results in the buoyancy system being lowered a further 7-8 cm in the water.

Large volumes of water must be pumped into the enclosed fish pen to maintain a favorable water environment for the fish. Advantageously, water can be pumped upward from a depth where the water temperature is more constant than at the surface. This also has the advantage of exposing the fish to fewer parasites, as parasites are typically found in the upper water layers. Larger water supply channels have the disadvantage of insufficient pressure, which can cause channel wall collapse. This can be counteracted by increasing the wall thickness. Consequently, the pipes will be more rigid. Rigid pipes also have the disadvantage of greater pressure from the water flow. In particular, the attachment of the pipe to the pipe housing and the attachment of the pipe housing to the fish pen's buoyancy system will be subject to greater stress.

Summary of the Invention

It is an object of the present invention to remedy or alleviate at least one of the several deficiencies of the prior art, or to at least provide a useful alternative to the prior art.

The above objects are achieved by a number of features which are described in detail in the following description and the appended claims.

The present invention relates to an outlet pool for a fish pen provided with at least one outlet hose extending from the outlet pool to the surface, the outlet pool comprising:

- a cylindrical housing, the upper portion of which is provided with a mounting collar arranged to be attached to the bottom of the fish pen, and the lower portion of which is provided with a through opening;

- a cylindrical outlet channel housed in the housing, wherein a filter is provided at the upper portion of the outlet channel, the filter covering the cross section of the outlet channel;

- an elongated annular space between the housing and the outlet channel;

- an inclined grille covering the entire annular space, the lowermost portion of the inclined grille being arranged slightly below the opening of the housing;

- an inclined bottom plate, sealingly covering the entire annular space; and

-Lower through opening, located at the lowest part of the base plate.

The outlet passage may be secured to the housing via at least one of a grille and a base plate. The grille may include a plurality of ribs oriented side by side. Alternatively, the grille may include a sieve plate. The base plate may include a fine-porous material. The opening may lead to a first pipe socket configured to sealably connect to the first outlet hose. The lower through-opening may be provided in the base plate at a lowermost portion thereof located at the inner jacket of the housing. The lower through-opening may be provided in a portion of the housing jacket between the lowermost portion of the grille and the lowermost portion of the base plate.

The lower opening may lead to a second tube socket that is configured to be sealedly connected to a second outlet hose. The filter may be conical in shape, with the tip of the filter facing upward. In an alternative embodiment, the filter may include a top plate, and a plurality of ribs may extend side by side between an outer edge of the top plate and an edge of the outlet channel, thereby forming elongated openings between the ribs, the elongated openings forming the filter slots. The ribs may be formed of tubes.

Also described is a buoyancy system for a floating fish pen for farming fish, wherein the buoyancy system may include at least two concentric rings, wherein at least two of the at least two concentric rings may have substantially the same diameter, and wherein a first ring of the at least two concentric rings may be loosely disposed over a second ring of the at least two concentric rings. At least two of the at least two concentric rings may have substantially the same diameter.

A plurality of elongated panels may be attached at least one end to at least one end of one of the at least two concentric rings, and the panels may extend around at least a portion of the other of the at least two concentric rings. The panels may be attached to a lower one of the two concentric rings and may extend around at least a portion of an upper one of the two concentric rings. A railing may be attached to the upper one of the two concentric rings.

Also described is a suspension device for attaching a bag in a closed fish pen to a buoyancy system, wherein the side edges of the suspension device may be provided with:

a groove formed between two opposing lips, the groove forming an elongated mouth extending from the edge to an elongated cavity in the suspension device, the diameter of the cavity being greater than the distance between the two opposing lips; and

a through-opening, the longitudinal axis of which is substantially perpendicular to the longitudinal extension of the cavity, which, in the position of use, is arranged above the cavity;

The suspension device may thus be displaceably attached to a bulb formed at the upper edge of the bag.

A bag is also described, wherein a portion of its upper edge may be provided with a bulb for removably placing it in a longitudinal cavity in a suspension device. The bulb may be formed along the entire circumferential upper edge of the bag. The bulb may be formed by folding the fabric of the bag around the elongated body and attaching it to itself with the aid of a fastening tool.

A suspension device is also described, wherein the suspension device may include a concave portion and a convex portion, wherein the concave portion may include:

- end edges and connecting sides;

- an elongated hollow profile, provided on the connection side;

- a lip extending from the hollow profile to the end edge; and

- an elongated groove arranged on the coupling side alongside the hollow profile, the groove comprising an outer mouth facing the coupling side and an inner cavity, the diameter of the cavity being greater than the width of the mouth;

The convex portion may include:

- end edges and connecting sides;

- an elongated hollow profile, provided on the connection side;

- a lip extending from the hollow profile to the end edge; and

- an elongated protruding guide arranged side by side with the hollow profile on the coupling side, the guide comprising a head and a neck, the head and the neck complementarily fitting respectively into the cavity and the mouth of the concave portion, the diameter of the head being smaller than the diameter of the cavity and greater than the width of the mouth;

The cavity of the female part can thus be moved laterally to the head of the male part to detachably connect the male and female parts and so that the hollow profiles of the female part and the male part together form an elongated cavity therebetween.

The suspension device may also be provided with an opening having a longitudinal axis, which extends substantially perpendicularly to the longitudinal direction of the cavity and, in the applied position, the opening may be arranged above the cavity.

The concave portion may be provided with a through opening from the outer surface to the connecting side, and the concave portion may be provided with a through opening from the outer surface to the connecting side, so that when the through opening of the concave portion is consistent with the through opening of the convex portion, a through opening is formed from the outside of the concave portion to the outside of the convex portion.

The convex portion may be provided with at least one through-hole extending from one end face of the convex portion to the opposite end face, and an opening may be formed from the outer side of the convex portion to the through-hole, so that a bolt can be disposed in the hole and a fastening member can be passed through the opening around the bolt. A screw or set screw may be oriented perpendicular to the connecting side and arranged to lock the convex portion and the concave portion to each other, so that the convex portion cannot move laterally relative to the concave portion, and vice versa.

Also described is an enclosed fish pen, wherein the walls may comprise a fluid-tight material, an upper portion of the fish pen may be provided with buoyancy means located in the water surface and provided with an inlet for water, and a lower portion of the fish pen may be provided with an outlet; wherein the depth of the fish pen constitutes the distance from the water surface to the outlet, the walls of the upper portion of the fish pen may form a spherical shape, and the walls of the bottom portion of the fish pen may form a conical shape.

The conical portion of the fish pen may have a depth Dc that constitutes substantially half of the depth D of the fish pen. Alternatively, the conical portion of the fish pen may have a depth Dc that constitutes substantially one-quarter of the depth D of the fish pen. The conical portion of the fish pen may have a depth Dc that constitutes substantially between one-half and one-quarter of the depth D of the fish pen. The conical portion of the fish pen may tangentially meet the spherical portion of the fish pen.

Also described is a protective net for a closed fish pen comprising walls of a soft material in the form of a fabric, wherein the protective net may comprise:

- a plurality of side-by-side substantially horizontal strips;

- a plurality of vertical straps, each extending from at least one horizontal strap to an adjacent horizontal strap, and the vertical straps being attached to the horizontal straps; wherein the plurality of vertical straps extend from an upper portion of the protective net to a lower portion of the protective net;

- the upper part of the protection net is provided with means for adjustably attaching the protection net to the buoyancy system of the fish pen;

- the lower part of the protection net is provided with means for attaching the protection net to the lower part of the fish pen; and

-Protection nets can be placed outside the closed fish enclosure.

Each horizontal strap can form a loop. In their longitudinal direction, the horizontal and vertical straps of the protection net can be adapted to the external geometry of the closed fish pen. The means for attaching the protection net to the buoyancy system can be arranged to vertically tighten or loosen the protection net relative to the buoyancy system. The horizontal and vertical straps can comprise wide strips.

Also described is an inlet system for an enclosed fish pen, wherein the fish pen is provided with a surrounding buoyancy system and an outlet is provided at a lower portion of the fish pen; the inlet system may include:

- a pump, located in a pump housing;

- an external water supply channel, the upper part of which leads to the inlet of the pump; and

- a guide channel, the outer end of which is in fluid communication with the outlet of the pump and the opposite inner end of which protrudes into the fish pen; wherein, inside the fish pen, the inlet system may further include an elongated flow generating tube, the elongated flow generating tube being rotatable about its longitudinal axis; wherein the flow generating tube is in fluid communication with the guide channel; wherein the flow generating tube may be provided with a plurality of openings, the openings being arranged in at least one row of holes.

The upper end of the surge generating tube may be rotatably disposed within a sleeve that is in fluid communication with the guide channel. An elliptical opening is provided in the wall of the surge generating tube for fluid communication with the sleeve. The upper end of the surge generating tube may be provided with an operating tool configured to rotate the surge generating tube about its longitudinal axis. The upper end of the surge generating tube may be provided with an upper stop ring and a lower stop ring, respectively disposed above and below the sleeve.

Also described is a surge generating tube for a container or for a closed fish pen, the surge generating tube being arranged inside the container or the fish pen, the surge generating tube being provided with:

- an opening located in the upper portion of the surge generating tube for fluid communication with a guide channel attached to the upper portion;

- a plurality of through openings located on the surface of the flow generating tube, arranged in a row of holes extending in the longitudinal direction of the flow generating tube;

- a damping member capable of displacement relative to the flow generating tube;

Furthermore, the opening has a length along the circumference of the flow generating tube that is equal to or greater than a width of the opening along the longitudinal direction of the flow generating tube.

Being displaceable means that the damping member can be displaced along the flow generating tube in the longitudinal direction of the flow generating tube. Being displaceable also means that the damping member can be rotated about the longitudinal axis of the flow generating tube. Being displaceable means that the damping member can be displaced along the flow generating tube in the longitudinal direction of the flow generating tube and rotated about the longitudinal axis of the flow generating tube.

The damping member is rotatable about the longitudinal axis of the flow generating tube and includes a first side plate and a second side plate, both of which extend longitudinally along the flow generating tube and are provided with a transverse plate to hold the first side plate and the second side plate together. The distance between the opposing edges of the side plates may be less than the width of the opening. The damping member may be disposed within the flow generating tube.

The damping member can be displaced in the longitudinal direction of the flow generating tube, and the damping member is provided with a plurality of belly bands, which extend around the circumference of the flow generating tube, thereby holding the first side panel and the second side panel together, wherein, when the damping member is in the open position, a side edge of the belly band or cross plate between the first side panel and the second side panel is substantially consistent with a side edge of the opening. The number of belly bands and cross plates can be equal to the number of openings. The width of the belly band or cross plate in the longitudinal direction of the flow generating tube can be greater than the width of the opening. The damping member can also be provided with a support plate, which extends in the longitudinal direction of the flow generating tube and which connects the belly bands.

The damping member of the surge generating tube may include a plate provided with a plurality of openings, the shape and number of the openings being consistent with the openings of the surge generating tube;

The damping member is movable along the longitudinal direction of the flow generating tube;

the damping member may be provided with a row of rudders in the longitudinal direction of the damping member, each rudder being hinged to the plate and each rudder being connected at its free end to a rod; and

- Each rudder may protrude into the middle of the opening of the plate.

The damping member of the surge generating tube may include a plate provided with a plurality of openings, the shape and number of the openings being consistent with the openings of the surge generating tube;

The damping member is movable along the longitudinal direction of the flow generating tube;

the damping member may be provided with two rows of rudders in the longitudinal direction of the damping member, each rudder being hinged to the plate and each rudder being connected at its free end to a rod; and

- a first row of rudders may be attached on one side of the opening of the board and a second row of rudders may be attached on the opposite side of the opening of the board;

- The rods of the first row of rudders can be connected to the rods of the second row of rudders by tie rods

A filter regulator for a filter in a closed fish pen is also described. The filter covers a cross section of an outlet channel in an outlet pool at the bottom of the fish pen, wherein the filter regulator may include:

- a regulator sleeve displaceably arranged on the outside of the filter; and

- A control mechanism that displaces the adjuster sleeve

The control mechanism may include an actuator attached to the regulator sleeve, the actuator extending from the regulator sleeve, through the filter, and then through the outlet passage to the water surface outside the fish pen. The actuator may include a tube or rod located within a guide tube. The guide tube may be attached to the interior of the outlet passage.

Filter regulators may include:

- a wire attached to the adjuster sleeve, the wire extending from the adjuster sleeve to the first pulley and over the first pulley to the control mechanism; and

- A control mechanism capable of displacing the adjuster sleeve by varying the tension on the wire.

The control mechanism may include a first capstan.The filter regulator may further include a second capstan disposed on a side of the fish pen diagonally opposite the first capstan, with a centerline extending from the second capstan to the block housing the first pulley.

The control mechanism may include a buoy that may be positioned inside the fish pen. A line may extend from a first pulley to a second pulley, past the second pulley to a third pulley, and past the third pulley to the buoy; the second pulley is positioned at a side edge of the fish pen; and the third pulley is positioned underwater at a side edge of the fish pen. The tackle may be attached to at least three lines that extend above the fish pen and are attached to each other in the middle of the fish pen.

Also described is an entry system for an enclosed fish pen, wherein the fish pen may be provided with a wraparound buoyancy system, and wherein an exit is provided at a lower portion of the fish pen; the entry system comprising:

- a pump, located in a pump housing;

- an external water supply channel, the upper portion of which leads to the inlet of the pump and the inlet portion of which is provided with a filter; and

- a guide channel having an outer end in fluid communication with the outlet of the pump and an opposite inner end projecting into the fish pen, wherein the portion of the external water supply channel between the inlet portion and the exterior thereof may comprise a portion comprising an adjustable-length channel comprising a channel wall of an elastic polymer material and a spiral portion of a rigid material housed in the channel wall, and a rope or line may extend from the filter to the buoyancy system.

The filter of the water supply channel may comprise a filter tube.The rope or line may extend substantially within the interior of the water supply channel between the filter and the buoyancy system.

Also described is an entry system for an enclosed fish pen, wherein the fish pen may be provided with a wraparound buoyancy system, and wherein an exit is provided at a lower portion of the fish pen; the entry system comprising:

- a pump, located in a pump housing;

- an external water supply channel, the upper portion of which leads to the inlet of the pump and the inlet portion of which is provided with a filter; and

- a guide channel having an inlet end in fluid communication with the outlet of the pump and an opposite inner end protruding into the fish pen, the external water supply channel comprising at least two water supply channels.

The number of the water supply channels may be at least three. Each water supply channel may be provided with a filter in an inlet portion. Each water supply channel may be connected to a filter chamber at the inlet portion.

The inlet system may further comprise a damper between the outlet of the pump and the inlet end of the pilot channel. The damper may comprise a check valve having two flappers.

Also described is an inlet system for an enclosed fish pen, wherein the fish pen is provided with a surrounding buoyancy system and the fish pen is provided with an outlet at a lower portion thereof; the inlet system comprising:

- a pump, in a pump housing;

- an external water supply channel, which leads to the pump inlet at its upper part and is provided with a filter at the inlet; and

- a guide channel in fluid communication at its inlet end with the pump outlet and projecting at its opposite inner end into the fish pen, the inlet system further comprising dampers at the pump outlet and the inlet end of the guide channel.

The damper may include a check valve having two flappers.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, examples of several preferred embodiments will be described, which are visualized in the accompanying drawings, in which:

FIG. 1A-1B shows a portion of an enclosed fish pen with a buoyancy system in A, and a schematic cross-section of two rings in the buoyancy system at a slightly different scale in B, where the rings are held together by a J-shaped plate;

FIG2 shows a perspective view, on a larger scale, of a suspension arrangement for attaching a seine net or fabric to a buoyancy system;

FIG3 shows, on a larger scale than FIG2 , a cross-section of a bulbous portion of a net or fabric arranged to cooperate with the suspension arrangement shown in FIG2 ;

FIG4 shows a cross section of the suspension device and the fastening member shown in FIG2 in the same scale as FIG3;

FIG5 shows a section through an alternative suspension arrangement on a slightly smaller scale than FIG3 ;

FIG6 shows the same content as FIG5 (but in another alternative embodiment);

FIG7 shows a side view of the suspension device shown in FIG5 at the same scale;

FIG8 shows a side view of the suspension device shown in FIG6 at the same scale;

FIG9 shows a side view of an outlet pool for a fish pen at a different scale;

FIG10 shows a perspective view of the outlet pool shown in FIG9 in exploded view at different scales;

FIG11 shows a top view of the outlet pool shown in FIG9 at a different scale;

FIG12 shows a partial cross-sectional view of the outlet pool shown in FIG9 at a different scale;

FIG13 shows a perspective view of an enclosed fish pen with an outlet pool from below at a different scale;

FIG14 is a perspective view showing details of the opening inside the outlet pool at a different scale;

FIG15 shows a side view of the geometry of a closed fish pen at a different scale;

FIG16 shows the same content as FIG15 in another embodiment;

FIG17 shows the same content as FIG15 in another embodiment;

FIG18 shows the same content as FIG15 in another embodiment;

FIG19 shows the same content as FIG15 in another embodiment;

FIG20 shows a schematic diagram of a protective net for a closed fish pen at different scales;

FIG21 shows a perspective view of an entrance system for a closed fish pen at a different scale;

FIG22 shows a top view of the inlet system shown in FIG21 at a different scale;

FIG23A-B shows a schematic side view of the surge generating tube and the guide channel of the inlet system at different scales;

FIG24 shows a perspective view, at a different scale, of an enclosed fish pen with an inlet system, an outlet tank, and hoses from the outlet tank to the surface, viewed slightly from below;

FIG25 shows a perspective view, at a different scale, of a closed fish pen with an inlet system and an outlet tank, viewed slightly from above;

Figures A-C in Figure 26 show the replaceable surge generating tube shown in Figure 23 at different scales, with A showing a perspective view, B showing a top view, and C showing a cross-section;

FIG. 27A-B shows a surge generating tube with a rotatable damper on the same scale as FIG. 26 ;

Figures A-E in Figure 28 show, on a larger scale, cross-sections of the surge generating tube shown in Figure 27 with dampers at different external locations;

Figures 29A-C show, on the same scale as Figure 28, an alternative embodiment having a damper inside the surge generating tube;

Figures A-C in Figure 30 show, on the same scale as Figure 26, a surge generating tube with an alternative damper;

FIG31 shows, on the same scale as FIG26 , a surge generating tube with an alternative damper;

FIG32 shows, on the same scale as FIG26 , a surge generating tube having another alternative damper;

FIG33 shows an alternative embodiment of the pump housing of the inlet system at different scales, A: damper in closed position, B: damper in open position;

FIG34 shows a perspective view of an alternative embodiment of an outlet pool, to the same scale as FIG10;

Fig. 35 shows a schematic diagram at different scales illustrating the regulation of water flowing out of the outlet pool;

Figure 36 shows, on the same scale as Figure 35, an alternative embodiment for regulating water flow out of the outlet pool; and

In Figure 37A-B, A shows a schematic diagram of another alternative embodiment for regulating water flowing out of the outlet pool at a different scale, while B shows a detail diagram at a larger scale; and

Figure 38 A-B shows, at different scales, an alternative embodiment of the water supply channel of the inlet system with two embodiments of the filter tube.

DETAILED DESCRIPTION

The drawings are relatively schematic and show only the details and equipment necessary for an understanding of the present invention. Furthermore, the drawings may be distorted with respect to the relative sizes of the details and components shown in the drawings. The drawings may also be somewhat simplified with respect to the form and level of detail of these details and components. Similarly, in general, equivalent or corresponding details in the drawings will be denoted by the same reference numerals hereinafter.

In the figures, reference numeral "1" indicates an enclosed fish pen. Enclosed fish pen 1 includes a watertight bag 10 (made of a fabric-like material), a buoyancy system 11, and railings 13. Fish pen 1 may also include a walkway 15, which rests on the buoyancy system 11 as shown in FIG1 . Fish pen 1 also includes an inlet system 2. Inlet system 2 includes a pump 20, which is disposed within a pump housing 21, as shown in FIG22 ; an external water supply channel 23 leading to the inlet of pump 20; and a guide channel 25, as shown in FIG21-23 and FIG25 . The guide channel 25 is in fluid communication with the outlet of pump 20 at its inlet end 250. The guide channel 25 extends through the buoyancy system 11 and through the bag 10, with its other end 259 protruding radially from the inside of the bag 10, as shown in FIG25 . The pump housing 21 is attached to the buoyancy system 11 by means of at least one mounting bracket 27. The pump housing 21 may optionally be provided with at least one external buoyancy body 218, as shown in Figures 1, 21 and 22. The inlet system 2 will be described in more detail below.

Buoyancy system 11 includes at least a first ring 111 and a second ring 112. Rings 111, 112 may have substantially the same diameter and be concentrically arranged. First ring 111 is arranged above second ring 112. Rings 111, 112 may be made of a polymer material such as polyethylene. Rings 111, 112 may be formed by extrusion and may have a circular cross-section. Rings 111, 112 may be made of pipe segments 115 that are joined together by welds 117 such that the longitudinal direction of first pipe segment 115' is offset from the longitudinal direction of second pipe segment 115". Polygonal rings 111, 112 are thereby formed, as shown in FIG1A. Rings 111, 112 may have 8 or 16 sides. The diameter of first pipe segment 115' may be the same as or different from the diameter of second pipe segment 115". For example, and not by way of limitation, the diameter of the pipe sections 115 ′, 115 ″ may be 400 mm to 1000 mm. The diameter may be smaller than the aforementioned values, and the diameter may also be larger than the aforementioned values.

The first and second rings 111, 112 are held together by a plurality of elongated, curved U-shaped plates 119, which are attached at either end to the wall of one of the rings 111, 112 and extend around the adjacent rings 111, 112. As shown in FIG1A , the plates 119 are attached to the second ring 112, and the plates 119 extend around the first ring 111, which is positioned at the top of the second ring 112. The plates 119 can also be attached to the upper ring of the rings 111, 112 and extend around the lower rings 111, 112 (not shown). The plates 119 can be made of a polymer material such as polyethylene, or made of metal. For example, and without limitation, the plates 119 can be 15 mm thick and 300 mm wide. The length of the plates 119 matches the diameter of the adjacent rings 111, 112.

FIG1B illustrates an alternative embodiment. Plate 119' is shown as being J-shaped. Plate 119' is attached to second ring 112, and plate 119' extends around a portion of first ring 111 that is arranged on the top of second ring 112. As shown in FIG1B , plate 119' can be attached to second ring 112 so that these plates 119' alternately face in opposite ways. In another alternative embodiment (not shown), plate 119' can be attached to first ring 111, and plate 119' extends around a portion of second ring 112 that is arranged below first ring 111.

First ring 111 and second ring 112 are loose relative to each other and are held together by plates 119, 119'. This provides buoyancy system 11 with the advantage of maintaining the flexibility of each of rings 111, 112. The present invention provides the advantage of a buoyancy system that approximates the buoyancy of bag 10. This contrasts with known buoyancy systems that consist of two or more concentric rings of different diameters, one floating side by side outside the other. The buoyancy of the outer ring contributes less to keeping bag 10 afloat than the buoyancy of the inner ring.

Railings 13 form a fence as is known in the art. Railings 13 may be composed of tubular elements of a polymer material such as polyethylene. Railings 13 are attached to upper rings 111 in a manner known per se. As is known in the art, railings 13 may support a jump net (not shown) or may be an attachment for a bird net (not shown). Fastening devices for bag 10 or for conventional seine netting may be welded to upper rings 111, 112.

In an embodiment not shown, the present invention can be combined with a third ring (not shown) having a larger diameter, located outside upper ring 111, and floating alongside upper ring 111. The third ring can also have a smaller diameter than rings 111 and 112. The third ring can be attached to upper ring 111 using various clamps known per se. This has the advantage of making walkway 15 wider and more stable, since it can rest on two rings.

Those skilled in the art will appreciate that the buoyancy system 11 may include more than two concentric rings 111, 112, wherein the concentric rings have substantially the same diameter and are disposed one above the other (one on top of the other). Those skilled in the art will also appreciate that the buoyancy system 11 is not limited to use in closed fish pens 1, but may also be used in open fish pens, which are known per se.

FIG2 shows a first exemplary embodiment of a suspension device 3 for removably attaching a bag 10 to a buoyancy system 11. Bag 10 is formed with a longitudinally thickened portion 103 or bulb at its upper edge 101. The bulb 103 can be formed in a known manner by folding the fabric 105 of the bag 10 around an elongated body 107, such as a rope or string, and attaching the fabric 105 to itself using fastening means (e.g., seams 109 or glue), or a combination of fastening means, such that the elongated body 107 is enclosed within the bulb 103, as shown in FIG3 . Along one side edge, the suspension device 3 is provided with a recess 33. Recess 33 is formed by an elongated mouth 35 located between two opposing lips 37, 37' and an elongated, substantially circular cavity 39. The diameter of cavity 39 is greater than the distance between the two opposing lips 37, 37'. The diameter of cavity 39 is slightly greater than the diameter of the bulb 103 of the bag 10. The diameter of the spherical portion 103 is greater than the distance between the lips 37, 37'. The suspension device 3 can be displaced along the spherical portion 103 in the longitudinal direction of the spherical portion 103.

The suspension device 3 is provided with a through opening 32 having a longitudinal axis 34 extending substantially perpendicularly to the longitudinal direction of the cavity 39. In the applied position, the through opening 32 is arranged above the cavity 39. An elongated fastening member 36, such as a rope, cable, line or belt, passes through the through opening 32 and is fixed to the buoyancy system 11.

The bag 10 is composed of a plurality of sectors (not shown) which are joined at their side edges by means of fastening means, for example by means of seams or by means of glue, or by means of a combination of a plurality of fastening means. The sectors are made of a fabric of a polymer material and may be provided with a further reinforcement. A suitable polymer material is polyurethane. The reinforcement may comprise a fabric reinforcement as is known in the art. The spherical portion 103 is formed before the sectors are joined at the upper edges of the sectors. The suspension device 3 is slid onto the spherical portion 103 before the sectors are joined at the upper edges of the sectors. The suspension device 3 can be displaced along the spherical portion 103 in the longitudinal direction of the spherical portion 103. The suspension device 3 is shorter than the spherical portion 103 of one sector. A plurality of suspension devices 103 can be slid onto the spherical portion 103 of one sector. This has the advantage that the suspension device 3 can be displaced laterally on the ball 103 so that the fastening member 36 can be arranged in the desired position relative to the fastening means (not shown in the figures) of the buoyancy system 11 for fastening the fastening member 36. This ensures that the bag 10 retains its stretched form without wrinkles and folds when it is attached to the buoyancy system 11.

An alternative embodiment of the suspension device 3 is shown in Figures 5 and 7. The suspension device 3 comprises a concave portion 31 and a convex portion 38. The concave portion 31 is provided with a circular, elongated hollow profile 319 on its connecting side 311. A lip 37' extends between the hollow profile 319 and the end edge 30. The concave portion 31 is also provided with at least one elongated groove 313 on its connecting side 311, which extends substantially parallel to the elongated hollow profile 319. Two grooves 313 are shown in the figures. The grooves 313 include an outer opening 315, which faces outward from the connecting side 311, and an inner cavity 317. The diameter of the cavity 317 is greater than the width of the opening 315.

The male portion 38 is provided with at least one protruding, elongated guide 383 on its connecting side 381. In the figure, the male portion 38 is shown as having two guides 383. The guides 383 include a head 387 and a neck 385. The head 387 and the neck 385 complement each other to fit the cavity 317 and the mouth 315 of the female portion 31, respectively. The length of the neck 385, as it protrudes from the connecting side 381, matches the depth and width of the mouth 315. The diameter of the head 387 is slightly smaller than the diameter of the cavity 317, as shown in the figure. The male portion 38 also has a circular, elongated hollow profile 389 on its connecting side 381. The lip 37 extends between the hollow profile 389 and the end edge 30.

When the loose male portion 38 is moved laterally relative to the loose female portion 31, the guide 383 is moved into the groove 313. The coupling side 381 of the male portion 38 faces the coupling side 311 of the female portion 31. Hollow profiles 319 and 389 together form an elongated cavity 39 having a mouth 35 located between lips 37 and 37'. The same result can be achieved by laterally moving the female portion 31 relative to the male portion 38. The head 387 of the guide 383 cannot be pulled laterally through the mouth 315 of the groove 313. This prevents the female portion 31 from separating from the male portion 38 due to the coupling side 311 and coupling side 38 being pulled apart in a direction perpendicular to these coupling sides 311 and 318.

The concave portion 31 has a through-opening 312 extending from the outer side 318 to the connecting side 311. The convex portion 38 has a through-opening 382 extending from the outer side 388 to the connecting side 381. The concave portion 31 is displaced relative to the convex portion 38 (or vice versa) until the through-opening 312 is aligned with the through-opening 382. These two through-openings 312 and 382 form the through-opening 32 in the suspension device 3. The opening 32 has a longitudinal axis 34 and extends substantially perpendicularly to the longitudinal axis of the cavity 39. In the deployed position, the through-opening 32 is positioned above the cavity 39. An elongated fastening member 36, such as a rope, cable, wire, or strap, is passed through the through-openings 312 and 382. The fastening member 36 locks the concave portion 31 and the convex portion 38, effectively preventing them from being displaced laterally relative to each other. The fastening member 36 is secured to the buoyancy system 11 .

For example, the concave portion 31 and the convex portion 38 can be made of a metal such as aluminum and formed by extruding them into rods in a manner known per se. In another embodiment, the concave portion 31 and the convex portion 38 can be made of a hard polymer material. If necessary, a piece of appropriate length is cut from the string. Subsequently, openings 312 and 382 are formed at the desired locations in the concave portion 31 and the convex portion 38, respectively, by drilling or grinding, for example.

An advantage of a two-part suspension device 3 comprising a concave portion 31 and a convex portion 38 is that it can be fitted to the ball portion 103 on the bag 10 after the bag 10 has been assembled and while the bag 10 is being filled with water, for example to enhance the attachment of the bag 10 to the buoyancy system 11. The suspension device 3 can also be removed from the bag 10 whenever required.

An alternative embodiment of a two-part suspension device 3 is shown in Figures 6 and 8. In this embodiment, the concave portion 31 is formed similarly to the previous embodiment shown in Figures 5 and 7, but without the through-opening 312. The convex portion 38 is also formed with at least one guide 383 and a hollow profile 389, which will not be described again. The convex portion 38 is formed without the through-opening 382. The convex portion 38 is provided with at least one through-hole 380, which is substantially aligned with the hollow profile 389 and extends from one end face 384 of the convex portion 38 to the opposite end face 384'. As shown in Figure 8, an opening 386 is formed between an outer side 388 of the convex portion 38 and the hole 380. A bolt 314 can be inserted through the hole 380 from one end face 384, 384' and secured to the nut 316 at the opposite end face 384, 384'. The fastening member 36 may enter the opening 386 and surround the bolt 314, and then exit the opening 386. The fastening member 36 may be secured to the buoyancy system 11. In this embodiment, the female portion 31 and the male portion 38 must be anchored to each other using one or more through screws or set screws 310 oriented perpendicular to the joining side 381 to prevent the female portion 31 and the male portion 38 from shifting laterally relative to each other.

FIG9 shows an outlet pool 4 for a fish pen 1. The outlet pool 4 can be used in an open fish pen 1 of a known type, in a closed fish pen 1 with rigid walls, or in a closed fish pen 1 with walls made of soft fabric. The outlet pool 4 is disposed in an opening in the lower portion 179 of the fish pen 1. The outlet pool 4 includes a housing 41. In the figures, the housing 41 is shown as a circular cylinder, but the housing 4 can also have other cross-sections, such as a polygonal cross-section. In the upper portion 410, the housing 41 has a flange 411 for attaching a collar 43. In the lower portion 439, the collar 43 has a flange 431 for attaching to the flange 411 of the housing 41. The flanges 411 and 431 can be fastened to each other using a plurality of bolts, as is known in the art. As shown in FIG. 14 , the housing 41 is provided with a through opening 413 in the lower portion 419 , and the opening 413 leads to a first pipe seat 415 that radially protrudes from the outer jacket of the housing 41 .

At the upper portion 430, the mounting collar 43 is provided with an attachment ring 433. The attachment ring 433 protrudes radially from the mounting collar 43 in a circumferential manner. The attachment ring 433 is configured to be attached to an open fish pen 1, a closed fish pen 1 with rigid walls, or a closed fish pen 1 with walls of a soft material in the form of fabric. Those skilled in the art will know how to attach, so this will not be described further.

The housing 41 houses a through-type outlet passage 45. As shown in Figure 12, the outlet passage 45 is provided with an inlet portion 451 at its upper portion 450. A filter 453 is attached to the inlet portion 451, thereby covering the cross-section of the outlet passage 45. The filter 453 shown is a cone with an apex protruding upward. The filter 453 is provided with a plurality of through holes 454. The outlet passage 45 opens at its lower portion 459. The lower portion 459 is formed with a recess 455. The outlet passage 45 is shown as a circular cylinder, but the outlet passage 45 may also have other cross-sections, such as a polygonal cross-section. The housing 41 and the outlet passage 45 form an annular space 46 between them.

An inclined grid 47 is disposed in the annular space 46. The grid 47 is attached to the inner jacket of the housing 41 and to the outer jacket of the outlet passage 45. The grid 47 remains fixed to the outlet passage 45 of the housing 41. The grid 47 shown includes ribs 471 oriented side by side, wherein water and sludge can pass between a plurality of ribs 471. In an alternative embodiment, the grid 471 may include a screen plate 47 having the number of holes and the diameter of the holes adapted to the target (not shown). As shown in FIG14 , the lowermost portion 479 of the grid 47 is attached to the inner jacket of the housing 41 and slightly below the through-opening 413. The uppermost portion 470 of the grid 47 is disposed on opposite sides of the diameter in the annular space 46. The grid 47 covers the entire annular space 46.

An inclined bottom plate 49 is disposed in the annular space 46, below the grille 47, and seals the annular space 46 against the housing 41 and the outlet passage 45. The bottom plate 49 secures the outlet passage 45 to the housing 41. The bottom plate 49 can be made of a solid plate or a fine-porous material. As shown, the bottom plate 49 can be oriented substantially parallel to the grille 47. This is not critical to the present invention, as the bottom plate 49 can be tilted in a direction different from that of the grille 47. As shown in Figures 12 and 14, a through-opening 493 is formed in the lowermost portion 499 of the bottom plate 49 on the inner jacket surface of the housing 41. The opening 493 leads to a second pipe socket 495 located on the bottom side of the bottom plate 49. In an alternative embodiment (not shown), the opening 493 can be disposed in the housing 41, with the lowermost portion 499 of the bottom plate 49 attached to the inner jacket of the housing 41 and slightly below the through-opening 493. The opening 493 leads to a second tube seat 495 which, in this alternative exemplary embodiment, projects radially from the outer jacket of the housing 41 .

As shown in Figure 13, the first outlet hose 91 is sealingly attached to the first pipe socket 415 at its lower end 919. The outlet hose 91 extends upward at its upper end (not shown) to a first suction pump (not shown) located on the ground (water surface). The first suction pump is configured to draw water through the outlet hose 91. The second outlet hose 99 is sealingly attached to the second pipe socket 495 at its lower end 999. The outlet hose 99 extends upward at its upper end (not shown) to a second suction pump (not shown) located on the ground (water surface). The second suction pump is configured to draw water through the outlet hose 99. The first and second suction pumps can be composed of the same pump. Those skilled in the art will appreciate that the first suction pump can be replaced with a so-called gas lift pump, which operates by blowing air into the lower portion of the outlet hose 91 to create a gas lift effect within the outlet hose 91. Accordingly, the second suction pump can also be replaced with a gas lift pump.

Because overpressure builds up inside the closed fish pen 1 when water is pumped into it, the water will flow out through the accessible opening. An outlet sump 4 is provided in this opening, located in the lower portion 179 of the fish pen. The outlet passage 45 is formed so that water can freely flow out of the fish pen 1 through it. A filter 453 prevents fish in the fish pen 1 from swimming out through the outlet passage 45. The filter 453 is provided with a large number of holes 454 to allow a large amount of water to flow through the outlet passage 45.

Dead fish (not shown) sink toward the lower portion 179 of the fish pen 1 and further toward the sloping bottom 172 of the fish pen. The water flow carries the dead fish toward the outlet tank 4. The fish are rejected by the conical filter 453 and sink into the annular space 46. Fish that sink directly into the fish pen 1 will strike the filter 453 and be directed into the annular space 46. In the annular space 46, the fish will rest on the inclined grate 47. Fish may also slide on the grate 47 toward the opening 413 in the housing 41 due to their own weight. Whenever needed, the first pump can be activated on the ground (water surface). Water is drawn up through the outlet hose 91. As a result, the water in the annular space 46 is drawn downward and out through the opening 413. Fish resting on the grate 47 will be carried away by the water flowing out of the opening 413 and through the first outlet hose 91 to the pump, where they are separated from the water flow in the filter container and disposed of in a known manner for dead fish.

Sludge, feces, and other particles that settle toward the sloping bottom 172 of the fish pen 1 will further descend toward the lower portion 179 of the fish pen and into the annular space 46. If necessary, a second pump is activated at the ground (water surface). Water is drawn in through the outlet hose 99. The water in the annular space 46 is thus drawn downward, passing through the ribs 471 in the grate 47 or the holes in the screen 47, and out through the opening 493. Sludge and small particles are carried along in the water flow, out through the opening 493, and through the second outlet hose 99 to the pump, where the sludge, feces, and particles are separated from the water flow and processed in a manner known for treating these materials.

Over time, particles will settle on filter 453, and filter 453 may become fouled by marine organisms (not shown). Consequently, aperture 454 will become less effective as an opening for water to pass through. The reduced water flow will cause the height difference between the water surface 17' inside fish pen 1 and the water surface 17 outside fish pen 1 to increase. This results in an increased load on bag 10 and buoyancy system 11 of fish pen 1. Filter 453 may be provided with a brushing system (not shown) for cleaning filter 453. Such a brushing system may be manually operated or may be provided with a motor or actuator for operation.

The alternative embodiment of outlet pool 4 ' is shown in Figure 34. Filter 453 ' is attached to inlet portion 451, thereby covers the cross section of outlet channel 45. Filter 453 ' comprises relatively flat top plate 456. Between the outer edge of top plate 456 and the edge of outlet channel 45, a plurality of ribs 457 extend side by side. Be formed with elongated opening 454 ' between rib 457, these elongated openings constitute filter slot 454 '. The advantage of this design is that effective filtration area is not limited by the cross section of outlet channel 45, but is limited by the height of filter 453 '. This height can be formed very large. Another advantage is that filter slot 454 ' can not be so easily clogged by particles, and the needs of cleaning filter 453 ' are reduced. Rib 457 can be made up of a plurality of pipes.

FIG35 shows a self-adjusting filter regulator 48. Filter regulator 48 includes a regulator sleeve 480 and a control mechanism. Regulator sleeve 480 is positioned outside of filter 453′, shown in FIG34 . Regulator sleeve 480 is displaceable relative to filter 453′. Filter regulator 488 may include an open-ended regulator sleeve 480, or it may be topped with a cover or sealing plate (not shown). Regulator sleeve 480 is attached to a line or rope 481. FIG35 shows line 481 attached to the upper portion of regulator sleeve 480. Line 481 extends upward to and over a first pulley 482′ located in the middle of fish pen 1, maintaining a substantially vertical orientation. From first pulley 482′, line 481 extends to and over a second pulley 482″. Second pulley 482″ is located at a side edge of fish pen 1. From second pulley 482", line 481 extends downward to and over third pulley 482'". Third pulley 482'" is located at the underwater side edge of fish pen 1. From third pulley 482'", line 481 extends to buoy 483 located on water surface 17' within fish pen 1. First pulley 482' is housed in a trolley 485, which is attached to a plurality of lines 484 secured to separate floating bodies 11' and extending to the middle of fish pen 1. Fish pen 1 may be provided with three or more lines 484, for example, six lines 484, which are attached to one another in the middle of fish pen 1. For example, lines 484 may meet at a distance of 0.5 to 1.0 meters above water surface 17'. For example, the third pulley 482'" may be disposed at a depth of 0.5 to 1.0 meters below the water surface 17'.

If the water level inside fish pen 1 increases due to a decrease in the filtration area of filter 453', buoy 483 will rise slightly. Exit sump 4 in lower portion 179 of fish pen 1 will sink because the increased weight of the water inside fish pen 1 lowers buoyancy system 11, thereby attaching bag 10 to it. Since buoy 483 rises slightly in the opposite direction of the sinking of exit sump 4, while lines 484 are secured to their separate floating bodies 11', buoy 483 exerts tension on lines 481 and moves regulator sleeve 480 upward relative to filter 453'. Consequently, the filtration area of filter 453' increases, and the water flow through exit sump 4 increases. In this situation, the amount of water inside fish pen 1 decreases, and buoy 483 exerts less tension on regulator sleeve 480, causing it to shift downward relative to filter 453'. Consequently, filter regulator 48 will self-regulate.

An alternative filter regulator 48' is shown in FIG36 . Filter regulator 48' includes a regulator sleeve 480, which is positioned outside of filter 453' shown in FIG34 . Filter regulator 48' can include an open-ended regulator sleeve 480, or it can be topped with a cover or sealing plate (not shown). Regulator sleeve 480 is attached to a line or rope 481 at its upper end. Line 481 extends upward to and over a first pulley 482' located in the middle of fish pen 1, aligning line 481 substantially vertically. From first pulley 482', line 481 extends to a first capstan 486'. First capstan 486' can be attached to railing 13 of the fish pen. A second winch 486" is attached to a diagonally opposite side of the fish pen 1, for example to railing 13 of the fish pen 1. A center line 487 is attached to the block 485 at one end and to the second winch 486" at the opposite end.

The second capstan 486" adjusts the free length of the center line 487 so that the pulley 485 is located above the outlet pool 4 located in the middle of the fish pen 1. The first capstan 486' controls the free length of the line 481 and, therefore, controls the position of the regulator sleeve 480 relative to the filter 453'. The water flow out of the outlet pool 4 is effectively regulated by the first capstan 486'. By shortening the free length of the line 481, the flow rate (water flow) can be increased, causing the regulator sleeve 480 to move upward along the filter 453' and increase the effective filtration area. By extending the free end of the line 481, the water flow can be reduced, causing the regulator sleeve 480 to move downward along the filter 453' and reduce the effective filtration area.

In the event of a loss of electrical power, the first capstan 486', or both the first capstan 486' and the second capstan 486", are arranged to release the lines 481, 487. The regulator sleeve 480 will thus be displaced all the way down the filter 453', and the flow of water through the outlet tank 4 will effectively stop. This has the advantage that a loss of electrical power will cause the pump 20 to stop supplying water to the fish pen 1 without causing water to flow out of the fish pen 1, and the fish pen 1 will retain its shape. An alternative filter regulator 48" is shown in FIG. 37. The filter regulator 48" comprises a regulator sleeve 480 disposed outside the filter 453' shown in FIG. 34. In this alternative embodiment, the regulator sleeve 480 is displaced relative to the filter 453' by a control mechanism comprising an actuator 488. The filter regulator 48" may comprise an open regulator sleeve 480, or the regulator sleeve 480 may be provided with a cover or sealing plate (not shown) on top. Actuator 488 can be a flexible tube or a flexible solid rod. Actuator 488 moves inside guide tube 489. Actuator 488 and guide tube 489 can form a tube-in-tube connection. Actuator 488 is attached to regulator sleeve 480. Actuator 488 and guide tube 489 extend from outlet channel 45 of outlet tank 4 to and above water surface 17 outside fish pen 1. Actuator 488 extends through outlet channel 45 and filter 453', protruding above filter 453' through an opening (not shown) in filter top plate 456. Guide tube 489 is shown attached to lower attachment 489' and upper attachment 489". Attachments 489' and 489" are fixed to the interior of outlet channel 45. Actuator 488 protrudes above upper attachment 489" outside guide tube 489.

The actuator 488 can be manually operated, for example, from the buoyancy system 11 of the fish pen 1. The actuator can also be operated by a motor, such as an electric motor (not shown), which is arranged to displace the actuator 488 relative to the guide tube 489. The motor operation can be arranged in such a way that when the electrical power is lost, the adjustment sleeve 480 will sink to the filter 453' by its own weight.

The regulator sleeve 480 described in the embodiment may be provided with a buoyancy tool (not shown in the figure) so that the regulator sleeve 480 has a very small negative buoyancy, for example, a buoyancy of -10 kg or -20 kg.

Figures 15-19 illustrate an enclosed fish pen 1, wherein the upper portion 170 of the fish pen is spherical and the lower portion 179 of the fish pen 1 is conical. In the figures, the depth of the fish pen 1 is indicated by arrow D. The depth D of the fish pen 1 extends from the water surface 17 to the outlet of the fish pen 1 in the conical lower portion 179. The depth Ds of the spherical upper portion 170 extends from the water surface 17 to the transition between the spherical upper portion 170 and the conical lower portion 179. The depth Dc of the conical lower portion 179 extends from the transition between the spherical upper portion 170 and the conical lower portion 179 to the outlet of the pool in the conical lower portion 179. This advantageously combines the properties of a spherical fish pen with those of a conical seine. Thus, the fish pen 1 combines the advantages of good seawater handling with a large volume. The fish pen 1 also has the advantage that the sloping bottom 172 of the fish pen 1 has a greater slope than the bottom of a spherical fish pen of the same diameter. Therefore, sludge and sediment will be more easily transported to the outlet of the fish pen 1.

In one embodiment, as shown in Figures 15-16 , the length of the imaginary radius r of the spherical upper portion 170 can be substantially the same as the depth D of the fish pen 1. In another embodiment, as shown in Figures 17-19 , the length of the imaginary radius r of the spherical upper portion 170 can be shorter than the depth D of the fish pen 1. Advantageously, the conical lower portion 179 of the fish pen 1, as shown in Figures 17-19 , connects tangentially to the spherical upper portion 170. This provides a smooth transition between the upper portion 170 and the lower portion 179 of the fish pen 1.

In one embodiment, as shown in Figures 15 and 17 , the conical lower portion 179 of the fish pen 1 can have a depth Dc that substantially constitutes half of the depth D of the fish pen 1. In an alternative embodiment, as shown in Figures 16 and 18 , the conical lower portion 179 of the fish pen 1 can have a depth Dc that substantially constitutes one-quarter of the depth D of the fish pen 1. In another alternative embodiment, as shown in Figure 19 , the conical lower portion 179 of the fish pen 1 can have a depth Dc that substantially constitutes 3/8 of the depth D of the fish pen 1. In other embodiments, the conical portion 179 can have a depth Dc that constitutes between one-quarter and one-half of the depth D of the fish pen.

FIG20 schematically illustrates a protective net 5 for an enclosed fish pen 1, the walls of which comprise a soft fabric material. The protective net 5 comprises a plurality of straps 51, which, when deployed, are arranged substantially horizontally and side by side. Each horizontal strap 51 forms a horizontal loop 53. The diameter of the loop 53 decreases from the upper portion 50 of the protective net 5 to the lower portion 59 of the protective net 5. A plurality of vertical straps 55, 56 extend from at least one loop 53 to an adjacent loop 53, with each vertical strap 55, 56 being secured to each of these loops. The straps 53, 55, 56 may be secured to one another by seams. Some vertical straps 55 extend continuously from the upper portion 50 to the lower portion 59 of the protective net 5. Other vertical straps 56 extend only over a portion of the protective net 5. For illustration purposes, the vertical straps 55, 56 are shown only along half the circumference of the protective net 5.

The straps 53, 55, and 56 of the protection net 5 can be made of wide strips. A lifting strap, known per se, is suitable for this purpose. The protection net 5 is provided with a fastening means, known per se, on its lower portion 59 for attaching it to the exit system of the fish pen 1. The exit system may include an exit pool 4, to which the vertical straps 55 can be attached, respectively, to the mounting collars 43. The protection net 5 is provided with a fastening means, known per se, on its upper portion 50 for adjustable attachment of the protection net 5 to the buoyancy system 11 of the fish pen 1. The protection net 5 can be tightened or loosened vertically relative to the buoyancy system 11.

The protective net 5 is joined together in such a way that the lengths of the horizontal straps 51 and the vertical straps 55, 56 match the outer geometry of the closed fish pen 1 when the fish pen is filled with water. The outer geometry of the closed fish pen 1 may consist of a spherical upper portion 170 and a conical lower portion 179. The protective net 5 is positioned outside the closed fish pen 1. The protective net 5 stabilizes the shape of the closed fish pen 1, where the walls comprise a soft material in the form of fabric. The protective net 5 also provides relief to the fabric 105 of the closed fish pen 1, allowing it to withstand greater forces before tearing.

As shown in FIG22 , the inlet system 2 of the fish pen 1 includes a pump 20. The pump 20 is disposed within a pump housing 21. The inlet end 250 of the guide channel 25 is in fluid communication with the outlet of the pump 20. As shown in FIG25 , the guide channel 25 extends through the buoyancy system 11, through the fabric 105 of the bag 10, and radially protrudes from the inside of the bag 10 at its opposite inner end 259. The guide channel 25 extends through the fabric 105 in a fluid-tight manner. Referring to FIG25 , this is achieved by an opening 106 in the fabric 105, which is provided with a collar (not shown) on the outside of the fabric 105. The guide channel 25 extends through the collar. As is known in the art, a hose clamp can be used to seal the collar against the guide channel 25. The advantage of a fluid-tight opening of the guide channel 25 in the fabric 105 is that surface water (which may contain pathogenic organisms) cannot enter the fish pen 1 through the opening 106.

The inner end 259 of the guide channel 25 is formed as a seat 258. The T-shaped tube 26 is arranged in the seat 258 by means of its tubular legs 260. The seat 258 and the legs 260 are provided with a means known per se that prevents the T-shaped tube 26 from rotating in the seat 258 about its longitudinal axis. Such means may include, for example, welding, locking bolts or lugs and corresponding grooves. As shown in FIG23A , the T-shaped tube 26 is provided with a tubular head 269. The longitudinal axis of the head 269 is perpendicular to the longitudinal axis of the legs 260. The head 269 forms a sleeve 269. In one side wall, the sleeve 269 is provided with an inlet (not shown in the figure) that complementarily fits the tubular legs 260. The sleeve 269 is welded to the legs 260 in a fluid-tight manner.

The elongated flow generating tube 6 extends into and through the sleeve 269 by means of its upper end 60. The flow generating tube 6 can rotate about its longitudinal axis in the sleeve 269. The flow generating tube is provided with an upper stop ring 61 and a lower stop ring 63 on its outer jacket. In the applied position, the upper stop ring 61 is arranged above the sleeve 269. In the applied position, the lower stop ring 63 is arranged below the sleeve 269. The function of the stop rings 61 and 63 is to prevent the flow generating tube 6 from being vertically displaced upward or downward in the sleeve 269.

The surge generating tube 6 is provided with a plurality of openings 65, and these openings are arranged in one or more rows of holes 67 on the surface of the surge generating tube 6. At least one row of holes 67 is oriented to be along the longitudinal direction of the surge generating tube 6. Fluid can flow out from the inner passage of the surge generating tube 6 through the openings 65. The upper end 60 of the surge generating tube 6 is provided with a sealing cap 62. As shown in Figure 23, the upper end 60 of the surge generating tube 6 is also provided with an operating tool 64. The operating tool 64 can be operated manually or by means of an actuator (not shown) of a known type. The operation of the operating tool 64 causes the surge generating tube 6 to rotate around its longitudinal axis. In a portion of the tube wall between the upper stop ring 61 and the lower stop ring 63, the surge generating tube 6 is provided with a through-type elliptical opening 68. The height of the opening 68 corresponds to the diameter of the inner passage of the leg 260 and the entrance of the sleeve 269. Opening 68 is longer than it is tall, so that when the surge tube 6 is rotated using operating tool 64, opening 68 does not obstruct fluid flow through the T-piece 26. Sleeve 269 and surge tube 6 are provided with a known tool (not shown) that reduces the degree of freedom of rotation of surge tube 6 so that a portion of the opening in surge tube 6 always corresponds to the inlet of sleeve 269. Flow tube 6 can be rotated into a position that facilitates water circulation within the fish pen 1. Water circulation depends on, among other factors, the amount of water flowing through inlet system 2, the water pressure, the diameter and volume of the fish pen 1, the rate of water flowing out of the surge tube 6, and the size and position of opening 65. As shown in Figures 24 and 25, the fish pen 1 can be provided with more than one inlet system 2.

The T-tube 26 is optionally provided with at least one inner float 283. The surge generating tube 6 is hung on the T-tube 26 and the guide channel 25 without any support from the bag 10 of the fish pen 1. The float 283 counteracts the deflection force on the T-tube 26 and the guide channel 25.

The opening 65 can be formed into a circular, oval or elongated slot shape. A row of holes 67 can extend from the lower end 69 of the surge generating tube 6 to the lower stop ring 63. In the illustrated embodiment, a row of holes 67 extends over the upper stop ring 61 from the lower end 69 of the surge generating tube 6. The sleeve 269 is provided with a slot 265 diametrically opposite to the inlet, and the opening 65 between the stop ring 61 and the stop ring 63 leads to these slots. In the part between the opening 68 and the upper stop ring 61 and the part between the opening 68 and the lower stop ring 63, the surge generating tube 6 is provided with a sealing element, which is, for example, an O-ring, which seals the annular space between the surge generating tube 6 and the sleeve 269. The surge generating tube 6 is provided with a sealing cover (not shown) at its bottom 69 so that water can only leave the surge generating tube 6 through the opening 65.

FIG26 shows an alternative surge generating tube 6'. The surge generating tube 6' is attached to the guide channel 25 at its upper portion 60', allowing water to flow through the guide channel 25 and into the surge generating tube 6' through openings 68'. The surge generating tube 6' is provided with a plurality of openings 65' in a row of holes 67' located on the surface of the surge generating tube 6'. The length of the openings 65' along the circumference of the surge generating tube 6' can be equal to or greater than the width of the openings 65' along the longitudinal direction of the surge generating tube 6'. The openings 65' can be rectangular, as shown in FIG26.

In one embodiment, as shown in Figure 27, the surge generating tube 6' may be provided with a damping member 600. The damping member 600 includes a first side plate 611 and a second side plate 613. The side plates 611 and 613 extend longitudinally along the surge generating tube 6'. The distance between the opposing edges of the side plates 611 and 613 (edge 621 and edge 623, respectively) is shown as being less than the width of the opening 65', but this distance may also be the same as or greater than the width of the opening 65'. A transverse plate 615 located between the side plates 611 and 613 maintains the distance between the side plates 611 and 613. The transverse plate 615 is provided with a through opening 631. The opening 631 is longitudinally along the circumference of the surge generating tube 6'. Screws 633 can pass through the opening 631 and be secured within screw holes 635 in the surface of the surge generating tube 6'. The surge generating tube 6' is provided with stoppers 637 on its outer surface, on both sides of a row of holes 67'. With the aid of an operating tool (not shown), the damping member 600 can be rotated from side to side about the longitudinal axis 699 of the surge generating tube 6' until the outer edge 618 of the side plate 611 or the outer edge 619 of the side plate 613 strikes the stop 637, 637'. This is shown in FIG. 28 . The screw 633 in the opening 631 also limits the rotational movement of the damping member 600. As shown in FIG. 27 and FIG. 28 , the damping member 600 can be positioned outside the surge generating tube 6'. In an alternative embodiment, as shown in FIG. 29 , the damping member 600 can be positioned inside the surge generating tube 6'.

A replaceable damping member 600' is shown in Figure 30A. The damping member 600' includes a first side panel 611' and a second side panel 613'. The side panels 611' and 613' extend longitudinally along the flow generating tube 6'. The distance between the opposing edges of the side panels 611' and 613' (edge 621' and edge 623', respectively) is shown as being less than the width of the opening 65', but this distance may also be the same as or greater than the width of the opening 65'. An abdominal band 616 located between the side panels 611 and 613 maintains the distance between the side panels 611 and 613. These abdominal bands 616 extend around the circumference of the flow generating tube 6'. The number of abdominal bands 616 matches the number of openings 65' in the flow generating tube 6'. With the aid of an operating tool (not shown), the damping member 600' can be rotated from side to side about the longitudinal axis 699 of the flow generating tube 6' until the outer edge 618' of the side plate 611' or the outer edge 619' of the side plate 613' strikes the stoppers 637, 637'. With the aid of a second operating tool (not shown), the damping member 600' can be moved axially in a first direction along the longitudinal axis of the flow generating tube 6', such that a portion of the belly band 616 covers a portion of the opening 65'. The damping member 600' can be displaced in a second direction along the longitudinal axis of the flow generating tube 6', such that when the damping member 600' is in the open position, the entire belly band 616 is positioned above or below the opening 65'. The width of the belly band 616 can be such that when the damping member 600' is in the closed position, the belly band 616 covers the entire opening 65'. Some of the belly band 616 can be replaced by transverse plates 615' (not shown).

An alternative damping member 600" is shown in Figure 30C. The damping member 600" is provided with a support plate 617. The support plate 617 extends longitudinally along the surge generating tube 6' and is connected to the abdominal band 616. In the applied position, when the damping member 600' surrounds the surge generating tube 6', the support plate 617 will be on the diametrically opposite side of the surge generating tube 6' relative to the row of holes 67'.

Another alternative damping member 650 is shown in Figure 31. Damping member 650 includes a plate 651 that can be displaced longitudinally along the surge generating tube 6' using a first operating tool 660. Plate 651 can be displaced in a guide 653 located outside the surge generating tube 6'. The longitudinal movement of plate 651 is limited by a stop 654 and an operating tool 660. Plate 651 is provided with a plurality of openings 655, the shape and number of which are consistent with openings 65'. Openings 655 can be slightly larger than openings 65', but openings 655 can also be the same size as or slightly smaller than openings 65'. In one embodiment, damping member 650 is provided with two rows of rudders 670, so that there is a rudder 670 on either side of each opening 665. Each rudder 670 is attached to plate 651 by a hinge 656. The rudders 670 in one rudder row 671 are connected at their free ends to rods 673 in such a way that the rudders 670 in one rudder row 671 have the same angle relative to the surface of the flow generating tube 6'. The rods 673 in the first rudder row 671 and the rods 673' in the second rudder row 671' are connected by tie rods 674, allowing the rudders 670 in the first rudder row 671 and the rudders 670 in the second rudder row 671' to move together. These rudder rows 671 and 671' are moved using a second operating tool 680. The first operating tool 660 is shown as a tube-in-tube connection. The outer tube 661 is fixed, but the inner tube or replaceable solid flexible rod 663 is movable within the outer tube 661. The outer tube 661 is secured to the flow generating tube 6' using brackets 665. The inner tube 663 is connected to the upper portion 659 of the plate 651. The inner tube 663 can move the plate 651 axially upward and downward along the surface of the flow generating tube 6'. The second operating tool 680 is shown as a tube-in-tube connection. The outer tube 681 is fixed, but the inner tube or replaceable solid flexible rod 683 can be displaced within the outer tube 681. The outer tube 681 is fixed to the surge generating tube 6' using a bracket 685. The inner tube 683 is connected to one of the multiple tie rods 674. The inner tube 681 can laterally displace the tie rod 674 to both sides relative to the opening 65'. As a result, both rudder rows 671 and 671' can rotate relative to the opening 65'. The replaceable damping member 650' is shown in Figure 32. In this replaceable embodiment, the damping member 650' includes a rudder row 671". The rudder row 671" is centrally arranged above the opening 655. The inner tube 683 is attached to the rod 673.

The operating tools 660, 680 may be composed of other types of actuators, such as electric actuators, pneumatic actuators, or hydraulic actuators as are known in the art.

When the damping member 600 shown in FIG27 is rotated as shown in FIG28 or FIG29 , one of the side plates 611 or 613 will cover a portion of the opening 65'. The direction of water flowing out of the gushing flow generating tube 6' is determined by the position of the side plates 611 or 613. When a portion of the opening 65' is covered by one of the side plates 611 or 613, the flow rate of the water flowing out of the gushing flow generating tube 6' increases. Therefore, the damping member can be used to control the direction of water flow.

When damping member 600' shown in Figure 30 is rotated, the same operation as described above for damping member 600 occurs. When damping member 600' is displaced along the longitudinal axis of the surge generating tube 6', a portion of the belly band 616 is displaced above the opening 65', and the flow rate of water exiting the surge generating tube 6' increases. Therefore, using damping member 600', it is possible to independently control the flow direction and flow rate of water. Similarly, the same effect can be achieved using replaceable damping members 650, 650'. Damping members 650, 650' are displaced longitudinally along the surge generating tube 6', causing opening 655 in plate 651 to shift relative to opening 65'. A portion of opening 65' is thus covered by plate 651. Rudders 670 control the direction of water flow. Placing each rudder 670 centrally above each opening 655 has proven advantageous. This reduces the number of rudders, and at the same time the rudder 670 is subjected to smaller forces than the rudder 670 provided on one side of the opening 655 .

In one embodiment, the pump housing 21 may be provided with a damper 24. As shown in FIG33 , the damper 24 is positioned between the outlet of the pump 20 and the inlet end 250 of the guide channel 25. The damper 24 is formed as a check valve having two flaps 241, 241'. The flaps 241, 241' are connected to a hinge 243 that extends diagonally across the interior of the pump housing 21. As shown in FIG33B , when the pump 20 displaces water upward through the pump housing into the inlet end 250 of the guide channel 25, the flaps 241, 241' face upward. As shown in FIG33A , when the pump 20 is stopped, the flaps 241, 241' fall back into the closed position, substantially preventing water from flowing downward from the guide channel 25 into the pump housing 21, through the pump 20, and further downward into the water supply channel 23.

The upper portion 230 of the external water supply channel 23 of the inlet system 2 opens into the inlet of the pump 20. The external water supply channel may be provided with a filter 233 at its inlet portion 239. The filter 233 may comprise a filter tube 233, as is known per se. In one embodiment, the water supply channel 23 may include an adjustable-length channel 235 located in a portion between the upper portion 230 and the inlet portion 239. The adjustable-length channel 235 may comprise a channel wall made of an elastic polymer material with a spiral portion made of a rigid material disposed thereon. The rigid material may comprise a metal such as steel or a polymer such as PVC. For example, such an adjustable-length channel 235 may be effectively 1.5 meters long in a collapsed state and 22 meters long in an expanded state. A counterweight (not shown) is attached to the filter tube 233. A rope or line (not shown) is attached to the filter tube 233 and extends upward to the buoyancy system 11. The rope or line may extend outside the water supply channel 23. The rope or line may extend substantially within the water supply channel 23. An advantage of having an adjustable-length channel 235 in the water supply channel 23 is that the lateral flexibility of the channel allows the channel to deform to a certain extent in response to water flow. Another advantage of having an adjustable-length channel 235 in the water supply channel 23 is that the effective length of the adjustable-length channel 235 can be easily and quickly adjusted by either releasing a rope or line into the filter tube 233 or pulling the rope or line closer. This allows, for example, the filter tube 233 to be positioned vertically deep enough for salmon parasite larvae, preventing them from entering the fish pen 1 with the incoming water. This also allows the filter tube 233 to be positioned at a depth where the water temperature is favorable, ensuring optimal growth for the fish in the fish pen 1.

A replaceable external water supply channel 23' is shown in Figure 38. The water supply channel 23' includes a plurality of separate water supply channels 23". Four water supply channels 23". are shown in Figure 37. The number of water supply channels 23" may be three or more than four. As shown in Figure 38A, each water supply channel 23" is provided with a filter tube 233' at its inlet portion 239'. The upper portion 230' of the water supply channel 23' is connected to the pump housing 21 and is in fluid communication with the pump 20. The water supply channels 23" may be attached to each other by one or more bands (not shown in the figure) between the upper portion 230' and the inlet portion 239' of the water supply channel 23".

An advantage of a plurality of thinner water supply channels 23" over an alternative water supply channel having the same cross-section as the total cross-section of the water supply channel 23' is that water flow from the desired depth can be maintained even if one of the plurality of water supply channels 23" is damaged or one of the plurality of water supply channels (for example in the filter tube 233') is blocked. An advantage of the thinner water supply channel 23' is also that it is more flexible in the water flow, which results in less stress on the attachment to the pump housing 21. The stress on the mounting bracket 27 of the pump housing 21 will also be less. An alternative embodiment of the inlet portion 239' of the water supply channel 23' is shown in Figure 38B. In this embodiment, the filter tube 233' of each individual water supply channel 23" is replaced by a common filter chamber 231, to which the inlet portion 239' is attached. The filter chamber 231 is formed by tubes or ribs 232 standing upright side by side along the circumference, and narrow grooves 234 are formed between the tubes or ribs 232. In the applied position, the tubes 232 have a substantially vertical orientation. The filter chamber 231 is also formed by tubes or ribs 236 standing side by side, and narrow grooves 238 are formed between the tubes or ribs 236, and the tubes 236 form the bottom in the filter chamber 231.

Figures 21, 22, 24, and 25 illustrate alternative buoyancy systems 11 as described in patent publications No. 20111704 and WO2013085392. The inlet system 2 can be used with a variety of the buoyancy systems 11 shown, and is not limited to use with any of the illustrated buoyancy systems. For example, the inlet system 2 can be used with known buoyancy systems comprising side-by-side concentric rings. Figure 25 illustrates an oxygenation system 8 within the fish pen 1. The oxygenation system 8 may include a channel with holes.

Claims (7)

1. A filter regulator (48, 48', 48”) for a filter (453') in a closed fish enclosure (1), said filter (453') covering the cross-section of an outlet channel (45) in an outlet pool (4) at the bottom (179) of said fish enclosure, characterized in that said filter regulator (48, 48', 48”) comprises: - The regulator sleeve (480) is displaceably disposed outside the filter (453'); and - A control mechanism that displaces the regulator sleeve (480), wherein the control mechanism includes an actuator (488) attached to the regulator sleeve (480); The actuator (488) extends from the regulator sleeve (480), passes through the filter (453'), and reaches the water surface (17) outside the fish enclosure (1) through the outlet channel (45); The actuator (488) includes a tube or rod located within the guide tube (489); The guide tube (489) is attached to the interior of the outlet channel (45). 2. A filter regulator for a filter (453') in a closed fish enclosure (1), the filter (453') covering the cross-section of an outlet channel (45) in an outlet pool (4) at the bottom (179) of the fish enclosure, characterized in that the filter regulator (48, 48', 48") comprises: - The regulator sleeve (480) is displaceably disposed on the outside of the filter (453'); - A control mechanism that displaces the regulator sleeve (480); and A line (481) is attached to the regulator sleeve (480), the line (481) extending from the regulator sleeve (480) to the first pulley (482') and across the first pulley to the control mechanism. 3. The filter regulator according to claim 2, wherein the control mechanism includes a first winch (486'), the line (481) extends from the regulator sleeve (480) to a first pulley (482') and across the first pulley to the first winch (486'), and the first winch (486') is capable of displacing the regulator sleeve (480) by changing the tension on the line (481). 4. The filter regulator according to claim 3, wherein the filter regulator (48') further includes a second winch (486"), which is disposed on the side of the fish enclosure (1) diagonally opposite to the first winch (486'), and a centerline (487) extends from the second winch (486") to a trolley (485) that accommodates the first pulley (482'). 5. The filter regulator according to claim 2, wherein the control mechanism includes a buoy (483), the line (481) extends from the regulator sleeve (480) to a first pulley (482') and passes over the first pulley to the buoy (483), the buoy (483) is placed inside the fish enclosure (1), and the buoy (483) is capable of displacing the regulator sleeve (480) by changing the tension on the line (481). 6. The filter regulator according to claim 5, wherein the line (481) extends from the first pulley (482') to the second pulley (482"), and across the second pulley (482") to the third pulley (482"), and across the third pulley (482") to the buoy (483); the second pulley (482") is disposed at the side edge of the fish enclosure (1); the third pulley (482") is disposed underwater at the side edge of the fish enclosure (1). 7. The filter regulator according to claim 6, wherein the trolley (485) is attached to at least three ropes (484) that extend over the fish enclosure (1) and are attached to each other at the middle of the fish enclosure (1).