NO20150070A1 - A feed spreader suitable for use in a fish pen - Google Patents

Description

A FEED SPREADER SUITABLE FOR USE IN A FISH PEN

Introduction

[0001 ] The present invention relates generally to the farm ing of fish. The invention has particular application to the farming of fish spedes such as salmon in open water and so will be generally described in this context. However, the invention is considered to have wider application and so could be used in the farming of other fish and sea life species.

Background of Invention

[0002] Modern fish farming techniques include the containment of fish utilising stock containment systems (or 'pens'). Each pen can contain a huge number of fish, and so one of the challenges is to ensure that the pen is supplied with a sufficient amount of feed to maintain the health and well-being of the fish.

[0003] It is generally accepted that feed should be uniform ly supplied over the surface of each pen in order to optimize feed intake. This is difficult to achieve manually, because many tons of feed are usually required for the fish in each pen on a daily basis. Thus, the supply of feed is mechanised.

[0004] Conventional feed systems utilise feed in pellet-form, and include a pneumatic system for spreading the pellets over the surface of the water in the pen. With these conventional systems, pellets are supplied from a feed supply though a feed nozzle located centrally within the pen and mounted on a flotation device above the water surface. The pellets are expelled from the nozzle by high pressure air. The high pressure air exiting the nozzle also causes the nozzle to rotate about a generally vertical axis, thereby expelling the pellets in a circular pattern about the nozzle.

[0005] These conventional arrangements are known to function adequately in terms of providing an automated feed system, and in terms of supplying the feed in a circular pattern about the feeder. However, they have been found to be generally deficient in terms of not being able to supply the feed evenly over substantially the entire water surface of the pen. This is because the high pressure air sources utilized in these systems are unable to expel the feed pellets with sufficient force to reach the outer-lying region of many pens, particularly larger pens. This deficiency is caused by the maximum nozzle rotation speed achievable using current pneumatic systems, which, in turn, is caused by insufficient air pressure being generated within the nozzle. In other words, the applicant has found that the nozzles of conventional, pneumatically actuated feed systems can't be caused to rotate at a high enough speed to expel pellets the distance required in many applications.

[0006] It would therefore be desirable to address this deficiency noted by the applicant with regard to existing pneumatically actuated fish feed systems.

Summary of Invention

[0007] According to a broad aspect of the present invention, there is provided a feed spreader for use in a fish pen.

[0008] The spreader includes a base portion provided on a buoyant structure, and an impeller rotatably mounted to the base portion. The impeller is rotatable about an approximately vertical axis when the spreader is in an in-use orientation.

[0009] The base portion includes a fluid flow path. The fluid flow path extends between a fluid inlet and a fluid outlet. The fluid inlet is provided for receiving fluid flow from a fluid source. The fluid outlet is directed at the impeller, such that, in use, fluid exiting the fluid outlet does so with sufficient pressure to cause the impeller to rotate relative to the base portion.

[0010] The feed spreader further includes a feed nozzle håving a feed flow path extending between a nozzle inlet and a nozzle outlet. The nozzle inlet is provided for receiving feed in pelletised, granular (or other suitable) form from a feed supply. The nozzle outlet is provided for directing feed outwardly from the nozzle and into the fish pen.

[0011 ] The nozzle is connected to the impeller, such that rotation of the impeller about the approximately vertical axis causes the nozzle to rotate about the approximately vertical axis.

[0012] It is envisaged that, in use, the feed spreader would typically be located in an approximately centrally located position within a fish pen, with feed directed through the nozzle outlet and spread radially about the fish pen over the surface of the water.

[0013] In one form, the nozzle provides a feed flow path exiting the nozzle outlet extending at least slightly upwardly at angle to horizontal. The upwardly extending angle may be selected depending, at least in part of the vertical displacement of the nozzle outlet above the surface of the water during use, as well as the specific operating parameters of the spreader, including the speed of rotation of the impeller and nozzle. The greater the vertical displacement of the nozzle outlet, the smaller the angle required to horizontal of the feed exiting the nozzle outlet in order to spread feed across the surface of the fish pen. Likewise, the greater the speed of rotation of the impeller and nozzle, the smaller the angle required of the feed exiting the nozzle outlet.

[0014] So far, the spreader has been generally described in terms of håving a single fluid flow. However, a more preferred arrangement is the provision of a plurality of fluid flow paths. In such an arrangement, each fluid flow path includes a respective fluid inlet and fluid outlet, with each fluid outlet each being directed at the impeller. Preferably, the fluid outlets are at least approximately equidistantly spaced about the impeller. The provision of a plurality of fluid flow paths has been found to provide a more efficient arrangement for generating rotation of the impeller, by virtue of the fact that a smaller overall flow rate of fluid to the spreader is generally required when multiple fluid flows paths are required, when compared to a similar arrangement håving a single fluid flow path.

[0015] Any suitable number of fluid flow paths may be provided, with four håving been determined to be a suitable number. With four fluid flow paths, the four fluid outlets can be approximately equidistantly spaced about the impeller at 90°.

[0016] lf the spreader includes more than one fluid flow path then a manifold may be provided for fluidly connecting the fluid inlet of each fluid flow path to the fluid source, to thereby provide the plurality of flow flows directed at the impeller. The fluid source would typically be the body of water in which the fish pen is located.

[0017] It is envisaged that the feed supply would be located remotely from the spreader, and would be connected to nozzle inlet via a conduit. The conduit may be of any suitable form, including a pipe or hose. Feed may be caused to flow from the feed supply towards the spreader by the provision of an air flow provided along conduit. The particular air flow rate adopted may be selected to achieve the desired feed flow rate. The air flow rate may be adjustable. The feed supply may adopt any suitable form, such as a feed barge, or a container mounted on or to the fish pen structure.

[0018] In use, the fluid fed into each fluid inlet is supplied under a relatively high pressure by a high pressure fluid source. A relatively high pressure is necessary in order to rotate the impeller. It is to be appreciated that the impeller is provided with a series of blades, and the relatively high pressure water impacts the blades in order to initiate rotation of the impeller, and to cause the impeller to continue to rotate. The specific water pressure or range of water pressures utilised may be selected as required.

[0019] The relatively high pressure fluid source typically includes a water pump associated with the spreader. The pump may be located adjacent the spreader, or remotely from the spreader such as at the edge of the pen, or on the feed barge or other structure. The pump supplies high pressure water, via a conduit, to each fluid inlet.

[0020] Preferably, the water pump includes a variable speed drive for varying the flow rate of water supplied to each fluid inlet or group of inlets for, in turn, varying the speed of rotation of the impeller relative to the base portion. This is a most desirable feature, because it enables the distance that feed is expelled from the nozzle to be varied to provide a more even coverage of feed across the surface of the fish pen, than may be achievable in the absence of a variable speed drive.

[0021 ] In a preferred form, the spreader includes a controller for controlling the variable speed drive. This, in turn, enables feed to be spread within the fish pen in a controlled manner.

[0022] In use, the controller may be capable of providing a sequence of ON and OFF signals to the variable speed drive. When an ON signal is provided the speed drive causes the pump to supply a desired flow rate of water to each of the fluid inlets to cause the nozzle to rotate at a desired rotation rate. An OFF signal may then be provided, at which time the pump does not supply any water to each fluid inlet, and so the nozzle continues to rotate at a decreasing rate of rotation by virtue of its (and the impeller's) momentum. This decreasing rate of rotation results in feed being expelled from the nozzle outlet at a decreasing distance from the spreader, such that a more even coverage of feed across the surface of the fish pen may be achieved than would be possible if the nozzle was caused to rotate at a constant speed.

[0023] The timing of the ON and OFF signals may be provided by the controller to the variable speed drive in the form of a variable timing sequence.

[0024] The controller may also control the flow and flow rate of feed to the nozzle.

[0025] In one form, the spreader is integrally formed with or mounted to the buoyant structure, such that the buoyant structure forms part of the spreader. The spreader may also be fitted or retro-fitted to an existing buoyant structure.

[0026] If the spreader includes a manifold then the manifold may be internally mounted within the buoyant structure, or be an integral part of the structure.

[0027] At least a portion of the feed nozzle outlet may be radially displaced from the approximately vertical axis. If so, then the spreader may further include a counter balance mounted to the impeller. The centre of gravity of the counterbalance may be radially displaced from the approximately vertical axis and positioned generally radially opposite the portion of the feed nozzle, thereby providing a relatively balanced mass rotating about the approximately vertical axis.

Brief Description of Drawings

[0028] It will be convenient to hereinafter describe a preferred embodiment of the invention with reference to the accompanying figures. The particularity of the figures is to be understood as not limiting the preceding broad description of the invention.

[0029] Figure 1 is a side view of a feed spreader according to one embodiment of the present invention.

[0030] Figure 2 is a side view of very sim ilar to that illustrated in Figure 1.

[0031 ] Figure 3 is an exploded perspective view of a portion of the feed spreader shown in Figure 1.

[0032] Figure 4 is an underside view of a component of the feed spreader shown in Figure 1.

[0033] Figure 5 is a plan view of a component of the feed spreader shown in Figure 1.

[0034] Figure 6 is a plan view of a component of the feed spreader shown in Figure 1.

Detailed Description

[0035] Any dimensions shown in the figures are to be understood as non-limiting. They are provided merely to assist in understanding one possible embodiment of the present invention.

[0036] Referring to the figures, there is shown a feed spreader 10 for use in a fish pen (not shown). The spreader 10 is provided for spreading feed about the surface of the pen. The feed may be of any suitable form. Pelletised feed is envisaged, although other suitable feed types, such as granular feed may also be utilised with the spreader 10. The pelletised feed used with the spreader 10 may be of any suitable pellet size.

[0037] The spreader includes a base portion 12 provided on a buoyant structure. The buoyant structure is provided in the form of a buoy 14, as shown in Figures 1 and 2.

[0038] The buoy 14 may form part of the spreader 10, and so the spreader 10 may be integrally formed or otherwise permanently connected to the buoy 14. Alternatively, the spreader 10 may be mounted (for example, bolted) to the buoy 14, which allows for retro-fitting of the spreader 10 to an existing buoy 14. The spreader 10 shown in Figures 1 and 2 has been retro-fitted to an existing buoy 14.

[0039] Figures 1 and 2 don't show the spreader 10 in its centrally located, in-use, position within a fish pen and floating on the surface of the water, although this can be envisaged.

[0040] The base portion 12 includes a base plate 12a and housing 12b. The housing 12b is secured to the base plate 12a by a plurality of bolts inserted through aligned apertures 12c (in the base plate 12a) and 12d (in the housing 12b), best seen in Figures 3 and 5.

[0041 ] The spreader 10 includes four legs 15 bolted to the underside of the base plate 12a. The spreader 10 is retained in position on the buoy 14 by bolting the lower end of each leg 15 to the buoy 14.

[0042] The spreader 10 includes an impeller 16, most clearly illustrated in Figures 3 and 4. The impeller 16 is of a generally annular shape, and includes a plurality of circumferentially positioned fins (or blades) 18 mounted thereto. Each blade 18 includes an actuating surface 20, upon which high pressure water impacts in order to rotate the impeller 16 relative to the base portion 12. The impeller 16 is receivable in the circular recess 22 (seen in Figures 3 and 5) provided in the underside 24 of the housing 12b. The impeller 16 is rotatable within the recess 22 about an approximately vertical axis Y-Y when the spreader 10 is in its in-use orientation. The in-use orientation is as shown in Figures 1 and 2.

[0043] It is to be noted that the impeller 16 is shown from the underside in Figure 4, whereas the housing 12b shown in Figure 5 is a plan view.

[0044] A disk 23 is also provided (shown in Figures 3 and 6), which is bolted to the impeller 16 and received (with the impeller 16) in the recess 22.

[0045] The housing 12b includes four fluid flow paths 26 (shown in Figure 5) equidistantly spaced about the recess 22. Each of the fluid flow paths 22 extends between a fluid inlet 28 and a fluid outlet 30. The fluid inlet 28 is provided for receiving high pressure fluid flow from a fluid source. The fluid outlets 30 are orientated such that the exiting fluid is directed at the actuating surfaces 20 of the impeller blades 18. When fluid (ie. water) is supplied at sufficient pressure it causes the impeller 16 and disk 23 to rotate within the recess 22. Some of the fluid entering the fluid flow paths 26 exits through the outlets 30. The remaining fluid exits the flow paths 26 through secondary outlets 32.

[0046] The feed spreader 10 also includes a feed nozzle 34. The feed nozzle 34 has a feed flow path extending between a nozzle inlet 36 and a nozzle outlet 38. The nozzle inlet 36 is provided for receiving feed from a feed supply via an infeed port 40 connected to the nozzle inlet 36. The nozzle outlet 38 is provided for directing feed outwardly from the nozzle 34 and into the fish pen.

[0047] The nozzle inlet 36 is connected about the central aperture 41 (see Figure 6) provided in the disk 23, such that rotation of the impeller 16 and disk 23 about the approximately vertical axis Y-Y causes the nozzle 34 to also rotate about the axis Y-Y at the same speed of rotation as the impeller 16 and disk 23. Figures 1 and 2 illustrate two positions of the nozzle during a 360° revolution about axis of rotation Y-Y. It can be seen that the two positions shown in Figures 1 and 2 are approximately 180° apart. The nozzle 34 rotates about axis Y-Y, but the infeed port 40 (and associated pipe inside buoy 14) remains stationary while the spreader 10 is operating. Thus, it is to be appreciated that a suitable connection must be provided between the rotating nozzle inlet 36 and the stationary pipe inside the buoy 14 associated with infeed port 40.

[0048] In use, the feed spreader 10 would typically be located in an approximately centrally located position within the fish pen, with feed directed through the nozzle outlet 38 and spread radially about the fish pen over the surface of the water.

[0049] The nozzle 34 provides a feed flow path 42 (shown in dashed lines in Figures 1 and 2) exiting the nozzle outlet 38 and extending at a slightly upward angle to the horizontal. The upwardly extending angle may be selected depending, at least in part, on the vertical displacement of the nozzle outlet 38 above the surface of the water during use, as well as the specific operating parameters of the spreader 10, including the speed of rotation of the impeller 16 and nozzle 34. The greater the vertical displacement of the nozzle outlet 38, the smaller the angle of the feed exiting the nozzle outlet 38 required in order to spread feed across the surface of the fish pen.

[0050] In Figures 1 and 2, a manifold 44 is shown. The manifold 44 is provided for fluidly connecting the fluid inlet 28 of each fluid flow path 26 to the fluid source via pipe 46. As previously indicated, the manifold 44 may be mounted or otherwise housed within the buoy 14. This would reduce the likelihood of the manifold components being damaged, and would provide a more aesthetically pleasing arrangement.

[0051] The feed supply is not shown in the figures, but would typically be located remotely from the spreader 10, such as at an edge region of the associated fish pen for ease of access by an operator. The feed is typically provided in bulk in a suitably located feed barge. The feed supply would be connected to infeed port 40 by a suitably sized pipe (not shown). Feed is caused to flow from the feed supply towards the spreader by the provision of an air flow/air pressure provided along conduit. The particular air flow rate/air pressure adopted may be selected as desired in order to achieve the desired feed rate. The air flow rate/pressure may be controllable and adjustable.

[0052] In use, the fluid (water) fed into each fluid inlet 36 would be is supplied at a sufficiently high pressure in order to rotate the impeller 16, disk 23 and nozzle 34. The water pressure necessary to rotate the impeller 16, disk 23 and nozzle 34 would typically be supplied by a water pump (not shown). The pump would be fluidly connected to the manifold 44 by the pipe 46. The specific water pressure supplied by the pump may be selected as desired, and need not be a fixed pressure. The pump may be positioned relative to the spreader 10 as desired.

[0053] The water pump includes a variable speed drive (not shown) for varying the flow rate of water flow supplied to each fluid inlet 36. The variable speed drive provides a means for readily adjusting the rotation speed of the impeller 16, disk 23 and nozzle 34. This is desirable, because it enables the distance that feed is expelled from the nozzle 34 to be varied so as to provide a more even coverage of feed across substantially the entire the surface of the fish pen (or at least a significant part of the fish pen) than would be achievable in the absence of a variable speed drive.

[0054] The spreader 10 also includes a controller (not shown) for controlling the variable speed drive. This, in turn, enables feed to be spread within the fish pen in a controlled manner. The controller may provide a means of automating the various operating parameters (such as the feed flow rate, and the water flow rate) of the spreader 10 and it may allow for the manual control of the spreader 10 operating parameters.

[0055] It is envisaged that water could be supplied to the impeller 16 in bursts, wherein the impeller 16 would reach a desired speed of rotation to supply feed through the nozzle 34 to the outer region of the pen. Once this desired speed of rotation has been reached, the pump could be temporarily switched OFF. This would cause the speed of rotation of the nozzle 34 to slowly decrease. In so doing, the distance that feed is spread reduces in a gradually decreasing radius about the spreader 10, thereby providing an effective way of spreading feed over at least a substantial portion of the water surface within the pen. This is because, when switched to OFF, the pump does not supply any water to each fluid inlet, and so the nozzle 34, impeller 16 and disk 23 continue to rotate at a decreasing rate of rotation by virtue of their combined momentum.

[0056] The speed of rotation of the nozzle 34 may be chosen to suit a specific application. The applicant has determined in an exemplary arrangement that a suitable maximum rotation speed of the nozzle 34 may be in the order of 300 to 320 revolutions per minute.

[0057] The ON and OFF sequence provided by the controller may be repeated at any desired frequency so as to provide a constant or at least periodic supply of feed. The timing of the ON and OFF signals may be automated by the controller. The applicant has found that maintaining the ON position for around twenty seconds to be a suitable time period; and they have found that maintaining the OFF position for around forty seconds provides adequate coverage of feed over the water surface of the pen. The time periods may be varied to suit specific applications. The ON and OFF sequence may be maintained for a desired overall feed time, following which the spreader may be shut down until the next desired feed time is reached.

[0058] A counter weight 48 is shown. The counterweight 48 is mounted to the disk 23 and counter balances the weight of the nozzle 34 during rotation of the nozzle 34 about the axis Y-Y.

[0059] A superstructure 50 is shown. It is to be appreciated that this is provided for supporting a bird net over the pen to prevent birds eating the feed. The superstructure 50 may or may not be provided on the spreader 10.

[0060] Finally, it is to be understood that various alterations, modifications and/or additions may be introduced into the construction and arrangement of the parts previously described without departing from the spirit or ambit of this invention.

[0061 ] Future patent applications may be filed in Australia or overseas on the basis of or claiming priority from the present application. It is to be understood that the following provisional claims are provided by way of example only, and are not intended to limit the scope of what may be claimed in any such future application. Features may be added to or omitted from the provisional claims at a later date so as to further define or re-define the invention or inventions.

Claims (18)

1. A feed spreader for use in a fish pen, the spreader including: a base portion provided on a buoyant structure; an impeller rotatably mounted to the base portion, with the impeller being rotatable about an approximately vertical axis when the spreader is in an in-use orientation; the base portion including fluid flow path, the fluid flow path extending between a fluid inlet and a fluid outlet; the fluid inlet for receiving fluid flow from a fluid source, and the fluid outlet being directed at the impeller, such that, in use, fluid exiting the fluid outlet does so with sufficient pressure to cause the impeller to rotate relative to the base portion; a feed nozzle håving a feed flow path extending between a nozzle inlet and a nozzle outlet; the nozzle inlet for receiving feed from a feed supply; and the nozzle outlet provided for directing feed outwardly from the nozzle and into the fish pen; wherein the nozzle is connected to the impeller, such that rotation of the impeller about the approximately vertical axis causes the nozzle to rotate about the approximately vertical axis.

2. A feed spreader according to claim 1, wherein, in use, the feed spreader is located in an approximately centrally located position within the fish pen, and feed is directed through the nozzle outlet over the surface of the water, and spread radially about the fish pen.

3. A feed spreader according to claim 1 or 2, wherein nozzle provides a feed flow path exiting the nozzle outlet extending upwardly at angle to horizontal.

4. A feed spreader according to any one of the preceding claims, including a plurality of fluid flow paths, with each fluid flow path including a respective fluid inlet and fluid outlet, with the fluid outlets each being directed at the impeller and being at least approximately equidistantly spaced about the impeller.

5. A feed spreader according to claim 4, including four fluid flow paths.

6. A feed spreader according to claim 4 or 5, including a manifold for fluidly connecting each of the fluid flow paths to a water supply.

7. A feed spreader according to any one of the preceding claims, wherein the feed supply is located remotely from the spreader and connected to the nozzle inlet by a conduit.

8. A feed spreader according to any one of the preceding claims, wherein the fluid supplied to each fluid inlet is supplied under a relatively high pressure by a relatively high pressure fluid source.

9. A feed spreader according to claim 8, wherein the relatively high pressure fluid source includes a water pump, such that the pump supplies relatively high pressure fluid to each fluid inlet in the form of relatively high pressure water.

10. A feed spreader according to claim 9, wherein the water pump is fluidly connected to each fluid inlet.

11. A feed spreader according to claim 9 or 10, the water pump including a variable speed drive for varying the flow rate of water flow supplied to each fluid inlet for, in turn, varying the speed of rotation of the impeller relative to the base portion.

12. A feed spreader according to claim 11, the spreader including a controller for controlling the variable speed drive.

13. A feed spreader according to claim 12, wherein, in use, the controller provides a sequence of ON and OFF signals to the variable speed drive.

14. A feed spreader according to claim 13, wherein the timing of the ON and OFF signals provided by the controller to the variable speed drive is a variable timing sequence.

15. A feed spreader according to any one of the preceding claims, wherein the spreader is integrally formed with or mounted to the buoyant structure.

16. A feed spreader according to claim 6, or any one of claims 7 to 15 when directly or indirectly dependent on claim 6, wherein the manifold is internally mounted within the buoyant structure.

17. A feed spreader according to any one of the preceding claims, wherein at least a portion of the feed nozzle outlet is radially displaced from the approximately vertical axis, the spreader further including a counter balance mounted to the impeller, the centre of gravity of the counterbalance being radially displaced from the approximately vertical axis and positioned generally radially opposite the portion of the feed nozzle.

18. A feed spreader according to any one of the preceding claims, wherein the feed is provided in pelletised or granular form.