Methods for pumping fish
The method and apparatus with an upstream bypass chamber and conical diffuser control fish pump flow to prevent upstream swimming, addressing the issue of reduced flow rate damage by mixing additional water, ensuring safe and efficient fish transport.
Patent Information
- Application Number
- JP2025516193
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-09-15
- Filing Date
- 2023-09-11
- Publication Date
- 2025-12-01
AI Technical Summary
Existing fish pumps for anadromous fish, such as salmon and sturgeon, face issues when the flow rate is reduced, allowing the fish to swim back upstream and potentially causing damage to the pump or the fish.
A method and apparatus using an upstream bypass chamber to mix additional water with the fish and water flow, reducing the amount of fish pumped while maintaining a sufficient flow rate to prevent upstream swimming, utilizing a bladeless centrifugal pump with features like a conical diffuser and grating to control flow.
Prevents anadromous fish from swimming back upstream by maintaining a high enough flow rate, thus avoiding damage to the pump and fish, while allowing flexible operation based on downstream requirements.
Smart Images
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Abstract
Description
Detailed Description of the Invention
[0001] [Field] FIELD OF THE INVENTION The present invention relates to a method for pumping fish, and more particularly to a method for pumping anadromous fish. [background] In aquaculture, fish are often pumped between locations for a variety of reasons. Fish may be pumped from one location to another to transfer the fish or to harvest the fish when they are fully grown. Additionally, fish may be pumped on board to perform fish delousing operations and then pumped back into the water to continue growing. Fish are typically pumped along with the water in which they live, i.e., the pump moves a certain amount of water and the fish along with it.
[0002] Typically, while pumping fish, the fish pump will run at its normal operating speed, resulting in water flow downstream of the pump at its normal output flow rate.
[0003] If downstream operators or processes require fewer or no fish to be pumped for a period of time, the pump must operate at a slower rate or be turned off, resulting in a slower downstream water flow than the normal output flow rate.
[0004] If the fish being pumped are anadromous, i.e., fish that swim upstream, such as salmon, smelt, and sturgeon, the fish may be able to swim faster than the reduced output flow rate and swim back to the pump, which is highly undesirable as it can cause damage to the fish and / or the pump, especially when the pump speed is increased again.
[0005] Japanese Patent Publication No. JPS6181321A discloses a solid material transfer device having a rotary solid material transfer pump that uses an impeller to force a liquid and the liquid as a transport medium to transfer solid materials.
[0006] It is an object of the present invention to ameliorate or mitigate at least one of the disadvantages of the prior art, or at least to provide a useful alternative to the prior art.
[0007] This object is achieved by the features specified in the following description and in the claims that follow. [overview] According to a first aspect of the present invention, there is provided a method for reducing the amount of fish pumped by a fish pump while maintaining a sufficient flow rate so that the fish cannot swim upstream back into the pump, the method comprising: providing an apparatus for pumping fish, the apparatus comprising: a fish pump having a main communication channel for delivering water and fish therethrough, an inlet and an outlet, the fish pump being positioned on the main communication channel and configured to pump the water and fish along the main communication channel; and an upstream bypass chamber positioned on the main communication channel upstream of the fish pump inlet, the upstream bypass chamber being configured to mix the flow of water into the main communication channel in use; supplying the fish and water into the main communication channel; and operating the fish pump to pump the fish and water along the main communication channel, characterized in that by mixing the flow of water into the main communication channel in the upstream bypass chamber, the amount of fish pumped is reduced while maintaining a sufficient flow rate downstream of the fish pump so that the fish cannot swim upstream back to the fish pump outlet.
[0008] The fish pump may be a bladeless centrifugal pump.
[0009] The upstream bypass chamber may include a central fluid communication channel that matches the diameter of the main communication channel.
[0010] The central fluid communication channel may include a grating configured to define an outer boundary within the upstream bypass chamber that the fish can reach as the fish and water pass through the upstream bypass chamber, allowing water to enter the central fluid communication channel through the grating.
[0011] The spacing of the grating can be suitably sized so that in use, fish pumped through the upstream bypass chamber cannot pass through the grating, yet a sufficient amount of water can pass through the grating and into the central fluid communication channel.
[0012] The upstream bypass chamber may include a conical diffuser configured to slow the flow of water into the main communication channel.
[0013] The upstream bypass chamber may comprise an enlarged chamber configured to slow the flow of water into the main communication channel.
[0014] The bypass chamber may include a fine grid configured to reduce the velocity of the flow of water entering the bypass chamber and mixing into the main communication channel.
[0015] The main communication channel may include a first shut-off valve and a second shut-off valve configured to control the flow of water and fish within the main communication channel.
[0016] The apparatus may further comprise an auxiliary pump configured to pump water into the upstream bypass chamber.
[0017] The device may further comprise a downstream bypass chamber disposed on the main communication channel downstream of the fish pump outlet, the downstream bypass chamber configured to remove water from the main communication channel in use so that the removed water can be recirculated to the upstream bypass chamber.
[0018] The apparatus may further comprise an auxiliary pump configured to pump water from the downstream bypass chamber to the upstream bypass chamber.
[0019] According to a second aspect of the present invention, there is provided a method for reducing the amount of fish pumped by a fish pump while maintaining a sufficient flow rate to prevent the fish from swimming upstream back into the pump, the method comprising the steps of providing an apparatus for pumping fish, the apparatus comprising a fish pump having a main communication channel for passing water and fish therethrough, an inlet and an outlet, the fish pump being disposed on the main communication channel and configured to pump water and fish along the main communication channel, an upstream bypass chamber disposed on the main communication channel upstream of the fish pump inlet, the upstream bypass chamber being configured to mix the flow of water in use, and a downstream bypass chamber disposed on the main communication channel downstream of the fish pump outlet, for removing water from the main communication channel in use. providing a fish pump that pumps the fish and water along the main communication channel; and a downstream bypass chamber configured to remove fish and water from the main communication channel and recirculate the removed water into the upstream bypass chamber and the main communication channel; supplying fish and water to the main communication channel; and operating a fish pump to pump the fish and water along the main communication channel, characterized by removing water from the main communication channel at the downstream bypass chamber, communicating the removed water from the downstream bypass chamber to the upstream bypass chamber, and mixing the removed water back into the main communication channel at the upstream bypass chamber, thereby reducing the amount of fish pumped while maintaining a sufficient flow rate downstream of the fish pump so that the fish cannot swim back upstream to the fish pump outlet.
[0020] The fish pump may be a bladeless centrifugal pump.
[0021] The upstream bypass chamber may include a central fluid communication channel that matches the diameter of the main communication channel.
[0022] The central fluid communication channel may include a grating configured to define an outer boundary within the upstream bypass chamber that the fish can reach as the fish and water pass through the upstream bypass chamber, allowing water to enter the central fluid communication channel through the grating.
[0023] The spacing of the grating can be appropriately sized so that in use, fish pumped through the upstream bypass chamber cannot pass through the grating, yet a sufficient amount of water can pass through the grating and into the central fluid communication channel.
[0024] The upstream bypass chamber may include a conical diffuser configured to slow the flow of water into the main communication channel.
[0025] The upstream bypass chamber may comprise an enlarged chamber configured to slow the flow of water into the main communication channel.
[0026] The bypass chamber may include a fine grid configured to reduce the velocity of water flowing into the bypass chamber and being mixed into the main communication channel.
[0027] The main communication channel may include a first shut-off valve and a second shut-off valve configured to control the flow of water and fish within the main communication channel.
[0028] The apparatus may further comprise an auxiliary pump configured to pump water into the upstream bypass chamber.
[0029] The apparatus may further comprise an auxiliary pump configured to pump water from the downstream bypass chamber to the upstream bypass chamber. [Brief explanation of the drawings]
[0030] Next, embodiments of the present invention will be described with reference to the following drawings. [Figure 1] 1 shows a hydraulic circuit diagram of a device for pumping fish. [Figure 2] 2 shows a bypass valve used in the device of FIG. 1; [Figure 3] 1 shows a hydraulic circuit diagram of an alternative embodiment of a device for pumping fish.
[0031] For clarity, some elements may not be numbered in some figures. Those skilled in the art will understand that the figures are merely illustrative. The relative proportions of individual elements may be distorted. DETAILED DESCRIPTION OF THE INVENTION
[0032] [Detailed description of the drawings] In the following description, for the sake of brevity, not all fluid communication connections will be described in detail, and it is assumed that one skilled in the art will be able to understand the fluid connections from the drawings without further explanation.
[0033] FIG. 1 illustrates an example of an apparatus 100 for pumping anadromous fish. The apparatus 100 includes a fish pump 110 having an inlet 110A and an outlet 110B. In the currently described embodiment, the fish pump 110 is a bladeless centrifugal pump. However, it will be understood that other suitable pump designs may be used, such as, but not limited to, a Coanda pump or a paddlewheel pump. The fish pump 110 is configured to pump water and fish through a main communication channel 120. The main communication channel 120 is a series of pipes suitable for transporting fish therein. The main communication channel 120 is connected to an upstream bypass chamber 130, the purpose and structure of which will be described in more detail below.
[0034] Still referring to FIG. 1, fish and water are fed into the main communication channel 120 at the inlet 110A side of the pump, are pumped by the pump 110, and continue to flow into the main communication channel 120 at the outlet 110B side of the pump 110.
[0035] If the downstream process requires fewer fish, or if the operator decides to reduce the flow of fish through the pump 110, additional water can be supplied to the pump 110 by mixing the additional water with the fish and water in the main communication channel 120 on the inlet 110A side of the pump. This mixing occurs in the upstream bypass chamber 130.
[0036] In this regard, additional water is supplied to flow along the bypass communication channel 131 into the main communication channel 120. To enhance the flow of water along the bypass communication channel 131, water may be pumped along the bypass communication channel 131 by a suitably positioned pump (not shown in FIG. 1 ). It will be appreciated that water may be supplied without the use of a pump. For example, water may be supplied from a water reservoir that is physically higher than the bypass chamber, thereby utilizing hydrostatic pressure to mix the water into the flow in the main communication channel 120.
[0037] As currently described, when additional water is supplied to pump 110, the amount of fish pumped decreases if pump 110 is maintained at the same pumping speed. This allows the water flow velocity at outlet 110B to be maintained regardless of the amount of fish pumped.
[0038] In other words, in the above example, the pump 110 is initially filled with water and fish and set to operating speed. This results in a water flow at outlet 110B at a particular rate. If the pump 110 is slowed to reduce the amount of fish being pumped, the water flow rate at outlet 110B will decrease. If the water flow rate at the outlet decreases sufficiently, anadromous fish may be able to swim back toward the pump outlet 110B, potentially causing damage to the pump 110 and / or the fish.
[0039] However, as previously mentioned, by supplying additional water to the main communication channel 120 on the inlet 110A side of the pump 110, the amount of fish being pumped is reduced but the flow rate at the outlet 110B is maintained. This ensures that a sufficiently high flow rate at the outlet 110B can be maintained so that the fish cannot swim back to the outlet 110B.
[0040] It will be understood that the upstream bypass chamber 130 may be any suitable connection between the bypass communication channel 131 and the main communication channel 120 such that the flow of water in the bypass communication channel 131 can mix with the flow of water and fish in the main communication channel 120.
[0041] 2, further details of a preferred upstream bypass chamber 130 can be seen. As previously mentioned, the upstream bypass chamber 130 is disposed in-line over the main communication channel 120. In this regard, an inlet 130A and an outlet 130B are connected to the main communication channel 120. A central fluid communication channel 132 is provided within the upstream bypass chamber 130, which, when assembled within the main communication channel 120, provides continuity of the main communication channel 120 such that fish can enter the upstream bypass chamber 130 at the inlet 130A and exit at the outlet 130B. In this regard, the diameter of the central fluid communication channel 132 matches the diameter of the main communication channel 120. That is, the central fluid communication channel 132 and the main communication channel 120 have the same or substantially similar diameters.
[0042] The upstream bypass chamber 130 also includes a conical diffuser 133 positioned to be fluidly connected to the bypass communication channel 131. The purpose of the conical diffuser 133 is to slow the flow of water from the bypass communication channel 131 into the upstream bypass chamber 130 to prevent stress to the fish in the central fluid communication channel 132.
[0043] In this regard, it is highly desirable that the water flow from the bypass communication channel 131 smoothly mix with the water flow in the central fluid communication channel 132. To this end, the upstream bypass chamber 130 includes an enlarged chamber 134 into which the flow from the conical diffuser 133 reaches. The central fluid communication channel 132 is provided with a grid that defines an outer boundary within which the fish can reach in the central fluid communication channel 132, while allowing water to flow from the enlarged chamber 134 into the central fluid communication channel 132. It will be appreciated that the grid spacing must be small enough so that the pumped fish cannot pass through the grid. However, the grid spacing must be large enough to allow a sufficient amount of water to flow from the enlarged chamber 134 into the central fluid communication channel 132.
[0044] 2, the upstream bypass chamber 130 includes a further flow reduction feature disposed between the conical diffuser 133 and the enlarged chamber 134. The further flow reduction feature includes a fine grid 135 that further reduces the velocity of water entering the enlarged chamber 134 from the conical diffuser 133.
[0045] Figure 3 shows an alternative apparatus 1000 for pumping anadromous fish. Similar reference numbers, with the addition of an '0', are used to indicate similar objects in Figure 3 as in the embodiment shown in Figures 1 and 2. For example, pump 110 in the embodiment of Figures 1 and 2 is labeled 1100 in Figure 3.
[0046] The apparatus 1000 includes a fish pump 1100 having an inlet 1100A and an outlet 1100B. As seen in the previous embodiments, the fish pump 1100 in the currently described embodiment is a bladeless centrifugal pump. However, it will be understood that other suitable pump designs may be used, such as, but not limited to, Coanda pumps and paddlewheel pumps. The fish pump 1100 is configured to pump water and fish from a fish origin 1110 to a fish destination 1120 over a main communication channel 1200. The main communication channel 1200 is a series of pipes suitable for transporting fish therein.
[0047] 3, the main communication channel 1200 is provided with a first shut-off valve 1201 and a second shut-off valve 1202. These are provided to allow for control of the flow within the main communication channel 1200. Depending on the type of pump 1100 used in other embodiments, the first shut-off valve 1201 and the second shut-off valve 1202 may not be required. For example, a vacuum pump (push-pull) or an injector pump (Coanda type) may not require the first shut-off valve 1201 and the second shut-off valve 1202.
[0048] The main communication channel 1200 is connected to an upstream bypass chamber 1300. Fish and water are supplied to the main communication channel 1200 on the inlet 1100A side of the pump 1100 and are pumped by the pump 1100 to continue to the main communication channel 1200 on the outlet 1100B side of the pump 1100.
[0049] Additional water can be supplied to the pump 1100 by mixing it with the fish and water in the main communication channel 1200 on the inlet 1100A side of the pump. The mixing occurs upstream in the bypass chamber 1300.
[0050] Additional water is supplied and flows along bypass communication channel 1310 to main communication channel 1200 .
[0051] To enhance the flow of water along the bypass communication channel 1310, water is pumped along the bypass communication channel 1310 by an auxiliary pump 1400. Again, it will be appreciated that in some alternative embodiments, the auxiliary pump 1400 may not be necessary.
[0052] Apparatus 1000 includes a number of shut-off valves located at various locations. In this regard, in the currently described embodiment, a third shut-off valve 1203, a fourth shut-off valve 1204, a fifth shut-off valve 1205, and a sixth shut-off valve 1206 are provided. It will be appreciated that more or fewer shut-off valves may be provided in other embodiments, depending on the particular arrangement and desired functionality.
[0053] 3, the third shutoff valve 1203 and the fourth shutoff valve 1204 are provided for selecting a water source to the auxiliary pump 1400. In this regard, when the fourth shutoff valve 1204 is opened, the fourth shutoff valve 1204 provides a supply of water from the auxiliary water source A to the auxiliary pump 1400.
[0054] Alternatively, water may be supplied to the auxiliary pump 1400 from near the outlet 1100B of the fish pump 1100. In this regard, some water is sucked from the main communication channel 1200 by the pump 1400 at the downstream bypass chamber 1500. In the currently described embodiment, the downstream bypass chamber 1500 is structurally identical to the upstream bypass chamber 1300, i.e., both the upstream bypass chamber 1300 and the downstream bypass chamber 1500 are as shown in FIG. 2. However, the downstream bypass chamber 1500 is positioned within the device 1000 such that water is removed from the main communication channel 1200 at the downstream bypass chamber 1500, rather than being added to the main communication channel 1200 as with the upstream bypass chamber 1300.
[0055] In the presently described embodiment, the upstream bypass chamber 1300 and the downstream bypass chamber 1500 are structurally identical, but this is not essential; in alternative embodiments, the upstream bypass chamber 1300 may be structurally different from the downstream bypass chamber 1500.
[0056] As shown in FIG. 3 , the provision of the downstream bypass chamber 1500 allows a fluid flow loop to be formed from the outlet 1100B of the fish pump 1100 back to the inlet 1100A. When downstream operations or an operator do not require fish for a period of time, the downstream bypass chamber 1500 and the auxiliary pump 1400 can be used to circulate water back to the main communication channel 1200. In this mode of operation, the third and fifth shutoff valves 1203 and 1205 are opened, and the auxiliary pump 1400 is activated. The open third shutoff valve 1203 provides fluid communication between the downstream bypass chamber 1500 and the auxiliary pump 1400. The open fifth shutoff valve 1205 provides fluid communication between the auxiliary pump 1400 and the upstream bypass chamber 1300. Therefore, regardless of the water supply from water source A or the downstream bypass chamber 1500, the fifth shutoff valve 1205 must be open for the auxiliary pump 1400 to pump water into the upstream bypass chamber 1300.
[0057] Because the entire pumping capacity (volume) of the fish pump 1100 is consumed by pumping the recirculating water, a continuous loop of very fast flowing water from outlet 1100B to inlet 1100A results in the fish pump 1100 not taking in any fish upstream of the upstream bypass chamber 1300, i.e., from the fish origin 1110. Most importantly, during this recirculation, the water flow velocity in the main communication channel 1200 at the pump's outlet 1100B, i.e., between outlet 1100B and downstream bypass chamber 1500, is maintained high enough to prevent fish from swimming upstream toward the pump. This therefore allows the operator to stop the flow of fish through the pump while maintaining a sufficiently high water-only flow so that fish downstream of the pump cannot swim upstream and reach the pump, which could cause damage to the pump and / or fish, as discussed above.
[0058] It will be appreciated that the fluid flow loop from the outlet 1100B of the fish pump 1100 back to the inlet 1100A can also be used to simply reduce the amount of fish being pumped, rather than completely stopping the pumping of fish. The volumetric flow rate required from the auxiliary pump 1400 to stop the flow of fish into the fish pump 1100 will depend on the specifications and configuration of the fish pump 1100 and the overall apparatus 1000, i.e., pipe dimensions, etc. Similarly, the volumetric flow rate required from the auxiliary pump 1400 to reduce the amount of fish being pumped will also depend on the specifications and configuration of the fish pump 1100 and the overall apparatus 1000, i.e., pipe dimensions, etc.
[0059] 3, the sixth shut-off valve 1206 can be used to drain water from the apparatus 1000 to point B. This may be used, for example, when cleaning the apparatus 1000. Alternatively, the sixth shut-off valve 1206 may be opened to ensure an exit path for the water if there is a malfunction and water is to be drained from the apparatus 1000. Alternatively, in some examples, point B may be another water source, with the sixth shut-off valve being opened to provide fluid communication between this alternative water source and the upstream bypass valve 1300.
[0060] As previously mentioned, the downstream bypass chamber 1500 may be similar to or identical to the upstream bypass chamber 1300. In this regard, the physical features of the upstream bypass chamber 1300 are also present in the downstream bypass chamber 1500.
[0061] That is, the downstream bypass chamber 1500 also includes a conical diffuser, an enlarged chamber, and a fine grid (not shown in FIG. 3). However, because the downstream bypass chamber 1500 is operating in the opposite direction to the upstream bypass chamber 1300, i.e., because the downstream bypass chamber 1500 is removing water from the main communication channel 1200 rather than adding water to it, the purpose of the conical diffuser, enlarged chamber, and fine grid is to allow water to be removed from the main communication channel 1200 at low flow rates. The conical diffuser accelerates the flow because it narrows the flow area to the diameter of the piping through which the flow must pass in the circulation loop.
[0062] It is highly advantageous to remove water at a slow rate in the main communication channel 1200 because a high velocity water flow from the main communication channel 1200 can result in the fish being sucked towards the auxiliary pump 1400 if the fish are in the downstream bypass chamber 1500. The sucking of fish towards the auxiliary pump 1400 can, in some instances, cause blockages in the downstream bypass chamber 1500 and thus affect the performance of the device 1000. Additionally or alternatively, the sucking of fish towards the auxiliary pump 1400 in the downstream bypass chamber 1500 can cause stress to the fish, which is highly undesirable.
[0063] Terms [Section 1] 1. A method of reducing the amount of fish pumped by a fish pump while maintaining a sufficient flow rate so that the fish cannot swim upstream back into the pump, comprising: 1. A device (100, 1000) for pumping fish, the device (100, 1000) comprising: a main communication channel (120, 1200) for conveying water and fish therethrough; a fish pump (110, 1100) having an inlet (110A, 1100A) and an outlet (110B, 1100B) and positioned on said main communication channel (120, 1200) and configured to pump water and fish along said main communication channel (120, 1200); an upstream bypass chamber (130, 1300) disposed on the main communication channel (120, 1200) upstream of the fish pump inlet (110A, 1100A), the upstream bypass chamber (130, 1300) configured to mix water flow into the main communication channel (120, 1200) in use; providing an apparatus (100, 1000) comprising: supplying fish and water to the main communication channel (120, 1200); activating the fish pump (110, 1100) to pump the fish and water along the main communication channel (120, 1200); reducing the amount of fish pumped while maintaining sufficient flow downstream of the fish pump (110, 1100) so that fish cannot swim back upstream to the fish pump outlet (110B, 1100B) by mixing the water flow in the main communication channel (120, 1200) in the upstream bypass chamber (130, 1300); the upstream bypass chamber (130, 1300) comprises a conical diffuser (133) configured to slow the flow of water into the main communication channel (120, 1200); method.
[0064] [Section 2] Item 1, wherein the fish pump (110, 1100) is a bladeless centrifugal pump. [Section 3] Item 1 or 2, the method according to item 1 or 2, wherein the upstream bypass chamber (130, 1300) comprises a central fluid communication channel (132) whose diameter matches the main communication channel (120, 1200). [Section 4] Item 3. The method described in paragraph 3, wherein the central fluid communication channel (132) comprises a lattice configured to define an outer boundary within the upstream bypass chamber (130, 1300) that the fish can reach as the fish and water pass through the upstream bypass chamber (130, 1300), allowing water to flow through the lattice into the central fluid communication channel. [Section 5] Item 5. The method according to item 4, wherein the spacing of the grid is appropriately sized so that fish pumped through the upstream bypass chamber (130, 1300) in use cannot pass through the grid, and so that a sufficient amount of water can pass through the grid and enter the central fluid communication channel (132).
[0065] [Section 6] 10. The method of any preceding claim, wherein the upstream bypass chamber (130, 1300) comprises an enlarged chamber (134) configured to slow the flow of water into the main communication channel (120, 1200). [Section 7] 10. The method of claim 9, wherein the bypass chamber (130, 1300) comprises a fine grid configured to reduce the velocity of water flowing into the bypass chamber (130, 1300) and mixing into the main communication channel (120, 1200). [Section 8] 10. The method of any of the preceding claims, wherein the main communication channel (1200) comprises a first shut-off valve (1201) and a second shut-off valve (1202) configured to control the flow of water and fish within the main communication channel (1200). [Section 9] 10. The method of any preceding claim, wherein the apparatus (1000) further comprises an auxiliary pump (1400) configured to pump water into the upstream bypass chamber (1300). [Section 10] Item 10. The method according to any one of items 1 to 9, wherein the device (1000) further comprises a downstream bypass chamber (1500) disposed on the main communication channel (1200) downstream of the fish pump outlet (1100B); The downstream bypass chamber (1500) is configured to remove water from the main communication channel (1200) in use so that the removed water can be recycled to the upstream bypass chamber (1300). [Section 11] Item 11. The method according to item 10, wherein the apparatus (1000) further comprises an auxiliary pump (1400) configured to pump water from the downstream bypass chamber (1500) to the upstream bypass chamber (1300).
[0066] [Section 12] 1. A method of reducing the amount of fish pumped by a fish pump (1100) while maintaining a sufficient flow rate so that the fish cannot swim upstream back into the pump (1100), comprising: Providing a device (1000) for pumping fish, the device (1000) comprising: a main communication channel (1200) for delivering water and fish therethrough; a fish pump (1100) having an inlet (1100A) and an outlet (1100B), positioned on the main communication channel (1200) and configured to pump water and fish along the main communication channel (1200); an upstream bypass chamber (1300) disposed on the main communication channel (1200) upstream of the fish pump inlet (1100A), the upstream bypass chamber (1300) configured to mix water flows in use; a downstream bypass chamber (1500) located on the main communication channel (1200) downstream of the fish pump outlet (1100B), configured to remove water from the main communication channel (1200) in use so that the removed water can be recirculated into the upstream bypass chamber (1300) and the main communication channel (1200); providing an apparatus (1000) comprising: supplying fish and water to the main communication channel (1200); activating the fish pump (1100) to pump the fish and water along the main communication channel (1200); removing water from the main communication channel (1200) in the downstream bypass chamber (1500); communicating the water removed from the downstream bypass chamber (1500) to the upstream bypass chamber (1300); mixing the removed water back into the main communication channel (1200) in the upstream bypass chamber (1300), thereby reducing the amount of fish being pumped while maintaining sufficient flow rate on the downstream side of the fish pump (1100) so that fish cannot swim back upstream to the fish pump outlet (1100B); the upstream bypass chamber (1300) comprises a conical diffuser (133) configured to slow the flow of the water into the main communication channel (1200).
[0067] [Section 13] Item 13. The method according to item 12, wherein the fish pump (1100) is a bladeless centrifugal pump. [Section 14] Item 14. The method according to item 12 or 13, wherein the upstream bypass chamber (1300) comprises a central fluid communication channel (132) whose diameter matches the diameter of the main communication channel (1200). [Section 15] 15. A method according to any one of claims 12 to 14, wherein the central fluid communication channel (132) comprises a lattice configured to define an outer boundary within the upstream bypass chamber (1300) that the fish can reach as the fish and water pass through the upstream bypass chamber (1300), allowing water to flow through the lattice into the central fluid communication channel (132). [Section 16] 16. A method according to any one of claims 12 to 15, wherein the spacing of the grating is of an appropriate size so that fish pumped through the upstream bypass chamber (1300) in use cannot pass through the grating, but so that a sufficient amount of water can pass through the grating and enter the central fluid communication channel (132). [Section 17] 17. The method of any of claims 12 to 16, wherein the upstream bypass chamber (1300) comprises an enlarged chamber configured to slow the flow of the water into the main communication channel (1200).
[0068] [Section 18] 17. The method according to any one of claims 12 to 16, wherein the bypass chamber (1300) comprises a fine grid configured to reduce the velocity of the water flowing into the bypass chamber (1300) and mixing into the main communication channel (1200). [Section 19] 19. A method according to any one of claims 12 to 18, wherein the main communication channel (1200) comprises a first shut-off valve (1201) and a second shut-off valve (1202) configured to control the flow of water and fish within the main communication channel (1200). [Section 20] 20. The method of any of claims 12 to 19, wherein the apparatus (1000) further comprises an auxiliary pump (1400) configured to pump water into the upstream bypass chamber (1300). [Section 21] 21. The method according to any one of claims 12 to 20, wherein the apparatus (1000) further comprises an auxiliary pump (1400) configured to pump water from the downstream bypass chamber (1500) to the upstream bypass chamber (1300).
Claims
1. 1. A method of reducing the amount of fish pumped by a fish pump while maintaining a sufficient flow rate so that the fish cannot swim upstream back into the pump, comprising:
1. A device (100, 1000) for pumping fish, comprising: a main communication channel (120, 1200) for conveying water and fish therethrough; a fish pump (110, 1100) having an inlet (110A, 1100A) and an outlet (110B, 1100B) and positioned on the main communication channel (120, 1200) and configured to pump water and fish along the main communication channel (120, 1200); an upstream bypass chamber (130, 1300) disposed on the main communication channel (120, 1200) upstream of the fish pump inlet (110A, 1100A), the upstream bypass chamber (130, 1300) configured to mix water flow into the main communication channel (120, 1200) in use; providing an apparatus (100, 1000) comprising: supplying fish and water to said main communication channel (120, 1200); activating the fish pump (110, 1100) to pump the fish and water along the main communication channel (120, 1200); mixing the flow of water in the upstream bypass chamber (130, 1300) within the main communication channel (120, 1200) to reduce the amount of fish being pumped while maintaining sufficient flow downstream of the fish pump (110, 1100) so that fish cannot swim back upstream to the fish pump outlet (110B, 1100B); the upstream bypass chamber (130, 1300) comprises a conical diffuser (133) configured to slow the flow of water into the main communication channel (120, 1200); method.
2. 2. The method of claim 1, wherein the upstream bypass chamber (130, 1300) comprises a central fluid communication channel (132) whose diameter matches that of the main communication channel (120, 1200); The method includes: the central fluid communication channel (132) having a lattice configured to define an outer boundary within the upstream bypass chamber (130, 1300) that the fish can reach as the fish and water pass through the upstream bypass chamber (130, 1300), allowing water to enter the central fluid communication channel through the lattice.
3. 3. The method of claim 2, wherein the spacing of the grate is appropriately sized so that, in use, fish pumped through the upstream bypass chamber (130, 1300) cannot pass through the grate, but a sufficient amount of water can pass through the grate and enter the central fluid communication channel (132).
4. A method according to any one of claims 1 to 3, wherein the upstream bypass chamber (130, 1300) comprises an enlarged chamber (134) configured to slow the flow of water into the main communication channel (120, 1200).
5. A method according to any one of claims 1 to 3, wherein the bypass chamber (130, 1300) is provided with a fine grid configured to reduce the velocity of the flow of water entering the bypass chamber (130, 1300) and mixing into the main communication channel (120, 1200).
6. A method according to any one of claims 1 to 3, wherein the apparatus (1000) further comprises an auxiliary pump (1400) configured to pump water into the upstream bypass chamber (1300).
7. 4. The method according to claim 1, wherein the device (1000) further comprises a downstream bypass chamber (1500) disposed on the main communication channel (1200) downstream of the fish pump outlet (1100B); The downstream bypass chamber (1500) is configured in use to remove water from the main communication channel (1200) so that the removed water can be recycled to the upstream bypass chamber (1300).
8. 8. The method of claim 7, wherein the apparatus further comprises an auxiliary pump configured to pump water from the downstream bypass chamber to the upstream bypass chamber.
9. 1. A method of reducing the amount of fish pumped by a fish pump (1100) while maintaining a sufficient flow rate so that the fish cannot swim upstream back into the pump (1100), comprising: Providing a device (1000) for pumping fish, the device (1000) comprising: a main communication channel (1200) for delivering water and fish therethrough; a fish pump (1100) having an inlet (1100A) and an outlet (1100B), positioned on the main communication channel (1200) and configured to pump water and fish along the main communication channel (1200); an upstream bypass chamber (1300) disposed on the main communication channel (1200) upstream of the fish pump inlet (1100A), the upstream bypass chamber (1300) configured to mix water flows in use; a downstream bypass chamber (1500) disposed on the main communication channel (1200) downstream of the fish pump outlet (1100B), the downstream bypass chamber (1500) configured to remove water from the main communication channel (1200) in use so that the removed water can be recirculated into the upstream bypass chamber (1300) and the main communication channel (1200); providing an apparatus (1000) comprising: Supplying fish and water to the main communication channel (1200); activating the fish pump (1100) to pump the fish and water along the main communication channel (1200); removing water from the main communication channel (1200) in the downstream bypass chamber (1500); communicating the water removed from the downstream bypass chamber (1500) to the upstream bypass chamber (1300); mixing the removed water back into the main communication channel (1200) in the upstream bypass chamber (1300), thereby reducing the amount of fish being pumped while maintaining sufficient flow rate on the downstream side of the fish pump (1100) so that fish cannot swim back upstream to the fish pump outlet (1100B); The method of claim 1, wherein the upstream bypass chamber (1300) comprises a conical diffuser (133) configured to slow the flow of the water into the main communication channel (1200).
10. 10. The method of claim 9, wherein the central fluid communication channel (132) comprises a lattice configured to define an outer boundary within the upstream bypass chamber (1300) that the fish can reach as the fish and water pass through the upstream bypass chamber (1300), and to allow water to enter the central fluid communication channel (132) through the lattice.
11. 11. The method of claim 10, wherein the spacing of the grate is appropriately sized so that, in use, fish pumped through the upstream bypass chamber (1300) cannot pass through the grate, but a sufficient amount of water can pass through the grate and enter the central fluid communication channel (132).
12. 12. The method of any of claims 9 to 11, wherein the upstream bypass chamber (1300) comprises an enlarged chamber configured to slow the flow of the water into the main communication channel (1200).
13. 12. The method of claim 9, wherein the bypass chamber (1300) comprises a fine grid configured to reduce the velocity of the water flowing into the bypass chamber (1300) and mixing into the main communication channel (1200).
14. 12. The method of any of claims 9 to 11, wherein the apparatus (1000) further comprises an auxiliary pump (1400) configured to pump water into the upstream bypass chamber (1300).
15. 12. The method of claim 9, wherein the apparatus (1000) further comprises an auxiliary pump (1400) configured to pump water from the downstream bypass chamber (1500) to the upstream bypass chamber (1300).