Cleaning unit for cleaning filter part of drain pipe or the like

Abstract

A cleaning unit 100 according to an aspect of the present invention includes: an annular or cylindrical base part 102 that is disposed around a filter part of a drain pipe; brushes 104 that are provided to the base part 102 and are directed to a surface of the filter part 9; and blades 106 that are provided on the outer circumferential surface of the base part 102 and extend outward in the radial direction of the base part 102. The blades 106 receive a flow of water in a water passage where the drain pipe is disposed, whereby the brushes 104 rotate about the axis integrally with the base part 102.

Description

Cleaning unit for cleaning the filter part of drain pipes, etc.

[0001] The present invention relates to a technique for cleaning a filter portion of a drain pipe or a water intake pipe.

[0002] As global demand for marine resources increases, efforts are underway to develop aquaculture technologies that will ensure a stable supply of aquatic organisms. In recent years, as the effects of global warming and marine pollution have become increasingly serious problems, land-based aquaculture, which has fewer of these impacts, has been attracting attention. Land-based aquaculture has the advantages of being less restricted by location than marine aquaculture, being less susceptible to weather and natural disasters by using indoor facilities, and reducing the burden that aquaculture places on the environment.

[0003] Land-based aquaculture systems are provided with a circulation path that purifies and circulates the water in the tanks used to raise aquatic organisms (also called "breeding water") to keep the water clean. The tanks are provided with a drainage structure that captures foreign matter before it is discharged (see Patent Document 1). In the drainage structure of Patent Document 1, a drain pipe is provided at the bottom of the tank, and a cylindrical filter is provided at the opening of the drain pipe. The filter has a mesh structure and prevents aquatic organisms from flowing into the drain pipe, i.e., from escaping from the tank.

[0004] Japanese Patent Application Laid-Open No. 2006-129862

[0005] However, this type of drainage structure makes the filter's mesh structure prone to clogging with foreign matter. If the filter becomes clogged and drainage is hindered, it can change the circulation flow rate of the aquarium, which can affect the system's filtration performance and potentially lead to a deterioration in water quality.

[0006] In systems that take water from a water source such as the sea or a river and supply it to an aquarium, a water intake pipe is installed at the water source, and similar problems can occur with this intake pipe. That is, a similar filter may be installed at the opening of the intake pipe to prevent aquatic organisms and foreign objects from the water source from entering the aquarium. In this case, it is also necessary to prevent the filter from clogging.

[0007] The present invention has been made in view of the above circumstances, and one of its objects is to provide a technique that enables easy cleaning of a filter portion provided in a drain pipe or a water intake pipe.

[0008] One aspect of the present invention is a cleaning unit for cleaning a filter section provided in a water pipe that functions as a drain pipe or a water intake pipe. This cleaning unit includes an annular or cylindrical base section arranged to surround the filter section, a brush provided on the base section and facing the surface of the filter section, and blades provided on the outer circumferential surface of the base section and extending radially outward from the base section. When the blades receive the water flow from a water channel in which the water pipe is arranged, the brush rotates integrally with the base section around its axis.

[0009] According to the present invention, a technique can be provided that allows for easy cleaning of a filter portion provided in a drain pipe or a water intake pipe.

[0010] FIG. 1 is a diagram showing an overview of the aquaculture system according to the first embodiment; FIG. 2 is a plan view showing the structure of the aquarium and its surroundings; FIG. 3 is a diagram showing the configuration of the cleaning unit; FIG. 4 is a diagram showing the installation structure of the cleaning unit in a drain pipe; FIG. 5 is a plan view showing the operation of the cleaning unit; FIG. 6 is a diagram showing the installation mode of the cleaning unit; FIG. 7 is a diagram showing the installation mode of the cleaning unit according to Modification 1; FIG. 8 is a diagram showing the installation mode of the cleaning unit according to Modification 2; FIG. 9 is a diagram showing the installation structure of the cleaning unit according to Modification 3; FIG. 10 is a diagram showing the configuration of the cleaning unit according to Modification 4; FIG. 11 is a diagram showing the configuration of the cleaning unit according to Modification 5; FIG. 12 is a plan view showing the structure of the aquarium and its surroundings according to the second embodiment; FIG. 13 is a diagram showing the installation mode of the drain pipe in the aquarium; FIG. 14 is a plan view showing the operation of the cleaning unit; FIG. 15 is a diagram showing the installation structure of the cleaning unit according to Modification 6.

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following embodiment and its modifications, substantially the same components are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

[0012] FIG. 1 is a diagram showing an overview of an aquaculture system according to a first embodiment. The aquaculture system 1 realizes closed-circulation land-based aquaculture and includes an aquarium 4 for raising aquatic organisms 2, a circulation path 6 for circulating the water (breeding water) in the aquarium 4, and a biological filtration tank 8 provided in the circulation path 6. A pump 12 is provided in the circulation path 6. Driving the pump 12 causes the breeding water to circulate through the circulation path 6. The pump 12 functions as a "circulation device" that adjusts the amount of water circulated. These aquaculture facilities are located in an indoor facility.

[0013] Land-based aquaculture methods are generally broadly divided into free-flowing and closed-circulation systems. The free-flowing system involves pumping water from the sea or river into an aquarium and then draining the contaminated water from the aquarium, i.e., maintaining the water purity through water exchange. In contrast, the closed-circulation system involves a circulation path for reusing the water stored in the aquarium and passing it through a filter tank installed in the circulation path to maintain the water purity. A semi-circulation system, which combines the free-flowing and closed-circulation systems, also exists, in which the water is circulated while a portion of it is exchanged. In this embodiment, the closed-circulation system, which is a type of land-based aquaculture, is adopted to prevent the introduction of pathogens from outside and reduce seasonal factors that affect water temperature, etc. The temperature of the water is set to a temperature suitable for the growth of the aquatic organisms 2.

[0014] In this embodiment, the aquatic organisms 2 are saltwater fish, but they may also be freshwater fish. They may also be shellfish, crustaceans, or other seafood. The composition of the rearing water is adjusted depending on whether the aquatic organisms 2 are saltwater organisms or freshwater organisms.

[0015] A physical filter 7 is provided downstream of the aquarium 4 in the circulation path 6, and a biological filtration tank 8 is provided downstream of that. A filter unit 9 is also provided in the drain pipe 5 installed in the aquarium 4. The drain pipe 5 functions as a cylindrical "water pipe." The filter unit 9 is made of a filter member such as a mesh filter or strainer, and has a porous structure that prevents aquatic organisms 2 from escaping from the aquarium 4 while capturing foreign matter contained in the breeding water. The physical filter 7 captures relatively small foreign matter that could not be removed by the filter unit 9. In other words, the filter unit 9 functions as a primary filter, and the physical filter 7 functions as a secondary filter. In this embodiment, a cleaning unit 100 is provided to remove foreign matter adhering to the surface of the filter unit 9 to prevent clogging of the filter unit 9, and details of this will be described later.

[0016] Toxic ammonia is generated in the aquarium 4 due to the metabolic activity of the aquatic organisms 2 and the decomposition of organic matter such as leftover food. For this reason, the breeding water is circulated and passed through the biological filtration tank 8 for biological filtration, where the ammonia is decomposed and converted into less toxic nitrate. The biological filtration tank 8 holds nitrifying bacteria (microorganisms) that oxidize ammonia in oxygen-containing water and convert it into nitrite and then nitrate.

[0017] A foam separator 14 and a denitrification tank 16 are connected to the biological filtration tank 8. Water discharged from the water tank 4 and introduced into the biological filtration tank 8 is then introduced into the foam separator 14 by driving a pump 18. The foam separator 14 separates organic matter contained in the water by adsorbing it into foam and floating it to the surface, and then returns the organic matter to the biological filtration tank 8.

[0018] The water nitrified in the biological filtration tank 8 is guided by the pump 20 to the denitrification tank 16 and then returned to the biological filtration tank 8. The denitrification tank 16 holds denitrifying bacteria, which reduce the nitrate contained in the filtered water to nitrogen gas and release it into the atmosphere. After being detoxified in this way, the water in the biological filtration tank 8 is pumped up by the pump 12 and supplied to the aquarium 4.

[0019] The aquaculture system 1 is further provided with an oxygen supplying device 22 and a feeding device 24. The oxygen supplying device 22 supplies oxygen into the water in the aquarium 4. The oxygen supplying device 22 functions as a "dissolved oxygen concentration adjusting device" that adjusts the amount of oxygen supplied to the aquarium 4. The feeding device 24 supplies food into the aquarium 4. The feeding device 24 functions as a "feeding adjusting device" that adjusts the amount of food to be fed to the aquatic organisms in the aquarium.

[0020] FIG. 2 is a plan view schematically illustrating the structure of the aquarium 4 and its surroundings. The aquarium 4 is a circular aquarium with a drain pipe 5 installed in its center. A water supply pipe 34 is provided penetrating the side wall 4a of the aquarium 4. The water supply pipe 34 is connected to the downstream piping of the biological filtration tank 8 to form a circulation path 6 and functions as a "water supply section" that supplies breeding water to the aquarium 4. The open end of the water supply pipe 34 (i.e., the water supply port) is oriented tangentially to the inner circumferential surface of the aquarium 4. Therefore, when breeding water is discharged from the water supply pipe 34, a unidirectional water flow centered on the drain pipe 5 is generated (see the arrow in the figure). In other words, the water supply pipe 34 functions as a "water flow generator" that generates a flow of breeding water within the aquarium 4.

[0021] In this way, a circular water flow, i.e., a swirling flow of the breeding water, is generated in the aquarium 4. It is known that in such a configuration, foreign matter tends to collect in the center of the aquarium 4. A filter unit 9 is provided at the opening of the drain pipe 5 so that the breeding water can be discharged while removing the foreign matter. In this embodiment, the upper end of the drain pipe 5 is open to form a discharge outlet, and the filter unit 9 is attached to cover this outlet. The lower end of the drain pipe 5 passes through the bottom of the aquarium 4 and is connected to an external pipe 36 (pipe upstream of the physical filter 7) that forms the circulation path 6.

[0022] The cleaning unit 100 is then installed so as to be fitted onto the filter unit 9. Because the drain pipe 5 is a so-called overflow pipe, the position of the discharge outlet is approximately the same as the height of the water surface Wf. The upper end surface of the filter unit 9 is exposed slightly above the water surface Wf. The cleaning unit 100 has a brush on the inside of its annular body and multiple blades on the outside. When the multiple blades receive the water flow, the cleaning unit 100 rotates autonomously, and the brush operates to sweep the surface of the filter unit 9. This makes it possible to remove foreign matter adhering to the surface of the filter unit 9 (details will be described later).

[0023] 3A and 3B are diagrams illustrating the configuration of the cleaning unit 100. Fig. 3A is a perspective view, and Fig. 3B is a plan view. The cleaning unit 100 includes an annular base portion 102, a plurality of brushes 104 provided inside the base portion 102, and a plurality of blades 106 provided on the outer peripheral surface of the base portion 102.

[0024] As shown in FIG. 3A , the base portion 102 is formed by vertically connecting a base member 110a (first base member) and a base member 110b (second base member). A plurality of blades 106 are provided at equal intervals around the circumferential direction of the base portion 102 to bridge the base members 110a and 110b. In other words, the base portion 102 is formed by vertically connecting the base members 110a and 110b with the plurality of blades 106. The base portion 102 has an opening 107 between the base ends of adjacent blades 106. In this embodiment, the base members 110a and 110b have the same shape (annular), and therefore, when there is no need to distinguish between them, they will be collectively referred to simply as the "base member 110."

[0025] As shown in FIG. 3B , the blades 106 are rectangular in side view and curved in plan view, with their base ends fixed to the base member 110. Slits 108 that open in the vertical direction are provided near the inner peripheral edges of the upper and lower ends of each blade 106. The upper and lower base members 110 are also provided with a plurality of slits 109 that correspond to the slits 108. The blades 106 and the upper and lower base members 110 are assembled such that the slits 108 and 109 fit together. The blades 106 are arranged at predetermined intervals (equidistantly spaced) symmetrically about the axis L of the base member 102, and extend radially outward from the base member 102. Each blade 106 has a concave curved surface on one side in the rotational direction about the axis L, and a convex curved surface on the other side.

[0026] In this embodiment, the brushes 104 are provided in a number corresponding to the number of blades 106. A brush 104 is provided at the base end of each blade 106. In this embodiment, a so-called channel brush is used as the brush 104. The brush 104 includes a long substrate 112 (channel material) and brush bristles 114 provided along the side of the substrate 112. The substrate 112 is attached to the base end of the blade 106 and fixed to the inside of the base portion 102, and is arranged to extend in the vertical direction. The brush bristles 114 are provided along the entire length of the substrate 112. The brush bristles 114 are continuously provided on the substrate 112 so as to correspond to the entire length of the filter portion 9 (see FIG. 4 ). The brush bristles 114 extend toward the opposite side of the substrate 112, i.e., toward the radially inward direction of the base portion 102. The multiple brushes 104 are arranged so that the tips of the brush bristles 114 are aligned with a predetermined inscribed circle C. This inscribed circle C follows the outer peripheral surface of the filter portion 9 (see FIG. 5).

[0027] 4A to 4C are diagrams showing the installation structure of the cleaning unit 100 on the drain pipe 5. Figures 4A to 4C show the installation process. For ease of explanation, the rearing water is not shown. As described above, the drain pipe 5 is installed so as to protrude upward from the center of the bottom of the aquarium 4. The filter unit 9 is attached and fixed so as to cover the drain outlet 5a at the upper end of the drain pipe 5 (Figures 4A and 4B).

[0028] From this state, the cleaning unit 100 is assembled so as to cover the filter unit 9 (FIGS. 4(B) and (C)). When the water level in the water tank 4 is at the set water level, the cleaning unit 100 is held in a position that covers almost the entire filter unit 9 (FIG. 4(C)). The specific gravity of the cleaning unit 100 is set in this manner. As shown in the figure, the base unit 102 is positioned to surround the filter unit 9. At this time, the brush 104 is directed toward the surface (outer periphery) of the filter unit 9.

[0029] 5 is a plan view showing the operation of the cleaning unit 100. The cleaning unit 100 rotates around the axis L when the multiple blades 106 receive the water flow. At this time, the inscribed circle C of the tips of the multiple brushes 104 follows the outer peripheral surface of the filter unit 9. As a result, the cleaning unit 100 rotates coaxially with the filter unit 9.

[0030] That is, the multiple brushes 104 rotate around their axis integrally with the base portion 102, sweeping the outer circumferential surface of the filter portion 9. The breeding water is introduced into the interior through openings in the base portion 102 formed between adjacent blades 106 (see the outlined arrows). In other words, the filter portion 9 can introduce the breeding water into the drain pipe 5 while preventing foreign matter from entering. As the cleaning unit 100 rotates, the brushes 104 scrape off foreign matter adhering to the outer circumferential surface of the filter portion 9, thereby cleaning the filter portion 9.

[0031] 6 is a diagram showing a schematic diagram of the installation of the cleaning unit 100. The thick arrows in the diagram indicate the flow of rearing water. In this embodiment, as described above, buoyancy is utilized to enable the cleaning unit 100 to maintain a position corresponding to the filter portion 9. The materials, sizes, and shapes of the components that make up the cleaning unit 100 are set accordingly.

[0032] The filter unit 9 is cylindrical and has a bottom, and is attached to the drain pipe 5 with its bottom facing up. The drain pipe 5 is an overflow pipe, and its upper opening forms the drain outlet 5a. When the water surface Wf becomes higher than the drain outlet 5a (i.e., when the water overflows), the breeding water is guided from the drain outlet 5a into the drain pipe 5. This keeps the water level in the aquarium 4 almost constant. For this reason, the filter unit 9 is configured to cover the drain outlet 5a and to have a height that anticipates overflow. In other words, in the height range where overflow may occur, foreign matter will adhere to the outer surface (side surface) of the filter unit 9. In particular, relatively light foreign matter floating on the water surface Wf is likely to adhere to the filter unit 9.

[0033] As shown in the figure, the cleaning unit 100 has a specific gravity such that it is not completely submerged in the water tank 4, but rather its upper end is exposed above the water surface Wf. The cleaning unit 100 is not fixed to either the drain pipe 5 or the filter unit 9, but floats near the water surface Wf in a manner that it is extrapolated onto the filter unit 9. As also shown in Figure 4(C), multiple brushes 104 abut in an annular shape on the outer peripheral surface of the filter unit 9, and the cleaning unit 100 is fitted into the filter unit 9. This prevents the cleaning unit 100 from falling off the drain pipe 5 and being washed downstream. The cleaning unit 100 can clean the outer peripheral surface of the filter unit 9 by rotating.

[0034] As described above, in this embodiment, a swirling flow (rotating flow) of rearing water is generated in the circular aquarium 4, and the drain pipe 5 is located in the center of the aquarium 4, which is the center of this swirl. With this configuration, foreign matter tends to collect in the center, but by providing the filter unit 9 to cover the drain outlet 5a, it is possible to drain the water while preventing the aquatic organisms 2 from escaping. In particular, by providing the cleaning unit 100 to cover the filter unit 9, it is possible to drain the water while removing relatively large foreign matter contained in the rearing water.

[0035] The cleaning unit 100 can be realized with a simple configuration in which a brush 104 is provided inside an annular base portion 102 and multiple blades 106 are provided on the outer peripheral surface of the base portion 102. Furthermore, these blades 106 rotate in response to the water flow, thereby allowing the cleaning unit 100 to operate autonomously. In other words, the brush 104 rotates integrally with the base portion 102 and cleans the outer peripheral surface of the filter portion 9 without the need for electrical power. Therefore, a control device for electrically driving the cleaning unit 100 is not required. In other words, this embodiment provides a technology that allows the filter portion 9 provided in the drain pipe 5 to be easily cleaned.

[0036] Furthermore, when relatively soft and fragile foreign matter such as droppings or leftover food from aquatic organisms 2 adheres to the filter section 9, the cleaning unit 100 can be operated to crush the foreign matter into small pieces, which can then be filtered out and discharged by the filter section 9. In this case, the filtered foreign matter can be removed by the physical filter 7 and foam separator 14 outside the aquarium tank 4.

[0037] [Modification] Figure 7 is a diagram showing a schematic diagram of an installation mode of a cleaning unit according to Modification 1. In the case of a water tank that is not an overflow type, a filter unit 109 may be installed underwater as shown in the figure. In this modification, a strainer having a porous structure is installed in drain pipe 105 as filter unit 109. In this case, the water level in water tank 4 can be set by, for example, modifying the structure of the water supply pipe.

[0038] In this modified example, the drain outlet 5a, which is the opening of the drain pipe 105, is underwater, and a filter unit 109 is installed to cover the drain outlet 5a. Foreign matter contained in the breeding water is introduced into the drain pipe 105 through the filter unit 109. In this configuration, foreign matter that does not float on the water surface Wf, i.e., foreign matter that flows in the water, adheres to the surface of the filter unit 109. In this case, the cleaning unit 100 needs to be submerged in water and kept in the position of the filter unit 109.

[0039] Therefore, the specific gravity of the cleaning unit 100 is increased (i.e., it is made of a material with a higher specific gravity than the breeding water), and the cleaning unit 100 is supported from below by the drain pipe 105. Specifically, a flange portion 111 that protrudes radially outward is provided at the top of the drain pipe 105, and the upper surface of the flange portion 111 supports the lower surface of the cleaning unit 100 (the lower surface of the base member 110). The cleaning unit 100 can rotate while sliding on the flange portion 111. In this modified example, the outer peripheral surface of the filter portion 109 can be cleaned by rotating the cleaning unit 100.

[0040] Foreign matter floating on the water surface Wf can be dealt with by having an operator scoop it up with a net or by installing a separate filter for capturing it. Separate equipment for removing foreign matter floating on the water surface of the water tank 4 may also be provided.

[0041] 8 is a diagram showing a schematic diagram of the installation of a cleaning unit according to Modification 2. The breeding water may contain foreign matter with a relatively high specific gravity. In such cases, the foreign matter tends to collect in the center of the bottom of the aquarium 4. In this modification, such foreign matter can also be discharged from the discharge pipe.

[0042] In this modified example, the drain pipe 125 has a double-pipe structure that includes an inner pipe 126 and an outer pipe 127 that are coaxial. The inner pipe 126 has a structure similar to that of the drain pipe 5 of the above embodiment. The outer pipe 127 has approximately the same height as the inner pipe 126 and has multiple openings 128 on the side surface at the lower end. A filter unit 9 is installed so as to cover the drain outlet 5a, which is the upper opening of the inner pipe 126.

[0043] When such a drain pipe 125 is used, if drainage occurs due to overflow in the inner pipe 126, the rearing water present in the passage between the inner pipe 126 and the outer pipe 127 is sucked up. In this modified example, this phenomenon is utilized to guide foreign matter c1 that has accumulated at the bottom of the aquarium 4 to the filter unit 9.

[0044] A cleaning unit 100 is disposed above the drain pipe 125. The cleaning unit 100 is fitted onto the upper part of the inner pipe 126 to which the filter unit 9 is attached, and is supported from below by the upper end surface of the outer pipe 127. With this configuration, the filter unit 9 can capture not only foreign matter c2 floating on the water surface Wf, but also foreign matter c1 sinking to the bottom of the water. These foreign matters can be removed by operating the cleaning unit 100. If these foreign matters are fragile, they can also be filtered out by the filter unit 9.

[0045] FIG. 9 is a schematic diagram showing the installation structure of a cleaning unit according to Modification 3. FIGS. 9A to 9C show the installation process. In this modification, a filter portion 136 is also provided on the drain pipe 135 itself. A lid-shaped filter portion 139 is provided to cover the drain outlet 5a of the drain pipe 135. The filter portion 136 is made up of a number of slits 137 provided on the side surface of the drain pipe 135.

[0046] The slits 137 are small holes of a predetermined length that extend in the circumferential direction of the drain pipe 135, and four slits 137 are provided at equal intervals in the circumferential direction of the drain pipe 135. Furthermore, a large number of slits 137 are arranged parallel to one another in the longitudinal direction (vertical direction) of the drain pipe 135. The opening width of the slits 137 (the size of the gap in the vertical direction) is approximately the same as the opening width of the mesh of the filter section 139. It goes without saying that the shape, size, number, etc. of the filter section 139 are not limited to those shown in the figure.

[0047] With this configuration, the range of the filter portion provided in the drain pipe 135 is large. Therefore, although the cleaning unit 130 has basically the same configuration as the above embodiment, its height is large enough to include the range of the filter portion.

[0048] When installing the cleaning unit 130, the filter part 139 is attached and fixed so as to cover the drain outlet 5a at the upper end of the drain pipe 135 (FIGS. 9A and 9B). From this state, the cleaning unit 130 is assembled so as to cover the filter parts 139 and 136 (FIGS. 9B and 9C). When the water level in the water tank 4 is at the set water level, the cleaning unit 130 is held in a position so as to cover almost the entire filter part 139 (FIG. 9C).

[0049] FIG. 10 is a diagram showing the configuration of a cleaning unit according to Modification 4. For ease of explanation, only the outlines of the base and blades are shown using two-dot chain lines. In this modification, the cleaning unit 140 has a spiral brush 144. The cleaning unit 140 includes an annular base 142, a plurality of brushes 144 provided inside the base 142, and a plurality of blades 146 provided on the outer circumferential surface of the base 142. The spacing between the upper and lower base members 110 is set so that the base 142 can correspond to the range of the filter portion of the drain pipe 135 described above.

[0050] The blades 146 are large and formed to match the height of the base portion 142. The brush 144 has a substrate 148 that extends spirally in the vertical direction. The substrate 148 is provided so as to span the multiple blades 146 and is fixed at scattered points to the base ends of the blades 146. With this configuration, when the cleaning unit 140 rotates left in the figure (counterclockwise in plan view), a thrust force (downward in this modified example) acts on the cleaning unit 140 along with the rotation (see the dashed-dotted arrow). In this modified example, the cleaning unit 140 is placed in the water tank so that such rotation occurs in relation to the shape of the blades 146.

[0051] A flange portion 145 that protrudes radially outward is provided at a predetermined position on the outer peripheral surface of the drain pipe 135, and the upper surface of the flange portion 145 supports the lower surface of the cleaning unit 140 (the lower surface of the base member 110). The cleaning unit 140 can rotate while sliding on the flange portion 145. In this modified example, the outer peripheral surfaces of the filter portions 136 and 139 can be cleaned by rotating the cleaning unit 140.

[0052] Furthermore, the thrust force acting on the cleaning unit 140 allows the position of the cleaning unit 140 to be stably maintained relative to the drain pipe 135 regardless of the height of the water surface Wf. This thrust force is also expected to sweep out foreign matter scraped off by the brush 144 in the axial direction of the drain pipe 135.

[0053] 11 is a diagram showing the configuration of a cleaning unit according to Modification 5. For ease of explanation, only the outlines of the drain pipe and filter portion are shown by two-dot chain lines. In this modification, the cleaning unit 150 further includes a brush 154 for cleaning the upper end surface of the filter portion 139.

[0054] The brush 154 includes a substrate 152 extending in the diameter direction of the base member 110, and brush bristles 155 extending from the substrate 152 toward the end face of the filter portion 139. The substrate 152 is fixed to the upper base member 110 so as to bridge over the base ends of the blades 146 that are diametrically opposed to each other. The brush bristles 155 are directed downward in the axial direction of the drain pipe 135, and their tips abut against the filter portion 139.

[0055] The cleaning unit 150 includes brushes 144 that are directed toward each side of the drain pipe 135 and the filter unit 139, and a brush 154 that is directed toward the upper end surface of the filter unit 139. Therefore, by rotating the cleaning unit 150, the entire surfaces of the filter units 136 and 139 can be cleaned.

[0056] Second Embodiment Fig. 12 is a plan view schematically illustrating a water tank and its surrounding structure according to a second embodiment. This embodiment employs a so-called raceway-type water tank 204. The water tank 204 has semicircular (R-shaped) corners 204a at both longitudinal ends. A water channel 232 is divided widthwise by a partition wall 230 extending longitudinally through the center of the water tank 204. The pair of divided water channels 232a, 232b are parallel to each other and connected at the corner 204a. A unidirectional (counterclockwise in the figure) flow is generated in the annular water channel 232 (see the arrow in the figure).

[0057] A water supply pipe 234 is provided so as to penetrate the side wall 204b of the aquarium 204. The water supply pipe 234 extends inside the aquarium 204 and branches into multiple pipes (branch pipes 234a) below the surface of the breeding water. The open end (i.e., water supply port) of each branch pipe 234a faces downstream of the aquarium 204, and breeding water is discharged downstream, thereby generating the unidirectional water flow described above.

[0058] Meanwhile, drain pipes 205 are provided near the upstream ends of water channels 232a, 232b in the flow path of water tank 204, i.e., in areas near the ends of each corner portion 204a (hereinafter also referred to as "specific areas"). Unlike drain pipe 5 of the first embodiment, drain pipe 205 extends from the side of water tank 204 in the width direction of water channels 232a, 232b. A cleaning unit 200 is attached to each drain pipe 205.

[0059] This specific area is known to be an area where the water flow is likely to change direction at the corner 204a, causing a localized vortex, and where foreign matter contained in the water flow is likely to collect (see Patent Document 1). A drain pipe 205 and a cleaning unit 200 are arranged to allow the rearing water to be drained while removing such foreign matter.

[0060] Figure 13 is a diagram showing the installation state of the drain pipe 205 in the water tank 204. To improve drainage efficiency, it is preferable to provide a filter section 136 (slits 137) over almost the entire length of the drain pipe 205 (see Figure 9). The base end of the drain pipe 205 is detachably attached to the external piping 36 and detachably fixed to the side wall 204b of the water tank 204. In this embodiment, the end of the drain pipe 205 on the partition wall 230 side is closed.

[0061] The drain pipe 205 is installed in the water tank 204 so as to generally cross the water channel 232. In this embodiment, as shown in the figure, the upper part of the drain pipe 205 is exposed above the water surface Wf, but it may also be submerged below the water surface Wf. As the cleaning unit 200, for example, the cleaning unit 130 of Modification 3 (see FIG. 9 ) can be used, but the cleaning unit 140 of Modification 4 or other cleaning units may also be used.

[0062] However, in this embodiment, since the drain pipe 205 occupies almost the entire width of the water channel 232, it is difficult to assemble the cleaning unit 200 after installing the drain pipe 205 in the water tub 204. For this reason, the drain pipe 205 is installed in the water tub 204 with the cleaning unit 200 already assembled to the drain pipe 205. In a modified example, the cleaning unit 200 may have a radially separated structure, and may be assembled to the drain pipe 205 after the drain pipe 205 is installed in the water tub 204.

[0063] FIG. 14 is a plan view illustrating the operation of the cleaning unit 200. The cleaning unit 200 rotates around its axis L as the multiple blades 106 receive the water flow in the water channel 232. The axis L is approximately parallel to the bottom surface of the water channel 232 and is located below the water surface Wf. At this time, the tips of the multiple brush bristles 114 run along the outer circumferential surface of the filter portion 136, causing the cleaning unit 200 to rotate coaxially with the filter portion 136. As the cleaning unit 200 rotates, the brush bristles 114 scrape off foreign matter adhering to the outer circumferential surface of the filter portion 136, thereby cleaning the filter portion 136. By arranging the drain pipe 205 in the width direction of the water channel 232 and parallel to its bottom surface, foreign matter can be captured across the entire width of the water channel 232.

[0064] [Modification] Figure 15 is a diagram schematically illustrating an installation structure of a cleaning unit according to Modification 6. 15(A) is a perspective view, and Figure 15(B) is a plan view. As shown in Figure 15(A), in this modification, a drain pipe 205 is installed upright in a raceway-type water tank 204, and the cleaning unit 200 is also installed upright. Specifically, the drain pipe 205 of the second embodiment is installed upright on the bottom surface of the water tank 204, and the cleaning unit 200 is installed so as to be inserted around the drain pipe 205.

[0065] 15(B), in this modification, cleaning unit 200 can be rotated and filter portion 136 of drain pipe 205 can be cleaned as long as there is a water flow in water channel 232. In this modification, because the top of drain pipe 205 is open, cleaning unit 200 can be easily assembled after drain pipe 205 is installed in water tank 204.

[0066] Although the preferred embodiments and modifications of the present invention have been described above, it goes without saying that the present invention is not limited to these specific embodiments, and various modifications are possible within the scope of the technical concept of the present invention.

[0067] [Other Modifications] In the first embodiment, the upper and lower base members 110 constituting the base portion 102 have the same shape, but they may have different shapes or sizes (diameters). In the above embodiment, the base member 110 has a circular shape in a plan view, but it may have a polygonal shape or other shapes in a plan view. In this case, the brushes 104 are also arranged so that the inner peripheral ends of the multiple brushes 104 form an inscribed circle that fits along the outer peripheral surface of the filter portion 9.

[0068] In the first embodiment described above, a configuration in which the same number of brushes 104 as the number of blades 106 are provided has been exemplified. An example has been shown in which a brush 104 is provided at the base end of each blade 106. In a modified example, the number of blades 106 and the number of brushes 104 may be different. A brush 104 may also be provided at each base end of some of the multiple blades 106.

[0069] In the first embodiment described above, a configuration in which brush 104 is provided at the base end of blade 106 has been exemplified. In a modified example, brush 104 may be provided at a position separated from blade 106 on the inner circumferential surface of base member 110. While the above embodiment shows an example in which multiple brushes 104 are provided, a single brush 104 may be provided inside base member 110. For example, if the spiral shape of brush 144 shown in FIG. 10 is extended in the circumferential direction, a cleaning unit using a single brush can be realized.

[0070] Furthermore, in the above embodiment, an example was shown in which a plurality of blades 106 were provided on the outer peripheral surface of the base member 110, but a single blade may be provided on the outer peripheral surface of the base member 110.

[0071] In the second embodiment, as shown in Fig. 12, an example was shown in which drain pipe 205 and cleaning unit 200 were installed near corner 204a of raceway-type water tub 204. In a modified example, they may be installed at a position away from corner 204a, such as near the center of water tub 204 in the longitudinal direction. Alternatively, they may be installed at corner 204a.

[0072] In the second embodiment described above, an example was shown in which the drain pipe 205 extends in the width direction of the water channel 232, that is, extends so as to be perpendicular to the water channel 232 in a plan view. In a modified example, the drain pipe 205 may be installed so as to form a predetermined angle (e.g., 0 to 80 degrees) with respect to the water channel 232 in a plan view, and the cleaning unit 200 may be assembled thereto.

[0073] In the second embodiment, the water supply pipe 234 is branched into multiple pipes inside the water tank 204. In a modified example, the water supply pipe may not be branched inside the water tank (i.e., the water supply pipe may have one water supply port).

[0074] In the second embodiment, an example was shown in which the water supply pipe 234 was installed in a special way to function as a "water flow generator." In a modified example, a pump may be installed in the aquarium to function as a "water flow generator." This allows for greater flexibility in installing the water supply pipe, such as by positioning the water inlet above the aquarium. In the above embodiment, a water flow was generated by orienting the water inlet of the water supply pipe 234 downstream. However, a structure for guiding rearing water downstream may also be provided near the water inlet in the aquarium 204 to serve as a "water flow generator." For example, a water flow toward the downstream side may be generated by partially installing a partition wall upstream of the water inlet.

[0075] In the above embodiment, an example was shown in which the aquaculture equipment of the aquaculture system was placed in an indoor facility, but for example, any aquaculture equipment other than the water tank may be installed outdoors.

[0076] In the above embodiment and modified example, the cleaning unit is applied to a drain pipe installed in a tank for closed-circulation land-based aquaculture. However, the cleaning unit may also be applied to a drain pipe installed in a tank for semi-circulation land-based aquaculture, in which the culture water is circulated while a portion of the water is replaced. Alternatively, the cleaning unit may be applied to a drain pipe installed in a tank for free-flow land-based aquaculture. When discharging water from the tank into the sea or river, foreign matter can be discharged while preventing aquatic organisms from escaping. Furthermore, in the case of semi-circulation or free-flow land-based aquaculture, the cleaning unit may be applied to a water intake pipe. This prevents aquatic organisms from entering the tank from the sea or river and suppresses the inflow of foreign matter.

[0077] Although not mentioned in the above embodiment, a separate facility for removing foreign matter floating on the water surface of the tank may be provided on the upstream or downstream side of the drain pipe.

[0078] In the above embodiment and modified example, a cleaning unit is applied to a drain pipe installed in a water tank as a "water passage pipe." In a modified example, a similar cleaning unit may be applied to a water intake pipe. That is, in a system that takes water from a water source such as the sea or a river and supplies it to a water tank, a water intake pipe is installed in the water source. In such a system, in order to prevent foreign matter from the water source from being introduced into the water tank, a water intake pipe with a similar configuration to the drain pipe may be used and a cleaning unit may be installed.

[0079] In the above embodiment, as shown in Fig. 3A, an example was shown in which the space surrounded by the upper and lower base members 110 constituting the base unit 102 and the adjacent blades 106 forms the opening 107. In a modified example, the base unit may have a cylindrical main body that is not separated into upper and lower base members, and the opening may be provided on the side of the main body. In other words, the opening may be formed separately from the multiple blades.

[0080] In the above embodiment, as shown in Figures 3, 10, etc., the brush bristles 114 are provided continuously on the base material 112 so as to correspond to the entire length of the filter part (filter member). In a modified example, the brush bristles may be provided intermittently on the base material so as to correspond to the entire length of the filter part (filter member). By shifting the height positions of the intermittent bristles of multiple brushes, it is possible to sweep the entire length of the filter part (filter member).

[0081] The present invention is not limited to the above-described embodiments and modifications, and the components can be modified without departing from the spirit of the invention. Various inventions can be formed by appropriately combining multiple components disclosed in the above-described embodiments and modifications. Furthermore, some components can be omitted from all the components shown in the above-described embodiments and modifications.

Claims

1. A cleaning unit for cleaning a filter section provided in a water pipe that functions as a drain pipe or a water intake pipe, comprising: an annular or cylindrical base section arranged to surround the filter section; a brush provided on the base section and directed toward the surface of the filter section; and blades provided on the outer circumferential surface of the base section and extending radially outward from the base section, wherein the blades receive the water flow of a water channel in which the water pipe is arranged, causing the brush to rotate around an axis integral with the base section.

2. A cleaning unit as described in claim 1, wherein the filter portion is a porous structure formed on the cylindrical side surface of the water pipe, or a cylindrical filter member attached to the open end of the water pipe, and the brush includes a substrate fixed to the inside of the base portion, and brush bristles extending from the substrate toward the outer circumferential surface of the filter portion.

3. The cleaning unit according to claim 2, wherein the brush bristles are provided on the base material continuously or intermittently so as to correspond to the entire length of the filter member.

4. The cleaning unit according to claim 2, wherein the brush is provided on an inner peripheral surface of the base portion.

5. The cleaning unit of claim 2, wherein said brush is provided at the base end of said vane.

6. A cleaning unit as described in claim 1 or 2, wherein the filter portion has an end face that is attached so as to cover the open end of the water pipe, and the brush includes: a substrate extending in the diameter direction of the base portion; and brush bristles extending from the substrate toward the end face of the filter portion.

7. A cleaning unit according to claim 1 or 2, wherein the base portion has an opening between the base ends of adjacent vanes.

8. A cleaning unit as described in claim 1 or 2, wherein the water passage pipe is a drain pipe provided in a flow path of breeding water in an aquarium tank of an aquaculture device, and the filter portion introduces breeding water into the inside of the drain pipe while suppressing the intrusion of foreign matter.

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