Aquafarming device

Abstract

This aquafarming device comprises: a tank for rearing aquatic organisms; a water supply unit for supplying rearing water to the tank; a drainage unit for discharging the rearing water from the tank through a drainage port formed in the tank; and an excluding unit for suppressing intrusion of aquatic organisms into a predetermined exclusion area set in the tank by allowing both or one of a medium that repels aquatic organisms and a medium that attracts aquatic organisms to act in the water.

Description

Aquaculture equipment

[0001] The present invention relates to a technique for collecting and removing unwanted objects in an aquarium.

[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] Japanese Patent No. 6362056 Japanese Patent No. 6741303 Japanese Patent Laid-Open No. 2006-129862

[0004] Crustaceans such as shrimp are one of the aquatic organisms cultivated in land-based aquaculture. In addition to molted shells, shrimp breeding tanks generate waste materials such as feces, leftover food, and dead bodies (hereinafter referred to as "garbage"). In land-based shrimp breeding, the water in the breeding tanks (hereinafter referred to as "breeding water") is purified and circulated to maintain clean water quality. To prevent shrimp from being discharged along with the breeding water, the drain outlet is usually equipped with a strainer with a mesh size that shrimp cannot pass through.

[0005] Among the waste, shrimp carcasses and molted shells are about the same size as the shrimp. In particular, molted shells are generated in large quantities due to the frequent molting that occurs as shrimp grow. These unwanted objects have difficulty passing through the strainer, so they are prone to clogging. However, if the strainer is removed, the shrimp will be discharged from the tank. Therefore, strainers are frequently cleaned at land-based shrimp farms. As such, under current circumstances, it takes a considerable amount of effort to remove waste from tanks where shrimp and other aquatic organisms are raised.

[0006] The present invention has been made in view of the above circumstances, and one of its objects is to provide a technique for efficiently collecting and removing unwanted objects in an aquarium.

[0007] In one embodiment of the present invention, the aquaculture device comprises an aquarium for raising aquatic organisms, a water supply unit that supplies breeding water to the aquarium, a drainage unit that discharges the breeding water from the aquarium through a drain outlet formed in the aquarium, and an exclusion unit that prevents aquatic organisms from invading a designated exclusion area set in the aquarium by applying, in the water, both or one of a medium that repels aquatic organisms and a medium that attracts aquatic organisms.

[0008] The present invention provides a technology that can efficiently collect and remove unwanted objects from an aquarium.

[0009] 11(a) is a schematic diagram of an aquaculture device according to a first embodiment. FIG. 11(b) is a schematic diagram of an aquaculture device according to a third embodiment. FIG. 11(c) is a schematic diagram of an aquaculture device according to a first embodiment. FIG. 11(d) is a schematic diagram of an aquaculture device according to a first embodiment. FIG. 11(a) is a schematic diagram of an aquaculture device having a drain outlet at the bottom. FIG. 11(b) is a schematic diagram of an aquaculture device having a drain outlet on the side wall. FIG. 11(c) is a schematic diagram of an aquaculture device having an L-shaped drain pipe with the drain outlet facing horizontally. FIG. 11(d) is a schematic diagram of an aquaculture device having an L-shaped drain pipe with the drain outlet facing downward. FIG. 12(a) is a schematic diagram of an aquaculture device having a drain outlet with a double-pipe structure. Figure 12(b) is a schematic diagram of an aquarium with a depression and a drain outlet in the center of the bottom, Figure 12(c) is a schematic diagram of an aquarium with a drain outlet in the deepest part of the bowl-shaped bottom, and Figure 12(d) is a schematic diagram of an aquarium with a slope and a drain outlet on the periphery of the bottom.

[0010] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. First, as a first embodiment, an overview of debris collection and removal in a circular aquarium will be described. Next, as a second embodiment, an overview of debris collection and removal in a raceway-type aquarium will be described. Furthermore, as a third embodiment, an overview of debris collection and removal in a rectangular parallelepiped aquarium will be described. In the following description, the first to third embodiments will be collectively referred to as "the present embodiment."

[0011] [First Embodiment] Figure 1 is a schematic diagram of an aquaculture device 100 according to a first embodiment. The aquaculture device 100 realizes closed-circulation land-based aquaculture and includes an aquarium 110 for raising aquatic organisms 101, a circulation path 111 for circulating water (breeding water) in the aquarium 110, and a biological filtration tank 141 provided in the circulation path 111. The circulation path 111 is provided with a drain outlet 112, a first pump 113, and a water supply port 114. By driving the first pump 113, the breeding water circulates through the circulation path 111. The first pump 113 functions as a "circulation device" that adjusts the amount of water circulated. These aquaculture facilities are arranged in an indoor facility.

[0012] Land-based aquaculture methods are generally broadly divided into free-flowing and closed-circulation systems. The free-flowing system pumps water from the sea or river into the tank 110, and then drains the contaminated water from the tank 110, i.e., maintains the water purity through water exchange. In contrast, the closed-circulation system has a circulation path 111 for reusing the water stored in the tank 110, and maintains the water purity by passing it through a filter tank installed in the circulation path 111. A semi-circulation system, which circulates the water while exchanging a portion of it, is also available as a compromise between the free-flowing and closed-circulation systems. In this embodiment, the closed-circulation system, even among land-based aquaculture systems, 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 101.

[0013] In this embodiment, the aquatic organism 101 refers to a shrimp, but it may also be a saltwater fish or a freshwater fish. The aquatic organism 101 may also be a crustacean or a shellfish other than shrimp, or other seafood. The composition of the rearing water is adjusted depending on whether the aquatic organism 101 is a saltwater organism or a freshwater organism.

[0014] A physical filter 140 is provided downstream of the aquarium 110 in the circulation path 111, and a biological filtration tank 141 is provided downstream of that. In this embodiment, no strainer is provided at the drain outlet 112. The physical filter 140 captures all the debris, such as the molted shells 102 and leftover food 103, discharged from the drain outlet 112.

[0015] Toxic ammonia is generated in the aquarium 110 due to the metabolic activity of aquatic organisms 101 and the decomposition of organic matter such as leftover food 103. For this reason, the breeding water is circulated and passed through the biological filtration tank 141 for biological filtration, where the ammonia is decomposed and converted into less toxic nitrate. The biological filtration tank 141 holds nitrifying bacteria (microorganisms) that oxidize ammonia in oxygen-containing water and convert it into nitrite and then nitrate.

[0016] A foam separator 142 is connected to the biological filtration tank 141. The water discharged from the water tank 110 and introduced into the biological filtration tank 141 is then introduced into the foam separator 142 by the drive of the second pump 115. The foam separator 142 separates the organic matter contained in the water by adsorbing it into foam and floating it to the surface, and then returns the water to the biological filtration tank 141.

[0017] The water nitrified in the biological filtration tank 141 is guided to the denitrification tank 143 by the operation of the third pump 116 and then returned to the biological filtration tank 141. The denitrification tank 143 holds denitrifying bacteria and reduces the nitrate contained in the filtered water to nitrogen gas, which is released into the atmosphere. After being detoxified in this way, the water in the biological filtration tank 141 is pumped up by the first pump 113 and supplied to the aquarium 110. Note that if the aquatic organism 101 is shrimp, the third pump 116 and denitrification tank 143 may not be provided.

[0018] The aquaculture device 100 is further provided with an oxygen supply device 144, a feeding device 150, and a power supply device 160. The oxygen supply device 144 supplies oxygen into the breeding water in the aquarium 110. The feeding device 150 functions as a "feeding section" that supplies food into the aquarium 110.

[0019] A conductive cable 161 extends from the power supply device 160. An electrode 162 is connected to the end of the conductive cable 161. The electrode 162 is provided around the center of the bottom of the aquarium 110. As will be described in detail later, a weak current is passed from the power supply device 160 to the electrode 162 to inhibit aquatic organisms 101 from invading the area surrounded by the electrode 162. The electrode 162 functions as an "exclusion section."

[0020] 2 is a perspective view showing the structure of the aquarium 110 and its surroundings in the first embodiment. For convenience of explanation, the oxygen supply device 144 and the feeding device 150 are not shown.

[0021] The water tank 110 in the first embodiment is a circular water tank having a circular shape in a plan view, and has a drain outlet 112 provided at the center of the bottom. Electrodes 162 connected to a power supply unit 160 via conductive cables 161 are provided around the drain outlet 112. While six electrodes 162 are provided in Fig. 2, the number of electrodes 162 may be less than six or seven or more.

[0022] A drain pipe 117 is provided from the drain outlet 112 downward in the aquarium 110. The drain pipe 117 functions as a "drainage section" that discharges the breeding water out of the aquarium 110. A water supply pipe 118 is provided so as to pass through the side wall 110a of the aquarium 110. The water supply pipe 118 is connected to the piping downstream of the biological filtration tank 141 to form a circulation path 111, and functions as a "water supply section" that supplies the breeding water to the aquarium 110.

[0023] The open end of the water supply pipe 118, i.e., the water supply port 114, is oriented in the tangent direction to the inner circumferential surface of the aquarium 110. Therefore, when breeding water is discharged from the water supply pipe 118, a unidirectional water flow is generated centered directly above the drain port 112 (see the arrow in the figure). In other words, a circular water flow, i.e., a swirling flow of breeding water, is generated in the aquarium 110. In the case of Figure 2, the water supply port 114 is oriented to the left, so a counterclockwise swirling flow is generated in the aquarium 110.

[0024] Figure 3 is a plan view (part 1) of the aquarium 110 in the first embodiment. For convenience of explanation, the aquatic organisms 101, molted exoskeleton 102, remaining food 103, drain port 112, oxygen supply device 144, feeding device 150, and electrodes 162 are not shown in Figure 3. Here, the setting of an exclusion zone 120, which is carried out as preparation before raising the aquatic organisms 101 (shrimp) in the aquarium 110, will be described. The exclusion zone 120 refers to an area from which shrimp should be excluded.

[0025] As described above, a counterclockwise swirling flow occurs in the circular aquarium 110. At this time, areas within the aquarium 110 have fast and slow flow velocities of the rearing water. More specifically, in the first embodiment, the flow velocity increases toward the side wall 110a of the aquarium 110 and decreases toward the center P. Furthermore, due to centrifugal force generated by the swirling flow of the rearing water and frictional resistance between the rearing water and the bottom of the aquarium 110, the rearing water near the water surface Wf of the aquarium 110 flows toward the side wall 110a. The rearing water near the side wall 110a flows toward the bottom of the aquarium 110. The rearing water near the bottom of the aquarium 110 flows toward the center P when the aquarium 110 is viewed from above. Due to the difference in swirling flow velocity and the water currents generated by the swirling flow, debris tends to accumulate near the bottom of the aquarium 110 and around the center P. Hereinafter, the area where debris tends to accumulate is also referred to as the accumulation area.

[0026] 3, a plurality of measurement points 119 are set in the aquarium 110. The measurement points 119 are locations where a current meter, a current direction meter, etc. are installed to measure the flow velocity and flow direction of the breeding water.

[0027] More specifically, a situation in which a flow meter is installed at each measurement point 119 to measure the flow velocity of the breeding water and an area with a relatively slow flow velocity is identified as a retention area will be described with reference to FIG. 3 as an example. For example, the retention area may be an area including the measurement point 119 with the slowest flow velocity and the measurement points 119 adjacent to that measurement point 119. Alternatively, an average flow velocity may be calculated from the flow velocities measured at all measurement points 119. In this case, an area including measurement points 119 with a flow velocity equal to or lower than the average flow velocity may be identified as a retention area. Using this method, a retention area is identified in the aquarium 110.

[0028] The measurement points 119 may be set at any location in the water tank 110. In the example shown in Figure 3, the center P is used as the reference point, and the measurement points 119 are set at equal intervals in the vertical and horizontal directions.

[0029] In Fig. 3, it is assumed that the flow velocity at each measurement point 119 is measured and the flow velocity at measurement point 119P located at center P is the slowest. In Fig. 3, the region including measurement point 119P and measurement points 119a to 119d adjacent to measurement point 119P in the vertical and horizontal directions, more specifically, the region inside the circle circumscribing measurement points 119a to 119d, is identified as the retention region.

[0030] In Figure 3, a flow direction meter is installed at each measurement point 119 to measure the flow direction of the breeding water at the bottom of the aquarium 110. Assume that the measurement results of the flow direction meter at each measurement point 119 reveal that the direction of the water flow in the radial direction of the circular aquarium 110 is concentrated at measurement point 119P. In this case, the area around measurement point 119P may be identified as the retention region. More specifically, the area inside a circle circumscribing measurement points 119a to 119d adjacent to measurement point 119P in the vertical and horizontal directions may be identified as the retention region. Alternatively, the retention region may be identified by combining the measurement results from the current meter and the flow direction meter.

[0031] 4 is a second plan view of the aquarium 110 according to the first embodiment. For ease of explanation, the drain port 112, the oxygen supply device 144, the feeding device 150, and the electrodes 162 are not shown in FIG.

[0032] As described above, when a swirling flow occurs, the area around the center P of the aquarium 110 becomes a retention area, and debris such as molted shells 102 and remaining food 103 accumulates therein. Therefore, in the first embodiment, a drain outlet 112 is provided at the center P of the aquarium 110. The drain outlet 112 is provided at the bottom of the aquarium 110.

[0033] Shrimp tend to gather in places where garbage accumulates (retention areas). Providing a drain outlet 112 in the retention area improves garbage discharge, but increases the risk of shrimp being discharged along with the garbage. To prevent shrimp from being discharged, it is necessary to keep shrimp away from the retention area (near the drain outlet). Therefore, the retention area is set as an area from which shrimp should be excluded, i.e., an exclusion area 120.

[0034] 5 is a plan view (part 3) of the aquarium according to the first embodiment. For convenience of explanation, the oxygen supply device 144 and the feeding device 150 are omitted from FIG.

[0035] In order to efficiently collect and quickly remove waste while reducing the above-mentioned risks, when raising aquatic organisms 101 (shrimp), electrodes 162 are installed in a manner that circumscribes the exclusion zone 120, as shown in FIG. 5 . A weak current is passed from a power supply 160 to the electrodes 162. An electric field is generated between adjacent electrodes 162 along the exclusion zone 120. In other words, an electrical barrier is formed surrounding the exclusion zone 120. Because aquatic organisms 101 have a dislike for electricity, this method can prevent aquatic organisms 101 from entering the exclusion zone 120. Passing a weak current through the electrodes 162 to keep aquatic organisms 101 away from the exclusion zone 120 is possible by applying known technology (see Patent Documents 1 and 2).

[0036] On the other hand, debris such as molted shells 102 and leftover food 103 passes through the gaps between the electrodes 162 and washes up in the exclusion area 120. The debris that washes up in the exclusion area 120 is discharged to the outside of the aquarium 110 through a drain outlet 112 located at the center P of the aquarium 110. In other words, by providing the electrodes 162, it is possible to separate the debris generated in the breeding water of the aquarium 110 from the aquatic organisms 101.

[0037] In summary, a strainer can be provided in the drain outlet 112 to prevent aquatic organisms 101 (shrimp) from being discharged from the aquarium 110. However, because debris accumulates in the strainer, cleaning the strainer places a burden on the worker. In the first embodiment, the drain outlet 112 is provided in an area of ​​the aquarium 110 where debris is likely to accumulate (retention area), and the retention area is designated as the exclusion area 120. Electrodes 162 are provided around the exclusion area 120, and a weak current is passed through them to generate an electric barrier. This method prevents shrimp from approaching the drain outlet 112, making it possible to prevent shrimp from being discharged and discharge debris from the aquarium 110 without using a strainer.

[0038] Second Embodiment Figure 6 is a schematic diagram of an aquaculture device 100 according to a second embodiment. In the second embodiment, a so-called raceway-type tank 110 is employed. The tank 110 has semicircular (R-shaped) corners 110b at both longitudinal ends. A water channel 122 is divided widthwise by a partition plate 121 extending longitudinally through the center of the tank 110. The pair of divided water channels 122a, 122b are parallel to each other and connected at the corner 110b. A unidirectional (counterclockwise in the figure) flow is generated in the annular water channel 122 (see the arrow in the figure).

[0039] A water supply pipe 118 is provided so as to penetrate the side wall 110a of the aquarium 110. The water supply pipe 118 extends inside the aquarium 110 and branches into multiple pipes (branch pipes 118a). The open end of each branch pipe 118a (i.e., the water supply port 114) faces downstream of the aquarium 110, and breeding water is discharged downstream, thereby generating the unidirectional water flow described above.

[0040] It is known that the area near the upstream end of the water channel 122a (122b), i.e., the area along the partition plate 121 near the downstream end of each corner 110b, is prone to localized vortices and debris accumulation due to the water flow changing direction at the corner 110b (see Patent Document 3). In other words, the location where the vortex occurs becomes a retention area, so a drain outlet 112 is provided at the bottom of the water tank 110 and within the retention area. In the second embodiment, the retention area identified in this manner is set as the exclusion area 120. In the second embodiment, the exclusion area 120 is preferably set within one-fifth of the upstream side of the partition plate 121 of the water channel 122a (122b). Furthermore, in the second embodiment, two exclusion areas 120 (drain outlets 112) are provided.

[0041] In a raceway-type aquarium 110, depending on the feeding position, fresh bait 104 may be discharged from the drain outlet 112 immediately after feeding. For example, suppose feeding is performed in the first area 123, which is located on the opposite side of the partition plate 121 from the exclusion area 120. In this case, the bait 104 will quickly drift to the exclusion area 120, increasing the probability that it will be discharged from the drain outlet 112. The bait 104 will not be ingested by the aquatic organisms 101 and will be wasted.

[0042] 6, in the second embodiment, feeding is carried out in a second region 124a (124b) in the waterway 122a (122b) located immediately downstream of and behind the exclusion region 120a (120b). The second region 124a located immediately behind the exclusion region 120a will be described below.

[0043] The second region 124a is at point Pa １ Including the point Pa １ is a point downstream of the exclusion area 120a, and is the point at which the linear distance to a point in the other exclusion area 120b is the maximum. １ is the area of ​​exclusion 120a and point Pa ２ The point Pb is a point on a line extending from the partition plate 121 toward the outside of the water tank 110 that is perpendicular to the side wall 110a and is in contact with the partition plate 121. In the second embodiment, the point Pb is set as the center of the drain outlet 112 and is located within the exclusion area 120b.

[0044] Also, a straight line is set that is perpendicular to the side wall 110a and tangent to the exclusion area 120b on the upstream side of the water channel 122. At this time, the perpendicular point with the water tank 110 is defined as point Pa ３ , the point of contact with the exclusion area 120b is ４ The second region 124a is defined as a point Pa １ and point Pa ２ and point Pa １ and point Pa ３ The midpoint of the side wall 110a (hereinafter referred to as the "region midpoint") Pa ５ The distance between the partition plate 121 and the area midpoint Pa is set upstream of the line connecting the partition plate 121 and the area midpoint Pa. ５ The line connecting the area midpoint Pa (hereinafter referred to as the "middle line") is perpendicular to the side wall 110a. ５ is set downstream of the exclusion area 120a and upstream of the exclusion area 120b. １ and point Pa ２ Downstream of the line connecting the points Pa and ３ and point Pa ４The second region 124a is set upstream of the line connecting the points Pa and P. １ and point Pa ２ The area shall be set downstream of the line connecting the above and upstream of the median line, within half the upstream range.

[0045] Point Pa １ In the second region 124a including the point Pa, the feeding pipe 151a extends from the side wall 110a of the aquarium 110 in the width direction of the water channel 122a. More specifically, the upstream boundary line of the feeding pipe 151a in the width direction is １ and point Pa ２ The feeding pipe 151a is provided with multiple feeding ports 152. The feed 104 stored in the feeding device 150 is fed from the feeding ports 152 via the feeding pipe 151a. The fed feed 104 drifts counterclockwise in the waterway 122. Similarly, a feeding pipe 151b is provided in the second area 124b immediately downstream of the exclusion area 120b, and feeding is carried out.

[0046] The position where the food 104 falls into the breeding water, in other words, the position where the food 104 is actually fed, is point Pa １ and point Pa ２ For example, the upstream boundary of the feeding port 152 in the width direction may be a point Pa １ and point Pa ２ The bait 104 may be thrown into the air and the point Pa １ and point Pa ２ Alternatively, the food 104 may be mixed in the rearing water in advance and fed to the fish at the point Pa. １ and point Pa ２ Alternatively, rearing water may be supplied at a position tangent to the line connecting the lines 101 and 102, and food 104 may be scattered thereon.

[0047] This method makes it possible to buy more time for fresh bait 104 to be discharged from drain outlet 112 compared to when feeding in first area 123. This increases the opportunities for aquatic organisms 101 to ingest bait 104. Since there is a higher possibility that aquatic organisms 101 will ingest all of the bait 104 before it is discharged from drain outlet 112, it is possible to reduce waste caused by early discharge of bait 104.

[0048] As in the first embodiment, the electrode 162 may be provided in a manner that circumscribes the exclusion area 120. As described above, the installation of the electrode 162 can prevent the aquatic organisms 101 (shrimp) from being expelled.

[0049] 7 is a side view showing the bottom structure of the aquarium 110 in the second embodiment. In this embodiment, the food 104 provided is formed as a lump, i.e., is solid. The specific gravity of the food 104 is equal to or greater than the specific gravity of the breeding water. Therefore, the food 104 sinks to the bottom of the aquarium 110 immediately after being provided.

[0050] In the aquarium 110 of the second embodiment, a unidirectional water flow occurs in the rearing water. The bait 104 that sinks to the bottom flows from upstream to downstream in the waterway 122. When the bait 104 is fed in the second area 124, it remains in the rearing water for a longer period of time than in the first area 123. This allows the aquatic organisms 101 to consume the bait 104 for a longer period of time.

[0051] One possible method for further extending the time that the aquatic organisms 101 consume the bait 104 is to modify the bottom structure of the aquarium 110. To this end, grooves 125 and protrusions 126 are provided on the bottom of the aquarium 110 as shown in FIG. 7. More specifically, the grooves 125 and protrusions 126 are provided on the bottom of the aquarium 110 in the width direction of the water channel 122a (122b). The grooves 125 and protrusions 126 may be provided in a regular order (for example, alternately) in the water flow direction, or in a random order. Only the grooves 125 or only the protrusions 126 may be provided.

[0052] The fed bait 104 repeats this process of being captured by the grooves 125 or protrusions 126 and being carried away by the water current. In the second embodiment, the depth of the grooves 125 is shallower than the length of the bait 104, and the height of the protrusions 126 is shorter than the length of the bait 104. Therefore, the bait 104 does not remain captured in the grooves 125 or protrusions 126 in the same place for an excessively long time, but moves downstream at appropriate time intervals. This method can slow the average movement speed of the bait 104 compared to when the bottom of the aquarium 110 is flat. Therefore, it is easier for the aquatic organisms 101 to ingest all of the bait 104.

[0053] In summary, in a raceway-type aquarium 110, debris tends to accumulate where local vortices occur due to changes in water flow direction at corners 110b. Therefore, a drain outlet 112 is provided at the location where the vortex occurs (retention area), and the retention area is designated as the exclusion area 120. In the second embodiment, feeding is performed in an area (second area 124) immediately downstream of and immediately following the exclusion area 120. This extends the time until the bait 104 is discharged from the drain outlet 112. Additionally, grooves 125 and protrusions 126 are provided on the bottom of the aquarium 110. This slows the average movement speed of the bait 104. These methods prevent the bait 104 from being discharged prematurely, providing the aquatic organisms 101 with ample opportunities to ingest the bait 104.

[0054] [Third Embodiment] Figure 8 is a schematic diagram of an aquaculture device 100 according to a third embodiment. The aquaculture device 100 in Figure 8 employs a rectangular parallelepiped aquarium 110. In the following description of the aquarium 110, the left-right direction is defined as the x-axis, the front-rear direction as the y-axis, and the up-down direction as the z-axis. For convenience of explanation, the water supply pipe 118, oxygen supply device 144, and feeding device 150 are omitted from Figure 8.

[0055] An air duct 127 is provided at the diagonally upper portion of the aquarium 110 (above the aquarium 110 in the positive y-axis and positive z-axis directions). Air is discharged from the open end (air outlet 128) of the air duct 127 toward the water surface Wf in the negative y-axis and negative z-axis directions. The air discharged from the air outlet 128 generates a swirling flow of the breeding water in the aquarium 110 centered on the x-axis (see the arrow in the figure). This swirling flow causes debris in the breeding water to gradually accumulate around the periphery of the bottom of the aquarium 110 in the positive y-axis and negative z-axis directions, more specifically, around the line connecting points A and B in Figure 8 . In other words, the area around the line connecting points A and B becomes the accumulation area. In the third embodiment, a drain outlet 112 is provided at point C, which is the midpoint between points A and B. Therefore, point C and its surroundings are defined as the exclusion area 120.

[0056] The aquaculture device 100 in the third embodiment is provided with two drain outlets 112. As described above, shrimp tend to gather in areas where debris is likely to accumulate (retention areas). If a drain outlet 112 is provided in the retention area, there is a high risk that shrimp will be expelled if the drain outlet 112 is left open. One way to avoid this risk is to open the drain outlet 112 only when a predetermined amount of debris has accumulated in the exclusion area 120. However, if there is only one drain outlet 112, the water will not be drained unless debris is accumulated, and therefore the breeding water will not circulate. Therefore, in the third embodiment, a first drain outlet 112a and a second drain outlet 112b are provided in the aquarium 110.

[0057] The first drain outlet 112a is provided exclusively for draining the breeding water. In the case of Figure 8, the first drain outlet 112a is provided at point D on the bottom of the aquarium 110, which is midway in the y-axis direction and furthest in the negative x-axis direction. The second drain outlet 112b is provided at point C within the exclusion zone 120, as described above. The second drain outlet 112b drains not only the breeding water but also debris accumulated in the exclusion zone 120. Both the breeding water and debris discharged from the first drain outlet 112a and the second drain outlet 112b flow into the physical filter 140.

[0058] The second drain outlet 112b is provided with a valve 129. Normally, the valve 129 provided on the second drain outlet 112b is closed. That is, when the valve is closed, the breeding water, garbage, and aquatic organisms 101 (shrimp) are not discharged from the second drain outlet 112b.

[0059] A camera 130 is provided directly above the second drain outlet 112b. The valve 129 and the camera 130 are connected to a discharge control device 200 (described later) via a communication network 131. The camera 130 captures images of the exclusion area 120 including the second drain outlet 112b (valve 129). The captured images are transmitted to the discharge control device 200 at regular time intervals.

[0060] The discharge control device 200 recognizes debris from the captured image and determines whether debris is trapped in the second drain outlet 112b (valve 129). As will be described in detail below, the discharge control device 200 opens the valve 129 when it determines that debris has trapped. When the valve 129 is opened, the breeding water and debris trapped in the second drain outlet 112b (valve 129) are discharged. When the discharge control device 200 determines that the debris has been successfully discharged, it closes the valve 129 again. Recognizing debris from captured images is possible by applying known technology.

[0061] 9 is a functional block diagram of the discharge control device 200. The discharge control device 200 is assumed to be a general-purpose computer such as a laptop PC. Each block described below represents a functional block, not a hardware configuration.

[0062] The discharge control device 200 includes an image acquisition unit 210, a retention determination unit 220, and a discharge control unit 230. The image acquisition unit 210 acquires captured images transmitted from the camera 130 in the water tank 110. The retention determination unit 220 determines whether or not debris has accumulated in the second drain outlet 112b (valve 129) based on the captured images acquired by the image acquisition unit 210. More specifically, for example, assume that the ratio of the area of ​​debris to the area of ​​the second drain outlet 112b (valve 129) in the captured image reaches or exceeds a predetermined value. At this time, the retention determination unit 220 determines that debris has accumulated in the second drain outlet 112b (valve 129). The retention determination unit 220 instructs the discharge control unit 230 to open the valve 129. The discharge control unit 230 receives the instruction from the retention determination unit 220 and opens the valve 129.

[0063] While the valve 129 is open, the discharge of debris and breeding water from the second drain outlet 112b and the capture of images by the camera 130 continue. For example, suppose the ratio of the area of ​​debris to the area of ​​the second drain outlet 112b (valve 129) in the captured image falls below a predetermined value. At this time, the retention determination unit 220 determines that the debris has been successfully discharged. The retention determination unit 220 instructs the discharge control unit 230 to close the valve 129. The discharge control unit 230 receives the instruction from the retention determination unit 220 and closes the valve 129. In this way, in the aquarium 110 of the third embodiment, debris is discharged only when debris is accumulated in the second drain outlet 112b (valve 129).

[0064] In summary, in the third embodiment, a vertical swirling flow is generated in the aquarium 110 by the wind discharged from the air supply pipe 127, and the bottom periphery of the aquarium 110 becomes a retention area. In the third embodiment, a portion of the retention area is set as the exclusion area 120. The aquarium 110 is provided with a first drain outlet 112a dedicated to draining water, as well as a second drain outlet 112b for discharging breeding water and debris into the exclusion area 120. A valve 129 that is normally closed is provided in the second drain outlet 112b. A camera 130 is provided directly above the second drain outlet 112b. The valve 129 and camera 130 are connected to the discharge control device 200. The camera 130 captures images of the exclusion area 120. The discharge control device 200 determines whether debris has accumulated based on the captured images. When the discharge control device 200 determines that debris has accumulated, the valve 129 is opened and the debris (breeding water) is discharged. According to this method, the breeding water is constantly circulated via the first drain outlet 112 a, and waste is automatically discharged from the second drain outlet 112 b only when necessary. Furthermore, since the second drain outlet 112 b is normally closed, the risk of the aquatic organisms 101 being discharged outside the aquarium 110 can be reduced.

[0065] As in the first and second embodiments, the electrode 162 may be provided in a manner that circumscribes the exclusion area 120. Providing the electrode 162 in addition to the valve 129 more reliably prevents the aquatic organisms 101 (shrimp) from being discharged. In the third embodiment, providing a strainer in the first drain outlet 112a enables the circulation of the breeding water while preventing the aquatic organisms 101 from being discharged. Furthermore, when debris accumulates in the second drain outlet 112b (valve 129), the valve 129 is opened. In other words, while the valve 129 is closed, the aquatic organisms 101 are not discharged from the second drain outlet 112b. Therefore, there is no need to constantly energize the electrode 162 to form an electrical barrier, which reduces power consumption and electrode wear.

[0066] In the present embodiment, the exclusion zone 120 is created by utilizing the water flow of the breeding water to collect debris. As a modification, an underwater structure 132 may be installed at the bottom of the aquarium 110 to create stagnation in the water flow and collect debris.

[0067] Figure 10 shows a side view of an aquarium 110 in which breeding water flows in one direction. A rectangular parallelepiped underwater structure 132 is provided at the bottom of the aquarium 110. In this case, stagnation of the water flow occurs in the shadow of the underwater structure 132 downstream of the aquarium 110, making it easy for debris to accumulate. Therefore, the location where the water flow stagnates is set as an exclusion zone 120. By providing a drainage outlet 112 in the exclusion zone 120, debris that has drifted ashore in the exclusion zone 120 can be collectively discharged out of the aquarium 110.

[0068] The underwater structure 132 is not limited to a rectangular parallelepiped object. For example, it may be a pipe laid at the bottom of the water tank 110, such as the drain pipe 117 or the water supply pipe 118. Alternatively, it may be a device such as a heater and a rectifier.

[0069] Fig. 11 is a schematic diagram showing an example of the installation of the drain outlet 112. In this embodiment, the drain outlet 112 may be installed not only at the bottom of the aquarium 110 as shown in Fig. 11(a), but also depending on the situation of the installation location of the aquarium 110.

[0070] For example, the drain outlet 112 may be provided on the side wall 110a of the aquarium 110 (FIG. 11(b)). Alternatively, an L-shaped drain pipe 117 may be provided inside the aquarium 110, and the breeding water may be sucked out sideways through the drain outlet 112 (FIG. 11(c)) or upwards (FIG. 11(d)).

[0071] 12 is a schematic diagram showing an example of the shape of the drain pipe 117 and the water tank 110. The shapes of the drain pipe 117 and the water tank 110 may be modified to allow for efficient collection and discharge of waste.

[0072] For example, in FIG. 12( a), the lower end of the drain pipe 117 penetrates the bottom of the aquarium 110 and is connected to the upstream piping of the physical filter 140. The drain pipe 117 has a double-pipe structure including an inner pipe 134 and an outer pipe 135, which are coaxially arranged. The outer pipe 135 has a height similar to that of the inner pipe 134 and has multiple openings 136 on the side of the lower end. When this type of drain pipe 117 is used, if drainage occurs due to overflow in the inner pipe 134, the breeding water present in the passage between the inner pipe 134 and the outer pipe 135 is sucked up. This modification utilizes this phenomenon to guide debris accumulated at the bottom of the aquarium 110 to the drain outlet 112.

[0073] 12(b), a depression 137 is provided in the center of the bottom of the aquarium 110. A drain outlet 112 is provided in the center of the depression 137. When the center of the bottom of the aquarium 110 is set as the exclusion area 120, debris that has washed up in the exclusion area 120 may be further allowed to sink into the depression 137, making it easier to discharge the debris from the drain outlet 112.

[0074] The bottom of the aquarium 110 in Figure 12(c) is formed in a cone shape. Debris tends to collect in the deepest part of the bottom of the cone-shaped aquarium 110 (the center of the bottom). For this reason, the center of the bottom of the aquarium 110 is set as an exclusion area 120, and a drain outlet 112 is provided therein. In this way, by allowing the debris to slide down toward the center of the bottom of the aquarium 110, the debris can be easily discharged from the drain outlet 112.

[0075] 12(d), it is assumed that the bottom periphery E of the water tank 110 is set as the exclusion area 120. In this case, a slope is provided toward the bottom periphery E, and a drain outlet 112 is provided at the bottom end of the slope. The slope may allow the debris to slide down, making it easier to discharge the debris from the drain outlet 112.

[0076] Although the aquarium 110 in this embodiment is described as not being provided with a strainer at the drain outlet 112, a strainer with a wide mesh may be provided. In this case, the mesh size should not be narrower than the overall width of the cross section of the aquatic organism 101 (shrimp).

[0077] In the aquarium 110 of this embodiment, electrodes 162 are provided around the exclusion zone 120 as a medium (exclusion section) that repels the aquatic organisms 101 (shrimp) so that the aquatic organisms 101 are not discharged through the drain outlet 112. As a modification, a light-emitting body, a sound-producing body, a device that generates bubbles, or the like may be provided instead of the electrodes 162. Alternatively, a device that generates, for example, a smell or sound that the aquatic organisms 101 like may be provided as a medium (exclusion section) for attracting the aquatic organisms 101 to a location other than the exclusion zone 120.

[0078] In the first embodiment, as a preparation before rearing the aquatic organisms 101 (shrimp), a retention area is identified based on the flow velocity and flow direction of the rearing water measured at each measurement point 119 using a current meter, a current direction meter, etc., and the exclusion area 120 is set. As a modification, a retention area may be identified based on other methods.

[0079] For example, weight sensors (not shown) are provided at multiple locations on the bottom of the aquarium 110. When a water current is generated in the breeding water in the aquarium 110, the weight of debris remaining on the weight sensors is measured. At this time, a location where the weight of debris measured by the weight sensor is equal to or greater than a predetermined value may be identified as a retention area. Alternatively, a water current may be generated in the breeding water in advance as a demonstration experiment, and a location where debris is actually confirmed to be retained by visual inspection may be identified as a retention area. A retention area may also be identified based on the results of predictions of flow speed and flow direction within the aquarium 110 using fluid analysis software.

[0080] In the first embodiment, the electrodes 162 are provided along the exclusion area 120. It has been described that an electrical barrier is formed to surround the exclusion area 120, thereby preventing the intrusion of aquatic organisms 101. As a modification, the voltage and frequency applied to the electrodes 162 may be changeable depending on the type of aquatic organism 101.

[0081] In the second embodiment, the groove 125 and the protrusion 126 are provided on the bottom of the water tank 110. As a modification, the groove 125 and the protrusion 126 may be provided on a circular water tank 110 as in the first embodiment, or on a rectangular parallelepiped water tank 110 as in the third embodiment.

[0082] The grooves 125 and protrusions 126 described in the second embodiment may be provided at equal intervals on the bottom of the aquarium 110, or may be provided at varying intervals. For example, the intervals may be shorter near the downstream side of the exclusion zone 120 and gradually longer as the fish move downstream toward the other exclusion zone 120. This method allows the food 104 immediately after feeding to remain in the breeding water for a long time, and the food 104 that has been fed for some time (residual food 103) to be quickly moved toward the exclusion zone 120.

[0083] In the second embodiment, the depth of the groove 125 is shallower than the length of the bait 104, and the height of the protrusion 126 is shorter than the length of the bait 104. The depth of the groove 125 and the height of the protrusion 126 may be changed depending on conditions such as the flow rate of the rearing water. For example, when the flow rate of the rearing water is fast, feeding frequency is low, or the density of aquatic organisms 101 (shrimp) in the rearing water is high, the bait 104 needs to be larger to ensure that the aquatic organisms 101 ingest the bait 104. As the bait 104 becomes larger, the sizes of the groove 125 and the protrusion 126 also need to be relatively larger. In such cases, the average movement speed of the bait 104 may be confirmed in advance through a demonstration experiment, and the optimal sizes of the groove 125 and the protrusion 126 may be determined based on the results.

[0084] In the third embodiment, the aquarium 110 is provided with two drain outlets 112. It has been described that the breeding water (debris) discharged from the first drain outlet 112a and the second drain outlet 112b both flow into the physical filter 140. As a modified example, only the drain pipe 117 extending from the first drain outlet 112a, which is dedicated to draining the breeding water, may be connected to the circulation path 111 consisting of the physical filter 140, the biological filtration tank 141, and the first pump 113. The drain pipe 117 extending from the second drain outlet 112b provided in the exclusion zone 120 may be connected to a second physical filter (not shown) separate from the physical filter 140. In other words, the debris in the aquarium 110 may be captured in a drainage path separate from the breeding water circulation path 111.

[0085] For example, a strainer is provided at the first drain outlet 112a, and small debris is collected in the physical filter 140 on the circulation path 111. A second physical filter on a drainage path separate from the circulation path 111 collects large debris that cannot pass through the strainer. In this manner, debris can be collected in the physical filter 140 and the second physical filter, respectively, and then separated. Furthermore, when the physical filter 140 and the second physical filter are provided, it is easier to collect only the shed shells 102 in the second physical filter, for example, compared to when only the physical filter 140 is provided. In other words, processing into a by-product can be easily performed.

[0086] In the third embodiment, the valve 129 is provided in the second drain outlet 112b. As a modification, the valve 129 may be provided in the drain pipe 117 extending from the second drain outlet 112b. That is, the second drain outlet 112b may be left open, and the discharge of waste may be controlled by opening and closing the valve 129 provided in the drain pipe 117. In this case, to prevent the discharge of aquatic organisms 101 (shrimp), an electrode 162 may be provided in a manner circumscribing the exclusion zone 120 including the second drain outlet 112b. Alternatively, a valve may be provided in the second drain outlet 112b in addition to the drain pipe 117, or a medium that repels aquatic organisms 101, such as a light-emitting body, a sound-producing body, or a bubble-generating device, may be provided in the second drain outlet 112b instead of the electrode 162.

[0087] In the third embodiment, it is assumed that the ratio of the area of ​​the second drain outlet 112b (valve 129) in the captured image showing the garbage reaches or exceeds a predetermined value. In this case, the retention determination unit 220 of the discharge control device 200 opens the valve 129 installed in the drain outlet 112 to discharge the garbage. As a modified example, the retention determination unit 220 determines whether or not an aquatic organism 101 (shrimp) is present above the second drain outlet 112b (valve 129) in the captured image. When the retention determination unit 220 determines that no shrimp is present above the second drain outlet 112b (valve 129), the retention determination unit 220 may cause the discharge control unit 230 to open the valve 129.

[0088] 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. An aquaculture device comprising: an aquarium for raising aquatic organisms; a water supply unit that supplies breeding water to the aquarium; a drainage unit that discharges the breeding water from the aquarium through a drain outlet formed in the aquarium; and an exclusion unit that applies, in water, both or one of a medium that repels the aquatic organisms and a medium that attracts the aquatic organisms, thereby preventing the aquatic organisms from invading a predetermined exclusion area set in the aquarium.

2. An aquaculture device as described in claim 1, wherein the water flow generated in the tank creates areas in the tank where the flow velocity is relatively high and areas where the flow velocity is relatively low, and the exclusion area is set in the area where the flow velocity is relatively low.

3. The aquaculture device described in claim 1, wherein a water flow generated in the aquarium creates an area in which unwanted objects generated in the aquarium accumulate, and the exclusion area is set in the area in which the unwanted objects accumulate.

4. The aquaculture device according to claim 1, wherein the exclusion area is set at the drain outlet.

5. An aquaculture device as described in claim 1, further comprising a feeding section that feeds the aquatic organisms into the tank, the specific gravity of the feed being equal to or greater than the specific gravity of the breeding water in the tank, and the bottom of the tank having grooves and / or protrusions that hinder the flow of the fed feed.

6. The aquaculture device according to claim 5, wherein the food for the aquatic organisms is solid food formed as a mass, the grooves are shallower than the length of the solid food, and the protrusions are protrusions with a height shorter than the length of the solid food.

7. The aquaculture device of claim 1, further comprising a feeding unit that feeds food for the aquatic organisms into the tank, wherein the tank is an elliptical tank having a partition plate extending longitudinally in the center, and the feeding unit feeds the food for the aquatic organisms downstream of a first retention area in which unwanted matter generated in the tank accumulates, upstream of a second retention area in which the unwanted matter accumulates, and at a point closer to the first retention area than the second retention area.

8. The aquaculture device according to claim 1, wherein the exclusion section generates an electric field in the exclusion area as a medium for repelling the aquatic organisms.

9. An aquaculture device as described in claim 1, wherein a first drain outlet and a second drain outlet are formed as the drain outlets, the drain section uses a pump to discharge the breeding water in the aquarium from both the first drain outlet and the second drain outlet, and the second drain outlet is formed in the exclusion area.

10. An aquaculture device as described in claim 9, further comprising: a camera that captures an image of the second drain outlet; and a retention determination unit that determines the amount of unwanted objects retained in the second drain outlet from the image captured by the camera, wherein the second drain outlet or the drain unit is configured to be openable and closable, and the drain unit discharges the unwanted objects from the second drain outlet when a predetermined discharge condition is met regarding the amount of unwanted objects retained.

11. The aquaculture device of claim 1, wherein the aquatic organisms are crustacean organisms.

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