Aquaculture green ecological circulation system with filtering sand cylinder

Abstract

The aquaculture green ecological circulation system comprises a culture box and a filter box, a partition net is arranged in the culture box, a plurality of arc-shaped hollow blocks are fixedly connected to the inner bottom of the culture box, and air nozzles are formed in the upper end, the left side and the right side of each arc-shaped hollow block; an air pump is installed on the front side of the breeding box, a plurality of supporting legs are fixedly connected to the lower end of the breeding box, the right sides of the two supporting legs located on the right side are jointly and fixedly connected with a strip-shaped box, the air outlet end of the air pump is communicated with the front side space of the strip-shaped box, and the rear side space of the strip-shaped box is communicated with a plurality of arc-shaped hollow blocks through air outlet pipes. According to the invention, the waste generated by breeding can be better cleaned, the filtering performance of the filter material is fully played, and continuous filtering can be carried out when the filter material is replaced, so that the stability of the breeding water quality is improved, the management cost is reduced, and the green and sustainable development of the breeding industry is promoted.

Description

Technical Field

[0001] This invention relates to the field of aquaculture technology, and in particular to a green ecological cycle system for aquaculture with a sand filter tank. Background Technology

[0002] In aquaculture, the stability and cleanliness of the aquatic environment directly affect the survival rate and growth quality of farmed organisms. Therefore, water circulation and filtration systems are a core component of aquaculture equipment. However, existing aquaculture circulation systems still have many technical limitations in practical applications, making it difficult to meet the demands for efficient, ecological, and low-cost aquaculture.

[0003] First, the existing systems are ineffective at removing waste, which can easily lead to water quality deterioration. During the aquaculture process, some of the waste produced by fish, such as feces and uneaten feed, will accumulate at the bottom of the aquaculture tank. Existing systems mostly rely on the natural flow of water to carry the waste into the filtration structure, lacking an active disturbance and directional transport mechanism. This results in long-term accumulation of waste at the bottom of the tank, which not only breeds harmful microorganisms but also leads to an increase in indicators such as ammonia nitrogen and nitrite in the water, increasing the risk of disease in farmed organisms. Frequent water changes are required to maintain water quality, which wastes water resources and affects the stability of aquaculture.

[0004] Secondly, low filtration efficiency and insufficient utilization of filter media are common problems. The spray structure of existing filtration systems is mostly a fixed design, and water can only be sprayed onto a local area of ​​the filter media. This easily causes local clogging and failure of the filter media, while the filter media in other areas does not play its full role, resulting in a decline in the overall filtration effect. At the same time, most systems only have one or two sets of filter media. When replacing the filter media, the filtration operation must be stopped, the water circulation is interrupted, which further affects the stability of water quality and increases the difficulty of aquaculture management.

[0005] Therefore, it is necessary to design a green ecological cycle system for aquaculture with a sand filter to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a green ecological cycle system for aquaculture with a filter sand tank. This invention can better clean up waste generated from aquaculture, fully utilize the filtration performance of the filter media, and continue filtration even when the filter media is replaced, thereby improving the stability of aquaculture water quality, reducing management costs, and promoting the green and sustainable development of the aquaculture industry.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A green ecological cycle system for aquaculture with a sand filter tank includes an aquaculture tank and a filter tank. The aquaculture tank is equipped with a mesh screen. Multiple arc-shaped hollow blocks are fixedly connected to the bottom of the aquaculture tank. Each arc-shaped hollow block has an air jet at its upper end and on both sides. An air pump is installed on the front side of the aquaculture tank. Multiple support legs are fixedly connected to the lower end of the aquaculture tank. A strip box is fixedly connected to the right side of the two support legs on the right side. The air outlet of the air pump is connected to the front space of the strip box. The rear space of the strip box is connected to the multiple arc-shaped hollow blocks through an air outlet pipe. By operating the air pump, the waste material deposited at the bottom of the aquaculture tank is lifted up.

[0008] Preferably, a circulation pump is installed on the right side of the breeding box, and the inlet end of the circulation pump is connected to the bottom space of the filter box through an inlet pipe. A return water hollow plate is installed on the inner wall of the right side of the breeding box, and the outlet end of the circulation pump is connected to the return water hollow plate through a return water pipe. Multiple return water ports are provided on the left side of the return water hollow plate, and an outlet is connected to the left side of the breeding box. An outlet pipe is connected to the left side of the outlet.

[0009] Preferably, a control panel is installed on the front side of the breeding box, a water spray hollow plate is installed on the inner right side of the breeding box, the return water pipe is connected to the water spray hollow plate through a bend, and a switching solenoid valve is provided between the return water pipe and the bend.

[0010] Preferably, the filter box is provided with two partitions, which divide the filter box into three spaces, and filter media is installed in each of the three spaces.

[0011] Preferably, the adjacent sides of the two cooperating support legs are rotatably connected to reciprocating screws, and the two reciprocating screws are threadedly connected to U-shaped frames. The lower end of the U-shaped frames is provided with a spray plate, and the lower end of the spray plate is provided with multiple spray nozzles. The multiple spray nozzles are located above the front and rear spaces of the filter box. The upper end of the reciprocating screws is equipped with a rotary joint, and the upper end of the rotary joint is connected to the water outlet pipe through a corrugated pipe. The lower end of the rotary joint is connected to the spray plate through a vertical pipe. The right side of the two reciprocating screws extends into the strip box and is fixedly connected to a fan.

[0012] Preferably, a vertical plate is fixedly connected inside the strip box, and the vertical plate is provided with air holes. The air holes and the air outlet end of the air injection pipe are on the same horizontal line, and the distance between the air holes and the corresponding impeller is the same as the distance between the air injection pipe and the corresponding impeller.

[0013] Preferably, a rectangular box is fixedly connected to the lower end of the U-shaped frame, the vertical tube passes through the rectangular box, a pneumatic rod is fixedly connected to the rear inner wall of the rectangular box, a moving block is fixedly connected to the telescopic end of the pneumatic rod, a gear is installed on the vertical tube, a rack that meshes with the gear is fixedly connected to the front side of the moving block, a turbidity sensor is installed on the front side of the filter box, and the sensing end of the turbidity sensor extends into the filter box.

[0014] The present invention has the following beneficial effects: 1. Compared with the prior art, the present invention generates convective airflow by driving the arc-shaped hollow block jet nozzle with an air pump. Combined with the directional water flow formed by the water spray hollow plate, it can thoroughly lift up the deposited feces and residual feed and bring them into the filter box. At the same time, the screen can prevent fish from interfering with the waste cleaning, greatly reduce the source of water pollution, and maintain the cleanliness of the aquaculture water in the long term. 2. Compared with the prior art, the present invention uses an air pump to drive the impeller to rotate the reciprocating screw, so that the spray plate moves back and forth with the U-shaped frame, expanding the spray coverage area and allowing the filter media to contact the water and waste evenly in all areas; at the same time, three sets of filter media are set up in the front, middle and rear, and the filter media can be used alternately by switching the spray plate, avoiding filtration interruption and further improving filtration efficiency. 3. Compared with the prior art, the present invention can start the air pump and switch the water flow path with one click through the control panel. The turbidity sensor can monitor the water quality in real time and automatically trigger the spray plate to turn, reducing manual intervention. There is no need to stop the machine when replacing the filter media. The intermediate filter media can temporarily take over the filtration work, reducing the complexity of operation and saving labor costs. 4. Compared with existing technologies, this invention achieves water reuse through a closed-loop circulation system, reducing the frequency of water changes and saving water resources; at the same time, the filter media is made of environmentally friendly materials such as quartz sand and biological filter media, which can naturally decompose some organic matter, avoiding the use of chemical agents, thus protecting the aquaculture ecology and reducing the input costs of agents and water resources.

[0015] In summary, this invention, through structural optimization and automated design, solves the problems of incomplete waste removal, low filtration efficiency, cumbersome operation, and resource waste in existing aquaculture systems. It achieves a balance between stable water quality, efficient filtration, convenient operation, and ecological energy conservation, significantly improving the economic and ecological benefits of aquaculture and possessing broad practical application value. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a green ecological cycle system for aquaculture with a sand filter tank proposed in this invention; Figure 2 for Figure 1 A structural diagram from the left side; Figure 3 for Figure 1A structural diagram from another perspective; Figure 4 for Figure 1 A half-section view; Figure 5 This is a schematic diagram of the structure of an arc-shaped hollow block; Figure 6 This is a structural diagram of the U-shaped frame and spray plate area; Figure 7 for Figure 6 Enlarged structural diagram at point A; Figure 8 This is a schematic diagram of the internal structure of the bar box.

[0017] In the diagram: 1. Breeding box, 2. Circulation pump, 3. Switching solenoid valve, 4. Return water pipe, 5. Bend, 6. Inlet water pipe, 7. Filter box, 8. Partition plate, 9. Filter media, 10. Control panel, 11. Air pump, 12. Air injection pipe, 13. Strip box, 14. Air outlet pipe, 15. Reciprocating screw, 16. U-shaped frame, 17. Spray plate, 18. Water outlet, 19. Return water hollow plate, 20. Turbidity sensor, 21. Water outlet pipe, 22. Corrugated pipe, 23. Partition mesh, 24. Arc-shaped hollow block, 25. Air jet, 26. Rotary joint, 27. Rectangular box, 28. Pneumatic rod, 29. Spray water hollow plate, 30. Spray nozzle, 31. Moving block, 32. Vertical pipe, 33. Gear, 34. Rack, 35. Fan wheel, 36. Vertical plate, 37. Air hole. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0019] Reference Figures 1-8A green ecological cycle system for aquaculture with a sand filter tank includes an aquaculture tank 1 and a filter tank 7. The filter tank 7 has two partitions 8, which are vertical plates of the same material as the filter tank 7. The height of the partitions 8 is 4 / 5 of the height of the filter tank 7. The partitions 8 are fixed to the inner wall of the filter tank 7 by hot-melt welding, and a 5-8cm gap is left between the bottom of the partitions 8 and the bottom of the filter tank 7 to facilitate the collection of filtered water. The two partitions 8 divide the filter tank 7 into three spaces, each containing filter media 9, which is a mixed layer of quartz sand and activated carbon. The aquaculture tank 1 has a mesh 23, which prevents farmed fish from entering the waste sedimentation area at the bottom of the tank while allowing water and waste particles smaller than the mesh size to pass through. Multiple arc-shaped hollow sections are fixedly connected to the inner bottom of the aquaculture tank 1. Block 24, multiple arc-shaped hollow blocks 24 are evenly distributed along the length of the bottom of the aquaculture tank 1. Each arc-shaped hollow block 24 has a jet nozzle 25 at its upper end and on both sides. An air pump 11 is installed on the front side of the aquaculture tank 1. Multiple support legs are fixedly connected to the lower end of the aquaculture tank 1. A strip box 13 is fixedly connected to the right side of the two support legs on the right side. The air outlet of the air pump 11 is connected to the front space of the strip box 13. The rear space of the strip box 13 is connected to the multiple arc-shaped hollow blocks 24 through an air outlet pipe 14. The air outlet pipe 14 includes a main pipe and multiple branch pipes. Each branch pipe is equipped with a check valve. By operating the air pump 11, the waste material deposited at the bottom of the aquaculture tank 1 is lifted. The airflow is ejected from the jet nozzle 25 at a speed of 1-2 m / s, which is sufficient to lift the deposited waste material into the water.

[0020] The right side of the breeding tank 1 is equipped with a circulation pump 2. The inlet of the circulation pump 2 is connected to the bottom space of the filter box 7 via an inlet pipe 6. A hollow return plate 19 is installed on the inner wall of the right side of the breeding tank 1. The outlet of the circulation pump 2 is connected to the hollow return plate 19 via a return pipe 4. Multiple return ports are provided on the left side of the hollow return plate 19. An outlet 18 is connected to the left side of the breeding tank 1. An outlet pipe 21 is connected to the left side of the outlet 18. The front side of the breeding tank 1 is equipped with... There is a control panel 10, which contains a controller. A water spray hollow plate 29 is installed on the inner right side of the breeding box 1. The return water pipe 4 is connected to the water spray hollow plate 29 through a bend 5. A switching solenoid valve 3 is installed between the return water pipe 4 and the bend 5. The switching solenoid valve is a two-position three-way solenoid valve with a nominal diameter that is the same as the inner diameter of the return water pipe 4. It is connected to the return water pipe 4 and the bend 5 through a flange. When the solenoid valve is energized, it opens the channel of the bend 5. When it is de-energized, it opens the channel of the return water hollow plate 19.

[0021] Two cooperating support legs are connected to reciprocating screws 15 on their adjacent sides. U-shaped brackets 16 are threaded onto the two reciprocating screws 15. A spray plate 17 is located at the lower end of the U-shaped bracket 16, and multiple spray nozzles 30 are located at the lower end of the spray plate 17. Initially, the multiple spray nozzles 30 are positioned above the front and rear spaces of the filter box 7, allowing water to enter the front and rear spaces of the filter box 7 for filtration. A rotary joint 26 is installed at the upper end of the reciprocating screws 15. The upper end of the rotary joint 26 is connected to the outlet pipe 21 via a corrugated pipe 22. The lower end of the device is connected to the spray plate 17 through the vertical pipe 32. The right side of the two reciprocating screws 15 extends into the strip box 13 and is fixedly connected to the impeller 35. The vertical plate 36 is fixedly connected inside the strip box 13. The vertical plate 36 is provided with air holes 37. The air holes 37 and the air outlet of the air injection pipe 12 are on the same horizontal line. The distance between the air holes 37 and the corresponding impeller 35 is the same as the distance between the air injection pipe 12 and the corresponding impeller 35. This ensures that the gas discharged from the air holes 37 and the gas sprayed from the air injection pipe 12 form a symmetrical driving force on the impeller 35, so that the impeller 35 rotates stably.

[0022] The U-shaped frame 16 has a rectangular box 27 fixedly connected to its lower end. A vertical tube 32 passes through the rectangular box 27. A pneumatic rod 28 is fixedly connected to the rear inner wall of the rectangular box 27. A moving block 31 is fixedly connected to the telescopic end of the pneumatic rod 28. A gear 33 is installed on the vertical tube 32. A rack 34 that meshes with the gear 33 is fixedly connected to the front side of the moving block 31. The rack 34 is a straight rack made of the same material as the gear 33. The length of the rack is consistent with the stroke of the pneumatic rod 28. The rack 34 is fixed to the front side of the moving block 31 by bolts. The tooth surface of the rack 34 fully meshes with the tooth surface of the gear 33, ensuring that the moving block 31... When moved, the gear 33 rotates synchronously. A turbidity sensor 20 is installed on the front side of the filter box 7. The turbidity sensor 20 is an online optical turbidity sensor with a measurement range of 0-1000 NTU and an accuracy of ±5%. The turbidity sensor 20 is fixed to the front wall of the filter box 7 through a threaded interface. The sensing end of the turbidity sensor 20 extends into the filter box 7, reaching 3-5 cm above the bottom of the filter box 7 to ensure direct contact with the water body to be monitored. It collects water turbidity data in real time and transmits the data to the controller for processing. The controller controls the pneumatic rod 28 based on the data.

[0023] The functional principle of this invention can be explained through the following operation: In the initial state, the circulating pump 2 is continuously running, and the power generated by its operation drives the water flow in the breeding tank 1. The water first flows out from the outlet 18 on the left side inside the breeding tank 1, enters the outlet pipe 21, is transported through the outlet pipe 21 to the rotary joint 26, and then through the vertical pipe 32 connected below the rotary joint 26, and finally is transported to the spray plate 17 at the lower end of the U-shaped frame 16. The lower end of the spray plate 17 is provided with multiple evenly distributed spray nozzles 30, and the water falls evenly into the independent spaces on the front and rear sides of the filter box 7 in the form of sprays through these spray nozzles 30.

[0024] The filter box 7 has two vertical partitions 8 inside, which strictly divide the internal space of the filter box 7 into three independent areas: front, middle, and rear. Each area is tightly filled with filter media 9 (the filter media can be quartz sand, activated carbon, biological filter media, etc., to remove different types of impurities). When water falls into the front and rear spaces of the filter box 7, it slowly permeates through the filter media 9 on both sides. The filter media 9 adsorbs, intercepts, and decomposes suspended impurities, some harmful microorganisms, and organic matter in the water, thereby purifying the water.

[0025] After being filtered by the filter media 9 on both the front and back sides, the water naturally drips into the bottom space inside the filter box 7 due to gravity (this space is a shared bottom area for the three zones, facilitating water collection). Subsequently, the inlet end of the circulation pump 2 is connected to the bottom space inside the filter box 7 through the inlet pipe 6. When the circulation pump 2 is running, it draws out the purified water collected here and then transports it to the return water hollow plate 19 installed on the inner wall of the right side of the aquaculture tank 1 through the return water pipe 4 connected to the outlet end of the circulation pump 2. The left side of the return water hollow plate 19 has multiple return water inlets facing the inside of the aquaculture tank 1. The purified water flows back into the aquaculture tank 1 evenly and gently through these return water inlets, providing clean water for the fish in the tank. This completes the basic water circulation filtration process in the initial state.

[0026] During this stage, the excrement produced by the fish in the breeding tank 1, as well as the uneaten food after feeding, will have two destinations: part of it cannot pass through the mesh 23 set in the breeding tank 1 due to its own gravity (the mesh 23 is installed horizontally in the middle and lower part of the breeding tank 1, which can prevent fish from entering the bottom area of ​​the tank, while allowing water and small waste to pass through), and gradually settles at the bottom of the breeding tank 1; the other part flows into the outlet pipe 21 along with the water flow in the initial circulation stage, and finally enters the filter box 7, where it is intercepted by the filter media 9 on the front and back sides.

[0027] As the system runs for longer, more and more waste will accumulate at the bottom of the aquaculture tank 1. If not cleaned in time, this can easily lead to water deterioration. At this time, the staff will issue two key control commands through the control panel 10 installed on the front of the aquaculture tank 1 (the control panel 10 is electrically connected to the electrical components in the system and can send control commands): one is to start the air pump 11, and the other is to control the operation of the electromagnetic switching valve between the return water pipe 4 and the bend pipe 5.

[0028] After the electromagnetic switching valve is activated, it changes the water flow path in the return water pipe 4, causing the circulating pump 2 to deliver a portion of the water to the return water pipe 4. This water is then diverted through the bend 5 to the hollow spray plate 29 installed on the inner right side of the breeding tank 1. The water is sprayed to the left through the spray nozzles of the hollow spray plate 29, forming a stable, directional water flow from left to right in the lower area of ​​the partition net 23. This water flow provides the power for the subsequent movement of waste materials.

[0029] Simultaneously, after the air pump 11 is started, it draws in and pressurizes outside air. The pressurized gas is then delivered through the air outlet of the air pump 11 to the front space of the strip box 13 connected to the right support leg of the breeding box 1. Subsequently, the gas in the rear space of the strip box 13 is delivered through multiple air outlet pipes 14 to multiple arc-shaped hollow blocks 24 fixedly connected to the bottom of the breeding box 1. Each arc-shaped hollow block 24 has air jets 25 on its upper surface and left and right sides. The gas is ejected at high speed from these air jets 25. Since the air jets from the air jets 25 of two adjacent arc-shaped hollow blocks 24 are directed in opposite directions, an air convection effect is formed. This effect can effectively lift the waste (feces, residual feed) deposited at the bottom of the breeding box 1 from the bottom of the box. The lifted waste is carried by the water flow from left to right formed by the water spray hollow plate 29 and flows into the water outlet pipe 21 with the water flow, and finally enters the filter box 7. It is intercepted and filtered by the filter media 9 on the front and back sides, thus achieving thorough cleaning of the waste at the bottom of the breeding box 1.

[0030] During the operation of the air pump 11, some of the gas in the front space of the strip box 13 will also flow through the air holes 37 on the vertical plate 36 to the two impellers 35 installed in the rear space of the strip box 13. The airflow impacts the blades of the impellers 35, causing the impellers 35 to rotate around their own axis. The central axis of the impellers 35 is fixedly connected to the right end of the reciprocating screw 15, so when the impellers 35 rotate, they will synchronously drive the two reciprocating screws 15 to rotate.

[0031] When the reciprocating screw 15 rotates, the reciprocating threads on its surface drive the U-shaped frame 16, which is threaded to it, to reciprocate left and right along the axis of the reciprocating screw 15. When the U-shaped frame 16 moves, it drives the spray plate 17 at the lower end to move left and right synchronously. The movement of the spray plate 17 ensures that the water sprayed from the spray nozzle 30 at the lower end can cover the entire upper area of ​​the space on both sides of the filter box 7, preventing the water from being concentrated on a certain part of the filter media 9, which would cause the local filter media 9 to become clogged due to excessive accumulation of waste. This ensures that the filter media 9 on both sides can be fully utilized, thereby improving the overall filtration efficiency.

[0032] As the filter media 9 is used for an extended period, the impurities it adsorbs and intercepts will gradually become saturated, leading to a decrease in filtration efficiency and an increase in turbidity in the water at the bottom of the filter box 7. At this time, the turbidity sensor 20 installed on the front of the filter box 7 will monitor the turbidity of the water in real time and convert the monitored turbidity data into an electrical signal, which is then transmitted to the system controller. When the controller determines that the turbidity data exceeds a preset threshold, it will automatically send a control command to retract the pneumatic rod 28 inside the rectangular box 27 at the lower end of the U-shaped frame 16.

[0033] The telescopic end of the pneumatic rod 28 is fixedly connected to the movable block 31. When it retracts, it drives the movable block 31 to move backward along the inner wall of the rectangular box 27. A rack 34 is fixedly connected to the front side of the movable block 31. The rack 34 meshes with the gear 33 installed on the vertical tube 32. Therefore, when the movable block 31 moves, the rack 34 drives the gear 33 to rotate around the axis of the vertical tube 32. The gear 33 is fixedly connected to the vertical tube 32, which in turn drives the vertical tube 32 and the spray plate 17 connected to the lower end to rotate together until the spray plate 17 rotates 90 degrees. At this time, the spraying direction of the spray plate 17 changes. The water transported from the breeding tank 1 passes through the spray plate 17 and no longer falls into the front and rear sides of the filter box 7, but instead falls onto the filter media 9 in the middle area, where the filter media 9 temporarily undertakes the filtration work.

[0034] During the operation of the filter media 9 in the middle area, the staff can replace the saturated filter media 9 on both the front and back sides. After the filter media 9 on both the front and back sides have been replaced, the staff presses the reset button on the control panel 10. The control panel 10 sends a reset command to the controller, which controls the pneumatic rod 28 to extend, driving the moving block 31 to move forward and back. The rack 34 moves in the opposite direction, driving the gear 33, the vertical pipe 32 and the spray plate 17 to rotate 90 degrees in the opposite direction. The spray plate 17 returns to its initial position and sprays water into the space on both sides of the filter box 7 again. The new filter media 9 is then put into use to continue to filter the water efficiently, ensuring the continuous and stable operation of the system.

[0035] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A green ecological cycle system for aquaculture with a sand filter, comprising an aquaculture tank (1) and a filter tank (7), characterized in that: The breeding box (1) is equipped with a partition net (23). Multiple arc-shaped hollow blocks (24) are fixedly connected to the bottom of the breeding box (1). Each arc-shaped hollow block (24) has an air jet port (25) at its upper end and on both sides. An air pump (11) is installed on the front side of the breeding box (1). Multiple support legs are fixedly connected to the lower end of the breeding box (1). A strip box (13) is fixedly connected to the right side of the two support legs on the right side. The air outlet of the air pump (11) is connected to the front space of the strip box (13). The rear space of the strip box (13) is connected to the multiple arc-shaped hollow blocks (24) through an air outlet pipe (14). By operating the air pump (11), the waste material deposited at the bottom of the breeding box (1) is lifted up.

2. The aquaculture green ecological cycle system with a sand filter tank according to claim 1, characterized in that: A circulation pump (2) is installed on the right side of the breeding box (1). The inlet end of the circulation pump (2) is connected to the bottom space of the filter box (7) through the water inlet pipe (6). A return water hollow plate (19) is installed on the inner wall of the right side of the breeding box (1). The outlet end of the circulation pump (2) is connected to the return water hollow plate (19) through the return water pipe (4). Multiple return water ports are provided on the left side of the return water hollow plate (19). An outlet (18) is connected to the left side of the breeding box (1). An outlet pipe (21) is connected to the left side of the outlet (18).

3. The aquaculture green ecological cycle system with a sand filter tank according to claim 2, characterized in that: A control panel (10) is installed on the front side of the breeding box (1), and a water spray hollow plate (29) is installed on the inner right side of the breeding box (1). The return water pipe (4) is connected to the water spray hollow plate (29) through a bend (5). A switching solenoid valve (3) is provided between the return water pipe (4) and the bend (5).

4. The aquaculture green ecological cycle system with a sand filter tank according to claim 2, characterized in that: The filter box (7) is provided with two partitions (8), which divide the filter box (7) into three spaces, and filter media (9) are installed in each of the three spaces.

5. The aquaculture green ecological cycle system with a sand filter tank according to claim 4, characterized in that: Two cooperating legs are connected to a reciprocating screw (15) on their adjacent sides. A U-shaped frame (16) is threaded onto the two reciprocating screws (15). A spray plate (17) is provided at the lower end of the U-shaped frame (16). A plurality of spray nozzles (30) are provided at the lower end of the spray plate (17). The plurality of spray nozzles (30) are located above the front and rear spaces of the filter box (7). A rotary joint (26) is installed at the upper end of the reciprocating screw (15). The upper end of the rotary joint (26) is connected to the water outlet pipe (21) through a corrugated pipe (22). The lower end of the rotary joint (26) is connected to the spray plate (17) through a vertical pipe (32). The right side of the two reciprocating screws (15) extends into the strip box (13) and is fixedly connected to a fan wheel (35).

6. The aquaculture green ecological cycle system with a sand filter tank according to claim 5, characterized in that: A vertical plate (36) is fixedly connected inside the strip box (13). The vertical plate (36) is provided with an air hole (37). The air hole (37) and the air outlet of the air injection pipe (12) are on the same horizontal line. The distance between the air hole (37) and the corresponding impeller (35) is the same as the distance between the air injection pipe (12) and the corresponding impeller (35).

7. A green ecological cycle system for aquaculture with a sand filter tank according to claim 5, characterized in that: A rectangular box (27) is fixedly connected to the lower end of the U-shaped frame (16). The vertical tube (32) passes through the rectangular box (27). A pneumatic rod (28) is fixedly connected to the inner rear wall of the rectangular box (27). A moving block (31) is fixedly connected to the telescopic end of the pneumatic rod (28). A gear (33) is installed on the vertical tube (32). A rack (34) that meshes with the gear (33) is fixedly connected to the front side of the moving block (31). A turbidity sensor (20) is installed on the front side of the filter box (7). The sensing end of the turbidity sensor (20) extends into the filter box (7).

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