Aquaculture pond dredging device

Abstract

This invention provides a sludge removal device for aquaculture ponds, which can adaptively distribute the water flow for flushing sludge and driving the turbine of a waterwheel assembly based on the travel speed at the bottom of the pond using hydraulic power. The sludge removal device has at least one cover plate and one water inlet pipe assembly radially arranged on the side of a central base. At the end of the cover plate and water inlet pipe assembly, a set of waterwheel assemblies is installed to receive the water flow from the water inlet pipe assembly, thereby driving the entire sludge removal device to rotate at the bottom of the pond. Simultaneously, it flushes the sludge at the bottom of the pond and guides it to form a vortex-like water flow, which is then concentrated and discharged from the central drain outlet, preventing the sludge from spreading. In particular, when the travel speed of the sludge removal device slows down, causing increased resistance to the water flow entering the waterwheel assembly, the water flow for flushing the sludge at the bottom of the pond can be adaptively increased to improve its flushing capacity, effectively solving the shortcomings of known technologies such as poor sludge removal efficiency and inconvenient maintenance.

Description

Technical Field

[0001] This invention relates to a sludge removal device for aquaculture ponds. The technical content involves using a water-driven waterwheel assembly to drive the entire sludge removal device to rotate and move around at the bottom of the pond. The waterwheel assembly can adaptively distribute the amount of water used to flush the sludge and drive the turbine of the waterwheel assembly according to the speed of movement. Background Technology

[0002] In aquaculture management, the accumulation of silt at the bottom of the pond has always been a major technical bottleneck that the industry is eager to overcome. Silt is primarily generated by human feeding; the higher the stocking density and the greater the amount of feed, the faster the silt accumulates. The silt contains fish and shrimp feces, uneaten feed, dead and deposited microalgae, and soil particles washed away by water flow. It is rich in organic matter, resulting in a very high bacterial count. This not only consumes dissolved oxygen in the water, creating an anaerobic environment, but also produces highly toxic hydrogen sulfide and continuously releases toxic ammonia (NH3).

[0003] Taking shrimp farming as an example, research shows that shrimp are very sensitive to the toxicity of hydrogen sulfide. As long as there is 0.0064 ppm of hydrogen sulfide in the water, shrimp will become stressed, and 0.013 ppm of hydrogen sulfide will paralyze them. The specific gravity of silt is only slightly greater than that of water, and it is easy to suspend in the water with the slightest disturbance, so it is difficult to remove. Especially in the later stages of farming, the amount of silt accumulated is huge, and the amount of feed increases, which increases the load on water quality. It is like a dangerous time bomb, which can easily induce diseases and mass mortality when the weather is bad or when there is a lack of oxygen at night.

[0004] Many studies recommend regular sludge removal during aquaculture, especially in high-density shrimp ponds where daily sludge removal is ideal. However, sludge removal must be done with extreme care, as even slight mishaps can disturb the sludge and release hydrogen sulfide, increasing the risk. Therefore, how to quickly and safely remove sludge has always been a difficult problem for aquaculture. Removing sludge raises concerns about hydrogen sulfide release, while neglecting to remove it leads to water quality deterioration, posing a significant hidden danger and threat to aquaculture operators and limiting stocking densities.

[0005] To solve the problem of removing silt from aquaculture ponds, one of the inventors in this case previously invented a Taiwan patent with publication number TWI331012, "Method and Apparatus for Removing Sediments from Aquaculture Ponds". Its structure is a rotatable and movable cover plate installed below the water surface. The inner end of the cover plate is fitted onto the drain outlet of the aquaculture pond, and a roller is pivotally mounted on the outer end. The roller is driven by a motor and transmission chain installed on the water surface, so that the roller can drive the cover plate to rotate around the drain outlet as the axis.

[0006] The cover plate has a row of brushes on its edge facing downwards in the direction of travel, making the cross-section of the cover plate roughly L-shaped and creating a semi-enclosed area between the cover plate and the top surface of the pool bottom. The bottom surface of the cover plate is equipped with multiple nozzles. When the roller drives the cover plate to rotate and move forward, the multiple nozzles can continuously spray water towards the drain outlet, so that the water flow washes away the silt at the bottom of the pool and causes the silt to move quickly to the drain outlet and be discharged.

[0007] Because a semi-enclosed area is created between the cover plate, the brush, and the top surface of the pool, the water jets from the multiple nozzles can generate a wall-jet effect. Furthermore, the Ippen principle creates negative pressure in the direction of the cover plate, allowing the water in the aquaculture pool to flow downwards from the cover plate. This, in turn, helps the water jets from the nozzles carry the sludge towards the drain and out, avoiding the problem of sludge spreading as in traditional methods of directly flushing it away. This achieves the effect of quickly removing sludge.

[0008] The aforementioned Taiwan patent TWI331012, after implementation, does indeed prevent the release of hydrogen sulfide during sludge removal due to disturbance, and offers advantages such as rapid sludge removal and reduced labor costs. However, the motor in TWI331012 must be positioned on the water surface, while the rollers are located at the bottom of the pool, with a distance of 2 to 3 meters or even longer between them. This results in an excessively long chain drive distance, especially when the rollers travel over uneven pool bottoms, causing the chain to alternate between loose and tight states, making it prone to loosening and malfunction. Furthermore, the uneven pool bottom frequently hinders the movement of the entire device, yet the motor continues to output power, which not only easily leads to motor damage and affects sludge removal efficiency, but also requires professional personnel to inspect and repair the chain, motor, and other drive components in the center of the aquaculture pool, incurring significant time and cost in maintenance. Therefore, the inventor envisions that further improvements to the known drive method could further enhance its practicality. Summary of the Invention

[0009] The purpose of this invention is to provide a sludge removal device for aquaculture ponds. This device uses hydraulic power to rotate and move around the bottom of the aquaculture pond while flushing and removing sludge. In particular, it can adaptively distribute the amount of water used to flush the sludge and drive the turbine of the waterwheel component according to the speed of movement, so as to achieve the purpose of removing sludge quickly and at a relatively low cost.

[0010] To achieve the above objectives, the present invention provides a sludge removal device for aquaculture ponds, which utilizes hydraulic power to rotate and move along the bottom of the pond while simultaneously flushing and removing sludge. The device includes:

[0011] A rotatable shaft is connected to a central seat of a drain outlet in the aquaculture pond. The central seat has a water inlet chamber and a drain chamber that are isolated from each other at the top and bottom. The water inlet chamber is connected to an external water pump for water intake. The drain chamber is located inside a housing that covers the upper outer perimeter of the drain outlet and has an opening on the side.

[0012] At least one cover plate is fixed to the side of the middle seat and extends radially. The cover plate can rotate synchronously with the middle seat and is inclined upward in the direction of travel. A scraper is provided at the bottom of the cover plate near the bottom of the aquaculture pond.

[0013] At least one set of inlet pipe assemblies extending radially from the inlet chamber, the inlet pipe assembly having at least one downwardly extending nozzle located below the cover plate and in front of the scraper, and the nozzle being able to spray water toward the opening of the drain chamber;

[0014] A waterwheel assembly is installed at the end of the inlet pipe assembly and the outer end of the cover plate. The waterwheel assembly includes a turbine that receives water flow from the inlet pipe and rotates accordingly, and a roller driven by the turbine to roll along the bottom of the aquaculture pond. This roller drives the entire sludge removal device to rotate around the drain outlet. During this rotation, the nozzle continuously sprays water towards the drain chamber, causing the sludge located below the cover plate and in front of the scraper to be flushed away by the water flow and discharged from the drain outlet.

[0015] When the waterwheel assembly slows down, increasing the resistance of the water flow entering the turbine through the inlet pipe assembly, the water flow rate distributed to the nozzle by the inlet pipe assembly increases relatively, thereby adaptively enhancing the flushing ability of the silt at the bottom of the pool.

[0016] The following further explains the implementation methods of each component:

[0017] In practice, a shaft sleeve extends downward from the top of the outer shell relative to the drain outlet; a drain pipe is provided inside the drain outlet, connecting to the outside of the aquaculture pond, and an upwardly extending shaft pipe is inserted and fixed on the drain pipe, and the shaft sleeve is sleeved on the shaft pipe, so that the outer shell and the shaft sleeve of the middle seat can rotate relative to the drain outlet and the shaft pipe with the shaft pipe as the axis.

[0018] During implementation, the pipe wall of the shaft connector is provided with multiple perforations, and each perforation is equipped with a movable door that can be automatically pushed by the water flow to open to the inside of the pipe wall.

[0019] In practice, the housing is detachably provided with an arc-shaped baffle that bends toward the drain cavity at the edge of the opening, so that the water flowing into the drain cavity from the opening forms a vortex-like flow along the baffle and is discharged from the drain outlet.

[0020] In practice, the water inlet chamber is located above the outer casing and includes an outer sleeve fixed above the outer casing, an inner tube axially located inside the outer sleeve, and a water inlet connector connecting the external water pump and the inner tube. The internal space of the outer sleeve forms the water inlet chamber, and its side is used for connecting the water inlet pipe assembly. The bottom of the water inlet connector is connected in series with the inner tube, so that the outer casing can synchronously drive the outer sleeve to rotate relative to the water inlet connector and the inner tube.

[0021] In practice, the waterwheel assembly further includes a support frame fixed to the outer end of the cover plate. The turbine and the roller are respectively pivotally mounted on the support frame, and a set of reduction gears and a chain are provided between the turbine and the roller, so that the turbine can drive the roller to rotate through the reduction gears and the chain.

[0022] In practice, the water inlet pipe assembly is provided with a bypass port connecting to the aquaculture pond near the end, and is provided with at least one set of switching valves that can distribute the flow of water from the turbine to the bypass port.

[0023] In practice, the outer end of the cover plate can be connected and abutted to the inner end of another cover plate, and an auxiliary wheel that can roll and move on the bottom of the pool is provided at the position where the two cover plates are connected and abutted. The auxiliary wheel is straddling the bottom surface of the two cover plates.

[0024] In practice, the water inlet pipe assembly includes at least a rigid pipe, a conical pipe, and a pipe connector connected in series. The nozzle extends downward from the rigid pipe and is positioned below the cover plate. The pipe connector can be connected to another water inlet pipe assembly so that its length can match the two interconnected cover plates.

[0025] In practice, the cover plate is equipped with a second auxiliary wheel behind the scraper, which can roll along the bottom of the pool.

[0026] Compared with prior art, the present invention has the following advantages:

[0027] 1. The present invention is set up entirely underwater and uses water power to drive the waterwheel assembly. The waterwheel assembly drives the entire dredging device to rotate and move around at the bottom of the pool, which improves upon the shortcomings of known technologies that use motors as power sources and are inconvenient to maintain.

[0028] 2. The present invention utilizes hydraulic drive to propel the entire dredging device in a circular motion at the bottom of the pool. Simultaneously, it can adaptively distribute the flow rate of water driving the turbine and flushing the sludge according to the speed of travel. When the resistance of the water flow from the inlet pipe assembly to the turbine of the waterwheel assembly increases, the flow rate of water distributed to the nozzle increases accordingly, thereby adaptively enhancing the flushing ability of the sludge at the bottom of the pool.

[0029] 3. The present invention provides an arc-shaped baffle on the side of the drainage chamber, so that after the sludge is pushed into the drainage chamber by the water flow, it can form a vortex-like water flow along the baffle and be concentrated and quickly discharged from the drainage outlet, thus avoiding the problem of sludge spreading due to the water flow washing the sludge back into the aquaculture pond.

[0030] 4. The cover plate and water inlet pipe assembly can be connected and expanded in a modular design. The turning radius of the sludge removal device can be adjusted according to the size of the aquaculture pond and the density of the sludge removal device, thus expanding the scope of application. Moreover, the modular design allows for a margin of movement between multiple cover plates and multiple water inlet pipe assemblies, which can accommodate slightly uneven pond bottom surfaces.

[0031] The following describes embodiments suitable for this invention, based on the technical means of this invention, and in conjunction with the accompanying drawings. Attached Figure Description

[0032] Figure 1 This is a perspective view of the present invention.

[0033] Figure 2 This is a three-dimensional view of the present invention from another angle.

[0034] Figure 3 This is a perspective view of the waterwheel assembly of the present invention.

[0035] Figure 4 This is a schematic diagram of the structure of the middle seat of the present invention.

[0036] Figure 5 This is a schematic diagram of the water flow from the water inlet chamber and water inlet pipe assembly to the nozzle and waterwheel assembly of the present invention.

[0037] Figure 6 This is a side view of the waterwheel assembly of the present invention.

[0038] Figure 7 This is a schematic diagram of the invention rotating and moving at the bottom of the aquaculture pond.

[0039] Figure 8 This is a schematic diagram of the water flow used in this invention to flush and remove silt from the bottom of a pool.

[0040] Explanation of reference numerals in the attached drawings: 100 sludge removal device; 200 pool bottom; 201 drain outlet; 202 drain pipe; 203 shaft connector; 204 perforation; 205 movable door panel; 206 drainage device; 300 water pump; 10 center seat; 11 water inlet chamber; 111 outer sleeve; 112 inner pipe; 113 water inlet connector; 12 drain chamber; 121 outer shell; 13 opening; 14 shaft connector sleeve; 15 arc-shaped baffle; 20 cover plate; 21 scraper; 22 auxiliary wheel; 23 second auxiliary wheel; 30 water inlet pipe assembly; 31 nozzle; 32 bypass port; 33 switch valve; 34 rigid pipe; 35 conical pipe; 36 pipe joint; 40 waterwheel assembly; 41 support frame; 42 turbine; 43 roller; 44 reduction gear set and chain. Detailed Implementation

[0041] like Figures 1 to 5 As shown, the present invention provides a sludge removal device 100 for aquaculture ponds, which uses water power to drive the device to rotate and move around the bottom 200 of the aquaculture pond while flushing and removing the sludge at the bottom 200. The sludge removal device 100 includes a central base 10, at least one cover plate 20, at least one water inlet pipe assembly 30, and a waterwheel assembly 40.

[0042] The middle seat 10 is rotatably connected to the drain outlet 201 of the aquaculture pond. The top and bottom of the middle seat 10 have a water inlet chamber 11 and a drain outlet chamber 12 that are isolated from each other. The water inlet chamber 11 is connected to an external water pump 300 for water intake. The drain outlet chamber 12 is located above and around the drain outlet 201, and has an opening 13 on the side so that the water in the aquaculture pond can enter the drain outlet chamber 12 through the opening 13 and then be discharged from the drain outlet 201.

[0043] To allow the middle seat 10 to rotate relative to the drain outlet 201 of the aquaculture pond, in practice, the drain cavity 12 of the middle seat 10 is located inside a housing 121, which covers the area around the drain outlet 201. A shaft sleeve 14 extends downward from the top of the housing 121 relative to the drain outlet 201. A drain pipe 202 communicating with the outside is provided inside the drain outlet 201. An upwardly extending shaft connector 203 is inserted and fixed onto the drain pipe 202, and the shaft sleeve 14 is fitted onto the shaft connector 203, allowing the housing 121 of the middle seat 10 and its drain cavity 12 to rotate relative to the drain outlet 201 and the shaft connector 203 with the shaft connector 203 as the axis.

[0044] The water inlet chamber 11 is located above the outer casing 121 and includes an outer sleeve 111 fixed above the outer casing 121, an inner tube 112 axially located inside the outer sleeve 111, and a water inlet connector 113 connecting the external water pump 300 and the inner tube 112. The internal space of the outer sleeve 111 forms the water inlet chamber 11, and its side is used for the connection of the water inlet pipe assembly 30. The bottom of the water inlet connector 113 is connected in series with the inner tube 112, so that the outer casing 121 can synchronously drive the outer sleeve 111 to rotate relative to the water inlet connector 113 without affecting the water inlet connector 113, the inner tube 112, and the external water pump 300 to inject water into the water inlet chamber 11.

[0045] The cover plate 20 is fixed above the side opening 13 of the middle seat 10 and rotates synchronously with the middle seat 10. The cover plate 20 is inclined upward in the direction of travel so as to cover the sludge on the bottom of the pond 200 when it moves. A scraper 21 is provided at the bottom rear of the cover plate 20 near the bottom of the aquaculture pond 200, so that the cross section of the cover plate 20 and the scraper 21 combined is roughly inverted L-shaped and creates a semi-enclosed area between the cover plate 20 and the top surface of the bottom of the pond 200.

[0046] The water inlet pipe assembly 30 extends radially from the water inlet chamber 11. The water inlet pipe assembly 30 is provided with at least one downwardly extending water inlet pipe assembly nozzle 31. The nozzle 31 is located below the cover plate 20 and in front of the scraper 21, and the nozzle 31 can spray water towards the opening 13 of the drain chamber 12. Since a semi-enclosed area is formed between the cover plate 20, the scraper 21 and the top surface of the pool bottom 200, the water sprayed by the nozzle 31 can generate a wall-jet effect, and according to the Bernoulli principle, a negative pressure is generated in the direction towards the cover plate 20, so that the aquaculture pool water can flow towards the bottom of the cover plate 20, thereby assisting the water sprayed by the nozzle 31 to carry the sludge along the scraper 21 towards the drain chamber 12 and then discharge it, while avoiding the spread of sludge.

[0047] like Figure 6 As shown, the waterwheel assembly 40 includes a support frame 41 fixed to the outer end of the cover plate 20. A turbine 42 and a roller 43 are pivotally mounted on the support frame 41 at the end of the water inlet pipe assembly 30. A reduction gear set and a chain 44 are provided between the turbine 42 and the roller 43. The turbine 42 rotates due to the impact of the water flow from the water inlet pipe assembly 30, and drives the roller 43 to roll on the bottom of the aquaculture pond 200 via the reduction gear set and chain 44. Figures 4 to 7 As shown, the water truck assembly 40 drives the entire sludge removal device 100 to rotate around the drain outlet 201 as the axis. During the movement, the nozzle 31 continuously sprays water toward the drain chamber 12, so that the sludge at the bottom of the pool 200 located below the cover plate 20 and in front of the scraper 21 is washed away by the water flow toward the drain chamber 12 and discharged through the shaft connector 203, the drain outlet 201 and the drain pipe 202.

[0048] In practice, the pipe wall of the shaft connector 203 is provided with a plurality of perforations 204. Each perforation 204 is equipped with a movable door 205 that can be automatically pushed inward by the water flow, allowing the sludge to flow into the drain pipe 202 and then be discharged. In addition, to ensure that the sludge can be discharged from the drain pipe 202, an external drainage device 206 is provided at the downstream end of the drain pipe 202. The external drainage device 206 can generate suction to draw in the sludge in the drain pipe 202, allowing the sludge to be discharged from the drain pipe 202 more smoothly.

[0049] With the above structure, the aquaculture pond dredging device 100 of the present invention can be submerged underwater as a whole, and the dredging is carried out by the hydraulic drive of an external pump. This reduces the vertical distance between the turbine 42 and the roller 43 by a lot compared to known technologies, overcoming the lack of power from motors and long chains in the prior art.

[0050] In addition, another feature of the present invention is that when the speed of the waterwheel assembly 40 slows down, resulting in increased resistance to the water flow entering the turbine 42 after passing through the water inlet pipe assembly 30, the water flow rate distributed by the water inlet pipe assembly 30 to the nozzle 31 increases relatively, thereby adaptively enhancing the flushing ability of the silt at the bottom of the pool 200.

[0051] For example, when the waterwheel assembly 40 of the entire dredging device 100 slows down due to the thick silt at the bottom of the pool 200, the water flow resistance from the inlet pipe 30 to the turbine 42 increases. In this case, the water flow in the inlet pipe assembly 30 can automatically increase the water flow distributed to the nozzle 31 to adaptively enhance the flushing ability of the silt at the bottom of the pool 200. After removing the silt at the bottom of the pool 200, the entire dredging device 100 can continue to rotate and move forward, effectively solving the shortcomings of known technologies such as poor dredging efficiency and inconvenient maintenance.

[0052] Furthermore, the dredging device 100 can also be manually adjusted in terms of its travel speed to accommodate adjustments in the size of the aquaculture pond or the stocking density. During implementation, the inlet pipe assembly 30 has a bypass port 32 near its end, connecting to the aquaculture pond, and at least one set of switching valves 33 that can distribute the water flow from the turbine 42 to the bypass port 32, adjusting the water flow to the turbine 42 according to the sludge deposition status, thereby adjusting the travel speed of the dredging device 100.

[0053] like Figure 2 , Figure 4 , Figure 8As shown, during implementation, the outer casing 121 has an arc-shaped baffle 15 that curves toward the drainage chamber 12 at the edge of the opening 13. When the entire sludge removal device 100 rotates and moves, the sludge at the bottom 200 of the pool located below the cover plate 20 and in front of the scraper 21 is pushed by the water flow toward the opening 13 and enters the drainage chamber 12. Guided by the baffle 15, the water forms a vortex-like flow and is discharged quickly and concentratedly from the drain outlet 201. This prevents the water from entering the drainage chamber 12 from flowing back into the pool water from the opening 13 if it cannot be discharged from the drain outlet 201 in time, thus avoiding the problem of sludge spreading.

[0054] When implementing the aforementioned arc-shaped baffle 15, it is best to fix it to the outer casing 121 in a detachable manner for the purpose of facilitating maintenance. For example, when the area around the drain outlet 201 is blocked by large fish carcasses or other debris, the arc-shaped baffle 15 can be removed to allow personnel to reach into the drain chamber 12 to remove the blockage.

[0055] Furthermore, to adapt to different pond sizes, the dredging device 100 features a modular design for the cover plate 20 and the water inlet pipe assembly 30. During implementation, the outer end of the cover plate 20 can connect and abut with the inner end of another cover plate 20. An auxiliary wheel 22 spanning between the bottom surfaces of the two cover plates 20 is located at the point where they connect and abut. A second auxiliary wheel 23 is located behind the scraper blade 21 on the cover plate 20. The auxiliary wheel 22 and the second auxiliary wheel 23 can roll along the bottom of the pond to assist the roller 43 in driving the entire dredging device 100 forward. During implementation, a handle is provided on the side edge of the cover plate 20 for the user to apply force to move the cover plate 20 for modular assembly.

[0056] like Figure 1 , Figure 2 , Figure 6 As shown, in practice, the water inlet pipe assembly 30 includes at least a rigid pipe 34, a conical pipe 35, and a pipe connector 36 connected in series. The nozzle 31 extends downward from the rigid pipe 34 and passes through the cover plate 20, positioned below the cover plate 20. The pipe connector 36 can be connected to another water inlet pipe assembly 30 so that its length can match the two interconnected cover plates 20, achieving a modular function. In this way, the number of cover plates 20 and water inlet pipe assemblies 30 assembled can be adjusted according to the size of the aquaculture pond and the density of the sludge removal device 100, and the turning radius of the sludge removal device 100 can be adjusted.

[0057] As shown in the figure, the cover plate 20 is basically composed of a metal frame and a plastic plate set in the frame. It has a slight bending elasticity. Therefore, when the entire sludge removal device 100 moves on the uneven pond bottom 200, the metal frame of the cover plate 20 and the serpentine tube 35 of the water inlet pipe assembly 30 can provide cushioning and mobility by bending slightly. It can be used in both indoor and outdoor aquaculture ponds, making its application range wider.

[0058] The above descriptions and accompanying drawings are merely illustrative of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any embodiments that are similar to or identical to the purpose, structure, device, or features of the present invention should fall within the patent protection scope of the present invention.

Claims

1. A sludge removal device for aquaculture ponds, characterized in that it utilizes hydraulic power to rotate and move along the bottom of the pond while simultaneously flushing and removing sludge, and is characterized in that... The device includes: A rotatable shaft is connected to a central seat of a drain outlet in the aquaculture pond. The central seat has a water inlet chamber and a drain chamber that are isolated from each other at the top and bottom. The water inlet chamber is connected to an external water pump for water intake. The drain chamber is located inside a housing. The housing covers the upper outer perimeter of the drain outlet and has an opening on the side. At least one cover plate is fixed to the side of the middle seat and extends radially. The cover plate is able to rotate and move synchronously with the middle seat and is inclined upward in the direction of movement. A scraper is provided at the bottom rear of the cover plate near the bottom of the aquaculture pond. At least one set of inlet pipe assemblies extending radially from the inlet chamber, the inlet pipe assembly having at least one downwardly extending nozzle located below the cover plate and in front of the scraper, and the nozzle being able to spray water toward the opening of the drain chamber; A waterwheel assembly is installed at the end of the inlet pipe assembly and the outer end of the cover plate. The waterwheel assembly includes a turbine that can be rotated by the water flow from the inlet pipe assembly, and a roller driven by the turbine to roll along the bottom of the aquaculture pond. This drives the entire sludge removal device to rotate around the drain outlet as an axis. During this rotation, the nozzle continuously sprays water towards the drain chamber, causing the sludge at the bottom of the pond below the cover plate and in front of the scraper to be flushed by the water flow towards the drain chamber and discharged from the drain outlet. When the waterwheel assembly slows down, increasing the resistance of the water flow entering the turbine through the inlet pipe assembly, the water flow rate distributed to the nozzle by the inlet pipe assembly increases relatively, thereby adaptively enhancing the flushing ability of the silt at the bottom of the pool.

2. The aquaculture pond dredging device as described in claim 1, characterized in that, The top of the housing extends downward relative to the drain outlet with a shaft sleeve; a drain pipe connected to the outside is provided inside the drain outlet, and an upwardly extending shaft pipe is inserted and fixed on the drain pipe, and the shaft sleeve is sleeved on the shaft pipe, so that the housing and shaft sleeve of the middle seat can rotate relative to the drain outlet and shaft pipe with the shaft pipe as the axis.

3. The aquaculture pond dredging device as described in claim 2, characterized in that, The pipe wall of the shaft connector has multiple perforations, and each perforation has a movable door that can be automatically pushed by the water flow to open to the inside of the pipe wall.

4. The aquaculture pond dredging device as described in claim 1, characterized in that, The housing is detachably provided with an arc-shaped baffle that curves toward the drain cavity at the edge of the opening, so that the water flowing into the drain cavity from the opening forms a vortex-like flow along the baffle and is discharged from the drain outlet.

5. The aquaculture pond dredging device as described in claim 1, characterized in that, The water inlet chamber is located above the outer casing and includes an outer sleeve fixed above the outer casing, an inner tube axially located inside the outer sleeve, and a water inlet connector connecting the external water pump and the inner tube. The internal space of the outer sleeve forms the water inlet chamber, and its side is used for connecting the water inlet pipe assembly. The bottom of the water inlet connector is connected in series with the inner tube, so that the outer casing can synchronously drive the outer sleeve to rotate relative to the water inlet connector and the inner tube.

6. The aquaculture pond dredging device according to any one of claims 1 to 5, characterized in that, The waterwheel assembly also includes a support frame fixed to the outer end of the cover plate. The turbine and the roller are respectively pivotally mounted on the support frame, and a set of reduction gears and a chain are provided between the turbine and the roller, so that the turbine can drive the roller to rotate through the reduction gears and the chain.

7. The aquaculture pond dredging device according to any one of claims 1 to 5, characterized in that, The inlet pipe assembly has a bypass port connecting to the aquaculture pond near its end, and at least one set of switching valves that can distribute the flow of water from the turbine to the bypass port.

8. The aquaculture pond dredging device according to any one of claims 1 to 5, characterized in that, The outer end of the cover plate can be connected and abutted to the inner end of another cover plate, and an auxiliary wheel that can roll and move on the bottom of the pool is provided at the position where the two cover plates are connected and abutted. The auxiliary wheel is straddling the bottom surface of the two cover plates.

9. The aquaculture pond dredging device as described in claim 8, characterized in that, The inlet pipe assembly includes at least a rigid pipe, a conical pipe, and a pipe connector connected in series. The nozzle extends downward from the rigid pipe and is positioned below the cover plate. The pipe connector allows another inlet pipe assembly to be connected in series, so that its length can match the two interconnected cover plates.

10. The aquaculture pond dredging device according to any one of claims 1 to 5, characterized in that, The cover plate has a second auxiliary wheel behind the scraper, which can roll along the bottom of the pool.

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