Aquaculture water quality detection sampling device

Abstract

The application provides a water quality detection sampling device for aquaculture, which comprises a sampling cylinder, a piston assembly, a pressure maintaining counterweight, a locking assembly and a depth trigger valve. The application does not need a pre-charged high-pressure nitrogen cylinder, a storage battery, an electronic sensor and a controller. All actions such as sinking counterweight, depth triggering water inlet, pressure maintaining and building, and underwater state indication are completed by pure mechanical mechanisms, which fundamentally avoids common faults such as electronic equipment water inlet short circuit, cylinder chronic leakage and battery power attenuation, so that the device has high reliability and task execution rate in long-term field operation, deep sea extreme environment and remote areas, and almost does not need professional maintenance. The setting of the piston assembly makes the pressure maintaining counterweight compress compressible gas instead of incompressible water when falling, so that the pressure building process is smooth and gradual, and the "liquid lock point" and instantaneous high-pressure water hammer caused by direct water compression are avoided.

Description

Technical Field

[0001] This invention relates to the field of mechanical equipment, and in particular to a water quality testing and sampling device for aquaculture. Background Technology

[0002] In fields such as water environment surveys, pollution monitoring, and deep-sea biological and geochemical research, obtaining water samples that accurately reflect the in-situ physicochemical properties is crucial. For deep water bodies (such as deep lakes, reservoirs, oceans, and groundwater), once the water sample leaves its original location, the dissolved gaseous components (such as methane, hydrogen sulfide, and carbon dioxide) are easily released due to the decrease in external pressure and temperature changes, leading to changes in pH value and shifts in redox potential. Volatile organic compounds may also be lost during the decompression process. Therefore, sampling devices with pressure-holding capabilities are key tools for obtaining high-quality in-situ water samples. Currently, existing pressure-holding sampling devices mainly rely on pre-filled high-pressure nitrogen cylinders or accumulators as pressure compensation elements. For example, Chinese patent CN104792578A discloses a liquid pressure-holding sampling cylinder, which uses two coaxially arranged cavities and two pistons to maintain sample pressure using compressed nitrogen in one cavity. Another example is Chinese patent CN104004648A, which discloses a deep-sea microbial pressure-holding transfer sampler, which is equipped with a counterweight mechanism to assist the device in sinking into deep water and has an independent accumulator for pressure holding. In addition, Chinese patent CN121720781A discloses a convenient pressure-holding gravity sampler, which uses a counterweight and control mechanism to achieve gravity sinking and pressure holding by sealing with a flap valve.

[0003] While the aforementioned existing technologies can achieve a certain degree of pressure-holding sampling, they still have the following drawbacks in practical operation and application: 1. Conventional pressure-holding sampling devices rely on high-pressure nitrogen pre-filled on shore as the pressure-holding power source. This not only requires complex filling equipment, but also requires regular checks of cylinder pressure and replacement of aging seals. In long-term field operations or under simple conditions, problems such as chronic cylinder leakage and insufficient pressure will seriously affect the reliability and efficiency of the mission. 2. Although some existing devices are equipped with counterweights or hammers to assist in sinking, their function is completed once they sink to the bottom. The gravitational potential energy of the counterweights is not further utilized, and the pressure holding function still relies on an independent compressed gas system, resulting in a complex overall structure, heavy weight, and low integration of the device. 3. Active acoustic beacons that rely on electricity and acoustic transducers can provide status information for underwater devices, but they are complex in structure and require battery maintenance. For purely mechanical pressure-holding samplers that pursue simplicity and high reliability, there is currently a lack of a passive indication method that can transmit the device status (such as sinking, bottoming, and sampling completion) to surface operators without external power. Summary of the Invention

[0004] (a) Technical problems to be solved To address the aforementioned problems in the prior art, the present invention provides a water quality testing and sampling device for aquaculture.

[0005] (II) Technical Solution To achieve the above objectives, the main technical solutions adopted by the present invention include: A water quality testing and sampling device for aquaculture includes a sampling cylinder, a piston assembly, a pressure-holding counterweight, a locking assembly, and a depth trigger valve. The sampling cylinder is provided with a counterweight cavity and a sampling cavity from top to bottom. Both the counterweight cavity and the sampling cavity are cylindrical cavities, and the diameter of the sampling cavity is larger than the diameter of the counterweight cavity. The piston assembly is installed inside the sampling chamber; The piston assembly includes an upper piston and a lower piston, which are spaced apart within the sampling chamber, and a buffer gas is filled between the upper piston and the lower piston. The locking assembly is disposed on the inner wall of the counterweight cavity, fixing the pressure-holding counterweight block in the counterweight cavity near the top wall. The trigger of the locking assembly is disposed on the interface between the counterweight cavity and the sampling cavity. After the piston assembly rises in the sampling cavity, it contacts the trigger of the locking assembly, causing the locking assembly to release the pressure-holding counterweight block and causing the pressure-holding counterweight block to fall automatically in the counterweight cavity. The depth trigger valve is installed at the bottom of the sampling cylinder and is connected to the sampling chamber. After the depth trigger valve reaches the water area at the predetermined depth, it will automatically open the water inlet channel and automatically close after the water inlet is completed.

[0006] Preferably, the locking assembly is provided in two sets, and the two sets of locking assemblies are disposed opposite to each other on the inner walls of the counterweight cavity. The locking assembly includes a drive gear, a transverse rack, a vertical rack, a limiting spring, and a locking rod. The transverse rack meshes with the drive gear and is located on the top side of the drive gear. The inner wall of the counterweight cavity has a transverse movable groove corresponding to the transverse rack. One end of the transverse rack is fixedly installed with the locking rod, and the locking rod extends into the counterweight cavity. The side wall of the pressure-holding counterweight block has a locking groove corresponding to the locking rod. The other end of the transverse rack is connected to the bottom wall of the transverse movable groove through a limiting spring. The vertical rack also meshes with the drive gear and is located on the side of the drive gear near the counterweight cavity. The inner wall of the counterweight cavity has a vertical movable groove corresponding to the vertical rack, and one bottom end of the vertical rack extends downward into the sampling cavity.

[0007] Preferably, the buffer gas is one of nitrogen, argon or helium.

[0008] Preferably, the upper piston is provided with a one-way valve, which allows gas to flow unidirectionally from the counterweight chamber to the buffer gas chamber between the upper and lower pistons, and prevents gas from flowing in the reverse direction from the buffer gas chamber to the counterweight chamber.

[0009] Preferably, it further includes a one-way stop mechanism. A connecting block is provided on the top of the pressure-holding counterweight. The one-way stop mechanism is installed at both ends of the connecting block. The one-way stop mechanism includes a movable gear, a guide rack, a drive shaft, and a ratchet assembly. The ratchet assembly is installed at the end of the connecting block and is connected to the drive shaft. The movable gear is installed at both ends of the drive shaft and meshes with the guide rack. The guide rack is disposed on the inner wall of the counterweight cavity. The side wall of the pressure-holding counterweight is recessed with a guide groove corresponding to the guide rack. The ratchet assembly allows the movable gear to only roll downwards.

[0010] Preferably, the pressure-holding counterweight is provided with a Helmholtz resonant cavity inside, and a vibrating metal diaphragm is provided at the opening of the Helmholtz resonant cavity.

[0011] Preferably, the top of the sampling tube is provided with a tube cover, and a sealing ring is provided at the connection between the sampling tube and the tube cover.

[0012] Preferably, it also includes a winch, a tow rope, and a detection pontoon; The winch is installed on the detection pontoon and is connected to the sampling cylinder via the traction rope.

[0013] (III) Beneficial Effects The beneficial effects of this invention are as follows: 1. The counterweight has the following three functions in one: (1) Sinking counterweight: Provides overall negative buoyancy to achieve rapid vertical sinking; (2) Pressure-holding power source: Its gravitational potential energy is converted into the pressure energy required for water sample pressure holding through compression of buffer gas, replacing the traditional high-pressure gas cylinder; (3) The built-in Helmholtz resonant cavity generates a specific frequency sound wave when released or touching the bottom, realizing passive indication of underwater status; 2. The piston assembly is designed so that the pressure-holding counterweight compresses compressible gas rather than incompressible water when it falls, making the pressure-building process smooth and gradual, avoiding the "liquid lock-up point" and instantaneous high-pressure water hammer caused by direct water pressure. 3. The entire device requires no pre-charged high-pressure nitrogen cylinders, no batteries, no electronic sensors or controllers. All actions, such as sinking counterweights, depth-triggered water intake, pressure holding and building up, and underwater status indication, are completed by purely mechanical mechanisms. This fundamentally avoids common faults such as water ingress and short circuits in electronic equipment, chronic leakage of gas cylinders, and battery power degradation. As a result, the device has extremely high reliability and mission execution rate in long-term field operations, extreme deep-sea environments, and remote areas, and requires almost no professional maintenance. Attached Figure Description

[0014] Figure 1 A partial cross-sectional view of a water quality testing and sampling device for aquaculture. Figure 2 This is a schematic diagram of the internal structure of a water quality testing and sampling device for aquaculture. Figure 3 for Figure 1 Enlarged diagram of section A in the middle; Figure 4 for Figure 2 Enlarged diagram of section B Figure 5 This is a schematic diagram of the locking assembly. Figure 6 This is a schematic diagram of the internal structure of the pressure-holding counterweight. Figure 7 This is a schematic diagram of the structure connecting the winch, traction rope, and sampling cylinder to the testing pontoon.

[0015] Explanation of reference numerals in the attached figures 1. Sampling tube; 11. Counterweight chamber; 12. Sampling chamber; 2. Piston assembly; 21. Upper piston; 22. Buffer gas; 23. Lower piston; 3. Pressure-holding counterweight; 31. Helmholtz resonant cavity; 32. Vibrating metal diaphragm; 33. Connecting block; 34. Locking groove; 4. Depth trigger valve; 5. Locking assembly; 51. Drive gear; 52. Horizontal rack; 53. Locking rod; 54. Limit spring; 55. Vertical rack; 56. Horizontal movable groove; 57. Vertical movable groove; 6. One-way stop mechanism; 61. Ratchet assembly; 62. Drive shaft; 63. Movable gear; 64. Guide rack; 7. Cylinder lid; 8. Inspect the floating vessel; 9. Winch. Detailed Implementation

[0016] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] Please refer to Figure 1 and Figure 2 The first embodiment of the present invention: A water quality testing and sampling device for aquaculture includes a sampling cylinder 1, a piston assembly 2, a pressure-holding counterweight 3, a locking assembly 5, and a depth trigger valve 4. The sampling cylinder 1 is provided with a counterweight cavity 11 and a sampling cavity 12 arranged from top to bottom. Both the counterweight cavity 11 and the sampling cavity 12 are cylindrical cavities, and the diameter of the sampling cavity 12 is larger than the diameter of the counterweight cavity 11. Piston assembly 2 is installed inside sampling chamber 12; The piston assembly 2 includes an upper piston 21 and a lower piston 23, which are spaced apart in the sampling chamber 12, and the space between the upper piston 21 and the lower piston 23 is filled with buffer gas 22. The locking component 5 is installed on the inner wall of the counterweight cavity 11, which fixes the pressure-holding counterweight 3 in the counterweight cavity 11 near the top wall. The trigger of the locking component 5 is installed on the interface between the counterweight cavity 11 and the sampling cavity 12. After the piston assembly 2 rises in the sampling cavity 12, it contacts the trigger of the locking component 5, which causes the locking component 5 to release the fixation of the pressure-holding counterweight 3, so that the pressure-holding counterweight 3 falls automatically in the counterweight cavity 11. The depth trigger valve 4 is installed at the bottom of the sampling cylinder 1 and is connected to the sampling chamber 12. After the depth trigger valve 4 reaches the water area of ​​the predetermined depth, it will automatically open the water inlet channel and automatically close after the water inlet is completed. In use, the sampling cylinder 1 is placed in the water area to be tested. Under the action of the pressure-holding counterweight 3, the sampling cylinder 1 can sink quickly and enter the deep water body. When the depth trigger valve 4 reaches the water area of ​​the predetermined depth, it will automatically open the water inlet channel. The external high-pressure water enters the sampling chamber 12 under the action of pressure difference and acts on the piston assembly 2, causing the lower piston 23 to move upward. This causes the pressure in the buffer gas chamber to rise. The pressure in the buffer gas chamber acts on the bottom of the upper piston 21, causing the upper piston 21 to move upward as well. After the upper piston 21 contacts the trigger of the locking assembly 5, the locking assembly 5 releases the restriction on the pressure-holding counterweight 3. Under the action of gravity, the pressure-holding counterweight 3 falls from the top of the counterweight chamber 11 and lands on the top of the upper piston 21. The pressure-holding counterweight 3 converts its gravitational potential energy into pressure energy and acts on the upper piston 21 to provide continuous pressure for the water sample in the sampling chamber 12, thus achieving the pressure-holding function.

[0018] In the above embodiments, the depth trigger valve 4 can be a GO-FLO ball valve or an SLDF-15 solenoid valve, which opens the water inlet channel by electronic control after reaching the water area of ​​the predetermined depth.

[0019] refer to Figure 4 and Figure 5 In this embodiment, the locking assembly 5 is provided in two sets, and the two sets of locking assemblies 5 are arranged opposite to each other on the inner walls of the counterweight cavity 11. The locking assembly 5 includes a drive gear 51, a transverse rack 52, a vertical rack 55, a limiting spring 54, and a locking rod 53. The transverse rack 52 meshes with the drive gear 51 and is located on the top side of the drive gear 51. The inner wall of the counterweight cavity 11 is provided with a transverse movable groove 56 corresponding to the transverse rack 52. A locking rod 53 is fixedly installed at one end of the transverse rack 52 and extends into the counterweight cavity 11. The side wall of the pressure-holding counterweight block 3 is provided with a locking groove 34 corresponding to the locking rod 53. The other end of the transverse rack 52 is connected to the bottom wall of the transverse movable groove 56 through a limiting spring 54. The vertical rack 55 also meshes with the drive gear 51 and is located on the side of the drive gear 51 near the counterweight cavity 11. The inner wall of the counterweight cavity 11 is provided with a vertical movable groove 57 corresponding to the vertical rack 55. One end of the bottom of the vertical rack 55 extends downward into the sampling cavity 12. In use, after the piston assembly 2 moves upward in the sampling chamber 12, it contacts the vertical rack 55 (i.e. the trigger of the locking assembly 5) and drives it to move upward. Under the action of the drive gear 51, the horizontal rack 52 moves away from the pressure-holding counterweight 3, so that the locking rod 53 disengages from the locking groove 34 on the pressure-holding counterweight 3, thereby releasing the fixation of the pressure-holding counterweight 3.

[0020] In this embodiment, a one-way valve is provided on the upper piston 21. The one-way valve allows gas to flow unidirectionally from the counterweight chamber 11 to the buffer gas chamber between the upper piston 21 and the lower piston 23, and prevents gas from flowing in the reverse direction from the buffer gas chamber to the counterweight chamber 11. In use, if the depth trigger valve 4 opens too abruptly, the water intake speed is extremely fast, the lower piston 23 moves upward at high speed, and the buffer gas chamber is compressed sharply. The one-way valve can absorb and buffer this pressure pulse, making the system pressure rise process smoother, and does not affect the pressure holding effect of the pressure holding counterweight 3.

[0021] In this embodiment, the buffer gas 22 is one of nitrogen, argon or helium; In use, due to the extremely low compressibility of water, if a single piston is used, the pressure-holding counterweight 3 will directly compress the water in the water sample chamber after release. This will either prevent the liquid lock from falling smoothly or generate instantaneous high-pressure water hammer, damaging the sample components or even the mechanical structure. In this embodiment, a double-piston design is adopted, and a buffer gas 22 is added between the two pistons. After the pressure-holding counterweight 3 is released, it falls on the upper piston 21 and presses down on the upper piston 21. The upper piston 21 compresses compressible gas instead of incompressible water. The gas acts as a "pressure buffer spring", transforming the impact-type fall of the pressure-holding counterweight 3 into a smooth and gradual pressure-building process. This fundamentally eliminates the liquid lock dead point and avoids the water hammer effect from damaging the water sample. The buffer gas 22 is nitrogen, which can withstand a sealed high-pressure environment without chemically reacting with the inner wall of the sampling cylinder 1, the piston, or any seals, thus ensuring the long-term stability of the internal environment of the device.

[0022] refer to Figure 3 The second embodiment of the present invention: Based on the above embodiment 1, it also includes a one-way stop mechanism 6. A connecting block 33 is provided on the top of the pressure-holding counterweight 3. One-way stop mechanisms 6 are installed at both ends of the connecting block 33. The one-way stop mechanism 6 includes a movable gear 63, a guide rack 64, a drive shaft 62, and a ratchet assembly 61. The ratchet assembly 61 is installed at the end of the connecting block 33 and is connected to the drive shaft 62. Movable gears 63 are installed at both ends of the drive shaft 62 and the movable gears 63 mesh with the guide rack 64. The guide rack 64 is provided on the inner wall of the counterweight cavity 11. The side wall of the pressure-holding counterweight 3 is recessed with a guide groove corresponding to the guide rack 64. The ratchet assembly 61 makes the movable gear 63 only able to roll downwards. In use, after the pressure-holding counterweight 3 falls, the movable gear 63 moves downward along the guide rack 64. With the ratchet assembly 61 in place, the pressure-holding counterweight 3 is locked in its upward retraction path after falling into place. The gravity of the pressure-holding counterweight 3 and the mechanical locking force of the one-way stop mechanism 6 work together to keep the gas chamber pressure steadily locked at the target value, thereby ensuring the pressure-holding effect.

[0023] It should be noted that the ratchet assembly 61 includes a ratchet and ratchet teeth. The drive shaft 62 is fixedly connected to the center of the ratchet. Through the cooperation of the ratchet and ratchet teeth, the drive shaft 62 can only drive the movable gear 63 to roll downwards.

[0024] refer to Figure 6 The third embodiment of the present invention: Based on the above embodiment 1, a Helmholtz resonant cavity 31 is provided inside the pressure-holding counterweight 3, and a vibrating metal diaphragm 32 is provided at the opening of the Helmholtz resonant cavity 31. In use, the impact force generated when the pressure-holding counterweight 3 falls is transmitted to the Helmholtz resonant cavity 31. The air column in the Helmholtz resonant cavity 31 is excited and generates sound waves of a specific frequency. The sound wave vibration is transmitted sequentially to the pressure-holding counterweight 3, the sampling cylinder 1, and the traction rope on the sampling cylinder 1 through the vibrating metal diaphragm 32. By checking the vibration of the traction rope, the testing personnel can transmit the status of the device to the surface operator without the need for external power.

[0025] In this embodiment, a cap 7 is provided on the top of the sampling cylinder 1, and a sealing ring is provided at the connection between the sampling cylinder 1 and the cap 7.

[0026] refer to Figure 7 In this embodiment, a winch 9, a traction rope, and a detection pontoon 8 are also included. The winch 9 is installed on the detection pontoon 8, and the winch 9 is connected to the sampling cylinder 1 through a traction rope. In use, the winch 9 is used to wind and unwind the traction rope to realize the deployment and retrieval of the sampling cylinder 1.

[0027] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention's specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

[0028] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A sampling device for water quality testing in aquaculture, characterized in that, Includes sampling cylinder, piston assembly, pressure holding counterweight, locking assembly, and depth trigger valve; The sampling cylinder is provided with a counterweight cavity and a sampling cavity from top to bottom. Both the counterweight cavity and the sampling cavity are cylindrical cavities, and the diameter of the sampling cavity is larger than the diameter of the counterweight cavity. The piston assembly is installed inside the sampling chamber; The piston assembly includes an upper piston and a lower piston, which are spaced apart within the sampling chamber, and a buffer gas is filled between the upper piston and the lower piston. The locking assembly is disposed on the inner wall of the counterweight cavity, fixing the pressure-holding counterweight block in the counterweight cavity near the top wall. The trigger of the locking assembly is disposed on the interface between the counterweight cavity and the sampling cavity. After the piston assembly rises in the sampling cavity, it contacts the trigger of the locking assembly, causing the locking assembly to release the pressure-holding counterweight block and causing the pressure-holding counterweight block to fall automatically in the counterweight cavity. The locking assembly is provided in two sets, and the two sets of locking assemblies are arranged opposite to each other on the inner walls of the counterweight cavity. The locking assembly includes a drive gear, a horizontal rack, a vertical rack, a limiting spring, and a locking rod. The transverse rack meshes with the drive gear and is located on the top side of the drive gear. The inner wall of the counterweight cavity has a transverse movable groove corresponding to the transverse rack. One end of the transverse rack is fixedly installed with the locking rod, and the locking rod extends into the counterweight cavity. The side wall of the pressure-holding counterweight block has a locking groove corresponding to the locking rod. The other end of the transverse rack is connected to the bottom wall of the transverse movable groove through a limiting spring. The vertical rack also meshes with the drive gear and is located on the side of the drive gear near the counterweight cavity. The inner wall of the counterweight cavity is provided with a vertical movable groove corresponding to the vertical rack, and one bottom end of the vertical rack extends downward into the sampling cavity. The depth trigger valve is installed at the bottom of the sampling cylinder and is connected to the sampling chamber. After the depth trigger valve reaches the water area of ​​the predetermined depth, it will automatically open the water inlet channel and automatically close after the water inlet is completed. The pressure-holding counterweight has a Helmholtz resonant cavity inside, and a vibrating metal diaphragm is provided at the opening of the Helmholtz resonant cavity.

2. The aquaculture water quality testing and sampling device according to claim 1, characterized in that, The buffer gas is one of nitrogen, argon or helium.

3. The aquaculture water quality testing and sampling device according to claim 1, characterized in that, The upper piston is equipped with a one-way valve, which allows gas to flow unidirectionally from the counterweight chamber to the buffer gas chamber between the upper and lower pistons, and prevents gas from flowing in the reverse direction from the buffer gas chamber to the counterweight chamber.

4. The aquaculture water quality testing and sampling device according to claim 1, characterized in that, It also includes a one-way stop mechanism. A connecting block is provided on the top of the pressure-holding counterweight. The one-way stop mechanism is installed at both ends of the connecting block. The one-way stop mechanism includes a movable gear, a guide rack, a drive shaft, and a ratchet assembly. The ratchet assembly is installed at the end of the connecting block and is connected to the drive shaft. The movable gear is installed at both ends of the drive shaft and meshes with the guide rack. The guide rack is provided on the inner wall of the counterweight cavity. The side wall of the pressure-holding counterweight is recessed with a guide groove corresponding to the guide rack. The ratchet assembly allows the movable gear to only roll downwards.

5. The aquaculture water quality testing and sampling device according to claim 1, characterized in that, The top of the sampling tube is provided with a tube cover, and a sealing ring is provided at the connection between the sampling tube and the tube cover.

6. The aquaculture water quality testing and sampling device according to claim 1, characterized in that, It also includes winches, towing ropes, and inspection pontoons; The winch is installed on the detection pontoon and is connected to the sampling cylinder via the traction rope.

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