A depth sampler

Abstract

The present application belongs to the technical field of mud sampling equipment, and discloses a depth fixing sampler, which comprises a fixing frame, a sampling unit, a lifting unit and a depth detection unit, wherein the fixing frame comprises a horizontal support and a vertical support, the vertical support is a U-shaped support, and an inner side of the vertical support is provided with a clamping groove; the sampling unit comprises a sampling cylinder, an end cover, an ear plate and a counterweight assembly; the lifting unit is installed on the fixing frame and comprises a winding drum rotatably connected to the inside of the fixing frame; the depth detection unit comprises a pull rope type displacement sensor and an ultrasonic liquid level sensor; and the control unit comprises a PLC controller, which is electrically connected with a driving motor, a solenoid valve one, a solenoid valve two, the pull rope type displacement sensor, the ultrasonic liquid level sensor and an encoder. The present application reduces the depth error caused by interference factors in the sampling process through the fusion of multiple sensors, improves the sampling accuracy, and can be used for sampling mud in the mud tank under multiple scenes such as any depth of the mud tank and each liquid level depth of the mud.

Description

Technical Field

[0001] This invention belongs to the technical field of mud sampling equipment, and particularly relates to a fixed-depth sampler. Background Technology

[0002] Dredging is a crucial engineering technology for maintaining unobstructed waterways and improving the aquatic environment. It plays a key role in port construction, waterway maintenance, and water conservancy projects. During dredging operations, mud sampling is a vital step in obtaining information about the properties of the dredged soil, guiding construction decisions, and assessing project quality. In particular, precise sampling at different depths within the mud chambers of large trailing suction hopper dredgers and sand dredgers is of great significance for understanding mud concentration distribution, soil changes, and pollution levels.

[0003] Current mud samplers mainly include various types such as gravity samplers, piston samplers, box samplers, hydraulic samplers, and pneumatic samplers. Gravity samplers are suitable for soft surface sediments and are simple to operate, but have low depth control accuracy. Piston samplers can collect deep, undisturbed samples with high accuracy, but their structure is complex. Hydraulic samplers have a wide range of applications, but the equipment is bulky. Intelligent samplers represent the future direction of technology development, integrating advanced technologies such as sensors and the Internet of Things. Existing fixed-depth sampling technologies mainly suffer from the following drawbacks: Low depth accuracy: Traditional samplers rely on rope scales, mechanical indicator blocks or single pressure sensors to calculate the descent depth, without considering the dynamic changes in mud tank level during operation; High reliance on manual labor: Manual observation of mud tank level and manual adjustment of descent length are required, which is cumbersome and prone to sampling failure due to human error. Limited applicability: It is usually only used for static sampling, and there is no fixed-depth sampling for dynamically changing liquids. Moreover, it is mostly single-point sampling, which cannot obtain continuous mud parameter changes along the depth direction. Low level of automation: Most samplers rely on purely mechanical structures or semi-manual operation, and lack automatic depth calibration and automatic opening and closing of sampling ports.

[0004] Therefore, it is necessary to invent a fixed-depth sampler to solve the above problems. Summary of the Invention

[0005] To address the aforementioned issues, this invention aims to provide a dredging equipment mud tank slurry depth sampler, which can achieve slurry solution sampling at any depth inside the mud tank or at any depth. By integrating multiple sensing devices, the sampling accuracy is improved, meeting the slurry sampling needs in various scenarios. At the same time, the use of automated control technology reduces the difficulty of operation.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a fixed-depth sampler, comprising: a fixed frame, including a horizontal support and a vertical support, wherein the vertical support is a U-shaped frame with a slot on the inner side, and an O-shaped guide opening is provided at the middle of the bottom end of the horizontal support; The lifting unit, installed on the fixed frame, includes a drum rotatably connected inside the fixed frame, a drive motor that drives the drum, and a steel wire rope wound on the drum. The sampling unit includes a sampling cylinder, an end cap installed at the top of the sampling cylinder, an ear plate installed at the top of the end cap, and a counterweight assembly installed at the bottom of the sampling cylinder; the sampling unit is connected to the end of the wire rope through the ear plate; the top of the end cap is provided with an exhaust port with a first solenoid valve, the side wall of the sampling cylinder is provided with an inlet with a second solenoid valve, and the lower part of the side wall of the sampling cylinder is provided with a manual drain port; the sampling unit is slidably connected inside the U-shaped frame.

[0007] The depth detection unit includes a pull-string displacement sensor, the housing of which is mounted on the fixed frame, and the end of its pull-string is connected to the end cap; and an ultrasonic liquid level sensor, which is fixedly mounted on the fixed frame. The control unit includes a PLC controller, which is electrically connected to the drive motor, the first solenoid valve, the second solenoid valve, the pull-rope displacement sensor, and the ultrasonic level sensor. The PLC controller is configured to, based on the target sampling depth and feedback signals from the pull-rope displacement sensor and the ultrasonic level sensor, control the operation of the drive motor to position the sampling unit at the target depth, and control the opening and closing of the first and second solenoid valves to complete the sampling.

[0008] As a preferred embodiment of the above technical solution, when the sampling cylinder enters the predetermined position, the second electromagnetic valve opens, allowing the object to enter the sampling cylinder along the liquid inlet. After the object inside the sampling cylinder has been in the predetermined position for a predetermined time, the first electromagnetic valve opens, causing the gas inside the sampling cylinder to be discharged along the exhaust port.

[0009] As a preferred embodiment of the above technical solution, a collar is provided on the outer side of the wire rope, and the collar is welded to the inside of the O-shaped guide opening of the transverse support of the fixing frame.

[0010] As a preferred embodiment of the above technical solution, the end cover is composed of an upper top cover, connecting posts and a lower top cover. The upper top cover is fixedly installed on the bottom end of the ear plate. Two connecting posts are symmetrically embedded in the bottom end of the upper top cover. The same lower top cover is fixedly installed between the bottom ends of the two connecting posts. The lower top cover is threadedly connected to the sampling cylinder. The exhaust port is opened on the lower top cover of the end cover.

[0011] As a preferred embodiment of the above technical solution, the counterweight assembly includes a fixed post fixedly installed in the middle of the lower top cover in the end cover. An annular counterweight plate is sleeved on the outer surface of the fixed post. A pressure plate coaxially arranged with the fixed post is provided on the topmost annular counterweight plate. Several screws are equidistantly connected through the outer surface of the pressure plate, and the screws are fixed to the lower top cover in the end cover by threaded connection.

[0012] As a preferred embodiment of the above technical solution, the maximum outer diameter of the pressure plate is greater than the maximum outer diameter of the annular counterweight plate, and the inner diameter of the pressure plate and the inner diameter of the annular counterweight plate are equal to the outer diameter of the fixed column.

[0013] As a preferred embodiment of the above technical solution, an L-shaped plate is fixedly installed on the back of the horizontal support of the fixing frame. A rotating component is connected to the inside of the L-shaped plate by a thread. A bearing is connected to the outer surface of the end of the rotating component. A pressure plate is fixedly installed on the outer surface of the bearing.

[0014] As a preferred embodiment of the above technical solution, the upper top cover of the end cap is integrally formed with T-shaped plates on both sides, and the T-shaped plates are disposed inside the slots of the U-shaped frame.

[0015] As a preferred embodiment of the above technical solution, the sampling cylinder and the lower top cover of the end cap are detachably connected.

[0016] As a preferred embodiment of the above technical solution, the sampling cylinder is a cylindrical or cubic container made of 316L stainless steel, with an inner wall coated with a polytetrafluoroethylene anti-stick coating. The first and second electromagnetic valves are specifically electromagnetic latching spring reset valves. The opening and closing control method and power supply method of the second electromagnetic valve are as follows: Power supply method: The power supply cable of the drive motor integrates a control cable, which is connected to the PLC controller via a waterproof connector. The PLC controller is electrically connected to the sampling unit via a flexible steel wire cable wound on a reel. The flexible steel wire cable is arranged parallel to the steel wire rope and fixed by a suspension cable clamp. The second electromagnetic valve on the side wall of the sampling cylinder and the first electromagnetic valve on the top both obtain power and receive control signals through this path. Opening and closing method: The second electromagnetic valve includes an electromagnetic drive mechanism for driving the valve core and an elastic element for resetting. When the PLC controller sends an instantaneous opening signal, the electromagnetic latch unlocks, and the valve opens under the action of the spring force. When the PLC controller sends a closing signal, the electromagnet reverses its action or the latch mechanism relocks. The end of the steel wire rope is connected to the hanging plate at the top of the sampling cylinder via a heavy-duty quick-release buckle, allowing for physical separation and mounting without tools. The end of the flexible steel wire cable wound on the drum integrates a waterproof aviation plug, which matches the aviation socket fixed to the side wall of the sampling cylinder. When the sampling cylinder needs to be disassembled, the PLC controller first cuts off the power to the circuit, the operator manually unlocks the locking mechanism of the aviation plug and unplugs the plug to achieve electrical isolation, then the sampling cylinder is completely separated. When installing a new sampling cylinder by thread, the aviation plug is inserted and locked, and finally the connection status is checked by the PLC controller to confirm that there is no problem.

[0017] The technical effects and advantages of this invention are as follows: 1. This invention reduces depth errors caused by interference factors during sampling by fusing multiple sensors, thereby improving sampling accuracy. It can also be used for sampling mud in mud tanks at any depth and at various mud liquid levels, enabling automated operation of the sampling process, reducing the danger of manual operation, and improving sampling efficiency. 2. The counterweight component ensures that the sampling unit can overcome various resistances and achieve rapid, uniform and vertical sinking. This not only shortens the operation time to reach the target depth, but more importantly, it maintains the vertical posture of the sampling tube, ensuring that the sampling port can be directly facing the mud layer at the expected depth, laying the foundation for high-precision sampling. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a fixed-depth sampler according to the present invention; Figure 2 This is a schematic diagram of another perspective of the structure of a depth sampler in this invention; Figure 3 This is a schematic diagram of the counterweight component in this invention; Figure 4 This is a schematic diagram of the installation structure of the pressure plate in this invention.

[0019] In the diagram: 1. Fixed frame; 2. U-shaped frame; 3. Drum; 4. Drive motor; 6. Steel wire rope; 7. Encoder; 8. Pull-rope displacement sensor; 9. Ear plate; 10. Sampling cylinder; 11. End cap; 12. Solenoid valve one; 13. Solenoid valve two; 15. Counterweight assembly; 151. Fixed column; 152. Annular counterweight plate; 153. Pressure plate; 154. Screw; 16. Ultrasonic liquid level sensor; 17. Collar; 18. PLC controller; 19. Manual drain port; 21. Pressure plate; 22. Rotating component; 23. L-shaped plate; 24. Bearing. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0021] Example 1: This invention provides, for example Figures 1 to 4 A fixed-depth sampler is shown, comprising: a fixed frame 1, including a horizontal support and a vertical support, the vertical support being a U-shaped frame 2 with a slot on the inner side, an O-shaped guide opening at the bottom center of the horizontal support, and a collar 17 welded and installed at the O-shaped guide opening, an L-shaped plate 23 fixedly installed on the back of the horizontal support of the fixed frame 1, a rotating part 21 being threadedly connected inside the L-shaped plate 23, a bearing 24 being connected to the outer surface of the end of the rotating part 21, a pressure plate 22 being fixedly installed on the outer surface of the bearing 24, and the top of the pressure plate 22 and the inner wall of the L-shaped plate 23 being in contact with each other; The lifting unit is installed on the fixed frame 1 and includes a drum 3 rotatably connected inside the fixed frame 1, a drive motor 4 that drives the drum 3, and a steel wire rope 6 wound on the drum 3. The sampling unit includes a sampling cylinder 10, an end cap 11 installed at the top of the sampling cylinder 10, an ear plate 9 installed at the top of the end cap 11, and a counterweight assembly 15 installed at the bottom of the sampling cylinder 10. The sampling unit is connected to the end of the wire rope 6 through the ear plate 9. The top of the end cap 11 is provided with an exhaust port with a solenoid valve 12, the side wall of the sampling cylinder 10 is provided with an inlet with a solenoid valve 13, and the lower part of the side wall of the sampling cylinder 10 is provided with a manual drain port 19. The sampling unit is slidably connected inside the U-shaped frame 2.

[0022] The depth detection unit includes a pull-rope displacement sensor 8, whose housing is mounted on the mounting bracket 1 and whose pull rope end is connected to the end cap 11; and an ultrasonic liquid level sensor 16, which is fixedly mounted on the mounting bracket 1. The control unit includes a PLC controller 18, which is electrically connected to a drive motor 4, a first solenoid valve 12, a second solenoid valve 13, a pull-string displacement sensor 8, and an ultrasonic level sensor 16. The PLC controller 18 is configured to control the drive motor 4 to operate to position the sampling unit to the target depth based on the target sampling depth and the feedback signals from the pull-string displacement sensor 8 and the ultrasonic level sensor 16, and to control the opening and closing of the first solenoid valve 12 and the second solenoid valve 13 to complete the sampling.

[0023] Current mud samplers mainly include various types such as gravity samplers, piston samplers, box samplers, hydraulic samplers, and pneumatic samplers. Gravity samplers are suitable for soft surface sediments and are simple to operate, but have low depth control accuracy. Piston samplers can collect deep, undisturbed samples with high accuracy, but their structure is complex. Hydraulic samplers have a wide range of applications, but the equipment is bulky. Intelligent samplers represent the future direction of technology development, integrating advanced technologies such as sensors and the Internet of Things. Existing fixed-depth sampling technologies mainly suffer from the following drawbacks: Low depth accuracy: Traditional samplers rely on rope scales, mechanical indicator blocks or single pressure sensors to calculate the descent depth, without considering the dynamic changes in mud tank level during operation; High reliance on manual labor: Manual observation of mud tank level and manual adjustment of descent length are required, which is cumbersome and prone to sampling failure due to human error. Limited applicability: It is usually only used for static sampling, and there is no fixed-depth sampling for dynamically changing liquids. Moreover, it is mostly single-point sampling, which cannot obtain continuous mud parameter changes along the depth direction. Low level of automation: Most samplers rely on purely mechanical structures or semi-manual operation, and lack automatic depth calibration and automatic opening and closing of sampling ports.

[0024] In this application, by fusing multiple sensors, the depth error caused by interference factors during the sampling process is reduced, and the sampling accuracy is improved. At the same time, it can be used for sampling mud in mud tanks at any depth and at various liquid levels, etc., to realize the automated operation of the sampling process, reduce the danger of manual operation, and improve the sampling efficiency.

[0025] In use, the horizontal support of the fixing frame 1 is placed on the protruding position of the edge of the clamping plate. Then, the rotating part 21 is rotated. The rotation of the rotating part 21 drives the pressure plate 22 to move under the action of the bearing 24, so that the pressure plate 22 is pressed and fixed with the protruding position of the edge of the clamping plate, thereby fixing the fixing frame 1. At this time, the sampling unit is suspended above the mud chamber opening by the U-shaped frame 2. All electrical lines are connected to supply power to the PLC controller 18, drive motor 4, various sensors and solenoid valves and complete the system self-test. On the human-machine interface (such as touch screen) of the PLC controller 18, the sampling mode (relative to the bottom depth of the mud chamber or relative to the mud surface depth) and the target sampling depth value (S) are set. When the operator issues a start command, the PLC controller 18 first controls the drive motor 4 to start, which in turn drives the drum 3 to release the wire rope 6. The sampling unit (including the sampling cylinder 10, end cap 11, counterweight assembly 15, etc.) begins to descend smoothly under gravity. The collar 17 acts as a guide and stabilizer. During the descent, the two sensors continuously operate and feed data back to the PLC controller 18. The pull-string displacement sensor 8 measures the extension length of its pull-string in real time, which directly corresponds to the downward displacement (L) of the sampling unit relative to its mounting reference point (usually the sensor body on the mounting bracket 1). The ultrasonic level sensor 16 transmits and receives ultrasonic waves in real time to measure the vertical distance (H) from the sensor mounting surface to the mud surface below. The core control algorithm of PLC controller 18 calculates the actual depth (D) of the sampling port (liquid inlet) of the sampling unit in real time based on the above sensor data and the set sampling mode. If it is the relative mud tank bottom mode, when D=L, the sampling command is triggered (the zero point needs to be calibrated in advance). In the relative mud surface mode, the ultrasonic sensor outputs the real-time mud surface depth as H, and the draw-wire sensor outputs the depth as L, D=LH; when D=S, a sampling command is triggered. The liquid level H measured in real time by the ultrasonic liquid level sensor 16 is used to dynamically correct the absolute displacement L measured by the pull-rope displacement sensor 8, thereby obtaining the true depth D relative to the liquid surface that is not affected by the rise and fall of the liquid surface, and realizing high-precision depth determination in dynamic environments. The controller also stores the liquid level change curve, which can trace back the liquid level fluctuation at the time of sampling, facilitating data verification later. The PLC controller 18 continuously compares the calculated H with the preset S. When H < S, it controls the driving motor 4 to continue lowering. When H approaches S, the PLC controller 18 reduces the speed of the driving motor 4 for precise fine-tuning. Until H is within the allowable error range of S, the PLC controller 18 immediately issues a stop command, the driving motor 4 stops rotating and is brake-locked, and the sampling unit is accurately positioned at the target depth; Alternatively, by synchronously monitoring the number of motor rotations through the encoder 7 installed on the output shaft of the driving motor 4, the PLC can convert the length of the wire rope 6 retracted and released accordingly, as a verification and backup of the data of the pull rope displacement sensor 8, improving the system reliability; After the sampling unit is stabilized at the target depth, the PLC controller 18 automatically executes the sampling sequence according to the preset program: The PLC controls the solenoid valve two 13 to open. Under the action of the static pressure difference, the mud at the target depth surges into the inside of the sampling cylinder 10 through the liquid inlet; After a predetermined time, the PLC controls the solenoid valve one 12 to open, discharging the air at the top of the sampling cylinder 10 to ensure that the mud sample can completely fill the container; When the sampling cylinder 10 is full (controlled by time), the PLC first closes the solenoid valve two 13 to cut off the feeding channel; then closes the solenoid valve one 12 to completely seal the obtained mud sample in the sampling cylinder 10; After sampling is completed, the PLC controller 18 controls the driving motor 4 to rotate in the reverse direction, winding the wire rope 6, and lifting the sampling unit at a constant speed; The sampling unit is lifted to the initial suspension position (confirmed by the displacement sensor or limit switch). The ear plate 9 drives the end cover 11 to slide back to the top along the inside of the U-shaped frame 2 to ensure a vertical posture when lowering next time; The operator will disassemble the end cover 11 and the sampling cylinder 10, remove the sampling cylinder 10. After cleaning or replacing the sampling cylinder 10, it can be reinstalled to the end cover 11. This installation method can choose the clamp connection method, and then the device resumes the standby state, preparing for the next sampling operation, or opening the manual drain port 19 to make the liquid drain along the manual drain port 19 of the sampling cylinder 10.

[0026] The key data during the entire sampling process, such as the liquid level height (H), lowering displacement (L), final sampling depth (D), sampling time, etc. at each time point, are all recorded and stored by the PLC controller 18. These data can be used to generate a sampling report, analyze the mud profile concentration distribution, or backtrack and verify the accuracy of the sampling operation and environmental conditions when needed.

[0027] Specifically, a drum 3 is rotatably connected inside the transverse support of the fixed frame 1. A drive motor 4 is installed at the end of the transverse support of the fixed frame 1 by screws. A steel wire rope 6 is wound around the outside of the drum 3. A collar 17 is fitted on the outside of the steel wire rope 6. The collar 17 is welded to the inside of the O-shaped guide opening of the transverse support of the fixed frame 1 to guide the steel wire rope 6. The inner wall of the collar 17 is at an arc angle to reduce friction with the steel wire rope 6. When the drum 3 winds the steel wire rope 6, an ear plate 9 is connected to the end of the steel wire rope 6. An ultrasonic liquid level sensor 16 is fixedly installed at one end of the fixed frame 1. A PLC controller 18 is installed at the top of the fixed frame 1 by screws. A U-shaped groove is opened inside the transverse support of the fixed frame 1. The fixed frame 1 includes a horizontal support and a vertical support. The vertical support is a U-shaped frame 2 with a slot on the inner side. The bottom center of the horizontal support has an O-shaped guide opening, and a collar 17 is welded and installed at the O-shaped guide opening. The vertical support (U-shaped frame 2) is fixedly installed at the bottom of the horizontal support. The ear plate 9 is slidably connected to the inside of the U-shaped frame 2. The bottom of the ear plate 9 is fixedly installed with an end cover 11. The end cover 11 is composed of an upper top cover, connecting columns, and a lower top cover. The upper top cover of the end cover 11 is fixedly installed at the bottom of the ear plate 9. Two connecting columns are symmetrically embedded at the bottom of the upper top cover. The same lower top cover is fixedly installed between the bottom ends of the two connecting columns. The lower top cover of the end cover 11 has an exhaust port, and a solenoid valve 12 is snapped and installed at the exhaust port. The lower top cover of the end cover 11 is detachably connected to a sampling cylinder 10 by a clamp. The sampling cylinder 10 is a cylindrical or cubic container. The material is 316L stainless steel, and the inner wall is coated with polytetrafluoroethylene anti-stick coating. In this application, it is cylindrical. The top of the outer surface of the sampling cylinder 10 is provided with a liquid inlet, and a solenoid valve 2 13 is installed inside the liquid inlet. A pull rope displacement sensor 8 is installed between the top of the ear plate 9 and the bottom of the fixing frame 1. The pull rope of the pull rope displacement sensor 8 is connected to the end cover 11. An encoder 7 is installed at the end of the fixing frame 1 located outside the drive motor 4. The PLC controller 18 is electrically connected to the encoder 7. The encoder 7 is an auxiliary setting. An L-shaped plate 23 is fixedly installed on the back of the horizontal support of the fixing frame 1. A rotating part 22 is connected to the inside of the L-shaped plate 23 by a thread. In this application, the rotating part 22 is a screw. A bearing 24 is connected to the outer surface of the end of the rotating part 21. A pressure plate 21 is fixedly installed on the outer surface of the bearing 24. The top of the pressure plate 21 is attached to the bottom of the inner wall of the L-shaped plate 23.

[0028] To achieve the goal of increasing the weight of the sampling cylinder 10 in the above embodiments, the following solution is provided: the counterweight assembly 15 includes a fixing post 151 fixedly installed in the middle of the lower top cover in the end cover 11. An annular counterweight plate 152 is sleeved on the outer surface of the fixing post 151. A pressure plate 153 is provided on the topmost annular counterweight plate 152, which is coaxially arranged with the fixing post 151. Several screws 154 are equidistantly connected through the outer surface of the pressure plate 153, and the screws 154 are fixed to the lower top cover in the end cover 11 by threaded connection.

[0029] In use, the screw 154 is removed, and then the annular counterweight 152 is fitted around the outside of the fixing post 151 as required. Then the pressure plate 153 is fitted around the outside of the fixing post 151 and above the annular counterweight 152. Then the screw 154 is turned to fix the annular counterweight 152 to the lower top cover of the end cover 11, thereby pressing and fixing the annular counterweight 152.

[0030] Specifically, the lower top cover of the end cover 11 has a fixed post 151 integrally formed in the middle. The outer surface of the fixed post 151 is fitted with a coaxially arranged annular counterweight plate 152. The topmost annular counterweight plate 152 is provided with a pressure plate 153 coaxially arranged with the fixed post 151. The top edge of the pressure plate 153 has six holes. Each of the six holes of the pressure plate 153 is connected to a screw 154, and the screw 154 is fixed to the lower top cover of the end cover 11 by a threaded connection.

[0031] Electromagnetic valve 12 and electromagnetic valve 23 are specifically electromagnetic latch-type spring return valves. The opening and closing control method and power supply method of electromagnetic valve 23 are as follows: Power supply method: The power supply cable of the drive motor 4 integrates a control cable, which is connected to the PLC controller 18 through a waterproof connector. The PLC controller 18 is electrically connected to the sampling unit through a flexible steel wire cable wound on the drum 3. The flexible steel wire cable is arranged in parallel with the steel wire rope 6 and fixed by a suspension cable clamp. Electromagnetic valve 23 on the side wall of the sampling cylinder 10 and electromagnetic valve 12 on the top both obtain power and receive control signals through this path. Opening and closing method: Electromagnetic valve 23 includes an electromagnetic drive mechanism for driving the valve core and an elastic element for resetting. When the PLC controller 18 sends an instantaneous opening signal, the electromagnetic latch unlocks, and the valve opens under the action of the spring force. When the PLC controller 18 sends a closing signal, the electromagnet reverses its action or the latch mechanism relocks. The flexible steel wire cable wound on the drum 3 has a waterproof aviation plug integrated at its end, which matches the aviation socket fixed to the side wall of the sampling tube 10. When the sampling tube needs to be disassembled, the PLC controller 18 first cuts off the power to the circuit, the operator manually unlocks the locking mechanism of the aviation plug and unplugs the plug to achieve electrical isolation, and then the sampling tube 10 is taken out. When replacing the new sampling tube 10, the new sampling tube 10 is then installed by thread, the aviation plug is inserted and locked, and finally the connection status is checked by the PLC controller 18 to confirm that there is no problem (this method is a disclosed method in the prior art and will not be described here).

[0032] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

Claims

1. A fixed-depth sampler, characterized in that, include: The fixed frame (1) includes a horizontal support and a vertical support. The vertical support is a U-shaped frame (2) with a slot on the inner side. The horizontal support has an O-shaped guide opening at the bottom center. The lifting unit is installed on the fixed frame (1) and includes a drum (3) rotatably connected inside the fixed frame (1), a drive motor (4) for driving the drum (3), and a wire rope (6) wound on the drum (3). The sampling unit includes a sampling cylinder (10), an end cap (11) installed at the top of the sampling cylinder (10), an ear plate (9) installed at the top of the end cap (11), and a counterweight assembly (15) installed at the bottom of the sampling cylinder (10). The sampling unit is connected to the end of the wire rope (6) through the ear plate (9). The top of the end cap (11) is provided with an exhaust port with a first electromagnetic valve (12), the side wall of the sampling cylinder (10) is provided with an inlet with a second electromagnetic valve (13), and the bottom of the sampling cylinder (10) is provided with a manual drain port (19). The sampling unit is slidably connected inside the U-shaped frame (2). The depth detection unit includes a pull-string displacement sensor (8), whose housing is mounted on the fixed frame (1), and whose pull-string end is connected to the end cap (11); and an ultrasonic liquid level sensor (16), which is mounted on the fixed frame (1). The control unit includes a PLC controller (18), which is electrically connected to the drive motor (4), the first solenoid valve (12), the second solenoid valve (13), the pull-rope displacement sensor (8), and the ultrasonic level sensor (16); and is configured to control the drive motor (4) to operate to position the sampling unit to the target depth based on the target sampling depth and the feedback signals of the pull-rope displacement sensor (8) and the ultrasonic level sensor (16), and to control the opening and closing of the first solenoid valve (12) and the second solenoid valve (13) to complete the sampling.

2. The depth-controlled sampler according to claim 1, characterized in that: When the sampling cylinder (10) enters the predetermined position, the second electromagnetic valve (13) opens, allowing liquid to enter the sampling cylinder (10) along the inlet. After the liquid inside the sampling cylinder (10) has been in the predetermined position for a predetermined time, the first electromagnetic valve (12) opens, causing the gas inside the sampling cylinder (10) to be discharged along the exhaust port.

3. The depth-controlled sampler according to claim 1, characterized in that: The wire rope (6) is fitted with a collar (17) on the outside, and the collar (17) is welded to the inside of the O-shaped guide opening of the transverse support of the fixed frame (1).

4. The depth-controlled sampler according to claim 1, characterized in that: The end cap (11) is composed of an upper top cover, connecting columns and a lower top cover. The upper top cover of the end cap (11) is fixedly installed at the bottom of the ear plate (9). Two connecting columns are symmetrically embedded at the bottom of the upper top cover. The same lower top cover is fixedly installed between the bottom ends of the two connecting columns. The lower top cover is threadedly connected to the sampling cylinder (10). The exhaust port is opened on the lower top cover in the end cap (11).

5. The constant-depth sampler according to claim 4, characterized in that: The counterweight assembly (15) includes a fixed post (151) fixedly installed in the middle of the lower top cover in the end cover (11). The outer surface of the fixed post (151) is fitted with an annular counterweight plate (152). The topmost annular counterweight plate (152) is provided with a pressure plate (153) coaxially arranged with the fixed post (151). Several screws (154) are equidistantly connected through the outer surface of the pressure plate (153), and the screws (154) are fixed to the lower top cover in the end cover (11) by threaded connection.

6. The depth-controlled sampler according to claim 5, characterized in that: The maximum outer diameter of the pressure plate (153) is greater than the maximum outer diameter of the annular counterweight plate (152), and the inner diameter of the pressure plate (153) and the inner diameter of the annular counterweight plate (152) are equal to the outer diameter of the fixed column (151).

7. The depth-controlled sampler according to claim 1, characterized in that: An L-shaped plate (23) is fixedly installed on the back of the horizontal support of the fixed frame (1). A rotating part (22) is connected inside the L-shaped plate (23) by a thread. A bearing (24) is connected to the outer surface of the end of the rotating part (22). A pressure plate (21) is fixedly installed on the outer surface of the bearing (24).

8. The constant-depth sampler according to claim 4, characterized in that: The top cover of the end cap (11) has T-shaped plates integrally formed on both sides, and the T-shaped plates are set inside the slots of the U-shaped frame (2).

9. The constant-depth sampler according to claim 1, characterized in that: The sampling tube (10) and the lower top cover of the end cap (11) are detachably connected.

10. The depth-controlled sampler according to claim 1, characterized in that: The sampling cylinder (10) is a cylindrical or cubic container made of 316L stainless steel with a polytetrafluoroethylene anti-stick coating on the inner wall. The electromagnetic valve one (12) and electromagnetic valve two (13) are specifically electromagnetic locking spring reset valves. The opening and closing control method and power supply method of the electromagnetic valve two (13) are as follows: Power supply method: The power supply cable of the drive motor (4) integrates the control cable. The control cable is connected to the PLC controller (18) through a waterproof connector. The PLC controller (18) is electrically connected to the sampling unit through a flexible steel wire cable wound on the drum (3). The flexible steel wire cable is arranged in parallel with the steel wire rope (6) and fixed by a hanging cable clamp. The electromagnetic valve two (13) on the side wall of the sampling cylinder (10) and the electromagnetic valve one (12) on the top both obtain power and receive control signals through this path. Opening and closing method: The electromagnetic valve Door 2 (13) includes an electromagnetic drive mechanism for driving the valve core and an elastic element for resetting; when the PLC controller (18) sends an instantaneous opening signal, the electromagnetic latch unlocks and the valve opens under the action of spring force; when the PLC controller (18) sends a closing signal, the electromagnet reverses or the latch mechanism relocks; a waterproof aviation plug is integrated at the end of the flexible steel wire cable wound on the drum (3), which matches the aviation socket fixed to the side wall of the sampling tube (10); when the sampling tube needs to be disassembled, the PLC controller (18) first cuts off the power supply of the circuit, the operator manually unlocks the locking mechanism of the aviation plug and unplugs the plug to achieve electrical isolation, then the sampling tube (10) is taken out, when replacing the new sampling tube (10), the sampling tube (10) is then installed by thread, the aviation plug is inserted and locked, and finally the connection status is checked by the PLC controller (18) to confirm that there is no problem.

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