A negative pressure sampling device for an online ammonia nitrogen analyzer of water quality

Abstract

The present invention relates to the technical field of water quality detection sampling, in particular to a negative pressure sampling device for an on-line water quality ammonia nitrogen analyzer. The present invention includes a hull, a rectangular installation hole is opened at the center of the hull, a lifting plate is installed at the bottom of the installation hole in a lifting manner, a sampling bucket for sampling is slidably installed above the lifting plate, and a filter screen for preventing waterweeds is arranged outside the sampling bucket. Through the setting of the lifting plate, the underwater weeds can be effectively blocked, which is beneficial to avoiding sundries such as underwater weeds or green algae from entering the sampling bucket, thus causing impurities to be mixed into the water in the sampling bucket and affecting the effective detection and analysis of the ammonia nitrogen content in the water quality. And through the setting of the filter screen, the impurities on the side of the sampling bucket in the water can also be effectively blocked, which is beneficial to avoiding the weeds and green algae on the side of the sampling bucket from entering the sampling bucket during the sampling process of the sampling bucket.

Description

Technical Field

[0001] The present invention relates to the field of water quality detection sampling, and particularly to a negative pressure sampling device for an on-line water quality ammonia nitrogen analyzer. Background Art

[0002] The analysis of the ammonia nitrogen content in water quality is an important means to evaluate the degree of water pollution and the water quality status. Ammonia nitrogen refers to the total concentration of dissolved ammonia and free ammonia ions in water, which usually comes from sources such as agriculture, industry, and urban wastewater. By measuring the ammonia nitrogen content in water, water quality safety can be ensured and water pollution can be prevented.

[0003] In the patent with the publication number CN216955990U, a water quality detection sampling unmanned patrol boat is disclosed, which includes an unmanned boat body and a control device arranged on the unmanned boat body, and also includes an airbag, a thruster, a detection component, and a sampler. The airbag is arranged at the bottom of the unmanned boat body.

[0004] However, the above device still has certain defects when in use. In the prior art, since there are often impurities such as weeds and green algae at the bottom of the water, during the sampling process, if the impurities such as weeds and green plants are sampled together, on the one hand, it will cause errors in the measured values during the water quality detection process, and on the other hand, there is also a risk of blocking the sampling equipment. Secondly, after sampling, the weight of the hull will increase due to the water sample. Since the buoyancy of the unmanned boat is limited, there is a certain risk of the unmanned boat sinking when the hull gains weight. Summary of the Invention

[0005] The purpose of the present invention is to solve the defects existing in the prior art, and a negative pressure sampling device for an on-line water quality ammonia nitrogen analyzer is proposed.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a negative pressure sampling device for an on-line water quality ammonia nitrogen analyzer, including a hull. A rectangular installation hole is opened at the center of the hull. A lifting plate is installed at the bottom of the installation hole in a lifting manner. A sampling bucket for sampling is slidably installed above the lifting plate. A filter screen for preventing waterweeds is arranged outside the sampling bucket. A plurality of scraping strips for cleaning the filter screen are abutted against the outside of the filter screen. The scraping strips are fixedly connected to the lifting plate. Floating airbags are arranged on both sides of the hull. An air pump is also arranged on the hull. The air pump is used for the sampling work of the sampling bucket, and the output end of the air pump is communicated with the floating airbags.

[0007] Preferably, an inverted U-shaped gantry is fixedly connected to the top of the hull. The two ends of the gantry are respectively fixedly connected to the side walls of the mounting holes. A second winding disc is rotatably mounted on the top of the gantry. A winding rope is fixedly connected to the second winding disc. One end of the winding rope away from the second winding disc is connected to the sampling bucket. A first motor is fixedly connected to one side of the top of the gantry. The output shaft of the first motor is fixedly connected to the side wall of the second winding disc. A circular hole is opened at the center of the gantry, and the winding rope passes through the circular hole.

[0008] Preferably, a piston plate is slidably connected inside the sampling bucket. A first cylinder is fixedly connected to the top of the piston plate. A second cylinder is fixedly connected to the bottom of the piston plate. One end of the first cylinder away from the piston plate penetrates through the top wall of the sampling bucket, and one end of the first cylinder away from the piston plate is fixedly connected to one end of the winding rope away from the second winding disc. One end of the second cylinder away from the piston plate penetrates through the bottom wall of the sampling bucket, and one end of the second cylinder away from the piston plate is fixedly connected to the center of the top of the lifting plate.

[0009] Preferably, a rotating groove is opened on the lifting plate. A rotating ring with an inverted "T" cross-section is rotatably sleeved in the rotating groove. The filter screen is fixedly connected to the top of the rotating ring and is located outside the sampling bucket. A water inlet for sampling is opened at the bottom of the sampling bucket. An electromagnetic valve is arranged in the water inlet. A plurality of scraping strips are fixedly connected to the top wall of the lifting plate and are located outside the rotating groove.

[0010] Preferably, a hollow mounting cylinder is fixedly connected to the bottom wall of the lifting plate. A rectangular sliding column is slidably connected inside the mounting cylinder. A reset spring is fixedly connected to the bottom of the rectangular sliding column. One end of the reset spring away from the rectangular sliding column is fixedly connected to the inner bottom wall of the mounting cylinder. A rack is fixedly connected to the top of the rectangular sliding column. The top wall of the rack is in movable contact with the bottom wall of the sampling bucket. The rack is meshed with a driving gear. The driving gear is fixedly connected to a transmission shaft. The transmission shaft is rotatably sleeved in the bracket. The bracket is fixedly connected to the top wall of the lifting plate. One end of the transmission shaft away from the driving gear is fixedly connected to a bevel gear. The bevel gear is meshed with a bevel gear ring. The bevel gear ring is fixedly connected to the inner wall of the filter screen.

[0011] Preferably, an air extraction pipe is communicated with the top of the sampling bucket. The air extraction pipe is wound around the first winding disc. A hollow rotating column is arranged on the first winding disc. One end of the air extraction pipe away from the sampling bucket is communicated with the hollow layer of the rotating column. A U-shaped frame is fixedly connected to one side of the gantry. The first winding disc is rotatably connected inside the U-shaped frame. The first winding disc is drivingly connected to a second motor. The second motor rotates synchronously with the first motor. The second motor is fixedly connected to the outer wall of the U-shaped frame. The hollow layer of the rotating column is also communicated with a connecting air pipe. The connecting air pipe is rotatably sleeved in the hollow layer of the rotating column. One end of the connecting air pipe away from the hollow layer of the rotating column is communicated with an air pump.

[0012] Preferably, an electromagnetic three-way valve is connected to the input end of the air pump. The electromagnetic three-way valve is a two-in-one-out three-way valve, and its output end is connected to the input end of the air pump. One of its two input ends is connected to a connecting air pipe, and the other input end is connected to an external air pipe. The end of the external air pipe away from the electromagnetic three-way valve is connected to the outside atmosphere. The connecting air pipe is connected to the air pump through the electromagnetic three-way valve.

[0013] Preferably, a U-shaped pipe is connected to the tops of the two floating air bags. A connecting head is provided on the U-shaped pipe. The output end of the air pump is connected to an air outlet pipe. The end of the air outlet pipe away from the air pump is connected to the connecting head. A rectangular ring groove is opened at the bottom of the mounting hole. A sealing air bag is arranged in the rectangular ring groove. The sealing air bag is in movable contact with the lifting plate. Both sides of the sealing air bag are connected to a first built-in pipe. The ends of the two first built-in pipes away from the sealing air bag are respectively connected to the two floating air bags. A one-way intake valve is arranged at the connection between the first built-in pipe and the floating air bag. Both sides of the sealing air bag are also connected to two second built-in pipes. The two second built-in pipes are also respectively connected to the two floating air bags. A one-way pressure valve is arranged at the connection between the sealing air bag and the second built-in pipe.

[0014] Preferably, a turbofan for driving it forward is provided at one end of the bottom of the hull, and a steering plate for controlling the steering of the hull is provided at the end of the bottom of the hull away from the turbofan.

[0015] Preferably, "L"-shaped power air pipes are fixedly connected to both sides of the end of the bottom of the hull away from the turbofan. The two power air pipes are respectively connected to the two floating air bags, and the ends of the two power air pipes away from the two floating air bags face the direction of the turbofan. A pneumatic valve is arranged inside the power air pipe.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. Through the setting of the lifting plate in the present invention, the weeds at the bottom of the water can be effectively blocked, which is beneficial to preventing underwater weeds, green algae and other sundries from entering the sampling bucket, thereby causing impurities to mix into the water in the sampling bucket, and thus affecting the effective detection and analysis of the ammonia nitrogen content in the water quality. And through the setting of the filter screen, the impurities on the side of the sampling bucket in the water can also be effectively blocked, which is beneficial to preventing weeds and green algae on the side of the sampling bucket from entering the sampling bucket during the sampling process of the sampling bucket, which is beneficial to further ensuring the cleanliness of the sampled water quality, so that the water sampled in the sampling bucket will not be mixed with impurities such as water plants and green algae, and at the same time, the situation that the water inlet is blocked by impurities such as water plants and green algae is also avoided.

[0018] 2. With the arrangement of the air pump in the present invention, after the air in the sampling bucket is pumped away by the air pump, it will enter the outlet pipe, then enter the U-shaped pipe through the outlet pipe, and finally enter the floating airbag through the U-shaped pipe. On the one hand, it can enable the gas in the sampling bucket to be discharged smoothly, and on the other hand, it can also make the floating airbag expand to increase the displacement of the hull, thereby increasing the buoyancy provided by the hull and facilitating the avoidance of the hull sinking.

[0019] 3. In the present invention, by controlling the electromagnetic three-way valve to connect the external air pipe with the input end of the air pump, and then controlling the air pump to continuously output air into the floating airbag, the floating airbag is in the maximum expansion state, and the buoyancy received by the hull in the water is also in the maximum state, which is beneficial to avoiding the situation of the hull sinking under the condition of weight gain. When the air pressure in the floating airbag reaches the preset air pressure value of the air pressure valve, the air pressure valve opens, and the pressurized gas in the floating airbag is discharged through the power air pipe. After the gas is discharged, it impacts in the water, providing power for the movement of the hull, assisting the turbofan to drive the hull to move effectively, accelerating the hull's return to the shore, and shortening the sampling return time of the hull. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 for the present invention Figure 1 is an enlarged schematic diagram of the structure of part A shown in the present invention;

[0022] Figure 3 is a schematic diagram of the overall structure of the present invention from another perspective;

[0023] Figure 4 is a schematic cross-sectional view of the structure of the sampling bucket of the present invention;

[0024] Figure 5 is a schematic cross-sectional view of the structure of the floating airbag of the present invention;

[0025] Figure 6 is a schematic diagram of the installation structure of the sampling bucket of the present invention;

[0026] Figure 7 is a schematic cross-sectional view of the structure of the rack of the present invention;

[0027] Figure 8 is a schematic cross-sectional view of the structure of the power air pipe of the present invention.

[0028] In the figure: 1, hull; 2, floating airbag; 3, first motor; 4, second motor; 5, filter screen; 6, power air pipe; 7, connector; 8, U-shaped pipe; 9, air outlet pipe; 10, lifting plate; 11, turbofan; 12, steering plate; 13, gantry; 14, sealing airbag; 15, first inner pipe; 16, sampling bucket; 17, winding rope; 18, first cylinder; 19, piston plate; 20, second cylinder; 21, air extraction pipe; 22, scraping strip; 23, bevel gear; 24, rack; 25, driving gear; 26, rectangular sliding column; 27, mounting cylinder; 28, return spring; 29, bevel gear ring; 30, air pump; 31, electromagnetic three-way valve; 32, external air pipe; 33, first winding disc; 34, second winding disc; 35, second inner pipe; 36, connecting air pipe. Detailed implementation mode

[0029] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious variations.

[0030] As shown in Figures 1 to 8 A negative pressure sampling device for an on-line water quality ammonia nitrogen analyzer, including a hull 1. A rectangular installation hole is opened at the center of the hull 1. A lifting plate 10 is installed at the bottom of the installation hole in a lifting manner. Above the lifting plate 10, a sampling bucket 16 for sampling is slidably installed. A filter screen 5 for preventing waterweeds is arranged outside the sampling bucket 16. A plurality of scraping strips 22 for cleaning the filter screen 5 are abutted against the outside of the filter screen 5. The scraping strips 22 are fixedly connected to the lifting plate 10. Floating airbags 2 are arranged on both sides of the hull 1. An air pump 30 is also arranged on the hull 1. The air pump 30 is used for the sampling work of the sampling bucket 16, and the output end of the air pump 30 is communicated with the floating airbag 2.

[0031] In specific implementation, when the lifting plate 10 is in the state of rising to the highest position, the bottom wall plate of the lifting plate 10 and the bottom wall plate of the hull 1 are on the same horizontal plane, that is, the lifting plate 10 can be embedded in the bottom of the hull 1.

[0032] As a further implementation scheme of the present invention, an inverted U-shaped gantry 13 is fixedly connected to the top of the hull 1. The two ends of the gantry 13 are respectively fixedly connected to the side wall plates of the installation hole. A second winding disc 34 is rotatably installed on the top of the gantry 13. A winding rope 17 is fixedly connected to the second winding disc 34. One end of the winding rope 17 away from the second winding disc 34 is connected to the sampling bucket 16. A first motor 3 is fixedly connected to one side of the top of the gantry 13. The output shaft of the first motor 3 is fixedly connected to one side wall plate of the second winding disc 34. A round hole is opened at the center of the gantry 13, and the winding rope 17 passes through the round hole.

[0033] In specific implementation, rounded corners are provided at both the top and bottom of the round hole, and the rounded corners are used to reduce the friction between the inner wall of the round hole and the winding rope 17.

[0034] As a further implementation of the present invention, a piston plate 19 is slidably connected inside the sampling bucket 16. A first cylinder 18 is fixedly connected to the top of the piston plate 19, and a second cylinder 20 is fixedly connected to the bottom of the piston plate 19. One end of the first cylinder 18 away from the piston plate 19 penetrates through the top wall plate of the sampling bucket 16, and one end of the first cylinder 18 away from the piston plate 19 is fixedly connected to one end of the winding rope 17 away from the second winding disc 34. One end of the second cylinder 20 away from the piston plate 19 penetrates through the bottom wall plate of the sampling bucket 16, and one end of the second cylinder 20 away from the piston plate 19 is fixedly connected to the center of the top of the lifting plate 10.

[0035] In specific implementation, the lengths of both the first cylinder 18 and the second cylinder 20 exceed the height of the sampling bucket 16.

[0036] As a further implementation of the present invention, a rotating groove is provided on the lifting plate 10. A rotating ring with an inverted "T" - shaped cross - section is rotatably sleeved in the rotating groove. The filter screen 5 is fixedly connected to the top of the rotating ring, and the filter screen 5 is located outside the sampling bucket 16. A water inlet for sampling is provided at the bottom of the sampling bucket 16, and a solenoid valve is arranged in the water inlet. A plurality of scraping strips 22 are fixedly connected to the top wall plate of the lifting plate 10, and the scraping strips 22 are located outside the rotating groove.

[0037] In specific implementation, the rotating groove and the rotating ring are both of an inverted "T" - shaped structure. During the process of sampling through the sampling bucket 16, the solenoid valve is opened, and when discharging the water in the sampling bucket 16, the solenoid valve is also opened.

[0038] It should be noted that a valve is provided at the top of the sampling bucket 16. When discharging the water in the sampling bucket 16, the valve is opened to supplement air into the sampling bucket 16.

[0039] As a further implementation of the present invention, a hollow mounting cylinder 27 is fixedly connected to the bottom wall plate of the lifting plate 10. A rectangular sliding column 26 is slidably connected inside the mounting cylinder 27. A return spring 28 is fixedly connected to the bottom of the rectangular sliding column 26, and one end of the return spring 28 away from the rectangular sliding column 26 is fixedly connected to the inner bottom wall plate of the mounting cylinder 27. A rack 24 is fixedly connected to the top of the rectangular sliding column 26. The top wall plate of the rack 24 is in movable contact with the bottom wall plate of the sampling bucket 16. The rack 24 is meshed with a driving gear 25. The driving gear 25 is fixedly connected to a transmission shaft, and the transmission shaft is rotatably sleeved in a bracket. The bracket is fixedly connected to the top wall plate of the lifting plate 10. One end of the transmission shaft away from the driving gear 25 is fixedly connected to a bevel gear 23, and the bevel gear 23 is meshed with a bevel gear ring 29. The bevel gear ring 29 is fixedly connected to the inner wall of the filter screen 5.

[0040] In specific implementation, a limiting plate is provided at the bottom of the rectangular sliding column 26. The limiting plate is slidably connected to the hollow part of the mounting column 27. The limiting plate is used to prevent the rectangular sliding column 26 from separating from the mounting column 27. After the sampling is completed, the water in the sampling bucket 16 is drained by opening the solenoid valve, so that the return spring 28 jacks up the rack 24, and then the rectangular sliding column 26 is reset. During the reset process, the filter screen 5 is also driven to rotate in the reverse direction, and the filter screen 5 can be cleaned twice.

[0041] As a further implementation of the present invention, an air extraction pipe 21 is connected to the top of the sampling bucket 16. The air extraction pipe 21 is wound around the first winding disc 33. A hollow rotating column is provided on the first winding disc 33. One end of the air extraction pipe 21 away from the sampling bucket 16 is communicated with the hollow layer of the rotating column. A U-shaped frame is fixedly connected to one side of the gantry 13. The first winding disc 33 is rotatably connected in the U-shaped frame. The first winding disc 33 is drivingly connected to a second motor 4. The second motor 4 rotates synchronously with the first motor 3. The second motor 4 is fixedly connected to the outer wall of the U-shaped frame. The hollow layer of the rotating column is also communicated with a connecting air pipe 36. The connecting air pipe 36 is rotatably sleeved in the hollow layer of the rotating column. One end of the connecting air pipe 36 away from the hollow layer of the rotating column is communicated with an air pump 30.

[0042] In specific implementation, the settings of the rotating column, the air extraction pipe 21, the connecting air pipe 36 and the first winding disc 33 are prior arts, which are commonly seen in the winding disc of a fire hose, so that water can still flow when the pipeline is in a wound state. This technology is a prior art and will not be disclosed in detail here.

[0043] As a further implementation of the present invention, an electromagnetic three-way valve 31 is connected to the input end of the air pump 30. The electromagnetic three-way valve 31 is a two-in-one-out three-way valve. Its output end is communicated with the input end of the air pump 30. One of its two input ends is communicated with the connecting air pipe 36, and the other input end is communicated with an external air pipe 32. One end of the external air pipe 32 away from the electromagnetic three-way valve 31 is communicated with the outside atmosphere. The connecting air pipe 36 is communicated with the air pump 30 through the electromagnetic three-way valve 31.

[0044] In specific implementation, through the setting of the electromagnetic three-way valve 31, gas can be effectively supplied to the sealing airbag 14 and the floating airbag 2, which is beneficial to ensuring the full inflation of the sealing airbag 14 and the floating airbag 2.

[0045] As a further embodiment of the present invention, the tops of two floating airbags 2 are connected to a U-shaped tube 8. A connector 7 is provided on the U-shaped tube 8. The output end of an air pump 30 is connected to an air outlet pipe 9. One end of the air outlet pipe 9 away from the air pump 30 is connected to the connector 7. A rectangular ring groove is formed at the bottom of the mounting hole. A sealing airbag 14 is arranged in the rectangular ring groove. The sealing airbag 14 is in movable contact with the lifting plate 10. Both sides of the sealing airbag 14 are connected to a first built-in tube 15. One ends of the two first built-in tubes 15 away from the sealing airbag 14 are respectively connected to the two floating airbags 2. A one-way intake valve is arranged at the connection between the first built-in tube 15 and the floating airbag 2. Both sides of the sealing airbag 14 are also connected to two second built-in tubes 35. The two second built-in tubes 35 are also respectively connected to the two floating airbags 2. A one-way pressure valve is arranged at the connection between the sealing airbag 14 and the second built-in tube 35.

[0046] In specific implementation, the one-way pressure valve is set with a pressure preset value. When the gas pressure in the sealing airbag 14 is higher than this pressure preset value, the one-way pressure valve opens. It should be noted that the one-way pressure valve can only allow the gas in the sealing airbag 14 to enter the floating airbag 2, and the one-way intake valve can only allow the gas in the floating airbag 2 to enter the sealing airbag 14.

[0047] As a further embodiment of the present invention, a turbofan 11 for driving it forward is arranged at one end of the bottom of the hull 1, and a steering plate 12 for controlling the steering of the hull 1 is arranged at the end of the bottom of the hull 1 away from the turbofan 11.

[0048] In specific implementation, by adding a signal receiver and a remote controller, the movement and sampling work of the hull 1 can be remotely controlled, which is convenient for technicians to operate on the shore. The hull 1 is set as an unmanned ship to reduce the resources consumed by sampling. This remote control technology is an existing technology, which is commonly found in fields such as remote control cars and remote control unmanned ships, and will not be disclosed in detail here.

[0049] As a further embodiment of the present invention, "L"-shaped power air pipes 6 are fixedly connected to both sides of the end of the bottom of the hull 1 away from the turbofan 11. The two power air pipes 6 are respectively connected to the two floating airbags 2, and one ends of the two power air pipes 6 away from the two floating airbags 2 face the direction of the turbofan 11. A pneumatic valve is arranged inside the power air pipe 6.

[0050] In specific implementation, the pneumatic valve is set with a pneumatic preset value. When the air pressure in the floating airbag 2 is higher than this pneumatic preset value, the pneumatic valve opens. It should be noted that the pneumatic preset value of the pneumatic valve is equal to the pressure preset value of the one-way pressure valve.

[0051] The working principle of the present invention:

[0052] When the present invention is in use, first, the device is moved to the position where sampling is required by the turbofan 11. During this process, the moving direction of the hull 1 is controlled by the steering plate 12. After the hull 1 is moved to the water area where sampling is required, the first motor 3 and the second motor 4 are controlled to work, thereby driving the second winding disc 34 and the first winding disc 33 to rotate, so that the winding rope 17 and the air extraction pipe 21 can be loosened, so that the lifting plate 10 and the sampling bucket 16 can descend, and then descend into the water, facilitating subsequent sampling work.

[0053] Through the settings of the first winding disc 33 and the second winding disc 34, the device can effectively carry out sampling work from underwater and can effectively sample water at different depths. At the same time, through the setting of the lifting plate 10, the weeds at the bottom of the water can be effectively blocked, which is beneficial to preventing underwater weeds, green algae and other impurities from entering the sampling bucket 16, thus causing impurities to mix into the water in the sampling bucket 16 and affecting the effective detection and analysis of the ammonia nitrogen content in the water quality. And through the setting of the filter screen 5, the impurities on the side of the sampling bucket 16 in the water can also be effectively blocked, which is beneficial to preventing weeds and green algae on the side of the sampling bucket 16 from entering the sampling bucket 16 during the sampling process of the sampling bucket 16, which is beneficial to further ensuring the cleanliness of the sampled water quality, so that the water sampled in the sampling bucket 16 will not be mixed with impurities such as water plants and green algae, and at the same time, the situation of the water inlet being blocked by impurities such as water plants and green algae is also avoided.

[0054] During the sampling process, the air pump 30 is controlled to start, and then the electromagnetic three-way valve 31 is controlled to connect the connecting air pipe 36 with the input end of the air pump 30. After the air pump 30 is started, it will extract air through the connecting air pipe 36 and the air extraction pipe 21, so that the air extraction pipe 21 can extract air from the sampling bucket 16, so that the air pressure above the piston plate 19 in the sampling bucket 16 is reduced. At the same time as the air pump 30 is started, the solenoid valve is also controlled to open, so that water can enter the chamber below the piston plate 19 in the sampling bucket 16 from the water inlet, thus completing the sampling work. During the sampling process, the lifting plate 10 is relatively stationary in the water under the action of gravity. After the gas in the sampling bucket 16 is extracted, it enters the space below the piston plate 19 in the sampling bucket 16 along with the water flow. At this time, the sampling bucket 16 will move downward relative to the piston plate 19, so that the water flow can enter the chamber below the piston plate 19 in the sampling bucket 16, thus completing the sampling work of the water.

[0055] After the sampling bucket 16 moves downward, the bottom wall plate of the sampling bucket 16 will abut against the rack 24, and then push the rack 24 downward to move. During the movement of the rack 24, it will push the rectangular sliding column 26 downward, thereby compressing the return spring 28. When the rack 24 moves, it will also drive the driving gear 25 to rotate. After the driving gear 25 rotates, it will drive the bevel gear 23 to rotate through the transmission shaft, so that the bevel gear 23 drives the bevel gear ring 29 to rotate. After the bevel gear ring 29 rotates, it will drive the filter screen 5 to rotate. During the rotation of the filter screen 5, relative movement will occur between its outer wall and the scraping strip 22, so that the scraping strip 22 can scrape off impurities such as weeds and green algae attached to the outer wall of the filter screen 5, which is beneficial to avoid the situation that the filter screen 5 is blocked by weeds and green algae and other impurities, and further ensures the smooth progress of the water sampling work.

[0056] After the air in the sampling bucket 16 is pumped away by the air pump 30, it will enter the air outlet pipe 9, then enter the U-shaped pipe 8 through the air outlet pipe 9, and finally enter the floating air bag 2 through the U-shaped pipe 8. On the one hand, it can make the gas in the sampling bucket 16 drain smoothly, and on the other hand, it can also make the floating air bag 2 expand to increase the displacement of the hull 1, thereby increasing the buoyancy provided by the hull 1, which is beneficial to avoid the situation of the hull 1 sinking.

[0057] After the gas enters the floating air bag 2, it will enter the sealed air bag 14 through the first built-in pipe 15 to make the sealed air bag 14 expand. After the sampling work of the sampling bucket 16 is completed, by controlling the first motor 3 and the second motor 4 to rotate in the reverse direction, the sampling bucket 16 and the lifting plate 10 are lifted. When the lifting plate 10 contacts the sealed air bag 14, since the sealed air bag 14 is in an expanded state, at this time the sealed air bag 14 can effectively abut against the lifting plate 10, so that the mounting hole is effectively blocked, which is beneficial to improve the integrity of the hull 1, further increase the displacement of the hull 1, and then increase the buoyancy of the hull 1, so as to achieve the purpose of improving the stability of the hull 1.

[0058] During the process of the sealed air bag 14 being compressed when it is in an expanded state, the air pressure in the sealed air bag 14 will gradually increase. When the water pressure in the sealed air bag 14 increases to the pressure preset value of the one-way pressure valve, the one-way pressure valve opens, so that the gas in the sealed air bag 14 enters the floating air bag 2, thereby further increasing the buoyancy received by the device. After the sampling work is completed, the lifting plate 10 will also carry some water, which is beneficial to maintaining the humidity in the mounting hole. Through a small amount of water, it is beneficial to avoid impurities such as sink green algae from solidifying and adhering to the lifting plate 10 due to drying. Through the wetting effect of a small amount of water, it is convenient to clean the waterweeds and green algae.

[0059] After the lifting plate 10 rises to fully abut against the sealing airbag 14, the external air pipe 32 is communicated with the input end of the air pump 30 by controlling the electromagnetic three-way valve 31. Subsequently, the air pump 30 is controlled to continuously output air into the floating airbag 2, so that the floating airbag 2 is in the maximum inflation state, and thus the buoyancy received by the hull 1 in the water is also in the maximum state. When the air pressure in the floating airbag 2 reaches the air pressure preset value of the air pressure valve, the air pressure valve opens, so that the pressurized gas in the floating airbag 2 is discharged through the power air pipe 6. After the gas is discharged, it impacts in the water, thereby providing power for the movement of the hull 1, assisting the turbofan 11 to drive the hull 1 to move effectively, accelerating the hull 1 to return to the shore, shortening the sampling return time of the hull 1. When sampling in the area far from the shore of a large lake, the sampling return time can be shortened, thereby reducing the occurrence of the change in the ammonia nitrogen content in the sampled water due to the consumption of time.

[0060] During the process of the hull 1 moving into the water and the hull 1 returning after sampling, through the setting of the first motor 3 and the lifting plate 10, the sampling bucket 16 can be tightly stretched between the lifting plate 10 and the gantry 13, which is beneficial to avoiding the shaking of the sampling bucket 16 during the movement of the hull 1, and thus avoiding the imbalance of the hull 1 caused by the shaking of the sampling bucket 16.

[0061] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A negative pressure sampling device for an on-line water quality ammonia nitrogen analyzer, comprising a hull (1), characterized in that: A rectangular mounting hole is formed at the center of the hull (1). A lifting plate (10) is mounted at the bottom of the mounting hole in a lifting manner. Above the lifting plate (10), a sampling bucket (16) for sampling is slidably mounted. A filter screen (5) for preventing waterweeds is arranged outside the sampling bucket (16). A plurality of scraping strips (22) for cleaning the filter screen (5) are abutted against the outside of the filter screen (5). The scraping strips (22) are fixedly connected to the lifting plate (10). Floating air bags (2) are arranged on both sides of the hull (1). An air pump (30) is further arranged on the hull (1). The air pump (30) is used for the sampling work of the sampling bucket (16), and the output end of the air pump (30) is communicated with the floating air bags (2). The tops of the two floating air bags (2) are communicated with a U-shaped pipe (8). A connector (7) is arranged on the U-shaped pipe (8). The output end of the air pump (30) is communicated with an air outlet pipe (9). One end of the air outlet pipe (9) away from the air pump (30) is communicated with the connector (7). A rectangular ring groove is formed at the bottom of the mounting hole. A sealing air bag (14) is arranged in the rectangular ring groove. The sealing air bag (14) is movably abutted against the lifting plate (10). Two first internal pipes (15) are communicated with both sides of the sealing air bag (14). One ends of the two first internal pipes (15) away from the sealing air bag (14) are respectively communicated with the two floating air bags (2). A one-way intake valve is arranged at the communication position between the first internal pipe (15) and the floating air bag (2). Two second internal pipes (35) are also communicated with both sides of the sealing air bag (14). The two second internal pipes (35) are also respectively communicated with the two floating air bags (2). A one-way pressure valve is arranged at the communication position between the sealing air bag (14) and the second internal pipe (35).

2. The negative pressure sampling device of an online water quality ammonia nitrogen analyzer according to claim 1, characterized in that: A U-shaped gantry (13) is fixedly connected to the top of the hull (1). The two ends of the gantry (13) are respectively fixedly connected to the side wall plates on both sides of the mounting hole. A second winding disc (34) is rotatably mounted on the top of the gantry (13). A winding rope (17) is fixedly connected to the second winding disc (34). One end of the winding rope (17) away from the second winding disc (34) is connected to the sampling bucket (16). A first motor (3) is fixedly connected to one side of the top of the gantry (13). The output shaft of the first motor (3) is fixedly connected to a side wall plate of the second winding disc (34). A circular hole is formed at the center of the gantry (13). The winding rope (17) passes through the circular hole.

3. The negative pressure sampling device of an online water quality ammonia nitrogen analyzer according to claim 2, characterized in that: A piston plate (19) is slidably connected inside the sampling bucket (16). A first cylinder (18) is fixedly connected to the top of the piston plate (19), and a second cylinder (20) is fixedly connected to the bottom of the piston plate (19). One end of the first cylinder (18) away from the piston plate (19) penetrates through the top wall plate of the sampling bucket (16), and one end of the first cylinder (18) away from the piston plate (19) is fixedly connected to one end of the winding rope (17) away from the second winding disc (34). One end of the second cylinder (20) away from the piston plate (19) penetrates through the bottom wall plate of the sampling bucket (16), and one end of the second cylinder (20) away from the piston plate (19) is fixedly connected to the center of the top of the lifting plate (10).

4. The negative pressure sampling device of an online water quality ammonia nitrogen analyzer according to claim 3, characterized in that: A rotating groove is formed in the lifting plate (10). A rotating ring with an inverted "T" - shaped cross - section is rotatably sleeved in the rotating groove. The filter screen (5) is fixedly connected to the top of the rotating ring, and the filter screen (5) is located outside the sampling bucket (16). A water inlet for sampling is formed at the bottom of the sampling bucket (16), and a solenoid valve is arranged in the water inlet. A plurality of scraping strips (22) are fixedly connected to the top wall plate of the lifting plate (10), and the scraping strips (22) are located outside the rotating groove.

5. The negative pressure sampling device of an online water quality ammonia nitrogen analyzer according to claim 4, characterized in that: A hollow mounting cylinder (27) is fixedly connected to the bottom wall plate of the lifting plate (10). A rectangular sliding column (26) is slidably connected inside the mounting cylinder (27). A return spring (28) is fixedly connected to the bottom of the rectangular sliding column (26), and one end of the return spring (28) away from the rectangular sliding column (26) is fixedly connected to the inner bottom wall plate of the mounting cylinder (27). A rack (24) is fixedly connected to the top of the rectangular sliding column (26). The top wall plate of the rack (24) is in movable abutment with the bottom wall plate of the sampling bucket (16). The rack (24) is meshed with a driving gear (25). The driving gear (25) is fixedly connected with a transmission shaft. The transmission shaft is rotatably sleeved in a bracket. The bracket is fixedly connected to the top wall plate of the lifting plate (10). One end of the transmission shaft away from the driving gear (25) is fixedly connected with a bevel gear (23). The bevel gear (23) is meshed with a bevel gear ring (29). The bevel gear ring (29) is fixedly connected to the inner wall of the filter screen (5).

6. The negative pressure sampling device of an on-line water quality ammonia nitrogen analyzer according to claim 5, characterized in that: An air extraction pipe (21) is communicated with the top of the sampling bucket (16). The air extraction pipe (21) is wound around the first winding disc (33). A hollow rotating column is arranged on the first winding disc (33). One end of the air extraction pipe (21) away from the sampling bucket (16) is communicated with the hollow layer of the rotating column. A U - shaped frame is fixedly connected to one side of the gantry (13). The first winding disc (33) is rotatably connected in the U - shaped frame. The first winding disc (33) is drivingly connected with a second motor (4). The second motor (4) rotates synchronously with the first motor (3). The second motor (4) is fixedly connected to the outer wall of the U - shaped frame. The hollow layer of the rotating column is also communicated with a connecting air pipe (36). The connecting air pipe (36) is rotatably sleeved in the hollow layer of the rotating column. One end of the connecting air pipe (36) away from the hollow layer of the rotating column is communicated with an air pump (30).

7. The negative pressure sampling device of an online water quality ammonia nitrogen analyzer according to claim 6, characterized in that: The input end of the air pump (30) is connected to an electromagnetic three-way valve (31). The electromagnetic three-way valve (31) is a two-in-one-out three-way valve. Its output end is connected to the input end of the air pump (30). One of its two input ends is connected to a connecting air pipe (36), and the other input end is connected to an external air pipe (32). The end of the external air pipe (32) away from the electromagnetic three-way valve (31) is connected to the outside atmosphere. The connecting air pipe (36) is connected to the air pump (30) through the electromagnetic three-way valve (31).

8. The negative pressure sampling device of an on-line water quality ammonia nitrogen analyzer according to claim 7, characterized in that: A turbofan (11) for driving the hull (1) forward is provided at one end of the bottom of the hull (1). A steering plate (12) for controlling the turning of the hull (1) is provided at the end of the bottom of the hull (1) away from the turbofan (11).

9. The negative pressure sampling device of an online water quality ammonia nitrogen analyzer according to claim 8, characterized in that: "L”-shaped power air pipes (6) are fixedly connected to both sides of the end of the bottom of the hull (1) away from the turbofan (11). The two power air pipes (6) are respectively connected to the two floating air bags (2), and the ends of the two power air pipes (6) away from the two floating air bags (2) face the direction of the turbofan (11). A pneumatic valve is provided inside the power air pipe (6).

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