Sampling device for detecting organic carbon in soil and sampling method thereof

Abstract

The invention discloses a sampling device for soil organic carbon detection and a sampling method thereof, and relates to the technical field of soil detection.The sampling device comprises barrels, upper soil containing barrels are fixed to the upper ends of the barrels, and a plurality of barrels can form a temporarily-fixed combined sampler by inserting the upper soil containing barrels into the bottom of one barrel; a lower soil containing barrel is inserted into the lower end of the lowermost barrel body; two groups of horizontally telescopic spiral conveying mechanisms are symmetrically arranged in the middle of each barrel body and are used for conveying soil of a corresponding layer into the upper soil containing barrel, and the two groups of spiral conveying mechanisms are simultaneously driven by one motor to move back to back and convey the soil. The sampling comprises the following steps: forming a sampling hole; assembling the combined sampler; placing a combined sampler; sampling is carried out; collecting the sampled soil; through the design of the combined sampler, it is ensured that soil of the corresponding layer can be independently collected, and mixing between the upper layer and the lower layer is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of soil detection, and more particularly to a sampling device and a sampling method for detecting soil organic carbon. Background Art

[0002] Soil organic carbon content is a key indicator for assessing soil fertility, environmental quality, and carbon cycle research. To accurately measure soil organic carbon content at different depths, specialized sampling devices are often required for soil sample collection. However, traditional soil sampling methods mostly use vertical drilling or insertion samplers. While this method is simple and direct, it has some significant challenges in practical application:

[0003] 1. Interference between soil layers: During vertical sampling, as the sampler penetrates deeper, the upper soil layer is easily carried into the lower layer, causing mixing between different soil layers. This mixing interferes with the original soil stratification information, making the sample obtained unable to accurately reflect the organic carbon content at a specific depth.

[0004] 2. Insufficient sampling accuracy: Traditional sampling methods make it difficult to ensure that each sampling is within the exact same depth range, which may lead to data inconsistency and increased errors, affecting the accuracy of subsequent analysis results.

[0005] 3. Operational complexity: In order to minimize inter-layer interference, operators often need to control the sampling process very carefully, including sampling speed, force, etc., which places high demands on the operator's experience and technical level.

[0006] Therefore, it is necessary to propose a sampling device and a sampling method for soil organic carbon detection to solve the above problems. Summary of the Invention

[0007] The purpose of the present invention is to solve the problems raised in the background technology.

[0008] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0009] A sampling device for soil organic carbon detection includes a barrel body with an upper soil cylinder fixed at the upper end. A plurality of barrel bodies can be formed into a temporarily fixed combined sampler by plugging the upper soil cylinder into the bottom of the upper barrel body, wherein the lower end of the lowermost barrel body is plugged into the lower soil cylinder;

[0010] Two sets of horizontally retractable screw conveying mechanisms are symmetrically arranged in the middle of each barrel body, which are used to convey the soil of the corresponding layer to the upper soil storage cylinder. The two sets of screw conveying mechanisms are simultaneously driven by a motor to move and convey the screw conveying mechanisms in the opposite direction.

[0011] Furthermore, the outer side surface of the lower soil storing barrel is symmetrically fixedly connected with a first limit rod, and both sides of the barrel body are provided with limit grooves for the first limit rod to be inserted, and the upper end of the first limit rod is sleeved with a block rod, and a socket for the plug-in rod is provided at the position corresponding to each upper soil storing barrel, and the plug-in rod passes through the block rod and is inserted into the socket.

[0012] Furthermore, the driving spiral conveying mechanism includes a sampling barrel that is symmetrically slidably inserted in the middle of the barrel body, a spiral auger conveying shaft that is rotatably connected to the end of the sampling barrel in the barrel body, and a driving mechanism. A discharge port is provided at the lower end of the sampling barrel in the barrel body, and the driving mechanism can simultaneously drive the sampling barrel to move backward and the spiral auger conveying shaft to rotate.

[0013] Furthermore, a second limiting rod is fixedly connected to the inner side of the barrel between the two sampling cylinders, and the opposite ends of the second limiting rod are respectively fixedly connected to protruding rods, and the side of the sampling cylinder is provided with a sliding groove for the protruding rod to be inserted.

[0014] Furthermore, a baffle is fixedly connected to the end of the sampling tube in the barrel body, and the spiral auger conveying shaft is rotatably connected to the middle of the baffle.

[0015] Furthermore, the driving mechanism includes a first gear fixedly connected to the end of the spiral auger conveying shaft in the barrel body, a screw rotatably connected above the sampling cylinder and parallel to the sampling cylinder, a transmission plate fixedly connected to one end of the sampling cylinder close to the first gear, and a driving assembly, and the driving assembly can drive the screw and the first gear to rotate simultaneously.

[0016] Furthermore, the drive assembly includes a mounting shaft rotatably connected to the inner side of the barrel body between the two screws, a gear shaft fixedly connected to the outer side of the mounting shaft, a third gear fixedly connected to the mounting shaft at both ends of the gear shaft, a fourth gear fixedly connected to both ends of the screw, and a drive module for driving the gear shaft to rotate, the gear shaft is meshed with the first gear, and the fourth gear is meshed with the third gear.

[0017] Furthermore, the driving module includes a motor fixedly connected to the inner side of the barrel and a second gear fixedly connected to the output shaft of the motor, and the second gear is meshed with the gear shaft.

[0018] A sampling method for detecting soil organic carbon, comprising the above-mentioned sampling device for detecting soil organic carbon, comprises the following steps:

[0019] S1. Open a sampling hole vertically to match the diameter of the outer side of the barrel;

[0020] S2. Assemble the combined sampler. According to the required sampling depth, select at least one barrel to assemble into the combined sampler.

[0021] S3. Place the combined sampler. After assembly is complete, place the combined sampler in the sampling hole.

[0022] S4. Sampling is performed, the control motor is started, and the two sampling cylinders are driven to move horizontally in opposite directions. At the same time, the spiral auger conveying shaft is driven to rotate, and the sampling cylinders are driven to insert into the soil at the corresponding position. The rotation of the spiral auger conveying shaft drives the soil into the sampling cylinders;

[0023] S5. Collect the sampled soil, and the soil falls into the corresponding upper soil cylinder or lower soil cylinder through the discharge port;

[0024] S6. After sampling is completed, the motor is controlled to reverse and reset the sampling barrel. Then the combined sampler is taken out from the sampling hole, the barrel body is disassembled, and the soil in the upper soil barrel or the lower soil barrel is taken out for organic carbon detection.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention ensures that the soil of the corresponding layer can be collected independently through the design of the combined sampler, avoiding mixing between the upper and lower layers.

[0027] 2. The present invention can effectively improve the sampling efficiency by arranging two sampling tubes in each barrel.

[0028] 3. The present invention, through the design of the motor, can simultaneously realize the horizontal movement of the sampling tube and the driving rotation of the spiral auger conveying shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the main view of the structure of the present invention.

[0030] Figure 2 It is a schematic diagram of the main view of the barrel body in the present invention.

[0031] Figure 3 It is a schematic front view of the connection structure at the first limiting rod in the present invention.

[0032] Figure 4 It is a schematic sectional view of the main view of the structure of the present invention.

[0033] Figure 5 It is a side view schematic diagram of the structure of the present invention.

[0034] Figure 6 This is a first stereoscopic schematic diagram of the driving mechanism of the present invention.

[0035] Figure 7 This is a second stereoscopic schematic diagram of the driving mechanism of the present invention.

[0036] Figure 8This is a third stereoscopic schematic diagram of the driving mechanism of the present invention.

[0037] Figure numerals: 1, barrel body; 2, upper soil cylinder; 3, lower soil cylinder; 4, limiting groove; 5, first limiting rod; 6, blocking rod; 7, jack; 8, plug rod; 9, sampling cylinder; 10, baffle; 11, spiral auger conveying shaft; 12, first gear; 13, mounting shaft; 14, gear shaft; 15, motor; 16, second gear; 17, third gear; 18, bearing seat; 19, screw; 20, transmission plate; 21, fourth gear; 22, second limiting rod; 23, slide groove; 24, protruding rod; 25, discharge port. DETAILED DESCRIPTION

[0038] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] See also Figures 1 to 8 A sampling device for soil organic carbon detection includes a barrel body 1 with an upper soil cylinder 2 fixed at the upper end. The barrel body 1 below the upper soil cylinder 2 is a hollow cylinder. Multiple barrel bodies 1 can be connected to the bottom of the upper barrel body 1 to form a temporary fixed combined sampler, thereby collecting soil at multiple depths. The difference is that a lower soil cylinder 3 is connected to the bottom of the lowest barrel body 1.

[0040] Two sets of horizontally retractable spiral conveying mechanisms are symmetrically arranged in the middle of each barrel body 1, which are used to convey the soil of the corresponding layer to the upper soil cylinder 2, so as to collect soil in two directions. The work efficiency is high, and after the sampling at this position is completed, the combined sampler can be rotated to collect soil at different positions of the same layer. The two sets of spiral conveying mechanisms are simultaneously driven by a motor 15 to move and convey the spiral conveying mechanisms in the opposite direction. The motor 15 is a servo motor, which can control the number of rotations of the controller to accurately control the position of the spiral conveying mechanism, and the design concept of low power consumption and energy saving is implemented throughout.

[0041] Specific, combined Figures 1 to 5As shown, in order to achieve temporary fixation of the combined sampler, a first limiting rod 5 is symmetrically fixedly connected to the outer side surface of the lower soil cylinder 3, and limiting grooves 4 for the first limiting rod 5 to be inserted are provided on both sides of the barrel body 1. Through the cooperation of the first limiting rod 5 and the limiting groove 4, relative rotation between the barrel bodies 1 can be prevented. In addition, a blocking rod 6 is sleeved on the upper end of the first limiting rod 5, and a socket 7 for the insertion rod 8 to be inserted is provided at the position corresponding to each upper soil cylinder 2. The insertion rod 8 passes through the blocking rod 6 and is inserted into the socket 7, thereby limiting the up and down movement of multiple barrel bodies 1, which is convenient for the overall use of the combined sampler.

[0042] Specific, combined Figures 4 to 8 As shown, the driving spiral conveying mechanism includes a sampling barrel 9 that is symmetrically slidably inserted in the middle of the barrel body 1, a spiral auger conveying shaft 11 that is rotatably connected to the end of the sampling barrel 9 in the barrel body 1, and a driving mechanism, wherein the outer side surfaces of the sampling barrel 9 and the spiral auger conveying shaft 11 need to be flush with the outer side surfaces of the barrel body 1, and will interfere with the sampling hole when the combined sampler is placed. A discharge port 25 is provided at the lower end of the sampling barrel 9 in the barrel body 1, and the driving mechanism can simultaneously drive the sampling barrel 9 to move backward and the spiral auger conveying shaft 11 to rotate. In order to facilitate the insertion of the sampling barrel 9 into the soil, a toothed or conical structure can also be provided on its end face.

[0043] Specific, combined Figure 7 and Figure 8 As shown, in order to prevent the two sampling cylinders 9 from rotating when moving horizontally, a second limiting rod 22 is fixedly connected to the inner side surface of the barrel body 1 between the two sampling cylinders 9, and the opposite ends on both sides of the second limiting rod 22 are fixedly connected with protruding rods 24. The side of the sampling cylinder 9 is provided with a sliding groove 23 for the protruding rod 24 to be inserted. The protruding rod 24 is arranged at the sampling cylinder 9 at the outer end to prevent interference with the moving distance of the sampling cylinder 9.

[0044] Specific, combined Figure 7 and Figure 8 As shown, in order to realize the installation of the spiral auger conveying shaft 11, a baffle 10 is fixedly connected to the end of the sampling tube 9 in the barrel body 1, and the spiral auger conveying shaft 11 is rotatably connected to the middle part of the baffle 10, wherein the spiral auger conveying shaft 11 is preferably such that the outer side surface can almost fit the model of the inner side surface of the sampling tube 9 to ensure the sampling and transmission of the soil.

[0045] Specific, combined Figures 6 to 8As shown, the driving mechanism includes a first gear 12 fixedly connected to the end of the spiral auger conveying shaft 11 in the barrel body 1, a screw 19 rotatably connected above the sampling barrel 9 and parallel to the sampling barrel 9, a transmission plate 20 fixedly connected to the end of the sampling barrel 9 close to the first gear 12, and a driving assembly. A positioning plate is provided at the upper end of the transmission plate 20. When the positioning plate is in contact with the inner side of the barrel body 1, the outer side of the sampling barrel 9 is flush with the outer side of the barrel body 1. The driving assembly can drive the screw 19 and the first gear 12 to rotate at the same time, thereby driving the sampling barrel 9 to move horizontally and rotate.

[0046] Specific, combined Figures 6 to 8 As shown, the driving assembly includes a mounting shaft 13 rotatably connected to the inner side of the barrel body 1 between the two lead screws 19, a gear shaft 14 fixedly connected to the outer side of the mounting shaft 13, a third gear 17 fixedly connected to the mounting shaft 13 at both ends of the gear shaft 14, a fourth gear 21 fixedly connected to both ends of the lead screw 19, and a driving module for driving the gear shaft 14 to rotate. The gear shaft 14 is set to be longer. As the gear shaft 14 drives the movement of the sampling cylinder 9, the first gear 12 will also move along the gear shaft 14. The gear shaft 14 and the first gear 12 The gear shaft 14 and the first gear 12 are meshed and connected, and the number of teeth of the gear shaft 14 is the same, or the number of teeth of the first gear 12 is designed to be smaller than the number of teeth of the gear shaft 14, which can drive the spiral auger conveying shaft 11 to rotate at a speed greater than the moving speed of the sampling barrel 9. The fourth gear 21 and the third gear 17 are meshed and connected, the third gear 17 is set as a small gear, and the fourth gear 21 is set as a large gear, which can slow down the moving speed of the sampling barrel 9. Overall, the moving speed of the sampling barrel 9 should be less than the rotation speed of the spiral auger conveying shaft 11, which is convenient for sampling soil.

[0047] Specifically, the driving module includes a motor 15 fixedly connected to the inner side of the barrel body 1 and a second gear 16 fixedly connected to the output shaft of the motor 15. The second gear 16 is meshed with the gear shaft 14 to achieve a single drive and two-way travel effect, which is more energy-saving.

[0048] For the screw 19 and the mounting shaft 13 rotatably mounted on the inner side of the barrel body 1 , a bearing seat 18 is provided at the end thereof. The bearing seat 18 is fixed on the inner side of the barrel body 1 , and the screw 19 and the mounting shaft 13 are rotatably connected to the corresponding bearing seats 18 respectively.

[0049] Among them, except for the driving module, the other parts of the spiral conveying mechanism are symmetrically arranged and installed about the axis center of the barrel body 1. However, since the third gear 17 drives the fourth gear 21 and the gear shaft 14 drives the first gear 12 in different directions of rotation, the rotation of the spiral auger conveying shaft 11 and the selection of the threads in the screw 19 and the transmission plate 20 should ensure that the spiral auger conveying shaft 11 can convey the material into the sampling barrel 9 and that the two screws 19 can drive the two sampling barrels 9 to move back in opposite directions when they rotate.

[0050] Directions:

[0051] Assemble the sampler. First, place the lower soil cylinder 3 flat, then insert the corresponding first limit rod 5 of the barrel body 1, and then insert the next barrel body 1 in the same way. The lower end of the barrel body 1 will be inserted into the outer side of the upper soil cylinder 2 at the upper end of the lower barrel body 1. Then, put the blocking rod 6 on the two first limit rods 5, and then insert the insertion rod 8 into the corresponding socket 7.

[0052] Sampling method:

[0053] The control motor 15 is started, driving the gear shaft 14 to rotate, and the gear shaft 14 drives the two first gears 12 and the two fourth gears 21 to rotate, so that the screw 19 drives the transmission plate 20 to move, and then drives the sampling barrel 9 to move horizontally under the restriction of the slide groove 23. At the same time, the first gear 12 will drive the spiral auger conveying shaft 11 to rotate, so that the sampling barrel 9 is inserted into the soil while rotating the spiral auger conveying shaft 11, driving the soil into the sampling barrel 9, and then falling into the upper soil holding barrel 2 or the lower soil holding barrel 3 from the discharge port 25.

[0054] A sampling method for detecting soil organic carbon, comprising the above-mentioned sampling device for detecting soil organic carbon, comprises the following steps:

[0055] S1. Drill a sampling hole vertically to a diameter that matches the outer surface of the barrel 1. For example, a Dutch auger or a drilling mechanism may be used. The appropriate equipment should be selected based on the depth of the soil to be sampled.

[0056] S2. Assemble the combined sampler. According to the depth of sampling required, select at least one barrel body 1 to assemble into a combined sampler. For example, if you need to collect soil at a depth of 1m, the height of the barrel body 1 is 0.5m, and the sampling tube 9 is at a position about 0.25m in the middle of the barrel body 1. When opening the sampling hole, the depth to be opened is 1.25m. And so on. When multiple barrel bodies 1 are combined, since the positions between the sampling tubes 9 are fixed and the upper soil tube 2 can be inserted into the lower end of the upper barrel body 1, the distance between the two adjacent sampling tubes 9 must be less than 0.5m, assuming it is 0.4m, that is, only soil with a spacing of 0.4m can be sampled. For example, it is recommended to sample in four layers in mountainous towns: 0-10cm, 10-30cm, 30-50cm, and 50-100cm, and take about 500g in each layer. Then the height of the barrel body 1 needs to match the height setting;

[0057] S3. Place the combined sampler. After assembly, place the combined sampler in the sampling hole. The combined sampler will fit into the sampling hole, thus preventing soil from other layers from falling into the sampling tube 9.

[0058] S4, sampling is performed, the control motor 15 is started, and the two sampling cylinders 9 are moved horizontally in opposite directions and back to back, and the auger conveying shaft 11 is also driven to rotate, driving the sampling cylinder 9 to insert into the soil at the corresponding position, and the soil is driven into the sampling cylinder 9 by the rotation of the auger conveying shaft 11;

[0059] S5. Collect the sampled soil, which falls into the corresponding upper soil container 2 or lower soil container 3 through the discharge port 25;

[0060] S6. After sampling is completed, the motor 15 is controlled to reverse and reset the sampling tube 9. The combined sampler is then removed from the sampling hole, the barrel 1 is disassembled, and the soil in the upper soil tube 2 or the lower soil tube 3 is taken out for organic carbon detection.

[0061] Organic carbon detection method

[0062] 1. Dissolved organic carbon (DOC)

[0063] Extraction: Add distilled water to 10 g of fresh soil sample at a soil-liquid ratio of 1:5, shake for 5 hours, and filter through a 0.45 μm filter membrane.

[0064] Detection: Directly measure using a total organic carbon analyzer (TOC analyzer).

[0065] 2. Particulate organic carbon (POC)

[0066] Separation:

[0067] Soil samples were dispersed with sodium hexametaphosphate, passed through a 53 μm sieve, and washed to retain particles on the sieve.

[0068] The undersize fraction is the non-POC component.

[0069] Determination: potassium dichromate oxidation method, absorbance measured at 585nm wavelength.

[0070] 3. Total organic carbon (TOC)

[0071] Combustion oxidation method:

[0072] The acidified sample is burned at 900°C, and the organic carbon is converted into CO2;

[0073] Detection method:

[0074] Non-dispersive infrared (NDIR);

[0075] Gas chromatography;

[0076] Elemental analyzer.

[0077] Classical oxidation method:

[0078] Potassium dichromate-sulfuric acid external heating method, titration or colorimetric determination.

[0079] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. The scope of patent protection of the present invention shall be based on the claims. Any equivalent structural changes made using the contents of the description of the present invention shall also be included in the scope of protection of the present invention.

Claims

1. A sampling device for detecting soil organic carbon, characterized in that: It includes a barrel body with an upper soil cylinder fixed on the upper end. A plurality of barrel bodies can be formed into a temporarily fixed combined sampler by plugging the upper soil cylinder into the bottom of the upper barrel body, wherein the lower end of the lowermost barrel body is plugged with a lower soil cylinder; Two sets of horizontally retractable screw conveying mechanisms are symmetrically arranged in the middle of each barrel body, which are used to convey the soil of the corresponding layer to the upper soil storage cylinder. The two sets of screw conveying mechanisms are simultaneously driven by a motor to move and convey the screw conveying mechanisms in the opposite direction.

2. A sampling device for soil organic carbon detection according to claim 1, characterized in that: The outer side surface of the lower soil holding barrel is symmetrically fixedly connected with a first limiting rod, and both sides of the barrel body are provided with limiting grooves for the first limiting rod to be inserted, and the upper end of the first limiting rod is sleeved with a blocking rod, and a socket for the plugging rod is provided at the position corresponding to each upper soil holding barrel, and the plugging rod passes through the blocking rod and is inserted into the socket.

3. The sampling device for soil organic carbon detection according to claim 1, characterized in that: The driving spiral conveying mechanism includes a sampling barrel symmetrically slidably inserted in the middle of the barrel body, a spiral auger conveying shaft rotatably connected to the end of the sampling barrel in the barrel body, and a driving mechanism. A discharge port is provided at the lower end of the sampling barrel in the barrel body. The driving mechanism can simultaneously drive the sampling barrel to move backward and the spiral auger conveying shaft to rotate.

4. The sampling device for soil organic carbon detection according to claim 3, characterized in that: A second limiting rod is fixedly connected to the inner side of the barrel between the two sampling cylinders, and the opposite ends of the second limiting rod are respectively fixedly connected to protruding rods. A sliding groove for inserting the protruding rods is opened on the side of the sampling cylinder.

5. The sampling device for soil organic carbon detection according to claim 3, characterized in that: The end of the sampling tube in the barrel body is fixedly connected with a baffle, and the spiral auger conveying shaft is rotatably connected to the middle of the baffle.

6. The sampling device for detecting soil organic carbon according to claim 4, characterized in that: The driving mechanism includes a first gear fixedly connected to the end of the spiral auger conveying shaft in the barrel body, a screw rotatably connected above the sampling cylinder and parallel to the sampling cylinder, a transmission plate fixedly connected to one end of the sampling cylinder close to the first gear, and a driving assembly. The driving assembly can drive the screw and the first gear to rotate simultaneously.

7. The sampling device for detecting soil organic carbon according to claim 6, characterized in that: The driving assembly includes a mounting shaft rotatably connected to the inner side of the barrel body between the two screws, a gear shaft fixedly connected to the outer side of the mounting shaft, a third gear fixedly connected to the mounting shaft at both ends of the gear shaft, a fourth gear fixedly connected to both ends of the screw and a driving module for driving the gear shaft to rotate, the gear shaft is meshed with the first gear, and the fourth gear is meshed with the third gear.

8. The sampling device for soil organic carbon detection according to claim 7, characterized in that: The driving module includes a motor fixedly connected to the inner side of the barrel and a second gear fixedly connected to the output shaft of the motor, and the second gear is meshed with the gear shaft.

9. A sampling method for detecting soil organic carbon, comprising the sampling device for detecting soil organic carbon according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Open a sampling hole vertically to match the diameter of the outer side of the barrel; S2. Assemble the combined sampler. According to the required sampling depth, select at least one barrel to assemble into the combined sampler. S3. Place the combined sampler. After assembly is complete, place the combined sampler in the sampling hole. S4. Sampling is performed, the control motor is started, and the two sampling cylinders are driven to move horizontally in opposite directions. At the same time, the spiral auger conveying shaft is driven to rotate, and the sampling cylinders are driven to insert into the soil at the corresponding position. The rotation of the spiral auger conveying shaft drives the soil into the sampling cylinders; S5. Collect the sampled soil, and the soil falls into the corresponding upper soil cylinder or lower soil cylinder through the discharge port; S6. After sampling is completed, the motor is controlled to reverse and reset the sampling barrel. Then the combined sampler is taken out from the sampling hole, the barrel body is disassembled, and the soil in the upper soil barrel or the lower soil barrel is taken out for organic carbon detection.

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