A soil leachate collection device

Abstract

The present application relates to the technical field of pollution detection sampling, and particularly relates to a soil leachate collecting device, which comprises an outer pipe and an inner pipe, a sliding groove and an outer collecting hole are arranged on the inner wall of the outer pipe, a locking ring and a conical plug head are arranged on the end part, a sliding block is arranged on the outer wall of the inner pipe, collecting micropores are arranged on the side wall in a region, and the inner pipe and the outer pipe are in sliding fit, so that the moving path of the collecting micropores covers the outer collecting hole; a cavity is formed at the sliding groove and is connected with a negative pressure supply mechanism, and the inner pipe extends to the storage section of the outer pipe and is provided with a negative pressure control mechanism. Through the sliding of the inner pipe, the dynamic switching of the collecting channel is realized, the negative pressure control mechanism is automatically controlled, the micropore blockage is avoided, the sample fidelity is ensured, the modular and detachable design reduces the use cost, various soil textures are adapted, and the device is suitable for in-situ collection of soil leachate.

Description

Technical Field

[0001] This invention relates to the field of pollution detection and sampling technology, specifically to a soil leachate collection device. Background Technology

[0002] Soil leachate, as a core product of soil-water-solute interactions, contains water quality parameters (such as pollutant concentration, nutrient content, and pH value) that are crucial foundational data for reflecting soil environmental quality, assessing groundwater pollution risks, and guiding contaminated site remediation. In scenarios such as farmland nutrient leaching monitoring, industrial contaminated site risk assessment, and landfill perimeter environmental monitoring, in-situ collection of accurate and undistorted soil leachate is a prerequisite for ensuring the scientific validity of monitoring data and the effectiveness of remediation plans.

[0003] Currently, the mainstream equipment for in-situ collection of soil leachate is the pore water sampler (also known as a negative pressure leachate meter or suction sampler). Among them, the ceramic head type pore water sampler is widely used in various soil environmental monitoring applications due to its advantages such as strong chemical stability, high filtration accuracy (the micropores of the ceramic head are very small, effectively trapping soil particles), and good soil compatibility. The core structure of this type of sampler typically includes a ceramic suction head, a connecting tube, a storage bottle, and a negative pressure generating device (such as an air pump or negative pressure gauge). Its working principle is as follows: after drilling a hole in the target sampling layer using a soil drill, the pre-treated ceramic suction head is pre-buried in the soil and left to stand for 24-72 hours to allow the ceramic suction head to fully contact the soil pores and reach water potential equilibrium; then, a negative pressure is applied to the storage bottle through the negative pressure generating device. Utilizing the pressure difference between the soil pore water and the storage bottle, the leachate in the soil pores is driven through the micropores of the ceramic suction head into the connecting tube, and finally collected in the storage bottle, achieving in-situ collection of leachate.

[0004] Existing soil leachate collection devices use ceramic heads with rigid collection channels of fixed pore size and position. During negative pressure extraction, even with strict control of the negative pressure value, the flow of leachate in the pores still carries some fine particles to the surface of the ceramic head. Especially when the soil moisture content is high and the pore connectivity is good, fine particles are prone to physical deposition at the micropore inlet of the ceramic head, gradually clogging the micropore channels. Clogging of the micropore channels will reduce the soil leachate collection efficiency and may even distort the composition of the soil leachate sample. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a soil leachate collection device that ensures efficient collection of soil leachate through a dynamic soil leachate collection channel and avoids distortion of soil leachate sample composition.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: a soil leachate collection device, comprising an outer tube and an inner tube, wherein at least one sliding groove is provided on the inner wall of the outer tube, and at least one external collection hole is provided on the side wall of the outer tube, wherein the external collection hole does not coincide with the sliding groove, a locking ring is detachably connected to one end of the outer tube, a plug head is detachably connected to the other end of the outer tube, and a storage section is provided at the end of the outer tube near the plug head. The outer wall of the inner tube is provided with sliding blocks of the same number and shape as the sliding grooves. Several collection micro-holes are opened on the side wall of the inner tube. The collection micro-holes are arranged along the length of the inner tube. The sliding blocks and the collection micro-holes do not coincide. An inner collection hole is opened at one end of the inner tube. The outer tube and the inner tube are slidably fitted together, and the sliding block and the sliding groove are slidably fitted together. When the inner tube slides, the movement path of the collecting micropores covers the outer collecting hole. A sealing strip is provided on the inner wall of the outer tube around the sliding groove. The sliding block, the sliding groove, the outer wall of the inner tube and the sealing strip are combined to form a cavity. A negative pressure supply mechanism for supplying negative pressure is provided in the cavity. The inner tube can slide to the storage section. The inner tube located in the storage section is provided with a negative pressure control mechanism for controlling the supply of negative pressure to the cavity.

[0007] Furthermore, the negative pressure supply mechanism includes a first negative pressure pipeline, which is connected to the cavity. The first negative pressure pipeline passes through a storage section and is parallel to the storage section. Several limiting holes are provided on the side wall of the storage section of the outer tube. The limiting holes are arranged along the length of the storage section and are all connected to the first negative pressure pipeline. A limiting pin is slidably fitted inside the limiting hole. The limiting pin is partially or entirely made of magnetic material. An elastic element is provided between the limiting pin and the limiting hole. Initially, the elastic element restricts the position of the limiting pin and blocks the connection between the limiting hole and the first negative pressure pipeline. The negative pressure supply mechanism also includes a second negative pressure pipeline, which is connected to a limiting hole, and one end of the second negative pressure pipeline is connected to a negative pressure generating element.

[0008] Furthermore, the negative pressure control mechanism includes a floating ring slidably connected to the storage section of the outer tube and a fixed ring fixedly connected to the outer wall of the inner tube; A permanent magnet is fixedly connected to the outer wall of the floating ring. The outer ring of the floating ring is made of floating material, and the inner ring of the floating ring is made of elastic material. The inner ring of the floating ring has a slot. The fixed ring is located at the end of the inner tube where the inner collection hole is opened. The height of the fixed ring is less than the height of the groove, so that the floating ring can float relative to the fixed ring.

[0009] Furthermore, a first sealing ring is provided on the inner wall of the locking ring near the end of the outer tube; A collection section is provided at the end of the outer tube away from the blockage head, and a second sealing ring is provided on the inner wall of the outer tube between the collection section and the storage section.

[0010] Furthermore, the plug head has a conical structure, and a third sealing ring is provided in the connection area between the plug head and the outer tube.

[0011] Furthermore, a limiting ring is provided on the inner wall of the middle part of the outer tube, and the inner tube slides in conjunction with the limiting ring. The diameter of the inner tube used to extend to the storage section is smaller than the diameter used to extend to the collection section.

[0012] Furthermore, a limiting boss is provided at the end of the outer tube near the locking ring.

[0013] Furthermore, when the inner tube extends to the bottom of the storage section, some of the collection micropores overlap with the outer collection pores.

[0014] Furthermore, the collecting micropores are arranged in different regions on the side wall of the inner tube, and each region's collecting micropores correspond to an independent external collecting hole; during the process of the inner tube moving from the bottom of the storage section to the top of the storage section, all the collecting micropores in a single region successively coincide with the corresponding external collecting hole.

[0015] Furthermore, the interval between adjacent limiting holes is less than or equal to the floating distance of the floating ring relative to the fixed ring.

[0016] The above approach has the following beneficial effects: This solution adopts an easy-to-disassemble structure, which allows for convenient assembly and disassembly of the collection device. Before collecting soil leachate, the collection device is prepared by pressing the inner tube. During the process, the temporary air between the inner and outer tubes is continuously discharged through the collection micropores, which can prevent fine soil particles from entering the collection micropores during the preparation of the collection device and interfering with the subsequent collection of soil leachate.

[0017] This scheme constructs a dynamically adjustable collection channel through the sliding fit of the outer and inner tubes. The collection micropores are arranged along the length of the inner tube, and their movement path covers the outer collection holes. During soil leachate collection, the inner tube can be automatically raised a short distance by negative pressure, allowing different collection micropores to sequentially overlap with the outer collection holes. This dynamic soil leachate collection method avoids the clogging problem caused by prolonged contact between a single micropore and the soil environment, reduces the probability of fine particle deposition, colloid adsorption, and crystal precipitation, ensures unobstructed collection channels, and solves the problems of collection efficiency and sample accuracy caused by the easy clogging of traditional fixed micropores.

[0018] This scheme achieves automatic control of the sampling process through a negative pressure control mechanism composed of a floating ring and a permanent magnet. As the leachate level in the storage section rises, the floating ring floats synchronously, and the permanent magnet on its outer wall is suspended at a corresponding height by a limiting pin, automatically connecting the negative pressure pipeline and driving the inner tube to rise and switch the collection micropores. As the inner tube drives the floating ring to rise, the negative pressure pipeline automatically disconnects, the inner tube stops moving, and leachate collection continues. This design achieves dynamic switching of the collection channel, avoiding the problem of reduced sampling efficiency caused by blockage in traditional equipment. By switching the collection micropores over short distances and intermittently, it effectively prevents sample composition distortion caused by solute adsorption or excessive desorption by blockages, ensuring the authenticity and reliability of the monitoring data. Attached Figure Description

[0019] Figure 1 This is an isometric view of the outer tube according to an embodiment of the present invention; Figure 2 This is a top view of the outer tube according to an embodiment of the present invention; Figure 3 for Figure 2 Sectional views of AA, BB, and CC; Figure 4 This is an isometric view of the inner tube according to an embodiment of the present invention; Figure 5 This is a top view of the inner tube according to an embodiment of the present invention; Figure 6 for Figure 5 DD sectional view; Figure 7 A floating ring isometric view according to an embodiment of the present invention; Figure 8 This is an isometric view of the unused state of the collection device assembly according to an embodiment of the present invention; Figure 9 This is a front view of the unused state after the collection device assembly is completed according to an embodiment of the present invention; Figure 10 This is a top view of the unused state after the collection device of this embodiment of the invention is assembled; Figure 11 for Figure 10 EE and FF sectional views; Figure 12 This is an isometric view of the collection device in its ready state after assembly, according to an embodiment of the present invention. Figure 13 This is a front view of the collection device in its prepared state after assembly, according to an embodiment of the present invention. Figure 14 A top view of the collection device in its prepared state after assembly, according to an embodiment of the present invention; Figure 15 for Figure 14 GG and HH sectional views; Figure 16This is an isometric view of the collection device in its combined state according to an embodiment of the present invention. Figure 17 This is a top view of the collection device in its combined state according to an embodiment of the present invention; Figure 18 for Figure 17 Sectional views of II and JJ; Figure 19 for Figure 18 A magnified schematic diagram of K.

[0020] The reference numerals in the accompanying drawings include: 10, outer tube; 11, locking ring; 12, plug head; 13, outer collection hole; 14, sliding groove; 15, first sealing ring; 16, second sealing ring; 17, limiting ring; 20, inner tube; 21, sliding block; 22, collection micro-hole; 23, fixing ring; 24, inner collection hole; 31, first negative pressure pipeline; 32, limiting hole; 33, second negative pressure pipeline; 34, connector; 35, limiting pin; 36, cylindrical spring; 40, floating ring; 41, permanent magnet; 42, slot. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] The following detailed description illustrates the specific implementation method: A soil leachate collection device includes an outer pipe 10 and an inner pipe 20. In this embodiment, both the outer pipe 10 and the inner pipe 20 are made of corrosion-resistant materials, such as PVC-U material and stainless steel material, to extend the service life of the collection device.

[0025] Combination Figures 1-3 The figures shown are axonometric views, top views, and AA, BB, and CC sections of the top view of the outer tube 10 in this embodiment: A locking ring 11 is detachably connected to the top of the outer tube 10 via a threaded connection, and a plug head 12 is detachably connected to the bottom of the outer tube 10 via a threaded connection. The plug head 12 has a conical structure, which facilitates the placement of the collection device into the soil. The inner wall of the outer tube 10 has symmetrically arranged sliding grooves 14 along its length, extending through the top of the outer tube 10. In some embodiments, the number of sliding grooves 14 can be adjusted to suit actual needs. A limiting ring 17 is integrally formed on the inner wall of the middle section of the outer tube 10. The limiting ring 17 restricts the sliding stroke of the inner tube and divides the interior of the outer tube 10 into a collection section and a storage section. The collection section is located near the locking ring 11, and the storage section is located near the plug head 12. A first sealing ring 15 is provided on the inner wall of the locking ring 11 near the outer tube 10, and a second sealing ring 16 is provided on the inner wall of the limiting ring 17.

[0026] The outer tube 10 has two sets of symmetrically arranged external collection holes 13 on its collection section sidewall, with each set of external collection holes 13 arranged along the length of the outer tube 10. Furthermore, to avoid interference between the sliding groove 14 and the external collection holes 13, the external collection holes 13 and the sliding groove 14 do not overlap, and in this embodiment, the external collection holes 13 are elongated holes. A first negative pressure pipeline 31 is also provided inside the sidewall of the outer tube 10. One end of the first negative pressure pipeline 31 is connected to the sliding groove 14, and the other end of the first negative pressure pipeline 31 passes through the storage section of the outer tube 10. The first negative pressure pipeline 31 passing through the storage section is parallel to the storage section and completely covers the storage section of the outer tube 10. A plurality of limiting holes 32 are provided on the sidewall of the storage section of the outer tube 10. The limiting holes 32 are arranged at equal intervals along the length of the storage section, perpendicular to the first negative pressure pipeline 31, and penetrate the sidewall of the outer tube 10.

[0027] In this embodiment, a second negative pressure pipeline 33 is fixedly connected to the outer wall of the outer tube 10. All limiting holes 32 are connected to the second negative pressure pipeline 33. A connector 34 is provided at one end of the second negative pressure pipeline 33, which is used to connect the second negative pressure pipeline 33 to the negative pressure generating device. The negative pressure generating device can be a syringe, an air bag, or a negative pressure pump, etc.

[0028] Each limiting hole 32 is independently connected to the first negative pressure pipeline 31. A limiting pin 35 is slidably fitted inside the limiting hole 32, and the end of the limiting pin 35 near the inner wall of the outer tube 10 is made of magnetic material. In some other embodiments, the limiting pin 35 is entirely made of magnetic material, and an elastic element is provided between the limiting pin 35 and the limiting hole 32. In this embodiment, the elastic element is a cylindrical spring 36. Initially, the cylindrical spring 36 restricts the position of the limiting pin 35, blocking the connection between the limiting hole 32 and the first negative pressure pipeline 31. When the connection between the limiting hole 32 and the first negative pressure pipeline 31 is blocked, the first negative pressure pipeline 31 and the second negative pressure pipeline 33 are not connected, that is, the negative pressure generated by the negative pressure generator cannot act on the sliding groove 14; when the connection between the limiting hole 32 and the first negative pressure pipeline 31 is not blocked, the first negative pressure pipeline 31 and the second negative pressure pipeline 33 are connected, that is, the negative pressure generated by the negative pressure generator acts on the sliding groove 14. In this embodiment, the first negative pressure pipeline 31, the limiting hole 32 (and its internal structure), and the second negative pressure pipeline 33 are defined as a negative pressure supply mechanism for supplying negative pressure.

[0029] A limiting boss is provided at one end of the outer tube 10 near the locking ring 11. The limiting boss is used to limit the depth of the entire collection device inserted into the soil layer.

[0030] Combination Figures 4-6 The figures shown are an isometric view, a top view, and a DD sectional view of the top view of the inner tube 20 in this embodiment: The outer wall of the inner tube 20 is provided with sliding blocks 21 of the same number and shape as the sliding grooves 14. In this embodiment, the sliding grooves 14 are fan-shaped, and the corresponding sliding blocks 21 are fan-shaped structures that match the sliding grooves 14. A plurality of collecting micropores 22 are opened on the side wall of the inner tube 20. The collecting micropores 22 are arranged in regions on the side wall of the inner tube 20, and each region's collecting micropores 22 correspond to an independent outer collecting hole 13. The collecting micropores 22 within each region are arranged along the length of the inner tube 20, and the sliding blocks 21 do not overlap with the collecting micropores 22. Part of the inner tube 20 is used to extend to the collecting section, and part is used to extend to the storage section. The diameter of the part used to extend to the storage section is smaller than the diameter of the part used to extend to the collecting section. An inner collecting hole 24 is opened at the bottom of the inner tube 20 used to extend to the storage section. Soil leachate that has passed through the outer collecting hole 13 and the collecting micropores 22 is introduced into the storage section through the inner collecting hole 24.

[0031] The collection device in this embodiment also includes a negative pressure control mechanism, which includes a floating ring 40 slidably connected to the storage section of the outer tube 10 and a fixed ring 23 fixedly connected to the outer wall of the inner tube 20. Figure 7As shown, a permanent magnet 41 is fixedly connected to the outer wall of the floating ring 40. The outer ring of the floating ring 40 is made of a floating material, and the inner ring is made of an elastic material (fluororubber can be used as a reference, as it has strong resistance to strong acids and alkalis). A groove 42 is opened in the inner ring of the floating ring 40. The fixed ring 23 is located at the end of the inner tube 20 where the inner collection hole 24 is opened. The fixed ring 23 is made entirely of an elastic material, and its height is less than the height of the groove 42, allowing the floating ring 40 to float relative to the fixed ring 23. During the floating process of the floating ring 40 in the storage section, the permanent magnet 41 on its outer wall floats along with it, and can apply magnetic attraction to the limiting pins 35 in the limiting holes 32 at different heights. When the limiting pins 35 compress the cylindrical springs 36, the first negative pressure pipeline 31 and the second negative pressure pipeline 33 are connected through the limiting holes 32.

[0032] This embodiment further explains the structure of a collection device in its unused, assembled state, in conjunction with... Figures 8-11 The figures shown are an isometric view of the unused state of the assembled collection device, a front view of the unused state of the assembled collection device, a top view of the unused state of the assembled collection device, and EE and FF sectional views of the top view of the unused state of the assembled collection device: When assembling the collection device, firstly, the plugging head 12 is fixedly connected to the bottom of the outer tube 10. The plugging head 12 seals the storage section to achieve temporary collection and storage of soil leachate. In this embodiment, a third sealing ring (not shown in the attached figure) is provided in the connection area between the plugging head 12 and the outer tube 10 to prevent leakage of the temporarily collected soil leachate. Then, the inner tube 20 is fitted into the locking ring 11, so that the sliding block 21 is located in the sliding groove 14. Finally, the locking ring 11 is fixedly connected to the top of the outer tube 10. The cooperation between the sliding block 21 and the limiting groove restricts the rotation of the inner tube 20, allowing the inner tube 20 to slide along the length of the outer tube 10. During the sliding of the inner tube 20 along the outer tube 10, the movement path of the collecting micropores 22 covers the outer collecting hole 13. A cavity is formed by the combination of sliding block 21, sliding groove 14, and outer wall of inner tube 20. To ensure the sealing of the cavity, a sealing strip is provided on the inner wall of outer tube 10 around sliding groove 14 in this embodiment. The sealing strip, sliding block 21, sliding groove 14, and outer wall of inner tube 20 form a cavity, which is connected to the first negative pressure pipeline 31.

[0033] This embodiment further describes the collection device in the ready state to further explain its principle, in conjunction with... Figures 12-15 The figures shown are, respectively, an isometric view of the collection device in its prepared state after assembly, a front view of the collection device in its prepared state after assembly, a top view of the collection device in its prepared state after assembly, and GG and HH sectional views of the top view of the collection device in its prepared state after assembly: When preparing the collection device, first connect the negative pressure generator externally via connector 34, place the outer tube 10 vertically into the soil layer, and then press the inner tube 20 downwards. During the pressing process, the air temporarily stored in the tube enters the inner tube 20 through the inner collection hole 24, and then is continuously discharged outwards through the collection micropores 22. The collection micropores 22 pass through the outer collection hole 13 in sequence, which can prevent soil particles from entering the micropores. When the inner tube 20 is pressed to the lowest part of the storage section, the bottom of the floating ring 40 abuts against the top of the plug head 12, and the fixed ring 23 squeezes the inner ring of the floating ring 40. After the inner ring of the floating ring 40 is deformed, the fixed ring 23 enters the slot 42. To ensure that the soil leachate can be collected normally, when the inner tube 20 extends to the bottom of the storage section, it must be ensured that some of the collection micropores 22 coincide with the outer collection hole 13, which can be used to collect the soil leachate.

[0034] This embodiment further describes the collection device in the ready state to further explain its principle, in conjunction with... Figures 16-19 The figures shown are, respectively, an axonometric view of the assembled collection device in its operational state, a top view of the assembled collection device in its operational state, a section II and a section JJ of the top view of the assembled collection device in its operational state, and a partially enlarged schematic diagram of section K in section II: When using the collection device, the inner tube 20 is released. During the preparation stage, the inner tube 20 is pressed to create negative pressure in the cavity. After releasing the inner tube 20, the negative pressure in the cavity causes the inner tube 20 to rise a short distance to reset. Soil leachate gradually enters the inner tube 20 through the outer collection hole 13 and the collection micropores 22, and then enters the storage section for temporary storage through the inner collection hole 24. As the amount of soil leachate temporarily stored in the storage section increases, it gradually rises due to the action of the outer ring made of floating material of the floating ring 40. However, the rising distance of the floating ring 40 is limited by the fixed ring 23, that is, the floating ring 40 can only rise to the distance that the fixed ring 23 can move within the slot 42. To ensure that the permanent magnet 41 fixed on the outer wall of the floating ring 40 effectively acts on the limiting pin 35 at the corresponding height after each floating rise, this embodiment sets the interval between adjacent limiting holes 32 to be less than or equal to the floating distance of the floating ring 40 relative to the fixed ring 23. When the permanent magnet 41 fixed on the outer wall of the floating ring 40 floats and rises to the height corresponding to any limiting hole 32, the limiting pin 35 in the limiting hole 32 is attracted by magnetic force and resists the elastic force of the cylindrical spring 36. The limiting hole 32 is connected to the first negative pressure pipeline 31, and the second negative pressure pipeline 33 is connected to the cavity through the limiting hole 32 and the first negative pressure pipeline 31. The negative pressure acts on the cavity, causing the inner tube 20 to rise a short distance. The collecting micro-holes 22 coincide with the corresponding outer collecting holes 13 in sequence, that is, the collecting micro-holes 22 that coincide with the outer collecting holes 13 are changed. During the ascent of the inner tube 20, the floating ring 40 rises. When the height of the floating ring 40 no longer corresponds to the limiting hole 32, the connection between the limiting hole 32 and the first negative pressure pipeline 31 is blocked, the second negative pressure pipeline 33 is no longer connected to the cavity, and the negative pressure no longer acts on the cavity. The inner tube 20 pauses its ascent, and the newly overlapping collection micropore 22 with the outer collection hole 13 continues to collect soil leachate. The floating ring 40 continues to float and rise with the increase of soil leachate. When the floating ring 40 floats and rises again to the height corresponding to any limiting hole 32, the above process is repeated. In this way, the collection micropore 22 used for collecting soil leachate dynamically switches during the collection process, avoiding soil clogging of the collection micropore 22, reducing the collection efficiency of soil leachate, and avoiding distortion of soil leachate sample composition. In addition, during the collection process, the amount of soil leachate collected can be preliminarily judged based on the length of the outer tube 10 extending from the inner tube 20. The length of the outer tube 10 extending from the inner tube 20 is proportional to the amount of soil leachate collected.

[0035] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A soil leachate collection device, comprising an outer pipe and an inner pipe, characterized in that, The inner wall of the outer tube is provided with at least one sliding groove, and the side wall of the outer tube is provided with at least one external collection hole. The external collection hole does not coincide with the sliding groove. One end of the outer tube is detachably connected to a locking ring, and the other end of the outer tube is detachably connected to a plug. A storage section is provided at the end of the outer tube near the plug. The outer wall of the inner tube is provided with sliding blocks of the same number and shape as the sliding grooves. Several collection micro-holes are opened on the side wall of the inner tube. The collection micro-holes are arranged along the length of the inner tube. The sliding blocks and the collection micro-holes do not coincide. An inner collection hole is opened at one end of the inner tube. The outer tube and the inner tube are slidably fitted together, and the sliding block and the sliding groove are slidably fitted together. When the inner tube slides, the movement path of the collecting micropores covers the outer collecting hole. A sealing strip is provided on the inner wall of the outer tube around the sliding groove. The sliding block, the sliding groove, the outer wall of the inner tube and the sealing strip are combined to form a cavity. A negative pressure supply mechanism for supplying negative pressure is provided in the cavity. The inner tube can slide to the storage section. The inner tube located in the storage section is provided with a negative pressure control mechanism for controlling the supply of negative pressure to the cavity.

2. The soil leachate collection device according to claim 1, characterized in that, The negative pressure supply mechanism includes a first negative pressure pipeline, which is connected to the cavity. The first negative pressure pipeline passes through a storage section and is parallel to the storage section. Several limiting holes are provided on the side wall of the storage section of the outer tube. The limiting holes are arranged along the length of the storage section and are all connected to the first negative pressure pipeline. A limiting pin is slidably fitted inside the limiting hole. The limiting pin is partially or entirely made of magnetic material. An elastic element is provided between the limiting pin and the limiting hole. Initially, the elastic element restricts the position of the limiting pin and blocks the connection between the limiting hole and the first negative pressure pipeline. The negative pressure supply mechanism also includes a second negative pressure pipeline, which is connected to a limiting hole, and one end of the second negative pressure pipeline is connected to a negative pressure generating element.

3. The soil leachate collection device according to claim 2, characterized in that, The negative pressure control mechanism includes a floating ring that is slidably connected to the storage section of the outer tube and a fixed ring that is fixedly connected to the outer wall of the inner tube; A permanent magnet is fixedly connected to the outer wall of the floating ring. The outer ring of the floating ring is made of floating material, and the inner ring of the floating ring is made of elastic material. The inner ring of the floating ring has a slot. The fixed ring is located at the end of the inner tube where the inner collection hole is opened. The height of the fixed ring is less than the height of the groove, so that the floating ring can float relative to the fixed ring.

4. The soil leachate collection device according to claim 1, characterized in that, A first sealing ring is provided on the inner wall of the locking ring near the end of the outer tube; A collection section is provided at the end of the outer tube away from the blockage head, and a second sealing ring is provided on the inner wall of the outer tube between the collection section and the storage section.

5. The soil leachate collection device according to claim 1, characterized in that, The plug head has a conical structure, and a third sealing ring is provided at the connection area between the plug head and the outer tube.

6. The soil leachate collection device according to claim 1, characterized in that, A limiting ring is provided on the inner wall of the middle part of the outer tube, and the inner tube slides in fit with the limiting ring. The diameter of the inner tube used to extend to the storage section is smaller than the diameter used to extend to the collection section.

7. The soil leachate collection device according to claim 1, characterized in that, A limit boss is provided at the end of the outer tube near the locking ring.

8. The soil leachate collection device according to claim 1, characterized in that, When the inner tube extends to the bottom of the storage section, some of the collection micropores overlap with the outer collection pores.

9. The soil leachate collection device according to claim 1, characterized in that, The collecting micropores are arranged in different regions on the side wall of the inner tube, and each region's collecting micropores correspond to an independent external collecting hole. During the process of the inner tube moving from the bottom of the storage section to the top of the storage section, all the collecting micropores in a single region successively coincide with the corresponding external collecting hole.

10. The soil leachate collection device according to claim 3, characterized in that, The interval between adjacent limiting holes is less than or equal to the floating distance of the floating ring relative to the fixed ring.

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