A sampling device for synchronously collecting solution, gas in situ soil

Abstract

This invention relates to the field of soil environmental monitoring technology, and in particular discloses a sampling device for simultaneously collecting in-situ soil solutions and gases. The device comprises a support frame unit, a sampling device installed within the support frame unit, a drive device installed on the support frame unit, and a controller for controlling the drive device and the sampling device. The sampling device includes an aperture opener for drilling, a collector for simultaneously collecting soil solutions and gases from the drilled hole, and a gas-liquid separation unit for separating the collected solutions and gases. This device is a complete sampling system that not only reduces equipment costs and improves sampling efficiency, but also ensures the correlation and accuracy of synchronous, in-situ sampling data. By simultaneously, in-situ, and isolatedly collecting soil solutions and soil gases from the same borehole and at the same depth, it avoids cross-contamination and atmospheric interference, significantly improving sampling efficiency and data comparability, and providing a reliable technical means for research on multi-media soil environments.

Description

Technical Field

[0001] This invention relates to the field of soil environmental monitoring technology, and in particular to a sampling device for simultaneously collecting solutions and gases in in-situ soil. Background Technology

[0002] Currently, sampling of soil solution and soil gas is mostly carried out using separate devices, which has problems such as complex operation, low efficiency, and poor data coordination, as detailed below:

[0003] 1. Limitations of soil solution sampling technology

[0004] Current soil solution sampling primarily employs in-situ, fixed-point continuous sampling. This method involves establishing negative pressure within the sampling head, causing soil pore water to enter the sampling system under potential difference. Sampling ceases once the negative pressure reaches equilibrium with the soil water potential. While this method enables continuous sampling, it requires pre-excavation of vertical profiles or drilling to install the sampling device, resulting in a large workload. Furthermore, repeated sampling necessitates manual replacement or emptying of the sampling bottles, making the operation cumbersome. In addition, traditional immersion extraction methods require post-sampling laboratory processing, which not only damages the soil structure but also fails to achieve in-situ continuous sampling, limiting both time and spatial representativeness.

[0005] 2. Deficiencies in soil gas sampling technology

[0006] Soil gas sampling currently relies mainly on two methods: one is to extract soil samples to the surface using a drilling rig and then seal them for sampling. This method severely disturbs the soil layers during drilling, causing gas mixing at different depths, and the samples are easily contaminated by the surface atmosphere during transfer, leading to distorted analysis results. The other method is to collect samples by burying sampling tubes in boreholes and connecting them to a vacuum pump. However, the drilling process often results in the sampling hole being directly connected to the atmosphere, and even if the hole is sealed afterward, it is difficult to completely prevent gas exchange, especially for trace reactive gases, making it difficult to guarantee the authenticity and accuracy of the sampling data.

[0007] 3. Low overall sampling efficiency due to system separation

[0008] In practical environmental surveys and scientific monitoring, it is often necessary to simultaneously collect soil solution and soil gas samples at the same location and depth to compare and analyze the migration and transformation patterns of substances in the two phases. The current practice is to deploy two independent sampling systems, which not only increases equipment costs, drilling workload, and on-site operation time, but may also introduce spatial and temporal errors due to differences in device location and asynchronous sampling times, affecting the correlation of data and the overall interpretability. Summary of the Invention

[0009] This invention discloses a sampling device for simultaneously collecting solutions and gases in in-situ soil, aiming to solve the technical problems existing in the prior art.

[0010] The present invention adopts the following technical solution:

[0011] A sampling device for simultaneously collecting solutions and gases from in-situ soil includes a support frame unit, a sampling device installed within the support frame unit, a drive device installed on the top plate of the support frame unit, and a controller for controlling the drive device and the sampling device; wherein,

[0012] The support frame unit includes a support frame that provides support, a top plate fixed to the top of the support frame, and a bottom plate unit located at the bottom and detachably connected to the support frame.

[0013] The sampling device includes an outer cylinder unit with its two ends fixed to the top plate and the bottom plate respectively, a rotation unit rotatably mounted on the top of the inner cavity of the outer cylinder of the outer cylinder unit, a collector and an aperture opener suspended on the rotation unit, and a gas-liquid separation unit connected to the collector.

[0014] The indexing unit includes a supporting turntable and a rotating body located at the upper end. The rotating body is located on the same horizontal central circle and can detachably suspend the hole opener and the collector. A horizontally extending positioning stop is provided around the periphery of the rotating body. Two positioning units with a central included angle β are provided on the inner wall of the outer cylinder. The positioning stop matches and positions the positioning units. Rotating the rotating body switches the working positions of the two: when rotating to the first positioning unit, the hole opener is located in the working position corresponding to the rack of the driving device, and the collector is located in the waiting position; when rotating back to the second positioning unit, the collector is located in the working position corresponding to the rack, and the hole opener is located in the waiting position.

[0015] The lower end of the rack of the drive device can be selectively and detachably connected to the tool at the work station to drive the hole opener to complete the drilling operation or drive the collector to complete the synchronous gas-liquid sampling operation.

[0016] In some embodiments, the support frame unit includes a support frame located in the middle for support, a top plate fixed to the top of the support frame, and a bottom plate unit located at the bottom and detachably connected to the support frame; the bottom plate unit has an annular conical pressure body at the bottom for easy entry into the soil, a bottom plate through hole for the hole opener to be inserted into, a sealing sleeve bonded to the bottom of the bottom plate around the bottom plate through hole, a pressure block at the top edge of the bottom plate, and a level for displaying the horizontal state of the bottom plate placed on the pressure block.

[0017] In some embodiments, the driving device includes a motor and meshing gears and racks driven by the motor. A vertical plate is fixedly mounted on the top plate, and a vertical guide rail matching the rack is provided in the middle of the vertical plate. The lower end of the rack is detachably connected to the hole opener or the collector. The center line of the top plate through-hole on the top plate through which the guide rail passes coincides with the center line of the bottom plate through-hole on the bottom plate through which the hole opener or the collector passes, so that the hole opener or the collector moves up and down to a preset position under the drive of the rack.

[0018] In some embodiments, the outer cylinder unit includes the outer cylinder, the inner cavity, an inner groove located at the upper end of the inner wall of the outer cylinder, and two positioning units with a center included angle β provided on the longitudinal wall of the inner groove. The top of the outer cylinder is also provided with a connecting plate fixedly connected to the top plate, and the bottom of the outer cylinder is provided with a plug for fastening to the bottom plate. A pressure ring is fitted at the lower end of the outer cylinder, and the pressure ring is pressed tightly on the bottom plate by fasteners to fasten the outer cylinder.

[0019] In some embodiments, the positioning unit includes a short protrusion, a concave portion, and a long protrusion arranged horizontally along the inner groove. When the rotating body is rotated so that the end of the positioning stop rod slides past the short protrusion and enters the concave portion, it is fixed to the first positioning unit. When the rotating body is rotated in the opposite direction so that the end of the positioning stop rod slides past the short protrusion and enters the concave portion, it is fixed to the second positioning unit.

[0020] In some embodiments, the central axis of the rotating body coincides with the central axis of the outer cylinder, the central part of the periphery of the rotating body is provided with a flange extending horizontally into the inner groove, the bottom of the flange is provided with the support turntable, the upper end of the flange is also provided with the positioning stop bar extending horizontally, and the top of the rotating body is equipped with a handle.

[0021] The upper surface of the rotating body is provided with two rotating through holes on the same central circle. A pair of springs are provided in the rotating through holes and are respectively pressed and connected to the ends of the hole opener and the collector. The rotating through hole located on the Y-axis corresponds to the rack. The springs are controlled by the controller to retract or extend.

[0022] In some embodiments, the hole opener and the collector have the same external dimensions, both including an upper U-shaped connecting end, a middle cylinder and a lower conical head; the rack is inserted into the middle of the U-shaped connecting end and connected thereto; the cylinder of the hole opener or the collector passes through the through hole in the base plate and fits tightly against the sealing sleeve.

[0023] In some embodiments, the hole opener includes a U-shaped connecting end, a cylindrical drill rod, and a drilling cone; the collector sequentially includes a U-shaped connecting end, a cylindrical collection cylinder, and a sampling cone; the end of the collection tube placed in the inner cavity of the collection cylinder is connected to the inner cavity of the cone through a final-stage filter screen; the outer side of the sampling cone is provided with several collection ring grooves, the walls of the collection ring grooves are densely covered with water inlet holes, the outer wall of the collection ring grooves is covered with a primary filter screen, the inner cavity of the cone is filled with filter cotton, and a secondary filter screen is also provided at the upper end of the inner cavity of the cone.

[0024] In some embodiments, the gas-liquid separation unit includes a gas-liquid storage device fixedly mounted on the side wall of the outer cylinder. The top of the gas-liquid storage device is sealed and connected to the collection pipe and the suction pipe connected to the air pump, respectively. The air pump is connected to the gas collection tank. An upper sensor and a lower sensor for sensing the liquid level are also installed on the inner wall of the gas-liquid storage device. A detachably connected drain pipe is installed at the bottom of the gas-liquid storage device.

[0025] Beneficial effects:

[0026] This invention discloses a sampling device for simultaneously collecting solutions and gases from in-situ soil. It comprises a support frame unit, a sampling device installed within the support frame unit, a drive device mounted on the top plate of the support frame unit, and a controller for controlling the drive device and the sampling device. The sampling device includes an aperture opener for creating a hole, a collector for simultaneously collecting soil solutions and gases from the hole, and a gas-liquid separation unit for separating the solutions and gases. The device for collecting solutions and gases forms a complete sampling system, significantly reducing equipment costs, drilling workload, and on-site operation time. It also ensures synchronous, in-situ sampling, guaranteeing the correlation and overall interpretability of the data. The structure of the base plate unit, the sealing sleeve bonded around the through-hole in the base plate, and the sealing rings between the gas-liquid storage device and the collection pipe and suction pipe ensure the authenticity and accuracy of the sampled data. The controller controls the drive distance of the drive device and the sampling time of the sampling device, saving time and effort while achieving precise control. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below, constituting a part of the present invention. The illustrative embodiments of the present invention and their descriptions explain the present invention and do not constitute an improper limitation of the present invention; in the accompanying drawings:

[0028] Figure 1 This is a schematic diagram of the technical solution structure for the data acquisition process provided in an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the technical solution structure for the drilling process provided in an embodiment of the present invention;

[0030] Figure 3 for Figure 2 AA section view;

[0031] Figure 4 for Figure 2 Enlarged view of M;

[0032] Figure 5 for Figure 1 A magnified view of N;

[0033] Figure 6 for Figure 2 View from direction B;

[0034] Figure 7 for Figure 3 A magnified view of Q;

[0035] Figure 8 for Figure 1 A magnified view of W.

[0036] In the picture:

[0037] Support frame unit 1; Top plate 11; Top plate through hole 111; Support frame 12; Bottom plate unit 13; Bottom plate 131; Bottom plate through hole 1311; Slot 1312; Annular cone pressing body 132; Sealing sleeve 133; Upper skirt 1331; Lower cylinder 1332; Pressing block 134; Vertical plate 14; Guide rail 15; Sampling device 2; Outer cylinder unit 21; Connecting plate 211; Outer cylinder 212; Inner groove 2121; Outer cylinder through hole 2122; Plug 2123; Inner cavity 213; Pressure ring 214; Positioning unit 215; Short protrusion 2151; Recess 2153; Long protrusion 2152; Hole opener 22; Drilling cone 221; Drill rod 222; U-shaped connecting end 223; Collector 23; Collection cylinder 231; Collection cylinder inner cavity 2311; Sampling cone 232; Collection ring 2321; Water inlet 2322; Primary filter 2323; Filter cotton 2324; Conical head cavity 2325; Secondary filter 2326; Final filter 2327; Circular partition 2328; Through hole 2329; Collection pipe 234; Sealing ring 2341; Gas-liquid separation unit 24; Gas-liquid storage tank 241; Upper sensor 242; Lower sensor 243; Gas collection tank 244; Suction pipe 245; Drain pipe 246; Water storage bottle 247; Rotation unit 25; Circular rotating body 251; Flange 2511; Positioning stop 2512; Handle 2513; Spring 2514; Rotating body through hole 2515; Support turntable 252; Drive device 3; Motor 31; Gear 32; Rack 33; Vacuum pump 34; Controller 4; Level 5; Fastener 6; Ground 7. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. In the description of the present invention, it should be noted that the term "comprising" mentioned in the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to"; "several" refers to no less than two.

[0039] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and 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 this invention.

[0040] Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments; 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.

[0041] The technical solutions disclosed in this invention, such as... Figures 1-8 As shown:

[0042] A sampling device for simultaneously collecting solutions and gases from in-situ soil includes a support frame unit 1, a sampling device 2 installed within the support frame unit 1, a drive device 3 installed on the top plate 11 of the support frame unit 1, and a controller 4 for controlling the drive device 3 and the sampling device 2; wherein,

[0043] The sampling device 2 includes an opening device 22 for making a hole, a collector 23 for simultaneously collecting soil solution and gas from the hole, and a gas-liquid separation unit 24 for separating the solution and gas.

[0044] Preferred embodiments of the present invention, such as Figures 1-8 As shown:

[0045] A sampling device for simultaneously collecting solutions and gases in in-situ soil includes a support frame unit 1, a sampling device 2 installed in the support frame unit 1, a drive device 3 installed on the top plate 11 of the support frame unit 1, and a controller 4 for controlling the drive device 3 and the sampling device 2.

[0046] Synchronous in-situ soil solution and gas collection refers to the direct on-site sampling and collection of solutions and gases in soil pores without damaging or removing large chunks of soil, and without altering or minimizing changes to the original stress state, density, and moisture content distribution of the soil at the target sampling point, while maintaining the soil's original burial location and natural structure.

[0047] The support frame unit 1 includes a support frame 12 located in the middle for support, a top plate 11 fixed to the top of the support frame 12, and a bottom plate unit 13 located at the bottom and detachably connected to the support frame 12.

[0048] The bottom ring of the base plate 131 of the base plate unit 13 is provided with an annular conical pressing body 132 around its bottom ring to facilitate the insertion of the base plate 131 into the soil. Multiple pressing blocks 134 are provided at the top edge of the base plate 131, and a level 5 for displaying the horizontal status of the base plate 131 is placed on each pressing block 134. The base plate 131 has a slot 1312 for inserting a plug 2123 located at the lower end of the outer cylinder 212. The base plate 131 also has a bottom plate through hole 1311 for matching the hole opener 22 or the collector 23, located at the bottom of the base plate 131. A sealing sleeve 133 is installed around the bottom plate through hole 1311. The sealing sleeve 133 has an upper skirt 1331 and a lower cylinder 1332. The upper skirt 1331 is bonded to the base plate 131 as a whole. When the hole opener 22 or the collector 23 passes through the lower cylinder 1332, it interacts with the lower cylinder 1332. The inner wall of 32 is in a tightly fitted state, i.e., a sealed state; the lower end of the outer cylinder 212 is fitted with a pressure ring 214, which is pressed onto the base plate 131 by fasteners 6. The tip of the screw of the fastener 6 is located inside the base plate 131 and does not protrude from the bottom plane, i.e., external gas cannot enter through the screw of the fastener 6; when the base plate unit 13 is pressed into the soil of the sampling area to a preset depth, i.e., the distance H1 between the bottom plane of the base plate 131 and the ground should not be less than 100mm, 120mm is selected in this embodiment, and the distance H2 between the lower end of the annular cone pressure body 132 and the ground should not be less than 300mm, 320mm is selected in this embodiment. The level is used to ensure that the base plate 131 is in a horizontal state before sampling. This ensures that external gas in the sampled area cannot enter the soil and the collector 23 when collecting samples, ensuring that the collected samples are in situ and the data is accurate and reliable. Figure 1 , Figure 2 As shown.

[0049] The driving device 3 includes a motor 31 that drives the orifice 22 and the collector 23 to move, a gear 32 and a rack 33 that mesh with each other under the drive of the motor 31, and a vacuum pump 34 for gas-liquid collection and separation.

[0050] When the hole opener 22 or the collector 23 extends through the bottom plate through hole 1311 and the sealing sleeve 133, the sealing sleeve 133 is in a tight-fitting and sealed state with the hole opener 22 and the collector 23; a vertical plate 14 is also fixedly mounted on the top plate 11, and a vertical guide rail 15 is provided in the middle of the vertical plate 14. The guide rail 15 matches the rack 33. The driving device 3 includes a motor 31 and a meshing gear 32 and rack 33 driven by the motor 31. The rack 33 moves along the guide rail 15 under the drive of the gear 32. The rack 33 moves up and down, and its lower end is detachably connected to the hole opener 22 or the collector 23 via bolts. When the rack 33 moves up and down along the guide rail 15, the guide rail 15 passes through the top plate through hole 111 on the top plate 11, and the hole opener 22 or the collector 23 passes through the bottom plate through hole 1311 on the bottom plate 131. That is, the center lines of the top plate through hole 111 and the bottom plate through hole 1311 coincide, so that the hole opener 22 or the collector 23 moves up and down to the preset working position under the drive of the rack 33. Figure 1 , Figure 2 , Figure 8 As shown.

[0051] The sampling device 2 includes an opening device 22 for making holes, a collector 23 for simultaneously collecting soil solution and soil gas from the opened holes, and a gas-liquid separation unit 24 for separating the solution and gas.

[0052] The sampling device 2 includes an outer cylinder unit 21 with its two ends fixed to the top plate 11 and the bottom plate 131 respectively; a rotation unit 25 rotatably mounted on the top end of the inner cavity of the outer cylinder 212 provided in the outer cylinder unit 21; and a collector 23 or a hole opener 22 suspended on the rotation unit 25 and fixed to the lower end of the rack 33. That is, the collector 23 and the hole opener 22 can be connected to the lower end of the rack 33 as a whole. When drilling is required, the hole opener... The device 22 is first fixed to the bottom of the rack 33. Under the push of the rack 33, the hole opener 22 is pressed into the soil. Under the control of the controller 4, it reaches the preset depth. Driven by the gear 32, the rack 33 moves up along the guide rail 15 to pull out the hole opener 22. Then, the rotating unit 25 is manually rotated to rotate the collector 23 to the working position at the top of the hole. The collector 23 is then fixed to the bottom of the rack 33. Under the push of the rack 33, the collector 23 is pressed into the hole to take a sample.

[0053] The sampling device 2 also includes a gas-liquid separation unit 24 installed on the outer side wall of the outer cylinder 212. The gas-liquid separation unit 24 is connected to the collector 23 through a collection pipe 234 and to a vacuum pump 34 through a suction pipe 245.

[0054] The outer cylinder unit 21 includes an outer cylinder 212, an inner cavity 213, an inner groove 2121 located at the upper end of the inner wall of the outer cylinder 212, and two positioning units 215 with a center included angle of β on the longitudinal wall of the inner groove 2121 (in this embodiment, β = 90°). The top of the outer cylinder 212 is also provided with a connecting plate 211 fixedly connected to the top plate 11, and the bottom of the outer cylinder 212 is provided with a plug 2123 for fastening and inserting into the bottom plate 131. The side wall of the outer cylinder 212 is provided with an outer cylinder through hole 2122 for the collection tube 234 to pass through. A pressure ring 214 is fitted onto the lower end of the outer cylinder 212, which stabilizes the outer cylinder 212. Figure 2 , Figure 3 As shown.

[0055] The indexing unit 25 includes a support turntable 252 and a circular rotating body 251 located at the upper end; the central axis of the circular rotating body 251 coincides with the central axis of the outer cylinder 212, and a horizontally extending flange 2511 is provided at the center of the periphery of the circular rotating body 251. The flange 2511 matches and fits the inner groove 2121. The support turntable 252 is placed at the bottom of the flange 2511 and is placed in the inner groove 2121. A horizontally extending positioning stop bar 2512 is provided at the upper end of the flange 2511, and a handle 2513 is installed on the top of the circular rotating body 251.

[0056] The circular rotating body 251 has two rotating through holes 2515 located on the same horizontal center circumference. A pair of springs 2514 are installed in the rotating through holes 2515, which are respectively pressed and connected to the end of the hole opener 22 or the collector 23. The rotating through hole 2515 located on the Y axis corresponds to the rack 33. The springs 2514 are controlled by the controller 4 to retract or extend.

[0057] A pair of springs 2514 are located on both sides of the U-shaped connecting end 223 at the top of the hole opener 22 or the collector 23. Both springs 2514 are connected to the controller 4 via wires (not shown in the figure). The controller 4 controls the springs 2514 to retract or extend. When the hole opener 22 or the collector 23 is not working, the springs 2514 extend, and the combined action of the elastic forces on both sides locks the upper end of the hole opener 22 or the collector 23 in place and suspends it in the inner cavity 213. When working is required, the springs 2514 are controlled to retract, fixing the upper end of the hole opener 22 or the collector 23 to the rack 33 by manually passing fasteners 6, thus enabling operation. Figures 1-3 As shown.

[0058] The positioning unit 215 includes a short protrusion 2151, a concave portion 2153, and a long protrusion 2152 arranged horizontally along the inner groove 2121 of the outer cylinder 212. Two positioning units 215 are provided, located at the first positioning unit position E and the second positioning unit position F, respectively. That is, the horizontal angle β between the centers of the first positioning unit position E and the second positioning unit position F is selected as 90°, and the short protrusions 2151 of the two positioning units 215 are adjacent to each other. Figure 3 , Figure 7 As shown.

[0059] The positioning unit 215 is matched and positioned with the positioning stop 2512 on the side of the rotating body 251 of the indexing unit 25. When the rotating body 251 is rotated so that the end of the positioning stop 2512 slides past the short protrusion 2151 and enters the recess 2153, it is blocked by the long protrusion 2152, that is, when it is fixed in the first positioning unit E position, the hole punch 22 suspended on the rotating body 251 is in the working position C position and performs drilling, and the collector 23 is in the waiting position D position; if the rotating body 251 is rotated so that the positioning stop 2512 is fixed in the second positioning unit F position, the collector 23 is in the working position C position, connected to the rack 33, and performs operation. Figure 1 — Figure 3 As shown.

[0060] The hole punch 22 and the collector 23 have the same external dimensions, both including an upper U-shaped connecting end 223, a middle cylinder, and a lower conical head; the middle part of the U-shaped connecting end 223 is connected to the rack 33 by fasteners; wherein, after the cylinder passes through the through hole 1311 of the base plate, the connection is tightly sealed by the sealing sleeve 133 to prevent external gas from entering the sampling area, ensuring the authenticity and accuracy of the sampling data, and during the hole punching process of the hole punch 22 and the sampling process of the collector 23, the U-shaped connecting end 223 is always located at the upper end of the base plate 131, such as Figure 1 , Figure 2 , Figure 6 , Figure 8 As shown.

[0061] The hole opener 22 includes a U-shaped connecting end 223, a cylindrical drill rod 222, and a drilling cone 221, both of which are solid metal.

[0062] The collector 23 includes a U-shaped connecting end 223, a cylindrical collecting cylinder 231, and a sampling cone 232. The collecting cylinder 231 has an inner cavity 2311. A circular partition 2328 is provided within the inner cavity 2311, at the connection point between the collecting cylinder 231 and the sampling cone 232. A through hole 2329 is provided in the center of the circular partition 2328, and a final-stage filter 2327 is installed on the through hole 2329. A collection tube 234 is placed in 2311. The end of the collection tube 234 is connected to the final filter screen 2327, and the outer wall of the collection tube 234 is sealed to the outer wall of the through hole 2329 with sealant to ensure the authenticity and accuracy of the sampling data. The sampling cone 232 is provided with several collection ring grooves 2321. In this embodiment, two layers of collection ring grooves 2321 are selected. The walls of the collection ring grooves 2321 are densely covered with water inlet holes 2322. The wall is covered with a primary filter screen 2323. The sampling cone head 232 has a cone head cavity 2325, in which filter cotton 2324 is placed. A concave secondary filter screen 2326 is also provided at the upper end of the cone head cavity 2325. The inner cavity 2311 of the collection cylinder and the inner cavity 2325 of the cone head are connected through a final filter screen 2327, and the outer diameter of the final filter screen 2327 matches the inner diameter of the collection tube 234. The soil solution and soil gas collected by the sampling cone 232 are both output to the gas-liquid separation unit 24 through the collection pipe 234. The pore sizes of the water inlet 2322, the primary filter 2323, the secondary filter 2326, and the final filter 2327 are set as needed. The primary filter 2323, located on the outer layer, is made of stainless steel and is used to intercept large soil particles in the first layer. The secondary filter 2326 and the final filter 2327, located on the inner layer, are fixed polymer separation membranes, which can be one or more of PVDF membranes, tetrafluoroethylene (PTFE) membranes, nylon membranes, and polyethersulfone (PES) membranes. In this embodiment, the thickness is set to 0.1 mm, which can more effectively intercept small soil particles. In this embodiment, the total length of the sampling cylinder 231 and the sampling cone 232 is selected as 1 m. Figure 5 As shown.

[0063] The gas-liquid separation unit 24 includes a gas-liquid storage tank 241 fixed on the outer wall of the outer cylinder 212. The top of the gas-liquid storage tank 241 is connected to the collection pipe 234 and the suction pipe 245 extending from the collector 23. The connection is sealed by a sealing ring 2341. The suction pipe 245 is connected to a vacuum pump 34, and the vacuum pump 34 is connected to a gas collection tank 244. In this embodiment, a Summa tank is selected. The tank is a stainless steel tank with special polishing and passivation treatment inside. It is pre-vacuumed, usually < 0.05 atm or < 50 mbar. The gas extracted by this device is mainly VOCs, and there are different specifications, such as 400mL, 1L, 3L, and 6L. Valves equipped with metal valve seats and polytetrafluoroethylene (PTFE) seals are selected.

[0064] The gas-liquid storage device 241 is also equipped with an upper sensor 242 and a lower sensor 243 on its inner wall. The upper sensor 242 is located at 9 / 10 of the volume of the gas-liquid storage device 241, and the lower sensor 243 is located at 1 / 10 of the volume of the gas-liquid storage device 241. A detachable drain pipe 246 is installed at the bottom of the gas-liquid storage device 241. The drain pipe 246 is connected to the water storage bottle 247, and the connection is sealed by a sealing ring 2341. The liquid collector for collecting VOCs water samples uses a 40mL brown glass bottle and a PTFE-coated silicone gasket for sampling.

[0065] Sampling process:

[0066] Step 1, Drilling process:

[0067] Holding the handle 2513, rotate the indexing unit 25. When the positioning stop 2512 is fixed in position E of the first positioning unit, the hole opener 22 is in the working position C. Under the control of the controller 4, the springs 2514 on both sides of the rotating through hole 2515 retract, releasing the hole opener 22. Under manual action, the bottom end of the rack 33 is fixed to the U-shaped connecting end 223 of the hole opener 22 by the fastener 6. At this time, the collector 23 is in the waiting position D. Under the control of the controller 4, the motor 31 drives the gear 32 to rotate, and the gear 32 drives the rack 33. The hole opener 22 is pushed into the soil and reaches a preset depth. After successful drilling, under the control of the controller 4, the motor 31 drives the gear 32 to reverse. The rack 33 moves upward along the guide rail 15, pulling the hole opener 22 out into the outer cylinder 212. Under manual action, the bottom end of the rack 33 is separated from the U-shaped connecting end 223 of the hole opener 22 by the fastener 6. The controller 4 is activated, and the springs 2514 on both sides of the rotating through hole 2515 pop out and press against the two outer planes of the U-shaped connecting end 223 from both sides. The hole opener 22 is suspended on the rotating body 251.

[0068] The second step, the leak detection process:

[0069] Block the sample outlet end of the collection tube 234, and use the vacuum pump 34 to check the sealing of the gas-liquid separation unit 24. If the sealing is not up to standard, repair it until it is up to standard. When the sealing is up to standard, sampling is carried out.

[0070] The third step, the sampling process:

[0071] Holding the handle 2513, continue to rotate the indexing unit 25. When the positioning stop 2512 is fixed in the second positioning unit F position, the collector 23 is located in the working position C position. Under the control of the controller 4, the springs 2514 on both sides of the rotating through hole 2515 retract, releasing the collector 23. Under manual action, the bottom end of the rack 33 is fixed to the U-shaped connecting end 223 of the collector 23 by the fastener 6. Under the control of the controller 4, the motor 31 drives the gear 32 to rotate, and the gear 32 drives the rack 33 to push the collector 23 into the hole and reach the preset bottom.

[0072] When preparing to collect gas, it is necessary to evacuate and clean the system and keep it stable. The purpose is to remove residual air from the probe and sampling pipeline and to stabilize the gas flow field in the soil around the sampling point, forming a representative gas flow. Under the control of controller 4, vacuum pump 34 starts evacuating at a low flow rate, usually 100-500 ml / min. The specific evacuation and cleaning time depends on the soil type (clay soil requires a longer time, while sandy soil is faster). In general, the total amount of gas extracted during the cleaning process is 3 to 5 times that of the entire closed system, and this part of the sample is discarded.

[0073] Sampling continues under the control of controller 4. Under negative pressure, soil solution and gas enter gas-liquid storage tank 241 through collection pipe 234. When the soil solution rises to the lower sensor 243, vacuum pump 34 is controlled to start transporting gas through suction pipe 245 to gas collection tank 244. When the soil solution rises to the upper sensor 242, vacuum pump 34 is controlled to stop working, so that gas-liquid storage tank 241 is at normal pressure. Drain pipe 246 is controlled to drain the solution into water storage bottle 247 for collection, and sample collection is completed.

[0074] Since VOCs are extracted, the collection tube 234 for vacuuming and water extraction is made of polytetrafluoroethylene (PTFE). In this embodiment, the outer diameter of the tube is 9.5 mm and the wall thickness is 1.8 mm. All pipes, joints, valves and other components that come into direct contact with the sample are made of polytetrafluoroethylene (PTFE).

[0075] Step 4, Sample Preservation:

[0076] 1. The collected liquid should be refrigerated immediately (0~4℃) and protected from light, and sent to the laboratory for analysis as soon as possible.

[0077] 2. After collecting the gas, the valve needs to be closed, the pressure recorded, and the SUMMA canister carefully placed in a special shockproof transport box. It should be transported and stored at room temperature (15-25°C) and sent to the laboratory for analysis as soon as possible.

[0078] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A sampling device for synchronously collecting solution, gas in situ soil, characterized in that: It includes a support frame unit, a sampling device installed within the support frame unit, a drive device installed on the top plate of the support frame unit, and a controller for controlling the drive device and the sampling device; wherein, The support frame unit includes a support frame located in the middle for support, a top plate fixed to the top of the support frame, and a bottom plate unit located at the bottom and detachably connected to the support frame. The bottom plate unit has an annular cone-shaped pressure body at the bottom for easy entry into the soil. The bottom plate has a bottom plate through hole for a hole opener to be inserted. A sealing sleeve is bonded around the bottom of the bottom plate near the bottom plate through hole. A pressure block is provided at the top edge of the bottom plate, and a level is placed on the pressure block to indicate the levelness of the bottom plate. The sampling device includes an outer cylinder unit with its two ends fixed to the top plate and the bottom plate respectively, a rotation unit rotatably mounted on the top of the inner cavity of the outer cylinder of the outer cylinder unit, a collector and an aperture opener suspended on the rotation unit, and a gas-liquid separation unit connected to the collector. The indexing unit includes a supporting turntable and a rotating body located at the upper end. The rotating body is located on the same horizontal central circle and can detachably suspend the hole opener and the collector. A horizontally extending positioning stop is provided around the periphery of the rotating body. Two positioning units with a central included angle β are provided on the inner wall of the outer cylinder. The positioning stop matches and positions the positioning units. Rotating the rotating body switches the working positions of the two: when rotating to the first positioning unit, the hole opener is located in the working position corresponding to the rack of the driving device, and the collector is located in the waiting position; when rotating back to the second positioning unit, the collector is located in the working position corresponding to the rack, and the hole opener is located in the waiting position. The driving device includes a motor and meshing gears and racks driven by the motor. A vertical plate is fixedly mounted on the top plate. A vertical guide rail matching the rack is provided in the middle of the vertical plate. The lower end of the rack is detachably connected to the hole opener or the collector. The center line of the top plate through-hole on the top plate through which the guide rail passes coincides with the center line of the bottom plate through-hole on the bottom plate through which the hole opener or the collector passes, so that the hole opener or the collector moves up and down to a preset position under the drive of the rack. The lower end of the rack of the driving device can be selectively connected to the tool in the working position to drive the hole opener to complete the drilling operation or drive the collector to complete the synchronous gas-liquid sampling operation.

2. The sampling device for simultaneously collecting solutions and gases in in-situ soil according to claim 1, characterized in that: The outer cylinder unit includes the outer cylinder, the inner cavity, an inner groove located at the upper end of the inner wall of the outer cylinder, and two positioning units with a center included angle β provided on the longitudinal wall of the inner groove. The top of the outer cylinder is also provided with a connecting plate fixedly connected to the top plate, and the bottom of the outer cylinder is provided with a plug for fastening to the bottom plate. A pressure ring is fitted at the lower end of the outer cylinder, and the pressure ring is pressed tightly to the bottom plate by fasteners to fasten the outer cylinder.

3. The sampling device for simultaneously collecting solutions and gases in in-situ soil according to claim 2, characterized in that: The positioning unit includes a short protrusion, a concave portion, and a long protrusion arranged horizontally along the inner groove. When the rotating body is rotated so that the end of the positioning stop rod slides past the short protrusion and enters the concave portion, it is fixed to the first positioning unit. When the rotating body is rotated in the opposite direction so that the end of the positioning stop rod slides past the short protrusion and enters the concave portion, it is fixed to the second positioning unit.

4. The sampling device for simultaneously collecting solutions and gases in in-situ soil according to claim 3, characterized in that: The central axis of the rotating body coincides with the central axis of the outer cylinder. The central part of the periphery of the rotating body is provided with a flange that extends horizontally into the inner groove. The support turntable is placed at the bottom of the flange. The positioning stop bar that extends horizontally is also provided at the upper end of the flange. The top of the rotating body is equipped with a handle. The upper surface of the rotating body is provided with two rotating through holes on the same central circle. A pair of springs are provided in the rotating through holes and are respectively pressed and connected to the ends of the hole opener and the collector. The rotating through hole located on the Y-axis corresponds to the rack. The springs are controlled by the controller to retract or extend.

5. The sampling device for simultaneously collecting solutions and gases in in-situ soil according to claim 4, characterized in that: The hole opener and the collector have the same external dimensions, both including an upper U-shaped connecting end, a middle cylinder and a lower conical head; the rack is inserted into the middle of the U-shaped connecting end and connected to it; the cylinder of the hole opener or the collector passes through the through hole of the base plate and fits tightly with the sealing sleeve.

6. The sampling device for simultaneously collecting solutions and gases in in-situ soil according to claim 5, characterized in that: The hole opener includes a U-shaped connecting end, a cylindrical drill rod, and a drilling cone; The collector includes a U-shaped connecting end, a cylindrical collection cylinder, and a sampling cone in sequence; the end of the collection tube placed in the inner cavity of the collection cylinder is connected to the inner cavity of the cone through a final-stage filter screen; the outer side of the sampling cone is provided with several collection ring grooves, the walls of the collection ring grooves are densely covered with water inlet holes, the outer wall of the collection ring grooves is covered with a primary filter screen, the inner cavity of the cone is filled with filter cotton, and a secondary filter screen is also provided at the upper end of the inner cavity of the cone.

7. The sampling device for simultaneously collecting solutions and gases in in-situ soil according to claim 6, characterized in that: The gas-liquid separation unit includes a gas-liquid storage device fixedly mounted on the side wall of the outer cylinder. The top of the gas-liquid storage device is sealed and connected to the collection pipe and the suction pipe connected to the air pump, respectively. The air pump is connected to the gas collection tank. An upper sensor and a lower sensor for sensing the liquid level are also installed on the inner wall of the gas-liquid storage device. A detachable drain pipe is installed at the bottom of the gas-liquid storage device.

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