Depth-keeping sampling equipment for underground water detection

Abstract

The invention relates to the technical field of auxiliary equipment for underground water detection, in particular to depth-keeping sampling equipment for underground water detection, the depth-keeping sampling equipment for underground water detection comprises a sampling cylinder and an inflation part, the sampling cylinder is provided with a sampling port, the sampling port is communicated with a detection well, and the sampling cylinder is sleeved with two base shells; the two base shells are respectively positioned on the upper and lower sides of the sampling port and are communicated with each other; each base shell is sleeved with an isolation air bag, the isolation air bags are communicated with the base shells, and the isolation air bags are configured to be capable of expanding when being inflated, and are used for separating a water body located at the sampling port from a water body located above the sampling port or a water body located below the sampling port in the axis direction of the sampling barrel; the water body sampled from the sampling port is always a water sample at the target depth, and the sampling error is reduced; an auxiliary air bag is arranged on the base shell in a communicating manner, is positioned between the two isolation air bags, and is configured to be capable of expanding during inflation so as to squeeze a water body positioned at the sampling opening into the sampling barrel through the sampling opening.

Description

Technical Field

[0001] The present invention relates to the technical field of auxiliary equipment for groundwater detection, and particularly to a depth-fixed sampling device for groundwater detection. Background Art

[0002] In the construction of the ecological environment protection and water resource security guarantee system, groundwater analysis and detection, as a key technical link, undertakes the core functions of evaluating water quality status, monitoring pollution dynamics, and supporting scientific decision-making. Its detection results not only directly affect the formulation of groundwater resource protection strategies and the implementation of environmental governance projects, but also are closely related to the guarantee of public drinking water safety; in the complete detection process system, the groundwater sampling link is the primary prerequisite for obtaining effective data, and the representativeness and integrity of the sampling samples fundamentally determine the reliability of the subsequent detection data and the scientific nature of the analysis conclusions.

[0003] In the process of sampling groundwater, sampling equipment is required. In related technologies, for example, Chinese Patent CN119246153B discloses a multifunctional groundwater sampling device. The multifunctional groundwater sampling device includes a sampling ring. When washing the well, the sampling ring and the submersible pump are placed into the groundwater monitoring well together, so that while the stagnant water is pumped out by the submersible pump, the impurities generated when the sampling ring and the submersible pump descend in the groundwater monitoring well are pumped out; subsequently, after the groundwater recovers and impurities such as silt settle, the groundwater is sampled in layers through the sampling ring.

[0004] However, there are also some problems in the actual use of existing sampling equipment: The groundwater system has significant physical characteristics of fluidity and continuity. When the sampling equipment performs the sampling task at a predetermined depth, the extraction behavior of the water body at the target depth will induce a complex hydraulic response mechanism. Under the coupled action of the gravity field and the water pressure difference, the water body above the target depth shows a dynamic process of rapid downward replenishment; at the same time, affected by the water pressure gradient inside and outside the monitoring well, the water body below will also have a reverse upward migration phenomenon, thereby forming a dynamic water flow replacement phenomenon. This water flow replacement effect directly leads to a systematic deviation between the actual sampling depth of the water sample and the predetermined target depth, and further causes significant differences in the key indicators such as chemical components, microbial content, and physical properties of the sample from the groundwater characteristics at the true target depth. The problem of distorted detection data caused by depth deviation may result in an underestimation or overestimation of the groundwater pollution degree, seriously interfering with the accuracy and reliability of environmental monitoring data, and even may lead to misjudgment and mismatch of groundwater pollution prevention and control strategies, having a substantial misleading impact on water resource protection and ecological restoration work. Summary of the Invention

[0005] Based on this, it is necessary to provide a fixed-depth sampling device for groundwater detection to address the problem of large sampling errors existing in the current groundwater sampling process.

[0006] The above object is achieved by the following technical solutions: A fixed-depth sampling device for groundwater detection, the fixed-depth sampling device for groundwater detection is configured to be able to sample the groundwater in a detection well; the fixed-depth sampling device for groundwater detection includes a sampling cylinder and an inflating member. The sampling cylinder is vertically placed in the detection well during sampling. A sampling port is provided on the sampling cylinder, and the sampling port communicates with the detection well. A first one-way valve is provided at the sampling port, and the opening direction of the first one-way valve is configured to be from outside to inside. Two base shells are detachably sleeved on the sampling cylinder. The two base shells are respectively located on the upper and lower sides of the sampling port and communicate with each other. An isolation airbag is sleeved on each base shell. The isolation airbag communicates with the base shell and is configured to be able to expand when inflated and separate the water body at the sampling port from the water body above or below the sampling port along the axial direction of the sampling cylinder. An auxiliary airbag is communicated with the base shell and is located between the two isolation airbags. The auxiliary airbag is configured to be able to expand when inflated to squeeze the water body at the sampling port into the sampling cylinder through the sampling port. A second one-way valve is provided at the connection between the auxiliary airbag and the base shell, and the second one-way valve is configured to be able to switch from a closed state to an open state when the air pressure value inside the base shell reaches a preset value. The inflating member communicates with the upper base shell and is configured to be able to fill the upper base shell with gas.

[0007] Further, the isolation airbag is inclined and forms an elliptical structure.

[0008] Further, the fixed-depth sampling device for groundwater detection further includes a flattening mechanism, and the flattening mechanism is configured to be able to flatten the isolation airbag circumferentially.

[0009] Further, the flattening mechanism includes a fixed ring frame and a flattening component. Each base shell is fixedly sleeved with the fixed ring frame, and the fixed ring frame is located inside the isolation airbag; at least one air vent group and at least one flattening component are arranged on each fixed ring frame. The air vent group includes a plurality of air vents, and the plurality of air vents are arranged at intervals in the circumferential direction and are all communicated with the base shell; the flattening component includes a rotating ring, the rotating ring is sleeved on the fixed ring frame and can rotate around the axis of the sampling tube. A plurality of guide vanes are arranged on the rotating ring, and a flow channel is formed between adjacent guide vanes, and the flow channel is communicated with the air vent; a plurality of fixed tubes are arranged on the outer peripheral wall of the rotating ring, the plurality of fixed tubes are arranged at intervals in the circumferential direction, the fixed tubes extend in the radial direction and are communicated with the flow channel, a sliding tube is sleeved on each fixed tube, the sliding tube can elastically slide in the radial direction, an installation frame is hinged on each sliding tube, a flattening roller is arranged on each installation frame, the axis of the flattening roller is parallel to the axis of the sampling tube, the flattening roller can rotate around its own axis and is configured to form a rolling fit with the inner side wall of the isolation airbag; an air outlet is arranged on each sliding tube, and the air outlet is communicated with the fixed tube and the isolation airbag.

[0010] Further, when the number of the flattening components on the fixed ring frame is two or more, at least one elastic ring is sleeved on each isolation airbag. The elastic ring is located between two adjacent flattening components on the same fixed ring frame and is configured to be able to draw an annular groove in the isolation airbag inward under the action of elasticity.

[0011] Further, a plurality of fixing blocks are arranged on the elastic ring, and the plurality of fixing blocks are arranged at intervals in the circumferential direction and are all fixed on the isolation airbag.

[0012] Further, an elastic member is connected between the sliding tube and the fixed tube, and under the action of the elastic member, the sliding tube has a tendency to move outward.

[0013] Further, the elastic member is a compression spring.

[0014] Further, the number of the sampling ports is multiple and they are arranged at intervals in the circumferential direction.

[0015] Further, the inflating member is an air pump.

[0016] The beneficial effects of the present invention are: During the sampling process of the depth - fixed sampling device for groundwater detection provided by the present invention, first, the depth - fixed sampling device for groundwater detection is placed at the target depth of the detection well. Then, gas is filled into the base shell through the inflating component. The gas then enters into the two isolation air bags and causes the isolation air bags to expand. Among them, the upper isolation air bag expands to separate the water body at the sampling port and the water body above the sampling port, and the lower isolation air bag expands to separate the water body at the sampling port and the water body below the sampling port. Thus, the water body at the target depth can be separated from the upper and lower water bodies, ensuring that the water body entering from the sampling port is always the water body at the target depth and reducing the sampling error. As the gas is continuously filled, the air pressure in the base shell gradually increases. When the air pressure value inside the base shell reaches the preset value, the second one - way valve switches from the closed state to the open state. The gas then enters into the auxiliary air bag and causes the auxiliary air bag to expand, thereby squeezing the water body at the sampling port into the sampling cylinder through the sampling port and the first one - way valve to complete the sampling.

[0017] Furthermore, by setting the isolation air bags to be inclined and form an elliptical structure, after the isolation air bags expand, compared with the annular structure, on the one hand, it can increase the contact area with the detection well, which is beneficial to improving the sealing effect. On the other hand, it can reduce the pressure borne by the local part of the isolation air bag, reduce the possibility of damage caused by excessive local pressure, and extend the service life of the isolation air bag.

[0018] Furthermore, by setting the flattening mechanism, during the expansion process of the isolation air bag, the flattening mechanism flattens the isolation air bag along the circumferential direction. While being beneficial to the more uniform expansion and deformation of the isolation air bag, it helps to reduce the gap between the isolation air bag and the inner wall of the detection well, thereby further improving the sealing effect between the isolation air bag and the detection well.

[0019] Furthermore, by setting the flattening mechanism and the elastic ring, during the process of filling gas into the isolation air bag, the gas drives the rotating ring to rotate through the guide vane, and then drives the flattening roller to rotate. During the rotation of the flattening roller, when there are large - particle impurities between the isolation air bag and the detection well, the flattening roller pushes the particle impurities to move. Since the flattening roller moves along an elliptical trajectory, the flattening roller can push the particle impurities into the groove, thereby reducing the wear of the particle impurities on the isolation air bag and being beneficial to extending the service life of the isolation air bag. At the same time, during the expansion process of the isolation air bag, the groove and the inner wall of the detection well jointly enclose a positive - pressure space, which can hinder the inter - communication between the water body at the target depth and the upper and lower water bodies, reducing the impact on the sampling accuracy. Description of the Drawings

[0020] Figure 1 It is a schematic cross - sectional structure diagram of the depth - fixed sampling device for groundwater detection provided by the embodiment of the present invention when sampling in the detection well; Figure 2For Figure 1 Partial enlarged structural schematic diagram at position A in Figure 3 Front view structural schematic diagram of the depth-fixed sampling device for groundwater detection provided by the embodiment of the present invention; Figure 4 Cross-sectional structural schematic diagram during the assembly of the base shell, isolation airbag and auxiliary airbag of the depth-fixed sampling device for groundwater detection provided by the embodiment of the present invention; Figure 5 Cross-sectional structural schematic diagram of the sampling cylinder of the depth-fixed sampling device for groundwater detection provided by the embodiment of the present invention; Figure 6 Three-dimensional structural schematic diagram of the flattening mechanism of the depth-fixed sampling device for groundwater detection provided by the embodiment of the present invention; Figure 7 Front view structural schematic diagram of the flattening mechanism of the depth-fixed sampling device for groundwater detection provided by the embodiment of the present invention; Figure 8 For Figure 7 Cross-sectional view in the B-B direction in Figure 9 Exploded view of the parts of the flattening mechanism of the depth-fixed sampling device for groundwater detection provided by the embodiment of the present invention; Figure 10 For Figure 9 Partial enlarged structural schematic diagram at position C in Figure 11 Three-dimensional structural schematic diagram of the elastic ring of the depth-fixed sampling device for groundwater detection provided by the embodiment of the present invention.

[0021] Wherein: 1. Sampling cylinder; 101. Sampling port; 102. Second flange; 1021. Second bolt hole; 1022. Communication hole; 103. Sampling pipe; 104. Sealing plug; 2. Base shell; 201. First flange; 2011. First bolt hole; 202. Communication port; 3. Isolation airbag; 301. Groove; 4. Auxiliary airbag; 5. Second one-way valve; 501. Valve core; 502. Pulling spring; 6. Flattening mechanism; 601. Fixed ring frame; 6011. Ventilation port; 6012. First mounting ring; 602. Flattening assembly; 6021. Rotating ring; 60211. Second mounting ring; 6022. Guide vane; 6023. Fixed pipe; 6024. Sliding pipe; 60241. Air outlet; 60242. Hinge frame; 6025. Mounting frame; 6026. Flattening roller; 6027. Compression spring; 7. Elastic ring; 701. Fixed block; 8. Detection well. Detailed implementation mode

[0022] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] The serial numbers assigned to the components in this document, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meanings. The terms "connection" and "coupling" as used herein, unless otherwise specified, both include direct and indirect connections (couplings). In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0024] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0025] Such as Figures 1 to 11As shown in the figure, a depth-fixed sampling device for groundwater detection provided by an embodiment of the present invention is configured to be able to sample the groundwater in the detection well 8, and is provided with a sampling cylinder 1 and an inflating member. The sampling cylinder 1 is vertically placed in the detection well 8 during sampling. A sampling port 101 is provided on the sampling cylinder 1, and the sampling port 101 communicates with the detection well 8; a first one-way valve is provided at the sampling port 101, and the opening direction of the first one-way valve is configured to be from outside to inside; two base shells 2 are detachably sleeved on the sampling cylinder 1, and the two base shells 2 are respectively located on the upper and lower sides of the sampling port 101 and communicate with each other; an isolation airbag 3 is sleeved on each base shell 2, and the isolation airbag 3 communicates with the base shell 2 and is configured to be able to expand when inflated, and separate the water body at the sampling port 101 from the water body above the sampling port 101 or the water body below the sampling port 101 along the axis direction of the sampling cylinder 1; an auxiliary airbag 4 is communicated with the base shell 2, and the auxiliary airbag 4 is located between the two isolation airbags 3. The auxiliary airbag 4 is configured to be able to expand when inflated, so as to squeeze the water body at the sampling port 101 into the sampling cylinder 1 through the sampling port 101; a second one-way valve 5 is provided at the communication part between the auxiliary airbag 4 and the base shell 2, and the second one-way valve 5 is configured to be able to switch from the closed state to the open state when the air pressure value inside the base shell 2 reaches a preset value; the inflating member communicates with the upper base shell 2 and is configured to be able to fill the inside of the upper base shell 2 with gas.

[0026] Specifically in this embodiment, the base shell 2 is of a cylindrical structure, and the bottom of the upper base shell 2 is provided with an open mouth, and the top of the lower base shell 2 is provided with an open mouth. To facilitate the detachable connection between the base shell 2 and the sampling cylinder 1, first flange plates 201 are fixedly sleeved at the bottom of the upper base shell 2 and the top of the lower base shell 2. A plurality of first bolt holes 2011 are vertically arranged on the plate surface of the first flange plate 201, and the plurality of first bolt holes 2011 are arranged at intervals along the circumferential direction. A second flange plate 102 is fixedly sleeved in the middle of the sampling cylinder 1. A plurality of second bolt holes 1021 are vertically arranged on the plate surface of the second flange plate 102, and the plurality of second bolt holes 1021 are arranged at intervals along the circumferential direction.

[0027] During the assembly process of the sampling cylinder 1 and the base shell 2, first, the lower end of the sampling cylinder 1 is inserted into the lower base shell 2 from top to bottom, and then the upper base shell 2 is sleeved on the upper end of the sampling cylinder 1 from top to bottom, so that the second flange plate 102 is clamped between the first flange plate 201 on the upper base shell 2 and the first flange plate 201 on the lower base shell 2, and the positions of the second bolt holes 1021 and the first bolt holes 2011 correspond. Then, bolts are respectively passed through the first bolt holes 2011 and the second bolt holes 1021, and then nuts are threadedly sleeved on the other ends of the bolts, so as to connect the sampling cylinder 1 and the two base shells 2 together.

[0028] To facilitate the mutual connection between the two base shells 2, a plurality of communication holes 1022 are vertically provided on the disk surface of the second flange 102. The plurality of communication holes 1022 are arranged at intervals in the circumferential direction and are all located inside the second bolt holes 1021. To facilitate the formation of the sampling port 101, a sampling pipe 103 is provided on the circumferential side wall of the second flange 102. The axis of the sampling pipe 103 extends along the radial direction of the sampling cylinder 1. The sampling port 101 is formed at the pipe orifice of the sampling pipe 103. The inner end of the sampling pipe 103 penetrates the second flange 102 and the sampling cylinder 1 inward to ensure that water can be introduced into the sampling cylinder 1.

[0029] To facilitate the extraction of water samples from the sampling cylinder 1, the top of the sampling cylinder 1 is provided with an open mouth, and a sealing plug 104 is detachably inserted at the top of the sampling cylinder 1. Optionally, the sealing plug 104 can be made of an elastic material such as rubber, and is press-fitted into the open mouth at the top of the sampling cylinder 1 during installation, and realizes the seal with the sampling cylinder 1 through its own elastic deformation. Optionally, the sealing plug 104 can also be made of a rigid material such as stainless steel, and is threadedly inserted into the open mouth at the top of the sampling cylinder 1 during installation, and realizes the seal with the sampling cylinder 1 through a sealing ring.

[0030] The first one-way valve can be set as a swing check valve and includes a valve flap. The valve flap is hinged in the sampling pipe 103 through a pin shaft. When the external pressure is greater than the internal pressure, the valve flap is pushed inward, and water enters the sampling cylinder 1 from the sampling port 101; when the internal pressure is greater than the external pressure, the valve flap closes under the action of gravity and water pressure to prevent the water from flowing back.

[0031] The second one-way valve 5 is set as a spring-loaded one-way valve and includes a valve core 501 and a tension spring 502. As Figure 2 shown, wherein the valve core 501 is a cylindrical structure and is horizontally arranged at the connection between the auxiliary airbag 4 and the base shell 2. The right end face of the valve core 501 is provided with an open mouth and is connected to the base shell 2. The left end face of the valve core 501 is in sealing contact with the base shell 2. A plurality of air guide holes are provided on the circumferential side wall at the left end of the valve core 501 to ensure that when the valve core 501 moves outward, the auxiliary airbag 4 and the base shell 2 can be connected through the air guide holes; the tension spring 502 is horizontally inserted into the valve core 501, with the left end provided on the left end face of the valve core 501 and the right end provided on the base shell 2. Under the action of the tension spring 502, the valve core 501 has a tendency to move inward to ensure that the second one-way valve 5 is initially in a closed state.

[0032] The isolation airbag 3 is of a ring-shaped shell structure and is fixedly sleeved on the base shell 2 during installation. To facilitate the connection between the base shell 2 and the isolation airbag 3, a plurality of communication ports 202 are provided on the circumferential side wall of the base shell 2, and the plurality of communication ports 202 are arranged at intervals in the circumferential direction. The auxiliary airbag 4 is of a spherical shell structure and is fixedly arranged on the circumferential side wall of the base shell 2 during installation. The inflating member is an air pump, which is placed at the wellhead of the inspection well 8 during installation and is connected to the upper base shell 2 through a hose, facilitating the injection of gas into the upper base shell 2.

[0033] During the sampling process, first, the fixed-depth sampling device for groundwater detection is lowered to the target depth of the inspection well 8 by a professional device below, and then the air pump is started. The air pump transports the outside air through the hose to the upper base shell 2. After the outside air enters the upper base shell 2, a part of it enters the lower base shell 2 through the communication hole 1022.

[0034] With the continuous injection of air, both isolation airbags 3 expand under the action of gas pressure. Among them, after the upper isolation airbag 3 expands, its outer side wall closely adheres to the inner wall of the inspection well 8, separating the water body at the sampling port 101 from the upper water body; the lower isolation airbag 3 undergoes the same expansion process, separating the water body at the sampling port 101 from the lower water body. Through this two-way isolation mechanism, a relatively independent water sample space is constructed around the sampling port 101, ensuring that the water body at the target depth is completely separated from the upper and lower water bodies, effectively avoiding the mixing of water samples caused by the flow and replenishment of the upper and lower water bodies, reducing the sampling error while ensuring the representativeness and accuracy of the collected water samples.

[0035] With the continuous operation of the air pump, the air in the base shell 2 accumulates continuously, and the air pressure value rises steadily. Under the action of the air pressure, the valve core 501 is pushed outward to move, and the tension spring 502 is stretched; when the air pressure value inside the base shell 2 reaches the preset value, the valve core 501 moves to connect the air guide hole with the auxiliary airbag 4, causing the second one-way valve 5 to switch from the closed state to the open state. At this time, the air enters the auxiliary airbag 4 under the drive of the pressure difference, causing it to gradually expand. The expansion of the auxiliary airbag 4 gradually increases the pressure of the water body at the sampling port 101. Under the action of the external water pressure, the first one-way valve opens, and the water body enters the sampling cylinder 1 from the sampling port 101, completing the water sample collection work.

[0036] After sampling is completed, turn off the air pump to isolate the air in the isolation airbag 3 from being discharged through the hose under the action of air pressure. The volume of the isolation airbag 3 becomes smaller. Then, use professional equipment below to lift the groundwater detection depth-fixed sampling device out of the detection well 8. Then, unscrew the nut from the bolt, and then remove the bolt from the first bolt hole 2011 and the second bolt hole 1021, and the sampling tube 103 can be removed from the base shell 2. Then, remove the sealing plug 104 from the sampling cylinder 1, and the water sample can be taken out of the sampling cylinder 1, which is convenient for the next detection process.

[0037] In a further embodiment, to improve the sealing effect between the isolation airbag 3 and the detection well 8, the isolation airbag 3 is arranged obliquely to form an elliptical structure.

[0038] Specifically in this embodiment, as Figure 3 shown, the isolation airbag 3 is arranged obliquely in the upper right direction, so that the upper and lower end faces of the isolation airbag 3 are both elliptical shapes, ensuring that an elliptical structure can be formed.

[0039] During use, in terms of the sealing effect, compared with the circular structure, the elliptical structure has a more fitting contact profile with the wall of the detection well 8 after expansion, and the contact area increases significantly. A larger contact area means that the friction between the two increases, and at the same time, the gas pressure can act more evenly on the contact surface, thereby forming a more reliable sealing barrier between the isolation airbag 3 and the wall of the detection well 8. It can not only effectively reduce the existence of gaps, but also reduce the risk of external water infiltration, ensuring that the target water sample is not contaminated during the collection process and maintaining its representativeness and authenticity.

[0040] In terms of pressure bearing, the inclined elliptical structure changes the pressure conduction path and distribution pattern; when subjected to external water pressure, the elliptical structure can more effectively disperse the pressure to each part, avoiding local pressure concentration. This pressure dispersion mechanism makes the pressure borne by each part of the isolation airbag 3 relatively balanced, significantly improving the tolerance of the isolation airbag 3 in a high-pressure environment, reducing the possibility of damage caused by excessive local pressure, and extending the service life of the isolation airbag 3.

[0041] In a further embodiment, to further improve the sealing effect between the isolation airbag 3 and the detection well 8, the groundwater detection depth-fixed sampling device is also provided with a flattening mechanism 6, and the flattening mechanism 6 is configured to be able to flatten the isolation airbag 3 along the circumferential direction.

[0042] Specifically in this embodiment, in actual work, due to the characteristics of the airbag material, uneven distribution of inflation pressure, and the irregularity of the inner wall of the inspection well 8, the isolation airbag 3 is prone to local over-expansion or under-expansion during the inflation process, resulting in uneven deformation. As a result, gaps are generated between the isolation airbag 3 and the inner wall of the inspection well 8, affecting the sealing effect and increasing the risk of water sample contamination. By providing a flattening mechanism 6, during the inflation and expansion of the isolation airbag 3, the flattening mechanism 6 can apply a circumferential flattening force to the isolation airbag 3 in real time, ensuring that the isolation airbag 3 is uniformly externally constrained and guided during inflation.

[0043] From a mechanical perspective, this uniform circumferential force effectively inhibits the over-expansion of the isolation airbag 3 caused by uneven stress in some parts, promoting the airbag to deform in a more regular and symmetrical manner during the inflation process. For example, when there are local protrusions or depressions on the inner wall of the inspection well 8, without the flattening mechanism 6, the isolation airbag 3 may exhibit inconsistent inflation at the corresponding positions. Under the action of the flattening mechanism 6, the airbag can adaptively conform to the contour of the inner wall of the inspection well 8 under the adjustment of the circumferential force, making the deformation more uniform. This uniform deformation not only helps the isolation airbag 3 to fully exert its sealing function but also reduces the risk of material fatigue and damage caused by local stress concentration, extending the service life of the isolation airbag 3.

[0044] At the same time, the intervention of the flattening mechanism 6 helps to reduce the gap between the isolation airbag 3 and the inner wall of the inspection well 8. Since the airbag can fit more closely and uniformly to the inner wall of the inspection well 8 under the guidance of the flattening mechanism 6, the gaps originally caused by uneven inflation are effectively eliminated or reduced. During the actual sampling process, smaller gaps mean a lower leakage probability, which can further prevent external water from seeping into the sampling area, ensuring that the collected water sample is always a pure water body at the target depth and guaranteeing the accuracy of sampling.

[0045] Further, the flattening mechanism 6 is arranged to include a fixed ring frame 601 and a flattening assembly 602. A fixed ring frame 601 is fixedly sleeved on each base shell 2, and the fixed ring frame 601 is located inside the isolation airbag 3; at least one air vent group and at least one flattening assembly 602 are arranged on each fixed ring frame 601. The air vent group includes a plurality of air vents 6011, and the plurality of air vents 6011 are arranged at intervals in the circumferential direction and are all communicated with the base shell 2; the flattening assembly 602 includes a rotating ring 6021, the rotating ring 6021 is sleeved on the fixed ring frame 601 and can rotate around the axis of the sampling tube 1. A plurality of guide vanes 6022 are arranged on the rotating ring 6021, and a flow channel is formed between adjacent guide vanes 6022, and the flow channel is communicated with the air vent 6011; a plurality of fixed tubes 6023 are arranged on the outer peripheral wall of the rotating ring 6021, and the plurality of fixed tubes 6023 are arranged at intervals in the circumferential direction. The fixed tubes 6023 extend in the radial direction and are communicated with the flow channel. A sliding tube 6024 is sleeved on each fixed tube 6023, and the sliding tube 6024 can elastically slide in the radial direction. An installation frame 6025 is hinged on each sliding tube 6024, and a flattening roller 6026 is arranged on each installation frame 6025. The axis of the flattening roller 6026 is parallel to the axis of the sampling tube 1, and the flattening roller 6026 can rotate around its own axis and is configured to be able to form a rolling fit with the inner side wall of the isolation airbag 3; an air outlet 60241 is arranged on each sliding tube 6024, and the air outlet 60241 is communicated with the fixed tube 6023 and the isolation airbag 3.

[0046] Specifically in this embodiment, the fixed ring frame 601 is of an annular structure, and the upper and lower end faces of the fixed ring frame 601 are both elliptical. The projection view of the fixed ring frame 601 on the vertical plane is a parallelogram, ensuring that it can adapt to the elliptical structure of the isolation airbag 3. A plurality of vent holes 6011 in the same vent hole group are arranged in an elliptical shape, and a plurality of communication holes 202 are arranged in an elliptical shape. The vent holes 6011 and the communication holes 202 are correspondingly communicated to ensure the stability during gas transmission. The rotating ring 6021 is of an elliptical structure, and its end face is parallel to the end face of the fixed ring frame 601. The cross-sectional shape of the rotating ring 6021 is C-shaped, and the opening faces inward. To facilitate the installation of the rotating ring 6021, two first mounting rings 6012 are sleeved on the outer peripheral wall of the fixed ring frame 601. The first mounting rings 6012 are of an elliptical structure, and their end faces are parallel to the end face of the fixed ring frame 601. The two first mounting rings 6012 are arranged at intervals along the axial direction. Second mounting rings 60211 are provided on the two inner peripheral walls of the rotating ring 6021 that are arranged at intervals. The second mounting rings 60211 are of an elliptical structure, and their end faces are parallel to the end face of the rotating ring 6021. The second mounting rings 60211 and the rotating ring 6021 form a stepped structure. When the rotating ring 6021 is installed, the two second mounting rings 60211 are clamped by the two first mounting rings 6012 and form a rotational fit, ensuring that the rotating ring 6021 can rotate around the axis of the sampling cylinder 1.

[0047] The guide vanes 6022 are inclined and arranged between the two second mounting rings 60211. A plurality of guide vanes 6022 are arranged at intervals in the circumferential direction, ensuring that when air passes through the guide vanes 6022, the guide vanes 6022 can drive the rotating ring 6021 to rotate under the drive of the air. The mounting frame 6025 is of a C-shaped structure, and is vertically arranged and the opening faces outward during installation. To facilitate the formation of a rotational fit with the flattening roller 6026, first hinge holes are provided on the two cantilevers of the mounting frame 6025, and first hinge posts are coaxially arranged on the two end faces of the flattening roller 6026. The first hinge posts are rotationally inserted into the first hinge holes during installation. To facilitate the formation of a hinge fit with the mounting frame 6025, a hinge frame 60242 is fixedly provided at the end of the sliding tube 6024 away from the fixed tube 6023. The hinge frame 60242 is of a C-shaped structure, and is horizontally arranged and the opening faces outward during installation. Second hinge holes are provided on the two cantilevers of the hinge frame 60242, and two second hinge posts are vertically arranged on the left and right side walls of the mounting frame 6025. The second hinge posts are rotationally inserted into the second hinge holes during installation.

[0048] In order to facilitate the elastic sliding of the sliding tube 6024 in the radial direction, an elastic member is connected between the sliding tube 6024 and the fixed tube 6023. Under the action of the elastic member, the sliding tube 6024 has a tendency to move outward. The elastic member is a compression spring 6027, which is inserted into the fixed tube 6023 and the sliding tube 6024, and the inner end of the compression spring 6027 is fixed on the fixed tube 6023, and the outer end is fixed on the hinge frame 60242. Under the action of the compression spring 6027, the sliding tube 6024 has a tendency to move outward, ensuring that the flattening roller 6026 can be pressed against the inner wall of the isolation airbag 3.

[0049] During the process of filling the isolation airbag 3 with air, when the air flows through the guide vane 6022, the guide vane 6022 drives the rotating ring 6021 to rotate under the drive of the air, and the rotating ring 6021 synchronously drives the flattening roller 6026 to rotate through the fixed tube 6023, the sliding tube 6024 and the mounting frame 6025. When the flattening roller 6026 rotates, it can always be set vertically due to the articulated cooperation of the mounting frame 6025 and the articulated frame 60242, so that it can fit tightly with the inner wall of the isolation airbag 3, and then can flatten the isolation airbag 3 along the circumferential direction.

[0050] In a further embodiment, when there are two or more flattening assemblies 602 on the fixed ring frame 601, at least one elastic ring 7 is sleeved on each isolation airbag 3. The elastic ring 7 is located between two adjacent flattening assemblies 602 on the same fixed ring frame 601, and is configured to be able to squeeze the isolation airbag 3 inward to form an annular groove 301 under the action of elasticity.

[0051] Specifically in this embodiment, taking the example of two flattening components 602 on the fixed ring frame 601, at this time, the number of elastic rings 7 is set to one, and it is sleeved on the middle part of the isolation airbag 3. Under the elastic action of the elastic ring 7, the isolation airbag 3 is tightened inward to form an annular groove 301.

[0052] During use, when air flows through the guide vane 6022, the guide vane 6022 drives the rotating ring 6021 to rotate under the drive of the air, and the rotating ring 6021 simultaneously drives the flattening roller 6026 to rotate; during the rotation of the flattening roller 6026, when there are larger granular impurities between the isolation airbag 3 and the detection well 8, the flattening roller 6026 pushes the granular impurities to move in the circumferential direction, and since the flattening roller 6026 moves along an elliptical trajectory, the flattening roller 6026 and the granular impurities are gradually misaligned in the vertical direction; when the flattening roller 6026 and the granular impurities are completely misaligned, the granular impurities fall into the groove 301 under the action of gravity, thereby reducing the direct friction between the isolation airbag 3 and the granular impurities during the continuous expansion process, and then reducing the wear of the isolation airbag 3, which helps to extend the service life of the isolation airbag 3.

[0053] Meanwhile, during the inflation process of the isolation airbag 3, the groove 301 formed by the elastic ring 7 and the inner wall of the inspection well 8 jointly enclose a relatively closed positive pressure space. The formation of this positive pressure space is based on the principle of fluid mechanics, that is, as the isolation airbag 3 continuously inflates, the volume of the groove 301 area decreases and the pressure increases. Since the pressure in this area is higher than the pressure of the surrounding water body, a pressure difference is formed, and this pressure difference effectively hinders the intercommunication between the water body at the target depth and the upper and lower water bodies. For example, when the upper water body attempts to flow downward, the pressure in the positive pressure space will form a reverse resistance to it and prevent it from flowing into the target water sample area; when the lower water body flows upward, it will also be blocked by the positive pressure space, which can further ensure the purity of the target water sample, effectively reduce the impact of the upper and lower water bodies on the sampling accuracy, and ensure that the collected water sample can truly and accurately reflect the water quality of the groundwater at the target depth.

[0054] In a further embodiment, to ensure that the elastic ring 7 can always be sleeved on the isolation airbag 3 and avoid loss, a plurality of fixing blocks 701 are provided on the elastic ring 7. The plurality of fixing blocks 701 are arranged at intervals in the circumferential direction and are all fixed on the isolation airbag 3.

[0055] In other embodiments, to improve the sampling efficiency, the number of sampling ports 101 is set to be multiple and arranged at intervals in the circumferential direction.

[0056] Specifically in this embodiment, to facilitate the formation of multiple sampling ports 101, the number of sampling tubes 103 is correspondingly set to be multiple and arranged at intervals in the circumferential direction, and a first one-way valve is inserted at each sampling port 101. In this way, during sampling, multiple sampling ports 101 can all introduce the water body at the target depth into the sampling cylinder 1, thereby improving the sampling efficiency.

[0057] In other embodiments, to improve the sampling efficiency, the number of auxiliary airbags 4 is set to be multiple and divided into two groups. One group of auxiliary airbags 4 is arranged on the circumferential side wall of the upper base shell 2 and arranged at intervals in the circumferential direction, and the other group of auxiliary airbags 4 is arranged on the circumferential side wall of the lower base shell 2 and arranged at intervals in the circumferential direction. In this way, during sampling, air can enter into the multiple auxiliary airbags 4, thereby increasing the rising rate of the water pressure at the sampling port 101, and further enabling a greater pressure difference to be generated on both sides of the first one-way valve. Under the action of a greater pressure difference, the rate at which the water body enters the sampling cylinder 1 from the sampling port 101 will increase, thereby improving the sampling efficiency.

[0058] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0059] The embodiments described above merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention.

Claims

1. A fixed-depth sampling device for groundwater detection, characterized in that, The depth-fixed sampling device for groundwater detection is configured to be able to sample the groundwater in the detection well; the depth-fixed sampling device for groundwater detection includes a sampling cylinder and an inflating member. The sampling cylinder is vertically placed in the detection well during sampling. A sampling port is provided on the sampling cylinder, and the sampling port communicates with the detection well. A first one-way valve is provided at the sampling port, and the opening direction of the first one-way valve is configured to be from outside to inside. Two base shells are detachably sleeved on the sampling cylinder. The two base shells are respectively located on the upper and lower sides of the sampling port and communicate with each other. An isolation airbag is sleeved on each base shell. The isolation airbag communicates with the base shell and is configured to be able to expand when inflated and separate the water body at the sampling port from the water body above or below the sampling port along the axis direction of the sampling cylinder. An auxiliary airbag is communicated with the base shell and is located between the two isolation airbags. The auxiliary airbag is configured to be able to expand when inflated to squeeze the water body at the sampling port into the sampling cylinder through the sampling port. A second one-way valve is provided at the connection between the auxiliary airbag and the base shell. The second one-way valve is configured to be able to switch from the closed state to the open state when the air pressure value inside the base shell reaches a preset value. The inflating member communicates with the upper base shell and is configured to be able to fill the inside of the upper base shell with gas.

2. The groundwater detection depth-fixed sampling device according to claim 1, characterized in that, The isolation airbag is inclined and forms an elliptical structure.

3. The depth-fixed sampling device for groundwater detection according to claim 2, wherein The depth-fixed sampling device for groundwater detection further includes a flattening mechanism, and the flattening mechanism is configured to be able to flatten the isolation airbag along the circumferential direction.

4. The depth-fixed sampling device for groundwater detection according to claim 3, wherein The flattening mechanism includes a fixed ring frame and a flattening component. The fixed ring frame is fixedly sleeved on each base shell, and the fixed ring frame is located inside the isolation airbag. At least one air vent group and at least one flattening component are provided on each fixed ring frame. The air vent group includes a plurality of air vents, and the plurality of air vents are arranged at intervals along the circumferential direction and all communicate with the base shell. The flattening component includes a rotating ring, and the rotating ring is sleeved on the fixed ring frame and can rotate around the axis of the sampling cylinder. A plurality of guide vanes are provided on the rotating ring, and a flow channel is formed between adjacent guide vanes. The flow channel communicates with the air vent. A plurality of fixed tubes are provided on the outer peripheral wall of the rotating ring, and the plurality of fixed tubes are arranged at intervals along the circumferential direction. The fixed tubes extend in the radial direction and communicate with the flow channel. A sliding tube is sleeved on each fixed tube, and the sliding tube can elastically slide in the radial direction. An installation frame is hinged on each sliding tube, and a flattening roller is provided on each installation frame. The axis of the flattening roller is parallel to the axis of the sampling cylinder. The flattening roller can rotate around its own axis and is configured to be able to form a rolling fit with the inner side wall of the isolation airbag. An air outlet is provided on each sliding tube, and the air outlet communicates with the fixed tube and the isolation airbag.

5. The depth-fixed sampling device for groundwater detection according to claim 4, wherein, When the number of the flattening components on the fixed ring frame is two or more, at least one elastic ring is sleeved on each of the isolation air bags. The elastic ring is located between two adjacent flattening components on the same fixed ring frame and is configured to be able to inwardly draw out an annular groove on the isolation air bag under the action of elasticity.

6. The fixed-depth sampling device for groundwater detection according to claim 5, characterized in that, A plurality of fixing blocks are arranged on the elastic ring. The plurality of fixing blocks are arranged at intervals in the circumferential direction and are all fixed on the isolation air bag.

7. The fixed-depth sampling device for groundwater detection according to claim 4, wherein, An elastic member is connected between the sliding tube and the fixed tube. Under the action of the elastic member, the sliding tube has a tendency to move outward.

8. The depth-fixed sampling device for groundwater detection according to claim 7, wherein, The elastic member is a compression spring.

9. The fixed-depth sampling device for groundwater detection according to claim 1, wherein The number of the sampling ports is multiple and they are arranged at intervals in the circumferential direction.

10. The groundwater detection depth-fixed sampling device according to claim 1, characterized in that, The inflation member is an air pump.

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