An in-situ thermal desorption cobble layer sampling device

Abstract

The application relates to the field of geological sampling, in particular to an in-situ thermal desorption pebble layer sampling device. The device comprises a drill rod, a driving mechanism and a sliding mechanism, the middle part of the drill rod is provided with an airflow channel, and the front end is connected with a sampling drill bit; the sampling drill bit comprises a sampling cylinder sleeve and a piston drill bit; the cylinder sleeve is provided with an air guide pipe, an air bag and a carry-over air distribution mechanism; the driving mechanism provides a drill rod rotating power and compressed air; and the sliding mechanism moves the driving mechanism. The sliding mechanism comprises sliding rails and a sliding seat; the driving mechanism comprises a pneumatic motor and the like; and the carry-over air distribution mechanism comprises a piston and the like. In addition, the sampling cylinder sleeve, a tunneling head, the air guide pipe and the like are provided with detailed structural settings. The application can efficiently and accurately sample in-situ thermal desorption pebble layers, avoids external interference on samples, and guarantees the sampling quality and reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of geological sampling, in particular to a device for sampling pebble layer in situ by thermal desorption. BACKGROUND

[0002] In the field of environmental science and geological engineering, in-situ thermal desorption technology is an important method for treating contaminated soil, especially deep pebble stratum. In order to evaluate the treatment effect of in-situ thermal desorption, it is necessary to sample and analyze the treated soil. In the traditional sampling operation, when sampling volatile organic compounds in high temperature environment, simple protective measures such as ordinary heat insulation containers are usually used to minimize the volatilization of volatile organic compounds in the sample, but this method is difficult to effectively resist the influence of high temperature. In the sampling work of pebble stratum, dry operation is a common means, which mainly uses ordinary drill bit to drill into the soil layer to obtain samples. However, the pebble stratum is complex, which contains large pieces of boulders, round gravel, gravel sand, medium sand and other loose materials, so that this conventional drilling method faces many difficulties. Sometimes, the method of pre-cleaning part of loose materials is also used, but the effect is still not ideal.

[0003] The existing technical means has obvious defects. On the one hand, ordinary protective measures cannot well prevent the volatilization of volatile organic compounds in the sample at high temperature, resulting in that the sample taken to the ground cannot meet the sampling requirements of volatile organic compounds, which seriously affects the accurate detection and analysis of volatile organic compounds. On the other hand, the dry operation has low sampling rate of loose materials in pebble stratum, and multiple underground sampling is needed to achieve the required sample capacity, which not only consumes a lot of time and labor cost, but also reduces the efficiency of sampling work, and even may cause additional disturbance to the stratum due to multiple sampling, affecting the final evaluation results. SUMMARY

[0004] In order to overcome the above-mentioned deficiencies of the prior art, the present application provides a device for sampling pebble layer in situ by thermal desorption, which can sample into pebble stratum, effectively improve the sampling rate of loose materials in pebble stratum, and avoid the volatilization of volatile organic compounds in the sample at high temperature, so that the sample taken to the ground meets the sampling requirements of volatile organic compounds.

[0005] The present application is realized by the following technical solutions:

[0006] An in-situ thermal desorption pebble layer sampling device includes a drill rod, a drive mechanism, and a sliding mechanism. The drill rod has an airflow channel arranged along its length in the middle, and a sampling drill bit is connected to its front end. The sampling drill bit includes a sampling cylinder sleeve and a piston drill bit slidably connected within the sampling cylinder sleeve. The bottom of the piston drill bit has a tunneling head for breaking up rock and soil, and a sealed cavity is formed between its upper end and the cylinder sleeve. The middle of the sampling cylinder sleeve has an air guide pipe arranged axially along the cylinder sleeve. The upper section of the air guide pipe has a venting groove communicating with the sealed cavity, and the lower section is fitted with an air bladder. An advance air distribution mechanism is located within the air guide pipe. The advance air distribution mechanism can be triggered when the piston drill bit moves to a set position to drive the air bladder to inflate and seal the port of the sampling cylinder sleeve. The drive mechanism provides rotational power to the drill rod and compressed air to the airflow channel. The sliding mechanism drives the drive mechanism to move in a set direction.

[0007] By adopting the above technical solution, compressed air is provided through the airflow channel of the drill rod, which, in conjunction with the drive mechanism, rotates the drill rod. During drilling, the compressed air pushes the piston drill bit against the lower end of the sampling cylinder sleeve for efficient rock and soil breaking, enabling drilling into the gravel layer. When the sampling position is reached, the supply of compressed air to the sealing cavity can be stopped. As the sampling cylinder sleeve continues to drill downwards, the sampled rock and soil pushes the piston drill bit upwards and enters the sampling cylinder sleeve. The advance air distribution mechanism is triggered when the piston drill bit moves to the set position, causing the air bladder to expand and seal the sampling cylinder sleeve port, encapsulating the sampled rock and soil within the sampling cylinder sleeve and preventing the volatilization of volatile organic compounds at high temperatures. The device as a whole can effectively improve sampling efficiency, avoiding the low recovery rate problem caused by the loose nature of gravel strata, and meeting the sampling requirements for volatile organic compounds and sample volume. Furthermore, the device can reduce additional disturbance to the strata during the sampling process, ensuring the accuracy of the final evaluation results.

[0008] Optionally, the sliding mechanism includes a slide rail and a slide block slidably connected to the slide rail, the slide rail being fixed to the frame; the frame is provided with a pushing mechanism for driving the slide block to move.

[0009] By adopting the above technical solution, the cooperation between the slide rail and the slide seat enables the drive mechanism to move along the set direction. The pushing mechanism can drive the slide seat to move and can accurately adjust the position of the drive mechanism, so that the sampling device can accurately reach the target sampling position, improve sampling efficiency and accuracy, and avoid repeated underground sampling. This solves the problem of low recovery rate in dry operations in gravel formations. In addition, the stable moving structure helps the device to complete sampling smoothly in high-temperature environments, prevents the volatilization of volatile organic compounds, and meets the sampling requirements for volatile organic compounds.

[0010] Optionally, the driving mechanism comprises a pneumatic motor arranged on the sliding seat, an output shaft of the pneumatic motor is in a hollow tubular structure, and a lower end of the output shaft is provided with a threaded part connected with the drill rod; an upper end of the pneumatic motor is provided with a supporting seat, and the supporting seat is provided with a sealing cover; the sealing cover is provided with an air inlet hole, the supporting seat is provided with an air outlet hole, a butt joint pipe matched with an upper end port of the output shaft of the pneumatic motor is slidably connected in the air outlet hole, the butt joint pipe is provided with a sealing ring at an air outlet thereof, and a first elastic member for butt joining the air outlet of the butt joint pipe with the upper end port of the output shaft of the pneumatic motor is arranged between the butt joint pipe and the supporting seat.

[0011] By adopting the above technical scheme, the pneumatic motor can provide rotary power for the drill rod, the hollow tubular structure of the output shaft can cooperate with compressed air to be delivered through the airflow channel, and the threaded part facilitates the connection of the drill rod with the output shaft; the sealing cover cooperates with the air inlet hole and the air outlet hole to realize the airflow circulation, the butt joint pipe is butt joined with the output shaft port, the sealing ring ensures the sealing, and the first elastic member enables the butt joint pipe to be stably butt joined with the output shaft port, thereby ensuring that the drill rod stably obtains power and compressed air supply, facilitating the smooth sampling operation in the in-situ thermal desorption pebble layer, reducing the volatilization of volatile organic compounds, and improving the sampling rate.

[0012] Optionally, the carry-over gas distribution mechanism comprises a piston slidably connected in the air guide pipe, the piston can be moved under the action of a pushing force provided by a second elastic member arranged in the air guide pipe, thereby driving the air in the air guide pipe to enter the air bag; a limiting groove is arranged in a side wall of the piston; a clamping piece is hingedly arranged in the air passage, a limiting part for clamping the limiting groove is arranged at a lower end of the clamping piece, and a pushing part is arranged at an upper end of the clamping piece; the pushing part is used for abutting against the piston drill bit during upward movement of the piston drill bit, thereby driving the clamping piece to be deflected, so that the limiting part is separated from the limiting groove; a third elastic member for driving the limiting part to clamp the limiting groove is arranged in the limiting groove.

[0013] By adopting the above technical scheme, the piston slidably connected in the air guide pipe and the second elastic member can make the piston move to drive the air in the air guide pipe to enter the air bag; through the limiting groove in the side wall of the piston, the clamping piece hingedly arranged in the air passage, the limiting part at the lower end of the clamping piece and the pushing part at the upper end of the clamping piece, and the third elastic member in the limiting groove, the carry-over gas distribution mechanism can be triggered when the piston drill bit moves upward to a set position, the clamping piece is deflected to make the limiting part separate from the limiting groove, thereby realizing the inflation of the air bag to seal the port of the sampling cylinder sleeve, avoiding the volatilization of volatile organic compounds in the sample, and improving the sampling efficiency and quality of the sampling device in the in-situ thermal desorption pebble layer.

[0014] Optionally, the sampling cylinder sleeve comprises a connecting head and a sampling sleeve which are detachably connected together; the connecting head is provided with an air channel communicated with the air guide pipe; the air guide pipe is detachably connected in a cavity of the sampling sleeve; and a reset pull rod extending out of the sampling cylinder sleeve is arranged at an upper end of the piston.

[0015] By adopting the technical scheme, the sampling cylinder sleeve is designed by adopting the detachable connecting head and the sampling sleeve, so that the installation, disassembly and maintenance of each component of the device are facilitated; the reset pull rod of the sampling cylinder sleeve is arranged at the upper end of the piston, so that the piston can be reset by manual operation, the in-situ thermal desorption pebble layer sampling device can be ensured to complete the sampling work more efficiently and stably, the problems of low sampling rate caused by the volatilization of volatile organic compounds in the sample due to high temperature and the loose substances in the pebble layer are avoided, and the sampling quality and efficiency are improved.

[0016] Optionally, the tunneling head is in a conical structure, and the tunneling head is provided with tunneling pieces arranged in a spiral manner; and the lower edge of the sampling cylinder sleeve is provided with tunneling teeth.

[0017] By adopting the technical scheme, the tunneling head in a conical structure and the tunneling pieces arranged in a spiral manner can effectively crush the rock and soil, so that the device can drill into the pebble layer; the tunneling teeth at the lower edge of the sampling cylinder sleeve can further improve the crushing efficiency, help the device to more smoothly perform the sampling work, reduce the sampling difficulty caused by the loose substances in the pebble layer, and improve the sample sampling rate.

[0018] Optionally, the lower end of the inner wall of the sampling cylinder sleeve or the lower end of the air guide pipe is provided with a limiting block matched with the piston drill bit, and the piston drill bit is provided with a clamping groove matched with the limiting block.

[0019] By adopting the technical scheme, the limiting block and the clamping groove are matched to limit the movement range of the piston drill bit, avoid excessive movement of the piston drill bit, ensure stable operation of the sampling device, effectively solve the problem of low sampling rate in the pebble layer and the need for repeated sampling, prevent the volatilization of volatile organic compounds due to excessive operation, meet the sampling requirements of volatile organic compounds, and the limiting block can also transmit torque to the piston drill bit, so that the piston drill bit rotates during drilling, and the drilling efficiency is improved.

[0020] Optionally, the middle part of the piston drill bit is provided with a through hole matched with the air guide pipe, and when the piston drill bit is in abutment with the limiting block, the through hole can cover the air bag; and the air guide pipe is provided with a soil breaking cone extending out of the through hole.

[0021] By adopting the technical scheme, when the piston drill bit is in abutment with the limiting block, the through hole of the piston drill bit can cover the air bag, so as to protect the air bag from external interference and damage; the soil breaking cone of the air guide pipe extends out of the through hole, so as to crush the rock and soil during the sampling process, reduce the drilling resistance, improve the sampling efficiency and success rate of the in-situ thermal desorption pebble layer, reduce the influence of the volatilization of volatile organic compounds in the sample due to high temperature, and avoid the problem of low dry method operation sampling rate caused by the loose substances in the pebble layer.

[0022] Optionally, the air guide tube comprises, from top to bottom, a large end section, a variable diameter section and a small end section; the air bag is sleeved on the small end section, and the small end section is provided with a gas permeable hole in communication with the inner cavity of the air bag; the upper support strip is circumferentially hinged at the variable diameter section, and the upper support strip can cover the air bag.

[0023] By adopting the above technical scheme, the air guide tube composed of the large end section, the variable diameter section and the small end section is provided, the air bag is sleeved on the small end section and is in communication with the inner cavity through the gas permeable hole, the upper support strip can cover the air bag in the unexpanded state and keep the large end section in the "same diameter" state, facilitating the design of the through hole of the piston drill bit, the upper support strip can limit the air bag in the expanded state or the unexpanded state, avoiding the air bag from shaking or being damaged at will, thereby improving the stability and reliability of the device, ensuring the sampling effect of the sampling device on the volatile organic compounds in the in-situ thermal desorption pebble layer, and helping to improve the sample taking rate in the pebble layer and reduce the number of repeated sampling.

[0024] Optionally, the upper support strip is made of a magnetic conductive material, and the small end section is provided with a permanent magnet at one end away from the hinged part of the upper support strip; the permanent magnet can generate a magnetic attraction force on the upper support strip to drive the upper support strip to cover the air bag.

[0025] By adopting the above technical scheme, the upper support strip is made of a magnetic conductive material and cooperates with the permanent magnet to generate a magnetic attraction force, so that the upper support strip covers the air bag, which can avoid the air bag from being accidentally expanded or damaged when not in use, ensure that the air bag can normally seal the port of the sampling cylinder when needed, effectively reduce the volatilization of volatile organic compounds caused by high temperature, and improve the sample taking rate in the pebble layer.

[0026] In summary, the present application has at least one of the following beneficial technical effects:

[0027] The present application can sample in the pebble layer, effectively improve the sample taking rate of loose substances in the pebble layer, and avoid the volatilization of volatile organic compounds in the sample at high temperature, so that the sample taken to the ground surface meets the sampling requirements of volatile organic compounds;

[0028] The sampling drill bit at the front end of the drill rod cooperates with the driving mechanism and the sliding mechanism to sample in the pebble layer, effectively improves the sample taking rate of loose substances in the pebble layer, and does not need to repeatedly sample underground, thereby saving time and labor cost and improving the sampling work efficiency;

[0029] The present application can reduce the additional disturbance to the stratum during sampling, and ensure the accuracy of the final evaluation result. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1is a structural schematic diagram of the in-situ thermal desorption pebble layer sampling device described in embodiment one;

[0031] Figure 2 is a structural schematic diagram of the sampling drill bit in a drilling state described in embodiment one;

[0032] Figure 3 is a structural schematic diagram of the piston drill bit described in embodiment one;

[0033] Figure 4 is a structural schematic diagram of the carryover gas distribution mechanism described in embodiment one;

[0034] Figure 5 is a structural schematic diagram of the clamping piece and the piston in a clamped state described in embodiment one;

[0035] Figure 6 is a structural schematic diagram of the sampling drill bit in a sampling state described in embodiment one;

[0036] Figure 7 is a structural schematic diagram of the piston drill bit and the clamping piece in an abutting state described in embodiment one;

[0037] Figure 8 is a structural schematic diagram of the driving mechanism described in embodiment one;

[0038] Figure 9 is a partial structural schematic diagram of the driving mechanism described in embodiment one;

[0039] Figure 10 is a structural schematic diagram of the piston drill bit described in embodiment two;

[0040] Figure 11 is a structural schematic diagram of the arrangement of the upper support strips described in embodiment two;

[0041] Figure 12 is a structural schematic diagram of the upper support strips in an unfolded state described in embodiment two.

[0042] In the figure: 1, rack; 11, slide rail; 12, hinged seat; 2, drill rod; 3, slide seat; 31, pushing mechanism; 4, sampling drill bit; 41, sampling cylinder sleeve; 411, connecting head; 4111, air channel; 412, sampling sleeve; 413, digging tooth; 42, piston drill bit; 421, digging head; 422, through hole; 423, clamping groove; 424, digging piece; 43, sealing cavity; 44, air guide pipe; 441, air passage groove; 442, large end section; 443, reducing section; 444, small end section; 4441, air permeable hole; 45, carry gas distribution mechanism; 451, piston; 4511, limiting groove; 452, second elastic; 453, clamping piece; 4531, limiting part; 4532, actuating part; 454, third elastic piece; 455, reset pull rod; 4551, limiting ring; 46, soil breaking cone; 47, upper support bar; 48, permanent magnet; 49, lower support bar; 5, driving mechanism; 51, pneumatic motor; 511, output shaft; 512, threaded part; 52, support seat; 53, sealing cover; 531, air inlet hole; 532, air outlet hole; 54, butt joint pipe; 55, first elastic piece; 6, air bag; 7, limiting block; 8, rock and soil; 9, operating arm. DETAILED DESCRIPTION

[0043] The technical solutions of the embodiments of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application. Embodiment one

[0044] Reference Figures 1 to 3The embodiment of the application discloses an in-situ thermal desorption cobble layer sampling device, which comprises a drill rod 2, a driving mechanism 5 and a sliding mechanism; the middle part of the drill rod 2 is provided with an airflow channel arranged along the length direction, and the front end is connected with a sampling drill bit 4; the sampling drill bit 4 comprises a sampling cylinder sleeve 41 and a piston drill bit 42 slidingly connected in the sampling cylinder sleeve 41; the bottom of the piston drill bit 42 is provided with a tunneling head 421 for crushing rock-soil 8, and a sealing cavity 43 is formed between the upper end and the cylinder sleeve; the middle part of the sampling cylinder sleeve 41 is provided with a gas guide pipe 44 arranged along the axial direction of the sampling cylinder sleeve 41; the upper section of the gas guide pipe 44 is provided with a gas passage groove 441 in communication with the sealing cavity 43, the lower section is provided with a gas bag 6, and the gas guide pipe 44 is provided with a gas feeding mechanism 45; the gas feeding mechanism 45 can be triggered when the piston drill bit 42 moves to the set position, so as to drive the gas bag 6 to expand and seal the port of the sampling cylinder sleeve 41; the driving mechanism 5 is used for providing rotary power for the drill rod 2 and providing compressed air for the airflow channel; the sliding mechanism is used for driving the driving mechanism 5 to move in the set direction; the inner wall of the sampling cylinder sleeve 41 is provided with a limiting block 7 close to the lower end sampling port for limiting the movement range of the piston drill bit 42, and the piston drill bit 42 is provided with a clamping groove 423 matched with the limiting block 7, so that the piston drill bit 42 can be prevented from moving excessively, and the stability of the sampling process is ensured.

[0045] Specifically, referring to Figure 1 , the sliding mechanism comprises a sliding rail 11 and a sliding seat 3 slidingly connected on the sliding rail 11, and the sliding rail 11 is fixed on the rack 1; the rack 1 is generally welded by using channel steel or I-beam, and has sufficient strength and stability; the sliding rail 11 is generally a linear guide rail, and the surface is subjected to quenching treatment to improve wear resistance; the sliding seat 3 can freely slide on the sliding rail 11 and is matched with the sliding rail 11 through a sliding block; the rack 1 is provided with a pushing mechanism 31 for driving the sliding seat 3 to move, and the pushing mechanism 31 can be a hydraulic oil cylinder or an electric screw rod; the movement of the sliding seat 3 on the sliding rail 11 is controlled through the pushing mechanism 31, so as to drive the driving mechanism 5 and the drill rod 2 to move; the rack 1 can be provided with a hinged seat 12, the rack 1 can be installed on an existing excavator operating arm 9, and the movement ability of the excavator is utilized to move the device to the set position.

[0046] Referring to Figure 1 , the rod body of the drill rod 2 is generally made of high-strength alloy steel and has good toughness and wear resistance; carbon fiber composite materials can also be used to reduce weight and improve strength; the rod body is in a cylindrical shape, and the airflow channel in the inside penetrates through the middle part of the rod body and is used for conveying compressed air and transmitting torque; in order to reduce the resistance of air flow, the inner wall of the airflow channel is smooth; as a standard part, the rod body front end can be connected with the sampling drill bit 4 through a threaded connection mode; when it is necessary to sample deep rock-soil 8, the rod bodies can be spliced.

[0047] Referring to Figures 2 to 3The sampling drill bit 4 comprises a sampling cylinder sleeve 41 and a piston drill bit 42 slidingly connected in the sampling cylinder sleeve 41; wherein the sampling cylinder sleeve 41 is generally made of wear-resistant stainless steel and has a cylindrical shape to provide a sliding space for the piston drill bit 42; the piston drill bit 42 can also be made of high-strength metal material and is provided with a boring head 421 at the bottom for crushing the rock-soil 8 and a sealing cavity 43 formed between the upper end and the cylinder sleeve.

[0048] With reference to Figure 3 The boring head 421 has a conical structure and is provided with boring pieces 424 arranged in a spiral manner, which can make the boring head 421 more effectively crush the rock-soil 8 when rotating, and a serrated boring head 421 can also be used. The lower edge of the sampling cylinder sleeve 41 is provided with boring teeth 413 to further enhance the crushing capacity.

[0049] With reference to Figure 3 The piston drill bit 42 is provided with a through hole 422 matched with the air guide pipe 44 in the middle, and the through hole 422 can cover the air bag 6 when the piston drill bit 42 is in abutting state with the limiting block 7; the outer wall of the piston drill bit 42 closely fits the inner wall of the sampling cylinder sleeve 41 to ensure smooth sliding and good sealing; when the piston drill bit 42 slides upward in the sampling cylinder sleeve 41, the volume of the sealing cavity 43 will change.

[0050] With reference to Figure 3 The air guide pipe 44 comprises a large end section 442, a variable diameter section 443 and a small end section 444 from top to bottom, and is generally made of aluminum alloy, which is light and corrosion-resistant, and can also be made of copper alloy; the air bag 6 is sleeved on the small end section 444, and the pipe wall of the small end section 444 is provided with a gas permeable hole 4441 communicating with the inner cavity of the air bag 6 for inflating the air bag 6.

[0051] With reference to Figures 4 to 5 The carry-over gas distribution mechanism 45 comprises a piston 451 slidingly connected in the air guide pipe 44, which can be moved by the pushing force provided by the second elastic member 452 arranged in the air guide pipe 44, so as to drive the air in the air guide pipe 44 to enter the air bag 6; the side wall of the piston 451 is provided with a limiting groove 4511, the air guide pipe 441 is hingedly connected with a clamping member 453, the lower end of the clamping member 453 is provided with a limiting portion 4531 for clamping the limiting groove 4511, and the upper end is provided with a poking portion 4532; the second elastic member 452 can be a spring, and the elastic coefficient thereof is selected according to actual needs; in order to facilitate the resetting of the piston 451, the upper end of the piston 451 is provided with a reset pull rod 455 extending out of the sampling cylinder sleeve 41, and the reset pull rod 455 is provided with a limiting ring 4551.

[0052] With reference to Figures 6 to 7When the sampling drill bit 4 reaches the specified position, the compressed air supplied to the air flow channel can be stopped, and then the piston drill bit 42 will move upward under the extrusion of the rock-soil 8 during the continuous sampling process, when the piston drill bit 42 moves to the set position, the driving part 4532 abuts against the piston drill bit 42, drives the clamping part 453 to deflect, so that the limiting part 4531 is disengaged from the limiting groove 4511, at this time the piston 451 moves under the action of the second elastic part 452, and the air is pressed into the air bag 6 to make the air bag 6 expand, thereby realizing the sealing of the port of the sampling cylinder 41 larger than the sampling cylinder 41, to prevent the rock-soil 8 from falling during the extraction of the sampling drill bit 4, and more importantly, to prevent the volatile organic compounds in the sample from volatilizing at high temperature.

[0053] With reference to Figures 8 to 9 The driving mechanism 5 includes a pneumatic motor 51 arranged on the sliding seat 3, the output shaft 511 of the pneumatic motor 51 is in a hollow tubular structure, and the lower end of the output shaft 511 is provided with a threaded part 512 connected with the drill rod 2, the drill rod 2 is connected with the output shaft 511 of the pneumatic motor 51 through threaded connection to realize power transmission; the upper end of the pneumatic motor 51 is provided with a support seat 52, the support seat 52 is provided with a sealing cover 53, the sealing cover 53 is provided with an air inlet hole 531 and an air outlet hole 532, the air outlet hole 532 is slidably connected with a butt joint pipe 54 matched with the upper port of the output shaft 511 of the pneumatic motor 51, the air outlet of the butt joint pipe 54 is provided with a sealing ring, and the butt joint pipe 54 and the support seat 52 are provided with a first elastic part 55 for driving the air outlet of the butt joint pipe 54 to butt joint with the upper port of the output shaft 511 of the pneumatic motor 51. The first elastic part 55 can be a rubber spring, which ensures the sealed connection between the butt joint pipe 54 and the output shaft 511.

[0054] The implementation principle of the embodiment is that the in-situ thermal desorption pebble layer sampling device effectively solves the problems of sampling of volatile organic compounds at high temperature and low sampling rate of pebble stratum through the cooperative work of the drill rod 2, the driving mechanism 5 and the sliding mechanism; the power source of the pneumatic motor 51 is compressed air, which can provide high torque and is suitable for drilling of rock-soil 8 with high hardness, and the compressed air can be further utilized to realize the control of different states of the piston drill bit 42 under the inherent air source; the rotation of the drill rod 2 and the design of the digging head 421 can efficiently crush the rock-soil 8, and the compressed air enters through the air flow channel to help sampling; the carry gas mechanism 45 is triggered when the piston drill bit 42 moves to the set position, so that the air bag 6 expands to seal the port of the sampling cylinder 41, thereby preventing the volatile organic compounds in the sample from volatilizing; the sliding mechanism accurately controls the drilling process, improves the accuracy and efficiency of sampling, has significant advantages compared with the traditional sampling method, and provides reliable samples for the evaluation of the in-situ thermal desorption treatment effect. Embodiment two

[0055] With reference to Figures 10 to 12The difference between the embodiment and the embodiment one is that the limiting blocks 7 are arranged on the breaking soil cone 46 instead of the inner wall of the sampling cylinder sleeve 41.

[0056] The variable diameter section 443 is a right angle bending structure, and the upper support strip 47 is hingedly connected to the variable diameter section 443 in the circumferential direction, and the upper support strip 47 is made of a magnetically conductive material, such as silicon steel; the small end section 444 is provided with a permanent magnet 48 at an end away from the hinged part of the upper support strip 47; the permanent magnet 48 can generate a magnetic attraction force on the upper support strip 47, driving the upper support strip 47 to cover the air bag 6, preventing the air bag 6 from shaking randomly when not inflated; when the air bag 6 is inflated, it will overcome the magnetic attraction force to open the upper support strip 47, and the right angle bending structure of the variable diameter section 443 can limit the upper support strip 47; it should be noted that a plurality of lower support strips 49 are hingedly connected to the lower end of the air bag 6.

[0057] The implementation principle of the embodiment is that the upper support strip 47 and the lower support strip 49 can limit the air bag 6 whether in the unfolded state or not, avoiding the air bag 6 from shaking randomly or being damaged, and the upper support strip 47 can also assist the air bag 6 to support the sampled rock-soil 8, reducing the direct contact between the air bag 6 and the hard material in the rock-soil 8, having a certain protection effect, thereby improving the stability and reliability of the device, ensuring the sampling effect of the sampling device on the volatile organic compounds in the in-situ thermal desorption pebble layer, and also helping to improve the sample taking rate in the pebble stratum and reduce the number of repeated sampling; the upper support strip 47 is made of a magnetically conductive material and cooperates with the permanent magnet 48 to generate a magnetic attraction force, so that the upper support strip 47 covers the air bag 6, which can avoid the air bag 6 from accidentally unfolding or being damaged when not in use, ensuring that the air bag 6 can normally play a role in sealing the port of the sampling cylinder sleeve 41 when needed, effectively reducing the volatilization of volatile organic compounds due to high temperature and improving the sample taking rate in the pebble stratum.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for part or all of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present application.

Claims

1. An in-situ thermal desorption cobble layer sampling device, characterized by, The utility model provides a kind of sampling device, including drill rod (2), driving mechanism (5) and sliding mechanism;The middle part of the drill rod (2) is equipped with airflow passage along the length direction, front end is connected with sampling drill bit (4);The sampling drill bit (4) includes sampling cylinder sleeve (41) and piston drill bit (42) slidingly connected in sampling cylinder sleeve (41);The bottom of the piston drill bit (42) is equipped with for breaking rock and soil (8) heading head (421), and upper end is formed with sealed cavity (43) between cylinder sleeve;The middle part of the sampling cylinder sleeve (41) is equipped with air guide pipe (44) along the axial direction of sampling cylinder sleeve (41);The upper section of the air guide pipe (44) is equipped with air passage (441) with sealed cavity (43) intercommunication, lower section is equipped with air bag (6), and air guide pipe (44) is in position gas distribution mechanism (45);The position gas distribution mechanism (45) can be triggered when piston drill bit (42) moves to set position, to drive air bag (6) to expand, and the port of sampling cylinder sleeve (41) is sealed;The driving mechanism (5) is used to provide rotary power for drill rod (2), and compressed air is provided for airflow passage;The sliding mechanism is used to drive driving mechanism (5) to move along the set direction;The position gas distribution mechanism (45) includes piston (451) slidingly connected in air guide pipe (44), and the piston (451) can be moved by the propelling force provided by the second elastic member (452) arranged in air guide pipe (44), to drive the air in air guide pipe (44) into air bag (6);The side wall of the piston (451) is equipped with limiting groove (4511);Air passage (441) is hinged with clamping piece (453), and the lower end of the clamping piece (453) is equipped with limiting portion (4531) for clamping limiting groove (4511), and the upper end is equipped with knob portion (4532);The knob portion (4532) is used to abut with piston drill bit (42) during the movement of piston drill bit (42), to drive clamping piece (453) to deflect, so that limiting portion (4531) is separated from limiting groove (4511);The limiting groove (4511) is equipped with third elastic member (454) for driving limiting portion (4531) to clamp limiting groove (4511);The sampling cylinder sleeve (41) includes connecting head (411) and sampling sleeve (412) detachably connected together;Air passage (4111) is arranged in the connecting head (411) and communicated with air guide pipe (44);The air guide pipe (44) is detachably connected in the cavity of sampling sleeve (412);The upper end of the piston (451) is equipped with reset pull rod (455) extending out of sampling cylinder sleeve (41).

2. The in-situ thermal desorption cobble layer sampling device of claim 1, wherein, The sliding mechanism includes slide rail (11) and sliding seat (3) slidingly connected on slide rail (11), and the slide rail (11) is fixed on rack (1);The rack (1) is equipped with push mechanism (31) for driving sliding seat (3) to move.

3. The in-situ thermal desorption cobble layer sampling device of claim 2, wherein, The driving mechanism (5) comprises a pneumatic motor (51) arranged on the sliding seat (3), the output shaft (511) of the pneumatic motor (51) is in a hollow tubular structure, and the lower end of the output shaft (511) is provided with a threaded part (512) connected with the drill rod (2); the upper end of the pneumatic motor (51) is provided with a support seat (52), and the support seat (52) is provided with a sealing cover (53); the sealing cover (53) is provided with an air inlet hole (531), the support seat (52) is provided with an air outlet hole (532), the air outlet hole (532) is slidably connected with a butt joint pipe (54) matched with the upper end port of the output shaft (511) of the pneumatic motor (51), the air outlet of the butt joint pipe (54) is provided with a sealing ring, and the first elastic member (55) for butt joint of the air outlet of the butt joint pipe (54) and the upper end port of the output shaft (511) of the pneumatic motor (51) is arranged between the butt joint pipe (54) and the support seat (52).

4. The in-situ thermal desorption cobble layer sampling device of claim 1, wherein, The driving head (421) is in a conical structure, and the driving head (421) is provided with driving blades (424) arranged in a spiral; the lower edge of the sampling cylinder sleeve (41) is provided with driving teeth (413).

5. The in-situ thermal desorption cobble layer sampling device of claim 1, wherein, The lower end of the inner wall of the sampling cylinder sleeve (41) or the lower end of the air guide pipe (44) is provided with a limiting block (7) matched with the piston drill bit (42), and the piston drill bit (42) is provided with a clamping groove (423) matched with the limiting block (7).

6. The in-situ thermal desorption cobble layer sampling device of claim 5, wherein, The middle part of the piston drill bit (42) is provided with a through hole (422) matched with the air guide pipe (44), and when the piston drill bit (42) is in abutting state with the limiting block (7), the through hole (422) can cover the air bag (6); the air guide pipe (44) is provided with a soil breaking cone (46) extending out of the through hole (422).

7. The in-situ thermal desorption cobble layer sampling device of claim 1, wherein, The air guide pipe (44) comprises a large end section (442), a variable diameter section (443) and a small end section (444) from top to bottom; the air bag (6) is sleeved on the small end section (444), and the pipe wall of the small end section (444) is provided with a gas permeable hole (4441) communicated with the inner cavity of the air bag (6); the upper support strip (47) is circumferentially hinged at the variable diameter section (443), and the upper support strip (47) can cover the air bag (6).

8. The in-situ thermal desorption cobble layer sampling device of claim 7, wherein, The upper support strip (47) is made of a magnetically conductive material, and one end of the small end section (444) away from the hinged part of the upper support strip (47) is provided with a permanent magnet (48); the permanent magnet (48) can generate a magnetic attraction force on the upper support strip (47) to drive the upper support strip (47) to cover the air bag (6).

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