Gas detection pre-processing apparatus and method for confined spaces

Abstract

The application discloses a kind of gas detection pretreatment device and method for limited space, it is related to gas detection technical field.In the application: including frame, frame is equipped with top mouth cavity, multiple gas storage cavities, each gas storage cavity is communicated with the sealing element of top mouth cavity, the power module of independent drive sealing element is arranged in the positioning lining of top mouth cavity, sealing element is also provided with reverse elastic module.Positioning lining and transverse partition form air gap, frame is equipped with the air valve of air cock, piston disc and pressure module are in gas storage cavity, top cover has corresponding switch unit, and gas pump and gas detection equipment are also configured.The application method is stored by independent gas storage cavity isolation, first fills gap, then high-pressure sampling, first exhaust to low pressure, then detects, realizes multiple-point gas non-cross contamination sampling and high-purity accurate detection.

Description

A gas detection pretreatment device and method for confined spaces Technical Field

[0001] This invention relates to the field of gas detection technology, and in particular to a gas detection pretreatment device and method for confined spaces. Background Technology

[0002] Confined spaces are typically complex environments with diverse gas compositions, and may contain toxic, harmful, or flammable and explosive gases. To analyze and simulate the gas environment of various confined spaces to the greatest extent possible, highly accurate detection and analysis of gases in these spaces is required. However, existing handheld or simple gas detectors have limited accuracy and cannot meet the extremely high requirements for gas detection and analysis. Therefore, it is necessary to first sample the gases within the confined space, and then use large-scale, multifunctional detection equipment in a laboratory to accurately analyze the gas composition.

[0003] However, existing gas sampling equipment has significant shortcomings in the processes of gas extraction, storage, and extraction. On the one hand, it is prone to contamination by other external gases, leading to contamination of the collected gas samples and affecting the accuracy of the test results. On the other hand, when extracting gas samples from different confined space areas, interference between different samples may occur during the gas sampling, storage, and extraction testing stages, making the test data unable to accurately reflect the gas conditions at each sampling point and complicating the safety assessment of confined spaces.

[0004] The existence of these problems makes it crucial to solve the technical challenges of efficient and continuous gas sampling in multiple confined spaces, while minimizing interference from ambient gases and other sampled gases. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0006] This invention provides a gas detection and pretreatment device for confined spaces, comprising a frame, a top cavity distributed on one side of a transverse partition, and multiple gas storage chambers distributed on the other side of the transverse partition and communicating with the top cavity. A bottom cover is fixedly installed on one side of each gas storage chamber, and a top cover is fixedly installed on one side of the top cavity. A sealing element is provided at the communication position between each gas storage chamber and the top cavity. A positioning bushing is fixedly installed in the top cavity, and the positioning bushing is equipped with multiple independent power modules. Each power module independently drives the sealing element to operate, and the sealing element is also equipped with an elastic module with the opposite driving action to the power module.

[0007] An air extraction gap is formed between the positioning bushing and the transverse partition. The positioning bushing is equipped with an air pressure detection module for detecting the air pressure in the air extraction gap. Two air nozzles connected to the air extraction gap are also installed on the outer periphery of the frame, and each air nozzle is equipped with an air valve. A piston disc is movably mounted inside the air storage chamber. A first pressure module is embedded in the side of the transverse partition facing the air storage chamber, and a second pressure module is embedded in the side of the bottom cover facing the air storage chamber. The top cover is equipped with multiple switch units, each of which is independently electrically connected to a power module and the first and second pressure modules configured in the air storage chamber, which are controlled by the power module in a linkage and sealing manner.

[0008] The pretreatment unit is also equipped with a gas pump for delivering sampling gas into the gas storage chamber and a gas detection device for extracting and detecting gas from the gas storage chamber.

[0009] As a preferred embodiment of the device of the present invention: the transverse partition has multiple conical openings, and the top cavity is connected to the gas storage cavity through the conical openings. The power module adopts an electromagnetic module, and the sealing component includes a sealing cone that mates with the conical openings and a push rod connected to the sealing cone. One end of the push rod faces the electromagnetic module and is embedded with a magnetic block.

[0010] The positioning bushing is equipped with a mounting cylinder, which runs from bottom to top through a bottom groove, a sliding groove, and an electromagnetic groove. The width of the sliding groove is smaller than that of the bottom groove, and the electromagnetic module is fixedly installed in the electromagnetic groove. The elastic module uses a tension spring, which is sleeved around the push rod. One end of the tension spring abuts against the sealing cone, and the other end is positioned in the bottom groove.

[0011] As a preferred technical solution of the device of the present invention: a sealing ring that cooperates with the sealing cone is provided on the inner wall of the cone, and a sliding ring that slides in contact with the wall surface of the slide is provided on the top ring side of the push rod.

[0012] As a preferred technical solution of the device of the present invention: the bottom cover is also provided with multiple air holes, each air hole is independently connected to an air storage chamber, and a metal filter screen is also provided at the position of the air hole.

[0013] As a preferred technical solution of the device of the present invention: the inner wall of the top cavity of the positioning bushing and the frame, and the position where the power module and the positioning bushing are installed are all provided with sealing structures, such as sealing rings, in order to prevent the dangerous gas source drawn in from coming into contact with the power supply, main board structure, etc. in the top cavity, so as to avoid combustion and explosion.

[0014] As a preferred embodiment of the device of the present invention: the switching unit is equipped with a touch-sensitive on / off switch, a full-load indicator light for displaying when the second pressure module is triggered, and an no-load indicator light for displaying when the first pressure module is triggered. The switching unit is electrically connected to the main board of the device via a wiring module. The main board is electrically connected to the electromagnetic module, the first pressure module, and the second pressure module. Signals from the first pressure module and the second pressure module are transmitted to the main board, which can output control signals for the electromagnetic module, the no-load indicator light, and the full-load indicator light.

[0015] As a preferred technical solution of the device of the present invention: the air pump outlet end is connected to one of the air nozzles through a quick-connect fitting, and the air pump inlet end is connected to a suction pipe inserted into a sealed space.

[0016] The gas detection preprocessing method provided in this invention includes a multi-point gas sampling stage and a gas detection stage.

[0017] (a) The process of multi-point gas sampling is as follows:

[0018] S1. Carry the pretreatment device, air pump and corresponding pipelines to the sampling point, place and connect the pretreatment device, air pump and corresponding pipelines.

[0019] S2. Open the air valves of the two air nozzles on the outer perimeter of the frame to connect the suction gap with the external air passage. Select any air storage chamber that does not currently store sampled gas as the target air storage chamber for storing the sampled gas.

[0020] S3. Start the air pump to extract gas from the confined space and introduce it into the pumping gap. After the initial pumping time reaches the system preset time, close the air valve of the air nozzle that is not connected to the air pump.

[0021] S4. Press the switch unit corresponding to the selected target air storage chamber. The switch unit sends a control signal to the corresponding power module. The power module drives the seal to overcome the force of the elastic module, causing the seal to disengage from the communication position between the top cavity and the air storage chamber, thus realizing the communication between the top cavity and the target air storage chamber.

[0022] S5. The gas in the extraction gap enters the gas storage chamber through the connecting position, and the piston disc in the gas storage chamber moves away from the transverse partition under the action of gas pressure.

[0023] S6. When the piston disc moves, triggering the second pressure module, and the air pressure detection module detects that the air pressure value of the suction gap is not lower than the system's preset high air pressure reference value P. max At that time, the system determines that the gas sampling of the target gas storage chamber is complete.

[0024] S7. After the gas sampling of the target gas storage chamber is completed, the power module stops driving, the seal is reset under the reaction force of the elastic module, and the connection between the top cavity and the gas storage chamber is resealed. At the same time, the air pump is turned off and the gas extraction operation is stopped.

[0025] S8. Following the above method, perform air extraction sampling on the enclosed spaces at different sampling points.

[0026] (II) The gas detection process is as follows:

[0027] S9. Transfer the pre-processing device that has completed sampling to the detection environment, connect one of the gas nozzles to the gas detection equipment, close the gas valve of the other gas nozzle, and only open the gas valve of the gas nozzle connected to the gas detection equipment.

[0028] S10. Start the gas detection equipment to allow the gas in the extraction gap to flow into the gas detection equipment.

[0029] The air pressure detection module monitors the air pressure changes in the air extraction gap in real time. When the air pressure value is not greater than the system's preset low air pressure reference value P... min At this time, the power module corresponding to any gas storage chamber that has been sampled is activated. The power module drives the seal to disengage from the communication position again, and the sampled gas in the target gas storage chamber enters the gas detection device through the top cavity and the suction gap. Among them, P min <P max .

[0030] S11. As the sampled gas from the target gas storage chamber flows out under negative pressure, the piston disc inside the target gas storage chamber gradually approaches the transverse partition. When the piston disc triggers the first pressure module, and the gas pressure detection module detects that the gas pressure value of the pumping gap is not greater than the low gas pressure reference value P... min At this point, the system determines that the gas in the target gas storage chamber has been detected. The power module is de-energized, and the seals are reset and sealed by the elastic module, closing the gas detection equipment and the gas valve of the nozzle.

[0031] S12. The sampled gas stored in different gas storage chambers is tested in accordance with the above method.

[0032] Compared with existing technologies, the beneficial effects of this invention are:

[0033] 1. This invention achieves isolated storage of gases from different sampling points by designing multiple independent gas storage chambers and combining independent control of sealing components and power modules, thus avoiding cross-contamination. The fit between the cone and the sealing cone, as well as the setting of the sealing ring, enhances the sealing performance and reduces the mixing of external gases.

[0034] 2. In gas sampling and collection, this invention first fully fills the confined space with gas through the extraction gap, and then performs high-pressure gas sampling through the storage chamber to ensure gas purity. During gas detection, the extraction gap is first vented to a low pressure state before gas is introduced into the storage chamber to reduce interference from residual gas. The detection is considered complete when the piston plate triggers the first pressure module and the gas pressure reaches the target, ensuring sufficient gas extraction. This achieves multi-point gas sampling without cross-contamination and high-purity, accurate detection. Attached Figure Description

[0035] Figure 1 is a schematic diagram of the structure of the device of the present invention when collecting gas in a closed space.

[0036] Figure 2 is a magnified structural diagram of part A in Figure 1.

[0037] Figure 3 is a schematic diagram of the disassembled structure of the main components of the device of the present invention.

[0038] Figure 4 is a schematic diagram of the frame and bottom cover in this invention.

[0039] Figure 5 is a schematic diagram of the structure of the sealing element and the positioning bushing in this invention.

[0040] Figure 6 is a schematic diagram of the structure of the gas detection device in this invention for extracting sampled gas from the gas storage chamber.

[0041] Figure 7 shows the switching unit in this invention.

[0042] Wherein: 1-Frame, 101-Top cavity, 102-Air extraction gap, 103-Air storage chamber, 104-Horizontal partition, 105-Conical opening, 106-Sealing ring, 107-First pressure module, 108-Air nozzle, 109-Air valve, 110-Quick-connector; 2-Piston disc; 3-Bottom cover, 301-Second pressure module, 302-Air hole, 303-Metal filter screen; 4-Sealing element, 401-Sealing cone, 402-Push rod, 403-Sliding element 404-Magnetic block; 5-Positioning bushing; 501-Mounting cylinder; 502-Bottom groove; 503-Slide groove; 504-Electromagnetic groove; 505-Air pressure detection module; 6-Tension spring; 7-Electromagnetic module; 8-Top cover; 801-Switch unit; 8011-On / off switch; 8012-Full load indicator light; 8013-No load indicator light; 802-Wiring module; 9-Air pump; 10-Ejection pipe; 11-Sealed space; 12-Gas detection equipment. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0044] Example 1: This invention designs a gas detection pretreatment device for confined spaces, the main structural design of which is as follows:

[0045] Frame 1: As shown in Figures 1, 2, and 4, it includes a top cavity 101 distributed on one side of the transverse partition 104 and multiple air storage chambers 103 distributed on the other side of the transverse partition 104 and communicating with the top cavity 101. A bottom cover 3 is fixedly installed on one side of the air storage chamber 103, and a top cover 8 is fixedly installed on one side of the top cavity 101. The transverse partition 104 has multiple conical openings 105, and the top cavity 101 communicates with the air storage chambers 103 through the conical openings 105. A sealing ring 106 that mates with a sealing cone 401 is disposed on the inner wall of the conical opening 105. A first pressure module 107 is embedded on the side of the transverse partition 104 facing the air storage chamber 103.

[0046] Top cavity 101: It is connected to the air storage cavity 103 through the conical opening 105, and the positioning bushing 5 is fixedly installed inside.

[0047] Gas storage chamber 103: It is connected to the top cavity 101 through a conical opening 105, and a piston disc 2 is movably disposed inside. Each gas storage chamber 103 is provided with a sealing element 4 at the position where it connects to the top cavity 101.

[0048] The diaphragm 104 separates the top cavity 101 and the air storage cavity 103, and has multiple conical openings 105. The first pressure module 107 is embedded on the side of the diaphragm 104 facing the air storage cavity 103.

[0049] Bottom cover 3: As shown in Figures 1, 3, and 4, the bottom cover 3 is fixedly installed on one side of the gas storage chamber 103, and the second pressure module 301 is embedded in the side of the bottom cover 3 facing the gas storage chamber 103. The bottom cover 3 also has multiple air holes 302, each of which is independently connected to a gas storage chamber 103, and a metal filter screen 303 is arranged at the location of the air hole 302.

[0050] Top cover 8: As shown in Figures 1, 2 and 3, the top cover 8 is equipped with multiple switch units 801. Each switch unit 801 is independently connected to a power module, a corresponding first pressure module 107 and a second pressure module 301 via electrical control.

[0051] Seal 4: As shown in Figures 2, 3, and 5, it includes a sealing cone 401 that mates with the conical opening 105, and a push rod 402 connected to the sealing cone 401. One end of the push rod 402 faces the electromagnetic module 7 and is fitted with a magnetic block 404. A sliding ring 403 is arranged on the top circumferential side of the push rod 402, which slides in contact with the wall of the slide groove 503.

[0052] Positioning bushing 5: As shown in Figures 2, 3, and 5, the positioning bushing 5 is fixedly installed inside the top cavity 101 and is equipped with multiple independent power modules. The positioning bushing 5 has an installation cylinder 501, which has a bottom groove 502, a sliding groove 503, and an electromagnetic groove 504 extending from bottom to top. The width of the sliding groove 503 is smaller than that of the bottom groove 502. An air extraction gap 102 is formed between the positioning bushing 5 and the transverse partition 104. The positioning bushing 5 is equipped with an air pressure detection module 505 for detecting the air pressure in the air extraction gap 102. A sealing structure (such as a sealing ring) is provided at the installation position where the positioning bushing 5 mates with the inner wall of the top cavity 101 of the frame 1.

[0053] Power module: As shown in Figures 2, 3, and 6, an electromagnetic module 7 is used, which is fixedly installed within the electromagnetic groove 504. Each power module independently drives the operation of a sealing element 4. A sealing structure (such as a sealing ring) is configured at the installation position where the power module mates with the positioning bushing 5.

[0054] Elastic module: As shown in Figures 2, 3 and 5, a tension spring 6 is used. The tension spring 6 is sleeved around the push rod 402. One end of the tension spring 6 abuts against the sealing cone 401 and the other end is placed in the bottom groove 502. The tension spring 6 has the opposite driving effect to the power module.

[0055] The air extraction gap 102, as shown in Figures 1, 2, and 6, is formed between the positioning bushing 5 and the transverse partition 104, and is connected to two air nozzles 108. The air extraction gap 102 is equipped with an air pressure detection module 505 for detecting its air pressure.

[0056] Air pressure detection module 505: As shown in Figures 1, 5 and 6, it is installed on the positioning bushing 5 and is used to detect the air pressure in the air extraction gap 102.

[0057] Air nozzle 108: As shown in Figures 1, 4, and 6, it is located on the periphery of the frame 1 and communicates with the air extraction gap 102, and is equipped with an air valve 109. One of the air nozzles 108 is connected to the air outlet of the air pump 9 through a quick-connect pipe 110.

[0058] Air valve 109: Located on air nozzle 108, it controls the opening and closing of air nozzle 108 and external air passage.

[0059] Piston disc 2: As shown in Figures 1 and 2, it is movably configured in the gas storage chamber 103 and can move under the action of gas pressure. It is used to trigger the first pressure module 107 and the second pressure module 301.

[0060] The first pressure module 107, as shown in Figures 1 and 2, is embedded in the side of the transverse partition 104 facing the gas storage chamber 103 and is electrically connected to the corresponding switch unit 801.

[0061] The second pressure module 301, as shown in Figures 1 and 2, is embedded on the side of the bottom cover 3 facing the gas storage chamber 103 and is electrically connected to the corresponding switch unit 801.

[0062] Switching unit 801: As shown in Figures 1, 2, and 7, it is configured on the top cover 8, and each unit is independently connected to a power module, a corresponding first pressure module 107, and a second pressure module 301 via electrical control. It is equipped with a touch-sensitive on / off switch 8011, a full-load indicator light 8012 indicating when the second pressure module 301 is triggered, and an no-load indicator light 8013 indicating when the first pressure module 107 is triggered. It is connected to the mainboard electrical control of the device via a wiring module 802.

[0063] Power module: As shown in Figures 2, 3 and 5, it adopts electromagnetic module 7, which is fixedly installed in electromagnetic groove 504 and independently drives the action of a sealing element 4.

[0064] Mounting cylinder 501: As shown in Figure 5, it is set on the positioning bushing 5 and has a bottom groove 502, a sliding groove 503, and an electromagnetic groove 504 running through it from bottom to top.

[0065] Bottom groove 502: It is formed at the bottom of the mounting cylinder 501, and its width is greater than that of the slide groove 503. One end of the tension spring 6 is installed inside it.

[0066] Slide groove 503: It is opened in the middle of the mounting cylinder 501, and its width is smaller than that of the bottom groove 502. It allows the push rod 402 to pass through, and the sliding ring 403 of the push rod 402 slides in contact with the wall of the slide groove 503.

[0067] Electromagnetic slot 504: It is formed on the top of the mounting cylinder 501 and the electromagnetic module 7 is fixedly installed inside it.

[0068] Elastic module: a tension spring 6 is used, which is sleeved around the push rod 402, with one end abutting against the sealing cone 401 and the other end disposed in the bottom groove 502.

[0069] Air pump 9: As shown in Figure 1, it is a device configured in the pretreatment unit for delivering sampling gas into the gas storage chamber 103. The outlet end is connected to one of the air nozzles 108 through a quick-connect fitting 110, and the inlet end is connected to a suction pipe 10 inserted into the sealed space 11.

[0070] Gas detection device 12: As shown in Figure 6, it is a device configured in the pretreatment unit for extracting and detecting gas in the gas storage chamber 103.

[0071] Wiring module 802: As shown in Figures 3 and 7, the switch unit 801 is connected to the main board of the device through it.

[0072] Quick-connect fitting 110: As shown in Figure 4, it is used for the mating connection between the air nozzle 108 and the external pipeline.

[0073] Air extraction pipe 10: As shown in Figure 1, one end is inserted into the sealed space 11, and the other end is connected to the air inlet of the air pump 9.

[0074] Example 2: This invention designs a gas detection pretreatment method for confined spaces. The main working principle is as follows:

[0075] (a) Air extraction mode:

[0076] Upon reaching the gas sampling point, the air pump 9 and the gas storage device of the present invention are configured, and one end of the extraction pipe 10 is inserted into the sealed space 11.

[0077] Start the air pump 9, open the air valves 109 of the two air nozzles 108, and press the switch unit 801 of any one of the no-load indicator lights 8013 that is always on. After a few seconds (the system preset time), close the air valve 109 on the air nozzle 108 that is not connected to the air pump 9.

[0078] When the pressed switch unit 801 is electrically connected to the electromagnetic module 7, it attracts the magnetic block 404, which drives the push rod 402 to move upward, while also overcoming the tension of the tension spring 6.

[0079] The sealing cone 401 disengages from the cone opening 105, and the airflow drawn from the sealed space 11 by the air pump 9 is introduced into the air extraction gap 102 and enters the air storage chamber 103 through the cone opening 105.

[0080] Piston disc 2, subjected to continuous airflow pressure, moves away from cone opening 105 and toward second pressure module 301. When piston disc 2 triggers second pressure module 301, and air pressure detection module 505 detects that the air pressure value is not lower than the system's preset high air pressure reference value P, max When the full load indicator light 8012 is constantly lit, the electromagnetic module 7 is de-energized, and under the action of the tension spring 6, the sealing cone 401 seals the cone opening 105 again, and the gas storage chamber 103 completes gas collection (at this time, the pressure signal detected by the second pressure module 301 is also very large. If the sample in the gas storage chamber 103 leaks during storage, the pressure detected by the second pressure module 301 will decrease, thus issuing a warning message, such as the full load indicator light 8012 changing from red to yellow, which may indicate that the gas storage chamber 103 is leaking, thus requiring subsequent maintenance of the gas storage chamber 103). Simultaneously, it is necessary to stop the air pump 9 from continuing to pump air (the air pump 9 can be manually controlled, or the motor can be controlled via an electrical control signal. Controlling via an electrical control signal requires additional configuration of an electrical control connection logic module or circuit, etc. This is a conventional electrical control coordination method, and this function can be achieved using existing technology).

[0081] Following the above method, air sampling was performed on the enclosed space 11 at different sampling points.

[0082] After each sampling, if air sampling is not to be continued, the air valves 109 of both air nozzles 108 must be closed.

[0083] (II) Detection Mode:

[0084] The pretreatment device that has completed the gas sampling is brought back to the laboratory. One of the gas nozzles 108 is connected to the gas detection device 12 through the gas tube, and the gas valve 109 of the gas nozzle 108 is opened (the gas valve 109 of the other gas nozzle 108 is closed).

[0085] Press any of the fully lit indicator lights 8012 on the switch unit 801 to start the gas detection device 12 (the gas detection device 12 is equipped with an air suction device), and the gas in the air suction gap 102 flows toward the gas detection device 12.

[0086] When the air pressure detection module 505 detects an air pressure value that is not greater than the system's preset low air pressure reference value P min Time (P) min <P max Low pressure reference value P min It needs to be set very small (e.g., control it as close to a vacuum state as possible; of course, as small as possible is fine, such as setting P). min (≤1kPa), ensuring that most of the "interference" gas in the extraction gap 102 can be discharged, thus ensuring the purity of the sampled gas output to the gas detection device 12), the electromagnetic module 7 connected to the pressed switch unit 801 is activated, attracting the magnetic block 404, driving the push rod 402 to move upward, the sealing cone 401 disengages from the cone opening 105, and the sampled gas in the gas storage chamber 103 enters the extraction gap 102 and the gas detection device 12.

[0087] Piston disc 2, subjected to continuous airflow pressure, gradually approaches cone opening 105 and moves towards first pressure module 107. When piston disc 2 triggers first pressure module 107, and air pressure detection module 505 detects that the air pressure value is not greater than the system's preset low air pressure reference value P,... min At this time, the no-load indicator light 8013 remains constantly lit. Simultaneously, the electromagnetic module 7 is de-energized, and under the action of the tension spring 6, the sealing cone 401 seals the cone opening 105 again, and the current gas storage chamber 103 completes the sampling gas output operation. At the same time, it is necessary to stop the gas detection device 12's pumping action (similar to the above pumping mode, the gas detection device 12 can be operated manually or automatically in linkage; existing technology can also achieve linkage control).

[0088] In the manner described above, the sampled gas stored in each gas storage chamber 103 can be extracted and tested using the gas detection device 12.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A gas detection pretreatment device for confined spaces, characterized in that: The system includes a frame (1), which has a top cavity (101) distributed on one side of a transverse partition (104) and multiple air storage chambers (103) distributed on the other side of the transverse partition (104) and communicating with the top cavity (101). A bottom cover (3) is fixedly installed on one side of each air storage chamber (103), and a top cover (8) is fixedly installed on one side of each top cavity (101). Each air storage chamber (103) is equipped with a sealing element (4) at the position where it communicates with the top cavity (101). A positioning bushing (5) is fixedly installed on the top cavity (101). The positioning bushing (5) is equipped with multiple independent power modules. Each power module independently drives the sealing element (4) to move. The sealing element (4) is also equipped with a function opposite to that of the power module. The elastic module; the positioning bushing (5) and the transverse partition (104) form an air extraction gap (102), the positioning bushing (5) is equipped with an air pressure detection module (505) for detecting the air pressure of the air extraction gap (102), and two air nozzles (108) communicating with the air extraction gap (102) are also provided on the periphery of the frame (1), and the air nozzles (108) are equipped with air valves (109); the transverse partition (104) has multiple conical openings (105), and the top cavity (101) is connected to the air storage cavity (103) through the conical openings (105); the power module adopts an electromagnetic module (7), and the sealing element (4) includes a sealing cone (401) that cooperates with the conical opening (105) and a push rod connected to the sealing cone (401). (402), one end of the push rod (402) faces the electromagnetic module (7) and is fitted with a magnetic block (404); the positioning bushing (5) is provided with an installation cylinder (501), the installation cylinder (501) is opened from bottom to top through a bottom groove (502), a sliding groove (503) and an electromagnetic groove (504), the width of the sliding groove (503) is smaller than that of the bottom groove (502), and the electromagnetic module (7) is fixedly installed in the electromagnetic groove (504); the elastic module adopts a tension spring (6), the tension spring (6) is sleeved on the periphery of the push rod (402), wherein one end of the tension spring (6) abuts against the sealing cone (401) and the other end is arranged in the bottom groove (502); the inner wall of the cone opening (105) is provided with a magnetic block (404) that is in contact with the sealing cone (7). 01) A matching sealing ring (106) is provided on the top ring side of the push rod (402) and a sliding ring (403) is provided to slide in contact with the wall of the slide groove (503); a piston disc (2) is movably arranged in the gas storage chamber (103); a first pressure module (107) is embedded on the side of the transverse partition (104) facing the gas storage chamber (103); a second pressure module (301) is embedded on the side of the bottom cover (3) facing the gas storage chamber (103); a plurality of switch units (801) are provided on the top cover (8); each switch unit (801) is independently electrically connected to a power module and the first pressure module (107) and the second pressure module (301) configured in the gas storage chamber (103) which is controlled by the power module in a linkage sealing manner;The pretreatment device is also equipped with a gas pump (9) for delivering sampling gas into the gas storage chamber (103), and a gas detection device (12) for extracting and detecting gas from the gas storage chamber (103).

2. The gas detection pretreatment device for confined spaces according to claim 1, characterized in that: The bottom cover (3) is also provided with multiple air holes (302), each air hole (302) is independently connected to an air storage chamber (103), and a metal filter screen (303) is also provided at the location of the air hole (302).

3. The gas detection pretreatment device for a confined space according to claim 1, characterized in that: The positioning bushing (5) and the inner wall of the top cavity (101) of the frame (1), as well as the position where the power module and the positioning bushing (5) are installed, are all provided with sealing structures.

4. A gas detection pretreatment device for confined spaces according to claim 1, characterized in that: The switch unit (801) is equipped with a touch-sensitive on / off switch (8011), a full load indicator light (8012) that displays when the second pressure module (301) is triggered, and an unload indicator light (8013) that displays when the first pressure module (107) is triggered.

5. A gas detection pretreatment device for confined spaces according to claim 1, characterized in that: The air pump (9) outlet end is connected to one of the air nozzles (108) through a quick-connect fitting (110), and the air pump (9) inlet end is connected to a suction pipe (10) inserted into a confined space.

6. A gas detection pretreatment method for confined spaces, characterized in that, A gas detection pretreatment device for a confined space according to any one of claims 1 to 5, comprising a multi-point gas sampling stage and a gas detection stage, is described below: (I) Multi-point gas sampling stage S1. Carry the pretreatment device, air pump (9) and corresponding pipelines to the sampling point, place and connect the pretreatment device, air pump (9) and corresponding pipelines; S2. Open the air valves (109) of the two air nozzles (108) on the periphery of the frame (1) to connect the gas extraction gap (102) with the external gas path; select any gas storage chamber (103) that has not stored sampled gas as the target gas storage chamber (103) to be stored sampled gas; S3. Start the air pump (9) to extract gas in the confined space and introduce it into the gas extraction gap (102). After the initial gas extraction reaches the system preset time, close the air valves (108) of the air nozzles (108) that are not connected to the air pump (9). 109); S4. Press the switch unit (801) corresponding to the selected target gas storage chamber (103). The switch unit (801) sends a control signal to the corresponding power module. The power module drives the seal (4) to overcome the force of the elastic module, so that the seal (4) is separated from the communication position between the top cavity (101) and the gas storage chamber (103), and realizes the communication between the top cavity (101) and the target gas storage chamber (103); S5. The gas in the suction gap (102) enters the gas storage chamber (103) through the communication position. The piston disc (2) in the gas storage chamber (103) moves away from the transverse partition (104) under the action of gas pressure; S6. When the piston disc (2) moves and triggers the second pressure module (301), and the gas pressure detection module (505) detects that the gas pressure value of the suction gap (102) is not lower than the system preset high gas pressure reference value P. max When the gas sampling of the target gas storage chamber (103) is completed, the system determines that the gas sampling of the target gas storage chamber (103) is completed; S7. After the gas sampling of the target gas storage chamber (103) is completed, the power module stops driving, the seal (4) is reset under the reaction force of the elastic module, and the connection position between the top cavity (101) and the gas storage chamber (103) is resealed. At the same time, the air pump (9) is turned off and the gas extraction operation is stopped; S8. In the same way, the gas extraction sampling is carried out on the limited space of different sampling points; (II) Gas detection link S9. The pre-processing device that has completed the sampling is transferred to the detection In the environment, connect one of the gas nozzles (108) to the gas detection device (12), close the gas valve (109) of the other gas nozzle (108), and only open the gas valve (109) of the gas nozzle (108) connected to the gas detection device (12); S10. Start the gas detection device (12) to allow the gas in the gas extraction gap (102) to flow into the gas detection device (12); the gas pressure detection module (505) monitors the gas pressure change in the gas extraction gap (102) in real time, and when the gas pressure value is not greater than the system's preset low gas pressure reference value P min When the system starts, the power module corresponding to any gas storage chamber (103) that has collected gas is activated. The power module drives the seal (4) to disengage from the communication position again. The sampled gas in the target gas storage chamber (103) enters the gas detection device (12) through the top cavity (101) and the gas extraction gap (102). Among them, P min <P max S11. As the sampled gas in the target gas storage chamber (103) flows out under negative pressure, the piston disk (2) in the target gas storage chamber (103) gradually approaches the transverse partition (104). When the piston disk (2) triggers the first pressure module (107), and the gas pressure detection module (505) detects that the gas pressure value of the gas extraction gap (102) is not greater than the low gas pressure reference value P, min When the system determines that the gas in the target gas storage chamber (103) has been detected; the power module is de-energized, the seal (4) is reset and sealed under the action of the elastic module, and the gas valve (109) of the gas detection device (12) and the gas nozzle (108) is closed; S12. The sampled gas stored in different gas storage chambers (103) is detected in the same way.

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