A gas sampling device

Abstract

This utility model proposes a gas sampling device, including a suction pump, a suction tank, and a sampling bag. The sampling bag has an integrally formed tube, the root of which connects to the inside of the sampling bag, and the head of which has a first internal thread interface. The suction tank has a canopy with a through-hole air inlet channel. The air inlet channel has an axial stepped sealing structure, which includes two or more decreasing aperture sections on the inner wall of the air inlet channel, decreasing in direction from the bottom side to the top side of the canopy, and a matching stepped surface on the outer wall of the tube. Radial seals are provided between adjacent aperture sections. The air inlet channel also has a locking mechanism for releasably restricting the circumferential rotation of the tube. An axial fixing component is provided on the outer side of the root of the tube for fixing the tube to the bottom side of the canopy. After the tube is inserted into the air inlet channel, the head of the tube is exposed outside the canopy, and the first internal thread interface can be screwed into an external sealing pin to seal the gas path.

Description

Technical Field

[0001] This utility model relates to the field of gas sampling, and in particular to a gas sampling device. Background Technology

[0002] During gas sampling, a commercially available gas sampling device is used. This device operates on the principle of pressure difference. Its core components include a vacuum pump, a sealed negative pressure tank, and a negative pressure bag placed inside the tank (the bag opening is connected to the outside atmosphere through an air inlet pipe). The opening of the negative pressure bag is usually fixed to the tank (or tank lid) with a rubber band or elastic band to maintain the tank's seal. During operation, the vacuum pump draws air from the tank to create a negative pressure (the air pressure is lower than the outside atmospheric pressure). Since the inside of the negative pressure bag is directly connected to the atmosphere, the air pressure is equal to atmospheric pressure. The resulting pressure difference drives outside gas to flow in through the air inlet pipe and fill the negative pressure bag. After sampling, the tank needs to be opened to remove the gas-filled negative pressure bag, and the bag opening or air inlet pipe needs to be knotted to seal the sample.

[0003] However, the existing technology of this scheme still has the following defects: insufficient sealing measures during collection, which affects the formation of negative pressure and reduces collection efficiency, and the sealing measures after collection are also weak, which may result in gas leakage.

[0004] Therefore, there is an urgent need for a gas sampling device that can reliably seal during and after the sampling process. Utility Model Content

[0005] To address the problems of insufficient sealing measures during and after gas collection in existing technologies, this utility model proposes a gas sampling device, the technical solution of which is as follows:

[0006] A gas sampling device includes a suction pump, a suction tank, and a sampling bag. The suction tank includes a tank body and a tank cover fixed to the tank body by a snap fastener. The suction pump is connected to the suction port of the suction tank through a hose. The sampling bag is provided with an integrally formed insert tube. The root of the insert tube is connected to the inside of the sampling bag, and the head is provided with a first internal thread interface.

[0007] The air extraction tank has a through air intake channel in its lid. The air intake channel has an axial stepped sealing structure. The axial stepped sealing structure includes two or more decreasing aperture sections on the inner wall of the air intake channel, with the decreasing direction from the bottom side of the lid to the top side, and a matching stepped surface on the outer wall of the insertion tube. A radial seal is provided between adjacent aperture sections.

[0008] The air intake channel is also equipped with a locking mechanism to releasably restrict the circumferential rotation of the insertion tube; and an axial fixing component is provided on the outer side of the root of the insertion tube to fix the insertion tube to the bottom side of the can lid.

[0009] After the tube is inserted into the air intake channel, the head of the tube is exposed outside the canister cap, and the first internal threaded interface can be screwed into an external sealing pin to seal the air passage.

[0010] Furthermore, the axis of the air intake channel is parallel to the axis of the can lid.

[0011] Furthermore, the radial seal is an O-ring, coaxially embedded in the stepped plane of the decreasing bore diameter section.

[0012] Furthermore, the locking mechanism includes an elastic locking pin that is radially slidable on the inner wall of the air intake channel, and a corresponding limiting groove is provided on the outer wall of the insertion tube. The elastic locking pin can be engaged in the limiting groove to fix the insertion tube and prevent the insertion tube from rotating.

[0013] Furthermore, the inner wall of the air intake channel is radially provided with a movable blind hole. One end of the elastic locking pin is a flat end and the other end is a spherical end. The flat end is located inside the movable blind hole. A spring is provided between the flat end and the inner end face of the movable blind hole. The two ends of the spring are fixedly connected to the flat end and the inner end face of the blind hole, respectively. An anti-disengagement baffle is provided at the opening of the movable blind hole. The elastic locking pin is restricted by the anti-disengagement baffle. The spherical end protrudes from the movable blind hole but cannot be completely disengaged from the movable blind hole.

[0014] Furthermore, the axial fixing assembly includes an externally threaded sleeve coaxially disposed on the outside of the insertion tube root, and the air intake channel is provided with a second internally threaded interface on the inner wall of the side near the bottom surface of the canister cover. The externally threaded sleeve can be coaxially screwed into the second internally threaded interface to restrict the axial displacement of the insertion tube.

[0015] Furthermore, the sampling bag is heat-sealed with an elastic strip on the side near the can lid. The elastic strip automatically rewinds when no force is applied, thus rolling up the sampling bag.

[0016] Furthermore, the elastic strip includes a metal core layer and an elastic buffer layer covering the metal core layer, the elastic buffer layer being made of silicone rubber.

[0017] Furthermore, a sealing gasket is provided on the underside of the sealing nail cap, which forms a seal when it comes into contact with the insertion tube opening when tightened.

[0018] The beneficial effects of this utility model are as follows: the gas sampling device forms multiple sealing barriers through the stepped sealing structure of the tube and the air inlet channel, combined with the radial sealing element. The locking mechanism restricts the circumferential rotation of the tube and the axial fixing component prevents displacement, thus improving the connection sealing performance. The elastic strip heat-sealed at the edge of the sampling bag can automatically roll up the bag body, making it easy to carry and install. After sampling, the tube port is sealed by tightening the sealing nail, forming a complete gas path sealing chain, effectively solving the leakage and contamination problems in the gas collection and storage process. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall design of this utility model;

[0020] Figure 2 This is a schematic diagram of the air intake channel of this utility model;

[0021] Figure 3 This is a top view of the sampling bag of this utility model in its rolled-up state;

[0022] Figure 4 This is a front view schematic diagram of the winding state of this utility model.

[0023] In the above attached figures: 1. Tank body; 2. Tank cover; 3. Air extraction port; 4. Sampling bag; 5. Insertion tube; 6. First internal thread interface; 7. Elastic coil; 8. Air inlet channel; 9. Decreasing diameter section; 10. Radial seal; 11. Elastic locking pin; 12. Spring; 13. Anti-detachment baffle; 14. Limiting groove; 15. External thread sleeve; 16. Second internal thread interface; 17. Sealing nail; 18. Sealing gasket; 19. Air pump; 20. Hose; 21. Bushing. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] like Figure 1 , Figure 2 , Figure 3 As shown, a gas sampling device includes a vacuum pump 19, a vacuum tank, and a sampling bag 4. The vacuum tank includes a tank body 1 and a tank cap 2 fixed to the tank body 1 by a snap fastener. The vacuum pump 19 is connected to the vacuum port 3 of the vacuum tank via a hose 20. The sampling bag 4 is provided with an integrally formed insertion tube 5. The root of the insertion tube 5 is connected to the inside of the sampling bag 4, and the root of the insertion tube 5 is provided with a bushing 21 integral with the sampling bag 4 to enhance the structural strength. The head of the insertion tube 5 is provided with a first internal thread interface 6. The integral forming reduces the leakage point at the connection between the sampling bag 4 and the insertion tube 5. The first internal thread interface 6 facilitates the later tightening of the sealing nail 17 to seal the gas passage.

[0026] like Figure 1 , Figure 2As shown, the canister cap 2 of the extraction tank has a through-hole air intake channel 8. Preferably, the axis of the air intake channel 8 is parallel to the axis of the canister cap 2. The air intake channel 8 is an axial stepped sealing structure, which includes two or more decreasing aperture sections 9 on the inner wall of the air intake channel 8, decreasing in the direction from the bottom side to the top side of the canister cap 2, and a matching stepped surface on the outer wall of the insertion tube 5. A radial seal 10 is provided between adjacent aperture sections. During the insertion of the insertion tube 5, the radial seal 10 installed on the stepped plane undergoes radial deformation due to the axial compression of the stepped surface, thereby effectively sealing the annular gap between the outer wall of the insertion tube 5 and the inner wall of the channel, forming a multi-stage radial sealing barrier to prevent gas leakage along this path. Preferably, the radial seal 10 is an O-ring, coaxially embedded in the stepped plane of the decreasing aperture section 9. The O-ring is a mature and reliable sealing element. Installing it in this position facilitates radial deformation during axial compression to achieve sealing, and it is easy to replace and maintain.

[0027] like Figure 1 , Figure 2 As shown, the air intake channel 8 is also equipped with a locking mechanism to releasably restrict the circumferential rotation of the insertion tube 5; and an axial fixing component is provided on the outer side of the root of the insertion tube 5 to fix the insertion tube 5 to the bottom side of the can lid 2; preferably, the locking mechanism includes an elastic pin 11 that is radially slidably disposed on the inner wall of the air intake channel 8, and a corresponding limiting groove 14 is provided on the outer wall of the insertion tube 5. The elastic pin 11 can be engaged in the limiting groove 14 to fix the insertion tube 5 and prevent the insertion tube 5 from rotating. The inner wall of the air intake channel 8 is radially provided with a movable blind hole. One end of the elastic pin 11 is a flat end and the other end is a spherical end. The flat end is located in the movable blind hole, and a spring 12 is provided between the flat end and the inner end face of the movable blind hole. The two ends of the spring 12 are fixedly connected to the flat end and the inner end face of the blind hole, respectively. An anti-disengagement baffle 13 is provided at the opening of the movable blind hole. The elastic pin 11 is restricted by the anti-disengagement baffle 13, and the spherical end protrudes out of the movable blind hole, but cannot be completely disengaged from the movable blind hole. After the insertion tube 5 is inserted into place, the elastic locking pin 11 automatically engages with the limiting groove 14 of the insertion tube 5 to prevent circumferential rotation during use. This ensures the correct alignment of the stepped sealing surface, prevents wear or loosening of the seal due to rotation, and especially prevents the insertion tube 5 from rotating during axial fixing operations. It can also be pulled out directly by manual force without the need for an additional release mechanism.

[0028] like Figure 1 , Figure 2As shown, after inserting the cannula 5 into the air inlet channel 8, the head of the cannula 5 is exposed outside the canister cap 2, and the first internal thread interface 6 can be screwed into the external sealing pin 17 to seal the air passage; preferably, a sealing gasket 18 is provided on the lower side of the sealing pin 17, which forms a seal when it comes into contact with the opening of the cannula 5 when tightened. When the sealing pin 17 is tightened, the sealing gasket 18 is in close contact with the end face of the cannula 5 to form a reliable end face seal, effectively sealing the air passage outlet of the sampling bag 4, preventing sample gas from escaping or external gas from seeping in, and ensuring the preservation quality of the sample after sampling.

[0029] like Figure 1 , Figure 2 As shown, preferably, the axial fixing assembly includes an externally threaded sleeve 15 coaxially disposed on the outer side of the root of the insertion tube 5. The air inlet channel 8 is provided with a second internally threaded interface 16 on the inner wall near the bottom surface of the canister cover 2. The externally threaded sleeve 15 can be coaxially screwed into the second internally threaded interface 16 to restrict the axial displacement of the insertion tube 5. Through the threaded connection, the root of the insertion tube 5 is firmly fixed to the bottom surface of the canister cover 2, preventing the insertion tube 5 from axially loosening or falling out due to the gravity of the sampling bag 4 or pulling during operation, ensuring the stability of the sealing structure and the reliability of the air circuit connection.

[0030] like Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, preferably, the sampling bag 4 has an elastic strip 7 heat-sealed on the side near the lid 2. The elastic strip 7 automatically rolls up when no force is applied, holding the sampling bag 4 in place. The elastic strip 7 includes a metal core layer and an elastic buffer layer covering the metal core layer, the elastic buffer layer being made of silicone rubber. When the sampling bag 4 is not inflated, the strip automatically rolls it up, reducing the risk of contaminant adhesion and contamination of the gas inside the bag, while also preventing damage from dragging and facilitating storage.

[0031] Additionally, it should be noted that before use, the condition of the sealing rings and seals must be checked. All O-rings must be inspected for integrity, ensuring they are free from damage, aging, or permanent deformation; replace them immediately if necessary. Check that the sealing gasket 18 of the sealing pin 17 is elastic and undamaged. Verify the functional mechanism, testing that the elastic locking pin 11 extends and retracts flexibly, the spring 12 is effective, and it can reliably engage and disengage from the limiting groove 14. Ensure the automatic winding function is normal and without jamming, and that the silicone buffer layer is undamaged.

[0032] Regarding operating procedures, the canister lid 2 and canister body 1 must be securely fastened with clips (existing technology, not elaborated upon, nor shown in the diagram) to ensure the overall sealing of the suction canister. Rotate the external threaded sleeve 15 at the base of the insertion tube 5 and screw it into the second internal threaded interface 16 at the bottom of the channel to ensure axial fixation. Clearly define the working negative pressure limit of the device design; the negative pressure inside the canister must not exceed this limit during sampling to prevent the sampling bag 4 from rupturing or failing to seal. The material of the sampling bag 4 and the sealing components (O-rings, sealing gasket 18, silicone) must be compatible with the gas to be tested to avoid chemical reactions, dissolution, or accelerated aging.

[0033] Regarding maintenance, the O-rings and gaskets 18 need to be inspected and replaced regularly according to the frequency of use to prevent aging and sealing failure. After use, clean the tubing 5, air inlet channel 8, and other parts that come into contact with gas promptly. Keep the device dry during storage, and the sampling bag 4 should be rolled up to avoid deformation of the seals due to prolonged pressure.

[0034] The omissions regarding existing technologies, such as the snap-locking of the tank lid 2, the installation and operation of the vacuum pump, etc., are all common knowledge in this field and will not be elaborated upon in the manual.

[0035] Summary of usage: Ensure the vacuum pump 19, vacuum tank (tank cap 2 and tank body 1 are securely connected), sampling bag 4 (rolled up), sealing pin 17, and the gas environment to be tested are ready. Check that the O-rings are intact and that the insertion tube 5 and channel are clean. Align the sampling bag 4 and insertion tube 5 with the air inlet channel 8 of the tank cap 2 and insert them. During insertion, the stepped surface of the insertion tube 5 will sequentially contact and axially compress the O-rings on the stepped surface of the channel, forming a seal. Simultaneously, the outer wall of the insertion tube 5 will press down the spherical end of the elastic locking pin 11 until the insertion tube 5 is fully inserted. Under the action of the spring 12, the locking pin will engage with the limiting groove 14 of the insertion tube 5, restricting its rotation.

[0036] Rotate the external threaded sleeve 15 at the base of the insertion tube 5 and screw it into the second internal threaded interface 16 at the bottom of the air intake channel 8 until it is tightened, thus fixing the axial position of the insertion tube 5. Start the vacuum pump 19. The vacuum pump 19 works by connecting to the vacuum port 3 of the vacuum tank through the hose 20, drawing out the gas in the vacuum tank and creating a negative pressure.

[0037] Under negative pressure, the ambient gas to be tested enters the sampling bag 4 through the insertion tube 5, gradually filling the sampling bag 4. The sealing pin 17 is screwed into the first internal thread interface 6 at the head of the insertion tube 5 until the sealing gasket 18 is tightly pressed against the opening of the insertion tube 5, forming a seal. At the same time, the vacuum pump 19 is turned off.

[0038] To remove the sampling bag 4, rotate the external threaded sleeve 15 in the opposite direction to disengage it from the second internal threaded interface 16. Finally, pull the insertion tube 5 outward with slight force (overcoming the resistance of the elastic retaining pin 11) to remove the sampling bag 4.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A gas sampling device, comprising a suction pump (19), a suction tank, and a sampling bag (4), wherein the suction tank comprises a tank body (1) and a tank cover (2) fixed to the tank body (1) by a snap fastener, and the suction pump (19) is connected to the suction port (3) of the suction tank via a hose (20), characterized in that: The sampling bag (4) is provided with an integrally formed insertion tube (5), the root of which is connected to the inside of the sampling bag (4), and the head is provided with a first internal thread interface (6); The canister cap (2) of the air extraction can is provided with a through air intake channel (8). The air intake channel (8) is an axial stepped sealing structure. The axial stepped sealing structure includes two or more decreasing aperture sections (9) provided on the inner wall of the air intake channel (8). The decreasing direction is from the bottom side of the canister cap (2) to the top side, and a matching stepped surface on the outer wall of the insertion tube (5). A radial seal (10) is provided between adjacent aperture sections. The air intake channel (8) is also provided with a locking mechanism to release the circumferential rotation of the insertion tube (5); and the outer side of the root of the insertion tube (5) is provided with an axial fixing component to fix the insertion tube (5) to the bottom side of the can cover (2). After inserting the tube (5) into the air intake channel (8), the head of the tube (5) is exposed outside the canister cap (2), and the first internal threaded interface (6) can be screwed into the external sealing pin (17) to seal the air passage.

2. The gas sampling device of claim 1, wherein: The axis of the air intake channel (8) is parallel to the axis of the can cover (2).

3. The gas sampling device of claim 1, wherein: The radial seal (10) is an O-ring, coaxially embedded in the stepped plane of the decreasing bore diameter section (9).

4. The gas sampling device of claim 1, wherein: The locking mechanism includes an elastic pin (11) that is radially slidably disposed on the inner wall of the air intake channel (8), and a corresponding limiting groove (14) is provided on the outer wall of the insertion tube (5). The elastic pin (11) can be inserted into the limiting groove (14) to fix the insertion tube (5) and prevent the insertion tube (5) from rotating.

5. The gas sampling device according to claim 4, characterized in that: The inner wall of the air intake channel (8) is radially provided with a movable blind hole. One end of the elastic locking pin (11) is a flat end and the other end is a spherical end. The flat end is located inside the movable blind hole. A spring (12) is provided between the flat end and the inner end face of the movable blind hole. The two ends of the spring (12) are fixedly connected to the flat end and the inner end face of the blind hole, respectively. An anti-detachment baffle (13) is provided at the opening of the movable blind hole. The elastic locking pin (11) is restricted by the anti-detachment baffle (13). The spherical end protrudes out of the movable blind hole, but cannot completely detach from the movable blind hole.

6. The gas sampling device of claim 1, wherein: The axial fixing assembly includes an external threaded sleeve (15) coaxially disposed on the outside of the root of the insertion tube (5). The air intake channel (8) is provided with a second internal threaded interface (16) on the inner wall of the bottom side of the canister cover (2). The external threaded sleeve (15) can be coaxially screwed into the second internal threaded interface (16) to restrict the axial displacement of the insertion tube (5).

7. The gas sampling device of claim 1, wherein: The sampling bag (4) is heat-sealed with an elastic strip (7) on the side near the can lid (2). The elastic strip (7) automatically rewinds when no force is applied, thus rolling up the sampling bag (4).

8. The gas sampling device of claim 7, wherein: The elastic strip (7) includes a metal core layer and an elastic buffer layer covering the metal core layer, the elastic buffer layer being made of silicone rubber.

9. The gas sampling device of claim 1, wherein: The sealing nail (17) has a sealing gasket (18) on the underside of the nail head, which forms a seal when it is tightened and comes into contact with the opening of the insertion tube (5).

10. The gas sampling device of claim 1, wherein: The root of the cannula (5) is provided with a bushing (21).

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