A gas sampling device

Abstract

This utility model discloses a gas sampling device, comprising: a sampling box, which is connected to a vacuum pump and a sampling gun via pipelines; wherein, a rotary valve assembly is provided at the end of the sampling box, which is used to switch the sampling path and control the on / off state of the sampling path. In this utility model, multiple sets of rotary valve assemblies are installed on the sampling box. After opening the rotary valve corresponding to the gas bag to be sampled, external gas can continuously flow into the sampling gas bag inside the sampling box through the sampling gun. Once the gas bag is saturated, the valve is closed to complete the sampling operation. This effectively avoids the repetitive action of repeatedly inserting and removing the gas bag during the cleaning process of the non-methane total hydrocarbon gas bag, and achieves automatic sample switching and sampling function simply by switching the rotary valves.

Description

Technical Field

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

[0002] Non-methane hydrocarbons (NMRs) are a collective term for all hydrocarbons in the atmosphere except for methane. They are complex in composition, encompassing a variety of volatile organic compounds such as alkanes, alkenes, and aromatic hydrocarbons (e.g., benzene and toluene). As a key air pollutant, NMRs are not only core precursors to photochemical smog and near-ground ozone pollution, leading to decreased air quality and reduced visibility, but some components are also irritating and toxic. Long-term or high-concentration exposure may have adverse effects on the human respiratory and nervous systems. Therefore, it is necessary to collect and test them using sampling equipment.

[0003] Existing sampling equipment for non-methane total hydrocarbons on the market can only collect samples using a single gas bag cleaning box. This requires operators to repeatedly insert and remove the gas bag during a single sampling process, significantly increasing the tediousness of the operation and potentially affecting the stability and accuracy of the sampling due to repeated operations. While similar sampling equipment on the market is equipped with multiple vacuum sampling boxes, which can basically meet the sampling requirements for non-methane total hydrocarbons, the increased number of boxes increases the overall size and weight of the equipment, causing inconvenience for on-site carrying, handling, and relocation. Furthermore, the need to insert and remove the gas bag still exists after sampling, failing to address the core pain point of repetitive operations. In terms of key functional performance, these devices cannot reach the same level as the target equipment, making it difficult to meet the needs of higher standards and more efficient sampling operations. Utility Model Content

[0004] The purpose of this invention is to provide a gas sampling device to solve the above problems.

[0005] To achieve the above objectives, this utility model specifically adopts the following technical solution, including:

[0006] The sampling box is connected to the vacuum pump and the sampling gun via pipelines;

[0007] The sampling box is equipped with a rotary valve assembly at its end, which is used to switch the sampling path and control the on / off state of the sampling path.

[0008] As a further description of the above technical solution, a mounting part is provided on the side wall of the sampling box, which is used to install the rotary valve assembly.

[0009] As a further description of the above technical solution, the installation section is symmetrically arranged in 4-6 groups.

[0010] As a further description of the above technical solution, the rotary valve assembly includes a rotary valve that snaps onto the docking portion of the sampling box.

[0011] As a further description of the above technical solution, a first connector is installed at one end of the rotary valve, and the first connector is connected to the sampling gun.

[0012] As a further description of the above technical solution, the first connector includes a snap-fit ​​part, and the snap-fit ​​part is provided with a snap-fit ​​groove.

[0013] As a further description of the above technical solution, a docking part is provided at one end of the snap-fit ​​part, which is used to connect to an external pipeline.

[0014] As a further description of the above technical solution, a rotating part is provided at the other end of the snap-fit ​​part, which is used to connect to the docking part of the sampling box.

[0015] As a further description of the above technical solution, a second connector is installed at the other end of the rotary valve, and each set of second connectors is connected to a set of sampling gas bags.

[0016] As a further description of the above technical solution, the second connector is connected to the diverter through a pipeline, and each diverter is connected to one or more sampling gas bags.

[0017] The beneficial effects of this utility model are as follows:

[0018] In this invention, the sampling box is equipped with multiple sets of rotary valve assemblies. After opening the rotary valve corresponding to the sampling gas bag to be sampled, external gas can continuously flow into the sampling gas bag inside the sampling box through the sampling gun. After the gas bag is saturated, the valve is closed to complete the sampling operation. This can effectively avoid the repetitive action of repeatedly inserting and removing the gas bag during the cleaning process of non-methane total hydrocarbons. The automatic sample changing and sampling function can be achieved simply by switching the rotary valve.

[0019] To more clearly illustrate the structural features and functions of this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the gas sampling device of this utility model;

[0021] Figure 2 yes Figure 1 Front view of the sampling box;

[0022] Figure 3 yes Figure 1 Top view of the sampling box;

[0023] Figure 4 yes Figure 1 Schematic diagram of the structure of the rotary valve assembly Figure 1 ;

[0024] Figure 5 yes Figure 1 Schematic diagram of the structure of the rotary valve assembly Figure 2 .

[0025] Figure label:

[0026] 1. Sampling box; 11. Mounting part; 2. Vacuum pump; 3. Sampling gun; 4. Rotary valve assembly; 41. Rotary valve; 42. First connector; 421. Snap-fit ​​part; 4211. Snap-fit ​​groove; 422. Connecting part; 423. Rotating part; 43. Second connector; 5. Diverter. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0028] Example 1:

[0029] like Figures 1-4 As shown, in one embodiment, a gas sampling device includes: a sampling box 1, wherein the sampling box 1 is made of a highly corrosion-resistant transparent material and has an overall sealed box structure, which can effectively prevent external gas leakage or internal gas contamination during the sampling process, ensuring sampling accuracy while allowing real-time monitoring of the collection status of the internal sampling gas bag.

[0030] For example, the sampling box 1 is connected to the vacuum pump 2 and the sampling gun 3 through pipelines; the pipeline connected to the vacuum pump 2 is used to extract the gas inside the sampling box 1, and the pipeline can be equipped with a pressure regulating valve to precisely control the vacuuming rate according to the sampling requirements; the pipeline connected to the sampling gun 3 is used to transmit the external gas to be collected, and both ends of the pipeline can be threaded sealing interfaces and wrapped with polytetrafluoroethylene sealing tape to further enhance airtightness and prevent gas leakage from affecting the sampling results.

[0031] Furthermore, a set of rotary valve components 4 is integrated at the front end of the sampling box 1 (near the operator) for switching sampling channels and controlling the on / off state of the sampling channels: all channels can be closed before sampling to ensure the sealing of the sampling box 1 during vacuuming; during sampling, a target channel can be opened individually to collect gas from a specific sampling gas bag; after sampling, the channels should be closed in time to prevent gas backflow in the sampling gas bag or the entry of external gas.

[0032] For example, to facilitate the installation and subsequent maintenance of the rotary valve assembly 4, a dedicated mounting part 11 is pre-machined on the side wall of the sampling box 1. The mounting part 11 is a protruding circular interface structure with a sealing groove on the inner wall of the interface, which can be embedded with an O-ring seal. It can provide a stable mounting base for the rotary valve assembly 41, ensuring that there is no loosening or leakage after the assembly is connected to the sampling box 1. At the same time, the modular design allows for quick disassembly and replacement when the rotary valve assembly 4 fails, without the need to disassemble the entire sampling box 1, which greatly improves maintenance efficiency.

[0033] Specifically, the installation unit 11 adopts a symmetrical layout with a total of 4-6 sets: it can meet the needs of regular batch sampling and is suitable for scenarios with fewer sampling points; it can also handle high-frequency, multi-sample sampling tasks, and can connect multiple sets of sampling air bags simultaneously or in stages to reduce sampling waiting time; it adapts to different on-site spatial environments, and each docking unit 422 is also printed with a number, which makes it easy for operators to quickly identify the corresponding sampling path and reduce the rate of operational errors.

[0034] Furthermore, the rotary valve assembly 4 includes a rotary valve 41, which is snapped onto the docking portion 422 of the sampling box 1.

[0035] It should be noted that a first connector 42 is installed at one end of the rotary valve 41, and the first connector 42 is connected to the sampling gun 3.

[0036] Specifically, the first connector 42 includes a snap-fit ​​portion 421, the outer diameter of which is slightly larger than other parts of the first connector 42, forming a raised structure. A rectangular snap-fit ​​groove 4211 is formed around its outer wall. Specifically, the snap-fit ​​groove 4211 has a width of 3-5mm and a depth of 2-3mm. The inner surface of the groove is smoothed to reduce frictional resistance with the mating part 422. When the first connector 42 is connected to the rotary valve 41, the snap-fit ​​protrusion of the rotary valve 41 will be embedded in the snap-fit ​​groove 4211 to achieve mechanical locking between the two. At the same time, a thin sealing gasket can be placed in the snap-fit ​​groove 4211 to further improve the airtightness of the connection and prevent gas from leaking from the gaps.

[0037] The snap-fit ​​part 421 has a tubular docking part 422 extending axially from the end facing the external pipeline. The outer diameter of the docking part 422 is designed to be 8-12mm according to the specifications of the external pipeline, so as to be compatible with sampling pipelines of different diameters. The inner wall of the docking part 422 is polished to a mirror smooth surface to reduce frictional resistance during gas flow and avoid impurities remaining in the pipeline. In use, the tubular docking part 422 connects to the external sampling pipeline to stably deliver the gas introduced by the sampling gun 3 into the sampling box 1.

[0038] On the other end of the snap-fit ​​part 421 facing the sampling box 1, a rotating part 423 is provided along the axial direction. When the rotating part 423 is screwed into the docking part 422 of the sampling box 1 until it fits against the end face of the docking part 422, it indicates that the connection is in place, which can effectively avoid damage to the parts due to excessive rotation.

[0039] Correspondingly, a second connector 43 is installed on the other end of the rotary valve 41, and each set of second connectors 43 is connected to a set of sampling gas bags. When connecting, the air inlet of the sampling gas bag is tightly fitted onto the second connector 43. The external part of the second connector 43 can be fitted with a clamp or other limiting structure to prevent the sampling gas bag from falling off during the inflation process.

[0040] Example 2:

[0041] Please continue reading. Figure 5 Based on Embodiment 1, in order to meet the needs of multiple parallel sampling or sample collection of different volumes, the second connector 43 can be connected to the diverter 5 in a sealed manner through a transparent inert hose according to the actual sampling task. Each diverter 5 is connected to one or more sampling gas bags. When multiple parallel samples need to be collected, the multiple outlets of the diverter 5 can be connected to multiple sampling gas bags respectively, and the valves can be opened simultaneously to achieve batch collection. When only a single sample is needed, the valves of other outlets can be closed, which greatly improves the sampling flexibility of the device.

[0042] Working principle: The sampling gas bag used to collect non-methane total hydrocarbons is pre-connected to the second connector 43 inside the rotary valve assembly 4 of the sampling box 1 or the diverter 5 connected to the second connector 43. After the sampling box 1 is closed, the vacuum pump 2 is used to evacuate the inside of the sampling box 1 to form a negative pressure. Then, all rotary valves 41 are closed and the rotary valve 41 connected to the sampling gas bag to be collected is opened, so that the external gas can continuously flow into the sampling gas bag inside the sampling box 1 through the sampling gun 3. After the gas bag is saturated, the valve is closed to complete the collection process of a set of sampling gas bags.

[0043] Repeat the above process until all the preset number of sampling gas bags have been collected. Then, turn off vacuum pump 2, open the sealing door of sampling box 1, remove the sampling gas bags one by one, seal the gas bag inlet with sealing clips, and mark the sampling time, location, temperature, pressure and other information on each gas bag. Finally, properly store the sampling gas bags and send them to the laboratory for non-methane total hydrocarbon content detection and analysis. The entire collection process is now complete.

[0044] Through the above technical solution, this application can effectively avoid the repetitive action of repeatedly inserting and removing the gas bag during the cleaning process of non-methane total hydrocarbon gas bag, and realize the automatic sample collection function by simply switching the rotary valve 41.

[0045] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A gas sampling device, characterized in that, include: The sampling box (1) is connected to the vacuum pump (2) and the sampling gun (3) through pipelines respectively; The sampling box (1) is provided with a rotary valve assembly (4) at its end. The rotary valve assembly (4) is used to switch the sampling path and control the on / off state of the sampling path.

2. The gas sampling device according to claim 1, characterized in that, The sampling box (1) has a mounting part (11) on its side wall, which is used to install the rotary valve assembly (4).

3. The gas sampling device according to claim 2, characterized in that, The mounting section (11) is symmetrically arranged in 4-6 groups.

4. The gas sampling device according to claim 1, characterized in that, The rotary valve assembly (4) includes a rotary valve (41) which is snapped onto the docking part (422) of the sampling box (1).

5. The gas sampling device according to claim 4, characterized in that, The rotary valve (41) is equipped with a first connector (42) at one end, and the first connector (42) is connected to the sampling gun (3).

6. The gas sampling device according to claim 5, characterized in that, The first connector (42) includes a snap-fit ​​part (421), and the snap-fit ​​part (421) is provided with a snap-fit ​​groove (4211).

7. The gas sampling device according to claim 6, characterized in that, One end of the snap-fit ​​part (421) extends to a docking part (422), which is used to connect to an external pipeline.

8. The gas sampling device according to claim 6, characterized in that, The other end of the snap-fit ​​part (421) is provided with a rotating part (423), which is used to connect to the docking part (422) of the sampling box (1).

9. The gas sampling device according to claim 4, characterized in that, The other end of the rotary valve (41) is equipped with a second connector (43), and each set of the second connector (43) is connected to a set of sampling gas bags.

10. The gas sampling device according to claim 9, characterized in that, The second connector (43) is connected to the diverter (5) through a pipeline, and each diverter (5) is connected to one or more sampling gas bags.

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