Air filter, gas analyzer and automatic gas quality control device

Abstract

The utility model provides an air filter, a gas analyzer and an automatic gas quality control device, the air filter comprises an air inlet base body, the air inlet base body is provided with an air inlet joint and a gas collection cavity, the air outlet end of the air inlet joint is communicated with the inlet end of the gas collection cavity, and at least the cross section of the inlet end of the gas collection cavity is gradually expanded towards the air circulation direction of the air filter; the air outlet base body is connected with the air inlet base body and is provided with an exhaust cavity and an air outlet connector; the membrane placement frame is located in the air inlet base body or the air outlet base body, and the outlet end of the air collection cavity communicates with the inlet end of the air exhaust cavity through the membrane placement frame; the filter membrane is arranged on one side, close to the gas collecting cavity, of the membrane placing frame. At least the cross section of the inlet end of the air collection cavity is gradually expanded towards the air circulation direction of the air filter, so that the inlet end of the air collection cavity is of the conical structure which is gradually expanded towards the air circulation direction, and the conical structure which is gradually expanded towards the air circulation direction can guide air sent out by the air inlet joint; the air is uniformly diffused to each part of the filter membrane, so that the air filtering efficiency can be improved.

Description

Technical Field

[0001] This application relates to the technical field of air filtration, and particularly to an air filter, a gas analyzer, and a gas automatic quality control device. Background Art

[0002] When a gas analyzer measures the gas concentration in the air online in real time, it is necessary to collect air from the outside through a sampling device for measurement. Due to environmental reasons in the outside air, there are situations where the particulate matter concentration is high or the air humidity is high. This easily causes the pipeline of the gas analyzer to be blocked or water to enter, resulting in a malfunction of the gas analyzer or even damage to the gas analyzer. Therefore, in practical applications, it is often necessary to introduce a filter to filter the air and then introduce the filtered air into the gas analyzer.

[0003] The Chinese utility model patent with the authorization publication number of CN209108824U discloses an air filter for a gas analyzer sampling device, which includes an air outlet joint, a connecting cylinder, and a drainage plug. The connecting cylinder connects the air outlet joint and the drainage plug; a filter screen support and a filter membrane are sequentially arranged between the air outlet joint and the connecting cylinder; the air outlet joint is equipped with a locking nut to fix the air outlet joint and the connecting cylinder; a joint A is provided on the air outlet joint, a joint B is provided on the side surface of the connecting cylinder, and a joint C is provided below the drainage plug. Air enters from the joint B on the side surface of the connecting cylinder 5 and enters the gas analyzer from the joint A on the top of the air outlet joint. Part of the particles in the air fall to the bottom of the air filter under the action of gravity, and part is filtered by the filter membrane, thus preventing the gas analyzer from being blocked; at the same time, the water vapor in the air deposits at the bottom of the air filter due to the influence of gravity during the process from the side joint B to the top joint A, reducing the humidity in the air and preventing water from entering the gas analyzer. Although the above air filter can improve the air filtration efficiency, however, the above air filter still has the problem of low filtration efficiency. Utility Model Content

[0004] The embodiments of this application provide an air filter, a gas analyzer, and a gas automatic quality control device to solve the problems existing in the related technologies. The technical solutions are as follows:

[0005] In a first aspect, the embodiments of this application provide an air filter, including:

[0006] An air inlet base body, the air inlet base body is provided with an air inlet joint and a gas collecting cavity. The air inlet end of the air inlet joint is used to communicate with the outside air, and the air outlet end of the air inlet joint is communicated with the inlet end of the gas collecting cavity. At least the cross-section of the inlet end of the gas collecting cavity gradually expands in the air flow direction of the air filter;

[0007] An air outlet matrix, the air outlet matrix is ​​connected to the air inlet matrix, the air outlet matrix and the air inlet matrix are arranged one by one along the air flow direction of the air filter, the air outlet matrix is ​​provided with an exhaust cavity and an air outlet joint, the air inlet end of the air outlet joint is connected with the outlet end of the exhaust cavity, and the air outlet end of the air outlet joint is used to be connected with a gas analyzer or a gas automatic quality control device;

[0008] A film mounting frame, the film mounting frame is located in the air inlet matrix or the air outlet matrix, and the film mounting frame connects the outlet end of the gas collecting cavity with the inlet end of the exhaust cavity;

[0009] The filter membrane is arranged on the side of the membrane frame close to the gas collecting cavity, and the filter membrane covers the outlet end of the gas collecting cavity. The diameter of the adapted air filter membrane is 80 mm, and the pore size is 5 μm.

[0010] In one embodiment, the outer peripheral wall of the air intake substrate is provided with an external thread structure;

[0011] The air filter also includes:

[0012] A connecting base, wherein the connecting base is sleeved on at least a portion of the outer peripheral wall of the air inlet base and the outer peripheral wall of the air outlet base, the connecting base has an internal thread structure, the internal thread structure and the external thread structure are adapted, and the air outlet base is sandwiched between the connecting base and the air inlet base.

[0013] In one embodiment, the gas outlet substrate has a mounting hole on one side close to the gas collecting cavity, and the mounting hole is arranged around the gas inlet end of the gas outlet cavity;

[0014] The film mounting frame is located in the mounting hole;

[0015] The filter membrane is provided with a filter portion and an outer edge portion, wherein the filter portion covers the outlet end of the gas collecting cavity, and the outer edge portion is arranged around the filter portion, and the outer edge portion is sandwiched between the air inlet matrix and the air outlet matrix.

[0016] In one embodiment, the inner side wall of the outlet end of the gas collecting cavity is provided with a plurality of first limiting protrusions, and the plurality of first limiting protrusions are arranged at intervals around the axial center line of the gas collecting cavity;

[0017] The side of the filter portion facing away from the film holder abuts against the first plurality of limiting protrusions, and the side of the film holder facing away from the filter membrane abuts against the bottom wall of the mounting hole, so that the film holder is clamped between the air inlet matrix and the air outlet matrix.

[0018] In one embodiment, a first positioning groove is further provided on a side of the air outlet base close to the air collecting cavity. The first positioning groove is closer to the air collecting cavity than the mounting hole, and the first positioning groove is arranged around the mounting hole.

[0019] The air inlet base is provided with a first positioning ring which is arranged around the outlet end of the air collecting cavity, and the first positioning ring is inserted into the first positioning groove.

[0020] The outer edge portion is clamped between the bottom wall of the first positioning groove and the first positioning ring.

[0021] In one embodiment, the air inlet base further has a second positioning groove which is arranged around the first positioning ring.

[0022] The air outlet base is further provided with a second positioning ring which is arranged around the first positioning groove. The second positioning ring is adapted to the second positioning groove, and the end of the second positioning ring abuts against the bottom wall of the second positioning groove.

[0023] In one embodiment, the connecting base includes:

[0024] A cylindrical portion which has the internal thread structure.

[0025] A limiting ring which is arranged on one end of the cylindrical portion and extends towards the axial center direction of the cylindrical portion. The air outlet base is clamped between the end of the limiting ring close to the internal thread structure and the air inlet base.

[0026] In one embodiment, the air inlet base, the air outlet base and the film placing frame are all structures made of PFA material.

[0027] In one embodiment, a plurality of support protrusions are provided on the bottom wall of the exhaust cavity. The plurality of support protrusions are arranged at intervals, and the end of the support protrusion departing from the bottom wall of the exhaust cavity abuts against the film placing frame.

[0028] And / or, a first limiting portion is arranged inside the air outlet end of the air inlet joint, and the first limiting portion is used for abutting against the air inlet pipe to limit the air inlet pipe from being inserted into the air collecting cavity.

[0029] A second limiting portion is arranged inside the air inlet end of the air outlet joint, and the second limiting portion is used for abutting against the air outlet pipe to limit the air outlet pipe from being inserted into the exhaust cavity.

[0030] In a second aspect, an embodiment of the present application provides a gas analyzer, including the above-mentioned air filter.

[0031] In a third aspect, an embodiment of the present application provides an automatic gas quality control device, including the above-mentioned air filter.

[0032] The advantages or beneficial effects in the above technical solutions at least include:

[0033] In the air filter of the present utility model, when in use, outside air enters from the intake end of the intake joint, and the outside air sequentially passes through the air collection cavity, the filter membrane, the membrane placement rack, and the exhaust cavity. Finally, the clean air filtered from dust, water liquid, etc. by the filter membrane enters the gas analyzer from the outlet joint. Among them, since at least the cross-section of the inlet end of the air collection cavity gradually expands in the air flow direction of the air filter, the inlet end of the air collection cavity is a tapered structure that gradually expands in the air flow direction. The tapered structure that gradually expands in the air flow direction can guide the air sent out by the intake joint, making the air evenly diffuse to each part of the filter membrane. Under the condition of combining with a suitable large-size filter membrane, it can not only improve the air filtration efficiency, but also improve the utilization rate of the filter membrane and extend the filter membrane replacement cycle.

[0034] The above summary is only for the purpose of the specification and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present application will become apparent by reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In the drawings, unless otherwise specified, the same reference numerals throughout the several views denote the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0036] Figure 1 is a three-dimensional structural schematic diagram of the air filter of the present utility model;

[0037] Figure 2 is a cross-sectional view of the air filter of the present utility model;

[0038] Figure 3 is Figure 2 a partial enlarged view of part A in

[0039] Figure 4 is a three-dimensional structural schematic diagram of the intake base in the present utility model;

[0040] Figure 5 is a three-dimensional structural schematic diagram of the outlet base in the present utility model.

[0041] REFERENCE NUMERALS

[0042] 1. Intake base; 11. Intake joint; 12. Air collecting chamber; 121. First limiting part; 13. External thread structure; 14. First limiting protrusion; 15. First positioning ring; 16. Second positioning groove; 2. Exhaust base; 21. Exhaust chamber; 22. Exhaust joint; 221. Second limiting part; 23. Mounting hole; 24. First positioning groove; 25. Second positioning ring; 26. Support protrusion; 27. Second limiting protrusion; 3. Membrane placement frame; 31. Limiting groove; 4. Filter membrane; 41. Filtering part; 42. Outer edge part; 5. Connecting base; 51. Internal thread structure; 52. Cylindrical part; 53. Limiting ring; 6. Intake pipe; 7. Exhaust pipe. Detailed implementation manners

[0043] In the following text, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present application. Therefore, the drawings and the description are considered to be exemplary in nature rather than restrictive.

[0044] Refer to Figures 1-5 , which shows an air filter according to a preferred embodiment of the present utility model, including:

[0045] An intake base 1, the intake base 1 is provided with an intake joint 11 and an air collecting chamber 12. The intake end of the intake joint 11 is used to communicate with the outside air, and the outlet end of the intake joint 11 is communicated with the inlet end of the air collecting chamber 12. At least the cross-section of the inlet end of the air collecting chamber 12 gradually expands in the air flow direction of the air filter.

[0046] An exhaust base 2, the exhaust base 2 is connected to the intake base 1, the exhaust base 2 and the intake base 1 are arranged one by one in the air flow direction of the air filter. The exhaust base 2 is provided with an exhaust chamber 21 and an exhaust joint 22. The intake end of the exhaust joint 22 is communicated with the outlet end of the exhaust chamber 21, and the outlet end of the exhaust joint 22 is used to communicate with a gas analyzer or a gas automatic quality control device.

[0047] A membrane placement frame 3, the membrane placement frame 3 is located inside the intake base 1 or the exhaust base 2, and the membrane placement frame 3 communicates the outlet end of the air collecting chamber 12 and the inlet end of the exhaust chamber 21.

[0048] A filter membrane 4, the filter membrane 4 is arranged on the side of the membrane placement frame 3 close to the air collecting chamber 12, and the filter membrane 4 covers the outlet end of the air collecting chamber 12.

[0049] When the air filter of the present utility model is in use, outside air enters from the intake end of the intake joint 11, and the outside air sequentially passes through the air collecting chamber 12, the filter membrane 4, the membrane placing frame 3, and the exhaust chamber 21. Finally, the clean air filtered by the filter membrane 4 to remove dust, water liquid, etc. enters the gas analyzer from the outlet joint 22. Among them, since at least the cross-section of the inlet end of the air collecting chamber 12 gradually expands in the air flow direction of the air filter, the inlet end of the air collecting chamber 12 is a tapered structure that gradually expands in the air flow direction. The tapered structure that gradually expands in the air flow direction can guide the air sent out by the intake joint 11, making the air evenly diffuse to each part of the filter membrane 4, which can not only improve the air filtration efficiency but also improve the utilization rate of the filter membrane 4.

[0050] In this embodiment, the diameter of the adapted filter membrane of this air filter is 80 mm. While increasing the filter membrane size (47 mm), the airtightness requirement is satisfied, and it can be used without replacement for a long time, extending the replacement cycle to the frequency requirement of once a month to reduce the frequency of station house operation and maintenance and improve the operation and maintenance efficiency.

[0051] Among them, it can be understood that the membrane placing frame 3 has a plurality of air permeable holes, which are spaced apart. The air permeable holes connect the outlet end of the air collecting chamber 12 and the inlet end of the exhaust chamber 21. And when the filter membrane 4 is arranged on the side of the membrane placing frame 3 close to the air collecting chamber 12, the plurality of air permeable holes are covered by the filter membrane 4.

[0052] See Figure 2 and Figure 3 , in one embodiment, the outer peripheral wall of the intake base 1 is provided with an external thread structure 13;

[0053] The air filter further includes:

[0054] A connecting base 5, which is sleeved on at least part of the outer peripheral wall of the intake base 1 and the outer peripheral wall of the outlet base 2. The connecting base 5 has an internal thread structure 51, and the internal thread structure 51 is adapted to the external thread structure 13, and the outlet base 2 is clamped between the connecting base 5 and the intake base 1. In this way, when assembling the air filter, only need to sleeve the connecting base 5 on at least part of the outer peripheral wall of the intake base 1 and the outer peripheral wall of the outlet base 2, and at the same time make the internal thread structure 51 and the external thread structure 13 adapted, then the intake base 1 and the outlet base 2 can be connected together, and the tool-free installation of the intake base 1 and the outlet base 2 can be realized. The installation operation is simple and convenient, and the installation efficiency is high. Among them, since the connecting base 5 is sleeved on the outer peripheral walls of both the intake base 1 and the outlet base 2, it will not increase the size of the air filter in the air flow direction, making the overall structure of the air filter more compact and more conducive to the miniaturization setting of the air filter, so as to facilitate the installation of the air filter on the gas analyzer without a support structure.

[0055] SeeFigure 3 In one embodiment, the side of the air outlet base body 2 close to the air collecting cavity 12 has a mounting hole 23, and the mounting hole 23 is arranged around the air inlet end of the exhaust cavity 21;

[0056] The membrane placing frame 3 is located in the mounting hole 23;

[0057] The filter membrane 4 is provided with a filtering part 41 and an outer edge part 42. The filtering part 41 covers the outlet end of the air collecting cavity 12, the outer edge part 42 is arranged around the filtering part 41, and the outer edge part 42 is clamped between the air inlet base body 1 and the air outlet base body 2. Since the side of the air outlet base body 2 close to the air collecting cavity 12 has a mounting hole 23 and the membrane placing frame 3 is located in the mounting hole 23, the membrane placing frame 3 is located inside the air outlet base body 2 close to the air collecting cavity 12, so that the filter membrane 4 is located on the side of the air outlet base body 2 close to the air collecting cavity 12. At the same time, since the filter membrane 4 is provided with a filtering part 41 and an outer edge part 42, the filtering part 41 covers the outlet end of the air collecting cavity 12, the outer edge part 42 is arranged around the filtering part 41, and the outer edge part 42 is clamped between the air inlet base body 1 and the air outlet base body 2, the filter membrane 4 can be installed on the membrane placing frame 3 without connectors. When replacing the filter membrane 4, only need to screw out the connecting base body 5 to release the connection between the air inlet base body 1 and the air outlet base body 2. After separating the air inlet base body 1 and the air outlet base body 2, the connection between the filter membrane 4 and the membrane placing frame 3 is released, and the filter membrane 4 located on the membrane placing frame 3 is taken off, and then a new filter membrane 4 is installed. The replacement operation of the filter membrane 4 is simple and convenient, which can greatly improve the replacement efficiency of the filter membrane 4. In addition, since the outer edge part 42 is clamped between the air inlet base body 1 and the air outlet base body 2, one side of the outer edge part 42 is in close contact with the air inlet base body 1, and the other side of the outer edge part 42 is in close contact with the air outlet base body 2, so as to seal the gap between one side of the outer edge part 42 and the air inlet base body 1 and the gap between the other side of the outer edge part 42 and the air outlet base body 2, prevent the air in the air collecting cavity 12 from leaking to the outside of the air filter through the gap between one side of the outer edge part 42 and the air inlet base body 1, and prevent the air in the exhaust cavity 21 from leaking to the outside of the air filter through the gap between the other side of the outer edge part 42 and the air outlet base body 2, improving the airtightness of the air filter.

[0058] See Figure 3 and Figure 5 In one embodiment, the hole wall of the mounting hole 23 is provided with a plurality of second limiting protrusions 27, and the plurality of second limiting protrusions 27 are arranged at intervals around the axial center line of the mounting hole 23. The outer peripheral wall of the membrane placing frame 3 has a limiting groove 31, and the limiting groove 31 is adapted to the second limiting protrusions 27 to reliably limit the membrane placing frame 3 in the mounting hole 23.

[0059] See Figure 4 In one embodiment, the inner side wall of the outlet end of the air collecting cavity 12 is provided with a plurality of first limiting protrusions 14, and the plurality of first limiting protrusions 14 are arranged at intervals around the axial center line of the air collecting cavity 12;

[0060] One side of the filtering part 41 facing away from the membrane placing frame 3 abuts against a plurality of first limiting protrusions 14, and the outer peripheral edge of the side of the membrane placing frame 3 facing away from the filter membrane 4 abuts against the bottom wall of the mounting hole 23, so as to clamp the membrane placing frame 3 between the air inlet base body 1 and the air outlet base body 2, realizing reliable limitation of the membrane placing frame 3 in the mounting hole 23. At the same time, since the membrane placing frame 3 is clamped between the air inlet base body 1 and the air outlet base body 2, the outer edge of the side of the membrane placing frame 3 facing away from the filter membrane 4 is in close contact with the bottom wall of the mounting hole 23, thereby sealing the gap between the outer edge of the side of the membrane placing frame 3 facing away from the filter membrane 4 and the bottom wall of the mounting hole 23, preventing air in the air collecting cavity 12 and the exhaust cavity 21 from leaking through the gap between the outer edge of the side of the membrane placing frame 3 facing away from the filter membrane 4 and the bottom wall of the mounting hole 23, and further improving the airtightness of the air filter.

[0061] See Figures 3-5 , in an embodiment, the side of the air outlet base body 2 close to the air collecting cavity 12 further has a first positioning groove 24, the first positioning groove 24 is closer to the air collecting cavity 12 than the mounting hole 23, and the first positioning groove 24 is arranged around the mounting hole 23;

[0062] The air inlet base body 1 is provided with a first positioning ring 15, the first positioning ring 15 is arranged around the outlet end of the air collecting cavity 12, and the first positioning ring 15 is inserted into the first positioning groove 24;

[0063] The outer edge part 42 is clamped between the bottom wall of the first positioning groove 24 and the first positioning ring 15. Since the first positioning ring 15 is inserted into the first positioning groove 24, it will not increase the size of the air filter in the air flow direction, making the overall structure of the air filter more compact, more conducive to the miniaturized design of the air filter. The small-sized air filter can improve the air flow response speed, thereby being conducive to improving the efficiency of the gas analyzer. At the same time, during assembly, the cooperation of the first positioning ring 15 and the first positioning groove 24 can realize the positioning of the air inlet base body 1 and the air outlet, enabling the air inlet base body 1 and the air outlet base body 2 to be quickly and correctly docked, which is conducive to improving the airtightness at the connection between the air inlet base body 1 and the air outlet base body 2 and can also improve the assembly efficiency.

[0064] See Figures 3-5 , in an embodiment, the air inlet base body 1 further has a second positioning groove 16, and the second positioning groove 16 is arranged around the first positioning ring 15;

[0065] The air outlet base body 2 is further provided with a second positioning ring 25. The second positioning ring 25 is arranged around the first positioning groove 24. The second positioning ring 25 is adapted to the second positioning groove 16, and the end of the second positioning ring 25 abuts against the bottom wall of the second positioning groove 16, so that the end of the second positioning ring 25 is in close fit with the bottom wall of the second positioning groove 16, which can seal the gap between the end of the second positioning ring 25 and the bottom wall of the second positioning groove 16, preventing air from leaking to the outside of the air filter through the gap between the end of the second positioning ring 25 and the bottom wall of the second positioning groove 16, thereby further improving the airtightness of the air filter. At the same time, since the second positioning ring 25 is adapted to the second positioning groove 16, during assembly, the intake base body 1 and the air outlet intake can be positioned by the cooperation of the second positioning ring 25 and the second positioning groove 16, enabling the intake base body 1 and the air outlet base body 2 to be quickly and correctly docked. This is beneficial to improving the airtightness at the connection between the intake base body 1 and the air outlet base body 2, and can also improve the installation efficiency. In addition, the second positioning groove 16 can accommodate the second positioning ring 25, without increasing the size of the air filter in the air flow direction, making the overall structure of the air filter more compact, which is more conducive to the miniaturized design of the air filter. A small-sized air filter can improve the air flow response speed, thus being beneficial to improving the efficiency of the gas analyzer.

[0066] Among them, two different types of filter membranes 4 (ePTFE pure membrane and PTFE membrane with PET support layer, both with a particle size of 5 μm and a diameter of 80 mm, and the membrane fluxes of the two are inconsistent) can be selected and installed in the air filter for airtightness detection. After testing, both can meet the requirements of flow rate: < 0.05 L / min (50 sccm); pressure < 250 mmHg, and can achieve better airtightness requirements, that is, the air filter has better airtightness performance.

[0067] See Figures 1-3 , in an embodiment, the connecting base body 5 includes:

[0068] A cylindrical part 52, and the cylindrical part 52 is provided with an internal thread structure 51;

[0069] A limiting ring 53, which is arranged at one end of the cylindrical part 52. The limiting ring 53 extends towards the axial center direction of the cylindrical part 52. The air outlet base body 2 is clamped between the end of the limiting ring 53 close to the internal thread structure 51 and the intake base body 1. Thus, during assembly, first, the air outlet base body 2 is inserted into the cylindrical part 52 and abuts against the limiting ring 53, and then the intake base body 1 is screwed into the cylindrical part 52 until the intake base body 1 abuts against the air outlet base body 2.

[0070] In one embodiment, the intake matrix 1, the outlet matrix 2, and the membrane placement frame 3 are all structures made of PFA (soluble polytetrafluoroethylene) material, so that the intake matrix 1, the outlet matrix 2, and the membrane placement frame 3 all have anti-adsorption properties, preventing dust in the air from adhering to the intake matrix 1, the outlet matrix 2, and the membrane placement frame 3. At the same time, the overall air filter is made lighter, facilitating the installation of the air filter with a non-support structure on the gas analyzer.

[0071] In one embodiment, the filter membrane 4 is a PTFE (Teflon) filter membrane 4, and high permeability is achieved regardless of the type of the filter membrane 4 (pure membrane ePTFE or filter membrane 4 with a PET support layer), and the filtering performance is good.

[0072] In one embodiment, the connection matrix 5 is a structure made of PC material, which reduces the material requirements of the connection matrix 5, thereby reducing the cost of the air filter. At the same time, the overall air filter is made lighter, facilitating the installation of the air filter with a non-support structure on the gas analyzer.

[0073] See Figures 2-3 , in one embodiment, a plurality of support protrusions 26 are provided on the bottom wall of the exhaust cavity 21. The plurality of support protrusions 26 are spaced apart. The end of the support protrusion 26 facing away from the bottom wall of the exhaust cavity 21 abuts against the membrane placement frame 3, so as to facilitate the support of the membrane placement frame 3 and prevent the membrane placement frame 3 from deforming, so that the filter membrane 4 can filter air.

[0074] See Figure 2 , in one embodiment, a first limiting portion 121 is provided inside the air outlet end of the intake joint 11. The first limiting portion 121 is used to abut against the intake pipe 6 to limit the insertion of the intake pipe 6 into the gas collection cavity 12, so as to prevent the intake pipe 6 from damaging the filter membrane 4. The intake pipe 6 is used to communicate with the outside air;

[0075] A second limiting portion 221 is provided inside the air inlet end of the air outlet joint 22. The second limiting portion 221 is used to abut against the air outlet pipe 7 to limit the insertion of the air outlet pipe 7 into the exhaust cavity 21, so as to prevent the air outlet pipe 7 from damaging the filter membrane 4. Among them, the air outlet pipe 7 is used to communicate with the gas analyzer.

[0076] It can be understood that the above-mentioned intake pipe 6 is the air input end. In practical applications, the intake pipe 6 can be a sampling branch of the sampling pipe. When the sampled air passes through the filter, it enters the automated quality control equipment or gas analyzer for on-line air monitoring through the air outlet pipe 7.

[0077] A preferred embodiment of the present utility model provides a gas analyzer, including the above-mentioned air filter.

[0078] For the gas analyzer of the present utility model, due to the adoption of the above air filter, and also because at least the cross-section of the inlet end of the gas collection chamber 12 gradually expands in the air flow direction of the air filter, the inlet end of the gas collection chamber 12 is a tapered structure that gradually expands in the air flow direction. The tapered structure that gradually expands in the air flow direction can guide the air sent out by the air inlet joint 11, enabling the air to be evenly diffused to all parts of the filter membrane 4. This can not only improve the air filtration efficiency but also increase the utilization rate of the filter membrane 4.

[0079] A preferred embodiment of the present utility model provides a gas automatic quality control device, including the above air filter.

[0080] For the gas automatic quality control device of the present utility model, due to the adoption of the above air filter, and also because at least the cross-section of the inlet end of the gas collection chamber 12 gradually expands in the air flow direction of the air filter, the inlet end of the gas collection chamber 12 is a tapered structure that gradually expands in the air flow direction. The tapered structure that gradually expands in the air flow direction can guide the air sent out by the air inlet joint 11, enabling the air to be evenly diffused to all parts of the filter membrane 4. This can not only improve the air filtration efficiency but also increase the utilization rate of the filter membrane 4.

[0081] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0082] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of these features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0083] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of various changes or substitutions, and these should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An air filter, characterized in that: include: An air intake matrix, wherein the air intake matrix is ​​provided with an air intake connector and an air collecting cavity, wherein the air intake end of the air intake connector is used to communicate with the outside air, and the air outlet end of the air intake connector is communicated with the inlet end of the air collecting cavity, and at least the cross section of the inlet end of the air collecting cavity gradually expands toward the air flow direction of the air filter; An air outlet matrix, the air outlet matrix is ​​connected to the air inlet matrix, the air outlet matrix and the air inlet matrix are arranged one by one along the air flow direction of the air filter, the air outlet matrix is ​​provided with an exhaust cavity and an air outlet joint, the air inlet end of the air outlet joint is connected with the outlet end of the exhaust cavity, and the air outlet end of the air outlet joint is used to be connected with a gas analyzer or a gas automatic quality control device; A film mounting frame, the film mounting frame is located in the air inlet matrix or the air outlet matrix, and the film mounting frame connects the outlet end of the gas collecting cavity with the inlet end of the exhaust cavity; The filter membrane is arranged on a side of the membrane frame close to the gas collecting cavity, and the filter membrane covers the outlet end of the gas collecting cavity.

2. An air filter according to claim 1, characterized in that: The outer peripheral wall of the air intake substrate is provided with an external thread structure; The air filter also includes: A connecting base, wherein the connecting base is sleeved on at least a portion of the outer peripheral wall of the air inlet base and the outer peripheral wall of the air outlet base, the connecting base has an internal thread structure, the internal thread structure and the external thread structure are adapted, and the air outlet base is sandwiched between the connecting base and the air inlet base.

3. An air filter according to claim 2, characterized in that: The gas outlet substrate has a mounting hole on one side close to the gas collecting cavity, and the mounting hole is arranged around the gas inlet end of the gas outlet cavity; The film mounting frame is located in the mounting hole; The filter membrane is provided with a filter portion and an outer edge portion, wherein the filter portion covers the outlet end of the gas collecting cavity, and the outer edge portion is arranged around the filter portion, and the outer edge portion is sandwiched between the air inlet matrix and the air outlet matrix.

4. An air filter according to claim 3, characterized in that: The inner side wall of the outlet end of the gas collecting cavity is provided with a plurality of first limiting protrusions, and the plurality of first limiting protrusions are arranged at intervals around the axial center line of the gas collecting cavity; The side of the filter portion facing away from the film holder abuts against the first plurality of limiting protrusions, and the side of the film holder facing away from the filter membrane abuts against the bottom wall of the mounting hole, so that the film holder is clamped between the air inlet matrix and the air outlet matrix.

5. An air filter according to claim 3, characterized in that: The air outlet substrate is further provided with a first positioning groove on one side close to the air collecting cavity, the first positioning groove is closer to the air collecting cavity than the mounting hole, and the first positioning groove is arranged around the mounting hole; The air inlet substrate is provided with a first positioning ring, the first positioning ring is arranged around the outlet end of the air collecting cavity, and the first positioning ring is inserted into the first positioning groove; The outer edge portion is sandwiched between the bottom wall of the first positioning groove and the first positioning ring.

6. An air filter according to claim 5, characterized in that: The air intake base also has a second positioning groove, and the second positioning groove is arranged around the first positioning ring; The air outlet base is further provided with a second positioning ring, which is arranged around the first positioning groove. The second positioning ring is adapted to the second positioning groove, and the end of the second positioning ring abuts against the bottom wall of the second positioning groove.

7. An air filter according to claim 2, characterized in that: The connecting matrix comprises: A cylindrical portion, wherein the cylindrical portion has the internal thread structure; A limiting ring is arranged on one end of the cylindrical portion, the limiting ring extends toward the axial center direction of the cylindrical portion, and the air outlet substrate is clamped between the end of the limiting ring close to the internal thread structure and the air inlet substrate.

8. An air filter according to claim 1, characterized in that: The bottom wall of the exhaust cavity is provided with a plurality of supporting protrusions, the plurality of supporting protrusions are arranged at intervals, and the ends of the supporting protrusions away from the bottom wall of the exhaust cavity abut against the film mounting frame; And / or, a first limiting portion is provided in the air outlet end of the air inlet connector, and the first limiting portion is used to abut against the air inlet pipe to limit the insertion of the air inlet pipe into the air collecting cavity; A second limiting portion is provided inside the air inlet end of the air outlet connector, and the second limiting portion is used to abut against the air outlet pipe to limit the insertion of the air outlet pipe into the exhaust cavity.

9. A gas analyzer, characterized in that An air filter comprising any one of claims 1-8.

10. Gas automatic quality control device, characterized in that: An air filter comprising the air filter according to any one of claims 1 to 8.

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