Constant-speed flue gas sampling device and method

Abstract

The invention discloses a constant-speed flue gas sampling device and method, and relates to the technical field of flue gas sampling, and the constant-speed flue gas sampling device comprises a controller arranged outside; a sampling tube; a small-diameter pipe for communicating one end of the right-angle pipe with one end of the sampling pipe is arranged between the right-angle pipe and the sampling pipe, the pipe diameter of the right-angle pipe is equal to that of the sampling pipe, and the pipe diameter of the small-diameter pipe is smaller than that of the right-angle pipe. When the sampling pipe generates negative pressure, the opening and closing mechanism adjusts the flow rate, so that the flow rate of smoke entering the right-angle pipe is consistent with the flow rate of exhausted smoke, particles in the smoke easily stay at the corner of the right-angle pipe due to the fact that the smoke passes through the corner of the right-angle pipe and the pressure intensity of the outer side is high, the flow rate of the particles in the small-diameter pipe is increased, and the pressure intensity of the particles in the small-diameter pipe is reduced. Therefore, the particles are not easy to stay at the corner of the right-angle pipe, so that laminar flow enters the small-diameter pipe and then enters the sampling pipe, the pressure is recovered, and the flow velocity of the airflow is consistent with that of the flue gas again.

Description

Technical Field

[0001] The invention relates to the technical field of smoke sampling, and in particular to a constant-speed smoke sampling device and method. Background Art

[0002] The flue gas sampling device is a common device on the market. It is a device that extracts the flue gas through a probe inserted into the flue and equipped with an extraction fan. The flue gas sampling device is equipped with corresponding instruments to convert the extracted sample concentration into an intuitive value for analysis and reference.

[0003] In the prior art, for example, a Chinese invention with publication number CN212059580U discloses a flue gas isokinetic sampling device, including a sampler, a controller, an extraction fan and a measuring instrument. The sampler and the extraction fan are both electrically connected to the controller, and the measuring instrument is respectively connected to the sampler and the extraction fan. The sampler includes a sampling tube, a heating rod arranged in the sampling tube, a headless bolt arranged in the heating rod and a probe mechanism inserted in the sampling tube. The probe mechanism includes a driving mechanism, a fixing mechanism and a rotating mechanism. The driving mechanism is used to drive the rotating mechanism to rotate, and the rotating mechanism is used to drive the fixing device to rotate. The fixing mechanism adjusts the aperture diameter of the probe mechanism under the drive of the rotating mechanism. The present invention has a compact structure, convenient loading and unloading, adjustable tube diameter, and wind speed matches the tube diameter size to achieve isokinetic sampling.

[0004] The sampling tube of the above device needs to go deep into the smoke exhaust for sampling, but the smoke flow direction is perpendicular to the sampling direction. During the isokinetic sampling process, some particles in the smoke are still thrown out, resulting in inaccurate detection results. Summary of the invention

[0005] The purpose of the present invention is to provide a constant-speed flue gas sampling device and method to solve the technical problem in the prior art that the sampling tube needs to go deep into the smoke exhaust for sampling, but the smoke flow direction and the sampling direction are perpendicular to each other. During the constant-speed sampling process, some particles in the smoke are still thrown out, resulting in inaccurate detection results.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: The present invention provides a constant-speed flue gas sampling device, comprising: Sampling tube; A right angle tube, one end of the right angle tube and one end of the sampling tube are connected by a small diameter tube; An opening and closing mechanism for controlling the air intake, wherein the entire opening and closing mechanism is installed on the other end of the right-angle tube; A flow detection component is used for detecting the gas flow rate, and the flow detection component is arranged as a whole on a right-angle tube.

[0007] A further improvement of the present invention is that the diameter of the right-angle tube is equal to the diameter of the sampling tube.

[0008] A further improvement of the present invention is that the diameter of the small-diameter tube is smaller than the diameter of the right-angle tube.

[0009] A further improvement of the present invention is that the opening and closing mechanism includes a rotating ring plate, a fixed ring plate and a plurality of triangular blocks, the fixed ring plate is fixed as a whole in the right-angle tube, the annular surface of the fixed ring plate is provided with a plurality of oblique grooves annularly distributed at equal distances around its central bearing, the outer wall of the triangular block is fixed with a guide column, and each guide column is entirely arranged in each oblique groove, the rotating ring plate is integrally rotatably installed in the right-angle tube, the annular surface of the rotating ring plate is provided with a plurality of arc grooves annularly distributed at equal distances around its central bearing, the outer wall of the triangular block is fixed with a sliding column, and each sliding column is respectively arranged in each arc groove.

[0010] A further improvement of the present invention is that the opening and closing mechanism further comprises a driving assembly, the driving assembly is entirely arranged on the right-angle tube, the driving assembly is connected to the rotating ring plate, and the driving assembly causes the rotating ring plate to rotate.

[0011] A further improvement of the present invention is that the driving component includes an electric push rod, and a first fixed plate and a second fixed plate are rotatably installed at both ends of the electric push rod, the first fixed plate is fixed to the rotating ring plate, the second fixed plate is fixed to the right-angle tube, and the electric push rod establishes an electrical connection with the controller.

[0012] A further improvement of the present invention is that the flow detection component includes a force-bearing component and a cylindrical shell, two cavities are opened inside the cylindrical shell, one of the cavities has a notch on its outer wall, the entire force-bearing component is arranged in the cavity with the notch, the force-bearing component includes a rotating rod and a plurality of force-bearing plates, and rotating holes are opened at both ends of the cavity with the notch, the two ends of the rotating rod are respectively rotatably installed in the rotating holes, and one end of the plurality of force-bearing plates is fixed on the rotating rod.

[0013] A further improvement of the present invention is that the flow detection assembly also includes an angular velocity sensor, and the angular velocity sensor is entirely installed in another cavity.

[0014] A further improvement of the present invention is that one end of the rotating rod is located in the detection hole of the angular velocity sensor.

[0015] The present invention also provides a constant-speed flue gas sampling method, comprising: Insert the right-angle tube deep into the smoke exhaust pipe, and make the central axis of the right-angle tube parallel to the central axis of the smoke exhaust pipe. At this time, the smoke enters along the right-angle tube. When the sampling tube generates negative pressure, the opening and closing mechanism adjusts the flow rate, so that the smoke flow rate entering the right-angle tube is consistent with the smoke flow rate of the smoke exhaust. Since the smoke passes through the corner of the right-angle tube, the pressure on the outside is strong, and the particles in the smoke are easy to stay at the corner of the right-angle tube. The flow rate in the small-diameter tube increases and the pressure decreases. As a result, the particles are not easy to stay at the corner of the right-angle tube, so as to maintain laminar flow into the small-diameter tube, and then to the sampling tube, the pressure is restored, and the flow rate of the airflow and the smoke are consistent again Compared with the prior art, the present invention has at least the following beneficial technical effects: The present invention provides a constant-speed flue gas sampling device and method, which inserts a right-angle tube deeply into a smoke exhaust pipe, and at the same time makes the central axis of the right-angle tube parallel to the central axis of the smoke exhaust pipe. At this time, the smoke enters along the right-angle tube. When the sampling tube generates negative pressure, the opening and closing mechanism adjusts the flow rate, so that the flow rate of the smoke entering the right-angle tube is consistent with the flow rate of the smoke exhaust. Since the smoke passes through the corner of the right-angle tube, the pressure on the outside is strong, and the particles in the smoke are easy to stay at the corner of the right-angle tube. The flow rate in the small-diameter tube increases and the pressure decreases. Therefore, the particles are not easy to stay at the corner of the right-angle tube, so that the laminar flow enters the small-diameter tube, and then enters the sampling tube, the pressure is restored, and the flow rate of the airflow is consistent with that of the smoke again. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a three-dimensional structural schematic diagram of the present invention; Figure 2 It is a schematic diagram of a partial three-dimensional structure of a right-angle tube of the present invention; Figure 3 It is a schematic diagram of the cross-sectional structure of the flow detection component of the present invention; Figure 4 It is a schematic diagram of the three-dimensional structure of the opening and closing mechanism of the present invention from a first viewing angle; Figure 5 is a schematic diagram of the three-dimensional structure of the opening and closing mechanism of the present invention from a second viewing angle; Figure 6 It is a schematic diagram of the triangular block distribution structure of the present invention; Figure 7 It is a schematic diagram of the cross-sectional structure of the right-angle tube and the small-diameter tube of the present invention.

[0018] Description of reference numerals: 1. Right-angle tube; 2. Small-diameter tube; 3. Sampling tube; 4. Opening and closing mechanism; 5. Flow detection assembly; 6. Rotating ring plate; 7. Fixed ring plate; 8. Triangular block; 9. Sliding column; 10. Inclined groove; 11. Guide column; 12. Electric push rod; 13. First fixed plate; 14. Second fixed plate; 15. Arc groove; 16. Angular velocity sensor; 17. Rotating rod; 18. Force plate; 19. Cylindrical shell. DETAILED DESCRIPTION

[0019] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0022] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0024] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0025] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0026] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0027] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0028] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0029] Example 1 refer to Figure 1-7 As shown, the present invention provides a constant-speed flue gas sampling device, comprising: Sampling tube 3; A right angle tube 1, a small diameter tube 2 is arranged between one end of the right angle tube 1 and one end of the sampling tube 3 to connect the two, the diameter of the right angle tube 1 is equal to the diameter of the sampling tube 3, and the diameter of the small diameter tube 2 is smaller than the diameter of the right angle tube 1; An opening and closing mechanism 4 for controlling the air intake, wherein the entire opening and closing mechanism 4 is mounted on the other end of the right-angle tube 1; The flow detection component 5 is used to detect the gas flow rate, and the flow detection component 5 is entirely arranged on the right-angle tube 1.

[0030] From the above connection relationship, it can be known that the right-angle tube 1 is deeply inserted into the smoke exhaust pipe, and at the same time, the central axis of the right-angle tube 1 is made parallel to the central axis of the smoke exhaust pipe. At this time, the smoke enters along the right-angle tube 1. When the sampling tube 3 generates negative pressure, the opening and closing mechanism 4 adjusts the flow rate, so that the flow rate of the smoke entering the right-angle tube 1 is consistent with the flow rate of the smoke exhaust. Since the smoke passes through the corner of the right-angle tube 1, the pressure on the outside is strong, and the particles in the smoke are easy to stay at the corner of the right-angle tube 1. The flow rate in the small-diameter tube 2 increases and the pressure decreases. Therefore, the particles are not easy to stay at the corner of the right-angle tube 1, thereby maintaining laminar flow into the small-diameter tube 2, and then to the sampling tube 3, the pressure is restored, and the flow rate of the airflow and the smoke are consistent again.

[0031] In this embodiment, the opening and closing mechanism 4 includes a rotating ring plate 6, a fixed ring plate 7 and a plurality of triangular blocks 8. The fixed ring plate 7 is fixed in its entirety in the right-angle tube 1. The annular surface of the fixed ring plate 7 is provided with a plurality of angular grooves 10 equidistantly distributed annularly around its central bearing. The outer wall of the triangular block 8 is fixed with a guide column 11. The entirety of each guide column 11 is arranged in each angular groove 10. The rotating ring plate 6 is integrally rotatably installed in the right-angle tube 1. The annular surface of the rotating ring plate 6 is provided with a plurality of arc grooves 15 equidistantly distributed annularly around its central bearing. The outer wall of the triangular block 8 is fixed with a Sliding columns 9, each sliding column 9 is respectively arranged in each arc groove 15, wherein the opening and closing mechanism 4 also includes a driving component, the driving component is arranged as a whole on the right-angle tube 1, the driving component is connected to the rotating ring plate 6, and the driving component causes the rotating ring plate 6 to rotate, the driving component includes an electric push rod 12, and the first fixed plate 13 and the second fixed plate 14 are rotatably installed at both ends of the electric push rod 12, the first fixed plate 13 is fixed to the rotating ring plate 6, and the second fixed plate 14 is fixed to the right-angle tube 1, and the electric push rod 12 establishes an electrical connection with the controller.

[0032] It can be known from the above connection relationship that the opening and closing mechanism 4 is an existing technology. Here, the specific structure of the opening and closing mechanism 4 is explained, and its working principle is briefly described. The electric push rod 12 is extended and retracted, thereby driving the rotating ring plate 6 to rotate forward and reverse. The rotating ring plate 6 makes the various triangular blocks 8 fit together to expand or shrink the hole.

[0033] In this embodiment, the flow detection component 5 includes a force-bearing component and a cylindrical shell 19. Two cavities are opened inside the cylindrical shell 19, and a notch is opened on the outer wall of one side of one cavity. The entire force-bearing component is arranged in the cavity with the notch. The force-bearing component includes a rotating rod 17 and a plurality of force-bearing plates 18. Rotating holes are opened at both ends of the cavity with the notch. The two ends of the rotating rod 17 are respectively rotatably installed in the rotating holes. One end of the plurality of force-bearing plates 18 is fixed on the rotating rod 17. The flow detection component 5 also includes an angular velocity sensor 16. The angular velocity sensor 16 is entirely installed in another cavity, and one end of the rotating rod 17 is located in the detection hole of the angular velocity sensor 16.

[0034] It can be known from the above connection relationship that the smoke pushes the force-bearing plate 18, and the force-bearing plate 18 drives the rotating rod 17 to rotate. The rotation speed of the rotating rod 17 is detected by the angular velocity sensor 16, and the controller controls the opening and closing mechanism 4 to perform hole shrinking and hole expanding movements.

[0035] The working principle of the present invention is as follows: the right-angle tube 1 is deeply inserted into the smoke exhaust pipe, and the central axis of the right-angle tube 1 is made parallel to the central axis of the smoke exhaust pipe. At this time, the smoke enters along the right-angle tube 1. When the sampling tube 3 generates negative pressure, the opening and closing mechanism 4 adjusts the flow rate (the smoke pushes the force-bearing plate 18, and the force-bearing plate 18 drives the rotating rod 17 to rotate. The rotation speed of the rotating rod 17 is detected by the angular velocity sensor 16, and the controller controls the opening and closing mechanism 4 to shrink and expand the hole), so that the flow rate of the smoke entering the right-angle tube 1 is consistent with the flow rate of the smoke exhaust. Since the smoke passes through the corner of the right-angle tube 1, the pressure on the outside is strong, and the particles in the smoke are easy to stay at the corner of the right-angle tube 1, the flow rate in the small-diameter tube 2 increases, and the pressure becomes smaller, so that the particles are not easy to stay at the corner of the right-angle tube 1, thereby maintaining laminar flow into the small-diameter tube 2, and then to the sampling tube 3, the pressure is restored, and the flow rate of the airflow is consistent with that of the smoke again.

[0036] Example 2 The present invention provides a constant-speed flue gas sampling method, comprising: Insert the right-angle tube 1 deep into the smoke exhaust pipe, and make the central axis of the right-angle tube 1 parallel to the central axis of the smoke exhaust pipe. At this time, the smoke enters along the right-angle tube 1. When the sampling tube 3 generates negative pressure, the opening and closing mechanism 4 adjusts the flow rate so that the smoke flow rate entering the right-angle tube 1 is consistent with the smoke flow rate of the smoke exhaust. Since the smoke passes through the corner of the right-angle tube 1, the pressure on the outside is strong, and the particles in the smoke are easy to stay at the corner of the right-angle tube 1. The flow rate in the small-diameter tube 2 increases and the pressure decreases. As a result, the particles are not easy to stay at the corner of the right-angle tube 1, thereby maintaining laminar flow into the small-diameter tube 2, and then to the sampling tube 3, the pressure is restored, and the airflow and the flow rate of the smoke are consistent again.

[0037] Among them, the flow rate of the flue gas in the right-angle tube 1 is ensured to be consistent with the flue gas flow rate in the exhaust pipe through the flow adjustment of the opening and closing mechanism 4. This equal flow rate design can avoid sampling deviations caused by flow rate differences, so that the obtained flue gas samples can better represent the flue gas conditions in the entire exhaust pipe, and improve the accuracy of sampling. Although the design of the right-angle tube 1 theoretically has the risk of particles staying at the corners, the introduction of the small-diameter tube 2 and the Bernoulli principle (increased flow rate and reduced pressure) effectively reduce the particle deposition at the corners of the right-angle tube 1. The high-speed flow in the small-diameter tube 2 reduces the particle residence time, making it more difficult for particles to accumulate at the corners of the right-angle tube 1, thereby ensuring the purity and representativeness of the sample. Through the optimized design, the system can keep the flue gas flowing in the small-diameter tube 2 in a laminar state. Laminar flow is conducive to reducing collisions and agglomeration between particles, further reducing particle loss and sampling errors. This is particularly important for application scenarios that require accurate analysis of flue gas composition or particle distribution. After the smoke enters the sampling tube 3 from the small diameter tube 2, the pressure gradually recovers, and the airflow and the flow rate of the smoke are consistent again. This process ensures the dynamic balance of the smoke during the sampling process and avoids sampling errors caused by changes in pressure or flow rate. The introduction of the opening and closing mechanism 4 provides the system with the flexibility of flow regulation, enabling it to adapt to the conditions of the smoke exhaust pipe under different working conditions. This adaptability enhances the versatility and reliability of the system, enabling it to play a role in a wider range of application scenarios. Since the system design reduces the risk of particle deposition and clogging, the need for regular cleaning and maintenance is reduced. This not only saves manpower and time costs, but also extends the service life of the equipment.

[0038] In summary, the present invention realizes efficient, accurate and reliable flue gas sampling through ingenious structural design and functional integration, providing strong support for flue gas emission monitoring and environmental protection.

[0039] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0040] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A constant-speed flue gas sampling device, characterized in that: include: Sampling tube (3); A right-angle tube (1), wherein a small-diameter tube (2) is provided between one end of the right-angle tube (1) and one end of the sampling tube (3) to connect the two ends; An opening and closing mechanism (4) for controlling the air intake amount, the opening and closing mechanism (4) being entirely mounted on the other end of the right-angle tube (1); A flow detection component (5) is used to detect the flow rate of gas, and the flow detection component (5) is arranged as a whole on the right-angle tube (1).

2. The isokinetic flue gas sampling device according to claim 1, characterized in that: The diameter of the right-angle tube (1) is equal to the diameter of the sampling tube (3).

3. The isokinetic flue gas sampling device according to claim 1, characterized in that: The diameter of the small-diameter tube (2) is smaller than the diameter of the right-angle tube (1).

4. The isokinetic flue gas sampling device according to claim 1, characterized in that: The opening and closing mechanism (4) comprises a rotating ring plate (6), a fixed ring plate (7) and a plurality of triangular blocks (8); the fixed ring plate (7) is entirely fixed in the right-angle tube (1); a plurality of angular grooves (10) are formed on the annular surface of the fixed ring plate (7) and are equidistantly distributed in annular shapes around its central bearing; a guide column (11) is fixed on the outer wall of the triangular block (8); each guide column (11) is entirely arranged in each angular groove (10); the rotating ring plate (6) is entirely rotatably mounted in the right-angle tube (1); a plurality of arc grooves (15) are formed on the annular surface of the rotating ring plate (6) and are equidistantly distributed in annular shapes around its central bearing; a sliding column (9) is fixed on the outer wall of the triangular block (8); each sliding column (9) is respectively arranged in each arc groove (15).

5. The isokinetic flue gas sampling device according to claim 4, characterized in that: The opening and closing mechanism (4) further comprises a driving assembly, the driving assembly being arranged as a whole on the right-angle tube (1), the driving assembly being connected to the rotating ring plate (6), and the driving assembly causing the rotating ring plate (6) to rotate.

6. The isokinetic flue gas sampling device according to claim 5, characterized in that: The driving assembly comprises an electric push rod (12), and a first fixing plate (13) and a second fixing plate (14) are rotatably mounted on both ends of the electric push rod (12), the first fixing plate (13) is fixed to the rotating ring plate (6), the second fixing plate (14) is fixed to the right-angle tube (1), and the electric push rod (12) is electrically connected to the controller.

7. The isokinetic smoke sampling device according to claim 6, characterized in that: The flow detection component (5) comprises a force-bearing component and a cylindrical shell (19). Two cavities are provided inside the cylindrical shell (19). A notch is provided on one side of the outer wall of one of the cavities. The entire force-bearing component is arranged in the cavity with the notch. The force-bearing component comprises a rotating rod (17) and a plurality of force-bearing plates (18). Rotating holes are provided at both ends of the cavity with the notch. Both ends of the rotating rod (17) are rotatably mounted in the rotating holes. One end of the plurality of force-bearing plates (18) is fixed to the rotating rod (17).

8. The isokinetic flue gas sampling device according to claim 7, characterized in that: The flow detection component (5) further comprises an angular velocity sensor (16), and the angular velocity sensor (16) is entirely mounted in another cavity.

9. The isokinetic flue gas sampling device according to claim 8, characterized in that: One end of the rotating rod (17) is located in the detection hole of the angular velocity sensor (16).

10. A constant-speed flue gas sampling method, characterized in that: The method is based on a constant-speed flue gas sampling device according to claim 1, comprising: The right-angle tube (1) is inserted deep into the smoke exhaust pipe, and the central axis of the right-angle tube (1) is parallel to the central axis of the smoke exhaust pipe. At this time, the smoke enters along the right-angle tube (1). When the sampling tube (3) generates negative pressure, the opening and closing mechanism (4) adjusts the flow rate, so that the flow rate of the smoke entering the right-angle tube (1) is consistent with the flow rate of the smoke exhaust. Since the smoke passes through the corner of the right-angle tube (1), the pressure on the outside is strong, and the particles in the smoke are easy to stay at the corner of the right-angle tube (1). The flow rate in the small-diameter tube (2) increases and the pressure decreases. Therefore, the particles are not easy to stay at the corner of the right-angle tube (1), so that the laminar flow is maintained to enter the small-diameter tube (2), and then to the sampling tube (3). The pressure is restored and the flow rate of the air flow is consistent with the flow rate of the smoke again.

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