Dynamic and static dual calibration device for dust instrument

Abstract

The utility model discloses a dynamic and static dual calibration device for a dust meter, which comprises a low-concentration dust environment simulation device, the low-concentration dust environment simulation device comprises a rack, a detection chamber is arranged on the rack, a dust feeding barrel is communicated above the detection chamber, and the upper end of the dust feeding barrel is communicated with a dust generating device and a blowing mechanism; a grid plate is arranged in the detection chamber and divides the detection chamber into an upper-layer chamber and a lower-layer chamber, a fixed support is further arranged on the grid plate, a first air outlet is formed in the side wall of the lower-layer chamber and connected with a first filtering device and a first air extractor, and a second air outlet is formed in the upper-layer chamber and connected with a second filtering device and a second air extractor; the second air outlet is fixedly connected with an air supply pipe, a jet device is arranged in the air supply pipe, the downstream of the horizontal wind tunnel is connected with a second filtering device and a second air extractor, the horizontal wind tunnel is provided with a wind speed detector and a detection head installation window, and the device can meet the dynamic and static dual calibration requirements of the dust instrument and is higher in accuracy.

Description

Technical Field

[0001] This utility model relates to the field of dust meter calibration technology, and in particular to a dynamic and static dual calibration device for dust meters. Background Technology

[0002] Currently, existing dust environment simulation equipment directly feeds the generated dust into a relevant container, and then completes the detection through a detection unit. At the same time, the simulation equipment can also be used to calibrate the detection elements. However, with the above method, the uniformity of dust distribution in the container is poor, which not only affects the detection accuracy, but also the low accuracy of the calibration of the detection elements will also affect the detection effect in subsequent use.

[0003] The applicant previously applied for a low-concentration dust environment simulation testing device, with authorization announcement number CN217111950U. This publication describes a low-concentration dust environment simulation testing device, but this device is suitable for static calibration of dust meters. That is, the dust meter is placed in a testing chamber where the dust is uniformly dispersed and its flow is very slow to ensure the uniformity of dust dispersion within the testing chamber. This results in more accurate calibration results.

[0004] However, some dust meters have unique application scenarios. For example, when detecting the concentration of flue gas in a chimney, it is necessary to sample the flue gas at the same velocity as the flue gas inside the chimney. This means that the dust meter needs to be sampled at the same velocity as the flue gas in the chimney for concentration detection. Therefore, the dynamic accuracy requirements of the dust meter are also higher. However, the accuracy of the dust meter in a static environment does not represent the accuracy in a dynamic environment. Therefore, there is currently no dual calibration device that can simultaneously meet both dynamic and static requirements. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a dynamic and static dual calibration device for dust meters, which can simultaneously meet the dynamic and static dual calibration requirements of dust meters, thus improving the detection accuracy of dust meters.

[0006] To solve the above-mentioned technical problems, the technical solution of this utility model is: a dynamic and static dual calibration device for dust meters, including a low-concentration dust environment simulation device. The low-concentration dust environment simulation device includes a frame, on which a detection chamber is provided. A vertically arranged dust feeding cylinder is connected above the detection chamber. A dust generating device and a blowing mechanism are connected to the upper end of the dust feeding cylinder. The air outlet direction of the blowing mechanism is tangent to the dust feeding cylinder. A grid plate for placing the dust meter is provided in the detection chamber. The grid plate divides the detection chamber into an upper chamber and a lower chamber. A fixing support for fixing the sampling head of the filter membrane sampling device is also provided on the grid plate. The lower chamber... A first air outlet is provided on the side wall of the chamber, and the first air outlet is connected to a first filter device and a first extraction device. A second air outlet is provided on the side wall of the upper chamber, and a supply pipe is fixedly connected to the second air outlet. The supply pipe is connected to the air inlet of the horizontal wind tunnel. A jet pump ejector is provided inside the supply pipe, and the outlet of the jet pump is connected to the horizontal wind tunnel. The air inlet of the jet pump is connected to the supply pipe. A second filter device and a second extraction device are connected downstream of the horizontal wind tunnel. An anemometer and a sampling head mounting window are provided on the horizontal wind tunnel. The sampling head mounting window is used to fix the sampling head of the standard measuring instrument and the sampling head of the measuring instrument to be calibrated.

[0007] As a preferred embodiment, the air supply duct includes a straight pipe section and a constricted pipe section. The straight pipe section is fixed to the side wall of the upper chamber via a flange. The large-diameter end of the constricted pipe section is connected to the straight pipe section. The jet pump ejector is fixed inside the straight pipe section. The bottom of the straight pipe section is provided with a compressed air inlet for the jet pump. An external housing is also fixed outside the straight pipe section, and the working pump of the jet pump is fixed inside the external housing.

[0008] As a preferred embodiment, the horizontal wind tunnel includes a flared pipe section and a horizontal uniform flow straight pipe section. The small-diameter end of the flared pipe section is connected to the large-diameter end of the constricted pipe section, and the large-diameter end of the flared pipe section is connected to the horizontal uniform flow straight pipe section. The detection head mounting window and the anemometer are both located on the horizontal uniform flow straight pipe section.

[0009] As a preferred embodiment, the detection head mounting window is located at the upper part of the horizontal uniform flow straight pipe section, and an upper cover plate is detachably installed on the detection head mounting window. The sampling head of the fixed standard detection instrument and the sampling head of the detection instrument to be calibrated are fixed on the upper cover plate.

[0010] As a preferred embodiment, a first sampling tube and a second sampling tube are fixed on the upper cover plate. The lower ends of the first sampling tube and the second sampling tube extend into the interior of the horizontal uniform flow straight pipe section. The lower end openings of the first sampling tube and the second sampling tube are horizontally set and face the air inlet side. The upper ends of the first sampling tube and the second sampling tube are respectively connected to the sampling head of the standard detection instrument and the sampling head of the detection instrument to be calibrated.

[0011] As a preferred embodiment, the lower end of the first sampling tube and the lower end of the second sampling tube are on the same cross-section, and the lower end of the first sampling tube and the lower end of the second sampling tube are close to the center of the horizontal uniform flow straight pipe section and are arranged symmetrically from left to right.

[0012] As a preferred embodiment, the horizontal uniform flow straight pipe section is also equipped with a temperature probe and a humidity probe, and the flared pipe section is also equipped with an air inlet for replenishing warm and humid air, which is connected to the warm and humid air replenishment system.

[0013] As a preferred embodiment, the horizontal wind tunnel is fixed on a movable support, and the bottom of the movable support is equipped with casters.

[0014] As a preferred embodiment, a pneumatic valve is installed between the air supply duct and the air inlet of the horizontal wind tunnel.

[0015] As a preferred embodiment, the first filter device and the second filter device are the same set of filter devices, and the first air extraction device and the second air extraction device are the same set of power devices.

[0016] After adopting the above technical solution, the effect of this utility model is as follows: The grid plate divides the detection chamber into an upper chamber and a lower chamber. The grid plate is also provided with a fixing support for fixing the sampling head of the filter membrane sampling device. A first air outlet is provided on the side wall of the lower chamber, and the first air outlet is connected to a first filter device and a first extraction device. A second air outlet is provided on the side wall of the upper chamber, and a supply pipe is fixedly connected to the second air outlet. The supply pipe is connected to the air inlet of a horizontal wind tunnel. A jet pump ejector is provided inside the supply pipe, and the outlet of the jet pump is connected to the horizontal wind tunnel. The suction port of the jet pump is connected to the supply pipe. A second filter is connected downstream of the horizontal wind tunnel. The system includes a filtration device and a second extraction device. The horizontal wind tunnel is equipped with an anemometer and a sampling head mounting window. This window is used to fix the sampling heads of both the standard and the instrument to be calibrated. Therefore, during static calibration, the dust meter to be calibrated simply needs to be placed on the grid plate. Calibration can be performed using either the membrane filter method or the standard dust meter. When using the membrane filter method, the membrane sampling head is fixed to a support. After sampling for a certain period, the membrane is weighed to determine the weight change before and after use, thus obtaining the particulate matter concentration. The particulate matter concentration of the instrument to be calibrated is then compared with the concentration obtained using the membrane filter method. When using the standard dust meter, another standard instrument is placed on the grid plate, and the data from the two instruments are compared for calibration. When dynamic calibration is required, the dust generating device and blowing mechanism deliver particulate matter into the upper chamber. After passing through the dust feed cylinder, the particulate matter is evenly dispersed within the upper chamber. At this point, the jet pump's ejector draws the dust-laden gas from the upper chamber into the air supply duct. Because the particulate matter has already undergone a uniform diffusion distribution process in the upper chamber, the uniformity of the dust-laden gas drawn into the air supply duct is higher. The dust-laden gas is then sent into the horizontal wind tunnel through the air supply duct, while a second extraction device downstream of the horizontal wind tunnel provides a constant suction force. The dust-laden gas flows uniformly within the horizontal wind tunnel, and the anemometer detects the current flow velocity. Then, the sampling heads of the standard instrument and the instrument to be calibrated are inserted into the wind tunnel through the sampling head installation window and sampled at a specified wind speed, thus achieving dynamic calibration. By controlling the power of the second extraction device to change the flow velocity in different horizontal wind tunnels, calibration can be performed at different wind speeds within the measurement range, improving the calibration effect. This dual dynamic and static calibration device can meet the dual dynamic and static calibration requirements of the instrument, resulting in better calibration performance.

[0017] Furthermore, the air supply duct includes a straight pipe section and a constricted pipe section. The straight pipe section is fixed to the side wall of the upper chamber via a flange. The large-diameter end of the constricted pipe section is connected to the straight pipe section. The jet pump ejector is fixed inside the straight pipe section. The bottom of the straight pipe section is provided with a compressed air inlet for the jet pump. An external housing is also fixed outside the straight pipe section. The working pump of the jet pump is fixed inside the external housing. The jet pump draws dust-laden air from the upper chamber into the air supply duct using the jet pump. After passing through the constricted pipe section, the gas enters the horizontal wind tunnel and undergoes a diffusion process to achieve a uniform distribution.

[0018] Furthermore, since the horizontal wind tunnel includes a flared pipe section and a horizontal uniform flow straight pipe section, the small-diameter end of the flared pipe section is connected to the large-diameter end of the constricted pipe section, and the large-diameter end of the flared pipe section is connected to the horizontal uniform flow straight pipe section. The detection head mounting window and the anemometer are both set on the horizontal uniform flow straight pipe section. After the constricted pipe section of the air supply pipe contracts, it enters a flared pipe section, making the dust distribution more uniform on the horizontal uniform flow straight pipe section. The fact that the detection head mounting window and the anemometer are both set on the horizontal uniform flow straight pipe section makes the detected wind speed more accurate. At the same time, the dust-laden gas particles sampled by the sampling head installed in the detection head mounting window are also more evenly distributed, ensuring the accuracy of the calibration results.

[0019] Furthermore, since the detection head installation window is located at the upper part of the horizontal uniform flow straight pipe section, a top cover plate is detachably installed on the detection head installation window. The sampling head of the fixed standard detection instrument and the sampling head of the detection instrument to be calibrated are fixed on the top cover plate. The detection head installation window can facilitate the installation and fixation of the sampling head of the standard detection instrument and the sampling head of the detection instrument to be calibrated.

[0020] Furthermore, since the first and second sampling tubes are fixed on the upper cover plate, and the lower ends of the first and second sampling tubes extend into the interior of the horizontal uniform flow straight pipe section, with the lower end openings of the first and second sampling tubes horizontally positioned and facing the air inlet side, and the upper ends of the first and second sampling tubes respectively connected to the sampling head of the standard detection instrument and the sampling head of the detection instrument to be calibrated, the first and second sampling tubes can be pre-fixed on the upper cover plate and the position of the lower end openings adjusted to face the air inlet side, thus maintaining consistency with the sampling state inside the chimney. In this way, the sampling heads of the standard detection instrument and the detection instrument to be calibrated can be directly connected to the first and second sampling tubes, making the detection operation simpler and more convenient.

[0021] Furthermore, since the lower end of the first sampling tube and the lower end of the second sampling tube are on the same cross-section, and the lower end of the first sampling tube and the lower end of the second sampling tube are close to the center of the horizontal uniform flow straight pipe section and are arranged symmetrically from left to right, the sampling consistency of the first sampling tube and the second sampling tube is better. Therefore, the error in the sampling process of the standard detection instrument and the detection instrument to be calibrated is smaller.

[0022] Furthermore, since the horizontal uniform flow straight pipe section is also equipped with temperature and humidity probes, and the flared pipe section is also equipped with a gas inlet for replenishing warm and humid air, and the gas inlet is connected to the warm and humid air replenishment system, the dust-laden gas in the horizontal wind tunnel can simulate dust-laden gas at a certain temperature and humidity, which is closer to the gas environment in the chimney, and the calibration effect is better.

[0023] Furthermore, since the horizontal wind tunnel is fixed on a movable support, and the bottom of the movable support is equipped with casters, the horizontal wind tunnel can be moved easily.

[0024] Furthermore, since a pneumatic valve is installed between the air supply pipe and the air inlet of the horizontal wind tunnel, the pneumatic valve can be closed when static calibration is required, thereby completely isolating the horizontal wind tunnel and the upper chamber. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] Figure 1 This is a three-dimensional structural view of the dual calibration device according to an embodiment of the present invention;

[0027] Figure 2 This is a side view of the dual calibration device according to an embodiment of the present invention;

[0028] Figure 3 This is a 3D diagram of a low-concentration dust environment simulation device;

[0029] Figure 4 This is a three-dimensional structural diagram of a horizontal wind tunnel;

[0030] Figure 5 This is a schematic diagram of the end face of a horizontal wind tunnel;

[0031] Figure 6 yes Figure 5 In the sectional view of AA;

[0032] In the attached diagram: 1. Frame; 2. Dust feed cylinder; 21. Air supply hood; 22. Conical section; 23. Straight section; 24. Neck; 3. Detection chamber; 31. Upper chamber; 32. Lower chamber; 4. Dust generating device; 5. Blowing mechanism; 51. Blower; 52. Filter cartridge; 53. Air supply pipe; 6. First air outlet; 7. Air supply pipe; 71. Straight pipe section; 72. Retracting pipe section; 8. External housing; 81. Jet pump; 9. Horizontal wind tunnel; 91. Flared pipe section; 92. Horizontal uniform flow straight pipe section; 93. Detector head mounting window; 94. Top cover plate; 95. First sampling tube; 96. Second sampling tube; 10. Anemometer; 11. Movable support; 12. Second filter device; 13. Fixed support. Detailed Implementation

[0033] The present invention will be further described in detail below through specific embodiments.

[0034] like Figure 1-6 As shown, a dynamic and static dual calibration device for dust meters includes a low-concentration dust environment simulation device. The low-concentration dust environment simulation device includes a frame 1, on which a detection chamber 3 is mounted. A vertically arranged dust feeding cylinder 2 is connected above the detection chamber 3. A dust generating device 4 and a blowing mechanism 5 are connected to the upper end of the dust feeding cylinder 2. The air outlet direction of the blowing mechanism 5 is tangent to the dust feeding cylinder 2. A grid plate for placing the dust meter is installed inside the detection chamber 3. The grid plate divides the detection chamber 3 into an upper chamber 31 and a lower chamber 32. A fixing support 13 for fixing the sampling head of the filter membrane sampling device is also provided on the grid plate. A mounting bracket 13 is installed on the side wall of the lower chamber 32. There is a first air outlet 6, which is connected to a first filter and a first extraction device. A second air outlet is provided on the side wall of the upper chamber 31. An air supply pipe 7 is fixedly connected to the second air outlet. The air supply pipe 7 is connected to the air inlet of the horizontal wind tunnel 9. The jet pump 81 is installed in the air supply pipe 7. The outlet of the jet pump 81 is connected to the horizontal wind tunnel 9. The air inlet of the jet pump 81 is connected to the air supply pipe 7. A second filter 12 and a second extraction device are connected downstream of the horizontal wind tunnel 9. An anemometer 10 and a detection head mounting window 93 are provided on the horizontal wind tunnel 9. The detection head mounting window 93 is used to fix the sampling head of the standard detection instrument and the sampling head of the detection instrument to be calibrated.

[0035] In this embodiment, the air supply duct 7 includes a straight pipe section 71 and a constricted pipe section 72. The straight pipe section 71 is fixed to the side wall of the upper chamber 31 by a flange. The large-diameter end of the constricted pipe section 72 is connected to the straight pipe section 71. The ejector of the jet pump 81 is fixed inside the straight pipe section 71. The bottom of the straight pipe section 71 is provided with a compressed air inlet for the ejector. An external housing 8 is also fixed outside the straight pipe section 71. The working pump of the jet pump 81 is fixed inside the external housing 8. Typically, the jet pump 81 includes a working pump and an ejector.

[0036] The horizontal wind tunnel 9 includes a flared pipe section 91 and a horizontally uniform flow straight pipe section 92. The small-diameter end of the flared pipe section 91 is connected to the large-diameter end of the constricted pipe section 72, and the large-diameter end of the flared pipe section 91 is connected to the horizontally uniform flow straight pipe section 92. The detection head mounting window 93 and the anemometer 10 are both mounted on the horizontally uniform flow straight pipe section 92. Furthermore, the detection head mounting window 93 is located on the upper part of the horizontally uniform flow straight pipe section 92, and an upper cover plate 94 is detachably mounted on the detection head mounting window 93. The sampling head of the fixed standard detection instrument and the sampling head of the detection instrument to be calibrated are fixed on the upper cover plate 94. A first sampling tube 95 and a second sampling tube 96 are fixed on the upper cover plate 94. The lower ends of the first sampling tube 95 and the second sampling tube 96 extend into the interior of the horizontal uniform flow straight pipe section 92. The lower end openings of the first sampling tube 95 and the second sampling tube 96 are horizontally positioned and face the air inlet side. The upper ends of the first sampling tube 95 and the second sampling tube 96 are respectively connected to the sampling head of the standard detection instrument and the sampling head of the detection instrument to be calibrated. The lower end openings of the first sampling tube 95 and the second sampling tube 96 are on the same cross-section and are close to the center of the horizontal uniform flow straight pipe section 92 and are arranged symmetrically from left to right.

[0037] In use, the first sampling tube 95 and the second sampling tube 96 can be pre-fixed on the upper cover plate 94 and the position of the lower end of the tube can be adjusted so that it faces the air inlet side, thus keeping in line with the sampling state inside the chimney. In this way, the sampling head of the standard detection instrument and the sampling head of the detection instrument to be calibrated can be directly connected to the first sampling tube 95 and the second sampling tube 96.

[0038] Temperature and humidity probes are installed on the horizontal straight pipe section 92, and a replenishment port for warm and humid air is installed on the flared pipe section 91, which is connected to the warm and humid air replenishment system. The horizontal wind tunnel 9 is fixed on the movable support 11, and casters are installed at the bottom of the movable support 11. A pneumatic valve is installed between the air supply pipe 7 and the air inlet of the horizontal wind tunnel 9.

[0039] In this embodiment, the first filter device and the second filter device 12 can be the same filter device, and the first air extraction device and the second air extraction device can also be the same power device. The first air extraction device and the second air extraction device are fans.

[0040] The dust feed cylinder 2 includes a straight cylinder section 23 and a conical cylinder section 22. The straight cylinder section 23 is connected to the detection chamber 3. The large end of the conical cylinder section 22 is connected to the straight cylinder section 23. An air supply hood 21 is provided at the upper end of the conical cylinder section. The lower end of the air supply hood 21 is provided with a constricted neck 24 and is connected to the small diameter end of the conical cylinder section 22.

[0041] In this embodiment, the structure of the dust generating device 4 can be detailed in the scheme described in CN202020319771.8. The blowing mechanism 5 includes an air supply pipe 53, the upper end of which is connected to the air supply hood 21. A fan box is also fixed on the frame 1. The fan box is located on one side of the feeding cylinder. A blower 51 is provided inside the fan box. The blower 51 is connected to a filter cartridge 52. The filter cartridge 52 is connected to the air supply pipe 53, thereby providing clean air and providing blowing power.

[0042] During static calibration, the pneumatic valve is closed to completely isolate the horizontal wind tunnel 9 from the upper chamber 31. The dust meter to be calibrated is simply placed on the grid plate. Calibration can be performed using either the filter membrane method or a standard dust meter. When using the filter membrane method, the filter membrane sampling head is fixed to the fixed support 13. After sampling for a certain period, the filter membrane is weighed to determine the weight change before and after use, thus obtaining the particulate matter concentration. The particulate matter concentration of the dust meter to be calibrated is then compared with the particulate matter concentration obtained using the filter membrane method. When using a standard dust meter, a standard measuring instrument is placed on the grid plate, and the data from the two instruments are compared for calibration.

[0043] When dynamic calibration is required, the dust generating device 4 and the blowing mechanism 5 feed particulate matter into the upper chamber 31. After passing through the dust feed cylinder 2, the particulate matter is evenly dispersed in the upper chamber 31. At this time, the jet pump 81 uses its ejector to draw the dust-laden gas in the upper chamber 31 into the air supply pipe 7. Since the particulate matter has already undergone a uniform diffusion distribution process in the upper chamber 31, the uniformity of the dust-laden gas drawn into the air supply pipe 7 is also higher. Then, the dust-laden gas is sent into the horizontal wind tunnel 9 through the air supply pipe 7. The downstream second extraction device provides a constant suction force, so that the dust-laden gas flows uniformly within the horizontal wind tunnel 9. The anemometer 10 can detect the current flow velocity. The sampling heads of the standard instrument and the instrument to be calibrated are directly connected to the first sampling tube 95 and the second sampling tube 96 to sample at a specified wind speed, thereby achieving dynamic calibration. In this way, the flow velocity of different horizontal wind tunnels 9 can be changed by controlling the power of the second extraction device, thereby performing calibration at different wind speeds within the measurement range, resulting in better calibration effect.

[0044] This application utilizes a greenhouse air supply system and a second air extraction device to simulate dust environments under different temperatures, humidity levels, and wind speeds within a horizontal wind tunnel 9. This allows for consideration of more factors during calibration, resulting in better and more accurate calibration. The selection principle is to first consider humidity differences, then temperature differences, and finally wind speed differences.

[0045] The pneumatic system, servo motor and other actuators, gear transmission mechanism, and lead screw and nut mechanism mentioned in this embodiment are all current conventional technologies. The 5th edition of the "Mechanical Design Handbook" published in Beijing in April 2008 (5th edition, 28th printing) details the specific structure, principle, and other designs of cylinders, motors, and other transmission mechanisms, which are existing technologies with clear and straightforward structures. The 3rd edition of "Modern Practical Pneumatic Technology" SMC training materials published by Machinery Industry Press on August 1, 2008, details vacuum components, gas circuits, and program control, indicating that the pneumatic structure in this embodiment is also existing technology and clear and straightforward. The book "Motor Drive and Speed ​​Regulation" published by Chemical Industry Press on July 1, 2015, also details motor control and limit switches. Therefore, the circuit and pneumatic connections are clear.

[0046] The above-described embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Any modifications and alterations to the technical solution of the present utility model without departing from its design spirit shall fall within the protection scope defined by the claims of the present utility model.

Claims

1. A dynamic and static dual calibration device for dust meters, comprising a low-concentration dust environment simulation device, wherein the low-concentration dust environment simulation device includes a frame, a detection chamber is provided on the frame, a vertically arranged dust feeding cylinder is connected above the detection chamber, a dust generating device and a blowing mechanism are connected to the upper end of the dust feeding cylinder, and the air outlet direction of the blowing mechanism is tangent to the dust feeding cylinder; a grid plate for placing dust meters is provided in the detection chamber, the grid plate dividing the detection chamber into an upper chamber and a lower chamber, and a fixing support for fixing the sampling head of a filter membrane sampling device is also provided on the grid plate, characterized in that: A first air outlet is provided on the side wall of the lower chamber, and the first air outlet is connected to a first filter device and a first extraction device. A second air outlet is provided on the side wall of the upper chamber, and a supply pipe is fixedly connected to the second air outlet. The supply pipe is connected to the air inlet of the horizontal wind tunnel. A jet pump ejector is provided inside the supply pipe, and the outlet of the jet pump is connected to the horizontal wind tunnel. The air inlet of the jet pump is connected to the supply pipe. A second filter device and a second extraction device are connected downstream of the horizontal wind tunnel. An anemometer and a sampling head mounting window are provided on the horizontal wind tunnel. The sampling head mounting window is used to fix the sampling head of the standard measuring instrument and the sampling head of the measuring instrument to be calibrated.

2. The dynamic and static dual calibration device for a dust meter as described in claim 1, characterized in that: The air supply pipe includes a straight pipe section and a constricted pipe section. The straight pipe section is fixed to the side wall of the upper chamber by a flange. The large-diameter end of the constricted pipe section is connected to the straight pipe section. The jet pump ejector is fixed inside the straight pipe section. The bottom of the straight pipe section is provided with a compressed air inlet for the jet pump. An external housing is also fixed outside the straight pipe section. The working pump of the jet pump is fixed inside the external housing.

3. The dynamic and static dual calibration device for a dust meter as described in claim 2, characterized in that: The horizontal wind tunnel includes a flared pipe section and a horizontal uniform flow straight pipe section. The small diameter end of the flared pipe section is connected to the large diameter end of the constricted pipe section, and the large diameter end of the flared pipe section is connected to the horizontal uniform flow straight pipe section. The detection head mounting window and the anemometer are both set on the horizontal uniform flow straight pipe section.

4. The dynamic and static dual calibration device for a dust meter as described in claim 3, characterized in that: The detection head mounting window is located at the upper part of the horizontal uniform flow straight pipe section. A top cover plate is detachably installed on the detection head mounting window. The sampling head of the fixed standard detection instrument and the sampling head of the detection instrument to be calibrated are fixed on the top cover plate.

5. The dynamic and static dual calibration device for a dust meter as described in claim 4, characterized in that: The upper cover plate is fixed with a first sampling tube and a second sampling tube. The lower ends of the first sampling tube and the second sampling tube extend into the interior of the horizontal uniform flow straight pipe section. The lower end openings of the first sampling tube and the second sampling tube are set horizontally and face the air inlet side. The upper ends of the first sampling tube and the second sampling tube are respectively connected to the sampling head of the standard detection instrument and the sampling head of the detection instrument to be calibrated.

6. The dynamic and static dual calibration device for a dust meter as described in claim 5, characterized in that: The lower end of the first sampling tube and the lower end of the second sampling tube are on the same cross-section, and the lower end of the first sampling tube and the lower end of the second sampling tube are close to the center of the horizontal uniform flow straight pipe section and are arranged symmetrically from left to right.

7. The dynamic and static dual calibration device for a dust meter as described in claim 6, characterized in that: Temperature and humidity probes are also installed on the horizontal uniform flow straight pipe section, and air inlet for replenishing warm and humid air is also installed on the flared pipe section. The air inlet is connected to the warm and humid air replenishment system.

8. The dynamic and static dual calibration device for a dust meter as described in claim 1, characterized in that: The horizontal wind tunnel is fixed on a movable support, and the bottom of the movable support is equipped with casters.

9. The dynamic and static dual calibration device for a dust meter as described in claim 1, characterized in that: A pneumatic valve is installed between the air supply pipe and the air inlet of the horizontal wind tunnel.

10. The dynamic and static dual calibration device for a dust meter as described in claim 9, characterized in that: The first filter device and the second filter device are the same set of filter devices, and the first air extraction device and the second air extraction device are the same set of power devices.

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