A high efficiency filter leak test apparatus and method

Abstract

This invention discloses a high-efficiency filter sealing performance testing device and method in the field of filter sealing performance testing technology, aiming to solve the problem of poor test results caused by the location and content limitations of traditional aerosol detection methods in the prior art. It includes a fixed support, on which an annular air chamber and a split air chamber located below the annular air chamber are fixedly installed. The annular air chamber has a hollow annular structure. The split air chamber includes a partition for dividing the inner cavity of the split air chamber into two. A test component and a filter to be tested are fixedly arranged above the annular air chamber. The test component includes a gas supply pipe for supplying gas containing aerosols. The gas supplied by the gas supply pipe is connected to the inner cavity of the annular air chamber through the filter to be tested. This invention is used for high-efficiency filter sealing performance testing, enabling aerosol accumulation during the testing process, making it easier to detect, thereby improving the accuracy of leak judgment and providing a more reliable basis.

Description

Technical Field

[0001] This invention relates to a high-efficiency filter sealing performance testing device and method, belonging to the field of filter sealing performance testing technology. Background Technology

[0002] High-efficiency particulate air (HEPA) filters are core components for air filtration. Through physical interception, they effectively block fine particles in the air and are widely used in air purification. The structure of an HEPA filter mainly consists of folded filter paper and a supporting frame. However, improper application of adhesive during the folding process can damage the filter paper's structure, and gaps that are difficult to observe can also occur during the sealing process. This leads to the failure of the filter paper's filtration function. Therefore, before leaving the factory, HEPA filters typically undergo a sealing test. A common method is to pass a gas containing aerosol through the filter paper and then measure the aerosol content downstream of the interception surface to determine if there is a leak. However, this method requires a photometer to scan a large area below the filter, which can easily lead to inaccurate judgments for minute leaks. Furthermore, this instantaneous scanning makes it difficult to determine the degree of leakage based on the amount of leakage, thus limiting its practical application. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-efficiency filter sealing performance testing device and method for testing the sealing performance of high-efficiency filters. It can achieve aerosol accumulation during the testing process, making it easier to detect, thereby improving the accuracy of leak judgment and providing a more reliable basis.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] This invention provides a high-efficiency filter sealing performance testing device, comprising a fixed bracket, on which an annular air chamber and a split air chamber located below the annular air chamber are fixedly mounted. The annular air chamber has a hollow annular structure. The split air chamber includes a partition for dividing its inner cavity into two parts. A testing component and a filter to be tested are fixedly disposed above the annular air chamber. The testing component includes a gas supply pipe for supplying gas containing aerosols. The gas supplied by the gas supply pipe is connected to the inner cavity of the annular air chamber through the filter to be tested. Hollow rotating grooves are provided at the lower end of the annular air chamber and the upper end of the split air chamber. Rotation within the hollow rotating grooves... A second filter is provided, and a drive assembly for rotating the second filter is also provided on the fixed bracket. The upper filter surface of the second filter is located in the inner cavity of the annular air chamber, and the lower filter surface of the second filter is in closed contact with the two inner cavities of the split air chamber. One inner cavity of the split air chamber is connected to an air inlet pipe, and the other inner cavity is connected to an exhaust pipe. A pressure air pipe located at the tangential position of the inner cavity of the annular air chamber is installed on the annular air chamber. A photometer assembly for detecting the aerosol content in the inner cavity of the annular air chamber is provided on the annular air chamber, and a light source for supplementing light to the detection position of the photometer assembly is also provided on the annular air chamber.

[0006] Specifically, the detection direction of the photometer assembly is located in the tangential direction of the inner wall of the annular ventilation chamber, and the illumination direction of the light source is perpendicular to the detection direction of the photometer assembly.

[0007] Specifically, the test assembly also includes a storage slot for positioning the filter under test. The filter under test is in close contact with the inner wall of the storage slot. A storage cover is hinged to the side wall of the storage slot. The storage cover can cover the storage slot to form a closed cavity. The air supply pipe is installed on the storage cover and can communicate with the closed cavity. The bottom of the storage slot can communicate with the inner cavity of the annular air chamber.

[0008] Specifically, an auxiliary air intake assembly is provided at the bottom of the storage slot. The auxiliary air intake assembly includes several connecting pipes that are connected to the bottom surface of the storage slot. Each connecting pipe has an air inlet on its side wall. Each connecting pipe has a mounting block installed at its lower end. Each mounting block is connected to a piston by a spring. Each piston is slidably disposed in the corresponding connecting pipe.

[0009] Specifically, the bottom surface of the inner wall of the storage tank is provided with a support block for supporting the filter to be tested, so that the bottom surface of the filter to be tested and the bottom surface of the inner cavity of the storage tank form a support cavity.

[0010] Specifically, the storage slot is also equipped with an auxiliary air pipe that can communicate with the supporting cavity.

[0011] Specifically, an exhaust pipe is also installed on the side wall of the annular air chamber.

[0012] This invention provides a method for testing the sealing performance of a high-efficiency filter, comprising the aforementioned sealing test apparatus, wherein the method includes:

[0013] The gas to be tested, containing aerosol, is introduced into the gas supply pipe, and the gas passes sequentially through the test filter, the inner cavity of the annular air chamber, and the secondary filter, so that the gas is finally discharged through the exhaust pipe.

[0014] Keep the second filter in a rotating state and backflush it through the air inlet pipe;

[0015] Airflow is supplied tangentially to the annular cavity, allowing the airflow to form an annular airflow through the annular cavity of the annular wind chamber.

[0016] After the rated time has elapsed, the aerosol content in the annular airflow is detected by the photometer assembly while ensuring supplemental lighting.

[0017] Specifically, after the aerosol content is measured, the gas supply passage of the gas supply pipe and the exhaust passage of the exhaust pipe are closed, while the backflush intake state of the air inlet pipe and the gas supply state of the pressure air pipe are maintained. The gas in the annular air chamber is extracted through the exhaust pipe set on the side wall of the annular air chamber.

[0018] Specifically, the air pressure on the air inlet side of the filter under test, the annular air chamber, and the exhaust pipe are monitored in real time, and it is ensured that the air pressure on the air inlet side of the filter is always greater than the air pressure in the annular air chamber, and the air pressure in the annular air chamber is always greater than the air pressure in the exhaust pipe.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0020] The high-efficiency filter sealing test device provided by this invention, by configuring an annular air chamber and a pressure duct, can form an annular airflow within the annular air chamber. At this time, the gas containing aerosol supplied by the air supply pipe can enter the annular air chamber through the filter under test, and the Bernoulli principle allows some of the aerosol to enter the annular airflow, thereby achieving the accumulation of aerosol in the annular airflow. The second filter realizes the exhaust and the return of the intercepted aerosol, thus ensuring the air pressure in the chamber while allowing the aerosol intercepted by the second filter to return to the annular air chamber. This helps to ensure the accurate aerosol accumulation amount for efficient detection by the photometer component, so as to determine whether there is a leak and provide more effective leakage degree parameters. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the testing device provided in an embodiment of the present invention;

[0022] Figure 2 This is the present invention. Figure 1 Enlarged view of the structure at point A of the test device provided in the embodiment;

[0023] Figure 3 This is another schematic diagram of the testing device provided in the embodiments of the present invention;

[0024] Figure 4 This is the present invention. Figure 3 Enlarged view of section B of the test device provided in the embodiment;

[0025] Figure 5 This is a front view of the testing apparatus provided in an embodiment of the present invention;

[0026] Figure 6 This is a side view of the testing device provided in an embodiment of the present invention;

[0027] Figure 7 This is the present invention. Figure 6 A cross-sectional view of the test apparatus provided in the embodiment;

[0028] Figure 8 This is the present invention. Figure 6 A DD-direction cross-sectional view of the test apparatus provided in the embodiment;

[0029] Figure 9 This is the present invention. Figure 7 Enlarged view of the structure at point E of the test device provided in the embodiment;

[0030] Figure 10 This is a schematic diagram of the structure of the annular air chamber provided in an embodiment of the present invention;

[0031] Figure 11 This is a schematic diagram of the structure of the split air chamber provided in an embodiment of the present invention;

[0032] Reference numerals: 1. Fixed bracket; 2. Annular air chamber; 3. Test assembly; 301. Storage slot; 302. Storage cover; 303. Air supply pipe; 4. Disconnecting air chamber; 5. Second filter; 6. Drive assembly; 7. Air inlet pipe; 8. Exhaust pipe; 9. Pressure air duct; 10. Light source; 11. Solenoid valve; 12. Photometer assembly; 13. Connecting pipe; 14. Mounting block; 15. Spring; 16. Piston; 17. Suction pipe; 18. Auxiliary air pipe. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0034] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances. Example 1

[0036] This invention provides a high-efficiency filter sealing performance testing device for testing the sealing performance of high-efficiency filters. It enables aerosol accumulation during testing, making it easier to detect leaks and thus improving the accuracy of leak detection and providing a more reliable basis. To achieve the device's structural function, it includes a fixed support 1, on which an annular air chamber 2 and a split air chamber 4 located below the annular air chamber 2 are fixedly mounted. (Refer to...) Figure 7 as well as Figure 10 As shown, the annular air chamber 2 can be configured to have a hollow annular structure, and according to... Figure 11 As shown, the configuration of the split-off air chamber 4 includes a partition for dividing the inner cavity of the split-off air chamber 4 into two separate inner cavities. To facilitate the placement of the filter under test and ventilation testing, a test assembly 3 and the filter under test are fixedly installed above the annular air chamber 2. The test assembly 3 should include a gas supply pipe 303 for supplying aerosol-containing gas. The specific configuration and fixing method are not limited here, as long as the gas supplied by the gas supply pipe 303 can connect with the inner cavity of the annular air chamber 2 through the filter under test without side leakage. Simultaneously, hollow rotating grooves are provided at the lower end of the annular air chamber 2 and the upper end of the split-off air chamber 4, as shown in the figure. Figure 10 , Figure 11 as well as Figure 7In this configuration, a second filter 5 is rotatably mounted within a hollow rotating groove. This second filter 5 is configured to intercept aerosol particles and to achieve backflushing of particles. It can be a PTFE membrane filter cartridge or a nano-micro PTFE fiber composite filter media, etc. A drive assembly 6 for rotating the second filter 5 is also mounted on the fixed bracket 1. This ensures that the upper filtration surface of the second filter 5 is in close contact with the inner cavity of the annular air chamber 2, and that the lower filtration surface of the second filter 5 is in sealed contact with the two separated inner cavities of the split air chamber 4. This allows the bottom surface of the second filter 5 to rotate when driven by the drive assembly 6 (such as a motor). To maintain the close contact between the two inner cavities of the split-off air chamber 4 and completely isolate them, an inlet pipe 7 is connected to one inner cavity of the split-off air chamber 4 and an exhaust pipe 8 is connected to the other inner cavity. Both the inlet pipe 7 and the exhaust pipe 8 are controlled by a solenoid valve 11 to control whether to allow air in or out. As a preferred configuration, a pressure valve can also be used. Thus, when the air supply pipe 303 supplies gas containing aerosols, it can pass through the inner cavity of the annular air chamber 2 and then be discharged through the second filter 5. If the filter under test leaks, gas containing aerosols will enter the annular air chamber 2 and the aerosols can be blocked. Within the annular air chamber 2, particles accumulate continuously, allowing for the detection of aerosol content after a rated operating time to determine if the tested filter is leaking or the extent of leakage. To avoid uneven aerosol distribution within the annular air chamber 2, which could affect the detection results due to variations in detection location and uniformity, a pressure duct 9 is installed on the annular air chamber 2, positioned tangentially to its interior. This pressure duct 9 supplies high-speed airflow into the annular air chamber 2, guiding the airflow through an arc-shaped surface to form an annular airflow within the chamber. Since this annular airflow is primarily concentrated on the side walls, the concentration of particles within the air chamber is significantly reduced. The airflow velocity is high near the inner wall of the annular air chamber 2, which allows aerosol particles to accumulate at the location of the annular airflow due to the pressure difference. In addition, the aerosol particles after backflushing by the second filter 5 will also return to the cavity of the annular air chamber 2, thus ensuring that no aerosol components are missed. Regarding the configuration of the detection mechanism, a photometer component 12 for detecting the aerosol content in the cavity of the annular air chamber 2 can be installed on the annular air chamber 2. At the same time, in order to avoid the particles being directly judged and detected, a light source 10 for supplementing light to the detection position of the photometer component 12 can also be installed on the annular air chamber 2, so that the particles can scatter light and thus be easily detected.During the testing process, to ensure a stable annular airflow within the annular air chamber 2, multiple pressure ducts 9 can be arranged in a circular array and connected to the annular air chamber 2. Furthermore, the air intake of the second filter 5 during backflushing, the air intake of the air supply pipe 303, and the air intake of the pressure ducts 9 should match the exhaust volume of the second filter 5. At this point, the air pressure within the annular air chamber 2 should be significantly higher than the air pressure inside the exhaust pipe 8. This testing method avoids the inability to effectively detect trace amounts of aerosols after leakage due to the large filtration surface of the high-efficiency filter. This method allows for the accumulation of airflow containing a large number of aerosol particles within the annular air chamber 2 over time. By amplifying the aerosol content, it becomes more readily detectable by the photometer component 12. Furthermore, the degree of leakage in the tested filter can be determined based on the operating time and the amount of accumulated aerosols, thus providing a reference for the type of filter defect (e.g., minor leaks may be caused by unstable adhesive coating leading to filter paper breakage, while large leaks may be due to poor encapsulation), thereby improving the upstream manufacturing process. It should be noted that aerosol particles can be either solid or liquid. When using solid particles, they are more likely to be blown out by the backflushing action of the second filter 5. Alternatively, a common method is to use a flow guide such as a Laskin nozzle to atomize PAO (polyalphacatalyst) or DOP (dioctyl phthalate) oil into aerosols with a particle size concentration of about 0.3 μm. In this case, in order to ensure efficient backflushing of aerosol particles, the second filter 5 can use PTFE membrane filter material and use the shearing force generated by high-pressure pulse backflushing to peel the aerosol particles off from the interception surface, thereby allowing them to return to the chamber of the annular air chamber 2.

[0037] This invention provides a high-efficiency filter sealing performance testing device. Since the inner cavity of the annular chamber 2 is annular, if the testing position of the photometer assembly 12 is directly perpendicular to the tangent of the inner wall of the annular chamber 2, two areas in its straight direction will be detected simultaneously. Furthermore, due to the unstable diffusion range of particles, after the light source 10 illuminates the area, the photometer assembly 12 cannot accurately calculate the rated volume range of the luminescent particles, making it difficult to estimate the overall particle content within the annular chamber 2. Therefore, the detection direction of the photometer assembly 12 can be located along the tangent of the inner wall of the annular chamber 2. The light source 10 is then used to irradiate particles passing through that position along the tangent. The illuminated area and detection position are limited, thus ensuring the content of luminescent particles under the rated volume detection, which is beneficial for accurately determining the total number of particles within the annular chamber 2, facilitating more reliable data for analysis and reference. In this case, the irradiation direction of the light source 10 should be perpendicular to the detection direction of the photometer assembly 12 to avoid light pollution caused by direct illumination from the light source 10 affecting the detection process.

[0038] This invention provides a high-efficiency filter sealing performance testing device. To achieve stable fixation and testing of the filter under test, the testing component 3 may also include a receiving groove 301 for positioning the filter under test. (See reference...) Figure 1 As shown, the storage slot 301 has a recess for placing the filter under test. The filter under test is positioned to fit snugly against the inner wall of the storage slot 301, thus creating an environment to prevent side leakage. A storage cover 302 is hinged to the side wall of the storage slot 301, covering the storage slot 301 to form a closed cavity. To supply air for testing, an air supply pipe 303 is installed on the storage cover 302 and communicates with the closed cavity. (Refer to...) Figure 7 As shown, the bottom of the receiving slot 301 should be able to communicate with the inner cavity of the annular air chamber 2. When it is necessary to test the sealing performance of the HEPA filter, the filter to be tested can be placed directly into the slot of the receiving slot 301, and then the receiving cover 302 can be fastened and sealed before introducing gas containing aerosol. This achieves the installation, positioning, sealing, and ventilation of the HEPA filter.

[0039] This invention provides a high-efficiency filter sealing performance testing device. During operation, the air pressure on the inlet side of the high-efficiency filter must be greater than the air pressure inside the annular chamber 2 to ensure that the gas supplied by the air supply pipe 303 can smoothly enter the annular chamber 2 due to the pressure difference. However, if the annular chamber 2 and the air supply pipe 303 are only connected through the high-efficiency filter under test, the air pressure inside the annular chamber 2 can easily increase rapidly, causing a decrease in the pressure difference across the high-efficiency filter. This can easily lead to unstable pressure control within the annular chamber 2 and affect the air intake effect. Furthermore, due to the continuous air supply from the pressure duct 9 and the inlet pipe 7, if the air pressure exceeds the air pressure inside the air supply pipe 303, it can easily cause reverse airflow, resulting in aerosols in the gas adhering to the high-efficiency filter in the opposite direction. This can easily damage the high-efficiency filter structure and significantly reduce the testing capability. Therefore, an auxiliary air intake component can be provided at the bottom of the receiving tank 301, which can be referred to... Figure 7 as well as Figure 9The design incorporates an auxiliary air intake assembly consisting of several connecting pipes 13 that are connected to the bottom surface of the storage slot 301. Each connecting pipe 13 has an air inlet on its side wall for air outlet. Each connecting pipe 13 has a mounting block 14 installed at its lower end, and each mounting block 14 is connected to a piston 16 via a spring 15. Each piston 16 is slidably installed within the corresponding connecting pipe 13. Through the design of this structure, the piston 16 and the air outlet side of the high-efficiency filter form a pressure side that supplies gas to the annular air chamber 2. That is, in the chamber at the pressure side, when the gas pressure meets the rated value, the piston 16 can be opened by compressing the spring 15 (in the normal state, the spring 15 abuts against the piston 16, so that the piston 16 is located above the air inlet, thus blocking the gas supply side environment). After the air inlet is opened, the closed chamber above the piston 16 begins to depressurize and discharge gas. When the pressure difference is insufficient or after it tends to be balanced with the gas pressure in the annular air chamber 2, the spring 15 causes the piston 16 to return to its original position, thereby ensuring that the gas can only flow from the air outlet side of the high-efficiency filter into the annular air chamber 2 and preventing the gas from flowing out in the opposite direction. In some preferred embodiments, the air inlet can be designed to be narrower at the top and wider at the bottom. Since the spring 15 provides elasticity, it can be stably compressed to a certain extent even when there is a large air pressure on the outlet side of the HEPA filter, ensuring stable exhaust. When the gas pressure increases, the gas exhaust demand increases, which is reflected in the piston 16 being able to adapt to the height position to meet the gas exhaust demand. At the same time, the descent of the piston 16 can continuously increase the air inlet surface area until it is in the appropriate position, which has a good auxiliary effect on stabilizing the gas pressure on the outlet side of the HEPA filter. When the narrow part of the air inlet cannot meet the excessive gas exhaust demand, the descent of the piston 16 will open the wider air inlet below, thereby realizing the instantaneous exhaust of gas on the outlet side of the HEPA filter and avoiding the problem of continuous pressure rise and ineffective balanced exhaust.

[0040] This invention provides a high-efficiency filter sealing performance testing device. In order to ensure that the gas on the outlet side of the high-efficiency filter can allow all the gas on the effective filtration surface to enter the annular air chamber 2, a support block for supporting the filter under test can be provided on the bottom surface of the inner wall of the receiving groove 301. The support block makes the bottom surface of the filter under test and the bottom surface of the inner cavity of the receiving groove 301 form a support cavity, thereby avoiding the bottom surface of the high-efficiency filter from directly contacting the bottom surface of the receiving groove 301, so that the actual effective testing surface is only the part of the high-efficiency filter corresponding to the connecting pipe 13.

[0041] This invention provides a high-efficiency filter sealing performance testing device. To facilitate the removal of the high-efficiency filter, the distance between the top surface of the support block and the top surface of the storage groove 301 can be set to be less than the height of the high-efficiency filter, so that the frame part of the high-efficiency filter can protrude from the surface plane of the storage groove 301 for easy removal. At this time, since the storage cover 302 is a hinged cover, its opening surface should be larger than the opening surface of the storage groove 301 to avoid failure to close properly and form a closed state. Alternatively, to allow the tested high-efficiency filter to be automatically ejected, an auxiliary air pipe 18 that can communicate with the support cavity can be installed on the storage groove 301. After the test is completed, pressurized gas is provided in the support cavity to make the bottom surface of the high-efficiency filter receive pressure, so that it can be automatically ejected for manual replacement. In some other preferred configurations, an air trough can also be used. By configuring a sliding and lifting top block (not shown in the figure) on the air trough, the top block can lift the HEPA filter when the auxiliary air pipe 18 is ventilated. In this case, the top block is preferably designed as a ring to ensure that it acts evenly on all parts of the bottom surface of the HEPA filter, ensuring uniform force and avoiding blockage.

[0042] This invention provides a high-efficiency filter sealing performance testing device. After use, aerosol-containing gas accumulates in the annular air chamber 2. If not cleaned in time, this will not only affect the next test but also cause contamination inside the chamber. Therefore, after the test, the amount of aerosol-containing gas can be reduced by directly venting it out. To this end, an exhaust pipe 17 is installed on the side wall of the annular air chamber 2. The exhaust pipe 17 can extract the gas in the annular air chamber 2 while forming an annular airflow. During extraction, the second filter 5 should be in the state of exhausting gas into the annular air chamber 2 to simultaneously clean the interception surface of the second filter 5. This method uses airflow cleaning to continuously reduce the aerosol content inside the annular air chamber 2 until the aerosol cannot be detected by the photometer component 12 or the aerosol content will not affect the subsequent test process. The extracted gas is discharged to avoid environmental pollution. In some other embodiments, for solid aerosol particles adhering to the inner wall of the annular air chamber 2, a pressure duct 9 can be selectively configured to discharge mist, using the mist to clean the inner cavity of the annular air chamber 2. At this time, a drain outlet can be provided on the side of the bottom of the annular air chamber 2 (the drain outlet should be located at the lowest position of the cross-section of the inner cavity of the annular air chamber 2 to prevent sewage from flowing to the filter surface of the second filter 5; alternatively, an anti-seepage structure can be provided above the second filter 5, such as an air inlet with its opening facing the lower part of the inner cavity of the annular air chamber 2 to prevent cleaning liquid from entering the surface of the second filter 5 from the air inlet). The drain outlet carries the attached aerosol particles out of the annular air chamber 2. For liquid aerosol particles, a pressure duct 9 can be selectively configured with a heating component to accelerate drying in the cavity by supplying hot air, so as to facilitate quick replacement of the test. This heating component is also applicable to the drying operation after mist cleaning. Other embodiments are not limited here. Example 2

[0043] This invention provides a method for testing the sealing performance of a high-efficiency particulate air (HEPA) filter. This method improves the reliability of the test by continuously accumulating the aerosol content on the outlet side of the HEPA filter. Furthermore, it allows for the acquisition of the corresponding leakage rate through time and accumulation parameters, providing a reference for defect types. This facilitates reverse engineering to improve the manufacturing process of HEPA filters. The method employs the sealing test apparatus described in Embodiment 1 and includes:

[0044] The gas to be tested containing aerosol is introduced through the gas supply pipe 303, and the gas passes through the test filter, the inner cavity of the annular air chamber 2 and the second filter 5 in sequence, and the gas is finally discharged through the exhaust pipe 8. In the event of a leak in the test filter, the second filter 5 intercepts the aerosol particles inside the annular air chamber 2.

[0045] Keep the second filter 5 in a rotating state and backflush the second filter 5 through the air inlet pipe 7 to avoid the accumulation of aerosol particles on the interception surface of the second filter 5 and allow the aerosol particles to move to the detection position.

[0046] Airflow is supplied tangentially to the inner cavity of the annular air chamber 2, so that the airflow can form an annular airflow through the annular inner cavity of the annular air chamber 2. The adsorption effect generated by the annular airflow causes the heavier aerosol particles to move towards the edge of the annular air chamber 2, and can move to the detection position under the drive of the annular airflow.

[0047] A rated detection time is set. After the rated time has elapsed, the photometer component 12 detects the aerosol content in the annular airflow under supplemental lighting conditions. By analyzing the aerosol content and the elapsed time, the aerosol leakage rate can be determined. A corresponding database can be established based on the data set, and more accurate defect type identification can be provided by fitting the database. Generally, a low leakage rate may correspond to defects such as filter paper breakage or poor adhesive coating, while a high leakage rate may be caused by poor filter paper sealing. This allows for reverse improvement of the upstream manufacturing process, providing more effective parameters for the manufacturing process.

[0048] This invention provides a high-efficiency filter sealing test method for efficiently removing aerosol particles contained in the annular air chamber 2 during continuous testing. After the aerosol content is measured, the air supply passage of the air supply pipe 303 and the exhaust passage of the exhaust pipe 8 are closed, while the air inlet pipe 7 is kept in a back-blowing state and the pressure air pipe 9 is kept in a supply state. The gas in the annular air chamber 2 is extracted through the exhaust pipe 17 set on the side wall of the annular air chamber 2. The aerosol particles are continuously carried by the annular airflow to the exhaust pipe 17 and discharged, thereby continuously reducing the content of aerosol particles in the annular airflow until the photometer assembly 12 no longer detects luminescent particles or no longer affects the subsequent detection process. In this step, it is important to ensure that the second filter 5 does not blow out aerosol particles in reverse to avoid affecting the subsequent detection process.

[0049] This invention provides a high-efficiency filter sealing test method. To avoid backflow and deviation between the actual and ideal air intake volume, the method monitors the air pressure on the air inlet side of the filter under test, the inner cavity of the annular air chamber 2, and the exhaust pipe 8 in real time. During operation, it ensures that the air pressure on the air inlet side of the filter is always greater than the air pressure inside the annular air chamber 2, and that the air pressure inside the annular air chamber 2 is always greater than the air pressure inside the exhaust pipe 8, thereby preventing the gas from failing to enter and exit smoothly. To stabilize the air supply process, the principle described in Embodiment 1 can also be referred to, which will not be elaborated further here.

[0050] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high efficiency filter seal test device, comprising: The system includes a fixed bracket (1), on which an annular air chamber (2) and a split air chamber (4) located below the annular air chamber (2) are fixedly installed. The annular air chamber (2) has a hollow annular structure. The split air chamber (4) includes a partition for dividing the inner cavity of the split air chamber (4) into two. A test assembly (3) and a filter to be tested are fixedly installed above the annular air chamber (2). The test assembly (3) includes a gas supply pipe (303) for supplying gas containing aerosol. The gas supplied by the gas supply pipe (303) is connected to the inner cavity of the annular air chamber (2) through the filter to be tested. A hollow rotating groove is provided at the lower end of the annular air chamber (2) and the upper end of the split air chamber (4). A second filter (5) is rotatably installed in the hollow rotating groove. The bracket (1) is also provided with a drive assembly (6) for driving the second filter (5) to rotate. The upper filter surface of the second filter (5) is located in the inner cavity of the annular air chamber (2). The lower filter surface of the second filter (5) and the two inner cavities of the split air chamber (4) are closed and in contact. One inner cavity of the split air chamber (4) is connected to an air inlet pipe (7) and the other inner cavity is connected to an exhaust pipe (8). The annular air chamber (2) is equipped with a pressure air pipe (9) located at the tangent position of the inner cavity of the annular air chamber (2). The annular air chamber (2) is provided with a photometer assembly (12) for detecting the aerosol content in the inner cavity of the annular air chamber (2). The annular air chamber (2) is also provided with a light source (10) for supplementing light to the detection position of the photometer assembly (12).

2. The high efficiency filter seal test device of claim 1, wherein, The detection direction of the photometer assembly (12) is located in the tangential direction of the inner wall of the annular wind chamber (2), and the irradiation direction of the light source (10) is perpendicular to the detection direction of the photometer assembly (12).

3. The high-efficiency filter sealing performance testing device according to claim 1, characterized in that, The test assembly (3) also includes a storage groove (301) for positioning the filter under test. The filter under test is in contact with the inner wall of the storage groove (301). A storage cover (302) is hinged to the side wall of the storage groove (301). The storage cover (302) can cover the storage groove (301) to form a closed cavity. The air supply pipe (303) is installed on the storage cover (302) and can communicate with the closed cavity. The bottom of the storage groove (301) can communicate with the inner cavity of the annular air chamber (2).

4. The high-efficiency filter sealing performance testing device according to claim 3, characterized in that, An auxiliary air intake assembly is provided at the bottom of the storage slot (301). The auxiliary air intake assembly includes several connecting pipes (13) that are connected to the bottom surface of the storage slot (301). Each connecting pipe (13) has an air inlet on its side wall. Each connecting pipe (13) has a mounting block (14) installed at its lower end. Each mounting block (14) is connected to a piston (16) by a spring (15). Each piston (16) is slidably disposed in the corresponding connecting pipe (13).

5. The high-efficiency filter sealing performance testing device according to claim 4, characterized in that, The bottom surface of the inner wall of the storage groove (301) is provided with a support block for supporting the filter to be tested, so that the bottom surface of the filter to be tested and the bottom surface of the inner cavity of the storage groove (301) form a support cavity.

6. The high-efficiency filter sealing performance testing device according to claim 5, characterized in that, The receiving slot (301) is also equipped with an auxiliary air pipe (18) that can communicate with the supporting cavity.

7. The high-efficiency filter sealing performance testing device according to claim 1, characterized in that, The side wall of the annular air chamber (2) is also equipped with an exhaust pipe (17).

8. A method for testing the sealing performance of a high-efficiency filter, using the sealing test apparatus according to any one of claims 1-7, characterized in that, The method includes: The gas supply pipe (303) introduces the gas to be tested containing aerosol, so that the gas passes through the test filter, the inner cavity of the annular wind chamber (2) and the second filter (5) in sequence, and the gas is finally discharged through the exhaust pipe (8); Keep the second filter (5) in a rotating state and backflush the second filter (5) through the air inlet pipe (7); Airflow is supplied in the tangential direction of the annular wind chamber (2) so that the airflow can form an annular airflow through the annular inner cavity of the annular wind chamber (2); After the rated time has elapsed, the aerosol content in the annular airflow is detected by the photometer assembly (12) under the condition of ensuring supplemental lighting.

9. The method for testing the sealing performance of a high-efficiency filter according to claim 8, characterized in that, After the aerosol content is measured, the gas supply passage of the gas supply pipe (303) and the exhaust passage of the exhaust pipe (8) are closed. The backflush air intake state of the air inlet pipe (7) and the gas supply state of the pressure air pipe (9) are maintained. The gas in the annular air chamber (2) is extracted through the air extraction pipe (17) set on the side wall of the annular air chamber (2) until the photometer assembly (12) no longer detects luminescent particles.

10. The method for testing the sealing performance of a high-efficiency filter according to claim 8, characterized in that, Real-time monitoring of the air pressure on the air inlet side of the filter under test, the inner cavity of the annular air chamber (2), and the exhaust pipe (8) is conducted, and during operation, the air pressure on the air inlet side of the filter is always greater than the air pressure in the annular air chamber (2), and the air pressure in the annular air chamber (2) is always greater than the air pressure in the exhaust pipe (8).

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