Filter material test bench air path system

Abstract

The application discloses a filter material test bench gas path system, which is characterized in that a gas source is connected to the inlet of the airflow pipeline, an electromagnetic valve, a pressure regulating valve and a filter are arranged on the airflow pipeline, the outlet end of the airflow pipeline is divided into multiple pipelines, and the multiple pipelines are respectively connected to an aerosol generator, an aerosol mixing cavity, a pneumatic device of an upstream clamp, a first clean air duct, a second clean air duct and a fourth clean air duct; the aerosol generator is connected to the aerosol mixing cavity; the aerosol mixing cavity is connected to the upstream clamp through an upstream aerosol pipeline; an upstream sampling pipeline and a downstream sampling pipeline are both connected to a suction pump; a downstream aerosol pipeline is connected to the suction pump; a slide valve is connected between the upstream aerosol pipeline and the downstream aerosol pipeline; and a suction pipeline is arranged on the upstream aerosol pipeline. The application can shorten the air duct cleaning time, enhance the cleaning effect, avoid the influence of aerosol on the filter material to be detected before detection, and improve the detection accuracy.

Description

Technical Field

[0001] This invention relates to the field of filter testing equipment technology, and in particular to a filter media testing platform air circuit system. Background Technology

[0002] The existing filter media testing platform works by fixing the filter media onto a fixture. An aerosol generator produces aerosol, which is then adjusted and electrostatically neutralized. The gas is then heated and uniformly mixed with filtered test air before entering the test area to pass through the filter media. To determine efficiency, airflow samples are taken upstream and downstream of the filter media. A photoelectric sensor (photometer) measures the particle concentration in the sampled airflow. The filtration efficiency of the filter media is obtained by comparing the ion concentrations in the upstream and downstream sampled gases. In the existing filter media testing station's gas path system, gas enters the pipeline through the gas source inlet, and is delivered to the aerosol generator and upstream fixture respectively through a solenoid valve, pressure regulating valve, and filter. The gas flow delivered to the aerosol generator is heated and electrostatically neutralized before entering the aerosol generator. The aerosol generated in the aerosol generator is delivered to the upstream fixture through pipeline. The gas flow and aerosol delivered to the upstream fixture pass through the filter media and enter the downstream fixture. The gas flow is then discharged outside the gas flow channel through pipelines, filters, pressure regulating valves, and a vacuum pump. Sampling tubes are installed on the upstream and downstream fixtures respectively. The gas sampled by the sampling tubes is delivered to the vacuum pump through a photoelectric sensor, filter, and throttle, and then discharged outside the gas flow channel.

[0003] Before using the air path system of the filter media testing station, the airflow channel needs to be cleaned with clean air. The clean air continuously dilutes the aerosol in the aerosol mixing chamber until its concentration is reduced to a low concentration value that the system determines is acceptable before the filter media can be tested. The cleaning process is as follows: the airflow enters the pipeline from the air source inlet, and is delivered to components such as the aerosol generator, upstream clamp, downstream clamp photoelectric sensor, etc., and finally reaches the vacuum pump, and is then discharged to the outside of the airflow channel. The cleaning process often takes two to three minutes, which is very inefficient. Moreover, because the airflow passes through many components and long pipelines from the air source inlet to the vacuum pump, it is impossible to completely remove the remaining aerosol in the pipeline, which affects the accuracy of the test results. After the cleaning process is completed, the aerosol generator will start working. The generated aerosol needs to slowly fill the aerosol mixing chamber and then fill the pipeline. The photoelectric sensor needs to determine that the aerosol state is stable before proceeding to the next step. This process also takes a long time, usually more than one or two minutes. During this process, the aerosol continuously passes through the filter material being tested, which will also affect the accuracy of the test results when the filter efficiency of the filter material is tested in the subsequent formal test. Summary of the Invention

[0004] The purpose of this invention is to address the problems described in the background art regarding the time-consuming and incomplete cleaning of the air path system in existing filter media testing stations, which affects the filter media testing results. Furthermore, the aerosol generator continuously passes through the tested filter media during the aerosol generation process, affecting the accuracy of the filter media testing results. This invention provides an air path system for filter media testing stations that can improve testing accuracy.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a filter media testing platform air path system, comprising an airflow pipeline, an upstream clamp, a downstream clamp, an aerosol generator, a heater, an electrostatic neutralizer, a vacuum pump, an upstream sampling pipeline, and a downstream sampling pipeline. The inlet of the airflow pipeline is connected to an air source. A solenoid valve, a pressure regulating valve, and a filter are installed on the airflow pipeline. The outlet of the airflow pipeline is divided into multiple pipelines. One pipeline is equipped with a heater and an electrostatic neutralizer, and its outlet is connected to an aerosol mixing chamber. Another pipeline delivers air to the aerosol generator, and is equipped with a solenoid valve and a pressure regulating valve. A third pipeline delivers air to the pneumatic device of the upstream clamp, and is equipped with a pressure regulating valve and a solenoid valve. The output end of the aerosol generator is connected to the aerosol mixing chamber via a pipeline. The output end of the aerosol mixing chamber is connected to the aerosol inlet of the upstream clamp via an upstream aerosol pipeline. The sampling end of the upstream sampling pipeline is connected to the upstream clamp, and the outlet end of the upstream sampling pipeline is connected to... The air inlet of the suction pump is connected to the downstream clamp, and the aerosol outlet of the downstream clamp is connected to the air inlet of the suction pump through the downstream aerosol pipe. A first differential pressure sensor is installed between the upstream and downstream clamps. A second differential pressure sensor, a filter, and a pressure regulating valve are installed on the downstream aerosol pipe. The sampling end of the downstream sampling pipe is connected to the downstream clamp, and the outlet end of the downstream sampling pipe is connected to the air inlet of the suction pump. A slide valve is connected between the upstream and downstream aerosol pipes. An air extraction pipe is installed on the upstream aerosol pipe between the slide valve and the upstream clamp. A solenoid valve is installed on the air extraction pipe. An air pump is installed at the outlet of the air extraction pipe. A first clean air passage is also connected between the airflow pipe and the sampling end of the upstream sampling pipe. A second clean air passage is also connected between the airflow pipe and the sampling end of the downstream sampling pipe. A third clean air passage is installed on the downstream aerosol pipe, and the two ends of the third clean air passage are respectively connected to the two ends of the second differential pressure sensor.

[0006] As a further improvement to the aforementioned filter media testing platform's gas path system, a throttle and a solenoid valve are installed in the first cleaning gas path, a throttle, a solenoid valve, and a filter are installed in the second cleaning gas path, and a solenoid valve and a filter are installed in the third cleaning gas path. The first cleaning gas path is used for rapid cleaning of the upstream sampling pipeline, controlling the flow and pressure of the gas path through the solenoid valve and throttle. The second cleaning gas path is used for rapid cleaning of the downstream sampling pipeline, controlling the flow and pressure of the gas path through the solenoid valve and throttle, and purifying the input gas through the filter. The third cleaning gas path is used for cleaning the downstream aerosol pipeline, controlling the flow of the gas path through the solenoid valve, and purifying the input gas through the filter.

[0007] As a further improvement to the air path system of the aforementioned filter media testing platform, an exhaust pipe is provided on the aerosol mixing chamber. By setting up the exhaust pipe, the airflow and aerosol discharge within the aerosol mixing chamber can be promoted during the cleaning of the aerosol generator, thereby improving cleaning efficiency.

[0008] As a further improvement to the air path system of the aforementioned filter media testing platform, photoelectric sensors, filters, and throttles are installed on both the upstream and downstream sampling pipelines. The photoelectric sensors detect and count particles in the sampled airflow, the filters remove particles from the airflow, and the throttles control the airflow pressure to stabilize the pressure delivered to the suction pump.

[0009] As a further improvement to the air path system of the filter media test bench mentioned above, solenoid valves are connected in parallel to the throttles of the upstream and downstream sampling pipelines. By connecting solenoid valves in parallel to the throttles, the solenoid valves are opened when cleaning the pipelines, allowing airflow to pass through the solenoid valves quickly and improving cleaning efficiency.

[0010] As a further improvement to the air path system of the aforementioned filter media testing platform, one output port of the slide valve is connected to an aerosol stabilization circulation channel. A solenoid valve is installed on the aerosol stabilization circulation channel, and the other end of the aerosol stabilization circulation channel is connected to a pipe leading to the aerosol generator. By setting up the aerosol stabilization circulation channel, after the pipe is cleaned but before the aerosol generated by the aerosol generator has stabilized, the aerosol output from the aerosol mixing chamber enters the aerosol stabilization circulation channel through the slide valve, and then returns to the aerosol generator from the pipe connected to it, forming an aerosol circulation channel. This allows the aerosol to gradually stabilize within the circulation channel. The solenoid valve on the aerosol stabilization circulation channel is used to control the opening and closing of the aerosol diffusion channel.

[0011] As a further improvement to the air path system of the aforementioned filter media testing platform, the outlet of the airflow pipeline is connected to a fourth cleaning air channel. This fourth cleaning air channel is equipped with a throttle, and its outlet is connected via pipes to the rear ends of both the upstream and downstream sampling pipelines. This configuration further accelerates the cleaning speed of the pipeline.

[0012] The present invention has the following positive effects: 1) The air path system of the filter media testing platform of the present invention is equipped with multiple sets of cleaning air channels. Before the filter media testing platform starts testing the filter media, the upstream clamp, downstream clamp, upstream aerosol pipeline, upstream sampling pipeline, downstream aerosol pipeline, downstream sampling pipeline, aerosol generator, and aerosol mixing chamber are quickly cleaned through the cleaning air channels. The cleaning time can be shortened to 3-5 seconds. It can quickly and thoroughly clean the upstream clamp, downstream clamp, airflow pipeline, aerosol pipeline, and aerosol sampling pipeline, and also quickly clean the inside of the aerosol generator. The cleaning is more thorough and improves the accuracy of subsequent filter media filtration performance testing; 2) The air path system of the filter media testing platform of the present invention is equipped with a sliding valve between the upstream aerosol pipeline and the downstream aerosol pipeline. After the cleaning stage is completed, the aerosol generator starts to work and generates aerosol. The aerosol concentration is unstable. During this process, the generated aerosol does not enter the upstream clamp but instead enters the aerosol stabilization circulation channel through a slide valve. It then returns to the aerosol generator via a pipe connected to it, forming a circulation that gradually stabilizes the aerosol. Simultaneously, a portion of the aerosol enters the downstream aerosol pipeline directly through the slide valve, filling both the downstream sampling and aerosol pipelines. A photoelectric sensor on the downstream sampling pipeline detects the generated aerosol. Once the aerosol generated by the aerosol generator stabilizes, the slide valve's path is changed, and the aerosol output from the aerosol mixing chamber is transported to the upstream clamp via the slide valve. Testing of the filter material can then begin. Because the aerosol-laden gas output from the aerosol generator does not enter the upstream clamp or pass through the filter material before testing, aerosol contamination of the filter material is avoided, resulting in more accurate test results during subsequent filter material testing. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the filter detection device of the present invention.

[0014] Figure 2 This is a schematic diagram of the airflow direction of the filter detection device of the present invention during the cleaning stage.

[0015] Figure 3 This is a schematic diagram of the airflow direction of the filter detection device of the present invention as the aerosol gradually reaches a stable stage.

[0016] Figure 4This is a schematic diagram of the airflow direction of the filter testing device of the present invention during the testing stage of the filter material to be tested.

[0017] The arrows in the diagram indicate the direction of airflow. Single lines represent airflow channels, and double lines represent aerosol channels.

[0018] The reference numerals in the figure are as follows: airflow duct 1, upstream clamp 2, downstream clamp 3, aerosol generator 4, aerosol mixing chamber 5, heater 6, electrostatic neutralizer 7, vacuum pump 8, upstream sampling line 9, downstream sampling line 10, upstream aerosol line 11, downstream aerosol line 12, first clean air duct 13, second clean air duct 14, third clean air duct 15, fourth clean air duct 16, aerosol stable circulation air duct 17, first differential pressure sensor 18, second differential pressure sensor 19, photoelectric sensor 20, solenoid valve 21, pressure regulating valve 22, filter 23, throttle 24, slide valve 25, exhaust pipe 26, pneumatic device 27, vacuum line 28. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below through embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] like Figure 1-4 The diagram shows a filter material testing platform air circuit system of the present invention, which includes an airflow pipe 1, an upstream clamp 2, a downstream clamp 3, an aerosol generator 4, a heater 6, an electrostatic neutralizer 7, an air pump 8, an upstream sampling pipe 9, a downstream sampling pipe 10, a first differential pressure sensor 18, a second differential pressure sensor 19, and a slide valve 25.

[0021] Gas is input into the gas source inlet through the gas duct 1. The input gas is either air or a purified detection medium gas. The gas duct 1 divides the gas into six channels, which are respectively delivered to the aerosol generator 4, the aerosol mixing chamber 5, the pneumatic device of the upstream clamp 2, the first cleaning air channel 13, the second cleaning air channel 14, and the fourth cleaning air channel 16. The gas duct 1 is equipped with a solenoid valve 21, a pressure regulating valve 22, and a filter 23. The solenoid valve 21 controls the opening and closing of the gas duct 1, the pressure regulating valve 22 controls the air pressure inside the gas duct 1, and the filter 23 filters the gas entering the gas duct 1 to make it clean air.

[0022] The first cleaning airway 13 is connected between the airflow pipe 1 and the sampling end of the upstream sampling pipe 9. A throttle and a solenoid valve are provided on the first cleaning airway 13. The first cleaning airway 13 is used to quickly clean the upstream sampling pipe 9. The opening and closing of the airway and the airflow pressure are controlled by the solenoid valve and the throttle.

[0023] The second cleaning airway 14 is connected between the airflow duct 1 and the sampling end of the downstream sampling duct 10. The second cleaning airway is equipped with a throttle valve, a solenoid valve, and a filter. The second cleaning airway 14 is used to quickly clean the downstream sampling duct. The opening and closing of the airway and the airflow pressure are controlled by the solenoid valve and throttle valve, and the input gas is filtered and purified by the filter.

[0024] The fourth cleaning airway 16 is connected to the outlet of the airflow duct 1. A throttle is installed on the fourth cleaning airway 16, and its outlet is connected via pipes to the rear ends of the upstream sampling duct 9 and the downstream sampling duct 10, respectively. By setting up the fourth cleaning airway 16, the rear ends of the upstream sampling duct 9 and the downstream sampling duct 10 can be cleaned, improving cleaning efficiency.

[0025] An aerosol stabilization circulation channel 17 is connected to one output port of the slide valve 25. A solenoid valve is installed on the aerosol stabilization circulation channel 17, and the other end of the channel is connected to a pipe leading to the aerosol generator 4. By setting up the aerosol stabilization circulation channel, after the pipe is cleaned but before the aerosol generated by the aerosol generator has stabilized, the aerosol output from the aerosol mixing chamber 5 enters the aerosol stabilization circulation channel 17 through the slide valve 25, and then returns to the aerosol generator 4 through the pipe, forming a circulation and gradually stabilizing the aerosol.

[0026] The upstream clamp 2 is a clamp driven by the pneumatic device 27. It can move towards or away from the downstream clamp 3 to clamp or loosen the filter material to be tested. The upstream clamp 2 is provided with an aerosol inlet and an upstream sampling port. The aerosol inlet is connected to the upstream aerosol pipeline 11. The input aerosol can be transmitted downward to the filter material to be tested. The upstream sampling port is used to connect to the upstream sampling pipeline 9.

[0027] An air extraction pipe 28 is provided on the upstream aerosol pipe 11. A solenoid valve is provided on the air extraction pipe 28. An air pump is provided at the outlet of the air extraction pipe 28. The air pump can draw gas from the upstream aerosol pipe 11 to clean the upstream aerosol pipe and remove residual aerosol.

[0028] The upstream sampling line 9 is used to sample and detect the aerosol-laden gas in the upstream fixture before it passes through the filter material to be tested. The upstream sampling line 9 is equipped with a photoelectric sensor 20, a filter, and a throttle. The sampling end of the upstream sampling line 9 is connected to the upstream fixture 2, and the outlet end of the upstream sampling line 9 is connected to the air inlet end of the vacuum pump 8. The sampled gas is detected by the photoelectric sensor 20, which calculates the number of particles in the gas. The filter removes these particles, ensuring the airflow delivered to the vacuum pump is clean. The throttle controls the airflow pressure to stabilize the pressure delivered to the vacuum pump. A solenoid valve is connected in parallel to the throttle. When cleaning the pipeline, the solenoid valve is opened, allowing the airflow to pass through quickly, improving cleaning efficiency.

[0029] The downstream clamp 3 is a fixed clamp. The downstream clamp 3 is set opposite to the upstream clamp 2. After the upstream clamp 2 moves downward and clamps the downstream clamp 3, a sealed gas passage is formed between the upstream clamp 2 and the downstream clamp 3. The aerosol entering the upstream clamp 2 from the aerosol inlet passes through the filter material to be tested and can enter the downstream clamp 3. It is then transported to the vacuum pump 8 through the downstream aerosol pipeline 12 connected to the downstream clamp 3. A second differential pressure sensor 19, a filter and a pressure regulating valve are provided on the downstream aerosol pipeline 12. A downstream sampling port is provided on the downstream clamp for connecting the downstream sampling pipeline 10.

[0030] A third cleaning air duct 15 is connected to the downstream aerosol pipe 12. The two ends of the third cleaning air duct 15 are respectively connected to the two ends of a second differential pressure sensor 19. The second differential pressure sensor, connected to the downstream aerosol pipe, is used to monitor the pressure difference across the third cleaning air duct to monitor the gas flow rate and whether the pipe is blocked. A solenoid valve and a filter are installed on the third cleaning air duct 15. The third cleaning air duct 15 is used to clean the downstream aerosol pipe 12. The solenoid valve controls the opening and closing of the air duct, and the filter purifies the input gas.

[0031] The downstream sampling line 10 is used to sample and detect the aerosol-laden gas in the downstream fixture 3 before it passes through the filter material to be tested. The downstream sampling line 10 is equipped with a photoelectric sensor, a filter, and a throttle. The sampling end of the downstream sampling line 10 is connected to the downstream fixture 3, and the outlet end of the downstream sampling line 10 is connected to the air inlet end of the vacuum pump 8. The sampled gas is detected by the photoelectric sensor, which calculates the number of particles in the gas. The filter removes these particles, ensuring the airflow delivered to the vacuum pump is clean. The throttle controls the airflow pressure to stabilize the pressure delivered to the vacuum pump. A solenoid valve is connected in parallel to the throttle. When cleaning the pipeline, the solenoid valve is opened, allowing the airflow to pass through quickly, improving cleaning efficiency.

[0032] The slide valve 25 is connected between the upstream aerosol pipe 11 and the downstream aerosol pipe 12. The slide valve 25 is used to change the aerosol delivery channel at different stages. During the cleaning stage, the upstream aerosol pipe 11 and the downstream aerosol pipe 12 are not connected. The gas output from the aerosol mixing chamber 5 enters the exhaust pipe 28 on the upstream aerosol pipe 11 through the slide valve 25 and is discharged through the exhaust pipe 28 to accelerate the cleaning of the aerosol generator 4 and the aerosol mixing chamber 5. After cleaning, the aerosol generation stage begins. At this stage, the aerosol is still unstable. The generated aerosol does not enter the upstream clamp but instead enters the aerosol stabilization circulation channel 17 through the slide valve 25. It then returns to the aerosol generator 4 through the pipe connected to the aerosol generator 4, forming a circulation and gradually stabilizing the aerosol. At the same time, the slide valve 25 connects the upstream aerosol pipe 11 and the downstream aerosol pipe 12. The airflow containing aerosol output from the aerosol mixing chamber 5 enters the downstream aerosol pipe 12 through the slide valve 25, filling the downstream sampling pipe 10 and the downstream aerosol pipe 12 with aerosol. The generated aerosol is detected by the photoelectric sensor on the downstream sampling pipe 10. Once the aerosol generated by the aerosol generator stabilizes, the filter material to be tested can be tested. When testing the filter material to be tested, the upstream aerosol pipe 11 and the downstream aerosol pipe 12 are disconnected by the slide valve 25. The airflow with aerosol output from the aerosol mixing chamber 5 enters the upstream clamp 2 through the upstream aerosol pipe 11, then passes down through the filter material to be tested, then enters the downstream clamp 3, and is then transported to the vacuum pump 8 through the downstream aerosol pipe 12.

[0033] Aerosol generator 4 is a device for generating aerosols. The aerosol generated in aerosol generator 4 is transported to aerosol mixing chamber 5, where it mixes with the gas that has been treated by heater 6 and electrostatic neutralizer 7 before entering aerosol mixing chamber 5, becoming the test medium for detecting the filtration performance of the filter material under test. A vent pipe 26 is provided on aerosol mixing chamber 5. By setting the vent pipe 26, the airflow and aerosol discharge within the aerosol mixing chamber can be promoted during the cleaning of the aerosol generator, thereby improving cleaning efficiency.

[0034] Heater 6 is used to heat the gas entering the aerosol mixing chamber 5.

[0035] The electrostatic neutralizer 7 is used to neutralize the gas entering the aerosol mixing chamber 5 and remove charged ions from it.

[0036] The vacuum pump 8 is used to draw in gas and create negative pressure in the pipeline, so that the gas entering from the gas source inlet and the aerosol generated in the aerosol generator 4 can be smoothly transported in the pipeline.

[0037] The first differential pressure sensor 18 is connected between the upstream clamp 2 and the downstream clamp 3 to detect the pressure difference between the upstream clamp 2 and the downstream clamp 3.

[0038] The filter media testing platform air path system of this invention, when testing the filtration performance of the filter media under test, first cleans the pipeline. During pipeline cleaning, the filter media under test is not placed between the upstream and downstream clamps; the upstream and downstream clamps are separated. Gas is input from the gas source inlet. The solenoid valves connected in parallel on the first, second, and third cleaning air channels and the throttle are opened. The airflow passes through the first, second, third, and fourth cleaning air channels to clean the residual aerosol in the pipeline. A portion of the airflow enters the aerosol generator. In the generator, another portion of the airflow simultaneously enters the aerosol mixing chamber through the pipes of the heater and the electrostatic neutralizer to clean the residual aerosol in the aerosol generator and the aerosol mixing chamber. This portion of the gas carrying aerosol reaches the extraction pipe through the slide valve and is then sucked out of the pipe by the air pump. Because the cleaning pipes are distributed to the upstream sampling pipe, the downstream sampling pipe, and the downstream aerosol pipe, the cleaning efficiency is high, and the cleaning of the gas path can be completed within 3-5 seconds. Compared with the cleaning time of 2-3 minutes required by the existing technology, the cleaning efficiency is greatly improved. After cleaning, close the solenoid valves connected in parallel on the first, second, and third cleaning air passages and the throttle. Place the filter material to be tested between the upstream and downstream clamps. The pneumatic device lowers the upstream clamp, clamping the filter material. Open the solenoid valve on the aerosol stabilization circulation air passage to begin aerosol generation. Initially, the aerosol concentration is low. The aerosol mixes evenly with the gas in the aerosol mixing chamber and then enters the downstream aerosol pipeline through a slide valve. Simultaneously, another portion of the aerosol enters the aerosol stabilization circulation air passage through a slide valve and returns to the aerosol generator through a pipeline connected to the aerosol generator, allowing the aerosol to gradually stabilize. Meanwhile, another portion of the aerosol enters the downstream aerosol pipeline and the downstream sampling pipeline through a slide valve. The photoelectric sensor in the downstream sampling pipeline monitors the aerosol flow. During the detection process, once the aerosol has stabilized, the solenoid valve on the aerosol stabilization circulation channel is closed. Simultaneously, the path of the slide valve is changed, disconnecting the upstream and downstream aerosol pipelines. The slide valve path is switched to the upstream clamp, and the aerosol output from the aerosol mixing chamber enters the upstream clamp through the slide valve. Then, it passes through the filter material to be tested between the upstream and downstream clamps and enters the downstream clamp. Finally, it is delivered to the suction pump for output through the downstream aerosol pipeline. At the same time, aerosol samples are taken in the upstream and downstream sampling pipelines. The number of particles in the aerosol before entering the filter material and the number of particles in the aerosol after passing through the filter material are detected by the corresponding photoelectric sensors to calculate the filtration efficiency of the filter material. Meanwhile, the pressure difference sensor between the upstream and downstream clamps detects the pressure difference of the airflow before and after passing through the filter material to calculate the initial resistance of the filter material.This invention, by setting up a cleaning air path and a sliding valve switching mechanism, can significantly improve the cleaning efficiency of pipelines during the cleaning stage and make the cleaning of aerosols in the pipeline more thorough, thereby improving the accuracy of the test of the filter media. Before the test of the filter media, the aerosol generated by the aerosol generator does not pass through the filter media, thus avoiding the influence of this part of the aerosol on the filter media and further improving the accuracy of the test of the filter media.

[0039] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A filter media testing platform air circuit system, characterized in that: It includes an airflow duct, an upstream clamp, a downstream clamp, an aerosol generator, a heater, an electrostatic neutralizer, a vacuum pump, an upstream sampling line, and a downstream sampling line. The inlet of the airflow duct is connected to a gas source and is equipped with a solenoid valve, a pressure regulating valve, and a filter. The outlet of the airflow duct branches into multiple lines. One line is equipped with a heater and an electrostatic neutralizer, and its outlet is connected to the aerosol mixing chamber. Another line delivers gas to the aerosol generator, which is equipped with a solenoid valve and a pressure regulating valve. A third line delivers gas to the pneumatic device of the upstream clamp, which is equipped with a pressure regulating valve and a solenoid valve. The output of the aerosol generator is connected to the aerosol mixing chamber via a pipe. The output of the aerosol mixing chamber is connected to the aerosol inlet of the upstream clamp via the upstream aerosol duct. The sampling end of the upstream sampling line is connected to the upstream clamp, and its outlet is connected to the airflow inlet of the vacuum pump. The downstream clamp... The aerosol outlet is connected to the airflow inlet of the suction pump via a downstream aerosol pipe. A first differential pressure sensor is installed between the upstream and downstream clamps. A second differential pressure sensor, a filter, and a pressure regulating valve are installed on the downstream aerosol pipe. The sampling end of the downstream sampling pipe is connected to the downstream clamp, and the outlet end of the downstream sampling pipe is connected to the airflow inlet of the suction pump. A slide valve is connected between the upstream and downstream aerosol pipes. A suction pipe is installed on the upstream aerosol pipe between the slide valve and the upstream clamp. A solenoid valve is installed on the suction pipe. An air pump is installed at the outlet of the suction pipe. A first clean air passage is also connected between the airflow pipe and the sampling end of the upstream sampling pipe. A second clean air passage is also connected between the airflow pipe and the sampling end of the downstream sampling pipe. A third clean air passage is installed on the downstream aerosol pipe, and the two ends of the third clean air passage are respectively connected to the two ends of the second differential pressure sensor. Photoelectric sensors, filters, and flow throttles are installed in both the upstream and downstream sampling pipelines; One output port of the slide valve is connected to an aerosol stabilizing circulation channel, and an aerosol stabilizing circulation channel is equipped with a solenoid valve. The other end of the aerosol stabilizing circulation channel is connected to a pipe leading to the aerosol generator. During the pipeline cleaning stage, the upstream aerosol pipeline and the downstream aerosol pipeline are disconnected by a slide valve, the filter material to be tested is not placed between the upstream clamp and the downstream clamp, and the upstream clamp and the downstream clamp are separated. When the aerosol generation is not yet stable, the generated aerosol does not enter the upstream clamp, but enters the aerosol stabilization circulation channel through the slide valve. At the same time, the slide valve connects the upstream aerosol pipeline and the downstream aerosol pipeline, and the airflow with aerosol output from the aerosol mixing chamber enters the downstream aerosol pipeline through the slide valve.

2. The air path system of the filter media testing platform according to claim 1, characterized in that: A throttle and a solenoid valve are provided on the first cleaning air passage, a throttle, a solenoid valve and a filter are provided on the second cleaning air passage, and a solenoid valve and a filter are provided on the third cleaning air passage.

3. The air path system of the filter media testing platform according to claim 1, characterized in that: The aerosol mixing chamber is equipped with an exhaust pipe.

4. The air path system of the filter media testing platform according to claim 1, characterized in that: Solenoid valves are connected in parallel to the throttles of the upstream and downstream sampling pipelines.

5. The air path system of the filter media testing platform according to claim 1, characterized in that: The outlet of the airflow pipeline is connected to a fourth cleaning airway, which is equipped with a throttle. The outlet of the fourth cleaning airway is connected to the rear end of the upstream sampling pipeline and the downstream sampling pipeline through pipes respectively.

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