A salinity tester for evaluating the filtration performance of a breathing filter

Abstract

This invention provides a salinity tester for evaluating the filtration performance of a respirator, comprising a cabinet, an aerosol generator, and a testing device. The aerosol generator includes an atomizer, a compressed air pump, a neutralizer, a mixing chamber, and a particle sorter, integrating aerosol generation, charge neutralization, particle size screening, and flow control into a single process. This simplifies operation, reduces manual intervention, and eliminates the charge on atomized particles through the neutralizer, preventing electrostatic interference with filtration performance evaluation and ensuring test results more closely approximate real-world usage scenarios. The testing device includes an upstream tester and a downstream tester, with the input and output terminals of the respirator under test sealed to the output terminal of the upstream tester and the input terminal of the downstream tester, respectively. The device can calculate the salinity filtration efficiency conveniently, intuitively, and accurately by analyzing the differences in the number or concentration of particulate matter within the sodium chloride aerosol tested by the upstream and downstream testers.

Description

Technical Field

[0001] This utility model relates to the field of medical device testing and inspection technology, specifically to a salinity tester for evaluating the filtration performance of a respiratory filter. Background Technology

[0002] Breathing filters are typically used clinically in conjunction with breathing circuits, anesthesia machines, and ventilators to filter particles, including microorganisms, from the patient's inhaled or exhaled air, preventing cross-infection and ensuring the health and safety of patients and healthcare workers. Filtration performance is a key performance indicator for evaluating whether a device can effectively prevent the penetration of harmful substances. Currently, the filtration performance of breathing filters can be evaluated using the saline aerosol test method, which simulates particulate matter penetration in a clinical environment and calculates the penetration value, usually expressed as a percentage.

[0003] Currently, the testing equipment and methods used to evaluate the saline filtration performance of breathing filters have the following drawbacks: the sodium chloride aerosol generated by traditional nebulizers often carries electrostatic charge, causing particles to deviate from the actual filtration scenario due to electrostatic adsorption or repulsion, and the test results are easily affected by charge effects; the lack of precise sorting of aerosol particle size makes it impossible to simulate the particle size distribution of a specific environment, thus making it difficult to accurately evaluate the true protective performance of the filter in actual application environments. Utility Model Content

[0004] To address the problems mentioned in the background section, this invention provides a salinity tester for evaluating the filtration performance of respiratory filters.

[0005] The present invention adopts the following technical solution: a salinity tester for evaluating the filtration performance of a respiratory filter, comprising a cabinet, an aerosol generator and a test device, wherein a test chamber and an installation chamber are respectively provided on the upper and lower sides inside the cabinet, and the test chamber and the installation chamber are used for the fixed installation of the aerosol generator and the test device.

[0006] The aerosol generating device includes an atomizer, a compressed air pump, a neutralizer, a mixing chamber, and a particle sorter. The atomizer is used to atomize sodium chloride solution into sodium chloride aerosol. The output end of the atomizer is connected to the input end of the compressed air pump through a first air pipe, and the output end of the compressed air pump is connected to the input end of the neutralizer through a second air pipe. The input end of the mixing chamber is fixedly installed on the output end of the neutralizer, and the input end of the particle sorter is fixedly installed on the output end of the mixing chamber.

[0007] The testing device includes an upstream tester and a downstream tester. The input end of the upstream tester is connected to the output end of the particle sorter. The input and output ends of the breathing filter under test are respectively sealed to the output end of the upstream tester and the input end of the downstream tester. The upstream tester is used to test the number or concentration of particulate matter in sodium chloride aerosol that has not been filtered by the breathing filter under test. The downstream tester is used to test the number or concentration of particulate matter in sodium chloride aerosol that has been filtered by the breathing filter under test.

[0008] Furthermore, the upstream tester includes a third air tube, a first connecting block, a first fixing plate, an upstream connecting pipe, a fourth air tube, and an upstream photometer. The third air tube connects the particle sorter output end and the first connecting block, and the first connecting block is fixedly installed in the test chamber by the first fixing plate.

[0009] One end of the upstream connecting tube and one end of the fourth air tube are respectively connected to the side of the first connecting block, wherein the upstream connecting tube is oriented towards the downstream tester, and the upstream connecting tube, the fourth air tube and the third air tube are connected. The input end of the upstream photometer is connected to the other end of the fourth air tube. The upstream photometer is used to test the quantity or concentration of sodium chloride aerosol particles in the first connecting block. The other end of the upstream connecting tube is sealed to the input end of the breathing filter to be tested.

[0010] Furthermore, the downstream tester includes a sliding connection assembly, a second connecting block, a downstream connecting tube, a fifth air tube, a sixth air tube, and a downstream photometer. The second connecting block is installed in the test chamber via the sliding connection assembly, which is used to adjust the distance between the upstream and downstream testers so that the respiratory filter under test can be sealed between the upstream and downstream testers. One end of the downstream connecting tube is mounted on the side of the second connecting block facing the upstream tester, and the other end of the downstream connecting tube is sealed to the output end of the respiratory filter under test.

[0011] One end of the fifth and sixth gas tubes are respectively connected to the side of the second connecting block, and the downstream connecting pipe is connected to the fifth and sixth gas tubes. The input end of the downstream photometer is connected to the other end of the sixth gas tube. The downstream photometer is used to test the quantity or concentration of sodium chloride aerosol particles in the second connecting block.

[0012] Furthermore, the sliding connection assembly includes a slide rail, a second fixing plate, and a locking knob. The slide rail is fixedly installed inside the test chamber, the second fixing plate is fixedly installed at the bottom of the second connecting block, and a slider that slides in accordance with the slide rail is fixedly installed at the bottom of the second fixing plate. A threaded hole is provided on the side of the slider, and the locking knob is threadedly connected to the threaded hole to fix the slider on the slide rail.

[0013] Furthermore, an exhaust pipe is fixedly installed on the side of the cabinet, and a flow meter and a flow control valve are installed on the exhaust pipe; the fifth air pipe is fixedly connected to the exhaust pipe.

[0014] Furthermore, the output ends of both the upstream and downstream photometers are connected to photometer exhaust pipes, and the other end of the photometer exhaust pipes extends out of the side of the cabinet.

[0015] Furthermore, the front of the installation compartment and the testing compartment are open, and a cabinet door is provided on the front of the installation compartment.

[0016] Furthermore, the top front of the cabinet 1 is equipped with a touch screen, a data interface, and a paper printing outlet.

[0017] Beneficial Effects: The salinity tester for evaluating the filtration performance of a respiratory filter in this patent integrates modules such as a compressed air pump, atomizer, neutralizer, and particle sorter to achieve an integrated process of aerosol generation, charge neutralization, particle size screening, and flow control. This simplifies operation, reduces manual intervention, and eliminates the charge of atomized particles through the neutralizer, avoiding interference from electrostatic effects on filtration performance evaluation and ensuring test results are closer to real-world usage scenarios. Furthermore, it can calculate the difference in the number or concentration of particulate matter in sodium chloride aerosol tested by upstream and downstream testers, thus providing a convenient, intuitive, and accurate way to detect salinity filtration efficiency. Attached Figure Description

[0018] Appendix Figure 1 This is a three-dimensional structural diagram of the testing instrument in this utility model.

[0019] Appendix Figure 2 This is a three-dimensional structural diagram of the testing instrument after removing the cabinet door 103 in this utility model.

[0020] Appendix Figure 3 This is an appendix to the utility model Figure 2 A magnified structural diagram of part A in the middle.

[0021] Appendix Figure 4 This is an appendix to the utility model Figure 2 A magnified structural diagram of part B.

[0022] The reference numerals in the attached drawings are explained as follows: Cabinet 1, Installation Chamber 101, Test Chamber 102, Cabinet Door 103, Atomizer 201, Compressed Air Pump 203, Neutralizer 205, Mixing Chamber 206, Particle Sorter 207, Third Air Pipe 301, First Connecting Block 302, First Fixing Plate 303, Upstream Connecting Pipe 304, Fourth Air Pipe 305, Upstream Photometer 306, Slide Rail 307, Second Fixing Plate 308, Locking Knob 309, Second Connecting Block 310, Downstream Connecting Pipe 311, Fifth Air Pipe 312, Sixth Air Pipe 313, Downstream Photometer 314. Detailed Implementation

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The content of the utility model will be further explained below in conjunction with the drawings:

[0024] Example 1

[0025] See attached document Figure 1 , 2 This embodiment provides a salinity tester for evaluating the filtration performance of a respiratory filter, which can perform charge neutralization and particle size screening of sodium chloride aerosol. It includes a cabinet 1, an atomizer 201, a compressed air pump 203, a neutralizer 205, a mixing chamber 206, a particle sorter 207, an upstream tester, and a downstream tester.

[0026] Inside the cabinet 1, a test chamber 102 and an installation chamber 101 are respectively opened on the upper and lower sides. The front of the installation chamber 101 and the test chamber 102 are open. A cabinet door 103 is provided on the front of the installation chamber 101. The atomizer 201, compressed air pump 203, neutralizer 205, mixing chamber 206, particle sorter 207, etc. are all installed in the installation chamber 101. The upstream tester and the downstream tester are installed in the test chamber 102. The test chamber 102 is designed to be open, which facilitates direct testing operations.

[0027] See attached document Figure 2 The output end of the atomizer 201 is connected to the input end of the compressed air pump 203 through the first air pipe 202, and the output end of the compressed air pump 203 is connected to the input end of the neutralizer 205 through the second air pipe 204. The input end of the mixing chamber 206 is fixedly installed on the output end of the neutralizer 205, and the input end of the particle sorter 207 is fixedly installed on the output end of the mixing chamber 206.

[0028] The atomizer 201 atomizes the sodium chloride solution into sodium chloride aerosol. The sodium chloride aerosol carries an electrostatic charge and is sequentially introduced into the neutralizer 205, mixing chamber 206, and particle sorter 207 via the compressed air pump 203. The neutralizer 205 is equipped with an ionizer to generate an ionized airflow. Through the combination of the mixing chamber 206 and the neutralizer 205, the aerosol particles reach a Boltzmann equilibrium state of charge neutralization. The neutralizer 205 eliminates the charge on the atomized sodium chloride particles, preventing interference from electrostatic effects on filtration performance evaluation. The particle sorter 207 employs a scanning flow particle sorter to monitor the median count of aerosol particles in real time, ensuring a median particle size of 0.075mm ± 0.020mm and a geometric standard deviation ≤ 1.86. This precise sorting of aerosol particles simulates the particle size distribution of a specific environment, ensuring that the test results accurately assess the filter's true protective performance in real-world applications.

[0029] See attached document Figure 1-3 The upstream tester includes a third air tube 301, a first connecting block 302, a first fixing plate 303, an upstream connecting pipe 304, a fourth air tube 305, and an upstream photometer 306.

[0030] The third air tube 301 connects the output end of the particle sorter 207 to the first connecting block 302, which is fixedly installed in the test chamber 102 by the first fixing plate 303. One end of the upstream connecting tube 304 and the fourth air tube 305 are respectively connected to the side of the first connecting block 302. The upstream connecting tube 304 is set towards the downstream tester and is a rigid tube. The first connecting block 302 is a communicating vessel or a T-joint, which connects the upstream connecting tube 304, the fourth air tube 305 and the third air tube 301. The input end of the upstream photometer 306 is connected to the other end of the fourth air tube 305. The upstream photometer 306 is used to test the quantity or concentration of sodium chloride aerosol particles in the first connecting block 302. The other end of the upstream connecting tube 304 is sealed to the input end of the breathing filter to be tested.

[0031] See attached document Figure 1 , 2 4. The downstream tester includes a slide rail 307, a second fixing plate 308, a locking knob 309, a second connecting block 310, a downstream connecting pipe 311, a fifth air pipe 312, a sixth air pipe 313, and a downstream photometer 314.

[0032] The slide rail 307 is an I-shaped slide rail, which is fixedly installed inside the test chamber 102. The second fixing plate 308 is fixedly installed at the bottom of the second connecting block 310. A slider that matches and slides with the slide rail 307 (I-shaped structure) is fixedly installed at the bottom of the second fixing plate 308. The second fixing plate 308 can only slide along the length of the slide rail 307 via the slider. A threaded hole is provided on the side of the slider. The locking knob 309 is threadedly connected to the threaded hole. When the locking knob 309 is screwed in along the threaded hole, the front end of the threaded rod of the locking knob 309 abuts against the side of the slide rail 307, fixing the slider on the slide rail 307, thereby fixing the position of the second fixing plate 308 and the second connecting block 310.

[0033] One end of the downstream connecting pipe 311 is installed on the side of the second connecting block 310 facing the upstream tester. The downstream connecting pipe 311 is a rigid pipe. One end of the fifth gas pipe 312 and the sixth gas pipe 313 are respectively connected to the side of the second connecting block 310. The second connecting block 310 is a communicating vessel or a tee connector, which connects the downstream connecting pipe 311, the fifth gas pipe 312 and the sixth gas pipe 313. The input end of the downstream photometer 314 is connected to the other end of the sixth gas pipe 313. The downstream photometer 314 is used to test the quantity or concentration of sodium chloride aerosol particles in the second connecting block 310.

[0034] When the second fixing plate 308 slides along the length of the slide rail 307, the upstream connecting pipe 304 and the downstream connecting pipe 311 move closer or further apart. The input end of the breathing filter to be tested is sealed onto the upstream connecting pipe 304. When the upstream connecting pipe 304 and the downstream connecting pipe 311 move closer together, the other end of the downstream connecting pipe 311 is sealed onto the output end of the breathing filter to be tested, so that the breathing filter to be tested can be sealed between the upstream connecting pipe 304 and the downstream connecting pipe 311. The position of the second fixing plate 308 and the second connecting block 310 is fixed by the locking knob 309 to prevent the breathing filter to be tested from detaching from the upstream connecting pipe 304 and the downstream connecting pipe 311 during the test, which would affect the accuracy of the test.

[0035] Sodium chloride aerosol passing through the breather filter under test (including that discharged from the fifth gas pipe 312 and the output terminals of the upstream photometer 306 and the downstream photometer 314) needs to be discharged outside the cabinet 1. An exhaust pipe 315 is fixedly installed on the side of the cabinet 1, and a flow meter 316 and a flow control valve 317 are installed on the exhaust pipe 315; the fifth gas pipe 312 is fixedly connected to the exhaust pipe 315. The flow meter 316 is used to monitor the gas flow rate in the pipeline, and the flow control valve 317 controls the gas flow rate.

[0036] The output ends of both the upstream photometer 306 and the downstream photometer 314 are connected to photometer exhaust pipes, and the other end of the photometer exhaust pipes extends out of the side of the cabinet 1.

[0037] A touch screen display 4, a data interface 5, and a paper output 6 are installed on the top front of the cabinet 1. The touch screen display 4 is used to display the working status of the equipment, the test data of the upstream photometer 306 and the downstream photometer 314, and can control the switching of the equipment and set the corresponding parameters. The data interface 5 is used for exporting and importing data, and the paper output 6 is used for printing test data.

[0038] The method or working principle of the salinity tester for evaluating the filtration performance of the respiratory filter in this patent is as follows: First, seal the input end of the respiratory filter to be tested onto the upstream connecting pipe 304, then loosen the locking knob 309, slide the second fixing plate 308 along the length of the slide rail 307 until the downstream connecting pipe 311 is sealed onto the output end of the respiratory filter to be tested, then tighten the locking knob 309 to fix the position of the second fixing plate 308.

[0039] Add the target amount of sodium chloride solution to the atomizer 205, and start the atomizer 201, compressed air pump 203, upstream photometer 306, and downstream photometer 314 to begin the saline aerosol test. During the test, the atomizer 201 atomizes the sodium chloride solution into sodium chloride aerosol. The sodium chloride aerosol carries an electrostatic charge and is sequentially introduced into the neutralizer 205, mixing chamber 206, and particle sorter 207 by the compressed air pump 203. The neutralizer 205 is equipped with an ionizer to generate an ionized airflow, allowing the aerosol particles to reach a Boltzmann equilibrium state of charge neutralization, thus eliminating the charge of the atomized sodium chloride particles. The particle sorter 207 uses a scanning flow particle sorter to accurately sort the aerosol particles by size. After sodium chloride aerosol enters the first connecting block 302, a portion enters the upstream photometer 306, which detects the quantity or concentration of sodium chloride aerosol particles. The other portion passes through the breath filter to be tested and enters the second connecting block 310. A portion of the sodium chloride aerosol entering the second connecting block 310 enters the downstream photometer 314, which detects the quantity or concentration of sodium chloride aerosol particles. The other portion is discharged outside the cabinet 1 through the fifth air pipe 312 and the exhaust pipe 315.

[0040] After the test, the difference in the number or concentration of particulate matter in the sodium chloride aerosol tested by the upstream photometer 306 and the downstream photometer 314 is calculated, and the test results are printed through the printing paper outlet 6, so as to conveniently, intuitively and accurately detect the saline filtration efficiency.

[0041] It should be noted that the respiratory filter being tested is in an unused state after being removed from its packaging or in a used state after being adjusted to simulate clinical use.

[0042] Obviously, modifications and / or additions can be made to the above-mentioned salinity tester for evaluating the filtration performance of respiratory filters and the corresponding methods, without departing from the scope and domain of this utility model.

[0043] It is equally clear that although this invention has described the salinity tester for evaluating the filtration performance of a respiratory filter in detail, those skilled in the art will certainly be able to obtain many other equivalent forms of the respiratory filter salinity tester and corresponding methods, which have the features described in the claims and are therefore within the scope of protection defined herein.

Claims

1. A salinity tester for evaluating the filtration performance of a respiratory filter, characterized in that: It includes a cabinet (1), an aerosol generator and a testing device. A testing chamber (102) and an installation chamber (101) are respectively opened on the upper and lower sides inside the cabinet (1). The testing chamber (102) and the installation chamber (101) are used for the fixed installation of the aerosol generator and the testing device. The aerosol generating device includes an atomizer (201), a compressed air pump (203), a neutralizer (205), a mixing chamber (206), and a particle sorter (207). The atomizer (201) is used to atomize sodium chloride solution into sodium chloride aerosol. The output end of the atomizer (201) is connected to the input end of the compressed air pump (203) through a first air pipe (202). The output end of the compressed air pump (203) is connected to the input end of the neutralizer (205) through a second air pipe (204). The input end of the mixing chamber (206) is fixedly installed on the output end of the neutralizer (205). The input end of the particle sorter (207) is fixedly installed on the output end of the mixing chamber (206). The testing device includes an upstream tester and a downstream tester. The input end of the upstream tester is connected to the output end of the particle sorter (207). The input and output ends of the breathing filter to be tested are respectively sealed to the output end of the upstream tester and the input end of the downstream tester. Both the upstream tester and the downstream tester are used to test the quantity or concentration of particulate matter in sodium chloride aerosol.

2. The salinity tester for evaluating the filtration performance of a respiratory filter according to claim 1, characterized in that: The upstream tester includes a third air tube (301), a first connecting block (302), a first fixing plate (303), an upstream connecting pipe (304), a fourth air tube (305), and an upstream photometer (306). The third air tube (301) is connected between the output end of the particle sorter (207) and the first connecting block (302). The first connecting block (302) is fixedly installed in the test chamber (102) by the first fixing plate (303). One end of the upstream connecting pipe (304) and the fourth air pipe (305) are respectively connected to the side of the first connecting block (302), wherein the upstream connecting pipe (304) is set towards the downstream tester, and the upstream connecting pipe (304), the fourth air pipe (305) and the third air pipe (301) are connected. The input end of the upstream photometer (306) is connected to the other end of the fourth air pipe (305). The upstream photometer (306) is used to test the quantity or concentration of sodium chloride aerosol particles in the first connecting block (302). The other end of the upstream connecting pipe (304) is sealed to the input end of the breathing filter to be tested.

3. The salinity tester for evaluating the filtration performance of a respiratory filter according to claim 2, characterized in that: The downstream tester includes a sliding connection assembly, a second connecting block (310), a downstream connecting tube (311), a fifth air tube (312), a sixth air tube (313), and a downstream photometer (314). The second connecting block (310) is installed in the test chamber (102) through the sliding connection assembly. The sliding connection assembly is used to adjust the distance between the upstream tester and the downstream tester so that the breathing filter under test can be sealed between the upstream tester and the downstream tester. One end of the downstream connecting tube (311) is installed with the side of the second connecting block (310) facing the upstream tester, and the other end of the downstream connecting tube (311) is sealed to the output end of the breathing filter under test. One end of the fifth gas tube (312) and the sixth gas tube (313) are respectively connected to the side of the second connecting block (310), and the downstream connecting pipe (311), the fifth gas tube (312) and the sixth gas tube (313) are connected. The input end of the downstream photometer (314) is connected to the other end of the sixth gas tube (313). The downstream photometer (314) is used to test the quantity or concentration of sodium chloride aerosol particles in the second connecting block (310).

4. The salinity tester for evaluating the filtration performance of a respiratory filter according to claim 3, characterized in that: The sliding connection assembly includes a slide rail (307), a second fixing plate (308), and a locking knob (309). The slide rail (307) is fixedly installed inside the test chamber (102). The second fixing plate (308) is fixedly installed at the bottom of the second connecting block (310). A slider that matches and slides with the slide rail (307) is fixedly installed at the bottom of the second fixing plate (308). A threaded hole is provided on the side of the slider. The locking knob (309) is threadedly connected to the threaded hole and is used to fix the slider on the slide rail (307).

5. The salinity tester for evaluating the filtration performance of a respiratory filter according to claim 3, characterized in that: An exhaust pipe (315) is fixedly installed on the side of the cabinet (1), and a flow meter (316) and a flow control valve (317) are installed on the exhaust pipe (315); the fifth air pipe (312) is fixedly connected to the exhaust pipe (315).

6. The salinity tester for evaluating the filtration performance of a respiratory filter according to claim 3, characterized in that: The output ends of the upstream photometer (306) and the downstream photometer (314) are both connected to photometer exhaust pipes, and the other end of the photometer exhaust pipe extends out of the side of the cabinet (1).

7. The salinity tester for evaluating the filtration performance of a respiratory filter according to claim 1, characterized in that: The front of the installation compartment (101) and the test compartment (102) are open, and a cabinet door (103) is provided on the front of the installation compartment (101).

8. The salinity tester for evaluating the filtration performance of a respiratory filter according to claim 1, characterized in that: The top front of the cabinet (1) is equipped with a touch screen (4), a data interface (5) and a paper output (6).

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