An aerosol collection device and method with adjustable sampling particle size

Abstract

The application relates to an aerosol collection device and method with adjustable sampling particle size, which comprises a collection shell, a mounting shell, a sampling carrier and a flow pump. A part of the collection shell is mounted in the mounting shell, and an air inlet is arranged at one end of the collection shell outside the mounting shell. Hard side walls are hingedly arranged on the opposite two side walls of the end of the collection shell in the mounting shell, and the two hard side walls are connected by two soft side walls to form a sample collection channel. A slit adjusting mechanism is arranged on the two hard side walls. The sampling carrier and the flow pump are both mounted in the mounting shell. The sampling carrier is in contact with the free ends of the two hard side walls or is arranged at a preset distance. The air suction port of the flow pump is arranged at a distance from the sampling carrier, and the air outlet of the flow pump is in communication with the outside of the mounting shell. The particle size collection range of the aerosol collector can be changed by adjusting the flow rate of the sample collection channel, and the adaptation to the collection requirements of aerosols with different particle sizes is realized conveniently and efficiently.

Description

Technical Field

[0001] This invention relates to the field of aerosol collection technology, specifically to an aerosol collection device and method with adjustable sampling particle size. Background Technology

[0002] The COVID-19 pandemic, which began in late 2019, has had a significant impact on the original social order of production and daily life. In 2021, the World Health Organization confirmed that the virus can be transmitted through aerosols. Therefore, aerosol sampling of environmental spaces is expected to become an important clue in investigating the spread of the epidemic. However, indoor and outdoor environments often differ greatly in size, requiring different sampling flow rates and particle sizes. Common samplers often have shortcomings in use and are difficult to meet diverse needs.

[0003] Common samplers include Anderson samplers, cyclone samplers, and slit impactor samplers. The Anderson sampler is one of the most widely used, employing stacked sieves with varying pore sizes to collect aerosol particles of different sizes. Its operating flow rate is typically fixed at 28.3 L / min. The particle size collected by different layers of the Anderson sampler is affected by the sieve size, and its collectable particle size is also fixed. It directly collects airborne bacteria onto nutrient agar plates, which can then be directly cultured. The number of colonies formed on the culture medium can be counted to deduce the initial airborne bacteria count. However, this sampler cannot operate for extended periods; otherwise, the airflow impact will cause excessive water loss from the nutrient agar plates. Also, if too many airborne bacteria are collected, the plaques in each sieve after culture may contain multiple bacteria, leading to a significantly lower count. Furthermore, this method cannot culture viruses; viruses impacting the culture plate still need to be washed out before further analysis.

[0004] A cyclone sampler is a sampling device that uses the centrifugal force generated by the high-speed rotation of gas to separate bioaerosol particles from the gas flow and impact them onto the surface of a solid medium or enrich them in a liquid medium. Due to structural differences, it is further divided into wet-wall cyclone samplers and dry-wall cyclone samplers. In a wet-wall cyclone sampler, bioaerosol particles contact the wet inner wall of the sampling tube during sampling, and then enter the sampling liquid. This type of sampler is characterized by high sampling efficiency, and the collected liquid sample can be directly used for subsequent experimental analysis. However, it is limited by disadvantages such as the volatile nature of the sampling liquid, instability in the sampling process, and the inability to operate below zero degrees Celsius. A dry-wall cyclone sampler uses a cyclone separation method to impact the bioaerosol sample into the sampling liquid, which can reduce problems such as sampling liquid evaporation to some extent. The sampling particle size of a cyclone sampler is affected by the structure of the cyclone cavity, but the sampling efficiency is often lower for particles smaller than 0.5 μm (such as viruses).

[0005] The slit impactor sampler is a high-flow-rate sampler that works by forcing airflow through a slit and rapidly impacting a sampling carrier, causing the airflow to disperse in all directions. Due to their inertial mass, aerosol particles separate from the airflow and impact the sampling carrier. Furthermore, the slit sampler significantly increases the sampleable area compared to a pinhole sampler, making it suitable for developing sampler structures with even higher flow rates. Traditional slit samplers, because their slits are mechanically machined and have a fixed width, require a fixed sampling flow rate to ensure a consistent range of sampled particle sizes, based on the aerodynamic requirements of the particles.

[0006] In summary, the above analysis shows that traditional aerosol samplers have fixed structures, fixed flow rates, and fixed sampling particle sizes. This often necessitates multiple samplers for specific needs, and if the flow rate of the sampler corresponding to a particular particle size is too low, a long waiting time is required. Alternatively, in projects requiring long-term monitoring, an excessively high flow rate for the sampler corresponding to the particle size can lead to sample saturation. Furthermore, due to differences in aerodynamic characteristics, simply changing the sampling flow rate without altering the sampler structure can cause a significant shift in the sampling particle size, thus affecting the sampling results. Summary of the Invention

[0007] In order to solve one or more technical problems existing in the prior art, the present invention provides an aerosol collection device and method with adjustable sampling particle size.

[0008] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: An aerosol collection device with adjustable sampling particle size includes a collection shell, a mounting shell, rigid sidewalls, soft sidewalls, a slit adjustment mechanism, a sampling carrier, and a flow pump. A portion of the collection shell is installed inside the mounting shell. An air inlet is provided at one end of the collection shell located outside the mounting shell. Rigid sidewalls are respectively hinged to the opposite side walls at one end of the collection shell located inside the mounting shell. The two rigid sidewalls are connected by two soft sidewalls and enclose to form a sample collection channel.

[0009] Each of the two rigid sidewalls is equipped with a slit adjustment mechanism to adjust the width of the slit between the free ends of the two rigid sidewalls. The sampling carrier and the flow pump are both installed inside the mounting housing. The sampling carrier is in contact with or spaced apart from the free ends of the two rigid sidewalls. The flow pump is located on the side of the sampling carrier away from the rigid sidewalls. The air intake of the flow pump is arranged at a certain distance from the sampling carrier. The air outlet of the flow pump is connected to the outside of the mounting housing.

[0010] The beneficial effects of this invention are: the adjustable sampling particle size aerosol collection device of this invention can adjust the particle size range of the sampled aerosol according to sampling requirements. It has two working modes: impact sampling mode and contact sampling mode. In impact sampling mode, the airflow nozzle is positioned a certain distance from the sampling carrier, allowing the airflow to change direction in this space. Due to their high inertia, aerosol particles are difficult to deflect. Therefore, particles with higher flow velocity and larger particle size are more likely to collide with the sampling carrier, while particles with lower flow velocity and smaller particle size are more easily deflected by fluid drag. The higher the flow velocity and the stronger the particle inertia, the greater the d-value of the collected particles. 50 The smaller the particle size, the better. Therefore, by adjusting the pump flow rate and the slit width, the flow rate of particles passing through the slit can be adjusted, thereby regulating the particle size collected. However, this reduction in slit size also has a boundary effect. When the flow rate is very high, the Reynolds number (Re) of the airflow near the slit surges, generating uncertain turbulence, which can lead to unpredictable sampling results. Therefore, there are limits to narrowing the slit and increasing the flow rate. When users need to collect particles smaller than this limit, they need to switch to contact sampling mode. In this mode, the slit is opened to its maximum value using the slit adjustment mechanism to reduce air resistance, placing the sampling carrier in contact with the slit. All airflow directly penetrates the sampling carrier, achieving the highest efficiency in sampling.

[0011] Based on the above technical solution, the present invention can be further improved as follows.

[0012] Furthermore, the sampling carrier is capable of covering the maximum width range of the free-end slits of the two rigid sidewalls.

[0013] The beneficial effect of adopting the above-mentioned further scheme is that when the contact sampling mode is used, the sampling carrier can completely cover the maximum width range of the slit, and all aerosols can be collected on the sampling carrier.

[0014] Furthermore, the slit adjustment mechanism includes an adjustment screw, which passes through and is threadedly connected to the side wall of the mounting housing, with one end of the adjustment screw located inside the mounting housing being movably connected to the rigid side wall.

[0015] The beneficial effect of adopting the above-mentioned further solution is that the setting of the adjusting screw facilitates the adjustment of the distance between the rigid sidewalls, thereby realizing the adjustment of the slit width.

[0016] Furthermore, elastic elements are connected between the two rigid sidewalls near the sides.

[0017] The beneficial effects of adopting the above-mentioned further scheme are: the setting of elastic elements is used to balance the compression of the slit adjustment structure and provide elastic force to stabilize the slit width. In order not to affect sampling, they are generally arranged on both sides of the long side of the slit.

[0018] Furthermore, the mounting housing is provided with a plug-in channel frame, one end of which is provided with a plug-in interface, and a position sensor is provided on the inner side wall of the mounting housing corresponding to the other end of the plug-in channel frame;

[0019] The sampling carrier is installed in the insertion channel frame by a pull-out sampling bracket. One end of the sampling bracket is located at the insertion interface, and the other end of the sampling bracket is provided with a positioning device that cooperates with the position sensor.

[0020] The beneficial effect of adopting the above-mentioned further solution is that it facilitates the insertion of the sampling bracket carrying the sampling carrier from the insertion interface into the insertion channel frame, thereby realizing the removal and placement of the sampling carrier.

[0021] Furthermore, the sampling bracket adopts a hollow structure, and the sampling carrier covers the hollow structure.

[0022] Furthermore, the insertion channel bracket is mounted on the mounting housing via a height adjustment mechanism, and multiple position sensors are provided on the inner sidewall of the mounting housing along the height direction.

[0023] The beneficial effects of adopting the above-mentioned further solutions are: the aerosol collection device with adjustable sampling particle size of the present invention can realize the change of sampling principle by moving the height of the sampling carrier, realize the collection of smaller particle sizes, and expand the sampling range that the slit sampling device could not originally achieve.

[0024] Furthermore, the inner wall of the collection housing is provided with a perforated plate to homogenize the airflow, and the perforated plate is arranged perpendicular to the airflow direction inside the collection housing.

[0025] The beneficial effect of adopting the above-mentioned further solution is that the perforated plate helps to further homogenize the airflow.

[0026] Furthermore, a controller and a flow sensor are provided at the outlet of the flow pump, and the flow sensor and the flow pump are respectively electrically connected to the controller.

[0027] The beneficial effect of adopting the above-mentioned further solution is that the setting of the flow sensor can realize the self-circulation regulation of the flow pump flow.

[0028] An adjustable sampling particle size aerosol collection method, implemented using the aforementioned aerosol collection device, includes the following steps:

[0029] Set the sampling volume V, sampling time t, and sampling particle size d. 50 And the particle density ρ, the sampling flow rate F is calculated using Formula 1; where, Formula 1:

[0030] Particle size d 50When the flow rate is less than the preset value, the sampling flow rate F of the flow pump is set, the slit between the free ends of the two rigid sidewalls is adjusted to the maximum width through the slit adjustment mechanism, and the sampling carrier is arranged in contact with the free ends of the two rigid sidewalls, that is, the contact sampling mode is adopted to start sampling.

[0031] Particle size d 50 When the value is not less than the preset value, use Formula 2 to calculate the U / W value; use Formula 3 to calculate Cc and look up the corresponding table to get Stk; use Formula 4 to calculate the W·U value; calculate W based on the U / W value and W·U value, and adjust the width of the slit between the free ends of the two rigid sidewalls to W through the slit adjustment mechanism, that is, start sampling using the impact sampling mode;

[0032] Formula 2: Stk is the Stokes number, U is the linear velocity of the aerosol passing through the slit, and η is the aerodynamic viscosity coefficient.

[0033] Formula 3: Cc is the sliding correction factor, and P is atmospheric pressure;

[0034] Formula 4: W·L·U=F; L is the slit length.

[0035] The beneficial effects of the aerosol collection method are: the aerosol collection method of the present invention can realize the switching and adjustment of two modes, impact sampling mode and contact sampling mode, and cover a wider range of aerosol collection particle size requirements. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the aerosol sampling device with adjustable sampling particle size of the present invention, which uses an impact sampling mode. Figure 1 ;

[0037] Figure 2 This is a schematic diagram of the aerosol sampling device with adjustable sampling particle size of the present invention, which uses an impact sampling mode. Figure 2 ;

[0038] Figure 3 This is a schematic diagram of the aerosol sampling device with adjustable sampling particle size of the present invention, which uses contact sampling mode.

[0039] Figure 4 This is a schematic diagram of the sampling bracket of the present invention;

[0040] Figure 5 For the sampling system d 50 -Stk relationship diagram.

[0041] The attached diagram lists the components represented by each number as follows:

[0042] 1. Aerodynamic shield; 2. Data collection housing; 3. Perforated plate; 4. Rigid sidewall; 5. Soft sidewall; 6. First slit adjustment mechanism; 7. Second slit adjustment mechanism; 8. Elastic element; 9. Sampling carrier; 10. Sampling bracket; 11. Position sensor; 12. Insertion channel frame; 13. Air extraction port; 14. Flow pump; 15. Air outlet; 16. Air inlet; 17. Mounting housing;

[0043] 101. Sampling frame; 102. Hollowed-out structure; 103. Supporting ribs; 104. Positioning device. Detailed Implementation

[0044] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0045] like Figures 1-4 As shown, an aerosol collection device with adjustable sampling particle size according to this embodiment includes a collection shell 2, a mounting shell 17, rigid sidewalls 4, soft sidewalls 5, a slit adjustment mechanism, a sampling carrier 9, and a flow pump 14. A portion of the collection shell 2 is installed inside the mounting shell 17. An air inlet 16 is provided at one end of the collection shell 2 located outside the mounting shell 17. Rigid sidewalls 4 are respectively hinged to the opposite side walls at one end of the collection shell 2 located inside the mounting shell 17. The two rigid sidewalls 4 are connected by two soft sidewalls 5 and enclose to form a sample collection channel.

[0046] Each of the two rigid sidewalls 4 is equipped with a slit adjustment mechanism to adjust the width of the slit between the free ends of the two rigid sidewalls 4. The sampling carrier 9 and the flow pump 14 are both installed inside the mounting housing 17. The sampling carrier 9 is in contact with or spaced from the free ends of the two rigid sidewalls 4. The flow pump 14 is located on the side of the sampling carrier 9 away from the rigid sidewalls 4. The air intake 13 of the flow pump 14 is spaced apart from the sampling carrier 9. The air outlet 15 of the flow pump 14 is connected to the outside of the mounting housing 17.

[0047] like Figures 1-3As shown, the sampling housing 2 in this embodiment includes a housing body and an aerodynamic shield 1. An air inlet 16 is formed by the gap between the aerodynamic shield 1 and the sampling housing 2, preventing large particles, dust, rainwater, and other interfering substances from entering the housing body. An airflow cavity is formed inside the sampling housing 2 to rectify the inhaled airflow into a uniform flow velocity. The rigid sidewall 4 is used to construct the air passage, with its lower edge being a free end forming a slit; it can be made of rigid plastic or metal plate, etc. The soft sidewall 5 has a certain plastic deformation capability and can be made of rubber, etc., used to construct the air passage and provide space for slit adjustment. The slit adjustment mechanism can be used to compress the slit to reduce its width. The slit adjustment mechanism can be driven manually or electrically. The sampling carrier 9 can be made of macroscopically porous and loose materials such as cotton, nylon fleece, foam, or foamed materials.

[0048] like Figures 1-3 As shown, the sampling carrier 9 in this embodiment can cover the maximum width range of the slits at the free ends of the two rigid sidewalls 4. When the contact sampling mode is used, the sampling carrier 9 can completely cover the maximum width range of the slits, enabling the vast majority of aerosols to be collected onto the sampling carrier 9.

[0049] like Figures 1-3 As shown, the slit adjustment mechanism in this embodiment includes an adjustment screw, which passes through and is threaded onto the side wall of the mounting housing 17. One end of the adjustment screw, located inside the mounting housing 17, is movably connected to the rigid side wall 4. The adjustment screw facilitates the adjustment of the distance between the rigid side walls, thereby enabling the adjustment of the slit width.

[0050] Specifically, the slit adjustment mechanism includes a first slit adjustment mechanism 6 and a second slit adjustment mechanism 7. The first slit adjustment mechanism 6 and the second slit adjustment mechanism 7 are respectively arranged corresponding to the two rigid sidewalls 4 and adjust the distance between the two rigid sidewalls 4.

[0051] like Figure 2 As shown, in this embodiment, elastic elements 8 are also connected between the two rigid sidewalls 4 near the sides. The elastic elements can be rubber or springs. The elastic elements are provided to balance the slit adjustment structure and provide elastic force to stabilize the slit width. To avoid affecting sampling, they are generally arranged on both sides of the long side of the slit.

[0052] like Figure 1 and Figure 3As shown, the mounting housing 17 in this embodiment is provided with a plug-in channel frame 12. One end of the plug-in channel frame 12 is provided with a plug-in interface, and the mounting housing 17 is provided with a position sensor 11 on the inner side wall corresponding to the other end of the plug-in channel frame 12. The sampling carrier 9 is installed in the plug-in channel frame 12 by a pull-out sampling bracket 10. One end of the sampling bracket 10 is located at the plug-in interface, and the other end of the sampling bracket 10 is provided with a positioning device that cooperates with the position sensor 11. This facilitates the insertion of the sampling bracket carrying the sampling carrier from the plug-in interface into the plug-in channel frame, realizing the placement and removal of the sampling carrier.

[0053] like Figure 4 As shown, the sampling bracket 10 in this embodiment adopts a hollow structure 102, and the sampling carrier 9 covers the hollow structure 102. Specifically, the sampling bracket 10 includes a sampling frame 101, and a support rib 103 is provided inside the sampling frame 101. The support rib 103 and the sampling frame 101 form a hollow structure 102. The positioning device 104 is disposed at one end of the sampling frame 101 near the position sensor 11. The positioning device 104 can be a magnet of a Hall element or a metal structure with conductive contacts, etc., used to cooperate with the position sensor to detect whether the sampling carrier is inserted properly and at what height, and at the same time to confirm that the sampling carrier is in an impact or contact sampling state.

[0054] like Figure 1 and Figure 3 As shown, in this embodiment, the insertion channel frame 12 is mounted on the mounting housing 17 via a height adjustment mechanism. Multiple position sensors 11 are provided along the height direction on the inner sidewall of the mounting housing 17, which can cooperate with a positioning device to detect the height of the sampling carrier, thereby determining whether the sampler is in impact sampling or contact sampling mode. This embodiment's adjustable-size aerosol sampling device can change the sampling principle by moving the height of the sampling carrier, enabling the collection of smaller particles and expanding the sampling range that slit-type sampling devices could not originally achieve. The height adjustment mechanism can be a height adjustment hole provided on the sidewall of the mounting housing 17, with multiple adjustment slots inside for engaging the insertion channel frame 12.

[0055] like Figures 1-3 As shown, the inner wall of the collection housing 2 in this embodiment is further provided with a perforated plate 3 to homogenize the airflow. The perforated plate 3 is arranged perpendicular to the airflow direction inside the collection housing 2. The perforated plate helps to further homogenize the airflow.

[0056] like Figures 1-3As shown, in this embodiment, a controller and a flow sensor are provided at the outlet 15 of the flow pump 14. The flow sensor and the flow pump 14 are respectively electrically connected to the controller. The flow sensor enables self-circulation adjustment of the flow pump flow, thereby stabilizing the sampled flow rate.

[0057] The adjustable sampling particle size aerosol collection device in this embodiment has two operating modes: impact sampling mode and contact sampling mode. Impact sampling mode refers to maintaining a distance between the airflow nozzle and the sampling carrier. The airflow is redirected in this space, and aerosol particles, due to their high inertia, are difficult to redirect. Therefore, particles with higher flow velocity and larger particle size are more likely to collide with the sampling carrier, while particles with lower flow velocity and smaller particle size are more easily redirected by fluid drag. Higher flow velocity and stronger particle inertia result in a larger sample size. 50 The smaller the particle size, the better. Therefore, by adjusting the pump flow rate and the slit width, the flow rate of particles passing through the slit can be adjusted, thereby regulating the particle size collected. However, this reduction in slit size also has a boundary effect. When the flow rate is very high, the Reynolds number (Re) of the airflow near the slit surges, generating uncertain turbulence, which can lead to unpredictable sampling results. Therefore, there are limits to narrowing the slit and increasing the flow rate. When users need to collect particles smaller than this limit, they need to switch to contact sampling mode. In this mode, the slit is opened to its maximum value using the slit adjustment mechanism to reduce air resistance, placing the sampling carrier in contact with the slit. All airflow directly penetrates the sampling carrier, achieving the highest efficiency in sampling.

[0058] This embodiment also provides an aerosol collection method with adjustable sampling particle size, implemented using the aforementioned aerosol collection device, and includes the following steps:

[0059] Set the sampling volume V, sampling time t, and sampling particle size d. 50 And the particle density ρ, the sampling flow rate F is calculated using Formula 1; where, Formula 1:

[0060] Particle size d 50 When the flow rate is less than the preset value, the sampling flow rate F of the flow pump 14 is set, the slit between the free ends of the two rigid sidewalls 4 is adjusted to the maximum width through the slit adjustment mechanism, and the sampling carrier 9 is arranged in contact with the free ends of the two rigid sidewalls 4, that is, the contact sampling mode is adopted to start sampling.

[0061] Particle size d 50 When the value is not less than the preset value, use Formula 2 to calculate the U / W value; use Formula 3 to calculate Cc and look up the corresponding table to get Stk; use Formula 4 to calculate the W·U value; calculate W based on the U / W value and W·U value, and adjust the width of the slit between the free ends of the two rigid sidewalls 4 to W through the slit adjustment mechanism, that is, start sampling using the impact sampling mode;

[0062] Formula 2: Stk is the Stokes number, U is the linear velocity of the aerosol passing through the slit, and η is the aerodynamic viscosity coefficient; Formula 2 is the Stokes equation, where Stk is the Stokes number, which is specific to a particular sampling system and needs to be confirmed experimentally for different cutoff particle sizes d. 50 The corresponding Stokes number is determined by dividing by d. 50 Under other conditions, particles of different sizes were passed through the collector, and a high-sensitivity particle size spectrometer was used at the inlet and outlet of the collector to measure the variation range of different particle sizes, thus determining the particle size that had decreased by 50%. Stk showed little variation within a certain range, generally between 0.05 and 0.25, for d... 50 The effect of particle size is limited, so it can be determined by d. 50 Determining the Stk value by looking up a table, while having some error, is superior to using a fixed Stk value. ρ is the average particle density, U is the linear velocity of the aerosol passing through the slit, and the flow of the aerosol through the airflow cavity and perforated plate helps to match the velocity of the particles with that of the airflow. Cc is the slip correction factor; η is the aerodynamic viscosity coefficient, which is a function of temperature and requires collecting the on-site temperature and looking it up in a table. Under normal conditions of 15℃ and one atmosphere, the value is 1.81 × 10⁻⁶. -5 Pa·s. W is the slit width, which is an unknown here. In solving formula two, since d 50 The input values ​​are U and W, which are unknown. The others are lookup values, which can be used to obtain the values ​​of U and W.

[0063] Formula 3: Cc is the sliding correction coefficient, and P is atmospheric pressure; Formula 3: Based on the numerical results of the literature "The Size Distribution of the Urban Aerosol in Vienna; Science of Total Environment, 1979, 13, 245-261", P is atmospheric pressure, d 50 For input values.

[0064] Formula 4: W·L·U=F; L is the slit length. The slit length L is a constant, and W·U can be calculated by dividing F by L. Therefore, the values ​​of W and U can be solved, and then the slit width can be adjusted manually or electrically to begin sampling.

[0065] Experimental example: For instance, at F = 200 L / min, L = 4 cm, the aerosol particles are made of polystyrene microspheres with a density of 1050 kg / m³. 3At that time, the d of the sampling system can be measured. 50 -Stk relationship as follows Figure 5 As shown, the trend line is fitted using a logarithmic function. The contact sampling threshold is 0.3 μm. When the required d 50 When the value is 2 μm, the stk value is 0.14, therefore impaction sampling is used. Through the above steps, W = 0.39 cm can be calculated. This allows adjusting the slit to this value for aerosol particle sampling.

[0066] The aerosol collection method in this embodiment can switch between two modes: impact sampling mode and contact sampling mode.

[0067] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this 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. Therefore, they should not be construed as limitations on this invention.

[0068] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0069] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0070] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0071] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0072] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An aerosol collection device with adjustable sampling particle size, characterized in that, The sample collection device includes a collection housing, a mounting housing, rigid sidewalls, flexible sidewalls, a slit adjustment mechanism, a sampling carrier, and a flow pump. A portion of the collection housing is installed inside the mounting housing. An air inlet is provided at one end of the collection housing located outside the mounting housing. Rigid sidewalls are hinged to opposite sidewalls at one end of the collection housing located inside the mounting housing. The two rigid sidewalls are connected and enclosed by two flexible sidewalls to form a sample collection channel. Each of the two rigid sidewalls is equipped with a slit adjustment mechanism to adjust the width of the slit between the free ends of the two rigid sidewalls. The sampling carrier and the flow pump are both installed inside the mounting housing. The sampling carrier is in contact with or at a preset distance from the free ends of the two rigid sidewalls. The flow pump is located on the side of the sampling carrier away from the rigid sidewalls. The air intake port of the flow pump is spaced apart from the sampling carrier. The air outlet of the flow pump is connected to the outside of the mounting housing. The flow pump is equipped with a controller and a flow sensor at its outlet, and the flow sensor and the flow pump are electrically connected to the controller respectively.

2. The aerosol collection device with adjustable sampling particle size according to claim 1, characterized in that, The sampling carrier can cover the maximum width range of the two rigid sidewall free end slits.

3. The aerosol collection device with adjustable sampling particle size according to claim 1, characterized in that, The slit adjustment mechanism includes an adjustment screw, which passes through and is threadedly connected to the side wall of the mounting housing. One end of the adjustment screw located inside the mounting housing is movably connected to the rigid side wall.

4. The aerosol collection device with adjustable sampling particle size according to claim 1, characterized in that, An elastic element is also connected between the two rigid sidewalls near the sides.

5. The aerosol collection device with adjustable sampling particle size according to claim 1, characterized in that, The mounting housing is provided with a plug-in channel frame, one end of which is provided with a plug-in interface, and a position sensor is provided on the inner side wall of the mounting housing corresponding to the other end of the plug-in channel frame. The sampling carrier is installed in the insertion channel frame by a pull-out sampling bracket. One end of the sampling bracket is located at the insertion interface, and the other end of the sampling bracket is provided with a positioning device that cooperates with the position sensor.

6. The aerosol collection device with adjustable sampling particle size according to claim 5, characterized in that, The sampling bracket has a hollow structure, and the sampling carrier covers the hollow structure.

7. The aerosol collection device with adjustable sampling particle size according to claim 5, characterized in that, The insertion channel frame is mounted on the mounting housing via a height adjustment mechanism, and multiple position sensors are provided on the inner sidewall of the mounting housing along the height direction.

8. The aerosol collection device with adjustable sampling particle size according to claim 1, characterized in that, The inner wall of the collection housing is also provided with a perforated plate to homogenize the airflow, and the perforated plate is arranged perpendicular to the airflow direction inside the collection housing.

9. A method for collecting aerosols with adjustable sampling particle size, characterized in that, The aerosol collection device according to any one of claims 1 to 8 is used to achieve this, comprising the following steps: Set the sampling volume V, sampling time t, and sampling particle size d. 50 And the particle density ρ, the sampling flow rate F is calculated using Formula 1; where, Formula 1: ; Particle size d 50 When the flow rate is less than the preset value, the sampling flow rate F of the flow pump is set, the slit between the free ends of the two rigid sidewalls is adjusted to the maximum width through the slit adjustment mechanism, and the sampling carrier is arranged in contact with the free ends of the two rigid sidewalls, that is, the contact sampling mode is adopted to start sampling. Particle size d 50 When the value is not less than the preset value, use Formula 2 to calculate the U / W value; use Formula 3 to calculate Cc and look up the corresponding table to get Stk; use Formula 4 to calculate the W·U value; calculate W based on the U / W value and W·U value, and adjust the width of the slit between the free ends of the two rigid sidewalls to W through the slit adjustment mechanism, that is, start sampling using the impact sampling mode; Formula 2: Stk is the Stokes number, U is the linear velocity of the aerosol passing through the slit, and η is the aerodynamic viscosity coefficient. Formula 3: Cc is the sliding correction factor, and P is atmospheric pressure. Formula 4: L is the slit length.

Images