Aerosol scattering measurement device and use method thereof

Abstract

The invention discloses an aerosol scattering measurement device and a use method thereof, and belongs to the field of light scattering measurement, the aerosol scattering measurement device comprises an aerosol scattering cylinder, the top and the bottom of the aerosol scattering cylinder are fixedly connected with a top cover and a bottom cover respectively, and a measurement assembly is arranged outside the aerosol scattering cylinder. An aerosol circulation assembly is arranged in the aerosol scattering cylinder and comprises an input pipe which is fixedly connected to the interior of the top cover, and the axis of the input pipe coincides with the axis of the top cover; by arranging the rotatable arc-shaped detection mechanism and the modularized arc-shaped sleeve plate and utilizing a single photoelectric detector to be matched with a precise gear transmission system, full-automatic and multi-angle scanning measurement of scattered light signals is realized, the use number of detectors is remarkably reduced, and the device cost and complexity are greatly reduced; moreover, the angle measurement range is effectively expanded, and an angle scattering distribution diagram with higher spatial resolution is obtained.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of light scattering measurement, and particularly relates to an aerosol scattering measurement device and a use method thereof. BACKGROUND

[0002] An aerosol is a solid or liquid particle suspended in a gaseous medium, and its physical and chemical properties have important influences on the atmospheric environment, human health and climate change. As a common aerosol particle measurement method, light scattering can realize rapid detection of parameters such as concentration, particle size distribution and composition by analyzing the scattering characteristics of particles on incident light. However, in order to realize scattering signal collection in a wide angle range, a conventional device usually needs to configure an independent high-sensitivity photodetector (such as a photomultiplier tube or an avalanche photodiode) and a matching optical system for each detection angle. This design idea leads to a large number of detectors, which not only makes the device structure complex, bulky and costly, but also brings about the problems of complicated signal wiring and synchronous control. Limited by mechanical structure layout and manufacturing cost, most devices can only cover limited scattering angles (usually focusing on forward or a few fixed angles), and it is difficult to obtain a high spatial resolution full-angle scattering distribution diagram, thereby limiting the accurate identification and characterization of non-spherical particles or complex mixed aerosols. Therefore, the application provides an aerosol scattering measurement device and a use method thereof. SUMMARY

[0003] The purpose of the present application is to provide an aerosol scattering measurement device and a use method thereof to solve the problems raised in the background.

[0004] To achieve the above purpose, the present application provides the following technical scheme: an aerosol scattering measurement device and a use method thereof, comprising an aerosol scattering column, a top cover and a bottom cover fixedly connected to the top and bottom of the aerosol scattering column respectively, a measurement assembly arranged outside the aerosol scattering column, and an aerosol flow assembly arranged inside the aerosol scattering column.

[0005] As a preferred embodiment, the aerosol flow assembly comprises an input pipe fixedly connected inside the top cover and having an axis coinciding with that of the top cover, and an exhaust pipe fixedly connected at the axis of the bottom cover and coinciding with the axis of the input pipe.

[0006] As a preferred embodiment, the measurement assembly comprises three incident holes arranged on one side of the aerosol scattering column, three emission holes arranged on the other side of the aerosol scattering column and opposite to the incident holes, and a laser emission tower arranged on one side of the incident holes.

[0007] In a preferred embodiment, the laser tower is fixedly connected to one side of the bottom cover, and three miniature collimating lenses whose axes coincide with the axes of the three incident holes are fixedly connected to the side of the laser tower facing the three incident holes.

[0008] In a preferred embodiment, a heat-conducting frame is fixedly connected inside the top cover, and a section of the input pipe inside the heat-conducting frame is a serpentine part. A heat dissipation fin plate located inside the heat-conducting frame is fixedly connected to the top of the laser emission tower.

[0009] In a preferred embodiment, the aerosol scattering column has symmetrically formed arc-shaped detection slits on both sides of the extension line of the entrance hole and the exit hole as the axis. Each arc-shaped detection slit has an arc-shaped sleeve plate attached to its outer side. Each arc-shaped sleeve plate has multiple detection holes corresponding to the arc-shaped detection slits at equal intervals inside. The contact surface between the arc-shaped sleeve plate and the aerosol scattering column has two limiting grooves, and the contact surface between the aerosol scattering column and the arc-shaped sleeve plate has limiting protrusions that are adapted to the limiting grooves.

[0010] In a preferred embodiment, a semi-circular ring-shaped fixing frame is fixedly connected to one side of the bottom of the bottom cover. A rotating arc plate is slidably connected inside the semi-circular ring-shaped fixing frame. Side plates are fixedly connected to both ends of the rotating arc plate. A photoelectric detector is fixedly connected to each side plate on the circumference of the detection hole.

[0011] In a preferred embodiment, a motor is fixedly connected to the bottom of the bottom cover near the side of the semi-circular ring-shaped fixing frame, a drive gear is fixedly connected to the output shaft of the motor, and transmission teeth are provided on the contact surface between the rotating arc plate and the drive gear.

[0012] In a preferred embodiment, the inner wall cross-section of the aerosol scattering column is a regular polygon, and a light-absorbing coating is provided on the inner wall surface corresponding to the non-detection angle.

[0013] This invention also proposes a method for using an aerosol scattering measurement device: S1. Connect the device to the power supply, perform a self-test of the control system, start the laser emission tower for a pre-test, and the heat dissipation fins dissipate the heat generated by the laser emission tower. Connect the external aerosol sampling pump to the input pipe. The aerosol sample is drawn in and flows through the serpentine section of the input pipe, where it exchanges heat with the heat dissipation fins. The sample is passively dried by the waste heat generated when the laser emission tower is working. The dried aerosol enters the sealed scattering cavity composed of the aerosol scattering column, top cover, and bottom cover, forming a stable measurement area. S2. Multiple lasers inside the laser tower are started sequentially according to a preset timing sequence. The laser beams emitted by each laser are collimated by their respective miniature collimating lenses and then enter the scattering cavity in parallel. They pass through the aerosol sample and generate multi-wavelength scattered light signals. S3. Start the motor. Through the meshing of the drive gear and the transmission gear, drive the rotating arc plate to rotate at a constant speed in the semi-circular ring-shaped fixed frame. The photodetectors fixed on both sides of the rotating arc plate move synchronously and align with each detection hole on the arc plate in turn. For each laser that is started, the photodetector completes a semi-circular scan. The system synchronously records the scattered light intensity data at different scattering angles. S4. The control system integrates and stores the multi-dimensional data collected in step S3, classified by laser wavelength and scattering angle, to generate a multi-wavelength angular scattering distribution map of aerosols. After the measurement is completed, the aerosols are discharged from the device through the discharge pipe.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This aerosol scattering measurement device and its usage method, through the combination of a rotatable arc-shaped detection mechanism and a modular arc-shaped sleeve, can achieve fully automatic, multi-angle scattering light scanning using only a single photodetector. While significantly reducing system cost and complexity, it expands the angle measurement range and obtains angular scattering distribution with higher spatial resolution.

[0015] This aerosol scattering measurement device and its usage method integrate multi-wavelength lasers and timing control technology, enabling precise excitation and differentiation of multi-band scattering signals in a single measurement, enriching the dimensions of optical characteristic analysis; at the same time, it utilizes laser heat dissipation to passively dry the intake air, effectively eliminating humidity interference, improving data accuracy, and requiring no additional circuit components.

[0016] The aerosol scattering measurement device and its usage method adopt a replaceable arc-shaped sleeve and light-absorbing coating design, which enables the system to have good configurability and stray light suppression capability. It can flexibly adapt to different measurement needs and effectively improve the signal-to-noise ratio and measurement reliability, realizing a compact structure and high degree of automation for accurate measurement of multi-wavelength and multi-angle aerosol optical properties. Attached Figure Description

[0017] Figure 1 This is a front view of the structure of the present invention; Figure 2 This is a schematic diagram showing the disassembled structure of the present invention; Figure 3 This is a partial cross-sectional view of the structure of the present invention; Figure 4 for Figure 3 Enlarged schematic diagram of A Figure 5This is a bottom view of the structure of the present invention; Figure 6 This is a schematic diagram of the internal structure of the heat conduction frame.

[0018] In the diagram: 1. Aerosol scattering column; 101. Entrance hole; 102. Arc-shaped detection slit; 103. Limiting protrusion; 2. Top cover; 201. Heat conduction frame; 3. Bottom cover; 4. Semi-circular ring-shaped fixing frame; 401. Rotating arc plate; 402. Side plate; 403. Transmission gear; 5. Laser emission tower; 501. Miniature collimating lens; 502. Heat dissipation fin plate; 6. Arc-shaped sleeve; 601. Detection hole; 602. Limiting groove; 7. Photodetector; 8. Input pipe; 801. Serpentine section; 9. Discharge pipe; 10. Motor; 11. Drive gear. Detailed Implementation

[0019] The present invention will be further described below with reference to embodiments.

[0020] The following embodiments are used to illustrate the present invention, but should not be used to limit the scope of protection of the present invention. The conditions in the embodiments can be further adjusted according to specific conditions, and simple improvements to the method of the present invention under the premise of the concept of the present invention are all within the scope of protection claimed by the present invention.

[0021] Please see Figures 1-6 This invention provides an aerosol scattering measurement device, comprising an aerosol scattering column 1, with a top cover 2 and a bottom cover 3 fixedly connected to the top and bottom of the aerosol scattering column 1, respectively. A measurement assembly is provided on the outside of the aerosol scattering column 1, including three entrance holes 101 on one side of the aerosol scattering column 1 and three exit holes facing the entrance holes 101 on the other side of the aerosol scattering column 1. A laser emission tower 5 is provided on one side of the entrance holes 101, and the laser emission tower 5 is fixedly connected to one side of the bottom cover 3. Three miniature collimating lenses 501, whose axes coincide with the axes of the three entrance holes 101, are fixedly connected to the side of the laser emission tower 5 facing the three entrance holes 101. A heat-conducting frame is fixedly connected inside the top cover 2. 201, the input pipe 8 is located inside the heat conduction frame 201, and the section is a serpentine part 801. The top of the laser emission tower 5 is fixedly connected to a heat dissipation fin plate 502 located inside the heat conduction frame 201. The aerosol scattering column 1 is symmetrically provided with arc-shaped detection slits 102 on both sides with the extension line of the entrance hole 101 and the exit hole as the axis. Each arc-shaped detection slit 102 is fitted with an arc-shaped sleeve plate 6 facing outward. Each arc-shaped sleeve plate 6 is provided with multiple detection holes 601 corresponding to the arc-shaped detection slits 102 at equal intervals inside. The contact surface between the arc-shaped sleeve plate 6 and the aerosol scattering column 1 is provided with two limiting grooves 602. The contact surface between the aerosol scattering column 1 and the arc-shaped sleeve plate 6 is provided with limiting protrusions 103 that are adapted to the limiting grooves 602. Subsequently, multiple lasers within laser emission tower 5 are activated sequentially according to a preset time sequence. The emitted laser beams of different wavelengths are collimated by their respective miniature collimating lenses 501. Laser emission tower 5 integrates a multi-wavelength light source. The miniature collimating lenses 501 ensure that the emitted laser light is parallel, achieving compact integration and "plug-and-play" functionality of the multi-wavelength light source. The collimating lenses guarantee that all excitation light paths are consistent, thus making the measurement data of different wavelengths comparable and enriching the dimensions of the measurement information. The laser beam passes parallel through the entrance aperture 101, traverses the scattering cavity, and generates aerosol particles within the excitation cavity. The scattered light is mounted on arc-shaped probe slits 102 symmetrically opened on both sides of the scattering cavity, with arc-shaped sleeves 6 clamped on them. The probe holes 601 evenly distributed on the sleeves are precisely positioned by the cooperation of the limiting protrusions 103 and the limiting grooves 602. The arc-shaped probe slits 102 provide the basic probe window. The arc-shaped sleeves 6, as modular components, define specific probe angles. The limiting structure ensures installation accuracy. The modular design allows users to quickly replace sleeves with different angle distributions according to experimental needs (such as emphasizing forward or backward scattering), greatly enhancing the flexibility and applicability of the device.

[0022] Please see Figure 6 The aerosol scattering column 1 is equipped with an aerosol flow assembly inside. The aerosol flow assembly includes an input pipe 8 fixedly connected inside the top cover 2 and whose axis coincides with the axis of the top cover 2. An exhaust pipe 9 is fixedly connected at the axis of the bottom cover 3 and whose axis coincides with the axis of the input pipe 8. When the device is in operation, the power is first turned on, and the control system completes a self-test. The external aerosol sampling pump draws in the aerosol sample to be tested through the input pipe 8. The design of its axis coinciding with the top cover 2 ensures that the airflow descends along the central axis, avoiding the generation of eddies. As the sample inlet channel, its central axis arrangement ensures stable airflow, ensuring the uniformity of aerosol distribution in the measurement area and improving the representativeness of the sampling. The airflow then flows through the serpentine section 801 of the input pipe 8. This section is encapsulated in the heat-conducting frame 201 and is in close contact with the heat dissipation fins 502 on the top of the laser emission tower 5. The serpentine section 801 increases the contact area between the airflow and the heat source and the heat exchange. The device uses a heat-conducting frame 201 as a heat transfer medium and a heat dissipation fin plate 502 to actively remove the waste heat generated during laser operation. The device's own waste heat is used to passively dry the aerosol, eliminating the need for additional energy consumption and components. This reduces the interference of humidity on light scattering measurements, improves data accuracy, and achieves energy recycling. The dried aerosol enters a sealed scattering cavity composed of an aerosol scattering column 1, a top cover 2, and a bottom cover 3, ensuring the stability and cleanliness of the measurement area and avoiding external interference, thus providing a foundation for accurate measurement. The discharge pipe 9 on the bottom cover 3 is responsible for discharging the measured aerosol, completing the entire airflow cycle.

[0023] Please see Figures 1-6A semi-circular ring-shaped fixing frame 4 is fixedly connected to one side of the bottom of the bottom cover 3. A rotating arc plate 401 is slidably connected inside the semi-circular ring-shaped fixing frame 4. Side plates 402 are fixedly connected to both ends of the rotating arc plate 401. A photoelectric detector 7 is fixedly connected to the circumference of each side plate 402 facing the detection hole 601. A motor 10 is fixedly connected to the bottom of the bottom cover 3 near the semi-circular ring-shaped fixing frame 4. A drive gear 11 is fixedly connected to the output shaft of the motor 10. Transmission teeth 403 are provided on the contact surface between the rotating arc plate 401 and the drive gear 11. The cross-section of the inner wall of the aerosol scattering column 1 is a regular polygon, and a light-absorbing coating is provided on the inner wall surface corresponding to the non-detection angle. Simultaneously, the motor 10 starts, and the drive gear 11 on its output shaft meshes with the transmission gear 403 on the rotating arc plate 401, driving the rotating arc plate 401 to slide smoothly within the semi-circular annular fixed frame 4. The photodetectors 7, fixed to the side plates 402 at both ends of the rotating arc plate 401, move synchronously, precisely aligning themselves with each detection hole 601 in sequence. The drive gear 11 and transmission gear 403 convert the rotational motion into arc-shaped translational motion. The semi-circular fixed frame 4 provides support and guidance. The rotating arc plate 401 and the side plates 402 form a rigid motion mechanism, supporting the detectors, thus enabling the use of a single photodetector 7 to scan the area within the semi-circular radius. Angular sequential scanning measurement replaces the traditional multi-detector array, significantly reducing the number of detectors and substantially lowering the cost, complexity, and signal synchronization difficulty of the device. For each initiated laser wavelength, photodetector 7 completes a semi-circular scan, and the system synchronously collects the intensity of scattered light from all angles. During this process, the regular polygonal inner wall of aerosol scattering column 1 and its light-absorbing coating play a role. The regular polygonal inner wall reflects stray light to non-detection directions, and the light-absorbing coating strongly absorbs these stray lights, suppressing stray light background in the cavity to the maximum extent, effectively improving the signal-to-noise ratio of the system and the sensitivity and reliability of the measurement. Ultimately, the control system integrates, processes, and stores all multi-dimensional data categorized by laser wavelength and scattering angle, generating a detailed aerosol multi-wavelength angular scattering distribution map. The entire measurement process, from sample pretreatment, multi-wavelength excitation, angle scanning to data acquisition, is automatically controlled by the program, ultimately achieving a high degree of automation and intelligent operation of the device.

[0024] This invention also proposes a method for using an aerosol scattering measurement device: S1. Connect the device to the power supply, perform a self-test of the control system, start the laser emitting tower 5 for a pre-test, and the heat dissipation fins 502 dissipate the heat generated by the laser emitting tower 5. Connect the external aerosol sampling pump to the input pipe 8. The aerosol sample is sucked in and flows through the serpentine section 801 of the input pipe 8, where it exchanges heat with the heat dissipation fins 502. The sample is passively dried by the waste heat generated when the laser emitting tower 5 is working. The dried aerosol enters the closed scattering cavity composed of the aerosol scattering column 1, the top cover 2, and the bottom cover 3, forming a stable measurement area. S2. Multiple lasers in the laser tower 5 are started sequentially according to a preset timing sequence. The laser beams emitted by them are collimated by their respective miniature collimating lenses 501 and then enter the scattering cavity in parallel. They pass through the aerosol sample and generate multi-wavelength scattered light signals. S3. Start the motor 10, and through the meshing of the drive gear 11 and the transmission gear 403, drive the rotating arc plate 401 to rotate at a constant speed in the semi-circular fixed frame 4. The photodetectors 7 fixed on both sides of the rotating arc plate 401 move synchronously and align with each detection hole 601 on the arc sleeve plate 6 in turn. For each laser that is started, the photodetector 7 completes a semi-circular scan, and the system synchronously records the scattered light intensity data at different scattering angles. S4. The control system integrates and stores the multi-dimensional data collected in step S3, classified by laser wavelength and scattering angle, and generates a multi-wavelength angular scattering distribution map of aerosol. After the measurement is completed, the aerosol is discharged from the device through the discharge pipe 9.

[0025] In the above scheme, it should be noted that: the laser tower 5 and the photodetector 7 in this application are both existing products, and the specific structure, electrical connection method (circuit layout) and working principle of the laser tower 5 and the photodetector 7 are all existing publicly disclosed technical means, which will not be described in detail here; It should also be noted that existing controllers (or controller systems) can also be used in this application, and the telecommunication connection method, circuit layout method and control principle between the controller (or controller system) and the electrical components (laser tower 5 and photodetector 7) of this application are all existing publicly disclosed technical means. At the same time, the controller (or controller system) can adopt conventional and mature existing products in the field, thereby realizing coordinated control of the electrical components (laser tower 5 and photodetector 7) of this application. Furthermore, the technical solution of this application does not involve the improvement of computer programs. Therefore, the specific control method between the controller (or controller system) and the electrical components of this application will not be described in detail here.

[0026] 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 of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An aerosol scattering measurement device, comprising an aerosol scattering column (1), characterized in that: The top and bottom of the aerosol scattering column (1) are fixedly connected with a top cover (2) and a bottom cover (3), respectively. The outside of the aerosol scattering column (1) is provided with a measuring component, and the inside of the aerosol scattering column (1) is provided with an aerosol flow component.

2. The aerosol scattering measurement device according to claim 1, characterized in that: The aerosol flow assembly includes an input pipe (8) fixedly connected inside the top cover (2) with its axis coinciding with the axis of the top cover (2), and an output pipe (9) fixedly connected at the axis of the bottom cover (3), with the output pipe (9) coinciding with the axis of the input pipe (8).

3. The aerosol scattering measurement device according to claim 2, characterized in that: The measuring component includes three entrance holes (101) on one side of the aerosol scattering column (1), three exit holes facing the entrance holes (101) on the other side of the aerosol scattering column (1), and a laser emitting tower (5) on one side of the entrance holes (101).

4. The aerosol scattering measurement device according to claim 3, characterized in that: The laser tower (5) is fixedly connected to one side of the bottom cover (3). On the side of the laser tower (5) facing the three entrance holes (101), there are three miniature collimating lenses (501) whose axes coincide with the axes of the three entrance holes (101).

5. The aerosol scattering measurement device according to claim 4, characterized in that: The top cover (2) is fixedly connected to a heat-conducting frame (201), and the input pipe (8) is located in a serpentine section (801) inside the heat-conducting frame (201). The top of the laser tower (5) is fixedly connected to a heat dissipation fin plate (502) located inside the heat-conducting frame (201).

6. The aerosol scattering measurement device according to claim 5, characterized in that: The aerosol scattering column (1) has symmetrical arc-shaped detection slits (102) on both sides with the extension line of the entrance hole (101) and the exit hole as the axis. Each arc-shaped detection slit (102) has an arc-shaped sleeve plate (6) on its outward side. Each arc-shaped sleeve plate (6) has multiple detection holes (601) at equal intervals inside, corresponding to the arc-shaped detection slits (102). The contact surface between the arc-shaped sleeve plate (6) and the aerosol scattering column (1) has two limiting grooves (602). The contact surface between the aerosol scattering column (1) and the arc-shaped sleeve plate (6) has limiting protrusions (103) that are adapted to the limiting grooves (602).

7. The aerosol scattering measurement device according to claim 6, characterized in that: A semi-circular ring-shaped fixing frame (4) is fixedly connected to one side of the bottom of the bottom cover (3). A rotating arc plate (401) is slidably connected inside the semi-circular ring-shaped fixing frame (4). Side plates (402) are fixedly connected to both ends of the rotating arc plate (401). A photodetector (7) is fixedly connected to the circumference of each side plate (402) facing the detection hole (601).

8. The aerosol scattering measurement device according to claim 7, characterized in that: A motor (10) is fixedly connected to the bottom of the bottom cover (3) near the semi-circular ring-shaped fixing frame (4). A drive gear (11) is fixedly connected to the output shaft of the motor (10). Transmission teeth (403) are provided on the contact surface between the rotating arc plate (401) and the drive gear (11).

9. The aerosol scattering measurement device according to claim 1, characterized in that: The inner wall cross-section of the aerosol scattering column (1) is a regular polygon, and a light-absorbing coating is provided on the inner wall surface corresponding to the non-detection angle.

10. A method of using an aerosol scattering measurement device, characterized in that: The aerosol scattering measurement device as described in any one of claims 1-9 further includes the following steps: S1. Connect the device to the power supply, perform a self-test of the control system, start the laser emitting tower (5) for a rehearsal, and the heat dissipation fins (502) discharge the heat generated by the laser emitting tower (5). Connect the external aerosol sampling pump to the input pipe (8). The aerosol sample is sucked in and flows through the serpentine part (801) of the input pipe (8) to exchange heat with the heat dissipation fins (502). The sample is passively dried by the waste heat generated when the laser emitting tower (5) is working. The dried aerosol enters the closed scattering cavity composed of the aerosol scattering column (1), the top cover (2) and the bottom cover (3) to form a stable measurement area. S2. Multiple lasers in the laser tower (5) are started in sequence according to a preset time sequence. The laser beams emitted by them are collimated by their respective micro collimating lenses (501) and then enter the scattering cavity in parallel, pass through the aerosol sample, and generate multi-wavelength scattered light signals. S3. Start the motor (10), and through the meshing of the drive gear (11) and the transmission gear (403), drive the rotating arc plate (401) to rotate at a constant speed in the semi-circular fixed frame (4). The photodetectors (7) fixed on both sides of the rotating arc plate (401) move synchronously and align with each detection hole (601) on the arc sleeve plate (6) in turn. For each laser that is started, the photodetector (7) completes a semi-circular scan, and the system synchronously records the scattered light intensity data at different scattering angles. S4. The control system integrates and stores the multi-dimensional data collected in step S3, classified by laser wavelength and scattering angle, and generates a multi-wavelength angular scattering distribution map of aerosol. After the measurement is completed, the aerosol is discharged from the device through the discharge pipe (9).

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