A portable low-concentration particulate matter sampling device

Abstract

The present application relates to the technical field of particle sampling, and specifically discloses a portable low-concentration particle sampling device, which includes a body with a built-in gas sensor and an air pressure sensor, a folding bracket arranged under the body, a filter threadedly connected to the side of the body away from the folding bracket, a cutter and a sampling head arranged on the side of the filter away from the body, the cutter includes a cutting cylinder, an impact plate and a collection plate placed in the cutting cylinder in sequence from one end of the sampling head to one end of the filter, a collection slot is provided on the collection plate, a storage bin is provided at the bottom of the collection plate, a leakage slot is provided on the collection plate, an active magnet is rotatably connected to the outer wall of the cutting cylinder, a passive magnet corresponding to the active magnet is slidably provided on the inner wall of the cutting cylinder, and the magnetic poles of the active magnet and the passive magnet close to each other are opposite, and a scraper is provided in the collection slot for the passive magnet. The present application has the effect of reducing the accumulation of large particles on the collection plate during long-term sampling operations.

Description

Technical Field

[0001] The present application relates to the technical field of particulate matter sampling, and in particular to a portable low-concentration particulate matter sampling device. Background Art

[0002] Portable particulate matter sampling equipment is a device specially used to collect and measure suspended particulate matter in the air. It has the characteristics of portability, easy operation, and a wide sampling range. The device uses mechanical principles to allow a certain volume of air to pass through a filter with a known mass (such as a filter membrane) at a constant rate. In this process, the particles floating in the air are retained on the filter.

[0003] The specific operation is to open the folding bracket and install the body on the folding bracket. Then, according to the actual working conditions and needs, assemble the filter, cutter and sampling head. Finally, install the assembled filter on the body to start the sampling operation. The operation time ranges from a few minutes to hundreds of hours. The principle of the particulate matter sampling equipment is as follows: the air pump in the body draws air and allows the air to enter from the sampling head. When the air passes through the cutter, the larger particles in the air hit the impact plate due to their greater inertia and are carried out by the airflow through the holes in the impact plate. At this time, the larger particles fall on the collection plate due to their lower speed after impact, while the smaller particles continue to move along the airflow and pass through the holes in the collection plate into the filter. The smaller particles are intercepted by the filter, and the air continues to enter the body through the connecting pipe. The capacitive gas sensor in the body detects the humidity of the air, and the air pressure sensor displays the air pressure in the body. Then, the air pressure, humidity, flow and other data are displayed on the display screen of the body. After the collection is completed, the measured particulate matter content in the air can be obtained by calculating the weight before and after the filter and the air volume during the collection.

[0004] Regarding the above-mentioned related technologies, the inventors believe that there are the following defects: when the body runs for a long time, a large number of large particles are likely to accumulate on the collection plate. At this time, the large particles are easily carried by the airflow and fall into the filter, thereby affecting the final sampling results. Summary of the Invention

[0005] In order to improve the problem of large amounts of particulate matter accumulating on the collection plate when the sampling operation takes a long time, the present application provides a portable low-concentration particulate matter sampling device.

[0006] The portable low-concentration particulate matter sampling device provided in this application adopts the following technical solution:

[0007] A portable low-concentration particulate matter sampling device, comprising a body, a folding bracket arranged below the body, a filter threadedly connected to the side of the body away from the folding bracket, a cutter and a sampling head arranged on the side of the filter away from the body, the cutter comprising a cutting cylinder, an impact plate and a collection plate placed in the cutting cylinder in sequence from one end of the sampling head to one end of the filter, an annular collection groove being provided on the collection plate, characterized in that a storage bin is detachably provided at the bottom of the collection plate, a leakage groove is provided on the collection plate, an active magnet is rotatably connected to the outer wall of the cutting cylinder, a passive magnet corresponding to the active magnet is slidably provided on the inner wall of the cutting cylinder, and the magnetic poles of the active magnet and the passive magnet close to each other are opposite, and a scraper strip is provided on the passive magnet in the collection groove.

[0008] By adopting the above technical solution, when the machine body has been running for a long time, the active magnet is rotated, and the passive magnet is rotated accordingly, and the scraping bar is also moved accordingly. At this time, the particles on the collection plate are scraped by the scraping bar until the particles are scraped into the leakage groove and fall from the leakage groove into the storage bin, and the cleaning operation of the collection plate can be completed. The cleaning structure is relatively simple and the entire cleaning process is relatively simple, which effectively avoids the large particles on the collection plate being blown into the filter by the airflow due to the large number of large particles, which interferes with the sampling results.

[0009] Optionally, the collection plate is provided with a baffle at the leakage groove, the bottom wall of the storage bin is rotatably connected to a rotating drum, a lifting rod is provided in the rotating drum, a sliding rod is vertically fixed on the lifting rod, the lifting rod is fixedly connected to the baffle, a lifting groove adapted to the sliding rod is inclined upward on the peripheral wall of the rotating drum, a driving assembly for driving the rotating drum to rotate is provided in the storage bin, and a limiting member for limiting the movement of the baffle only in the vertical direction is also provided in the storage bin.

[0010] By adopting the above technical solution, when the scraper is not in the scraping operation, the baffle blocks the leakage groove to prevent the airflow from entering the storage bin, thereby preventing small particles in the airflow from entering the storage bin; when the active magnet is rotated to move the scraper, the driving assembly is used to rotate the drum, the slide bar moves downward in the lifting groove, and the lifting bar also moves downward, that is, the baffle moves downward, and the scraper can now scrape the large particles on the collection plate into the storage bin; when the scraping operation is completed, the driving assembly is used to rotate the drum in the opposite direction, thereby moving the slide bar upward, that is, the baffle moves upward, and at this time the baffle blocks the leakage groove, and the process of the baffle descending and rising again is relatively short, which has little effect on the error of the entire long sampling process.

[0011] Optionally, the driving component includes a U-shaped magnet rotatably arranged on the rotating drum and limit blocks arranged in the storage bin on both sides of the U-shaped magnet, the end of the U-shaped magnet facing the direction of movement of the scraper bar is attracted to the end of the active magnet close to the collecting plate, and the end of the U-shaped magnet facing away from the direction of movement of the scraper bar is repelled from the end of the master-slave magnet close to the collecting plate. When the scraper bar moves to the side of the leakage groove facing the direction of movement of the scraper bar, the U-shaped magnet and the opposite end of the active magnet are opposite and the baffle is lower than the collecting plate. When the scraper bar moves to the side of the leakage groove facing away from the direction of movement of the scraper bar, the U-shaped magnet and the same end of the active magnet are opposite and the baffle rises to be flush with the inner bottom wall of the collecting groove.

[0012] When the U-shaped magnet and the active magnet are opposite to each other, the U-shaped magnet is repelled by the active magnet and moves in the opposite direction of the active magnet. At this time, the baffle moves up, that is, the process of controlling the movement of the baffle only requires the staff to rotate the active magnet, which is relatively simple to operate and does not damage the cutting cylinder, thereby ensuring the sealing of the cutter.

[0013] Optionally, the scraper bar is elastically hinged on the passive magnet, and the scraper bar is in an arc shape that fits the slot wall of the collection slot. The collection plate is provided with a locking member for locking the scraper bar to fit the slot wall of the collection slot.

[0014] By adopting the above technical solution, when scraping operation is required, the locking state of the scraping strip is released and the scraping operation can be carried out. When the scraping operation is completed, the scraping strip is folded over by the locking part until it is against the wall of the collection groove, thereby preventing the scraping strip from interfering with the main collection area of ​​the collection groove.

[0015] Optionally, the locking member is a blocking rod fixed to the collection plate, and the blocking rod is located on a side of the leakage groove that is away from the moving direction of the scraper strip.

[0016] By adopting the above technical solution, after the scraping bar scrapes the large particles to the leakage trough and leaks them into the storage bin, the active magnet continues to rotate to make the scraping bar continue to move. At this time, the baffle bar is pressed against the scraping bar and causes the scraping bar to rotate until the scraping bar fits into the wall of the collection trough, completing the scraping operation. During this process, the baffle bar also scrapes the large particles adhered to the scraping surface of the scraping bar into the leakage trough to prevent large particles from adhering to the scraping bar.

[0017] Optionally, a nozzle penetrating the collection plate is provided in the storage bin, and the nozzle and the baffle are located on both sides of the scraper bar. An elastic containing bag containing adhesive is provided in the storage bin, and when the elastic containing bag is filled with adhesive, the elastic containing bag is in an expanded state, the nozzle is communicated with the elastic containing bag, and an opening and closing part for controlling the opening and closing of the nozzle is also provided in the storage bin.

[0018] By adopting the above technical solution, before sampling in relatively dry areas, adhesive is added to the elastic holding bag and the scraper is placed in a scraping state. When sampling begins, the nozzle is first opened by the opening and closing part and the active magnet is rotated. At this time, the scraper moves in the direction of the active magnet and gradually rotates toward the wall of the collection trough. The nozzle sprays adhesive to the scraper surface on the back of the scraper until the scraper is in a retracted state, and the active magnet is moved again to open and move the scraper. At this time, the adhesive adhered to the scraper is smeared on the bottom wall of the collection trough to further prevent large particles from jumping in the collection trough or even being blown into the filter by the airflow; after the scraper has finished scraping and is in a retracted state, the nozzle continues to spray adhesive on the scraper to ensure that the scraper provides adhesive for the bottom wall of the collection trough during the next scraping cycle.

[0019] Optionally, a control port is opened on the peripheral wall of the nozzle, and the nozzle is sealed with an elastic membrane at the control port. The opening and closing part is an opening and closing rod fixedly connected to the U-shaped magnet, and when the U-shaped magnet is pressed against the limit block on the side facing the moving direction of the scraper strip, the opening and closing rod presses the elastic membrane.

[0020] By adopting the above technical solution, the active magnet is moved. When the U-shaped magnet moves synchronously with the active magnet, the opening and closing rod gradually loosens the squeeze on the elastic membrane. At this time, the elastic containing bag is acted upon by its own elastic force, allowing the adhesive to smoothly pass through the nozzle to the position of the elastic membrane. When the active magnet is continued to be moved so that the opposite ends of the U-shaped magnet and the active magnet are mutually isotropic, the U-shaped magnet is instantly rebounded to abut against the limit block located on the side of the U-shaped magnet facing the moving direction of the scraper strip. At this time, the opening and closing rod presses the elastic membrane again, thereby completing the closure of the nozzle.

[0021] Optionally, an elastic hook is fixed to the end of the scraper strip away from the end hinged to the passive magnet.

[0022] By adopting the above technical solution, when the active magnet is moved to rotate the scraper bar until it is in contact with the wall of the collection trough, the elastic hook and the baffle bar are abutted, thereby indirectly increasing the resistance of the active magnet when it moves, so as to remind the staff of the position status of the scraper bar at this time; when the active magnet continues to rotate, the scraper bar breaks through the restriction of the elastic hook, that is, the elastic hook is squeezed until it passes through the baffle bar smoothly.

[0023] In summary, this application includes at least one of the following beneficial technical effects:

[0024] 1. Rotating the active magnet causes the passive magnet to move accordingly, which in turn causes the scraper to move synchronously. The scraper then scrapes the particles on the collection plate until the large particles are scraped off to the trough and fall into the storage bin, completing the collection plate cleaning operation. The cleaning structure is relatively simple and the entire cleaning process is relatively simple, effectively preventing the large particles on the collection plate from being blown into the filter by the airflow due to the large number of large particles on the collection plate, which may interfere with the sampling results.

[0025] 2. Rotate the active magnet, and the U-shaped magnet moves with the active magnet, that is, when the scraper moves in the direction close to the leakage groove, the U-shaped magnet is attracted by the active magnet, and then the U-shaped magnet and the active magnet move synchronously, causing the baffle to move down; when the scraper moves to the side of the leakage groove that is opposite to the moving direction of the scraper, the scraper continues to move in the direction away from the leakage groove. During this process, the U-shaped magnet first continues to move synchronously with the active magnet until the U-shaped magnet hits the limit block located on the side of the U-shaped magnet that is opposite to the moving direction of the scraper. The active magnet continues to move but the U-shaped magnet cannot move. Until the opposite surfaces of the U-shaped magnet and the active magnet are mutually homologous, the U-shaped magnet is repelled by the active magnet and moves in the opposite direction to the active magnet. At this time, the baffle moves up, that is, the process of controlling the movement of the baffle only requires the staff to rotate the active magnet, which is relatively simple to operate and does not damage the cutting cylinder, thereby ensuring the sealing of the cutter.

[0026] 3. Move the active magnet. When the U-shaped magnet moves synchronously with the active magnet, the opening and closing rod gradually releases the pressure on the elastic membrane. At this time, the scraper moves in the direction of the active magnet and gradually rotates toward the wall of the collection trough, and the nozzle sprays adhesive on the side of the scraper facing away from the scraping surface of the scraper. When the active magnet is continued to move so that the opposite ends of the U-shaped magnet and the active magnet are mutually isotropic, the U-shaped magnet is instantly rebounded to abut against the limit block located on the side of the U-shaped magnet facing the direction of movement of the scraper. At this time, the opening and closing rod presses the elastic membrane again, thereby completing the closure of the nozzle, and the active magnet is moved again to open and move the scraper. At this time, the adhesive adhered to the scraper is smeared on the bottom wall of the collection trough to further prevent large particles from jumping in the collection trough or even being blown into the filter by the airflow. When the scraper has finished scraping and is in the retracted state, the nozzle continues to spray adhesive on the scraper, and the cycle is repeated to ensure that the scraper provides adhesive to the bottom wall of the collection trough during the next scraping cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application;

[0028] Figure 2 This is a schematic diagram of the explosion structure of the embodiment of the present application, mainly used to show the cutter when it is not in the scraping operation;

[0029] Figure 3 yes Figure 2 A magnified schematic diagram of part A;

[0030] Figure 4 This is a schematic diagram of the structure of the cutter when the impact plate is hidden and the scraping strip is in an unscratching state.

[0031] Figure numerals: 11, body; 12, folding bracket; 13, filter; 14, cutter; 141, cutting cylinder; 142, impact plate; 143, collection plate; 1431, collection trough; 15, sampling head; 21, storage bin; 22, leakage trough; 31, active magnet; 32, passive magnet; 33, scraper; 41, baffle; 42, rotating drum; 421, lifting trough; 43, lifting rod; 44, sliding rod; 45, limiter; 5, driving assembly; 51, U-shaped magnet; 52, limit block; 61, gear lever; 62, elastic hook; 71, nozzle; 72, elastic containing bag; 73, elastic membrane; 74, opening and closing rod. DETAILED DESCRIPTION

[0032] The following is combined with Figure 1-4 This application is described in further detail.

[0033] The present application embodiment discloses a portable low-concentration particulate matter sampling device. Figure 1 and Figure 2The portable low-concentration particulate matter sampling device includes a body 11 with a built-in gas sensor and an air pressure sensor, a folding bracket 12 threadedly connected to the bottom of the body 11, a filter 13 threadedly connected to the side of the body 11 away from the folding bracket 12, a cutter 14 threadedly connected to the side of the filter 13 away from the body 11, and a sampling head 15 threadedly connected to the end of the filter 13, wherein the cutter 14 can be zero, one, two, etc. In the embodiment of the present application, there are two cutters 14, and the cutter 14 includes a cutting cylinder 141, a direction from one end of the sampling head 15 to one end of the filter 13 An impact plate 142 and a collection plate 143 are sequentially placed in the cutting cylinder 141. The collection plate 143 is provided with an annular collection groove 1431. An active magnet 31 is rotatably connected to the outer wall of the cutting cylinder 141. A passive magnet 32 ​​corresponding to the active magnet 31 is slidably connected to the inner wall of the cutting cylinder 141. A scraper 33 is provided in the collection groove 1431 of the passive magnet 32. A storage bin 21 is placed at the bottom of the collection plate 143 in the cutting cylinder 141. A leakage groove 22 is provided on the collection plate 143. The magnetic poles of the active magnet 31 and the passive magnet 32 ​​at the ends adjacent to each other are of opposite polarity.

[0034] During long-term collection operations, the staff can rotate the active magnet 31 to rotate the passive magnet 32, and then move the scraper 33. At this time, the particles on the collection plate 143 are scraped by the scraper 33 until the large particles are scraped off to the leakage groove 22 and fall from the leakage groove 22 into the storage bin 21, thus completing the cleaning operation of the collection plate 143. The cleaning structure is relatively simple and the entire cleaning process is relatively simple, which effectively avoids the large particles on the collection plate 143 being blown into the filter 13 by the airflow due to the large number of large particles, which interferes with the sampling results.

[0035] Reference Figure 2 and Figure 3 The collecting plate 143 is blocked with a baffle 41 at the leakage groove 22, and the bottom wall of the storage bin 21 is rotatably connected to the rotating drum 42. The bottom of the baffle 41 is fixed with a lifting rod 43 in the rotating drum 42, and a slide rod 44 is vertically fixed on the lifting rod 43. The peripheral wall of the rotating drum 42 is inclined upward to provide a lifting groove 421 adapted to the slide rod 44. A driving assembly 5 for driving the rotating drum 42 to rotate is provided in the storage bin 21. A limit member 45 for limiting the baffle 41 to move only in the vertical direction is also provided in the storage bin 21. The limit member 45 can be a telescopic rod fixed between the bottom wall of the storage bin 21 and the baffle 41.

[0036] When the scraping strip 33 is not in the scraping operation, the baffle 41 blocks the leakage groove 22 to prevent the air flow from entering the storage bin 21, thereby preventing small particles in the air flow from also entering the storage bin 21, effectively reducing the error of the collection operation; when the active magnet 31 is rotated to move the scraping strip 33, the driving component 5 is used to rotate the drum 42, and the slide bar 44 moves downward in the lifting groove 421, and the lifting rod 43 also moves downward, that is, the baffle 41 moves downward, at this time the scraping strip 33 can scrape the large particles on the collection plate 143 into the storage bin 21; when the scraping operation is completed, the driving component 5 is used to rotate the drum 42 in the opposite direction, thereby moving the slide bar 44 upward, that is, moving the baffle 41 upward, at this time the baffle 41 blocks the leakage groove 22, and the entire process of the baffle 41 from descending to rising again is relatively short, and can be completed in only a few seconds, which has little effect on the error generated in the entire long sampling process.

[0037] Reference Figure 2 and Figure 3 The driving assembly includes a U-shaped magnet 51 rotatably arranged on the rotating drum 42 and a limit block 52 fixed to the storage bin 21 on both sides of the U-shaped magnet 51. The end of the U-shaped magnet 51 facing the direction of movement of the scraper bar 33 is attracted to the end of the active magnet 31 close to the collecting plate 143, and the end of the U-shaped magnet 51 facing away from the moving direction of the scraper bar 33 is repelled from the ends of the master and slave magnets close to the collecting plate 143. When the scraper bar 33 moves to the side of the leakage groove 22 facing the moving direction of the scraper bar 33, the opposite ends of the U-shaped magnet 51 and the active magnet 31 are opposite and the baffle 41 is lower than the collecting plate 143. When the scraper bar 33 moves to the side of the leakage groove 22 facing away from the moving direction of the scraper bar 33, the U-shaped magnet 51 and the same ends of the active magnet 31 are opposite and the baffle 41 rises to be flush with the inner bottom wall of the collecting groove 1431.

[0038] The active magnet 31 is rotated, and the U-shaped magnet 51 moves with the active magnet 31. That is, when the scraper 33 moves toward the direction close to the drain groove 22, the U-shaped magnet 51 is attracted by the active magnet 31, and then the U-shaped magnet 51 and the active magnet 31 move synchronously, causing the baffle 41 to descend. When the scraper 33 moves to the side of the drain groove 22 that is opposite to the moving direction of the scraper 33, the scraper 33 continues to move away from the drain groove 22. During this process, the U-shaped magnet 51 first continues to move synchronously with the active magnet 31 until the U-shaped magnet 51 is at the U-shaped magnet. When the U-shaped magnet 51 is against the limit block 52 on the side facing away from the moving direction of the scraper 33, the active magnet 31 continues to move while the U-shaped magnet 51 cannot move until the opposite surfaces of the U-shaped magnet 51 and the active magnet 31 are of the same polarity. At this time, the U-shaped magnet 51 is repelled by the active magnet 31 and moves in the opposite direction to the active magnet 31. At this time, the baffle 41 moves up, that is, the process of controlling the movement of the baffle 41 only requires the staff to rotate the active magnet 31. The operation is relatively simple, and the cutting cylinder 141 is not damaged, thereby ensuring the sealing of the cutter 14.

[0039] Reference Figure 4 The scraper strip 33 is hinged on the passive magnet 32, and a torsion spring is connected between the scraper strip 33 and the passive magnet 32. The scraper strip 33 is in an arc shape that fits the groove wall of the collection groove 1431. The collection plate 143 is provided with a locking member for locking the scraper strip 33 to fit the groove wall of the collection groove 1431. The locking member is a baffle fixed to the collection plate 143, and the baffle is located on the side of the leakage groove 22 that is away from the moving direction of the scraper strip 33. The end of the scraper strip 33 away from the end hinged with the passive magnet 32 ​​is fixed with an elastic hook 62. The scraper strip 33 is a rubber strip that is more efficient in removing large particles mixed with adhesives, and the rubber strip is softer than the steel strip, and causes less wear on the collection plate 143.

[0040] When the active magnet 31 is rotated to make the scraper 33 scrape the large particles to the drain groove 22 and drain into the storage bin 21, the active magnet 31 is continued to be rotated to make the scraper 33 continue to move. At this time, the blocking rod and the scraper bar 33 are pressed tightly and the scraper bar 33 is rotated until the scraper bar 33 is in contact with the groove wall of the collection groove 1431 and the elastic hook 62 is pressed tightly against the blocking rod 61, thereby preventing the scraper bar 33 from interfering with the main collection area of ​​the collection groove 1431. The elastic hook 62 and the blocking rod also indirectly increase the resistance of the active magnet 31 when moving, so as to remind the staff of the position status of the scraper bar 33 at this time. At this time, the scraping operation is completed. During this process, the blocking rod also scrapes the large particles adhered to the scraping surface of the scraper bar 33 into the drain groove 22 to prevent the large particles from adhering to the scraper bar 33. When the scraping operation is needed, it is only necessary to rotate the active magnet 31 to make the scraper bar 33 move. During this process, the elastic hook 62 is squeezed to pass smoothly between the blocking rod 61 and the groove wall of the collection groove 1431.

[0041] Reference Figure 3 and Figure 4 A nozzle 71 that passes through the collection plate 143 is provided in the storage bin 21, and the nozzle 71 and the baffle are located on both sides of the scraper 33. An elastic receiving bag 72 containing an adhesive is provided in the storage bin 21, and the adhesive is vaseline. When the elastic receiving bag 72 is filled with adhesive, the elastic receiving bag 72 is in an expanded state, and the nozzle 71 is connected to the elastic receiving bag 72. An opening and closing part for controlling the opening and closing of the nozzle 71 is also provided in the storage bin 21. A control port is provided on the peripheral wall of the nozzle 71, and the nozzle 71 is sealed with an elastic membrane 73 at the control port. The opening and closing part is an opening and closing rod 74 fixed to the U-shaped magnet 51, and when the U-shaped magnet 51 is tightly pressed against the limit block 52 on the side facing the moving direction of the scraper 33, the opening and closing rod 74 presses the elastic membrane 73.

[0042] Before sampling in a relatively dry area, an adhesive is added to the elastic holding bag 72 and the scraping strip 33 is in a scraping state. The active magnet 31 is moved. When the U-shaped magnet 51 moves synchronously with the active magnet 31, the opening and closing rod 74 gradually releases the squeeze on the elastic membrane 73. At this time, the scraping strip 33 moves in the direction of the active magnet 31 and gradually rotates toward the groove wall of the collection groove 1431. The nozzle 71 sprays the adhesive on the side of the scraping strip 33 that is opposite to the scraping surface of the scraping strip 33. When the active magnet 31 is continued to be moved so that the opposite ends of the U-shaped magnet 51 and the active magnet 31 are mutually isotropic, the U-shaped magnet 51 is instantly rebounded to the position opposite to the U-shaped magnet 51. The limit block 52 on the side of the moving direction of the scraper 33 is abutted. At this time, the opening and closing rod 74 presses the elastic membrane 73 again, thereby completing the closure of the nozzle 71; and the active magnet 31 is moved again to make the scraper 33 open and move. At this time, the adhesive adhering to the scraper 33 is smeared on the bottom wall of the collection groove 1431 to further prevent large particles from jumping in the collection groove 1431 or even being blown into the filter 13 by the airflow; after the scraper 33 has finished scraping and is in the retracted state, the nozzle 71 continues to spray the adhesive onto the scraper 33, and the cycle is repeated to ensure that the scraper 33 provides adhesive to the bottom wall of the collection groove 1431 in the next scraping cycle.

[0043] The implementation principle of a portable low-concentration particulate matter sampling device in the embodiment of the present application is as follows: rotating the active magnet 31 causes the passive magnet 32 ​​to rotate accordingly, and then the scraper 33 also moves accordingly. At this time, the particles on the collection plate 143 are scraped by the scraper 33, and at the same time, the U-shaped magnet 51 moves with the active magnet 31, that is, when the scraper 33 moves in the direction close to the leakage groove 22, the U-shaped magnet 51 is attracted by the active magnet 31, and then the U-shaped magnet 51 and the active magnet 31 move synchronously, causing the baffle 41 to descend, and the scraper 33 scrapes the large particles into the leakage groove 22, and falls from the leakage groove 22 into the storage bin 21; continue to move the active magnet 31 to cause the scraper 33 to continue to move, at this time the baffle rod and the scraper 33 are pressed against each other and the scraper 33 is rotated until the scraper 33 is in contact with the groove wall of the collection groove 1431, and the elastic hook 62 is pressed against the baffle rod 61, thereby preventing the scraper 33 from interfering with the main collection area of ​​the collection groove 1431 At the same time, the U-shaped magnet 51 continues to move synchronously with the active magnet 31, and the opening and closing rod 74 gradually releases the squeeze on the elastic membrane 73. At this time, the elastic holding bag 72 is acted upon by its own elastic force, allowing the adhesive to pass smoothly through the nozzle 71 at the position of the elastic membrane 73, and the adhesive is sprayed through the nozzle 71 to the side of the scraping strip 33 facing away from the scraping surface, until the opposite ends of the U-shaped magnet 51 and the active magnet 31 are of the same polarity. At this time, the U-shaped magnet 51 is instantly rebounded to the position aligned with the position of the U-shaped magnet 51. The limit block 52 on the side facing the moving direction of the scraper 33 is abutted, and the lifting rod 43 rises, that is, the baffle 41 rises to be flush with the inner bottom wall of the collection groove 1431. At the same time, the opening and closing rod 74 presses the elastic membrane 73, so that the nozzle 71 is in a closed state; when the active magnet 31 is moved again, the elastic hook 62 is squeezed, so that the scraper 33 moves smoothly to be free from the fixation of the gear lever 61. At this time, the scraper 33 is rotated by the torsion spring, which facilitates the subsequent scraping operation of the scraper 33.

[0044] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A portable low-concentration particulate matter sampling device, comprising a body (11) with a built-in gas sensor and an air pressure sensor, a folding bracket (12) arranged below the body (11), a filter (13) threadedly connected to the body (11) on a side away from the folding bracket (12), a cutter (14) and a sampling head (15) arranged on a side of the filter (13) away from the body (11), the cutter (14) comprising a cutting cylinder (141), an impact plate (142) and a collection plate (143) sequentially placed in the cutting cylinder (141) from one end of the sampling head (15) to one end of the filter (13), the collection plate (143) being provided with an annular collection groove (1431), characterized in that: The bottom of the collecting plate (143) is detachably provided with a storage bin (21), the collecting plate (143) is provided with a leakage groove (22), the outer wall of the cutting cylinder (141) is rotatably connected with an active magnet (31), the inner wall of the cutting cylinder (141) is slidably provided with a passive magnet (32) corresponding to the active magnet (31), and the magnetic poles of the active magnet (31) and the passive magnet (32) at one end close to each other are of opposite polarity, and the passive magnet (32) is provided with a scraper (33) in the collecting groove (1431); The collecting plate (143) is provided with a baffle (41) at the leakage groove (22); the inner bottom wall of the storage bin (21) is rotatably connected with a rotating drum (42); a lifting rod (43) is provided in the rotating drum (42); a sliding rod (44) is vertically fixed to the lifting rod (43); the lifting rod (43) is fixedly connected to the baffle (41); a lifting groove (421) adapted to the sliding rod (44) is obliquely opened upward on the peripheral wall of the rotating drum (42); a driving assembly (5) for driving the rotating drum (42) to rotate is provided in the storage bin (21); and a limiting member (45) for limiting the baffle (41) to move only in the vertical direction is also provided in the storage bin (21); The driving assembly (5) comprises a U-shaped magnet (51) rotatably arranged on the rotating drum (42) and limit blocks (52) arranged in the storage bin (21) and located on both sides of the U-shaped magnet (51), wherein the end of the U-shaped magnet (51) facing the moving direction of the scraper (33) is attracted to the end of the active magnet (31) close to the collecting plate (143), and the end of the U-shaped magnet (51) facing away from the moving direction of the scraper (33) is attracted to the end of the active magnet (31) close to the collecting plate (143). When the scraper (33) moves to the side of the drain groove (22) facing the moving direction of the scraper (33), the U-shaped magnet (51) and the opposite ends of the active magnet (31) are opposite to each other and the baffle (41) is lower than the collecting plate (143); when the scraper (33) moves to the side of the drain groove (22) facing away from the moving direction of the scraper (33), the U-shaped magnet (51) and the same ends of the active magnet (31) are opposite to each other and the baffle (41) rises to be flush with the inner bottom wall of the collecting groove (1431).

2. A portable low-concentration particulate matter sampling device according to claim 1, characterized in that: The scraper strip (33) is elastically hinged on the passive magnet (32), and the scraper strip (33) is in an arc shape that fits the groove wall of the collection groove (1431). The collection plate (143) is provided with a locking member for locking the scraper strip (33) to fit the groove wall of the collection groove (1431).

3. A portable low-concentration particulate matter sampling device according to claim 2, characterized in that: The locking member is a blocking rod fixedly connected to the collecting plate (143), and the blocking rod is located on a side of the leakage groove (22) facing away from the moving direction of the scraper strip (33).

4. A portable low-concentration particulate matter sampling device according to claim 3, characterized in that: The storage bin (21) is provided with a nozzle (71) penetrating the collection plate (143), and the nozzle (71) and the blocking rod are located on both sides of the scraper (33). The storage bin (21) is provided with an elastic containing bag (72) containing an adhesive, and when the elastic containing bag (72) is filled with adhesive, the elastic containing bag (72) is in an expanded state, and the nozzle (71) is connected to the elastic containing bag (72). The storage bin (21) is also provided with an opening and closing member for controlling the opening and closing of the nozzle (71).

5. A portable low-concentration particulate matter sampling device according to claim 4, characterized in that: A control port is provided on the peripheral wall of the nozzle (71), and an elastic film (73) is sealed on the nozzle (71) at the control port. The opening and closing member is an opening and closing rod (74) fixedly connected to the U-shaped magnet (51), and when the U-shaped magnet (51) is pressed against the limit block (52) located on the side of the U-shaped magnet (51) facing the moving direction of the scraper (33), the opening and closing rod (74) presses the elastic film (73).

6. A portable low-concentration particulate matter sampling device according to claim 1, characterized in that: An elastic hook (62) is fixedly connected to the end of the scraper strip (33) away from the end where the scraper strip (33) is hinged to the passive magnet (32).

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