A test device and method for simulating dust diffusion during bulk material transfer

Abstract

The present invention relates to the fields of visual analysis, measurement and loading, and specifically to a test device and method for simulating dust diffusion during the transfer of bulk materials. The device comprises an axial flow fan, a guide box and a material transfer box connected in sequence; the material transfer box comprises a transparent test box and a movable top surface arranged therein; the movable top surface is provided with an upper material port and a coal feeder; a guide plate is provided in the guide box; an air outlet is provided on the right side panel of the test box, a dust concentration meter is provided inside, and a camera is provided in the front for collecting images and processing the image grayscale to obtain the dust concentration value. The present invention can simulate the dust situation generated during the transfer of bulk materials, and study multiple variables such as transfer angle and speed, drop height, wind direction, and wind speed. The method comprehensively determines the dust concentration based on the image grayscale and the dust concentration meter, can determine the influence of the dust concentration meter on the regularity of airflow and dust, and can reduce the influence of reflection, transparent box, shooting angle, etc. on the camera shooting.

Description

Technical Field

[0001] The present invention relates to the fields of visual analysis, measurement and loading, and in particular to a test device and method for simulating dust diffusion in a bulk material transfer process. Background Art

[0002] When coal is mined using open-pit mining, the mined coal is often loaded into trucks using feeders for transport. The mined coal is a bulk material, and the feeder-assisted transport process generates dust. This high dust volume reduces visibility, hinders operator operation and transport, and can easily cause explosions, leading to workplace accidents. The high dust volume also poses a health risk to workers. Therefore, studying the dust diffusion patterns during bulk material transport is crucial for guiding safe production. However, direct on-site testing disrupts normal production, and the vast transport space makes data measurement difficult. Furthermore, the constant adjustment of equipment placement to meet testing requirements is challenging. Therefore, conducting laboratory experiments to study the dust diffusion patterns during bulk material transport and guide engineering practice can both save costs and accelerate research, improving its comprehensiveness. Summary of the Invention

[0003] Aiming at the problem of dust diffusion law in bulk material transportation, the present invention proposes a test device for simulating dust diffusion in the bulk material transportation process, comprising a test bench, on which an axial flow fan, a guide box and a material transfer box are connected in sequence from left to right; the material transfer box comprises a rectangular transparent test box, the top surface of the test box is provided with a movable top surface, and the movable top surface can move up and down in the test box; an upper material port is provided on the movable top surface, and a coal feeder is provided on the left side of the upper material port, and the coal feeder is provided with an angle adjuster for adjusting the feeding angle; the test bench comprises a plurality of test benches, wherein the plurality of test benches are provided with ... A mine car is arranged just below the upper material opening in the test box; an opening connected to the guide box is provided on the left side panel of the test box, and a number of rotatable guide plates are arranged at intervals along the front-to-back direction in the guide box, and the guide plates can change the direction of the airflow when they rotate; a side air outlet is provided on the right side panel of the test box; a dust concentration meter is also provided in the test box, and a camera is also provided just in front of the test box, and the camera is used to collect images in the test box during the test, and the grayscale of the image is processed by a computer to obtain the dust concentration value at each position in the test box.

[0004] Preferably, the device for controlling the vertical movement of the movable top surface relative to the test box adopts a hydraulic rod, which is arranged between the bottom panel of the test box and the movable top surface, or between the movable top surface and the top edges of the four side panels.

[0005] Preferably, the coal feeder is further provided with a hopper, and the hopper is used to supply bulk materials to the coal feeder.

[0006] Preferably, the guide box adopts a rectangular parallelepiped structure.

[0007] Preferably, the test bench is also provided with a computer, and the computer is used to collect, store and process test data.

[0008] Preferably, a plurality of the dust concentration meters are provided at different locations.

[0009] Preferably, a guide box is also provided on the side of the side air outlet of the right side panel, and a number of rotatable guide plates are arranged in the guide box at intervals along the front-to-back direction. The opening on the right side panel is the same size as the opening on the left side panel and is positioned relative to each other. The guide box structure on the left side of the left side panel and the guide plates therein are the same as the guide box on the right side of the right side panel and the guide plate structure therein.

[0010] Preferably, the test device also includes a dust removal structure, which includes a dust removal bellows. The dust removal bellows is provided with a first air duct and a second air duct. The first air duct is connected to several openings on the bottom panel of the test box through several branch pipes, and the second air duct is detachably connected to the side air outlet. A filtering device is provided in the dust removal bellows.

[0011] The present invention also provides a test method for simulating dust diffusion during bulk material transfer, using the test apparatus described above, comprising the following steps:

[0012] S1: calibrate different test conditions, where the corresponding variables under the different test conditions mainly include transfer angle, transfer speed, drop height, wind direction, wind speed or wind pressure;

[0013] S2: Turn on the axial flow fan, allowing air to flow from the right side of the test chamber to the left side; start the coal feeder to transport coal; obtain a first dust concentration using a dust concentration meter, and simultaneously take a photo using a camera, and obtain a second dust concentration based on grayscale processing;

[0014] S3: After each calibration working condition test is completed, the test box is dusted, and then other calibration working conditions are tested with reference to step S2;

[0015] S4: Take out the dust concentration meter from the test box, and perform the same test as steps S2-S3 using the working conditions calibrated in step S1. Take a picture with a camera, obtain the grayscale value, and obtain the third dust concentration based on the grayscale value.

[0016] S5: For each calibration test condition, a dust concentration deviation value resulting from the airflow change caused by the installation of the dust concentration meter is obtained based on the difference between the second dust concentration and the third dust concentration; the dust concentration deviation value resulting from the installation of the dust concentration meter is removed by using the first dust concentration to obtain a relatively accurate dust concentration value; the relatively accurate dust concentration value corresponds to the relatively accurate grayscale value obtained in step S4;

[0017] Obtain the relationship between relatively accurate dust concentration values ​​and relatively accurate grayscale values ​​through data fitting;

[0018] S5: In subsequent tests, a dust concentration meter is not set up. A camera is directly used to take pictures to obtain relatively accurate grayscale values ​​at different locations. Based on the relationship between the relatively accurate dust concentration value and the relatively accurate grayscale value established in step S4, the relatively accurate dust concentration at different locations is obtained.

[0019] The key means and beneficial effects of the present invention are:

[0020] 1. The test apparatus of the present invention can simulate the dust generated during the transport of bulk coal and study the effects of various variables, including transport angle, transport speed, drop height, wind direction, and wind speed (or pressure), on dust concentration. The present invention utilizes a circulating dust removal mechanism to maximize and rapidly remove dust from the test chamber at the conclusion of the test.

[0021] 2. The test method of the present invention proposes a comprehensive dust concentration determination method based on image grayscale and a dust concentration meter, which can reduce the impact of the dust concentration meter setting on wind flow and dust generation patterns, and can reduce the impact of camera shooting on reflections, transparent boxes, shooting angles, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of the test device for simulating dust diffusion during bulk material transfer according to the present invention;

[0023] Figure 2 This is a front view of a test device for simulating dust diffusion during bulk material transfer according to the present invention;

[0024] Figure 3 This is a left view of the test device for simulating dust diffusion during bulk material transfer according to the present invention;

[0025] Figure 4 2. It is a top view of the test device for simulating dust diffusion during bulk material transfer according to the present invention;

[0026] In the figure, there are a coal feeder 1, an angle adjuster 2, a hopper 3, a test box 40, a movable plate 41, a side air inlet 42, an upper feed inlet 43, a hydraulic rod 44, a guide box 50, a guide plate 51, an axial flow fan 6, a camera 7, a dust removal bellows 80, a first air duct 81, a second air duct 82, a computer 9, a test bench 10, a mine car 11, and a dust concentration meter 12. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be described in more detail below with reference to the accompanying drawings in the embodiments of the present invention.

[0028] Example 1

[0029] like Figure 1-4As shown, the test device for simulating dust diffusion during bulk material transfer of the present invention includes a test bench 10, on which an axial flow fan 6, a guide box 50 and a material transfer box are connected in sequence from left to right; the material transfer box includes a rectangular transparent test box 40, the top surface of the test box 40 is provided with a movable top surface 41, and the movable top surface 41 can move up and down in the test box 40. The device for controlling the movable top surface 41 to move up and down relative to the test box 40 adopts a hydraulic rod 44, and the hydraulic rod 44 can be set between the bottom panel of the test box 40 and the movable top surface 41. The test box 40 is provided with a plurality of hydraulic rods 44, each of which is provided with a plurality of hydraulic rods 45. The hydraulic rods 44 are arranged at the four corners of the test box 40 to ensure stability; an upper material port 43 is provided at the center of the movable top surface 41, and a coal feeder 1 is provided on the left side of the upper material port 43. The coal feeder 1 is provided with an angle adjuster 2 for adjusting the feeding angle, and the coal feeder 1 is also provided with a hopper 3 for supplying bulk materials to the coal feeder 1; the upper material port 43 is provided in the test box 40, and a coal feeder 1 is provided on the left side of the upper material port 43. 3 is provided directly below a mine car 11 for receiving bulk materials transported by the coal feeder 1; the left panel of the test box 40 is provided with an opening connected to the guide box 50, and a plurality of rotatable guide plates 51 are provided in the guide box 50 at intervals along the front-to-back direction. When the guide plates 51 rotate, they can change the direction of the airflow (the length direction of the guide plates is the left-right direction, the rotation axis is located at the center position of the length direction, and the rotation axis is vertically arranged). The guide box 50 adopts a rectangular parallelepiped structure; the right panel of the test box 40 is provided with a side air outlet 42; the test bench 10 is also provided with a computer The computer 9 is used to collect, store and process test data; a dust concentration meter 12 is also provided in the test box 40 for measuring dust concentration, and multiple dust concentration meters 12 can be set at different positions. A camera 7 is also provided in front of the test box 40, and the camera 7 is used to collect images in the test box 40 during the test, and the grayscale of the image is processed by the computer to obtain the dust concentration value at each position in the test box 40; the dust concentration measured by the dust concentration meter 12 can be calibrated with the dust concentration obtained by the camera 7.

[0030] Example 2

[0031] On the basis of implementation one, in order to improve the accuracy of wind direction adjustment, a guide box 50 is also provided on one side of the side air outlet 42 of the right side panel, and a plurality of rotatable guide plates 51 are arranged at intervals along the front-to-back direction in the guide box 50. The opening (side air outlet 42) on the right side panel is the same size as the opening on the left side panel and is positioned relative to each other. The structure of the guide box 50 on the left side of the left side panel (and the guide plates 51 therein) is the same as the structure of the guide box 50 on the right side of the right side panel (and the guide plates 51 therein).

[0032] Example 3

[0033] Based on Example 1 or Example 2, the test device also includes a dust removal structure, which includes a dust removal bellows 80. The dust removal bellows 80 is provided with a first air duct 81 and a second air duct 82. The first air duct 81 is connected to several openings on the bottom panel of the test box 40 through several branch pipes, and the second air duct 82 is detachably connected to the side air outlet 42. The dust removal bellows 80, the first air duct 81, the second air duct 82 and the material transfer box form a circulating air path, for example, air is discharged from the first air duct 81 and air is inhaled from the second air duct 82, or air is discharged from the second air duct 82 and air is inhaled from the first air duct 81. A filtering device is provided in the dust removal bellows 80 for filtering dust.

[0034] In the test device in the above embodiment of the present invention, the coal feeder 1 can adjust different feeding angles (transfer angles) through the angle adjuster 2, and the coal feeder 1 itself can also be set to different feeding speeds (transfer speeds); different drop heights can be set by setting different positions of the movable top surface 41 (the maximum drop height in the figure), and different wind directions can be adjusted by adjusting the angle of the guide plate 51. The axial flow fan 6 can be set to different powers, corresponding to different wind speeds and wind pressures. That is, the test device of the present invention can adjust the above variables to achieve the measurement of dust concentration under different working conditions.

[0035] Setting up dust concentration measurement based on image grayscale and dust concentration measurement based on the dust concentration meter 12 can utilize the measurement accuracy of the dust concentration meter 12 to correct the image grayscale measurement parameters, and can obtain a full range of dust concentration conditions based on image grayscale.

[0036] In addition, the dust removal structure provided in the present invention can achieve the best dust removal effect through a circulating dust removal method.

[0037] Example 4

[0038] On the basis of Example 1, Example 2 or Example 3, the present invention further proposes a test method for simulating dust diffusion during bulk material transfer, comprising the following steps:

[0039] S1: calibrate different test conditions, where the corresponding variables under the different test conditions mainly include transfer angle, transfer speed, drop height, wind direction, and wind speed (or wind pressure);

[0040] S2: Bulk coal is loaded into the hopper 3, and the axial flow fan 6 is turned on, causing air to flow from the right side to the left side of the test chamber 40. The coal feeder 1 is started to transport the coal, and the transported coal falls into the mine car 11 through the upper feed port 43. Dust is generated during the dropping process. A first dust concentration is obtained by the dust concentration meter 12, and at the same time, a photo is taken by the camera 7, and a second dust concentration is obtained by the computer 9 based on grayscale processing.

[0041] S3: After each calibration working condition test is completed, the material transfer box is dusted, and then other calibration working conditions are tested with reference to step S2;

[0042] S4: Remove the dust concentration meter 12 from the test chamber 40, and perform the same test as in steps S2-S3 using the operating conditions calibrated in step S1. Take photos using the camera 7, obtain a grayscale value using the computer 9, and obtain a third dust concentration based on the grayscale value. Since the dust concentration meter 12 is not installed in the test chamber 40 at this time, the airflow is not affected by the dust concentration meter 12, and the dust concentration is not affected by the installation of the dust concentration meter 12. The grayscale value at this time is relatively accurate (when the dust concentration meter 12 is installed, it will affect the airflow and thus the diffusion pattern of the dust, so the relative grayscale value is not accurate).

[0043] S5: For each calibration test condition, a dust concentration deviation value resulting from the change in airflow caused by the installation of the dust concentration meter 12 is obtained based on the difference between the second dust concentration and the third dust concentration; the dust concentration deviation value resulting from the installation of the dust concentration meter 12 is removed by using the first dust concentration to obtain a relatively accurate dust concentration value; the relatively accurate dust concentration value corresponds to the relatively accurate grayscale value in step S4; at least one set of relatively accurate grayscale values ​​and their corresponding relatively accurate dust concentration values ​​can be obtained for each calibration test condition;

[0044] The relationship between the relatively accurate dust concentration value and the relatively accurate gray value is obtained by data fitting and other data processing means (such as using the relatively accurate gray value as the horizontal coordinate and the corresponding relatively accurate dust concentration value as the vertical coordinate to perform data fitting to obtain a fitting curve);

[0045] S5: In subsequent tests, the dust concentration meter 12 is omitted, and camera 7 is used to directly obtain relatively accurate grayscale values ​​at different locations. Based on the relationship between the relatively accurate dust concentration value and the relatively accurate grayscale value established in step S4, the relatively accurate dust concentration at different locations is obtained. This can be used to guide actual projects, such as setting worker operating positions to minimize dust concentration, or selecting appropriate parameters for bulk material transfer to minimize dust concentration.

[0046] In the above-mentioned test process, the materials stored in the mine car 11 were cleared out before each test.

[0047] Those skilled in the art can make various corresponding changes and modifications based on the above technical solutions and concepts, and all of these changes and modifications should be included in the scope of protection of the claims of the present invention.

Claims

1. A test device for simulating dust dispersion during bulk material transfer, including a test bench, characterized in that: An axial flow fan, a guide box and a material transfer box are connected to the test bench from left to right in sequence; the material transfer box includes a rectangular transparent test box, the top surface of the test box is provided with a movable top surface, and the movable top surface can move up and down in the test box; an upper material port is provided on the movable top surface, and a coal feeder is provided on the left side of the upper material port, and the coal feeder is provided with an angle adjuster for adjusting the feeding angle; a mine car is provided in the test box just below the upper material port; an opening connecting to the guide box is provided on the left side panel of the test box, and a number of rotatable guide plates are provided in the guide box at intervals along the front-to-back direction, and the guide plates can change the direction of the airflow when rotated; a side air outlet is provided on the right side panel of the test box; a dust concentration meter is also provided in the test box, and a camera is also provided in the front of the test box, and the camera is used to collect images in the test box during the test, and obtain the dust concentration value at each position in the test box by processing the grayscale of the image through a computer.

2. The test device according to claim 1, characterized in that The device for controlling the upward and downward movement of the movable top surface relative to the test box adopts a hydraulic rod, which is arranged between the bottom panel of the test box and the movable top surface, or between the movable top surface and the top edges of the four side panels.

3. The test device according to claim 1, characterized in that The coal feeder is further provided with a hopper for supplying bulk materials to the coal feeder.

4. The test device according to claim 1, characterized in that The guide box adopts a rectangular parallelepiped structure.

5. The test device according to claim 1, characterized in that The test bench is also provided with a computer, which is used for collecting, storing and processing test data.

6. The test device according to claim 1, characterized in that A plurality of dust concentration meters are arranged at different locations.

7. The test device according to any one of claims 1 to 6, characterized in that: A guide box is also provided on the side of the side air outlet of the right side panel, and a number of rotatable guide plates are arranged in the guide box at intervals along the front-to-back direction. The opening on the right side panel is the same size as the opening on the left side panel and is positioned oppositely. The guide box structure on the left side of the left side panel and the guide plates therein are the same as the guide box on the right side of the right side panel and the guide plate structure therein.

8. The test device according to claim 7 further includes a dust removal structure, the dust removal structure includes a dust removal bellows, the dust removal bellows is provided with a first air duct and a second air duct, the first air duct is connected to a plurality of openings on the bottom panel of the test box through a plurality of branch pipes, the second air duct is detachably connected to the side air outlet, and a filtering device is provided in the dust removal bellows.

9. A test method for simulating dust diffusion during bulk material transfer, using the test apparatus according to any one of claims 1 to 8, characterized in that: The steps include: S1: calibrate different test conditions, where the corresponding variables under the different test conditions mainly include transfer angle, transfer speed, drop height, wind direction, wind speed or wind pressure; S2: Turn on the axial flow fan, allowing air to flow from the right side of the test chamber to the left side; start the coal feeder to transport coal; obtain a first dust concentration using a dust concentration meter, and simultaneously take a photo using a camera, and obtain a second dust concentration based on grayscale processing; S3: After each calibration working condition test is completed, the test box is dusted, and then other calibration working conditions are tested with reference to step S2; S4: Take out the dust concentration meter from the test box, and perform the same test as steps S2-S3 using the working conditions calibrated in step S1. Take a picture with a camera, obtain the grayscale value, and obtain the third dust concentration based on the grayscale value. S5: For each calibration test condition, a dust concentration deviation value resulting from the airflow change caused by the installation of the dust concentration meter is obtained based on the difference between the second dust concentration and the third dust concentration; the dust concentration deviation value resulting from the installation of the dust concentration meter is removed by using the first dust concentration to obtain a relatively accurate dust concentration value; the relatively accurate dust concentration value corresponds to the relatively accurate grayscale value obtained in step S4; Obtain the relationship between relatively accurate dust concentration values ​​and relatively accurate grayscale values ​​through data fitting; S5: In subsequent tests, a dust concentration meter is not set up. A camera is directly used to take pictures to obtain relatively accurate grayscale values ​​at different locations. Based on the relationship between the relatively accurate dust concentration value and the relatively accurate grayscale value established in step S4, the relatively accurate dust concentration at different locations is obtained.

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