A dust concentration detection device and a measuring method for underground coal mine drilling construction

Abstract

This invention provides a dust concentration detection device and measurement method for underground drilling in coal mines. It includes a hemispherical glass body with an open top, containing a cleaning unit. The cleaning unit includes a vertically arranged annular cleaning frame, the center of which is collinear with the axial centerline of the glass body. A motor support frame is coaxially mounted on the top of the glass body, forming a spherical body with a hollow top. The bottom of the motor support frame is connected to the glass body, and its vertical top is connected to a coaxially mounted sleeve. An explosion-proof motor is also coaxially mounted inside the sleeve, with its output shaft connected to the top of the cleaning frame. The output shaft drives the cleaning frame to rotate around the central axis of the glass body. A point light source is also coaxially mounted on the inner top of the cleaning frame. A shadow sensor is also installed on the outer bottom wall of the glass body. The device of this invention has a fast response speed and can quickly capture instantaneous shadow changes, thereby achieving real-time continuous measurement.

Description

Technical Field

[0001] This invention belongs to the field of environmental monitoring technology, and relates to the detection of dust concentration in underground coal mines, specifically to a dust concentration detection device and measurement method for underground drilling operations in coal mines. Background Technology

[0002] During underground drilling operations in coal mines, pneumatic drilling generates a large amount of dust. This dust not only pollutes the construction environment but also harms the health of workers. Therefore, dust suppression devices are widely used underground. Currently, most underground dust suppression devices use tap water atomization spraying to extinguish dust, adjusting the water volume of the atomization spraying system based on visually measured dust concentration. However, due to the lack of real-time dust monitoring equipment, closed-loop control cannot be achieved. Too little water results in poor dust suppression, while too much water easily causes water accumulation on the site. To address the issue of dust suppression equipment's inability to sense dust concentration in real time and thus accurately control the mist volume, there is an urgent need to develop a dust concentration detection device for underground drilling operations in coal mines, enabling real-time monitoring of dust concentration underground. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a dust concentration detection device and measurement method for underground drilling in coal mines, thereby solving the technical problem that it is difficult to simultaneously achieve both accuracy and real-time performance in dust concentration monitoring during underground drilling in coal mines.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0005] A dust concentration detection device for underground drilling in coal mines includes a vertically open hemispherical glass body. A cleaning unit is installed inside the glass body. The cleaning unit includes a vertically arranged annular cleaning frame, the center of which is collinear with the axial centerline of the glass body. A motor support frame is also coaxially installed at the vertical top of the glass body. The motor support frame and the glass body are spliced ​​together to form a spherical body with a hollow top. The vertical bottom of the motor support frame is connected to the glass body, and the vertical top of the motor support frame is connected to a coaxially installed sleeve.

[0006] An explosion-proof motor is also coaxially installed inside the sleeve. The bottom of the output shaft of the explosion-proof motor is connected to the top of the cleaning rack, and the output shaft of the explosion-proof motor drives the cleaning rack to rotate around the central axis of the glass body.

[0007] A point light source is also coaxially mounted on the top inner side of the cleaning rack.

[0008] A shadow sensor is also installed on the bottom outer wall of the glass body, and a slag discharge hole is also coaxially opened on the bottom of the glass body, which runs radially through the side wall.

[0009] The present invention also has the following technical features.

[0010] Specifically, the cross-section of the cleaning rack is groove-shaped, and the cleaning unit also includes air ducts and water pipes. The air ducts and water pipes are arranged side by side and nested in the groove of the cleaning rack, and the air ducts and water pipes are arranged around the entire ring of the cleaning rack.

[0011] Multiple air outlets penetrating the sidewalls are also provided on the vertical middle sections on both sides of the air duct, and the multiple air outlets are evenly distributed along the circumference of the air duct.

[0012] Multiple water outlets penetrating the sidewalls are also provided on the vertical middle sections on both sides of the water pipe, and the multiple water outlets are evenly distributed along the circumference of the water pipe.

[0013] The cleaning rack is also equipped with an arc-shaped brush on its vertically lower semicircular ring. The arc-shaped brush is arranged along the circumference of the cleaning rack and is located vertically below multiple air outlets and multiple water outlets.

[0014] Specifically, the cleaning unit also includes multiple fan-shaped air blowing nozzles, each corresponding to an air outlet, and the fan-shaped air blowing nozzles are installed at the air outlet on the air duct.

[0015] The cleaning unit also includes multiple fan-shaped water purging nozzles, each corresponding to a water outlet, and the fan-shaped water purging nozzles are installed at the water outlet on the water pipe.

[0016] The vertical top of the arc-shaped brush is lower than the vertical top of the glass body in the vertical direction.

[0017] The outlet of the fan-shaped air purging nozzle located at the bottom of the vertical column is lower than the top of the glass body in a vertical position, and the outlet of the fan-shaped water purging nozzle located at the bottom of the vertical column is lower than the top of the glass body in a vertical position.

[0018] Specifically, the motor support frame includes multiple quarter-circular support rings, which are evenly distributed along the circumference of the glass body, and one end of each support ring is connected to the vertical top of the glass body.

[0019] The sleeve is coaxially arranged with the glass body. Multiple support ring mounting grooves are radially formed on the vertical bottom end face of the sleeve. Each support ring mounting groove corresponds to a support ring. The other end of the support ring is embedded in the support ring mounting groove and connected to the sleeve.

[0020] A glass body bottom support is also installed on the outer bottom of the glass body.

[0021] This invention also protects a method for measuring dust concentration during underground drilling in coal mines. This method utilizes the dust concentration detection device described above for underground drilling in coal mines, and specifically includes the following steps:

[0022] Step 1: Obtain the incident light intensity: Obtain the incident light intensity of a point light source in clean air .

[0023] Step 2, measure the intensity of transmitted light: The dust concentration detection device was placed at the drilling site in the coal mine. First, the device was cleaned, then a point light source was turned on. The light emitted from the point light source passed through the narrow slits in the dust and illuminated the shadow sensor. Due to the change in the shading rate caused by the dust, the shadow sensor output different electrical signals. The intensity of the transmitted light after passing through the dust was obtained from these electrical signal results. .

[0024] Step 3: Calculate the dust concentration using Lambert-Beer's Law: Based on the incident light intensity obtained in step one The transmitted light intensity obtained in step two Calculate the optical density of dust at underground drilling sites in coal mines. Then, the mass extinction coefficient was calibrated based on the experiment. The dust concentration at the coal mine drilling site was calculated using the Lambert-Beer law. .

[0025] Compared with the prior art, the present invention has the following technical effects.

[0026] (I) The device in this invention has a fast response speed and can quickly capture instantaneous shadow changes, thereby realizing real-time continuous measurement; at the same time, the detection device is non-contact, avoiding damage to the object being detected; in addition, the detection device is small in size and portable, and can be placed in alley areas where large equipment cannot enter, protecting the health of operators.

[0027] (II) In the device of the present invention, the arc-shaped brush installed on the cleaning rack rotates around the central axis of the glass body under the drive of the explosion-proof motor, which can clean the inner wall of the dust concentration detection device, realize the automatic cleaning of the device, and ensure the accuracy and reliability of the detection.

[0028] (III) The device in this invention has a built-in point light source, which is suitable for the dim lighting environment in coal mines and has strong anti-interference ability; the main body shell of the device, i.e. the glass body, adopts a hemispherical structure design to reduce the influence of horizontal wind direction on the measured dust results.

[0029] (IV) The device in this invention can not only detect the concentration of dust at the underground construction site, but also provide detection signal feedback for the on-site dust removal equipment, providing strong technical support and guarantee for underground dust detection.

[0030] (V) The method in this invention converts the change in the shading rate of dust shadows on the shadow sensor into an electrical signal, and obtains the dust concentration based on the change in the electrical signal, thus achieving real-time monitoring downhole; in addition, the overlap of dust projections does not affect the measurement results. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of the device in this invention.

[0032] Figure 2 This is a schematic diagram of the structure of the glass body, motor support frame, and sleeve connected in the device of the present invention.

[0033] Figure 3 This is a schematic diagram of the structure of the cleaning unit and the explosion-proof motor in the device of the present invention.

[0034] Figure 4 This is a schematic diagram of the cleaning rack in the device of the present invention.

[0035] Figure 5 This is a cross-sectional view of the cleaning rack in the device of the present invention at section AA.

[0036] The meanings of the labels in the diagram are as follows: 1-glass body, 2-cleaning unit, 3-motor support frame, 4-sleeve, 5-explosion-proof motor, 6-point light source, 7-shading sensor, 8-sludge discharge hole, 9-support ring, 10-support ring mounting groove, 11-bottom bracket of glass body.

[0037] 201-Cleaning rack, 202-Air duct, 203-Water pipe, 204-Air outlet, 205-Water outlet, 206-Curved brush, 207-Fan-shaped air blowing nozzle, 208-Fan-shaped water blowing nozzle.

[0038] The specific content of the present invention will be further described in detail below with reference to the embodiments. Detailed Implementation

[0039] It should be noted that, unless otherwise specified, all devices, components and methods in this invention adopt commonly used devices, components and methods known in the art in the prior art. For example, the glass body adopts a known glass body, the explosion-proof motor adopts a known explosion-proof motor, and the arc-shaped brush adopts a known arc-shaped brush.

[0040] Following the above technical solution, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made on the basis of the technical solution of the present invention fall within the protection scope of the present invention.

[0041] Example 1: This embodiment provides a dust concentration detection device for underground drilling operations in coal mines, such as... Figures 1 to 3 As shown, the device includes a vertically open hemispherical glass body 1, a cleaning unit 2 inside the glass body 1, and a vertically arranged annular cleaning rack 201, the center of which is collinear with the axial center line of the glass body 1. A motor support frame 3 is also coaxially arranged at the vertical top of the glass body 1. The motor support frame 3 and the glass body 1 are spliced ​​together to form a spherical body with a hollow top. The vertical bottom of the motor support frame 3 is connected to the glass body 1, and the vertical top of the motor support frame 3 is connected to a sleeve 4 arranged coaxially.

[0042] An explosion-proof motor 5 is also coaxially installed inside the sleeve 4. The bottom of the output shaft of the explosion-proof motor 5 is connected to the top of the cleaning rack 201. The output shaft of the explosion-proof motor 5 drives the cleaning rack 201 to rotate around the central axis of the glass body 1.

[0043] like Figure 1 As shown, a point light source 6 is also coaxially mounted on the inner top of the cleaning rack 201.

[0044] like Figure 1 As shown, a shadow sensor 7 is also installed on the bottom outer wall of the glass body 1, and a slag discharge hole 8 is coaxially opened on the bottom of the glass body 1, which runs radially through the side wall.

[0045] In this embodiment, the axial direction of the explosion-proof motor 5 is vertical. In this embodiment, the sleeve 4 is hollow inside and open at both ends along the axial direction; the explosion-proof motor 5 is installed in the sleeve 4 using a commonly known installation method in the art.

[0046] In this embodiment, the explosion-proof motor 5 is a hollow motor. The pipe corresponding to the external air source passes through the interior of the explosion-proof motor 5 and connects to the air duct 202 using a method commonly known in the art. The pipe corresponding to the external water source passes through the interior of the explosion-proof motor 5 and connects to the water pipe 203 using a method commonly known in the art. The explosion-proof motor 5 is a motor commonly known in the art. The external air source and the external water source are both commonly known in the art.

[0047] In this embodiment, the shadow sensor 7 is installed on the outer wall of the glass body 1 to ensure that the shadow sensor 7 is not worn during the cleaning of sludge and water. The glass body 1 is designed with a hemispherical rather than a conical structure, which not only facilitates the cleaning of sludge and water, but also minimizes the influence of surface glass refraction.

[0048] In this embodiment, the slag discharge hole 8 is used to discharge the dry dust on the inner surface of the glass body 1 and the slag-water mixture after cleaning by the fan-shaped water blowing nozzle 208 to the outside of the dust concentration detection device in this embodiment.

[0049] In this embodiment, when the point light source 6 is turned on to detect dust concentration, the explosion-proof motor 5 does not work, that is, the arc-shaped brush 206 on the cleaning frame 201 does not rotate.

[0050] As a preferred embodiment of this invention, such as Figures 3 to 5 As shown, the cross-section of the cleaning rack 201 is groove-shaped. The cleaning unit 2 also includes an air duct 202 and a water pipe 203. The air duct 202 and the water pipe 203 are arranged side by side and nested in the groove of the cleaning rack 201. The air duct 202 and the water pipe 203 are arranged around the entire ring of the cleaning rack 201.

[0051] Multiple air outlets 204 penetrating the sidewalls are also provided on the vertical middle sections on both sides of the air duct 202. The multiple air outlets 204 are evenly distributed along the circumference of the air duct 202.

[0052] Multiple water outlets 205 penetrating the sidewalls are also provided on the vertical middle sections on both sides of the water pipe 203. The multiple water outlets 205 are evenly distributed along the circumference of the water pipe 203.

[0053] An arc-shaped brush 206 is also installed on the vertically lower semicircular ring of the cleaning rack 201. The arc-shaped brush 206 is arranged along the circumference of the cleaning rack 201 and is located vertically below multiple air outlets 204 and multiple water outlets 205.

[0054] As a preferred embodiment, the cleaning unit 2 further includes a plurality of fan-shaped air blowing nozzles 207, each corresponding to an air outlet 204, and the fan-shaped air blowing nozzles 207 are installed at the air outlet 204 on the air duct 202.

[0055] The cleaning unit 2 also includes multiple fan-shaped water purging nozzles 208, which correspond one-to-one with the water outlets 205. The fan-shaped water purging nozzles 208 are installed at the water outlets 205 on the water pipes 203.

[0056] The vertical top of the arc-shaped brush 206 is lower than the vertical top of the glass body 1 in the vertical direction.

[0057] The outlet of the fan-shaped air purging nozzle 207 located at the bottom of the vertical column is lower than the top of the glass body 1 in a vertical position, and the outlet of the fan-shaped water purging nozzle 208 located at the bottom of the vertical column is lower than the top of the glass body 1 in a vertical position.

[0058] In this embodiment, the explosion-proof motor 5 drives the cleaning frame 201 to rotate in both forward and reverse directions. An arc-shaped brush 206 is mounted on the cleaning frame 201, further driving its rotation. The rotation of the arc-shaped brush 206 cleans the dust adhering to the inner surface of the glass body 1. The fan-shaped air blowing nozzle 207 primarily cleans dry dust adhering to the inner surface of the glass body 1, while the fan-shaped water blowing nozzle 208 primarily cleans stubborn wet dust adhering to the inner surface of the glass body 1. A cleaning agent can be added to the water in the water pipe 203 to improve the cleaning effect. The cleaning agent used is a commonly known cleaning agent in the art.

[0059] As a preferred embodiment, the motor support frame 3 includes a plurality of quarter-circular support rings 9, which are evenly distributed along the circumference of the glass body 1, and one end of each support ring 9 is connected to the vertical top of the glass body 1.

[0060] The sleeve 4 is coaxially arranged with the glass body 1. Multiple support ring mounting grooves 10 are radially opened on the vertical bottom end face of the sleeve 4. The support ring mounting grooves 10 correspond one-to-one with the support rings 9. The other end of the support ring 9 is embedded in the support ring mounting groove 10 and connected to the sleeve 4.

[0061] A glass body bottom bracket 11 is also installed on the outer side of the bottom of the glass body 1.

[0062] In this embodiment, the bottom support 11 of the glass body allows the bottom of the glass body 1 to be suspended in the air; the bottom support 11 of the glass body adopts a support commonly known in the art.

[0063] In this embodiment, there are four support rings 9. One end of each support ring 9 is connected to the glass body 1, and the other end is connected to the sleeve 4. This ensures that the motor support frame 3 is a single integral part and that the glass body 1 and the sleeve 4 are coaxial, providing a mechanism for the explosion-proof motor 5 to drive the arc-shaped brush 206 and clean the glass body 1. The connection between one end of the four support rings 9 and the glass body 1 adopts a commonly known connection method in the art, such as using transparent silicone adhesive. The silicone used is a commonly known silicone in the art. This connection method avoids drilling, maintains the integrity of the glass body 1, and is more visually concealed.

[0064] In this embodiment, the sleeve 4 and the four support rings 9 are all supported by steel, and the other ends of the sleeve 4 and the four support rings 9 are connected by welding. The steel material is a commonly known steel material in the art.

[0065] In this embodiment, the shadow sensor 7 is a silicon photodiode with high linearity and good stability, located on the bottom outer side of the glass body 1. It is bonded to the glass body 1 using transparent silicone to ensure that the spectral response of the silicon photodiode matches the specific wavelength LED of the point light source 6. In a further preferred embodiment, the point light source 6 is a red LED with a wavelength of 660nm, commonly known in the art, because the silicon photodiode has high responsivity in this wavelength band and can also avoid some ambient light interference. The silicon photodiode used is a commonly known silicon photodiode in the art.

[0066] Example 2: This embodiment discloses a method for measuring dust concentration during underground drilling operations in coal mines. The method utilizes the dust concentration detection device for underground drilling operations in coal mines described in Embodiment 1. The method specifically includes the following steps: Step 1: Obtain the incident light intensity: Obtain the incident light intensity of point light source 6 in clean air. .

[0067] In this embodiment, the incident light intensity of point light source 6 in clean air is obtained. The method employs commonly known methods in this field.

[0068] Step 2, measure the intensity of transmitted light: The dust concentration detection device is placed at the drilling site in a coal mine. First, the device is cleaned, then point light source 6 is turned on. The light emitted from point light source 6 passes through the narrow slits in the dust and illuminates the shadow sensor 7. Due to the change in the shading rate caused by the dust, the shadow sensor 7 outputs different electrical signals. The intensity of the transmitted light after passing through the dust is obtained from the electrical signal results. .

[0069] In step two, the specific process of the cleaning and testing device is as follows: the explosion-proof motor 5 drives the cleaning frame 201 to rotate forward or backward, and the arc-shaped brush 206 rotates around the central axis of the glass body 1, thereby cleaning the dust on the inner surface of the glass body 1; at the same time, the air duct 202 can blow away the dry dust in the glass body 1 through multiple fan-shaped air blowing nozzles 207, and the water pipe 203 can clean the wet dust in the glass body 1 through multiple fan-shaped water blowing nozzles 208, thus realizing the cleaning and testing device.

[0070] In this embodiment, a further preferred method for cleaning the detection device is as follows: the explosion-proof motor 5 drives the cleaning frame 201 to rotate, causing the arc-shaped brush 206 to rotate and clean. First, medium-pressure compressed gas at 0.5 MPa is used to clean the detection device through multiple fan-shaped air blowing nozzles 207. If the shadow sensor 7 detects that the cleaning standard has been met, the cleaning process is terminated; if not, high-pressure water at 1.0 MPa is sprayed through multiple fan-shaped water blowing nozzles 208 for cleaning, followed by air drying through multiple fan-shaped air blowing nozzles 207. This "blowing-judgment-spraying-drying" cycle can be repeated until the shadow sensor 7 confirms that the cleaning standard requirements are met. Furthermore, the waste liquid or sludge generated during cleaning can be collected after being discharged through the sludge drain hole 8, serving as a backup sample for subsequent calibration of the dust concentration detection device using distillation. The specific method for the shadow sensor 7 to detect that the cleanliness standard has been met is as follows: The point light source 6 is turned on, and the dust concentration inside the device is determined by the dust shadow occlusion rate on the shadow sensor 7. If the clean air standard known in the art is met, then the dust concentration detection device in this embodiment meets the cleanliness standard. The method of detecting dust concentration through waste liquid or sludge water by distillation adopts a commonly used method known in the art.

[0071] In this embodiment, the intensity of transmitted light after passing through the dust is obtained from the electrical signal output by the shadow sensor 7. The method employs commonly known methods in this field.

[0072] Step 3: Calculate the dust concentration using Lambert-Beer's Law: Based on the incident light intensity obtained in step one The transmitted light intensity obtained in step two Calculate the optical density of dust at underground drilling sites in coal mines. Then, the mass extinction coefficient was calibrated based on the experiment. The dust concentration at the coal mine drilling site was calculated using the Lambert-Beer law. .

[0073] In step three, the optical density of dust at the coal mine drilling site is calculated. The specific process is as follows: ; In the formula: Optical density of dust at underground drilling sites in coal mines; It is a logarithmic function with base e; The incident light intensity is expressed in W / m². 2 ; Transmitted light intensity, in W / m 2 .

[0074] In step three, the mass extinction coefficient is experimentally calibrated. The specific process is as follows: Step 301: Using the same type of dust as that tested in Step 2, a known and uniform concentration is generated in the experimental chamber.

[0075] Step 302: Measure the optical density at the known dust concentration obtained in step 301 using a light transmission method instrument.

[0076] Step 303: Only change the dust concentration in step 301, and repeat steps 301 and 302 multiple times to obtain the optical density of the same type of dust under different known dust concentrations as in step two. Then, fit the obtained multiple sets of data to determine the mass extinction coefficient of the same type of dust as in step two. .

[0077] In step three, the dust concentration at the coal mine drilling site is calculated using the Lambert-Beer law. The specific method is as follows: ; In the formula: Dust concentration at underground drilling sites in coal mines, expressed in g / m³. 3 ; Optical density of dust at underground drilling sites in coal mines; m is the mass extinction coefficient. 2 / g; This represents the path length of light through a dusty gas, measured in meters (m).

[0078] In this embodiment, the equipment and method for measuring the optical density at a known dust concentration in step 301 using a light transmission method are all commonly used equipment and methods known in the art.

[0079] In this embodiment, the mass extinction coefficient It integrates the ability of dust particles to absorb and scatter light, and its value is closely related to the physicochemical properties of dust particles such as particle size distribution, shape, color, and refractive index.

[0080] In this embodiment, the dust concentration is calculated using either the light transmission method or the light absorption method, a scientific method based on the Lambert-Beer Law. Its core principle is that dust particles absorb and scatter light, leading to a decrease in transmitted light intensity, the degree of which is proportional to the dust concentration. When dust blocks light and forms a shadow, the shadow sensor 7 converts the change in the dust shadow's shading rate into an electrical signal. Based on the electrical signal, the intensity of the transmitted light after passing through the dust is obtained. This allows for the calculation of dust concentration at the coal mine drilling site. This enables real-time monitoring of dust concentration underground. The "dust shadow shading rate" refers to the ratio of the shadow cast by dust on the surface of the shadow sensor 7 to the surface of the shadow sensor 7 itself.

[0081] The reason why the overlapping of dust projections does not affect the measurement results when the device in this embodiment is in use is as follows: When light passes through a dusty gas, each dust particle independently absorbs and scatters a portion of the light. Regardless of whether the dust particles are sparsely distributed or closely overlapped along the beam path, the total light intensity attenuation caused by all dust particles depends only on the "total amount" of dust particles, and is independent of their "spatial arrangement." Specifically: First, independent attenuation: when a beam of intensity is When light passes through a dust-containing gas, each dust particle in the path independently intercepts it, either absorbing or scattering a portion of the photons. The light intensity attenuation caused by each dust particle is denoted as . .

[0082] Second, linear superposition: Under the assumption of low to medium concentrations, i.e., no secondary scattering of light between dust particles, the light intensity attenuation caused by each dust particle is linearly superimposed. Therefore, the total transmitted light intensity after passing through all dust particles... for:

[0083] The key to this formula is that, regardless of whether the dust particles are dispersed in the beam or overlap in projection, as long as the total number and properties of the dust particles remain unchanged, the total light intensity attenuation is a constant.

[0084] Conclusion: Optical density The extinction coefficient is related only to the total mass of the dust particles and the mass of the dust itself. It is related to the path length of light through dusty gas. The specific location and overlap of dust particles are irrelevant; the total mass of the dust particles is the dust concentration. The path length of light through dusty gas The product of.

[0085] In this embodiment, the apparatus is used under the assumption that the experimentally calibrated mass extinction coefficient is... The value is 0.15m 2 / g, the path length of light through dust-containing gas It was 0.5m; during one measurement, 1000W / m 2 , 800W / m 2 Dust concentration at underground drilling sites in coal mines The specific method is as follows: ; .

Claims

1. A dust concentration detection device for underground drilling in coal mines, comprising a vertically open hemispherical glass body (1), characterized in that, The glass body (1) is provided with a cleaning unit (2). The cleaning unit (2) includes a ring-shaped cleaning rack (201) arranged vertically. The center of the cleaning rack (201) is collinear with the axial center line of the glass body (1). A motor support frame (3) is also coaxially arranged at the top vertical direction of the glass body (1). The motor support frame (3) and the glass body (1) are spliced ​​together to form a spherical body with a hollow top. The bottom vertical direction of the motor support frame (3) is connected to the glass body (1), and the top vertical direction of the motor support frame (3) is connected to the sleeve (4) arranged coaxially. An explosion-proof motor (5) is also coaxially installed inside the sleeve (4). The bottom of the output shaft of the explosion-proof motor (5) is connected to the top of the cleaning rack (201). The output shaft of the explosion-proof motor (5) drives the cleaning rack (201) to rotate around the central axis of the glass body (1). A point light source (6) is also coaxially mounted on the inner top of the cleaning rack (201). A shadow sensor (7) is also installed on the bottom outer wall of the glass body (1), and a slag discharge hole (8) is coaxially opened on the bottom of the glass body (1) and runs through the side wall.

2. The dust concentration detection device for underground drilling in coal mines as described in claim 1, characterized in that, The cleaning rack (201) has a groove-shaped cross section. The cleaning unit (2) also includes an air duct (202) and a water pipe (203). The air duct (202) and the water pipe (203) are arranged side by side and nested in the groove of the cleaning rack (201). The air duct (202) and the water pipe (203) are arranged around the entire ring of the cleaning rack (201). Multiple air outlets (204) penetrating the sidewalls are respectively opened on the vertical middle section on both sides of the air duct (202), and the multiple air outlets (204) are evenly distributed along the circumference of the air duct (202); Multiple water outlets (205) penetrating the sidewalls are respectively opened on the vertical middle section on both sides of the water pipe (203), and the multiple water outlets (205) are evenly distributed along the circumference of the water pipe (203); The cleaning rack (201) is also equipped with an arc-shaped brush (206) on the vertically lower semicircular ring. The arc-shaped brush (206) is arranged along the circumference of the cleaning rack (201) and is located vertically below multiple air outlets (204) and multiple water outlets (205).

3. The dust concentration detection device for underground drilling in coal mines as described in claim 2, characterized in that, The cleaning unit (2) further includes multiple fan-shaped air blowing nozzles (207), which correspond one-to-one with the air outlet (204). The fan-shaped air blowing nozzles (207) are installed at the air outlet (204) on the air duct (202). The cleaning unit (2) further includes multiple fan-shaped water blowing nozzles (208), each of which corresponds to a water outlet (205). The fan-shaped water blowing nozzles (208) are installed at the water outlet (205) on the water pipe (203). The vertical top of the arc-shaped brush (206) is lower than the vertical top of the glass body (1) in the vertical direction; The outlet of the fan-shaped air purging nozzle (207) located at the bottom of the vertical column is lower than the top of the glass body (1) in the vertical direction, and the outlet of the fan-shaped water purging nozzle (208) located at the bottom of the vertical column is lower than the top of the glass body (1) in the vertical direction.

4. The dust concentration detection device for underground drilling in coal mines as described in claim 1, characterized in that, The motor support frame (3) includes multiple quarter-circular support rings (9), which are evenly arranged along the circumference of the glass body (1). One end of each support ring (9) is connected to the vertical top of the glass body (1). The sleeve (4) is coaxially arranged with the glass body (1). Multiple support ring mounting grooves (10) are radially opened on the vertical bottom end face of the sleeve (4). The support ring mounting grooves (10) correspond one-to-one with the support rings (9). The other end of the support ring (9) is embedded in the support ring mounting groove (10) and connected to the sleeve (4). The bottom outer side of the glass body (1) is also equipped with a glass body bottom bracket (11).

5. A method for measuring dust concentration during underground drilling in coal mines, characterized in that, This method employs the dust concentration detection device for underground drilling in coal mines as described in any one of claims 1 to 4, and specifically includes the following steps: Step 1: Obtain the incident light intensity: Obtain the incident light intensity of the point light source (6) in clean air. ; Step 2, measure the intensity of transmitted light: The dust concentration detection device was placed at the drilling site in the coal mine. The detection device was cleaned first, and then the point light source (6) was turned on. The light emitted by the point light source (6) passed through the narrow gap of the dust and shone onto the shadow sensor (7). Due to the effect of the dust on the shading rate, the shadow sensor (7) output different electrical signal results. The intensity of the transmitted light after passing through the dust was obtained through the results of the electrical signal. ; Step 3: Calculate the dust concentration using Lambert-Beer's Law: Based on the incident light intensity obtained in step one The transmitted light intensity obtained in step two Calculate the optical density of dust at underground drilling sites in coal mines. Then, the mass extinction coefficient was calibrated based on the experiment. The dust concentration at the coal mine drilling site was calculated using the Lambert-Beer law. .

6. The method for measuring dust concentration during underground drilling in coal mines as described in claim 5, characterized in that, In step two, the specific process of the cleaning and testing device is as follows: the explosion-proof motor (5) drives the cleaning frame (201) to rotate forward or backward, and the arc-shaped brush (206) rotates around the central axis of the glass body (1) to clean the dust on the inner surface of the glass body (1); at the same time, the air duct (202) can blow dry dust in the glass body (1) through multiple fan-shaped air blowing nozzles (207), and the water pipe (203) can clean wet dust in the glass body (1) through multiple fan-shaped water blowing nozzles (208), and finally realize the cleaning and testing device.

7. The method for measuring dust concentration during underground drilling in coal mines as described in claim 5, characterized in that, In step three, the optical density of dust at the coal mine drilling site is calculated. The specific process is as follows: ； In the formula: Optical density of dust at underground drilling sites in coal mines; It is a logarithmic function with base e; The incident light intensity is expressed in W / m². 2 ; Transmitted light intensity, in W / m 2 .

8. The method for measuring dust concentration during underground drilling in coal mines as described in claim 5, characterized in that, In step three, the experimental calibration of the mass extinction coefficient is described. The specific process is as follows: Step 301: Using the same type of dust as that tested in Step 2, a known and uniform concentration is generated in the experimental chamber; Step 302: Measure the optical density at the known dust concentration obtained in step 301 using a light transmission method instrument; Step 303: Only change the dust concentration in step 301, and repeat steps 301 and 302 multiple times to obtain the optical density of the same type of dust under different known dust concentrations as in step two. Then, fit the obtained multiple sets of data to determine the mass extinction coefficient of the same type of dust as in step two. .

9. The method for measuring dust concentration during underground drilling in coal mines as described in claim 5, characterized in that, In step three, the dust concentration at the coal mine drilling site is calculated using the Lambert-Beer law. The specific method is as follows: ； In the formula: Dust concentration at underground drilling sites in coal mines, expressed in g / m³. 3 ; Optical density of dust at underground drilling sites in coal mines; m is the mass extinction coefficient. 2 / g; This represents the path length of light through a dusty gas, measured in meters (m).

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