Spark detection system for dust removal ventilation pipeline

Abstract

The invention relates to the technical field of optical detectors, in particular to a spark detection system for a dust removal ventilating duct, which comprises a filtering convex lens embedded into or clung to a detection port on the outer wall of the dust removal ventilating duct, and the focal length of the filtering convex lens is smaller than the pipe diameter of the dust removal ventilating duct; a light inlet of the light guide pipe is covered by the convex surface of the filtering convex lens; the infrared diode circuit board is packaged to be circular, is embedded into the light outlet and is provided with an infrared diode arranged in the center of the infrared diode circuit board; the controller determines the average irradiation intensity through calculation; infrared radiation emitted by sparks in the dust removal ventilation pipeline is focused by the light filtering convex lens, then is emitted into the light guide pipe, is reflected and refracted in the light guide pipe, and then is irradiated to the diode detection end of the infrared diode circuit board, so that high-sensitivity spark detection is carried out. According to the invention, after focusing of the filtering convex lens, the infrared diode with relatively low cost can carry out spark detection with a large photosensitive range and high sensitivity in a dust removal ventilation pipeline.

Description

Technical Field

[0001] The invention relates to the field of light detector technology, and in particular to a spark detection system for a dust removal ventilation duct. Background Art

[0002] In recent years, with the rapid development of industrial automation technology, dust removal ventilation ducts are required to transport dust in the production of panels, furniture, food, tobacco, metal, automobile and chemical industries. Specifically, dust removal ventilation ducts are specially used to discharge harmful substances such as dust and smoke, effectively collect harmful substances and discharge clean gas to the outside to reduce the concentration of pollutants in the gas. Among them, wood shavings, fibers, dust and other types of dust are very likely to generate sparks due to static electricity, friction and collision during transportation. In the extremely dry environment of dust removal ventilation ducts, fires and even explosions are very likely to occur. Therefore, it is necessary to use spark detection devices to detect the infrared radiation emitted by sparks with high sensitivity.

[0003] At present, due to the small detection range of the infrared diode of the spark detection device, a light guide is usually installed on the infrared diode to enhance the light flux received by the infrared diode through the refraction and reflection of the infrared light in the light guide. However, the coupling efficiency of the light guide is high only when the radiation angle of the light emitted by the spark matches the light receiving angle of the optical fiber light guide column, but this efficient coupling is difficult to achieve, resulting in the loss of most of the infrared radiation generated by the spark. Summary of the invention

[0004] To this end, the present invention provides a spark detection system for dust removal ventilation ducts, in which the infrared radiation emitted by the sparks in the dust removal ventilation duct is focused by the filtering convex lens, then emitted into the light guide tube, and after reflection and refraction in the light guide tube, it irradiates the diode detection end of the infrared diode circuit board, thereby achieving a low-cost infrared diode with a larger spark detection range in the dust removal ventilation duct, and further enhancing the light flux received by the diode through the filtering convex lens and the light guide tube, thereby achieving spark detection with a large photosensitivity range and high sensitivity.

[0005] To achieve the above object, the present invention provides a spark detection system for a dust removal ventilation duct, comprising:

[0006] A filter convex lens is embedded in a detection port on the outer wall of the dust removal ventilation duct or attached to the outer wall surrounding the detection port, the detection port runs through both inner and outer sides of the dust removal ventilation duct, and the focal length of the filter convex lens is smaller than the diameter of the dust removal ventilation duct;

[0007] A light guide tube, whose light inlet is covered by the convex surface of the filter convex lens, and the distance from the light inlet to the center of the convex surface is less than or equal to the focal length of the filter convex lens;

[0008] An infrared diode circuit board, packaged in a circular shape, embedded in the light outlet of the light guide, having an infrared diode arranged at the center thereof, wherein the central axis of the light guide and the central axis of the filter convex lens are located on the same straight line;

[0009] The infrared radiation emitted by the spark in the dust removal ventilation duct is focused by the filter convex lens and then irradiated into the light guide tube. After being reflected and refracted in the light guide tube, the infrared radiation is concentrated on the infrared diode to detect the spark.

[0010] A controller is connected to the infrared diode circuit board, and is used to determine the average irradiation intensity by calculation according to the infrared intensity collected by the infrared diode, so as to determine the spark safety level in the dust removal ventilation duct.

[0011] Furthermore, a light shielding plate is arranged on the periphery of the filter convex lens, and the light shielding plate surrounds and seals the portion from the filter convex lens to the light inlet, forming a vacuum chamber through which only the filter convex lens is transparent.

[0012] Furthermore, the inner wall of the light guide tube at the light outlet is fixed to the outer periphery of the concave lens, and the infrared diode circuit board is fixed to the bottom wall of the light guide tube at the light outlet;

[0013] The infrared diode is located at the center of the concave lens, and the central axis of the concave lens and the central axis of the filtering convex lens are located on the same straight line.

[0014] Furthermore, two detection ports on opposite sides of the outer wall of the dust removal ventilation duct are respectively provided with a detection device consisting of a group of the filtering convex lens, the light guide tube, the infrared diode circuit board and the concave lens, and there is an overlapping area in the focusing ranges of the filtering convex lenses of the two groups of the detection devices.

[0015] Further, the spark detection system also includes a temperature sensor for detecting the temperature of the spark of the dust removal ventilation duct;

[0016] The controller is equipped with a distance calculation formula for the spark travel distance, specifically:

[0017]

[0018] Wherein, x is the distance the spark moves, T is the spark temperature detected by the temperature sensor, h is the radius of the dust removal ventilation duct, ε is the emissivity of the spark, σ is the Boltzmann constant, and P is the average irradiation intensity;

[0019] The controller substitutes the average irradiation intensity, the spark temperature and the radius into the distance calculation formula to obtain the spark movement distance, and determines the degree of fire according to the spark movement distance.

[0020] Further, the spark detection system also includes an alarm device communicatively connected to the controller;

[0021] Determining the spark safety level according to the spark moving distance is specifically as follows:

[0022] The controller determines whether there is too much dust in the dust removal ventilation duct according to the comparison result of the spark movement distance and the distance safety threshold, and if so, controls the alarm device to issue a dust alarm.

[0023] Furthermore, the controller is equipped with a speed calculation formula for the spark movement speed, specifically:

[0024]

[0025] Wherein, v is the spark moving speed, L is the focusing range of the filter convex lens, x is the spark moving distance, and t is the spark duration;

[0026] The controller obtains the focusing range L according to the curvature of the filtering convex lens;

[0027] The controller substitutes the spark moving distance, the focusing range and the spark duration into the speed calculation formula to obtain the spark moving speed.

[0028] Furthermore, the spark detection system also includes a spray system for spraying and extinguishing the dust removal ventilation duct;

[0029] The controller determines whether the dust flow rate in the dust removal ventilation duct is too fast based on the comparison result of the spark movement speed and the speed safety threshold. If so, the controller controls the alarm device to sound a ventilation alarm, and / or reduces the ventilation speed of the dust removal ventilation duct, and / or controls the operation of the spray system.

[0030] In particular, the detection and alarm of the spark moving distance and the spark moving speed can be realized through the filtering convex lens, the light guide tube and the infrared diode circuit board.

[0031] Furthermore, the main controller generates a spark model according to the temperature of the spark and the average irradiation intensity, extracts spark features of the spark model through a neural network, compares the spark features with a spark feature library, and derives the cause of the spark.

[0032] Furthermore, the main controller controls the operation of the spray system, specifically:

[0033] The main controller compares the spark signature with a spark signature library to determine whether the cause of the spark is dust ignition, pipe wall friction ignition or static electricity ignition, and sets the operating mode of the sprinkler system accordingly.

[0034] In particular, by collecting values ​​from the detection device and temperature sensor and extracting features through a neural network, a reasonable inference on the cause of the spark can be achieved, and the spray system can perform more targeted spraying work.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. The infrared radiation emitted by the spark in the dust removal ventilation duct is focused by the filter convex lens, then shot into the light guide tube, reflected and refracted in the light guide tube, and irradiated on the diode detection end of the infrared diode circuit board, so that the low-cost infrared diode can have a larger spark detection range in the dust removal ventilation duct, and the light flux received by the diode is further enhanced by the filter convex lens and the light guide tube, thereby realizing a large photosensitivity range and high sensitivity spark detection.

[0037] 2. Through the filtering convex lens, light guide tube and infrared diode circuit board, the spark moving distance and spark moving speed can be detected and alarmed.

[0038] 3. By collecting values ​​from the detection device and temperature sensor and extracting features through a neural network, a reasonable guess about the cause of the spark can be made, and the spray system can perform a more targeted spraying operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic diagram of the structure of a filter convex lens and a light guide tube for detecting sparks according to an embodiment of the present invention;

[0040] Figure 2 A schematic diagram of the structure of a light guide tube and an infrared diode circuit board according to an embodiment of the present invention;

[0041] Figure 3 A schematic diagram of the structure of a dust removal ventilation duct according to an embodiment of the present invention provided with a detection device for detecting sparks;

[0042] Figure 4 It is a schematic diagram of the packaging simulation effect of the infrared diode circuit board according to an embodiment of the present invention;

[0043] Figure 5 A schematic diagram of a spark model according to an embodiment of the present invention;

[0044] Figure 6 FIG. 4 is a schematic diagram of another spark model according to an embodiment of the present invention.

[0045] In the figure: 1, spark; 2, filter convex lens; 3, light guide tube; 4, light shielding plate; 5, concave lens; 6, infrared diode circuit board; 61, diode detection end; 7, shell; 8, dust removal ventilation duct. DETAILED DESCRIPTION

[0046] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0047] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0048] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0049] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] like Figures 1 to 6 As shown, the present invention provides a spark detection system for dust removal ventilation ducts, in which the infrared radiation emitted by the sparks in the dust removal ventilation duct is focused by the filtering convex lens and then emitted into the light guide tube, and after being reflected and refracted in the light guide tube, it irradiates the diode detection end of the infrared diode circuit board, thereby achieving a low-cost infrared diode with a larger spark detection range in the dust removal ventilation duct, and further enhancing the light flux received by the diode through the filtering convex lens and the light guide tube, thereby achieving spark detection with a large photosensitivity range and high sensitivity.

[0051] in, Figure 1 A schematic diagram of the structure of a filter convex lens and a light guide tube for detecting sparks according to an embodiment of the present invention; Figure 2 A schematic diagram of the structure of a light guide tube and an infrared diode circuit board according to an embodiment of the present invention; Figure 3A schematic diagram of the structure of a dust removal ventilation duct according to an embodiment of the present invention provided with a detection device for detecting sparks; Figure 4 It is a schematic diagram of the packaging simulation effect of the infrared diode circuit board according to an embodiment of the present invention; Figure 5 A schematic diagram of a spark model according to an embodiment of the present invention; Figure 6 FIG. 4 is a schematic diagram of another spark model according to an embodiment of the present invention.

[0052] These include: 1. spark; 2. filter convex lens; 3. light guide tube; 4. light shielding plate; 5. concave lens; 6. infrared diode circuit board; 61. diode detection end; 7. shell; 8. dust removal ventilation duct.

[0053] Embodiment 1:

[0054] like Figures 1 to 6 As shown, this embodiment proposes a spark detection system for a dust removal ventilation duct 8, comprising: a filter convex lens 2, which is embedded in a detection port on the outer wall of the dust removal ventilation duct 8 or attached to the outer wall surrounding the detection port, the detection port runs through the inner and outer sides of the dust removal ventilation duct 8, so that the detection port is blocked by the filter convex lens 2 and the dust in the dust removal ventilation duct 8 does not flow out through the detection port, the focal length of the filter convex lens 2 is smaller than the diameter of the dust removal ventilation duct 8; a light guide 3, whose light inlet is covered by the convex surface of the filter convex lens 2, and the distance from the light inlet to the center of the convex surface is less than or equal to the focal length of the filter convex lens 2; an infrared diode circuit board 6, the package is set to be circular, and the embedded The light outlet of the light guide 3 has an infrared diode 61 arranged at the center thereof, and the central axis of the light guide 3 and the central axis of the filtering convex lens 2 are located on the same straight line; the infrared radiation emitted by the spark in the dust removal ventilation duct 8 is focused by the filtering convex lens 2 and then injected into the light guide 3, and after being reflected and refracted in the light guide 3, it is concentrated on the infrared diode 61 to perform high-sensitivity spark detection; a controller, the controller is connected to the infrared diode circuit board 6, and the controller is used to determine the average irradiation intensity by calculation according to the infrared intensity collected by the infrared diode 61, so as to determine the safety level of the spark in the dust removal ventilation duct 8.

[0055] It is understandable that if Figure 1As shown, the light intake range of the light guide 3 is the cone-shaped area where the light inlet can receive light. This cone-shaped area is small, so when it is set on the side wall of the dust removal ventilation duct 8, the coverage range of the length of the dust removal ventilation duct 8 is small, so only using the light guide 3 cannot achieve high-sensitivity spark detection of the dust removal ventilation duct 8. Therefore, the light inlet of the light guide 3 is covered by the convex surface of the filter convex lens 2, so that the range of light received by the light guide 3 is expanded to the cone-shaped area composed of the normal line of the convex surface of the filter convex lens 2, thereby increasing the light intensity and the range of light received by the light guide 3, so that the light guide 3 cooperates with the infrared diode circuit board 6 to achieve high-sensitivity spark detection.

[0056] It can be understood that the focal length of the filtering convex lens 2 is smaller than the diameter of the dust removal ventilation duct 8, ensuring that the image of the sparks in the dust removal ventilation duct 8 passing through the filtering convex lens 2 is not an image on the same side, and the distance from the light inlet to the center of the convex surface is less than or equal to the focal length of the filtering convex lens 2, ensuring that the light passing through the filtering convex lens 2 can be injected into the light guide 3.

[0057] Furthermore, a shading plate 4 is disposed on the periphery of the filter convex lens 2 , and the shading plate 4 surrounds and seals the portion from the filter convex lens 2 to the light inlet, forming a vacuum chamber through which only the filter convex lens 2 is transparent.

[0058] Furthermore, the inner wall of the light guide 3 at the light outlet is fixed to the outer periphery of the concave lens 5, and the infrared diode circuit board 6 is fixed to the bottom wall of the light guide 3 at the light outlet; the infrared diode 61 is located at the center of the concave lens 5, and the central axis of the concave lens 5 and the central axis of the filtering convex lens 2 are located on the same straight line.

[0059] Specifically, Figure 4 The infrared diode circuit board 6 shown is embedded in the Figure 2 In the light outlet at the bottom of the light guide tube 3 shown. More specifically, Figure 4 The infrared diode 61 in the infrared diode circuit board 6 shown, that is, the photosensitive element D2 shown in the figure is set at the center of the infrared diode circuit board 6, and its periphery is a circuit for bandpass filtering it, preferably extracting and separating the high-frequency signal of about 100HZ collected by the photosensitive element D2.

[0060] Furthermore, the inner wall of the light guide 3 at the light outlet is fixed to the outer periphery of the concave lens 5, and the infrared diode circuit board 6 is fixed to the bottom wall of the light guide 3 at the light outlet; the infrared diode 61 is located at the center of the concave lens 5, and the central axis of the concave lens 5 and the central axis of the filtering convex lens 2 are located on the same straight line.

[0061] It can be understood that by providing a plurality of detection devices, spark detection without blind spots in the dust removal ventilation duct 8 can be achieved.

[0062] For details, see Figure 3 The controller, the filtering convex lens 2, the light guide 3, the infrared diode circuit board 6 and the concave lens 5 are integrated in the shell of the detection device. By installing the shell on the detection port of the side wall of the dust removal ventilation duct 8, the convenient setting of the detection device can be achieved.

[0063] Further, see Figure 3 The spark detection system further includes a temperature sensor for detecting the temperature of the spark in the dust removal ventilation duct 8; the controller is equipped with a distance calculation formula for the spark moving distance, specifically:

[0064]

[0065] Among them, x is the spark movement distance, T is the spark temperature detected by the temperature sensor, h is the radius of the dust removal ventilation duct 8, ε is the spark emissivity, σ is the Boltzmann constant, and P is the average irradiation intensity; the controller substitutes the average irradiation intensity, the spark temperature and the radius into the distance calculation formula to obtain the spark movement distance, and determines the spark safety level according to the spark movement distance.

[0066] The derivation process of the distance calculation formula and the process of the controller determining the average irradiation intensity by calculation according to the infrared intensity collected by the infrared diode 61 are as follows:

[0067] It is understandable that the distance calculation formula can be transformed into:

[0068]

[0069] The average irradiation intensity P is the energy Q0 received by the infrared diode 61 per unit time divided by the photosensitive area S of the infrared diode 61 .

[0070] Specifically, the relationship between the total energy Q radiated by the spark to the surroundings and the received energy Q0 is:

[0071]

[0072] In the formula, Q0 is the energy received by the infrared diode 61 per unit time, Q is the total energy radiated by the spark to the surroundings, S is the photosensitive area of ​​the diode detection end, h is the radius of the dust removal ventilation duct, d is the spark diameter, and it is determined experimentally that the spark diameter is a unit diameter of 1 cm, so it can be simplified and omitted in the formula, and x is the distance the spark moves.

[0073] Where, Q=EA=Eπd 2 , where Q is the total energy radiated by the spark to the surroundings, E is the radiation power of the spark, A is the radiation surface area of ​​the spark, and d is the spark diameter. According to experiments, the spark diameter is determined to be a unit diameter of 1 cm.

[0074] According to the radiation law and the relationship between the emissivity of an object and blackbody radiation, the formula for the radiation power of a spark can be obtained: E = εσT 4 , where E is the radiation power of the spark, ε is the emissivity of the spark, σ is the Boltzmann constant, and T is the spark temperature detected by the temperature sensor.

[0075] Therefore, the distance calculation formula can be obtained by substituting the above formulas one by one.

[0076] Furthermore, the spark detection system also includes an alarm device communicatively connected to the controller; the spark safety level is determined based on the spark movement distance, specifically: the controller determines whether there is too much dust in the dust removal ventilation duct 8 based on the comparison result of the spark movement distance and the distance safety threshold, and if so, controls the alarm device to issue a dust alarm.

[0077] It can be understood that no matter the cause of the spark is dust ignition, dust friction with the duct wall or static electricity between dust, the dust in the dust removal ventilation duct 8 is an ignition material for sparks. Therefore, the sparks generated by the dust will move with the exhaust air. If the spark movement distance is long, it means that the dust in the dust removal ventilation duct 8 is relatively large and dense, so that the sparks can move a longer distance along the dense dust.

[0078] Specifically, the controller sets a plurality of distance safety thresholds that increase in sequence, according to the spark movement distance

[0079] Furthermore, the controller is equipped with a speed calculation formula for the spark movement speed, specifically:

[0080]

[0081] Among them, v is the spark movement speed, L is the focusing range of the filtering convex lens 2, x is the spark movement distance, and t is the spark duration; the controller obtains the focusing range L according to the curvature of the filtering convex lens 2; the controller substitutes the spark movement distance, the focusing range and the spark duration into the speed calculation formula to obtain the spark movement speed.

[0082] Furthermore, the spark detection system also includes a sprinkler system for spraying and extinguishing the dust removal ventilation duct 8; the controller determines whether the dust flow rate in the dust removal ventilation duct 8 is too fast based on the comparison result of the spark movement speed and the speed safety threshold, and if so, controls the alarm device to sound a ventilation alarm, and / or reduces the ventilation speed of the dust removal ventilation duct 8, and / or controls the operation of the sprinkler system.

[0083] Preferably, the controller selects one of the alarm devices to perform ventilation alarm, reduce the ventilation speed or ventilation volume of the dust removal ventilation duct 8, and control the operation of the spray system to reduce safety risks. It is understandable that the controller can also simultaneously control the alarm device to perform ventilation alarm, reduce the ventilation speed or ventilation volume of the dust removal ventilation duct 8, and control the operation of the spray system.

[0084] In particular, the detection and alarm of the spark moving distance and the spark moving speed can be realized through the filtering convex lens 2, the light guide tube 3 and the infrared diode circuit board 6.

[0085] Furthermore, the main controller controls the operation of the sprinkler system, specifically: the main controller compares the spark signature with a spark signature library, determines that the cause of the spark is one of dust ignition, pipe wall friction ignition or electrostatic ignition, and sets the operation mode of the sprinkler system accordingly.

[0086] Furthermore, the main controller compares the spark signature with a spark signature library to determine whether the cause of the spark is dust ignition, pipe wall friction ignition or static electricity ignition, and sets the operation mode of the sprinkler system accordingly.

[0087] In particular, by collecting values ​​from the detection device and temperature sensor and extracting features through a neural network, a reasonable inference on the cause of the spark can be achieved, and the spray system can perform more targeted spraying work.

[0088] Specifically, a spark feature library and a spark model training set are generated by feature annotation of the spark model obtained in the experiment. The spark model training set is used to train a convolutional neural network model (CNN) and adjust its training parameters. When it is evaluated that the convolutional neural network model has basically converged and its feature annotation of the spark model training set is accurate enough, the convolutional neural network model is used to generate a feature extractor of the spark model. The feature extractor is used to process the spark model to extract accurate spark features. The spark features are compared with the spark feature library to obtain the cause of the spark.

[0089] More specifically, Figure 5 and Figure 6As shown, the spark model is obtained based on the average irradiance intensity P detected by the diode detection end 61 at multiple time points and the temperature T of the spark of the dust removal ventilation duct 8 detected by the temperature sensor. Figure 5 The spark model shown has an average irradiance intensity P and temperature T concentrated at the same time point, so it is determined by the controller as an accidental dust ignition. Figure 6 The temperatures T of the spark models shown are all concentrated at the same time point, and the duration of the average irradiation intensity P is relatively long, so it is judged that the dust rubs against the duct wall of the dust removal ventilation duct 8 for a long time, resulting in duct wall friction ignition. The average irradiation intensity P of the spark model judged to be electrostatic ignition is greater than the average irradiation intensity P of the spark model judged to be dust ignition, and the temperature T is also greater than the temperature T of the spark model judged to be dust ignition.

[0090] Specifically, for dust ignition, the controller controls the spray system to spray continuously at low or medium water pressure. For pipe wall friction ignition, the controller controls the spray system to spray continuously or spray multiple times at short intervals. For static electricity ignition, continuous high water pressure spraying is performed to ensure that the charge carried by the dust is fully in contact with the water without generating static electricity.

[0091] In summary, in this embodiment, the infrared radiation emitted by the spark in the dust removal ventilation duct 8 is focused by the filtering convex lens 2, then injected into the light guide 3, and after being reflected and refracted in the light guide 3, it is irradiated on the diode detection end 61 of the infrared diode circuit board 6, so that the low-cost infrared diode can have a larger spark detection range in the dust removal ventilation duct 8, and the light flux received by the diode is further enhanced by the filtering convex lens 2 and the light guide 3, thereby realizing a large photosensitivity range and high sensitivity spark detection; through the filtering convex lens 2, the light guide 3 and the infrared diode circuit board 6, the detection and alarm of the spark movement distance and the spark movement speed can be realized; through the collection values ​​of the detection device and the temperature sensor, the features are extracted through the neural network, and a reasonable speculation on the cause of the spark is realized, and the spray system can perform a more targeted spraying work.

[0092] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A spark detection system for dust removal ventilation ducts, characterized in that: include: A filter convex lens (2) is embedded in a detection port on the outer wall of the dust removal ventilation duct (8) or adhered to the outer wall surrounding the detection port, the detection port runs through both inner and outer sides of the dust removal ventilation duct (8), and the focal length of the filter convex lens (2) is smaller than the diameter of the dust removal ventilation duct (8); A light guide tube (3), the light inlet of which is covered by the convex surface of the filter convex lens (2), and the distance from the light inlet to the center of the convex surface is less than or equal to the focal length of the filter convex lens (2); An infrared diode circuit board (6) is packaged in a circular shape and embedded in the light outlet of the light guide (3), and has an infrared diode (61) arranged at the center thereof, wherein the central axis of the light guide (3) and the central axis of the filter convex lens (2) are located on the same straight line; The infrared radiation emitted by the spark in the dust removal ventilation duct (8) is focused by the filter convex lens (2) and then irradiated into the light guide tube (3). After being reflected and refracted in the light guide tube (3), the infrared radiation is concentrated and irradiated onto the infrared diode (61) to detect the spark; A controller is connected to the infrared diode circuit board (6), and is used to determine the average irradiation intensity by calculation according to the infrared intensity collected by the infrared diode (61), so as to determine the spark safety level in the dust removal ventilation duct (8).

2. The spark detection system for dust removal ventilation duct according to claim 1, characterized in that: A light shielding plate (4) is arranged on the periphery of the filter convex lens (2), and the light shielding plate (4) surrounds and seals the portion from the filter convex lens (2) to the light inlet, forming a vacuum chamber through which only the filter convex lens (2) is transparent.

3. The spark detection system for dust removal ventilation duct according to claim 1, characterized in that: The inner wall of the light guide tube (3) at the light outlet is fixed to the outer periphery of the concave lens (5), and the infrared diode circuit board (6) is fixed to the bottom wall of the light guide tube (3) at the light outlet; The infrared diode (61) is located at the center of the concave lens (5), and the central axis of the concave lens (5) and the central axis of the filtering convex lens (2) are located on the same straight line.

4. The spark detection system for dust removal ventilation duct according to claim 3, characterized in that: Two detection ports on opposite sides of the outer wall of the dust removal ventilation duct (8) are respectively provided with a detection device consisting of a group of the filter convex lens (2), the light guide tube (3), the infrared diode circuit board (6) and the concave lens (5), and the focusing ranges of the filter convex lenses (2) of the two groups of the detection devices have overlapping areas.

5. The spark detection system for dust removal ventilation duct according to any one of claims 1 to 4, characterized in that: Also included is a temperature sensor for detecting the temperature of the spark of the dust removal ventilation duct (8); The controller is equipped with a distance calculation formula for the spark travel distance, specifically: Wherein, x is the distance traveled by the spark, T is the spark temperature detected by the temperature sensor, h is the radius of the dust removal ventilation duct (8), ε is the emissivity of the spark, σ is the Boltzmann constant, and P is the average irradiation intensity; The controller substitutes the average irradiation intensity, the spark temperature and the radius into the distance calculation formula to obtain the spark movement distance, and determines the spark safety level according to the spark movement distance.

6. The spark detection system for dust removal ventilation duct according to claim 5, characterized in that: Also included is an alarm device communicatively connected to the controller; Determining the spark safety level according to the spark moving distance is specifically as follows: The controller determines whether there is too much dust in the dust removal ventilation duct (8) based on the comparison result of the spark movement distance and the distance safety threshold, and if so, controls the alarm device to issue a dust alarm.

7. The spark detection system for dust removal ventilation duct according to claim 6, characterized in that: The controller is equipped with a speed calculation formula for the spark movement speed, specifically: Wherein, v is the speed of the spark movement, L is the focusing range of the filter convex lens (2), x is the distance the spark moves, and t is the duration of the spark; The controller obtains the focusing range L according to the curvature of the filtering convex lens (2); The controller substitutes the spark moving distance, the focusing range and the spark duration into the speed calculation formula to obtain the spark moving speed.

8. The spark detection system for dust removal ventilation duct according to claim 7, characterized in that: It also includes a spray system for spraying the dust removal ventilation duct (8) to extinguish fire; The controller determines whether the dust flow rate in the dust removal ventilation duct (8) is too fast based on the comparison result between the spark movement speed and the speed safety threshold, and if so, controls the alarm device to issue a ventilation alarm, and / or reduces the ventilation speed of the dust removal ventilation duct (8), and / or controls the operation of the spray system.

9. The spark detection system for dust removal ventilation duct according to claim 8, characterized in that: The main controller generates a spark model according to the temperature of the spark and the average irradiation intensity, extracts spark features of the spark model through a neural network, compares the spark features with a spark feature library, and obtains the cause of the spark.

10. The spark detection system for dust removal ventilation duct according to claim 9, characterized in that: The main controller controls the operation of the spray system, specifically: The main controller compares the spark signature with a spark signature library, determines that the cause of the spark is one of dust ignition, pipe wall friction ignition or static electricity ignition, and sets the operating mode of the spray system accordingly.

Images