A dust collector filter bag and a leak detection method and preparation method thereof

Abstract

The application discloses a dust collector filter bag and a leak detection method and a preparation method thereof. The dust collector filter bag comprises a bag body for filtering dust, and a conductive grid arranged on the bag body. The conductive grid comprises conductive polymer wires and non-conductive polymer wires. The conductive polymer wires are uniformly arranged in a radial direction or a weft direction. The conductive polymer wires and the non-conductive polymer wires are arranged in a cross manner. Under the action of external factors, the conductive polymer wires are damaged first or simultaneously with the bag body. In the leak detection process of the dust collector filter bag, no external circuit, external power supply and other devices are needed except for a signal monitor, so that the leak detection cost of the filter bag is greatly reduced, and the detection process is convenient and simple and has a high leak detection accuracy.

Description

Technical Field

[0001] This invention relates to the field of industrial dust emissions, and in particular to a dust collector filter bag and its leak detection and preparation methods. Background Technology

[0002] Baghouse dust collectors are widely used in thermal power plants, steel metallurgy, cement kilns, and other fields involving industrial dust emissions. Industrial dust emissions are large in volume and contain harmful substances such as heavy metals, significantly impacting the regional environment and human health; therefore, the stability of baghouse dust collectors is crucial. Studies have shown that leakage in a single filter bag in a baghouse dust collector can reduce the overall efficiency of the dust collector from 99.9% to 85%. Therefore, it is necessary to monitor individual filter bag leaks in the baghouse dust collector in real time and replace them promptly.

[0003] Current methods for leak detection of existing dust collector filter bags, such as particulate matter concentration monitoring, are cumbersome and time-consuming, and do not provide immediate measurement results. Other methods, like airflow disturbance fiber optic monitoring and particulate matter-sensor charge induction methods, require external sensors. Therefore, existing methods for leak detection of dust collector filter bags suffer from drawbacks such as high cost, low monitoring accuracy, and complex equipment, and no mature industrial application examples exist to date.

[0004] Therefore, the present invention provides a dust collector filter bag and a leak detection method and preparation method thereof, in order to at least partially solve the above-mentioned problems. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a dust collector filter bag and its leak detection method and preparation method, which solves the problems of high detection cost, complicated leak detection steps and inaccurate leak detection results in the process of leak detection of filter bags in bag dust collectors.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0009] In a first aspect, embodiments of the present invention provide a dust collector filter bag, comprising:

[0010] The bag is used to filter dust;

[0011] A conductive mesh is disposed on the bag body. The conductive mesh includes conductive polymer lines and non-conductive polymer lines. The conductive polymer lines are uniformly arranged radially or uniformly arranged latitudinally. The conductive polymer lines and the non-conductive polymer lines are arranged in an intersecting pattern.

[0012] Under the influence of external factors, the conductive polymer thread may break before the bag body or the conductive polymer thread may break simultaneously with the bag body.

[0013] Optionally, the conductive polymer wire and the bag body are made of the same material.

[0014] Optionally, the dust collector filter bag includes:

[0015] A signal detection instrument is connected to the conductive mesh and is used to detect the resistance signal of the conductive mesh.

[0016] Secondly, embodiments of the present invention provide a leak detection method for dust collector filter bags, used for dust collector filter bags as described in the first aspect above, comprising the following steps:

[0017] When the dust collector filter bag is in normal working condition, the resistance signal of the dust collector filter bag is obtained as a background signal;

[0018] When the dust collector filter bag is in working condition, the real-time resistance signal of the dust collector filter bag is acquired;

[0019] The real-time resistance signal minus the background signal is used as the sensing signal.

[0020] The damage status of the filter bag is determined based on the sensor signal.

[0021] Optionally, when the sensing signal is 0, the filter bag is in normal working condition;

[0022] When the sensor signal is non-zero, the filter bag is in a state of impending or already damaged.

[0023] Optionally, if the sensing signal is less than a preset value, the filter bag is about to break.

[0024] If the sensor model is greater than or equal to the preset value, the filter bag is damaged.

[0025] The preset value is related to the resistance of the dust collector filter bag.

[0026] Optionally, the degree of damage to the filter bag is determined based on the sensing signal, and the mathematical expression of the sensing signal and the number of damaged conductive polymer lines is as follows:

[0027]

[0028] Where △R is the sensing signal, n bThe number of broken conductive polymer lines in the conductive grid is given by ρ, where ρ is the conductivity of the conductive polymer line, L is the length of the conductive polymer line, n is the total number of conductive polymer lines in the conductive grid, and S is the total number of conductive polymer lines in the conductive grid. t The cross-sectional area of ​​the conductive polymer line in the conductive mesh.

[0029] Thirdly, embodiments of the present invention provide a method for preparing a dust collector filter bag, for use in the dust collector filter bag described in the first aspect above, comprising the following steps:

[0030] A non-conductive polymer wire is immersed in a conductive liquid adhesive, and the polymer wire is then removed and dried to obtain a conductive polymer wire.

[0031] A conductive mesh is spun using the conductive polymer yarn and the non-conductive polymer yarn;

[0032] The conductive mesh is embedded into the bag body.

[0033] Optionally, the conductive liquid adhesive is one of graphene liquid adhesive, carbon-containing liquid adhesive, silver-containing liquid adhesive, and copper-containing liquid adhesive.

[0034] Optionally, the conductive mesh is embedded into the bag body by one of the following methods: needle punching, hydroentangling, meltblowing, and coating.

[0035] (III) Beneficial Effects

[0036] The beneficial effects of this invention are as follows: This invention provides a dust collector filter bag and its leak detection and preparation method. The dust collector filter bag includes: a bag body for filtering dust; and a conductive mesh disposed on the bag body. The conductive mesh includes conductive polymer lines and non-conductive polymer lines, with the conductive polymer lines arranged radially or latitudinally, and the conductive and non-conductive polymer lines arranged in a cross pattern. Under the influence of external factors, the conductive polymer lines may break before or simultaneously with the bag body. Compared to existing technologies, the leak detection steps for this filter bag are simpler and can achieve high-precision leak detection. Specifically, the resistance signal of the conductive mesh of the filter bag can be detected, and the damage state of the filter bag can be determined by the change in the resistance signal of the conductive mesh. During the leak detection process, this dust collector filter bag requires no external circuit, external power supply, or other devices except for a signal monitor, greatly reducing the cost of filter bag leak detection. The leak detection process is convenient, simple, and has a high leak detection accuracy. The operating parameters of the dust collector can be adjusted in a timely manner based on the leak detection results, thereby ensuring the working stability of the dust collection operation. Attached Figure Description

[0037] Figure 1 This is a schematic diagram illustrating the preparation of the conductive polymer wire and conductive mesh in Example 1 of a dust collector filter bag according to the present invention.

[0038] Figure 2 This is a schematic diagram of the conductive polymer wire of a dust collector filter bag and the thermogravimetric analysis and strength test curves of the filter bag according to the present invention.

[0039] Figure 3 Background signal curves under multiple states for an embodiment 1 of the dust collector filter bag of the present invention;

[0040] Figure 4 This is a sensor signal curve diagram of an embodiment 1 of the dust collector filter bag of the present invention under mechanical damage.

[0041] Figure 5 This is a sensor signal curve diagram under thermal damage for a second embodiment of a dust collector filter bag of the present invention;

[0042] Figure 6 This is a sensor signal curve diagram of an embodiment 3 of the dust collector filter bag of the present invention under acid and alkali corrosion.

[0043] Figure 7 This is a graph showing the relationship between the sensing signal and the number of failed conductive polymer wires in an embodiment 1 of the dust collector filter bag of the present invention.

[0044] Figure 8 This is a flowchart of a leak detection method for dust collector filter bags according to the present invention;

[0045] Figure 9 This is a flowchart of a method for preparing a dust collector filter bag according to the present invention. Detailed Implementation

[0046] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] The dust collector filter bag proposed in this embodiment of the invention includes: a bag body and a conductive mesh, wherein the conductive mesh is disposed in the bag body. During the operation of the dust collector, the degree of damage to the conductive mesh can be determined by detecting the resistance signal of the conductive mesh and by the change in the detected resistance signal, thereby determining the degree of damage to the dust collector filter bag.

[0048] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0049] In a first aspect, embodiments of the present invention provide a dust collector filter bag, comprising:

[0050] The bag is used to filter dust;

[0051] A conductive mesh is set in the bag body. The conductive mesh includes conductive polymer lines and non-conductive polymer lines. The conductive polymer lines are uniformly arranged radially or uniformly arranged latitudinally. The conductive polymer lines and non-conductive polymer lines are arranged in an intersecting pattern.

[0052] Under the influence of external factors, the conductive polymer thread may break before the bag body or the conductive polymer thread may break at the same time as the bag body.

[0053] In this technical solution, the dust collector filter bag mentioned includes: a bag body and a conductive mesh. The conductive mesh is set in the bag body. During the operation of the dust collector, the degree of damage to the conductive mesh can be determined by detecting the resistance signal of the conductive mesh and the change in the detected resistance signal, thereby determining the degree of damage to the dust collector filter bag.

[0054] refer to Figure 1 The conductive mesh consists of conductive and non-conductive polymer wires. Specifically, the conductive polymer wires are uniformly arranged radially or uniformly arranged latitudinally, meaning all conductive polymer wires are aligned in the same direction. During dust collector operation, the filter bag is affected by external conditions, causing damage. The conductive polymer wires may break before or simultaneously with the bag body. The damage state of the filter bag can be determined based on changes in the resistance signal of the conductive polymer wires.

[0055] It should be noted that when the conductive polymer lines break before the filter bag, the detected resistance signal of the conductive mesh changes. This indicates that the filter bag is under strong external influence, is being attacked by external factors, and the conductive polymer lines in the conductive mesh have undergone geometric changes, suggesting that the filter bag may be about to rupture and leak. Under some high-intensity external conditions, the time difference between the bag body and the filter bag is extremely short, causing the conductive polymer lines and the bag body to break simultaneously.

[0056] It should be noted that maintaining a consistent orientation of the conductive polymer wires is beneficial for detecting changes in the resistance signal. If the conductive polymer wires are arranged in an alternating pattern, creating a complex parallel circuit in the conductive mesh, the change in resistance signal between a damaged filter bag and an intact filter bag will be subtle, making it difficult to determine the filter bag's condition.

[0057] For example, factors affecting filter bag breakage include, but are not limited to, mechanical damage, thermal damage, chemical corrosion, and all conditions that may cause filter bag breakage.

[0058] For example, the conductive polymer wire can be a single strand or a multi-strand wire. A conductive grid can be formed by using a single strand of conductive polymer wire and a non-conductive polymer wire, or a conductive grid can be formed by using a multi-strand conductive polymer wire and a non-conductive polymer wire. This application does not limit the scope of the application.

[0059] For example, the conductive polymer wire can be made of polymethyl methacrylate (PMMA) polymer wire.

[0060] This application discloses a dust collector filter bag that can detect the resistance signal of the conductive mesh in the filter bag, and determine the working status of the filter bag by the change in the resistance signal. Leak detection of this filter bag does not rely on commercial sensors, significantly reducing the cost of filter bag leak detection. The conductive mesh is embedded during the filter bag manufacturing stage, requiring no external circuitry, external power supply, or other devices besides a signal monitor. This is convenient, simple, and offers high detection accuracy, enabling the prediction of the filter bag's working status and timely adjustment of the dust collector's production parameters, thereby ensuring the stability of dust collection operations.

[0061] In this technical solution, the conductive polymer wire and the bag body are made of the same material.

[0062] By ensuring that the conductive polymer wires and the filter bag are made of the same material, the filter bag can better guarantee that the conductive polymer wires fail before or simultaneously with the filter bag under different external factors, such as mechanical damage, acid and alkali corrosion, and increased temperature. Furthermore, the damage status of the filter bag can be determined based on the change in the resistance signal of the conductive polymer wires.

[0063] refer to Figure 2 For example, polymethyl methacrylate (PMMA) polymer threads were selected as the conductive polymer threads and non-conductive polymer threads as the materials for preparing the bag body. Thermogravimetric analysis and strength testing were performed on the conductive polymer threads and the bag body.

[0064] refer to Figure 2 -(a), before acid-base aging, a1 represents the thermogravimetric curve of the bag made of methyl methacrylate (PMMA) under thermogravimetric analysis, a2 represents the thermogravimetric curve of the conductive polymer wire made of methyl methacrylate (PMMA) under thermogravimetric analysis, a3 represents the thermogravimetric differential curve of the conductive polymer wire made of methyl methacrylate (PMMA) under thermogravimetric analysis, and a4 represents the thermogravimetric differential curve of the bag made of methyl methacrylate (PMMA) under thermogravimetric analysis. It can be seen that the conductive polymer wire fails before the bag as the temperature increases.

[0065] refer to Figure 2-(b), after acid and alkali aging, b1 represents the thermogravimetric curve of the bag made of methyl methacrylate (PMMA) under thermogravimetric analysis, b2 represents the thermogravimetric curve of the conductive polymer wire made of methyl methacrylate (PMMA) under thermogravimetric analysis, b3 represents the thermogravimetric differential curve of the conductive polymer wire made of methyl methacrylate (PMMA) under thermogravimetric analysis, and b4 represents the thermogravimetric differential curve of the bag made of methyl methacrylate (PMMA) under thermogravimetric analysis. It can be seen that the conductive polymer wire fails before the bag as the temperature increases.

[0066] refer to Figure 2 -(c), c1 represents the change curve of the bag made of methyl methacrylate (PMMA) with increasing strength before acid and alkali aging, and c2 represents the change curve of the bag made of methyl methacrylate (PMMA) with increasing strength after acid and alkali aging.

[0067] refer to Figure 2 -(d), d1 represents the curve of change of the conductive polymer wire made of methyl methacrylate (PMMA) with the increase of strength after acid and alkali aging, and d2 represents the curve of change of the conductive polymer wire made of methyl methacrylate (PMMA) with the increase of strength before acid and alkali aging.

[0068] In this technical solution, the dust collector filter bag includes:

[0069] A signal detection instrument, connected to a conductive grid, is used to detect the resistance signal of the conductive grid.

[0070] For example, the signal detection instrument mentioned above can be a digital multimeter, or any other detection instrument capable of detecting the resistance signal of a conductive grid can be selected; this application does not limit this.

[0071] refer to Figure 1 For example, conductive polymer wires can be used to connect the two ends of radially arranged conductive polymer wires, thereby connecting the two ends of the conductive polymer wires of a single filter bag to a pair of endpoints of a multi-channel digital multimeter, and connecting the two ends of the conductive polymer wires of multiple filter bags to other endpoints of the multi-channel digital multimeter respectively.

[0072] Secondly, refer to Figure 8 This invention provides a leak detection method for dust collector filter bags, used for dust collector filter bags as described in the first aspect above, comprising the following steps:

[0073] Step S110: When the dust collector filter bag is in normal working condition, obtain the resistance signal of the dust collector filter bag as the background signal;

[0074] For example, the normal working state of the dust collector filter bag includes, but is not limited to, the dust collector standby state, the dust collector vibration state, the dust collector vibration + pulse cleaning state, and the dust collector vibration + dust holding + pulse cleaning state.

[0075] refer to Figure 3 , Figure 3 The resistance signals of the conductive mesh obtained under multiple normal conditions can be used as background signals.

[0076] Step S120: When the dust collector filter bag is in working condition, acquire the real-time resistance signal of the dust collector filter bag;

[0077] Step S130: Subtract the background signal from the real-time resistance signal to obtain the sensing signal. Determine the damage status of the filter bag based on the sensing signal.

[0078] It should be noted that different states of the sensor signal represent different working states of the filter bag. When the sensor signal dynamically increases, it indicates that the filter bag is being attacked by external factors and that the conductive polymer lines in the conductive mesh have undergone geometric changes, and the filter bag may be about to break and leak. When the sensor signal increases to a certain extent, the conductive polymer lines in the conductive mesh have failed, and the filter bag has already broken.

[0079] It should be noted that the sensing signal strength and detection accuracy can be adjusted as needed. The sensing signal strength is adjusted by controlling the resistance value of the conductive polymer wire, and the methods include, but are not limited to, changing the conductivity of the conductive polymer wire and controlling the cross-sectional area of ​​the conductive polymer wire. The detection accuracy is optimized by changing the arrangement density of the conductive polymer wire in the conductive grid, that is, the total number of conductive polymer wires in the conductive grid can be increased.

[0080] In this technical solution, the filter bag is in normal working condition when the sensor signal is 0.

[0081] When the sensor signal is non-zero, the filter bag is in a state of impending or already damaged.

[0082] It should be noted that the sensing signal is the real-time measured resistance signal minus the background signal. Under normal working conditions of the dust collector filter bag, the measured real-time resistance signal is the background signal. Therefore, when the sensing signal is 0, the filter bag is in normal working condition.

[0083] It should be noted that when the dust collector filter bag is subjected to external force, the conductive polymer lines in the conductive mesh undergo geometric changes. Due to the influence of external force, the resistance of the conductive mesh changes, causing the measured real-time resistance signal to change, which in turn causes the sensing signal to change. Therefore, when the sensing signal is non-zero, the filter bag is in a state of impending or already damaged.

[0084] In this technical solution, the filter bag will break when the sensing signal is less than a preset value;

[0085] If the sensor value is greater than or equal to the preset value, the filter bag is already damaged;

[0086] The preset value is related to the resistance of the dust collector filter bag.

[0087] It should be noted that if the dust collector filter bag is subjected to external force but is not yet damaged, the conductive polymer lines in the conductive mesh may undergo geometrical changes without breaking. Under these conditions, the filter bag may be about to rupture and leak. If the sensor signal is lower than the preset value, the filter bag is about to rupture; if the sensor signal is greater than or equal to the preset value, the filter bag has already ruptured. Comparing the sensor signal with the preset value allows for predictive assessment of the filter bag's operating status and adjustment of the dust collector's operating status, thereby ensuring the stability of the dust collector during dust removal operations.

[0088] For example, the preset value is related to the resistance of the dust collector filter bag. Factors affecting the resistance of the dust collector filter bag include, but are not limited to, the number of conductive polymer wires in the conductive mesh, the cross-sectional area of ​​the conductive polymer wires, and the type of conductive liquid adhesive. When the resistance of the dust collector filter bag is different, the preset value will also change.

[0089] For example, refer to Figure 4 , Figure 4 This indicates the sensor signal monitored under the influence of mechanical damage. It can be seen that the sensor signal dynamically increases within the range of 0Ω to 3Ω. This means that when the background signal remains unchanged, the detected real-time resistance signal increases due to the influence of external conditions, resulting in a larger sensor signal. At this time, the filter bag has not yet been damaged, but its geometric shape may have changed.

[0090] For example, refer to Figure 5 , Figure 5 The table shows the sensor signals monitored under the influence of thermal damage. It can be seen that the sensor signal dynamically increases in the range of 0Ω to 3Ω. This means that when the background signal remains unchanged, the detected real-time resistance signal increases due to the influence of external conditions, resulting in a larger sensor signal. At this time, the filter bag has not yet been damaged, but its geometric shape may have changed.

[0091] In this technical solution, the filter bag is already damaged when the sensing signal is within the second preset range;

[0092] The second preset range is greater than 3Ω.

[0093] It should be noted that when the sensor signal is greater than 3Ω, the filter bag is already damaged.

[0094] For example, refer to Figure 4 , Figure 4 The sensor signal monitored under the influence of mechanical damage shows that the average value of the sensor signal fluctuates around 3Ω over time, indicating that the filter bag has developed holes and is damaged.

[0095] For example, refer to Figure 5 , Figure 5 The sensor signal monitored under the influence of thermal damage shows that the average value of the sensor signal fluctuates around 3Ω as time increases, which indicates that the filter bag has developed holes and is damaged.

[0096] For example, refer to Figure 6 , Figure 6 This indicates that the monitored sensor signals, under the influence of acid and alkali corrosion, have a longer timeframe due to the prolonged impact of acid and alkali corrosion on the filter bags. Figure 6 The filter bags tested were those that had been damaged by acid and alkali corrosion. It can be seen that the average value of the sensing signal fluctuates around 3Ω.

[0097] In this technical solution, the degree of damage to the filter bag is determined based on the sensor signal. The mathematical expression of the sensor signal and the number of damaged conductive polymer lines is as follows:

[0098]

[0099] Where ΔR is the sensing signal, n b Let ρ be the number of broken conductive polymer lines in the conductive grid, ρ be the conductivity of the conductive polymer line, L be the length of the conductive polymer line, n be the total number of conductive polymer lines in the conductive grid, and S be the total number of conductive polymer lines in the conductive grid. t This represents the cross-sectional area of ​​the conductive polymer lines in the conductive grid.

[0100] It should be noted that the sensing signal is the real-time resistance signal minus the background signal. Under the same normal operating conditions, the background signal remains unchanged. Therefore, the sensing signal is positively correlated with the real-time resistance signal. The real-time resistance signal is affected by the number of failed conductive polymer lines, and the aforementioned sensing signal is positively correlated with the number of failed conductive polymer lines in the conductive grid.

[0101] It should be noted that when determining the degree of failure of a dust collector filter bag, the sensor signal can be obtained by measuring the background signal and the real-time resistance signal. The conductivity of the conductive polymer wire, the length of the conductive polymer wire, the total number of conductive polymer wires in the conductive grid, and the cross-sectional area of ​​the conductive polymer wires in the conductive grid are known parameters. Therefore, the number of damaged conductive polymer wires in the conductive grid can be calculated according to the above formula, and then the degree of damage to the filter bag can be calculated.

[0102] For example, refer to Figure 7 , Figure 7 Characterizing the relationship between the sensing signal and the number of failed conductive PMMA polymer wires, by... Figure 7 It can be seen from calculations and actual measurements that the sensing signal of the PMMA filter bag containing the conductive mesh is linearly related to the number of failed conductive PMMA polymer lines. The equivalent circle diameter of the damaged area is (n b -1)s, where s is the spacing between the conductive PMMA polymer lines. The difference between the actual measured sensor signal of the failed conductive PMMA polymer line and the calculated sensor signal of the failed conductive PMMA polymer line is within the allowable error range, indicating the rationality of the above formula. By calculating the above parameters, the number of damaged conductive polymer lines can be accurately determined, thereby achieving precise control over the degree of filter bag damage.

[0103] Thirdly, refer to Figure 9 This invention provides a method for preparing a dust collector filter bag, used for the dust collector filter bag described in the first aspect, comprising the following steps:

[0104] Step S210: Immerse the non-conductive polymer wire in conductive liquid adhesive, remove the polymer wire and dry it to obtain a conductive polymer wire;

[0105] For example, a single strand of polymer wire can be impregnated in a liquid adhesive containing a conductive substance, and the impregnated single strand of polymer wire can be wound to prepare a multi-strand conductive polymer wire.

[0106] Step S220: Use conductive polymer yarns and non-conductive polymer yarns to spin a conductive mesh; use conductive polymer yarns as radial or weft yarns, and spin them together with non-conductive polymer yarns to form a conductive mesh.

[0107] Step S230: Embed the conductive mesh into the bag body.

[0108] refer to Figure 1 , Figure 1 A schematic diagram illustrating the fabrication of the polymer wire, conductive mesh, and bag body, exemplarily provided. (Refer to...) Figure 1 -(a) A single-strand polymer wire is impregnated in a liquid adhesive containing a conductive material, and the impregnated single-strand polymer wire is wound to prepare a multi-strand conductive polymer wire. For example, refer to... Figure 1 -(b) Using a needle-punching method, a conductive mesh is embedded into the surface or shallow surface of the filter bag during the filter bag production stage, for example, see reference. Figure 1 -(c), the direction indicated by the arrow is the arrangement direction of the conductive polymer lines, which can be arranged radially or laterally to prepare a conductive mesh.

[0109] In this technical solution, the conductive liquid adhesive is one of graphene liquid adhesive, silver-containing liquid adhesive, carbon-containing liquid adhesive, and copper-containing liquid adhesive. For example, a single-strand polymer wire of the same material as the filter bag is immersed in a liquid adhesive containing conductive substances, such as graphene liquid adhesive, silver-containing liquid adhesive, carbon-containing liquid adhesive, or copper-containing liquid adhesive, and the immersed single-strand polymer wire is wound to prepare a multi-strand conductive polymer wire.

[0110] In this technical solution, the conductive mesh is embedded into the bag body by one of the following methods: needle punching, hydroentangling, melt blowing, and coating. For example, the conductive mesh can be embedded into the surface or shallow surface of the filter bag during the filter bag production stage by methods such as needle punching, hydroentangling, melt blowing, and coating.

[0111] Example 1: Monitoring of filter bag breakage under mechanical damage

[0112] A single strand of polymethyl methacrylate (PMMA) polymer wire was impregnated in graphene liquid adhesive, and the impregnated single strand of PMMA polymer wire was wound to prepare multi-strand conductive PMMA polymer wire (hereinafter referred to as conductive PMMA polymer wire); the conductive PMMA polymer wire was spun into a conductive mesh as radial wire.

[0113] refer to Figure 2 Thermogravimetric analysis and strength tests were performed on conductive meshes and PMMA filter bags containing conductive PMMA polymer lines, which determined that the conductive polymer lines in the conductive mesh failed before the filter bags.

[0114] The conductive mesh is embedded into the shallow surface of the PMMA filter bag during the filter bag production stage using a needle punching method. The two ends of the radially arranged conductive PMMA polymer wires are connected together using conductive PMMA polymer wires. The two ends of a single filter bag are connected to a pair of endpoints of a multi-channel digital multimeter, and the two ends of multiple filter bags are connected to the other endpoints of the multi-channel digital multimeter.

[0115] refer to Figure 3 After the PMMA filter bag containing the conductive mesh is installed in the bag filter, the resistance signal of the conductive mesh is measured as a background signal under multiple states, such as the standby state of the bag filter, the vibration state of the dust collector, the vibration + pulse cleaning state of the dust collector, and the vibration + dust holding + pulse cleaning state of the dust collector.

[0116] The resistance signal of the conductive grid in each PMMA filter bag is monitored online. The measured resistance signal is subtracted from the background signal and used as the sensing signal. The characteristics of the sensing signal are analyzed to determine the status of the filter bag. Figure 4As shown, the dynamic increase of the sensing signal indicates that the filter bag (including the conductive mesh) has undergone geometric changes in the conductive polymer lines in the conductive mesh under mechanical stretching, and the filter bag may be about to break and leak; after a period of time, the sensing signal increases to a certain extent, indicating that the conductive polymer lines in the conductive mesh have failed and the filter bag has broken.

[0117] The following describes in detail, using the PMMA filter bag in Example 1, embodiments of the method of the present invention under the influence of factors other than mechanical damage.

[0118] Example 2: Monitoring of filter bag breakage under thermal damage

[0119] The resistance signal of the conductive grid in each PMMA filter bag is monitored online. The measured resistance signal is subtracted from the background signal and used as the sensing signal. The characteristics of the sensing signal are analyzed to determine the status of the filter bag. For example... Figure 5 As shown, the dynamic increase of the sensing signal indicates that the filter bag (including the conductive mesh) has undergone geometric changes in the conductive polymer lines in the conductive mesh due to thermal damage, and the filter bag may be about to break and leak; after a period of time, the sensing signal increases to a certain extent compared with the initial signal, indicating that the conductive polymer lines in the conductive mesh have failed and the filter bag has broken.

[0120] Example 3: Monitoring of filter bag damage under acid and alkali corrosion

[0121] The resistance signal of the conductive grid in each PMMA filter bag is monitored online. The measured resistance signal is subtracted from the background signal and used as the sensing signal. The characteristics of the sensing signal are analyzed to determine the status of the filter bag. Figure 6 As shown, the sensing signal has increased compared to the initial signal, indicating that the conductive polymer wires in the conductive mesh have failed and the filter bag has been damaged.

[0122] In this embodiment, after the PMMA filter bag detects the background signal, it is artificially damaged by acid and alkali corrosion and then reinstalled into the baghouse dust collector. Therefore, no dynamic increase in the sensor signal was observed in this embodiment. This embodiment also demonstrates that the filter bag leak detection method proposed in this invention can identify filter bags that are already damaged before the baghouse dust collector is officially started.

[0123] Referring to the above embodiments, the leak detection method provided by the present invention is applicable to the leakage caused by various factors such as mechanical damage, thermal damage, and chemical corrosion of filter bags of various materials, with an accuracy rate of more than 99%.

[0124] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0125] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0126] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0127] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0128] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for leak detection of dust collector filter bags, characterized in that, The dust collector filter bag includes: The bag is used to filter dust; A conductive mesh is disposed on the bag body. The conductive mesh includes conductive polymer lines and non-conductive polymer lines. The conductive polymer lines are uniformly arranged radially or uniformly arranged latitudinally. The conductive polymer lines and the non-conductive polymer lines are arranged in an intersecting pattern. All conductive polymer wires are arranged in the same direction; Under the influence of external factors, the conductive polymer wire breaks first relative to the bag body or the conductive polymer wire breaks at the same time as the bag body; The method for leak detection of the dust collector filter bag includes the following steps: When the dust collector filter bag is in normal working condition, the resistance signal of the dust collector filter bag is obtained as a background signal; When the dust collector filter bag is in working condition, the real-time resistance signal of the dust collector filter bag is acquired; The real-time resistance signal minus the background signal is used as the sensing signal, and the damage state of the filter bag is determined based on the sensing signal. When the sensor signal is 0, the filter bag is in normal working condition; When the sensor signal is non-zero, the filter bag is in a state of impending or already damaged. The degree of damage to the filter bag is determined based on the sensing signal. The mathematical expression of the sensing signal and the number of damaged conductive polymer lines is as follows: ； in, Let n be the sensing signal. b The number of broken conductive polymer lines in the conductive grid is given by ρ, where ρ is the conductivity of the conductive polymer line, L is the length of the conductive polymer line, n is the total number of conductive polymer lines in the conductive grid, and S is the total number of conductive polymer lines in the conductive grid. t The cross-sectional area of ​​the conductive polymer line in the conductive mesh.

2. The leak detection method for a dust collector filter bag according to claim 1, characterized in that, The conductive polymer wire and the bag body are made of the same material.

3. The leak detection method for a dust collector filter bag according to claim 1, characterized in that, include: A signal detection instrument is connected to the conductive mesh and is used to detect the resistance signal of the conductive mesh.

4. The leak detection method for a dust collector filter bag according to claim 1, characterized in that, If the sensing signal is less than a preset value, the filter bag is about to break. If the sensing signal is greater than or equal to the preset value, the filter bag is damaged. The preset value is related to the resistance of the dust collector filter bag.

5. The leak detection method for a dust collector filter bag according to claim 1 further includes a method for preparing the dust collector filter bag, the preparation method comprising the following steps: A non-conductive polymer wire is immersed in a conductive liquid adhesive, and the polymer wire is then removed and dried to obtain a conductive polymer wire. A conductive mesh is spun using the conductive polymer yarn and the non-conductive polymer yarn; The conductive mesh is embedded into the bag body.

6. A leak detection method for a dust collector filter bag according to claim 5, characterized in that, The conductive liquid adhesive is one of graphene liquid adhesive, carbon-containing liquid adhesive, silver-containing liquid adhesive, and copper-containing liquid adhesive.

7. A leak detection method for a dust collector filter bag according to claim 5, characterized in that, The method for embedding the conductive mesh into the bag body is one of the following: needle punching, hydroentangling, meltblowing, and coating.

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