An old filter bag pressure type filter bag detection system

Abstract

A pressure-type filter bag detection system for used filter bags includes a first conveying platform, a cage, and an air pipe. The first conveying platform has a through hole, and the cage is vertically connected to the inner wall of the through hole. The cage is a cylindrical structure with openings at the top and bottom, and its shape matches that of the filter bag. Multiple sets of detection devices are axially arranged on the outer circumference of the cage. Each set of detection devices includes a detector, an optical fiber, and multiple gratings mounted on the optical fiber. Gratings are placed between adjacent reinforcing bars in the cage. The optical fiber is wound around the outer circumference of the cage, and the detector is connected to one end of the optical fiber. The air pipe is positioned relative to the upper end of the cage. This design can not only determine the degree of damage to the filter bag but also easily locate the position of the damage.

Description

Technical Field

[0001] This invention relates to a detection technology for used filter bags, belonging to the field of baghouse dust collector technology, and particularly to a pressure-type filter bag detection system for used filter bags. Background Technology

[0002] With the rapid advancement of industrialization, air pollution has intensified. Industrial smoke and dust from industries such as coal-fired power plants and waste incineration are significant contributors to particulate matter and smog formation. Therefore, controlling industrial smoke and dust emissions is a primary means of addressing smog and improving air quality. In practical engineering applications, baghouse dust collectors can filter exhaust gases, offering high dust removal efficiency and effective dust cleaning, making them a key tool for controlling industrial smoke and dust emissions. As the core component of a baghouse dust collector, the filter bag's condition directly affects the dust removal efficiency and lifespan of the entire system. Filter bags can be damaged to varying degrees under the influence of various factors. For example, excessively high-temperature gases emitted during industrial production can exceed the filter bag's temperature limit, leading to filter bag fatigue and affecting filtration performance. Acidic or alkaline substances in the emitted flue gas can corrode the filter bags. Immediately after emission, high-temperature water vapor condenses on the filter bag surface, corroding it. Simultaneously, dust in the flue gas combines with water on the filter bag, forming clumps that cannot be removed, thus affecting cleaning efficiency. During operation, filter bags require periodic air cleaning with a spray gun. Frequent cleaning and excessive contact between high-speed compressed gas and the filter bag accelerate the wear of the filter bag fabric fibers, causing deformation and physical fatigue.

[0003] To prevent the above situations, filter bags need to be repaired promptly after damage. While current detection technologies can detect filter bag damage, they fail to classify, rate, and repair the bags. For example, patent CN206342997U uses a gas flow detector to detect filter bag damage. Based on the detection of a sudden increase in gas flow in the gas guide tube due to filter bag damage or thinning, the control system stops detection after detecting the increased flow signal. This detection technology only detects the gas flow during filter bag operation and determines whether the filter bag is damaged, but it cannot further determine whether the filter bag meets the repair conditions. Therefore, although this patent detects filter bag damage, it does not further determine the extent of the damage. Patent CN200968897Y determines whether there are damaged filter bags in a single row of filter bags by measuring the pressure difference between the total pressure value of the gas in the outlet blowpipe of a single row of filter bags in a baghouse dust collector and the static pressure value of the gas in the housing. This filter bag monitoring solution determines the damage to the filter bag by detecting the pressure difference; however, this detection method cannot directly determine the extent of the filter bag damage.

[0004] After determining the extent of filter bag damage, repair is necessary. However, manually locating and repairing the damaged areas is labor-intensive and increases the difficulty of repair, thus reducing the efficiency of filter bag repair to some extent.

[0005] The information disclosed in this background section is intended only to enhance understanding of the overall background of this application and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to overcome the defects and problems of existing technologies that cannot determine the degree of filter bag damage and are inconvenient to locate the location of filter bag damage, and to provide a pressure-type filter bag detection system for old filter bags that can determine the degree of filter bag damage and conveniently locate the location of filter bag damage.

[0007] To achieve the above objectives, the technical solution of the present invention is: A pressure-type filter bag testing system for used filter bags includes a first conveying platform, a cage, and an air pipe. The first conveying platform has a through hole, and the inner wall of the through hole is vertically connected to the cage. The cage is a cylindrical structure with openings at the top and bottom, and the cage matches the shape of the filter bag. Multiple sets of testing devices are arranged axially on the outer circumferential surface of the cage. Each set of testing devices includes a detector, an optical fiber, and multiple gratings arranged on the optical fiber. A grating is arranged between two adjacent reinforcing bars in the cage. The optical fiber is wound around the outer circumferential surface of the cage. The detector is connected to one end of the optical fiber. The air pipe is arranged relative to the upper end of the cage.

[0008] The cage frame includes an annular plate and multiple reinforcing bars. The annular plate is fitted to the inner wall of the through hole, and the multiple reinforcing bars are circumferentially distributed on the lower side of the annular plate.

[0009] The detection device further includes a connecting column, which is connected to one of the steel bars in the cage. The optical fiber is connected to the outer circumferential surface of the plurality of steel bars. One end of the optical fiber passes through the connecting column and is connected to the detector, and the other end of the optical fiber passes through the connecting column and is connected to the light source.

[0010] The connecting column is a horizontally placed cylindrical structure. One end of the connecting column is connected to a steel bar in the cage frame, and the other end of the connecting column is located on the outside of the cage frame.

[0011] Multiple gratings are provided between adjacent steel bars.

[0012] A gap is provided between the annular plate and the upper end of the through hole.

[0013] A second conveying platform is provided above the first conveying platform. The output end of the second conveying platform is arranged relative to the through hole, and the input end of the second conveying platform is provided with a pressure cap, which matches the inner diameter of the filter bag.

[0014] The cap is a cylindrical structure with an opening at the top.

[0015] Multiple sets of the detection devices are equally spaced on the outer circumferential surface of the cage.

[0016] The shape of the trachea matches the through hole.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention relates to a pressure-type filter bag detection system for used filter bags. A light source emits light waves into an optical fiber, which then transports the filter bag into a through-hole. The open end of the filter bag fits over the through-hole, and an air pipe moves downwards and presses against the filter bag. The air pipe and filter bag are in a closed state. Gas is introduced into the filter bag through the air pipe, causing the filter bag to slowly expand. Once the filter bag is full of gas, it rests against a cage. When the gas passing through the filter bag comes into contact with the grating, it causes the grating to deform, resulting in a wavelength shift. This change is collected and analyzed by a detector. By comparing the values, the outflow rate of gas per unit time at each location on the filter bag can be determined. This outflow rate corresponds to the degree of damage. Simultaneously, the location of filter bag damage can be identified, facilitating repair. Therefore, this invention can determine the degree of filter bag damage and easily locate the location of filter bag damage.

[0018] 2. In this invention's pressure-type filter bag detection system, the cage frame is connected to multiple steel bars and annular plates, making the filter bag inflation process more stable. Optical fibers are fixed to the steel bars via connecting columns, allowing the fibers to pass through and their length to be adjusted in advance to accommodate cage frames of different diameters. Multiple gratings are installed between adjacent steel bars, enabling the detection of multiple sets of values ​​and resulting in more accurate readings. Therefore, this invention offers stable operation and high detection accuracy.

[0019] 3. In this invention, a pressure-type filter bag testing system for used filter bags utilizes a second conveying platform and a pressure cap. When the filter bag is conveyed to the through-hole, the pressure cap is conveyed into the filter bag via the second conveying platform. During ventilation, the pressure cap moves downwards within the filter bag under its own weight and the force of the gas, making the unfolding process of the filter bag smoother and more stable, resulting in more accurate test values. After testing, the filter bag falls back down, allowing the pressure cap to be removed for subsequent testing. Therefore, this invention is convenient to use, operates stably, and offers high testing accuracy. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention in its non-operating state.

[0021] Figure 2 This is a structural schematic diagram of the present invention in one working state.

[0022] Figure 3 This is a structural schematic diagram of another working state of the present invention.

[0023] Figure 4 This is a schematic diagram of the cage structure in this invention.

[0024] Figure 5 This is a cross-sectional schematic diagram of the optical fiber, reinforcing bar, and connecting column in this invention.

[0025] Figure 6 This is a schematic diagram of the pressure cap structure in this invention.

[0026] Figure 7 This is a schematic diagram of the filter bag and the cap in this invention.

[0027] In the diagram: 1. First conveying platform; 2. Cage frame; 21. Ring plate; 22. Reinforcing bar; 3. Through hole; 4. Air pipe; 5. Detection device; 51. Optical fiber; 52. Connecting column; 53. Detector; 6. Second conveying platform; 7. Pressure cover; 8. Filter bag. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] See Figures 1 to 7 A pressure-type filter bag testing system for old filter bags is disclosed. The testing system includes a first conveying platform 1, a cage frame 2, and an air pipe 4. The first conveying platform 1 has a through hole 3. The inner wall of the through hole 3 is vertically connected to the cage frame 2. The cage frame 2 is a cylindrical structure with openings at the top and bottom. The cage frame 2 matches the shape of the filter bag. Multiple sets of testing devices 5 are arranged axially on the outer circumferential surface of the cage frame 2. Each set of testing devices 5 includes a detector 53, an optical fiber 51, and multiple gratings arranged on the optical fiber 51. A grating is arranged between two adjacent reinforcing bars 22 in the cage frame 2. The optical fiber 51 is wound around the outer circumferential surface of the cage frame 2. The detector 53 is connected to one end of the optical fiber 51. The air pipe 4 is arranged relative to the upper end of the cage frame 2.

[0030] The cage frame 2 includes an annular plate 21 and a plurality of reinforcing bars 22. The annular plate 21 is fitted with the inner wall of the through hole 3, and the plurality of reinforcing bars 22 are circumferentially distributed on the lower side of the annular plate 21.

[0031] The detection device 5 further includes a connecting column 52, which is connected to one of the steel bars 22 in the cage 2. The optical fiber 51 is connected to the outer circumferential surface of the plurality of steel bars 22. One end of the optical fiber 51 passes through the connecting column 52 and is connected to the detector 53. The other end of the optical fiber 51 passes through the connecting column 52 and is connected to the light source.

[0032] The connecting column 52 is a horizontally placed cylindrical structure. One end of the connecting column 52 is connected to a steel bar 22 in the cage frame 2, and the other end of the connecting column 52 is located on the outside of the cage frame 2.

[0033] Multiple gratings are provided between adjacent steel bars 22.

[0034] A gap is provided between the annular plate 21 and the upper end of the through hole 3.

[0035] A second conveying platform 6 is provided above the first conveying platform 1. The output end of the second conveying platform 6 is arranged relative to the through hole 3. A pressure cap 7 is provided at the input end of the second conveying platform 6. The pressure cap 7 matches the inner diameter of the filter bag.

[0036] The pressure cap 7 is a cylindrical structure with an opening at the top.

[0037] Multiple sets of the detection devices 5 are equally spaced on the outer periphery of the cage 2.

[0038] The shape of the trachea 4 matches the through hole 3.

[0039] The principle of this invention is explained as follows: The grating used in this invention is existing technology, and its structure and principle will not be described in detail here. A conveyor belt is provided above the first conveying platform 1, and the conveying end of the conveyor belt is arranged relative to the through hole 3.

[0040] During operation, the filter bag 8 is first folded and placed on the conveyor belt, while the pressure cap 7 is placed on the second conveyor platform 6. When the filter bag 8 and the pressure cap 7 are conveyed to the through hole 3, the open end of the filter bag 8 is fitted onto the through hole 3, and the pressure cap 7 is located inside the filter bag 8. At this time, the air pipe 4 is moved downwards to press on the filter bag 8 and gas is introduced into the filter bag 8. The pressure cap 7 moves downwards under the force of the gas, and the filter bag 8 slowly bulges from top to bottom. When the pressure cap 7 moves to the bottom of the filter bag 8, the filter bag 8 is filled with gas and abuts against the steel bar 22. After the gas passes through the filter bag 8, it contacts the grating. The detector 53 collects and separates the values ​​of the grating deformation (i.e., wavelength offset) of all the gratings in each group of detection devices 5. After the test is completed, the air tube 4 is moved upward, and the filter bag 89 is moved from top to bottom, detached from the steel bar 22 and falls down. Then, the pressure cap 7 in the fallen filter bag 8 is taken out and placed on the second conveyor platform 6. At the same time, the next filter bag 8 to be tested is placed on the conveyor belt for the next filter bag 8 damage test.

[0041] Example 1: See Figures 1 to 7 A pressure-type filter bag testing system for used filter bags is disclosed. The testing system includes a first conveying platform 1, a cage frame 2, and an air pipe 4. The first conveying platform 1 has a through hole 3. The inner wall of the through hole 3 is vertically connected to the cage frame 2. The cage frame 2 is a cylindrical structure with openings at the top and bottom. The cage frame 2 matches the shape of the filter bag. Multiple sets of testing devices 5 are arranged axially on the outer circumferential surface of the cage frame 2. Each set of testing devices 5 includes a detector 53, an optical fiber 51, and multiple gratings arranged on the optical fiber 51. A grating is arranged between each pair of adjacent reinforcing bars 22 in the cage frame 2. The optical fiber 51 is wound around the outer circumferential surface of the cage frame 2. The detector 53 is connected to one end of the optical fiber 51. The air pipe 4 is arranged relative to the upper end of the cage frame 2. The cage frame 2 includes an annular plate 21 and multiple reinforcing bars 22. The annular plate 21 is fitted to the inner wall of the through hole 3. The multiple reinforcing bars 22 are circumferentially distributed on the lower side of the annular plate 21. The detection device 5 further includes a connecting column 52, which is connected to one of the reinforcing bars 22 in the cage 2. An optical fiber 51 is connected to the outer circumferential surface of multiple reinforcing bars 22. One end of the optical fiber 51 passes through the connecting column 52 and is connected to the detector 53, while the other end passes through the connecting column 52 and is connected to a light source. The connecting column 52 is a horizontally placed cylindrical structure. One end of the connecting column 52 is connected to one of the reinforcing bars 22 in the cage 2, and the other end is located on the outside of the cage 2. Multiple gratings are provided between adjacent reinforcing bars 22. A gap is provided between the annular plate 21 and the upper end of the through hole 3. The shape of the air pipe 4 matches the through hole 3.

[0042] In this embodiment, the filter bag 8 is first folded, and then the filter bag 8 and the pressure cap 7 are placed on the conveyor belt and the second conveyor platform 6 respectively. Then the conveyor belt and the second conveyor platform 6 are started, so that the filter bag 8 falls into the through hole 3 first, and the pressure cap 7 falls into the filter bag 8 later. Then the air pipe 4 is moved downward and pressed down on the filter bag 8. At this time, the air pipe 4 and the filter bag 8 are in a closed state, and then gas is introduced into the air pipe 4. After the gas is introduced into the filter bag 8, it causes the pressure cap 7 to move downwards. After the pressure cap 7 moves to the first group of detection devices 5, the gas passes through the filter bag 8 and comes into contact with the grating, causing the grating to deform. The pressure cap 7 continues to move downwards until it leaves the first group of detection devices 5. The detector 53 collects and processes the values ​​at each grating in the first group of detection devices 5 to obtain the corresponding gas flow rate value. Then, each gas flow rate value is compared to determine whether there are any individual gas flow rate values ​​that differ significantly from the other gas flow rate values. If there are some gas flow rate values ​​that differ significantly from the other gas flow rate values, it is determined that the filter bag corresponding to these gas flow rate values ​​is damaged. The greater the difference, the greater the degree of damage. Then, these gas flow rate values ​​are removed, and the other gas flow rate values ​​are summed and averaged. If there is no significant difference, all gas flow rate values ​​are summed and averaged. The pressure cap 7 continues to move downwards and contacts the second set of detection devices 5. The damage level of the filter bag 8 at that location and the corresponding average value are obtained according to the above operation. The above operation is repeated until the pressure cap 7 passes the last set of detection devices 5 and is located at the bottom of the filter bag 8. The detection data collection is completed. The average values ​​obtained by each set of detection devices 5 are compared to determine whether there are any individual average values ​​that differ significantly from the other average values. If there are some average values ​​that differ significantly from the other average values, it means that the filter bag 8 around the locations of these sets of detection devices 5 is damaged. The greater the difference, the greater the damage level of the filter bag 8 around the location. If there is no significant difference, it means that the overall damage level of the filter bag 8 is small. Finally, move the air tube 4 upwards so that it detaches from the filter bag 8. The filter bag 8 falls downwards from the cage 2. Remove the cap 7 from the fallen filter bag 8 and place it on the second conveyor platform 6. Repair the corresponding position of the filter bag 8 according to the degree of damage detected. At the same time, place the next filter bag 8 to be tested on the conveyor belt for the next filter bag 8 to be tested.

[0043] Example 2: The basic content is the same as in Example 1, except that: See Figure 6 The pressure cap 7 is a cylindrical structure with an opening at the top.

[0044] Example 3: The basic content is the same as in Example 1, except that: See Figure 4Multiple sets of the detection devices 5 are equally spaced on the outer periphery of the cage 2.

[0045] Example 4: The basic content is the same as in Example 1, except that: First, fold the filter bag 8. Then, place the filter bag 8 and the pressure cap 7 on the conveyor belt and the second conveyor platform 6 respectively. Start the conveyor belt and the second conveyor platform 6 so that the filter bag 8 falls into the through hole 3 first, followed by the pressure cap 7. Then, move the air pipe 4 downwards and press down on the filter bag 8. At this time, the air pipe 4 and the filter bag 8 are in a closed state. Then, gas is introduced into the air pipe 4. After the gas enters the filter bag 8, it drives the pressure cap 7 to move downwards. At this time, the filter bag 8 is fixed in the cage 2, and the pressure cap 7 moves from the top of the filter bag 8. Move to the bottom of filter bag 8 and support filter bag 8. At this time, filter bag 8 is filled with gas. After maintaining this for a period of time, when the airflow in filter bag 8 is relatively stable, the airflow passes through filter bag 8 and comes into contact with the grating, causing the grating to deform. The detector 53 collects and processes the values ​​(i.e. wavelength offset) at each grating in each group of detection devices 5 to obtain the corresponding gas flow value. After the gas flow at each point of filter bag 8 is collected, move the air pipe 4 upward so that the air pipe 4 is separated from filter bag 8, and filter bag 8 falls downward from cage 2.

[0046] The above description is only a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. Any equivalent modifications or changes made by those skilled in the art based on the content disclosed in the present invention should be included within the scope of protection set forth in the claims.

Claims

1. A pressure-type filter bag detection system for used filter bags, characterized in that: The detection system includes a first conveying platform (1), a cage (2), and an air pipe (4). The first conveying platform (1) has a through hole (3). The inner wall of the through hole (3) is connected to the cage (2) in the vertical direction. The cage (2) is a cylindrical structure with openings at the top and bottom. The cage (2) matches the shape of the filter bag. Multiple sets of detection devices (5) are arranged axially on the outer periphery of the cage (2). Each set of detection devices (5) includes a detector (53), an optical fiber (51), and multiple detectors arranged on the optical fiber (51). A grating is provided between each pair of adjacent steel bars (22) in the cage (2). The optical fiber (51) is wound around the outer circumference of the cage (2). The detector is connected to one end of the optical fiber (51). The air tube (4) is arranged relative to the upper end of the cage (2). The cage (2) includes an annular plate (21) and multiple steel bars (22). The annular plate (21) is in contact with the inner wall of the through hole (3). The multiple steel bars (22) are circumferentially distributed on the lower side of the annular plate (21). A second conveying platform (6) is provided above the first conveying platform (1). The output end of the second conveying platform (6) is arranged relative to the through hole (3). A pressure cap (7) is provided at the input end of the second conveying platform (6). The pressure cap (7) matches the inner diameter of the filter bag. The detector (53) is used to collect and process the values ​​at each grating in the detector (5) when the pressure cap (7) moves downward to leave the detector (5) to obtain the corresponding gas flow value. Then, each gas flow value is compared to determine whether there are individual gas flow values ​​that are significantly different from other gas flow values. If there are some gas flow values ​​that are significantly different from other gas flow values, it is determined that the filter bag corresponding to these gas flow values ​​is damaged. The greater the difference, the greater the degree of damage. Then, these gas flow values ​​are removed, and the other gas flow values ​​are summed and averaged. If there is no significant difference, sum all gas flow values ​​and take the average value. After the detection data is collected, compare the average values ​​obtained by each group of detection devices to determine whether there are any individual average values ​​that are significantly different from other average values. If there are some average values ​​that are significantly different from other average values, it means that the filter bags of these detection devices (5) are all damaged. The greater the difference, the greater the degree of damage to the filter bags. If there is no significant difference, it means that the overall degree of damage to the filter bags is small.

2. The pressure-type filter bag detection system for used filter bags according to claim 1, characterized in that: The detection device (5) further includes a connecting column (52), which is connected to one of the steel bars (22) in the cage (2). The optical fiber (51) is wound around the outer circumference of the plurality of steel bars (22). One end of the optical fiber (51) passes through the connecting column (52) and is connected to the detector. The other end of the optical fiber (51) passes through the connecting column (52) and is connected to the light source.

3. The pressure-type filter bag detection system for used filter bags according to claim 2, characterized in that: The connecting column (52) is a horizontally placed cylindrical structure. One end of the connecting column (52) is connected to a steel bar (22) in the cage frame (2), and the other end of the connecting column (52) is located on the outside of the cage frame (2).

4. The pressure-type filter bag detection system for used filter bags according to claim 2, characterized in that: Multiple gratings are provided between adjacent steel bars (22).

5. The pressure-type filter bag detection system for used filter bags according to claim 1, characterized in that: A gap is provided between the annular plate (21) and the upper end of the through hole (3).

6. The pressure-type filter bag detection system for used filter bags according to claim 1, characterized in that: The pressure cap (7) is a cylindrical structure with an opening at the top.

7. The pressure-type filter bag detection system for used filter bags according to claim 1, characterized in that: Multiple sets of the detection devices (5) are equally spaced on the outer periphery of the cage (2).

8. The pressure-type filter bag detection system for used filter bags according to claim 1, characterized in that: The shape of the trachea (4) matches the through hole (3).

Images