A detection system for detecting damage of filter bag by relative air pressure method

Abstract

A detection system for detecting filter bag damage by relative air pressure method, comprising a filter bag, a base and a cage, the base is provided with a perforation, and one end of the cage is fixed in the single perforation; the cage comprises a top cover, a ring bottom beam and a plurality of cage vertical ribs, the plurality of cage vertical ribs are uniformly distributed on the circumferential side of the top cover and the ring bottom beam, and the top cover, the ring bottom beam and the cage vertical ribs form a cylindrical grid structure; a plurality of interval openings are formed between the cage vertical ribs in pairs, at least one optical fiber is arranged in each interval opening, and a plurality of optical gratings are uniformly arranged on the optical fiber; the optical fiber is parallel to the cage vertical rib, and both ends of the optical fiber are fixed on the top cover and the ring bottom beam respectively; the filter bag is a hollow bag body with an open end, and the bag body covers the plurality of interval openings and the optical fiber to form an inflation cavity; in application, the inflation and expansion of the filter bag pushes the optical fiber to deform, causes the wavelength of the optical grating to change, obtains the deformation curve, and can reflect the damage of the filter bag. Therefore, the detection result of the design is accurate.

Description

Technical Field

[0001] This invention relates to a filter bag damage detection system, belonging to the field of dust collector leak detection equipment, and particularly to a filter bag damage detection system using the relative air pressure method. Background Technology

[0002] With the rapid improvement of industrial levels, air pollution has become more severe. Industrial smoke and dust, represented by coal-fired power plants and waste incineration, are one of the important factors in the formation of atmospheric particulate matter and smog. Therefore, controlling industrial smoke and dust emissions is the main means to solve smog and improve air quality. In practical engineering applications, filter bags can filter exhaust gas and are one of the main means to effectively control industrial smoke and dust emissions.

[0003] During use, filter bags are damaged to varying degrees by high-temperature gases, acidic and alkaline substances, dust, water vapor, and physical weathering and abrasion generated in industrial production, affecting their filtration performance. Regular inspection of filter bags is necessary. However, the location and extent of damage vary depending on the factors, thus requiring assessment of filter bag wear.

[0004] Patent application CN201110432212.3, filed on December 21, 2011, discloses a filter bag damage detection device for baghouse dust collectors. This device places a detection optical fiber at the filter bag opening during the air filtration process. The detected light signal is converted into an amplified electrical signal by a silicon photodiode in a photodetector. The data is then processed and analyzed, with the voltage value reflecting the dust concentration inside the filter bag, thus determining whether the filter bag is damaged. While this design can detect filter bag damage, it cannot accurately identify the location and extent of the damage during the detection process, leading to discrepancies between the final detection results and the actual situation, resulting in low accuracy.

[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 shortcomings and problems of low accuracy of detection results in the existing technology, and to provide a detection system for detecting filter bag damage by relative air pressure method with higher accuracy of detection results.

[0007] To achieve the above objectives, the technical solution of the present invention is: a detection system for detecting filter bag damage by relative air pressure method, the detection system comprising a filter bag, a base and at least two cages, the base having at least two perforations, and one end of each cage being fixed in a single perforation;

[0008] The cage frame includes a top cover, a bottom ring beam, and several cage vertical ribs. The several cage vertical ribs are evenly distributed on the circumferential side of the top cover and the bottom ring beam, forming a cylindrical grid structure together with the top cover and the bottom ring beam.

[0009] The cage vertical ribs are arranged in pairs with each other to form multiple gaps. Each gap contains at least one optical fiber, and multiple gratings are evenly arranged on the optical fiber. The optical fiber is parallel to the cage vertical ribs and its two ends are fixed to the top cover and the bottom beam, respectively.

[0010] The filter bag is a hollow bag with one open end. Its sealed end passes through the bottom beam and contacts the top cover. Its open end passes through a perforation and is fixed to the base. The bag body covers multiple spaced openings and forms an air-filled cavity with the optical fiber.

[0011] The top cover is a disc, the bottom beam is a circle, and the several cage vertical ribs are slender strips. One end of the several cage vertical ribs is connected to the bottom side of the top cover, and the other end passes through the bottom beam and extends outward. The outward-extending end is fixed in the perforation.

[0012] One end of the optical fiber is connected to the side of the top cover to form a first fixed end, and the other end of the optical fiber is fixed to the bottom beam to form a second fixed end and then extends outward to form a free end.

[0013] The number of cage frames is ≥5, and they are evenly distributed on the base. The number of perforations is the same as that of the cage frames.

[0014] The number of slots in a single cage is ≤6.

[0015] The number of optical fibers in a single slot is ≤3.

[0016] The number of gratings is 8 to 20.

[0017] An annular fastener is provided at the perforation on the outer side of the opening end of the base. Its inner diameter is the same as the diameter of the perforation, and it is used to press the opening end of the filter bag tightly onto the base.

[0018] The ring-shaped fastener is a ring-shaped magnetic fastener.

[0019] A piston pin is provided inside the perforation. The piston pin includes a piston body and a piston shaft connected vertically. The piston body is a disc with an outer diameter that matches the inner diameter of the cage. The piston shaft is a cylinder with a diameter smaller than that of the piston body. A piston perforation is provided at the axis of the piston body and the piston shaft that is interconnected.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] 1. The present invention provides a detection system for detecting filter bag damage using a relative pressure method, comprising a filter bag, a base, and at least two cage frames. The base has at least two perforations, and one end of each cage frame is fixed within a single perforation. Each cage frame includes a top cover, a bottom ring beam, and several vertical ribs. The vertical ribs are evenly distributed on the circumferential sides of the top cover and the bottom ring beam, forming a cylindrical grid structure together with the top cover and the bottom ring beam. Multiple spacing openings are formed between the vertical ribs in pairs, and at least one optical fiber is installed within each spacing opening. Multiple gratings are evenly distributed on the optical fiber. The optical fiber is parallel to the vertical ribs, and its two ends are... The filter bag is fixed to the top cover and the bottom beam. It is a hollow bag with one open end. The sealed end passes through the bottom beam and contacts the top cover, while the open end passes through a perforation and is fixed to the base. The bag covers multiple spaced openings, forming an air-filled cavity with the optical fiber. In application, this design utilizes the expansion of the filter bag to deform the optical fiber, causing a change in the wavelength of the grating. The deformation curve is then obtained, reflecting the damage to the filter bag. By establishing a standard part and the part to be tested, the deformation curves are compared to confirm the specific damaged part and state of the filter bag, resulting in a relatively accurate detection result. Therefore, this invention can not only detect filter bags but also provides highly accurate results.

[0022] 2. In the relative pressure method for detecting filter bag damage according to the present invention, the top cover is a disc shape, the bottom beam is a circle shape, and several cage vertical ribs are slender strips. One end of each cage vertical rib is connected to the bottom side of the top cover, and the other end passes through the bottom beam and extends outward, with the outward-extending end fixed in a perforation. In application, this design, through the grid structure of the cage frame, obtains a larger and more even filter bag expansion area, avoiding the filter bag's inability to expand or insufficient expansion due to an overly dense cage frame structure, thus affecting the accuracy of the grating wavelength change. Therefore, the detection results of the present invention are more accurate.

[0023] 3. In the relative pressure method for detecting filter bag damage according to the present invention, one end of the optical fiber is connected to the side of the top cover to form a first fixed end, and the other end of the optical fiber is fixed to the bottom beam to form a second fixed end, then extends outward through a through-hole to form a free end. In application, the area between the two fixed ends of the optical fiber covers the gap, allowing the filter bag to fully contact the optical fiber when it expands, ensuring that the expansion of the filter bag is consistent with the change in grating wavelength, thereby ensuring the accuracy of the detection results. Therefore, the detection results of the present invention have high accuracy. Attached Figure Description

[0024] Figure 1 This is one of the structural schematic diagrams of the present invention.

[0025] Figure 2 This is the second structural schematic diagram of the present invention.

[0026] Figure 3 This is a schematic diagram showing the relative positions of the annular fixing member in this invention.

[0027] Figure 4 This is a schematic diagram of the cage structure in this invention.

[0028] Figure 5 This is a schematic diagram showing the relative positions of the optical fibers in this invention.

[0029] Figure 6 This is a schematic diagram showing the relative positions of the first fixed end, the second fixed end, and the free end in this invention.

[0030] Figure 7 This is a schematic diagram showing the relative positions of the filter bags in this invention.

[0031] Figure 8 This is a schematic diagram of the structure of the grating in this invention.

[0032] Figure 9 This is a cross-sectional view of the piston pin in this invention.

[0033] In the diagram: Filter bag 1, sealing end 11, opening end 12, air filling chamber 13, base 2, perforation 21, annular fastener 22, cage frame 3, top cover 31, bottom ring beam 32, cage vertical rib 33, cylindrical grid structure 34, spacer opening 35, optical fiber 4, first fixed end 41, second fixed end 42, free end 43, grating 5, piston pin 6, piston body 61, piston shaft 62, piston perforation 63. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] See Figure 1 — Figure 9A detection system for detecting filter bag damage using a relative pressure method, the detection system comprising a filter bag 1, a base 2 and at least two cages 3, wherein the base 2 has at least two perforations 21 and one end of each cage 3 is fixed in a single perforation 21;

[0036] The cage frame 3 includes a top cover 31, a bottom ring beam 32 and several cage vertical ribs 33. The several cage vertical ribs 33 are evenly distributed on the circumferential side of the top cover 31 and the bottom ring beam 32, and together with the top cover 31 and the bottom ring beam 32, they form a cylindrical grid structure 34.

[0037] The cage vertical ribs 33 are arranged in pairs with each other to form multiple gaps 35. Each gap 35 contains at least one optical fiber 4, and multiple gratings 5 ​​are evenly arranged on the optical fiber 4. The optical fiber 4 is parallel to the cage vertical ribs 33, and its two ends are fixed to the top cover 31 and the bottom beam 32 respectively.

[0038] The filter bag 1 is a hollow bag with one open end. Its sealed end 11 passes through the bottom beam 32 and contacts the top cover 31. Its open end 12 passes through the perforation 21 and is fixed to the base 2. The bag body covers multiple spacers 35 and forms an air-filled cavity 13 with the optical fiber 4.

[0039] The top cover 31 is a disc, the bottom beam 32 is a circle, and the several cage vertical ribs 33 are slender strips. One end of the several cage vertical ribs 33 is connected to the side bottom surface of the top cover 31, and the other end passes through the bottom beam 32 and extends outward. The outward-extending end is fixed in the perforation 21.

[0040] One end of the optical fiber 4 is connected to the side of the top cover 31 to form a first fixed end 41. The other end of the optical fiber 4 is fixed to the bottom beam 32 to form a second fixed end 42 and then extends outward to form a free end 43.

[0041] The number of cage frames 3 is ≥ 5, and they are evenly distributed on the base 2. The number of perforations 21 is the same as that of cage frames 3.

[0042] The number of intervals 35 within a single cage 3 is ≤ 6.

[0043] The number of optical fibers 4 in a single slot 35 is ≤3.

[0044] The number of gratings 5 ​​is 8 to 20.

[0045] An annular fastener 22 is provided on the base 2 at the perforation 21 located outside the opening end 12. Its inner diameter is the same as the diameter of the perforation 21, and it is used to press the opening end 12 of the filter bag 1 onto the base 2.

[0046] The annular fastener 22 is an annular magnetic fastener.

[0047] A piston pin 6 is provided inside the perforation 21. The piston pin 6 includes a piston body 61 and a piston shaft 62 connected vertically. The piston body 61 is a disc with an outer diameter that is the same as the inner diameter of the cage 3. The piston shaft 62 is a cylinder with a diameter smaller than that of the piston body 61. A piston perforation 63 is provided at the axis of the piston body 61 and the piston shaft 62, which are mutually penetrating.

[0048] The principle of this invention is explained as follows:

[0049] In this invention, since the fiber density of different areas of the filter bag 1 may vary to some extent during the manufacturing process, but the difference will not be too large, the deformation curve of the filter bag 1 after expansion reflected by the wavelength of the grating 5 may vary, but the change pattern is basically the same. If the deformation curve of the test piece and the standard piece are significantly different, it can be determined that the test piece is damaged or blocked. If the deformation curves are slightly different but the change pattern is basically the same, it can be determined that the test piece itself may have differences, thereby eliminating the error in the final test result caused by differences in the manufacturing process.

[0050] Example 1:

[0051] See Figure 1 — Figure 9 A detection system for detecting filter bag damage using a relative pressure method is disclosed. The system includes a filter bag 1, a base 2, and at least two cage frames 3. The base 2 has at least two perforations 21, and one end of each cage frame 3 is fixed within a single perforation 21. Each cage frame 3 includes a top cover 31, a bottom ring beam 32, and several vertical cage ribs 33. These vertical ribs 33 are evenly distributed on the circumferential sides of the top cover 31 and the bottom ring beam 32, forming a cylindrical grid structure 34 together with the top cover 31 and the bottom ring beam 32. Multiple slots 35 are formed in pairs parallel to each other. At least one optical fiber 4 is provided in each slot 35. Multiple gratings 5 ​​are evenly arranged on the optical fiber 4. The optical fiber 4 is parallel to the cage vertical rib 33, and its two ends are fixed to the top cover 31 and the bottom beam 32 respectively. The filter bag 1 is a hollow bag with one open end. Its sealed end 11 passes through the bottom beam 32 and contacts the top cover 31. Its open end 12 passes through the perforation 21 and is fixed to the base 2. The bag body covers multiple slots 35 and forms an air-filled cavity 13 with the optical fiber 4.

[0052] In this application, the testing system includes at least two cages 3. One cage 3 contains an unused filter bag 1 as a standard, while the other cages 3 contain filter bags 1 to be tested as test pieces. During the testing process, gas is supplied to the inflation chambers 13 of the standard and test pieces. As the gas increases, the filter bag 1 expands. The expanded bag is squeezed outward through the gap 35, which in turn pushes the optical fiber 4 set on the gap 35 to deform. The deformed optical fiber 4 causes the wavelength of the grating 5 to shift. Detecting this shift can determine the location of the grating 5 and its corresponding filter bag location. At the same time, it can also reflect the magnitude of the external force on that location, i.e., the magnitude of the impact force of the leaked gas (the gas flow rate per unit time), thus reflecting the damage or blockage of that location. By observing the wavelength change pattern of the grating 5, a corresponding deformation curve is generated. Any slight deformation will affect the wavelength of the grating 5 and be reflected in the deformation curve. By comparing the deformation curves of the standard and test pieces, the specific location and extent of damage to the filter bag 1 can be determined.

[0053] Example 2:

[0054] The basic content is the same as in Example 1, except that:

[0055] One end of the optical fiber 4 is connected to the side of the top cover 31 to form a first fixed end 41. The other end of the optical fiber 4 is fixed to the bottom beam 32 to form a second fixed end 42 and then extends outward through the through hole 21 to form a free end 43.

[0056] In the application, the initial wavelength of the grating 5 needs to be kept stable. Therefore, both ends of the optical fiber 4 need to be fixed to ensure that the expansion of the filter bag 1 is consistent with the wavelength change of the grating 5 after deformation. The free end 43 can be equipped with a corresponding demodulator to capture the signal of the grating 5 and plot its deformation curve for subsequent detection and comparison.

[0057] Example 3:

[0058] The basic content is the same as in Example 1, except that:

[0059] The number of cage frames 3 is ≥ 5, and they are evenly distributed on the base 2. The number of perforations 21 is the same as the number of cage frames 3.

[0060] In application, an excessive number of cages 3 or their uneven distribution will cause excessive airflow to overflow, which will then act on the optical fibers 4 on other cages 3, affecting the detection results.

[0061] Example 4:

[0062] The basic content is the same as in Example 1, except that:

[0063] The number of slots 35 in a single cage 3 is ≤ six; the number of optical fibers 4 in a single slot 35 is ≤ three.

[0064] In applications, too many gaps 35 will prevent the filter bag 1 from expanding sufficiently, thus making it impossible to obtain an accurate deformation curve; while too many optical fibers 4 will also limit the expansion of the filter bag 1, affecting the accuracy of the acquired data.

[0065] Example 5:

[0066] The basic content is the same as in Example 1, except that:

[0067] The number of gratings 5 ​​is 8 to 20.

[0068] In application, the number of gratings 5 ​​is related to the area to be detected in filter bag 1, which directly affects the accuracy of the deformation curve. If the number is small, the area reflected by the wavelength change of grating 5 will be large, and vice versa. Therefore, it is necessary to set them reasonably.

[0069] Example 6:

[0070] The basic content is the same as in Example 1, except that:

[0071] An annular fastener 22 is provided on the base 2 at the perforation 21 located outside the opening end 12. Its inner diameter is the same as the diameter of the perforation 21, and it is used to press the opening end 12 of the filter bag 1 onto the base 2.

[0072] Preferably, the annular fixing member 22 is an annular magnetic suction member.

[0073] In application, the annular fastener 22 can fix the open end 12 of the filter bag 1 to prevent the bag opening from shifting during the inflation process; while the annular magnetic suction can achieve this effect conveniently and quickly, which is beneficial to improving detection efficiency.

[0074] Example 7:

[0075] The basic content is the same as in Example 6, except that:

[0076] See Figure 9 A piston pin 6 is provided in the perforation 21. The piston pin 6 includes a piston body 61 and a piston shaft 62 connected vertically. The piston body 61 is a disc body with an outer diameter that is the same as the inner diameter of the cage 3. The piston shaft 62 is a cylinder. A piston perforation 63 is provided at the axis of the piston body 61 and the piston shaft 62.

[0077] Preferably, the number of piston pins 6 is the same as the number of cages 3.

[0078] In application, the sealed end 11 of the filter bag 1 is first inserted into the cage 3, and then the open end 12 is fixed to the base by the annular fastener 22. At this time, the bag body of the filter bag 1 will collapse downward due to gravity and produce wrinkles. Then the piston pin 6 extends inward through the perforation 21 to stretch the filter bag 1 so that it can better adhere to the cage 3. Then the piston pin 6 extends outward until the piston body 61 overlaps with the perforation 21, which plays a similar role to a piston seal. At this time, the piston pin 6 can better fix and seal the filter bag 1, and the piston perforation 63 set inside can be used as a gas input channel for gas input.

[0079] 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 detection system for detecting filter bag damage using a relative pressure method, characterized in that: The detection system includes a filter bag (1), a base (2) and at least two cages (3). The base (2) has at least two perforations (21), and one end of each cage (3) is fixed in a single perforation (21). The cage frame (3) includes a top cover (31), a bottom ring beam (32) and several cage vertical ribs (33). The several cage vertical ribs (33) are evenly distributed on the circumferential side of the top cover (31) and the bottom ring beam (32), and together with the top cover (31) and the bottom ring beam (32), they form a cylindrical grid structure (34). The cage vertical ribs (33) are parallel to each other and form multiple gaps (35). Each gap (35) contains at least one optical fiber (4). Multiple gratings (5) are evenly arranged on the optical fiber (4). The optical fiber (4) is parallel to the cage vertical ribs (33) and its two ends are fixed to the top cover (31) and the bottom beam (32) respectively. The filter bag (1) is a hollow bag with one end open. Its sealed end (11) passes through the bottom beam (32) and contacts the top cover (31). Its open end (12) passes through the perforation (21) and is fixed on the base (2). Its bag body covers multiple spacers (35) and forms an air-filled cavity (13) with the optical fiber (4). The top cover (31) is a disc, the bottom ring beam (32) is a circle, the several cage vertical ribs (33) are long and thin strips, one end of the several cage vertical ribs (33) is connected to the side bottom surface of the top cover (31), the other end passes through the bottom ring beam (32) and extends outward, and the outward extending end is fixed in the perforation (21). One end of the optical fiber (4) is connected to the side of the top cover (31) to form a first fixed end (41), and the other end of the optical fiber (4) is fixed to the bottom beam (32) to form a second fixed end (42) and then extends outward to form a free end (43). A piston pin (6) is provided inside the perforation (21). The piston pin (6) includes a piston body (61) and a piston shaft (62) connected vertically. The piston body (61) is a disc with an outer diameter that is the same as the inner diameter of the cage (3). The piston shaft (62) is a cylinder with a diameter smaller than that of the piston body (61). Piston perforations (63) are provided at the axis of the piston body (61) and the piston shaft (62). The number of piston pins (6) is the same as the number of cages (3). The piston pins (6) extend inward from the perforation (21) to stretch the filter bag (1).

2. The detection system for detecting filter bag damage using the relative pressure method according to claim 1, characterized in that: The number of cage frames (3) is ≥5 and they are evenly distributed on the base (2). The number of perforations (21) is the same as that of the cage frames (3).

3. The detection system for detecting filter bag damage using the relative pressure method according to claim 1, characterized in that: The number of gaps (35) in a single cage (3) is ≤6.

4. A detection system for detecting filter bag damage using the relative pressure method according to any one of claims 1-3, characterized in that: The number of optical fibers (4) in a single said spacer (35) is ≤3.

5. A detection system for detecting filter bag damage using the relative pressure method according to any one of claims 1-3, characterized in that: The number of gratings (5) is 8 to 20.

6. A detection system for detecting filter bag damage using the relative pressure method according to any one of claims 1-3, characterized in that: An annular fastener (22) is provided at the perforation (21) located outside the opening end (12) on the base (2). Its inner diameter is consistent with the diameter of the perforation (21) and is used to press the opening end (12) of the filter bag (1) onto the base (2).

7. The detection system for detecting filter bag damage using the relative pressure method according to claim 6, characterized in that: The annular fastener (22) is an annular magnetic fastener.

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