A comparison filter bag detection system

Abstract

A comparative filter bag detection system includes an outer air chamber, a ventilation cage, and a movable cylinder arranged sequentially from the outside to the inside. The outer air chamber includes a side cylinder, a top cover, a bottom cover, an inner cavity, and an air pipe. The ventilation cage includes a top ring, side walls, and a bottom opening. The side walls have ventilation structures connecting the inner cavity and the inner cavity. The movable cylinder includes a hollow upper cylinder and a lower movable disc. The side walls of the lower movable disc have multiple air holes communicating with its inner cavity. The top surface of the lower movable disc is aligned with the bottom opening of the upper hollow cylinder. The center of the top surface of the lower movable disc is connected to a gas flow meter via a detection tube. The upper hollow cylinder drives the lower movable disc to reciprocate up and down along the central axis of the side walls. This design not only accurately detects damage to old filter bags but also has high detection efficiency and is easy to operate.

Description

Technical Field

[0001] This invention relates to a filter bag detection technology, belonging to the field of filter bag detection, and particularly to a comparative filter bag detection system. 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 the formation of particulate matter and smog. 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 one of the main methods for effectively controlling industrial smoke and dust emissions.

[0003] Currently, filter bags are the core component of baghouse dust collectors, and their condition directly affects the dust collection efficiency and service life of the dust collector. Filter bags used for filtering high-temperature exhaust gases generally include Meta-Tas fiber, polyphenylene sulfide fiber, polyimide fiber, polytetrafluoroethylene fiber, or glass fiber. Meta-Tas fiber has good high-temperature resistance and strong acid and alkali resistance, but fiber hydrolysis needs to be considered under high-temperature conditions. Polyphenylene sulfide fiber has good temperature resistance and excellent acid and alkali resistance, but its toughness is poor, and it is susceptible to oxidation under high-temperature conditions. Polyimide fiber has high tensile strength, excellent heat resistance, flame retardancy, and acid resistance, but alkalis have a significant corrosive effect on this fiber, and it is prone to hydrolysis under high temperature and humidity conditions. Polytetrafluoroethylene fiber is resistant to high temperatures, acids and alkalis, and oxidation, but its high price limits its widespread use. Glass fiber, while resistant to high temperatures and relatively inexpensive, has low strength and folding endurance, which limits the filtration velocity. In comparison, aramid fibers have excellent properties such as ultra-high strength, high temperature resistance, and acid and alkali resistance, and have a long life cycle. Therefore, aramid needle-punched felt filter bags are currently the main type of filter bags.

[0004] Although aramid needle-punched felt filter bags have excellent performance, they can still break during actual use. The reasons include:

[0005] Firstly, the high-temperature gases emitted during industrial production are too high, exceeding the temperature limit that the filter bags can withstand, causing the filter bags to break and affecting their filtration performance.

[0006] Secondly, the flue gas contains acidic and alkaline substances, which can cause a certain degree of corrosion to the filter bags. The moment the flue gas is emitted, the high-temperature water vapor comes into contact with the surface of the filter bags and causes condensation, which corrodes the filter bags. At the same time, the dust in the flue gas combines with the water on the filter bags to form clumps that cannot be removed, thus affecting the filtration effect.

[0007] Third, the cleaning method can also cause damage to the filter bag. During operation, the filter bag needs to be cleaned with a spray gun every once in a while. Due to the frequent cleaning, the high-speed compressed gas or liquid comes into excessive contact with the filter bag body, which accelerates the wear of the filter bag fabric fibers and causes the filter bag body to break.

[0008] Once the filter bag is damaged, it must be repaired or replaced in time. Otherwise, the filtration performance of the filter bag will be greatly reduced, and dust-laden flue gas will be discharged into the atmosphere, resulting in excessive emissions and air pollution. At the same time, the high-temperature gas emitted by the filter bag will become a safety hazard and cause additional losses to the factory.

[0009] Therefore, filter bags need to be inspected after three to four years of use for timely replacement. At this time, considering the cost of use, if the used filter bags can be accurately inspected to determine the extent and location of damage, severely damaged filter bags can be replaced, while those with minor damage can be recycled and repaired, which can effectively improve the utilization efficiency of filter bags and save factory costs.

[0010] However, existing filter bag testing mainly focuses on quality inspection of newly installed and unused filter bags, lacking specialized damage inspection for the characteristics of older filter bags.

[0011] 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

[0012] The purpose of this invention is to overcome the defects and problems of existing technologies that cannot detect damage to old filter bags, and to provide a comparative filter bag detection system that can detect damage to old filter bags.

[0013] To achieve the above objectives, the technical solution of the present invention is: a comparison-type filter bag detection system, comprising an external air chamber, an air cage and a movable cylinder, wherein the external air chamber includes an air chamber side cylinder and an air chamber top cover and an air chamber bottom cover that are sealed to its top and bottom, the air chamber top cover, the air chamber side cylinder and the air chamber bottom cover together form an internal air chamber cavity, and an air chamber pipe communicating with the internal air chamber cavity is provided on the cylinder wall of the air chamber side cylinder;

[0014] The ventilation cage includes a cage side wall and a cage top ring and a cage bottom opening connected to its two ends. The top cover of the air chamber has a cover opening in the middle. The cage bottom opening is connected to the top surface of the bottom cover of the air chamber. One end of the cage side wall is connected to the cage bottom opening. The other end of the cage side wall passes through the inner cavity of the air chamber and the cover opening in sequence and is connected to the cage top ring. The cage top ring is set higher than the top cover of the air chamber. A ventilation structure connecting the inner cavity of the cage and the inner cavity of the air chamber is provided on the cage side wall.

[0015] The movable cylinder includes an upper hollow cylinder and a lower movable disc; the upper hollow cylinder is a hollow structure with openings at both ends, and the lower movable disc is a hollow structure with an inner cavity inside. Multiple air holes communicating with the inner cavity are opened on the side circumference of the lower movable disc. The bottom and top surfaces of the lower movable disc are sealed. The perimeter of the top surface of the lower movable disc is aligned with the bottom opening of the upper hollow cylinder. The top opening of the upper hollow cylinder is higher than the top ring of the cage. The middle of the top surface of the lower movable disc is connected to the bottom of a detection tube. The top of the detection tube is connected to a gas flow meter. The gas flow meter passes sequentially through the detection tube, the inner cavity of the disc, the air holes, and the ventilation structure before connecting to the inner cavity of the gas chamber.

[0016] The lower movable plate is located inside the cage side enclosure, and the upper hollow cylinder drives the lower movable plate to move up and down along the central axis of the cage side enclosure.

[0017] There are two chamber air tubes, one located on one side of the chamber side tube and the other located on the other side of the chamber side tube.

[0018] The top of the detection tube is positioned below the top opening, and both the detection tube and the gas flow meter are located inside the upper hollow cylinder.

[0019] The cage side enclosure includes multiple cage vertical rods, all of which are parallel to each other in pairs. Adjacent cage vertical rods are sandwiched together to form a rod gap, which is the ventilation structure. All cage vertical rods are evenly arranged along the same circumference. The top of all cage vertical rods is connected to the bottom of the cage top ring, and the bottom ends of all cage vertical rods together form a cage bottom opening. At this time, the bottom ends of all cage vertical rods are connected to the top surface of the air chamber bottom cover.

[0020] The cage side enclosure includes a side enclosure body and multiple side enclosure through holes, which are ventilation structures.

[0021] The ventilation cage contains a filter bag to be monitored. The filter bag includes a bag sidewall and a bag bottom and a bag top connected to its two ends. The bag bottom is attached to the cage bottom opening located at its bottom, and the bag top opening is connected to the cage top ring. The bag sidewall extends vertically, and the outer wall of the bag sidewall is attached to the inner wall of the cage sidewall. The movable cylinder slides up and down along the inner wall of the bag sidewall. The inner cavity of the filter bag is connected to the air chamber cavity after passing through the bag sidewall and the ventilation structure in sequence.

[0022] The diameter of the bag top opening is the same as the diameter of the bag side circumference, and the diameter of the bag top opening is smaller than the diameter of the cage top ring; the connection between the bag top opening and the cage top ring means that the bag top opening is turned outward and fitted onto the ring body of the cage top ring.

[0023] The cross-sectional shapes of the cage sidewalls, bag sidewalls, and movable cylinders are consistent, all being circular, elliptical, or polygonal.

[0024] The cross-sectional areas of the cage sidewall, bag sidewall, and movable cylinder decrease sequentially, and the cross-sections of the upper hollow cylinder and the lower movable plate are the same.

[0025] The disc air hole includes an internal air passage and air plates A and B connected to the passage wall. The two ends of the internal air passage are an air inlet and an air outlet, respectively. The air inlet is located near the internal cavity of the air chamber, and the air outlet is located near the internal cavity of the disc. The diameter of the air outlet is larger than the diameter of the air inlet. The fixed ends of air plates A and B are located near the air inlet, and the free ends of air plates A and B are located near the air outlet.

[0026] The volume of the external air chamber is two to five times that of the ventilation cage.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. A comparative filter bag detection system of the present invention includes an outer air chamber, a ventilation cage, and a movable cylinder arranged sequentially from the outside to the inside. The outer air chamber includes a side cylinder, a top cover, a bottom cover, an inner cavity, and a ventilation pipe. The ventilation cage includes a top ring, a side ring, and a bottom opening. A ventilation structure connecting the inner cavity and the inner cavity is provided on the side ring. The movable cylinder includes an upper hollow cylinder and a lower movable disc. The upper hollow cylinder is a hollow structure with openings at both ends. The lower movable disc... It has a hollow structure with an inner cavity inside the lower movable plate. Multiple air holes communicating with the inner cavity are opened on the side of the lower movable plate. The top surface of the lower movable plate is aligned with the bottom opening of the upper hollow cylinder. The top opening of the upper hollow cylinder is set higher than the top ring of the cage. The middle of the top surface of the lower movable plate is connected to the bottom of the detection tube. The top of the detection tube is connected to the gas flow meter. The gas flow meter is connected to the inner cavity of the gas chamber after passing through the detection tube, the inner cavity of the plate, the air holes of the plate, and the ventilation structure. In application, first connect the top opening of the filter bag to be tested to the top ring of the cage. Then, use the movable cylinder to push the filter bag into the ventilation cage until the lower movable disc presses the bottom of the filter bag tightly against the bottom opening of the cage. At the same time, the side wall of the upper hollow cylinder is tightly attached to the inner wall of the bag's side wall. Then, ventilate or draw air into the chamber cavity through the chamber air pipe to create a stable gas environment in the chamber cavity. On this basis, the lower movable disc is then gradually drawn upwards in stages through the upper hollow cylinder... Each stage corresponds to an annular area on the bag's side wall. During the upward drawing process, the gas in the chamber cavity can only enter from the side of the bag's side wall, that is, it passes through the ventilation structure, the disc air hole, the disc cavity, and the detection tube in sequence before entering the gas flow meter. Therefore, the gas flow meter can record the gas flow rate change at each stage until the lower movable disc is drawn out of the filter bag, thus obtaining the gas flow rate values ​​for all stages. At this point, the following two processing methods can be performed:

[0029] The first method involves comparing the gas flow rate at each height stage with the air permeability of the sidewall of the unused filter bag. If the flow rate increases significantly, it is determined that there is breakage at this height stage, i.e., a broken stage has been identified.

[0030] The second approach involves first drawing a gas flow rate change line corresponding to the sidewall of the bag, based on the gas flow rate values ​​at each height stage. By comparing these lines, we can identify height stages with significantly different flow rates (focusing primarily on stages with sudden increases in flow rate), which are also classified as damage stages.

[0031] Finally, the discovered damage stages are examined in detail (e.g., visually), which easily identifies the specific damage points, thereby improving detection accuracy and reducing overall detection time. Therefore, this invention not only provides highly accurate damage detection for used filter bags but also boasts high detection efficiency and ease of operation.

[0032] 2. In the comparative filter bag detection system of the present invention, the number of chamber air tubes is preferably two. One chamber air tube is located on one side of the chamber side cylinder, and the other chamber air tube is located on the other side of the chamber side cylinder. More preferably, there are two types of chamber air tubes, each with an air intake or exhaust function, to facilitate various adjustments to the gas environment within the chamber cavity. Simultaneously, they can cooperate with the reciprocating motion of the upper hollow cylinder in the vertical direction to detect the damage to the filter bag using different detection methods, thereby improving the accuracy of the detection. Therefore, the present invention offers diverse detection methods and high accuracy.

[0033] 3. In the comparative filter bag detection system of the present invention, the cage sidewall preferably includes multiple cage vertical rods. All cage vertical rods are evenly arranged along the same circumference. The top of all cage vertical rods is connected to the bottom of the cage top ring, and the bottom ends of all cage vertical rods together form a cage bottom opening. At this time, the bottom ends of all cage vertical rods are connected to the top surface of the air chamber bottom cover. At the same time, all cage vertical rods are parallel to each other, and adjacent cage vertical rods are separated by rod gaps. These rod gaps serve as ventilation structures. In application, the cage vertical rods not only create rod gaps as ventilation structures, but also provide guidance for the filter bag to be tested in the vertical direction, facilitating the natural expansion of the filter bag and the smooth loading of the hollow cylinder inside the filter bag. The rods reciprocate up and down. Furthermore, the rod gaps provide ample space, serving not only as a ventilation structure connecting the filter bag and the air chamber, but also without restricting the natural expansion of the filter bag. Filter bags typically have cylindrical sidewalls, which bulge outwards upon natural expansion. The rod gaps do not restrict this bulging, facilitating the natural expansion of the filter bag. This, in turn, allows the upper hollow cylinder to move smoothly up and down inside the filter bag (the up-and-down movement of the upper hollow cylinder also acts as a sorting process for the filter bag, ensuring its full expansion). This ensures the accuracy of subsequent gas flow detection, thereby improving the accuracy of filter bag detection. Therefore, this invention facilitates the natural expansion of the filter bag to be detected, thus improving the accuracy of filter bag detection.

[0034] 4. In the comparative filter bag detection system of the present invention, the disc air vent includes an internal air channel and gas plates A and B connected to the channel wall. The two ends of the internal air channel are an air inlet and an air outlet, respectively. The air inlet is located near the inner cavity of the air chamber, and the air outlet is located near the inner cavity of the disc. The diameter of the air outlet is larger than the diameter of the air inlet (making the cross-section of the internal air channel an isosceles trapezoid). The fixed ends of gas plates A and B are located near the air inlet, and the free ends of gas plates A and B are located near the air outlet. In application, gas plates A and B extend along the direction from the air inlet to the air outlet to act as one-way valves, ensuring that gas can only flow from the ventilation structure to the inner cavity of the disc and will not flow back, thus ensuring smooth detection by the gas flow meter. Therefore, the present invention can guide the flow of gas and ensure the accuracy of detection.

[0035] 5. In the comparative filter bag detection system of the present invention, the volume of the external air chamber is preferably two to five times the volume of the ventilation cage. During application, when the upper hollow cylinder moves upwards vertically, it gradually releases the space below the lower movable plate, thereby increasing the overall space within the external air chamber. This has a certain impact on the gas pressure or gas flow rate in the gas environment. If the external air chamber has a larger volume relative to the ventilation cage, it can effectively overcome this impact, ensuring the gas flow meter detection is achieved. That is, it can still detect changes in gas flow rate at each height stage, thus ensuring the smooth progress of filter bag detection. Therefore, the present invention has a strong buffering effect and high detection accuracy. Attached Figure Description

[0036] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0037] Figure 2 yes Figure 1 A sectional view.

[0038] Figure 3 yes Figure 2 Enlarged schematic diagram of the top ring of the middle cage.

[0039] Figure 4 yes Figure 2 Enlarged schematic diagram of the bottom opening of the middle cage.

[0040] Figure 5 This is a three-dimensional structural diagram of the ventilation cage in this invention.

[0041] Figure 6 This is a three-dimensional structural diagram of the movable cylinder in this invention.

[0042] Figure 7 This is a schematic diagram of the connection of the movable cylinder inserted into the ventilation cage in this invention.

[0043] Figure 8 This is a three-dimensional structural diagram of the lower movable plate being pulled upwards in this invention.

[0044] Figure 9 yes Figure 8 A sectional view.

[0045] Figure 10 This is a schematic diagram of the structure of the side body and the side through hole in this invention.

[0046] Figure 11 This is a schematic diagram of the structure of gas sheet A and gas sheet B in this invention.

[0047] In the diagram: 1. External air chamber, 11. Top cover of air chamber, 111. Pressure gauge of cover, 112. Flow meter of cover, 12. Side cylinder of air chamber, 13. Bottom cover of air chamber, 14. Inner cavity of air chamber, 15. Air pipe of chamber, 16. Middle opening of cover, 2. Ventilation cage, 21. Top ring of cage, 22. Side wall of cage, 221. Through hole of side wall, 222. Bottom opening of cage, 23. Vertical rod of cage, 24. Gap between rods, 25. Inner cavity of cage, 26. Ventilation structure, 27. Movable cylinder, 3. Upper hollow cylinder, 4. Bottom opening, 41. Top opening, 42. Lower movable plate, 5. Inner cavity of plate, 51. Air hole of plate, 52. Air passage in hole, 53. Air inlet of hole, 531. Air outlet of hole, 532. Air plate A, 54. Air plate B, 55. Fixed end, 56. Free end, 57. Detection tube, 6. Gas flow meter, 7. Filter bag, 8. Top opening of bag, 81. Side wall of bag, 82. Bottom of bag, 83. Annular area, 84. Detailed Implementation

[0048] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] See Figure 1 — Figure 11 A comparative filter bag detection system includes an external air chamber 1, an air cage 2, and a movable cylinder 3. The external air chamber 1 includes an air chamber side cylinder 12 and an air chamber top cover 11 and an air chamber bottom cover 13 that are sealed to its top and bottom. The air chamber top cover 11, the air chamber side cylinder 12, and the air chamber bottom cover 13 together form an internal air cavity 14, and an air pipe 15 communicating with the internal air cavity 14 is opened on the cylinder wall of the air chamber side cylinder 12.

[0050] The ventilation cage 2 includes a cage side wall 22 and a cage top ring 21 and a cage bottom opening 23 connected to its two ends. The air chamber top cover 11 has a cover opening 16 in the middle. The cage bottom opening 23 is connected to the top surface of the air chamber bottom cover 13. One end of the cage side wall 22 is connected to the cage bottom opening 23. The other end of the cage side wall 22 passes through the air chamber cavity 14 and the cover opening 16 in sequence and is connected to the cage top ring 21. The cage top ring 21 is set higher than the air chamber top cover 11. A ventilation structure 27 is provided on the cage side wall 22 to connect the cage cavity 26 and the air chamber cavity 14.

[0051] The movable cylinder 3 includes an upper hollow cylinder 4 and a lower movable disc 5. The upper hollow cylinder 4 is a hollow structure with openings at both ends, and the lower movable disc 5 is a hollow structure. The lower movable disc 5 has an inner cavity 51 inside, and multiple air holes 52 communicating with the inner cavity 51 are opened on the side of the lower movable disc 5. The bottom and top surfaces of the lower movable disc 5 are sealed structures. The top surface of the lower movable disc 5 is aligned with the bottom opening 41 of the upper hollow cylinder 4. The top opening 42 of the upper hollow cylinder 4 is set higher than the top ring 21. The middle of the top surface of the lower movable disc 5 is connected to the bottom of the detection tube 6. The top of the detection tube 6 is connected to the gas flow meter 7. The gas flow meter 7 is connected to the inner cavity 14 of the gas chamber after passing through the detection tube 6, the inner cavity 51, the air holes 52, and the ventilation structure 27.

[0052] The lower movable plate 5 is located inside the cage side enclosure 22, and the upper hollow cylinder 4 drives the lower movable plate 5 to move up and down along the central axis of the cage side enclosure 22.

[0053] There are two chamber air tubes 15, one chamber air tube 15 is located on one side of the air chamber side cylinder 12, and the other chamber air tube 15 is located on the other side of the air chamber side cylinder 12.

[0054] The top of the detection tube 6 is positioned below the top opening 42, and both the detection tube 6 and the gas flow meter 7 are located inside the upper hollow cylinder 4.

[0055] The cage side enclosure 22 includes multiple cage vertical rods 24, all of which are parallel to each other in pairs. Adjacent cage vertical rods 24 are sandwiched together to form a rod gap 25, which is the ventilation structure 27. All cage vertical rods 24 are evenly arranged along the same circumference. The top of all cage vertical rods 24 is connected to the bottom of the cage top ring 21. The bottom ends of all cage vertical rods 24 together form a cage bottom opening 23. At this time, the bottom ends of all cage vertical rods 24 are connected to the top surface of the air chamber bottom cover 13.

[0056] The cage side enclosure 22 includes a side enclosure body 221 and a plurality of side enclosure through holes 222 thereon, which are ventilation structures 27.

[0057] The ventilation cage 2 contains a filter bag 8 to be monitored. The filter bag 8 includes a bag side wall 82 and a bag bottom 83 and a bag top opening 81 connected to its two ends. The bag bottom 83 is attached to the cage bottom opening 23 located at its bottom. The bag top opening 81 is connected to the cage top ring 21. The bag side wall 82 extends vertically, and the outer wall of the bag side wall 82 is attached to the inner wall of the cage side wall 22. The movable cylinder 3 slides up and down along the inner wall of the bag side wall 82. The inner cavity of the filter bag 8 is connected to the air chamber cavity 14 after passing through the bag side wall 82 and the ventilation structure 27.

[0058] The diameter of the bag top opening 81 is the same as the diameter of the bag side circumference 82, and the diameter of the bag top opening 81 is smaller than the diameter of the cage top ring 21; the connection between the bag top opening 81 and the cage top ring 21 means that the bag top opening 81 is turned outward and fitted onto the ring body of the cage top ring 21.

[0059] The cross-sectional shapes of the cage side panel 22, the bag side panel 82, and the movable tube 3 are consistent, all being circular, elliptical, or polygonal.

[0060] The cross-sectional areas of the cage sidewall 22, bag sidewall 82, and movable cylinder 3 decrease sequentially, and the cross-sections of the upper hollow cylinder 4 and the lower movable plate 5 are the same.

[0061] The air vent 52 includes an internal air passage 53 and air plates A 54 and B 55 connected to the passage wall. The two ends of the internal air passage 53 are an air inlet 531 and an air outlet 532, respectively. The air inlet 531 is located near the air chamber 14, and the air outlet 532 is located near the internal cavity 51. The diameter of the air outlet 532 is larger than the diameter of the air inlet 531. The fixed ends 56 of the air plates A 54 and B 55 are located near the air inlet 531, and the free ends 57 of the air plates A 54 and B 55 are located near the air outlet 532.

[0062] The volume of the external air chamber 1 is two to five times the volume of the ventilation cage 2.

[0063] The principle of this invention is explained as follows:

[0064] When the upper hollow cylinder 4 drives the lower movable disc 5 to perform a vertical upward movement inside the bag side circumference 82, it gradually releases the space below the lower movable disc 5, thereby increasing the overall space for gas in the gas chamber 14. This will have a certain impact on the gas pressure or gas flow rate in the gas environment, such as a decrease in gas pressure or a slowdown in flow rate. This change will continue as the upward movement continues. Assuming the upward movement rate is constant, the change in gas pressure or gas flow rate in the gas chamber 14 should be relatively stable after each upward movement. Therefore, we can record the gas pressure or gas flow rate in the gas chamber 14 after each upward movement. The flow rate is monitored (by the pressure gauge 111 or flow meter 112 on the top cover 11 of the air chamber) to obtain the monitoring value corresponding to each height stage. The change trajectory line is then drawn accordingly. If a significant deviation is found between the monitoring value corresponding to a certain height stage and the trajectory line (such as a deviation in the rate of change), it can be proven that there is an unusual situation in the annular area on the side wall 82 of the bag corresponding to that height stage, such as a drop caused by damage or an rise caused by blockage. This allows the damaged or blocked parts to be detected. The detected parts are then visually inspected to accurately find the specific location of the damage or blockage, thereby improving the overall detection efficiency.

[0065] Example 1:

[0066] See Figure 1 — Figure 11 A comparative filter bag detection system includes an external air chamber 1, an air cage 2, and a movable cylinder 3. The external air chamber 1 includes an air chamber side cylinder 12 and an air chamber top cover 11 and an air chamber bottom cover 13 sealed to its top and bottom, respectively. The air chamber top cover 11, the air chamber side cylinder 12, and the air chamber bottom cover 13 together form an internal air cavity 14, and an air pipe 15 communicating with the internal air cavity 14 is opened on the cylinder wall of the air chamber side cylinder 12. The air cage 2 includes a cage side circumference 22 and a movable cylinder 3. The cage top ring 21 and cage bottom opening 23 are connected at both ends. The air chamber top cover 11 has a cover opening 16 in the middle. The cage bottom opening 23 is connected to the top surface of the air chamber bottom cover 13. One end of the cage side ring 22 is connected to the cage bottom opening 23. The other end of the cage side ring 22 passes through the air chamber cavity 14 and the cover opening 16 in sequence and then connects to the cage top ring 21. The cage top ring 21 is set higher than the air chamber top cover 11. The cage side ring 22 has a passage that connects the cage inner cavity 26 and the air chamber inner cavity 14. Air structure 27; the movable cylinder 3 includes an upper hollow cylinder 4 and a lower movable disc 5; the upper hollow cylinder 4 is a hollow structure with openings at both ends, and the lower movable disc 5 is a hollow structure. An inner cavity 51 is opened inside the lower movable disc 5, and multiple air holes 52 communicating with the inner cavity 51 are opened on the side circumference of the lower movable disc 5. The bottom and top surfaces of the lower movable disc 5 are sealed structures, and the perimeter of the top surface of the lower movable disc 5 is aligned and connected to the bottom opening 41 of the upper hollow cylinder 4. The top opening 42 of the cylinder 4 is set higher than the top ring 21 of the cage. The middle part of the top surface of the lower movable plate 5 is connected to the bottom of the detection tube 6. The top of the detection tube 6 is connected to the gas flow meter 7. The gas flow meter 7 is connected to the gas chamber cavity 14 after passing through the detection tube 6, the inner cavity 51 of the plate, the air hole 52 of the plate, and the ventilation structure 27 in sequence. The lower movable plate 5 is located inside the cage side wall 22, and the upper hollow cylinder 4 drives the lower movable plate 5 to move up and down along the central axis of the cage side wall 22.

[0067] In application, first place the filter bag 8 to be tested inside the ventilation cage 2, allowing it to extend naturally along the direction of the ventilation cage 2. The top opening 81 of the filter bag 8 is connected to the top ring 21 of the cage. Then, use the movable cylinder 3 to move up and down inside the bag side 82 to comb the bag side 82, thereby making the bag side 82 fully unfolded. At this time, press the lower movable plate 5 tightly onto the bottom 83 of the bag. Then, supply or evacuate air into the chamber cavity 14 through the chamber air pipe 15 to create a stable gas environment in the chamber cavity 14. Then, gradually pull the lower movable plate 5 up and down. Each height stage is recorded, and the gas flow meter 7 corresponding to that height stage is recorded. Each height stage corresponds to an annular area 84 on the bag sidewall 82, thereby obtaining the gas flow rate corresponding to each annular area 84. This continues until the lower movable plate 5 is pulled out from the top of the bag sidewall 82. At this point, all the detected gas flow rates are compared. If a sudden increase in value is found, it is determined that the corresponding annular area 84 is damaged, which is the damage stage. By visually inspecting the damage stage, the more specific damage can be easily found.

[0068] Example 2:

[0069] The basic content is the same as in Example 1, except that:

[0070] The cage side enclosure 22 includes multiple cage vertical rods 24, all of which are parallel to each other in pairs. Adjacent cage vertical rods 24 are sandwiched together to form a rod gap 25, which is the ventilation structure 27. All cage vertical rods 24 are evenly arranged along the same circumference. The top of all cage vertical rods 24 is connected to the bottom of the cage top ring 21. The bottom ends of all cage vertical rods 24 together form a cage bottom opening 23. At this time, the bottom ends of all cage vertical rods 24 are connected to the top surface of the air chamber bottom cover 13.

[0071] Alternatively, the cage side enclosure 22 may include a side enclosure body 221 and a plurality of side enclosure through holes 222 thereon, which are ventilation structures 27.

[0072] Example 3:

[0073] The basic content is the same as in Example 1, except that:

[0074] The ventilation cage 2 contains a filter bag 8 to be monitored. The filter bag 8 includes a bag side panel 82 and a bag bottom 83 and a bag top opening 81 connected to its two ends. The bag bottom 83 is attached to the cage bottom opening 23 located at its bottom. The bag top opening 81 is connected to the cage top ring 21. The bag side panel 82 extends vertically, and the outer wall of the bag side panel 82 is attached to the inner wall of the cage side panel 22. The movable cylinder 3 slides up and down along the inner wall of the bag side panel 82. The inner cavity of the filter bag 8 is connected to the air chamber cavity 14 after passing through the bag side panel 82 and the ventilation structure 27. Preferably, the diameter of the bag top opening 81 is the same as the diameter of the bag side panel 82, and the diameter of the bag top opening 81 is smaller than the diameter of the cage top ring 21. The connection between the bag top opening 81 and the cage top ring 21 means that the bag top opening 81 is turned outward and fitted onto the ring of the cage top ring 21.

[0075] Example 4:

[0076] The basic content is the same as in Example 1, except that:

[0077] The air vent 52 includes an internal air passage 53 and air plates A 54 and B 55 connected to the passage wall. The two ends of the internal air passage 53 are an air inlet 531 and an air outlet 532, respectively. The air inlet 531 is located near the air chamber 14, and the air outlet 532 is located near the internal cavity 51. The diameter of the air outlet 532 is larger than the diameter of the air inlet 531. The fixed ends 56 of the air plates A 54 and B 55 are located near the air inlet 531, and the free ends 57 of the air plates A 54 and B 55 are located near the air outlet 532.

[0078] 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 comparative filter bag detection system, characterized in that: The comparative filter bag detection system includes an external air chamber (1), an air cage (2), and a movable cylinder (3). The external air chamber (1) includes an air chamber side cylinder (12) and an air chamber top cover (11) and an air chamber bottom cover (13) that are sealed to its top and bottom. The air chamber top cover (11), the air chamber side cylinder (12), and the air chamber bottom cover (13) together form an air chamber cavity (14). A chamber air pipe (15) communicating with the air chamber cavity (14) is provided on the cylinder wall of the air chamber side cylinder (12). The ventilation cage (2) includes a cage side wall (22) and a cage top ring (21) and a cage bottom opening (23) connected to its two ends. The top cover (11) of the air chamber has a cover opening (16) in the middle. The cage bottom opening (23) is connected to the top surface of the bottom cover (13) of the air chamber. One end of the cage side wall (22) is connected to the cage bottom opening (23). The other end of the cage side wall (22) passes through the inner cavity of the air chamber (14) and the cover opening (16) in sequence and is connected to the cage top ring (21). The cage top ring (21) is set higher than the top cover (11) of the air chamber. A ventilation structure (27) connecting the inner cavity of the cage (26) and the inner cavity of the air chamber (14) is provided on the cage side wall (22). The movable cylinder (3) includes an upper hollow cylinder (4) and a lower movable disc (5); the upper hollow cylinder (4) is a hollow structure with openings at both ends, and the lower movable disc (5) is a hollow structure. The lower movable disc (5) has an inner cavity (51) inside, and multiple air holes (52) communicating with the inner cavity (51) are opened on the side of the lower movable disc (5). The bottom and top surfaces of the lower movable disc (5) are sealed structures, and the top surface of the lower movable disc (5) is sealed around the upper hollow cylinder. The bottom opening (41) of the core cylinder (4) is aligned and connected. The top opening (42) of the upper hollow cylinder (4) is set higher than the cage top ring (21). The middle of the top surface of the lower movable plate (5) is connected to the bottom of the detection tube (6). The top of the detection tube (6) is connected to the gas flow meter (7). The gas flow meter (7) is connected to the gas chamber cavity (14) after passing through the detection tube (6), the inner cavity of the plate (51), the air hole of the plate (52), and the ventilation structure (27). The lower movable plate (5) is located inside the cage side wall (22), and the upper hollow cylinder (4) drives the lower movable plate (5) to move up and down along the central axis of the cage side wall (22); The cage side enclosure (22) includes multiple cage vertical rods (24). All cage vertical rods (24) are parallel to each other, and adjacent cage vertical rods (24) are sandwiched together to form a rod gap (25). This rod gap (25) is the ventilation structure (27). All cage vertical rods (24) are evenly arranged along the same circumference. The top of all cage vertical rods (24) is connected to the bottom of the cage top ring (21). The bottom ends of all cage vertical rods (24) together form a cage bottom opening (23). At this time, the bottom ends of all cage vertical rods (24) are connected to the top surface of the air chamber bottom cover (13).

2. The comparative filter bag detection system according to claim 1, characterized in that: The number of chamber air tubes (15) is two, one chamber air tube (15) is located on one side of the air chamber side tube (12), and the other chamber air tube (15) is located on the other side of the air chamber side tube (12).

3. A comparison-type filter bag detection system according to claim 1 or 2, characterized in that: The top of the detection tube (6) is set below the top opening (42), and both the detection tube (6) and the gas flow meter (7) are located inside the upper hollow cylinder (4).

4. A comparison-type filter bag detection system according to claim 1 or 2, characterized in that: The cage side enclosure (22) includes a side enclosure body (221) and a plurality of side enclosure through holes (222) opened thereon, which are ventilation structures (27).

5. A comparison-type filter bag detection system according to claim 1 or 2, characterized in that: The ventilation cage (2) contains a filter bag (8) to be monitored. The filter bag (8) includes a bag side wall (82) and a bag bottom (83) and a bag top opening (81) connected to its two ends. The bag bottom (83) is attached to the cage bottom opening (23) located at its bottom. The bag top opening (81) is connected to the cage top ring (21). The bag side wall (82) extends vertically. The outer wall of the bag side wall (82) is attached to the inner wall of the cage side wall (22). The movable cylinder (3) slides up and down along the inner wall of the bag side wall (82). The inner cavity of the filter bag (8) is connected to the air chamber cavity (14) after passing through the bag side wall (82) and the ventilation structure (27).

6. The comparative filter bag detection system according to claim 5, characterized in that: The diameter of the bag top opening (81) is the same as the diameter of the bag side circumference (82), and the diameter of the bag top opening (81) is smaller than the diameter of the cage top ring (21); the connection between the bag top opening (81) and the cage top ring (21) means that the bag top opening (81) is turned outward and fitted onto the ring body of the cage top ring (21).

7. The comparative filter bag detection system according to claim 5, characterized in that: The cross-sectional shapes of the cage sidewall (22), bag sidewall (82), and movable tube (3) are consistent, all being circular, elliptical, or polygonal; The cross-sectional areas of the cage sidewall (22), bag sidewall (82), and movable cylinder (3) decrease sequentially, and the cross-sections of the upper hollow cylinder (4) and lower movable plate (5) are consistent.

8. A comparison-type filter bag detection system according to claim 1 or 2, characterized in that: The disc air hole (52) includes an internal air passage (53) and an air plate A (54) and an air plate B (55) connected to the passage wall. The two ends of the internal air passage (53) are an air inlet (531) and an air outlet (532), respectively. The air inlet (531) is located near the air chamber cavity (14), and the air outlet (532) is located near the disc cavity (51). The diameter of the air outlet (532) is larger than the diameter of the air inlet (531). The fixed ends (56) of the air plate A (54) and the air plate B (55) are both located near the air inlet (531), and the free ends (57) of the air plate A (54) and the air plate B (55) are both located near the air outlet (532).

9. A comparison-type filter bag detection system according to claim 1 or 2, characterized in that: The volume of the external air chamber (1) is two to five times the volume of the ventilation cage (2).

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