A deformable large-area filter bag and a method for cleaning the same

Abstract

The present application relates to dust removal technical field, specifically to a kind of deformable easy ash removal large-area filter bag, comprising: filter bag, for cylinder type;Opening, it is set in the end of filter bag, external spray equipment is towards opening, to carry out spray compressed air to filter bag by opening;The folding mode of filter bag is spiral pleat;And, along the length direction of filter bag, the number of spiral pleat is at least two adjacent sections, and the spiral direction of two adjacent spiral pleats is opposite;Folding support, it is set in the inside of filter bag, to drive filter bag along spiral pleat compression or stretch.The filter bag of the present application is released and unfolded along with folding support, since it is folded according to spiral pleat, centrifugal force is generated when filter bag is unfolded along spiral pleat, can effectively remove the dust with greater surface tackiness of filter material, simultaneously cooperate with the instantaneous release of compressed air at the center of filter bag opening end, so that the dust on the surface of filter bag is efficiently removed.

Description

Technical Field

[0001] This invention relates to the field of dust removal technology, and in particular to a deformable, easy-to-clean large-area filter bag and its cleaning method. Background Technology

[0002] Baghouse dust collectors are the mainstream technology for industrial dust removal and flue gas purification. As the core component, the filter bag's filtration area, cleaning effect, and operating resistance directly determine the dust removal efficiency, equipment energy consumption, and service life.

[0003] Currently, most conventional filter bags in existing technologies have a cylindrical planar structure, which limits the effective filtration area. To increase the air volume handled, the equipment size needs to be significantly increased. Although pleated filter bags can increase the filtration area, dust easily accumulates at the base of the pleats, and cleaning is incomplete. In particular, sticky dust can easily cause blockage, leading to a rapid increase in the filter bag's resistance. Even when pleated filter bags are used with traditional pulse cleaning, they only rely on airflow. For dust deep within the pleats or highly sticky dust, the dust removal effect is still poor, and residues remain even after multiple cleanings. Long-term operation will reduce filtration efficiency and shorten the filter bag's lifespan.

[0004] For example, Chinese invention patent CN119971646A discloses a pleated dust collector filter bag and a baghouse dust collector. The filter bag has multiple transverse pleats, with elastic bands on the sides connecting to these pleats, keeping them in a semi-open state to increase the filtration area. During pulse backflushing, a lifting frame is first moved upwards or downwards by a drive assembly, causing some of the transverse pleats on the bag to open and others to compress before backflushing. Although the pleated dust collector filter bag in the aforementioned patent can remove dust from the semi-open transverse pleats using pulses, because the pleats are always in a semi-open state, residual dust remains at the roots of the pleats even after cleaning, failing to guarantee effective cleaning.

[0005] Therefore, the present invention provides a deformable, easy-to-clean large-area filter bag and a cleaning method thereof. Summary of the Invention

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a deformable and easy-to-clean large-area filter bag and its cleaning method, thereby solving the technical problems of existing filter bags relying solely on compressed air blowing, which still has a poor dust removal effect on dust in the folds of the filter bag or highly sticky dust, and leaves residues after multiple cleanings, resulting in low filtration efficiency and short filter bag life after long-term operation.

[0007] To achieve the above objectives, the first aspect of the present invention provides a deformable and easy-to-clean large-area filter bag, comprising: a filter bag, which is cylindrical; an opening located at the end of the filter bag, with an external blowing device facing the opening to blow compressed air onto the filter bag through the opening; the filter bag being folded in a spiral pleat manner; and, along the length direction of the filter bag, the number of spiral pleats is at least two adjacent segments, the two adjacent spiral pleats being arranged vertically and in opposite spiral directions; and a folding bracket located inside the filter bag to drive the filter bag to compress or extend along the spiral pleats.

[0008] Optionally, the folding bracket includes: a guide rail, which is disposed inside the filter bag along its length; a slider, which is disposed on the guide rail and slidably connected to the guide rail; and a segmented support ring, which is disposed on the outside of the slider and connected to both the slider and the filter bag.

[0009] Optionally, a spiral pleat is provided between every two adjacent segmented support rings along the length of the filter bag.

[0010] Optionally, when the slider moves downward, it causes the corresponding segmented support ring to move downward, thus extending the spiral folds; when the slider moves upward, it causes the corresponding segmented support ring to move upward, thus compressing the spiral folds.

[0011] Optionally, each spiral pleat is formed by multiple folded units enclosing the filter bag radially.

[0012] Optionally, the folding unit includes: an upper folding surface; and a lower folding surface, which is positioned below the upper folding surface along an inward concave fold line. The upper and lower folding surfaces fold or extend synchronously along the inward concave fold line to achieve the folding or extension of the filter bag.

[0013] Optionally, along the setting direction of the concave fold line, the upper and lower fold surfaces are folded synchronously in a clockwise direction or extended synchronously in a counterclockwise direction, then the spiral folds are in the first spiral direction; along the setting direction of the concave fold line, the upper and lower fold surfaces are folded synchronously in a counterclockwise direction or extended synchronously in a clockwise direction, then the spiral folds are in the second spiral direction.

[0014] Alternatively, the filter bag may be made of at least one of polyester needle-punched felt, aramid needle-punched felt, fiberglass woven fabric or PTFE membrane filter media.

[0015] A second aspect of the present invention provides a method for cleaning a deformable, easily cleanable large-area filter bag, applied to the deformable, easily cleanable large-area filter bag of the first aspect, the method comprising: Step 1, Initial state: The spiral pleats of the filter bag remain folded and filter dust-laden gas; Step 2, dust removal trigger: When the resistance or time set value is reached, the folding bracket is released under electric drive, so that the filter bag changes from a compressed state to an extended state, and the dust in the spiral pleats falls off naturally. Step 3, Mechanical cleaning: As the folded support extends, the spiral pleats of the filter bag become stretched, and the resulting centrifugal force shakes off the sticky dust. Step 4, Airflow cleaning: The folding bracket is fully extended, and the blowing device blows compressed air toward the opening to remove stubborn dust; Step 5, Reset Cycle: After each section of spiral folds is cleaned, the folded bracket is restored to its compressed state before the next section of spiral folds is cleaned.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a deformable, easily cleanable, large-area filter bag. The filter bag is folded and compressed using a folding bracket, resulting in increased effective filtration area. As the filter bag unfolds, the spiral folds generate centrifugal force, effectively removing sticky dust from the filter material surface, especially at the folds. Simultaneously, compressed air is released instantaneously at the center of the filter bag's opening, efficiently removing dust from the surface. Compared to existing transversely pleated filter bags or ordinary cylindrical filter bags, the spiral folds of this invention allow for a greater number of continuous folds along the circumference of a filter bag of the same size, significantly increasing the filtration area. Compared to existing longitudinal folds, the spirally pleated filter bag of this embodiment is shorter under the same filtration area conditions, without increasing the bag's length or volume. In other words, with a shorter filter bag length, this invention increases the filtration area and, through the spiral folds, increases the centrifugal force during dust removal and extension, ensuring highly efficient dust removal. Within the same length and space, the filter bag of the present invention has a significantly higher filtration area and dust removal effect than the existing transverse and longitudinal pleated filter bags, achieving low-resistance filtration and high-efficiency dust removal rate throughout the service life of the filter bag.

[0017] Furthermore, after each segment of the filter bag is cleaned, the corresponding folding bracket returns to its compressed state, causing the filter bag in that segment to revert to its folded state along the spiral pleats. The cleaning process is then repeated for the next segment until all segments are cleaned, thus completing the entire filter bag cleaning process. Because the filter bag uses a segmented cleaning method, when one segment is in the unfolded state, the other segments are in the compressed state. This design eliminates the need to increase the length of the filter bag to ensure cleaning effectiveness, and therefore avoids the need to modify the dust collector to provide more space for the spiral pleated filter bags.

[0018] In summary, when the filter bag reaches the cleaning node, the filter bag of the present invention can achieve three-stage cleaning. The first stage is that the filter bag reaches an extended state along the spiral pleats, and the filter bag changes from pleats to flatness, and the dust accumulated in the pleats is naturally shaken off. The second stage is that as the spiral pleats are released, the filter bag generates centrifugal force, which then shakes off the more sticky dust on the outer surface of the filter bag. The third stage is that when the folding bracket is fully unfolded, the external jet blowing device sprays compressed air from the opening of the filter bag into the interior of the filter bag instantaneously, thereby removing the more sticky dust remaining on the outer surface of the filter bag. Attached Figure Description

[0019] Figure 1 A schematic diagram of the filter bag of the present invention being cleaned by jet air cleaning; Figure 2 This is a schematic diagram of the folding bracket of the present invention; Figure 3 This is a schematic diagram of the slider sliding along the guide rail according to the present invention; Figure 4 This is a schematic diagram of the connection between the slider and the guide rail according to the present invention; Figure 5 This is a schematic diagram showing the continuous change of a section of the spiral pleats of the filter bag of the present invention extending in a counterclockwise direction (first spiral direction). Figure 6 This is a schematic diagram showing the change of a section of the spiral pleats of the filter bag of the present invention as it extends in a clockwise direction (second spiral direction). Figure 7 for Figure 6 A structural diagram of two adjacent folded units (marked with red boxes); Figure 8 This is a diagram illustrating the dust removal effect of the polyester needle-punched felt filter bag with a compression ratio of 1:3 according to the present invention. Figure 9 This is a diagram showing the dust removal effect of the PTFE membrane filter bag with a compression ratio of 1:5 according to the present invention.

[0020] Explanation of reference numerals in the attached figures: 1. Filter bag; 2. Opening; 3. Folding bracket; 31. Guide rail; 32. Slider; 33. Segmented support ring; 4. Folding unit; 41. Upper folding surface; 42. Lower folding surface; 43. Concave fold line; 5. Pulse blowing equipment. Detailed Implementation

[0021] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0022] Embodiments of the present invention provide a deformable, easy-to-clean large-area filter bag 1, such as... Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, it includes: a filter bag 1, which is cylindrical; an opening 2, which is located at the end of the filter bag 1, and an external blowing device 5 facing the opening 2 to blow compressed air onto the filter bag 1 through the opening 2; the filter bag 1 is folded in a spiral pleat manner; and, along the length direction of the filter bag 1, the number of spiral pleats is at least two adjacent segments, the two adjacent spiral pleats are arranged vertically and in opposite spiral directions; and a folding bracket 3, which is located inside the filter bag 1 to drive the filter bag 1 to compress or extend along the spiral pleats.

[0023] For example, such as Figure 1 and Figure 5 As shown, the filter bag 1 in this embodiment is arranged longitudinally with the opening 2 facing upward, and the number of spiral pleats along the length of the filter bag 1 is 10 segments.

[0024] For example, such as Figure 2 and Figure 3 As shown, in this embodiment, there are two folding brackets 3. The two folding brackets 3 are inserted into the interior of the filter bag 1 along the axial direction of the filter bag 1. The folding brackets 3 are made of elastic metal or composite elastic material, thereby providing a stable extensibility force for the compression and expansion of the filter bag 1.

[0025] For example, such as Figure 1 , Figure 5 , Figure 6 and Figure 7 As shown, since the filter bag 1 is folded in a spiral pleat manner, when the filter bag 1 is stretched along the spiral pleat by the folding bracket 3, the filter bag 1 will unfold along the spiral pleat, thereby generating centrifugal force. Under the influence of centrifugal force, the sticky dust on the surface of the filter bag 1, especially at the pleats, is effectively removed.

[0026] For example, with Figure 1 For example, Figure 1The filter bag 1 consists of two adjacent spiral pleats extending from the middle. The upper spiral pleat extends counterclockwise in the first spiral direction, while the lower spiral pleat extends clockwise in the second spiral direction. Because the spiral directions of the two adjacent spiral pleats are opposite, and the upper and lower spiral pleats are symmetrically arranged relative to the middle connection point, the two symmetrically unfolded spiral pleats allow the filter bag 1 to nearly fully unfold and flatten at the connection point. This prevents dust from accumulating at the connection point, facilitating dust removal. Furthermore, during the extension of the filter bag 1, the upper spiral pleats extend clockwise, while the lower spiral pleats extend counterclockwise. This results in opposite directions of centrifugal force between the two adjacent spiral pleats. To a certain extent, the impact of these two opposite centrifugal forces on the internal folded support 3 is greatly reduced. This avoids uneven stress on the folded support 3 caused by the same centrifugal force, which would reduce the stability of the folded support 3 with increasing dust removal frequency, thus reducing the service life of the filter bag 1.

[0027] In one possible embodiment, such as Figure 2 , Figure 3 and Figure 4 As shown, the folding bracket 3 includes: a guide rail 31, which is disposed inside the filter bag 1 along the length direction of the filter bag 1; a slider 32, which is disposed on the guide rail 31 and slidably connected to the guide rail 31; and a segmented support ring 33, which is disposed on the outside of the slider 32 and is connected to both the slider 32 and the filter bag 1.

[0028] For example, refer to Figure 4 As shown, in this embodiment, the slider 32 is connected by bolts. For example, the slider 32 is divided into two parts, each of which has a recessed portion that matches the guide rail 31. The two parts are then interlocked and fixed together by bolts, with the guide rail 31 sandwiched between them. Alternatively, the slider 32 may be fitted onto the guide rail 31, and it may also be divided into two parts, which are fixed together by interlocking without the need for bolts. Specifically, the sliding and fixing methods between the slider 32 and the guide rail 31 are existing technologies and are not specifically limited here.

[0029] For example, the segmented support ring 33 is fixedly connected to the slider 32 by bolts, so that the segmented support ring 33 slides as the slider 32 slides along the guide rail 31. The inner side of the segmented support ring 33 is connected to the slider 32, and the outer side of the segmented support ring 33 is connected to the filter bag 1, thereby realizing the compression or expansion of the filter bag 1.

[0030] For example, such as Figure 2 and Figure 3As shown, the number of sliders 32 matches the number of guide rails 31. In this embodiment, there are two guide rails 31, so correspondingly, two sliders 32 are needed for each segmented support ring 33. The two sliders 32 on each segmented support ring 33 are at the same horizontal height, thus ensuring that the segmented support rings 33 connected to the sliders 32 are horizontally positioned. With this configuration, the sliders 32 drive the segmented support rings 33 to slide along the guide rails 31. During the compression or expansion of the filter bag 1, this helps to ensure that the circumferential compression or expansion height of the cylindrical filter bag 1 is the same. This configuration prevents the filter bag 1 from having a large expansion on one side and a small expansion on the other. On the side with a small expansion, the filter bag 1 generates less outward force, making it less likely for dust to be shaken off. Therefore, the above configuration helps to ensure the dust removal effect of the filter bag 1.

[0031] In one possible embodiment, such as Figure 1 and Figure 2 As shown, along the length of the filter bag 1, a spiral pleat is provided between every two adjacent segmented support rings 33.

[0032] For example, the number of segmented support rings 33 in this embodiment is matched with the number of spiral pleats. For instance, if there are 10 spiral pleats, then there are 11 segmented support rings 33, with each pair of adjacent segmented support rings 33 consisting of one spiral pleat. Thus, as the slider 32 slides along the guide rail 31, the segmented support rings 33 cause the filter bag 1 to compress or expand.

[0033] In one possible embodiment, such as Figure 1 , Figure 2 and Figure 3 As shown, when slider 32 moves downward, it drives the corresponding segmented support ring 33 to move downward, thus extending the spiral folds; when slider 32 moves upward, it drives the corresponding segmented support ring 33 to move upward, thus compressing the spiral folds.

[0034] For example, in this embodiment, the spiral pleats are divided into two segments, and correspondingly, there are three segmented support rings 33. That is, two segmented support rings 33 are disposed at the upper and lower ends of the filter bag 1, and there is also one segmented support ring 33 in the middle of the two spiral pleats. For ease of description, from top to bottom, they are the first segmented support ring 33, the second segmented support ring 33, and the third segmented support ring 33. When the filter bag 1 reaches the dust removal node, if the spiral pleats need to be extended, the second segmented support ring 33 slides downward first, so the upper spiral pleats are extended first. After the upper spiral pleats are cleaned, the second segmented support ring 33 moves upward to the previous position, that is, the upper spiral pleats return to the compressed state before dust removal. Then the third segment support ring 33 located at the lower end of the filter bag 1 moves downward, so that the lower spiral pleats are stretched. Then the third segment support ring 33 moves upward to the previous position, that is, the lower spiral pleats are restored to the compressed state before cleaning, thus completing the cleaning of the filter bag with two spiral pleats in this embodiment.

[0035] In one possible embodiment, such as Figure 1 , Figure 5 , Figure 6 and Figure 7 As shown, each spiral pleat is formed by multiple folding units 4 enclosing the filter bag 1 radially.

[0036] For example, such as Figure 1 , Figure 5 , Figure 6 and Figure 7 As shown, the filter bag 1 itself is integrally formed, and the multiple folding units 4 are also integrally formed. Moreover, the dimensions of the multiple folding units 4 are exactly the same. This is beneficial for the filter bag 1 to effectively maintain the consistency of the amount of change and the synchronicity of the aging during the compression or stretching process along the spiral folds.

[0037] For example, such as Figure 1 , Figure 5 , Figure 6 and Figure 7 As shown, the multiple folding units 4 that make up the same spiral fold are completely identical, that is, the size, spiral direction and angle, and material of the folding unit 4 are completely identical.

[0038] In one possible embodiment, such as Figure 1 , Figure 5 , Figure 6 and Figure 7 As shown, the folding unit 4 includes: an upper folding surface 41; and a lower folding surface 42, which is disposed below the upper folding surface 41 along the concave fold line 43. The upper folding surface 41 and the lower folding surface 42 are folded or extended synchronously along the concave fold line 43 to realize the folding or extension of the filter bag 1.

[0039] For example, such as Figure 1 , Figure 5 , Figure 6 and Figure 7 As shown, both the upper folded surface 41 and the lower folded surface 42 are triangular, and they are folded inward along the concave fold line 43 towards the inside of the filter bag 1. Since the filter bag 1 in this embodiment is an external filter bag 1, the filtered dust accumulates on the outer surface of the filter bag 1. Therefore, by setting the concave fold line 43 in the folding unit 4, during the dust removal process, as the upper folded surface 41 and the lower folded surface 42 extend outward along the concave fold line 43, the dust on the outer surface of the filter bag 1 is shaken off by the outward expansion force of the folding unit 4.

[0040] In one possible embodiment, such as Figure 1 , Figure 5 , Figure 6 or Figure 7 As shown, if the upper folded surface 41 and the lower folded surface 42 are folded synchronously in a clockwise direction or extended synchronously in a counterclockwise direction along the setting direction of the concave fold line 43, then the spiral fold is the first spiral direction; if the upper folded surface 41 and the lower folded surface 42 are folded synchronously in a counterclockwise direction or extended synchronously in a clockwise direction along the setting direction of the concave fold line 43, then the spiral fold is the second spiral direction.

[0041] For example, refer to Figure 1 The spiral folds unfolding above and Figure 5 The spiral folds shown, when the concave fold line 43 is set from the upper left to the lower right, represent the first spiral direction. At this time, the upper fold surface 41 and the lower fold surface 42 fold synchronously in a clockwise direction or extend synchronously in a counterclockwise direction.

[0042] For example, refer to Figure 1 The spiral folds unfolding below, and Figure 6 and Figure 7 The spiral folds shown, when the concave fold line 43 is set from the lower left to the upper right, represent the second spiral direction. At this time, the upper fold surface 41 and the lower fold surface 42 fold synchronously in a counterclockwise direction or extend synchronously in a clockwise direction.

[0043] In one possible embodiment, the filter bag 1 is made of at least one of polyester needle-punched felt, aramid needle-punched felt, fiberglass woven fabric or PTFE membrane filter material.

[0044] For example, the PTFE-coated filter material in this embodiment is a polytetrafluoroethylene-coated membrane.

[0045] For example, depending on the needs of the actual application scenario, the filter bag 1 can be made of any of the above-mentioned materials. For instance, in waste incineration or chemical plant environments, where both high temperature resistance and corrosion resistance are required, PTFE membrane filter media is used. Alternatively, in iron smelting or cement plants, where better stability and more consistent dimensions are needed for the filter bag 1, fiberglass woven fabric is selected.

[0046] For example, depending on the needs of the actual application scenario, the filter bag 1 can also be made of a composite material of two materials, that is, the filter bag 1 is made of composite filter media. For example, in power plant applications for boiler flue gas purification, the filter bag 1 operates at high temperatures and the dust is somewhat corrosive. In this application scenario, a composite material of fiberglass woven fabric and PTFE membrane is used, which takes into account the stability and corrosion resistance of both materials.

[0047] This invention also provides a method for cleaning a deformable, easily cleanable large-area filter bag 1, applied to the deformable, easily cleanable large-area filter bag 1 described in the above embodiments. The cleaning method includes: Step 1, Initial state: The spiral pleats of filter bag 1 remain folded and filter dust-laden gas; Step 2, dust removal trigger: When the resistance or time set value is reached, the folding bracket 3 is released under electric drive, so that the filter bag 1 changes from a compressed state to an extended state, and the dust in the spiral pleats falls off naturally. Step 3, mechanical dust removal: As the folded support 3 extends, the spiral pleats of the filter bag 1 become extended, and the resulting centrifugal force shakes off the sticky dust. Step 4, airflow cleaning: The folding bracket 3 is fully unfolded, and the blowing device 5 blows compressed air toward the opening 2 to remove stubborn dust; Step 5, Reset Cycle: After each section of spiral folds is cleaned, the folding bracket 3 returns to its compressed state before the next section of spiral folds is cleaned.

[0048] Based on the above-described dust removal method, the following embodiments are provided to better demonstrate the advantages of the filter bag 1 and the dust removal method of the present invention.

[0049] Example 1 For dust-laden gas treatment scenarios in mine crushing workshops, please refer to the attached document. Figure 1The present invention uses a large-area deformable and easy-to-clean filter bag 1. The filter bag 1 is made of fold-resistant polyester needle-punched felt (treated with oil and water resistance). The filter bag 1 has a diameter of 300mm and a maximum unfolded length of 1800mm. The ratio of the unfolded length of the spiral pleats to the maximum compressed length (compression ratio) is 1:3, that is, the length of the folding bracket 3 is 1800mm and the maximum compressed length is 600mm. The filter bag 1 is fitted outside the segmented support ring 33. The matching external blowpipe blows compressed air at a pressure of 0.3-0.4MPa. The dust removal trigger condition is set when the resistance of the filter bag 1 reaches 1000Pa.

[0050] The test results are as follows: Filtration area: When filter bag 1 is in a compressed state (folded support 3 compressed to 600mm), the density of the spiral pleats is at its maximum, and the effective filtration area reaches 2.8m². 2 The effective filtration area of ​​a standard cylindrical polyester filter bag of the same specifications is only 0.9m². 2 The effective filtration area depends on the ratio of the length of the filter bag in its extended spiral pleats to its length in its maximum compressed state, i.e., the compression ratio. With a compression ratio of 1:3, filter bag 1 can achieve a filtration area 3.1 times that of a standard filter bag of the same specifications.

[0051] Dust removal effect: After 30 minutes of filtration operation, the resistance of filter bag 1 rises to 1000Pa, triggering the three-stage dust removal program.

[0052] First-stage dust removal (dust removal trigger in step 2): The segmented support ring 33 at the bottom of the folding bracket 3 slides down along the guide rail 31 under the action of the slider 32. The filter bag 1 gradually extends from the spiral pleated state to the flat state. The dust accumulated at the root of the spiral pleats (mainly limestone dust, with a small amount of sticky dust) falls off naturally, with a falling rate of 85%. Second-stage dust removal (mechanical dust removal in step 3): As the spiral pleats are further unfolded, the resulting centrifugal force further throws off the sticky dust on the outer surface of filter bag 1. The third stage of cleaning (airflow cleaning in step 4): Subsequently, compressed air is sprayed instantaneously through the nozzle to the opening 2 of the filter bag 1. At this time, the resistance of the filter bag 1 drops to 800Pa. Then, each section of the filter bag 1 unfolds and is cleaned in sequence. Finally, the resistance of the filter bag 1 stabilizes at 100Pa, and the cleaning thoroughness reaches more than 98%.

[0053] Operational stability: Filter bag 1 in Example 1 operated continuously for approximately 4.5 hours, referencing Appendix Figure 8 A total of 10 dust cleaning cycles were completed. The filter bag 1 was undamaged and undeformed. The slider 32 and the guide rail 31 slid smoothly without any jamming. After each dust cleaning, the resistance returned to 100Pa, the operating resistance was stable, and there was no dust clogging of the filter bag 1 pores. This meets the long-term operating requirements of the high dust concentration working conditions in the mine crushing workshop.

[0054] Example 2 For waste incineration flue gas treatment scenarios, please refer to the appendix. Figure 1 The present invention uses a large-area deformable and easy-to-clean filter bag 1. The filter bag 1 is made of fold-resistant PTFE membrane filter material with a membrane thickness of 0.12mm. The filter bag 1 has a diameter of 350mm and a maximum unfolded length of 2500mm. The ratio of the unfolded length of the spiral pleats to the maximum compressed length (i.e., the compression ratio) is 1:5, that is, the length of the folding support 3 is 2500mm and the maximum compressed length is 500mm. The filter bag 1 is fitted onto the outside of the segmented support ring 33. Compressed air is blown through the matching external blowpipe at a pressure of 0.4-0.5MPa. The dust removal trigger condition is set when the resistance of the filter bag 1 reaches 1000Pa and the dust concentration in the flue gas is 800-1200mg / m³. 3 It contains a small amount of corrosive, sticky dust (such as chloride dust).

[0055] The test results are as follows: Filtration area: When filter bag 1 is in a compressed state (folded support 3 compressed to 500mm), the spiral pleats are dense and uniform, achieving an effective filtration area of ​​5.2m². 2 The effective filtration area of ​​a standard cylindrical PTFE membrane filter bag of the same specifications is only 1.0m². 2 Based on a compression ratio of 1:5, the effective filtration area is 5.2 times that of ordinary filter bag 1 of the same specification, which fully demonstrates the decisive role of the high compression ratio of spiral pleats in increasing the filtration area of ​​filter bag 1. The filtration efficiency is over 99%, which meets the high-efficiency filtration requirements for waste incineration flue gas.

[0056] Dust removal effect: After 45 minutes of filtration operation, the resistance of filter bag 1 rose to 1000Pa, triggering the three-stage dust removal program.

[0057] First-stage dust removal (dust removal trigger in step 2): The segmented support ring 33 at the bottom of the folded bracket 3 slides down along the guide rail 31 under the action of the slider 32, and the filter bag 1 gradually flattens out. Under the mechanical action of the extension of the folded bracket 3, 78% of the corrosive and sticky dust accumulated in the spiral folds naturally falls off. Second-stage dust removal (mechanical dust removal in step 3): As the spiral pleats are further unfolded, the generated centrifugal force further throws off the sticky dust on the outer surface of filter bag 1, at which point the resistance of filter bag 1 drops to 380Pa. The third stage of cleaning (airflow cleaning in step 4): Subsequently, compressed air is sprayed instantaneously through the blowpipe onto the opening 2 of filter bag 1 to precisely remove the stubborn, sticky dust remaining on the outer surface of filter bag 1. After this stage, each stage is cleaned sequentially from top to bottom. Due to the high stickiness of the dust, the final resistance of filter bag 1 fluctuates within 110±20 Pa in different cleaning cycles, but the thoroughness of cleaning still reaches over 90%, with no dust residue accumulation.

[0058] Operational stability: Filter bag 1 in Example 2 operated continuously for approximately 3 hours, referencing Appendix Figure 9 After completing 5 cleaning cycles, the membrane of filter bag 1 remained intact without any damage or detachment. Filter bag 1 exhibits excellent folding resistance, showing no signs of wrinkling fatigue or damage after multiple compression-stretch cycles. After each cleaning, the resistance recovered to 110±20Pa, with minimal fluctuations in operating resistance. Its service life is expected to be 1.5 times that of ordinary PTFE filter bags, making it suitable for long-term treatment of corrosive and sticky dust in waste incineration flue gas.

[0059] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0060] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0061] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A deformable, easy-to-clean large-area filter bag, characterized in that, include: The filter bag is cylindrical. An opening is provided at the end of the filter bag, and an external blowing device faces the opening to blow compressed air onto the filter bag through the opening; The filter bag is folded in a spiral pleat manner; Furthermore, along the length of the filter bag, the number of spiral pleats is at least two adjacent segments, and the two adjacent spiral pleats are arranged vertically and in opposite spiral directions; A folding support is disposed inside the filter bag to compress or extend the filter bag along the spiral pleats.

2. The deformable, easy-to-clean large-area filter bag according to claim 1, characterized in that, The folding bracket includes: A guide rail is disposed inside the filter bag along the length of the filter bag; A slider is mounted on the guide rail and is slidably connected to the guide rail. A segmented support ring is disposed on the outside of the slider and is connected to both the slider and the filter bag.

3. The deformable and easy-to-clean large-area filter bag according to claim 2, characterized in that: Along the length of the filter bag, a spiral pleat is provided between every two adjacent segmented support rings.

4. The deformable and easy-to-clean large-area filter bag according to claim 3, characterized in that: When the slider moves downward, it drives the corresponding segmented support ring to move downward, and the spiral folds extend. When the slider moves upward, it drives the corresponding segmented support ring to move upward, thus compressing the spiral folds.

5. The deformable and easy-to-clean large-area filter bag according to claim 1, characterized in that, Each of the spiral pleats is formed by multiple folding units enclosing the filter bag radially.

6. The deformable and easy-to-clean large-area filter bag according to claim 5, characterized in that, The folding unit includes: Upper fold surface; The lower folded surface is located below the upper folded surface along the concave fold line. The upper folded surface and the lower folded surface fold or extend synchronously along the concave fold line to realize the folding or extension of the filter bag.

7. The deformable and easy-to-clean large-area filter bag according to claim 6, characterized in that: If the upper fold surface and the lower fold surface are folded synchronously in a clockwise direction or extended synchronously in a counterclockwise direction along the setting direction of the concave fold line, then the spiral fold is the first spiral direction; If the upper and lower folded surfaces are folded simultaneously in a counterclockwise direction or extended simultaneously in a clockwise direction along the direction of the concave fold line, then the spiral fold is in the second spiral direction.

8. The deformable and easy-to-clean large-area filter bag according to claim 1, characterized in that: The filter bag is made of at least one of polyester needle-punched felt, aramid needle-punched felt, fiberglass woven fabric or PTFE membrane filter material.

9. A method for cleaning a deformable, easily cleanable large-area filter bag, applied to the deformable, easily cleanable large-area filter bag as described in any one of claims 1 to 8, characterized in that, The dust removal method includes: Step 1, Initial state: The spiral pleats of the filter bag remain folded and filter dust-laden gas; Step 2, dust removal trigger: When the resistance or time set value is reached, the folding bracket is released under electric drive, so that the filter bag changes from a compressed state to an extended state, and the dust in the spiral pleats falls off naturally. Step 3, Mechanical cleaning: As the folded support extends, the spiral pleats of the filter bag become stretched, and the resulting centrifugal force shakes off the sticky dust. Step 4, Airflow cleaning: The folding bracket is fully extended, and the blowing device blows compressed air toward the opening to remove stubborn dust; Step 5, Reset Cycle: After each section of spiral folds is cleaned, the folded bracket is restored to its compressed state before the next section of spiral folds is cleaned.

Images