Efficient flue gas dedusting filter bag

Abstract

The application discloses a flue gas efficient dust removal filter bag, which comprises a circular bag bottom, a plurality of filter cloths and a plurality of connecting cloths, the number of the filter cloths is equal to that of the connecting cloths and the filter cloths and the connecting cloths are alternately distributed, adjacent filter cloths and connecting cloths are connected with each other, and the filter cloths and all the connecting cloths are connected with the circular bag bottom; the connecting cloth comprises a main body section located at the lower part and a top section located at the top part; the main body section is vertically strip-shaped and is in a crimped shape, and the top section is fan-shaped after being unfolded; a plurality of first elastic ropes and a plurality of second elastic ropes are connected at the main body section, the first elastic ropes and the second elastic ropes are alternately distributed in the vertical direction, and the length of the first elastic rope is greater than that of the second elastic rope without external force. The dust removal filter bag can reduce abrasion and efficiently remove dust.

Description

Technical Field

[0001] This application relates to the field of environmental protection, specifically to a high-efficiency dust removal filter bag for flue gas. Background Technology

[0002] Baghouse dust collectors are among the most widely used and efficient dust removal devices in the field of industrial flue gas treatment. Their core component is the filter bag. During filtration, dust-laden flue gas penetrates from the outside of the filter bag to the inside, and dust is trapped on the outer surface of the bag, forming a dust cake layer. When the pressure difference between the inside and outside of the filter bag reaches a set value, the pulse cleaning system is activated. Compressed air is instantly injected from the bag opening into the bag, causing the filter bag to expand rapidly and vibrate, peeling off the dust cake layer from the outer surface and causing it to fall into the ash hopper.

[0003] During pulse cleaning, a violent interaction occurs between the filter bag and the internal cage: at the moment of the pulse, the filter bag expands outward and detaches from the cage; after the pulse ends, the filter bag rapidly retracts under its own elasticity and external negative pressure, violently slapping against the vertical ribs of the cage. This high-frequency "expansion-slapping" cycle is the main cause of longitudinal wear, fiber fatigue breakage, and even wear-through damage to the filter bag's belly. At the same time, the pulsed high pressure creates an instantaneous impact on the sealing connection between the bag opening and the tube sheet hole. Traditional bag opening sealing structures relying on metal elastic retaining rings are prone to stress relaxation under long-term high-frequency impact, leading to short-circuit leakage of dust from the bag opening and affecting emission standards.

[0004] Furthermore, the traditional filter bag cleaning mechanism mainly relies on the inertial shaking generated by the uniform expansion of the filter bag and the stripping by reverse airflow. This "stretching and stripping" method has limited efficiency in stripping highly viscous or densely packed powder cake layers, resulting in high residual resistance of the filter bag after cleaning and increased energy consumption of the system. Summary of the Invention

[0005] Purpose of the invention: This application aims to overcome the deficiencies of the prior art and provide a high-efficiency dust removal filter bag for flue gas.

[0006] Technical solution: A dust collector filter bag includes a circular bottom, multiple filter cloths, and multiple connecting cloths. The number of filter cloths is equal to the number of connecting cloths and they are alternately distributed. Adjacent filter cloths and connecting cloths are connected to each other, and all filter cloths and all connecting cloths are connected to the circular bottom. The connecting cloth includes a main body section at the bottom and a top section at the top. The main body section is a vertical strip and is pleated, while the top section unfolds into a fan shape. Multiple first elastic ropes and multiple second elastic ropes are connected to the main body section. One end of the first elastic rope is fixedly connected to one side of the main body section, and the other end is fixedly connected to the other side of the main body section. The first elastic ropes and second elastic ropes are alternately distributed in the vertical direction. When there is no external force, the length of the first elastic rope is greater than that of the second elastic rope.

[0007] Furthermore, both ends of the first elastic rope are fixed by mechanical anchoring.

[0008] Furthermore, the first elastic rope has anti-retraction expansion ends at both ends, which are fixed by sewing with sewing thread.

[0009] Furthermore, both ends of the second elastic rope are fixed by mechanical anchoring.

[0010] Furthermore, the two ends of the second elastic rope are respectively formed with anti-retraction expansion ends, which are fixed by sewing with sewing thread.

[0011] Furthermore, the connecting cloth has 8 units, and the filter cloth has 8 units.

[0012] Furthermore, after the dust collector filter bag is installed, the filter cloth includes a filter cloth body and a bent portion located above the filter cloth body. The filter cloth body is arc-shaped, with multiple bent portions and multiple top sections alternately distributed, and adjacent bent portions and top sections are connected to each other.

[0013] Furthermore, the circular bag bottom is welded to the filter cloth or sewn together with a sewing thread.

[0014] Furthermore, the circular bag bottom is welded to the connecting fabric or sewn together with sewing thread.

[0015] Furthermore, the first elastic rope is made of PTFE elastic filament or silicone elastic thread.

[0016] Furthermore, the second elastic cord is made of PTFE elastic filament or silicone elastic thread.

[0017] Furthermore, the silicone elastic thread is a high-temperature resistant silicone elastic thread.

[0018] Furthermore, the connecting fabric includes a base fabric and a covering layer, with both the first elastic cord and the second elastic cord located between the base fabric and the covering layer.

[0019] Furthermore, the filter cloth and the connecting cloth are connected by ultrasonic welding or sewing.

[0020] Furthermore, the specifications of the eight connecting fabrics are exactly the same.

[0021] Furthermore, the dust-facing side of the filter cloth is covered with a PTFE film.

[0022] Furthermore, the base fabric is on the outside, and the covering layer is on the inside.

[0023] Furthermore, the base fabric does not contain a PTFE film.

[0024] Therefore, the base fabric is not covered with a film, which maintains the flexibility and breathability of the base fabric, which is conducive to the free deformation of the pleats, does not affect the stretching action of the elastic rope, and prevents the PTFE film from falling off at the pleats due to repeated stretching.

[0025] Furthermore, after the dust removal filter bag is installed, the angle corresponding to the filter cloth is greater than 40 degrees.

[0026] Furthermore, the circular bag bottom is made of the same material as the filter cloth, and its thickness is greater than that of the filter cloth.

[0027] Furthermore, the circular bag bottom is made of polyester needle-punched felt, polyphenylene sulfide needle-punched felt, or polytetrafluoroethylene needle-punched felt.

[0028] Furthermore, the filter cloth is polyester needle-punched felt, polyphenylene sulfide needle-punched felt, or polytetrafluoroethylene needle-punched felt.

[0029] Furthermore, the base fabric is polyester needle-punched felt, polyphenylene sulfide needle-punched felt, or polytetrafluoroethylene needle-punched felt.

[0030] Furthermore, the covering layer is polyester needle-punched felt, polyphenylene sulfide needle-punched felt, or polytetrafluoroethylene needle-punched felt.

[0031] Furthermore, the filter cloth, base cloth, and cover layer are made of the same material.

[0032] Beneficial effects: The filter bag of this application has the following advantages over the prior art, 1) Low impact force during pulse cleaning effectively protects the filter bag: After pulse cleaning, the pressure inside the bag is released, and the stretched elastic ropes retract elastically, converting the kinetic energy of the filter bag's return stroke into elastic potential energy and releasing it gradually. This allows the connecting cloth to gently return the filter cloth to the cage surface, rather than violently impacting the cage frame ribs as with traditional filter bags. The pleated structure unfolds when the long elastic ropes are stretched and wrinkles again when they retract, further absorbing the impact energy of the return stroke. This buffering mechanism significantly reduces the high-frequency hard impact and frictional wear between the filter bag's belly and the cage frame, effectively extending the filter bag's service life.

[0033] 2) Excellent top sealing effect after filter bag installation: The top of the connecting cloth unfolds outward in a fan shape, forming a flexible annular sealing surface together with the top of the filter cloth. During installation, this flexible annular sealing surface is pressed tightly onto the tube sheet by the pressure ring, forming a surface contact seal. Compared with the line contact seal of the traditional metal elastic retaining ring, it has a higher fault tolerance and can effectively compensate for the microscopic unevenness of the tube sheet surface.

[0034] 3) Excellent dust removal effect: During pulse dust removal, the long elastic rope segments of the connecting cloth are significantly stretched, and the wrinkles are unfolded; the short elastic rope segments are stretched less. This difference in stretching between adjacent segments creates dense shear displacement on the surface of the connecting cloth, resulting in highly efficient shearing and peeling action on the powder cake layer covering it. Compared to the single stretching and peeling method that relies on the overall uniform expansion of traditional filter bags, this composite dust removal mode combining stretching and shearing can more effectively break up and peel off highly viscous or densely packed powder cake layers, resulting in more thorough dust removal and lower residual resistance. At the same time, the long and short elastic ropes are alternately distributed in the vertical direction, evenly distributing shear force along the entire length of the bag from the opening to the bottom, solving the problem of incomplete dust removal in the bottom area of ​​traditional filter bags due to pulse energy attenuation. Attached Figure Description

[0035] Figure 1 This is a first-person view diagram of the filter bag; Figure 2 This is a magnified view of region A.

[0036] Figure 3 This is a schematic diagram of the filter bag from a second perspective. Figure 4 This is a magnified view of region B.

[0037] To make it clear, Figure 3-4 In the middle, a portion of the covering layer of one of the connecting fabrics was cut off. Detailed Implementation

[0038] Reference numerals: 1. Circular bag bottom; 2. Filter cloth; 2.1 Filter cloth body; 2.2 Bending part; 3. Connecting fabric; 3.1 Main body section; 3.1.1 Base fabric; 3.1.2 Covering layer; 3.2 Top section; 4.1 First elastic rope; 4.2 Second elastic rope.

[0039] like Figure 1-4As shown, a high-efficiency dust removal filter bag for flue gas includes a circular bag bottom 1, multiple filter cloths 2, and multiple connecting cloths 3. The number of filter cloths 2 is equal to the number of connecting cloths 3 and they are alternately distributed. Adjacent filter cloths 2 and connecting cloths 3 are connected to each other. All filter cloths 2 and all connecting cloths 3 are connected to the circular bag bottom 1. The connecting cloth 3 includes a main body section 3.1 located at the bottom and a top section 3.2 located at the top. The main body section 3.1 is a vertical strip and is wrinkled, while the top section 3.2 unfolds into a fan shape. At point 3.1, there are multiple first elastic ropes 4.1 and multiple second elastic ropes 4.2. One end of the first elastic rope 4.1 is fixedly connected to one side of the main body segment 3.1, and the other end is fixedly connected to the other side of the main body segment 3.1. One end of the second elastic rope 4.2 is fixedly connected to one side of the main body segment 3.1, and the other end is fixedly connected to the other side of the main body segment 3.1. The first elastic ropes 4.1 and the second elastic ropes 4.2 are alternately distributed in the vertical direction. When there is no external force, the length of the first elastic rope 4.1 is greater than that of the second elastic rope 4.2.

[0040] The connecting cloth 3 has 8 sections, and the filter cloth 2 has 8 sections. After the dust collector filter bag is installed, the filter cloth 2 includes a filter cloth body 2.1 and a bent portion 2.2 located above the filter cloth body 2.1. The filter cloth body 2.1 is arc-shaped, and multiple bent portions 2.2 and multiple top sections 3.2 are alternately distributed, with adjacent bent portions 2.2 and top sections 3.2 connected to each other. The circular bag bottom 1 is welded to the filter cloth 2 or sewn together; the circular bag bottom 1 is welded to the connecting cloth 3 or sewn together. The first elastic rope 4.1 is made of PTFE elastic yarn or silicone elastic yarn; the second elastic rope 4.2 is made of PTFE elastic yarn or silicone elastic yarn. The connecting cloth 3 includes a base cloth 3.1.1 and a covering layer 3.1.2, with the first elastic rope 4.1 and the second elastic rope 4.2 located between the base cloth 3.1.1 and the covering layer 3.1.2. The filter cloth 2 and the connecting cloth 3 are connected by ultrasonic welding or sewing together. The eight connecting fabrics 3 are all identical in specifications. The dust-facing side of the filter cloth 2 is covered with a PTFE film. After the dust collector filter bag is installed, the angle corresponding to the filter cloth 2 is greater than 40 degrees; the circular bag bottom 1 is made of the same material as the filter cloth 2, and its thickness is greater than that of the filter cloth 2. The filter cloth 2 is made of polyester needle-punched felt, polyphenylene sulfide needle-punched felt, or polytetrafluoroethylene needle-punched felt; the base fabric 3.1.1 is made of polyester needle-punched felt, polyphenylene sulfide needle-punched felt, or polytetrafluoroethylene needle-punched felt; the covering layer 3.1.2 is made of polyester needle-punched felt, polyphenylene sulfide needle-punched felt, or polytetrafluoroethylene needle-punched felt. The filter cloth 2, the base fabric 3.1.1, and the covering layer 3.1.2 are made of the same material.

[0041] The working principle of the filter bag in this application is as follows: I. Filtering Status Under normal filtration conditions, the dust collector operates under negative pressure. Dust-laden flue gas penetrates from the outside of the filter bag to the inside, and the dust is intercepted on the outer surface of the filter cloth and connecting cloth, forming a dust cake layer. At this time, the long elastic ropes inside the connecting cloth are in a state of natural contraction or slight stretching under the action of external negative pressure. The surface of the connecting cloth maintains a wrinkled shape, and the filter cloth and connecting cloth are tightly attached to the surface of the cage, maintaining a stable filtration shape.

[0042] II. Pulse cleaning status When the pressure difference between the inside and outside of the filter bag reaches the set value, the pulse cleaning system is activated, and compressed air is instantly sprayed into the bag from the bag opening. The pressure inside the bag rises sharply, and the high-pressure gas squeezes the filter bag radially outward. During this process: the long elastic ropes inside the connecting cloth are stretched significantly under the high pressure inside the bag, and the folds in their sections unfold, allowing the connecting cloth to displace outward in that section; the short elastic ropes, due to their own length limitations or higher elastic modulus, have a significantly smaller stretching amplitude than the long elastic ropes. This difference in stretching between adjacent sections forms multiple dense shear displacement zones along the vertical direction on the surface of the connecting cloth. The powder cake layer covering the connecting cloth and its interface with the filter cloth is subjected to a combined force of stretching and shearing, and is effectively broken and peeled off.

[0043] III. Reset state after dust removal After the pulse cleaning cycle ends, the high pressure inside the bag is released, the stretched elastic ropes recoil, the connecting cloth surface wrinkles again, and the filter cloth gently returns to its original position on the cage surface. The reformation of the wrinkles and the elastic recoil of the ropes absorb the return impact energy, avoiding the problem of traditional filter bags violently hitting the cage ribs after the pulse cleaning, effectively protecting the filter bag from mechanical damage. The filter bag then returns to its filtration state and enters the next working cycle.

[0044] Although the present invention has been illustrated and described with reference to preferred embodiments, those skilled in the art should understand that various changes and modifications can be made to the present invention without departing from the scope defined by the claims.

Claims

1. A high-efficiency dust removal filter bag for flue gas, characterized in that, The bag includes a circular bottom, multiple filter cloths, and multiple connecting cloths. The number of filter cloths is equal to the number of connecting cloths and they are alternately distributed. Adjacent filter cloths and connecting cloths are connected to each other, and all filter cloths and all connecting cloths are connected to the circular bottom. The connecting cloths include a main body section at the bottom and a top section at the top. The main body section is a vertical strip with pleats, and the top section unfolds into a fan shape. Multiple first elastic ropes and multiple second elastic ropes are connected to the main body section. One end of the first elastic rope is fixedly connected to one side of the main body section, and the other end is fixedly connected to the other side of the main body section. The first elastic ropes and second elastic ropes are alternately distributed in the vertical direction. When there is no external force, the length of the first elastic rope is greater than that of the second elastic rope.

2. The high-efficiency dust removal filter bag for flue gas according to claim 1, characterized in that, The connecting cloth has 8 pieces, and the filter cloth has 8 pieces; after the dust removal filter bag is installed, the filter cloth includes a filter cloth body and a bent portion located above the filter cloth body. The filter cloth body is arc-shaped, and multiple bent portions and multiple top sections are alternately distributed, with adjacent bent portions and top sections connected to each other.

3. The high-efficiency dust removal filter bag for flue gas according to claim 1, characterized in that, The circular bag bottom is welded to the filter cloth or sewn together with a sewing thread; the circular bag bottom is welded to the connecting cloth or sewn together with a sewing thread.

4. The high-efficiency dust removal filter bag for flue gas according to claim 1, characterized in that, The first elastic rope is made of PTFE elastic filament or silicone elastic thread; the second elastic rope is made of PTFE elastic filament or silicone elastic thread.

5. The high-efficiency dust removal filter bag for flue gas according to claim 1, characterized in that, The connecting fabric includes a base fabric and a covering layer, with the first elastic rope and the second elastic rope both located between the base fabric and the covering layer.

6. The high-efficiency dust removal filter bag for flue gas according to claim 1, characterized in that, The filter cloth and the connecting cloth are connected by ultrasonic welding or by sewing.

7. The high-efficiency dust removal filter bag for flue gas according to claim 1, characterized in that, The circular bag bottom is made of the same material as the filter cloth, but its thickness is greater than that of the filter cloth.

8. The high-efficiency dust removal filter bag for flue gas according to claim 1, characterized in that, The dust-facing side of the filter cloth is covered with a PTFE film.

9. The high-efficiency dust removal filter bag for flue gas according to claim 1, characterized in that, After the dust collector filter bag is installed, the angle corresponding to the filter cloth is greater than 40 degrees.

10. A high-efficiency dust removal filter bag for flue gas according to claim 5, characterized in that, The filter cloth is made of polyester needle-punched felt, polyphenylene sulfide needle-punched felt, or polytetrafluoroethylene needle-punched felt; the base fabric is made of polyester needle-punched felt, polyphenylene sulfide needle-punched felt, or polytetrafluoroethylene needle-punched felt; and the covering layer is made of polyester needle-punched felt, polyphenylene sulfide needle-punched felt, or polytetrafluoroethylene needle-punched felt.

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