Chimney noise reduction structure and processing technology

Abstract

The chimney noise reduction structure comprises a frame body and a smoke inlet in the bottom of the frame body, a square pipe frame is arranged on the inner wall of the frame body, connecting beams fixed to the square pipe frame are arranged at end openings of the two ends of the frame body, a mesh plate is fixed to the square pipe frame, a plurality of noise reduction columns are arranged in the frame body, and the noise reduction columns are arranged in the frame body. The two ends of each silencing column are provided with an upper connecting cover and a lower connecting cover, the silencing columns are vertically fixed between the two sets of connecting beams through the upper connecting covers and the lower connecting covers, the inner wall of the frame body is provided with a plurality of sets of resistive silencing mechanisms, the resistive silencing mechanisms are all arranged between the silencing columns, and each set comprises two resistive silencing mechanisms which are oppositely arranged; every two vertically adjacent silencing mechanisms are arranged in a staggered mode. According to the chimney silencing structure, interference and noise reduction can be conducted on smoke in multiple directions, howling sound generated by the smoke in a chimney is effectively reduced, the overall structure is stable, the chimney silencing structure is not affected by acid smoke or alkaline smoke, corrosion resistance is high, the machining technology is simplified, and the chimney silencing structure is suitable for application and popularization.

Description

Technical Field

[0001] This invention relates to the field of chimney noise reduction technology, and in particular to a chimney noise reduction structure and processing technology. Background Technology

[0002] As the core facility for flue gas emission in industrial production, the noise generated by chimneys during the flue gas emission process often becomes one of the main noise sources in the factory area and surrounding environment. The noise is frequent and lasts for a long time, which has a certain impact on the surrounding environment of the factory area.

[0003] The main reasons for noise generated during flue gas emission are as follows: First, when flue gas flows in the pipe, it encounters structures such as bends, valves, and reducers, which will cause turbulence due to sudden changes in flow velocity. Vortices in the airflow are constantly generated and broken, which causes the pipe wall to vibrate and radiate noise. This turbulent noise is the dominant sound source of the chimney. Secondly, in the smoke exhaust system, the induced draft fan (or blower) is the main source of vibration. The friction between the impeller and the flue gas when the impeller rotates at high speed, as well as the mechanical vibration of the motor, will also generate a lot of noise. In addition, when the flue gas is ejected from the outlet, it creates a speed difference with the surrounding still air, and the two mix violently to produce jet noise.

[0004] Prolonged noise not only affects the external environment, but also causes severe vibrations that loosen and crack structures such as flues, increasing maintenance costs. Therefore, factories usually install noise reduction structures at chimneys to avoid these problems.

[0005] Traditional silencing methods typically involve installing sound-absorbing cotton or perforated plates, which have a simple structure and are not suitable for noise reduction in large chimneys, resulting in unsatisfactory performance. In addition, in factories such as chip manufacturing, aerospace, and petrochemicals, the flue gas is usually acidic or alkaline. When in use, acidic or alkaline flue gas will corrode traditional silencing structures, affecting their overall service life and resulting in high replacement or maintenance costs. Summary of the Invention

[0006] The purpose of this invention is to solve the above-mentioned problems by providing a chimney silencing structure and processing technology that can interfere with and reduce the noise of flue gas from multiple directions, effectively reduce the whistling sound generated by the flue gas in the chimney, and has a stable overall structure that is not affected by acidic or alkaline flue gas and has strong corrosion resistance.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: a chimney silencing structure, comprising a frame and a smoke inlet at the bottom of the frame, a square tube frame provided on the inner wall of the frame, connecting beams fixed to the square tube frame at both ends of the frame, a perforated plate fixed on the square tube frame, a plurality of silencing columns provided inside the frame, an upper connecting cover and a lower connecting cover provided at both ends of the silencing column, and the silencing column being vertically fixed between two sets of connecting beams through the upper connecting cover and the lower connecting cover.

[0008] Preferably, the inner wall of the frame is provided with multiple sets of resistive silencing mechanisms. The resistive silencing mechanisms are all located between the silencing columns. Each set of resistive silencing mechanisms consists of two units and is arranged opposite to each other. The two adjacent sets of silencing mechanisms are staggered.

[0009] Preferably, the resistive silencing mechanism includes an extension plate with through holes on its surface. Multiple lifting rings are provided below the extension plate, with the outer diameter of the multiple lifting rings decreasing sequentially from top to bottom. Each pair of adjacent lifting rings is connected by a tension spring, and the uppermost lifting ring is connected to the extension plate by a tension spring. The multiple lifting rings can swing in an undirected manner after being disturbed by flue gas.

[0010] Preferably, the resistive silencing mechanism further includes a corrugated plate, which is disposed between the two resistive silencing mechanisms, and the two ends of the corrugated plate are fixed to the outer wall of the lowest lifting ring.

[0011] Preferably, the plurality of silencers are evenly distributed within the frame. The upper and lower connecting covers are each provided with mounting holes for fixing to the connecting beam. The lower connecting cover is also provided with air inlets around its perimeter. Each silencer has a fixing tube inside. The top end of the fixing tube is fixed to the inner wall of the upper connecting cover, and the bottom end does not contact the lower connecting cover. The outside of the fixing tube is provided with multiple arc-shaped curved plates, and the inside is provided with multiple eccentric columns along its own length. The multiple eccentric columns are connected by connecting ropes. The eccentric columns can swing inside the fixing tube and touch the inner wall of the fixing tube.

[0012] Preferably, the inner wall of the silencing column is also provided with multiple elliptical interference rings, with each pair of adjacent interference rings vertically offset. The multiple interference rings are suspended by a suspension rod, and the suspension rod is provided with a baffle plate corresponding to the interference ring, the baffle plate contacting the bottom of the interference ring.

[0013] Preferably, the inner wall of the frame is further provided with sound-absorbing cotton wrapped with a polytetrafluoroethylene film, and the sound-absorbing cotton is glass fiber cotton with a specification of 32kg / m³.

[0014] Preferably, the inner and outer walls of the frame and the sound-absorbing column are coated with Teflon, wherein the thickness of the Teflon coating is not less than 200 μm.

[0015] A manufacturing process for a chimney sound-absorbing structure includes the following steps: Step 1: Laser cutting, punching and bending of tubes. The square tube frame and connecting beam are made of 304 stainless steel industrial tubes, which are cut to the predetermined size and then punched and bent. Step 2: Skeleton welding. The skeleton is welded using laser welding according to the drawings. The welding degree is full welding to ensure that the pipe opening is completely sealed. Step 3: Sheet metal bending process. Laser cutting is performed according to the frame hole positions and drawings. After cutting, bending is performed to make the smoke inlet fit the pipe. Step 4: Outer panel installation and welding; Step 5: All-around sandblasting treatment. Sandblasting removes surface oil stains and increases the adhesion of Teflon. Step 6: Apply Teflon coating to the sandblasted areas; Step 7: Paint film inspection. Paint film inspection is performed during product assembly to ensure the Teflon thickness is marked. Step 8: Transportation protection. During transportation, the interior is fully wrapped with bubble wrap, the exterior is protected with cardboard, and the bottom is covered with a wooden pallet and foam board.

[0016] Preferably, step 6 further includes the following steps: 6.1: Apply Teflon primer in one coat, with a thickness of 50-60μm. The primer has a solid content of 50-60%. After spraying, place the primer in an oven to heat up. 6.2: Secondary spraying, the thickness of the secondary spraying is 100-120μm, the solid content of the spraying primer is 60-70%, and it is sent into the baking oven again for heating; 6.3: After three coats, the Teflon coating thickness shall not be less than 200μm, and the coating shall be allowed to air dry naturally for 3 hours after spraying.

[0017] This invention discloses a chimney silencing structure, comprising a frame and a flue gas inlet at the bottom of the frame. The inner wall of the frame is provided with a square tube frame, and connecting beams fixed to the square tube frame are provided at both ends of the frame. A perforated plate is fixed on the square tube frame. Multiple silencing columns are provided inside the frame, and each silencing column has an upper connecting cover and a lower connecting cover at both ends. The silencing column is vertically fixed between two sets of connecting beams via the upper and lower connecting covers. Multiple sets of resistive silencing mechanisms are provided on the inner wall of the frame, all located between the silencing columns. Each set of resistive silencing mechanisms consists of two units arranged opposite each other, with adjacent sets staggered. Compared with existing technologies, this chimney silencing structure has the advantages of multi-directional noise reduction of flue gas, effectively reducing the whistling sound generated by flue gas inside the chimney, stable overall structure, unaffected by acidic or alkaline flue gas, strong corrosion resistance, and simplified processing technology. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of a chimney silencing structure according to the present invention. Figure 1 .

[0019] Figure 2 This is a schematic diagram of the overall structure of a chimney silencing structure according to the present invention. Figure 2 .

[0020] Figure 3This is a schematic diagram of the internal structure of the frame in a chimney silencing structure according to the present invention.

[0021] Figure 4 This is a schematic diagram showing the arrangement of the resistive silencing mechanism in a chimney silencing structure according to the present invention. Figure 1 .

[0022] Figure 5 This is a schematic diagram showing the arrangement of the resistive silencing mechanism in a chimney silencing structure according to the present invention. Figure 2 .

[0023] Figure 6 This is a schematic diagram of the resistive silencing mechanism in a chimney silencing structure according to the present invention.

[0024] Figure 7 This is a schematic diagram of the arrangement of multiple sound-absorbing columns in a chimney sound-absorbing structure according to the present invention.

[0025] Figure 8 This is a schematic diagram of the internal structure of the sound-absorbing column in a chimney sound-absorbing structure according to the present invention. Figure 1 .

[0026] Figure 9 This is a schematic diagram of the internal structure of the sound-absorbing column in a chimney sound-absorbing structure according to the present invention. Figure 2 .

[0027] Figure 10 This is a schematic cross-sectional view of the sound-absorbing column in a chimney sound-absorbing structure according to the present invention.

[0028] Figure 11 For the present invention Figure 8 A magnified structural diagram of point A in the middle.

[0029] Figure 12 For the present invention Figure 9 A magnified structural diagram at point B in the middle.

[0030] Figure 13 A schematic diagram showing the noise simulation results after applying the silencing structure of this invention to a chimney.

[0031] In the diagram: 1. Frame; 11. Extension plate; 111. Through hole; 112. Lifting ring; 113. Tension spring; 114. Corrugated plate; 2. Smoke inlet; 3. Connecting beam; 4. Square tube frame; 5. Mesh plate; 6. Silencing column; 61. Upper connecting cover; 62. Lower connecting cover; 621. Air inlet; 63. Fixed pipe; 64. Curved plate; 65. Interference ring; 651. Hanging rod; 652. Grid plate; 66. Eccentric column; 661. Connecting rope. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings. The drawings are simplified schematic diagrams, illustrating only the basic structure of the invention in a schematic manner, and therefore only show the components relevant to the invention.

[0033] Please refer to Figure 1-5 A chimney silencing structure includes a frame 1 and a smoke inlet 2 at the bottom of the frame 1. The inner wall of the frame 1 is provided with a square tube frame 4. The two ends of the frame 1 are provided with connecting beams 3 that are welded and fixed to the square tube frame 4. A perforated plate 5 is fixed on the square tube frame 4. Multiple silencing columns 6 are provided inside the frame 1. The silencing columns 6 are provided with silencing holes on all four sides. The two ends of the silencing columns 6 are provided with an upper connecting cover 61 and a lower connecting cover 62. The silencing columns 6 are vertically fixed between two sets of connecting beams 3 through the upper connecting cover 61 and the lower connecting cover 62.

[0034] The inlet 2 connects to the flue port, and the frame 1 is set vertically. Similarly, the multiple silencers 6 inside the frame 1 are also kept vertical. When in use, the flue gas is discharged outward from inside the frame 1. After the flue gas enters the frame 1, some of the noise is absorbed by the mesh plate holes 5. When the flue gas comes into contact with the inner and outer walls of the silencers 6, it will also achieve noise reduction, thereby reducing the whistling sound generated when the flue gas is discharged.

[0035] The number of silencers 6 is determined according to the size of the flue and the requirements for smoke exhaust and noise reduction. It can be 4, 9, 16, etc. In this embodiment, four silencers 6 are used as an example.

[0036] In this embodiment, the inner wall of the frame 1 is provided with multiple sets of resistive silencing mechanisms. The resistive silencing mechanisms are all located between the silencing columns 6. Each set of resistive silencing mechanisms consists of two units and is arranged opposite to each other. The two adjacent sets of silencing mechanisms are staggered.

[0037] Please refer to this again. Figure 4-5 In other words, the multiple sets of resistive silencing mechanisms are arranged in multiple layers, with two in each layer, and the adjacent sides are staggered. This arrangement can realize the reflection, interference and resonance of flue gas sound waves inside the frame 1, which not only adjusts the flue gas flow path, but also reduces the intensity of noise propagating outward, thereby achieving the effect of silencing and noise reduction.

[0038] Please refer to this again. Figure 6 The resistive silencing mechanism includes an extension plate 11, the surface of which is provided with through holes 111. A plurality of lifting rings 112 are provided below the extension plate 111. The outer diameter of the plurality of lifting rings 112 decreases from top to bottom. Each pair of adjacent lifting rings 112 is connected by a tension spring 113. The uppermost lifting ring 112 is connected to the extension plate 11 by a tension spring 113. The plurality of lifting rings 112 can swing in an undirected manner after being disturbed by flue gas.

[0039] The extension plate 11 provides stable support for the entire structure, facilitating the installation and fixation of other noise reduction components. The through holes 111 on the surface of the extension plate 11 not only reduce the weight of the entire structure but also facilitate the smooth flow of flue gas, thereby improving noise reduction efficiency. The multiple lifting rings 112 are spaced evenly and their outer diameters decrease from top to bottom, allowing them to swing erratically when disturbed by flue gas. This helps to further disperse and absorb sound waves, thereby enhancing the noise reduction effect. To ensure that the lifting rings 112 can swing or bounce flexibly, each pair of adjacent lifting rings 112 is connected by a tension spring 113. This elastic connection allows the lifting rings 112 to freely extend, retract, and rotate when subjected to external forces.

[0040] In addition, each hanging ring 112 is also provided with a through hole at the center to ensure that the flue gas flows smoothly upward and avoids excessive interference with the exhaust.

[0041] Furthermore, the resistive silencing mechanism also includes a corrugated plate 114, which is disposed between the two resistive silencing mechanisms, with both ends of the corrugated plate 114 fixed to the outer wall of the lowermost lifting ring 112.

[0042] At this time, each set of resistive silencing mechanism and corrugated plate 114 penetrates the frame 1 laterally. After multiple sets are staggered, the frame 1 can be separated multiple times to achieve multiple reflections, interferences and resonances, and multiple adjustments to the flue gas flow path, so as to achieve silencing and noise reduction to the greatest extent while ensuring the smooth discharge of flue gas.

[0043] In use, the flue gas first enters the frame 1 through the flue gas inlet 2, and then passes through the resistive silencer mechanism at the bottom. It is understandable that sound-absorbing holes can also be provided on the extension plate 11, the lifting ring 112, and the corrugated plate 114.

[0044] Please refer to Figure 7-12 Multiple silencing columns 6 are evenly distributed within the frame 1 to ensure the balance of the entire silencing system. The upper connecting cover 61 and the lower connecting cover 62 are provided with mounting holes for fixing to the connecting beam 3, ensuring that the connecting beam 3 can firmly fix the silencing columns 6 between the upper and lower connecting covers, thereby enhancing the stability of the overall structure. The lower connecting cover 62 is also provided with air inlets 621 around its perimeter so that flue gas can enter the silencing column 6 from the air inlets 621 at the bottom. The silencing column 6 is provided with a fixing tube 63. The top end of the fixing tube 63 is fixed to the inner wall of the upper connecting cover 61, and the bottom end does not contact the lower connecting cover 62. In other words, the bottom end of the fixed tube 63 is suspended, meaning that the bottom end does not contact the lower connecting cover 62. This arrangement not only facilitates the flow of flue gas into the fixed tube 63 from the bottom, but also avoids unnecessary vibration transmission caused by the force of the flue gas blowing, thus preventing secondary noise generation. The fixed tube 63 is provided with multiple arc-shaped bending plates 64 on its outside. The arc-shaped bending plates 64 can not only effectively guide the airflow, but also enhance the sound absorption effect. When the flue gas flows in the sound absorption column 6, the arc-shaped inner wall can interfere with the sound waves, so that the sound waves are reflected and eliminated inside. In addition, multiple eccentric columns 66 are provided inside the fixed tube 63 along its own length direction. The multiple eccentric columns 66 are connected by connecting ropes 661. The eccentric columns 66 can swing inside the fixed tube 63 and touch the inner wall of the fixed tube 63.

[0045] The eccentric columns 66 are interconnected by connecting ropes 661 to form a dynamic silencing structure. When the flue gas enters the silencing column 6 from the bottom air inlet 621, the blowing force of the flue gas will blow the lowest eccentric column 66, allowing the eccentric column 66 to swing freely within the fixed tube 63. During the swinging process, the eccentric column 66 can touch the inner wall of the fixed tube 63. At this time, the sound wave generated by the contact between the eccentric column 66 and the fixed tube 63 cancels out the whistling sound wave of the flue gas, which can effectively eliminate the noise of flue gas emission and further improve the silencing effect.

[0046] In this embodiment, the eccentric column 66 is a hollow stainless steel barrel, which is lightweight and ensures high corrosion resistance and durability. Furthermore, its hollow design significantly reduces its weight compared to a solid structure, facilitating disturbance of the flue gas. The connecting rope 661 is flexible, allowing for adaptability to the eccentric column 66's swing in different directions. This ensures smooth contact and friction with the inner wall of the fixed pipe during its undirected swing, achieving the desired disturbance effect. This allows the eccentric column 66 to effectively absorb and attenuate noise generated during flue gas flow, resulting in excellent noise reduction. By combining flue gas flow optimization with noise control, a highly efficient and quiet flue gas emission effect is achieved.

[0047] The inner wall of the silencing column 6 is also provided with multiple elliptical interference rings 65. Each pair of adjacent interference rings 65 are vertically staggered to ensure that the sound waves can effectively interfere and attenuate during propagation. The multiple interference rings 65 are suspended by a suspension rod 651. The suspension rod 651 is provided with a baffle plate 642 corresponding to the interference ring 65. The baffle plate 642 contacts the bottom of the interference ring 65. The baffle plate 642 not only plays an auxiliary fixing role, but also directly contacts the bottom of the interference ring 65, further enhancing the stability and silencing effect of the entire silencing structure.

[0048] When in use, the external noise reduction of the silencer column 6 is achieved through its own noise reduction holes, while the internal noise reduction is achieved through the flow of flue gas inside and outside the fixed pipe 63, thereby maximizing the efficiency and effectiveness.

[0049] The inner wall of the frame 1 is also provided with sound-absorbing cotton wrapped with polytetrafluoroethylene film, and the sound-absorbing cotton is glass fiber cotton with a specification of 32kg / m³.

[0050] In actual use, the flue gas is usually acidic or alkaline, which can easily corrode the entire silencing structure. To improve the overall service life, the inner and outer walls of the frame 1 and the silencing column 6 are coated with Teflon, and the thickness of the Teflon coating is not less than 200μm.

[0051] Understandably, since the flue gas will come into contact with all internal components, all small parts, including the frame 1, silencer column 6, square tube frame 4, connecting beam 3, and bolts, gaskets, etc., need to be coated with polytetrafluoroethylene to ensure that the overall structure is resistant to acid and alkali corrosion and improves its service life.

[0052] Based on the above embodiments, the perforated plate 5, the silencing post 6, and other silencing holes have a specification of 3mm, and the spacing between each pair of adjacent silencing holes is 3mm.

[0053] like Figure 13 As shown, the original factory chimney noise is usually 75-90dB. After using this silencing structure, the noise can be reduced to below 53dB, which is a significant effect.

[0054] This invention also discloses a processing technology for a chimney silencing structure, comprising the following steps: Step 1: First, laser cutting, punching and bending are carried out. The square tube frame and connecting beam are made of high-quality 304 stainless steel industrial tubes. They are precisely cut according to the pre-set dimensions. Then, the cut tubes are punched and bent to ensure that their shape and size meet the design requirements. Step 2: Next, the frame welding is carried out. The frame welding process is strictly carried out according to the design drawings, using high-precision laser welding technology to ensure that the welding degree reaches the full welding standard, thereby ensuring that the pipe opening is completely sealed, effectively preventing external gas from entering the pipe and avoiding corrosion of the inner wall of the pipe; Step 3: Sheet metal bending process. According to the requirements of the frame hole positions and design drawings, laser cutting technology is used for precise cutting. After cutting, bending is performed to ensure that the smoke inlet and the pipe fit perfectly, thereby improving the sealing and stability of the overall structure. Step 4: Install and weld the outer panels. Install the outer panels onto the frame according to the design requirements and weld them in place to ensure a tight fit between the outer panels and the frame, thereby enhancing the overall structural strength. Step 5: Perform all-round sandblasting. Sandblasting thoroughly removes surface oil stains and other impurities, increases surface roughness, thereby increasing the adhesion of the Teflon coating and laying a good foundation for subsequent spraying work. Step 6: Apply Teflon coating to the sandblasted areas using an electrostatic spray gun; Specifically, the steps include the following: 6.1: First, apply Teflon primer with a thickness of 50-60μm in one coat and a solid content of 50-60%. After spraying, place the workpiece in an oven for heating treatment to ensure that the primer is fully cured. After spraying, place it in the oven and heat it to 180℃ at a rate of 5℃ / min, and hold it for 30 minutes to allow the primer to cure and form a chemical bond with the metal surface. 6.2: Next, a second spray coating is applied, with a thickness of 100-120μm and a primer solid content of 60-70%. The coating is then placed back into the baking oven, heated to 200℃, and held for 40 minutes to enhance the density of the coating (porosity ≤1%). 6.3: Finally, apply three coats of Teflon. The total thickness of the Teflon coating after the three coats should not be less than 200μm to meet the requirements of corrosion resistance and wear resistance. Do not bake immediately after spraying. Allow it to air dry naturally for 3 hours to allow the solvent in the coating to evaporate slowly and avoid the formation of bubbles due to rapid heating, so as to ensure that the Teflon coating achieves the best effect. Step 7: Conduct paint film testing. During product assembly, the Teflon coating is tested to ensure that the coating thickness meets the standard requirements, and the results are marked and recorded to ensure product quality. Step 8: Protect the product during transportation. During the transportation process, use bubble wrap to fully wrap the inside, add cardboard for external protection, and add wooden pallets and foam boards at the bottom to prevent collisions and damage during transportation, ensuring that the product arrives at its destination safely.

[0055] In this process, the temperature uniformity in the baking oven is ≤±5℃ to avoid local overheating that could lead to coating decomposition; the thickness deviation of the three coating layers is ≤5μm to ensure consistent coating performance.

[0056] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A chimney sound-absorbing structure, characterized in that, The frame includes a frame body and a smoke inlet at the bottom of the frame body. The inner wall of the frame body is provided with a square tube frame. The two ends of the frame body are provided with connecting beams fixed to the square tube frame. A perforated plate is fixed on the square tube frame. The frame body is provided with multiple silencing columns. The two ends of the silencing columns are provided with upper connecting covers and lower connecting covers. The silencing columns are vertically fixed between two sets of connecting beams through the upper connecting covers and lower connecting covers.

2. The chimney silencing structure according to claim 1, characterized in that, The inner wall of the frame is provided with multiple sets of resistive silencing mechanisms. The resistive silencing mechanisms are all located between the silencing columns. Each set of resistive silencing mechanisms consists of two units and is arranged opposite to each other. The two adjacent sets of silencing mechanisms are staggered.

3. The chimney silencing structure according to claim 2, characterized in that, The resistive silencing mechanism includes an extension plate with through holes on its surface. Multiple lifting rings are provided below the extension plate, with the outer diameter of the multiple lifting rings decreasing sequentially from top to bottom. Each pair of adjacent lifting rings is connected by a tension spring, and the uppermost lifting ring is connected to the extension plate by a tension spring. The multiple lifting rings can swing in an undirected manner after being disturbed by flue gas.

4. The chimney silencing structure according to claim 3, characterized in that, The resistive silencing mechanism also includes a corrugated plate, which is disposed between the two resistive silencing mechanisms, with both ends of the corrugated plate fixed to the outer wall of the lowest lifting ring.

5. The chimney silencing structure according to claim 1, characterized in that, Multiple sound-absorbing columns are evenly distributed within the frame. Both the upper and lower connecting covers have mounting holes for fixing to the connecting beam. The lower connecting cover also has air inlets around its perimeter. Each sound-absorbing column has a fixing tube inside. The top end of the fixing tube is fixed to the inner wall of the upper connecting cover, while the bottom end does not contact the lower connecting cover. The outside of the fixing tube has multiple arc-shaped curved plates, and the inside has multiple eccentric columns along its own length. The multiple eccentric columns are connected by connecting ropes. The eccentric columns can swing inside the fixing tube and touch the inner wall of the fixing tube.

6. The chimney silencing structure according to claim 5, characterized in that, The inner wall of the silencing column is also provided with multiple elliptical interference rings. Each pair of adjacent interference rings is vertically staggered. The multiple interference rings are suspended by a suspension rod. The suspension rod is provided with a baffle plate corresponding to the interference ring. The baffle plate contacts the bottom of the interference ring.

7. The chimney silencing structure according to claim 1, characterized in that, The inner wall of the frame is also provided with sound-absorbing cotton wrapped in polytetrafluoroethylene film, and the sound-absorbing cotton is glass fiber cotton with a specification of 32kg / m³.

8. The chimney silencing structure according to claim 1, characterized in that, The inner and outer walls of the frame and the sound-absorbing column are coated with Teflon, wherein the thickness of the Teflon coating is not less than 200μm.

9. A processing method for a chimney silencing structure according to any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Laser cutting, punching and bending of tubes. The square tube frame and connecting beam are made of 304 stainless steel industrial tubes, which are cut to the predetermined size and then punched and bent. Step 2: Skeleton welding. The skeleton is welded using laser welding according to the drawings. The welding degree is full welding to ensure that the pipe opening is completely sealed. Step 3: Sheet metal bending process. Laser cutting is performed according to the frame hole positions and drawings. After cutting, bending is performed to make the smoke inlet fit the pipe. Step 4: Outer panel installation and welding; Step 5: All-around sandblasting treatment. Sandblasting removes surface oil stains and increases the adhesion of Teflon. Step 6: Apply Teflon coating to the sandblasted areas; Step 7: Paint film inspection. Paint film inspection is performed during product assembly to ensure the Teflon thickness is marked. Step 8: Transportation protection. During transportation, the interior is fully wrapped with bubble wrap, the exterior is protected with cardboard, and the bottom is covered with a wooden pallet and foam board.

10. The processing technology of the chimney silencing structure according to claim 9, characterized in that, Step 6 further includes the following steps: 6.1: Apply Teflon primer in one coat, with a thickness of 50-60μm. The primer has a solid content of 50-60%. After spraying, place the primer in an oven to heat up. 6.2: Secondary spraying, the thickness of the secondary spraying is 100-120μm, the solid content of the spraying primer is 60-70%, and it is sent into the baking oven again for heating; 6.3: After three coats, the Teflon coating thickness shall not be less than 200μm, and the coating shall be allowed to air dry naturally for 3 hours after spraying.

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