Noise reduction device of rectangular air pipe

Abstract

The invention relates to the technical field of ventilation systems, in particular to a noise reduction device of a rectangular air duct, which comprises an air duct main body, a micropore resonance sound absorption layer is arranged in the air duct main body, and the outer wall of the micropore resonance sound absorption layer is coated with a gradient density sound absorption glass wool layer; the connecting assembly is arranged in the air pipe body, and the gradient density sound absorption glass wool layer and the micropore resonance sound absorption layer are detachably fixed to the air pipe body through the connecting assembly; the gradient density sound absorption glass wool layer and the micropore resonance sound absorption layer are matched with the air pipe body in shape, and a cavity is formed between the gradient density sound absorption glass wool layer and the inner wall of the air pipe body. By arranging the composite structure of the micropore sound absorption plate and the gradient density glass wool, the problem that low-frequency noise and medium-high-frequency noise are difficult to consider in the prior art is solved, full-band efficient sound absorption is achieved, in addition, the overall structure of the device is compact, and the excellent broadband noise reduction effect is achieved on the premise that a small space in an air pipe is occupied.

Description

Technical Field

[0001] This application relates to the field of ventilation system technology, and in particular to a noise reduction device for a rectangular air duct. Background Technology

[0002] With the increasing demand for ventilation systems in commercial buildings and large shopping malls, the noise problem of rectangular ducts, as a common air circulation facility, is receiving more and more attention. Since air flowing in ducts generates noise at different frequencies, how to effectively suppress these noises, especially reduce mid-to-high frequency and low-frequency noise, has become an urgent problem to be solved in duct design.

[0003] Currently, noise reduction techniques for rectangular ducts mainly rely on methods such as externally wrapping with sound-absorbing cotton, adding silencers, or optimizing the duct structure (e.g., adding guide vanes). In addition, some studies have used porous materials or Helmholtz resonant structures to absorb noise in specific frequency bands. While these traditional techniques can alleviate noise problems to some extent, they still have some shortcomings.

[0004] The existing technical solutions mentioned above have the following drawbacks: First, external noise reduction measures (such as sound-absorbing cotton wrapping) occupy a large space and are easily restricted by the layout of the shopping mall's ceiling; second, traditional silencers or guide vanes will change the internal flow field of the duct, increasing pressure loss and energy consumption; third, the low-frequency noise control effect is poor, while the sound-absorbing materials for high-frequency noise are often thick and expensive. Furthermore, due to the large number of duct models, it is difficult to manufacture modular noise reduction equipment to adapt to the different sizes and layout requirements of shopping mall ducts, resulting in poor flexibility. Therefore, this application provides a noise reduction device for rectangular ducts. Summary of the Invention

[0005] This application provides a noise reduction device for rectangular air ducts to address the common problem of noise generation during the use of air ducts.

[0006] The above-mentioned technical objective of this application is achieved through the following technical solution: A noise reduction device for a rectangular air duct, comprising: The air duct body has a microporous resonant sound-absorbing layer inside, and the outer wall of the microporous resonant sound-absorbing layer is covered with a gradient density sound-absorbing glass wool layer. A connecting component is provided inside the duct body, and the gradient density sound-absorbing glass wool layer and the microporous resonant sound-absorbing layer are detachably fixed to the duct body through the connecting component. The gradient density sound-absorbing glass wool layer and the microporous resonant sound-absorbing layer are shaped to fit the main body of the duct, and a cavity is provided between the gradient density sound-absorbing glass wool layer and the inner wall of the duct. By adopting the above solution, the low-frequency and mid-to-high frequency noise problems that are difficult to address simultaneously with traditional technologies are solved, achieving efficient sound absorption across the entire frequency band; the gradient density sound-absorbing glass wool layer and the microporous resonant sound-absorbing layer can be quickly installed and removed from the duct, making it highly adaptable and easy to install and maintain.

[0007] Preferably, the connecting component includes a C-shaped clip and a guide rail. The clip is fixed to the inner wall of the duct body, and the guide rail is installed on the outer wall of the gradient density sound-absorbing glass wool layer. The guide rail is slidably engaged with the clip. By adopting the above solution, the installation process does not require complicated tools; simply pushing the guide rail along the clip track completes the positioning. This not only simplifies the installation process but also ensures a stable connection between components. Even when subjected to airflow impact or vibration during duct operation, the structure maintains stability and is not prone to loosening or detachment. At the same time, this detachable connection method facilitates the later cleaning, replacement, or upgrading of the sound-absorbing layer, greatly improving the maintenance efficiency and flexibility of the duct system.

[0008] Preferably, a fixing screw is installed on the guide rail, and mounting holes are opened on the gradient density sound-absorbing glass wool layer and the microporous resonant sound-absorbing layer at positions corresponding to the fixing screw. The fixing screw passes through the mounting hole and a locking nut is threaded onto its end. By adopting the above solution, it is convenient to install the guide rail on the gradient density sound-absorbing glass wool layer and the microporous resonant sound-absorbing layer. This fixing method facilitates the individual replacement or repair of the guide rail or sound-absorbing layer when needed, reducing maintenance costs and time.

[0009] Preferably, a support sleeve is fitted onto the fixing screw, and the support sleeve is disposed between the gradient density sound-absorbing glass wool layer and the duct wall. By adopting the above solution, a cavity for forming a Helmholtz resonance system is constructed between the duct wall and the gradient density sound-absorbing glass wool layer, further enhancing the absorption effect of low-frequency noise; moreover, the support sleeve is made of a material with certain elasticity and sound insulation properties, such as rubber or foam plastic, which can ensure the stability of the cavity while also absorbing vibrations generated during duct operation to a certain extent, reducing secondary noise pollution caused by vibration, and further improving the overall noise reduction effect.

[0010] Preferably, a groove is formed on the side of the guide rail away from the gradient density sound-absorbing glass wool layer, and a through hole is formed in the middle of the groove. The fixing screw is inserted through the through hole, and a mounting plate is fixed on the side of the fixing screw away from the gradient density sound-absorbing glass wool layer. The mounting plate is locked in the groove. By adopting the above solution, it is convenient to disassemble or replace the fixing screw and related components when necessary. Simply remove the mounting plate from the groove, and the fixing screw can be easily pulled out from the through hole for corresponding maintenance or replacement work, reducing maintenance difficulty and cost.

[0011] Preferably, the sidewall of the duct body is provided with an outer protective layer, a thermal insulation layer, and a duct wall from the outside to the inside. By adopting the above solution, not only is the structural strength of the duct body enhanced, enabling it to withstand greater external pressure and internal airflow impact, but its durability and service life are also significantly improved, reducing the risk of corrosion and damage caused by environmental factors. At the same time, the presence of the thermal insulation layer effectively reduces heat loss during gas transportation, improving energy efficiency, which is especially important for gas transportation systems that need to maintain a specific temperature. In addition, the thermal insulation layer can also absorb and isolate external noise to a certain extent, working together with the internal sound-absorbing layer to form a multi-layered noise reduction system, further improving the overall noise reduction effect.

[0012] Preferably, the gradient density sound-absorbing glass wool layer is composed of multiple layers of glass wool with gradually varying densities. By adopting the above scheme, glass wool layers of different densities are composited, resulting in gradient density sound-absorbing glass wool layers having different sound absorption coefficients in different frequency ranges, thus broadening the sound absorption frequency range and improving the overall performance of the noise reduction device.

[0013] Preferably, the microporous resonant sound-absorbing layer is composed of four precision microporous sound-absorbing plates, and the surface of the microporous resonant sound-absorbing layer is provided with an oleophobic coating. By adopting the above solution, a large sound-absorbing area is achieved, which can effectively absorb mid-to-high frequency noise; the oleophobic coating on the surface can effectively prevent oil, dust and other impurities from adhering to the surface of the microporous resonant sound-absorbing layer, keeping its surface clean and its pores unobstructed, thereby ensuring the stability and durability of its sound absorption performance, reducing the problem of reduced sound absorption effect caused by impurities clogging, extending the service life of the noise reduction device and reducing maintenance costs.

[0014] Preferably, a fixed bracket is provided at the bottom of the duct body, and support screws are symmetrically fixed at both ends of the fixed bracket. A mounting seat is slidably installed on the support screws, and a locking nut, threadedly connected to the support screw, is provided on the inner side of the mounting seat. By adopting the above solution, a stable support is provided for the duct body, ensuring its stability during operation and preventing shaking or displacement. This reduces additional noise and vibration caused by duct instability, further improving the overall performance and reliability of the noise reduction device. Furthermore, this adjustable installation method facilitates later maintenance and repair of the duct body. Simply loosening the locking nut and adjusting the position of the mounting seat allows for easy disassembly or installation of the duct body, reducing maintenance difficulty and cost.

[0015] In summary, this application has the following technical effects: 1. By setting up a composite structure of microporous sound-absorbing panels and gradient density glass wool, the problem of low-frequency and mid-to-high-frequency noise, which is difficult to solve by traditional technology, is solved at the same time, achieving efficient sound absorption across the entire frequency range.

[0016] 2. The device has a compact overall structure and achieves excellent broadband noise reduction effect while occupying a small amount of space in the air duct. Compared with traditional external sound-absorbing materials, it greatly reduces space occupation and perfectly meets the compact installation requirements of shopping mall air ducts.

[0017] 3. The guide rail snap-fit ​​connection system supports flexible disassembly and size adjustment, making the noise reduction components compatible with different specifications of air ducts and greatly improving installation efficiency. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the buckle and guide rail structure of the present invention; Figure 3 This is a partial cross-sectional view of the present invention; Figure 4 yes Figure 3 Enlarged view of point A in the middle; Figure 5 This is the front view of the present invention; Figure 6 This is a partial structural schematic diagram of the present invention; Figure 7 This is a cross-sectional schematic diagram of the duct body in this invention; Figure 8 This is a side view of the present invention.

[0019] In the diagram, 1. Duct body; 2. Gradient density sound-absorbing glass wool layer; 3. Microporous resonant sound-absorbing layer; 4. Cavity; 5. Clip; 6. Mounting base; 7. Support screw; 8. Fixing bracket; 9. Locking nut one; 10. Guide rail; 11. Recessed groove; 12. Mounting plate; 13. Fixing screw; 14. Mounting hole; 15. Support sleeve; 16. Locking nut two; 17. Outer protective layer; 18. Thermal insulation layer; 19. Duct wall. Detailed Implementation

[0020] The present application will be further described in detail below with reference to the accompanying drawings.

[0021] Reference Figures 1 to 8 As shown in the figure, a noise reduction device for a rectangular duct according to an embodiment of the present invention includes: The air duct body 1 has a microporous resonant sound-absorbing layer 3 inside, and the outer wall of the microporous resonant sound-absorbing layer 3 is covered with a gradient density sound-absorbing glass wool layer 2. A connecting component is provided inside the duct body 1, and the gradient density sound-absorbing glass wool layer 2 and the microporous resonant sound-absorbing layer 3 are detachably fixed to the duct body 1 through the connecting component. The gradient density sound-absorbing glass wool layer 2 and the microporous resonant sound-absorbing layer 3 are adapted to the shape of the duct body 1, and a cavity 4 is provided between the gradient density sound-absorbing glass wool layer 2 and the inner wall of the duct body 1.

[0022] The device has a compact overall structure and achieves excellent broadband noise reduction effect while occupying a small amount of space in the duct. The gradient density sound-absorbing glass wool is directly bonded to the microporous resonant sound-absorbing layer 3. When the airflow passes through the inside of the microporous resonant sound-absorbing layer 3, it can effectively absorb mid-to-high frequency noise (500-4000Hz). Energy conversion is achieved through the viscous dissipation of sound waves in the micropores and fiber friction. A cavity 4 of 20-30mm is set between the gradient density sound-absorbing glass wool and the inner wall of the duct body 1, thus forming a Helmholtz resonance system. When the depth of the cavity 4 is 1 / 4 wavelength, it can specifically absorb specific low-frequency noise (such as 125-250Hz). Through this structural design, excellent noise control effect can be obtained in a wide frequency range. In addition, connecting components are used to enable quick assembly and disassembly of the gradient density sound-absorbing glass wool layer 2 and the microporous resonant sound-absorbing layer 3 from the duct body 1, which is highly adaptable and easy to assemble and maintain.

[0023] The connecting assembly includes a C-shaped buckle 5 and a guide rail 10. The buckle 5 is fixed to the inner wall of the duct body 1, and the guide rail 10 is installed on the outer wall of the gradient density sound-absorbing glass wool layer 2. The guide rail 10 is slidably engaged in the buckle 5.

[0024] The sliding snap-fit ​​structure between the C-type buckle 5 and the guide rail 10 eliminates the need for complex tools during installation. Simply push the guide rail 10 along the buckle 5 track to complete the positioning. This not only simplifies the installation process but also ensures a stable connection between components. Even when subjected to airflow impact or vibration during duct operation, the structure remains stable and is less prone to loosening or falling off. At the same time, this detachable connection method facilitates the cleaning, replacement, or upgrading of the sound-absorbing layer in the future, greatly improving the maintenance efficiency and flexibility of the duct system.

[0025] A fixing screw 13 is installed on the guide rail 10. The gradient density sound-absorbing glass wool layer 2 and the microporous resonant sound-absorbing layer 3 are provided with mounting holes 14 at positions corresponding to the fixing screw 13. The fixing screw 13 passes through the mounting hole 14 and is threaded with a locking nut 16 at its end.

[0026] The fixing screw 13 passes through the mounting holes 14 on the gradient density sound-absorbing glass wool layer 2 and the microporous resonant sound-absorbing layer 3, and is then tightened by the locking nut 16. This makes it easy to install the guide rail 10 on the gradient density sound-absorbing glass wool layer 2 and the microporous resonant sound-absorbing layer 3. This fixing method makes it easy to replace or repair the guide rail 10 or the sound-absorbing layer separately when needed, reducing maintenance costs and time.

[0027] A support sleeve 15 is fitted onto the fixing screw 13, and the support sleeve 15 is disposed between the gradient density sound-absorbing glass wool layer 2 and the duct wall 19.

[0028] By installing a support sleeve 15 between the duct wall 19 and the gradient density sound-absorbing glass wool layer 2, a cavity 4 for forming a Helmholtz resonance system is constructed between the two, further enhancing the absorption effect of low-frequency noise. Furthermore, the support sleeve 15 is made of a material with certain elasticity and sound insulation properties, such as rubber or foam plastic, which can ensure the stability of the cavity 4 while absorbing vibrations generated during duct operation to a certain extent, reducing secondary noise pollution caused by vibration, and further improving the overall noise reduction effect. In addition, support sleeves 15 of different lengths can be used according to actual installation needs to flexibly adjust the size of the cavity 4 between the gradient density sound-absorbing glass wool layer 2 and the duct wall 19, thereby adapting to the low-frequency noise absorption requirements of different frequency ranges.

[0029] A groove 11 is provided on the side of the guide rail 10 away from the gradient density sound-absorbing glass wool layer 2. A through hole is provided in the middle of the groove 11. The fixing screw 13 is inserted through the through hole. An mounting plate 12 is fixed on the side of the fixing screw 13 away from the gradient density sound-absorbing glass wool layer 2. The mounting plate 12 is limited and engaged in the groove 11.

[0030] The cooperation between the recess 11 and the mounting plate 12 provides positioning and guidance for the installation of the fixing screw 13, making the installation process more accurate and convenient, and improving installation efficiency. At the same time, this facilitates operation when it is necessary to disassemble or replace the fixing screw 13 and related components. Simply remove the mounting plate 12 from the recess 11, and the fixing screw 13 can be easily pulled out from the through hole for corresponding maintenance or replacement work, reducing maintenance difficulty and cost.

[0031] The sidewall of the duct body 1 is provided with an outer protective layer 17, a thermal insulation layer 18 and a duct wall 19 from the outside to the inside.

[0032] The outer protective layer 17 is made of aluminized zinc-coated steel sheet, which has excellent corrosion resistance after special surface treatment; the thermal insulation layer 18 is made of centrifugal glass wool, which has both thermal insulation and auxiliary noise reduction functions; the duct wall 19 is made of galvanized steel sheet, and the overall rigidity is ensured by the ring reinforcing rib design; this multi-layer composite structure not only enhances the structural strength of the duct body 1, enabling it to withstand greater external pressure and internal airflow impact, but also significantly improves its durability and service life, reducing the risk of corrosion and damage caused by environmental factors; at the same time, the presence of the thermal insulation layer 18 effectively reduces the heat loss of the duct during gas transportation, improving energy utilization efficiency, which is especially important for gas transportation systems that need to maintain a specific temperature; in addition, the thermal insulation layer 18 can also absorb and isolate external noise to a certain extent, working together with the internal sound-absorbing layer to form a multi-layer noise reduction system, further improving the overall noise reduction effect.

[0033] The gradient density sound-absorbing glass wool layer 2 is composed of multiple layers of glass wool with gradually varying densities.

[0034] By combining glass wool layers of different densities, the gradient density sound-absorbing glass wool layer 2 has different sound absorption coefficients in different frequency ranges, which broadens the sound absorption frequency range and improves the overall performance of the noise reduction device.

[0035] The microporous resonant sound-absorbing layer 3 is composed of four precision microporous sound-absorbing plates, and the surface of the microporous resonant sound-absorbing layer 3 is provided with an oleophobic coating.

[0036] The structure formed by four precision microporous sound-absorbing panels gives the microporous resonant sound-absorbing layer 3 a large sound-absorbing area, which can effectively absorb mid-to-high frequency noise. The oleophobic coating (such as nano titanium dioxide) on the surface can effectively prevent oil, dust and other impurities from adhering to the surface of the microporous resonant sound-absorbing layer 3, keeping its surface clean and its pores unobstructed, thereby ensuring the stability and durability of its sound absorption performance, reducing the problem of reduced sound absorption effect caused by impurities clogging, extending the service life of the noise reduction device and reducing maintenance costs.

[0037] The bottom of the duct body 1 is provided with a fixed bracket 8, and the fixed bracket 8 is symmetrically fixed with support screws 7 at both ends. A mounting seat 6 is slidably installed on the support screw 7, and a locking nut 9 that is threadedly connected to the support screw 7 is provided on the inner side of the mounting seat 6.

[0038] The structure of the fixed bracket 8 and the supporting screw 7 provides a stable support for the duct body 1, ensuring its stability during operation and preventing shaking or displacement. This reduces additional noise and vibration caused by duct instability, further improving the overall performance and reliability of the noise reduction device. In addition, this adjustable installation method facilitates the maintenance and repair of the duct body 1 in the later stages. Simply loosen the locking nut 9 and adjust the position of the mounting base 6 to easily disassemble or install the duct body 1, reducing maintenance difficulty and cost.

[0039] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A noise reduction device for a rectangular air duct, characterized in that: include: The air duct body (1) has a microporous resonant sound-absorbing layer (3) inside, and the outer wall of the microporous resonant sound-absorbing layer (3) is covered with a gradient density sound-absorbing glass wool layer (2). The connecting component is located inside the duct body (1). The gradient density sound-absorbing glass wool layer (2) and the microporous resonant sound-absorbing layer (3) are detachably fixed to the duct body (1) through the connecting component. The gradient density sound-absorbing glass wool layer (2) and the microporous resonant sound-absorbing layer (3) are adapted to the shape of the duct body (1), and a cavity (4) is provided between the gradient density sound-absorbing glass wool layer (2) and the inner wall of the duct body (1).

2. The noise reduction device for a rectangular duct according to claim 1, characterized in that: The connecting component includes a C-type buckle (5) and a guide rail (10). The buckle (5) is fixed on the inner wall of the duct body (1), and the guide rail (10) is installed on the outer wall of the gradient density sound-absorbing glass wool layer (2). The guide rail (10) is slidably engaged in the buckle (5).

3. The noise reduction device for a rectangular duct according to claim 2, characterized in that: A fixing screw (13) is installed on the guide rail (10). The gradient density sound-absorbing glass wool layer (2) and the microporous resonant sound-absorbing layer (3) are provided with mounting holes (14) at positions corresponding to the fixing screw (13). The fixing screw (13) passes through the mounting hole (14) and a locking nut (16) is threaded on its end.

4. The noise reduction device for a rectangular duct according to claim 3, characterized in that: A support sleeve (15) is fitted on the fixing screw (13), and the support sleeve (15) is located between the gradient density sound-absorbing glass wool layer (2) and the duct wall (19).

5. The noise reduction device for a rectangular duct according to claim 4, characterized in that: The guide rail (10) has a groove (11) on the side away from the gradient density sound-absorbing glass wool layer (2). A through hole is provided in the middle of the groove (11). The fixing screw (13) is inserted through the through hole. A mounting plate (12) is fixed on the side of the fixing screw (13) away from the gradient density sound-absorbing glass wool layer (2). The mounting plate (12) is limited and engaged in the groove (11).

6. The noise reduction device for a rectangular duct according to claim 1, characterized in that: The sidewall of the duct body (1) is provided with an outer protective layer (17), a thermal insulation layer (18) and a duct wall (19) from the outside to the inside.

7. The noise reduction device for a rectangular duct according to claim 1, characterized in that: The gradient density sound-absorbing glass wool layer (2) is composed of multiple layers of glass wool with gradually varying densities.

8. The noise reduction device for a rectangular duct according to claim 1, characterized in that: The microporous resonant sound-absorbing layer (3) is composed of four precision microporous sound-absorbing plates, and the surface of the microporous resonant sound-absorbing layer (3) is provided with an oleophobic coating.

9. A noise reduction device for a rectangular duct according to claim 1, characterized in that: The bottom of the duct body (1) is provided with a fixed bracket (8), and the fixed bracket (8) is symmetrically fixed with support screws (7) at both ends. A mounting seat (6) is slidably installed on the support screw (7), and a locking nut (9) is provided on the inner side of the mounting seat (6) and threadedly connected to the support screw (7).

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