A noise reduction louver structure for wideband noise

Abstract

The application relates to a noise reduction louver structure for wideband noise, comprising a window frame and a louver array installed in the window frame, the louver array comprising a plurality of parallel arranged louvers, the louvers being filled with sound absorption layers, the louvers comprising first flow guide sections and second flow guide sections, the first flow guide sections and the second flow guide sections being connected with each other through bending parts with opposite convex directions, the spacing between the first flow guide sections of adjacent louvers and the spacing between the second flow guide sections being greater than the spacing between the bending parts, and the louvers being provided with perforated areas. The application realizes effective control of wideband noise through the synergistic effect of multiple acoustic mechanisms. The sound labyrinth effect of the sound absorption layer is mainly responsible for absorbing medium and high frequency noise; the first flow guide sections, the second flow guide sections and the bending parts are specially designed for attenuating low frequency noise; and the central sound absorption area formed by the V-shaped layout further enhances the overall sound absorption effect, realizing wideband noise reduction from low frequency to high frequency.

Description

Technical Field

[0001] This application relates to the field of noise-reducing louver technology, and in particular to a noise-reducing louver structure for broadband noise. Background Technology

[0002] Venetian blinds, as common ventilation components, are widely used in buildings and industrial equipment. However, traditional venetian blinds have significant shortcomings in noise control: for low-frequency noise, their penetrating power is strong, and ordinary venetian blinds are almost ineffective in blocking it; for high-frequency noise, although there is some attenuation effect, the noise reduction is limited. Currently, most noise-reducing venetian blinds on the market focus on a single frequency band and cannot cope with wide-band noise environments simultaneously.

[0003] In high-noise environments such as industrial plants, cooling towers, and power plants, the noise generated by equipment typically covers a wide frequency range from low to high frequencies. Traditional solutions often require installing separate silencers outside the louvers, but this results in a complex system structure, large space occupation, high cost, and a significant impact on ventilation efficiency. How to effectively control broadband noise while maintaining good ventilation performance has always been a pressing technical challenge in this field.

[0004] Existing noise-reducing louvers typically employ the following methods: first, simply increasing the thickness of the sound-absorbing material, which significantly increases air resistance; second, using a simple perforated panel structure, but only effective for specific frequency bands; and third, using a complex multi-cavity structure, but with high manufacturing costs and difficult maintenance. None of these solutions achieve a good balance between broadband noise reduction and ventilation efficiency.

[0005] Therefore, there is an urgent need for an innovative louver structure that can effectively attenuate noise across the entire frequency range, from low to high frequencies, while maintaining low ventilation resistance. Summary of the Invention

[0006] Therefore, it is necessary to provide a noise-reducing louver structure for broadband noise, which can solve the shortcomings of traditional louvers that cannot effectively attenuate low-frequency and high-frequency noise at the same time, and that it is difficult to balance noise reduction and ventilation performance.

[0007] A noise-reducing venetian blind structure for broadband noise includes a window frame and a blade array installed within the window frame. The blade array includes multiple parallel blades, each blade is filled with a sound-absorbing layer, and each blade includes a first guide section and a second guide section. The first and second guide sections are connected to each other by bends with opposite protrusion directions. The spacing between the first guide sections and the second guide sections of adjacent blades is greater than the spacing between the bends. The blades are provided with perforated areas.

[0008] As a preferred embodiment of the noise-reducing louver structure for broadband noise described in this invention, the blade array comprises at least two sets, with corresponding blades in the two sets of blade arrays arranged symmetrically in a V-shape. The second guide sections of the corresponding blades in each set are adjacent to each other and have a gap distance, together forming a wedge-shaped central sound-absorbing zone.

[0009] As a preferred embodiment of the noise-reducing louver structure for broadband noise described in this invention, an upper airflow guiding mechanism is provided directly above the central sound-absorbing zone. The cross-section of the upper airflow guiding mechanism is an inverted isosceles trapezoid, with its lower base connected to the window frame and its upper base facing the direction of the central sound-absorbing zone.

[0010] As a preferred embodiment of the noise-reducing louver structure for broadband noise described in this invention, the projections of the two inclined surfaces of the upper airflow guiding mechanism in the vertical direction overlap with the projections of the bent portions of the adjacent blades in the vertical direction.

[0011] As a preferred embodiment of the noise-reducing louver structure for broadband noise described in this invention, a lower flow guiding mechanism is provided below the central sound-absorbing zone and on both sides of the V-shaped structure. The cross-section of the lower flow guiding mechanism is a right-angled trapezoid with its hypotenuse facing the central sound-absorbing zone.

[0012] As a preferred embodiment of the noise-reducing louver structure for broadband noise described in this invention, the projection of the upper edge of the inclined side of the lower guide mechanism in the vertical direction overlaps with the projection of the bent portion of the adjacent blade in the vertical direction.

[0013] As a preferred embodiment of the noise-reducing louver structure for broadband noise described in this invention, the sound-absorbing layer includes multiple mutually isolated cavities, which together with the perforated area constitute a resonant sound-absorbing structure for attenuating low-frequency noise.

[0014] As a preferred embodiment of the noise-reducing louver structure for broadband noise described in this invention, the opening ratio of the perforated area is between 5% and 80%.

[0015] As a preferred embodiment of the noise-reducing louver structure for broadband noise described in this invention, the louvers are connected to the window frame via connecting pieces.

[0016] As a preferred embodiment of the noise-reducing louver structure for broadband noise described in this invention, the bending angle of the bending portion is between 100° and 170°.

[0017] The beneficial effects of this invention are: This invention achieves effective control of broadband noise through the synergistic effect of multiple acoustic mechanisms. The acoustic labyrinth effect of the sound-absorbing layer is mainly responsible for absorbing mid-to-high frequency noise; the first guide section, the second guide section, and the bend section are specifically designed to attenuate low-frequency noise; the central sound-absorbing zone formed by the V-shaped layout further enhances the overall sound absorption effect, achieving broadband noise reduction from low to high frequencies.

[0018] By designing the spacing between the guide sections of adjacent blades to be greater than the spacing between the bends, sufficient airflow channels are provided while ensuring an effective sound wave attenuation path, effectively reducing ventilation resistance. The streamlined guide section design and specific bend angle further optimize airflow organization, reducing turbulence and pressure loss.

[0019] The precise coordination between the upper and lower airflow guiding mechanisms and the blade structure ensures that the airflow can pass smoothly through the louvers, reducing wind resistance and preventing the generation of airflow-generated noise. The inverted isosceles trapezoidal upper airflow guiding mechanism, the unperforated first airflow guiding section, and the spacing between each set of corresponding blades also have a rainproof and airflow guiding function.

[0020] All noise reduction and airflow diversion functions are integrated into the louver's own structure, eliminating the need for additional sound-absorbing equipment and saving space and cost. The modular design facilitates manufacturing, installation, and maintenance.

[0021] By adjusting parameters such as the perforation ratio and bending angle of the perforated area, the design can be optimized for different noise spectrum characteristics to meet the application needs of various industrial, commercial and civil buildings. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall structure of the noise-reducing venetian blinds according to an embodiment of this application; Figure 2 This is a longitudinal cross-sectional structural diagram of the noise-reducing venetian blinds according to an embodiment of this application; Figure 3 This is a partial structural schematic diagram of the blade array according to an embodiment of this application; Figure 4 This is a schematic diagram of the blade structure according to an embodiment of this application; Figure 5 This is a schematic diagram illustrating the transmission loss of different diameters and opening ratios of the perforated area in an embodiment of this application. Explanation of reference numerals in the attached figures: 1000, Window frame; 2000, Blade; 2100, First guide section; 2200, Second guide section; 2300, Bend; 2400, Perforated area; 3000, sound-absorbing layer; 4000, upper flow guiding mechanism; 5000, lower guide mechanism. Detailed Implementation

[0024] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0025] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0027] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," 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, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0028] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0029] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0030] According to one aspect of this application, embodiments of this application provide a noise-reducing venetian blind structure for broadband noise, please refer to [further details omitted]. Figures 1 to 5 The noise-reducing louver structure includes a window frame 1000 and a blade array installed within the window frame 1000. The blade array includes multiple parallel blades 2000, each filled with a sound-absorbing layer 3000. Each blade 2000 includes a first guide section 2100 and a second guide section 2200. The first guide section 2100 and the second guide section 2200 are connected to each other by bending portions 2300 with opposite protrusion directions. The distance between the first guide section 2100 and the second guide section 2200 of adjacent blades 2000 is greater than the distance between the bending portions 2300. Each blade 2000 is provided with a perforated area 2400.

[0031] In this embodiment, the noise-reducing louver structure for broadband noise includes a window frame 1000 and a blade array installed within the window frame 1000. A bent channel is formed between adjacent blades 2000 of the blade array. After passing through the S-shaped bent channel, the sound waves are attracted to the surface of the sound-absorbing layer 3000 and undergo multiple reflections, converting sound energy into heat energy to absorb mid-to-high frequency noise. The perforated area 2400 and the cavity in the sound-absorbing layer 3000 form a Hellheimer resonator, which, by adjusting the cavity volume and perforation parameters, targets and attenuates low-frequency noise. The structure of the bent channel causes sound waves from different paths to interfere and cancel each other out, achieving broadband noise reduction from low to high frequencies.

[0032] In one embodiment, please refer to [the relevant documentation / reference]. Figure 2 and Figure 3The blade array comprises at least two sets, with corresponding blades 2000 in the two sets arranged symmetrically in a V-shape. The second guide sections 2200 of two adjacent blades 2000 are close to each other and have a gap, together forming a wedge-shaped central sound-absorbing zone. The perforated area 2400 is set on the second guide section 2200 and arranged above the central sound-absorbing zone. The V-shaped structure forms a deeper and more complex sound wave trap. After the sound wave enters the V-shaped structure, it undergoes multiple reflections and turns before passing through, further increasing the attenuation of the sound wave. The central sound-absorbing zone becomes a more effective sound energy convergence and dissipation center. For normally incident and near-normally incident sound waves, the noise reduction effect is significantly improved. The V-shaped layout superimposes the noise reduction effects of the two arrays in physical space, achieving the goal of achieving a higher noise reduction amount in a limited space. The structure is compact and efficient.

[0033] In one embodiment, please refer to [the relevant documentation / reference]. Figure 2 , Figure 3 and Figure 4 The blade 2000 is made of aluminum alloy profile with a continuous bent cross-section, including a first guide section 2100 and a second guide section 2200. The first guide section 2100 and the second guide section 2200 are connected to each other by bent portions 2300 with opposite protrusion directions, forming an acoustic labyrinth structure. The first guide section 2100 is smooth and without perforations, while the lower part of the second guide section 2200 has a perforated area 2400. The spacing W1 between the first guide sections 2100 and the spacing W2 between the second guide sections 2200 of adjacent blades 2000 are both greater than the spacing W3 between the bent portions 2300, i.e., W1>W3, W2>W3. This structure maintains a narrower spacing at the bends of the acoustic labyrinth to enhance sound wave reflection, while maintaining a wider spacing in the guide sections of the airflow channel to reduce wind resistance. The cavity of the blade 2000 is filled with a sound-absorbing layer 3000. The sound-absorbing layer 3000 can be made of centrifugal glass wool or rock wool, with a density of 48-64 kg / m³. 3 It is responsible for absorbing mid-to-high frequency noise.

[0034] In one embodiment, please refer to [the relevant documentation / reference]. Figure 1 and Figure 2 An upper airflow guide mechanism 4000 is installed directly above the central sound-absorbing zone. The cross-section of the upper airflow guide mechanism 4000 is an inverted isosceles trapezoid. Its ends and bottom surface are connected to the window frame 1000, and its top surface faces the direction of the central sound-absorbing zone. The inverted isosceles trapezoidal upper airflow guide mechanism 4000 can smoothly guide the airflow from the top towards the central sound-absorbing zone, preventing this part of the airflow from directly passing over the central sound-absorbing zone and entering the interior. The spacing between the inverted isosceles trapezoidal upper airflow guide mechanism 4000, the unperforated first airflow guide section 2100, and each set of corresponding blades 2000 also has a rainproof airflow guide function.

[0035] In one embodiment, see Figure 2The vertical projections of the two inclined surfaces of the upper guide mechanism 4000 overlap with the vertical projections of the bent portions 2300 of the adjacent blades 2000. The guide surface of the inverted isosceles trapezoidal upper guide mechanism 4000 and the bent portions 2300 of the blades 2000 achieve a seamless geometric connection, allowing the airflow to be smoothly introduced into the central sound-absorbing zone of the V-shaped structure, avoiding airflow separation and energy loss at the inlet.

[0036] In one embodiment, see Figure 2 Below the central sound-absorbing zone, on both sides of the V-shaped structure, there is a lower flow guide mechanism 5000. The cross-section of the lower flow guide mechanism 5000 is a right trapezoid, and its end is connected to the window frame 1000. Its hypotenuse faces the direction of the central sound-absorbing zone. The right trapezoidal lower flow guide mechanism 5000 is located on both sides of the outlet of the V-shaped channel, which can effectively guide the outflowing airflow to diffuse smoothly downward and backward, help restore static pressure, reduce outlet vortices, and thus further reduce the total resistance of the system.

[0037] The vertical projection of the upper edge of the inclined side of the lower guide mechanism 5000 overlaps with the vertical projection of the bent portion 2300 of the adjacent blade 2000. This projection overlap ensures a smooth transition of airflow from the V-shaped channel outlet to the downstream, helping to restore static pressure and reduce outlet vortices. The upper guide mechanism 4000 and the lower guide mechanism 5000, together with the blade 2000, form a complete, streamlined airflow organization system, ensuring low wind resistance and low-noise ventilation.

[0038] In one embodiment, the sound-absorbing layer 3000 includes multiple mutually isolated cavities. The cavities and the perforated area 2400 together constitute a resonant sound-absorbing structure for attenuating low-frequency noise. By designing the volume of the cavities and the perforation parameters of the perforated area 2400, specific low-frequency peak noise that needs to be attenuated can be precisely targeted to achieve a low-frequency noise reduction effect.

[0039] In one embodiment, when the waterproofing requirement is small or nonexistent, the perforated area 2400 can be extended to the remaining part of the blade 2000. The smaller the waterproofing requirement, the larger the area of ​​the perforated area 2400 covering the blade 2000, until it completely covers it. The larger the proportion of the perforated area 2400 on the blade 2000, the better the noise reduction effect. Figure 5 As shown, the aperture ratio of the perforated area 2400 is between 5% and 80%, and the perforation diameter is between 3 and 8 mm. The aperture ratio and perforation diameter are selected according to actual needs. The higher the aperture ratio and the smaller the perforation diameter, the better the noise reduction effect.

[0040] In one embodiment, please refer to [the relevant documentation / reference]. Figure 2 , Figure 3 and Figure 4The blade 2000 is connected to the window frame 1000 via a connecting piece. By changing the position of the connecting piece, the overall tilt angle of the blade 2000 can be adjusted, thereby adjusting the ventilation volume and noise reduction performance of the louver within a certain range and enhancing the adaptability of the louver to different application scenarios.

[0041] In one embodiment, the bending angle of the bending portion 2300 is between 100° and 170°. This angle range ensures sufficient sound wave reflection while avoiding excessively sharp corners that could lead to airflow separation and vortex generation.

[0042] In this embodiment, the noise-reducing louver mainly consists of a window frame 1000 and two sets of V-shaped symmetrical blade arrays. The cross-section of a single blade 2000 is a continuously bent shape. The blade 2000 is made of aluminum profile, and its internal cavity is filled with a sound-absorbing layer 3000. Dense perforations are machined on the second guide section 2200, forming a perforated area 2400, with an opening ratio preferably of 25%. Furthermore, within the sound-absorbing layer 3000, multiple independent cavities are formed by pre-set partitions. These cavities, together with the perforated area 2400, constitute a resonant sound-absorbing unit for low frequencies.

[0043] After the two sets of blade arrays are installed in a V-shape symmetrically, the second guide sections 2200 of adjacent blades 2000 approach each other, forming a wedge-shaped central sound-absorbing zone. Above the central sound-absorbing zone, an upper guide mechanism 4000 is installed. Its cross-section is an inverted trapezoid, and the projection of its two inclined surfaces in the vertical direction overlaps with the projection of the bent portion 2300 of the adjacent blade 2000. On both sides below the central sound-absorbing zone, a pair of lower guide mechanisms 5000 are installed. Their cross-section is a right-angled trapezoid, and the projection of the upper edge of its inclined side in the vertical direction overlaps with the projection of the bent portion 2300 of the adjacent blade 2000. This alignment ensures that the airflow can be seamlessly guided. The blades 2000 are connected to the window frame 1000 through the connecting pieces at their ends, and the tilt angle can be adjusted to adapt to different needs.

[0044] Working principle: When broadband noise passes through: High-frequency noise above 1000Hz is mainly absorbed through the viscous resistance and thermal conduction of the sound-absorbing layer 3000.

[0045] Mid-frequency noise in the 250-1000Hz range undergoes multiple reflections and interferences in the acoustic labyrinth, and is gradually consumed by the 3000 sound-absorbing layer.

[0046] Low-frequency noise below 250Hz excites resonance between the perforated area 2400 and the cavity, and the acoustic energy is dissipated within the resonant cavity through friction and viscosity.

[0047] Residual noise enters the central sound-absorbing zone and is further absorbed and attenuated.

[0048] Meanwhile, the ventilation airflow enters smoothly under the guidance of the upper guide mechanism 4000, passes through the optimized streamlined channel, and is finally smoothly discharged by the lower guide mechanism 5000. The entire process has low pressure loss and low airflow noise.

[0049] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0050] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A noise-reducing venetian blind structure for broadband noise, comprising a window frame and a blade array installed within the window frame, characterized in that: The blade array includes multiple parallel blades, each blade is filled with a sound-absorbing layer, and each blade includes a first guide section and a second guide section. The first guide section and the second guide section are connected to each other by bends with opposite protrusion directions. The distance between the first guide section and the second guide section of adjacent blades is greater than the distance between the bends. The blade is provided with a perforated area.

2. The noise-reducing venetian blind structure for broadband noise as described in claim 1, characterized in that, The blade array includes at least two groups, with corresponding blades in the two groups arranged symmetrically in a V-shape. The second guide sections of the corresponding blades in each group are adjacent to each other and have a gap, together forming a wedge-shaped central sound-absorbing zone.

3. The noise-reducing louver structure for broadband noise as described in claim 2, characterized in that, An upper airflow guiding mechanism is provided directly above the central sound-absorbing zone. The cross-section of the upper airflow guiding mechanism is an inverted isosceles trapezoid, with its lower base connected to the window frame and its upper base facing the central sound-absorbing zone.

4. The noise-reducing venetian blind structure for broadband noise as described in claim 3, characterized in that, The projections of the inclined surfaces on both sides of the upper guide mechanism in the vertical direction overlap with the projections of the bent portions of the adjacent blades in the vertical direction.

5. The noise-reducing louver structure for broadband noise as described in claim 2, characterized in that, Below the central sound-absorbing zone, on both sides of the V-shaped structure, there is a lower flow guiding mechanism. The cross-section of the lower flow guiding mechanism is a right trapezoid, with its hypotenuse facing the central sound-absorbing zone.

6. The noise-reducing venetian blind structure for broadband noise as described in claim 5, characterized in that, The projection of the upper edge of the inclined side of the lower guide mechanism in the vertical direction overlaps with the projection of the bent portion of the adjacent blade in the vertical direction.

7. The noise-reducing venetian blind structure for broadband noise as described in claim 1, characterized in that, The sound-absorbing layer includes multiple mutually isolated cavities, which together with the perforated area constitute a resonant sound-absorbing structure for attenuating low-frequency noise.

8. The noise-reducing venetian blind structure for broadband noise as described in claim 1, characterized in that, The perforation rate of the perforated area is between 5% and 80%.

9. The noise-reducing venetian blind structure for broadband noise as described in claim 1, characterized in that, The blades are connected to the window frame via connecting pieces.

10. The noise-reducing venetian blind structure for broadband noise as described in claim 1, characterized in that, The bending angle of the bent portion is between 100° and 170°.

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