Noise reduction assembly and range hood

Abstract

The utility model provides a kind of noise reduction assembly and range hood, it is related to range hood technical field.The noise reduction assembly includes first side plate, second side plate and multilayer sound absorption structure;First side plate and second side plate are oppositely inclined to set, and form the groove body between first side plate and second side plate by notch to groove bottom groove width gradually reduces;The notch of groove body is towards the propagation direction of noise;The plate surface of first side plate and second side plate in groove body can all reflect sound wave;Multilayer sound absorption structure is sequentially arranged in groove body along the depth direction of groove body, each layer sound absorption structure is used to absorb noise, and the noise frequency range absorbed by multilayer sound absorption structure is all different.The noise reduction assembly receives noise by groove body and reflects noise by side plate to converge it in groove body, then utilizes multilayer sound absorption structure to absorb noise of different frequency, effectively improves the noise reduction effect.

Description

Technical Field

[0001] This utility model relates to the field of range hood technology, and in particular to a noise reduction component and a range hood. Background Technology

[0002] With increasing demands for kitchen air quality, range hoods have become widely used as important ventilation equipment, and their noise levels are receiving more and more attention. Currently, range hoods use a non-enclosed flow channel structure in conjunction with a fan to extract and exhaust cooking fumes. The noise generated by the fan during operation is transmitted through the duct below, affecting the environment and human health.

[0003] To reduce noise during fan operation, existing range hoods typically use sound-absorbing materials to cover the inner wall of the duct. However, sound waves usually propagate in a straight line inside the duct, resulting in short contact time with the sound-absorbing material. This leads to limited sound absorption effect of the material, and conventional sound-absorbing materials have poor absorption performance for mid-to-low frequency noise. Utility Model Content

[0004] The purpose of this utility model is to provide a noise reduction component and a range hood to alleviate the technical problems existing in the prior art. To reduce the noise of the range hood fan during operation, sound-absorbing materials are usually covered on the inner wall of the pipe or a sound barrier is set on the inner wall of the fan casing. However, sound waves usually propagate in a straight line in the pipe and the contact time with the sound-absorbing material is short, resulting in limited sound absorption effect of the sound-absorbing material. In addition, conventional sound-absorbing materials have poor absorption performance for mid- and low-frequency noise.

[0005] In a first aspect, the present invention provides a noise reduction component, including a first side plate, a second side plate and a multi-layer sound-absorbing structure; The first side plate and the second side plate are inclined relative to each other, and a groove is formed between the first side plate and the second side plate, with the groove width gradually decreasing from the groove opening to the groove bottom; The opening of the tank faces the direction of noise propagation so that the tank can receive noise; the surfaces of the first and second side plates located inside the tank can reflect sound waves. The multi-layer sound-absorbing structure is arranged sequentially along the depth direction of the tank. Each layer of the sound-absorbing structure is used to absorb noise, and the noise frequency range absorbed by the multi-layer sound-absorbing structure is different.

[0006] In an optional embodiment, the sound-absorbing structure includes at least three layers, and at least one layer of the sound-absorbing structure is a mid-to-high frequency sound-absorbing structure, at least one layer of the sound-absorbing structure is a mid-to-low frequency sound-absorbing structure, and at least one layer of the sound-absorbing structure is a low frequency sound-absorbing structure. Mid-to-high frequency sound-absorbing structures are used to absorb mid-frequency and high-frequency noise, mid-to-low frequency sound-absorbing structures are used to absorb mid-frequency and low-frequency noise, and low-frequency sound-absorbing structures are used to absorb low-frequency noise.

[0007] In an optional implementation, the mid-to-high frequency sound-absorbing structure, the mid-to-low frequency sound-absorbing structure, and the low frequency sound-absorbing structure are distributed sequentially from the opening to the bottom of the groove.

[0008] In an optional implementation, the mid-to-high frequency sound-absorbing structure is a sound-absorbing structure formed by manufacturing broadband sound-absorbing materials.

[0009] In an optional embodiment, the low-to-medium frequency sound-absorbing structure is a sound-absorbing structure made of porous material, and the flow resistance of the low-to-medium frequency sound-absorbing structure to sound waves is greater than that of the high-to-medium frequency sound-absorbing structure to sound waves.

[0010] In an optional embodiment, the low-frequency sound-absorbing structure includes a noise-reducing plate, which is installed between a first side plate and a second side plate and forms a Helmholtz resonant cavity between the first side plate and the second side plate. The noise reduction board has perforations that connect to the Helmholtz resonant cavity.

[0011] In an optional implementation, the noise reduction board has multiple sets of perforations, and the diameters of the perforations in each set are not equal.

[0012] In an optional embodiment, each layer of sound-absorbing structure can be detachably installed between the first side panel and the second side panel.

[0013] In an optional embodiment, the angle between the first side plate and the second side plate within the tank is an acute angle.

[0014] Secondly, this utility model provides a range hood, including a fan and a noise reduction component of any of the aforementioned embodiments; The noise reduction components are located below the fan, with the slot opening of the trough facing the fan.

[0015] The noise reduction component provided by this utility model includes a first side plate, a second side plate, and a multi-layer sound-absorbing structure. The first and second side plates are arranged at relative inclinations, forming a groove between them where the groove width gradually decreases from the opening to the bottom. The opening of the groove faces the direction of noise propagation, enabling the groove to receive noise. The surfaces of the first and second side plates within the groove can reflect sound waves. The multi-layer sound-absorbing structure is sequentially arranged within the groove along its depth direction. Each layer of the sound-absorbing structure is used to absorb noise, and the frequency ranges of noise absorbed by the multi-layer sound-absorbing structure are all different. The noise reduction component provided by this utility model is used to absorb and reduce the noise generated by the fan in a range hood. Since the noise propagation path of the fan is from top to bottom, the noise reduction component can be installed below the fan, with the opening of the groove facing the fan. In this case, the first and second side plates are positioned along the noise propagation path of the fan, and the opening of the groove faces the direction of noise propagation. The opening of the groove serves as the noise inlet, receiving and guiding external noise into the groove. When the range hood starts and the fan begins operation, the noise it generates propagates from top to bottom, entering the tank through the slot opening. Since the surfaces of the first and second side plates within the tank can reflect sound waves, the noise waves undergo multiple reflections between the first and second side plates as they propagate towards the bottom of the tank. This convergence of the noise waves within the tank creates a reverberant sound field. Furthermore, the tank contains multiple layers of sound-absorbing structures distributed along its depth, each absorbing different noise frequencies. Therefore, as the noise propagates towards the bottom, not only are reflections observed, but different frequency bands of noise are absorbed by their corresponding sound-absorbing structures. This expands the noise reduction component's absorbed frequency range, achieving broadband noise reduction while effectively eliminating reverberant noise and reducing the noise intensity propagating downstream from the fan.

[0016] Compared with the prior art, the noise reduction component provided by this utility model receives the noise generated by the fan during operation through a trough whose width gradually decreases from the trough opening to the trough bottom. At the same time, the noise sound waves are reflected multiple times through the first side plate and the second side plate, which prolongs the sound wave action path and makes it converge in the trough. Then, the multi-layer sound absorption structure is used to absorb noise of different frequencies to achieve broadband noise reduction, which effectively improves the noise reduction effect.

[0017] The range hood provided by this utility model includes a fan and the aforementioned noise reduction component; the noise reduction component is disposed below the fan with the slot opening of the trough facing the fan. Since the range hood provided by this utility model includes the aforementioned noise reduction component, it has the same beneficial effects as the aforementioned noise reduction component. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the fan and the local noise reduction component provided in an embodiment of the present utility model; Figure 2 A cross-sectional view of a local noise reduction component provided in an embodiment of this utility model; Figure 3 A cross-sectional view of the multi-layer sound-absorbing structure provided in an embodiment of this utility model; Figure 4 An exploded view of the multi-layer sound-absorbing structure provided in the embodiment of this utility model; Figure 5 This is a schematic diagram of the structure of the smoke hood provided in an embodiment of the present utility model.

[0020] Icons: 1-First side panel; 2-Second side panel; 3-Gateway; 4-Fan; 5-Mid-high frequency sound absorption structure; 6-Mid-low frequency sound absorption structure; 7-Low frequency sound absorption structure; 70-Noise reduction board; 700-Perforation; 71-Helmholtz resonant cavity; 8-Outer shell; 9-Smoke hood. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0023] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0024] Example: like Figures 1-4As shown, the noise reduction component provided in this embodiment includes a first side plate 1, a second side plate 2, and a multi-layer sound-absorbing structure. The first side plate 1 and the second side plate 2 are arranged at relative inclinations, and a groove 3 is formed between the first side plate 1 and the second side plate 2, with the groove width gradually decreasing from the groove opening to the groove bottom. The groove opening of the groove 3 faces the direction of noise propagation so that the groove 3 can receive noise. The plate surfaces of the first side plate 1 and the second side plate 2 located in the groove 3 can reflect sound waves. The multi-layer sound-absorbing structure is arranged sequentially in the groove 3 along the depth direction of the groove 3. Each layer of the sound-absorbing structure is used to absorb noise, and the noise frequency range absorbed by the multi-layer sound-absorbing structure is different.

[0025] The noise reduction component provided in this embodiment is used to absorb and reduce the noise generated by the fan 4 in the range hood during operation. Based on the propagation path of the noise generated by the fan 4 during operation from top to bottom ( Figure 5 The arrows in the image indicate the noise propagation path, therefore, during use, such as Figure 1 and Figure 5 As shown, the noise reduction component can be installed below the fan 4, with the opening of the tank 3 facing the fan 4. The first side plate 1 and the second side plate 2 are positioned along the noise propagation path of the fan 4 during operation, and the opening of the tank 3 faces the direction of noise propagation. The opening of the tank 3 serves as the noise inlet, guiding external noise into the tank.

[0026] When the range hood starts and the fan 4 begins operation, the noise it generates propagates from top to bottom, entering the trough 3 through its opening. Since the surfaces of the first side plate 1 and the second side plate 2 within the trough 3 can reflect sound waves, the noise waves will undergo multiple reflections between the first side plate 1 and the second side plate 2 after entering the trough 3. As the noise propagates towards the bottom of the trough, it will converge within the trough 3, forming a reverberant sound field. Furthermore, because the trough 3 is equipped with multiple layers of sound-absorbing structures distributed sequentially along its depth, and each layer absorbs noise at different frequency ranges, the noise not only undergoes reflection as it propagates towards the bottom of the trough, but different frequency bands of noise can also be absorbed by their corresponding sound-absorbing structures. This expands the noise frequency range absorbed by the noise reduction component, achieving broadband noise reduction and effectively eliminating reverberant noise, thus reducing the noise intensity propagated downstream by the fan 4.

[0027] Compared with the prior art, the noise reduction component provided in this embodiment receives the noise generated by the operation of the fan 4 through the trough 3, which has a gradually decreasing width from the trough opening to the trough bottom. At the same time, the noise sound waves are reflected multiple times through the first side plate 1 and the second side plate 2, which prolongs the sound wave action path and makes it converge in the trough 3. Then, the multi-layer sound absorption structure is used to absorb noise of different frequencies to achieve broadband noise reduction, which effectively improves the noise reduction effect.

[0028] When the first side plate 1 and the second side plate 2 are arranged at relative inclinations, the sides of the first side plate 1 and the second side plate 2 located at the bottom of the tank 3 can abut against each other, such as... Figure 2 As shown, the cross-section of the tank 3 is V-shaped at this time; or, there may be a gap between the sides of the first side plate 1 and the second side plate 2 located at the bottom of the tank 3. In this case, the cross-section of the tank 3 is an inverted trapezoid. However, it should be noted that the width of the gap must be less than the width of the opening of the tank 3 so that the first side plate 1 and the second side plate 2 can still form a tank 3 with the width gradually decreasing from the opening to the bottom of the tank.

[0029] To ensure that both the first side plate 1 and the second side plate 2 have good reflection effects on noise sound waves, this embodiment preferably uses both the first side plate 1 and the second side plate 2 as rigid plates. There are no restrictions on the material of the rigid plates, as long as they can have good reflectivity of sound waves. Specifically, the material of the rigid plates can be metal or alloy and other high-strength materials.

[0030] like Figure 3 and Figure 4 As shown, the sound-absorbing structure includes at least three layers, and at least one layer is a mid-to-high frequency sound-absorbing structure 5, at least one layer is a mid-to-low frequency sound-absorbing structure 6, and at least one layer is a low frequency sound-absorbing structure 7; the mid-to-high frequency sound-absorbing structure 5 is used to absorb mid-frequency and high-frequency noise, the mid-to-low frequency sound-absorbing structure 6 is used to absorb mid-frequency and low-frequency noise, and the low frequency sound-absorbing structure 7 is used to absorb low-frequency noise.

[0031] Low frequency, mid frequency, and high frequency refer to the frequency of noise. Low frequency usually refers to noise with a frequency between 20 Hz and 500 Hz, mid frequency usually refers to noise with a frequency between 500 Hz and 2000 Hz, and high frequency usually refers to noise with a frequency above 2000 Hz.

[0032] Since the frequency of the noise generated by the fan 4 during operation is mainly concentrated below 1000 Hz, this embodiment can absorb the noise of the fan 4 during operation across the entire frequency band by setting up a mid-to-high frequency sound absorption structure 5, a mid-to-low frequency sound absorption structure 6, and a low frequency sound absorption structure 7, thereby effectively improving the noise reduction effect.

[0033] Furthermore, such as Figure 3 and Figure 4 As shown, the mid-to-high frequency sound absorption structure 5, the mid-to-low frequency sound absorption structure 6, and the low frequency sound absorption structure 7 are distributed sequentially from the opening to the bottom of the groove 3.

[0034] This arrangement places the mid-to-high frequency sound-absorbing structure 5 close to the opening of the groove, the mid-to-low frequency sound-absorbing structure 6 in the middle area of ​​the groove 3, and the low frequency sound-absorbing structure 7 close to the bottom of the groove.

[0035] After the noise enters the tank 3, the sound pressure is relatively low near the opening of the tank, but the incident angle of the sound wave is diverse. Therefore, the mid-to-high frequency noise is concentrated at this position. Setting a mid-to-high frequency sound-absorbing structure 5 at this position can fully absorb the mid-to-high frequency noise in the noise, and at the same time effectively reduce the initial reflection of the noise, thereby effectively improving the noise absorption effect.

[0036] As the noise continues to propagate, the sound pressure will increase significantly in the central area of ​​the tank 3 due to the convergence of sound waves. At this time, the incident direction of the sound waves tends to be perpendicular to the first side plate 1 and the second side plate 2. Therefore, the low-frequency noise is more concentrated at this location. Setting the low-frequency sound-absorbing structure 6 at this location can effectively absorb the low-frequency noise in the noise, thereby further improving the noise absorption effect.

[0037] Near the bottom of the tank 3, reverberation energy is concentrated, and low-frequency noise is concentrated in this area. Therefore, setting a low-frequency sound-absorbing structure 7 at this location can maximize the absorption of the low-frequency sound waves that converge here, thereby effectively improving the noise reduction effect of the noise reduction component on low-frequency noise.

[0038] The mid-to-high frequency sound-absorbing structure 5 can be formed by mixing mid-frequency and high-frequency sound-absorbing materials, or it can be formed by using broadband sound-absorbing materials. To simplify the manufacturing process of the mid-to-high frequency sound-absorbing structure 5, this embodiment preferably uses a broadband sound-absorbing material to form the mid-to-high frequency sound-absorbing structure 5.

[0039] Among them, broadband sound-absorbing materials refer to materials that can effectively absorb sound over a wide frequency range, such as foam.

[0040] Accordingly, the mid-to-low frequency sound-absorbing structure 6 can be formed by mixing mid-frequency and low-frequency sound-absorbing materials, or it can be made of porous materials. To simplify the manufacturing process of the mid-to-low frequency sound-absorbing structure 6, this embodiment preferably uses a porous material to form the sound-absorbing structure 6, and the flow resistance of the mid-to-low frequency sound-absorbing structure 6 to sound waves is greater than that of the mid-to-high frequency sound-absorbing structure 5 to sound waves.

[0041] When the flow resistance of the low-frequency sound-absorbing structure 6 to the sound waves is greater than that of the mid-high frequency sound-absorbing structure 5 to the sound waves, the material of the low-frequency sound-absorbing structure 6 is a porous fiber material.

[0042] like Figure 4 As shown, the low-frequency sound absorption structure 7 includes a noise reduction plate 70, which is installed between the first side plate 1 and the second side plate 2 and forms a Helmholtz resonant cavity 71 between the first side plate 1 and the second side plate 2; the noise reduction plate 70 is provided with a perforation 700 communicating with the Helmholtz resonant cavity 71.

[0043] When noise propagates within the tank 3, it eventually enters the Helmholtz resonant cavity 71 through the perforation 700 on the noise reduction plate 70. Then, under the action of the Helmholtz resonance effect, its acoustic energy is converted into heat energy and dissipated, thereby achieving the purpose of noise reduction.

[0044] Furthermore, the perforations 700 on the noise reduction plate 70 can be in multiple sets, and the apertures of the multiple sets of perforations 700 are not equal.

[0045] When the apertures of multiple sets of perforations 700 are not equal, the Helmholtz resonant cavity 71 can be used to absorb and reduce noise in different frequency bands, thereby achieving a wideband noise reduction effect. Therefore, in this embodiment, it is preferred that the apertures of multiple sets of perforations 700 on the noise reduction plate 70 are not equal.

[0046] Each group of perforations 700 may include multiple perforations 700, and the diameters of the multiple perforations 700 in any group of perforations 700 may be equal.

[0047] To facilitate the installation, disassembly, and replacement of each layer of sound-absorbing structure, this embodiment preferably allows each layer of sound-absorbing structure to be detachably installed between the first side plate 1 and the second side plate 2.

[0048] Specifically, each layer of sound-absorbing structure can be fixed between the first side plate 1 and the second side plate 2 by means of adhesive bonding, snap-fitting, or mechanical fixing.

[0049] Since the noise generated by the fan 4 during operation is mainly concentrated below 1000 Hz, and the angle between the first side plate 1 and the second side plate 2 within the tank 3 satisfies constructive acoustic interference, low-frequency sound waves will converge, thus facilitating the absorption and noise reduction of low-frequency sound waves. Therefore, in this embodiment, it is preferable that the angle between the first side plate 1 and the second side plate 2 within the tank 3 is an acute angle. When the angle between the first side plate 1 and the second side plate 2 within the tank 3 is an acute angle, constructive acoustic interference can be fully satisfied.

[0050] Specifically, let θ be the angle between the first side plate 1 and the second side plate 2 in the tank 3, let λ be the wavelength of the sound wave, and let d be the width of the tank at the opening of the tank 3. When λ > 2d × sin(θ / 2), the sound wave will form constructive interference due to multiple reflections in the tank 3, and the sound pressure will converge and increase towards the bottom of the tank. Taking d = 0.2 meters as an example, θ less than 90 degrees can fully satisfy the constructive interference condition of low frequency sound waves.

[0051] To facilitate the centralization of the structure of noise reduction components, such as Figure 1 and Figure 2 As shown, the noise reduction component provided in this embodiment may also include a housing 8, with a first side plate 1 and a second side plate 2 installed inside the housing 8.

[0052] Furthermore, the cross-section of the outer shell 8 can be V-shaped, in which case the first side plate 1 and the second side plate 2 can be respectively attached and fixed to the two inclined side walls of the outer shell 8.

[0053] like Figure 5 As shown, this embodiment also provides a range hood, which includes a fan 4 and a noise reduction component; the noise reduction component is disposed below the fan 4 and the slot opening of the trough 3 faces the fan 4.

[0054] Noise propagation path as follows Figure 5 As shown by the arrow, during the operation of the fan 4, noise is usually transmitted from the fan 4 to the smoke collection hood 9 below it, and then propagates outward through the smoke collection hood 9. In this embodiment, by setting a noise reduction component below the fan 4 and making the slot of the groove 3 in the noise reduction component face the fan 4, the groove 3 can effectively receive the noise and reflect the noise sound waves multiple times through the first side plate 1 and the second side plate 2, extending the sound wave action path and converging it in the groove 3. Then, the multi-layer sound absorption structure is used to absorb noise of different frequencies to achieve broadband noise reduction, thereby effectively blocking the noise at the fan 4 from propagating to the smoke collection hood 9 and improving the noise reduction effect.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A noise reduction component, characterized in that, It includes a first side panel (1), a second side panel (2), and a multi-layer sound-absorbing structure; The first side plate (1) and the second side plate (2) are inclined relative to each other, and a groove (3) is formed between the first side plate (1) and the second side plate (2) with the groove width gradually decreasing from the groove opening to the bottom of the groove. The opening of the groove (3) faces the direction of noise propagation so that the groove (3) can receive noise; the surfaces of the first side plate (1) and the second side plate (2) located inside the groove (3) can reflect sound waves. The multi-layered sound-absorbing structures are sequentially arranged in the groove (3) along the depth direction of the groove (3). Each layer of the sound-absorbing structure is used to absorb noise, and the noise frequency range absorbed by the multi-layered sound-absorbing structures is different.

2. The noise reduction component according to claim 1, characterized in that, The sound-absorbing structure comprises at least three layers, and at least one layer of the sound-absorbing structure is a mid-to-high frequency sound-absorbing structure (5), at least one layer of the sound-absorbing structure is a mid-to-low frequency sound-absorbing structure (6), and at least one layer of the sound-absorbing structure is a low frequency sound-absorbing structure (7). The mid-to-high frequency sound-absorbing structure (5) is used to absorb mid-frequency and high-frequency noise, the mid-to-low frequency sound-absorbing structure (6) is used to absorb mid-frequency and low-frequency noise, and the low-frequency sound-absorbing structure (7) is used to absorb low-frequency noise.

3. The noise reduction component according to claim 2, characterized in that, The mid-to-high frequency sound-absorbing structure (5), the mid-to-low frequency sound-absorbing structure (6), and the low frequency sound-absorbing structure (7) are distributed sequentially from the opening to the bottom of the groove (3).

4. The noise reduction component according to claim 2, characterized in that, The mid-to-high frequency sound-absorbing structure (5) is a sound-absorbing structure made of broadband sound-absorbing material.

5. The noise reduction component according to claim 2, characterized in that, The low-frequency sound-absorbing structure (6) is a sound-absorbing structure made of porous material, and the flow resistance of the low-frequency sound-absorbing structure (6) to sound waves is greater than that of the high-frequency sound-absorbing structure (5) to sound waves.

6. The noise reduction component according to claim 3, characterized in that, The low-frequency sound-absorbing structure (7) includes a noise-reducing plate (70), which is installed between the first side plate (1) and the second side plate (2) and forms a Helmholtz resonant cavity (71) between the first side plate (1) and the second side plate (2). The noise reduction plate (70) is provided with a perforation (700) that communicates with the Helmholtz resonant cavity (71).

7. The noise reduction component according to claim 6, characterized in that, The noise reduction plate (70) has multiple sets of perforations (700), and the diameters of the perforations (700) in the multiple sets are not equal.

8. The noise reduction component according to any one of claims 1-7, characterized in that, Each layer of the sound-absorbing structure can be detachably installed between the first side plate (1) and the second side plate (2).

9. The noise reduction component according to any one of claims 1-7, characterized in that, The angle between the first side plate (1) and the second side plate (2) within the groove (3) is an acute angle.

10. A range hood, characterized in that, Includes a fan (4) and a noise reduction component as described in any one of claims 1-9; The noise reduction component is located below the fan (4) and the slot of the trough (3) faces the fan (4).

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