Flue gas passage and extractor hood

Abstract

The utility model provides a kind of flue gas passage and range hood, flue gas passage is used for range hood, flue gas passage has flue gas inlet and flue gas outlet, flue gas passage includes main passage, this main passage includes: first sound-absorbing surface, first sound-absorbing surface is located in main passage and is with flue gas inlet acute angle included angle;And, first reflecting surface, first reflecting surface is located in main passage and is with flue gas outlet acute angle included angle. Among them, first sound-absorbing surface is used to absorb the sound wave entering from flue gas inlet, and first reflecting surface is used to reflect the sound wave entering from flue gas outlet. Thus, it can avoid oil fume to stay near the ceiling of kitchen and can reasonably reduce noise.

Description

Technical Field

[0001] This utility model relates to the field of oil fume extraction technology, and in particular to a smoke duct and an oil fume extractor. Background Technology

[0002] Cooking inevitably produces fumes, which are typically removed by range hoods. However, while most fumes are successfully expelled, a small portion escapes and lingers in the upper space near the kitchen ceiling. Specifically, the negative pressure generated by a range hood can only control the fumes within a certain range of its inlet. If the fumes rise too quickly and exceed the controlled area, they will escape and remain near the ceiling for an extended period.

[0003] To address the aforementioned problems, the existing technology involves increasing the exhaust volume of the range hood itself, thereby enhancing its ability to absorb and control cooking fumes and reducing their escape. However, simply increasing the exhaust volume of the range hood generates significant noise, which, if not reasonably mitigated, can seriously impact the health of people in the kitchen and their cooking experience.

[0004] Therefore, there is a market demand for fume extraction ducts and range hoods that can prevent cooking fumes from lingering near the kitchen ceiling and can reasonably reduce noise. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a smoke duct and a range hood in order to prevent oil fumes from lingering near the ceiling of the kitchen and to reasonably reduce noise.

[0006] The present invention solves the above-mentioned technical problems through the following technical solution:

[0007] A flue gas duct for a range hood, the flue gas duct having a flue gas inlet and a flue gas outlet, the flue gas duct including a main channel, the main channel comprising:

[0008] A first sound-absorbing surface, located within the main channel and forming an acute angle with the flue gas inlet; and a first reflective surface, located within the main channel and forming an acute angle with the flue gas outlet.

[0009] The first sound-absorbing surface is used to absorb sound waves entering from the flue gas inlet, and the first reflective surface is used to reflect sound waves entering from the flue gas outlet.

[0010] In this design, a first sound-absorbing surface is installed in the main channel of the flue gas duct. The first sound-absorbing surface forms an acute angle with the flue gas inlet. Therefore, when noise is generated at a location such as below the range hood (e.g., a stovetop), the noise enters the flue gas inlet and impacts the first sound-absorbing surface, thus being absorbed by it. Any remaining sound waves not completely absorbed by the first sound-absorbing surface are transmitted into the interior of the main channel through the acute angle between the first sound-absorbing surface and the flue gas inlet, preventing the sound waves from being directly transmitted back to the sound source and confining them within the main channel.

[0011] Furthermore, a first reflective surface is installed in the main channel of the flue gas duct. The first reflective surface forms an acute angle with the flue gas outlet, so that when noise is generated at locations such as exhaust pipes and fans above the range hood, the noise enters the flue gas outlet and is reflected back above the range hood by the first reflective surface. Any remaining sound waves that are not completely reflected back above the range hood by the first reflective surface are reflected back into the main channel by the acute angle between the first reflective surface and the flue gas outlet, thus trapping the sound waves within the main channel.

[0012] Therefore, even if you choose to increase the exhaust volume of the range hood itself to prevent cooking fumes from lingering near the kitchen ceiling, the smoke duct in this solution can still reasonably reduce noise.

[0013] Preferably, the main channel further includes: a second sound-absorbing surface disposed relative to the first reflective surface, the second sound-absorbing surface being located within the main channel and forming an acute angle with the flue gas inlet, the second sound-absorbing surface being used to absorb part of the sound waves reflected from the first reflective surface; and a second reflective surface disposed relative to the first sound-absorbing surface, the second reflective surface being located within the main channel and forming an acute angle with the flue gas outlet, the second reflective surface being used to reflect part of the sound waves entering from the flue gas outlet back to the first sound-absorbing surface.

[0014] In this design, the second sound-absorbing surface, positioned relative to the first reflective surface, is also located within the main channel and forms an acute angle with the flue gas inlet. This second sound-absorbing surface further absorbs sound waves reflected from the first reflective surface into the main channel, further eliminating noise. Similarly, any remaining sound waves not completely absorbed by the second sound-absorbing surface are transmitted into the main channel through the acute angle between the second sound-absorbing surface and the flue gas inlet, further confining the sound waves within the main channel.

[0015] Furthermore, the second reflective surface, positioned relative to the first sound-absorbing surface, is also located within the main channel and forms an acute angle with the smoke outlet. This second reflective surface further reflects sound waves transmitted from the first sound-absorbing surface into the main channel upwards towards the range hood. Similarly, any remaining sound waves not completely reflected back to the top of the range hood are reflected back into the main channel by the acute angle between the second reflective surface and the smoke outlet, further confining the sound waves within the main channel.

[0016] Therefore, through the aforementioned secondary absorption and secondary reflection, the flue gas passage in this scheme further reduces noise in a reasonable way.

[0017] Preferably, the first reflective surface and the first sound-absorbing surface are joined together in the middle section of the main channel to form the first wall of the main channel; and / or, the second reflective surface and the second sound-absorbing surface are joined together in the middle section of the main channel to form the second wall of the main channel.

[0018] In this solution, the first reflective surface and the first sound-absorbing surface are joined together in the middle section of the main channel to form the first wall of the main channel, and the second reflective surface and the second sound-absorbing surface are joined together in the middle section of the main channel to form the second wall of the main channel. Thus, the aforementioned reflective surface and sound-absorbing surface are directly formed during the preparation of the main channel, without the need for separate preparation and installation of the aforementioned reflective surface and sound-absorbing surface, thereby improving the efficiency of implementation.

[0019] Preferably, the length of the edge on the first wall facing the flue gas inlet is less than the length of the edge on the first wall facing the flue gas outlet; and / or, the length of the edge on the second wall facing the flue gas inlet is less than the length of the edge on the second wall facing the flue gas outlet.

[0020] In this design, the length of the edge facing the flue gas inlet on the first wall is shorter than the length of the edge facing the flue gas outlet on the first wall, and the length of the edge facing the flue gas inlet on the second wall is shorter than the length of the edge facing the flue gas outlet on the second wall. This results in the main channel being arranged with a longer width at the flue gas inlet and a shorter width at the flue gas outlet. This allows the flue gas inlet to cover a wider area below the range hood and facilitates a smooth acceleration of the flue gas within the main channel, which is beneficial to the efficiency of conveying the flue gas to the exhaust duct.

[0021] Preferably, the main channel further includes two side walls, which together with the first and second walls form the main channel; wherein the cross-sectional projection of the main channel relative to the horizontal plane decreases from the flue gas inlet to the flue gas outlet.

[0022] In this scheme, the two side walls, together with the first and second walls, form the main channel. As a result, the cross-sectional projection of the main channel relative to the horizontal plane changes from large to small from the flue gas inlet to the flue gas outlet. This arrangement makes the opening area of ​​the main channel larger at the flue gas inlet and smaller at the flue gas outlet, which also facilitates the smooth acceleration of the flue gas in the main channel and is beneficial to the efficiency of the flue gas to the exhaust pipe.

[0023] Preferably, the angle between the first sound-absorbing surface and the flue gas inlet is greater than the angle between the second reflective surface and the flue gas inlet.

[0024] In this solution, by using an angle between the first sound-absorbing surface and the smoke inlet that is greater than the angle between the second reflective surface and the smoke inlet, the smoke inlet can be extended further away from the user, thereby facilitating the extraction of smoke from locations such as walls where range hoods are installed, resulting in more comprehensive smoke extraction.

[0025] Preferably, the projection of the first sound-absorbing surface relative to the horizontal plane and the projection of the second reflective surface relative to the horizontal plane at least partially overlap.

[0026] In this scheme, the projection of the first sound-absorbing surface relative to the horizontal plane and the projection of the second reflective surface relative to the horizontal plane overlap at least partially. Thus, when sound waves that are not completely absorbed by the first sound-absorbing surface are transmitted back to the sound source, the second reflective surface can partially receive the aforementioned sound waves and reflect them back to the main channel, thereby further confining the sound waves in the main channel to the maximum extent.

[0027] Preferably, the flue gas duct also includes a duct shell, which is fitted outside the main duct. The inner surface of the duct shell and the outer surface of the main duct together form a noise reduction chamber. The main duct has multiple noise reduction holes that connect the interior of the main duct to the noise reduction chamber.

[0028] In this design, noise reduction holes are distributed along the main channel, and a channel shell is fitted over the main channel. The inner surface of the channel shell and the outer surface of the main channel together form a noise reduction chamber. Thus, after the flue gas enters the main channel and before it is directed to the exhaust pipe, the flue gas can first expand and diffuse using the noise reduction chamber. The expansion in the noise reduction chamber reduces the initial flow velocity of the flue gas, thus avoiding noise that may be caused by excessively high flow velocity when the flue gas enters the main channel.

[0029] Preferably, the noise reduction chamber is equipped with sound-absorbing materials.

[0030] In this solution, sound-absorbing materials are installed in the noise reduction chamber to reduce noise that may be caused by vibration.

[0031] A range hood includes the aforementioned smoke duct, which is connected to an external exhaust pipe.

[0032] In this solution, the range hood, with the aforementioned smoke duct, can still reasonably reduce noise even if the range hood's exhaust volume is increased to prevent fumes from lingering near the kitchen ceiling.

[0033] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of this utility model.

[0034] The positive and progressive effects of this utility model are as follows: the smoke duct and range hood in this utility model can prevent oil fumes from lingering near the kitchen ceiling and can reasonably reduce noise. Attached Figure Description

[0035] Figure 1 This is a three-dimensional structural diagram of a range hood according to an embodiment of the present invention;

[0036] Figure 2 This is a three-dimensional structural diagram of a flue gas passage according to an embodiment of the present invention;

[0037] Figure 3 This is a side view sectional structural diagram of a range hood according to an embodiment of the present invention.

[0038] Explanation of reference numerals in the attached figures:

[0039] 10 range hoods

[0040] flue gas passage 20

[0041] flue gas inlet 21

[0042] Flue gas outlet 22

[0043] Main Channel 23

[0044] First sound-absorbing surface 101

[0045] First reflecting surface 102

[0046] Second sound-absorbing surface 103

[0047] Second reflective surface 104

[0048] First wall surface 201

[0049] Second wall 202

[0050] Side wall 203

[0051] Channel housing 300

[0052] Noise Reduction Room 301

[0053] Noise Reduction Hole 302

[0054] Sound absorbing material 303 Detailed Implementation

[0055] The present invention will be further described below by way of embodiments, but the present invention is not limited to the scope of the embodiments.

[0056] like Figure 1-3 As shown, a flue gas passage 20 is used for a range hood 10. The flue gas passage 20 has a flue gas inlet 21 and a flue gas outlet 22. The flue gas passage 20 includes a main passage 23, which includes:

[0057] The first sound-absorbing surface 101 is located inside the main channel 23 and forms an acute angle with the flue gas inlet 21; and the first reflective surface 102 is located inside the main channel 23 and forms an acute angle with the flue gas outlet 22.

[0058] The first sound-absorbing surface 101 is used to absorb sound waves entering from the flue gas inlet 21, and the first reflective surface 102 is used to reflect sound waves entering from the flue gas outlet 22.

[0059] In practical implementation, a first sound-absorbing surface 101 is provided in the main channel 23 of the flue gas duct 20. The first sound-absorbing surface 101 forms an acute angle with the flue gas inlet 21. Thus, when noise is generated at a location such as a stove below the range hood 10, the noise enters the flue gas inlet 21 and impacts the first sound-absorbing surface 101, thereby being absorbed by the first sound-absorbing surface 101. Any remaining sound waves not completely absorbed by the first sound-absorbing surface 101 are transmitted to the interior of the main channel 23 through the acute angle between the first sound-absorbing surface 101 and the flue gas inlet 21, preventing the sound waves from being directly transmitted back to the sound source and confining the sound waves within the main channel 23.

[0060] Furthermore, a first reflective surface 102 is provided in the main channel 23 of the flue gas duct 20. The first reflective surface 102 forms an acute angle with the flue gas outlet 22. Thus, when noise is generated at a location above the range hood 10, such as an exhaust duct or a fan, the noise enters the flue gas outlet 22 and is reflected back above the range hood 10 by the first reflective surface 102. Any remaining sound waves that are not completely reflected back above the range hood 10 by the first reflective surface 102 are reflected back into the main channel 23 by the acute angle between the first reflective surface 102 and the flue gas outlet 22, thereby trapping the sound waves within the main channel 23.

[0061] Therefore, even if the range hood 10 itself is chosen to increase its exhaust volume to prevent fumes from lingering near the kitchen ceiling, the smoke duct 20 in this solution can still reasonably reduce noise.

[0062] Furthermore, in specific implementation, a sound-absorbing coating or a porous structure with sound-absorbing effect can be provided on the first sound-absorbing surface 101 to achieve optimized sound absorption function; the first reflective surface 102 can be polished to achieve optimized sound wave reflection function.

[0063] Furthermore, in this embodiment, a single first sound-absorbing surface 101 and a single first reflective surface 102 constitute a set of the simplest working units. In actual implementation, those skilled in the art should also be able to conceive of setting multiple first sound-absorbing surfaces 101 and multiple first reflective surfaces 102 in the main channel 23, thereby further optimizing the noise reduction effect; this embodiment does not limit this.

[0064] like Figure 1-3 As shown, the main channel 23 further includes: a second sound-absorbing surface 103 disposed relative to the first reflective surface 102, the second sound-absorbing surface 103 being located within the main channel 23 and forming an acute angle with the flue gas inlet 21, the second sound-absorbing surface 103 being used to absorb part of the sound waves reflected from the first reflective surface 102; and a second reflective surface 104 disposed relative to the first sound-absorbing surface 101, the second reflective surface 104 being located within the main channel 23 and forming an acute angle with the flue gas outlet 22, the second reflective surface 104 being used to reflect part of the sound waves entering from the flue gas outlet 22 back to the first sound-absorbing surface 101.

[0065] In practical implementation, the second sound-absorbing surface 103, which is positioned relative to the first reflective surface 102, is also located within the main channel 23 and forms an acute angle with the flue gas inlet 21. Thus, the second sound-absorbing surface 103 further absorbs the sound waves reflected from the first reflective surface 102 into the interior of the main channel 23, further eliminating noise. Similarly, any remaining sound waves not completely absorbed by the second sound-absorbing surface 103 are transmitted into the interior of the main channel 23 via the acute angle between the second sound-absorbing surface 103 and the flue gas inlet 21, further confining the sound waves within the main channel 23.

[0066] Furthermore, the second reflective surface 104, which is disposed relative to the first sound-absorbing surface 101, is also located within the main channel 23 and forms an acute angle with the smoke outlet 22. Thus, the second reflective surface 104 further reflects sound waves transmitted from the first sound-absorbing surface 101 into the interior of the main channel 23 towards the top of the range hood 10. Similarly, sound waves that are not completely reflected back to the top of the range hood 10 by the second reflective surface 104 are reflected back into the interior of the main channel 23 by the acute angle between the second reflective surface 104 and the smoke outlet 22, further confining the sound waves within the main channel 23.

[0067] Therefore, through the aforementioned secondary absorption and secondary reflection, the flue gas passage 20 in this scheme further reduces noise in a reasonable way.

[0068] Furthermore, in specific implementation, those skilled in the art should be able to conceive of setting up multiple sets of first reflective surfaces 102 and second sound-absorbing surfaces 103, as well as multiple sets of first sound-absorbing surfaces 101 and second reflective surfaces 104. A set of first reflective surfaces 102 and second sound-absorbing surfaces 103 and their adjacent set of first sound-absorbing surfaces 101 and second reflective surfaces 104 constitute a bend in the main channel 23, thereby using multiple bends to trap sound waves in the main channel 23.

[0069] like Figure 1-3 As shown, the first reflective surface 102 and the first sound-absorbing surface 101 are joined together in the middle section of the main channel 23 to form the first wall surface 201 of the main channel 23; and the second reflective surface 104 and the second sound-absorbing surface 103 are joined together in the middle section of the main channel 23 to form the second wall surface 202 of the main channel 23.

[0070] In practical implementation, the first reflective surface 102 and the first sound-absorbing surface 101 are joined together in the middle section of the main channel 23 to form the first wall surface 201 of the main channel 23, and the second reflective surface 104 and the second sound-absorbing surface 103 are joined together in the middle section of the main channel 23 to form the second wall surface 202 of the main channel 23. Thus, the aforementioned reflective and sound-absorbing surfaces are directly formed when the main channel 23 is prepared, without the need for separate preparation and installation of the aforementioned reflective and sound-absorbing surfaces, thereby improving the efficiency of implementation.

[0071] like Figure 1-3 As shown, the length of the edge of the first wall 201 facing the flue gas inlet 21 is less than the length of the edge of the first wall 201 facing the flue gas outlet 22; and the length of the edge of the second wall 202 facing the flue gas inlet 21 is less than the length of the edge of the second wall 202 facing the flue gas outlet 22.

[0072] In practice, the length of the edge of the first wall 201 facing the flue gas inlet 21 is less than the length of the edge of the first wall 201 facing the flue gas outlet 22, and the length of the edge of the second wall 202 facing the flue gas inlet 21 is less than the length of the edge of the second wall 202 facing the flue gas outlet 22. This makes the main channel 23 longer at the flue gas inlet 21 and shorter at the flue gas outlet 22, so that the flue gas inlet 21 can cover a wider area below the range hood 10, and also facilitates the smooth acceleration of the flue gas in the main channel 23, which is beneficial to the efficiency of the flue gas to the exhaust pipe.

[0073] In this embodiment, the edge length of the first wall surface 201 facing the flue gas inlet 21 is the same as the edge length of the second wall surface 202 facing the flue gas inlet 21, and the edge length of the first wall surface 201 facing the flue gas outlet 22 is the same as the edge length of the second wall surface 202 facing the flue gas outlet 22. This results in a relatively simple and neat shape for the flue gas inlet 21 and the flue gas outlet 22, facilitating the production of the flue gas passage 20. However, in actual implementation, those skilled in the art should be able to conceive of making necessary adjustments to the specific shape of the flue gas inlet 21 or the flue gas outlet 22 according to the actual situation. For example, a circular flue gas inlet 21 and a circular flue gas outlet 22 could be chosen. In this case, those skilled in the art can correspondingly set the diameter of the flue gas inlet 21 to be larger than the diameter of the flue gas outlet 22.

[0074] like Figure 1-3 As shown, the main channel 23 also includes two side walls 203. The two side walls 203 are provided with arcs that match the side edges of the first wall 201 and the second wall 202. The two side walls 203, together with the first wall 201 and the second wall 202, form the main channel 23. The cross-sectional projection of the main channel 23 relative to the horizontal plane changes from large to small from the flue gas inlet 21 to the flue gas outlet 22.

[0075] In practical implementation, the two side walls 203 together with the first wall 201 and the second wall 202 form the main channel 23. As a result, the cross-sectional projection of the main channel 23 relative to the horizontal plane changes from large to small from the flue gas inlet 21 to the flue gas outlet 22. This makes the main channel 23 arranged in a way that the opening area is large at the flue gas inlet 21 and small at the flue gas outlet 22. This also makes it easier for the flue gas to accelerate smoothly in the main channel 23, which is beneficial to the efficiency of the flue gas to the exhaust pipe.

[0076] like Figure 1-3 As shown, the angle between the first sound-absorbing surface 101 and the flue gas inlet 21 is greater than the angle between the second reflective surface 104 and the flue gas inlet 21.

[0077] In practice, by adopting an angle between the first sound-absorbing surface 101 and the flue gas inlet 21 that is greater than the angle between the second reflective surface 104 and the flue gas inlet 21, the flue gas inlet 21 can be extended further away from the user, thereby facilitating the absorption of smoke from locations such as walls where the range hood 10 is installed, making the smoke absorption more comprehensive.

[0078] like Figure 1-3 As shown, the projection of the first sound-absorbing surface 101 relative to the horizontal plane and the projection of the second reflective surface 104 relative to the horizontal plane at least partially overlap.

[0079] In specific implementation, the projection of the first sound-absorbing surface 101 relative to the horizontal plane and the projection of the second reflective surface 104 relative to the horizontal plane overlap at least partially. Thus, when sound waves that are not completely absorbed by the first sound-absorbing surface 101 are transmitted back to the sound source, the second reflective surface 104 can partially receive the aforementioned sound waves and reflect them back to the main channel 23, thereby further confining the sound waves in the main channel 23 to the maximum extent.

[0080] like Figure 1-3 As shown, the flue gas passage 20 also includes a passage shell 300, which is fitted outside the main passage 23. The inner surface of the passage shell 300 and the outer surface of the main passage 23 together form a noise reduction chamber 301. The main passage 23 has a plurality of noise reduction holes 302 that connect the interior of the main passage 23 with the noise reduction chamber 301.

[0081] In specific implementation, noise reduction holes 302 are distributed on the main channel 23, and the main channel 23 is covered with a channel shell 300. The inner surface of the channel shell 300 and the outer surface of the main channel 23 together form a noise reduction chamber 301. Thus, after the flue gas enters the main channel 23 and before the flue gas is sent to the exhaust pipe, the flue gas can first expand and diffuse using the noise reduction chamber 301. The expansion made in the noise reduction chamber 301 reduces the initial flow velocity of the flue gas, avoiding the noise that may be caused by the excessive flow velocity of the flue gas when it enters the main channel 23.

[0082] In this embodiment, the noise reduction hole 302 is actually a circular hole of uniform size. However, in actual implementation, those skilled in the art should be able to conceive of adjusting the size of the noise reduction hole 302 according to actual needs. For example, the noise reduction hole 302 near the flue gas inlet 21 can be set to a larger diameter, and the noise reduction hole 302 near the flue gas outlet 22 can be set to a smaller diameter, thereby improving the efficiency of expansion and diffusion of flue gas when it enters the flue gas inlet 21. This embodiment does not limit this.

[0083] like Figure 1-3 As shown, sound-absorbing material 303 is installed in the noise reduction chamber 301.

[0084] In practice, the noise reduction chamber 301 is equipped with sound-absorbing material 303, which reduces the noise that may be caused by vibration.

[0085] Specifically, the sound-absorbing material 303 used in this embodiment is a sound-absorbing cotton. As an alternative implementation, those skilled in the art should also be able to conceive of using other types of sound-absorbing materials 303 or vibration-damping materials to achieve a similar sound-absorbing effect, such as using spring modules or foam plastics. This embodiment does not limit this.

[0086] A range hood 10 includes the aforementioned smoke passage 20, which is connected to an external exhaust pipe.

[0087] In practice, the range hood 10, with the aforementioned smoke duct 20, can still reasonably reduce noise even if the range hood 10 itself is increased to prevent fumes from lingering near the kitchen ceiling.

[0088] The range hood 10 can be controlled by a voice module, which is equipped with a controller, a voice receiving module, and a voice parsing module. The voice receiving module receives user commands, and the voice parsing module parses the commands. Based on the parsed commands, the controller controls the range hood 10 to perform corresponding operations, thereby realizing the intelligent control of the range hood 10 and improving the user experience.

[0089] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A flue gas passage for a range hood, said flue gas passage having a flue gas inlet and a flue gas outlet, characterized in that, The flue gas passage includes a main passage, the main passage comprising: A first sound-absorbing surface, located within the main channel and forming an acute angle with the flue gas inlet; and a first reflective surface, located within the main channel and forming an acute angle with the flue gas outlet. The first sound-absorbing surface is used to absorb sound waves entering from the flue gas inlet, and the first reflective surface is used to reflect sound waves entering from the flue gas outlet.

2. The flue gas passage as described in claim 1, characterized in that, The main channel further includes: a second sound-absorbing surface disposed relative to the first reflective surface, the second sound-absorbing surface being located within the main channel and forming an acute angle with the flue gas inlet, the second sound-absorbing surface being used to absorb part of the sound waves reflected from the first reflective surface; and a second reflective surface disposed relative to the first sound-absorbing surface, the second reflective surface being located within the main channel and forming an acute angle with the flue gas outlet, the second reflective surface being used to reflect part of the sound waves entering from the flue gas outlet back to the first sound-absorbing surface.

3. The flue gas passage as described in claim 2, characterized in that, The first reflective surface and the first sound-absorbing surface are joined together in the middle section of the main channel to form the first wall surface of the main channel; and / or, the second reflective surface and the second sound-absorbing surface are joined together in the middle section of the main channel to form the second wall surface of the main channel.

4. The flue gas passage as described in claim 3, characterized in that, The length of the edge on the first wall facing the flue gas inlet is less than the length of the edge on the first wall facing the flue gas outlet; and / or, the length of the edge on the second wall facing the flue gas inlet is less than the length of the edge on the second wall facing the flue gas outlet.

5. The flue gas passage as described in claim 4, characterized in that, The main channel also includes two side walls, which together with the first wall and the second wall form the main channel; wherein, the cross-sectional projection of the main channel relative to the horizontal plane changes from large to small from the flue gas inlet to the flue gas outlet.

6. The flue gas passage as described in claim 2, characterized in that, The angle between the first sound-absorbing surface and the flue gas inlet is greater than the angle between the second reflective surface and the flue gas inlet.

7. The flue gas passage as described in any one of claims 2-6, characterized in that, The projection of the first sound-absorbing surface relative to the horizontal plane and the projection of the second reflective surface relative to the horizontal plane overlap at least partially.

8. The flue gas passage as described in any one of claims 1-6, characterized in that, The flue gas passage also includes a passage shell, which is fitted over the main passage. The inner surface of the passage shell and the outer surface of the main passage together form a noise reduction chamber. The main passage has a plurality of noise reduction holes that connect the interior of the main passage to the noise reduction chamber.

9. The flue gas passage as described in claim 8, characterized in that, The noise reduction chamber is equipped with sound-absorbing materials.

10. A range hood, characterized in that, The range hood includes a flue gas passage as described in any one of claims 1-9, and the flue gas passage is connected to an external exhaust pipe.

Images