Noise-reduction smoke exhaust system

Abstract

The utility model provides a noise-reducing smoke exhaust system, which relates to the field of kitchen electric equipment and comprises an auxiliary fan, an indoor fan, a public flue, a noise-reducing box body, a smoke collecting device, a first pipeline and a second pipeline, the first pipeline is arranged on a pipeline between the public flue and the noise-reducing box body, and the second pipeline is arranged on a pipeline between the public flue and the noise-reducing box body. The second pipeline is arranged on a pipeline between the noise reduction box body and the smoke collecting device, the sectional area of a ventilation opening, communicated with the first pipeline, of the noise reduction box body is larger than that of a ventilation opening of the first pipeline, and the sectional area of a ventilation opening, communicated with the second pipeline, of the noise reduction box body is larger than that of a ventilation opening of the second pipeline; the sectional area of the noise reduction box body is 2-5 times of the sectional area of at least one of the first pipeline and the second pipeline, and the length of the single side, penetrating through the noise reduction box body, of fluid is not larger than 350 mm. The noise generated in the operation state of the auxiliary fan enters a large space from a relatively small space in the transmission process, the energy loss of the noise is reduced, and therefore the noise is reduced, and the use experience of a user is improved.

Description

Technical Field

[0001] The present application relates to the field of kitchen appliances, and in particular to a noise-reducing smoke exhaust system. Background Art

[0002] Range hoods are indispensable for modern kitchen appliances. Currently, most high-rise residential buildings adopt centralized exhaust methods. Central range hood systems are often used for exhaust in high-rise residential buildings. The central range hood system includes range hoods and auxiliary fans inside the kitchen. Range hoods are used for users on high floors. Under the suction of the auxiliary fans, the exhaust air volume of users on high floors will be greater, which will reduce the air volume increase of the external unit for low floors. It is necessary to adjust the angle of the electric valve to control the exhaust air volume of users on high floors. However, this resistance adjustment method consumes energy and will also increase the noise of the range hood operation. For low floors, under the auxiliary fan auxiliary exhaust, the exhaust air volume of the range hood increases, and the noise of the range hood operation will also increase.

[0003] When the auxiliary fan runs at a high speed, the noise generated by the outdoor unit can easily be transmitted into the room through the pipe. Even when the user's range hood is not turned on but the auxiliary fan is running, users on several floors close to the outdoor unit are prone to noise, resulting in a poor user experience. Utility Model Content

[0004] In response to one of the above-mentioned problems, the present application provides a noise-reducing smoke exhaust system, which does not require the installation of additional noise reduction devices. The noise generated by the auxiliary fan in operation enters a larger space from a relatively small space during the transmission process, thereby causing energy loss and achieving the noise reduction effect. It is not only energy-saving and environmentally friendly, but also improves the user experience.

[0005] The present application provides a noise-reducing smoke exhaust system, including a noise-reducing smoke exhaust system, characterized in that it includes an auxiliary fan, an indoor fan, a common flue, a noise reduction box, a smoke collecting device, a first pipe and a second pipe, wherein the first pipe is arranged on a pipe between the common flue and the noise reduction box, and the second pipe is arranged on a pipe between the noise reduction box and the smoke collecting device.

[0006] The noise reduction box is connected to the first pipe and the second pipe, the cross-sectional area of ​​the vent of the noise reduction box connected to the first pipe is larger than the cross-sectional area of ​​the vent of the first pipe, and the cross-sectional area of ​​the vent of the noise reduction box connected to the second pipe is larger than the cross-sectional area of ​​the vent of the second pipe.

[0007] The cross-sectional area of ​​the noise reduction box is 2 to 5 times the cross-sectional area of ​​at least one of the first pipe and the second pipe, and the single-side length of the fluid passing through the noise reduction box is no more than 350 mm.

[0008] In a possible implementation manner, the noise reduction box is arranged inside the suspended ceiling.

[0009] In a possible implementation manner, the indoor fan is accommodated inside the noise reduction box.

[0010] In a possible implementation manner, sound-absorbing cotton is further included, and the sound-absorbing cotton is arranged on the outer wall of the indoor fan.

[0011] In a possible implementation manner, it also includes an electric valve and an indoor and outdoor joint adjustment control device, wherein the indoor and outdoor joint adjustment control device is connected to the electric valve and the indoor fan, and the indoor and outdoor joint adjustment control device can adjust the speed of the indoor fan and the opening of the electric valve.

[0012] In a possible implementation manner, the noise reduction box includes a wind wheel and a driving device, the wind wheel is connected to the driving device, and the wind wheel can drive the fluid in the noise reduction box to flow.

[0013] In a possible implementation manner, a preset range of the diameter of the wind wheel is 200 mm to 260 mm.

[0014] In a possible implementation manner, the driving device of the indoor fan is a DC motor.

[0015] In a possible implementation manner, a check valve is further included, and the check valve is sleeved on the electric valve.

[0016] In a possible implementation manner, the indoor fan is provided with an air outlet hood, and the first duct is sleeved on the air outlet hood.

[0017] The beneficial effects of a noise reduction smoke exhaust system provided by the present application are as follows:

[0018] The present application provides a noise-reducing smoke exhaust system, including an auxiliary fan, an indoor fan, a common flue, a noise reduction box, a smoke collecting device, a first pipe and a second pipe. The first pipe is arranged on the pipe between the common flue and the noise reduction box, the second pipe is arranged on the pipe between the noise reduction box and the smoke collecting device, the noise reduction box is connected with the first pipe and the second pipe, the cross-sectional area of ​​the vents connecting the noise reduction box and the first pipe is larger than the cross-sectional area of ​​the vents of the first pipe, the cross-sectional area of ​​the vents connecting the noise reduction box and the second pipe is larger than the cross-sectional area of ​​the vents of the second pipe, the cross-sectional area of ​​the noise reduction box is 2 to 5 times the cross-sectional area of ​​at least one of the first pipe and the second pipe, the single-side length of the fluid passing through the noise reduction box is not more than 350 mm, the noise generated in the operating state of the auxiliary fan enters a larger space from a relatively small space during the transmission process, the energy loss of the noise is reduced, thereby achieving the noise reduction effect and improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of the structure of a noise reduction box provided in an embodiment of the present application;

[0021] Figure 2 A schematic structural diagram of a noise reduction box from another angle provided in an embodiment of the present application;

[0022] Figure 3 A schematic structural diagram of a noise reduction box from another angle provided in an embodiment of the present application;

[0023] Figure 4 This is a schematic diagram of the structure inside a kitchen using a smoke exhaust system provided in an embodiment of the present application;

[0024] Figure 5 This is a schematic diagram of the structure of a multi-floor kitchen using the smoke exhaust system provided in an embodiment of the present application;

[0025] The following is a supplementary description of the attached drawings:

[0026] 10. Auxiliary fan; 11. Auxiliary pipeline; 12. Flue base; 13. Public flue; 14. Fire damper; 15. Electric valve; 16. First pipeline; 20. Indoor fan; 21. Second pipeline; 201. Noise reduction box; 30. Smoke collection device. DETAILED DESCRIPTION

[0027] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] The term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present application. In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may include one or more of the features explicitly or implicitly. Moreover, the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here.

[0029] A noise-reducing smoke exhaust system provided in an embodiment of the present application is described below in conjunction with the accompanying drawings. The smoke exhaust system of the present application is particularly suitable for users on multiple floors.

[0030] A noise-reducing smoke exhaust system, characterized in that it includes an auxiliary fan 10, an indoor fan 20, a common flue 13, a noise reduction box 201, a smoke collecting device 30, a first pipe 16 and a second pipe 21, the first pipe 16 is arranged on the pipeline between the common flue 13 and the noise reduction box 201, the second pipe 21 is arranged on the pipeline between the noise reduction box 201 and the smoke collecting device 30, the noise reduction box 201 is connected with the first pipe 16 and the second pipe 21, the cross-sectional area of ​​the vents through which the noise reduction box 201 is connected to the first pipe 16 is larger than the cross-sectional area of ​​the vents of the first pipe 16, the cross-sectional area of ​​the vents through which the noise reduction box 201 is connected to the second pipe 21 is larger than the cross-sectional area of ​​the vents of the second pipe 21, the cross-sectional area of ​​the noise reduction box 201 is 2 to 5 times the cross-sectional area of ​​at least one of the first pipe and the second pipe, and the single-side length of the fluid passing through the noise reduction box is not more than 350 mm.

[0031] In this way, the noise generated by the auxiliary fan 10 in operation enters a larger space from a relatively small space during the transmission process, thereby causing energy loss and achieving the effect of noise reduction, which not only saves energy and is environmentally friendly but also enhances the user experience.

[0032] Specifically, the noise generated by the auxiliary fan 10 in the working state is transmitted from the pipeline assembly to the inside of the noise reduction box 201. Due to the sudden increase in the cross-section from the first pipeline 16 to the noise reduction box 201, the noise enters a larger space from a relatively small space, which helps to dissipate the noise and thus reduce the noise. The blocking of the indoor fan 20 by the noise reduction box 201 can also further isolate the noise.

[0033] Understandably, the existing building fumes are generally discharged directly on the roof through the public flue 13. For some projects with relatively high environmental protection requirements, such as those with greening or functional requirements on the roof, or low-rise buildings, villas and other low-rise projects, it is easy to cause fume pollution and affect the living environment of the community.

[0034] Furthermore, the smoke exhaust system includes an auxiliary fan 10, a fire damper 14, an electric valve 15, an indoor fan 20, a smoke collecting device 30 and a pipeline assembly. The pipeline assembly includes an auxiliary pipe 11, a common flue 13, a first pipe 16 and a second pipe 21. The fumes generated by the user in the kitchen can pass through the smoke collecting device 30, the second pipe 21, the first pipe 16, the common flue 13 and the auxiliary pipe 11 in sequence, so that the fumes are discharged to the outside.

[0035] Specifically, the second pipe 21 is arranged in the indoor range hood, one end of the second pipe 21 is connected to the noise reduction box 201, and the other end is connected to the smoke collecting device 30; the first pipe 16 is arranged above the user's ceiling, one end of the first pipe 16 is connected to the noise reduction box 201, and the other end is connected to the public flue 13. The second pipe 21 is used to discharge the oil smoke collected by the smoke collecting device 30, and the inner diameter of the second pipe 21 is greater than or equal to 220 mm. The first pipe 16 is used to discharge the oil smoke to the public flue, and the inner diameter of the first pipe 16 is greater than or equal to 160 mm.

[0036] In one embodiment, the auxiliary duct 11 is arranged between the auxiliary fan 10 and the flue base 12, so that the auxiliary fan 10 is connected to the common flue 13, the common flue 13 is arranged between the flue base 12 and the fire damper 14, the first duct 16 is arranged between the fire damper 14 and the indoor fan 20, the second duct 21 is arranged between the smoke collection device 30 and the indoor fan 20, and the second duct 21 is arranged inside the range hood.

[0037] In one embodiment, the cross-sectional area of ​​the noise reduction box 201 is 2 to 5 times the cross-sectional area of ​​the first pipe 16 and 2 to 5 times the cross-sectional area of ​​the second pipe 21 .

[0038] In one embodiment, the cross-sectional area of ​​the noise reduction box 201 is 2 to 3 times the cross-sectional area of ​​the first pipe 16 and 2 to 3 times the cross-sectional area of ​​the second pipe 21 .

[0039] In one embodiment, the single side dimension of the noise reduction box 201 does not exceed 300 mm.

[0040] In another embodiment, the single-side dimension of the noise reduction box 201 perpendicular to the wall does not exceed 300 mm, and the single-side dimension of the noise reduction box 201 parallel to the wall is greater than 300 mm.

[0041] Furthermore, the noise reduction box 201 is arranged inside the suspended ceiling. The suspended ceiling can isolate the noise reduction box 201, that is, the suspended ceiling blocks the noise of the indoor fan 20, thereby achieving a good noise reduction effect.

[0042] In one embodiment, the noise reduction box 201 is disposed above the suspended ceiling, and the suspended ceiling and the noise reduction box 201 cooperate with each other to achieve a double noise reduction effect.

[0043] Furthermore, the indoor fan 20 is accommodated in the noise reduction box 201. In this way, the noise reduction box 201 can effectively reduce the noise generated by the indoor fan 20 and improve the overall noise reduction effect.

[0044] Specifically, the indoor fan 20 is accommodated inside a noise reduction box 201, and the noise reduction box 201 is arranged above the suspended ceiling. The noise generated by the indoor fan 20 in the working state is isolated and absorbed by the noise reduction box 201 and the suspended ceiling at the same time, thereby significantly reducing the noise of the indoor fan 20 from being transmitted to the indoor space and reducing the impact of noise on users.

[0045] Furthermore, the cross-sectional area of ​​the vent connecting the noise reduction box 201 and the second pipe 21 is greater than or equal to the cross-sectional area of ​​the vent connecting the noise reduction box 201 and the first pipe 16. Setting the cross-sectional area of ​​the air outlet of the noise reduction box 201 can ensure that sufficient ventilation volume enters the interior of the noise reduction box 201 through the second pipe 21, thereby effectively reducing the noise generated by the indoor fan.

[0046] Specifically, the noise reduction box 201 includes two air outlets of the indoor fan 20, one air outlet is connected to the first pipe 16, and is used to discharge the oil smoke to the common flue 13; the other air outlet is connected to the second pipe 21, and is used to discharge the oil smoke generated by the user when cooking.

[0047] Furthermore, it also includes sound-absorbing cotton, which is arranged on the outer wall of the indoor fan 20. By covering the sound-absorbing cotton, the noise transmitted by the auxiliary fan 10 and the noise generated by the indoor fan 20 are further reduced.

[0048] Optionally, the sound-absorbing cotton can be mineral fiber, polyester fiber, polyurethane foam or foam plastic, etc. Among them, glass fiber and rock wool have good sound absorption performance and high temperature resistance.

[0049] Specifically, sound-absorbing cotton is used to absorb echo and noise, reduce noise propagation, and improve the indoor acoustic environment.

[0050] Furthermore, it also includes an electric valve 15 and an indoor and outdoor joint adjustment control device, which is connected to the electric valve 15 and the indoor fan 20, and the indoor and outdoor joint adjustment control device can adjust the speed of the indoor fan 20 and the opening of the electric valve 15. The indoor and outdoor joint adjustment control device can intelligently adjust the speed of the indoor fan 20 and the opening of the electric valve 15, thereby realizing dynamic adjustment of the air volume.

[0051] Specifically, the indoor and outdoor joint control device adjusts the indoor fan 20, the auxiliary fan 10 and the electric valve 15 based on the air output of each user's range hood, thereby adjusting the real-time air output of each user's range hood to meet customer needs.

[0052] Furthermore, the noise reduction box 201 includes a wind wheel and a driving device, the wind wheel is connected to the driving device, and the wind wheel can drive the fluid flow in the noise reduction box 201. In this way, the wind wheel drives the fluid flow in the noise reduction box 201, promotes the fluid flow in the noise reduction box 201, and reduces the retention of odor and pollutants.

[0053] Specifically, the wind wheel is mainly composed of blades, bearings and other parts. The blades are fan-shaped or blade-shaped, which can suck in and discharge the fluid in the range hood. The number and shape of the blades can be adjusted according to the size and design requirements of the range hood. The material is usually metal or plastic. Metal blades have good heat resistance and corrosion resistance, while plastic blades are light and durable. The bearing is the supporting part of the wind wheel. It is located in the center of the wind wheel and plays the role of supporting and fixing the wind wheel.

[0054] Optionally, the bearing adopts a rolling bearing or a sliding bearing. The rolling bearing uses balls or rollers for support and has smaller friction and higher rotation speed, while the sliding bearing uses lubricating oil for lubrication and is suitable for situations with higher rotation speeds.

[0055] The drive device is the power source that drives the wind wheel, usually using an AC motor or a DC motor. The AC motor has a higher speed and a larger output power, while the DC motor has a smaller size and a higher efficiency.

[0056] Furthermore, the diameter of the wind wheel is 200 mm to 260 mm. A suitable wind wheel diameter can provide a larger air volume and a stronger suction force, thereby more effectively sucking the kitchen fume into the range hood and improving the smoke extraction effect.

[0057] In one embodiment, the diameter of the wind wheel is 160 mm to 220 mm.

[0058] In this embodiment, the diameter of the wind wheel is 220 mm, so that the overall size of the noise reduction box 201 is reduced.

[0059] Furthermore, the driving device of the indoor fan 20 is a DC motor. Compared with an AC motor, a DC motor has a higher power supply efficiency. A DC variable frequency motor has stable performance and a long service life, which can improve the reliability of the equipment, reduce maintenance costs and failure rates, and extend the service life of the equipment.

[0060] Specifically, the driving device of the indoor fan 20 and the auxiliary fan 10 of this embodiment is a DC motor. The use of a DC motor as the driving device of the indoor fan 20 and the auxiliary fan 10 can adjust the frequency and speed according to the actual load demand to meet different working conditions, thereby greatly improving the efficiency of the equipment and reducing energy consumption.

[0061] Furthermore, it also includes a check valve and an electric valve 15, and the check valve is sleeved on the electric valve 15. When the electric valve 15 is closed, the check valve can prevent the fluid from flowing back in the pipeline, thereby extending the service life of the equipment.

[0062] Specifically, the electric valve 15 is used to adjust the fluid in the pipeline, that is, it can adjust the air output of the range hood.

[0063] Furthermore, the indoor fan 20 is provided with an air outlet hood, and the first pipe 16 is sleeved on the air outlet hood. The air outlet hood can effectively guide the air discharged by the indoor fan 20, so that the air is evenly distributed indoors, avoiding the situation of insufficient or excessive local ventilation, reducing wind resistance, reducing the energy consumption of the fan, and improving the energy efficiency of the system.

[0064] Specifically, the first pipe 16 is mounted on the air outlet cover to protect the fan outlet from the external environment, thereby extending the service life of the fan and pipeline equipment. The air outlet cover can beautify the indoor space, make the fan outlet look neater and more beautiful, and improve the overall performance of the system.

[0065] The following introduces specific embodiments of the present application based on the above technical solution.

[0066] Example 1

[0067] See also Figure 1-3A noise reduction smoke exhaust system comprises an auxiliary fan 10, an indoor fan 20, a common flue 13, a noise reduction box 201, a smoke collecting device 30, a first pipe 16 and a second pipe 21, wherein the first pipe 16 is arranged on the pipeline between the common flue 13 and the noise reduction box 201, the second pipe 21 is arranged on the pipeline between the noise reduction box 201 and the smoke collecting device 30, the noise reduction box 201 is connected with the first pipe 16 and the second pipe 21, the cross-sectional area of ​​the vents of the noise reduction box 201 connected with the first pipe 16 is greater than the cross-sectional area of ​​the vents of the first pipe 16, the cross-sectional area of ​​the vents of the noise reduction box 201 connected with the second pipe 21 is greater than the cross-sectional area of ​​the vents of the second pipe 21, the cross-sectional area of ​​the noise reduction box 201 is 2 to 5 times the cross-sectional area of ​​at least one of the first pipe and the second pipe, and the single side length of the fluid passing through the noise reduction box is not greater than 350 mm. The indoor fan 20 is accommodated in the noise reduction box 201.

[0068] The cross-sectional area of ​​the noise reduction box 201 is 2 to 3 times the cross-sectional area of ​​the first pipe 16 and 2 to 3 times the cross-sectional area of ​​the second pipe 21 .

[0069] The noise reduction box 201 includes an indoor fan 20 and two air outlets, one of which is connected to the first pipe 16 for discharging oil smoke, and the other is connected to the second pipe 21 for discharging oil smoke generated by the user when cooking. It also includes sound-absorbing cotton, which is arranged on the outer wall of the indoor fan 20. It also includes an electric valve 15 and an indoor and outdoor joint adjustment control device, which is connected to the electric valve 15 and the indoor fan 20, and the indoor and outdoor joint adjustment control device can adjust the speed of the indoor fan 20 and the opening of the electric valve 15.

[0070] The indoor and outdoor joint control device adjusts the indoor fan 20, the auxiliary fan 10 and the electric valve 15 based on the air output of each user's range hood, thereby adjusting the real-time air output of each user's range hood to meet customer needs.

[0071] The noise reduction box 201 includes a wind wheel and a driving device, the wind wheel is connected to the driving device, and the wind wheel can drive the fluid flow of the noise reduction box 201. The diameter of the wind wheel in the indoor fan 20 is 220 mm, and it also includes a check valve and an electric valve 15, and the check valve is sleeved on the electric valve 15. The indoor fan 20 is provided with an air outlet hood, and the first pipeline 16 is sleeved on the air outlet hood.

[0072] Example 2

[0073] The similarities between Example 2 and Example 1 are not repeated here. The difference between Example 2 and Example 1 is that the noise reduction box 201 of Example 2 is arranged on the ceiling, thereby improving the noise reduction effect.

[0074] The above disclosures are only several preferred embodiments of the present invention, which cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A noise-reducing smoke exhaust system, characterized in that: The invention comprises an auxiliary fan (10), an indoor fan (20), a common flue (13), a noise reduction box (201), a smoke collecting device (30), a first pipe (16) and a second pipe (21), wherein the first pipe (16) is arranged on a pipeline between the common flue (13) and the noise reduction box (201), and the second pipe (21) is arranged on a pipeline between the noise reduction box (201) and the smoke collecting device (30). The noise reduction box (201) is in communication with the first pipe (16) and the second pipe (21); the cross-sectional area of ​​the vent opening of the noise reduction box (201) in communication with the first pipe (16) is larger than the cross-sectional area of ​​the vent opening of the first pipe (16); the cross-sectional area of ​​the vent opening of the noise reduction box (201) in communication with the second pipe (21) is larger than the cross-sectional area of ​​the vent opening of the second pipe (21); The cross-sectional area of ​​the noise reduction box (201) is 2 to 5 times the cross-sectional area of ​​at least one of the first pipe and the second pipe, and the single-side length of the fluid passing through the noise reduction box is no more than 350 mm.

2. The noise-reducing smoke exhaust system according to claim 1, characterized in that: The noise reduction box is arranged inside the suspended ceiling.

3. The noise-reducing smoke exhaust system according to claim 1, characterized in that: The indoor fan (20) is accommodated inside the noise reduction box (201).

4. The noise-reducing smoke exhaust system according to claim 3, characterized in that: It also includes sound-absorbing cotton, which is arranged on the outer wall of the indoor fan (20).

5. The noise-reducing smoke exhaust system according to claim 3, characterized in that: It also includes an electric valve (15) and an indoor and outdoor joint adjustment control device, wherein the indoor and outdoor joint adjustment control device is connected to the electric valve (15) and the indoor fan (20), and the indoor and outdoor joint adjustment control device can adjust the rotation speed of the indoor fan (20) and the opening degree of the electric valve (15).

6. The noise-reducing smoke exhaust system according to any one of claims 1 to 3, characterized in that: The noise reduction box (201) comprises a wind wheel and a driving device, the wind wheel is connected to the driving device, and the wind wheel can drive the flow of fluid in the noise reduction box (201).

7. The noise-reducing smoke exhaust system according to claim 6, characterized in that: The preset range of the diameter of the wind wheel is 200 mm to 260 mm.

8. The noise-reducing smoke exhaust system according to claim 3, characterized in that: The driving device of the indoor fan (20) is a DC motor.

9. The noise-reducing smoke exhaust system according to claim 5, characterized in that: It also comprises a check valve, which is sleeved on the electric valve (15).

10. The noise-reducing smoke exhaust system according to claim 4, characterized in that: The indoor fan (20) is provided with an air outlet cover, and the first pipe (16) is sleeved on the air outlet cover.

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