Noise reduction structure for air inlet of fan

Abstract

The utility model relates to a fan air inlet noise reduction structure and relates to the field of fans, the fan air inlet noise reduction structure comprises a mounting shell and a noise reduction screen plate, the mounting shell is fixedly mounted on a fan shell, the noise reduction screen plate is fixedly arranged on the inner side wall of the mounting shell, a filling cavity is defined by the noise reduction screen plate and the mounting shell, and the filling cavity is filled with a sound absorption body; and external air can enter the air inlet hole of the impeller through the middle channel of the noise reduction screen plate. Noise generated by gas can directly enter the sound absorption body through the meshes of the noise reduction mesh plate, more sound waves enter the sound absorption body, medium-high frequency noise absorption is enhanced through viscous friction, meanwhile, the meshes of the noise reduction mesh plate can adjust impedance of the sound waves on the surface of the sound absorption cotton, sound reflection is reduced, and the sound absorption bandwidth is improved; and therefore, the noise reduction effect at the air inlet of the fan is improved.

Description

Technical Field

[0001] This application relates to the field of wind turbines, and in particular to a noise reduction structure for a wind turbine inlet. Background Technology

[0002] As key equipment in industrial and civil fields, fans are used in drying systems for car washes, pharmaceutical machinery, and glass machinery. Primarily used in car wash drying systems, aerodynamic efficiency and noise control have always been core areas for technological optimization. During fan intake, the airflow periodically sheds vortices as it bypasses the inlet edge or support structure, generating low-frequency discrete noise. Therefore, noise reduction treatment is necessary at the fan inlet.

[0003] The prior art, disclosed in patent application CN215949866U, describes a high-efficiency, energy-saving centrifugal fan. This prior art reduces the risk of high-pressure airflow back through the gap between the suction hood and the impeller by incorporating a first airtight ring, a second airtight ring, and sound-absorbing cotton within the ring grooves. Simultaneously, it utilizes the flow-blocking and sound-absorbing properties of the sound-absorbing cotton to reduce noise. However, in this prior art, the sound-absorbing cotton only provides static flow blocking through the ring grooves, resulting in insufficient absorption efficiency for high-frequency jet noise due to the isolation of the sound absorption path. This leads to poor noise reduction at the fan's inlet. Utility Model Content

[0004] To address the problem that sound-absorbing cotton's absorption efficiency is insufficient due to static flow obstruction via the ring groove, resulting in poor noise reduction at the fan inlet caused by isolation of the sound absorption path, this application provides a fan inlet noise reduction structure.

[0005] The noise reduction structure for a fan inlet provided in this application adopts the following technical solution:

[0006] A noise reduction structure for a fan inlet includes a mounting shell and a noise reduction mesh plate. The mounting shell is fixedly mounted on the fan housing, and the noise reduction mesh plate is fixedly disposed on the inner side wall of the mounting shell, forming a filling cavity with the mounting shell. The filling cavity is filled with a sound absorber, and outside air can enter the air inlet of the impeller through the middle channel of the noise reduction mesh plate.

[0007] By adopting the above technical solution, when the fan is working, outside air enters the impeller through the middle channel of the noise reduction mesh plate. As the gas passes through the noise reduction mesh plate, the noise generated by the gas can directly enter the sound absorption body through the mesh of the noise reduction mesh plate, allowing more sound waves to enter the interior of the sound absorption body. Through viscous friction, the absorption of mid-to-high frequency noise is enhanced. At the same time, the mesh of the noise reduction mesh plate can adjust the impedance of sound waves on the surface of the sound-absorbing cotton, reduce sound reflection, increase the sound absorption bandwidth, and thus improve the noise reduction effect at the air inlet of the fan.

[0008] Preferably, the two ends of the noise reduction mesh are a large opening and a small opening, respectively. Air enters the noise reduction mesh through the large opening, and the cross-sectional area of ​​the noise reduction mesh gradually decreases from the large opening to the small opening.

[0009] By adopting the above technical solution, the airflow velocity gradually increases when the air enters the noise reduction mesh, which helps more noise enter the sound absorber and can adjust the impedance of the sound wave on the surface of the sound absorber, reduce sound reflection, and further improve the noise reduction effect of the fan inlet.

[0010] Preferably, the mounting housing includes a mounting ring segment, an intermediate segment, and a connecting ring segment. The mounting ring segment and the connecting ring segment are respectively disposed at both ends of the intermediate segment. The mounting ring segment is fixedly installed on the outer wall of the fan housing, and the connecting ring segment is disposed opposite to the air inlet of the impeller.

[0011] By adopting the above technical solution, the noise reduction structure can be stably installed on the fan casing. The connection ring section and the air inlet of the impeller are set opposite to each other, which facilitates the smooth entry of air into the impeller and ensures the stability of the relative position between the mounting casing and the impeller. This ensures the normal operation of the entire noise reduction structure and improves the stability of noise reduction at the fan inlet.

[0012] Preferably, the middle section includes a receiving section and two straight edge sections, the two straight edge sections are respectively located at both ends of the receiving section, the two ends of the noise reduction mesh are respectively fixedly installed on the two straight edge sections and fit against the straight edge sections, and the filling cavity is formed between the receiving section and the noise reduction mesh.

[0013] By adopting the above technical solution, the stability of the noise reduction mesh plate installation is improved by using the bonding between the straight edge section and the noise reduction mesh plate, so that the noise reduction mesh plate and the receiving section form a stable filling cavity.

[0014] Preferably, a first arc-shaped ring segment is used to transition between one of the straight edge segments and the mounting ring segment, and between the other straight edge segment and the connecting ring segment.

[0015] By adopting the above technical solutions, the connection between the various parts of the mounting shell is made smoother, reducing airflow resistance and turbulence, further reducing the possibility of noise generation, and improving the overall structural strength and stability of the mounting shell.

[0016] Preferably, the receiving segment includes a first segment and a second segment, and the first segment and the second segment are connected by a second arc-shaped ring segment.

[0017] By adopting the above technical solution, the structural transition of the receiving section is made smoother, which can reduce the resistance and turbulence of airflow and further improve the flow stability of airflow in the filling cavity, thereby enhancing the absorption and reduction effect of noise.

[0018] Preferably, the second segment is recessed in the direction of gas flow F to form a groove within the filling cavity.

[0019] By adopting the above technical solution, forming a groove in the filling cavity can increase the sound absorption space, allowing more sound waves to be absorbed by the sound absorber in the groove, thereby further improving the noise reduction effect at the air inlet of the fan.

[0020] Preferably, the transition between the first segment and one of the straight edge segments, and between the second segment and another straight edge segment, is achieved by using a circular arc transition.

[0021] By adopting the above technical solution, the structural transition of the mounting shell is made smoother, reducing turbulence and resistance of airflow when passing through this part, and further improving the noise reduction effect.

[0022] Preferably, the mounting shell is manufactured using a one-piece molding process.

[0023] By adopting the above technical solutions, the manufacturing of the mounting shell is made simpler, which is conducive to mass production and can ensure the integrity and stability of the mounting shell structure.

[0024] Preferably, the mounting shell is made of PE (polyethylene) material.

[0025] By adopting the above technical solution, the mounting shell has better formability, is lightweight and has high strength, making it easy to mass-produce and install on the fan.

[0026] In summary, this application includes at least one of the following beneficial technical effects:

[0027] 1. As the gas passes through the noise reduction mesh, the noise generated by the gas can directly enter the sound absorber through the mesh of the noise reduction mesh, allowing more sound waves to enter the interior of the sound absorber. The absorption of mid-to-high frequency noise is enhanced through viscous friction. At the same time, the mesh of the noise reduction mesh can adjust the impedance of sound waves on the surface of the sound-absorbing cotton, reduce sound reflection, increase the sound absorption bandwidth, and thus improve the noise reduction effect at the air inlet of the fan.

[0028] 2. The mounting shell is integrally molded and made of PE material, which facilitates mass production and installation on the fan;

[0029] 3. By combining noise-reducing mesh panels and sound absorbers, the noise from the strong airflow at the fan inlet is effectively reduced, and mass production and installation on the fan are facilitated, minimizing the impact on fan operation. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a noise reduction structure for a fan inlet according to an embodiment of this application.

[0031] Figure 2This is a structural diagram used to demonstrate the connection between the mounting shell and the noise reduction mesh.

[0032] Figure 3 It is a cross-sectional view of the assembly structure of the mounting shell and the noise reduction mesh.

[0033] Figure 4 yes Figure 3 Enlarged view of section A.

[0034] Explanation of reference numerals in the attached drawings: 1. Fan housing; 11. Air inlet; 2. Mounting shell; 21. Mounting ring section; 22. Middle section; 221. Receiving section; 2211. First section; 2212. Second section; 2213. Second arc-shaped ring section; 2214. Groove; 222. Straight edge section; 223. First arc-shaped ring section; 23. Connecting ring section; 3. Noise reduction mesh plate; 31. Large opening end; 32. Small opening end; 4. Filling cavity; 5. Sound absorber; 6. Air inlet. Detailed Implementation

[0035] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0036] This application discloses a noise reduction structure for a fan inlet.

[0037] Reference Figure 1 , Figure 2 A noise reduction structure for a fan inlet includes a mounting shell 2 and a noise reduction mesh plate 3. The fan housing 1 has an air inlet 11 opposite to the air inlet hole 6 of the impeller. The mounting shell 2 is fixedly mounted on the fan housing 1 and inserted into the inner cavity of the fan housing 1 through the air inlet 11. Both the mounting shell 2 and the noise reduction mesh plate 3 are rotating bodies, and their axes of rotation are collinear. The noise reduction mesh plate 3 has a conical structure, with one end being a large opening 31 and the other end a small opening 32. The diameter of the noise reduction mesh plate 3 gradually decreases from the large opening 31 to the small opening 32. Airflow enters the noise reduction mesh plate 3 through the large opening 31 and exits through the small opening 32.

[0038] Reference Figure 2 , Figure 3 The noise reduction mesh plate 3 is fixedly installed on the mounting shell 2, and a filling cavity 4 is formed between the mesh plate 3 and the mounting shell 2. The filling cavity 4 is filled with a sound absorber 5. In this embodiment, the sound absorber 5 is sound-absorbing cotton.

[0039] When the fan is operating, outside air enters the impeller through the central channel of the noise-reducing mesh plate 3. As the gas passes through the mesh plate 3, the noise generated can directly enter the sound absorber 5 through the mesh openings. The mesh openings allow more sound waves to enter the sound absorber 5, enhancing the absorption of mid-to-high frequency noise through viscous friction. Simultaneously, the mesh openings of the noise-reducing mesh plate 3 can adjust the impedance of sound waves on the surface of the sound-absorbing cotton, reducing sound reflection and increasing the sound absorption bandwidth, thereby improving the noise reduction effect at the fan inlet. The conical tapering structure gradually reduces the airflow cross-sectional area and smoothly increases the flow velocity, preventing airflow separation and vortex shedding caused by abrupt changes in cross-section. It also helps more noise enter the sound absorber 5 and adjusts the impedance of sound waves on the surface of the sound absorber 5, reducing sound reflection and further improving the noise reduction effect at the fan inlet.

[0040] In this embodiment, the mounting shell 2 is made of PE (polyethylene) material, which makes the mounting shell 2 more malleable, lightweight and strong, easy to mass-produce and install on the fan. In addition, the mounting shell 2 is manufactured by injection molding process, which makes the manufacturing of the mounting shell 2 simpler, facilitates mass production, and ensures the integrity and stability of the mounting shell 2 structure.

[0041] Reference Figure 1 , Figure 2 The mounting housing 2 includes a mounting ring section 21, an intermediate section 22, and a connecting ring section 23. The mounting ring section 21 is located on the outer wall of the fan housing 1 and is fixedly connected to the fan housing 1 by bolts. The intermediate section 22 is located between the mounting ring section 21 and the connecting ring section 23.

[0042] Reference Figure 3 , Figure 4 The intermediate section 22 includes a receiving section 221 and two straight edge sections 222. The receiving section 221 is located between the two straight edge sections 222. One straight edge section 222 is connected to the mounting ring section 21 via a first arc-shaped ring section 223, creating a smooth transition between the straight edge section 222 and the mounting ring section 21. The other straight edge section 222 is also connected to the connecting ring section 23 via a first arc-shaped ring section 223, creating a smooth transition between the straight edge section 222 and the connecting ring section 23. The arrangement of the two first arc-shaped ring sections 223 makes the connection between the various parts of the mounting shell 2 smoother, reduces airflow resistance and turbulence, further reduces the possibility of noise generation, and improves the overall structural strength and stability of the mounting shell 2.

[0043] Reference Figure 3 , Figure 4The surfaces of the two straight edge segments 222 are parallel to the conical surface of the noise-reducing mesh plate 3. Both ends of the noise-reducing mesh plate 3 are respectively positioned on and attached to the two straight edge segments 222. The noise-reducing mesh plate 3 and the two straight edge segments 222 are fixedly installed using rivets. The attachment of the straight edge segments 222 to the noise-reducing mesh plate 3 improves the stability of the installation, allowing the noise-reducing mesh plate 3 and the receiving section 221 to form a stable filling cavity 4.

[0044] Reference Figure 3 , Figure 4 A filling cavity 4 is formed between the receiving section 221 and the noise-reducing mesh plate 3. The receiving section 221 includes a first section 2211 and a second section 2212. The first section 2211 is connected to a straight edge section 222 with a smooth arc transition. The second section 2212 is connected to another straight edge section 222 with a smooth arc transition. The first section 2211 and the second section 2212 are connected by a second arc-shaped ring section 2213, so that the first section 2211 and the second section 2212 have a smooth transition connection. The middle part of the second section 2212 is concave in the direction of gas flow F, so that the middle part of the second section 2212 forms a groove 2214. The groove 2214 increases the space of the filling cavity 4, which can fill more sound absorbers 5, so that more sound waves can be absorbed by the sound absorbers 5 in the groove 2214, further improving the noise reduction effect at the air inlet of the fan.

[0045] Reference Figure 3 , Figure 4 The connecting ring section 23 is located at the end of the mounting shell 2 along the F direction and is positioned opposite to the air inlet 6 of the impeller. The gas flowing out from the noise reduction mesh plate 3 enters the interior of the impeller along the connecting ring section 23, which facilitates the smooth entry of air into the impeller and ensures the stability of the relative position between the mounting shell 2 and the impeller, thereby ensuring the normal operation of the entire noise reduction structure and improving the stability of the noise reduction at the fan inlet.

[0046] The implementation principle of the noise reduction structure for a fan inlet in this embodiment is as follows: Noise generated by the gas can directly enter the sound absorber 5 through the mesh of the noise reduction mesh plate 3. The mesh design allows more sound waves to enter the sound absorber 5, enhancing the absorption of mid-to-high frequency noise through viscous friction. Simultaneously, the mesh of the noise reduction mesh plate 3 can adjust the impedance of sound waves on the surface of the sound-absorbing cotton, reducing sound reflection and increasing the sound absorption bandwidth, thereby improving the noise reduction effect at the fan inlet. The conical tapering structure gradually reduces the airflow cross-sectional area and gradually increases the flow velocity, avoiding airflow separation and vortex shedding caused by abrupt changes in cross-section. It also helps more noise enter the sound absorber 5 and can adjust the impedance of sound waves on the surface of the sound absorber 5, reducing sound reflection and further improving the noise reduction effect at the fan inlet.

[0047] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A fan air inlet noise reduction structure, characterized in that: The device includes a mounting shell (2) and a noise reduction mesh plate (3). The mounting shell (2) is fixedly mounted on the fan housing (1). The noise reduction mesh plate (3) is fixedly disposed on the inner side wall of the mounting shell (2) and forms a filling cavity (4) with the mounting shell (2). The filling cavity (4) is filled with a sound absorber (5). Outside air can enter the air inlet (6) of the impeller through the middle channel of the noise reduction mesh plate (3).

2. The fan inlet noise reduction structure of claim 1, wherein: The two ends of the noise reduction mesh plate (3) are a large opening (31) and a small opening (32), respectively. Air enters the noise reduction mesh plate (3) through the large opening (31), and the cross-sectional area of ​​the noise reduction mesh plate (3) gradually decreases from the large opening (31) to the small opening (32).

3. The fan inlet noise reduction structure of claim 1, wherein: The mounting housing (2) includes a mounting ring section (21), an intermediate section (22), and a connecting ring section (23). The mounting ring section (21) and the connecting ring section (23) are respectively disposed at both ends of the intermediate section (22). The mounting ring section (21) is fixedly installed on the outer wall of the fan housing (1), and the connecting ring section (23) is disposed opposite to the air inlet (6) of the impeller.

4. The fan inlet noise reduction structure of claim 3, wherein: The middle section (22) includes a receiving section (221) and two straight edge sections (222). The two straight edge sections (222) are located at both ends of the receiving section (221). The two ends of the noise reduction mesh plate (3) are fixedly installed on the two straight edge sections (222) and fit against the straight edge sections (222). The filling cavity (4) is formed between the receiving section (221) and the noise reduction mesh plate (3).

5. The fan inlet noise reduction structure of claim 4, wherein: One of the straight edge segments (222) and the mounting ring segment (21) are connected by a first arc-shaped ring segment (223), and the other straight edge segment (222) and the connecting ring segment (23) are connected by a first arc-shaped ring segment (223).

6. The fan inlet noise reduction structure of claim 4, wherein: The receiving section (221) includes a first section (2211) and a second section (2212), and the first section (2211) and the second section (2212) are connected by a second arc-shaped ring section (2213).

7. The fan inlet noise reduction structure of claim 6, wherein: The second segment (2212) is recessed in the direction of gas flow F so as to form a groove (2214) in the filling cavity (4).

8. The fan inlet noise reduction structure of claim 6, wherein: The first segment (2211) and one of the straight edge segments (222) are connected by a circular arc transition, as are the second segment (2212) and another straight edge segment (222).

9. The fan inlet noise reduction structure of claim 1, wherein: The mounting shell (2) is manufactured using a one-piece molding process.

10. The air intake noise reduction structure of a fan according to claim 1, characterized by: The mounting shell (2) is made of PE (polyethylene) material.

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