A double-layered sound attenuation device for a bend of a ventilation system

Abstract

The utility model discloses a double -deck sound -absorbing device for bend place of ventilation system, include: box body shell, flange connecting mouth and double -deck sound -absorbing component, the double -deck sound -absorbing component includes two layers of microporous board and the sound absorption layer of intercalation between it, wherein: the double -deck sound -absorbing component forms double -deck airflow channel in the box body shell inside, for prolonging sound wave reflection path to enhance interference sound -absorbing, two layers of microporous board intercalate constitute the resonance cavity, for absorbing low -frequency eddy current noise, the aperture of microporous board is configured as through friction loss reduces sound energy, and the sound absorption layer is attached to the inside of microporous board to enhance broadband noise reduction.

Description

Technical Field

[0001] This utility model relates to the field of noise reduction technology for ventilation systems, specifically to a double-layer silencing device for use at bends in ventilation systems. Background Technology

[0002] The demand for elbow silencers in cleanroom ventilation systems stems from the stringent standards of noise control and air cleanliness in clean environments. Elbows, as a common connection structure in ventilation ducts, are prone to generating turbulence, eddies, and secondary noise due to airflow deflection. This is particularly evident in high-end manufacturing fields such as semiconductors and biopharmaceuticals, where high-powered fans and dense ductwork result in significant low-frequency vibration noise (e.g., 100-300Hz) at elbows, which traditional straight-duct silencers struggle to effectively suppress. Furthermore, cleanrooms require silencer materials to be antibacterial, dust-resistant, and have smooth surfaces to avoid becoming sources of contamination. Traditional elbow silencers, with their rough internal airflow design and difficult maintenance, are prone to compromising cleanliness levels and require targeted optimization.

[0003] Most current elbow silencers are designed as single-layer elbow silencers: they mainly change the propagation path of sound waves by altering the geometry of the pipe elbow structure, utilizing the reflection and interference effects caused by the sudden change in acoustic impedance to achieve noise reduction. For low-frequency issues, resonant or expanded cavity structures are used to enhance sound wave interference. In terms of materials, the surface is coated with an antibacterial nano-coating or made entirely of stainless steel to meet the requirements of easy cleaning and sterility; the structure tends to be modular, supporting rapid disassembly and maintenance. However, existing technologies still face problems such as limited low-frequency noise reduction efficiency (especially <200Hz), increased pressure drop due to complex flow guidance design, and the risk of dust accumulation after long-term use of multi-layer composite structures. Single-layer structures have limited attenuation effects on high-frequency noise, a narrow noise reduction bandwidth, and insufficient adaptability to complex noise environments; eddies are easily formed at elbows due to airflow separation, which not only increases pressure loss and energy consumption but may also induce secondary noise. Summary of the Invention

[0004] The purpose of this utility model is to provide a double-layer silencing device for elbows in ventilation systems, in order to solve the technical problems existing in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A double-layer silencer for use at bends in ventilation systems, comprising:

[0007] Enclosure shell, flange connection port, and double-layer sound-absorbing components;

[0008] The double-layer sound-absorbing assembly includes inner and outer microporous plates and a sound-absorbing layer sandwiched between them, wherein:

[0009] The double-layer sound-absorbing component forms a double-layer airflow channel inside the outer shell of the enclosure, which is used to extend the sound wave reflection path to enhance interference sound absorption;

[0010] The inner and outer microporous plates are spliced ​​together to form a resonant cavity, which is used to absorb low-frequency eddy current noise.

[0011] The pore size of the microporous plate is configured to reduce sound energy through frictional loss, and the sound-absorbing layer is attached to the inner side of the microporous plate to enhance broadband noise reduction.

[0012] In some embodiments, the double-layer sound-absorbing assembly is fixed inside the housing shell by a support structure, including:

[0013] External support welded to the outer shell of the enclosure;

[0014] The outer microporous plate is fixed to the outer support;

[0015] The inner microplate is connected to the outer microplate via an inner support.

[0016] In some embodiments, the outer microporous plate is fixed to the outer support by a pop rivet, the inner support is connected to the outer microporous plate by a pop rivet, and the inner microporous plate is connected to the inner support by a pop rivet.

[0017] In some embodiments, the sound-absorbing layer is sound-absorbing cotton, which is attached to the inner microporous plate and the outer microporous plate on the side near the inner cavity of the box.

[0018] In some embodiments, the bend of the outer casing is a fan-shaped cavity structure, which is used to smoothly guide the gas flow and reduce airflow noise.

[0019] In some embodiments, the inner microporous plate is flush with the flange connection to maintain a stable airflow direction.

[0020] In some embodiments, the outer microporous plate is 90° arc-shaped on the left and right sides of the bend and fan-shaped on the top and bottom sides, and is spliced ​​with the inner microporous plate to form a double-layer resonant cavity.

[0021] In some embodiments, the outer shell of the enclosure is formed by pressing and welding galvanized steel sheet with the edges pressed together, and flange connections are located at both ends of the enclosure.

[0022] The beneficial effects that a double-layer silencer device for elbows in a ventilation system disclosed in this application may bring include, but are not limited to:

[0023] Good airflow stability: The elbow of the silencer cavity adopts a fan-shaped structure, which makes the change of gas flow direction relatively gentle, reducing the noise generated by airflow.

[0024] Strong sound absorption capacity: The device consists of a double-layer microporous plate with sound-absorbing cotton inside, which reduces the energy of the airflow multiple times to enhance the sound absorption capacity; the flow guide baffle separates the airflow path to enhance interference noise reduction.

[0025] The low-frequency noise reduction effect is significant: the inner and outer microporous plates are spliced ​​together to form the internal resonant cavity of the silencer. When low-frequency noise passes through the resonant area, the energy is absorbed, resulting in a significant noise reduction effect. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the present invention.

[0027] Figure 2 This is a schematic diagram from another perspective of the present invention;

[0028] Figure 3 for Figure 1 AA sectional view.

[0029] Illustration: 1-Outer shell of the enclosure; 2-Flange connection; 3-Outer support; 4-Inner support; 5-Inner microporous plate; 6-Outer microporous plate; 7-Sound-absorbing layer. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0031] Conversely, this application covers any substitutions, modifications, equivalent methods, and schemes made within the spirit and scope of this application as defined in the claims. Furthermore, to provide the public with a better understanding of this application, certain specific details are described in detail below. However, this application can be fully understood by those skilled in the art even without these detailed descriptions.

[0032] like Figure 1-3 The diagram illustrates a double-layer silencing device for bends in ventilation systems, comprising: a housing 1, a flange connection 2, and a double-layer silencing assembly; the bend of the housing 1 has a fan-shaped cavity structure to smoothly guide gas flow and reduce airflow noise. The double-layer silencing assembly includes inner and outer microporous plates and a sound-absorbing layer 7 sandwiched between them, wherein:

[0033] The double-layer silencing assembly forms a double-layer airflow channel inside the outer shell 1 of the enclosure, which is used to extend the sound wave reflection path to enhance interference silencing; the inner and outer microporous plates are spliced ​​together to form a resonant cavity for absorbing low-frequency eddy current noise; the outer shell 1 is formed by pressing and welding galvanized steel plate with the edges pressed, and the flange connection port 2 is located at both ends of the enclosure. The aperture of the microporous plate is configured to reduce sound energy through friction loss, and the sound-absorbing layer 7 is attached to the inner side of the microporous plate to enhance broadband noise reduction.

[0034] In some embodiments, the outer microperforated plate 6 is fixed to the outer support 3 by blind rivets, the inner support 4 is connected to the outer microperforated plate 6 by blind rivets, and the inner microperforated plate 5 is connected to the inner support 4 by blind rivets. The sound-absorbing layer is sound-absorbing cotton, which is attached to the inner microperforated plate 5 and the outer microperforated plate 6 on the side near the inner cavity of the enclosure. In some embodiments, the inner microperforated plate 5 is flush with the flange connection port 2 to maintain stable airflow direction. The outer microperforated plate 6 has a 90° arc shape on the left and right sides at the bend and a fan shape on the top and bottom sides, forming a double-layer resonant cavity with the inner microperforated plate 5.

[0035] The double-layer microporous structure design: With the arrangement of the double-layer microporous plates, the airflow undergoes multiple frictions, resulting in rapid energy loss. The outer microporous plate 6 acts as a flow guide baffle to separate the airflow path and extend the sound wave reflection path to enhance interference noise reduction; the two microporous plates form a resonant cavity, which has a significant effect on reducing low-frequency noise.

[0036] The fan-shaped cavity design of the bend silencer minimizes the impact on gas velocity and direction, thus ensuring lower noise levels. The outlet has the same cross-sectional area as the cavity, ensuring stable airflow direction and volume.

[0037] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A double-layer silencer for use at elbows in ventilation systems, characterized in that, include: The enclosure (1), flange connection (2), and double-layer sound-absorbing components; The double-layer sound-absorbing assembly includes inner and outer microporous plates and a sound-absorbing layer (7) sandwiched between them, wherein: The double-layer silencing component forms a double-layer airflow channel inside the outer shell (1) of the housing, which is used to extend the sound wave reflection path to enhance interference silencing; The inner and outer microporous plates are spliced ​​together to form a resonant cavity, which is used to absorb low-frequency eddy current noise. The aperture of the microporous plate is configured to reduce sound energy through frictional loss, and the sound-absorbing layer (7) is attached to the inner side of the microporous plate to enhance broadband noise reduction.

2. The double-layer silencer device for elbows in a ventilation system according to claim 1, characterized in that: The double-layer sound-absorbing assembly is fixed inside the outer shell (1) of the enclosure by a bracket structure, including: The outer bracket (3) is welded to the outer shell (1) of the box; The outer microporous plate (6) is fixed on the outer support (3); The inner microplate (5) is connected to the outer microplate (6) via the inner support (4).

3. The double-layer silencer device for elbows in a ventilation system according to claim 2, characterized in that: The outer microporous plate (6) is fixed to the outer bracket (3) by a core-pulling rivet, the inner bracket (4) is connected to the outer microporous plate (6) by a core-pulling rivet, and the inner microporous plate (5) is connected to the inner bracket (4) by a core-pulling rivet.

4. The double-layer silencer device for elbows in a ventilation system according to claim 1, characterized in that: The sound-absorbing layer (7) is sound-absorbing cotton, which is attached to the inner microporous plate (5) and the outer microporous plate (6) on the side close to the inner cavity of the box.

5. The double-layer silencer for a bend in a ventilation system according to claim 1, characterized in that: The bend of the outer shell (1) of the box is a fan-shaped cavity structure, which is used to smoothly guide the gas flow and reduce airflow noise.

6. The double-layer silencer for a bend in a ventilation system according to claim 2, characterized in that: The inner microporous plate (5) is flush with the flange connection (2) to maintain a stable airflow direction.

7. The double-layer silencer for a bend in a ventilation system according to claim 2, characterized in that: The outer microporous plate (6) is 90° arc-shaped on the left and right sides of the bend and fan-shaped on the upper and lower sides, and is spliced ​​with the inner microporous plate (5) to form a double-layer resonant cavity.

8. The double-layer silencer for a bend in a ventilation system according to claim 1, characterized in that: The outer shell (1) of the box is formed by pressing and welding galvanized steel plate with the edges closed, and the flange connection (2) is located at both ends of the box.

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