Impedance compound type pipeline muffler

Abstract

The utility model provides a kind of impedance composite formula pipeline muffler, four means of physical barrier, material sound absorption, cavity resonance, airflow dredge are passed through in this design, realize the efficient control of full-band noise, it includes shell outer plate, the both ends of shell outer plate are communicated with reducing pipe, two reducing pipes are communicated with connecting pipe, two connecting pipes are communicated with butt flange, shell outer plate is sequentially provided with cylindrical sound-absorbing structure, sound-absorbing sheet structure and flow diffuser from top to bottom in it, cylindrical sound-absorbing structure is contacted with a connecting pipe, flow diffuser is communicated with another connecting pipe, the inside of shell outer plate is provided with damping layer, the inside of damping layer is provided with annular sound-absorbing cotton, the inside of annular sound-absorbing cotton is provided with metal ring, multiple perforated plates are set on the metal ring, the cylindrical sound-absorbing structure includes metal pipe, the inside of metal pipe is provided with cylindrical sound-absorbing cotton.

Description

Technical Field

[0001] This utility model relates to the field of pipeline silencer technology, and in particular to an impedance composite pipeline silencer. Background Technology

[0002] A silencer is a device that blocks sound propagation while allowing airflow; it is an important measure to eliminate dynamic noise from steam emissions. Pipe silencers are mainly used for effective noise reduction of steam emissions from industrial thermal equipment such as boilers and steam turbines. Most existing pipe silencers employ an impedance composite silencing principle, adding a resistive sound-absorbing cotton structure outside the expansion chamber. They are designed based on the spectral characteristics of the residual noise emitted by the pressure-reducing body to effectively absorb the remaining noise.

[0003] Traditional silencers rely on a single resistive or reactive structure, which makes it difficult to effectively handle low-frequency noise (such as vibration and resonance). Single-mechanism silencers (such as pure sound-absorbing cotton or expansion cavity) are only effective for mid-to-high frequency or narrow frequency bands. When high-speed airflow passes through, it is easy to generate turbulence, resulting in secondary high-frequency noise. Utility Model Content

[0004] To address the shortcomings of existing technologies, the present invention solves the following technical problem: traditional silencers rely on a single resistive or reactive structure, which makes it difficult to effectively handle low-frequency noise (such as vibration and resonance). Single-mechanism silencers (such as pure sound-absorbing cotton or expansion cavity) are only effective for mid-to-high frequencies or narrow frequency bands. When high-speed airflow passes through in a concentrated manner, turbulence is easily generated, resulting in secondary high-frequency noise. Therefore, an impedance composite duct silencer is provided.

[0005] To achieve the above objectives, this utility model provides: An impedance composite duct silencer includes an outer shell, with reducing pipes connected to both ends of the outer shell, connecting pipes connected to both reducing pipes, and connecting flanges connected to both connecting pipes. Inside the outer shell, from top to bottom, are arranged a cylindrical sound-absorbing structure, a sound-absorbing plate structure, and a diffuser. The cylindrical sound-absorbing structure is in contact with one connecting pipe, and the diffuser is connected to the other connecting pipe.

[0006] Preferably, a damping layer is provided on the inner side of the outer shell panel, a circular sound-absorbing cotton is provided on the inner side of the damping layer, and a metal ring is provided on the inner side of the circular sound-absorbing cotton.

[0007] Preferably, the metal ring has multiple perforated plates.

[0008] Preferably, the cylindrical sound-absorbing structure includes a metal tube, the inner side of which is provided with cylindrical sound-absorbing cotton, and the cylindrical sound-absorbing cotton is provided with multiple perforated metal plates, each of which is provided with ventilation holes.

[0009] Preferably, the metal tube has multiple openings, and an air layer is reserved between the metal ring and the metal tube.

[0010] Preferably, the sound-absorbing plate structure includes a cross-shaped metal keel, a metal casing is provided on the outer side of the cross-shaped metal keel, the metal casing is fixedly installed to the bottom of the metal round tube, a cross-shaped sound-absorbing cotton is provided on the inner side of the cross-shaped metal keel, and multiple round holes are opened on the outer side of the cross-shaped metal keel.

[0011] Preferably, the diffuser is installed on the bottom side of the cross-shaped metal keel, and the diffuser is a metal shell with multiple metal cylinders on its outer side.

[0012] Compared with the prior art, the advantages of this utility model are: 1. High-efficiency noise reduction across the entire frequency band, combining resistive silencing (sound-absorbing materials) and reactive silencing (resonance cavity / expansion chamber), covering noise across the entire frequency range of 20Hz-20kHz (the range audible to the human ear), and is particularly adept at handling low-frequency noise (a challenge for traditional silencers).

[0013] 2. Multiple noise reduction mechanisms work together to achieve multi-level dissipation of sound energy (friction loss, resonance loss, and sound wave interference cancellation) through the series combination of damping and vibration reduction layer + sound absorption cotton + perforated plate + air layer + airflow dispersion structure.

[0014] 3. The layered modular design (sound-absorbing structure → silencer → diffuser) adapts to the pipe space, and the metal frame (metal ring, keel) ensures mechanical strength and durability.

[0015] 4. Optimized airflow design: the variable diameter pipe smoothly transitions the airflow, and the diffuser evenly disperses the fluid, avoiding turbulence-induced noise and reducing pressure loss.

[0016] This invention achieves efficient control of noise across the entire frequency band through four methods: physical isolation, material sound absorption, cavity resonance, and airflow guidance. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the main structure of this design; Figure 2 An exploded view of the reducer, cylindrical sound-absorbing structure, silencer structure, diffuser, and connecting pipes used in this design. Figure 3 This is a structural diagram of the outer shell, circular sound-absorbing cotton, metal ring, air layer, metal tube, cylindrical sound-absorbing cotton, and metal perforated plate in this design. Figure 4 This is a three-dimensional structural diagram of the outer shell, diffuser, connecting pipe, and sound-absorbing plate in this design.

[0018] In the diagram: 1. Outer shell panel; 11. Damping layer; 12. Circular sound-absorbing cotton ring; 13. Metal ring; 14. Air layer; 2. Reducer; 3. Connecting pipe; 31. Butt flange; 4. Cylindrical sound-absorbing structure; 41. Metal circular tube; 42. Cylindrical sound-absorbing cotton; 43. Metal perforated plate; 44. Vent hole; 5. Sound-absorbing sheet structure; 51. Cross-shaped metal keel; 52. Cross-shaped sound-absorbing cotton; 53. Circular hole; 54. Metal enclosure shell; 6. Diffuser; 61. Diffuser hole. Detailed Implementation

[0019] The embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0020] See Figure 1-4 As shown, an impedance composite pipe silencer includes an outer shell plate 1. Both ends of the outer shell plate 1 are connected to reducing pipes 2. Both reducing pipes 2 are connected to connecting pipes 3. Both connecting pipes 3 are connected to mating flanges 31. Inside the outer shell plate 1, from top to bottom, there are cylindrical sound-absorbing structures 4, sound-absorbing plate structures 5, and diffusers 6. The cylindrical sound-absorbing structure 4 is in contact with one connecting pipe 3, and the diffuser 6 is connected to the other connecting pipe 3.

[0021] Specifically, the outer shell 1 serves as the main supporting structure, isolating external environmental noise. The reducer 2 connects pipes of different diameters, reducing energy loss caused by sudden airflow changes. The connecting pipe 3 and mating flange 31 are standardized pipe interfaces for easy installation and sealing.

[0022] In this embodiment, a damping layer 11 is provided on the inner side of the outer shell 1, a circular sound-absorbing cotton 12 is provided on the inner side of the damping layer 11, and a metal ring 13 is provided on the inner side of the circular sound-absorbing cotton 12, with multiple perforated plates on the metal ring 13.

[0023] Specifically, the damping layer 11 can suppress the vibration of the metal plate, reduce mid-to-low frequency structural noise, and block the path of sound waves propagating through the shell.

[0024] The circular sound-absorbing cotton 12 is a porous material that uses friction to dissipate mid-to-high frequency sound energy and achieve resistive noise reduction.

[0025] The perforated metal ring 13 can form a Helmholtz resonant cavity. When the sound wave frequency matches the cavity resonant frequency, air friction consumes specific low-frequency noise resistance and noise reduction.

[0026] In this embodiment, the cylindrical sound-absorbing structure 4 includes a metal tube 41, and a cylindrical sound-absorbing cotton 42 is provided on the inner side of the metal tube 41. A plurality of metal perforated plates 43 are provided on the cylindrical sound-absorbing cotton 42, and each of the plurality of metal perforated plates 43 is provided with a vent hole 44. A plurality of 45 are opened on the metal tube 41, and an air layer 14 is reserved between the metal ring 13 and the metal tube 41.

[0027] Specifically, air layer 14 utilizes the principle of sound wave reflection interference to cancel out low-frequency sound energy expansion chamber noise reduction.

[0028] The metal tube 41 serves as a supporting frame, with surface openings 45 allowing sound waves to enter. The cylindrical sound-absorbing cotton 42 absorbs mid-to-high frequency airflow noise, and the metal perforated plate 43 protects the sound-absorbing cotton. Its vent holes 44, together with the sound-absorbing cotton, form a micro-perforated plate resonant structure, enhancing mid-frequency noise reduction.

[0029] In this embodiment, the sound-absorbing sheet structure 5 includes a cross-shaped metal keel 51, and a metal casing 54 is provided on the outside of the cross-shaped metal keel 51. The metal casing 54 is fixedly installed on the bottom of the metal round tube 41. A cross-shaped sound-absorbing cotton 52 is provided on the inside of the cross-shaped metal keel 51, and a plurality of round holes 53 are opened on the outside of the cross-shaped metal keel 51.

[0030] Specifically, the cross-shaped metal keel 51 forms a support and divides the airflow channels, while the cross-shaped sound-absorbing cotton 52 is used to fill the gaps between the keels, increasing the sound-absorbing surface area. The metal-encased shell 54 and the circular hole 53 form a secondary resonant cavity, optimizing sound attenuation for specific frequency bands such as 500-2000Hz.

[0031] In this embodiment, the diffuser 6 is installed on the bottom side of the cross-shaped metal keel 51. The diffuser 6 is a metal round shell, and multiple metal cylinders 61 are opened on the outer side of the diffuser 6.

[0032] Specifically, diffuser 6 is used to disperse the concentrated airflow into multiple fine streams, reducing flow velocity and high-frequency turbulence noise. The metal cylinder 61 has an expansion chamber effect to dissipate low-frequency acoustic energy, while guiding the airflow for smooth output.

[0033] Operating mode: During use, the connecting flange 31 is used to connect the pipe. The sound enters the interior of the outer shell 1 through the connecting flange 31 and the connecting pipe 3. The outer shell 1 is equipped with a diffuser 6, a sound-absorbing plate structure 5 and a damping layer 11, multiple sound-absorbing cotton, a perforated plate and an air layer 14, which are connected in series in the sound-absorbing section of the outer shell. The combination of the above materials makes the sound absorption and noise reduction effect more prominent. It can simultaneously control the propagation of low frequency, mid frequency, high frequency and noise in multiple frequency bands, and effectively control the frequency from 20Hz to 20000Hz.

[0034] This utility model is not limited to the above-described preferred embodiment. Anyone can derive other products in various forms under the guidance of this utility model. However, regardless of any changes made in its shape or structure, any technical solution that is the same as or similar to this utility model is within its protection scope.

Claims

1. An impedance composite duct silencer, comprising an outer shell (1), characterized in that: Both ends of the outer shell plate (1) are connected to reducing pipes (2), and both reducing pipes (2) are connected to connecting pipes (3). Both connecting pipes (3) are connected to docking flanges (31). The outer shell plate (1) is provided with a cylindrical sound-absorbing structure (4), a sound-absorbing plate structure (5) and a diffuser (6) from top to bottom. The cylindrical sound-absorbing structure (4) is in contact with one connecting pipe (3), and the diffuser (6) is connected to the other connecting pipe (3).

2. The impedance composite pipe silencer according to claim 1, characterized in that: The outer shell (1) has a damping layer (11) on its inner side, a circular sound-absorbing cotton (12) on its inner side, and a metal ring (13) on its inner side.

3. The impedance composite pipe silencer according to claim 2, characterized in that: The metal ring (13) has multiple perforated plates.

4. The impedance composite pipe silencer according to claim 3, characterized in that: The cylindrical sound-absorbing structure (4) includes a metal tube (41), and a cylindrical sound-absorbing cotton (42) is provided on the inner side of the metal tube (41). Multiple metal perforated plates (43) are provided on the cylindrical sound-absorbing cotton (42), and ventilation holes (44) are provided on the multiple metal perforated plates (43).

5. The impedance composite pipe silencer according to claim 4, characterized in that: The metal tube (41) has multiple openings (45), and an air layer (14) is reserved between the metal ring (13) and the metal tube (41).

6. The impedance composite pipe silencer according to claim 1, characterized in that: The sound-absorbing plate structure (5) includes a cross-shaped metal keel (51), a metal casing (54) is provided on the outside of the cross-shaped metal keel (51), the metal casing (54) is fixedly installed on the bottom of the metal round tube (41), a cross-shaped sound-absorbing cotton (52) is provided on the inside of the cross-shaped metal keel (51), and multiple round holes (53) are opened on the outside of the cross-shaped metal keel (51).

7. The impedance composite duct silencer according to claim 1, characterized in that: The diffuser (6) is installed on the bottom side of the cross metal keel (51). The diffuser (6) is a metal shell, and multiple metal cylinders (61) are opened on the outside of the diffuser (6).

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