Transparent defibration broadband straight pipe type micro-perforated plate silencer

Abstract

The utility model discloses a transparent defibration broadband straight pipe type micro-perforated plate silencer which comprises a silencer shell, a silencer inner wall and an air spring layer located between the silencer shell and the silencer inner wall. A plurality of through holes penetrating through the thickness direction are formed in the perforated surface protection supporting layer, a plurality of micro cracks are formed in the micro crack film sound absorption layer, and the micro cracks and the through holes are distributed correspondingly. The silencer adopts a transparent structure, so that the internal state of the silencer is convenient to observe; fiber porous sound absorption materials such as mineral wool are not filled, so that pollution and silencing performance degradation are avoided; and the perforated surface protection supporting layer is compounded with the micro-crack film sound absorption layer, so that the low-and-medium-frequency silencing performance of the silencer is also enhanced.

Description

Technical Field

[0001] The utility model relates to the technical field of sound attenuation and noise reduction, in particular to a transparent defiberized broadband straight-tube micro-perforated plate muffler. Background Art

[0002] A silencer is an acoustic device that allows air to pass smoothly while significantly attenuating sound energy. It is mainly classified into resistive silencers and reactive silencers. Resistive silencers are generally filled with porous sound-absorbing materials such as mineral wool for sound attenuation. Fibers are easily dispersed under the action of strong airflow, and sound-absorbing materials are prone to degradation of sound absorption performance under the effects of airflow dispersion, water vapor penetration, and fiber sedimentation. Pollutants such as dust, mold, and viruses easily accumulate on the surface of fiber materials. Its high and medium frequency sound attenuation performance is superior, but its medium and low frequency sound attenuation performance is insufficient. Resistive silencers mainly use the changes in acoustic impedance such as sudden changes in the cross-sectional area of ​​the pipe to produce reflections and interference to achieve the purpose of sound attenuation. They mainly include expansion chamber resistive silencers and resonance cavity resistive silencers. They have good medium and low frequency sound attenuation performance, and generally have a relatively narrow sound attenuation bandwidth.

[0003] Transparent mufflers facilitate visualization of internal airflow, enabling quick location of accumulation areas of contaminants such as dust, mold, and viruses. They also identify areas of concentrated resistance loss and turbulence and eddy currents, enabling improvements to the design, manufacture, or installation of the muffler. Defiberized mufflers prevent the release of fine fiber particles into the airflow, posing a health risk. They also reduce the accumulation and growth of contaminants such as dust, mold, and viruses on fiber surfaces. They are particularly suitable for air conditioning system piping in medical, food, and school applications, where cleanliness requirements are high.

[0004] Therefore, it is considered to provide a transparent defiberized broadband straight tube micro-perforated plate silencer with a transparent structure, without filling fiber sound-absorbing materials such as mineral wool, and without adding expansion or contraction structures; it is convenient to observe the internal state of the silencer, avoid pollution, and improve the sound elimination performance. Utility Model Content

[0005] In view of the above technical problems, the utility model provides a transparent defiberized broadband straight tube micro-perforated plate silencer that solves at least some of the above technical problems. It adopts a transparent structure, which is convenient for observing the internal state of the silencer. It is not filled with fibrous porous sound-absorbing materials such as mineral wool to avoid pollution and degradation of sound-absorbing performance. It does not set an expansion or contraction structure to avoid large local resistance loss. The use of a perforated protective support layer and a composite micro-slit film sound-absorbing layer also enhances the sound-absorbing performance of the silencer in the medium and low frequency bands and the mechanical strength of the inner wall of the silencer.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] The utility model provides a transparent defiberized broadband straight tube micro-perforated plate muffler, comprising: a muffler shell, a muffler inner wall, and an air spring layer, wherein:

[0008] The muffler housing is a straight pipe airflow channel with two open ends;

[0009] The muffler inner wall is arranged inside the muffler shell as the inner wall of the air flow channel, and the muffler inner wall includes: a perforated protective surface support layer and a micro-slit film sound absorption layer; the micro-slit film sound absorption layer covers the surface of the perforated protective surface support layer, the perforated protective surface support layer is provided with a plurality of through holes extending through the thickness direction, and the micro-slit film sound absorption layer is provided with a plurality of micro cracks, and the micro cracks are distributed corresponding to the through holes;

[0010] The air spring layer is located between the muffler shell and the muffler inner wall and is not filled with sound absorbing material;

[0011] The muffler shell, the perforated face support layer and the micro-slit film sound absorption layer are all transparent structures.

[0012] Preferably, the thickness of the perforated armor support layer is 0.5 mm to 3.0 mm; the diameter of the through hole is 1.0 mm to 5.0 mm.

[0013] Preferably, the cross-section of the through hole is circular or polygonal.

[0014] Preferably, the width of the microcracks is 0.05 mm to 0.5 mm.

[0015] Preferably, the through hole is covered with at least one microcrack.

[0016] Preferably, the micro-slit film sound-absorbing layer is a transparent film with a thickness of 0.02 mm to 0.5 mm, and is made of any one of the following materials: polyethylene terephthalate, polypropylene, polyvinyl chloride plastic, and polycarbonate.

[0017] Preferably, the air spring layer has a thickness of 10 mm to 200 mm and is filled with air.

[0018] Preferably, the thickness of the muffler shell is 2mm-30mm, and is made of any of the following transparent materials: glass, PC board, acrylic board.

[0019] Compared with the prior art, the technical solution of the present invention has at least the following beneficial technical effects:

[0020] 1. The utility model provides a transparent defiberizing broadband straight-tube micro-perforated plate silencer, which has a simple structure and a reasonable layout. It adopts a transparent structure, which is convenient for observing the internal state of the silencer. It is not filled with fibrous porous sound-absorbing materials such as mineral wool, and no expansion or contraction structure is added. It mainly relies on the micro-perforated plate sound-absorbing structure for sound attenuation, which can achieve defiberization to avoid pollution and obtain acoustic performance with a high sound absorption coefficient and a wide sound absorption frequency band.

[0021] 2. The utility model provides a transparent defiberized broadband straight-tube micro-perforated plate silencer, in which a large number of micro-cracks are provided on the micro-slit film sound-absorbing layer, which can provide sufficient sound resistance with low acoustic reactance, maximize the matching of the characteristic impedance of the propagation medium, and thus obtain broadband sound-absorbing performance in the medium and low frequency bands; the use of transparent materials is helpful to observe the circulation of internal airflow, check the accumulation areas of pollutants such as dust, mold and viruses, locate the local resistance loss concentration areas and the turbulence and eddy current occurrence areas, judge whether the sound-absorbing material is damaged or failed and the degree of performance attenuation, and thus improve the design, manufacture or installation of the silencer; without filling with fibrous porous sound-absorbing materials such as mineral wool, defiberization is achieved, which can prevent fine fiber particles from escaping into the airflow and threatening human health, and reduce the accumulation and growth of pollutants such as dust, mold and viruses on the surface of fiber materials. It is especially suitable for air-conditioning system pipelines in medical, food, school and other places with high requirements on cleanliness.

[0022] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be achieved and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention.

[0026] Figure 1 This is a schematic diagram of the appearance structure of a transparent defiberized broadband straight tube micro-perforated plate muffler provided by the utility model.

[0027] Figure 2 This is a schematic top view of the structure of a transparent defiberized broadband straight tube micro-perforated plate muffler provided by the utility model.

[0028] Figure 3 The utility model provides a side view of the structure of a transparent defiberized broadband straight tube micro-perforated plate muffler.

[0029] Among them, 1-muffler shell; 2-muffler inner wall; 3-air spring layer; 21-perforated protective surface support layer; 22-micro-slit film sound absorption layer; 211-through hole; 221-micro-crack. DETAILED DESCRIPTION

[0030] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0031] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", "front end", "rear end", "two ends", "one end", "the other end", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as a limitation on the present invention.

[0032] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "provided with," "connected," etc. should be understood in a broad sense. For example, "connected" can mean a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be internal communication between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0033] Reference Figures 1 to 3 As shown, the embodiment of the present invention provides a transparent, defiberized, broadband, straight-tube, micro-perforated plate muffler. This muffler is not filled with fibrous porous sound-absorbing materials such as mineral wool, thus avoiding the problems of fiber dispersion and sedimentation, which can lead to performance degradation and insufficient mid- and low-frequency sound absorption performance. It also does not incorporate expansion or contraction structures, thus avoiding the problems of large resistance losses and insufficient sound absorption bandwidth. The muffler primarily relies on a micro-perforated plate sound absorption structure for sound absorption, and comprises a muffler housing 1, a perforated protective support layer 21, a micro-slit film sound absorption layer 22, and an air spring layer 3.

[0034] The following is a detailed introduction to the above components and their working principles:

[0035] In this embodiment, the micro-slit film sound-absorbing layer 22 primarily serves as a sound absorber and is provided with a large number of micro-slits 221. In a preferred embodiment of this embodiment, the width of the micro-slits 221 ranges from 0.05 mm to 0.5 mm, and the thickness of the micro-slit film sound-absorbing layer 22 ranges from 0.02 mm to 0.5 mm. The material of the micro-slit film sound-absorbing layer 22 is preferably a transparent material such as polyethylene terephthalate (PET), polypropylene (PP), polyvinyl chloride (PVC), or polycarbonate (PC). The micro-slit film sound-absorbing layer 22 in this example, together with the air spring layer 3 and the muffler housing 1 (which primarily serves as a sound barrier, preventing airflow noise from being transmitted through the muffler housing), forms a Helmholtz resonator, which can be considered a resonant system consisting of a mass and a spring. When sound waves in the airflow are incident obliquely or grazingly on the surface of the structure, the air column within the microcracks 221 of the microcrack film sound-absorbing layer 22 acts as a mass, reciprocating like a piston under the pressure of the sound waves. The air within the air spring layer 3 acts as a spring, exerting a restoring force on the piston. Due to the frictional damping effect of the walls of the microcracks 221, some of the sound energy is converted into heat and consumed. When the frequency of the incident sound wave approaches the natural frequency of the system, resonance occurs, and the air column vibrates at its maximum velocity, resulting in the greatest frictional loss and the greatest absorption of sound energy, resulting in an absorption peak. The microcrack film sound-absorbing layer 22 has a very small thickness, which facilitates the processing and preparation of the microcracks and facilitates obtaining an acoustic impedance that matches the characteristic impedance of air, achieving excellent sound absorption performance.

[0036] In one specific embodiment, the micro-slit film sound absorbing layer 22 is too thin to support itself, so it is attached to the perforated face support layer 21. The side of the perforated face support layer 21 facing the muffler housing 1 covers the micro-slit film sound absorbing layer 22, which to a certain extent protects the micro-slits 221 from being blocked by dust or flocs, makes it easier for high-frequency sound waves to enter the structure, and reduces the reflection of high-frequency sound waves on the perforated face support layer 21. The perforated face support layer 21 is mainly used to support and protect the micro-slit film sound absorbing layer 22 and to facilitate the permeation of sound waves and airflow. It is provided with a plurality of through holes 211 along the thickness direction of the plate. The cross-section of the through holes 211 is preferably circular or polygonal. As a preferred embodiment of this embodiment, the perforated face support layer 21 has a thickness of 0.5 mm to 3.0 mm, and the diameter of the through-holes 211 is 1.0 to 5.0 mm. The through-holes 211 correspond to the microcracks 221 provided in the micro-slit film sound-absorbing layer 22, and are covered with at least one microcrack 221. The larger through-holes 211 in the perforated face support layer 21 contribute little acoustic resistance and reactance, and their impact on sound absorption performance is negligible. The micro-slit film sound-absorbing layer 22 is attached to the perforated face support layer 21 by heat pressing or bonding with a transparent adhesive, with the adhesive thickness not exceeding 0.05 mm.

[0037] It should be noted that under the influence of gas flow and sound wave pressure, the microcracks 221 in the micro-slit thin film sound-absorbing layer 22 have a very low perforation rate, the air particles within them vibrate at a high speed, and their aspect ratio is large. This high-speed vibration of the air particles makes it less likely to cause blockage by fine particles such as dust. In particular, the length direction of the microcracks 221 aligns with the direction of airflow within the airflow channel, which helps reduce deformation of the microcracks 221 under high-speed airflow.

[0038] Furthermore, in this embodiment, the air spring layer 3 is mainly used to cooperate with the micro-slit film sound-absorbing layer 2 to adjust the acoustic impedance and obtain better sound absorption performance. The interior of the air spring layer 3 is filled with air and has a thickness of 10mm-200mm. As a preferred implementation method of this embodiment, a partition can also be set inside the air spring layer 3. The partition can divide the interior of the air spring layer 3 into multiple cavities to prevent sound waves from propagating horizontally in the cavity, which is conducive to widening the sound absorption bandwidth. In addition, the partition can also increase the overall structural strength. Springs can also be added as support.

[0039] Furthermore, in this embodiment, the muffler housing 1 primarily serves as a sound barrier, reducing the sound energy penetrating the muffler channel. It also forms a sealed cavity, thereby fulfilling the function of the air spring layer 3. The thickness of the muffler housing 1 is relatively large, ranging from 2 mm to 30 mm. The muffler housing 1 is made of a transparent material, such as glass, fiberglass reinforced plastic, PC board, acrylic board, or other transparent plate material.

[0040] Furthermore, in this embodiment, transition pipes and flanges may be preferably provided at both ends of the muffler to connect with the flow pipe.

[0041] Through the description of the above implementation, those skilled in the art can know that the embodiment of the present invention provides a transparent defiberized broadband straight-tube micro-perforated plate silencer. The silencer has a simple structure and a reasonable layout. It adopts a transparent structure, which is convenient for observing the internal state of the silencer. It is not filled with fibrous porous sound-absorbing materials such as mineral wool, and is not equipped with expansion or contraction structures. It mainly relies on the micro-perforated plate sound-absorbing structure for sound elimination, which can achieve defiberization to avoid pollution and obtain acoustic performance with a high sound absorption coefficient and a wide sound absorption frequency band. The silencer has a high sound absorption coefficient and a wide sound absorption frequency band; a large number of microcracks are set on the membrane layer, and the width of the microcracks is small, which can provide sufficient sound resistance. The membrane layer with a smaller thickness and the microcracks with a larger perforation rate help to reduce the acoustic impedance. In addition, the microcracks have an acoustic impedance characteristic similar to that of a slit, that is, the characteristic of minimum acoustic impedance under the same sound impedance, and sufficient sound impedance is conducive to improving the sound absorption coefficient, and smaller acoustic impedance helps to expand the sound absorption bandwidth.

[0042] This specification adopts a progressive description, and the same or similar parts between the various embodiments can be referred to each other. The unexplained parts of the embodiments of the present invention can be obtained from the corresponding product specifications or the existing technology in the field, which are common knowledge in the field. The above embodiments of the present invention are described in detail, and the principles and implementation methods of the present invention are explained. The description of the above embodiments is only used to help understand the core concept of the present invention.

[0043] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A transparent defiberized broadband straight tube micro-perforated plate muffler, characterized in that: include: A muffler shell (1), a muffler inner wall (2), and an air spring layer (3), wherein: The muffler housing (1) is a straight pipe-type air flow channel with openings at both ends; The muffler inner wall (2) is arranged inside the muffler outer shell (1), and the muffler inner wall (2) comprises: a perforated surface support layer (21) and a micro-slit film sound absorption layer (22); the micro-slit film sound absorption layer (22) covers the surface of the perforated surface support layer (21), the perforated surface support layer (21) is provided with a plurality of through holes (211) extending through the thickness direction, and the micro-slit film sound absorption layer (22) is provided with a plurality of micro cracks (221), and the micro cracks (221) are distributed correspondingly to the through holes (211); The air spring layer (3) is located between the muffler outer shell (1) and the muffler inner wall (2) and is not filled with sound absorbing material; The muffler shell (1), the perforated face support layer (21) and the micro-slit film sound absorption layer (22) are all transparent structures.

2. A transparent defiberized broadband straight tube micro-perforated plate muffler according to claim 1, characterized in that: The thickness of the perforated face support layer (21) is 0.5 mm to 3.0 mm; the diameter of the through hole (211) is 1.0 mm to 5.0 mm.

3. A transparent defiberized broadband straight tube micro-perforated plate muffler according to claim 1, characterized in that: The cross section of the through hole (211) is circular or polygonal.

4. A transparent defiberized broadband straight tube micro-perforated plate muffler according to claim 1, characterized in that: The width of the micro cracks (221) is 0.05 mm to 0.5 mm.

5. The transparent defiberized broadband straight tube micro-perforated plate muffler according to claim 1, characterized in that: The through hole (211) is covered with at least one microcrack (221).

6. The transparent defiberized broadband straight tube micro-perforated plate muffler according to claim 1, characterized in that: The micro-slit film sound-absorbing layer (22) is a transparent film with a thickness of 0.02 mm to 0.5 mm, and is made of any one of the following materials: polyethylene terephthalate, polypropylene, polyvinyl chloride plastic, and polycarbonate.

7. The transparent defiberized broadband straight tube micro-perforated plate muffler according to claim 1, characterized in that: The thickness of the air spring layer (3) is 10 mm to 200 mm.

8. The transparent defiberized broadband straight tube micro-perforated plate muffler according to claim 1, characterized in that: The muffler shell (1) is made of any one of the following: glass, PC board, acrylic board; the shell thickness is 2mm-30mm.

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