Drop-shaped silencer

Abstract

The utility model discloses a drop-shaped silencer which comprises a silencer shell and a plurality of sound absorber units arranged in the silencer shell, the section of each sound absorber unit is in the shape of a falling drop, and therefore a long and narrow ventilation path similar to the Bernoulli principle is formed between every two adjacent sound absorber units, and the front portion of the long and narrow ventilation path is thin and the rear portion of the long and narrow ventilation path is thick. The water-drop-shaped silencer has the good streamline characteristic, the resistance of fluid in the flowing process can be reduced, the impact of the fluid on the inner wall of the silencer is reduced, and therefore noise is reduced. Meanwhile, the water-drop-shaped structure can effectively change the propagation path of sound waves, so that the sound waves are reflected and refracted in the silencer for multiple times, and the silencing effect is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of environmental noise, in particular to a water-drop-shaped muffler. Background Art

[0002] With the development of industry and the improvement of people's living standards, the noise pollution generated by various mechanical equipment and transportation tools is becoming increasingly serious. As an important device for reducing noise pollution, mufflers have been widely used in various fields. A muffler refers to an air flow pipeline that simultaneously meets the two major indicators of sound absorption performance and ventilation performance. Noise reduction devices such as pipelines and elbows with sound-absorbing linings or pipelines with sudden changes in cross-sectional area and other discontinuous acoustic impedances can be used to attenuate or reflect the noise in the pipeline. The former is called a resistive muffler, the latter is called a reactive muffler, and there is also an impedance composite muffler. Most of the existing mufflers adopt the impedance composite sound absorption principle.

[0003] A muffler device generally must simultaneously meet the two major indicators of sound absorption performance and ventilation performance; the ventilation performance, that is, the aerodynamic performance, is one of the important indicators for evaluating the performance of a muffler and is an important factor that should be considered first in the design of a muffler. However, it is difficult to have both good sound absorption performance and aerodynamic performance in existing products. That is, when a large amount of sound absorption is obtained in a traditional muffler, usually a greater resistance loss is required to achieve it. When the resistance loss is small, a large sound absorption performance cannot be obtained. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a water-drop-shaped muffler that takes both sound absorption performance and aerodynamic performance into account, so as to overcome the deficiencies in the prior art. The design inspiration of the water-drop-shaped muffler of the utility model comes from the shape of water droplets in nature. The water-drop-shaped structure has good streamline characteristics, can reduce the resistance of the fluid during the flow process, reduce the impact of the fluid on the inner wall of the muffler, and thus reduce the generation of noise. At the same time, the water-drop-shaped structure can also effectively change the propagation path of sound waves, making the sound waves reflect and refract multiple times inside the muffler, further improving the sound absorption effect.

[0005] According to one aspect of the utility model, there is provided a water-drop-shaped muffler, characterized in that the water-drop-shaped muffler includes a muffler housing (10) and a plurality of sound absorption body units (20) arranged inside the muffler housing, wherein the cross-section of the sound absorption body unit (20) is in the shape of a falling water droplet, thereby forming a narrow ventilation path that is thinner in the front and thicker in the back similar to the Bernoulli principle between adjacent sound absorption body units.

[0006] According to an embodiment of the present utility model, wherein the muffler housing (10) is columnar with openings at both ends, the upper and lower end faces of the sound-absorbing body unit (20) are respectively fixed to the bottom and top surfaces of the muffler housing (10) and thus disposed inside the muffler housing, and the plurality of sound-absorbing body units (20) are evenly spaced inside the muffler housing.

[0007] According to an embodiment of the present utility model, wherein the side wall (101) of the columnar muffler housing is a composite structure, including an outer protective panel, an inner perforated panel, and a sound-absorbing layer disposed between the outer and inner layers.

[0008] According to an embodiment of the present utility model, wherein the sound-absorbing body unit (20) includes an outer perforated panel layer (21) and a micro-perforated plate (24). The cross-section of the perforated panel layer (21) is in the shape of a falling water droplet, including a semi-circular head windward deflector (211), an intermediate arc connecting portion (212), and a pointed tail (213). The micro-perforated plate (24) is disposed between the windward deflector (211) and the intermediate arc connecting portion (212). The perforation diameters on the windward deflector (211) and the micro-perforated plate (24) are less than 1.0 mm, and the perforation rate is 1% - 5%. The pore diameters on the intermediate arc connecting portion (212) and the pointed tail (213) are 2.5 mm - 3 mm, and the perforation rate is 25% - 30%.

[0009] According to an embodiment of the present utility model, wherein the sound-absorbing body unit (20) further includes a resistive sound-absorbing material (22), which is filled in the space formed by the intermediate arc connecting portion (212), the pointed tail (213), and the micro-perforated plate (24), and a non-alkali water-repellent fiberglass cloth is laid flat on the inner side of the space to protect the resistive sound-absorbing material.

[0010] According to an embodiment of the present utility model, wherein the sound-absorbing body unit (20) further includes an inner support plate (23) disposed inside the space, and the inner support plate (23) is a perforated plate.

[0011] According to an embodiment of the present utility model, wherein the resistive sound-absorbing material (22) is centrifugal glass wool, and the bulk density is 16 kg / m 3 ~48 kg / m 3 。

[0012] According to an embodiment of the present utility model, wherein the muffler housing (10) is an assembled structure, including a longitudinal shell plate (101-1) and a transverse shell plate (101-2), and the longitudinal shell plate (101-1) and the transverse shell plate (101-2) are connected by a stepped lap joint (101-3).

[0013] According to the embodiments of the present utility model, a resistance cavity is formed between the microplate (24) and the windward flow deflector (211), which functions as a filter for sound waves.

[0014] The present utility model is a new type of noise elimination and reduction device designed and developed based on years of application in noise control projects and combined with the characteristics of the enterprise itself. It can be widely used in noise elimination systems such as subways, power plants, ships, and building air ducts, and has the characteristics of strong noise elimination ability, saving storage space, convenient transportation, light handling, and simple installation. Compared with traditional mufflers, the drop-shaped muffler of the present utility model has a higher noise elimination effect under the same conditions. For example, in the low-frequency band, the muffler of the present utility model can achieve a noise reduction effect of 3 dB to 5 dB; in the high-frequency band, the noise reduction effect is more obvious, reaching 6 dB to 8 dB. In addition, the drop-shaped muffler of the present utility model also has a relatively wide noise elimination frequency band, which can cover most common noise frequency bands. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Some specific embodiments of the present utility model will be described in detail hereinafter with reference to the drawings in an exemplary but non-limiting manner. The same reference numerals in the drawings denote the same or similar components or parts. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. The objectives and features of the present utility model will become more apparent in view of the following description in conjunction with the drawings, in which:

[0016] Figure 1 is a front view structural schematic diagram of a drop-shaped muffler according to an embodiment of the utility model;

[0017] Figure 2 is a sectional schematic diagram of a drop-shaped muffler according to an embodiment of the utility model along the air flow direction;

[0018] Figure 3 is a structural schematic diagram of an absorber unit of a drop-shaped muffler according to an embodiment of the utility model;

[0019] Figure 4 is a schematic diagram of Bernoulli's principle; and

[0020] Figure 5 is a schematic diagram of the air flow direction of a drop-shaped muffler according to an embodiment of the utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The present utility model will be further described in detail below in conjunction with the drawings and specific embodiments, but the embodiments or descriptions are not used to limit the protection scope of the present utility model.

[0022] Figure 1 is a front view structural schematic diagram of a drop-shaped muffler according to an embodiment of the utility model; Figure 2Schematic cross-sectional view of a water-droplet-shaped muffler along the air flow direction according to an embodiment of the utility model; Figure 3 Schematic structural view of the sound-absorbing body unit of the water-droplet-shaped muffler according to an embodiment of the utility model.

[0023] Referring to the accompanying drawings, the water-droplet-shaped muffler of the embodiment may include a muffler housing 10 and a plurality of sound-absorbing body units 20 disposed within the muffler housing 10. The sound-absorbing body units 20 are generally columnar in shape, and their cross-sections are in the shape of a falling water droplet, thereby forming a narrow ventilation path that is thinner at the front and thicker at the back, similar to the Bernoulli principle, between adjacent sound-absorbing body units 20. That is, each of the sound-absorbing body units has a cross-sectional shape similar to a water droplet, with a semi-circular shape at the windward end and a pointed shape at the other end, that is, the shape along the air flow direction is the shape of a falling water droplet, that is, a water-droplet-shaped sound-absorbing body unit; this can effectively absorb and eliminate sound waves, thereby reducing noise.

[0024] One end of the muffler housing 10 is an air inlet, and the other end is an air outlet. The sound-absorbing body unit on the air inlet side has a semi-circular cross-section at the bottom of the water droplet, and the cross-section of the sound-absorbing unit on the air outlet side is the pointed part of the water droplet. As shown in the figure, the muffler housing 10 is tubular. Taking a rectangular tube as an example, it is surrounded by four side walls 101 on the top, bottom, left, and right. That is, it includes two longitudinal shell plates 101-1 and two transverse shell plates 101-2. The longitudinal shell plates 101-1 and the transverse shell plates 101-2 can be connected by a stepped lap joint 101-3. The structure of each side wall 101 is a composite structure. For example, it can be a conventional outer plate + sound-absorbing structure + inner plate. The outer plate is a protective panel, the inner plate is a perforated plate, and the middle is a resistive sound-absorbing material or a special sound-absorbing structure. More specifically, the protective panel can be an unperforated metal plate, and the perforated plate preferably has a hole diameter of 2.5 mm to 3 mm and a perforation rate of 25% to 30%. The sound-absorbing structure can be a resistive sound-absorbing material or a special sound-absorbing structure, and a non-alkali water-repellent fiberglass cloth is laid flat inside the perforated plate to protect the sound-absorbing material. In this way, each side wall 101 can achieve a good sound-absorbing effect. Refer to Figure 1 and 2 , a number of sound-absorbing body units are arranged at equal intervals within the muffler housing 10, and the upper and lower ends of the sound-absorbing body units are directly fixed to the two transverse shell plates 101-2 of the muffler housing 10.

[0025] As Figure 3 shown, the sound-absorbing body unit 20 may include an outer perforated panel layer 21, a resistive sound-absorbing material 22, an inner support plate 23 disposed inside the perforated panel layer 21, and a microporous plate 24.

[0026] The cross-section of the perforated panel layer 21 is in the shape of a falling water droplet, which is a central axisymmetric body; one end is a semi-circular head windward deflector 211 at the bottom of the water droplet, the other end is a pointed tail 213 at the top of the water droplet, and the middle part is in an arc transition shape, that is, the middle arc connecting part 212. The microporous plate 24 is arranged between the windward deflector 211 and the middle arc connecting part 212, thereby forming a resistance cavity between the microporous plate 24 and the windward deflector 211, which plays a filtering function on the sound wave. In addition, the perforation diameters on the windward deflector 211 and the microporous plate 24 are less than 1.0 mm, and the perforation rate is 1% - 5%; the aperture diameters on the middle arc connecting part 212 and the pointed tail 213 are 2.5 mm - 3 mm, and the perforation rate can be 25% - 30%. Different perforation rates and different cavity depths with different plate thicknesses can be selected according to the noise frequency range to be eliminated, so as to control the spectral performance of the muffler and make it obtain a good sound absorption effect.

[0027] In order to strengthen its structural strength, a plurality of inner support plates 23 can be arranged as stiffening ribs in the space enclosed by the pointed tail 213 and the middle arc connecting part 212 in the perforated panel layer 21, and a resistive sound-absorbing material 22 can be filled inside; the inner support plate 23 can be a perforated circular plate, for example, a galvanized steel plate with a thickness of 0.8 - 1.2 mm can be used. The perforated panel layer 21 can also be made of a galvanized steel plate with a thickness of 0.8 - 1.2 mm.

[0028] The resistive sound-absorbing material 22 can be, for example, a conventionally known sound-absorbing material, such as centrifugal glass wool, with a bulk density of 16 kg / m 3 ~48 kg / m 3 ,such as a superfine fiber centrifugal glass wool board with a bulk density of 32 kg / m 3 ; and an alkali-free hydrophobic glass fiber cloth can be laid flat on the inner side of the perforated panel layer 21 to protect the sound-absorbing material. The section filled with the resistive sound-absorbing material 22 can form a resistive section.

[0029] The muffler of the present invention belongs to an impedance composite muffler, and has excellent sound absorption performance, with a relatively wide sound absorption frequency band, which can cover most common noise frequency bands. More specifically, the cross-sectional shape of the sound absorber of the muffler of the present invention is like that of a falling water droplet, which reduces the wind pressure resistance loss and has excellent aerodynamic performance. For example, by changing the propagation path of the sound wave, the sound wave can be reflected and refracted multiple times inside the muffler, further improving the sound absorption effect; for example, the water droplet-shaped structure design of the muffler has a streamlined feature, which can reduce the fluid resistance, reduce the impact of the airflow on the inner wall of the muffler, and reduce the generation of secondary noise. For example, a narrow ventilation path similar to the Bernoulli principle with a narrow front and a thick rear is formed between adjacent sound absorber units (see attached Figure 4 and attached Figure 5) In addition, the muffler of the present utility model has the advantages of simple structure, low manufacturing cost, convenient storage and transportation of the muffler due to its assembled structure, good sound absorption effect, etc., and is applicable to various occasions where noise pollution needs to be reduced.

[0030] The present utility model has been described above through specific embodiments, but the present utility model is not limited to these specific embodiments. Those skilled in the art should understand that various modifications, equivalent replacements, changes, etc. can be made to the present utility model, and as long as these transformations do not deviate from the spirit of the present utility model, they should be within the protection scope of the present utility model. In addition, the "one embodiment" mentioned above in multiple places represents different embodiments, and of course, all or part of them can also be combined in one embodiment.

Claims

1. A water-drop-shaped muffler, characterized in that, The water-drop-shaped muffler includes a muffler housing (10) and a plurality of sound-absorbing body units (20) disposed inside the muffler housing. Among them, the cross-section of the sound-absorbing body unit (20) is in the shape of a falling water drop, thereby forming a long and narrow ventilation path with a thinner front and a thicker rear similar to the Bernoulli principle between adjacent sound-absorbing body units.

2. The water-drop-shaped muffler according to claim 1, wherein, The muffler housing (10) is columnar with openings at both ends. The upper and lower end faces of the sound-absorbing body unit (20) are respectively fixed to the bottom and top surfaces of the muffler housing (10) and thus disposed inside the muffler housing, and the plurality of sound-absorbing body units (20) are evenly spaced inside the muffler housing.

3. The droplet-shaped muffler according to claim 2, characterized in that, The side wall (101) of the columnar muffler housing is a composite structure, including an outer protective panel, an inner perforated panel, and a sound-absorbing layer disposed between the outer and inner layers.

4. The droplet-shaped muffler according to claim 1, characterized in that, The sound-absorbing body unit (20) includes an outer perforated panel layer (21) and a micro-perforated plate (24). The cross-section of the perforated panel layer (21) is in the shape of a falling water drop, including a semi-circular head windward deflector (211), an intermediate arc connecting portion (212), and a pointed tail (213). The micro-perforated plate (24) is disposed between the windward deflector (211) and the intermediate arc connecting portion (212). The perforation apertures on the windward deflector (211) and the micro-perforated plate (24) are less than 1.0 mm, and the perforation rate is 1% - 5%; the apertures on the intermediate arc connecting portion (212) and the pointed tail (213) are 2.5 mm - 3 mm, and the perforation rate is 25% - 30%.

5. The water-drop-shaped muffler according to claim 4, characterized in that, The sound-absorbing body unit (20) further includes a resistive sound-absorbing material (22), which is filled inside the space formed by the intermediate arc connecting portion (212), the pointed tail (213), and the micro-perforated plate (24), and a non-alkali water-repellent fiberglass cloth is laid flat on the inner side of the space to protect the resistive sound-absorbing material.

6. The droplet-shaped muffler according to claim 5, characterized in that, The sound-absorbing body unit (20) further includes an inner support plate (23) disposed inside the space, and the inner support plate (23) is a perforated plate.

7. The water droplet-shaped muffler according to claim 5, characterized in that, The resistive sound-absorbing material (22) is centrifugal glass wool with a bulk density of 16 kg / m 3 ~ 48 kg / m 3 .

8. The water-drop-shaped muffler according to claim 1, wherein The muffler housing (10) is an assembled structure, including a longitudinal shell plate (101-1) and a transverse shell plate (101-2), and the longitudinal shell plate (101-1) and the transverse shell plate (101-2) are connected by a stepped lap joint (101-3).

9. The droplet-shaped muffler according to claim 4, characterized in that, A reactive cavity is formed between the micro-perforated plate (24) and the windward deflector (211), which functions as a filter for sound waves.

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