A resonance diffusion type elbow muffler

Abstract

The present invention provides a resonant diffusion type elbow silencer, comprising a diffusion structure, a shell and a connector; it may also include a microporous guide plate. The diffusion structure comprises a diffuser; micropores are arranged on the diffuser and / or the microporous guide plate; a cavity is formed between the diffusion structure and / or the microporous guide plate and the shell, and sound waves enter the cavity through the microporous structure and are reflected multiple times to generate resonance; the cavity is a special-shaped structure with a variable cross-section; and multiple resonant diffusion type elbow silencers can be connected by a connector. The present invention has a simple structure, is easy to manufacture, and has a good silencing effect, a wide silencing frequency band, high stability, and strong adaptability.

Description

Technical Field

[0001] The present invention belongs to the technical field of mufflers, and specifically relates to noise reduction mufflers in ventilation ducts, vents, smoke exhausts and other fields such as industrial, fire protection, civil and commercial use. Background Art

[0002] Silencer is usually divided into resistive silencer, reactive silencer and impedance composite silencer. Commonly used elbow silencer is a kind of resistive silencer. Their muffler principle is mostly to achieve the purpose of muffler by utilizing the sound absorption performance of foam or fiber porous resistive materials and vertically changing the direction of sound wave propagation. The muffler characteristic of resistive elbow silencer is that it has good muffler performance at around 1000Hz, but the muffler frequency band is narrow, and the effect of medium and low frequencies is poor, especially in the frequency band below 500Hz; the impedance composite elbow silencer has a complex structure and a particularly large resistance coefficient, which is not conducive to processing and production, and adds extra weight.

[0003] The existing microporous plate elbow silencer has a relatively good low-frequency effect. It uses the acoustic resistance of its own perforated plate and eliminates the foam or fiber porous resistive material inside the resistive silencer, simplifying the silencer structure. The principle is that a cavity is left inside the microporous silencer element, and the sound is attenuated in the silencer channel through multiple reflections of the internal sound waves and the resonance sound absorption of the cavity. However, the silencer frequency band is very narrow. Even if a double-layer microperforated plate elbow silencer is used, the expansion of the sound absorption frequency band is very limited. Moreover, the double-layer microporous plate structure is complex, which is not conducive to processing and manufacturing. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides a silencer which has a simple structure, is easy to manufacture, has good sound-absorbing effect, a wide sound-absorbing frequency band, and high stability and is suitable for use in ventilation ducts, vents, smoke exhaust, and other fields such as industrial, fire protection, civil, and commercial use.

[0005] The present invention is achieved through the following technical solutions: a resonant diffusion elbow silencer, which includes an outer shell, a connecting piece, a diffusion structure, and optionally, a microporous guide plate; an internal channel is formed in the diffusion structure and / or the microporous guide plate; wherein the diffusion structure includes a diffuser, and optionally, micropores are arranged on the diffuser; a cavity is formed between the diffusion structure and / or the microporous guide plate and the outer shell, and the cavity is an irregular and special-shaped structure with a variable cross-section.

[0006] Furthermore, the resonant diffusion elbow silencer can be used alone or in series combination via connectors; when combined, the overall combination can be in an arc shape or in a serpentine shape.

[0007] Furthermore, in the same resonant diffusion type elbow muffler, a plurality of diffusion structures may be arranged continuously, or the diffusion structure and the microporous guide plate may be arranged at intervals.

[0008] Furthermore, the shape of the diffuser is one of arc-shaped protrusions, rectangular protrusions, conical protrusions, trapezoidal protrusions and corrugations, or any combination of the above shapes; it can also be any combination of diffusers of the above shapes of different sizes.

[0009] Furthermore, in the same resonant diffusion type elbow silencer, different diffuser structures may have diffusers of the same shape, or diffusers of the same size; or different diffuser structures may have diffusers of different shapes, or diffusers of different sizes; similarly, in a plurality of connected resonant diffusion type elbow silencers, the diffusion structures in different resonant diffusion type elbow silencers may have diffusers of the same shape, or diffusers of the same size; or the diffuser structures in different resonant diffusion type elbow silencers may have diffusers of different shapes, or diffusers of different sizes.

[0010] Furthermore, the diffuser is composed of a diffuser plate, which can be a metal plate, a plastic plate, a plywood, a gypsum board, a plexiglass, a cardboard, or a particle board. The diffuser can be composed of one of the above diffuser plates or a combination of any several diffuser plates; wherein the thickness of a single-layer diffuser plate is 0.1-30 mm.

[0011] Further, the micropore diameter of the diffuser and / or the microporous guide plate is ≤1mm, and the perforation rate is ≤6%. Further, the micropore diameter of the diffuser and / or the microporous guide plate is 0.05-1.0mm, and the perforation rate is 0.5%-6%. In the present invention, due to the presence of the diffusion structure, the porosity of the diffuser and / or the microporous guide plate can be limited to ≤6%, the pore diameter can be limited to ≤1mm, and the perforation rate is 0.5%-6%. The muffler effect of the muffler within the above range is almost the same. Further, the smaller the porosity / pore diameter, the easier it is to be blocked, so the present invention further limits the porosity to 0.5%-6% and the pore diameter to 0.05-1mm to improve the scope of application and service life of the present invention.

[0012] Furthermore, the cross-section of the shell may be rectangular, circular, elliptical, etc., and the angle of the elbow is not limited.

[0013] Furthermore, the shell material can be a metal plate, preferably, one of galvanized steel plate, aluminum alloy steel plate, and stainless steel plate; it can also be a non-metal plate, preferably, one of plexiglass, fiberglass, plastic plate, cardboard, and particle board; the thickness of the shell is 0.1-150mm.

[0014] Furthermore, the cavity is filled with a resistive material, the resistive material is foam, asbestos or fiber-like material, and the resistive material is in the form of particles or layers.

[0015] Furthermore, the shell, the diffuser structure and the connecting piece may be connected by riveting, bolting, welding or bonding to form a silencer.

[0016] The beneficial effects of the present invention are as follows: Overall, the present invention has a simple structure, is easy to manufacture, has a good sound-absorbing effect, a wide sound-absorbing bandwidth, and high stability, and effectively improves the sound absorption of medium frequencies and low frequencies below 500 Hz. Specifically: (1) When sound waves are incident, they hit the diffuser, part of the sound waves are emitted, and then further interfere with other sound waves to achieve the purpose of sound absorption; (2) Multiple diffusion structures and / or microporous guide plates are connected, or multiple resonant diffusion elbow silencers are connected, forming an arc channel as a whole, which can further reflect sound waves and further eliminate sound compared to a straight channel; (3) By setting micropores on the diffuser and / or microporous guide plate, the sound waves pass through the micropores into the cavity formed by the diffusion structure and / or microporous guide plate and the outer shell, and the sound waves are reflected multiple times to form resonance, thereby achieving the purpose of sound absorption; (4) The diffusion structure and / or microporous guide plate are set as an arc elbow as a whole, and the outer shell is set as a rectangle (it can also be other shapes), but in general, the cavity formed between the diffusion structure and / or microporous guide plate and the outer shell is a special-shaped structure cavity with an irregular cross-section. The special-shaped structure cavity has a resistant sound absorption effect. At the same time, due to the cavity Depth change can further help to widen the silencing band. In addition, it also increases the overall stiffness and stability of the elbow silencer. There is no need to set up a separate partition inside to increase the strength or form a resonance cavity, so it is lighter in weight. (5) Multiple elbow silencers can be connected and adapted as needed, and have strong applicability. (6) The cavity can be filled with resistive materials as needed to further increase the low- and medium-frequency silencing. (7) The part of the diffusion structure that contacts the airflow is streamlined and has low resistance. (8) The combination of diffusers of different shapes increases the number of reflections of sound waves and is more conducive to changing the propagation direction of sound waves, further widening the silencing band. (9) The shape of each diffusion structure corresponds to a peak silencing frequency band (five times the chord length of a single diffusion structure is approximately equal to the peak silencing frequency band). The diffusion structure can be designed specifically according to a specific frequency band, and the number of a certain type of diffusion structure can be increased to enhance the silencing of a certain frequency band. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the resonance diffusion type elbow muffler;

[0018] Figure 2 It is a schematic diagram of the combined use of multiple resonance diffusion elbow silencers;

[0019] Figure 3 It is a schematic diagram of a resonant diffusion elbow muffler with added resistive material;

[0020] Figure 4It is a schematic diagram of a resonant diffusion type elbow muffler composed of a local diffuser, a resistive material and a microporous guide plate;

[0021] Figure 5 It is a schematic diagram of a resonant diffusion type elbow muffler with a combination of diffusers of different shapes, resistive materials and microporous guide plates;

[0022] Figure 6 It is a schematic diagram of a diffuser-enhanced resonant diffusion elbow muffler of the same shape;

[0023] Figure 7 This is a schematic diagram of the resonance diffusion elbow silencer principle that can be used for one inlet and two outlets, or two inlets and one outlet.

[0024] Figure 8 It is a schematic diagram of a central (ball) resonant diffusion elbow muffler.

[0025] In the figure: (1) is the diffuser, (2) is the shell, (3) is the connecting part, (4) is the resistive material, and (5) is the guide microporous plate. DETAILED DESCRIPTION

[0026] like Figure 1 As shown, a resonant diffusion type elbow silencer includes a shell 2, a connector 3, and a diffusion structure; an internal channel is formed in the diffusion structure; wherein the diffusion structure includes a diffuser 1; a cavity is formed between the diffusion structure and the shell 2, and the cavity is an irregular shaped structure with a variable cross-section; optionally, micropores are arranged on the diffuser.

[0027] like Figure 2 As shown, the combined use of three resonant diffusion elbow silencers has a noise reduction capacity approximately equal to three times that of one silencer.

[0028] like Figure 3 As shown, the cavity is filled with a resistive material 4, which may be foam, asbestos or fiber-like material, and the resistive material is in the form of particles or layers.

[0029] like Figure 4 As shown, a microporous guide plate 5 is added, and its resistance is smaller due to its streamlined shape; at the same time, the combination of the diffusion structure and the resistive material further enhances the silencing performance of the medium and low frequencies and further broadens the silencing band of the low frequency band.

[0030] like Figure 5As shown in the figure, different shapes of diffusers increase the number of sound wave reflections, are more conducive to changing the propagation direction of sound waves, increasing the interference effect and reflection times of sound waves, and further improving the sound attenuation of mid- and low-frequency. The shape of each diffusion structure corresponds to a peak sound-absorbing frequency band (five times the length of the arc chord of a single diffusion structure is approximately equal to the peak sound-absorbing frequency band). The diffusion structure can be designed specifically according to certain specific frequency bands, thereby further widening the sound-absorbing frequency band.

[0031] like Figure 6 As shown, in the same-shaped diffuser-reinforced resonant diffusion elbow silencer, the number of diffusers 1 of the same shape is almost doubled, and the number of reflections of sound waves is approximately doubled, thereby increasing the sound attenuation; the shape of each diffusion structure corresponds to a peak sound attenuation frequency band, and the diffusion structure can be specifically designed according to a specific frequency band, so that the sound attenuation of a specific frequency band can be increased by increasing the number of diffusion structures.

[0032] like Figure 7 As shown, the resonant diffusion elbow silencer principle can be used for one inlet and two outlets, or two inlets and one outlet. It has a wider range of adaptability and can be installed at the noise source location where there is such a scenario. It can control noise from the source, which is more in line with modern silencer concepts and has a better silencer effect.

[0033] like Figure 8 As shown, the central (ball) type resonant diffusion elbow silencer, the diffuser 1 constitutes one or more central spheres, wherein the central sphere can diffuse the sound waves 360° in space, the central sphere interacts with the diffusion structures on the four sides inside the silencer, the number of reflections will be greatly increased, thereby increasing the sound attenuation and widening the sound attenuation frequency band; the central sphere occupies a smaller volume than other central diffusion structures, which can save materials and reduce weight; in addition, the spherical surface is a streamlined structure, and its resistance is also smaller.

[0034] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in the field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A resonance diffusion elbow muffler, characterized in that: It includes an outer shell, a connector, and a diffusion structure, wherein the diffusion structure includes a microporous guide plate; an internal channel is formed in the diffusion structure and the microporous guide plate; wherein the diffusion structure includes a diffuser, and micropores are arranged on the diffuser; a cavity is formed between the diffusion structure, the microporous guide plate and the outer shell, and the cavity is an irregular shaped structure with a variable cross-section; the micropores on the diffuser and the microporous guide plate have a diameter of ≤1mm and a perforation rate of ≤6%; when a sound wave is incident and hits the diffuser, part of the sound wave is reflected and then further interferes with other sound waves to achieve the purpose of sound elimination; the cavity formed between the diffusion structure, the microporous guide plate and the outer shell is a shaped structure cavity with an irregular cross-section, and the shaped structure cavity has a resistive sound elimination effect; and the sound elimination amount of the mid-frequency and low-frequency below 500Hz is improved.

2. A resonance diffusion elbow muffler as claimed in claim 1, characterized in that: A resonant diffusion type elbow muffler includes more than one inlet and more than one outlet.

3. A resonance diffusion elbow muffler as claimed in claim 1, characterized in that: The diffuser has a shape of one or a combination of arc-shaped protrusions, rectangular protrusions, conical protrusions, trapezoidal protrusions and corrugations.

4. A resonance diffusion elbow muffler as claimed in claim 3, characterized in that: The diffuser is a central ball type, the central ball is composed of diffusers, there are one or more central balls, the central balls are arranged continuously or at intervals along the center line of the elbow muffler, and the central ball interacts with the diffuser inside the elbow muffler.

5. A resonance diffusion elbow muffler as claimed in claim 3, characterized in that: In the same resonant diffusion elbow silencer, different diffuser structures have diffusers of the same or different shapes, and the diffusers have the same or different sizes.

6. A resonant diffusion elbow muffler according to any one of claims 1 to 5, characterized in that: In the same resonant diffusion elbow muffler, a plurality of diffusion structures are arranged continuously, or the diffusion structure and the microporous guide plate are arranged at intervals.

7. A resonant diffusion elbow muffler according to any one of claims 1 to 3, characterized in that: The diffuser is composed of a diffuser plate, and the diffuser plate is selected from one or more of a metal plate, a plastic plate, a plywood, a gypsum board, an organic glass, a paperboard, and a particle board.

8. A resonant diffusion elbow muffler according to any one of claims 1 to 5, characterized in that: The shell is made of metal plate or non-metal plate, and the thickness of the shell is 0.1-150mm.

9. A resonance diffusion elbow muffler as claimed in claim 8, characterized in that: The metal plate is selected from a galvanized steel plate, an aluminum alloy plate, and a stainless steel plate.

10. A resonance diffusion elbow muffler as claimed in claim 8, characterized in that: The non-metallic board is selected from a plastic board, a paperboard, and a particle board.

11. A resonant diffusion elbow muffler according to any one of claims 1 to 5, characterized in that: The cavity is filled with a resistive material, wherein the resistive material is foam or asbestos, and the resistive material is in the form of particles or layers.

12. A resonance diffusion elbow muffler according to any one of claims 1 to 5, characterized in that: The shell, the diffuser structure and the connecting piece are connected to form a muffler by one or more of riveting, bolting, welding or bonding.

13. A resonant diffusion elbow muffler according to any one of claims 1 to 5, characterized in that: The resonance diffusion type elbow silencer is used alone or in series combination through the connecting piece.

14. A resonance diffusion elbow muffler as claimed in claim 12, characterized in that: In a plurality of connected resonant diffusion type elbow mufflers, the diffusion structures in different resonant diffusion type elbow mufflers have diffusers of the same or different shapes.

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