Targeting low-frequency side type silencer and silencing sheet thereof

Abstract

The invention provides a silencing sheet of a targeted low-frequency side type silencer. The silencing sheet comprises a front section part, a side type resonance plate, a sealing plate, an internal partition plate and a framework. The front section part is a pore plate or a particle plate or a gap; the side resonance plate is one or more of a metal plate, a wood plate, a plastic plate, a cement plate and a particle plate; a plurality of silencing sheets can be connected in sequence to form a combined silencing sheet structure. The targeted low-frequency side type muffler comprising the muffling sheet or the combined muffling sheet structure can be used for muffling a certain specific frequency, and particularly, the low-frequency muffling effect is better than that of a traditional resistive muffler; and the device has the advantages of simple structure, convenience in installation and low cost.

Description

Technical Field

[0001] The present invention relates to the field of industrial ventilation silencer / noise reduction, and in particular to a targeted low-frequency side silencer for use in scenarios where a silencer is required, where the low-frequency component of a sound source is prominent, or where a high noise reduction amount is required, or where a high noise reduction amount is required for certain specific frequencies. Background Art

[0002] Mufflers are common products in the field of noise reduction, and are mainly divided into resistive mufflers, reactive mufflers, and impedance composite mufflers. The commonly used mufflers in the field of ventilation mufflers are mainly resistive mufflers, which are widely used because of their high cost performance. The muffler performance of the resistive muffler mainly depends on the filled sound-absorbing material. Due to the insufficient low-frequency sound absorption performance of the sound-absorbing material and the high-frequency failure of the resistive muffler, the main muffler frequency band of the common resistive muffler is concentrated in the mid-frequency, that is, 500Hz-2000Hz.

[0003] Insufficient low-frequency sound attenuation has always been the bottleneck of resistive silencers. In order to improve the low-frequency sound attenuation effect, some people have designed resonant sound absorption structures to improve low-frequency sound attenuation, such as micro-perforated plate silencers. However, due to the limited adjustment space and the fact that micro-perforated plates require a large cavity depth for low-frequency sound absorption, excessive cavity depth will reduce the sound absorption peak, resulting in the difficulty in effectively improving the low-frequency sound attenuation. The sound attenuation improvement is not obvious, and the application is subject to certain restrictions. There are also Helmholtz resonator principles. Helmholtz resonant silencers can achieve sound absorption at different frequencies and are also used in silencers. Especially when there is a high sound pressure level at a certain frequency in the sound source, and it is difficult for the silencer to effectively reduce the noise at this frequency, the noise reduction of the silencer will be greatly affected. In the actual application of silencers, the sound attenuation of a 3m long resistive silencer is only 13dB. At the same time, due to the complex design and manufacturing of the Helmholtz resonator and its low cost performance, there are few actual applications.

[0004] Due to the lack of low-frequency noise reduction of resistive silencers, in actual applications, after the sound source is silenced and noise reduced, the frequencies that affect the total sound level are basically concentrated below 500Hz. To improve the low-frequency noise reduction, resistive silencers are an option, but the main application area of ​​resistive silencers is engine silencers. For industrial ventilation silencers, due to the limitations of installation space, resistance loss requirements and cost, resistive silencers are rarely used and have a low cost-effectiveness. Therefore, in the field of industrial ventilation silencers, it is very critical to improve the low-frequency noise reduction below 500Hz.

[0005] The prior art document (CN214897604U) discloses an internal side resonance structure and a silencer composed of the same structure, which adjusts the number of groups of the internal side resonance structure in the silencer, or uses internal side resonance structures of different structures in the same silencer, or adjusts and matches the length L1, cavity width d1, resistive sound absorbing material width d2, etc. of the internal side resonance plate in the internal side resonance structure, so as to customize the design for different noise reduction requirements and meet the use of different scenarios. However, in previous technical research, due to the difficulty in installing the internal steel plate, the complex processing and manufacturing, the low-frequency noise reduction performance was not significantly improved, and there were certain limitations in the application.

[0006] Therefore, for frequencies below 500 Hz, or for separate sound attenuation and noise reduction at a certain frequency, for sound sources with modulated sound, or sound sources with high sound pressure levels of the fundamental frequency and its harmonics, it has become a technical problem in this field to produce a targeted low-frequency side-type silencer with simple structure, controllable cost, and no impact on the construction and installation of existing silencers. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention provides a targeted low-frequency side-type silencer and a silencer plate thereof. The silencer plate has a simple structure, is easy to install, and has low cost. It can silence a specific frequency. The targeted low-frequency side-type silencer prepared thereby is superior to the traditional resistive silencer in terms of low-frequency silence.

[0008] A silencer plate for a targeted low-frequency side silencer, comprising: a front section 1, a side resonance plate 2, a sealing plate 3, an internal partition plate 4 and a skeleton 5; characterized in that the front section 1 and the side resonance plate 2 are in the same plane, forming the surfaces on the front and rear sides of the silencer plate; the sealing plates 3 are four in total, forming the side surfaces around the silencer plate; the internal partition plate 4 is placed inside the silencer plate, parallel to the side resonance plate 2, and seamlessly connected to the sealing plate 3; the skeleton 5 constitutes a hexahedral grid of the silencer plate; the front section 1, the side resonance plate 2, the sealing plate 3, and the internal partition plate 4 are all arranged on the skeleton 5.

[0009] Furthermore, the length L of the side resonance plate 2 is less than or equal to 5 meters, and the width W of the sound-absorbing plate is less than or equal to 600 mm.

[0010] Furthermore, the front section 1 is a perforated plate or a particle plate or a gap, and the side resonance plate 2 is one or more of a metal plate, a wooden plate, a plastic plate, a cement plate, and a particle plate.

[0011] Furthermore, the perforation rate of the orifice plate (or gap) of the front section 1 is not less than 1%.

[0012] Furthermore, the side resonance plate 2 may also be a composite plate, wherein a layer of metal perforated plate is arranged on the outer side of a single-layer side resonance plate.

[0013] Furthermore, two one-way partitions 7 may be arranged in the sound-absorbing plate. The one-way partitions 7 are arranged on both sides of the internal partition 4 , and the length of the one-way partition 7 is smaller than the length of the internal partition 4 .

[0014] Furthermore, an internal resistive material 8 is provided on the inner side of the sound-absorbing sheet.

[0015] Furthermore, a combined silencer plate structure for a targeted low-frequency side silencer is provided, which is composed of more than two sections of silencer plates connected in sequence; in particular, it is composed of four sections of silencer plates, the first section of silencer plates and the second section of silencer plates have the same size, the third section of silencer plates and the fourth section of silencer plates have the same size, and the first section of silencer plates and the third section of silencer plates have different sizes.

[0016] A targeted low-frequency side-type silencer, wherein a plurality of the silencer sheet structures are evenly arranged inside the silencer sheet, and the arrangement direction of the silencer sheets is consistent with the sound propagation direction.

[0017] A targeted low-frequency side-type silencer has a plurality of the combined silencer sheet structures evenly arranged inside, and the arrangement direction of the combined silencer sheet structures is consistent with the sound propagation direction.

[0018] Beneficial effects: 1. It can silence a specific frequency, especially at low frequencies, which is better than traditional resistive silencers; the silencer is almost always above 20dB when the frequency is below 200Hz, which is significantly better than the prior art at 200Hz and below by about 10-15dB. 2. It has a simple structure, is easy to install, and has low cost. 3. The low-frequency silencer has a wide bandwidth and high sound absorption. Compared with traditional silencers, the low-frequency sound absorption is significantly improved. Even compared with micro-perforated plate silencers and Helmholtz resonance silencers, its sound absorption volume and sound absorption frequency band are also advantageous, and its cost is lower than the above two silencers. 4. The production is simple and can be constructed through sheet metal processing. The sound attenuation of the muffler can be improved by adding resistive sound-absorbing materials in the channel; 5. The opening of the muffler is at the first arrival position in the direction of sound wave propagation. As the only entrance for sound waves to enter, perforated plates, micro-perforated plates, and micro-particle sound-absorbing plates can be used to increase the sound resistance, thereby adjusting the sound attenuation frequency and improving the sound attenuation; 6. The use of fiber sound-absorbing materials is reduced, and the product has the characteristics of green and low carbon, which is a new innovation in the field of ventilation and noise reduction. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 : Schematic diagram of the three-dimensional structure of the muffler; Figure 2 : Schematic diagram of the three-dimensional structure of the front section of the muffler is a perforated plate; Figure 3: Schematic diagram of a targeted low-frequency side-type muffler; Figure 4 : A schematic diagram of a targeted low-frequency side-type muffler with other structural muffler plates; Figure 5 : Schematic diagram of the structure of the combined silencer; Figure 6 : Front view of the combined muffler structure; Figure 7 : A cross-sectional schematic diagram of the structure of the combined silencer; Figure 8 : Schematic diagram of a targeted low-frequency side silencer with a combined silencer plate structure. DETAILED DESCRIPTION

[0020] In order to more clearly understand the purpose, technical scheme and technical effect of the present invention, the present invention is further described below, but the protection scope of the present invention is not limited to the following embodiments.

[0021] Embodiment 1: like Figure 1-2 As shown, a silencer plate 6 of a targeted low-frequency side silencer comprises: a front section 1, a side resonance plate 2, a sealing plate 3, an internal partition plate 4 and a skeleton 5; wherein the front section 1 and the side resonance plate 2 are in the same plane, forming the surfaces of the front and rear sides of the silencer plate 6; the sealing plates 3 are four in total, forming the side surfaces around the silencer plate 6; the internal partition plate 4 is placed inside the silencer plate 6, parallel to the side resonance plate 2, and seamlessly connected to the sealing plate 3; the skeleton 5 constitutes a hexahedral grid of the silencer plate 6; the front section 1, the side resonance plate 2, the sealing plate 3, and the internal partition plate 4 are all arranged on the skeleton 5.

[0022] The length of the muffler sheet 6 is equal to the sum of the length L1 of the front section 1 and the length L of the side resonance plate 2, and the width of the muffler sheet 6 is W. The length L is less than or equal to 5 meters, and the width W is less than or equal to 600 mm.

[0023] like Figure 2 As shown, the front section 1 is a perforated plate, and the side resonance plate 2 is a metal plate.

[0024] Furthermore, the front section 1 may also be a particle plate or a void. Furthermore, the perforation rate of the perforated plate (or void) of the front section 1 is not less than 1%.

[0025] Furthermore, the side resonance plate 2 can be one or more of a metal plate, a wood plate, a plastic plate, a cement plate, and a particle board. Furthermore, the side resonance plate 2 can also be a composite plate, with a layer of metal perforated plate disposed outside a single-layer side resonance plate.

[0026] Embodiment 2: like Figure 1-3 As shown, a targeted low-frequency side-type silencer has a flow rate of 50% and three silencer plates are evenly arranged inside.

[0027] Embodiment 3: like Figure 4 As shown, two one-way partitions 7 can also be arranged in the sound-absorbing plate 6. The one-way partitions 7 are arranged on both sides of the internal partition 4. The length of the one-way partition 7 is smaller than the length of the internal partition 4. The increase of the one-way partition 7 can increase the length of L, thereby achieving sound absorption of a lower frequency band in a smaller spatial length.

[0028] Embodiment 4: like Figure 5-8 As shown, a combined muffler structure of a targeted low-frequency side muffler is composed of the four muffler sheets 6 in Example 1, wherein the length L1 of the front section 1 of the first and second muffler sheets is 100 mm, and the sum of the length L1 of the front section 1 and the length L of the side resonance plate 2 is 480 mm; the length L1 of the front section 1 of the third and fourth muffler sheets is 100 mm, and the sum of the length L1 of the front section 1 and the length L of the side resonance plate 2 is 1000 mm; the height of the four muffler sheets 6 is 600 mm. Wherein, an internal resistive material 8 is arranged inside the sound-absorbing sheet 6 .

[0029] like Figure 8 As shown, a targeted low-frequency side-type muffler has a flow rate of 50% and three combined muffler structures are evenly arranged inside. The muffler performance is tested, and the results are shown in the table: Table 1 Comparison of noise reduction performance of mufflers with different structures Frequency f / Hz 63 80 100 125 160 200 250 315 400 500 Embodiment 4 Muffler 24 17 30 25 28 26 17 14 16 21 Traditional resistive muffler 3m long 5.7 5.3 7.9 9.9 14.1 18.8 21.5 24.7 33 38.5 From Table 1, we can see that: 1. The muffler has a sound attenuation of more than 20dB when the frequency is lower than 200Hz.

[0030] 2. Compared with the traditional resistive muffler, the muffler provided by Implementation 4 has a significantly higher muffler volume when the frequency is lower than 200Hz, and the increase is 6.2-22.1dB. For the sound source with a tuned sound at 100Hz and the sound source with heavy low-frequency components, it can achieve a better muffler effect.

[0031] The above embodiments are only specific descriptions of feasible implementation methods of the present invention, and are not intended to limit the patent protection scope of the present invention. Any equivalent implementation or modification that does not deviate from the present invention should be included in the patent scope of this case.

Claims

1. A muffler sheet targeting a low-frequency side muffler, comprising: A front section, a side resonance plate, a sealing plate, an internal partition and a frame; characterized in that the front section and the side resonance plate are in the same plane, forming the surfaces on the front and rear sides of the sound-absorbing plate; there are four sealing plates in total, forming the side surfaces around the sound-absorbing plate; the internal partition is placed inside the sound-absorbing plate, parallel to the side resonance plate, and seamlessly connected to the sealing plate; the frame constitutes a hexahedral grid of the sound-absorbing plate; the front section, the side resonance plate, the sealing plate and the internal partition are all arranged on the frame.

2. A muffler sheet targeting a low-frequency side-type muffler as claimed in claim 1, characterized in that: The length L of the side resonance plate is less than or equal to 5 meters, and the width W of the sound-absorbing plate is less than or equal to 600 mm.

3. A muffler sheet for targeting low-frequency side-type mufflers as claimed in claim 1, characterized in that: The front section is a perforated plate, a particle plate or a gap, and the side resonance plate is one or more of a metal plate, a wooden plate, a plastic plate, a cement plate and a particle plate.

4. A muffler sheet for targeting low-frequency side-type mufflers as claimed in claim 3, characterized in that: The side resonance plate is a composite plate, and a layer of metal perforated plate is arranged on the outer side of a single-layer side resonance plate.

5. A muffler sheet for targeting low-frequency side-type mufflers as claimed in claim 1, characterized in that: Two one-way partitions are also arranged in the sound-absorbing plate, and the one-way partitions are arranged on both sides of the internal partition.

6. A muffler sheet for targeting low-frequency side-type mufflers as claimed in claim 1, characterized in that: An internal resistive material is arranged inside the sound-absorbing sheet.

7. A combined muffler structure for a low-frequency side-type muffler, characterized in that: The utility model is composed of more than two sound-absorbing sheets as described in any one of claims 1 to 6 connected in sequence.

8. A targeted low-frequency side muffler, characterized in that: A plurality of sound-absorbing sheet structures as described in any one of claims 1 to 8 are arranged inside the sound-absorbing sheet, and the arrangement direction of the sound-absorbing sheet is consistent with the sound propagation direction.

9. A targeted low-frequency side muffler, characterized in that: A plurality of combined sound-absorbing sheet structures as described in claim 7 are arranged inside the structure, and the arrangement direction of the combined sound-absorbing sheet structures is consistent with the sound propagation direction.

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