Impedance type composite muffler

Abstract

The application discloses an impedance type composite silencer, which comprises a shell, one end of the shell is provided with an air inlet, the other end of the shell is provided with an air outlet, a first mesh plate is arranged in the shell, the first mesh plate divides the shell into a first chamber and a second chamber, the first chamber is located at the outer layer of the second chamber, the second chamber is communicated with the air inlet, the first chamber is communicated with the air outlet, the first chamber is filled with silencing material, when gas enters the second chamber through the air inlet, the gas enters the first chamber after being preliminarily silenced by passing through the first mesh plate, the gas is secondarily silenced by the silencing material in the first chamber, and is discharged through the air outlet, the coating type combination of the resistance type silencing structure and the impedance type silencing structure not only improves the silencing effect of the full frequency band, but also avoids the problem that the traditional segmented superposition type silencer is large in size.

Description

Technical Field

[0001] This application relates to the field of silencer technology, and more specifically to an impedance-type composite silencer. Background Technology

[0002] In industrial production, oil-free screw blowers are widely used in various applications requiring clean compressed air, such as textiles, chemicals, food processing, and wastewater treatment, due to their high efficiency, energy saving, and oil-free pollution characteristics. However, oil-free screw blowers generate significant noise during operation, mainly composed of low-to-mid-frequency noise caused by mechanical operation and airflow pulsation, and mid-to-high-frequency noise caused by airflow disturbance or resonance. This noise not only harms the health of operators but also pollutes the surrounding environment. Currently, silencers are mostly used to reduce blower noise. Common silencers are mainly divided into two categories: resistive silencers and reactive silencers. Resistive silencers utilize the sound-absorbing properties of sound-absorbing materials (such as fiberglass, flame-retardant sponge, and felt) to absorb and gradually attenuate noise propagating along the duct as it passes through the sound-absorbing material. They have a good noise reduction effect on mid-to-high-frequency noise, but low-frequency sound waves have longer wavelengths and higher energy, making them difficult for sound-absorbing materials to absorb effectively. On the other hand, commonly used sound-absorbing materials (such as fiberglass and flame-retardant sponge) are prone to pulverization and detachment under high temperature, pressure, and airflow impact conditions. The detached material may enter the pipeline with the airflow, even reaching the operating point, causing equipment blockage and posing a significant safety hazard. Furthermore, sound-absorbing materials are prone to melting or blockage by carbon deposits and sludge under long-term high-temperature environments, thus reducing or eliminating their noise-absorbing effect. Reactor-type silencers reduce noise by using sudden expansion (or contraction) of the pipeline cross-section or by using a bypass resonant cavity, causing certain frequencies of sound waves propagating along the pipeline to be reflected and interfered at abrupt changes. This type of silencer has a better noise-absorbing effect on low and mid-frequency noise because low-frequency sound waves are more easily reflected and interfered at abrupt changes in the pipeline cross-section. Reactor-type silencers are less effective at reducing high-frequency noise because high-frequency sound waves have shorter wavelengths, making it difficult for abrupt changes in the pipeline cross-section to produce effective reflection and interference.

[0003] Currently, noise control for oil-free screw blowers mainly relies on a single type of silencer, namely a resistive silencer or a reactive silencer. However, a single type of silencer cannot effectively solve both low-frequency and high-frequency noise problems simultaneously. Therefore, Chinese utility model patent CN214118480U discloses an impedance silencer for a Roots blower, comprising an outer cylinder, a resistive section, and a reactive section. The resistive section and the reactive section are disposed within the outer cylinder. The resistive section is connected to the outlet of the Roots blower. The outer cylinder includes an upper end face and a lower end face. An upper sealing plate is provided on the upper end face, and the upper sealing plate is connected to a first throat. A lower sealing plate is provided on the lower end face, and the lower sealing plate is connected to a second throat. The first throat is adjacent to the end of the reactive section away from the resistive section, and the second throat is adjacent to the end of the resistive section away from the reactive section. A first flange is provided on the first throat, and a second flange is provided on the second throat. In this technical solution, the airflow first passes through the resistive section to eliminate mid- and high-frequency noise, and then enters the buffer structure of the reactive section (i.e., the first and second mesh tubes) through the flow cavity to eliminate low- and mid-frequency noise, converting sound energy into heat energy and eliminating low, mid, and high-frequency noise. Although the combination of resistive and reactive silencers achieves a comprehensive noise reduction effect on low, mid, and high-frequency noise, the segmented and superimposed design of the resistive and reactive sections results in a longer overall structure, increasing the length of the entire silencer. This not only increases the size and weight of the equipment but also restricts installation space, increasing the difficulty of installation and maintenance. Therefore, there is still a need for a silencer that combines the advantages of resistive and reactive silencers, which can not only achieve comprehensive control of low, mid, and high-frequency noise but also improve the reliability and service life of the equipment without increasing the overall structural length. Summary of the Invention

[0004] The technical problem to be solved by this application is to provide an impedance-type composite muffler, which improves the muffler effect across the entire frequency band by combining an impedance-type muffler structure and an anti-type muffler structure in an enveloping superposition, and avoids the problem of increased size caused by the dispersed structure of traditional segmented superposition mufflers.

[0005] This application provides an impedance-type composite silencer, including a housing. One end of the housing has an air inlet, and the other end has an air outlet. A first perforated plate is installed inside the housing, dividing the interior of the housing into a first chamber and a second chamber. The first chamber is located outside the second chamber. The second chamber is connected to the air inlet, and the first chamber is connected to the air outlet. The first chamber is filled with sound-absorbing material. When gas enters the second chamber through the air inlet, the gas passes through the first perforated plate for initial sound absorption before entering the first chamber. The gas then undergoes secondary sound absorption through the sound-absorbing material in the first chamber and is discharged through the air outlet.

[0006] In this technical solution, the housing is the main structure of the silencer, serving to house and fix the internal components. It has an inlet and an outlet at each end for gas entry and exit. A first perforated plate is installed inside the housing, dividing the internal space into a first chamber and a second chamber. The second chamber is connected to the inlet, allowing gas to enter first. The first chamber is located outside the second chamber and is connected to the outlet, allowing gas to exit. Sound-absorbing material is filled in the first chamber as a resistive sound-absorbing structure. When high-frequency sound waves come into contact with the sound-absorbing material, they are absorbed and scattered by the tiny pores within the material. Due to friction and viscous resistance, sound energy is converted into heat energy, thus eliminating most of the mid- and high-frequency noise. A first perforated plate is installed in the second chamber as a resistive sound-absorbing structure, allowing gas to enter through multiple small holes. The airflow is divided and diffused. When the airflow passes through these small holes, the sound waves are reflected and interfered within the holes, thereby reducing low and mid-frequency noise. The first chamber is located on the outer periphery of the second chamber. The resistive silencing structure is covered by the reactive silencing structure, so that the airflow first undergoes preliminary silencing through the resistive silencing structure (the first perforated plate) and then enters the reactive silencing structure (the silencing material in the first chamber) for secondary silencing. This not only improves the silencing effect but also avoids the problem of increased volume caused by the dispersed structure of traditional segmented stacked silencers, saving installation space. It is suitable for noise control of various industrial equipment, such as oil-free screw blowers and Roots blowers. It can effectively reduce the noise generated during equipment operation, improve the working environment, and reduce noise pollution to the surrounding environment. It has wide applicability and good market prospects.

[0007] As an improvement, a sealing plate adapted to the first perforated plate is installed in the second chamber. The sealing plate separates the first perforated plate from the air outlet, allowing gas in the second chamber to pass through the first perforated plate into the first chamber. In this technical solution, the sealing plate is adapted to the first perforated plate, ensuring a tight fit and effective sealing. The main function of the sealing plate is to separate the first perforated plate from the air outlet, forcing gas in the second chamber to pass through the first perforated plate before entering the first chamber and flowing to the air outlet. This alters the gas flow path, requiring it to undergo initial noise reduction through the first perforated plate, thus improving the stability and reliability of the noise reduction effect.

[0008] As an improvement, a baffle plate adapted to the air outlet is installed inside the housing. The baffle plate connects the first chamber and the air outlet, and the gas in the first chamber is gathered by the baffle plate and discharged through the air outlet. In this technical solution, the baffle plate is adapted to the air outlet, and its main function is to connect the first chamber and the air outlet, forming an efficient gas flow channel. After the gas is treated by the sound-absorbing material in the first chamber, it can be gathered by the baffle plate, thus being discharged from the muffler more orderly, avoiding gas turbulence and secondary noise generation at the air outlet. The design of the baffle plate not only enhances the integration of the muffler but also improves its overall performance.

[0009] As an improvement, the sealing plate and the first perforated plate are integrally formed. The guide plate is provided with multiple through holes, which are used to connect the first chamber and the air outlet. The integral structure improves the overall stability and sealing performance, and reduces the performance degradation or noise increase caused by loosening or leakage at the connection. The guide plate has a ring structure and is provided with multiple through holes, which are used to connect the first chamber and the air outlet. The gas in the first chamber can enter the guide plate through these holes and finally be discharged from the air outlet, optimizing the gas flow path and ensuring that the airflow can be discharged from the muffler smoothly and orderly.

[0010] As an improvement, the first perforated plate is uniformly distributed with multiple first small holes, and adjacent first small holes are arranged in an equilateral triangle. In this technical solution, the uniformly distributed first small holes can evenly divide the airflow into multiple small airflows before entering the first chamber, avoiding excessive concentration or sparseness of local airflow, thereby effectively reducing noise in all directions. The equilateral triangle arrangement of the first small holes maximizes the utilization of the perforated plate area, while ensuring that the path length and resistance of the airflow when passing through the first small holes are relatively consistent, enhancing the reflection and interference effect of sound waves in the first small holes, and further improving the noise reduction efficiency. On the other hand, the equilateral triangle arrangement of the small holes maximizes the utilization of the perforated plate area, allowing more small holes to be arranged in a limited space, thereby improving the noise reduction effect.

[0011] As an improvement, the total area of ​​the multiple first small holes is greater than 1.5 times the area of ​​the air inlet. In this technical solution, by increasing the total area of ​​the first small holes, the airflow can be more fully dispersed when passing through the first perforated plate. When the airflow passes through the first perforated plate, since the total area of ​​the first small holes is greater than 1.5 times the area of ​​the air inlet, the airflow is divided into more small airflow streams, increasing the contact area between the airflow and the first perforated plate, thereby enhancing the reflection and interference phenomena of sound waves during propagation. Through the design of the first perforated plate, after the airflow enters from the air inlet, it first passes through a region with a suddenly expanded cross-sectional area (i.e., the area of ​​the first small holes of the first perforated plate) and then enters the first chamber. This abrupt change in cross-section causes the sound waves to be reflected and interfered during propagation, effectively reducing low and mid-frequency noise.

[0012] As an improvement, the diameter of the first small hole is 3 mm ± 1 mm. In this technical solution, the optimal diameter of the first small hole is 3 mm, which ensures that the airflow can be effectively divided into multiple small airflows when passing through the first small hole, while maintaining the uniformity and stability of the airflow. The 3 mm diameter of the first small hole can effectively handle low and medium frequency noise, and also has a certain silencing effect on high frequency noise. The selection of the diameter of the first small hole ensures that the airflow resistance when passing through the perforated plate is relatively small, which improves the airflow efficiency and reduces energy loss. Furthermore, the 3 mm diameter of the small hole allows for the arrangement of more small holes in a limited space, thereby improving the overall silencing effect of the silencer without significantly increasing the volume or length of the silencer.

[0013] As an improvement, a second perforated plate is installed in the first chamber, and the sound-absorbing material is installed between the inner wall of the shell and the second perforated plate. In this technical solution, the second perforated plate is installed in the first chamber, located between the first perforated plate and the inner wall of the shell. The second perforated plate further divides the airflow, increases the path length and resistance of the airflow, and disperses the airflow again after entering the first chamber, further enhancing the sound-absorbing effect. The sound-absorbing material is installed between the inner wall of the shell and the second perforated plate, forming a sandwich structure, which allows the sound-absorbing material to absorb and scatter sound waves more effectively, converting sound energy into heat energy, thereby further reducing noise. At the same time, the presence of the second perforated plate also protects the sound-absorbing material, preventing it from being directly exposed to the airflow and being washed away or damaged. With the protection of the second perforated plate, the sound-absorbing material is not easy to fall off under the impact of airflow, further improving the reliability and safety of the silencer. The dual effect of the first and second perforated plates disperses the airflow multiple times after entering the first chamber, increasing the contact area and time between the airflow and the sound-absorbing material, thereby further enhancing the absorption effect of mid- and high-frequency noise.

[0014] As an improvement, the outer periphery of the silencing material is covered with a stainless steel mesh to prevent the silencing material from falling off. In this technical solution, the stainless steel mesh is arranged around the outer periphery of the silencing material, forming a protective layer that wraps around the silencing material. The silencing material is prone to pulverization and breakage under high temperature and airflow impact. The main function of the stainless steel mesh is to prevent pulverized and broken silencing material from being carried out by the airflow, avoiding particles being transported to the customer's air consumption end. It also avoids the reduction in silencing effect or equipment blockage caused by the silencing material falling off, thus improving the reliability of the silencer. The stainless steel mesh has good high temperature resistance and corrosion resistance, enabling it to work stably for a long time under harsh working conditions. Furthermore, the stainless steel mesh has high strength and can effectively withstand the impact of airflow.

[0015] As an improvement, the second perforated plate is provided with a plurality of small second holes evenly distributed therefrom, the diameter of which is 5 mm ± 1 mm. In this technical solution, the even distribution of the small holes on the second perforated plate ensures that the airflow is evenly divided when passing through it, avoiding excessive concentration or sparseness of airflow in certain areas. The presence of the small second holes further divides the airflow into finer segments after passing through the first perforated plate, increasing the path length and resistance of the airflow, thereby enhancing the noise reduction effect. The preferred diameter of the small second holes is 5 mm, which allows for the absorption of high-frequency noise while also addressing low-to-mid-frequency noise, further improving the overall performance of the silencer.

[0016] As an improvement, the sound-absorbing material is stainless steel sound-absorbing filler. In this technical solution, stainless steel is used as the sound-absorbing filler, replacing traditional porous fillers such as glass fiber and flame-retardant sponge. Stainless steel filler has higher high-temperature resistance, corrosion resistance, and impact resistance, and can work stably for a long time under harsh working conditions. It avoids the problem of traditional fillers easily pulverizing and breaking under high temperature and airflow impact, thus improving the reliability of the silencer. Stainless steel sound-absorbing filler is usually granular, fibrous, or other porous structures, which can provide a large specific surface area for absorbing and scattering sound waves, and has a good sound-absorbing effect on medium and high frequency noise. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of an impedance-type composite silencer according to this application.

[0018] Figure 2 This is a cross-sectional structural schematic diagram of an impedance-type composite silencer according to this application.

[0019] Figure 3 For this application Figure 2 A magnified view of a portion of point A in the middle.

[0020] Figure 4 This is a schematic diagram of the arrangement of the first small hole in this application.

[0021] The figure shows: 1. Shell; 11. Air inlet; 12. Air outlet; 2. First perforated plate; 21. First small hole; 3. Sound-absorbing material; 4. Sealing plate; 6. Guide plate; 7. Second perforated plate; 71. Second small hole. Detailed Implementation

[0022] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements.

[0023] In the accompanying drawings, the thickness, size, and shape of the objects have been slightly exaggerated for illustrative purposes. The drawings are for illustrative purposes only and are not drawn to scale.

[0024] It should also be understood that the terms "comprising," "including," "having," "containing," and "including," when used in this specification, indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof. The terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (the specific types and constructions may be the same or different), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0025] Furthermore, it should be noted that the terms "installation," "setting," "equipped with," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components; they can refer to a direct installation on another component or the possible presence of another intermediate component. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] like Figures 1 to 4As shown, this application discloses an impedance-type composite silencer, including a housing 1. One end of the housing 1 has an air inlet 11, and the other end has an air outlet 12. The housing 1 is the main structure of the silencer, serving to house and fix the internal components. The two ends have the air inlet 11 and the air outlet 12 for gas entry and exit. A first perforated plate 2 is installed inside the housing 1, dividing the interior of the housing 1 into a first chamber and a second chamber. The first chamber is located outside the second chamber. The second chamber communicates with the air inlet 11, and the first chamber communicates with the air outlet 12. The interior is filled with sound-absorbing material 3. When gas enters the second chamber through the air inlet 11, it undergoes initial sound absorption through the first mesh plate 2 before entering the first chamber. The gas then undergoes secondary sound absorption through the sound-absorbing material 3 within the first chamber and is discharged through the air outlet 12. The first mesh plate 2 is installed inside the housing 1, dividing the internal space of the housing 1 into a first chamber and a second chamber. The second chamber is connected to the air inlet 11, and gas first enters the second chamber. The first chamber is located outside the second chamber and is connected to the air outlet 12. The gas is ultimately discharged through the first chamber, which is filled with sound-absorbing material. 3. As a resistive noise reduction structure, high-frequency sound waves are absorbed and scattered by the tiny pores inside the sound-absorbing material when they come into contact with it. Due to friction and viscous resistance, the sound energy is converted into heat energy, thereby eliminating most of the mid- and high-frequency noise. A first perforated plate 2 is installed in the second chamber as a resistive noise reduction structure. Multiple small holes on the first perforated plate 2 divide and diffuse the incoming airflow. When the airflow passes through these small holes, the sound waves are reflected and interfered within the holes, thereby reducing low- and mid-frequency noise. The first chamber is located on the outer periphery of the second chamber, and the resistive noise reduction structure is wrapped around the resistive noise reduction structure, making... The airflow first undergoes initial noise reduction through the resistance-type silencing structure (first perforated plate 2), and then enters the anti-reactive silencing structure (silencing material 3 in the first chamber) for secondary noise reduction. This not only improves the noise reduction effect, but also avoids the problem of increased volume caused by the dispersed structure of traditional segmented stacked silencers, saving installation space. It is suitable for noise control of various industrial equipment, such as oil-free screw blowers and Roots blowers. It can effectively reduce the noise generated during equipment operation, improve the working environment, and reduce noise pollution to the surrounding environment. It has wide applicability and good market prospects.

[0027] More specifically, such as Figure 2As shown, a sealing plate 4 adapted to the first perforated plate 2 is installed in the second chamber. The sealing plate 4 is used to separate the first perforated plate 2 from the air outlet 12, so that the gas in the second chamber can pass through the first perforated plate 2 to enter the first chamber. The sealing plate 4 is adapted to the first perforated plate 2 to ensure that the sealing plate 4 can fit tightly against the first perforated plate 2 to form a good sealing effect. The main function of the sealing plate 4 is to separate the first perforated plate 2 from the air outlet 12, so that the gas in the second chamber must first pass through the first perforated plate 2 before entering the first chamber and then flowing to the air outlet 12. This changes the flow path of the gas, so that it must pass through the first perforated plate 2 for preliminary noise reduction treatment, thereby improving the stability and reliability of the noise reduction effect.

[0028] More specifically, such as Figure 2 As shown, a baffle plate 6 adapted to the air outlet 12 is installed inside the housing 1. The baffle plate 6 is used to connect the first chamber and the air outlet 12. The gas in the first chamber is gathered by the baffle plate 6 and discharged through the air outlet 12. The baffle plate 6 is adapted to the air outlet 12. The main function of the baffle plate 6 is to connect the first chamber and the air outlet 12 to form an efficient gas flow channel. After the gas is treated by the sound-absorbing material 3 in the first chamber, it can be gathered by the baffle plate 6 and discharged from the muffler in a more orderly manner, avoiding the turbulence of gas at the air outlet 12 and the generation of secondary noise. The design of the baffle plate 6 not only enhances the integration of the muffler, but also improves the overall performance of the muffler.

[0029] More specifically, such as Figure 2 As shown, the sealing plate 4 and the first mesh plate 2 are an integral structure. The guide plate 6 is provided with multiple through holes to connect the first chamber and the air outlet 12. The integral structure improves the overall stability and sealing performance, and reduces the performance degradation or noise increase caused by loosening or leakage at the connection. The guide plate 6 has an annular structure and is provided with multiple through holes. These through holes are used to connect the first chamber and the air outlet 12. The gas in the first chamber can enter the guide plate 6 through these holes and finally be discharged from the air outlet 12, which optimizes the gas flow path and ensures that the airflow can be discharged from the muffler smoothly and orderly.

[0030] More specifically, such as Figure 3 and Figure 4As shown, a plurality of first holes 21 are evenly distributed on the first mesh plate 2. Adjacent first holes 21 are arranged in an equilateral triangle. The evenly distributed first holes 21 can evenly divide the airflow into multiple small airflows before entering the first chamber, avoiding excessive concentration or sparseness of local airflow, thereby effectively reducing noise in all directions. The equilateral triangle arrangement of the first holes 21 maximizes the use of the area of ​​the mesh plate, while ensuring that the path length and resistance of the airflow when passing through the first holes 21 are relatively consistent, enhancing the reflection and interference effect of sound waves in the first holes 21, and further improving the noise reduction efficiency. On the other hand, the equilateral triangle arrangement of the holes can maximize the use of the area of ​​the mesh plate, allowing more holes to be arranged in a limited space, thereby improving the noise reduction effect.

[0031] More specifically, such as Figure 3 and Figure 4 As shown, the total area of ​​the multiple first holes 21 is greater than 1.5 times the area of ​​the air inlet 11. By increasing the total area of ​​the first holes 21, the airflow can be more fully dispersed when passing through the first mesh plate 2. When the airflow passes through the first mesh plate 2, since the total area of ​​the first holes 21 is greater than 1.5 times the area of ​​the air inlet 11, the airflow is divided into more small airflow streams, which increases the contact area between the airflow and the first mesh plate 2, thereby enhancing the reflection and interference phenomena of sound waves during propagation. Through the design of the first mesh plate 2, after the airflow enters from the air inlet 11, it first passes through a region with a suddenly expanded cross-sectional area (i.e., the area of ​​the first holes 21 of the first mesh plate 2), and then enters the first chamber. This sudden change in cross-section causes the sound waves to be reflected and interfered during propagation, effectively reducing low and mid-frequency noise.

[0032] More specifically, such as Figure 3 and Figure 4 As shown, the diameter of the first small hole 21 is 3 mm ± 1 mm. The optimal diameter of the first small hole 21 is 3 mm, which ensures that the airflow can be effectively divided into multiple small airflows when passing through the first small hole 21, while maintaining the uniformity and stability of the airflow. The 3 mm diameter of the first small hole 21 can handle low and medium frequency noise well, and also has a certain silencing effect on high frequency noise. The selection of the diameter of the first small hole 21 can ensure that the airflow resistance is relatively small when passing through the perforated plate, which improves the airflow efficiency and reduces energy loss. In addition, the 3 mm small hole diameter allows more small holes to be arranged in a limited space, thereby improving the overall silencing effect of the silencer without significantly increasing the volume or length of the silencer.

[0033] More specifically, such as Figure 2As shown, a second perforated plate 7 is installed in the first chamber. Sound-absorbing material 3 is installed between the inner wall of the shell 1 and the second perforated plate 7. The second perforated plate 7 is installed in the first chamber, located between the first perforated plate 2 and the inner wall of the shell 1. The second perforated plate 7 further divides the airflow, increasing the path length and resistance of the airflow, causing the airflow to be dispersed again after entering the first chamber, further enhancing the sound-absorbing effect. The sound-absorbing material 3 is installed between the inner wall of the shell 1 and the second perforated plate 7, forming a sandwich structure, allowing the sound-absorbing material 3 to more effectively absorb and scatter sound waves. Sound energy is converted into heat energy, thereby further reducing noise. At the same time, the presence of the second perforated plate 7 also protects the sound-absorbing material 3, preventing it from being directly exposed to the airflow and being washed away or damaged. With the protection of the second perforated plate 7, the sound-absorbing material 3 is not easy to fall off under the impact of airflow, further improving the reliability and safety of the silencer. The dual effect of the first perforated plate 2 and the second perforated plate 7 makes the airflow dispersed multiple times after entering the first chamber, increasing the contact area and time between the airflow and the sound-absorbing material 3, thereby further enhancing the absorption effect of mid- and high-frequency noise.

[0034] More specifically, the outer periphery of the silencing material 3 is covered with stainless steel mesh. The stainless steel mesh is used to prevent the silencing material 3 from falling off. The stainless steel mesh is arranged on the outer periphery of the silencing material 3 to form a protective layer, wrapping the silencing material 3. The silencing material 3 is prone to pulverization and breakage under high temperature and airflow impact. The main function of the stainless steel mesh is to prevent the pulverized and broken silencing material 3 from being carried out by the airflow, avoiding the particles being transported to the customer's air consumption end by the airflow. It also avoids the reduction of silencing effect or equipment blockage caused by the silencing material 3 falling off, thus improving the reliability of the silencer. The stainless steel mesh has good high temperature resistance and corrosion resistance, and can work stably for a long time under harsh working conditions. In addition, the stainless steel mesh has high strength and can effectively withstand the impact of airflow.

[0035] More specifically, such as Figure 2 As shown, a plurality of second small holes 71 are evenly distributed on the second mesh plate 7. The diameter of the second small holes 71 is 5 mm ± 1 mm. The even distribution of the multiple small holes on the second mesh plate 7 ensures that the airflow can be evenly divided when passing through the second mesh plate 7, avoiding excessive concentration or sparseness of local airflow. The presence of the second small holes 71 causes the airflow to be further divided into finer airflow after passing through the first mesh plate 2, further increasing the path length and resistance of the airflow, thereby enhancing the noise reduction effect. The diameter of the second small holes 71 is preferably 5 mm, which can absorb high-frequency noise while processing low-frequency noise, further improving the overall performance of the silencer.

[0036] More specifically, the sound-absorbing material 3 is stainless steel sound-absorbing filler. Stainless steel is used as the sound-absorbing filler to replace traditional porous fillers such as glass fiber and flame-retardant sponge. Stainless steel filler has higher high temperature resistance, corrosion resistance and impact resistance, and can work stably for a long time under harsh working conditions. It avoids the problem of traditional fillers being easy to pulverize and break under high temperature and airflow impact, thus improving the reliability of the silencer. Stainless steel sound-absorbing filler is usually granular, fibrous or other porous structure, which can provide a large specific surface area for absorbing and scattering sound waves, and has a good sound-absorbing effect on medium and high frequency noise.

[0037] This application is not limited to the above-described preferred embodiments. Anyone can derive other products in various forms under the guidance of this application. However, regardless of any changes made to their shape or structure, any technical solution that is the same as or similar to that of this application falls within the protection scope of this application.

Claims

1. An impedance type compound muffler, characterized by comprising: The device includes a housing (1), one end of which is provided with an air inlet (11) and the other end of which is provided with an air outlet (12). A first mesh plate (2) is installed inside the housing (1). The first mesh plate (2) divides the interior of the housing (1) into a first chamber and a second chamber. The first chamber is located on the outer layer of the second chamber. The second chamber is connected to the air inlet (11) and the first chamber is connected to the air outlet (12). The first chamber is filled with sound-absorbing material (3). When gas enters the second chamber through the air inlet (11), the gas passes through the first mesh plate (2) for initial sound absorption and then enters the first chamber. The gas undergoes secondary sound absorption through the sound-absorbing material (3) in the first chamber and is discharged through the air outlet (12).

2. The impedance-type composite silencer according to claim 1, characterized in that, The second chamber is equipped with a sealing plate (4) that is compatible with the first mesh plate (2). The sealing plate (4) is used to separate the first mesh plate (2) from the air outlet (12) so that the gas in the second chamber passes through the first mesh plate (2) and enters the first chamber.

3. The impedance-type composite silencer according to claim 2, characterized in that, The housing (1) is equipped with a guide plate (6) adapted to the air outlet (12). The guide plate (6) is used to connect the first chamber and the air outlet (12). The gas in the first chamber is gathered by the guide plate (6) and discharged through the air outlet (12).

4. The impedance-type composite silencer according to claim 3, characterized in that, The sealing plate (4) and the first mesh plate (2) are integrally formed. The guide plate (6) is provided with multiple through holes, which are used to connect the first chamber and the air outlet (12).

5. The impedance-type composite silencer according to claim 1, characterized in that, The first perforated plate (2) has a plurality of first holes (21) evenly distributed on it, and adjacent first holes (21) are arranged in an equilateral triangle.

6. The impedance-type composite silencer according to claim 5, characterized in that, The total area of ​​the multiple first holes (21) is greater than 1.5 times the area of ​​the air inlet (11).

7. An impedance-type composite silencer according to claim 5, characterized in that, The diameter of the first small hole (21) is 3 mm ± 1 mm.

8. An impedance-type composite silencer according to claim 1, characterized in that, The first chamber is equipped with a second perforated plate (7), and the sound-absorbing material (3) is installed between the inner wall of the shell (1) and the second perforated plate (7).

9. An impedance-type composite silencer according to claim 1 or 8, characterized in that, The outer periphery of the sound-absorbing material (3) is covered with stainless steel mesh, which is used to prevent the sound-absorbing material (3) from falling off.

10. An impedance-type composite silencer according to claim 1, characterized in that, The sound-absorbing material (3) is a stainless steel sound-absorbing filler.

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