Graded sound attenuation and noise reduction structure of vacuum pump unit

Abstract

The utility model discloses a graded sound attenuation and noise reduction structure of a vacuum pump unit, which comprises an outer corrugated noise reduction pipe, an inner hollow material storage pipe fixedly arranged in the outer corrugated noise reduction pipe, and a double-layer interval type exhaust structure arranged at the central axis position in the inner hollow material storage pipe, the air inlet end and the air outlet end of the double-layer spaced exhaust structure communicate with an air inlet and an air outlet of the inner hollow material storage pipe correspondingly, and the air inlet and the air outlet of the inner hollow material storage pipe both penetrate to the outside of the outer corrugated noise reduction pipe. By means of the double-layer spaced exhaust structure, airflow is slowed down and expanded, noise is reduced, then sound waves are further absorbed and reflected in the asphalt-based damping rubber layer and the inner hollow storage pipe, propagation of the sound waves is reduced, effective absorption space is provided for low-frequency noise due to application of the ceramic fiber blanket, and noise reduction is achieved. And finally, scattering and attenuation of sound waves are completed by the outer corrugated noise reduction pipe.

Description

Technical Field

[0001] This utility model relates to the field of pipe fitting noise reduction technology, specifically a graded noise reduction structure for vacuum pump units. Background Technology

[0002] The primary function of a vacuum pump is to reduce the air pressure in a sealed space by extracting gas, thereby creating a vacuum and facilitating processes such as semiconductor manufacturing, vacuum packaging, and vacuum drying. However, a common problem during vacuum pump operation is significant exhaust noise at the exhaust pipe location. This noise is closely related to factors such as airflow velocity, gas dynamics, mechanical vibration, exhaust pipe design, and insufficient sound insulation. First, the high-speed flow of gas during exhaust generates turbulence, thus causing noise; second, collisions and friction between gas molecules during exhaust also increase noise. Furthermore, the vibration of moving parts inside the vacuum pump is transmitted to the exhaust pipe through the pump body, causing resonance and further amplifying the noise. At present, in order to effectively control exhaust noise, various measures can be taken, such as optimizing the exhaust pipe design, installing silencers, using sound insulation materials, and regularly maintaining the vacuum pump to ensure its normal operation. Among these, installing silencers and sound insulation materials on the outside of the exhaust pipe is the first choice, but its noise reduction effect is not obvious. This is because the frequency range of vacuum pump exhaust noise is wide, including low-frequency and high-frequency components. The propagation characteristics of sound waves of different frequencies in sound insulation materials are different. Low-frequency sound waves require thicker materials or more layers to be effectively absorbed, while high-frequency sound waves are relatively easy to be absorbed by thin layers of materials. However, the existing noise reduction methods are insufficient in terms of noise reduction levels and number of layers, resulting in some frequency sound waves not being effectively attenuated, thus making the overall noise level still high. Utility Model Content

[0003] The purpose of this invention is to provide a graded noise reduction structure for vacuum pump units. An inner hollow storage tube and a double-layered, spaced-out exhaust structure are sequentially installed inside an outer corrugated noise reduction tube. The inner hollow storage tube is filled with asphalt-based damping adhesive and completely covers the outside of the double-layered, spaced-out exhaust structure. A ceramic fiber blanket is then wrapped between the inner hollow storage tube and the outer corrugated noise reduction tube. By utilizing the double-layered, spaced-out exhaust structure, the asphalt-based damping adhesive layer, the inner hollow storage tube, the ceramic fiber blanket, and the outer corrugated noise reduction tube, the high and low frequency noise generated during the operation of the vacuum pump exhaust pipe is gradually attenuated and suppressed, thereby solving the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a graded noise reduction structure for a vacuum pump unit, comprising an outer corrugated noise reduction tube, an inner hollow storage tube fixedly installed inside the outer corrugated noise reduction tube, and a double-layer interval exhaust structure installed at the central axis position inside the inner hollow storage tube. The air inlet and exhaust ends of the double-layer interval exhaust structure are respectively connected to the air inlet and exhaust outlet of the inner hollow storage tube. The air inlet and exhaust outlet of the inner hollow storage tube both extend to the outside of the outer corrugated noise reduction tube. A noise reduction cavity is provided between the inner hollow storage tube and the double-layer interval exhaust structure. The noise reduction cavity is filled with asphalt-based damping adhesive. At least one layer of ceramic fiber blanket is bonded to the outer wall surface of the inner hollow storage tube.

[0005] Preferably, the double-layered intermittent exhaust structure includes an outer expansion pipe fixed on the left and right inner walls of the inner hollow storage pipe, a central air guide pipe, and an air guide hole provided on the outer wall of the central air guide pipe for communicating with the outer expansion pipe. The air inlet end of the central air guide pipe is connected to the air inlet of the inner hollow storage pipe, and the exhaust end of the outer expansion pipe is connected to the exhaust outlet of the inner hollow storage pipe.

[0006] Preferably, the end of the outer expansion pipe away from the exhaust of the inner hollow storage pipe extends to the outer wall of the central air guide pipe and is integrally formed with the central air guide pipe, and one end of the central air guide pipe is provided with a flow guide port.

[0007] Preferably, sealing rings are installed on both the left and right inner walls of the hollow storage tube, and the two sealing rings are respectively located at the ends of the central air guide tube and the outer expansion tube that are far apart from each other.

[0008] Preferably, a switching valve is installed on one side of the top end of the external corrugated noise reduction tube, and the discharge pipe of the switching valve extends into the noise reduction cavity.

[0009] Preferably, an annular stainless steel tightening sleeve is fitted on the outer wall of the hollow storage tube, and the inner wall of the annular stainless steel tightening sleeve abuts against the outermost ceramic fiber blanket.

[0010] Compared with the prior art, the beneficial effects of this utility model are: the staged noise reduction structure of the vacuum pump unit allows the airflow to pass through the double-layer interval exhaust structure, which first slows down and expands the airflow, reducing the generation of noise. Then, the sound waves are further absorbed and reflected in the asphalt-based damping rubber layer and the inner hollow storage tube, reducing the propagation of the sound waves. The application of ceramic fiber blanket provides an effective absorption space for low-frequency noise. Finally, the outer corrugated noise reduction tube completes the scattering and attenuation of sound waves through its unique structure.

[0011] The double-layered, spaced-out exhaust structure alters the airflow path and speed, causing sound waves to be repeatedly reflected and refracted in different layers of material, thus effectively suppressing high-frequency noise. Meanwhile, the asphalt-based damping rubber in the inner hollow storage tube is specifically designed to absorb low-frequency sound waves and reduce their propagation efficiency. The addition of ceramic fiber blankets provides additional absorption space for low-frequency sound waves, further enhancing the control of low-frequency noise. Finally, the outer corrugated noise reduction tube effectively scatters and reflects sound waves, thereby significantly reducing the exhaust noise of the vacuum pump and improving the working environment at the vacuum pump unit. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the main structure of this utility model;

[0013] Figure 2 This is a schematic diagram of the front cross-sectional structure of this utility model;

[0014] Figure 3 This is a three-dimensional structural diagram of the present invention;

[0015] Figure 4 This is a three-dimensional cross-sectional structural diagram of the present invention;

[0016] Figure 5 This is a three-dimensional cross-sectional view of the hollow storage tube of this utility model.

[0017] In the diagram: 1. Outer corrugated noise reduction pipe; 2. Inner hollow storage pipe; 201. Noise reduction chamber; 3. Double-layer interval exhaust structure; 301. Centrally placed air guide pipe; 302. Outer expansion pipe; 303. Air guide hole; 304. Flow guide port; 4. Sealing ring; 5. Switch valve; 6. Ceramic fiber blanket; 7. Annular stainless steel tightening sleeve. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0019] Please see Figure 1-5An embodiment of this utility model provides a graded noise reduction structure for a vacuum pump unit, including an outer corrugated noise reduction pipe 1, an inner hollow storage pipe 2 fixedly installed inside the outer corrugated noise reduction pipe 1, and a double-layer interval exhaust structure 3 installed at the central axis position inside the inner hollow storage pipe 2. The air inlet and exhaust end of the double-layer interval exhaust structure 3 are respectively connected to the air inlet and exhaust outlet of the inner hollow storage pipe 2. The air inlet and exhaust outlet of the inner hollow storage pipe 2 both extend to the outside of the outer corrugated noise reduction pipe 1. A noise reduction cavity 201 is provided between the inner hollow storage pipe 2 and the double-layer interval exhaust structure 3. The noise reduction cavity 201 is filled with asphalt-based damping adhesive. At least one layer of ceramic fiber blanket 6 is bonded to the outer wall surface of the inner hollow storage pipe 2.

[0020] The double-layer interval exhaust structure 3 includes an outer expansion pipe 302 fixed on the left and right inner walls of the inner hollow storage pipe 2, a central air guide pipe 301, and an air guide hole 303 provided on the outer wall of the central air guide pipe 301 for communicating with the outer expansion pipe 302. The air inlet end of the central air guide pipe 301 is connected to the air inlet of the inner hollow storage pipe 2, and the exhaust end of the outer expansion pipe 302 is connected to the exhaust port of the inner hollow storage pipe 2.

[0021] The airflow enters the central air guide pipe 301 through the air inlet of the inner hollow storage pipe 2. At this time, the airflow is forced to slow down in the central air guide pipe 301 and enters the outer expansion pipe 302 through several air guide holes 303. The outer expansion pipe 302 guides the airflow to the outside of the noise reduction structure, thereby reducing noise by changing the path and velocity of the airflow.

[0022] The outer expansion pipe 302 extends to the outer wall of the central air guide pipe 301 at the end away from the inner hollow storage pipe 2 and is integrally formed with the central air guide pipe 301. A guide port 304 is provided at one end of the central air guide pipe 301, and the guide port 304 serves to accelerate the airflow.

[0023] Sealing rings 4 are installed on the left and right inner walls of the hollow storage pipe 2. The two sealing rings 4 are located at the far ends of the central air guide pipe 301 and the outer expansion pipe 302, respectively. A switch valve 5 is installed on one side of the top of the outer corrugated noise reduction pipe 1. The discharge pipe of the switch valve 5 extends into the noise reduction chamber 201. The operator can open the switch valve 5 and add asphalt-based damping adhesive into the noise reduction chamber 201 of the hollow storage pipe 2 through the switch valve 5 until the entire chamber is filled with asphalt-based damping adhesive. During this process, the sealing rings 4 play a role in strengthening the sealing of the ends of the outer expansion pipe 302 and the central air guide pipe 301, preventing the asphalt-based damping adhesive from entering the outer expansion pipe 302 and the central air guide pipe 301.

[0024] An annular stainless steel tightening sleeve 7 is fitted on the outer wall of the inner hollow storage tube 2. The inner wall of the annular stainless steel tightening sleeve 7 abuts against the outermost ceramic fiber blanket 6. The high temperature resistance of the ceramic fiber blanket 6 enables it to be used for a long time in high temperature environment, ensuring the stability and durability of the noise reduction effect. The annular stainless steel tightening sleeve 7 wraps around the outside of the ceramic fiber blanket 6 to maintain the structural stability of the ceramic fiber blanket 6.

[0025] In this embodiment, the air inlet of the hollow storage tube 2 is first installed to the exhaust pipe of the vacuum pump via a flange. When the vacuum pump operates and exhausts gas, the gas enters the double-layered interval exhaust structure 3 through the air inlet of the hollow storage tube 2. At this time, the airflow has a high velocity and kinetic energy. However, after entering the double-layered interval exhaust structure 3, the airflow is forced to slow down. Due to the deceleration and expansion of the airflow, the energy of the sound wave is effectively dispersed and attenuated, thereby reducing the intensity of the exhaust noise. The decelerated airflow is finally discharged through the exhaust port of the hollow storage tube 2. The asphalt-based damping rubber located inside the hollow storage tube 2 and wrapped around the outer wall of the double-layered interval exhaust structure 3 can effectively absorb the energy of the sound wave. That is, when the airflow passes through the double-layered interval exhaust structure 3, the sound wave will interact with the asphalt-based damping rubber layer. The asphalt-based damping adhesive reduces the reflection and propagation of sound waves, effectively isolating vibrations and reducing the transmission of mechanical noise. When sound waves enter the inner hollow storage pipe 2, some sound waves are reflected inside the pipe, forming an interference phenomenon, which further reduces the intensity of the sound waves. When sound waves penetrate the inner hollow storage pipe 2 and the ceramic fiber blanket 6, the propagation speed of the sound waves is slowed down again due to the fiber structure of the materials, thus achieving sound wave attenuation. The outer corrugated noise reduction pipe 1 is the last link in the outer protection and sound wave treatment. The outer corrugated noise reduction pipe 1 not only enhances the structural strength of the pipe, but also effectively scatters and reflects sound waves through its corrugated shape. That is, when sound waves enter the outer corrugated noise reduction pipe 1, they are interfered with by the corrugations, and the propagation path of the sound waves is changed, thereby achieving the dispersion and attenuation of sound wave energy, thus forming a complete noise reduction process.

[0026] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A staged noise reduction structure for a vacuum pump unit, characterized in that: The device includes an outer corrugated noise reduction pipe (1), an inner hollow storage pipe (2) fixedly installed inside the outer corrugated noise reduction pipe (1), and a double-layer interval exhaust structure (3) installed at the central axis position inside the inner hollow storage pipe (2). The air inlet and exhaust end of the double-layer interval exhaust structure (3) are connected to the air inlet and exhaust outlet of the inner hollow storage pipe (2), respectively. The air inlet and exhaust outlet of the inner hollow storage pipe (2) both extend to the outside of the outer corrugated noise reduction pipe (1). A noise reduction cavity (201) is provided between the inner hollow storage pipe (2) and the double-layer interval exhaust structure (3). The noise reduction cavity (201) is filled with asphalt-based damping adhesive. At least one layer of ceramic fiber blanket (6) is bonded to the outer wall surface of the inner hollow storage pipe (2).

2. The staged noise reduction structure for the vacuum pump unit according to claim 1, characterized in that: The double-layer interval exhaust structure (3) includes an outer expansion pipe (302), a central air guide pipe (301), and an air guide hole (303) provided on the outer wall of the central air guide pipe (301) for communicating with the outer expansion pipe (302). The air inlet end of the central air guide pipe (301) is connected to the air inlet of the inner hollow storage pipe (2), and the exhaust end of the outer expansion pipe (302) is connected to the exhaust port of the inner hollow storage pipe (2).

3. The staged noise reduction structure for the vacuum pump unit according to claim 2, characterized in that: The outer expansion pipe (302) extends away from the inner hollow storage pipe (2) to the outer wall of the central air guide pipe (301) and is integrally formed with the central air guide pipe (301). One end of the central air guide pipe (301) is provided with a flow guide port (304).

4. The staged noise reduction structure for the vacuum pump unit according to claim 2, characterized in that: Sealing rings (4) are installed on the left and right inner walls of the hollow storage pipe (2). The two sealing rings (4) are located at opposite ends of the central air guide pipe (301) and the outer expansion pipe (302).

5. The staged noise reduction structure for the vacuum pump unit according to claim 1, characterized in that: A switching valve (5) is installed on one side of the top of the external corrugated noise reduction tube (1), and the discharge pipe of the switching valve (5) extends into the noise reduction cavity (201).

6. The staged noise reduction structure for the vacuum pump unit according to claim 1, characterized in that: The outer wall of the hollow storage tube (2) is fitted with an annular stainless steel tightening sleeve (7), and the inner wall of the annular stainless steel tightening sleeve (7) abuts against the outermost ceramic fiber blanket (6).

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