Screw vacuum pump exhaust muffler

Abstract

The utility model belongs to screw vacuum pump technical field, concretely relates to screw vacuum pump exhaust muffler. In view of the deficiency that the existing screw vacuum pump exhaust muffler fails to better give consideration to the sound attenuation effect and volume, the utility model adopts the following technical scheme: the screw vacuum pump exhaust muffler includes: cylinder, has annular wall, air inlet end wall and air outlet end wall, air inlet, exhaust port, first baffle, along the radial setting of cylinder, first pipeline, second baffle, along the radial setting of cylinder, second pipeline, first baffle is close to air inlet, second baffle is close to exhaust port, and first baffle and second baffle divide the cylinder into axially distributed air inlet chamber, middle chamber and air outlet chamber, first pipeline is connected with air inlet chamber and air outlet chamber, and second pipeline is connected with middle chamber and exhaust port, and the screw vacuum pump exhaust muffler still includes the return channel that is connected with middle chamber and air outlet chamber, the utility model has the advantages of: the sound attenuation path is longer and the structure is relatively compact.

Description

Technical Field

[0001] This utility model belongs to the field of screw vacuum pump technology, specifically relating to a screw vacuum pump exhaust silencer. Background Technology

[0002] During operation, screw vacuum pumps generate pulse noise due to their periodic exhaust characteristics. Therefore, an exhaust silencer needs to be connected to the exhaust end of the screw vacuum pump to reduce noise. This is especially true when the screw vacuum pump is installed in production lines, cleanrooms, or other areas with workers, where the requirements for the exhaust silencer are even higher. Furthermore, sometimes the medium handled by screw vacuum pumps contains dust; therefore, resistive material silencers are not suitable.

[0003] Existing exhaust silencers for screw vacuum pumps still have room for improvement in terms of noise reduction effect and / or structural complexity.

[0004] As disclosed in CN 221703916 U, a vacuum pump exhaust port silencer includes a shell, an inner cylinder, a through hole, a flow guiding structure disposed in the inner cylinder, a gas flow channel, a receiving cavity, sound-absorbing cotton disposed in the receiving cavity, an inlet pipe disposed on the shell, an outlet pipe disposed on the shell, and a one-way valve disposed on the inner wall of the shell; the one-way valve is used to restrict the gas from flowing unidirectionally from the inlet pipe into the gas flow channel; the flow guiding structure is used to guide the gas in the gas flow channel to the through hole. The silencer described in utility model CN ​​221703916 U, by setting a one-way valve, allows gas to flow only from the inlet pipe to the receiving cavity, effectively preventing dust or impurities from being drawn back into the vacuum pump from the inlet pipe, thus avoiding damage or wear to the vacuum pump. This reduces noise from the gas discharged from the vacuum pump while improving its service life. However, it has multiple layers inside and out, making its structure relatively complex and difficult to manufacture. At the same time, it mainly relies on resistive silencers (expansion chamber silencers or expansion chamber silencers), resulting in poor noise reduction.

[0005] As disclosed in patent application CN 219605572 U, a noise-reducing screw vacuum pump includes a screw vacuum pump body and an exhaust port. The exhaust port is located on one side of the pump body. A noise reduction mechanism includes an exhaust pipe, a nylon check valve, a connecting pipe, an external silencer pipe, an outlet, an internal silencer pipe (first and second parts), an internal silencer pipe (third part), and a noise-reducing baffle. One end of the exhaust pipe is fixedly connected to the exhaust port via a flange. The inlet end of the nylon check valve is connected to the flange at the other end of the exhaust pipe. The outlet end of the nylon check valve is fixedly connected to one end of the external silencer pipe via a connecting pipe. While the noise reduction mechanism in patent application CN 219605572 U lacks a multi-layered structure and is relatively simple, it still employs a single reactive silencer structure, resulting in poor noise reduction and a large size. Summary of the Invention

[0006] This invention addresses the shortcomings of existing screw vacuum pump exhaust silencers, which fail to adequately balance noise reduction effect and size. It provides a screw vacuum pump exhaust silencer that improves noise reduction while maintaining a compact size.

[0007] To achieve the above objectives, this utility model adopts the following technical solution: a screw vacuum pump exhaust silencer, wherein the screw vacuum pump exhaust silencer comprises:

[0008] The cylinder has an annular wall, an inlet end wall, and an outlet end wall;

[0009] Air intake;

[0010] Exhaust port;

[0011] The first partition is arranged radially along the cylinder;

[0012] First pipeline;

[0013] The second baffle is arranged radially along the cylinder body;

[0014] Second pipeline;

[0015] The first partition is close to the air inlet, and the second partition is close to the exhaust outlet. The first and second partitions divide the cylinder into an axially distributed air inlet chamber, an intermediate chamber, and an exhaust chamber. The first pipe connects the air inlet chamber and the exhaust chamber, and the second pipe connects the intermediate chamber and the exhaust outlet.

[0016] The screw vacuum pump exhaust silencer also includes a return channel connecting the intermediate chamber and the exhaust chamber.

[0017] This utility model discloses a screw vacuum pump exhaust silencer. Noise enters the intake chamber through the inlet, where it acts as a first-stage expansion chamber, reflecting and interfering with sound waves for initial noise reduction. Noise then enters the exhaust chamber through a first pipe, which acts as a second-stage expansion chamber, reflecting and interfering with sound waves again for secondary noise reduction. Noise returns from the exhaust chamber to the intermediate chamber via a return channel, contributing to noise reduction while maintaining a compact structure. Noise then enters the second pipe from the intermediate chamber and is finally discharged through the exhaust port. The noise reduction path is relatively long, and the structure is quite compact.

[0018] As an improvement, the second partition also has multiple small holes to form the aforementioned return channel, or the second partition is provided with a third pipe that forms the aforementioned return channel.

[0019] As an improvement, the first partition only has a first pipe hole that connects to the first pipe, so that all the gas in the intake chamber can only flow from the first channel to the exhaust chamber.

[0020] As an improvement, an end-wall hole is opened on the outlet end wall of the cylinder, and the diameter of the end-wall hole is smaller than the diameter of the second pipe.

[0021] As an improvement, the diameter of the exhaust port is larger than the diameter of the end wall hole.

[0022] As an improvement, the air inlet end of the first pipe is flush with the first baffle.

[0023] As an improvement, multiple small holes are opened at the outlet end of the first pipe; multiple small holes are opened at the inlet end of the second pipe.

[0024] As an improvement, the first baffle is located near the air inlet and has only a first pipe hole for connecting to the first pipe; the second baffle is located near the exhaust outlet and has a first pipe hole for the first pipe, a second pipe hole for the second pipe, and multiple small holes.

[0025] The cylinder body, air inlet, air outlet, first baffle, first pipe, second baffle and second pipe are all made of stainless steel.

[0026] As an improvement, the screw vacuum pump exhaust silencer also includes a check valve located at the air inlet. The check valve includes a support rod fixed to the cylinder, a valve seat fixed to the support rod, a spring sleeved on the valve seat, and a movable component. The movable component includes a seal, and the spring exerts a force on the movable component to move towards the air inlet.

[0027] As an improvement, the seal is a fluororubber plate, and the movable assembly also includes a movable seat, a valve plate baffle, and an elastic retaining ring. The movable seat is T-shaped, and the fluororubber plate is located between the valve plate baffle and the large diameter part of the movable seat. A groove is opened on the movable seat, and the elastic retaining ring is located in the groove and axially limits the valve plate baffle, the fluororubber plate, and the movable seat.

[0028] As an improvement, the screw vacuum pump exhaust silencer also includes an end cap connected to the air inlet end wall of the cylinder by screws and a sealing ring, with the air inlet located on the end cap and the support rod fixed on the end cap.

[0029] The beneficial effects of this screw vacuum pump exhaust silencer are as follows: After noise enters the intake chamber through the inlet, the intake chamber acts as the first-stage expansion chamber, where sound waves are reflected and interfered, achieving initial noise reduction; the noise enters the exhaust chamber through the first pipe, where the exhaust chamber acts as the second-stage expansion chamber, where sound waves are reflected and interfered again, achieving secondary noise reduction; the noise returns from the exhaust chamber to the intermediate chamber through the return channel, achieving a certain level of noise reduction while also making the structure compact; the noise enters the second pipe from the intermediate chamber and is finally discharged through the exhaust port; the noise reduction path is relatively long and the structure is relatively compact, resulting in a longer noise reduction path for the same volume and a smaller volume for the same noise reduction performance. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the exhaust silencer of the screw vacuum pump according to Embodiment 1 of this utility model.

[0031] Figure 2 This is an exploded view of the screw vacuum pump exhaust silencer according to Embodiment 1 of this utility model.

[0032] Figure 3 This is a cross-sectional view of the screw vacuum pump exhaust silencer according to Embodiment 1 of this utility model.

[0033] In the diagram, 1 is the cylinder body; 11 is the annular wall; 12 is the inlet end wall; 13 is the outlet end wall; and 131 is the end wall hole.

[0034] 2. Air intake;

[0035] 3. Exhaust port;

[0036] 4. First partition;

[0037] 5. First pipeline;

[0038] 6. Second partition;

[0039] 7. Second pipeline;

[0040] 8. End caps;

[0041] 9. Check valve; 91. Support rod; 92. Valve seat; 93. Spring; 94. Movable seat; 95. Seal; 96. Valve plate baffle; 97. Elastic retaining ring;

[0042] A. Inlet chamber; B. Outlet chamber; C. Intermediate chamber. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be explained and described below. However, the following embodiments are only preferred embodiments of the present invention and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of the present invention.

[0044] See Figures 1 to 3 The screw vacuum pump exhaust silencer of this utility model embodiment includes:

[0045] The cylinder has an annular wall, an inlet end wall, and an outlet end wall;

[0046] Air intake;

[0047] Exhaust port;

[0048] The first partition is arranged radially along the cylinder;

[0049] First pipeline;

[0050] The second baffle is arranged radially along the cylinder body;

[0051] Second pipeline;

[0052] The first partition is close to the air inlet, and the second partition is close to the exhaust outlet. The first and second partitions divide the cylinder into an axially distributed air inlet chamber, an intermediate chamber, and an exhaust chamber. The first pipe connects the air inlet chamber and the exhaust chamber, and the second pipe connects the intermediate chamber and the exhaust outlet.

[0053] The screw vacuum pump exhaust silencer also includes a return channel connecting the intermediate chamber and the exhaust chamber.

[0054] This utility model discloses a screw vacuum pump exhaust silencer. Noise enters the intake chamber through the inlet, where it acts as a first-stage expansion chamber, reflecting and interfering with sound waves for initial noise reduction. Noise then enters the exhaust chamber through a first pipe, which acts as a second-stage expansion chamber, reflecting and interfering with sound waves again for secondary noise reduction. Noise returns from the exhaust chamber to the intermediate chamber via a return channel, contributing to noise reduction while maintaining a compact structure. Noise then enters the second pipe from the intermediate chamber and is finally discharged through the exhaust port. The noise reduction path is relatively long, and the structure is quite compact.

[0055] Example 1

[0056] See Figures 1 to 3 The screw vacuum pump exhaust silencer of this utility model embodiment includes:

[0057] The cylinder 1 has an annular wall 11, an air inlet end wall 12, and an air outlet end wall 13;

[0058] Air inlet 2;

[0059] Exhaust port 3;

[0060] The first partition 4 is arranged radially along the cylinder 1;

[0061] First pipe 5;

[0062] The second partition 6 is arranged radially along the cylinder 1;

[0063] Second pipe 7;

[0064] The first partition 4 and the second partition 6 divide the cylinder 1 into an axially distributed air inlet chamber A, an intermediate chamber C and an air outlet chamber B. The air inlet end of the first pipe 5 is located in the air inlet chamber A and the air outlet end is located in the air outlet chamber B. The air inlet end of the second pipe 7 is located in the intermediate chamber C and the air outlet end is connected to the exhaust port 3.

[0065] In this configuration, the first baffle 4 is located near the air inlet 2 and has only a first pipe hole connecting to the first pipe 5. The second baffle 6 is located near the exhaust outlet 3 and has a first pipe hole for the first pipe 5, a second pipe hole for the second pipe 7, and multiple small holes. The small holes in the second baffle 6 form a return channel. In other embodiments, a separate third pipe can also be provided as a return channel. By using the small holes in the second baffle 6 to form the return channel, the diameters of the first pipe 5 and the second pipe 7 can be larger under the same conditions, resulting in smoother exhaust. Compared to using a separate third pipe, the small holes in the second baffle 6 provide better noise reduction.

[0066] In this embodiment, an end wall hole 131 is provided on the air outlet end wall 13 of the cylinder 1, and the diameter of the end wall hole 131 is smaller than the diameter of the second pipe 7.

[0067] In this embodiment, the diameter of the exhaust port 3 is larger than the diameter of the end wall hole 131.

[0068] In this embodiment, the air inlet end of the first pipe 5 is flush with the first partition 4.

[0069] In this embodiment, the outlet end of the first pipe 5 has multiple small holes; the inlet end of the second pipe 7 has multiple small holes.

[0070] In this embodiment, the first partition 4 is close to the air inlet 2, and the first partition 4 only has a first pipe hole that connects to the first pipe 5; the second partition 6 is close to the exhaust port 3, and the second partition 6 has a first pipe hole for the first pipe 5, a second pipe hole for the second pipe 7, and multiple small holes.

[0071] In this embodiment, the cylinder 1, air inlet 2, air outlet 3, first partition 4, first pipe 5, second partition 6, and second pipe 7 are all made of stainless steel.

[0072] In this embodiment, the screw vacuum pump exhaust silencer also includes a check valve 9 located at the air inlet 2. The check valve 9 includes a support rod 91 fixed on the cylinder 1, a valve seat 92 fixed to the support rod 91, a spring 93 sleeved on the valve seat 92, and a movable component. The movable component includes a sealing element 95, and the spring 93 exerts a force on the movable component to move towards the air inlet 2.

[0073] In this embodiment, the sealing element 95 is a fluororubber plate, and the movable component also includes a movable seat 94, a valve plate baffle 96, and an elastic retaining ring 97. The movable seat 94 is T-shaped, and the fluororubber plate is located between the valve plate baffle 96 and the large diameter portion of the movable seat 94. A groove is provided on the movable seat 94, and the elastic retaining ring 97 is located in the groove and axially limits the valve plate baffle 96, the fluororubber plate, and the movable seat 94.

[0074] In this embodiment, the screw vacuum pump exhaust silencer also includes an end cover 8 connected to the air inlet end wall 12 of the cylinder 1 by screws and a sealing ring, an air inlet 2 is provided on the end cover 8, and a support rod 91 is fixed on the end cover 8.

[0075] In this embodiment, the stainless steel components can be fixed together by welding.

[0076] The working principle of the screw vacuum pump exhaust silencer in this embodiment is as follows: After the noise (airflow) enters the intake chamber A through the intake port 2, the intake chamber A (larger than the intake port 2) serves as the first-stage expansion chamber. Sound waves are reflected and interfered in the first-stage expansion chamber, achieving initial noise reduction. The noise then enters the exhaust chamber B through the first pipe 5 (most of the noise enters the exhaust chamber B through the large hole in the first pipe 5, and a small portion enters the exhaust chamber B through the small hole in the first pipe 5, where the small hole provides some noise reduction). The exhaust chamber B serves as the second-stage expansion chamber, where sound waves are reflected and interfered again, achieving secondary noise reduction. Furthermore, all the noise passes through the small hole in the second partition 6. The noise has a good silencing effect; the noise enters the intermediate chamber C from the outlet chamber B through the small hole of the second partition 6, which plays a third silencing role and also shifts the sound wave frequency from low frequency to high frequency; the noise enters the second pipe 7 from the intermediate chamber C, and the noise is reflected and interfered in the curved second pipe 7, which plays a fourth silencing role (most of the noise enters through the large hole of the second pipe 7, and a small part enters through the small hole of the second pipe 7, which plays a certain silencing role); after the noise comes out of the second pipe 7, it passes through the end wall hole 131 of the outlet end wall 13 of the cylinder 1. The diameter of the end wall hole 131 is smaller than that of the exhaust port 3, which plays a fifth silencing role, and finally is discharged through the exhaust port 3.

[0077] The beneficial effects of the screw vacuum pump exhaust silencer of Embodiment 1 of this utility model are as follows: After the noise enters the intake chamber A through the intake port 2, the intake chamber A serves as the first-stage expansion chamber, where sound waves are reflected and interfered, achieving a preliminary silencing effect; the noise enters the exhaust chamber B through the first pipe 5, where the exhaust chamber B serves as the second-stage expansion chamber, where sound waves are reflected and interfered again, achieving a secondary silencing effect; the noise returns from the exhaust chamber B to the intermediate chamber C through the small holes of the second partition 6, achieving a certain silencing effect while also shifting the sound wave frequency from low frequency to high frequency. Compared to opening small holes on the side of the pipe where only a small amount of noise passes through, all the noise will pass through the small holes of the second partition 6, resulting in a better silencing effect; the noise enters the second pipe 7 from the intermediate chamber C and is finally discharged through the exhaust port 3; the silencing path is relatively long and the structure is relatively compact; the wind resistance is low and the exhaust is smooth; the main body is made of stainless steel, which is easy to process and maintain; dust and other impurities will not or will be adsorbed into the inside of the silencer, making it suitable for handling media containing dust; the check valve 9 is easy to disassemble and assemble.

[0078] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes, but is not limited to, the content described in the above specific embodiments. Any modifications that do not depart from the functional and structural principles of the present invention will be included within the scope of the claims.

Claims

1. A screw vacuum pump exhaust silencer, characterized in that: The screw vacuum pump exhaust silencer includes: The cylinder (1) has an annular wall (11), an inlet end wall (12) and an outlet end wall (13); Air inlet (2); Exhaust port (3); The first partition (4) is arranged radially along the cylinder (1); First pipe (5); The second partition (6) is arranged radially along the cylinder (1); Second pipe (7); Among them, the first partition (4) is close to the air inlet (2), the second partition (6) is close to the exhaust outlet (3), the first partition (4) and the second partition (6) divide the cylinder (1) into an axially distributed air inlet chamber (A), intermediate chamber (C) and air outlet chamber (B), the first pipe (5) connects the air inlet chamber (A) and the air outlet chamber (B), and the second pipe (7) connects the intermediate chamber (C) and the exhaust outlet (3); The screw vacuum pump exhaust silencer also includes a return channel connecting the intermediate chamber (C) and the exhaust chamber (B).

2. The screw vacuum pump exhaust silencer according to claim 1, characterized in that: The second partition (6) also has multiple small holes to form the aforementioned return channel, or the second partition (6) is provided with a third pipe, which forms the aforementioned return channel.

3. The screw vacuum pump exhaust silencer according to claim 1, characterized in that: The first partition (4) has only a first pipe hole for connecting the first pipe (5).

4. The screw vacuum pump exhaust silencer according to claim 1, characterized in that: An end wall hole (131) is provided on the outlet end wall (13) of the cylinder (1), and the diameter of the end wall hole (131) is smaller than the diameter of the second pipe (7); and / or, The diameter of the vent (3) is larger than the diameter of the end wall hole (131); and / or, The air inlet end of the first pipe (5) is flush with the first partition (4).

5. The screw vacuum pump exhaust silencer according to claim 1, characterized in that: The first pipe (5) has multiple small holes at its outlet end; the second pipe (7) has multiple small holes at its inlet end.

6. The screw vacuum pump exhaust silencer according to claim 1, characterized in that: The first pipe (5) is a straight pipe; the second pipe (7) is a bent pipe.

7. The screw vacuum pump exhaust silencer according to claim 1, characterized in that: The cylinder (1), air inlet (2), exhaust outlet (3), first baffle (4), first pipe (5), second baffle (6) and second pipe (7) are all made of stainless steel.

8. The screw vacuum pump exhaust silencer according to any one of claims 1 to 7, characterized in that: The screw vacuum pump exhaust silencer also includes a check valve (9) located at the air inlet (2). The check valve (9) includes a support rod (91) fixed on the cylinder (1), a valve seat (92) fixed to the support rod (91), a spring (93) sleeved on the valve seat (92), and a movable component. The movable component includes a seal (95), and the spring (93) exerts a force on the movable component to move towards the air inlet (2).

9. The screw vacuum pump exhaust silencer according to claim 8, characterized in that: The sealing element (95) is a fluororubber plate. The movable component also includes a movable seat (94), a valve plate baffle (96), and an elastic retaining ring (97). The movable seat (94) is T-shaped. The fluororubber plate is located between the valve plate baffle (96) and the large diameter portion of the movable seat (94). A groove is opened on the movable seat (94). The elastic retaining ring (97) is located in the groove and axially limits the valve plate baffle (96), the fluororubber plate, and the movable seat (94).

10. The screw vacuum pump exhaust silencer according to claim 8, characterized in that: The screw vacuum pump exhaust silencer also includes an end cover (8) connected to the air inlet end wall (12) of the cylinder (1) by screws and a sealing ring. The air inlet (2) is located on the end cover (8), and the support rod (91) is fixed on the end cover (8).

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