Air inlet silencing filter for compressor

Abstract

The utility model discloses an air inlet silencing filter for a compressor. The air inlet silencing filter comprises a silencer shell, an air inlet pipe and a silencing pipe, the silencer shell is of a round cup-shaped structure, an opening in the bottom of the silencer shell is sealed through a pipe plate, the air inlet pipes are evenly arranged on the periphery of the inner wall of the silencer shell, and the air inlet ends of the air inlet pipes penetrate through the pipe plate on the bottom face of the silencer shell to be communicated with the outside. The silencing pipe is arranged in the center of the silencer shell, silencing holes are evenly distributed in the pipe wall of the silencing pipe, the top of the silencing pipe is sealed through a sealing plate, and the tail of the silencing pipe is communicated with the exterior of the silencer shell through a connecting pipe.

Description

Technical Field

[0001] This utility model relates to the field of silencers, and in particular to an intake silencer filter for compressors. Background Technology

[0002] Reciprocating compressors are widely used due to their high energy efficiency through multi-stage compression and operating pressure range of 1.0-35.0 MPa. However, fundamentally, their suction process is pulsed, resulting in relatively high suction noise. Reducing the suction noise of reciprocating compressors is a crucial issue for those working in the industry.

[0003] Noise can be measured using sound pressure or sound power. Since sound power is also derived from sound pressure, this article will only use sound pressure to explain it.

[0004] The harm of noise to humans depends not only on the sound pressure level but also on the frequency of the sound; generally, high frequencies are more harmful. Considering the impact of noise on the human body, it is generally desirable for compressor noise to be below 85 dB(A), which has a relatively low impact on human health.

[0005] Our company has designed a combined silencer that combines the functions of a resistive silencer and a reactive silencer, reducing the noise at the intake port of a reciprocating compressor to below 85 dB(A) while also providing a filtering effect. Summary of the Invention

[0006] The problem to be solved by this utility model is to propose an improvement or replacement solution to address the shortcomings of the prior art, especially an improvement or replacement solution that improves the noise reduction effect and has a filtering effect.

[0007] To solve the above problems, the present invention adopts the following solution: an intake silencer filter for a compressor, characterized in that the intake silencer filter includes a silencer housing, an intake pipe, and a silencer tube; the silencer housing has a circular cup-shaped structure, and its bottom opening is sealed with a tube sheet; the intake pipe is evenly arranged around the inner wall of the silencer housing, and the intake end of the intake pipe passes through the tube sheet on the bottom surface of the silencer housing and connects to the outside; the silencer tube is located in the center of the silencer housing, and its tube wall is evenly distributed with silencer holes; the top of the silencer tube is sealed with a sealing plate, and the tail end is connected to the outside of the silencer housing through a connecting pipe.

[0008] Furthermore, the intake silencer filter for the compressor is characterized in that a central filter element is provided inside the silencer housing; the central filter element has a cup-shaped structure and is inverted on the silencer pipe.

[0009] Furthermore, the intake silencer filter for the compressor is characterized in that the length of the intake pipe is greater than 2 / 3 of the length of the silencer filter housing.

[0010] Furthermore, the intake silencer filter for the compressor is characterized in that a hexagonal head bolt is provided on the sealing plate at the top of the silencer pipe, and a matching through hole and sealing ring are provided on the top of the silencer housing, with the hexagonal head bolt passing through the top of the silencer housing and being fixed.

[0011] Furthermore, the intake silencer filter for the compressor is characterized in that the diameter of the intake pipe is 1 / 20 of the diameter of the silencer housing, and the diameter of the silencer pipe is 1 / 3 of the diameter of the silencer housing.

[0012] Furthermore, the intake silencer filter for the compressor is characterized in that a clamp is provided at the connection between the silencer housing and the tube sheet, and is welded to both the silencer housing and the tube sheet to strengthen the connection between the silencer housing and the tube sheet.

[0013] Furthermore, the intake silencer filter for the compressor is characterized in that the connecting pipe has a flange at its tail end for sealing connection with the compressor.

[0014] Furthermore, the intake silencer filter for the compressor is characterized in that a bend is provided between the connecting pipe and the compressor, and the bend is bent at 90°.

[0015] The technical effects of this invention are as follows: The intake pipe is a single pipe with a small orifice. Multiple intake pipes are provided within each muffler housing, evenly distributed on the inner wall of the muffler housing. External air enters the muffler housing through these small-diameter intake pipes. The remaining cavity within the muffler housing (the space between the muffler pipe and the inner wall of the muffler housing) is equivalent to a Helmholtz resonator, with the inlet of the intake pipe connected to the Helmholtz resonator. By appropriately designing the cross-sectional area and length of the intake pipe and the cavity volume (resonator), the phase of the sound waves is disrupted, resulting in sound reduction. Maximum noise reduction can be achieved within a very narrow frequency range.

[0016] At the same time, the combination of the intake pipe and the muffler housing allows noise of certain frequencies to be reflected back to the sound source or absorbed significantly, thus playing a role in resistive noise reduction.

[0017] Meanwhile, the centrally located filter element on the silencer pipe also plays a role in resistive noise reduction. External air passes through the non-woven fabric air filter element with a filtration accuracy of 4μm, eliminating noise and filtering out particles larger than 4μm in the atmosphere to ensure the cleanliness of the air drawn into the compressor.

[0018] When the air inside the muffler housing passes through the central filter element, it enters the muffler tube through the silencing holes on the muffler tube. The change in volume causes noise of certain specific frequencies to be reflected back to the sound source or to be absorbed significantly, thus playing a role in noise reduction.

[0019] This application divides the entire air intake duct into an intake pipe and a muffler pipe, with the disconnection point located inside the muffler housing, i.e., an extended cavity is provided at the disconnection point, and improvements are made to the intake pipe, muffler pipe, and cavity.

[0020] Single-cavity expansion silencer, this is the simplest reactive silencer, with a noise reduction of:

[0021]

[0022] K-------Proportionality coefficient

[0023] As can be seen from the formula, the maximum noise reduction occurs when sinKl2=1, that is... Where n = 1, 2, 5, ...,

[0024] again α--------Speed ​​of sound, m / s, w--------Angular velocity of the compressor, w=2πf

[0025] so,

[0026] f n It is the maximum silencing frequency; the larger l2 is, the higher f becomes. n It moves towards lower frequencies.

[0027] It can also be seen from the formula that if sinKl2=0, then △L w =0, meaning the muffler is not effective in reducing noise. In this case:

[0028] muffler for f p The frequency has no effect. That is, it allows f to... p This frequency is acceptable.

[0029] To address the issue of missing certain frequencies, this design employs an insertion tube method.

[0030] 1) If the inlet (silencer pipe) and outlet (inlet) are designed in the same direction, then the length l2 through which the airflow passes in the silencer is twice the length l of the silencer, that is, l2 = 2l.

[0031] 2) The air inlet is designed to consist of several tubes, the length of which is... The flow passage cross section is S, and nS = S (flow passage cross section of the silencer).

[0032] 3) The air outlet is designed to consist of a single tube, the length of which is... The flow passage cross section is S.

[0033] when At that time, it can be eliminated The frequency when n is an odd number.

[0034] when When n is even, the frequency of passing through can be eliminated.

[0035] When the length of one end is The length of the other end is When the insertion length is (indicated by insertion length), a noise reduction curve with no passing frequency can be obtained, which means that it has a noise reduction effect on sound waves of any frequency.

[0036] An air filter is installed between the intake and exhaust pipes.

[0037] The ingenuity of this design lies in:

[0038] The air inlet and outlet are in the same direction, reducing the volume by half;

[0039] The air inlet uses multiple tubes, which meets the requirements of the flow cross-section without significantly increasing the volume.

[0040] The filter element is accurately positioned, easy to install, and convenient to replace. Its design structure is completely consistent with theoretical principles.

[0041] It has a noise-absorbing effect on sound waves of any frequency. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the intake silencer filter structure.

[0043] Figure 2 for Figure 1 Cross-sectional view along direction A.

[0044] Figure 3 for Figure 1 Cross-sectional view along the B direction.

[0045] Among them, 1 is flange, 2 is connecting pipe, 3 is tube sheet, 4 is clamp, 5 is air inlet pipe, 6 is silencer pipe, 7 is silencer housing, 8 is sealing plate, and 9 is hexagonal head bolt. Detailed Implementation

[0046] The present invention will now be described in further detail with reference to the accompanying drawings.

[0047] An intake silencer filter for a compressor includes a silencer housing, an intake pipe, and a silencer tube. The silencer housing has a circular cup-shaped structure, with its bottom opening sealed by a tube sheet. The intake pipe is evenly arranged around the inner wall of the silencer housing, and its intake end passes through the tube sheet on the bottom surface of the silencer housing to connect with the outside. The silencer tube is located in the center of the silencer housing, with silencer holes evenly distributed on its wall. The top of the silencer tube is sealed by a sealing plate, and its tail is connected to the outside of the silencer housing via a connecting pipe. A central filter element is provided inside the silencer housing. The central filter element has a cup-shaped structure and is inverted on the silencer tube. The length of the intake pipe is specified. The length of the silencer is greater than 2 / 3 of the length of the silencer filter housing; the sealing plate at the top of the silencer pipe is equipped with hexagonal head bolts, and the top of the silencer housing is equipped with matching through holes and sealing rings. The hexagonal head bolts pass through the top of the silencer housing and are fixed in place; the diameter of the air inlet pipe is 1 / 20 of the diameter of the silencer housing, and the diameter of the silencer pipe is 1 / 3 of the diameter of the silencer housing; a clamp is provided at the connection between the silencer housing and the tube sheet, and is welded to both the silencer housing and the tube sheet to strengthen the connection between them; a flange is provided at the end of the connecting pipe for sealing connection with the compressor; a bend is provided between the connecting pipe and the compressor, and the bend is bent at 90°.

[0048] Let the total flow cross-sectional area of ​​the muffler be S, the diameter of the muffler's intake pipe be d, and the number of pipes be n. After determining the diameter and number of intake pipes, then determine the diameter of the muffler housing.

[0049] Let the diameter of the silencer pipe be d0, then

[0050] An intake silencer filter is installed at the compressor's air inlet. Outside air enters the silencer housing through the intake pipe, a small-diameter pipe connected to a cavity within the silencer housing. Based on the principle of reactive silencing, noise of certain frequencies is reflected back to the sound source or significantly absorbed. Simultaneously, the intake pipe, silencer housing, and silencer tube form a resonant silencer. Adjusting the diameter and length of the intake pipe causes phase repulsion of sound waves, achieving maximum noise reduction.

[0051] The centrally located filter between the intake pipe and the muffler allows outside air to pass through a non-woven fabric filter with a filtration accuracy of 4µm, eliminating noise. At the same time, it filters out particles larger than 4µm from the atmosphere, ensuring the cleanliness of the air drawn into the compressor.

[0052] Above the air outlet, an elbow is designed. At the end of the elbow and on the compressor inlet flange, a reducing connector is also designed. The diameter of the reducing elbow suddenly increases when it enters the compressor suction port. These designs are equivalent to changing the acoustic impedance. When the sound wave passes through the interface of different acoustic impedance, part of the sound energy is reflected back, similar to the reflection of light waves through different interfaces.

[0053] An air filter is installed between the intake and exhaust pipes.

[0054] The ingenuity of this design lies in the fact that the air inlet and outlet are in the same direction, reducing the volume by half; the air inlet uses multiple tubes to meet the flow cross-section requirements without significantly increasing the volume. The filter element is accurately positioned, easy to install, and convenient to replace. Its design structure is completely consistent with theoretical principles.

Claims

1. An intake silencer filter for a compressor, characterized in that, The intake silencer filter includes a silencer housing (7), an intake pipe (5), and a silencer pipe (6); the silencer housing (7) has a circular cup-shaped structure, and its bottom opening is sealed with a tube plate (3). The intake pipe (5) is evenly arranged around the inner wall of the silencer housing (7). The intake end of the intake pipe (5) passes through the tube plate (3) on the bottom surface of the silencer housing (7) and is connected to the outside. The silencer pipe (6) is located in the center of the silencer housing (7). The silencer holes are evenly distributed on its pipe wall. The top of the silencer pipe (6) is sealed with a sealing plate (8), and the tail is connected to the outside of the silencer housing (7) through a connecting pipe (2).

2. The intake silencer filter for a compressor according to claim 1, characterized in that, The muffler housing (7) is provided with a central filter element (10); the central filter element (10) has a cup-shaped structure and is upside down on the muffler pipe (6).

3. The intake silencer filter for a compressor according to claim 1, characterized in that, The length of the intake pipe (5) is greater than 2 / 3 of the length of the muffler housing (7).

4. The intake silencer filter for a compressor according to claim 1, characterized in that, The sealing plate (8) at the top of the silencer pipe (6) is provided with a hexagonal head bolt (9), and the top of the silencer housing (7) is provided with a matching through hole and sealing ring. The hexagonal head bolt (9) passes through the top of the silencer housing (7) and is fixed.

5. The intake silencer filter for a compressor according to claim 1, characterized in that, The diameter of the air intake pipe is 1 / 20 of the diameter of the muffler housing, and the diameter of the muffler pipe is 1 / 3 of the diameter of the muffler housing.

6. The intake silencer filter for a compressor according to claim 1, characterized in that, A clamp (4) is provided at the connection between the muffler housing (7) and the tube sheet (3), and is welded to both the muffler housing (7) and the tube sheet (3) to strengthen the connection between the muffler housing (7) and the tube sheet (3).

7. The intake silencer filter for a compressor according to claim 1, characterized in that, The connecting pipe (2) is provided with a flange (1) at its tail end for sealing connection with the compressor.

8. The intake silencer filter for a compressor according to claim 1, characterized in that, A bend is provided between the connecting pipe (2) and the compressor. The bend is bent at 90° to further reduce noise.

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