Nitrogen generator exhaust gas exhaust device

Abstract

The utility model discloses a kind of nitrogen generator exhaust gas exhaust devices, including the exhaust pipe of composite noise reduction pipe, it has air inlet pressure reduction section, porous diffusion sound attenuation section and exhaust flow stabilizing section in turn coaxially communicated along air inlet to air outlet direction.Porous diffusion sound attenuation section has interlayer by outer tube wall and perforated inner tube wall, interlayer fills porous sound-absorbing material and is provided with resonance bottle cavity tube, the neck of this resonance bottle cavity tube is connected with perforation to form Helmholtz resonance cavity.The outlet of exhaust flow stabilizing section is equipped with honeycomb flow stabilizer.The utility model realizes the pressure and flow rate reduction of source by gradually expanding air inlet pressure reduction section;Combining the resistance sound attenuation of porous sound-absorbing material and the resistance sound attenuation of Helmholtz resonance cavity, the efficient absorption to wideband noise, especially difficult to handle low-frequency noise is realized;Finally, secondary noise is suppressed by honeycomb flow stabilizer, compact structure, noise reduction effect is remarkable, especially suitable for nitrogen generator periodic high-pressure exhaust gas discharge operating condition.

Description

Technical Field

[0001] This utility model relates to the field of noise reduction technology for nitrogen generator exhaust gas, specifically a nitrogen generator exhaust gas device. Background Technology

[0002] During operation, to ensure the regeneration of the molecular sieve and the stability of the system pressure, the nitrogen generator needs to periodically and rapidly discharge the residual gas enriched with oxygen and other components (commonly referred to as "desorption waste gas" or "venting waste gas") into the atmosphere through an exhaust device. It is important to note that the "waste gas" mentioned here does not refer to gas containing harmful pollutants that requires purification. Its main components are nitrogen, oxygen, and a small amount of argon, which are essentially clean air components, and the emission itself does not cause chemical pollution to the environment.

[0003] However, the emission process of such exhaust gases presents significant challenges. Due to the high emission pressure and high flow rate, the gas generates strong broadband aerodynamic noise in the pipes and at the outlet, with sound pressure levels often reaching 100-120 decibels or even higher. This high-intensity noise not only severely pollutes the working environment and affects the physical and mental health of operators, but also violates increasingly stringent industrial noise emission standards.

[0004] In existing technologies, common methods for dealing with exhaust noise from nitrogen generators are rather simplistic and crude, typically involving simply wrapping the exhaust pipe with a layer of noise-reducing cotton or installing a soundproof cover. This approach is primarily effective in suppressing mid-to-high frequency noise, but its noise reduction effect is very limited for the mid-to-low frequency components that constitute the majority of exhaust noise energy, especially the low-frequency noise generated by high-speed airflow impact and turbulence.

[0005] Therefore, we propose a nitrogen generator exhaust device. Utility Model Content

[0006] (a) Technical problems to be solved To address the shortcomings of existing technologies, this utility model provides a nitrogen generator exhaust device. Through the three-stage synergistic effect of intake pressure reduction, composite silencing (combination of resistive and reactive) and exhaust flow stabilization, it achieves efficient suppression of broadband noise, especially low-frequency noise, from the high-pressure exhaust of the nitrogen generator, effectively solving the problems in the background technology.

[0007] (II) Technical Solution To achieve the above objectives, the technical solution adopted by this utility model is as follows: a nitrogen generator exhaust device, comprising an exhaust pipe, wherein the exhaust pipe is a composite noise reduction pipe, which sequentially includes an intake pressure reducing section, a porous diffusion silencing section, and an exhaust flow stabilizing section coaxially connected and internally interconnected along the intake direction to the exhaust direction; the porous diffusion silencing section includes an outer pipe wall and an inner pipe wall, an interlayer is provided between the inner wall of the outer pipe wall and the outer wall of the inner pipe wall, the interlayer is filled with porous sound-absorbing material, the inner wall of the inner pipe wall has a perforation, a resonant cavity tube is provided in the interlayer, the bottleneck of the resonant cavity tube is fixedly connected to the perforation, and the resonant cavity tube is wrapped with porous sound-absorbing material; the outlet end of the exhaust flow stabilizing section is connected to the atmosphere, and a honeycomb flow stabilizer is fixedly installed at the lower end of the inner cavity of the exhaust flow stabilizing section.

[0008] Preferably, the diameter of the perforations on the inner tube wall ranges from 1 mm to 5 mm, and the opening rate ranges from 30% to 50%.

[0009] Preferably, the inlet end of the air intake pressure reducing section is used to connect to the exhaust gas source of the nitrogen generator, and the cross-sectional area of ​​the flow channel of the air intake pressure reducing section gradually increases along the air intake direction, forming a gradually expanding structure.

[0010] Preferably, the porous sound-absorbing material is one of glass wool, rock wool, sintered metal fiber, or foam ceramic.

[0011] Preferably, the cross-sectional area of ​​the resonant bottle cavity tube is larger than the cross-sectional area of ​​its bottleneck, forming a Helmholtz resonant cavity.

[0012] Preferably, the cross-sectional area of ​​the intake decompression section gradually increases along the intake direction, and the cone angle of the resulting gradually expanding structure is 8° to 15°.

[0013] (III) Beneficial Effects Compared with the prior art, the present invention provides a nitrogen generator exhaust device, which has the following beneficial effects: 1. This nitrogen generator exhaust device, through a three-section composite structure of an intake pressure reducing section, a porous diffusion silencing section and an exhaust flow stabilizing section, achieves multi-stage and synergistic noise reduction targeting different mechanisms of exhaust noise generation; the intake pressure reducing section, through its gradually expanding structure, effectively reduces the initial pressure and flow velocity of exhaust gas when it enters the device, weakening the airflow impact energy at the source and laying the foundation for subsequent noise reduction.

[0014] 2. The nitrogen generator exhaust device, by setting a sandwich structure filled with porous sound-absorbing material in the porous diffusion silencing section and combining it with the perforated inner pipe wall, constructs a resistive silencing unit, which can efficiently and broadband absorb the mid-to-high frequency noise components in the depressurized exhaust gas.

[0015] 3. The exhaust gas device for a nitrogen generator forms a Helmholtz resonant cavity structure by setting a resonant bottle cavity tube connected to the perforation in the interlayer of the porous diffusion silencing section. This structure has a significant selective absorption effect on low-frequency noise of a specific frequency, effectively making up for the shortcomings of resistive silencing in the low-frequency range, and achieving targeted reduction of broadband noise, especially difficult-to-treat low-frequency noise.

[0016] 4. This nitrogen generator exhaust device, by setting a honeycomb flow stabilizer at the outlet end of the exhaust flow stabilization section, can effectively streamline the outlet airflow, reduce the generation of turbulence and vortex, further suppress the secondary noise caused by airflow disturbance, improve exhaust stability, and reduce the risk of exhaust whistling.

[0017] 5. This nitrogen generator exhaust device organically integrates resistive noise reduction (porous sound-absorbing material) and reactive noise reduction (Helmholtz resonant cavity, structural abrupt interface) into the same pipe section. It has a compact structure and achieves efficient broadband noise reduction effect in a limited space. It is particularly suitable for the working conditions of periodic high-pressure exhaust gas emission from nitrogen generators. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of a nitrogen generator exhaust device according to the present invention.

[0019] Figure 2 This is a schematic diagram of the porous diffusion and silencing section in a nitrogen generator exhaust device according to the present invention.

[0020] Figure 3 This is a side cross-sectional view of the porous diffusion silencing section in a nitrogen generator exhaust device according to the present invention.

[0021] Figure 4 This is a schematic diagram of the exhaust flow stabilization section in a nitrogen generator exhaust device according to the present invention.

[0022] In the diagram: 1. Intake decompression section; 2. Porous diffusion silencing section; 3. Exhaust flow stabilization section; 4. Outer pipe wall; 5. Inner pipe wall; 6. Perforation; 7. Resonance bottle cavity tube; 8. Porous sound-absorbing material; 9. Honeycomb flow stabilizer. Detailed Implementation

[0023] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0024] like Figure 1-4 As shown, this utility model provides a nitrogen generator exhaust device, including an exhaust pipe, which is a composite noise reduction pipe. Along the air intake direction to the air outlet direction, it includes an intake pressure reducing section 1, a porous diffusion silencing section 2, and an exhaust flow stabilizing section 3, which are coaxially connected and internally interconnected.

[0025] The cross-sectional area of ​​the inlet depressurization section 1 gradually increases along the inlet direction (i.e., the direction of exhaust gas flow), forming a gradually expanding structure. The cone angle of this gradually expanding structure is preferably between 8° and 15°. The purpose of this design is that when the high-pressure, high-speed nitrogen generator exhaust gas enters the inlet depressurization section 1 from the inlet, the expansion of the flow channel cross-section allows the gas to expand, thereby effectively reducing the initial pressure and velocity of the exhaust gas and weakening the energy of the airflow impact at the noise source. This creates more favorable conditions for the subsequent porous diffusion silencing section 2 to perform deep noise reduction, avoiding direct impact of high-speed airflow on the silencing structure.

[0026] The porous diffusion silencing section 2 is connected downstream of the intake pressure reducing section 1. Its specific structure includes a cylindrical outer tube wall 4 and a coaxially arranged cylindrical inner tube wall 5 inside it. An annular sandwich is formed between the inner wall of the outer tube wall 4 and the outer wall of the inner tube wall 5. This sandwich is filled with a porous sound-absorbing material 8. In this embodiment, the porous sound-absorbing material 8 can be selected from glass wool, rock wool, sintered metal fibers, or foam ceramics. These materials have abundant interconnected micropores, enabling them to efficiently convert sound energy into heat energy.

[0027] A large number of perforations 6 are uniformly formed on the inner wall of the inner tube 5 (i.e., the side facing the airflow channel). The diameter of the perforations 6 is preferably between 1 mm and 5 mm, and the opening ratio (the proportion of the perforated area to the total area of ​​the inner tube wall) is preferably between 30% and 50%. This part of the structure constitutes the main body of the resistive silencer. When the exhaust gas carrying mid-to-high frequency noise passes through the perforated inner tube wall 5, the sound waves enter the interlayer through the perforations 6 and excite the vibration of air molecules inside the porous sound-absorbing material 8. The sound energy is consumed through friction and viscosity, thereby achieving the purpose of absorbing mid-to-high frequency noise.

[0028] To further enhance the elimination of low-frequency noise, several resonant cavity tubes 7 are also installed in the interlayer. The cross-sectional area of ​​the body of the resonant cavity tube 7 is significantly larger than that of its bottleneck, thus forming a typical Helmholtz resonant cavity structure. The bottleneck of the resonant cavity tube 7 is fixedly connected to and remains open to the perforations 6 on the inner tube wall 5, allowing the cavity of the resonant cavity tube 7 to be connected to the main airflow channel through the bottleneck and perforations 6. At the same time, the resonant cavity tube 7 is tightly wrapped by porous sound-absorbing material 8 in the interlayer. The Helmholtz resonant cavity has a very strong selective absorption effect on low-frequency noise with frequencies close to its natural frequency. When the frequency of low-frequency noise in the exhaust gas matches the natural frequency of the resonant cavity tube 7, it will cause a violent resonance of the air column at the neck, thereby consuming a large amount of sound energy through friction and dissipation effects.

[0029] The exhaust flow stabilization section 3 is connected downstream of the porous diffusion silencer section 2, and its outlet is open to the atmosphere. After the noise reduction treatment of the first two sections, there may still be some turbulence in the airflow. In order to suppress the secondary noise caused by airflow disturbance and prevent exhaust whistling, a honeycomb flow stabilizer 9 is fixedly installed at the outlet end of the inner cavity of the exhaust flow stabilization section 3. The flow stabilizer 9 is composed of a large number of parallel fine channels, which can effectively divide the large-scale vortex into small-scale vortices, sort out the airflow, and make it more stable and uniformly discharged, thereby further reducing noise.

[0030] The working principle of this utility model is as follows: The high-pressure exhaust gas generated by the nitrogen generator first enters the intake pressure reduction section 1, where it undergoes initial pressure reduction and velocity reduction through the expansion of the flow channel cross-section. Subsequently, the airflow enters the porous diffusion and silencing section 2. In this section, broadband noise in the exhaust gas is treated in multiple stages: mid-to-high frequency noise is mainly absorbed by the resistive silencing structure composed of the perforated inner pipe wall 5 and the porous sound-absorbing material 8 behind it; specific low-frequency noise is selectively and efficiently absorbed through the Helmholtz resonant cavity (resonant bottle cavity tube 7). Finally, the noise-reduced airflow enters the exhaust flow stabilization section 3, where it is smoothly and with low turbulence discharged into the atmosphere by the honeycomb flow stabilizer 9, maximizing the suppression of secondary noise at the exhaust port.

[0031] It should be noted that, in this document, relational terms such as first and second (number one, number two), etc., are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0032] 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.

Claims

1. A nitrogen generator exhaust device, comprising an exhaust pipe, characterized in that: The exhaust pipe is a composite noise reduction pipe, which includes, along the air intake direction to the air outlet direction, a coaxially connected and internally connected intake pressure reduction section (1), a porous diffusion silencing section (2), and an exhaust flow stabilizing section (3); the porous diffusion silencing section (2) includes an outer pipe wall (4) and an inner pipe wall (5), and an interlayer is provided between the inner wall of the outer pipe wall (4) and the outer wall of the inner pipe wall (5), the interlayer is filled with porous sound-absorbing material (8), the inner wall of the inner pipe wall (5) is provided with a perforation (6), a resonant cavity tube (7) is provided in the interlayer, the bottleneck of the resonant cavity tube (7) is fixedly connected to the perforation (6), and the resonant cavity tube (7) is wrapped by the porous sound-absorbing material (8); the outlet end of the exhaust flow stabilizing section (3) is connected to the atmosphere, and a honeycomb flow stabilizer (9) is fixedly installed at the lower end of the inner cavity of the exhaust flow stabilizing section (3).

2. The nitrogen generator exhaust device according to claim 1, characterized in that: The diameter of the perforations (6) on the inner tube wall (5) ranges from 1 mm to 5 mm, and the opening rate ranges from 30% to 50%.

3. The nitrogen generator exhaust device according to claim 1, characterized in that: The inlet end of the air intake pressure reducing section (1) is used to connect to the nitrogen generator exhaust gas source. The cross-sectional area of ​​the flow channel of the air intake pressure reducing section (1) gradually increases along the air intake direction, forming a gradually expanding structure.

4. The nitrogen generator exhaust device according to claim 1, characterized in that: The porous sound-absorbing material (8) is one of glass wool, rock wool, sintered metal fiber or foam ceramic.

5. The nitrogen generator exhaust device according to claim 1, characterized in that: The cross-sectional area of ​​the body of the resonant bottle cavity tube (7) is larger than the cross-sectional area of ​​its bottleneck, forming a Helmholtz resonant cavity.

6. The nitrogen generator exhaust device according to claim 1, characterized in that: The cross-sectional area of ​​the air intake decompression section (1) gradually increases along the air intake direction, and the cone angle of the resulting gradually expanding structure is 8° to 15°.

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