Silencing cylinder with staged noise reduction structure and noise reduction control method

Abstract

The invention discloses a silencing cylinder with a staged noise reduction structure, which is characterized in that a first air chamber and a second air chamber are arranged in a shell, and the shell is also provided with an air inlet channel and an air outlet channel; the control valve is arranged on the air inlet channel and used for controlling the air inlet channel to be communicated or closed with the first air chamber; the first pressure reducing valve is arranged between the first air chamber and the second air chamber, and when the pressure intensity of the first air chamber is larger than a preset value P1, the first air chamber exhausts air to the second air chamber through the first pressure reducing valve; the second pressure reducing valve is arranged on the second air chamber, and when the pressure intensity of the second air chamber is larger than a preset value P2, air, exhausted through the second pressure reducing valve, of the second air chamber is exhausted through the air outlet channel. The motor has a good noise suppression effect and a compact appearance size at the same time. The invention further discloses a noise reduction control method of the silencing cylinder with the staged noise reduction structure, noise suppression is conducted on the initial stage and the final stage of exhaust, and the good noise suppression effect is achieved.

Description

Technical Field

[0001] This invention relates to the field of oxygen generator technology, and in particular to a silencer with a staged noise reduction structure and a noise reduction control method. Background Technology

[0002] An oxygen concentrator is a machine that produces oxygen using air separation technology. Home-use oxygen concentrators primarily utilize the adsorption properties of molecular sieves. Through physical principles and powered by a compressor, they separate nitrogen and oxygen from the air to obtain a high concentration of oxygen. This type of oxygen concentrator produces oxygen rapidly and at a high concentration, making it suitable for oxygen therapy and health maintenance for various groups. However, these concentrators generate significant noise during nitrogen removal. Therefore, existing oxygen concentrators are generally equipped with a nitrogen removal noise reduction device. Traditional noise reduction devices typically use simple sound-absorbing cotton and extend the noise transmission path. However, due to the limited internal space of oxygen concentrators, especially high-flow oxygen concentrators where the molecular sieve and compressor occupy a larger volume, the size of the nitrogen removal noise reduction device is limited, resulting in poor noise reduction effectiveness when used with high-flow oxygen concentrators. Summary of the Invention

[0003] The present invention provides a silencer with a staged noise reduction structure to solve the above-mentioned technical problems.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: A silencer with a staged noise reduction structure includes: The shell has a first air chamber and a second air chamber inside, and the shell also has an air inlet channel and an air outlet channel. A control valve is located on the intake passage and is used to control the connection or closure of the intake passage with the first air chamber. The first pressure reducing valve is located between the first air chamber and the second air chamber. When the pressure in the first air chamber is greater than the preset value P1, the first air chamber exhausts gas to the second air chamber through the first pressure reducing valve. The second pressure reducing valve is installed on the second air chamber. When the pressure in the second air chamber is greater than the preset value P2, the air discharged from the second air chamber through the second pressure reducing valve is discharged through the air outlet channel.

[0005] Preferably, the housing is further provided with a composite air passage, which includes: a second absorption and reflection chamber, a third exhaust passage, a fourth exhaust passage, a fourth absorption and reflection chamber, and a fifth exhaust passage. A second pressure reducing valve is located between the second air chamber and the second absorption and reflection chamber. When the pressure in the second air chamber is greater than a preset value P2, the second air chamber exhausts gas to the second absorption and reflection chamber through the second pressure reducing valve. The gas in the second absorption and reflection chamber enters the third absorption and reflection chamber through the third exhaust passage. The gas in the third absorption and reflection chamber enters the fourth absorption and reflection chamber through the fourth exhaust passage. The gas in the fourth absorption and reflection chamber is discharged into the exhaust passage through the fifth exhaust passage.

[0006] Preferably, the composite air passage further includes: a first exhaust passage, a first absorption and reflection chamber, and a second exhaust passage. The first exhaust passage connects the intake passage and the first absorption and reflection chamber. The control valve is also used to control the connection or closure of the intake passage and the first exhaust passage. The second exhaust passage connects the first absorption and reflection chamber and the second absorption and reflection chamber.

[0007] Preferably, the composite air passage further includes a first convection chamber located between the first absorption and reflection chamber and the second absorption and reflection chamber. The first exhaust passage, the second exhaust passage, and the third exhaust passage all pass through the first convection chamber, and each of the first exhaust passage, the second exhaust passage, and the third exhaust passage is provided with a first air hole that connects to the first convection chamber.

[0008] Preferably, the composite air passage further includes a second convection chamber located between the third absorption and reflection chamber and the fourth absorption and reflection chamber. The third exhaust passage, the fourth exhaust passage, and the fifth exhaust passage all pass through the second convection chamber, and each of the third exhaust passage, the fourth exhaust passage, and the fifth exhaust passage is provided with a second air hole that connects to the second convection chamber.

[0009] Preferably, the shell is cylindrical, and the composite air passage, the first air chamber and the second air chamber are all arranged along the length direction of the shell, and the first air chamber and the second air chamber are arranged opposite each other in the length direction perpendicular to the shell, with the composite air passage located between the first air chamber and the second air chamber.

[0010] Preferably, the composite airway is arranged sequentially from one end of the shell to the other, including a second absorption and reflection chamber, a first convection chamber, a first absorption and reflection chamber, a fourth absorption and reflection chamber, a second convection chamber, and a third absorption and reflection chamber; The air intake passage passes through the second absorption and reflection chamber from the end of the housing and then connects to the first exhaust passage. The end of the first exhaust passage away from the air intake passage passes through the first convection chamber and then connects to the first absorption and reflection chamber. One end of the second exhaust channel is connected to the first absorption and reflection chamber, and the other end passes through the first convection chamber and then connects to the second absorption and reflection chamber. One end of the third exhaust channel is connected to the second absorption and reflection chamber, and the other end passes through the first convection chamber, the first absorption and reflection chamber, the fourth absorption and reflection chamber, and the second convection chamber in sequence before connecting to the third absorption and reflection chamber. The fourth exhaust channel is connected to the third absorption and reflection chamber at one end and passes through the second convection chamber at the other end, connecting to the fourth absorption and reflection chamber. One end of the fifth exhaust passage is connected to the fourth absorption and reflection chamber, and the other end passes through the second convection chamber and then connects to the exhaust passage. The end of the exhaust passage away from the fifth exhaust passage passes through the third absorption and reflection chamber and exits the housing away from the end of the intake passage. The third exhaust passage is arranged along the centerline of the casing. The first and second exhaust passages are located on both sides of the third exhaust passage. The fourth and fifth exhaust passages are also located on both sides of the third exhaust passage. The control valve is located in the air intake channel. The air intake channel is equipped with an air intake bypass. One end of the air intake bypass is connected to the air intake channel, and the other end passes through the second absorption and reflection chamber and then connects to the first air chamber. The control valve allows air to be discharged into the first air chamber or the first exhaust channel by blocking the air intake channel or the air intake bypass. The first pressure reducing valve is located in the third absorption and reflection chamber. The inlet of the first pressure reducing valve is connected to the first gas chamber, and the outlet is connected to the second gas chamber. The second pressure reducing valve is located at the second absorption and reflection chamber. The inlet of the second pressure reducing valve is connected to the second gas chamber, and the outlet is connected to the second absorption and reflection chamber.

[0011] Preferably, the first exhaust channel, the second exhaust channel, and the third exhaust channel are all arranged along the length direction of the shell and each has at least two first air holes along the length direction, and the size of the at least two first air holes gradually increases from the second absorption and reflection chamber toward the first absorption and reflection chamber. The third, fourth, and fifth exhaust channels are all arranged along the length of the shell and each has at least two second vents along the length. The size of the at least two second vents gradually increases from the third absorption and reflection chamber toward the fourth absorption and reflection chamber.

[0012] Preferably, the first air holes on the first and second exhaust channels are staggered from the first air holes on the third exhaust channel, and the second air holes on the fourth and fifth exhaust channels are staggered from the second air holes on the third exhaust channel.

[0013] A noise reduction control method for a silencer with a staged noise reduction structure includes the following steps: S1, Pre-stamping the silencer cylinder S11, the regulating control valve allows air from the intake passage to enter the first air chamber. When the pressure in the first air chamber reaches the preset value P1, the first pressure reducing valve opens to allow air from the first air chamber to enter the second air chamber. S12, when the pressure in the second chamber reaches the preset value P2, the second pressure reducing valve opens to allow the air in the second chamber to enter the second absorption and reflection chamber, and the control valve is adjusted to stop exhausting into the first chamber. S13, the pressure in the first air chamber is maintained at the preset value P1, the pressure in the second air chamber is maintained at the preset value P2, and the silencer completes the pre-pressurization preparation. S2, initial stage exhaust S21, the regulating control valve allows the air in the intake passage to be discharged into the first air chamber. At this time, the pressure in the first air chamber is higher than the preset value P1, and the first pressure reducing valve opens to allow the air in the first air chamber to enter the second air chamber. S22, after the air in the first chamber enters the second chamber, the pressure in the second chamber is higher than the preset value P2. The second pressure reducing valve opens, allowing the air in the second chamber to enter the second absorption and reflection chamber. The air in the second absorption and reflection chamber is discharged through the composite air passage and the outlet passage. S3, exhaust at the end of the stage S31, when the intake pressure in the intake passage drops to a preset value P3 (P3 < P1), the regulating control valve causes the air in the intake passage to be discharged into the first exhaust passage. S32, the gas from the first exhaust passage is absorbed, reflected and convectioned through the composite air passage before being discharged from the exhaust passage.

[0014] Beneficial effects: First, the muffler with a staged noise reduction structure disclosed in this application sets up two air chambers, a first air chamber and a second air chamber, which can maintain a preset pressure value. The first air chamber and the second air chamber are designed to decrease in pressure relative to the initial exhaust pressure according to the design value, thereby reducing the pressure difference during each stage of exhaust and effectively reducing the noise generated by the large pressure difference. Compared with the method of adding sound-absorbing cotton and extending the transmission path, this application has both a better noise suppression effect and a more compact size.

[0015] Secondly, the noise reduction control method of the muffler with a staged noise reduction structure disclosed in this application suppresses noise in the initial and final stages of exhaust by adjusting the control valve in conjunction with the first air chamber, the second air chamber and the composite air passage. By combining the control of pressure difference and the extension of the transmission path, a better noise suppression effect is achieved. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1This is a schematic diagram of a silencer with a staged noise reduction structure disclosed in Embodiment 1 of the present invention; Figure 2 This is a top view of a silencer with a staged noise reduction structure disclosed in Embodiment 1 of the present invention; Figure 3 for Figure 2 Sectional view of AA; Figure 4 for Figure 2 Sectional view of BB; Figure 5 for Figure 2 Sectional view of CC; Figure 6 for Figure 3 Sectional view of DD; Figure 7 for Figure 6 A magnified view of a section of section I; Figure 8 for Figure 3 Sectional view of EE; Figure 9 for Figure 8 A magnified view of part II.

[0018] In the diagram: 11. Intake passage; 111. Fourth exhaust passage; 112. Fifth exhaust passage; 12. Exhaust passage; 13. Housing; 131. First absorption and reflection chamber; 132. Second absorption and reflection chamber; 133. Third absorption and reflection chamber; 134. Fourth absorption and reflection chamber; 14. Control valve; 141. First convection chamber; 142. Second convection chamber; 15. Second pressure reducing valve; 151. Second pressure reducing valve cylinder; 152. Second piston; 153. Second spring; 16. First pressure reducing valve; 161. First pressure reducing valve cylinder; 162. First piston; 163. First spring; 17. Intake bypass; 181. First air port; 182. Second air port; 191. First air chamber; 192. Second air chamber; 101. First exhaust passage; 102. Second exhaust passage; 103. Third exhaust passage. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1 A silencer with a staged noise reduction structure, combined with Figures 1-9 As shown, it includes: The housing 13 has a first air chamber 191 and a second air chamber 192 inside, and the housing 13 is also provided with an air inlet channel 11 and an air outlet channel 12. Control valve 14 is provided on the air intake passage 11 and is used to control the connection or closure of the air intake passage 11 with the first air chamber 191; The first pressure reducing valve 16 is located between the first air chamber 191 and the second air chamber 192. When the pressure of the first air chamber 191 is greater than the preset value P1, the first air chamber 191 exhausts gas to the second air chamber 192 through the first pressure reducing valve 16. The second pressure reducing valve 15 is installed on the second air chamber 192. When the pressure of the second air chamber 192 is greater than the preset value P2, the air discharged from the second air chamber 192 through the second pressure reducing valve 15 is discharged through the air outlet channel 12.

[0021] This application employs two chambers, a first chamber 191 and a second chamber 192, capable of maintaining preset pressure values. The first chamber 191 and the second chamber 192 are designed with a gradient decreasing relative to the initial exhaust pressure, reducing the pressure difference at each exhaust stage. This effectively reduces noise generated by large pressure differences. Compared to methods involving adding sound-absorbing cotton and extending the transmission path, this application achieves both good noise suppression and a more compact size. This application is applicable to nitrogen exhaust silencing in medical oxygen concentrators and other similar exhaust silencing scenarios.

[0022] For medical oxygen concentrators, the noise sources mainly include gas path noise and mechanical vibration noise. Gas path noise primarily includes nitrogen exhaust noise, cooling air noise, and high-pressure air friction noise, while mechanical vibration noise mainly includes compressor operating noise and fan noise. Mechanical vibration noise can usually be reduced to an acceptable range through casing silencing design; however, the separated nitrogen must be discharged, typically using a silencer. During the molecular sieve decomposition stage of a medical oxygen concentrator, the internal pressure is much higher than the standard atmospheric pressure of the external space. When the gas is discharged, under the influence of the pressure difference, the gas flows rapidly from the high-pressure area to the low-pressure area. The high-speed airflow impacts pipes, valves, and other components, causing vibration and generating noise. Simultaneously, the sudden pressure release during rapid gas discharge creates a strong pressure wave at the interface between the gas and the surrounding air, causing severe air turbulence and generating noise. Due to the characteristics of medical oxygen concentrators, this process repeats every few seconds, making nitrogen exhaust noise the largest component of gas path noise.

[0023] This application designs the preset pressure value P1 of the first gas chamber 191 to be slightly lower than the initial nitrogen venting pressure of the molecular sieve tank, and designs the preset pressure value P2 of the second gas chamber 192 to be slightly lower than the preset pressure value P1 of the first gas chamber 191, forming a two-stage exhaust with a small pressure difference, fundamentally reducing noise generation and avoiding passive absorption after noise generation, thereby achieving significant attenuation of exhaust noise.

[0024] Preferably, the housing 13 is further provided with a composite air passage, which includes: a second absorption and reflection chamber 132, a third exhaust passage 103, a third absorption and reflection chamber 133, a fourth exhaust passage 111, a fourth absorption and reflection chamber 134, and a fifth exhaust passage 112. A second pressure reducing valve 15 is disposed between the second air chamber 192 and the second absorption and reflection chamber 132. When the pressure of the second air chamber 192 is greater than a preset value P2, the second air chamber 192 exhausts gas to the second absorption and reflection chamber 132 through the second pressure reducing valve 15. The gas in the second absorption and reflection chamber 132 enters the third absorption and reflection chamber 133 through the third exhaust passage 103. The gas in the third absorption and reflection chamber 133 enters the fourth absorption and reflection chamber 134 through the fourth exhaust passage 111. The gas in the fourth absorption and reflection chamber 134 is discharged into the exhaust passage 12 through the fifth exhaust passage 112.

[0025] This application first uses a two-stage exhaust system formed by the first gas chamber 191 and the second gas chamber 192 to target the initial stage of nitrogen venting from the molecular sieve tank, and then uses a composite gas channel to suppress noise during the final stage of nitrogen venting from the molecular sieve tank. The noise generated by the exhaust is effectively reduced by the reflection and absorption of the second absorption and reflection chamber 132, the third absorption and reflection chamber 133, and the fourth absorption and reflection chamber 134. At the same time, the tortuous path formed by the second absorption and reflection chamber 132, the third exhaust channel 103, the third absorption and reflection chamber 133, the fourth exhaust channel 111, the fourth absorption and reflection chamber 134, and the fifth exhaust channel 112 allows for a longer gas flow path within a limited space, which enhances the noise reduction effect.

[0026] Preferably, the composite air duct further includes: a first exhaust passage 101, a first absorption and reflection chamber 131, and a second exhaust passage 102. The first exhaust passage 101 connects the intake passage 11 and the first absorption and reflection chamber 131. The control valve 14 is also used to control the connection or closure of the intake passage 11 and the first exhaust passage 101. The second exhaust passage 102 connects the first absorption and reflection chamber 131 and the second absorption and reflection chamber 132. By adding the first exhaust passage 101, the first absorption and reflection chamber 131, and the second exhaust passage 102, the gas in the intake passage 11 can also enter the first exhaust passage 101 under the control of the control valve 14. This gas can be silenced by four absorptions and reflections through the first absorption and reflection chamber 131, the second absorption and reflection chamber 132, the third absorption and reflection chamber 133, and the fourth absorption and reflection chamber 134. Thus, the composite air duct can complete the noise suppression of the two parts of exhaust in the initial and final stages. Firstly, noise suppression occurs during the exhaust process from the second gas chamber 192 to the second absorption and reflection chamber 132 after the pressure in the second gas chamber 192 exceeds the preset value P2. A portion of the gas entering the second absorption and reflection chamber 132 is reflected and absorbed within it, while the remaining portion flows along the third exhaust channel 103, the third absorption and reflection chamber 133, the fourth exhaust channel 111, the fourth absorption and reflection chamber 134, and the fifth exhaust channel 112. Secondly, noise suppression occurs during the process where the initial nitrogen venting pressure of the molecular sieve tank is less than the preset value P3 (i.e., the inlet pressure of the inlet channel 11 drops to the preset value P3), preventing further exhaust to the first gas chamber 191. This nitrogen is then directly vented from the molecular sieve tank to the first exhaust channel 101, and this portion of the gas flows along the entire composite gas path.

[0027] Preferably, the composite air duct further includes a first convection chamber 141 located between the first absorption and reflection chamber 131 and the second absorption and reflection chamber 132. The first exhaust channel 101, the second exhaust channel 102, and the third exhaust channel 103 all pass through the first convection chamber 141, and each of these channels has a first vent 181 connecting to the first convection chamber 141. When the gas passes through the first exhaust channel 101, the second exhaust channel 102, and the third exhaust channel 103, some of the gas enters the first convection chamber 141 through the first vent 181. Multiple collisions between gases and between the gas and the inner wall of the first convection chamber 141 achieve noise reduction, further enhancing the sound absorption effect.

[0028] Preferably, the composite air duct further includes a second convection chamber 142 located between the third absorption and reflection chamber 133 and the fourth absorption and reflection chamber 134. The third exhaust channel 103, the fourth exhaust channel 111, and the fifth exhaust channel 112 all pass through the second convection chamber 142, and each of the third exhaust channel 103, the fourth exhaust channel 111, and the fifth exhaust channel 112 is provided with a second air hole 182 communicating with the second convection chamber 142. When the gas passes through the third exhaust channel 103, the fourth exhaust channel 111, and the fifth exhaust channel 112, some of the gas enters the second convection chamber 142 through the second air hole 182, and the noise is further eliminated through multiple collisions between gases and between gases and the inner wall of the second convection chamber 142.

[0029] Preferably, the housing 13 is cylindrical, and the composite air passage, the first air chamber 191, and the second air chamber 192 are all arranged along the length direction of the housing 13. The first air chamber 191 and the second air chamber 192 are arranged opposite each other in a direction perpendicular to the length of the housing 13, and the composite air passage is located between the first air chamber 191 and the second air chamber 192. This layout fully utilizes the length and lateral dimensions of the housing 13, ensuring both the volume of the first air chamber 191 and the second air chamber 192 and allowing for a longer flow path in the composite air passage.

[0030] Specifically, the shell 13 is a cylindrical structure sealed at both ends. The composite air passage is arranged along the axis of the shell 13. The cross-section of the first air chamber 191 and the second air chamber 192 is a minor arc shape with equal shape. The composite air passage, the first air chamber 191 and the second air chamber 192 form a "sandwich" structure in the transverse direction of the shell 13, making the whole structure more compact and regular.

[0031] Preferably, the composite airway is arranged sequentially from one end of the housing 13 to the other end as a second absorption and reflection chamber 132, a first convection chamber 141, a first absorption and reflection chamber 134, a fourth absorption and reflection chamber 134, a second convection chamber 142, and a third absorption and reflection chamber 133; The intake passage 11 passes through the second absorption and reflection chamber 132 from the end of the housing 13 and then connects to the first exhaust passage 101. The end of the first exhaust passage 101 away from the intake passage 11 passes through the first convection chamber 141 and then connects to the first absorption and reflection chamber 131. The second exhaust channel 102 is connected to the first absorption and reflection chamber 131 at one end and to the second absorption and reflection chamber 132 after passing through the first convection chamber 141 at the other end. One end of the third exhaust channel 103 is connected to the second absorption and reflection chamber 132, and the other end passes through the first convection chamber 141, the first absorption and reflection chamber 131, the fourth absorption and reflection chamber 134, and the second convection chamber 142 in sequence before connecting to the third absorption and reflection chamber 133. The fourth exhaust channel 111 is connected at one end to the third absorption and reflection chamber 133, and at the other end it passes through the second convection chamber 142 and then connects to the fourth absorption and reflection chamber 134; One end of the fifth exhaust passage 112 is connected to the fourth absorption and reflection chamber 134, and the other end passes through the second convection chamber 142 and is connected to the exhaust passage 12. The end of the exhaust passage 12 away from the fifth exhaust passage 112 passes through the third absorption and reflection chamber 133 and exits the end of the housing 13 away from the intake passage 11. The third exhaust passage 103 is arranged along the center line of the housing 13. The first exhaust passage 101 and the second exhaust passage 102 are located on both sides of the third exhaust passage 103. The fourth exhaust passage 111 and the fifth exhaust passage 112 are also located on both sides of the third exhaust passage 103. The control valve 14 is located in the air intake channel 11. The air intake channel 11 is provided with an air intake bypass 17. One end of the air intake bypass 17 is connected to the air intake channel 11, and the other end passes through the second absorption and reflection chamber 132 and is connected to the first air chamber 191. The control valve 14 allows air to be discharged into the first air chamber 191 or the first exhaust channel 101 by blocking the air intake channel 11 or the air intake bypass 17. The first pressure reducing valve 16 is located at the third absorption and reflection chamber 133. The inlet of the first pressure reducing valve 16 is connected to the first air chamber 191, and the outlet is connected to the second air chamber 192. The second pressure reducing valve 15 is located at the second absorption and reflection chamber 132. The inlet of the second pressure reducing valve 15 is connected to the second gas chamber 192, and the outlet is connected to the second absorption and reflection chamber 132.

[0032] The regulating control valve 14 can easily control the connection between the intake passage 11 and the intake bypass 17, thereby controlling the rapid entry of gas into the adjacent first air chamber 191. The first pressure reducing valve 16 is set at a position away from the intake in the first air chamber 191, which is conducive to the flow of gas along the first air chamber 191 and ensures that the entire first air chamber 191 is filled; similarly, the second pressure reducing valve 15 can also ensure that the entire second air chamber 192 is filled.

[0033] The regulating control valve 14 allows for convenient control of the connection between the intake channel 11 and the first exhaust channel 101. Gas is discharged into the first absorption and reflection chamber 131 through the first exhaust channel 101, where sound waves are reflected and absorbed. Then, the gas is discharged into the second absorption and reflection chamber 132 through the second exhaust channel 102, where sound waves are reflected and absorbed. Next, the gas is discharged into the third absorption and reflection chamber 133 through the third exhaust channel 103, where sound waves are reflected and absorbed. Then, the gas is discharged into the fourth absorption and reflection chamber 134 through the fourth exhaust channel 111, where sound waves are reflected and absorbed. Finally, the gas is discharged from the housing 13 through the fifth exhaust channel 112 and the exhaust channel 12. The gas undergoes four absorption and reflection processes within the silencer to achieve noise reduction, and the tortuous flow path formed by the composite air passages is longer and smoother, which helps to improve the absorption and reflection effects. Compared to traditional nitrogen purging silencers, this silencer is equipped with targeted noise suppression structures for different stages of nitrogen purging. It no longer relies solely on extending the airway, adding sound-absorbing cotton, or increasing the number of nitrogen purging silencers to suppress noise, thus achieving an extremely excellent noise reduction effect.

[0034] Specifically, the first air chamber 191, the second air chamber 192, the second absorption and reflection chamber 132, the first convection chamber 141, the fourth absorption and reflection chamber 134, the second convection chamber 142, and the third absorption and reflection chamber 133 are obtained by isolating the shell 13 with a sound-absorbing wall. When a sound wave encounters the sound-absorbing wall, some of the energy is reflected back. At the same time, the porous structure inside the sound-absorbing wall material can absorb the incident sound wave and convert it into heat energy.

[0035] Specifically, the intake channel 11, the first exhaust channel 101, the second exhaust channel 102, the third exhaust channel 103, the fourth exhaust channel 111, the fifth exhaust channel 112, and the exhaust channel 12 are all machined from round tubes of the same diameter. The intake channel 11 and the first exhaust channel 101 are integrally machined, as are the fifth exhaust channel 112 and the exhaust channel 12. Round holes corresponding to each channel are opened on the sound-absorbing wall. Each channel is fixed to the sound-absorbing wall, ensuring a seal at the penetration point. The specific process, such as welding, ultrasonic welding, or fusion welding, is selected based on the material. Except for the intake channel 11 and the exhaust channel 12, which protrude from the end face of the housing 13, the ports of each channel are flush with the corresponding sound-absorbing wall.

[0036] The third exhaust passage 103 is coaxially arranged with the housing 13. The portion of the passage extending into the first convection chamber 141 has first air holes 181 on both the upper and lower sides, and the portion extending into the second convection chamber 142 has second air holes 182 on both the upper and lower sides.

[0037] The first exhaust passage 101 and the second exhaust passage 102 are located on the upper and lower sides of the third exhaust passage 103, respectively. The axes of the first exhaust passage 101, the second exhaust passage 102, and the third exhaust passage 103 are arranged vertically along the diameter of the housing 13 in the vertical direction. The fourth exhaust passage 111 is coaxially arranged with the second exhaust passage 102, and the fifth exhaust passage 112 is coaxially arranged with the first exhaust passage 101.

[0038] The first pressure-reducing valve 16 is located above the axis of the housing 13. The first pressure-reducing valve 16 includes a first pressure-reducing valve cylinder 161, a first piston 162, and a first spring 163. The first piston 162 and the first spring 163 are located inside the first pressure-reducing valve cylinder 161. One end of the first pressure-reducing valve cylinder 161 is fixed to the silencing wall of the third absorption and reflection chamber 133 facing the first air chamber 191, and the other end extends out of the third absorption and reflection chamber 133 and enters the second air chamber 192. The first pressure-reducing valve cylinder 161 is fixed to the silencing wall of the third absorption and reflection chamber 133, and the connection is sealed. An inlet for the first pressure-reducing valve 16 is opened on the silencing wall of the third absorption and reflection chamber 133 facing the first air chamber 191, and an outlet for the first pressure-reducing valve 16 is opened on the portion of the first pressure-reducing valve cylinder 161 that extends into the second air chamber 192. The first spring 163 pushes the first piston 162 to block the inlet of the first pressure-reducing valve 16. The parameters of the first spring 163 are matched with the preset value P1 of the first air chamber 191 to ensure that the first pressure reducing valve 16 opens when the air pressure in the first air chamber 191 is greater than P1.

[0039] The second pressure-reducing valve 15 is located below the axis of the housing 13. The second pressure-reducing valve 15 includes a second pressure-reducing valve cylinder 151, a second piston 152, and a second spring 153. The second piston 152 and the second spring 153 are located inside the second pressure-reducing valve cylinder 151. One end of the second pressure-reducing valve cylinder 151 is fixed to the silencing wall of the second absorption and reflection chamber 132 facing the first air chamber 191, and the other end is fixed to the silencing wall of the second absorption and reflection chamber 132 facing the second air chamber 192. The second pressure-reducing valve cylinder 151 is fixed to the silencing wall of the third absorption and reflection chamber 133, and the connection is sealed. The inlet of the second pressure-reducing valve 15 is opened on the silencing wall of the second absorption and reflection chamber 132 facing the second air chamber 192, and the outlet of the second pressure-reducing valve 15 is opened on the side wall of the second pressure-reducing valve cylinder 151. The second spring 153 pushes the second piston 152 to block the inlet of the second pressure-reducing valve 15. The parameters of the second spring 153 are matched with the preset value P2 of the second air chamber 192 to ensure that the second pressure reducing valve 15 opens when the air pressure in the second air chamber 192 is greater than P2.

[0040] Specifically, control valve 14 can be a ball valve. The rotation of control valve 14 is controlled by a motor driving a gear. Control valve 14 blocks the inlet of intake bypass 17, connecting intake passage 11 with the first exhaust passage 101. Control valve 14 also blocks intake passage 11, connecting intake passage 11 with intake bypass 17. This control method is only a reference example; there are various ways to control the rotation of control valve 14, and these are not the main focus of this invention and will not be described in detail.

[0041] The preset values ​​P1 (i.e., the opening pressure P1 of the first pressure reducing valve 16) and P2 (i.e., the opening pressure P2 of the second pressure reducing valve 15) are related to the initial nitrogen discharge pressure of the molecular sieve tank. This pressure is related to specific design parameters not related to this invention, such as the volume of the molecular sieve tank and the operating sequence of the oxygen generator's solenoid valve. These parameters can be set according to the actual design parameters during practical application of this invention, thereby designing the first spring 163 and the second spring 153 to satisfy the opening pressures P1 and P2. Additionally, copper sleeves are needed at the positions where the rear end of the control valve 14 enters the first gas chamber 191, the rear end of the second pressure reducing valve 15, the rear end of the first pressure reducing valve 16, and the rear end of the control valve 14 enters the air intake channel 11 to act as throttling orifices. Since this part is not a major component of this invention, it is not detailed in the drawings for the sake of simplicity. The size of the throttling orifice is generally 1mm / 1.2mm / 1.4mm. The specific selection needs to be calculated based on parameters such as the volume of the molecular sieve tank, the volume of the first gas chamber 191 and the second gas chamber 192, and the preset values ​​P1 and P2.

[0042] Preferably, the first exhaust channel 101, the second exhaust channel 102, and the third exhaust channel 103 are all arranged along the length direction of the housing 13 and each has at least two first air holes 181 along the length direction. The size of the at least two first air holes 181 gradually increases from the second absorption and reflection chamber 132 toward the first absorption and reflection chamber 131. In this embodiment, the first exhaust channel 101 and the second exhaust channel 102 are each provided with three first air holes 181, and the third exhaust channel 103 is provided with three first air holes 181 on each of its upper and lower sides.

[0043] The third exhaust channel 103, the fourth exhaust channel 111, and the fifth exhaust channel 112 are all arranged along the length of the housing 13 and each has at least two second vents 182 along its length. The size of the at least two second vents 182 gradually increases from the third absorption and reflection chamber 133 toward the fourth absorption and reflection chamber 134. In this embodiment, the fourth exhaust channel 111 and the fifth exhaust channel 112 each have three second vents 182, and the third exhaust channel 103 has three second vents 182 on each of its upper and lower sides.

[0044] By setting different diameters for adjacent first vents 181 and adjacent second vents 182, the gas pressure flowing out of the first vent 181 is also different, thus adjusting the gas flow rate of the first vent 181; the gas pressure flowing out of the second vent 182 is also different, thus adjusting the gas flow rate of the second vent 182.

[0045] Preferably, the first air holes 181 on the first exhaust channel 101 and the second exhaust channel 102 are staggered from the first air holes 181 on the third exhaust channel 103, and the second air holes 182 on the fourth exhaust channel 111 and the fifth exhaust channel 112 are staggered from the second air holes 182 on the third exhaust channel 103. That is, the first air holes 181 on the first exhaust channel 101 and the second exhaust channel 102 are not coaxial with the first air holes 181 on the upper and lower sides of the third exhaust channel 103. This increases the number of collisions between gases and between gases and the sound-absorbing wall.

[0046] Example 2 A noise reduction control method for a silencer with a staged noise reduction structure A noise reduction control method for a silencer with a staged noise reduction structure disclosed in Example 1 includes the following steps: S1, Pre-stamping the silencer cylinder S11, the regulating control valve allows air from the intake channel to enter the first chamber. When the pressure in the first chamber reaches the preset value P1, the first pressure reducing valve opens, allowing air from the first chamber to enter the second chamber. While nitrogen is being discharged from the first chamber to the second chamber, it is necessary to ensure that the pressure inside the molecular sieve tank is higher than the pressure inside the first chamber to guarantee continued exhaust from the molecular sieve tank to the first chamber. This can be achieved by designing the first chamber according to the volume of nitrogen inside the molecular sieve tank and the size of the exhaust throttling orifice.

[0047] S12, when the pressure in the second chamber reaches the preset value P2, the second pressure reducing valve opens to allow the air in the second chamber to enter the second absorption and reflection chamber, and the regulating control valve stops exhausting into the first chamber.

[0048] S13, the pressure in the first air chamber is maintained at the preset value P1, the pressure in the second air chamber is maintained at the preset value P2, and the silencer completes the pre-pressurization preparation.

[0049] S2, initial stage exhaust S21, when the molecular sieve tank starts a nitrogen purging cycle, the regulating control valve allows the gas in the inlet channel to be discharged into the first gas chamber. At this time, the pressure in the first gas chamber is higher than the preset value P1, and the first pressure reducing valve opens to allow the gas in the first gas chamber to enter the second gas chamber.

[0050] S22, after the air in the first chamber enters the second chamber, the pressure in the second chamber is higher than the preset value P2. The second pressure reducing valve opens, allowing the air in the second chamber to enter the second absorption and reflection chamber. The air in the second absorption and reflection chamber is discharged through the composite air passage and the outlet passage. Because the pressure difference between the first chamber and the molecular sieve tank is much smaller than the pressure difference between the molecular sieve tank and the external standard atmospheric pressure, the noise is significantly reduced during two-stage exhaust.

[0051] S3, exhaust at the end of the stage S31, when the intake pressure in the intake channel drops to the preset value P3 (P3 < P1), the control valve is adjusted to allow the air in the intake channel to be discharged into the first exhaust channel; at this time, the pressure of the molecular sieve tank is less than the preset value P1 of the first gas chamber (which can be calculated by the exhaust time, but this method is not unique), and the pressure of the molecular sieve tank cannot maintain the exhaust to the first gas chamber, so that the remaining nitrogen in the molecular sieve tank is directly discharged into the first exhaust channel.

[0052] S32, the air from the first exhaust passage is absorbed, reflected, and convectioned by the composite air passage before being discharged from the outlet passage. This application uses a control valve in conjunction with the first air chamber, the second air chamber, and the composite air passage to suppress noise in the initial and final stages of exhaust. By combining pressure difference control and extending the transmission path, a better noise suppression effect is achieved.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A silencer with a staged noise reduction structure, characterized in that, include: The housing (13) is provided with a first air chamber (191) and a second air chamber (192), and the housing (13) is also provided with an air inlet channel (11) and an air outlet channel (12). A control valve (14) is provided on the air intake passage (11) and is used to control the connection or closure of the air intake passage (11) with the first air chamber (191); The first pressure reducing valve (16) is located between the first air chamber (191) and the second air chamber (192). When the pressure of the first air chamber (191) is greater than the preset value P1, the first air chamber (191) exhausts gas to the second air chamber (192) through the first pressure reducing valve (16). The second pressure reducing valve (15) is installed on the second air chamber (192). When the pressure of the second air chamber (192) is greater than the preset value P2, the gas discharged from the second air chamber (192) through the second pressure reducing valve (15) is discharged through the air outlet channel (12).

2. A silencer with a staged noise reduction structure according to claim 1, characterized in that, The housing (13) is also provided with a composite air passage, which includes: a second absorption and reflection chamber (132), a third exhaust passage (103), a third absorption and reflection chamber (133), a fourth exhaust passage (111), a fourth absorption and reflection chamber (134), and a fifth exhaust passage (112). The second pressure reducing valve (15) is located between the second air chamber (192) and the second absorption and reflection chamber (132). When the pressure of the second air chamber (192) is greater than the preset value P2, the second air chamber (192) exhausts gas to the second absorption and reflection chamber (132) through the second pressure reducing valve (15). The gas in the second absorption and reflection chamber (132) enters the third absorption and reflection chamber (133) through the third exhaust passage (103). The gas in the third absorption and reflection chamber (133) enters the fourth absorption and reflection chamber (134) through the fourth exhaust passage (111). The gas in the fourth absorption and reflection chamber (134) is discharged into the exhaust passage (12) through the fifth exhaust passage (112).

3. A silencer with a staged noise reduction structure according to claim 2, characterized in that, The composite air passage further includes: a first exhaust passage (101), a first absorption and reflection chamber (131) and a second exhaust passage (102). The first exhaust passage (101) connects the intake passage (11) and the first absorption and reflection chamber (131). The control valve (14) is also used to control the connection or closure of the intake passage (11) and the first exhaust passage (101). The second exhaust passage (102) connects the first absorption and reflection chamber (131) and the second absorption and reflection chamber (132).

4. A silencer with a staged noise reduction structure according to claim 3, characterized in that, The composite air passage also includes a first convection chamber (141) located between the first absorption and reflection chamber (131) and the second absorption and reflection chamber (132). The first exhaust passage (101), the second exhaust passage (102), and the third exhaust passage (103) all pass through the first convection chamber (141), and each of the first exhaust passage (101), the second exhaust passage (102), and the third exhaust passage (103) is provided with a first air hole (181) that connects to the first convection chamber (141).

5. A silencer with a staged noise reduction structure according to claim 4, characterized in that, The composite air passage also includes a second convection chamber (142) located between the third absorption and reflection chamber (133) and the fourth absorption and reflection chamber (134). The third exhaust passage (103), the fourth exhaust passage (111), and the fifth exhaust passage (112) all pass through the second convection chamber (142), and the third exhaust passage (103), the fourth exhaust passage (111), and the fifth exhaust passage (112) are all provided with a second air hole (182) that connects to the second convection chamber (142).

6. A silencer with a staged noise reduction structure according to claim 5, characterized in that, The shell (13) is cylindrical. The composite air passage, the first air chamber (191) and the second air chamber (192) are all arranged along the length direction of the shell (13). The first air chamber (191) and the second air chamber (192) are arranged opposite each other in the length direction perpendicular to the shell (13). The composite air passage is located between the first air chamber (191) and the second air chamber (192).

7. A silencer with a staged noise reduction structure according to claim 6, characterized in that, The composite airway is arranged from one end of the shell (13) to the other end as follows: second absorption and reflection chamber (132), first convection chamber (141), first absorption and reflection chamber (131), fourth absorption and reflection chamber (134), second convection chamber (142), and third absorption and reflection chamber (133). The air intake channel (11) passes through the second absorption and reflection chamber (132) from the end of the housing (13) and then connects to the first exhaust channel (101). The first exhaust channel (101) passes through the first convection chamber (141) at the end away from the air intake channel (11) and then connects to the first absorption and reflection chamber (131). The second exhaust channel (102) is connected to the first absorption and reflection chamber (131) at one end and to the second absorption and reflection chamber (132) after passing through the first convection chamber (141) at the other end. One end of the third exhaust channel (103) is connected to the second absorption and reflection chamber (132), and the other end passes through the first convection chamber (141), the first absorption and reflection chamber (131), the fourth absorption and reflection chamber (134), and the second convection chamber (142) in sequence before connecting to the third absorption and reflection chamber (133). The fourth exhaust channel (111) is connected to the third absorption and reflection chamber (133) at one end and to the fourth absorption and reflection chamber (134) after passing through the second convection chamber (142) at the other end. One end of the fifth exhaust channel (112) is connected to the fourth absorption and reflection chamber (134), and the other end passes through the second convection chamber (142) and is connected to the exhaust channel (12). The end of the exhaust channel (12) away from the fifth exhaust channel (112) passes through the third absorption and reflection chamber (133) and exits the end of the housing (13) away from the intake channel (11). The third exhaust channel (103) is arranged along the center line of the housing (13), the first exhaust channel (101) and the second exhaust channel (102) are located on both sides of the third exhaust channel (103), and the fourth exhaust channel (111) and the fifth exhaust channel (112) are also located on both sides of the third exhaust channel (103); The control valve (14) is located in the air intake channel (11). The air intake channel (11) is provided with an air intake bypass (17). One end of the air intake bypass (17) is connected to the air intake channel (11), and the other end passes through the second absorption and reflection chamber (132) and then connects to the first air chamber (191). The control valve (14) allows air to be discharged into the first air chamber (191) or the first exhaust channel (101) by blocking the air intake channel (11) or the air intake bypass (17). The first pressure reducing valve (16) is located at the third absorption and reflection chamber (133). The inlet of the first pressure reducing valve (16) is connected to the first gas chamber (191), and the outlet is connected to the second gas chamber (192). The second pressure reducing valve (15) is located at the second absorption and reflection chamber (132). The inlet of the second pressure reducing valve (15) is connected to the second gas chamber (192), and the outlet is connected to the second absorption and reflection chamber (132).

8. A silencer with a staged noise reduction structure according to claim 7, characterized in that, The first exhaust channel (101), the second exhaust channel (102), and the third exhaust channel (103) are all arranged along the length direction of the shell (13) and each has at least two first air holes (181) along the length direction. The size of the at least two first air holes (181) gradually increases from the second absorption and reflection chamber (132) toward the first absorption and reflection chamber (131). The third exhaust channel (103), the fourth exhaust channel (111), and the fifth exhaust channel (112) are all arranged along the length of the shell (13) and each has at least two second vents (182) along the length. The size of the at least two second vents (182) gradually increases from the third absorption and reflection chamber (133) toward the fourth absorption and reflection chamber (134).

9. A silencer with a staged noise reduction structure according to claim 8, characterized in that, The first air hole (181) on the first exhaust channel (101) and the second exhaust channel (102) are staggered from the first air hole (181) on the third exhaust channel (103), and the second air hole (182) on the fourth exhaust channel (111) and the fifth exhaust channel (112) are staggered from the second air hole (182) on the third exhaust channel (103).

10. A noise reduction control method for a silencer with a staged noise reduction structure as described in any one of claims 1-9, characterized in that, Includes the following steps: S1, Pre-stamping the silencer cylinder S11, the regulating control valve allows air from the intake passage to enter the first air chamber. When the pressure in the first air chamber reaches the preset value P1, the first pressure reducing valve opens to allow air from the first air chamber to enter the second air chamber. S12, when the pressure in the second chamber reaches the preset value P2, the second pressure reducing valve opens to allow the air in the second chamber to enter the second absorption and reflection chamber, and the control valve is adjusted to stop exhausting into the first chamber. S13, the pressure in the first air chamber is maintained at the preset value P1, the pressure in the second air chamber is maintained at the preset value P2, and the silencer completes the pre-pressurization preparation. S2, initial stage exhaust S21, the regulating control valve allows the air in the intake passage to be discharged into the first air chamber. At this time, the pressure in the first air chamber is higher than the preset value P1, and the first pressure reducing valve opens to allow the air in the first air chamber to enter the second air chamber. S22, after the air in the first chamber enters the second chamber, the pressure in the second chamber is higher than the preset value P2. The second pressure reducing valve opens, allowing the air in the second chamber to enter the second absorption and reflection chamber. The air in the second absorption and reflection chamber is discharged through the composite air passage and the outlet passage. S3, exhaust at the end of the stage S31, when the intake pressure in the intake passage drops to a preset value P3 (P3 < P1), the regulating control valve causes the air in the intake passage to be discharged into the first exhaust passage. S32, the gas from the first exhaust passage is absorbed, reflected and convectioned through the composite air passage before being discharged from the exhaust passage.

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