A low-temperature liquid tank car gas venting silencer

Abstract

The utility model relates to a kind of sound attenuation devices, specifically a kind of low-temperature liquid tank car gas venting sound attenuation device, including the connecting part for being detachably connected with tank body, the sound attenuation part being communicated with connecting part arrangement;Sound attenuation part has double-layer structure, including the inner bag being communicated with connecting part, several sound attenuation holes are arranged on inner bag wall, sound attenuation part further includes the outer tube being fixed to the outside of inner bag, the setting position of outer tube covers sound attenuation hole, and there is spacing between outer tube and inner bag.The utility model can effectively reduce the noise in the process of gas venting, and high safety, convenient to install, suitable for the gas venting process of low-temperature liquid tank car.

Description

Technical Field

[0001] This utility model relates to a silencing device, specifically a silencing device for gas venting in cryogenic liquid tank trucks. Background Technology

[0002] Cryogenic liquids (such as liquid nitrogen) are stored in stationary storage tanks. At the cryogenic liquid filling site, the liquid is sequentially pumped from the storage tank through filling pumps, pipes, and valves into the tanker truck. During the filling process, and after the cryogenic liquid enters the tank, some vaporizes, causing excessive pressure inside the tanker truck. A slight increase in pressure slows down the filling efficiency, while a severe increase leads to overpressure. Therefore, it is necessary to manually open the vent valve on the tanker to release the gas (such as nitrogen) inside the tanker truck (this process is also called "gas venting"), thereby reducing the pressure inside the tanker truck.

[0003] The existing vent valve structure includes a vent valve fixed on the tank body, as well as a downstream pipeline connected to the vent valve for guidance. When the vent valve is manually opened, the vent valve will emit noise exceeding 85 decibels due to the high gas pressure, causing auditory fatigue to the operator. Long-term exposure to the vent environment will further damage the operator's hearing. Utility Model Content

[0004] To address the aforementioned shortcomings in the existing technology, this utility model aims to provide a gas venting silencing device for cryogenic liquid tank trucks, thereby reducing noise during the gas venting process.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a gas venting silencing device for a cryogenic liquid tanker includes a connecting part for detachable connection with the tank body and a silencing part connected to the connecting part; the silencing part has a double-layer structure, including an inner liner connected to the connecting part, a plurality of silencing holes arranged on the inner liner wall, and an outer tube fixed outside the inner liner, the outer tube being positioned to cover the silencing holes, and a gap being present between the outer tube and the inner liner.

[0006] As a limitation of this utility model: the end of the inner liner away from the connecting part is a closed structure.

[0007] As a limitation of this utility model: the inner liner has a hollow cylindrical structure, and the diameter of the sound-absorbing hole is 1 / 10 to 1 / 5 of the diameter of the inner liner.

[0008] As a limitation of this utility model: the total area of ​​a plurality of silencers is greater than 1.5 times the cross-sectional area of ​​the inner liner.

[0009] As a limitation of this utility model: the inner liner is covered with a wire mesh layer, and the mesh size of the wire mesh is smaller than the size of the sound-absorbing holes.

[0010] As a limitation of this utility model: the diameter of the silencing hole is 5mm, and the mesh count of the wire mesh is 100.

[0011] As a limitation of this utility model: the outer tube is fixedly connected to a deflector tube, and the deflector tube is an arc-shaped tube.

[0012] As a limitation of this utility model: there are two directional pipes, which are symmetrically arranged on both sides of the outer pipe diameter.

[0013] As a limitation of this utility model: the end of the deflector away from the muffler is perpendicular to the muffler and the end of the deflector close to the muffler.

[0014] As a limitation of this utility model: the connecting part is a ram's horn joint connected to the end of the silencing part.

[0015] By adopting the above technical solution, the beneficial effects achieved by this utility model compared with the prior art are as follows: (1) This device effectively reduces the impact of noise on the surrounding environment during gas venting by utilizing the principles of throttling and pressure reduction and small-hole injection. Specifically, throttling and pressure reduction is achieved by appropriately designing the throttling section so that the pressure of high-pressure gas is reduced to the critical value when passing through the silencer hole. The uniformly distributed silencer holes are equivalent to a multi-stage series structure, which can disperse the primary pressure drop of the venting into several small pressure drops. Since the exhaust noise power is directly proportional to the higher power of the pressure drop, changing the sudden pressure venting to the gradual pressure reduction in the silencer section before venting can control the flow velocity in the silencer device to the critical flow velocity, thus preventing the generation of shock wave noise. Small-hole injection is based on the principle that the peak frequency of injection noise is inversely proportional to the nozzle diameter. If the nozzle diameter becomes smaller, the noise energy radiated by the nozzle will shift from low frequency to high frequency, thus reducing low frequency noise and increasing high frequency noise. When the aperture is small enough (reaching the mm level), the injection noise will shift to the frequency range that the human ear is not sensitive to, thereby achieving the purpose of reducing audible sound. (2) The outer pipe of this utility model is connected to a deflector pipe. By adjusting the installation angle of this device, the deflector pipe is made to face the ground, and the pressure of the venting gas will reach 4 kg. Directly venting pressurized gas will blow towards the personnel directly opposite the outlet of the outer pipe. The curved pipe of the deflector pipe makes the venting gas vent downward, so as not to accidentally injure the passers-by and improve safety. (3) The setting of the wire mesh can further reduce the nozzle diameter, thereby further enhancing the noise reduction effect; (4) The connection part adopts a horn valve, which is easy to purchase and convenient to install.

[0016] In summary, this invention can effectively reduce noise during the gas venting process, and is highly safe and easy to install, making it suitable for the gas venting process of cryogenic liquid tank trucks. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 This is a partial cross-sectional view of an embodiment of the present utility model; Figure 2 for Figure 1 Enlarged view of section A in the middle; Figure 3 This is a top view of an embodiment of the present utility model.

[0019] In the diagram: 1-Connecting part, 2-Inner liner, 3-Outer tube, 4-Silence hole, 5-Wire mesh layer, 6-Deflector tube. Detailed Implementation

[0020] The preferred embodiments of this utility model are described below with reference to the accompanying drawings. It should be understood that the cryogenic liquid tanker gas venting and silencing device described herein is a preferred embodiment and is only used for illustration and explanation of this utility model, and does not constitute a limitation thereof.

[0021] The directional terms or positional relationships used in this utility model, such as "up," "down," "left," and "right," are based on the positional relationships in the accompanying drawings of this utility model. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component must have a specific orientation, or that it must be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the content protected by this utility model. Example

[0022] This implementation example Figures 1 to 3 As shown, a gas venting silencing device for a cryogenic liquid tanker includes a connecting part 1 for detachable connection to the tank body, a silencing part communicating with the connecting part 1, and a deflector pipe 6 communicating with the silencing part.

[0023] The connecting part 1 is used for detachable connection with the downstream pipeline of the vent valve. Specifically, in this embodiment, the connecting part 1 is one half of a swivel joint, and the other half of the swivel joint is fixed at the outlet of the downstream pipeline. By connecting the two halves of the swivel joint, this device can be quickly connected to the original vent structure of the tank when venting is required. Of course, in addition to the swivel joint, the connecting part 1 can also be other existing structures that can achieve quick and detachable connection, such as pipe clamps or threaded connection structures, etc.

[0024] The silencing section is cylindrical in shape, with an open upper end that connects to the connecting section 1. Specifically, a shoulder is provided at the end of the silencing section for engaging with a ram's horn connector. This shoulder limits the connection between the ram's horn connector and the end of the silencing section. The connection between the two is welded, forming an integral structure. Alternatively, the connection can be detachable. The main body of the silencing section has a double-layer structure, including an inner liner 2 that communicates with the connecting section 1, and an outer tube 3 fixed outside the inner liner 2. Both the inner liner 2 and the outer tube 3 are hollow cylindrical structures. The lower end of the inner liner 2 is closed, while the lower end of the outer tube 3 is open. The inner liner 2 and the outer tube 3 are welded together at their upper ends. The main parts are separated from each other, and there is a gap between the outer wall of the inner liner 2 and the inner wall of the outer tube 3. A plurality of silencers 4 are evenly distributed on the wall of the inner liner 2. Here, "evenly distributed" means that the silencers 4 are arranged in a circular array along the circumference of the wall of the inner liner 2, and also evenly distributed along the axial direction of the wall of the inner liner 2. The outer tube 3 is positioned to cover the silencers 4, so that the gas released from the silencers 4 enters the cavity formed between the outer tube 3 and the inner liner 2. Further, the diameter of the silencers 4 is 1 / 10 to 1 / 5 of the diameter of the inner liner 2. In this embodiment, the diameter of the inner liner 2 is 40 mm, the diameter of the silencers 4 is 5 mm, and the total area of ​​the plurality of silencers 4 is greater than 1.5 times the cross-sectional area of ​​the inner liner 2, which can effectively reduce the gas pressure. During high-frequency operation, the silencer structure in this application can provide a larger exhaust cavity, making the exhaust smoother. The outer wall of the inner liner 2 is wrapped with a wire mesh layer 5. The mesh size of the wire mesh is smaller than the size of the silencer hole 4, which is equivalent to further reducing the nozzle diameter. In this embodiment, the wire mesh is a 100-mesh wire mesh that conforms to the ASTM E11 standard, that is, there are 100 holes in an area of ​​1 square centimeter.

[0025] The outer pipe 3 is fixedly connected to a deflector pipe 6, which is an arc-shaped pipe. One end of the deflector pipe 6 is fixedly connected to the outer pipe 3, and the other end of the deflector pipe 6 is an open structure, which can change the direction of gas discharge, allowing the vented gas to be discharged downwards, preventing accidental injury to passersby. Specifically, in this embodiment, two deflector pipes 6 are provided, symmetrically arranged on both sides of the outer pipe 3's diameter, forming a three-way structure with the outer pipe 3. The end of the deflector pipe 6 away from the muffler is perpendicular to both the muffler and the end of the deflector pipe 6 close to the muffler, so that when the muffler is installed horizontally on the tank, the deflector pipe 6 can exhaust gas downwards.

[0026] It should be noted that the vent valve on the tank is usually set horizontally. That is, when gas needs to be vented, after the device is installed through the jack joint, the silencer extends horizontally, and the deflector pipe 6 can vent downward. In other embodiments, if the vent valve is set in other directions, the venting direction of the deflector pipe 6 needs to be adapted to change, as long as the venting direction is directed towards the bottom.

Claims

1. A gas venting silencer for cryogenic liquid tank trucks, characterized in that: Includes a connecting part for detachable connection with the tank body and a sound-absorbing part connected to the connecting part; The silencing part has a double-layer structure, including an inner liner that communicates with the connecting part. The inner liner wall is provided with a number of silencing holes. The silencing part also includes an outer tube fixed outside the inner liner. The outer tube is positioned to cover the silencing holes, and there is a gap between the outer tube and the inner liner.

2. The cryogenic liquid tanker gas venting silencer according to claim 1, characterized in that: The end of the inner liner away from the connecting part is a closed structure.

3. The cryogenic liquid tanker gas venting silencer according to claim 2, characterized in that: The inner liner has a hollow cylindrical structure, and the diameter of the sound-absorbing hole is 1 / 10 to 1 / 5 of the inner liner diameter.

4. The cryogenic liquid tanker gas venting silencer according to claim 3, characterized in that: The total area of ​​several sound-absorbing holes is greater than 1.5 times the cross-sectional area of ​​the inner liner.

5. The cryogenic liquid tanker gas venting silencer according to claim 4, characterized in that: The inner liner is covered with a wire mesh layer, and the mesh size of the wire mesh is smaller than the size of the sound-absorbing holes.

6. The cryogenic liquid tanker gas venting silencer according to claim 5, characterized in that: The diameter of the sound-absorbing hole is 5mm, and the mesh count of the wire mesh is 100.

7. The cryogenic liquid tanker gas venting silencer according to any one of claims 1 to 6, characterized in that: The outer tube is fixedly connected to a deflector tube, which is an arc-shaped tube.

8. The gas venting silencer for cryogenic liquid tank trucks according to claim 7, characterized in that: There are two directional control pipes, which are symmetrically arranged on both sides of the outer pipe diameter.

9. The gas venting silencer for cryogenic liquid tank trucks according to claim 8, characterized in that: The end of the deflector furthest from the muffler is perpendicular to both the muffler and the end of the deflector closest to the muffler.

10. The cryogenic liquid tanker gas venting silencer according to any one of claims 1 to 6, 8, and 9, characterized in that: The connecting part is a ram's horn connector that connects to the end of the silencing part.

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