A laboratory dedicated ventilation duct

Abstract

The utility model discloses a laboratory special ventilation pipeline, include: first pipeline for conveying waste gas, second pipeline, coaxial sleeve is located first pipeline outside, and with first pipeline between annular protection gap is formed, coaxial double pass joint for connecting a plurality of first pipeline and second pipeline, coaxial double pass joint can simultaneously connect the inner flow channel of two adjacent first pipeline and two adjacent protection gap, wherein, protection gap is configured to fill with pressure controllable protective gas, the pressure of protective gas in protection gap is set to be higher than the atmospheric pressure of pipeline outside environment, and lower than the pressure of waste gas in first pipeline, and the detection probe of barometer is provided in protection gap.

Description

Technical Field

[0001] This utility model relates to the field of laboratory equipment technology, specifically a laboratory-specific ventilation duct. Background Technology

[0002] In laboratories specializing in chemistry, biology, and materials science, ventilation and exhaust systems are critical infrastructure for ensuring personnel safety and environmental cleanliness. Waste gases generated during experiments, containing acidic or alkaline gases, organic solvent vapors, and toxic or harmful substances, must be safely transported outdoors or to waste gas treatment facilities via dedicated piping systems.

[0003] Currently, laboratory ventilation and exhaust ducts generally adopt a single-layer pipe structure, and the materials are mostly stainless steel, PP, PVC, or fiberglass. These traditional pipes have the following significant defects and safety hazards in long-term use: If even a small leak occurs in the pipe body or at a joint, flammable and toxic gases will directly diffuse into the laboratory environment, posing a serious threat to personnel safety; for negative pressure or vacuum systems, outside air can seep into the pipe and may react with the internal gases, causing a hazard. Leaks are often very small and difficult to detect in a timely manner. Utility Model Content

[0004] This invention provides a laboratory-specific ventilation duct, the purpose of which is to solve the leakage risk of traditional laboratory gas ducts in the prior art.

[0005] This utility model provides a laboratory-specific ventilation duct, comprising: The first pipeline is used to transport exhaust gas; The second pipeline is coaxially sleeved outside the first pipeline, and an annular protective gap is formed between them. A coaxial dual-channel connector is used to connect multiple sections of the first pipeline and the second pipeline. The coaxial dual-channel connector can simultaneously connect the inner flow channels of two adjacent sections of the first pipeline and the protective gaps of two adjacent sections. The protective gap is configured to be filled with a pressure-controllable protective gas. The pressure of the protective gas in the protective gap is set to be higher than the atmospheric pressure of the external environment of the pipeline and lower than the pressure of the exhaust gas in the first pipeline. A pressure gauge detection probe is installed in the protective gap.

[0006] Furthermore, at least one coaxial bracket is provided within the protective gap, the coaxial bracket being used to support the first pipeline and keep it coaxial with the second pipeline.

[0007] Furthermore, the coaxial support includes a support ring, the outer edge of which abuts against the inner wall of the second pipeline and the inner edge of which abuts against the outer wall of the first pipeline, and the support ring is provided with at least one second through hole for allowing protective gas to flow within the protective gap.

[0008] Furthermore, the coaxial dual-channel connector includes: a first sleeve fitted onto the end of the first pipeline and a second sleeve fitted onto the end of the second pipeline; a spacer ring is provided between the first sleeve and the second sleeve, and the spacer ring has at least one first through hole for connecting the protective gap between two adjacent pipeline sections.

[0009] Furthermore, the second pipeline or the coaxial dual-channel connector is provided with a port for inflating the protective gap or connecting a pressure monitoring device.

[0010] Furthermore, a support rod arranged axially along the first pipeline is also inserted inside the support ring to enhance the structural strength of the coaxial bracket.

[0011] This utility model has at least the following beneficial effects: This invention provides a laboratory-specific ventilation duct with a double-layered structure. The inner layer serves as the primary exhaust gas passage, while the annular protective gap between the outer and inner layers constitutes a robust second safety barrier. Even if the inner pipe leaks due to long-term corrosion or accidental damage, toxic and harmful exhaust gases are first confined within the completely sealed protective gap, preventing direct diffusion into the laboratory environment and fundamentally ensuring personnel safety. A pressure gauge connected to the lateral protective gas port indicates a leak in the inner pipe upon abnormal pressure rise, providing a passive safety warning. Because the protective gap maintains an inert gas pressure higher than atmospheric pressure, even minor imperfections in the outer pipe or joint seals will only cause a small amount of inert gas to leak outwards, while external air and moisture cannot penetrate against the pressure difference, thus preventing contamination of the hazardous exhaust gases in the inner pipe. After installation, the tedious "soap bubble method" leak detection is unnecessary for each joint. The sealing performance of all outer piping can be verified by simply pressurizing or vacuuming the entire protective gap system through the lateral protective gas port of any connector, greatly simplifying the installation and commissioning process. The presence of the outer pipe provides additional mechanical protection for the core inner pipe, preventing damage to the inner pipe due to collisions, scratches, etc., and extending the service life of the entire piping system. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of a laboratory-specific ventilation duct according to the present invention; Figure 2This is a schematic cross-sectional view of a laboratory-specific ventilation duct according to the present invention. Figure 3 This is a schematic diagram of the structure of a coaxial dual-channel connector for a laboratory-specific ventilation duct according to the present invention; Figure 4 This is a front view of a coaxial dual-channel connector for a laboratory-specific ventilation duct according to the present invention. Figure 5 This is a schematic diagram of the structure of a coaxial support for a laboratory-specific ventilation duct according to the present invention; Figure 6 This is a possible structural schematic diagram of a support ring for a laboratory-specific ventilation duct according to the present invention. Figure 7 This is a possible structural schematic diagram of a support ring for a laboratory-specific ventilation duct according to the present invention. Figure 8 This is a schematic diagram of the structure of the third clamping sleeve of a laboratory-specific ventilation duct according to the present invention; In the diagram: 1. First pipeline; 2. Second pipeline; 3. Coaxial dual-channel connector; 4. Coaxial bracket; 5. First ferrule; 6. Second ferrule; 7. First annular retainer; 8. Second annular retainer; 9. Spacer ring; 10. Inner flow channel; 11. First through hole; 12. Second through hole; 13. Third through hole; 14. Fourth through hole; 15. Support ring; 16. Support rod; 17. Third ferrule. Detailed Implementation

[0013] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0014] Please see Figure 1-7This utility model provides a laboratory-specific ventilation duct, including a first duct 1 and a second duct 2 sleeved outside the first duct 1, with an annular protective gap between the first duct 1 and the second duct 2. A coaxial support 4 is provided within the gap to ensure that the first duct 1 and the second duct 2 are coaxially arranged. The coaxial dual-channel connector 3 is fixedly connected to both ends of the first duct 1 and the second duct 2, respectively. The coaxial dual-channel connector 3 includes a first retaining sleeve 5 and a second retaining sleeve 6. The first retaining sleeve 5 communicates with the first duct 1, and the second retaining sleeve 6 connects to the second duct 2. The second duct 2 is filled with inert gas. The coaxial support 4 is a hollow support. The air pressure between the first duct 1 and the second duct 2 is greater than the indoor atmospheric pressure but less than the air pressure inside the first duct 1. A pressure gauge probe is provided inside the first duct 1 and the second duct 2.

[0015] The first pipeline 1 is made of stainless steel and has undergone electrochemical polishing, resulting in a high degree of smoothness on the inner wall, making it suitable for conveying high-purity or corrosive gases; the second pipeline 2 is made of lower-cost 304 stainless steel, serving as a mechanical protection and sealing function.

[0016] In an embodiment of this utility model, the first pipeline 1 and the second pipeline 2 are of equal length.

[0017] In an embodiment of this utility model, the first pipeline 1 is sealed to the first ferrule 5, and the second pipeline 2 is sealed to the second ferrule 6.

[0018] As an optional embodiment, the first sleeve 5 has an inner flow channel 10. The first sleeve 5 is a circular sleeve, and the two ends of the first sleeve 5 are respectively provided with axial first circular slots 7. The first circular slots 7 are fitted onto one end of the first pipe 1 to connect the two first pipes 1. The inner flow channel 10 is opened on the inner edge of the first sleeve 5.

[0019] As an optional embodiment, the second sleeve 6 is sleeved outside the first sleeve 5, and the two ends of the second sleeve 6 are respectively provided with second annular slots 8. The second annular slots 8 are sleeved at one end of the second pipe 2 for connecting the two second pipes 2.

[0020] As an example of implementation, a spacer ring 9 is fixedly connected between the second ferrule 6 and the first ferrule 5. The spacer ring 9 has a plurality of first through holes 11 axially opened. Each first through hole 11 is axially opened and evenly distributed on the spacer ring 9. Each first through hole 11 is used to connect the protective gap between the two first pipes 1 and the second pipe 2.

[0021] In an embodiment of this utility model, the coaxial bracket 4 is fixedly connected within the first pipeline 1 and the second pipeline 2. The coaxial bracket 4 includes multiple support rings 15, each of which is sequentially disposed within a protective gap. The outer edge of each support ring 15 abuts against the inner edge of the second pipeline 2, and the inner edge of each support ring 15 abuts against the outer edge of the second pipeline 2. Multiple second through holes 12 are formed on each support ring 15, and each second through hole 12 is evenly distributed on the support ring 15. Each second through hole 12 is axially oriented, allowing the protective gap between the first pipeline 1 and the second pipeline 2 to be connected. This ensures that the first pipeline 1 remains centered on the second pipeline 2 during long-distance laying and does not contact the second pipeline 2. Each support ring 15 is evenly disposed between the first pipeline 1 and the second pipeline 2.

[0022] As an alternative embodiment, multiple contacts on the inner edge of the support ring 15 gently abut against the outer edge of the first conduit 1, and the open second through hole 12 ensures free flow of gas within the protective gap.

[0023] As an optional embodiment, each of the support rings 15 is provided with a plurality of support rods 16 axially inserted to improve the support strength of the support rings 15. The support rings 15 are provided with a plurality of third through holes 13 axially opened, and each of the support rods 16 is inserted into the third through hole 13.

[0024] The coaxial bracket 4 and its support ring 15 ensure that the first pipeline 1 can always be accurately maintained in the center position of the second pipeline 2 during long-distance laying. This not only avoids friction and wear caused by the inner pipe contacting the outer pipe due to gravity or vibration, but also ensures that the cross-sectional area of ​​the annular protective gap is uniform everywhere, providing the necessary conditions for stable pressure and smooth flow of protective gas.

[0025] The second through-hole 12 ensures complete connectivity between the protective gaps separated by the coaxial bracket 4, forming an unobstructed whole. When a leak occurs at any location, causing a pressure change, the pressure wave can quickly propagate throughout the entire protective gap through these through-holes, ensuring that the pressure sensor can detect the signal without delay, thereby guaranteeing the sensitivity and reliability of the early warning system.

[0026] A support rod 16 is further inserted inside the support ring 15, enhancing the overall structural strength and rigidity of the coaxial bracket 4. This allows the piping system to withstand greater radial pressure and axial load, maintaining excellent stability and coaxial accuracy even in complex installation environments or long-distance suspended installations.

[0027] As an example of implementation, the spacer ring 9 has a plurality of fourth through holes 14, the length of each support rod 16 being the sum of the length of the first pipe 1 and the thickness of the coaxial dual-channel connector 3, and the fourth through hole 14 being used to connect two support rods 16.

[0028] In an embodiment of this utility model, the second pipeline 2 is externally connected to a make-up air pump and an inert gas source.

[0029] In an embodiment of this utility model, after several first pipelines 1 and second pipelines 2 are connected sequentially through a coaxial dual-channel connector 3, sealing connectors are fixedly connected to both ends of the overall pipeline. The sealing connector includes a third sleeve 17 and an inner flow channel 10. The third sleeve 17 has a third circular opening on one side. The third circular opening is fitted onto the inner edge of the first pipeline 1 and the outer edge of the second pipeline 2. The inner edge of the third circular opening has an inner flow channel 10. The third circular opening completely seals the protective gap of the overall pipeline. The third sleeve is connected to upstream and downstream equipment respectively.

[0030] The required length of the first pipe 1, the second pipe 2, and several coaxial dual-channel connectors 3 are connected and assembled into a complete piping system.

[0031] Slowly inject nitrogen into the protective gaps of the entire piping system using a make-up gas pump until the pressure reaches a safe value, such as 0.2 bar. This pressure is higher than atmospheric pressure but much lower than the main gas pressure of the first pipeline. Close the make-up gas valve and observe the pressure gauge. If the pressure remains constant for a period of time, it proves that the outer layer of the entire system is well sealed.

[0032] At this point, it is safe to introduce 5 bar of gas into the first pipeline 1.

[0033] In this state: If a minor leak occurs somewhere in the first pipeline 1, 5 bar of hydrogen gas will enter the 0.2 bar protective gap, causing the pressure to rise rapidly, the pressure gauge reading to change, and thus issuing a warning.

[0034] If the second pipe 2 is defective, 0.2 bar of nitrogen will slowly leak outwards, but external air cannot enter the protective gap or come into contact with the first pipe 1, thus ensuring that the gas in the first pipe 1 will not leak into the laboratory and cause harm.

[0035] The first ferrule 5, the second ferrule 6, and the third ferrule 17 are sealed and welded to the first pipeline 1 and the second pipeline 2, and the connection is filled with sealant to ensure sealing performance. The specific sealing method is a conventional technical means in the field. The core of this application is to protect the safety redundancy design of the coaxial pipeline. The specific sealing method itself will not be described in detail.

Claims

1. A laboratory-specific ventilation duct, characterized in that, include: The first pipeline (1) is used to transport waste gas; The second pipe (2) is coaxially sleeved outside the first pipe (1) and forms an annular protective gap between it and the first pipe (1); A coaxial dual-channel connector (3) is used to simultaneously connect the inner flow channels (10) of two adjacent sections of the first pipeline (1) and the protective gaps of the two adjacent sections. The protective gap is configured to be filled with a pressure-controllable protective gas. The pressure of the protective gas in the protective gap is set to be higher than the atmospheric pressure of the external environment of the pipeline and lower than the pressure of the exhaust gas in the first pipeline (1). A pressure gauge detection probe is installed in the protective gap.

2. The laboratory-specific ventilation duct according to claim 1, characterized in that, At least one coaxial bracket (4) is provided in the protective gap. The coaxial bracket (4) is used to support the first pipeline (1) and keep it coaxial with the second pipeline (2).

3. A laboratory-specific ventilation duct according to claim 2, characterized in that, The coaxial support (4) includes a support ring (15), the outer edge of which abuts against the inner wall of the second pipeline (2) and the inner edge of which abuts against the outer wall of the first pipeline (1). The support ring (15) is provided with at least one second through hole (12) for allowing protective gas to flow in the protective gap.

4. A laboratory-specific ventilation duct according to claim 1, characterized in that, The coaxial dual-channel connector (3) includes: a first sleeve (5) fitted at the end of the first pipeline (1) and a second sleeve (6) fitted at the end of the second pipeline (2); a spacer ring (9) is provided between the first sleeve (5) and the second sleeve (6), and at least one first through hole (11) is provided on the spacer ring (9) for connecting the protective gap of two adjacent pipeline sections.

5. A laboratory-specific ventilation duct according to claim 1, characterized in that, The second pipeline (2) or the coaxial dual-channel connector (3) is provided with a port for inflating the protective gap or connecting a pressure monitoring device.

6. A laboratory-specific ventilation duct according to claim 3, characterized in that, The support ring (15) is also provided with a support rod (16) arranged along the axial direction of the first pipeline to enhance the structural strength of the coaxial bracket (4).

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