Air sampling multi-stage dehumidifying device for rail transit
By adding a multi-stage dehumidification structure to the air sampling device, the problem of water droplet condensation in high humidity environments was solved, achieving both stability and economy in gas monitoring.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JINHUA ZHENGAN FIRE-FIGHTING INSPECTION & TESTING CO LTD
- Filing Date
- 2025-08-18
- Publication Date
- 2026-06-26
AI Technical Summary
Existing rail transit air sampling devices are prone to water droplet condensation in high humidity environments, which can lead to short circuits on circuit boards and poor monitoring results. Furthermore, frequent disassembly and inspection increase workload and affect sealing and monitoring effectiveness.
A three-stage venting structure, a gradient wetting membrane, absorbent cotton, a two-stage extrusion structure, and a primary water droplet guiding structure are added to the air sampling device to collect, guide, and extrude water vapor and water droplets, respectively, to prevent them from entering the gas analysis module.
It effectively prevents water droplets and water vapor from entering the gas analysis module, avoiding functional damage and economic losses, reducing the frequency of inspections by staff, and ensuring the normal operation of gas monitoring.
Smart Images
Figure CN224415282U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of air sampling technology, specifically to a multi-stage dehumidification device for air sampling in rail transit. Background Technology
[0002] With the continuous development of society, economy and technology, light rail and subway have gradually become the preferred mode of travel for people. In order to ensure the fire safety of rail transit and to detect fire alarm information as soon as possible, stations are usually equipped with very early air sampling alarm systems, also known as air sampling early smoke detectors or aspirating smoke detectors. These are fire early warning devices that actively collect air samples for smoke analysis and are mainly used in special environments such as high spaces and enclosed cabinets.
[0003] This early-stage air sampling alarm system typically uses multiple sampling tubes to sample gases. The gases are ultimately collected in a single pipe and enter a preliminary filtration module. The filter sponge in the filtration module primarily adsorbs moisture or condensed water droplets from the air, while other particulate matter enters the gas analysis module via a U-shaped tube for analysis. However, during periods of high humidity, such as the "return to spring" weather in southern China, the humid air can easily permeate the air sampling tubes in a short time, condensing into water droplets that then flow and are adsorbed by the filter sponge. In severe cases, water droplets may even seep out of the filter sponge and enter the gas analysis module via the U-shaped tube, causing short circuits on the circuit board. This not only disrupts normal gas monitoring but also results in economic losses. Therefore, to ensure normal gas environment monitoring, staff must frequently disassemble and inspect the air sampling device. This not only increases the workload but also, with increased disassembly and reassembly frequency, can lead to poor sealing of the sampling device, affecting monitoring results.
[0004] Existing sampling devices have made some improvements to this. For example, the moisture-proof device for a smoke detector disclosed in CN217767581U is moisture-proof by adding water-absorbing material, which has a certain dehumidification effect. However, in order to prevent water droplets from flowing into the gas analysis module during the humid spring weather, the water-absorbing material needs to be set large enough. However, this will greatly increase the volume of the original air sampling device and will also hinder air circulation, affecting the monitoring effect. Summary of the Invention
[0005] The purpose of this invention is to address the shortcomings of existing technologies and provide a multi-stage dehumidification device for air sampling in rail transit. By adding corresponding dehumidification structures before, inside, and after the filter module in the original air sampling device, water vapor and water droplets are guided and collected, achieving multiple protections and preventing water droplets from flowing into the gas analysis module. This avoids affecting gas monitoring and also avoids economic losses.
[0006] To solve the above problems, the present invention adopts the following solution:
[0007] A multi-stage dehumidification device for air sampling in rail transit includes a sampling collection tube, a filter module, a U-shaped tube, and a gas analysis module of the original air sampling device; it also includes a three-stage drainage structure installed in the middle of the U-shaped tube after the filter module to collect dripping water seeping from the filter sponge in the filter module; the three-stage drainage structure includes a drainage tube connected to the bottom of the U-shaped tube and a collection bottle detachably connected to the drainage tube, the bottom of the collection bottle is also connected to a drainage pipe with its lower end connected to the outside, and a drainage control valve is installed in the middle of the drainage pipe to control whether it is connected to the outside.
[0008] This solution employs a three-stage drainage structure, allowing water seeping from the filter sponge to flow along the U-shaped tube into the drainage tube and then into the collection bottle. This prevents water from flowing into the gas analysis module, thus avoiding damage to the air sampling device and economic losses. During regular inspections, staff can rotate and open the drainage control valve to drain the accumulated water. This also helps to understand the water seepage situation of the air sampling device during periods of high humidity.
[0009] Preferably, the drainage tube is equipped with a gradient wetting membrane, with its upper surface being hydrophilic and its lower surface being superhydrophobic. This ensures that water droplets, water vapor, etc., can only flow unidirectionally into the collection bottle from the U-shaped tube and cannot flow back through, thereby further reducing the probability of water droplets flowing into the gas analysis module.
[0010] Preferably, absorbent cotton is provided above the gradient wetting membrane. The absorbent cotton is connected to the inner wall of the drainage tube through an annular support frame, which has flow gaps corresponding to both sides of the U-shaped tube.
[0011] By setting up absorbent cotton, some of the water vapor that may still exist in the sampled gas can be absorbed, reducing the amount of water vapor flowing into the gas analysis module. At the same time, the flow gap ensures that the dripping water can flow smoothly into the collection bottle along the flow gap.
[0012] Preferably, the lower part of the drainage tube is equipped with a liquid level sensor connected to the air sampling system. When the water in the collection box accumulates to the liquid level sensor, the liquid level sensor receives the signal and transmits it to the air sampling system. The system then alerts the staff through warning lights or message prompts to promptly clean the water in the collection bottle.
[0013] Preferably, the device also includes a secondary extrusion structure installed in the filter module for extruding the adsorbed water in the filter sponge. The secondary extrusion structure includes a linear pushing mechanism connected to an extrusion plate. Under the action of the linear pushing mechanism, the extrusion plate can squeeze the filter sponge between the extrusion plate and the inner wall of the filter module housing, thereby squeezing out the adsorbed water in the filter sponge and achieving the water removal effect of the filter sponge.
[0014] Preferably, the filter module also includes a humidity sensor connected to the air sampling system to transmit humidity signals and control the linear actuator to start. A preset humidity level is set for the humidity sensor; when the humidity reaches the set value, the air sampling system controls the linear actuator to start, compressing the filter sponge.
[0015] Preferably, the U-shaped tube opening is connected to the side of the filter sponge away from the drive motor, so that it corresponds to the position when the filter sponge is flattened, ensuring that the water dripping out of the filter sponge flows into the U-shaped tube as much as possible.
[0016] Preferably, the device also includes a primary water droplet guiding structure, which is detachably installed on the sampling collection tube before the filter module to guide water droplets and promote water vapor condensation into water droplets, thereby reducing the amount of water droplets and water vapor flowing into the filter sponge.
[0017] The primary water droplet guiding structure includes an installation connecting pipe, inside which a water droplet forming guiding membrane is obliquely arranged. The water droplet forming guiding membrane can promote the condensation of water vapor into water droplets and only allows gas other than water droplets to pass through. The lower end of the water droplet forming guiding membrane forms a water accumulation area with the wall of the installation connecting pipe. The water accumulation area has a water outlet, and a water droplet collection box is detachably connected to the water outlet through a pipe. An automatic drain valve is also provided at the water outlet.
[0018] A primary water droplet guiding structure is set up to further reduce water vapor and condensation in the pipe, preventing the filter sponge from absorbing too much water vapor and causing it to frequently reach the humidity value and activate the linear pushing mechanism. Therefore, the filter sponge is prevented from being squeezed and dehydrated frequently, which would affect its filtration effect.
[0019] Preferably, the lower end of the water droplet forming guide membrane is provided with a support grid to support the water droplet forming guide membrane, while not affecting the passage of other gases, ensuring the reliable use of the water droplet forming guide membrane and avoiding easy damage.
[0020] Preferably, the water droplet forming guiding membrane is a superhydrophilic porous membrane, and the automatic drain valve is a float-type automatic drain valve.
[0021] The beneficial effects of this utility model are as follows:
[0022] This invention features a three-stage drainage structure, allowing water dripping from the filter sponge to flow into the drainage tube and then into a collection bottle. This prevents water from flowing into the gas analysis module, thus avoiding damage to the air sampling device and economic losses. During regular inspections, staff can rotate and open the drainage control valve to drain the accumulated water. This also helps to understand the water leakage situation of the air sampling device during periods of high humidity.
[0023] This invention, by adding a two-stage extrusion structure, can squeeze out the adsorbed water inside the filter sponge and guide it into the U-shaped tube, thereby achieving the water removal effect of the filter sponge and preventing excessive adsorption of water from affecting its own filtration function. This further ensures the normal operation of gas monitoring.
[0024] This invention adds a primary water droplet guiding structure, enabling the device to collect water vapor or water droplets condensed from water vapor in stages, achieving multiple protections and further reducing the probability of water vapor or water droplets flowing into the gas analysis module, thus avoiding damage to the circuit board of the gas analysis module. It also reduces the impact of water vapor on gas monitoring and analysis. Attached Figure Description
[0025] Figure 1 This is a two-dimensional structural schematic diagram of Example 1;
[0026] Figure 2 This is a schematic diagram of the internal structure of the three-stage bleeder structure in Example 2;
[0027] Figure 3 This is a top view of the absorbent cotton and the annular support frame in Example 2;
[0028] Figure 4 This is a two-dimensional structural schematic diagram of Example 3;
[0029] Figure 5 This is a schematic diagram of the internal structure of the two-stage extrusion structure in Example 3;
[0030] Figure 6 This is a two-dimensional structural schematic diagram of Example 4;
[0031] Figure 7 This is a schematic diagram of the internal structure of the primary water droplet guiding structure in Example 4.
[0032] Figure label:
[0033] Sampling collection tube 10, filtration module 20, U-shaped tube 30, gas analysis module 40, filter sponge 21, three-stage effluent structure 50, two-stage extrusion structure 60, primary water droplet guiding structure 70, drainage tube 51, collection bottle 52, gradient wetting membrane 53, absorbent cotton 541, annular support frame 542, flow gap 543, liquid level sensor 55, effluent pipe 56, effluent control valve 57, linear push mechanism 61, extrusion plate 62, humidity sensor 63, drive motor 611, lead screw 612, reduction assembly 613, mounting connection pipe 71, water droplet forming guiding membrane 72, water accumulation area 73, water outlet 74, water droplet collection box 75, automatic drain valve 76, support grid 77. Detailed Implementation
[0034] This invention provides a multi-stage dehumidification device for air sampling in rail transit. It is mainly used to solve the problem of water droplets condensing and flowing into the gas analysis module 40 due to the high humidity during the "return to spring" weather in southern China. In multiple embodiments of this invention, corresponding dehumidification structures are added sequentially before, inside, and after the filter module 20 in the original air sampling device to guide and collect water vapor and water droplets, achieving multiple protections and preventing water droplets from flowing into the gas analysis module 40. This avoids affecting gas monitoring and causing economic losses.
[0035] Example 1:
[0036] refer to Figure 1 The multi-stage dehumidification device for air sampling includes a sampling collection tube 10, a filter module 20, a U-shaped tube 30, and a gas analysis module 40 arranged sequentially along the gas flow direction in the original air sampling device; it also includes a three-stage drainage structure 50, which is installed in the middle of the U-shaped tube 30 after the filter module 20, for collecting dripping water seeping from the filter sponge 21 in the filter module 20. It includes a drainage tube 51 connected to the bottom of the U-shaped tube 30 and a collection bottle 52 detachably connected to the drainage tube 51. The collection bottle 52 is connected to the drainage tube 51 by a thread. The bottom of the collection bottle 52 is also connected to a drainage tube 56. The lower end of the drainage tube 56 is connected to the outside. A drainage control valve 57 is installed in the middle of the drainage tube 56 to control whether it is connected to the outside (since the control valve structure for controlling flow or blocking is existing technology and is relatively common, its structure is not described in detail in this embodiment and the accompanying drawings).
[0037] During regular inspections, staff can rotate and open the drain control valve 57 to drain the water accumulated in the collection bottle 52. If long-term use causes problems with the drain control valve 57, the collection bottle 52 can be unscrewed to pour out the water.
[0038] Example 2:
[0039] refer to Figure 2Based on Embodiment 1, this embodiment further provides a gradient wetting membrane 53 inside the drainage tube 51. The upper surface of the membrane is hydrophilic and the lower surface is superhydrophobic. This ensures that water droplets, water vapor, etc., can only flow unidirectionally from the U-shaped tube 30 into the collection bottle 52. The water vapor accumulated in the collection bottle 52 cannot pass through the gradient wetting membrane 53 into the U-shaped tube 30, thus ensuring that water droplets will not flow into the gas analysis module 40, achieving multiple protections.
[0040] refer to Figure 2 , Figure 3 To enable the structure to absorb some of the water vapor that may still be present in the sampled gas, an absorbent cotton 541 is provided above the gradient wetting membrane 53. The absorbent cotton 541 is connected to the inner wall of the drainage tube 51 through an annular support frame 542. The annular support frame 542 has flow gaps 543 corresponding to both sides of the U-shaped tube 30 to ensure that the dripping water flowing down from the U-shaped tube 30 can smoothly pass through the flow gaps 543, and then through the gradient wetting membrane 53 into the collection bottle 52.
[0041] refer to Figure 2 The lower part of the drainage tube 51 is equipped with a liquid level sensor 55 that is connected to the air sampling system. When the water in the collection bottle 52 accumulates to the liquid level sensor 55, the liquid level sensor 55 receives the signal and transmits it to the air sampling system. The system then reminds the staff to clean the water in the collection bottle 52 in a timely manner through warning lights or message prompts.
[0042] Example 3:
[0043] refer to Figure 4 , Figure 5 Based on Example 2, this embodiment adds a two-stage extrusion structure 60 to extrude the filter sponge 21, squeezing out the adsorbed water and guiding it into the U-shaped tube 30. This achieves the water removal effect of the filter sponge 21 and avoids excessive adsorbed water from affecting its own filtration function, thus ensuring the normal operation of gas monitoring.
[0044] refer to Figure 5 The secondary extrusion structure 60 is installed in the filter module 20 and includes a linear push mechanism 61. The linear push mechanism 61 is connected to an extrusion plate 62. Under the action of the linear push mechanism 61, the extrusion plate 62 can squeeze the filter sponge 21 between the extrusion plate 62 and the inner wall of the filter module 20, thereby squeezing out the adsorbed water in the filter sponge 21.
[0045] Specifically, the linear drive mechanism 61 can be driven by a linear motor or by a lead screw structure. In this embodiment, a lead screw structure is selected, including a drive motor 611 and a lead screw 612 connected between the drive motor 611 and the housing of the filter module 20. The extrusion plate 62 is slidably connected to the lead screw 612 by a thread. The drive motor 611 is equipped with a reduction gear 613 to ensure that the lead screw 612 rotates smoothly and with minimal vibration.
[0046] Furthermore, a humidity sensor 63 is also installed within the filter module 20. The humidity sensor 63 is connected to the air sampling system and is used to transmit humidity signals to control the linear actuator 61 to start. A certain humidity is preset for the humidity sensor 63. When the humidity is detected to reach the set value, the air sampling system controls the linear actuator 61 to start, compressing the filter sponge 21.
[0047] refer to Figure 4 The U-shaped tube 30 is connected to the side of the filter sponge 21 away from the drive motor 611, so that it corresponds to the position of the filter sponge 21 when it is flattened, ensuring that the water dripping out of the filter sponge 21 flows into the U-shaped tube 30 as much as possible.
[0048] Example 4:
[0049] refer to Figure 6 This embodiment adds a primary water droplet guiding structure 70 based on embodiment 2 or embodiment 3, which is used to initially collect water droplets condensed in the sampling collection tube 10 and some water vapor in the air, further realizing the dehumidification and drying of the air sampling system and preventing water droplets or water vapor from flowing into the gas analysis module 40.
[0050] refer to Figure 7 The primary water droplet guiding structure 70 is installed on the sampling collection tube 10 before the filter module 20. It includes a mounting connecting tube 71. A water droplet forming guiding membrane 72 is obliquely arranged inside the mounting connecting tube 71. The water droplet forming guiding membrane 72 can promote the condensation of water vapor into water droplets and only allows gas molecules other than water droplets to pass through. The lower end of the water droplet forming guiding membrane 72 forms a water accumulation area 73 with the pipe wall of the mounting connecting tube 71. The water accumulation area 73 has a water outlet 74. The water outlet 74 is detachably connected to a water droplet collection box 75 through a pipe. An automatic drain valve 76 is also provided at the water outlet 74.
[0051] When water vapor condenses into water droplets on the water droplet forming guide membrane 72, it can slide down the inclined membrane surface into the water accumulation area 73. When the water accumulates to a certain extent in the water accumulation area 73, the automatic drain valve 76 can be opened automatically to discharge the water from the outlet 74 into the water droplet collection box 75. During regular inspections, staff can periodically disassemble the water droplet collection box 75 and empty the water inside.
[0052] Furthermore, a support grid 77 is provided at the lower end of the water droplet forming guide membrane 72 to support the water droplet forming guide membrane 72, while not affecting the passage of other gases, ensuring the reliable use of the water droplet forming guide membrane 72 and avoiding easy damage.
[0053] Preferably, the water droplet forming guide membrane 72 can be a superhydrophilic porous membrane, such as PTEE or ceramic composite membrane. The superhydrophilic porous membrane accelerates the adsorption and condensation of water vapor into water droplets through its superhydrophilic surface, and then utilizes its microporous structure to prevent liquid water from passing through while other gases can pass through. Alternatively, a metal-organic framework coated porous substrate material can be used. In this embodiment, a superhydrophilic porous membrane is selected.
[0054] The automatic drain valve 76 is a float-type automatic drain valve 76, which has a float. As water droplets accumulate in the water accumulation area 73, the float gradually rises using its own buoyancy in the water, and drives the valve connected to it and blocked at the outlet 74 to rotate, thereby opening the outlet 74.
[0055] Furthermore, the primary water droplet guiding structure 70 is detachably installed on the sampling collection tube 10 via threads. Therefore, when the water droplet forming guiding film 72 in this structure fails or is ineffective, this structure can be replaced or removed to ensure smooth flow of the sampling gas.
[0056] In this utility model, the embodiment with the best effect is the structure added based on embodiment 3, and its working process is as follows:
[0057] The sampling gas flows into the sampling collection tube 10 along the pipe. If it has condensed into water droplets inside the pipe wall, the water droplets flow directly along the pipe wall to the water droplet forming guide film 72, and then flow into the water accumulation area 73. Meanwhile, the water vapor in the gas can form water droplets on the surface of the water droplet forming guide film 72, and then flow into the water accumulation area 73. When it accumulates to a certain extent in the water accumulation area 73, the automatic drain valve 76 can be opened automatically to drain the accumulated water.
[0058] After running for a certain period of time, water vapor will still pass through and be adsorbed by the filter sponge 21. When the adsorption reaches a certain level and the humidity reaches the preset humidity signal transmitted by the humidity sensor 63, the linear push mechanism 61 is started to squeeze the filter sponge 21, squeeze out the adsorbed water inside, and let it flow into the drainage pipe 51 along the U-shaped tube 30.
[0059] The adsorbed water then flows along the drainage pipe 51 and is temporarily stored in the collection bottle 52, which is cleaned regularly by staff. Alternatively, if the water in the collection bottle 52 accumulates to a certain level due to prolonged lack of cleaning, the liquid level sensor 55 will send a signal to remind staff to clean it.
Claims
1. A multi-stage dehumidification device for air sampling in rail transit, comprising a sampling collection tube (10), a filter module (20), a U-shaped tube (30), and a gas analysis module (40), characterized in that, It also includes a three-stage drainage structure (50), which is installed in the middle of the U-shaped pipe (30) after the filter module (20) to collect the dripping water that seeps out of the filter sponge (21) in the filter module (20); The three-stage venting structure (50) includes a drainage pipe (51) connected to the bottom of the U-shaped tube (30) and a collection bottle (52) detachably connected to the drainage pipe (51). The bottom of the collection bottle (52) is also connected to a venting pipe (56) whose lower end is connected to the outside. The venting pipe (56) is equipped with a venting control valve (57) that can control its connection to or blockage from the outside.
2. The multi-stage dehumidification device for air sampling in rail transit according to claim 1, characterized in that, The drainage tube (51) is provided with a gradient wetting membrane (53), the upper surface of which is hydrophilic and the lower surface is superhydrophobic. The gradient wetting membrane (53) is used to ensure that the dripping water can only flow into the collection bottle (52) from the U-shaped tube (30) in one direction.
3. The multi-stage dehumidification device for air sampling in rail transit according to claim 2, characterized in that, Above the gradient wetting membrane (53) is an absorbent cotton (541), which is connected to the inner wall of the drainage tube (51) through an annular support frame (542). The annular support frame (542) has flow gaps (543) corresponding to both sides of the U-shaped tube (30).
4. The multi-stage dehumidification device for air sampling in rail transit according to claim 1, characterized in that, The lower part of the drainage tube (51) is provided with a liquid level sensor (55) that is connected to the air sampling system.
5. The multi-stage dehumidification device for air sampling in rail transit according to claim 1, characterized in that, It also includes a secondary extrusion structure (60), which is installed in the filter module (20) to extrude the adsorbed water in the filter sponge (21); The secondary extrusion structure (60) includes a linear push mechanism (61), which is connected to an extrusion plate (62) and can extrude the filter sponge (21) between the extrusion plate (62) and the inner wall of the housing of the filter module (20).
6. The multi-stage dehumidification device for air sampling in rail transit according to claim 5, characterized in that, The filter module (20) is also equipped with a humidity sensor (63), which is connected to the air sampling system and is used to transmit humidity signals to control the start of the linear actuator (61).
7. The multi-stage dehumidification device for air sampling in rail transit according to claim 5, characterized in that, One end of the U-shaped tube (30) is connected to the side of the filter sponge (21) away from the drive motor (611) so that the end of the tube corresponds to the position of the filter sponge (21) when it is flattened.
8. The multi-stage dehumidification device for air sampling in rail transit according to any one of claims 1-7, characterized in that, It also includes a primary water droplet guiding structure (70), which is detachably installed on the sampling collection tube (10) before the filter module (20) to guide water droplets and promote water vapor condensation into water droplets, thereby reducing the water droplets and water vapor flowing into the filter sponge (21); The primary water droplet guiding structure (70) includes an installation connecting pipe (71), in which a water droplet forming guiding membrane (72) is obliquely arranged. The water droplet forming guiding membrane (72) can promote the condensation of water vapor into water droplets and only allows gas other than water droplets to pass through. The lower end of the water droplet forming guiding membrane (72) forms a water accumulation area (73) with the wall of the installation connecting pipe (71). The water accumulation area (73) has a water outlet (74). The water outlet (74) is detachably connected to a water droplet collection box (75) through a pipe. An automatic drain valve (76) is also provided at the water outlet (74).
9. The multi-stage dehumidification device for air sampling in rail transit according to claim 8, characterized in that, The lower end of the water droplet forming guide membrane (72) is provided with a support grid (77) for supporting the water droplet forming guide membrane (72).
10. The multi-stage dehumidification device for air sampling in rail transit according to claim 8, characterized in that, The water droplet forming guide membrane (72) is a superhydrophilic porous membrane, and the automatic drain valve (76) is a float-type automatic drain valve (76).