A fire detector and alarm for utility tunnels

Abstract

A pipe gallery fire detector includes an upper housing and a base, with a sampling net positioned between the upper housing and the base. An air intake assembly is located within a containment space enclosed by the upper housing, base, and sampling net, allowing air to flow through the sampling net. The sampling net has a self-cleaning assembly for cleaning both sides. A smoke sensor is located within the containment space to measure smoke particles in the gas within the space. An exhaust unit is located on the base. This invention efficiently cleans the entire inner and outer surfaces of the sampling net. Compared to existing technologies that only clean one side, leading to secondary blockages caused by residue falling off the uncleaned side, this dual-sided simultaneous cleaning method fundamentally and thoroughly removes impurities from inside and outside the pores, significantly reducing the blockage rate and ensuring continuous and smooth airflow through the sampling net into the containment space. This maintains the accuracy and stability of the smoke sensor detection and greatly reduces the frequency of manual maintenance required due to blockages.

Description

Technical Field

[0001] This utility model relates to the field of fire alarm technology, specifically to a fire detection alarm for pipe gallery. Background Technology

[0002] A fire alarm is a fire safety device used to detect fires and issue an alarm signal. In utility tunnels, electrical, gas, and heating pipelines are densely packed and the space is enclosed. Once a fire is triggered by overheated cables or a gas leak, the fire will spread rapidly along the pipelines, accompanied by toxic smoke and the risk of explosion. Therefore, fire detectors and alarms are commonly installed in utility tunnels as crucial equipment to ensure their safe operation.

[0003] Chinese patent CN212009799U provides an automatic fire alarm device, which specifically forms a circuit by electrically connecting a circuit control board, a battery, and a smoke sensor to realize the alarm for fire. In addition, it also provides an easy-to-remove filter and a scraper assembly at the bottom of the smoke alarm. The upper and lower sets of scraper assemblies wet-scrape the filter, realizing the automatic cleaning of the smoke alarm.

[0004] The aforementioned existing technologies rely on natural convection to allow smoke to reach the smoke sensor. However, due to the enclosed space and complex airflow within the utility tunnel, smoke spreads slowly; typically, smoke from a distance of 20 meters from the fire source takes more than 60 seconds to reach the sensor. This leads to a higher rate of missed early fire detections and fails to meet the mandatory safety standards for rapid response in utility tunnel fires. Furthermore...

[0005] The scraper assembly uses a single-sided cleaning mechanism, which can only remove dirt from one side of the filter screen; dust, oil and other impurities on the uncleaned side continue to fall off under the turbulence of airflow and re-embed themselves inside the mesh, causing secondary blockage. Utility Model Content

[0006] The main purpose of this utility model is to provide a fire detector and alarm for pipe gallery, which solves the problem that the sampling net quickly becomes clogged again when the above-mentioned equipment is used because only one side of the sampling net is cleaned.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0008] A fire detector and alarm for a utility tunnel includes an upper housing and a base, with a sampling net provided between the upper housing and the base;

[0009] An air intake assembly is provided inside the receiving space surrounded by the upper housing, base, and sampling net to allow air to flow through the sampling net;

[0010] The sampling net is equipped with a self-cleaning component for cleaning both sides of the sampling net;

[0011] The containment space is equipped with a smoke sensor to measure smoke particles in the gas within the containment space;

[0012] The base is equipped with an exhaust vent.

[0013] In a preferred embodiment, an audible and visual alarm is provided on the outer surface of the base, and a circuit board is provided inside the upper housing. The circuit board is equipped with a controller and a signal transmitter.

[0014] The containment space is equipped with several ultrasonic sensors, which are located on the surface of the base and are used to measure the gas flow rate of the gas passing through the sampling net.

[0015] In the preferred embodiment, the base is provided with a first guide rail, the bottom of the upper housing is provided with a second guide rail, and the circumference of the accommodating space is provided with several support rollers;

[0016] The support roller is located on the back side of the non-working area of ​​the sampling net; the journals at both ends of the support roller are inserted into the bearing seats of the upper housing or base to achieve rotatable support.

[0017] In a preferred embodiment, the upper and lower edges of the sampling net are provided with dovetail flanges; both the first guide rail and the second guide rail are provided with grooves that mate with the dovetail flanges.

[0018] In the preferred embodiment, the air intake component is an explosion-proof miniature diaphragm pump, and it is not located in the middle of the bottom of the upper housing.

[0019] In a preferred embodiment, the self-cleaning component includes a motor located at the top of the inner wall of the upper housing, the output end of the motor being provided with a rotating shaft, and the rotating shaft being provided with a first gear;

[0020] Two cleaning rollers are movably inserted inside the upper housing, and the two cleaning rollers contact the inner and outer outer walls of the sampling net respectively;

[0021] The cleaning roller is provided with a second gear at its end, wherein the second gear meshes with the first gear, and the two second gears mesh with each other;

[0022] Two conveying rollers are movably inserted inside the upper housing, and the bottom of the first gear is fixedly connected to the top of one of the conveying rollers; the cleaning roller is located between the two conveying rollers;

[0023] Two extrusion rollers are movably inserted inside the upper housing;

[0024] The sampling mesh bypasses the extrusion rollers and conveyor rollers.

[0025] In a preferred embodiment, the base contains several temperature sensors that are in direct contact with the airflow.

[0026] In a preferred embodiment, a sealing ring is provided at the joint between the upper housing and the base.

[0027] In a preferred embodiment, the groove opening width of the first guide rail is 0.05-0.1 mm wider than the top width of the dovetail flange.

[0028] In the preferred embodiment, the cleaning roller is provided with a stainless steel roller body, the surface of which is provided with spiral grooves, and nylon bristles are provided in the spiral grooves.

[0029] This utility model provides a fire detector and alarm for utility tunnels. By adopting the above solution, it has the following beneficial effects:

[0030] 1. Through active suction and multi-sensor technology, specifically using an explosion-proof miniature diaphragm pump to actively suck up smoke-containing gas from the pipe gallery, and smoke and temperature sensors to directly contact the airflow for real-time, multi-parameter detection, the sensitivity and alarm accuracy of detecting early fires in the complex environment of the pipe gallery are greatly improved.

[0031] 2. It can efficiently clean the entire inner and outer surfaces of the sampling net. Compared with the existing technology that only cleans one side, which causes the residue on the uncleaned side to fall off and cause secondary blockage, this double-sided synchronous cleaning method can fundamentally and thoroughly remove impurities inside and outside the pores, significantly reduce the blockage rate, and ensure that air flows smoothly through the sampling net into the containment space, thereby maintaining the accuracy and stability of the smoke sensor detection and greatly reducing the frequency of manual maintenance required due to blockage.

[0032] 3. The sampling net is precisely fitted with the first guide rail of the base and the second guide rail at the bottom of the upper shell through the dovetail flanges on the upper and lower edges. Combined with the support rollers set along the circumference of the accommodating space and supported by the bearing seat, the flatness and running trajectory of the sampling net are maintained, ensuring the stable and reliable operation of the self-cleaning process in the high dust and vibration environment of the pipe gallery. Attached Figure Description

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0034] Figure 1 This utility model provides a perspective view of the main structure of a fire detector and alarm device for utility tunnels.

[0035] Figure 2 This utility model provides a partial structural cross-sectional view of a fire detector and alarm device for utility tunnels.

[0036] Figure 3 This utility model provides a top-view exploded view of a portion of the structure of a pipe gallery fire detection and alarm device;

[0037] Figure 4 This utility model provides a partial structural plan view of a fire detection and alarm device for utility tunnels.

[0038] In the diagram: 1. Upper housing; 2. Circuit board; 3. Controller; 4. Signal transmitter; 5. Motor; 6. Shaft; 7. First gear; 8. Cleaning roller; 9. Second gear; 10. Conveying roller; 11. Squeezing roller; 12. Base; 13. First guide rail; 14. Sampling net; 15. Second guide rail; 16. Support roller; 17. Smoke sensor; 18. Audible and visual alarm. Detailed Implementation

[0039] In the embodiments of this application, such as Figure 1 As shown, this utility model provides a pipe gallery fire detection alarm, including: an upper housing 1 and a base 12;

[0040] Sampling net 14 is disposed between the upper housing 1 and the base 12;

[0041] The intake assembly is configured to allow air to flow through the sampling net 14 and is placed inside the receiving space surrounded by the upper housing 1, the base 12 and the sampling net 14;

[0042] The self-cleaning component is configured to clean both sides of the sampling net 14;

[0043] Smoke sensor 17 is configured to measure smoke particles in the gas contained in the containment space;

[0044] An exhaust section, which is placed on the base 12, is configured to exhaust gas from the containment space;

[0045] Circuit board 2, on which controller 3 is connected.

[0046] like Figure 1 As shown, the upper housing 1 and the base 12 together constitute the housing of the pipe gallery fire detector and alarm, which is connected by several support rods. In this invention, the pipe gallery fire detector and alarm can be fixed on the ventilation path at the top of the pipe gallery, avoiding pipe obstruction to capture rising smoke, focusing on covering areas with dense cables, ventilation openings, and branch nodes of the pipe gallery. During installation, the upper housing 1 is rigidly connected to the pre-installed rust-proof metal bracket using bolts, with anti-loosening washers added to resist vibration. Power and signal lines are connected to the internal circuit board through the base interface, ultimately achieving comprehensive fire monitoring of high-risk areas throughout the pipe gallery without blind spots.

[0047] In one embodiment, the upper housing 1 and the base 12 can be made of 316L stainless steel, with fluororubber sealing rings added at the joints to meet the standards for explosive environments and prevent electric sparks from igniting flammable gases in the pipe gallery.

[0048] In this invention, the sampling net 14 serves as an air inlet, allowing air to enter its interior through the pores on the surface of the sampling net 14, i.e., into the containment space.

[0049] In one embodiment, the sampling mesh 14 is preferably model GKN Sinter Metals Sinterflo® P1-316L, with an air permeability deviation of <±3%, ensuring the stability of the sensor airflow.

[0050] like Figure 3 and Figure 4 As shown, the installation method of the sampling net 14 with the upper housing 1 and the base 12 is illustrated, that is, the cooperation relationship with multiple rollers, and the position of the guide rail.

[0051] This utility model also includes: a first guide rail 13 and a second guide rail 15, and a plurality of support rollers 16 arranged along the circumference of the accommodating space; wherein, the first guide rail 13 is bolted to the base 12, and the second guide rail 15 is bolted to the bottom of the upper housing 1; the first guide rail 13 and the second guide rail 15 are used to guide the sampling net 14 to move and constrain the sampling net 14 to prevent it from derailing.

[0052] The sampling mesh 14 has die-cast stainless steel dovetail flanges at its upper and lower edges, with flange dimensions of 2mm in height, 1.8mm in top width, and 2.2mm in bottom width. Correspondingly, the first guide rail 13 and the second guide rail 15 are both provided with grooves that mate with the dovetail flanges of the sampling mesh 14. The groove opening width of the first guide rail 13 is 1.85mm (0.05mm larger than the top width of the flange), the groove depth is 3mm, and a 0.2mm thick PTFE self-lubricating film is attached inside the groove, with a friction coefficient μ<0.05.

[0053] The groove opening of the second guide rail 15 faces downwards, with a groove width tolerance of ±0.01mm. Beryllium copper alloy spring plates are installed on both sides of the groove opening, so that when the sampling net 14 moves, the spring plates continuously provide downward pressure, ensuring that the flange always fits against the bottom of the groove, and the amplitude is <0.1mm under vibration conditions.

[0054] The support roller 16 is positioned on the back side of the non-working area of ​​the sampling net 14 and contacts the back side of the non-working area of ​​the sampling net 14. The support roller 16 maintains the flatness and running trajectory of the sampling net 14. The support roller provides support through physical contact, preventing the sampling net 14 from sagging, shifting, or shaking due to gravity or uneven tension, and ensuring its stable passage through the cleaning area.

[0055] The two ends of the support roller 16 are movably inserted into the upper housing 1 and the base 12, respectively. That is, the journals at both ends of the support roller 16 are inserted into the mounting holes or bearing seats of the upper housing 1 or the base 12 to achieve rotatable support.

[0056] To address the problem of slow natural convection leading to delayed alarm response, this invention features an air intake assembly (not shown in the attached diagram) installed at the bottom center of the upper housing 1. By actively drawing air from the pipe gallery into the containment space, it ensures that smoke quickly reaches the smoke sensor 17, further improving the sensitivity when dealing with low-concentration smoke or distant fire sources and reducing missed alarms.

[0057] In one embodiment, the intake component is preferably an explosion-proof miniature diaphragm pump, model KNF UNMP830KNDC, with an operating voltage of 12VDC, compatible with alarm circuits, and a power of ≤3W.

[0058] Dust, metal debris, and fibrous material (measured PM2.5 peak > 500 μg / m³) generated during the construction / maintenance of utility tunnels can clog the sampling mesh, reducing the amount of air drawn into the containment space. This invention incorporates a self-cleaning component in the utility tunnel fire detector to solve the problem of detection failure caused by dust and oil clogging the sampling mesh.

[0059] Specifically, such as Figure 2 As shown, the self-cleaning component includes:

[0060] Motor 5 is installed on the top of the inner wall of the upper housing 1 and serves as the power source for the cleaning mechanism. After starting, it drives the entire cleaning process.

[0061] The rotating shaft 6 is connected to the output end of the motor 5 and is used to transmit rotational power;

[0062] The first gear 7 is fixed to the bottom of the rotating shaft 6 and rotates with the motor 5;

[0063] Two cleaning rollers 8 are movably inserted inside the upper housing 1, and directly clean the inner and outer walls of the sampling net 14 by rotating. A second gear 9 is fixed to the top of the cleaning rollers 8;

[0064] Two second gears 9 mesh with each other, and one of the second gears 9 meshes with the first gear 7; the first gear 7 drives the second gear 9 to rotate relative to each other, thereby driving the cleaning roller 8 to rotate;

[0065] Two conveying rollers 10 are movably inserted inside the upper housing 1, and the bottom of the first gear 7 is fixedly connected to the top of one of the conveying rollers 10; they move with the motor 5 to move the sampling net 14 to ensure that the entire surface is cleaned.

[0066] Two extrusion rollers 11 are movably inserted inside the upper housing 1.

[0067] The two cleaning rollers 8 are driven by meshing second gears 9 and rotate synchronously in opposite directions. This counter-rotation creates a bidirectional shearing force on the inner and outer surfaces of the sampling mesh 14. The inner surface cleaning roller rotates in the opposite direction to the mesh's movement, forcefully scraping away deep-seated oil and dirt embedded in the pores; while the outer surface cleaning roller rotates in the same direction as the mesh, sweeping away loose dust. This bidirectional force completely removes blockages from the pores, avoiding the residue caused by unidirectional cleaning.

[0068] In one embodiment, the cleaning roller 8 is made of 304 stainless steel, with a spiral groove laser-engraved on the surface at a depth of 0.3 mm and a guide angle of 45°; antistatic nylon bristles with a diameter of 0.1 mm are embedded in the grooves, with a density of 200 bristles / cm².

[0069] In this invention, a motor 5 drives two counter-rotating cleaning rollers 8 to simultaneously scrape away accumulated dust from the inner and outer surfaces of the sampling net 14, thoroughly removing impurities and preventing repeated clogging of the pores caused by residue falling off after single-sided cleaning. A conveying roller 10 pulls the sampling net 14 directionally along the first guide rail 13 and the second guide rail 15, ensuring the entire net surface passes through the brushing area of ​​the cleaning rollers 8 without any omissions, eliminating blind spots present in fixed cleaning methods. This invention's cleaning assembly employs double-sided synchronous cleaning, achieving simultaneous removal of dirt from the inner and outer surfaces of the sampling net, reducing the false alarm rate to 0.3 times per year.

[0070] The journals at both ends of the extrusion roller 11 are inserted into the guide grooves inside the upper housing 1 (not shown in the attached drawings).

[0071] A compression spring is fitted on the outside of the journal. One end of the spring rests against the end plate at the end of the journal, and the other end is pressed by an adjusting bolt screwed into the housing. Rotating the adjusting bolt can push the spring to generate radial pressure, forcing the two extrusion rollers to move closer to the center and press the sampling net 14.

[0072] The operating principle of this self-cleaning component is as follows: the starting motor 5 drives the rotating shaft 6 to rotate, which in turn drives the first gear 7 to rotate; the first gear 7 meshes with one of the second gears 9, causing the two meshing second gears 9 to rotate relative to each other, thereby synchronously driving the two cleaning rollers 8 to rotate in opposite directions, and performing double-sided brushing of the inner and outer walls of the sampling net 14 that runs through it; at the same time, the bottom of the first gear 7 is directly linked to a conveying roller 10, which pulls the sampling net 14 to move directionally within the first guide rail 13 and the second guide rail 15, ensuring that the entire net surface is thoroughly cleaned; during this process, the two squeezing rollers 11 come together to press the sampling net 14, blocking external impurities from penetrating the mesh, and achieving efficient, anti-clogging, and continuous self-cleaning.

[0073] In this invention, several ultrasonic sensors are installed within the accommodating space and mounted on the surface of the base 12. These sensors are configured to measure the gas flow rate through the sampling net 14. When the ultrasonic sensors detect abnormal airflow or blockage, they directly connect to the controller 3 via a signal, which then activates the self-cleaning mechanism of the sampling net 14. In one embodiment, the preferred ultrasonic sensor model is SICK FTMg-01, which meets the requirements for environmental adaptability in pipe racks and high-precision detection of low flow rates.

[0074] In this invention, the smoke sensor 17 is installed at the center of the base 12, away from the exhaust section, and arranged at a 90-degree angle to the ultrasonic sensor. In one embodiment, the smoke sensor 17 is preferably model SICK DFS60E-001312, which meets the explosion-proof requirements of the pipe gallery.

[0075] In this invention, a temperature sensor is also installed inside the containment space to quickly detect the temperature of the smoke entering the containment space. This sensor is located alongside the smoke sensor 17 within the containment space of the base 12 and is in direct contact with the airflow. In one embodiment, the temperature sensor is preferably a TE Connectivity PT100.

[0076] like Figure 2 As shown, in this utility model, a circuit board 2 is provided at the bottom of the inner wall of the upper shell 1, and a controller 3, a signal transmitter 4 and a TI BQ25703 power management chip are provided at the top of the circuit board 2.

[0077] Among them, the preferred model of controller 3 is STMicroelectronics STM32H743VIH6, with an operating temperature of -40~105℃ (wide temperature environment of the pipe gallery). Signal transmitter 4 is used to send fire alarm signals to the pipe gallery monitoring center in real time. The TIBQ25703 power management chip dynamically manages the seamless switching between the main power supply (24VDC) and the backup battery (12V lithium battery pack), ensuring that the equipment can continue to work for more than 24 hours when the power supply to the pipe gallery is interrupted. It also reports the battery status and fault codes in real time through the I²C interface, eliminating the risk of fire missed due to power failure from the root and meeting the mandatory power supply standards for fire protection equipment.

[0078] In this utility model, the audible and visual alarm 18 is installed on the outer surface of the receiving space of the base 12. The preferred model is Honeywell XAL-240-SP-R, and the 120dB alarm sound can cover an area with a radius of >50m.

[0079] When this utility model is in use, the explosion-proof diaphragm pump is activated to actively draw air from the pipe gallery, so that the airflow is filtered through the sampling net 14 and enters the containment space formed by the upper shell 1 and the base 12; the smoke sensor 17 and the temperature sensor detect the smoke concentration and temperature rise rate in the airflow in real time, while the ultrasonic sensor monitors the flow rate change; when the flow rate drops by more than 30%, the controller 3 triggers self-cleaning, that is, the motor 5 drives the double cleaning rollers 8 to rotate in the opposite direction, simultaneously scraping off the dust on the inner and outer surfaces of the sampling net 14, while the conveying roller 10 pulls the sampling net to move along the first guide rail 13 and the second guide rail 15 to achieve full coverage cleaning, and the squeezing roller 11 closes to block the intrusion of external impurities; according to the smoke and temperature data, the controller 3 immediately activates the audible and visual alarm 18 and reports remotely through the signal transmitter 4. During this period, the power management chip ensures 0ms switching between main and backup power, achieving 24 / 7 pipe gallery fire detection without missed detection and a false alarm rate of ≤0.3 times / year.

[0080] The above embodiments are merely preferred technical solutions of this utility model and should not be considered as limitations on this utility model. The protection scope of this utility model should be the technical solution described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the protection scope of this utility model.

Claims

1. A pipe gallery fire detection alarm, characterized by: It includes an upper shell (1) and a base (12), with a sampling net (14) provided between the upper shell (1) and the base (12). An air intake assembly is provided inside the receiving space surrounded by the upper housing (1), the base (12) and the sampling net (14) to allow air to flow through the sampling net (14). The sampling net (14) is equipped with a self-cleaning component for cleaning both sides of the sampling net (14); A smoke sensor (17) is installed in the containment space to measure smoke particles in the gas in the containment space; An exhaust section is provided on the base (12).

2. The fire detection and alarm system for pipe galleries according to claim 1, characterized in that: The outer surface of the base (12) is provided with an audible and visual alarm (18), and the upper housing (1) is provided with a circuit board (2). The circuit board (2) is provided with a controller (3) and a signal transmitter (4). The containment space is equipped with several ultrasonic sensors located on the surface of the base (12) to measure the gas flow rate of the gas passing through the sampling net (14).

3. The fire detection and alarm system for pipe galleries according to any of claims 1 or 2, characterized in that: The base (12) is provided with a first guide rail (13), the bottom of the upper shell (1) is provided with a second guide rail (15), and the circumference of the accommodating space is provided with several support rollers (16). The support roller (16) is located on the back side of the non-working area of ​​the sampling net (14); the journals at both ends of the support roller (16) are inserted into the bearing seats of the upper housing (1) or the base (12) to achieve rotatable support.

4. A pipe gallery fire detection alarm according to claim 3, characterised in that: The sampling net (14) has dovetail flanges on its upper and lower edges; the first guide rail (13) and the second guide rail (15) are both provided with grooves that cooperate with the dovetail flanges.

5. The fire detection and alarm system for pipe racks as claimed in claim 1 wherein: The suction assembly is an explosion-proof miniature diaphragm pump and is not located in the middle of the bottom of the upper housing (1).

6. A fire detection alarm for a pipe rack as defined in claim 1, wherein: The self-cleaning component includes a motor (5) located at the top of the inner wall of the upper housing (1), and the output end of the motor (5) is provided with a rotating shaft (6), and the rotating shaft (6) is provided with a first gear (7). Two cleaning rollers (8) are movably inserted inside the upper housing (1), and the two cleaning rollers (8) contact the inner and outer walls of the sampling net (14) respectively; The cleaning roller (8) is provided with a second gear (9) at its end, wherein the second gear (9) meshes with the first gear (7), and the two second gears (9) mesh with each other; Two conveying rollers (10) are movably inserted inside the upper housing (1), and the bottom of the first gear (7) is fixedly connected to the top of one of the conveying rollers (10); the cleaning roller (8) is located between the two conveying rollers (10); Two extrusion rollers (11) are movably inserted inside the upper housing (1). The sampling net (14) passes around the extrusion roller (11) and the conveying roller (10).

7. A pipe gallery fire detection alarm according to claim 1, wherein: Several temperature sensors are installed in the housing space of the base (12), and the temperature sensors are in direct contact with the airflow.

8. The fire detection and alarm system for pipe racks as claimed in claim 1 wherein: A sealing ring is provided at the joint between the upper housing (1) and the base (12).

9. A fire detector and alarm for a utility tunnel according to claim 4, characterized in that: The groove opening width of the first guide rail (13) is 0.05-0.1mm wider than the top width of the dovetail flange.

10. A pipe gallery fire detection alarm according to claim 6, characterized in that: The cleaning roller (8) is provided with a stainless steel roller body, and a spiral groove is provided on the surface, with nylon bristles provided in the spiral groove.

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