Duct fire extinguishing device

Abstract

To provide an in-duct fire extinguishing device that can simplify fire extinguishing facilities and reduce costs. [Solution] The duct fire extinguishing device 1 of the present invention is a device installed inside a duct 101, and includes a tank 10 filled with an inert gas (carbon dioxide gas, nitrogen gas, etc.) and a fire extinguishing liquid (potassium carbonate liquid, purified water, etc.), a nozzle 20 equipped with an outlet 51 for spraying the inert gas and fire extinguishing liquid filled in the tank 10 into the duct 101, and a heat-sensitive valve 30 that closes the outlet 51 of the nozzle 20 when the temperature inside the duct 101 is below a set value and opens the outlet 51 of the nozzle 20 when the temperature inside the duct 101 exceeds the set value.

Description

[Technical Field]

[0001] This invention relates to an in-duct fire extinguishing device that extinguishes a fire that breaks out inside a duct that discharges flammable gases, smoke, etc.

[0002] When flammable gases generated in paint factories or smoke generated in restaurants such as yakiniku restaurants are forcibly exhausted through ducts, fires can break out inside the duct due to an abnormality in the exhaust fan or ignition from outside the duct. In such cases, conventional methods include spraying water into the duct from a fire hose connected to a fire hydrant to extinguish the fire, or spraying water on the exterior wall of the duct to cool the heated duct and prevent the fire from spreading to other areas.

[0003] However, conventional methods of spraying water inside the duct have the problem that it takes time to extinguish the fire and the fire spreads widely, and when spraying water on the exterior wall of the duct, the equipment around the duct gets wet, causing further damage.

[0004] Therefore, Patent Document 1 proposes a configuration in which a pipe is installed between an existing fire hydrant and a duct, a nozzle is attached to one end of the pipe, the other end is connected to a fire hose with a joint, and the nozzle is pulled into the duct. If a fire breaks out in the duct, the pipe is connected to the existing fire hydrant with a joint and opened. Water is then sprayed from the nozzle into the duct, quickly extinguishing the fire that has broken out in the duct.

[0005] Patent Document 2 proposes an in-duct fire extinguishing device that provides a plurality of water nozzles extending from a water supply pipe installed in a duct with respective open / close covers for opening and closing the water outlets, and restricts the opening angle of each open / close cover to a fixed angle that allows the extinguishing fluid discharged from each water nozzle's outlet to collide with the backside of the open / close cover and be reflected toward the inner wall of the duct. According to this system, under normal circumstances (when no fire is occurring), the water outlets of the water nozzles installed in the duct are blocked by the open / close covers, so that foreign matter does not adhere to the water outlets and cause clogging. Furthermore, in the event of a fire, the extinguishing fluid discharged from the water nozzles' outlets collides with the backside of the open / close cover, opening the open / close cover by a predetermined angle, effectively extinguishing the fire inside the duct with the extinguishing fluid.

[0006] Furthermore, Patent Document 3 describes a fire extinguisher equipped with a water jet head that can advance and retreat relative to a duct, which is installed outside the duct, and when a fire breaks out in the duct and a detection signal is emitted from a fire detector, the water jet head of the fire extinguisher advances into the duct and the fire that has broken out in the duct is extinguished by the fire-extinguishing water sprayed from the water jet head. Therefore, under normal circumstances (when no fire has broken out), the water jet head is located outside the duct, which prevents clogging of the water jet head due to adhesion of foreign matter such as paint contained in the exhaust gas flowing through the duct. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Utility Model Application Publication No. 62-006851 [Patent Document 2] Japanese Utility Model Application Publication No. 63-106458 [Patent Document 3] Japanese Patent Publication No. 62-074379 Summary of the Invention [Problem to be solved by the invention]

[0008] However, the in-duct fire extinguishing systems proposed in Patent Documents 1 to 3 require equipment installed outside the duct, such as fire hydrants, pressurized water supply devices, and piping, which are activated when a fire detector detects a fire in the duct and supply fire extinguishing liquid (fire water) into the duct.In addition, a fire detector is also required, which creates the problem of complicating the overall configuration of the fire extinguishing system and increasing costs.

[0009] The present invention has been made in view of the above problems, and its object is to provide an in-duct fire extinguishing device that can simplify the fire extinguishing equipment and reduce costs. [Means for solving the problem]

[0010] In order to achieve the above object, the in-duct fire extinguishing device described in claim 1 is a device installed inside a duct, and is characterized by comprising: a tank filled with an inert gas and a fire-extinguishing liquid; a nozzle equipped with an outlet for spraying the inert gas and the fire-extinguishing liquid filled in the tank into the duct; and a heat-sensitive valve that closes the outlet of the nozzle when the temperature inside the tank is below a set value and opens the outlet of the nozzle when the temperature inside the tank exceeds the set value.

[0011] The invention of claim 2 is characterized in that, in the invention of claim 1, the inert gas is carbon dioxide gas or nitrogen gas.

[0012] The invention of claim 3 is characterized in that, in the invention of claim 1, the fire extinguishing liquid is potassium carbonate liquid or purified water. [Effects of the Invention]

[0013] According to this device, when a fire breaks out in the duct and the temperature inside the duct exceeds a set value (e.g., 150°C), the heat-sensitive valve opens the nozzle outlet, and the inert gas and extinguishing liquid filled in the tank are sprayed into the duct from the nozzle outlet, thereby effectively and quickly extinguishing the fire inside the duct through the extinguishing action of the inert gas and extinguishing liquid.

[0014] As mentioned above, a fire that occurs inside a duct can be extinguished only by the in-duct fire extinguishing device installed inside the duct, so there is no need to install equipment such as fire hydrants, pressurized water supply devices, and piping outside the duct, which was previously necessary, thereby simplifying the fire extinguishing equipment and reducing costs.

[0015] Furthermore, if a fire breaks out inside the duct and the temperature inside the duct exceeds a set value, the heat-sensitive valve automatically opens the nozzle outlet, eliminating the need for a fire detector to detect the fire and activate a fire hydrant or pressurized water supply device, thereby further simplifying the fire extinguishing equipment and reducing costs. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram showing the overall configuration of a fire extinguishing system equipped with an in-duct fire extinguishing device according to the present invention; [Figure 2] 1 is a perspective view of an in-duct fire extinguishing device according to the present invention; [Figure 3] 3 is a front view of the in-duct fire extinguishing device according to the present invention (view in the direction of arrow A in FIG. 2). [Figure 4] 3 is a side view of the in-duct fire extinguishing device according to the present invention (view in the direction of arrow B in FIG. 2). [Figure 5] FIG. 5 is a cross-sectional view taken along line CC in FIG. [Figure 6] FIG. 5 is an exploded view of FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along the line DD in FIG. 6. [Figure 8] 6A and 6B are enlarged detailed views of part E in FIG. 5, in which (a) shows a normal state (when no fire has occurred) and (b) shows a state when a fire has occurred. DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

[0018] [Overall configuration of the fire extinguishing system] First, the overall configuration of a fire extinguishing system equipped with an in-duct fire extinguishing device 1 according to the present invention will be described with reference to FIG.

[0019] 1 shows a store 100 such as a yakiniku restaurant, with a duct (smoke exhaust duct) 101 extending from the top of the store 100. A portion of the duct 101 is configured as a duct piece 101A, which is detachably connected to a duct body 101B by a flange 102. An in-duct fire extinguishing device 1 according to the present invention is installed inside the duct piece 101A.

[0020] In addition, a fire damper 110 is disposed in the vicinity of the in-duct fire extinguishing device 1 in the duct 101 (more precisely, downstream in the direction of smoke flowing through the duct 101). Here, the fire damper 110 rotates in the direction of the arrow about an axis 111 to open and close the flow path in the duct 101, and a driving source (not shown), such as a motor, that opens and closes the fire damper 110 is electrically connected to a fire detector 120 installed in the duct 101.

[0021] Furthermore, an exhaust fan 130 is provided downstream of the fire damper 110 in the duct 101 (downstream in the direction of smoke flow), and when this exhaust fan 130 is driven, smoke generated inside the store 100 is sucked into the duct 101 and finally discharged into the atmosphere. A drive source such as a motor that drives this exhaust fan 130 is electrically connected to the fire detector 120.

[0022] [Duct fire extinguishing device] Next, the configuration of the in-duct fire extinguishing device 1 according to the present invention will be described below with reference to FIGS.

[0023] The in-duct fire extinguishing system 1 according to the present invention is a device for extinguishing a fire that breaks out in a duct 101, and includes a tank 10 in the form of a sealed container with both longitudinal ends of a cylinder closed, and a nozzle 20 inserted from above into the tank 10 and fixed in the center of the longitudinal direction (left-right direction in FIG. 3) of the tank 10. Here, support plates 11 bent into an L-shape are attached to the lower outer periphery of both longitudinal ends of the tank 10, respectively.

[0024] Furthermore, nozzle 20, which is inserted vertically into tank 10 from above and fixed in the center of the tank 10 in the longitudinal direction, has a circular hole-shaped passage 21 penetrating through the center, as shown in Figures 5 and 7, and a circular concave valve seat 22 is formed on the upper surface of the upper half of nozzle 20 that protrudes upward from the outer periphery of tank 10, as shown in Figure 7. Here, as shown in Figures 5 and 7, the lower end of nozzle 20 inserted into tank 10 does not contact the inner circumferential wall of tank 10, and a gap δ is formed between them. Therefore, passage 21 of nozzle 20 opens into tank 10.

[0025] 5 and 8(a), a thin, circular, sheet-like heat-sensitive valve 30 is placed on a circular, concave valve seat 22 formed on the upper surface of the nozzle 20, and as shown in Fig. 8(a), this heat-sensitive valve 30 is fixed by a cap 50 via a retaining collar 40. A circular hole-shaped passage 41 penetrates the center of the retaining collar 40.

[0026] Here, the heat-sensitive valve 30 is composed of a valve body of a heating valve (not shown) that is made up of a resin film that melts when a fire breaks out in the duct 101 and the temperature inside the duct 101 rises above a predetermined set temperature (for example, 150°C), a thin stainless steel plate with a center hole sandwiching this film, and a thin stainless steel plate with a cover that covers the center hole.

[0027] The cap 50 is a cylindrical member with a bottom that secures the thermal valve 30 to the valve seat 22 of the nozzle 20 via the retaining collar 40, and has a circular nozzle hole 51 at the center of its top (see FIGS. 5, 7, and 8). As shown in FIG. 7, a female thread 52 is formed on the inner circumferential surface of the cap 50. By placing the cap 50 over the upper end of the nozzle 20 and threading the female thread 52 into the male thread 23 formed on the outer periphery of the upper end of the nozzle 20 and rotating the cap 50, the cap 50 is screwed onto the outer periphery of the upper end of the nozzle 20 (see FIGS. 5 and 8(a)). As a result, the thermal valve 30 is secured to the valve seat 22 of the nozzle 20 via the retaining collar 40. As shown in FIGS. 4 to 7, the outer periphery of the cap 50 is formed with engagement grooves 50a at two opposing locations to allow engagement with a tool (not shown) for rotating the cap 50.

[0028] As will be described later, under normal conditions when no fire has occurred in the duct 101, the temperature inside the duct 101 is below a predetermined set temperature, so the resin film of the heat-sensitive valve 30 does not melt, and the passage 21 of the nozzle 20 and the outlet 51 of the cap 50 are closed by the valve body of the heat-sensitive valve 30, as shown in Figure 8(a).

[0029] In the duct fire extinguishing system 1 configured as described above, an inert gas such as carbon dioxide gas or nitrogen gas and a fire extinguishing liquid are filled in the tank 10. Here, potassium carbonate liquid, purified water, etc. are used as the fire extinguishing liquid.

[0030] Therefore, under normal conditions where no fire has occurred in the duct 101 and the temperature inside the duct 101 is below a predetermined set value, the passage 21 of the nozzle 20 and the nozzle 51 of the cap 50 are closed by the heat-sensitive valve 30 as described above (see Figure 8(a)), so the inert gas and fire-extinguishing liquid filled in the tank 10 will not spray into the duct 101 from the nozzle 51 of the cap 50.

[0031] [Function of the duct fire extinguishing device] Next, the operation of the fire extinguishing system shown in FIG. 1 including the in-duct fire extinguishing apparatus 1 configured as above and the in-duct fire extinguishing apparatus 1 according to the present invention will be described.

[0032] In the fire extinguishing system shown in Fig. 1, when exhaust fan 130 is driven, smoke generated in store 100, such as a yakiniku restaurant, is drawn by exhaust fan 130 into duct 101. However, under normal conditions, when fire detector 120 installed in duct 101 does not detect a fire in duct 101, fire damper 110 installed in duct 101 is in an open state, as shown by the solid line in Fig. 1, allowing smoke to flow through duct 101. Therefore, smoke generated in store 100 is drawn into duct 101 by exhaust fan 130 and is discharged into the atmosphere from the end of duct 101. As a result, store 100 does not become filled with smoke.

[0033] If a fire breaks out in duct 101 for some reason, causing the temperature inside duct 101 to exceed a set value and causing fire detector 120 to detect a fire inside duct 101, a detection signal is output from fire detector 120 and sent to fire damper 110 and exhaust fan 130. Then, fire damper 110 rotates from the open position shown by the solid line in Figure 1 to the closed position shown by the chain line. This prevents smoke from being drawn into duct 101 and traps the smoke inside duct 101.

[0034] Furthermore, if a fire breaks out in the duct 101 and the temperature inside the duct 101 rises above a predetermined set temperature, the heat-sensitive valve 30 of the in-duct fire extinguishing device 1 according to the present invention melts as shown in Figure 8(b) to open the passage 21 of the nozzle 20 and the outlet 51 of the cap 50, so that the inert gas (carbon dioxide gas or nitrogen gas) and fire-extinguishing liquid (potassium carbonate liquid or purified water) filled in the tank 101 pass through the passage 21 of the nozzle 20 and are forcefully sprayed out from the outlet 51 of the cap 50 into the duct 101, extinguishing the fire. Therefore, even if a fire breaks out in the duct 101, the fire is quickly extinguished in a short time and prevented from spreading to other areas.

[0035] Incidentally, the duct fire extinguishing device 1 used to extinguish fires in the duct 101 as described above is replaced with a new one. In this case, the duct section 101A on which the duct fire extinguishing device 1 is installed is removed from the duct main body 101B at the flanges 102, 103, and the duct section 101A on which the new duct fire extinguishing device 1 is installed is attached to the duct main body 101B at the flanges 102, 103, and the new duct fire extinguishing device 1 installed on this duct section 101A continues to be used to extinguish fires in the duct 101.

[0036] As described above, in a fire extinguishing system equipped with the in-duct fire extinguishing device 1 of the present invention, a fire that occurs in the duct 101 is extinguished only by the in-duct fire extinguishing device 1 installed in the duct 101, so there is no need to install equipment such as fire hydrants, pressurized water supply devices, and piping outside the duct 101, which was previously necessary, thereby simplifying the fire extinguishing equipment and reducing costs.

[0037] Furthermore, when a fire breaks out in the duct 101 and the temperature inside the duct 101 exceeds a set value, the heat-sensitive valve 130 melts due to the heat and opens the outlet 51 opening in the cap 50 of the nozzle 20, eliminating the need for a fire detector to detect a fire and activate a fire hydrant, pressurized water supply device, or the like, thereby further simplifying the fire extinguishing equipment and reducing costs. Note that, in this embodiment, a fire detector 120 is provided that sends a detection signal to the fire damper 110 and the exhaust fan 130 when a fire breaks out, but this fire detector 120 does not send a detection signal to the intra-duct fire extinguishing system 1 when a fire breaks out in the duct 101. In other words, a fire detector is not essential for the operation of the intra-duct fire extinguishing system 1.

[0038] In the above embodiment, an in-duct fire extinguishing device that is installed in a duct (smoke exhaust duct) that exhausts smoke generated in a store such as a yakiniku restaurant has been described as an example, but the in-duct fire extinguishing device of the present invention can be installed in a duct that exhausts flammable gas generated in a paint factory or any other duct.

[0039] Furthermore, in this embodiment, the heat-sensitive valve 30 melts and opens the nozzle 51 when a fire breaks out and the temperature inside the tank 10 exceeds a set temperature. However, any other type of heat-sensitive valve can be used. For example, a heat-sensitive valve can be used in which a thin first metal valve body with a circular hole formed in its center is overlapped with a thin second metal valve body with a closing portion that closes the circular hole in the first valve body and the two are joined together with an adhesive. With such a heat-sensitive valve, when the temperature inside the tank rises above a predetermined set value due to a fire, the adhesive strength of the adhesive joining the first and second valve bodies weakens, opening the circular hole in the first valve body. This opens the heat-sensitive valve, allowing the inert gas and fire-extinguishing liquid inside the tank to be sprayed into the duct and extinguishing the fire that has broken out inside the duct.

[0040] In addition, the application of the present invention is not limited to the embodiments described above, and it goes without saying that various modifications are possible within the scope of the utility model registration claims and the technical ideas described in the specification and drawings. [Explanation of symbols]

[0041] 1. Duct fire extinguishing system 10 Tank 20 nozzles 21 Passage 22 Valve seat 30 Heat-sensitive valve 40 Presser collar 41 Passage 50 caps 51 spout 100 stores 101 Duct 110 Fire damper 120 Fire detector 130 Exhaust fan

Claims

1. A device installed in a duct, a tank filled with an inert gas and a fire extinguishing liquid; a nozzle having an ejection port for ejecting the inert gas and the fire-extinguishing liquid agent filled in the tank into the duct; a heat-sensitive valve that closes the outlet of the nozzle when the temperature inside the tank is below a set value and opens the outlet of the nozzle when the temperature inside the tank exceeds the set value; An in-duct fire extinguishing device comprising:

2. 2. The in-duct fire extinguishing system according to claim 1, wherein the inert gas is carbon dioxide gas or nitrogen gas.

3. 2. The duct fire extinguishing system according to claim 1, wherein the fire extinguishing liquid is potassium carbonate liquid or purified water.

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