Disaster prevention equipment

Abstract

To provide a disaster prevention facility capable of preventing and suppressing expansion of a fire and extinguishing a fire by discriminating a semiconductor manufacturing gas fire by silane gas or the like.SOLUTION: In a fire detection device, a signal detection section 16 performs: irradiating a detection object with light of a prescribed wavelength; detecting a detection value A1 from a light receiving signal obtained at a front scattering angle 40°; detecting a detection value A2 from the light receiving signal obtained at a back scattering angle 110°; and detecting a detection value A3 from the light receiving signal obtained at a scattering angle 90°, a discrimination section 18 discriminates that a fire is a semiconductor manufacturing gas fire generating monodisperse particles when a predetermined discrimination condition is satisfied, which corresponds to Rayleigh scattering to allow the detection value A3 to be the minimum value with respect to the detection value A1 and the detection value A2, and a detection output section 20, when the detection value A1 or the detection value A2 satisfies a predetermined fire detection condition in a state where the semiconductor manufacturing gas fire is discriminated, outputs a discrimination result that the fire is the semiconductor manufacturing fire together with a fire to the outside.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to disaster prevention equipment such as a smoke detector for detecting a fire caused by leakage of flammable gas used in semiconductor manufacturing or the like.

Background Art

[0002] Conventionally, certain gases used in semiconductor manufacturing and compounds used as raw materials in the chemical industry are such that the gas itself is toxic and highly flammable, and many substances have toxic combustion-generated gases. For example, gases such as silane gas used as a doping gas in semiconductor manufacturing and phosphine gas used as an epitaxial gas spontaneously ignite and burn explosively when leaking to the outside and coming into contact with air. For example, in the case of silane gas, silicon dioxide SiO2 is generated.

[0003] As a fire detection device for these gases and chemical materials, a smoke detector is widely used. The smoke detector irradiates light from a light-emitting element onto fine particles of combustion products flowing into a smoke detection unit in the detector, and captures scattered light by the fine particles with a light-receiving element to detect the presence of combustion products.

[0004] Also, conventionally, a fire detection device such as a smoke detector that receives scattered light of light with different scattering angles and different wavelengths to identify the type of smoke is known. For example, for two light-emitting elements, by making the scattering angles with respect to the light-receiving element different, a difference in scattered light due to the type of smoke is created. At the same time, by making the wavelengths of the light emitted from the two light-emitting elements different, a difference in scattering characteristics due to the wavelength is created. Due to the synergistic effect of this difference in scattering angle and difference in wavelength, a significant difference is brought about in the light intensity of scattered light due to the type of smoke, improving the accuracy of smoke identification to prevent false alarms due to cooking steam or the like. Also, for smoke caused by a fire, it is possible to identify the type of smoke corresponding to combustion products such as black smoke and white smoke.

[0005] Furthermore, there are known fire detection devices that detect flames by converting the 4.5 μm band infrared radiation emitted in conjunction with the CO2 resonance of the combustion flame into an electrical signal using a pyroelectric sensor, and then extracting the flame-specific flicker frequency component from this electrical signal to determine the presence or absence of a flame. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2004-325211 [Patent Document 2] Japanese Patent Publication No. 2020-035029 [Patent Document 3] Japanese Patent Publication No. 2020-135263 [Patent Document 4] Patent No. 4014188 [Patent Document 5] Patent No. 4404329 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, conventional smoke detectors cannot distinguish between combustion products resulting from the leakage and combustion of gases used in semiconductor manufacturing and combustion products from ordinary fires, such as general fires, oil fires, or electrical fires, which occur when ordinary machinery or structures accidentally catch fire.

[0008] Furthermore, even with conventional fire detection devices that detect flames, there is a high possibility that they will not be able to detect gas leak fires, unlike fires involving ordinary carbon-containing materials, because CO2 that emits infrared radiation in the 4.5 μm band associated with CO2 resonance is not produced during combustion.

[0009] On the other hand, if semiconductor manufacturing gases such as silane gas or phosphine gas burn, extinguishing the fire with water must never be done to prevent the generation of toxic gases, and similarly, extinguishing the fire with halon extinguishing gas is also unsuitable. The use of carbon dioxide or dry chemical extinguishing agents is required. However, in the case of fires involving machinery or structures, it is possible to extinguish them with water as a normal fire, and extinguishing them with halon extinguishing agents is also acceptable.

[0010] In other words, in semiconductor manufacturing, it is necessary to correctly identify the combustion material in a fire and use the appropriate fire extinguishing agent, and for this purpose, there is a need for fire detection devices that can identify combustion materials such as silane gas and phosphine gas.

[0011] The present invention aims to provide fire prevention equipment that can identify fires caused by semiconductor manufacturing gases such as silane gas, and enable fire prevention, suppression, or extinguishing. [Means for solving the problem]

[0012] (Fire detection device 1) The present invention is a fire detection device characterized by detecting smoke-generating fires and predetermined gas fires that generate monodisperse particles, and identifying which type of fire it is.

[0013] Here, "monodisperse particles" refer to particles that exhibit a well-distributed size distribution, and the concept includes monodisperse combustion products. For example, it refers to particles where the value obtained by dividing the standard deviation of the size distribution by the mean size is small, for example, 0.1 or less.

[0014] (Fire alarm including identification results) If the system identifies that the fire is a smoke fire or a specified gas fire, it will output the identification result along with the fire information.

[0015] (Control based on identification results) The fire prevention equipment using the aforementioned fire detection device, Depending on the identification result of the fire detection device, different control measures will be applied to prevent, suppress, or extinguish the fire.

[0016] (Gas fire for semiconductor manufacturing) In addition, when the identification result of the fire detection device is a gas fire for semiconductor manufacturing, the control shall be to stop the supply of semiconductor gas and / or release an inert gas to the fire occurrence area.

[0017] (Fire detection device 2) The present invention is a fire detection device that detects a fire in a monitoring area, a signal detection unit that irradiates light to a detection target in the monitoring area accompanied by a light action and detects a plurality of detection signals received at different scattering angles, an identification unit that identifies whether it is a smoldering fire generating smoke or a gas fire for semiconductor manufacturing generating monodisperse particles based on the plurality of detection signals detected by the signal detection unit, a detection output unit that outputs the identification result to the outside together with the fire when any one of the plurality of detection signals satisfies a predetermined fire detection condition in a state where it is identified by the identification unit that it is a smoldering fire or a gas fire for semiconductor manufacturing, and is characterized by including the above.

[0018] (Gas for semiconductor manufacturing) The gas for semiconductor manufacturing is silane gas or phosphine gas.

[0019] In the following description, a method of irradiating light of a predetermined wavelength to a detection target and detecting three detection signals received at three different scattering angles is referred to as a "one wavelength three scattering angle method", a method of irradiating light of a predetermined wavelength to a detection target and detecting two detection signals received at two different scattering angles is referred to as a "one wavelength two scattering angle method", and further, a method of irradiating light of two different wavelengths to a detection target and detecting two detection signals received at two different scattering angles is referred to as a "two wavelength two scattering angle method".

[0020] (One wavelength three scattering angle method: Identification and detection of gas fire for semiconductor manufacturing) The signal detection unit detects a signal associated with the light action by the detection target by at least a first optical setting, a second optical setting, and a third optical setting, As the first optical setting, the target to be detected is irradiated with light of a predetermined wavelength, and the received signal of the scattered light obtained at a predetermined forward scattering angle less than 90° is detected as a forward scattering detection signal. As a second optical setting, the target to be detected is irradiated with light of a predetermined wavelength, and the received signal of the scattered light obtained at a predetermined backscatter angle greater than 90° is detected as a backscatter detection signal. As a third optical setting, the target to be detected is irradiated with light of a predetermined wavelength, and the received signal of the scattered light obtained at a scattering angle of 90° is detected as a 90° scattering detection signal. The identification unit identifies a semiconductor manufacturing gas fire based on the forward scattering detection signal, backscatter detection signal, and 90° scattering detection signal detected by the signal detection unit, when predetermined identification conditions corresponding to Rayleigh scattering where the 90° scattering detection signal is at its minimum value are met. When the identification unit has identified that it is a semiconductor manufacturing gas fire, the detection output unit outputs the identification result that it is a semiconductor manufacturing gas fire, along with the fire information, to the outside if the predetermined fire detection conditions are met based on the forward scatter detection signal or the back scatter detection signal.

[0021] (1 wavelength, 3 scattering angles method: identification and detection of smoke-emitting fires) The identification unit identifies a smoke fire based on the forward scattering detection signal, back scattering detection signal, and 90° scattering detection signal detected by the signal detection unit, if the predetermined identification conditions corresponding to Rayleigh scattering where the 90° scattering detection signal is at its minimum value are not met. When the identification unit has identified that it is a smoke fire, and other predetermined fire detection conditions are met based on the forward scatter detection signal or the back scatter detection signal, the detection output unit outputs the identification result that it is a smoke fire along with the fire to the outside.

[0022] Here, "Rayleigh scattering," as is well known, is the scattering of light by particles smaller than the wavelength of light, and the scattering intensity (amount of scattered light) is distributed almost the same in front and behind, with a minimum at a scattering angle of 90°. On the other hand, "Mie scattering" is known as the scattering of light by particles larger than the wavelength of light, and the scattering intensity is greater in the front than behind.

[0023] Smoke particles, mainly composed of carbon oxides and water, generated by smoke-generating fires including general fires, oil fires, and electrical fires, are widely distributed in size, ranging from small particles (particle diameter) of approximately 0.001 μm to several μm (1 nm to several thousand nm) to large particles. Particles larger than the wavelength of light irradiating the target undergo Mie scattering, while particles smaller than the wavelength of light undergo Rayleigh scattering, resulting in a combined scattering of both.

[0024] In contrast, gases that ignite when leaked into the atmosphere, such as silane gas used in semiconductor manufacturing, produce monodisperse particles. These particles are very small, with a particle size (diameter) of approximately 0.05 μm to 0.06 μm (50 nm to 60 nm), and are smaller than the wavelength of light irradiated onto the target, resulting in Rayleigh scattering. Therefore, when predetermined identification conditions corresponding to Rayleigh scattering are met, it can be identified that the fire is caused by a semiconductor manufacturing gas such as silane gas.

[0025] (Structure of the first smoke detection unit using a 1-wavelength, 3-scattering-angle method: 1 LED + 3 PDs) The signal detection unit is, A light-emitting unit that irradiates the object to be detected with light of a predetermined wavelength, A first light receiving unit receives scattered light obtained at a forward scattering angle when light of a predetermined wavelength is irradiated onto the object to be detected and outputs a forward scattering detection signal, A second light receiving unit receives scattered light obtained at a backscatter angle when light of a predetermined wavelength is irradiated onto the object to be detected and outputs a backscatter detection signal. A third light receiving unit receives scattered light obtained at a scattering angle of 90° when light of a predetermined wavelength is irradiated onto the target to be detected, and outputs a 90° scattering detection signal. It is equipped with.

[0026] (Structure of the second smoke detection unit using a 1-wavelength, 3-scattering-angle method: 3 LEDs + 1 PD) The signal detection unit is, A light receiving unit receives scattered light of a predetermined wavelength irradiated onto the target to be detected and outputs a scattering detection signal, a backscatter detection signal, or a 90° scattering detection signal. A first light-emitting unit irradiates the object to be detected with light of a predetermined wavelength such that scattered light at a forward scattering angle is incident on the light-receiving unit and a forward scattering detection signal is output. A second light-emitting unit irradiates the object to be detected with light of a predetermined wavelength such that scattered light at a backscatter angle is incident on the light-receiving unit and a backscatter detection signal is output. A third light-emitting unit irradiates the object to be detected with light of a predetermined wavelength such that scattered light with a scattering angle of 90° is incident on the light-receiving unit and a 90° scattering detection signal is output. It is equipped with.

[0027] (1 wavelength 2 scattering angle method: Identification and detection of gas leaks and fires) The signal detection unit detects signals associated with the optical action of the object being detected using at least a first optical setting and a second optical setting. As a first optical setting, the detection target is irradiated with light of a predetermined wavelength and the received signal of scattered light obtained at a predetermined forward scattering angle less than 90° is detected as forward scattered light, or the received signal of scattered light obtained at a predetermined back scattering angle greater than 90° is detected as a backscatter detection signal. As a second optical setting, the target to be detected is irradiated with light of a predetermined wavelength, and the received signal of the scattered light obtained at a scattering angle of 90° is detected as a 90° scattering detection signal. The identification unit identifies a semiconductor manufacturing gas fire when the ratio of the forward scattering detection signal to the 90° scattering detection signal, or the ratio of the backscattered light to the 90° scattering detection signal, satisfies predetermined identification conditions corresponding to Rayleigh scattering. When the identification unit has identified that it is a semiconductor manufacturing gas fire, and the predetermined fire detection conditions are met based on the forward scatter detection signal or back scatter detection signal, the detection output unit outputs the identification result that it is a semiconductor manufacturing gas fire, along with the fire information, to the outside.

[0028] (1 wavelength 2 scattering angle method: identification and detection of smoke-emitting fires) The identification unit identifies a smoke fire when the ratio of the forward scattering detection signal to the 90° scattering detection signal, or the ratio of the backscattered light to the 90° scattering detection signal, satisfies predetermined identification conditions corresponding to smoke. The detection output unit outputs the identification result indicating that it is a smoke fire, along with the fire itself, to the outside if the identification unit has identified that it is a smoke fire and other predetermined fire detection conditions are met based on the forward scatter detection signal or the back scatter detection signal.

[0029] (One wavelength, three scattering angles method and one wavelength, two scattering angles method: Distinguishing between white smoke fires and black smoke fires) The identification unit identifies a white smoke fire when the ratio of the forward scattering detection signal to the 90° scattering detection signal, or the ratio of the backscattered light to the 90° scattering detection signal, satisfies predetermined identification conditions corresponding to white smoke, and identifies a black smoke fire when it satisfies predetermined identification conditions corresponding to black smoke. The detection output unit outputs the identification result indicating that it is a white smoke fire along with the fire to the outside when the identification unit has identified that it is a white smoke fire and other predetermined fire detection conditions are met based on the forward scattering detection signal or the backward scattering detection signal. The detection output unit outputs the identification result indicating that it is a black smoke fire along with the fire to the outside when the identification unit has identified that it is a black smoke fire and other predetermined fire detection conditions are met based on the forward scattering detection signal or the backward scattering detection signal.

[0030] (Structure of the first smoke detection unit using a single wavelength double scattering method: 1 LED + 2 PDs) The signal detection unit is, A light-emitting unit that irradiates the object to be detected with light of a predetermined wavelength, A first light receiving unit that receives scattered light obtained at a forward scattering angle when the target is irradiated with light of a predetermined wavelength and outputs a forward scattering detection signal, or a second light receiving unit that receives scattered light obtained at a back scattering angle when the target is irradiated with light of a predetermined wavelength and outputs a back scattering detection signal, A third light receiving unit receives scattered light obtained at a scattering angle of 90° when light of a predetermined wavelength is irradiated onto the target to be detected, and outputs a 90° scattering detection signal. A place equipped with.

[0031] (Structure of the second smoke detection unit using a single wavelength double scattering method: 2 LEDs + 1 PD) The signal detection unit is, A light receiving unit receives scattered light of a predetermined wavelength irradiated onto the target to be detected and outputs a forward scattering detection signal and a 90° scattering detection signal, or a back scattering detection signal and a 90° scattering detection signal. A first light-emitting unit that irradiates the target to be detected with light of a predetermined wavelength such that scattered light at a forward scattering angle is incident on the light-receiving unit and a forward scattering detection signal is output, or a second light-emitting unit that irradiates the target to be detected with light of the predetermined wavelength such that scattered light at a back scattering angle is incident on the light-receiving unit and a back scattering detection signal is output, A third light-emitting unit irradiates the object to be detected with light of a predetermined wavelength such that scattered light with a scattering angle of 90° is incident on the light-receiving unit and a 90° scattering detection signal is output. A place equipped with.

[0032] (Two-wavelength two-scattering method: Identification and detection of gas combustion products) The signal detection unit detects signals associated with the optical action of the object being detected, using at least a first optical setting and a second optical setting. As a first optical setup, the object to be detected is irradiated with light of a predetermined first wavelength, and the received signal of the scattered light obtained at a predetermined forward scattering angle is detected as a forward scattering detection signal. As a second optical setting, the target to be detected is irradiated with light of a predetermined second wavelength different from the first wavelength, and the received signal of the scattered light obtained at a predetermined backscatter angle is detected as a backscatter detection signal. The identification unit identifies a semiconductor manufacturing gas fire when the ratio of the product of the first wavelength and the forward scattering detection signal to the product of the second wavelength and the backscatter detection signal satisfies predetermined identification conditions corresponding to Rayleigh scattering. When the identification unit has identified that it is a semiconductor manufacturing gas fire, and the predetermined fire detection conditions are met based on the forward scattering detection signal or the back scattering detection signal, the detection output unit outputs the identification result that it is a semiconductor manufacturing gas fire to the outside along with the fire.

[0033] (Two-wavelength, two-scattering-angle method: for identifying and detecting typical fires) The identification unit identifies a smoke fire when the ratio of the product of the first wavelength and the forward scattering detection signal to the product of the second wavelength and the backscatter detection signal satisfies predetermined identification conditions corresponding to smoke. The detection output unit outputs the identification result indicating that it is a smoke fire, along with the fire itself, to the outside if the identification unit has identified that it is a smoke fire and other predetermined fire detection conditions are met based on the forward scatter detection signal or the back scatter detection signal.

[0034] (Two-wavelength, two-scattering-angle method: Distinguishing between white and black smoke) The identification unit identifies a white smoke fire when the ratio of the product of the first wavelength and the forward scattering detection signal to the product of the second wavelength and the backscatter detection signal satisfies predetermined smoke identification conditions corresponding to white smoke, and identifies a black smoke fire when it satisfies predetermined smoke identification conditions corresponding to black smoke. The detection output unit outputs an identification result indicating that it is a white smoke fire along with the fire information if the identification unit has identified that it is a smoke fire and other predetermined fire detection conditions are met based on the forward scatter detection signal or the back scatter detection signal. The detection output unit outputs an identification result indicating that it is a black smoke fire along with the fire information if the identification unit has identified that it is a black smoke fire and other predetermined fire detection conditions are met based on the forward scatter detection signal or the back scatter detection signal.

[0035] (Smoke detection unit structure using a two-wavelength, two-scattering method: 2 LEDs + 1 PD) The signal detection unit is, A light receiving unit that outputs a forward scattering detection signal when it receives scattered light of a first wavelength irradiated onto the target object, and outputs a backscatter detection signal when it receives scattered light of a second wavelength irradiated onto the target object, A first light-emitting unit irradiates the object to be detected with light of a first wavelength such that scattered light at a forward scattering angle is incident on the light-receiving unit and a forward scattering detection signal is output. A second light-emitting unit irradiates the object to be detected with light of a second wavelength such that scattered light at a backscatter angle is incident on the light-receiving unit and a backscatter detection signal is output. It is equipped with.

[0036] (Disaster prevention equipment 1) The present invention relates to a fire prevention system using the aforementioned fire detection device, The system comprises a receiver and a detector that detects a fire and transmits a fire signal to the receiver. The sensor is characterized by being equipped with a signal detection unit, an identification unit, and a detection output unit.

[0037] (Disaster prevention equipment 2) The present invention relates to a fire prevention system using the aforementioned fire detection device, The system comprises a receiver and a detector that detects a fire and transmits a fire signal to the receiver. The sensor is equipped with a signal detection unit. The receiver is characterized by being equipped with an identification unit and a detection output unit.

[0038] (Control based on fire identification results) The receiver of the fire prevention equipment controls the fire prevention, suppression, or extinguishing process according to the identification result output from the detection output unit.

[0039] (Control based on fire identification results) If the receiver of the fire prevention equipment identifies a semiconductor manufacturing gas fire, the control system will shut off the supply of semiconductor manufacturing gas and / or release inert gas into the fire area.

[0040] (Fire detection method 1) The present invention is a fire detection method characterized by detecting a smoke-generating fire and a predetermined gas fire that generates monodisperse particles, and identifying which type of fire it is.

[0041] (Fire alarm including identification results) If the system identifies that the fire is a smoke fire or a specified gas fire, it will output the identification result along with the fire information.

[0042] (Control based on identification results) Depending on the identification result, different control measures will be applied to prevent, suppress, or extinguish the fire.

[0043] (Gas fires in semiconductor manufacturing) If the identification result is a semiconductor manufacturing gas fire, the control measures will be to stop the supply of semiconductor gas and / or release inert gas into the fire area.

[0044] (Fire detection method 2) The present invention is a fire detection method for detecting a fire in a monitored area, The signal detection unit irradiates light onto the target to be detected in the monitoring area involving light action and detects multiple detection signals received at different scattering angles. The identification unit identifies, based on multiple detection signals detected by the signal detection unit, whether it is a smoke-generating fire producing smoke or a semiconductor manufacturing gas fire producing monodisperse particles. When the detection output unit has identified that it is either a smoke fire or a semiconductor manufacturing gas fire, and any of the multiple detection signals satisfy the predetermined fire detection conditions, the identification result is output externally along with the fire information. It is characterized by the following:

[0045] (Gas used in semiconductor manufacturing) The gases used in semiconductor manufacturing are silane gas or phosphine gas. [Effects of the Invention]

[0046] (Effectiveness of fire detection devices) According to the fire detection device of the present invention, when a fire occurs in a monitored area, multiple signals are detected by setting multiple different scattering angles as signals from combustion products that are the target of detection in the monitored area accompanied by optical effects. Based on these signals, if the particle size of the burning object is smaller than the wavelength of the irradiated light, the light scattering intensity is distributed substantially uniformly in front and behind, and the scattering intensity is smallest at a scattering angle of 90°, and the predetermined identification conditions corresponding to Rayleigh scattering are satisfied, then it is identified as a semiconductor manufacturing gas fire in which gases such as silane gas or phosphine gas used in semiconductor manufacturing burn and produce monodisperse particles. The identification result, along with the fire, indicating that a semiconductor manufacturing gas fire has been identified is output externally to provide notification, enabling control such as stopping the supply of semiconductor manufacturing gases and / or releasing inert gas to the fire area, thereby enabling safe and reliable fire extinguishing.

[0047] (Effects of identifying and detecting gas leaks and fires using a one-wavelength, three-scattering-angle method) Furthermore, in the one-wavelength, three-scattering-angle method, when light is irradiated onto the combustion product to be detected, the intensity distribution of light due to Rayleigh scattering, which is the scattering of particles smaller than the wavelength of light, is distributed almost uniformly in front and behind, and is minimized at a scattering angle of 90°. Therefore, a forward scattering detection signal, a back scattering detection signal, and a 90° scattering detection signal are detected, and when the predetermined identification conditions corresponding to Rayleigh scattering where the 90° scattering detection signal is minimized are met, it is identified as a gas fire for semiconductor manufacturing using silane gas or phosphine gas, enabling reliable detection and response to semiconductor manufacturing gas fires at an early stage.

[0048] (Effects of identifying and detecting smoke-generating fires using a one-wavelength, three-scattering-angle method) Furthermore, in the one-wavelength, three-scattering-angle method, the intensity distribution of light in Mie scattering, which is the scattering of particles larger than the wavelength of light, shows that forward scattering is greater than backward scattering. Since the size of smoke particles in a smoke fire is widely distributed from sizes smaller to larger than the wavelength of light irradiating the target, it results in a composite scattering of Rayleigh scattering and Mie scattering. In this composite scattering, the identification condition corresponding to Rayleigh scattering, which is minimized by a 90° scattering detection signal, is not satisfied. Therefore, in this case, it is identified as a smoke fire, and even in monitoring areas where semiconductor equipment using silane gas or phosphine gas is installed, it becomes possible to extinguish smoke fires using, for example, water or halon fire extinguishing gas.

[0049] (Effects of the first smoke detection unit structure using a 1-wavelength, 3-scattering-angle method) Furthermore, in the one-wavelength, three-scattering-angle system, the signal detection unit arranges three light-receiving units for each light-emitting unit to receive scattered light at forward scattering angles, back scattering angles, and a scattering angle of 90°, thereby enabling reliable detection of three types of signals with different scattering angles in a simple configuration. In addition, by emitting light from a single light-emitting unit, signals from each light-receiving unit can be obtained simultaneously.

[0050] (Effects of the second smoke detection section structure using a 1-wavelength, 3-scattering-angle method) Furthermore, in the one-wavelength, three-scattering-angle method, the signal detection unit arranges three light-emitting units for each light-receiving unit so that scattered light at the forward scattering angle, back scattering angle, and 90° scattering angle is received, thereby enabling reliable detection of three types of signals with different scattering angles in a simple configuration. In this case, each light-emitting unit emits light sequentially, and each signal is obtained in order.

[0051] (Effects of identifying and detecting gas leak fires using a one-wavelength, two-scattering-angle method) Furthermore, in the one-wavelength, two-scattering-angle method, the signal detection unit irradiates the combustion product to be detected with light and detects either a forward scattering detection signal or a backscattering detection signal, along with a 90° scattering detection signal. The identification unit identifies that the fire is caused by a semiconductor manufacturing gas such as silane gas or phosphine gas if the ratio of the forward scattering detection signal to the 90° scattering detection signal, or the ratio of the forward scattering detection signal to the 90° scattering detection signal, satisfies predetermined identification conditions corresponding to Rayleigh scattering, thereby enabling reliable detection and response to semiconductor manufacturing gas fires at an early stage.

[0052] (Effects of identifying and detecting a normal fire using a one-wavelength, two-scattering-angle method) Furthermore, the identification unit identifies a smoke fire if the ratio of the forward scattering detection signal to the 90° scattering detection signal, or the ratio of the forward scattering detection signal to the 90° scattering detection signal, does not satisfy the predetermined identification conditions corresponding to Rayleigh scattering. This enables the extinguishing of smoke fires using, for example, water or halon fire extinguishing gas, even in monitoring areas where semiconductor equipment using silane gas or phosphine gas is installed.

[0053] (Effects of the first smoke detection unit structure using a 1-wavelength, 2-scattering-angle method) Furthermore, in the one-wavelength, two-scattering-angle method, the signal detection unit arranges two light-emitting units for each light-emitting unit, receiving scattered light at the forward scattering angle and a 90° scattering angle, or the back scattering angle and a 90° scattering angle, thereby enabling the detection of two types of signals with different scattering angles in a simple configuration. In addition, by emitting light from one light-emitting unit, signals can be obtained simultaneously from each light-receiving unit.

[0054] (Effects of the second smoke detection section structure using a 1-wavelength, 2-scattering-angle method) Furthermore, in the one-wavelength, two-scattering-angle method, the signal detection unit arranges two light-emitting units for each light-receiving unit so that it receives both forward-scattered light and scattered light at a 90° scattering angle, or back-scattered light and scattered light at a 90° scattering angle. This allows for the detection of two types of signals with different scattering angles in a simple configuration. In this case, each light-emitting unit emits light sequentially, and the light-receiving unit outputs each signal in sequence.

[0055] (Effects of distinguishing between white and black smoke using the 1-wavelength, 3-scattering-angle method and the 1-wavelength, 2-scattering-angle method) Furthermore, in the 1-wavelength 3-scattering-angle method and the 1-wavelength 2-scattering-angle method, when smoke is identified as that of a normal fire, if the ratio of forward-scattered light to the 90° scattering detection signal, or the ratio of back-scattered light to the 90° scattering detection signal, satisfies predetermined identification conditions corresponding to white smoke, it is identified as a white smoke fire. If the ratio satisfies predetermined identification conditions corresponding to black smoke, it is identified as a black smoke fire. By outputting the identification result, such as whether it is a white smoke fire or a black smoke fire, along with the fire information, it becomes possible to take measures such as rapid evacuation guidance and firefighting in the case of black smoke fires, which pose a high risk of fire.

[0056] (Effects of identifying and detecting gas combustion products using a two-wavelength, two-scattering method) Furthermore, in the two-wavelength, two-scattering-angle method, the signal detection unit creates a difference in scattering characteristics due to the scattering angle by making the scattering angle relative to the detection target different for the forward scattering angle and the back scattering angle. Simultaneously, it creates a difference in scattering characteristics due to the wavelength by making the wavelength of the light irradiated onto the detection target different for the first wavelength and the second wavelength. The synergistic effect of this difference in scattering angle and wavelength creates a significant difference in the scattering intensity of the scattered light from monodisperse particles generated in semiconductor manufacturing gas fires such as silane gas and phosphine gas, and from smoke generated in smoke fires. The identification unit identifies that it is a semiconductor manufacturing gas fire such as silane gas or phosphine gas if the ratio of the multiplication value of the first wavelength and the forward scattering detection signal to the multiplication value of the second wavelength and the back scattering detection signal satisfies predetermined identification conditions corresponding to Rayleigh scattering, enabling reliable detection and response to semiconductor manufacturing gas fires at an early stage.

[0057] (Identification and detection of smoke-generating fires using a two-wavelength, two-scattering-angle method) Furthermore, in the two-wavelength, two-scattering-angle system, the identification unit identifies a smoke fire if the ratio of the multiplication value of the first wavelength and the forward scattering detection signal to the multiplication value of the second wavelength and the backscattering detection signal does not satisfy predetermined identification conditions corresponding to monodisperse particles generated in a semiconductor manufacturing gas fire. This enables the extinguishing of smoke fires using, for example, water or halon fire extinguishing gas, even in monitoring areas where semiconductor equipment using silane gas or phosphine gas is installed.

[0058] (Distinguishing between white and black smoke using a two-wavelength, two-scattering-angle method) Furthermore, in the two-wavelength, two-scattering-angle system, if the ratio of the multiplication value of the first wavelength and the forward scattering detection signal to the multiplication value of the second wavelength and the backscattering detection signal satisfies predetermined identification conditions corresponding to white smoke, it is identified as a white smoke fire. If it satisfies predetermined identification conditions corresponding to black smoke, it is identified as a black smoke fire. By outputting the identification result, such as whether it is a white smoke fire or a black smoke fire, along with the fire information, it becomes possible to take measures such as rapid evacuation guidance and firefighting in the case of black smoke fires, which pose a high risk of fire.

[0059] (Effects of the smoke detection unit structure using a two-wavelength, two-scattering-angle method) Furthermore, in the two-wavelength, two-scattering-angle method, the signal detection unit arranges two light-emitting units that emit light of different wavelengths to a single light-receiving unit, so that the scattered light at the forward scattering angle and the back scattering angle is received. This enables reliable detection of forward and back scattering detection signals with different wavelengths and scattering angles with a simple configuration. In this case, each light-emitting unit emits light sequentially, and the light-receiving unit outputs each signal in order.

[0060] (Effects of the first disaster prevention equipment) The present invention relates to a fire prevention system using the aforementioned fire detection device, and by providing a signal detection unit, identification unit, and detection output unit all in the detector, it can be addressed by changing only the detector itself. Even with existing equipment, it can be easily addressed by removing the detector mounted on the base and replacing it with a detector that is equipped with a signal detection unit, identification unit, and detection output unit.

[0061] (Effects of the second disaster prevention equipment) The present invention relates to a fire prevention system using the aforementioned fire detection device, wherein the detector is equipped with a signal output unit and the receiver is equipped with an identification unit and a detection output unit, thereby eliminating the need to modify the detector and allowing the system to be addressed by modifying only the receiver.

[0062] (Effectiveness of fire detection methods) The present invention provides a fire detection method that achieves the same effects as the fire detection device described above. [Brief explanation of the drawing]

[0063] [Figure 1] This is an explanatory diagram illustrating the basic concepts of the fire detection device, fire prevention equipment, and fire detection method of the present invention. [Figure 2] This is an explanatory diagram of a disaster prevention equipment showing a specific embodiment of the present invention, which corresponds to the P-type disaster prevention equipment shown in Figure 1. [Figure 3] This is an explanatory diagram showing a smoke detection unit equipped with a signal detection unit. Figure 3(A) shows the structure of the first smoke detection unit using a 1-wavelength, 3-scattering-angle method, and Figure 3(B) shows the structure of the second smoke detection unit using a 1-wavelength, 3-scattering-angle method. [Figure 4] This is an explanatory diagram showing the scattering intensity as a function of the scattering angle for Rayleigh scattering and Lie scattering. [Figure 5] This is a characteristic graph showing the scattering intensity as a function of the scattering angle for white smoke, black smoke, and silicon dioxide. [Figure 6] Figure 3(A) is an explanatory diagram that shows, in list format, the forward scattering detection values, backscatter detection values, and 90° scattering detection values ​​A1 to A3 corresponding to the type of smoke detected in the first smoke detection section structure, the relative values ​​when 90° scattering detection value A3 is set to 1, the ratio of backscatter detection values ​​to 90° scattering detection values ​​for distinguishing between white smoke and black smoke, and the conditions for distinguishing between white smoke and black smoke. [Figure 7] This is a flowchart illustrating the control operation according to the sensor embodiment shown in Figure 2. [Figure 8] This is an explanatory diagram of a disaster prevention system showing a specific embodiment of the present invention, targeting a P-type disaster prevention system that uses a smoke detection unit with a one-wavelength, two-scattering-angle method. [Figure 9] This is an explanatory diagram showing the smoke detection unit structure corresponding to the signal detection unit in Figure 8. [Figure 10] This is an explanatory diagram showing, in list format, the ratios and identification conditions for white smoke or black smoke, based on the backscatter detection value A2 and the 90° scattering detection value A3 detected in the first smoke detection section structure shown in Figure 9(A). [Figure 11] This is an explanatory diagram showing a specific embodiment of the present invention for a P-type disaster prevention system equipped with a signal detection unit using a two-wavelength, two-scattering-angle method. [Figure 12] This is an explanatory diagram showing the structure of the smoke detection unit using a two-wavelength, two-scattering-angle method. [Figure 13] This diagram is an explanatory chart that shows, in list format, the forward scattering detection value A1 and backscatter detection value A2 at the first wavelength, the forward scattering detection value A1 and backscatter detection value A2 at the second wavelength, the ratio of the product of the first wavelength and the forward scattering detection value to the product of the second wavelength and the backscatter detection value, and the identification conditions for white smoke or black smoke, corresponding to the type of smoke detected by the smoke detection unit structure shown in Figure 11. [Figure 14] This is an explanatory diagram illustrating other basic concepts of the fire detection device, fire prevention equipment, and fire detection method of the present invention, which determine a fire on the receiver side. [Figure 15] This is an explanatory diagram of a disaster prevention equipment showing a specific embodiment of the present invention, which corresponds to the R-type disaster prevention equipment shown in Figure 13. [Figure 16] Figure 14 is a flowchart showing the control operation of the R-type disaster prevention equipment embodiment in a time chart format. [Modes for carrying out the invention]

[0064] Embodiments of the fire detection device, fire prevention equipment, and fire detection method according to the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to these embodiments.

[0065] [Basic Concepts of the Embodiment] Figure 1 is an explanatory diagram showing the basic concept of an embodiment of the present invention corresponding to the first fire prevention equipment, and the basic concept of the embodiment will be explained with reference to Figure 1. This embodiment generally relates to a fire detection device, the first fire prevention equipment, and a fire detection method. An embodiment corresponding to the second fire prevention equipment will be described separately.

[0066] A "fire detection device" is a device that detects fires in a monitored area, and the concept includes, for example, smoke detectors, fire detectors, and fire alarms.

[0067] Here, "monitoring area" refers to the area that is monitored by the fire detection device, and is a concept that includes a certain area of ​​outdoor or indoor space, such as rooms, corridors, and stairwells in a building.

[0068] The fire detection device is, for example, a detector 12 in a fire prevention system consisting of a receiver 10 and a detector 12, and includes a signal detection unit 16, an identification unit 18, and a detection output unit 20.

[0069] The "signal detection unit 16" detects signals from objects in a monitoring area that involve optical effects, using multiple optical settings with different scattering angles, and detects multiple signals obtained by said optical settings.

[0070] Here, "detection target of the monitoring area with light effect" refers to smoke, which is a combustion product generated in the event of a fire. For example, it is something that generates scattered light when irradiated with light. In addition to smoke generated in general fires, oil fires, electrical fires, etc., in this embodiment, it is a concept that includes monodisperse particles generated in a predetermined gas fire, such as monodisperse particles generated in a semiconductor manufacturing gas fire, such as silane gas used as a doping gas in semiconductor manufacturing or phosphine gas used as an epitaxial gas.

[0071] For example, silane gas (SiH4) is toxic, and regulations stipulate that firefighting should not be attempted unless the leak is contained. Extinguishing agents used include powder extinguishing agents, foam extinguishing agents, and CO2. Because it reacts violently with water, potentially producing toxic gases, water should not be used in initial firefighting efforts; therefore, firefighting activities must be conducted separately from those for smoke fires. When silane gas leaks into the air, it reacts with oxygen at room temperature and burns easily. The lower flammability limit of silane gas is around 1%, and it is extremely unstable in the presence of oxygen. Upon contact with air, it spontaneously ignites and burns explosively, producing silicon dioxide (SiO2) as monodisperse particles. The chemical formula for silane gas combustion is: SiH4 + 2O2 → SiO2 + 2H2O This is because silicon dioxide (SiO2) produced in a silane gas fire has a particle size of, for example, about 50 nm to 60 nm.

[0072] Furthermore, "multiple different optical settings" refers to detecting multiple signals obtained by irradiating the target to be detected in the monitoring area with light of a predetermined wavelength and receiving the scattered light obtained at different scattering angles.

[0073] "Multiple different optical settings" are, as an example, a first optical setting in which the target is irradiated with light of a predetermined wavelength and the received signal of scattered light obtained at a predetermined forward scattering angle θ1 less than 90° is detected as a forward scattering detection signal; a second optical setting in which the target is irradiated with light of a predetermined wavelength and the received signal of scattered light obtained at a predetermined back scattering angle θ2 greater than 90° is detected as a back scattering detection signal; and a third optical setting in which the target is irradiated with light of a predetermined wavelength and the received signal of scattered light obtained at a scattering angle of 90° is detected as a 90° scattering detection signal.

[0074] The configuration and structure of the signal detection unit 16 are arbitrary, but for example, it is a one-wavelength, three-scattering-angle method in which a predetermined wavelength of light is irradiated onto the object to be detected and three detection signals received at three different scattering angles are detected. As a smoke detection unit structure for the one-wavelength, three-scattering-angle method, for example, there is a first smoke detection unit structure consisting of one light-emitting element and three light-receiving elements, and a second smoke detection unit structure consisting of three light-emitting elements that irradiate the same wavelength of light as one light-receiving element.

[0075] The "identification unit 18" identifies whether a fire is a smoke-generating fire that produces smoke, or a fire using a predetermined gas that produces monodisperse particles, such as silane gas or phosphine gas used in semiconductor manufacturing, based on multiple detection signals detected by the signal detection unit. For example, it identifies a fire as a semiconductor manufacturing gas fire when the multiple detection signals satisfy predetermined identification conditions corresponding to Rayleigh scattering.

[0076] As mentioned above, "Rayleigh scattering" is the scattering of light by particles smaller than the wavelength of light, and the scattering intensity (amount of scattered light) is distributed almost uniformly in front and behind, and is minimum at a scattering angle of 90°. The silicon dioxide particles produced in semiconductor manufacturing gas fires, such as silane gas fires, are very small, for example, in the range of 50nm to 60nm, and are smaller than the wavelength of the irradiated light, resulting in Rayleigh scattering. For this reason, the identification unit 18 identifies that it is a silane gas fire when, for example, predetermined identification conditions corresponding to Rayleigh scattering where the 90° scattering detection signal is minimum are met.

[0077] Furthermore, the "identification unit 18" identifies a smoke fire when the predetermined identification conditions corresponding to Rayleigh scattering, where the 90° scattering detection signal is at its minimum value, are not met. Smoke produced in smoke fires, including general fires, oil fires, and electrical fires, is mainly composed of carbon oxides and water as organic matter burns, and the particle size is generally distributed in the range of 0.0001 μm to several μm. Therefore, particles smaller than the wavelength of the irradiated light undergo Rayleigh scattering, and particles larger than the wavelength of light undergo Mie scattering, resulting in a composite scattering that combines both.

[0078] As mentioned earlier, "Mie scattering" is the scattering of light by particles larger than the wavelength of light, and the scattering intensity of light is greater when scattering forward than when scattering backward. Since the smoke from a smoke fire is a combination of Rayleigh scattering and Mie scattering, the scattering intensity of light is not minimized at a scattering angle of 90°. Therefore, the identification unit identifies a smoke fire when the identification condition corresponding to Rayleigh scattering, which results in the minimum value of the 90° scattering detection signal, is not met.

[0079] Furthermore, when the identification unit 18 identifies that it is a smoke fire, it further identifies whether it is a white smoke fire producing white smoke or a black smoke fire producing black smoke. For example, the identification unit identifies that it is a white smoke fire when the ratio of the forward scattering detection signal to the 90° scattering detection signal, or the ratio of the backscattered light to the 90° scattering detection signal, satisfies predetermined identification conditions corresponding to white smoke, and identifies that it is a black smoke fire when predetermined identification conditions corresponding to black smoke are satisfied.

[0080] White smoke is a whitish smoke mainly composed of moisture, produced when materials such as wood or cloth smolder (burn), and is also called burning smoke. Black smoke, on the other hand, is a dark smoke produced when materials such as objects ignite and burn, and is also called combustion smoke. Common combustion materials in white smoke fire models that primarily produce white smoke include wood and cotton wicks, while common combustion materials in black smoke fire models that primarily produce black smoke include kerosene.

[0081] The "detection output unit 20" outputs to the outside that it is a predetermined gas fire along with the fire when the identification unit 18 has identified that it is a predetermined gas fire and any of the multiple detection signals satisfy the predetermined fire detection conditions. For example, when the identification unit 18 has identified that it is a semiconductor manufacturing gas fire such as silane gas or phosphine gas, and the predetermined fire detection conditions are satisfied based on the forward scatter detection signal or back scatter detection signal, the "detection output unit 20" outputs to the outside that it is a semiconductor manufacturing gas fire along with the fire.

[0082] Here, "when the predetermined fire detection conditions are met" means that any of the multiple signals satisfy the predetermined threshold condition or accumulation condition, and this concept includes, for example, when the predetermined threshold is exceeded, or when the state of exceeding the predetermined threshold continues for a predetermined accumulation time.

[0083] Furthermore, this embodiment uses a signal detection unit 16 that employs a 1-wavelength 2-scattering-angle method, which is a simplified version of the 1-wavelength 3-scattering-angle method. It detects a forward scattering detection signal and a 90° scattering detection signal, or a back scattering detection signal and a 90° scattering detection signal, based on the first and second optical settings. Its configuration and structure are arbitrary, but for example, there is a first smoke detection unit structure consisting of one light-emitting element and two light-receiving elements, and a second smoke detection unit structure consisting of two light-emitting elements that irradiate one light-receiving element with light of the same wavelength.

[0084] In conjunction with the one-wavelength, two-scattering-angle signal detection unit 16, the identification unit 18 identifies that the fire is a semiconductor manufacturing gas fire, such as silane gas or phosphine gas, when the ratio of the forward scattering detection signal to the 90° scattering detection signal, or the ratio of the back scattering detection signal to the 90° scattering detection signal, satisfies predetermined identification conditions corresponding to Rayleigh scattering. On the other hand, if the predetermined identification conditions corresponding to Rayleigh scattering are not satisfied, the identification unit 18 identifies that the fire is a smoke fire.

[0085] Furthermore, when the identification unit 18 identifies that it is a smoke fire, it identifies that it is a white smoke fire if the ratio of the forward scattering detection signal to the 90° scattering detection signal, or the ratio of the backscattered light to the 90° scattering detection signal, satisfies predetermined identification conditions corresponding to white smoke, similar to the one-wavelength, three-scattering-angle method, and identifies that it is a black smoke fire if it satisfies predetermined identification conditions corresponding to black smoke. The detection output unit 20 then outputs the identification result, indicating whether it is a white smoke fire or a black smoke fire, to the outside along with the fire information.

[0086] Furthermore, this embodiment provides a signal detection unit 16 that uses a two-wavelength, two-scattering-angle method to make the difference in scattering intensity according to the detection target more pronounced due to the difference in wavelength in addition to the difference in scattering angle. The signal detection unit 16, for example, has a first optical setting in which it irradiates the detection target with light of a predetermined first wavelength and detects the received signal of the scattered light obtained at a predetermined forward scattering angle as a forward scattering detection signal, and a second optical setting in which it irradiates the detection target with light of a predetermined second wavelength different from the first wavelength and detects the received signal of the scattered light obtained at a predetermined back scattering angle as a back scattering detection signal. Its configuration and structure are arbitrary, but for example, it has a smoke detection unit structure composed of one light-receiving element and two light-emitting elements that irradiate with light of different wavelengths.

[0087] In conjunction with the two-wavelength, two-scattering-angle signal detection unit 16, the identification unit 18 identifies a semiconductor manufacturing gas fire, such as silane gas or phosphine gas, when the ratio of the product of the first wavelength and the forward scattering detection signal to the product of the second wavelength and the backscattering detection signal satisfies predetermined identification conditions corresponding to Rayleigh scattering, and identifies a smoke fire when predetermined identification conditions corresponding to smoke from a smoke fire are satisfied.

[0088] Furthermore, when the identification unit 18 identifies that it is a smoke fire, it identifies that it is a white smoke fire if the ratio of the multiplication value of the first wavelength and the forward scattering detection signal to the multiplication value of the second wavelength and the backscatter detection signal satisfies predetermined identification conditions corresponding to white smoke, and identifies that it is a black smoke fire if it satisfies predetermined identification conditions corresponding to black smoke. The detection output unit 20 then outputs the identification result, indicating whether it is a white smoke fire or a black smoke fire, to the outside along with the fire information.

[0089] The following explanation describes the case where the "monitoring area" is a "room in a building," the "signal detection unit 16" is a "1-wavelength 3-scattering-angle method," a "1-wavelength 2-scattering-angle method," or a "2-wavelength 2-scattering-angle method," the "forward scattering detection signal," "backward scattering detection signal," and "90° scattering detection signal" detected by each method are "forward scattering detection value A1," "backward scattering detection value A2," and "90° scattering detection value A3," and the "semiconductor manufacturing gas fire producing monodisperse particles exhibiting Rayleigh scattering" is a "silane gas fire producing silicon oxide exhibiting Rayleigh scattering." Note that each scattering detection value A1 to A3 is a concept that includes scattering intensity, scattered light amount, and signal amount.

[0090] [Specific details of the embodiment] The specific details of the embodiments of the fire detection device, fire prevention equipment, and fire detection method will be explained in more detail. The details will be explained in the following sections. AP-type disaster prevention equipment a1. Shinki a2.Sensor b. Signal detection unit b1.1 Wavelength 3-scattering angle signal detection unit b2.1 Structure of the first smoke detection unit using the 3-wavelength scattering angle method b3.1 Structure of the second smoke detection unit using the wavelength 3 scattering angle method c. Sensor control section d. Identification unit d1. Identification function d2. Rayleigh scattering d3. Mie scattering d4. Complex scattering d5. Scattering characteristics of the object being detected d6. Identification of silane gas fires d7. Identification of smoke-generating fires d8. Distinguishing between white smoke fires and black smoke fires e. Detection output section e1. Detection conditions for silane gas fires e2. Detection conditions for smoke fires e3. Transmission of fire alarm signals based on fire detection f. Control operation of sensors g. Embodiment equipped with a 1 wavelength 2 scattering angle type signal detection unit g1.1 Wavelength 2 Scattering Angle Method First Smoke Detection Section Structure g2.1 Wavelength 2 scattering angle method second smoke detection section structure g3.1 Wavelength 2 scattering angle type identification unit Embodiment equipped with a signal detection unit using a 2-wavelength 2-scattering angle method. h1.2 wavelength 2 scattering angle method signal detection unit H2.2 wavelength 2 scattering angle method smoke detection unit structure h3.2 wavelength 2 scattering angle type identification unit h4. Identification of Silane Gas Fires and Smoke Fires h5. Rayleigh scattering and wavelength i. Basic concepts of other embodiments JR-type disaster prevention equipment j1.sensor j2. Receiver j3. Transmission control j4. Receiver identification unit j5. Receiver detection output section Control operation of the j6.R type disaster prevention equipment k. Modified form of the present invention

[0091] [aP-type disaster prevention equipment] Figure 2 is an explanatory diagram showing a specific embodiment of the present invention, corresponding to a P-type (Proprietary-type) fire prevention system, as shown in Figure 1. Here, a "P-type fire prevention system" is a system in which the receiver 10 monitors for fires on a per-signal line basis, to which the detectors 12 are connected.

[0092] As shown in Figure 2, the P-type disaster prevention equipment of this embodiment includes a receiver 10 and multiple detectors 12. Note that Figure 2 shows one detector 12 as a representative example. The receiver 10 is installed in a manager's room or disaster prevention center, and the detectors 12 are connected to a signal line 14 that runs from the receiver 10 to a monitoring area such as a room in the building.

[0093] In this configuration, the room being monitored is equipped with semiconductor manufacturing equipment that uses silane gas. The detector 12 in this embodiment transmits a fire alarm signal to the receiver 10 that includes an identification result indicating that the fire is either a silane gas fire or a smoke fire. Furthermore, in the case of a smoke fire, the detector 12 in this embodiment transmits a fire alarm signal that includes an identification result indicating that the fire is either a white smoke fire or a black smoke fire. In addition to the detector 12 in this embodiment, a known, highly sensitive scattered light smoke detector that detects smoke produced by a smoke fire may also be connected to the receiver 10.

[0094] The signal line 14 drawn from the receiver 10 includes a positive signal line 14a and a negative signal line (common signal line) 14b, and supplies power from the receiver 10 to the detector 12, and transmits a fire alarm signal including the aforementioned identification result from the detector 12 to the receiver 10.

[0095] (a1. Receiver) The receiver 10 of the Type P fire prevention equipment will now be described in more detail. The receiver 10 comprises a receiver control unit 46, a line receiving unit 48, a display unit 50, an operation unit 52, an alarm unit 54, and a transmission unit 56. The line receiving unit 48 is provided for each signal line 14 drawn out in a monitoring area, for example, by floor of a building, and receives a fire alarm signal that includes identification information indicating that a silane gas fire has been identified in conjunction with a fire from the detector 12 of this embodiment, or that a smoke fire has been identified. It outputs this received detection signal to the receiver control unit 46, and further outputs the received detection signal for a smoke fire by separating it into a white smoke fire detection signal and a black smoke fire detection signal. In addition, if the line receiving unit 48 receives a fire alarm signal from a known scattered light detector, it outputs a received detection signal for a smoke fire to the receiver control unit 46.

[0096] The receiver control unit 46 is composed of a computer circuit equipped with a CPU, memory, and various input / output ports. When it receives a received detection signal for a silane gas fire or a smoke fire output from the line receiving unit 48, it performs a fire alarm operation. The fire alarm operation of the receiver control unit 46 activates the fire indicator light on the display unit 44 and the area indicator light that shows the area where the fire occurred. It also displays whether it is a silane gas fire or a smoke fire on the display or the like, and in the case of a smoke fire, it displays whether it is a white smoke fire or a black smoke fire. In addition, the alarm unit 48 outputs a main audible alarm including an alarm voice message and performs an area audible alarm by activating the area sound device installed in the monitoring area where the fire occurred.

[0097] The alarm display and audio message for a silane gas fire by the alarm unit 48 are optional, but may include phrases such as "Silane gas detected. A silane gas fire has occurred." In addition to the alarm display and audio message, the alarm unit 48 may also provide guidance on usable extinguishing agents for silane gas fires, prohibiting water and instructing the use of carbon dioxide or dry chemical extinguishing agents. It can also instruct the alarm transmission unit 56 to control the interlocking of smoke control equipment and to notify external fire departments of the fire.

[0098] Furthermore, the receiving control unit 46 outputs control signals from the transmission unit 56 to the transmission destination to control the fire prevention, suppression, or extinguishing measures, depending on the identification result of whether it is a silane gas fire or a smoke fire. For example, if the identification result is a silane gas fire, the receiving control unit 46 instructs the transmission unit 56 to output a control signal to stop the supply of silane gas to the semiconductor manufacturing equipment, and also to output a control signal to inert gas fire extinguishing equipment such as carbon dioxide fire extinguishing equipment to release an inert gas such as carbon dioxide gas into the fire area.

[0099] (a2.sensor) The detector 12 of this embodiment, which functions as a fire detection device, comprises a signal detection unit 16, a detector control unit 24, an alarm circuit unit 26, a power supply unit 28, a light emission drive unit 38, and light receiving amplification units 40, 42, and 44.

[0100] [b. Signal detection unit] (b1.1 Wavelength 3 Scattering Angle Signal Detection Unit) The signal detection unit 16, which uses a one-wavelength, three-scattering-angle method and is provided in the detector 12, will be described in more detail. The signal detection unit 16 irradiates a target to be detected, such as silicon oxide produced in a silane gas fire or smoke produced in a smoke fire, with light of a predetermined wavelength λ, and detects a forward scattering detection value A1 based on a forward scattering detection signal obtained by receiving scattered light obtained at a predetermined forward scattering angle θ1 according to a first optical setting, a back scattering detection value A2 based on a back scattering detection signal obtained by receiving scattered light obtained at a predetermined back scattering angle θ2 according to a second optical setting, and a 90° scattering detection value A3 based on a 90° scattering detection signal obtained by receiving scattered light obtained at a scattering angle of 90° according to a third optical setting. Its configuration and structure are arbitrary, but for example, a light-emitting element 30, a first light-receiving element 32, a second light-receiving element 34, and a third light-receiving element 36 are arranged in a smoke detection section, which is a space inside the detector into which outside air flows but outside light is blocked.

[0101] Figure 3 is an explanatory diagram showing the smoke detection section structure of the signal detection unit 16. Figure 3(A) shows an embodiment of the first smoke detection section structure corresponding to the signal detection unit 16 in Figure 2, and Figure 3(B) shows a second smoke detection section structure as another embodiment.

[0102] (b2.1 Wavelength 3 Scattering Angle Method First Smoke Detection Section Structure) The structure of the first smoke detection unit using the one-wavelength, three-scattering-angle method will be explained in more detail. As shown in Figure 3(A), the structure of the first smoke detection unit using the one-wavelength, three-scattering-angle method has a light-emitting element 30, a first light-receiving element 32, a second light-receiving element 34, and a third light-receiving element 36 arranged within a smoke detection unit 58 into which smoke from the outside flows and external light is shielded, with each element having a planar arrangement where their optical axes are located in the same plane. The light-emitting element 30 is driven to emit light at predetermined intervals by the light-emitting drive unit 38 shown in Figure 2, and the received signals from the first to third light-receiving elements 32, 34, and 36 are amplified by the light-receiving amplification units 40, 42, and 44, and then sequentially read by the A / D conversion of the sensor control unit 24.

[0103] The type of light-emitting element 30 is arbitrary, but for example, a near-infrared LED (light-emitting diode) is used, and the light with wavelength λ is, for example, light in the range of a central wavelength of 400 nm to 1000 nm, for example, light with a near-infrared wavelength of λ = 900 nm. The first to third photodetectors 32, 34, and 36 use photodiodes PD that are sensitive from the infrared region to the visible light region.

[0104] As a first optical setting of the signal detection unit 16, the first light-receiving element 32 is positioned at a scattering angle θ1 with respect to point P (smoke detection point) where its optical axis intersects with the optical axis of the light-emitting element 30. The scattering angle θ1 is set to a predetermined angle less than 90°, for example, a forward scattering angle of θ1 = 40°. When the light-emitting drive unit 38 drives the light-emitting element 30 to emit light, light with a wavelength λ = 900 nm is irradiated onto the smoke flowing into point P. The scattered light from the smoke (forward scattered light) corresponding to the scattering angle θ1 = 40° is incident on the first light-receiving element 32 and received. A forward scattering detection signal is output as a received signal, which is amplified by the light-receiving amplifier unit 40 and read by the sensor control unit 24 after A / D conversion, thereby detecting a forward scattering detection value A1 corresponding to the smoke concentration.

[0105] Furthermore, as a second optical setting of the signal detection unit 16, the second light-receiving element 34 is positioned at a scattering angle θ2 with respect to point P (smoke detection point) where its optical axis intersects with the optical axis of the light-emitting element 30. The second scattering angle θ2 is set to a predetermined angle exceeding 90°, for example, a backscattering angle of θ2 = 110°. When the light-emitting drive unit 38 drives the light-emitting element 30 to emit light, and light with a wavelength λ = 900 nm is irradiated onto the smoke flowing into point P, the scattered light (backscattered light) from the smoke corresponding to the scattering angle θ2 = 110° is incident on the second light-receiving element 34 and received. A backscatter detection signal is output as a received signal, which is amplified by the light-receiving amplifier unit 42 and read by the sensor control unit 24 after A / D conversion, thereby detecting a backscatter detection value A2 corresponding to the smoke concentration.

[0106] Furthermore, as a third optical setting of the signal detection unit 16, the third light-receiving element 36 is positioned at a scattering angle θ3 = 90° with respect to point P (smoke detection point) where its optical axis intersects with the optical axis of the light-emitting element 30. When the light-emitting drive unit 38 drives the light-emitting element 30 to emit light, and light with a wavelength λ = 900 nm is irradiated onto the smoke flowing into point P, the scattered light from the smoke corresponding to the scattering angle θ3 = 90° is incident on the third light-receiving element 36 and received. A 90° scattering detection signal is output as a received signal, which is amplified by the light-receiving amplifier unit 44 and read by the sensor control unit 24 after A / D conversion, thereby detecting a 90° scattering detection value A3 corresponding to the smoke concentration.

[0107] (b3.1 Wavelength 3 Scattering Angle Method Second Smoke Detection Section Structure) The second smoke detection unit structure using the one-wavelength, three-scattering-angle method will be explained in more detail. The second smoke detection unit structure shown in Figure 3(B) can be used instead of the first smoke detection unit structure shown in Figure 3(A). As shown in Figure 3(B), the second smoke detection unit structure using the one-wavelength, three-scattering-angle method has a light-receiving element 60, a first light-emitting element 62, a second light-emitting element 64, and a third light-emitting element 66 arranged within the smoke detection unit 58, with each of their optical axes arranged in a planar configuration. The first to third light-emitting elements 62, 64, and 66 are sequentially driven to emit light at predetermined intervals, and the received light signal from the light-receiving element 60 is amplified and then sequentially read by the sensor control unit 24 through A / D conversion synchronized with the emission of light from the first to third light-emitting elements 62, 64, and 66.

[0108] The first to third light-emitting elements 62, 64, and 66 use near-infrared LEDs, for example, emitting light with a near-infrared wavelength of λ = 900 nm. The light-receiving element 60 uses a photodiode PD that is sensitive from the infrared region to the visible light region.

[0109] As a first optical setting of the signal detection unit 16, the first light-emitting element 62 is positioned so that when light is shone on point P, where its optical axis intersects with the optical axis of the photodetector 60, the photodetector 60 receives the scattered light obtained at a scattering angle θ1. The scattering angle θ1 is set to a predetermined angle less than 90°, for example, a forward scattering angle of θ1 = 40°. When light with a wavelength of λ = 900 nm is shone on the smoke flowing into point P by the emission of light from the first light-emitting element 62, the scattered light from the smoke (forward scattered light) corresponding to the scattering angle θ1 = 40° is incident on the photodetector 60 and received, and a forward scattering detection signal is output as a received signal, and a forward scattering detection value A1 corresponding to the smoke density is detected.

[0110] Furthermore, as a second optical setting of the signal detection unit 16, the second light-emitting element 64 is positioned so that when light is shone on point P where its optical axis intersects with the optical axis of the photodetector 60, the photodetector 60 receives the scattered light obtained at a scattering angle θ2. The scattering angle θ2 is set to a predetermined angle exceeding 90°, for example, a backscattering angle of θ2 = 110°. When light with a wavelength λ = 900 nm is shone on the smoke flowing into point P by the emission of light from the second light-emitting element 64, the scattered light (backscattered light) from the smoke corresponding to the scattering angle θ2 = 110° is incident on and received by the photodetector 60, a backscattering detection signal is output as a received signal, and a backscattering detection value A2 corresponding to the smoke density is detected.

[0111] Furthermore, as a third optical setting of the signal detection unit 16, the third light-emitting element 66 is positioned so that when light is shone on point P where its optical axis intersects with the optical axis of the photodetector 60, the photodetector 60 receives the scattered light obtained at a scattering angle θ3 = 90°. When light with a wavelength λ = 900 nm is shone on the smoke flowing into point P by the emission of light from the third light-emitting element 66, the scattered light from the smoke corresponding to the scattering angle θ3 = 90° is incident on and received by the third photodetector 36, a 90° scattering detection signal is output as a received signal, and a 90° scattering detection value A3 corresponding to the smoke density is detected.

[0112] [c. Sensor control section] The detector control unit 24 of the detector 12 will now be described in more detail. The detector control unit 24 is composed of a computer circuit equipped with a CPU, memory, and various input / output ports, and as functions realized by the execution of a program, it has the functions of the identification unit 18 and the detection output unit 20, which are components of the fire detection device according to this embodiment.

[0113] The sensor control unit 24 sequentially reads signals from the light receiving and amplifying units 40, 42, and 44 by A / D conversion in synchronization with the timing of the light emission drive of the light-emitting element 30 at predetermined intervals, thereby acquiring forward scattering detection value A1, back scattering detection value A2, and 90° scattering detection value A3 corresponding to the smoke concentration. The identification unit 18 identifies whether it is a silane gas fire or a smoke fire based on the acquired forward scattering detection value A1, back scattering detection value A2, and 90° scattering detection value A3. The detection output unit 20, when it finds that predetermined fire detection conditions are met based on the acquired forward scattering detection value A1 or back scattering detection value A2, activates the alarm circuit unit 26, short-circuiting the positive signal line 14a and the negative signal line 14b to a low impedance and allowing a fire alarm current to flow, thereby transmitting a fire alarm signal to the receiver 10, which includes identification information indicating whether it is a silane gas fire or a smoke fire along with the fire.

[0114] [d. Identification section] (d1. Identification function) The identification unit 18 of the detector 12 will now be described in more detail. Based on the forward scattering detection value A1, the back scattering detection value A2, and the 90° scattering detection value A3 detected from the light received signal of the signal detection unit 16, the identification unit 18 identifies that it is a silane gas fire producing silicon oxide when the identification conditions corresponding to Rayleigh scattering are met, and identifies that it is a smoke fire producing smoke when the identification conditions corresponding to Rayleigh scattering are not met. Furthermore, in the case of a smoke fire, it identifies whether it is a white smoke fire producing white smoke or a black smoke fire producing black smoke.

[0115] When light of a predetermined wavelength is irradiated onto the target object that has flowed into the smoke detection section 58 of the sensor 12 from the monitoring area, the scattering characteristics will be Rayleigh scattering, Mie scattering, or a combination of both, depending on the size of the particle being detected.

[0116] (d2. Rayleigh scattering) Let's explain Rayleigh scattering in more detail. Figure 4(A) is an explanatory diagram showing the scattering intensity distribution (scattered light quantity distribution) of Rayleigh scattering by particles smaller than the wavelength of light. When light indicated by arrow 70 is shone on particles 68 smaller than the wavelength of light, the intensity distribution of scattered light becomes almost uniform in front and behind, and is minimum at a scattering angle of 90°. Silicon oxide produced as monodisperse particles in a silane gas fire has a particle size distributed in the range of approximately 50 nm to 60 nm. Since the particle size is small compared to the wavelength of light λ = 900 nm irradiated onto the target, Rayleigh scattering occurs.

[0117] (d3. Mie scattering) Let's explain Mie scattering in more detail. Figure 4(B) is an explanatory diagram showing the scattering intensity distribution (scattered light quantity distribution) of light due to Mie scattering by particles larger than the wavelength of light. When light indicated by arrow 70 is shone on particles 78 larger than the wavelength of light, the intensity distribution of scattered light shows that scattering in the forward direction is greater than scattering in the backward direction. Silicon oxide produced in a silane gas fire does not exhibit Mie scattering because its particle size is small compared to the wavelength of the irradiated light λ = 900 nm.

[0118] (d4. Complex scattering) Let's explain composite scattering in more detail. Smoke produced in smoke-generating fires, including general fires, oil fires, and electrical fires, is mainly composed of carbon combustion products and water, and its particle size is distributed over a wide range, for example, from 1 nm to several thousand nm (0.001 μm to several μm). Therefore, particles smaller than the wavelength of light irradiated onto the detection target undergo Rayleigh scattering, and particles larger than the wavelength of 900 nm undergo Mie scattering, resulting in composite scattering of Rayleigh and Mie scattering for the smoke as a whole. For this reason, in the case of smoke from a smoke-generating fire where the detection target is composite scattering, the forward scattering detection value A1, backscatter detection value A2, and 90° scattering detection value A3 will not show a minimum value corresponding to Rayleigh scattering.

[0119] (d5. Scattering characteristics of the detected object) The scattering characteristics of the combustion products to be detected will be explained in more detail. Figure 5 is a characteristic graph showing the relationship between the scattering angle and scattering intensity (amount of scattered light) of combustion products, and shows the white smoke characteristics 80 from the combustion of cotton wick, the black smoke characteristics 82 from the combustion of kerosene, and the silicon oxide characteristics 84 from a silane gas fire. Note that the white smoke characteristics 80 and black smoke characteristics 82 are the smoke characteristics of smoke-generating fires. Furthermore, since the particle size of white smoke is relatively large and black smoke is relatively small, the scattering intensity is large for the white smoke characteristics 80 and small for the black smoke characteristics 82, and the silicon oxide characteristics 84 are even lower than the black smoke characteristics 82.

[0120] In the signal detection unit 16 shown in Figure 3(A), as indicated by the dotted line in Figure 5, a forward scattering detection value A1 is detected at a scattering angle θ1 = 40°, a backscatter detection value A2 is detected at a scattering angle θ2 = 110°, and a 90° scattering detection value A3 is detected at a scattering angle θ3 = 90°. Furthermore, a backscatter detection value A4 at a scattering angle of 140° is shown for reference. Note that the values ​​at the intersections of the dotted lines for scattering angles of 40°, 90°, 110°, and 140° in Figure 5 represent the scattering intensities corresponding to the respective detection values ​​A1 to A4.

[0121] FIG. 6(A) shows in a list format the forward scattering detection value A1 at a scattering angle θ1 = 40°, the backward scattering detection value A2 at a scattering angle θ2 = 110°, and the 90° scattering detection value A3 at a scattering angle θ3 = 90° for the white smoke characteristic 80, black smoke characteristic 82, and silicon oxide characteristic 84 in FIG. 5. Further, the backward scattering detection value A4 at a scattering angle of 140° is shown for reference. Also, FIG. 6(B) shows in a list format the relative values of the forward scattering detection value A1, the backward scattering detection value A2, and the backward scattering detection value A4 when the 90° scattering detection value A3 is set to 1.

[0122] (d6. Identification of silane gas fire) As shown in FIGS. 5 and 6(A)(B), the silicon oxide characteristic 84 generated in a silane gas fire has, between the forward scattering detection value A1, the backward scattering detection value A2, and the 90° scattering detection value A3, (A3 < A1) and (A3 < A2) such a relationship, and since the 90° scattering detection value A3 is the minimum value, it can be determined as Rayleigh scattering. Therefore, when the discrimination unit 18 satisfies the discrimination condition corresponding to Rayleigh scattering where the 90° scattering detection value A3 is the minimum value based on the forward scattering detection value A1, the backward scattering detection value A2, and the 90° scattering detection value A3, it discriminates that the detection target is silicon oxide and that it is a silane gas fire.

[0123] (d7. Identification of smoldering fire) On the other hand, as shown in FIGS. 5 and 6(A)(B), the white smoke characteristic 80, which is one aspect of a smoldering fire, has, between the forward scattering detection value A1, the backward scattering detection value A2, and the 90° scattering detection value A3, (A1 > A3 > A2) such a relationship established. Since the discrimination unit 18 determines that the 90° scattering detection value A3 is not the minimum value, the detection target is the smoke of a smoldering fire corresponding to a composite scattering combining Rayleigh scattering and Mie scattering, and it discriminates that it is a smoldering fire.

[0124] Also, the black smoke characteristic 82, which is another aspect of a smoldering fire, similarly has, between the forward scattering detection value A1, the backward scattering detection value A2, and the 90° scattering detection value A3, (A1 > A3 > A2) The relationship holds true, and the identification unit 18 identifies that the detected object is smoke from a smoke fire corresponding to a combined scattering of Rayleigh scattering and Mie scattering, since the 90° scattering detection value A32 is not the minimum value, and that it is a smoke fire. In this embodiment, the identification unit 18 does not identify whether it is a smoke fire, but rather identifies whether it is a white smoke fire or a black smoke fire, as will be explained next.

[0125] (d8. Distinguishing between white smoke fires and black smoke fires) The identification of white smoke fires and black smoke fires will be explained in more detail. The identification unit 18 identifies whether the detected object is a white smoke fire or a black smoke fire, depending on whether the detected object is white smoke or black smoke, based on, for example, the ratio R=A2 / A3 of the backscatter detection value A2 and the 90° scattering detection value A3.

[0126] Figure 6(C) shows a list of the ratio R between the backscatter detection value A2 and the 90° scattering detection value A3 in Figure 6(A), where R=0.71 for white smoke and R=1.01 for black smoke. Based on these, the identification unit 18 sets an identification threshold Rth, for example Rth=0.8, as a condition for distinguishing between white smoke and black smoke, as shown in Figure 6(D). If the ratio R is less than or equal to the threshold Rth=0.8, it identifies it as white smoke and a white smoke fire. If the ratio R exceeds the threshold Rth=0.8, it identifies it as black smoke and a black smoke fire.

[0127] Furthermore, the identification unit 18 is arbitrary in distinguishing between white smoke fires and black smoke fires. In addition to the ratio R=A2 / A3 between the backscatter detection value A2 and the 90° scattering detection value A3, it also determines the ratio R=A1 / A3 between the forward scattering detection value A1 and the 90° scattering detection value A3, or the ratio R=A1 / A2 between the forward scattering detection value A1 and the backscatter detection value A2. If the predetermined identification conditions corresponding to white smoke are met, it is identified as a white smoke fire, and if the predetermined identification conditions corresponding to black smoke are met, it is identified as a black smoke fire.

[0128] [e. Detection output section] The detection output unit 20 of the detector 12 will be explained in more detail. The detection output unit 20, provided in the detector control unit 24, outputs the identification result of the identification unit 18 to the outside along with the fire when, while the identification result of the identification unit 18 has been obtained, at least one of the acquired forward scattering detection value A1 and backward scattering detection value A2 satisfies the predetermined fire detection conditions. Here, we will explain using fire detection based on the forward scattering detection value A1 as an example, but the same applies to the backward scattering detection value A2.

[0129] (e1. Detection conditions for silane gas fires) The fire detection conditions of the detection output unit 20 when the identification unit 18 obtains an identification result indicating a silane gas fire will be explained in more detail. The scattering intensity due to Rayleigh scattering of silicon oxide produced in a silane gas fire is, as shown in the silicon oxide characteristics 84 in Figure 5, for example, about 1 / 100th the strength of the white smoke characteristics 80. For this reason, if the fire detection conditions for white smoke are set to detect a white smoke fire when the smoke concentration reaches a predetermined threshold Dth0 = 10 (% / m) or higher, then for silicon oxide in a silane gas fire, the smoke concentration threshold is set to, for example, Dth1 = 0.1 (% / m), and when the forward scattering detection value A1 is equal to or exceeds the threshold Dth1 = 0.1 (% / m), the system detects that there is a fire and outputs the identification result indicating a silane gas fire to the outside.

[0130] Furthermore, as another fire detection condition for silane gas fires, it is also possible to detect a fire when a predetermined accumulation condition is met in addition to the fire detection condition based on a smoke concentration threshold. For example, if the smoke concentration threshold Dth1 = 0.1 (% / m) or higher continues for a predetermined accumulation time T1, for example T1 = 10 seconds or more, a fire is detected, and the identification result that it is a silane gas fire is output to the outside. In the case of a silane gas fire, there is a high possibility that the leaked silane gas will burn explosively and spread to surrounding structures and equipment, and in this case smoke from a smoke fire may be generated and may not be distinguishable from silicon oxide, so it is desirable to set the accumulation condition so that a silane gas fire can be detected in a short time, for example, less than 10 seconds.

[0131] (e2. Detection conditions for smoke-generated fires) The fire detection conditions of the detection output unit 20 when the identification unit 18 has obtained an identification result for a smoke fire, that is, when an identification result for whether it is a white smoke fire or a black smoke fire has been obtained, will be explained in more detail. The fire detection conditions of the detection output unit 20 when the identification unit 18 has obtained an identification result for whether it is a white smoke fire or a black smoke fire are arbitrary, but when the forward scattering detection value A1 satisfies a predetermined smoke density threshold condition, it detects that there is a fire and outputs an identification result to the outside indicating that it is a white smoke fire or a black smoke fire along with the fire. Here, the "smoke density threshold condition" is the condition under which a fire is detected when the forward scattering detection value A1 is equal to or greater than a predetermined smoke density threshold Dth0. For example, if the detector 12 is a detector with two levels of sensitivity, it will detect a white smoke fire or a black smoke fire when the forward scattering detection value A1 is equal to or greater than the smoke density threshold Dth0 = 10 (% / m) corresponding to the two levels of sensitivity.

[0132] A "Type 2 sensitivity detector" refers to a detector with a nominal operating concentration K of 10 (% / m) as defined by law. In an operational test, when immersed in an airflow at a wind speed of 20 cm to 40 cm / sec containing smoke with a concentration of (nominal operating concentration K) × 1.5 = 10 (% / m) × 1.5 = 15 (% / m), the detector must activate within 30 seconds. In a non-operation test, when immersed in an airflow at a wind speed of 20 cm to 40 cm / sec containing smoke with a concentration of (nominal operating concentration K) × 0.5 = 10 (% / m) × 0.5 = 5 (% / m), the detector must not activate within 5 minutes, for example, in the case of a non-accumulative type. In addition to such Type 2 sensitivity detectors with K=10 (% / m), a "Type 1 sensitivity detector" with a nominal operating concentration K=5 (% / m) or a "Type 3 sensitivity detector" with a nominal operating sensitivity K=15 (% / m) may also be used.

[0133] Alternatively, as another fire detection condition, if a predetermined smoke concentration threshold condition is met and a predetermined accumulation condition is met, it may be possible to detect that it is a fire caused by white smoke or black smoke. For example, if the detector 12 is a detector with two levels of sensitivity, if the forward scattering detection value A1 is at or above the smoke concentration threshold Dth0 = 10 (% / m) corresponding to the two levels of sensitivity for a predetermined accumulation time T0, for example T0 = 20 seconds or more, it will be possible to detect that it is a fire and output to the outside the identification result that it is a white smoke fire or a black smoke fire along with the fire.

[0134] (e3. Transmission of fire alarm signals based on fire detection) When the detection output unit 20 detects a silane gas fire, a white smoke fire, or a black smoke fire, the sensor control unit 24 instructs the alarm circuit unit 26 to transmit a fire alarm signal, including identification information for the type of fire, to the receiver 10 as an output to the outside.

[0135] The transmission of a fire alarm signal by the alarm circuit 26 is optional, but for example, the fire alarm signal may be transmitted by short-circuiting the positive signal line 14a and the negative signal line 14b to a predetermined low impedance and flowing a predetermined alarm current for a predetermined time, and then by disconnecting the positive signal line 14a and the negative signal line 14b to a low impedance and flowing a pulse current corresponding to a predetermined code indicating that it is a silane gas fire, a white smoke fire, or a black smoke fire, thereby transmitting a fire identification signal, and this is repeated periodically. Alternatively, different alarm currents may be set for each type of fire (silane gas fire, white smoke fire, or black smoke fire) to transmit the fire alarm signal.

[0136] [f. Control operation of the sensor] Figure 7 is a flowchart showing the control operation according to the embodiment of the sensor in Figure 2, and represents the control operation of the sensor control unit 24.

[0137] As shown in Figure 7, in step S1, the sensor control unit 24 acquires a forward scattering detection value A1, a back scattering detection value A2, and a 90° scattering detection value A3 corresponding to the smoke concentration detected by the signal detection unit 16.

[0138] Next, it is determined whether the 90° scattering detection value A3 obtained in step S2 is the minimum value that satisfies the identification conditions corresponding to Rayleigh scattering. If it is determined that it is the minimum value, the process proceeds to step S3, where it is identified as a silane gas fire. Subsequently, the process proceeds to step S9, where it is determined that the fire detection conditions set for the identified silane gas fire are satisfied, for example, if the forward scattering detection value A1 satisfies the threshold condition based on a threshold of 0.1 (% / m). The process then proceeds to step S10, where a fire alarm signal including the identification result that it is a silane gas fire is transmitted to the receiver 10, and a fire alarm indicating a silane gas fire is output.

[0139] On the other hand, if it is determined in step S2 that the 90° scattering detection value A3 is not the minimum value, the process proceeds to step S4, where the ratio R=A2 / A3 of the 90° scattering detection value A3 and the backscatter detection value A2 is calculated. The process then proceeds to step S5, where it is determined that the white smoke identification condition based on the threshold Rth1 is met, and the process proceeds to step S6, where it is identified as a white smoke fire. If it is determined that the white smoke identification condition in step S5 is not met, the process proceeds to step S7, where it is identified as a black smoke fire.

[0140] If it is identified as a white smoke fire in step S6, or as a black smoke fire in step S7, the system proceeds to step S8. For example, if it is determined that the predetermined fire detection conditions based on the forward scattering detection value A1 are met, the system proceeds to step S9 to detect that it is a fire producing white or black smoke. A fire alarm signal including the fire and the identification result that it is a white smoke fire or a black smoke fire is transmitted to the receiver 10, and a fire alarm indicating that a black smoke fire or a white smoke fire has been detected is output. For example, by notifying of a high-risk black smoke fire, it becomes possible to take measures such as prompt evacuation guidance or fire reporting.

[0141] After transmitting a fire alarm signal containing fire identification information in step S9, if recovery is determined in step S10 based on the interruption of power supply to the signal line 14 due to the recovery operation at the receiver 10, the process returns to step S1.

[0142] [g. Embodiment of the 1-wavelength, 2-scattering-angle method] An embodiment of the one-wavelength, two-scattering-angle method will be described in more detail. Figure 8 is an explanatory diagram showing a specific embodiment of the present invention for a P-type disaster prevention system in which a one-wavelength, two-scattering-angle signal detection unit 16 is provided on the sensor 12.

[0143] As shown in Figure 8, the P-type disaster prevention equipment of this embodiment includes a receiver 10 and a plurality of detectors 12. The configuration of the receiver 10 and detectors 12 is basically the same as that of the disaster prevention equipment in Figure 2, but it differs in that the signal detection unit 16 of the detector 12 is configured to support a one-wavelength, two-scattering-angle method. The signal detection unit 16 of the detector 12 includes a light-emitting element 30, a second light-receiving element 34, and a third light-receiving element 36.

[0144] (g1. Structure of the first smoke detection unit using the 1 wavelength 2 scattering angle method) The structure of the first smoke detection unit using the one-wavelength, two-scattering-angle method will be explained in more detail. Figure 9(A) shows the structure of the first smoke detection unit using the one-wavelength, two-scattering-angle method, corresponding to the signal detection unit 16 in Figure 8. It comprises a light-emitting element 30, a second light-receiving element 34, and a third light-receiving element 36, and is a simplified configuration from the first smoke detection unit structure using the one-wavelength, three-scattering-angle method shown in Figure 3(A), by removing the first light-emitting element 32.

[0145] The signal detection unit 16, which has a first smoke detection unit structure using a one-wavelength, two-scattering-angle method, has a light-emitting element 30 driven to emit light at predetermined intervals by a light-emitting drive unit 38 shown in Figure 8, and the received signals from the second and third light-receiving elements 34 and 36 are amplified by light-receiving amplification units 42 and 44 and then sequentially read by the sensor control unit 24 through A / D conversion.

[0146] The light-emitting element 30 is irradiated with light of, for example, a near-infrared wavelength of λ=900nm. The second and third photodetectors 34 and 36 use photodiodes PD that are sensitive from the infrared region to the visible light region.

[0147] As the first optical setting of the signal detection unit 16, the second light receiving element 34 is set to a backscattering angle of, for example, θ2 = 110°. When light from the light-emitting element 30 is irradiated onto smoke flowing into point P, a backscatter detection signal is output by receiving the scattered light from the smoke corresponding to the scattering angle θ2 = 110°. This signal is amplified by the light receiving amplifier 42 and read by the sensor control unit 24 after A / D conversion, thereby detecting a backscatter detection value A2 corresponding to the smoke concentration.

[0148] Furthermore, as a second optical setting for the signal detection unit 16, the third light-receiving element 36 is arranged at a scattering angle θ3 = 90°. When light from the light-emitting element 30 is irradiated onto the smoke flowing into point P, a 90° scattering detection signal is output by receiving the scattered light from the smoke corresponding to the scattering angle θ3 = 90°. This signal is amplified by the light-receiving amplifier 44 and read by the sensor control unit 24 after A / D conversion, thereby detecting a 90° scattering detection value A3 corresponding to the smoke concentration.

[0149] (g2.1 Wavelength 2 Scattering Angle Method Second Smoke Detection Section Structure) The structure of the second smoke detection unit using the one-wavelength, two-scattering-angle method will be explained in more detail. Figure 9(B) is a second smoke detection unit structure using the one-wavelength, two-scattering-angle method that can be replaced with Figure 9(A), and is equipped with a light-receiving element 60, a second light-emitting element 64, and a third light-emitting element 66. It is a simplified configuration from the second smoke detection unit structure using the one-wavelength, three-scattering-angle method shown in Figure 3(B), by removing the first light-emitting element 32.

[0150] The second and third light-emitting elements 64 and 66 are sequentially driven to emit light at predetermined intervals, and the received light signals from the light-receiving element 60 are amplified and then sequentially read by the sensor control unit 24 through A / D conversion synchronized with the emission of light from the second and third light-emitting elements 64 and 66.

[0151] The second and third light-emitting elements 64 and 66 use near-infrared LEDs, for example, to emit light with a near-infrared wavelength of λ = 900 nm. The light-receiving element 60 uses a photodiode PD that is sensitive from the infrared region to the visible light region.

[0152] As the first optical setting of the signal detection unit 16, the second light-emitting element 64 is arranged so that when light is shone on point P, for example, the light-receiving element 60 receives scattered light obtained at a scattering angle θ2 = 110°, and a backscatter detection signal is output from the light-receiving element 60, and a backscatter detection value A2 corresponding to the smoke density is detected.

[0153] Furthermore, as a second optical setting for the signal detection unit 16, the third light-emitting element 66 is arranged so that when light is shone on point P, the light-receiving element 60 receives the scattered light obtained at a scattering angle θ3 = 90°, and a 90° scattering detection signal is output from the light-receiving element 60, and a 90° scattering detection value A3 corresponding to the smoke concentration is detected.

[0154] (g3.1 Wavelength 2 Scattering Angle Identification Unit) The identification unit 18, which uses a one-wavelength, two-scattering-angle method, will now be explained in more detail. Based on the backscatter detection value A2 and the 90° scattering detection value A3 detected by the signal detection unit 16, the identification unit 18 identifies that it is a silane gas fire if the identification conditions corresponding to Rayleigh scattering are met. In the case of smoke fires, it identifies whether it is a white smoke fire or a black smoke fire.

[0155] Figure 10(A) shows the ratio R=A2 / A3 of the backscatter detection value A2 and the 90° scattering detection value A3 in Figure 6(A) in a list format, where R=0.71 for white smoke, R=1.01 for black smoke, and R=1.11 for silicon oxide. Based on these, the identification unit 18 sets the first threshold Rth1 for distinguishing between white smoke and black smoke as the identification condition for white smoke, black smoke, and silicon oxide, as shown in Figure 10(B), with Rth1=0.8, and the second threshold Rth2 for distinguishing between white smoke or black smoke produced in a smoke fire and silicon oxide produced in a silane gas fire, with Rth2=1.1. As a result, the identification unit 18 identifies that if the ratio R is Rth1 = 0.8 or less, it is a white smoke fire because it is white smoke; if the ratio R is in the range of Rth1 = 0.8 to Rth2 = 1.1, it is a black smoke fire because it is black smoke; and further, if the ratio R is Rth2 = 1.1 or more, it identifies that it is a silane gas fire because it is silicon oxide.

[0156] The identification unit 18 is optional in distinguishing between white smoke fires, black smoke fires, and silane gas fires. In addition to the ratio R=R2 / R3 between the backscatter detection value A2 and the 90° scattering detection value A3, it also determines the ratio R=A1 / A3 between the forward scattering detection value A1 and the 90° scattering detection value A3, or the ratio R=A1 / A2 between the forward scattering detection value A1 and the backscatter detection value A2. If the predetermined identification conditions corresponding to white smoke are met, it is identified as a white smoke fire. If the predetermined identification conditions corresponding to black smoke are met, it is identified as a black smoke fire. Furthermore, if the identification conditions for silicon oxide corresponding to Rayleigh scattering are met, it is identified as a silane gas fire. The detection output unit 20 using the 1-wavelength 2-scatter angle method is the same as in the case of the 1-wavelength 3-scatter angle method described above, so its explanation is omitted.

[0157] [h.2 wavelength 2 scattering angle method embodiment] Figure 11 is an explanatory diagram showing a specific embodiment of the present invention for a P-type disaster prevention system in which a sensor is equipped with a two-wavelength, two-scattering-angle signal detection unit. As shown in Figure 11, the P-type disaster prevention system of this embodiment comprises a receiver 10 and a plurality of sensors 12. The configuration of the receiver 10 and sensors 12 is basically the same as that of the disaster prevention system in Figure 2, but it differs in that the signal detection unit 16 of the sensor 12 is configured to support the two-wavelength, two-scattering-angle method. The signal detection unit 16 of the sensor 12 is equipped with a light-receiving element 90, a first light-emitting element 92, and a second light-emitting element 94.

[0158] (Signal detection unit using the h1.2 wavelength 2 scattering angle method) The signal detection unit 16 using a two-wavelength, two-scattering-angle method will be explained in more detail. The signal detection unit 16 using a two-wavelength, two-scattering-angle method provided in the detector 12 clearly exhibits the characteristics of Rayleigh scattering caused by silicon oxide in a silane gas fire. To achieve this, the wavelength of light used to detect the backscattering detection value A2 is set to a shorter wavelength than the wavelength of light used to detect the forward scattering detection value A1, thereby enhancing the ability to distinguish silicon oxide based on the forward scattering detection value A1 and the backscattering detection value A2.

[0159] (Smoke detection unit structure using the h2.2 wavelength 2 scattering angle method) The structure of the smoke detection unit using the two-wavelength, two-scattering-angle method will be explained in more detail. Figure 12 shows the smoke detection unit structure using the two-wavelength, two-scattering-angle method, corresponding to the signal detection unit 16 in Figure 11. The light-receiving element 90, the first light-emitting element 92, and the second light-emitting element 94 are arranged within the smoke detection unit 58, with their respective optical axes arranged in a planar configuration. The first and second light-emitting elements 92 and 94 are sequentially driven to emit light at predetermined intervals by the light-emitting drive units 38a and 38b. The light-receiving signal from the light-receiving element 90 is amplified by the light-receiving amplification unit 40 and then sequentially read by the sensor control unit 24 through A / D conversion synchronized with the light emission of the first and second light-emitting elements 92 and 94.

[0160] The first and second light-emitting elements 92 and 94 use near-infrared LEDs. The first light-emitting element 92 emits light with a predetermined first wavelength λ1, for example, λ1 = 900 nm. In contrast, the second light-emitting element 94 emits light with a predetermined second wavelength λ2, which is shorter than the wavelength λ1 of the first light-emitting element 92, for example, λ2 = 500 nm. The photodetector 90 uses a photodiode PD that is sensitive to wavelengths from 400 nm to 1000 nm in the infrared to visible light region.

[0161] As a first optical setting of the signal detection unit 16, the first light-emitting element 92 is positioned so that when light of a first wavelength λ1 = 900 nm is irradiated onto point P where the optical axis of the first light-emitting element 92 intersects with the optical axis of the photodetector 90, the photodetector 90 receives the scattered light obtained at a scattering angle θ1. The scattering angle θ1 is set to a predetermined angle other than 90°, for example, a forward scattering angle of θ1 = 40°. When light of a first wavelength λ1 = 900 nm is emitted from the first light-emitting element 92 and irradiates the smoke flowing into point P, the scattered light from the smoke (forward scattered light) corresponding to the scattering angle θ1 = 40° is incident on the photodetector 90 and received, a forward scattering detection signal is output as a received signal, and a forward scattering detection value A1 corresponding to the smoke density is detected.

[0162] Furthermore, as a second optical setting of the signal detection unit 16, the second light-emitting element 94 is positioned so that when light of a second wavelength λ2 = 500 nm is irradiated onto point P where the optical axis of the second light-emitting element 94 intersects with the optical axis of the photodetector 60, the photodetector 90 receives the scattered light obtained at a scattering angle θ2. The scattering angle θ2 is set to a predetermined angle other than 90°, for example, a backscattering angle of θ2 = 120°. When light of a second wavelength λ2 = 500 nm is emitted from the second light-emitting element 64 and irradiates the smoke flowing into point P, the scattered light (backscattered light) from the smoke corresponding to the scattering angle θ2 = 120° is incident on the photodetector 60 and received, a backscattering detection signal is output as a received signal, and a backscattering detection value A2 corresponding to the smoke density is detected.

[0163] (h3.2 wavelength 2 scattering angle method identification unit) The identification unit 18, which uses a two-wavelength, two-scattering-angle method, will now be explained in more detail. Based on the forward scattering detection value A1 detected by the signal detection unit 16 at a first wavelength λ1=900nm and a scattering angle θ1=30°, and the backscattering detection value A2 detected at a second wavelength λ2=500nm and a scattering angle θ2=120°, the identification unit 18 identifies that the detected object is silicon oxide and therefore a silane gas fire if the identification conditions corresponding to Rayleigh scattering are met. If the identification conditions corresponding to Rayleigh scattering are not met, the identification unit 18 identifies whether the fire is a white smoke fire caused by white smoke or a black smoke fire caused by black smoke.

[0164] Figure 13(A) shows a list of the scattering intensities of forward scattering detection values ​​A1 for white smoke, black smoke, and silicon oxide at the first wavelength λ1 = 900 nm and scattering angle θ1 = 30° in Figure 12, and Figure 13(B) shows a list of the scattering intensities of backscatter detection values ​​A2 for white smoke, black smoke, and silicon oxide at the second wavelength λ2 = 500 nm and scattering angle θ2 = 120° in Figure 12.

[0165] The identification unit 18 determines the ratio R of the product of the first wavelength λ1 and the forward scattering detection value A1 (λ1·A1) and the product of the second wavelength λ2 and the backscatter detection value A2 (λ2·A2), R = (λ1·A1) / (λ2·A2) The system determines the ratio R, and if the ratio R satisfies the identification conditions corresponding to Rayleigh scattering, it identifies that it is a silane gas fire because it is silicon oxide. The identification unit 18 also identifies whether it is a white smoke fire or a black smoke fire if the ratio R satisfies the identification conditions for white smoke or black smoke of a smoke fire corresponding to combined scattering of Rayleigh scattering and Mie scattering.

[0166] (h4. Identification of combustion products) Figure 13(C) shows in a list format the ratio R of the product of the first wavelength λ1 and the forward scattering detection value A1 in Figure 13(A), and the product of the second wavelength λ2 and the backscatter detection value A2 in Figure 13(B). For white smoke, R=8.0, for black smoke, R=2.3, and for silicon oxide, R=0.1. Based on these, the identification unit 18 sets the first threshold Rth1 for distinguishing between white smoke and black smoke as identification conditions for white smoke, black smoke, and silicon oxide, as shown in Figure 13(D), with Rth1=5, and the second threshold Rth2 for distinguishing between smoke produced in a smoke fire containing white and black smoke and silicon oxide produced in a silane gas fire, with Rth2=1. Therefore, the identification unit 18 identifies that if the ratio R is Rth1=5 or greater, the detected object is white smoke and thus it is a white smoke fire; if the ratio R is in the range of Rth2=1 to Rth1=5, the detected object is black smoke and thus it is a black smoke fire; and further, if the ratio R is Rth2=1 or less, the detected object is silicon oxide and thus it is a silane gas fire.

[0167] In this two-wavelength, two-scattering-angle identification unit 18, by making the scattering angles relative to the detection target different, with a forward scattering angle θ1 = 30° and a back scattering angle θ2 = 120°, a difference in scattering characteristics due to the scattering angle is created. At the same time, by making the wavelengths of the light irradiated onto the detection target different, with a first wavelength λ1 = 900 nm and a second wavelength λ2 = 500 nm, a difference in scattering characteristics due to the wavelength is created. Due to the synergistic effect of this difference in scattering angle and wavelength, the scattering intensity of the scattered light from silicon oxide generated in a silane gas fire is increased. The system creates a significant difference in the scattering intensity of scattered light from white smoke and black smoke produced by smoke fires. Furthermore, the identification unit 18 does not use the ratio of forward scattering detection value A1 to backscatter detection value A2, but rather calculates the ratio R of the product of the first wavelength λ1 and the forward scattering detection value A1 (λ1·A1) and the product of the second wavelength λ2 and the backscatter detection value A2 (λ2·A2). This reflects the differences due to the wavelength ratio (λ1 / λ2), further enhancing the ability to distinguish between silane gas fires caused by silicon oxide, white smoke fires caused by white smoke, and black smoke fires caused by black smoke.

[0168] (h5. Rayleigh scattering and wavelength) Silicon oxide, produced as monodisperse particles in a silane gas fire, has a particle size distributed approximately between 50 nm and 60 nm, which is smaller than the wavelength of the irradiating light (900 nm or 500 nm), resulting in Rayleigh scattering. Here, in Rayleigh scattering, there is a relationship between the scattering intensity I and the wavelength λ such that the scattering intensity I is inversely proportional to the fourth power of the wavelength λ. I∝1 / λ 4 It is known that this is the case. Therefore, for forward scattering detection value A1 at wavelength λ1 = 900 nm, back scattering detection value A2 at wavelength λ2 = 500 nm is, 1 / (λ1 / λ2) 4 = 1 / (900 / 500 4 There is a relationship where the intensity decreases by a certain amount (approximately 1 / 10th), and the significant difference in scattering intensity due to the difference in wavelength and scattering angle makes it possible to improve the ability to distinguish silicon dioxide, the target of detection.

[0169] Furthermore, the identification of white smoke, black smoke, and silicon oxide by the two-wavelength, two-scattering-angle identification unit 18 is arbitrary. In addition to the ratio R=(λ1·A1 / λ2·A2), the ratio R=(λ1·A1 / λ2·A3) of the product of the first wavelength λ1 and the forward scattering detection value A1 and the product of the second wavelength λ2 and the 90° scattering detection value A3 may be calculated, or the ratio R=(λ1·A2 / λ2·A3) of the product of the first wavelength λ1 and the backscattering detection value A2 and the product of the second wavelength λ2 and the 90° scattering detection value A3 may be calculated. If the predetermined identification conditions corresponding to white smoke are met, it is identified as a white smoke fire; if the predetermined identification conditions corresponding to black smoke are met, it is identified as a black smoke fire; and further, if the identification conditions for silicon oxide corresponding to Rayleigh scattering are met, it is identified as a silane gas fire. Furthermore, the detection output unit 18 for the two-wavelength, two-scattering-angle method is the same as in the case of the one-wavelength, three-scattering-angle method described above, so its explanation is omitted.

[0170] [i. Other basic concepts of the embodiment] Figure 14 is an explanatory diagram showing another basic concept of an embodiment corresponding to the second fire prevention equipment. In this fire alarm system, which is an example of the second fire prevention equipment equipped with a receiver 10 and a detector 12, the detector 12 is provided with a signal detection unit 16 for the fire detection device, and the receiver 10 is provided with an identification unit 18 and a detection output unit 20 for the fire detection device.

[0171] The signal detection unit 16 of the detector 12 and the identification unit 18 and detection output unit 20 of the receiver 10 are basically the same as the signal detection unit 16, identification unit 18 and detection output unit 20 provided on the detector 12 in Figure 1. However, they differ in that the forward scattering detection value A1, the back scattering detection value A2, and the 90° scattering detection value A3 detected by the signal detection unit 16 of the detector 12 are transmitted to the receiver 10 via the transmission line 114. The identification unit 18 and detection output unit 20 of the receiver 10 detect that there is a fire when the predetermined fire detection conditions are met while an identification result for a silane gas fire, white smoke fire, or black smoke fire is obtained, and output the identification result along with the fire.

[0172] [JR-type disaster prevention equipment] The embodiment corresponding to the second type of fire prevention equipment will be described in more detail. Figure 15 is an explanatory diagram of the R-type (Record-type) fire prevention equipment, showing the specific details of the embodiment corresponding to Figure 14. Here, "R-type fire prevention equipment" is equipment that monitors fire for each detector 12 (on a detector-by-detector basis) by transmitting data between the receiver 10 and the detector 12.

[0173] As shown in Figure 15, the R-type disaster prevention equipment of this embodiment comprises a receiver 10 and a detector 12, with the detector 12 connected to a transmission line 114 that extends from the receiver 10 to a monitoring area such as a room in a building. The transmission line 114 extending from the receiver 10 comprises a positive transmission line 114a and a negative transmission line (common transmission line) 114b, supplying power from the receiver 10 to the detector 12 and transmitting and receiving signals between the receiver 10 and the detector 12 using a predetermined transmission method. A dedicated power supply line may also be provided.

[0174] (j1.sensor) The detector 12 of the R-type fire prevention equipment will be described in more detail. The detector 12 of the R-type fire prevention equipment, like the detector 12 of the P-type fire prevention equipment in Figure 2, is equipped with a signal detection unit 16 having a first smoke detection unit structure of the 1 wavelength 3 scattering angle method shown in Figure 3(A), a detector control unit 24, a power supply unit 28, a light emission drive unit 38, and light receiving amplification units 40, 42, 44. However, it differs in that it is equipped with a transmission unit 86 for transmitting and receiving signals to and from the receiver 10 using a predetermined transmission method. Furthermore, the detector control unit 24 does not have the functions of the identification unit 18 and the detection output unit 20, which are components of the fire detection device of the present invention shown in Figure 2; these are provided on the receiver 10 side.

[0175] (j2. Receiver) The receiver 10 of the R-type fire prevention equipment will now be described in more detail. The receiver 10 of the R-type fire prevention equipment is equipped with a receiver control unit 46, a display unit 50, an operation unit 52, an alarm unit 54, and a transmission unit 56, similar to the receiver 10 of the P-type fire prevention equipment shown in Figure 2. However, it differs in that it is equipped with a transmission unit 88 to send and receive signals to and from the detector 12 using a predetermined transmission method. Furthermore, the receiver control unit 46 is equipped with the functions of an identification unit 18 and a detection output unit 20, which are components of the fire detection device of the present invention, as functions realized by the execution of a program. The identification unit 18 and detection output unit 20 provided in the receiver 10 are basically the same as the identification unit 18 and detection output unit 20 provided in the detector 12 of the P-type fire prevention equipment shown in Figure 2.

[0176] (j3. Transmission control) The transmission control of the R-type disaster prevention equipment will be explained in more detail. In the R-type disaster prevention equipment, each detector 12 is assigned a unique address, and the receiver 10 transmits a batch A / D conversion command signal at a predetermined period, for example, every minute. All detectors 12 that receive the batch A / D conversion command signal receive scattered light at different scattering angles in the signal detection unit 16, and then convert the forward scattering detection value A1, back scattering detection value A2, and 90° scattering detection value A3 using A / D conversion and store (store) them. Subsequently, the receiver 10 transmits call signals specifying the detector addresses sequentially and performs polling to cause each detector 12 to send back a response signal including the forward scattering detection value A1, back scattering detection value A2, and 90° scattering detection value A3.

[0177] (j4. Receiver identification unit) The identification unit 18 of the receiver 10 will now be explained in more detail. The identification unit 18 of the receiver 10 is the same as the identification unit 18 of the detector 12 installed in the P-type fire prevention equipment described above. Each time the receiver receives the forward scattering detection value A1, the back scattering detection value A2, and the 90° scattering detection value A3 from each detector 12 by polling, it identifies that the detected object is silicon oxide and therefore it is a silane gas fire if the identification conditions corresponding to Rayleigh scattering where the 90° scattering detection value A3 is the minimum value are met, based on the forward scattering detection value A1, the back scattering detection value A2, and the 90° scattering detection value A3.

[0178] (J5. Receiver detection output section) The detection output unit 20 of the receiver 10 will now be described in more detail. When the identification unit 18 identifies that it is a silane gas fire, the detection output unit 20 of the receiver 10 specifies the sensor address corresponding to the identification result of the silane gas fire and centrally acquires the forward scattering detection value A1, the back scattering detection value A2, and the 90° scattering detection value A3. For example, when the forward scattering detection value A1 is equal to or exceeds a predetermined threshold of 0.1 (% / m) and the fire detection conditions are met, it outputs an identification result indicating that a silane gas fire has been identified along with a fire, and performs fire alarm processing including sounding of the main audible alarm and area audible alarm, displaying the fire location and silane gas fire based on the sensor address that was determined to be a fire, and interlocking control of smoke control equipment.

[0179] Furthermore, if the identification unit 18 identifies that it is a white smoke fire or a black smoke fire, the detection output unit 20 of the receiver 10 centrally acquires the forward scattering detection value A1, the backward scattering detection value A2, and the 90° scattering detection value A3 by specifying the detector address corresponding to the identification result of the white smoke fire or black smoke fire. For example, if the forward scattering detection value A1 is equal to or exceeds a predetermined threshold of 10 (% / m), the fire detection condition is met, and the identification result that it is a white smoke fire or a black smoke fire is output along with the fire, and fire alarm processing is performed, including sounding of the main sound alarm and area sound alarm, displaying the location of the fire and whether it is a white smoke fire or a black smoke fire based on the detector address that was determined to be a fire, and interlocking control of smoke control equipment.

[0180] (j6. Control operation of R-type disaster prevention equipment) The control operation of the R-type disaster prevention equipment will be explained in more detail. Figure 16 is a flowchart showing the control operation according to the embodiment of the R-type disaster prevention equipment in Figure 15, in a time chart format.

[0181] As shown in Figure 16, in step S11, the receiver 10 performs fire monitoring transmission processing by sending a batch A / D conversion command signal at a predetermined interval, for example, a 1-minute interval, followed by a call signal specifying the detector address, and receives a response signal from the detector 12. On the other hand, in step S12, the detector 12 performs fire monitoring response processing by receiving the batch A / D conversion command signal from the receiver 10, storing the forward scattering detection value A1, the back scattering detection value A2, and the 90° scattering detection value A3 obtained at that time, and then, upon receiving a call signal specifying its own address, transmits a response signal in step S13 that includes the forward scattering detection value A1, the back scattering detection value A2, and the 90° scattering detection value A3.

[0182] Next, in step S14, when the receiver 10 receives the forward scattering detection value A1, the back scattering detection value A2, and the 90° scattering detection value A3 from the sensor 12, it proceeds to step S25. Based on the received forward scattering detection value A1, the back scattering detection value A2, and the 90° scattering detection value A3, if it determines that the identification condition for silicon oxide corresponding to Rayleigh scattering where the 90° scattering detection value A3 is the minimum value is met, it proceeds to step S26 and identifies that it is a silane gas fire. Alternatively, if it determines in step S25 that the identification condition for Rayleigh scattering where the 90° scattering detection value A3 is the minimum value is not met, it proceeds to step S27 and identifies that it is a white smoke fire or a black smoke fire, for example, based on the ratio R of the back scattering detection value A2 and the 90° scattering detection value A3.

[0183] If it is identified in step S16 that it is a silane gas fire, or if it is identified in step S17 that it is a white smoke fire or a black smoke fire, the process proceeds to step S18, where an A / D conversion command signal specifying the address of the detector 12 corresponding to the identification result and a call signal are transmitted. In response, the detector 12 transmits the forward scattering detection value A1, the back scattering detection value A2, and the 90° scattering detection value A3 in step S19, and the receiver 10 performs a process of centrally receiving the forward scattering detection value A1, the back scattering detection value A2, and the 90° scattering detection value A3.

[0184] Next, if the receiver 10 determines in step S20 that the predetermined fire detection conditions corresponding to a silane gas fire, white smoke fire, or black smoke fire, for example, the forward scattering detection value A1, are met, it proceeds to step S21 and performs fire alarm processing, including sounding the main audible alarm and the area audible alarm, displaying the location of the fire based on the sensor address that was determined to be a fire, outputting a display indicating that a silane gas fire, white smoke fire, or black smoke fire has been detected, and interlocking control of smoke control equipment.

[0185] Next, in step S22, when the receiver 10 determines that the system has been restored due to the recovery operation following the extinguishing of the fire, it sends a recovery signal to the detector 12 in step S23 and returns to the fire monitoring transmission process in step S11. Also, when the detector 12 determines that it has received the recovery signal in step S24, it returns to the fire monitoring response process in step S12.

[0186] Although the R-type fire prevention equipment shown in Figure 15 uses a 1-wavelength, 3-scattering-angle fire detection device as an example, a 1-wavelength, 2-scattering-angle or 2-wavelength, 2-scattering-angle fire detection device, as described for the P-type fire prevention equipment, may also be used.

[0187] [k. Variations of the present invention] A modified embodiment of the present invention will be described in more detail.

[0188] (Phosphine gas) The above embodiment uses silane gas as an example of a semiconductor manufacturing gas that burns in reaction with oxygen in the atmosphere, but phosphine gas (PH3) can also be detected. Phosphine gas (PH3) is toxic, and it is stipulated that firefighting should not be attempted unless the leak is sealed. Powder fire extinguishing agents and foam fire extinguishing agents should be used. Since it reacts violently with water and there is a risk of generating toxic gases, water should not be used in initial firefighting, and therefore, as with silane gas, firefighting activities must be carried out separately from smoke fires.

[0189] Phosphine gas (PH3) reacts with oxygen in the atmosphere and burns violently. The chemical formula during combustion is: 8PH3 + 8O2 → P4O 10 +6H2O This is how it works. P4O is produced as monodisperse particles during the combustion of phosphine gas. 10 For example, the particle size is generally in the range of 50 nm to 60 nm, and since the particle size is smaller than the wavelength of the irradiated light, it exhibits Rayleigh scattering, and similar to silicon oxide (SiO2) produced in a silane gas fire, P4O produced by the combustion of phosphine gas according to the above embodiment. 10 The system identifies that it is a phosphine gas fire and outputs the identification result, indicating that a phosphine gas fire has been identified, along with the fire itself, to an external source.

[0190] Furthermore, the above embodiments are not limited to silane gas fires or phosphine gas fires, but can be applied to the identification of fires of combustion products of appropriate gases or chemicals that react with oxygen in the atmosphere and burn.

[0191] (Identification of non-fire factors) The identification unit 18 in the above embodiment identifies silicon oxide in a silane gas fire and white smoke and black smoke, which are types of smoke in a smoke fire, but it may also be configured to identify non-fire factors. "Non-fire factors" are particles that should not be detected as a fire, and include, for example, oil fumes, steam, vapor, dust, and cigarette smoke generated by factors other than fire.

[0192] Non-fire factors such as steam and vapor have larger particle sizes compared to white smoke, resulting in higher scattering intensity at forward scattering angles compared to white smoke during a fire. As a result, for example, the forward scattering detection value A1 from scattered light at a scattering angle of 40° due to irradiation with light of wavelength 900nm is sufficiently large, and the ratio R of this value to the backscatter detection value A2 from scattered light at a scattering angle of 110° is even larger than the ratio in the case of white smoke. Therefore, the identification unit 18 identifies the detected object as a non-fire factor such as steam or vapor when, for example, the ratio R of the forward scattering detection value A1 to the backscatter detection value A2 satisfies predetermined non-fire identification conditions. When the identification unit 18 identifies a non-fire factor, the detection output unit 20 does not output a message indicating that a fire has been detected, even if the forward scattering detection value A1 satisfies predetermined fire detection conditions, thereby preventing the generation of a false fire alarm.

[0193] (fire alarm) The above embodiment uses as an example a fire detection device configuration for fire prevention equipment equipped with a receiver and a detector, but a fire detection device may also be configured using, for example, a residential fire alarm equipped with means for detecting a fire from smoke density and means for warning of a fire. In the case of a fire alarm, the fire alarm will be equipped with the functions of a signal detection unit 16, an identification unit 18, and a detection output unit 20, which constitute a fire detection device, similar to the detector 12 of the fire prevention equipment shown in Figures 1 and 2.

[0194] (others) Furthermore, the present invention includes appropriate modifications that do not impair its purpose and advantages, and is not limited by the numerical values ​​shown in the above embodiments. [Explanation of Symbols]

[0195] 10: Receiver 12: Sensor 14: Signal line 16: Signal detection unit 18: Identification section 20: Detection output section 24: Sensor Control Unit 26: Alarm circuit section 28: Power supply section 30: Light-emitting element 32: First photodetector 34: Second photodetector 36: Third photodetector 38, 38a, 38b: Light-emitting drive unit 40, 42, 44: Light receiving and amplification section 46: Receiver Control Unit 48: Line receiving unit 50: Display section 52:Operation unit 54: Alarm section 56: Transfer Department 58: Smoke Detection Department 60: Photodetector 62,92: First light-emitting element 64,94: Second light-emitting element 66: Third light-emitting element 80: White smoke characteristics 82: Black smoke characteristics 84: Properties of silicon dioxide 86,88: Transmission section 114: Transmission line

Claims

1. In a monitoring area where semiconductor manufacturing gases are used, smoke-generating fires and semiconductor manufacturing gas fires that produce monodisperse particles are detected based on the characteristics of scattered light for combustion products, and the type of fire is identified and the result is output. A fire prevention system characterized by stopping the supply of the semiconductor manufacturing gas and / or releasing a fire extinguishing agent corresponding to the type of semiconductor manufacturing gas to the fire area when the result of the identification is a semiconductor manufacturing gas fire.

2. In a monitoring area where semiconductor manufacturing gases are used, smoke-generating fires and semiconductor manufacturing gas fires that produce monodisperse particles are detected based on the characteristics of scattered light for combustion products, and the type of fire is identified and the result is output. A fire prevention system characterized by stopping the supply of the semiconductor manufacturing gas and / or releasing an inert gas into the fire area when the result of the identification is a semiconductor manufacturing gas fire.

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