Flame detector operation test device

Abstract

The present invention provides a flame detector operation test device that can perform an operation test on a flame detector, which detects the occurrence of a fire by detecting light in two or more wavelength ranges emitted by a flame, by irradiating the flame detector with test light. [Solution] In an operational test apparatus for a flame detector, comprising a lamp and a lens (23) positioned in front of the lamp, capable of emitting light of a predetermined wavelength in a certain direction, the lens is configured such that a filter layer (23A) is partially provided that transmits light in a predetermined wavelength band corresponding to the wavelength detected by the flame detector under test, and blocks or attenuates light outside the predetermined wavelength band. Furthermore, the filter layer is configured to transmit light in wavelength bands not included in the visible light wavelength range.

Description

Technical Field

[0001] The present invention relates to a technique effective for use in an operating test device for a flame detector that irradiates light of a predetermined wavelength to perform an operating test of the flame detector.

Background Art

[0002] Fire detectors used in fire alarm systems include various types such as thermal detectors using thermistors, photoelectric smoke detectors, and flame detectors equipped with elements such as infrared sensors that capture light of a wavelength specific to flames for detection, and are used appropriately according to the installation location. For example, in a hydrogen station equipped with facilities for supplying hydrogen, which is the fuel of a fuel cell vehicle, in order to detect a fire caused by hydrogen leakage that occurs when filling a hydrogen vehicle with hydrogen, as shown in FIG. 1, a flame detector 50 that detects light of a specific wavelength emitted by a hydrogen flame is installed at a high place of a building 40 such as a canopy (roof).

[0003] Conventionally, in order to confirm the operation of a flame detector, a flame detector operating tester (hereinafter referred to as an operating tester) has been used. The operating tester is implemented by irradiating a flame detector with pseudo-flames (test light) of a specific wavelength from a lamp built inside the main body. As an invention regarding a flame detector operating tester having such a function, there is one described in Patent Document 1. In addition, since a flame detector is generally installed at a high place inside a facility, there is a desire for an operator to perform the operation of the operating tester while standing on the ground, so there is an operating tester having a configuration that allows an operator to operate on the ground and irradiate test light obliquely upward (Patent Documents 2 and 3).

[0004] In the operating tester described in Patent Document 3, a filter is arranged in front of the lamp in order to irradiate the flame detector with light of a specific wavelength emitted by the flame to be detected. In addition, in the operating tester described in Patent Document 1, a light shielding plate having a plurality of apertures is arranged in front of the lamp, and is configured to reproduce and irradiate test light having the same spectral ratio as that of the flame according to the area ratio of the plurality of apertures.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2007-264847 [Patent Document 2] Japanese Patent Publication No. 2003-173481 [Patent Document 3] Japanese Patent Application Publication No. 11-110657 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The operational test device described in Patent Document 1 has the problem that, because the test device is placed in contact with the front of the fire detector during the operational test, it is not suitable for testing detectors installed at high places within the facility by irradiating them with test light from the ground. On the other hand, the operational tester described in Patent Document 2 is configured to detect the occurrence of a fire by detecting infrared radiation emitted by a flame using an infrared transmission filter. However, it has the problem that it cannot be applied as an operational tester to test the operation of a flame detector that detects the occurrence of a fire by detecting not only infrared radiation, such as in a hydrogen flame, but also light in other wavelength ranges such as ultraviolet radiation.

[0007] The present invention has been made in view of the above-mentioned problems, and its objective is to provide a flame detector operation test device that can perform an operation test on a flame detector, which detects the occurrence of a fire by detecting light in two or more wavelength ranges emitted by a flame, by irradiating the flame detector with test light. [Means for solving the problem]

[0008] To solve the above problems, this invention provides: In a flame detector operation test device comprising a lamp and a lens positioned in front of the lamp, capable of emitting light of a predetermined wavelength in a certain direction, The lens is configured such that it partially has a filter layer that transmits light in a predetermined wavelength band corresponding to the wavelength detected by the flame detector under test, and blocks or attenuates light outside of that predetermined wavelength band.

[0009] According to the flame detector operation test device having the above configuration, since the lens has both a portion with a filter layer and a portion without a filter layer, it is possible to perform an operation test on a flame detector, which detects the occurrence of a fire by detecting light in two or more wavelength ranges emitted by a flame, by irradiating it with test light according to the detection conditions.

[0010] Furthermore, preferably, the predetermined wavelength band is configured to be set to at least within the range of infrared wavelengths or ultraviolet wavelengths. Furthermore, the filter layer is configured to block light in the visible light wavelength range. According to the above configuration, even if the flame detector under test detects the occurrence of a fire by detecting light of wavelengths other than the visible light wavelength range, the test light can be irradiated onto the flame detector to perform an operational test.

[0011] Preferably, the filter layer is composed of a coating made of a material having selective light transmission properties that is partially formed on the surface of the lens. With this configuration, lenses with partially provided filter layers can be easily and inexpensively manufactured, thereby reducing the manufacturing cost of the operational testing equipment.

[0012] Furthermore, preferably, the area ratio of the filter layer to the surface area of ​​the lens is set to 90%. [Effects of the Invention]

[0013] The flame detector operation test device of the present invention has the effect of being able to perform an operation test by irradiating a flame detector, which detects the occurrence of a fire by detecting light in two or more wavelength ranges emitted by a flame, with test light. [Brief explanation of the drawing]

[0014] [Figure 1] It is an external view showing an example of a hydrogen station where a flame detector is installed. [Figure 2] It is a perspective view showing one embodiment of a flame detector operation test device according to the present invention. [Figure 3] It is an exploded perspective view showing the state where the lens part of the flame detector operation test device shown in FIG. 2 is disassembled. [Figure 4] (A) is a cross-sectional view showing the internal structure of the light emitting part and the lens part of the flame detector operation test device of FIG. 2, and (B) is an enlarged cross-sectional view showing a part of the periphery of the lens in (A) in an enlarged manner. [Figure 5] It is a graph showing the spectra (spectral distributions) of a hydrogen flame and a halogen lamp (halogen lamp). [Figure 6] It is a front view showing an example of the shape and pattern of a filter layer provided on the surface of the glass lens of the flame detector operation test device of the embodiment. [Figure 7] It is a view showing examples of other shapes and patterns of the filter layer provided on the surface of the glass lens.

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments when the flame detector operation test device according to the present invention is applied to an operation test device for a flame detector that detects a hydrogen flame as an example will be described with reference to the drawings. FIG. 3 shows an exploded perspective view showing one embodiment of the flame detector operation test device, and FIG. 4 shows a cross-sectional view showing the state where the lens part of the flame detector operation test device of FIG. 3 is disassembled. The flame detector operation test device of this embodiment has a function of holding the handle provided on the test device main body by a human hand and irradiating a pseudo-flame (test light) having a wavelength peculiar to a hydrogen flame from a lamp built into the main body to the flame detector.

[0016] As shown in Figures 2 and 3, the flame detector operation test device (hereinafter referred to as the test device) 10 of this embodiment comprises a cylindrical frame made of aluminum or resin, a lens portion 12 attached to the front end of the test device body 11, and a back cover 13 attached to cover the opening at the rear end of the test device body 11. A handle 14 is provided on the outer surface of the tester body 11, and a switch button 15 for turning on a lamp is provided on the upper surface of the handle 14. In addition, legs 16A and 16B are provided on the outer surface of the tester body 11 opposite the handle 14 to maintain a stable posture when the tester 10 is placed on it.

[0017] Meanwhile, the inside of the test apparatus body 11 houses the halogen lamp 31 that constitutes the light-emitting section, the bulb socket which serves as the lamp's receptacle, the bulb support bracket, as well as a battery, a charging connector, and the lamp's drive circuit. Of these, the light-emitting section is located at the front of the test apparatus body 11, and as shown in Figure 3, a lens section 12 that covers the front of the halogen lamp 31 is provided on the front side of the test apparatus body 11. Here, the halogen lamp 31 used emits light that is close to the spectrum of sunlight as test light, and this test light includes light in the ultraviolet and infrared wavelength bands characteristic of hydrogen flames. The specific configuration of the light-emitting section will be described later.

[0018] As shown in Figure 3, the lens section 12 includes a lens retaining nut 21 that can be fitted to the front opening edge of the tester body 11, a reflector 22 having an opening in the center through which a halogen lamp 31 is inserted and which reflects the light emitted by the halogen lamp 31 forward, a glass lens 23 for transmitting light, and a cylindrical lens cover 24 that is attached to the front of the tester body 11 with the reflector 22 and glass lens 23 housed inside. Although not particularly limited, a bowl-shaped parabolic mirror is used for the reflector 22, and the glass lens 23 is made of quartz glass. The glass lens 23 is equipped with an optical filter function that transmits ultraviolet and infrared rays of wavelengths specific to hydrogen flames and blocks light in unwanted wavelength ranges. The glass lens 23 may have curvature and be an optical lens, or it may be flat without curvature. Preferably, the curvature of the glass lens 23 is designed in combination with the shape of the reflector 22. Specific examples of the glass lens 23 with an optical filter function will be described in detail later.

[0019] A male threaded portion 11a is formed on the outer circumferential surface of the front end of the test device body 11, and a female threaded portion 24a is formed on the inner circumferential surface of the front end of the lens cover 24, as shown in Figure 4(A). By screwing the female threaded portion 24a onto the male threaded portion 11a, the lens cover 24 is attached to the front side of the test device body 11 so as to cover the light-emitting part having the halogen lamp 31. In this configuration, the reflector 22 and the glass lens 23 are fixed in place by having their edges sandwiched between the lens retaining nut 21 and the front edge of the lens cover 24. Furthermore, in this embodiment, a thin, annular heat insulating spacer 25 made of a resin with low thermal conductivity is interposed between the reflector 22 and the glass lens 23, and a waterproof and heat insulating O-ring 26 made of heat-resistant rubber is interposed between the glass lens 23 and the lens cover 24.

[0020] The glass lens 23 and reflector 22 become hot due to the heat from the halogen lamp 31, but the presence of insulating spacers 25 and O-rings 26 in front of and behind the glass lens 23 makes it difficult for heat to transfer between the reflector 22, glass lens 23, and lens cover 24. This prevents temperature unevenness from occurring in the lens and reduces the performance of the lens. In addition, quartz glass can crack due to rapid changes in temperature or localized thermal strain (differences in temperature distribution), but the insulating rings 25 and O-rings 26 prevent the quartz glass lens 23 from cracking due to thermal stress.

[0021] Furthermore, multiple heat dissipation fins 11b and 24b are provided on the outer circumference of the front of the tester body 11 and the outer circumference of the lens cover 24, and are configured to suppress the temperature rise of the light-emitting section having the halogen lamp 31. Furthermore, as shown in Figure 4(B), a gap a may be created on the front side of the edge of the glass lens 23, and a gap b may be created around the glass lens 23. By providing such gaps, heat can be less easily transferred between the reflector 22, the glass lens 23, and the lens cover 24.

[0022] Furthermore, the gap a is created by providing a right-angle step portion 24c on the inner surface of the lens cover 24 to restrict the forward position when screwing in the lens retaining nut 21. In other words, when screwing the lens retaining nut 21 all the way into the lens cover 24 to clamp the edge of the reflector 22, the vertical wall of the right-angle step portion 24c acts as a stopper, preventing further movement. The gap b can be created by setting the outer diameter of the glass lens 23 to be smaller than the inner diameter of the corresponding part of the lens cover 24. In particular, in the case of a glass lens 23 having an optical filter layer formed on its surface, as described below, the difference in thermal expansion coefficients between the lens material and the filter layer material may cause the filter layer to easily peel off due to the temperature rise of the glass lens 23. Therefore, having a configuration that reduces heat transfer from the lens cover 24 as described above is extremely effective.

[0023] Next, a specific example of the glass lens 23 in the test apparatus 10 of this embodiment will be described using Figures 5 to 7. Figure 5 shows the spectra (spectral distribution) of a hydrogen flame (Hy) and a halogen lamp (halogen lamp). In Figure 5, A represents the wavelength range of visible light. As can be seen from Figure 5, the hydrogen flame has several characteristic spectral peaks in the infrared region. Therefore, in the test apparatus of this embodiment, as mentioned above, a glass lens 23 is used that has an optical filter function that transmits light similar to the spectrum characteristic of the hydrogen flame and blocks light in unwanted wavelength bands.

[0024] The glass lens 23 is made of anhydrous or low-water synthetic quartz glass, and this quartz glass transmits light across the entire wavelength range. On the other hand, the flame detector being tested in this embodiment is equipped with sensors sensitive to light in three wavelength bands: ΔλUV, ΔλIRm, and ΔλIRs, as shown in Figure 5, and detects the occurrence of a hydrogen flame based on the signal amount obtained from these sensors. That is, a hydrogen flame is determined when a certain amount of ultraviolet wavelength (ΔλUV) light is detected and the amount of light at the dominant wavelength (ΔλIRm) is sufficiently greater than the amount of light at the reference wavelength (ΔλIRs). However, the light emitted by the halogen lamp 31 has a greater amount of light at the reference wavelength (ΔλIRs) than at the dominant wavelength (ΔλIRm). Therefore, in the operation test of the detector, it is necessary to dim the light at the reference wavelength (ΔλIRs).

[0025] Therefore, in the glass lens 23 of the test apparatus 10 of this embodiment, as shown in Figure 6, light of the main wavelength (ΔλIRm) is transmitted, and the reference wavelength (Δλ IRsA filter layer (high-pass filter: HPF) 23A that blocks (attenuates) light with wavelengths shorter than T is provided on the surface of the lens in a circular shape. The filter layer 23A is formed by depositing a layer (coating) of a material having selective light transmission characteristics (transmission wavelength range), such as chromium oxide, onto the surface of the lens by vapor deposition. Figure 5 shows that the transmission wavelength band of this filter layer 23A is T F It is shown as follows.

[0026] By the way, when the filter layer 23A is formed over the entire surface of the lens, the ultraviolet wavelength (Δλ) characteristic of hydrogen flames is UV Light of wavelengths up to ) is blocked, making it impossible to detect with a flame detector. Therefore, in the embodiment shown in Figure 6, the filter layer 23A is partially formed on the central part of the glass lens 23 surface, excluding the edges, and the peripheral part of the lens is an uncoated area of ​​the filter layer 23A. In addition, in order to obtain wavelengths and intensities that match the characteristics of the flame detector, the area ratio of the filter layer 23A to the entire lens surface is set to, for example, 90%. Note that the area ratio is not limited to 90%, and should be set appropriately according to the selective light transmission characteristics (transmission wavelength range) and transmittance of the material of the filter layer 23A, the type of lamp used, the wavelength of light detected by the flame detector under test, etc. This allows test light having a wavelength and intensity that matches the detection characteristics of the flame detector under test to be irradiated from the test device 10 to the flame detector.

[0027] The formation pattern of the filter layer 23A is not limited to that shown in Figure 6; any shape or pattern can be used as long as the area ratio is within a predetermined range. Figures 7(a) to 7(f) show examples of other shapes and patterns of the filter layer 23A. Of these, Figure 7(a) shows a lens 23 with a circular uncovered filter layer 23B in the center of its surface; Figure 7(b) shows a lens 23 with a ring-shaped filter layer 23A on its surface, with uncovered filter layers 23B in the center and around the periphery; Figure 7(c) shows a lens 23 with multiple circular filter layers 23A dispersed on its surface. Furthermore, Figure 7(d) shows a lens 23 with a polygonal filter layer 23A (a pentagon in the figure) in the center of its surface; Figure 7(e) shows a lens 23 with multiple rectangular filter layers 23A dispersed on its surface; and Figure 7(f) shows a lens 23 with a cross-shaped uncovered filter layer 23B on its surface.

[0028] Although the present invention has been described above based on embodiments, the present invention is not limited to the above embodiments and can be modified as appropriate without departing from the spirit of the invention. For example, in the above embodiments, quartz glass is used as the glass lens 23 and a chromium oxide film is used as the filter layer 23A, but other materials having similar properties to those in the embodiments may be used. Also, in the above embodiments, a halogen lamp is used, but halogen lamps such as xenon lamps and LED lamps, or heat sources such as infrared heaters may be used.

[0029] Furthermore, although the above embodiment described the application of the present invention to a tester for a flame detector that detects fires caused by hydrogen leaks, the present invention is not limited to flame detectors that detect fires caused by hydrogen leaks, but can be used in testers that are generally used for flame detectors that detect the occurrence of a fire by detecting the wavelengths contained in the flame. Furthermore, although the above embodiment described the case where the device is applied to a portable testing device with a handle, it is also possible to apply it to a non-portable testing device. [Explanation of symbols]

[0030] 10. Operational testing device (tester) for flame detectors 11. Tester unit (main unit case) 11a Male thread part 11b Fin 12 Lens section 13 Case back 14 Handle 15 Switch buttons 16A,16B Legs 21 Lens retaining nut 22 Reflectors 23 Glass lenses 23A Filter layer 23B Uncoated portion of the filter layer 24 Lens Cover 24a Threaded part 24b fins 24c Right angle step 25 Insulation Spacers 26 O-rings 31 Halogen lamp 50 Flame detectors

Claims

1. A flame detector operation test device comprising a lamp and a lens positioned in front of the lamp, capable of emitting light of a predetermined wavelength in a certain direction, The flame detector operation test apparatus is characterized in that the lens is partially provided with a filter layer that transmits light in a predetermined wavelength band corresponding to the wavelength detected by the flame detector under test and blocks or attenuates light outside the predetermined wavelength band.

2. The flame detector operation test apparatus according to claim 1, characterized in that the predetermined wavelength band is set to at least within the range of infrared wavelengths or ultraviolet wavelengths.

3. The flame detector operation test apparatus according to claim 2, characterized in that the filter layer blocks light in the visible light wavelength range.

4. The flame detector operation test apparatus according to any one of claims 1 to 3, characterized in that the filter layer is composed of a coating made of a material having selective light transmission properties partially formed on the surface of the lens.

5. The flame detector operation test apparatus according to claim 4, characterized in that the area ratio of the filter layer to the surface area of ​​the lens is set to 90%.

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