JP2007032988A - Flue flame detection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flue flame detection system capable of detecting accurately and surely a flame in a flue by simple constitution and control, and capable of self-diagnosing a trouble and contamination in a component. <P>SOLUTION: This flue flame detection system is provided with an ultraviolet detector 9, an ultraviolet ray emitter 10, a shutter 11 and a controller 25. The shutter 11 opens and closes an optical path of an ultraviolet ray from the flame in the flue 2 to the ultraviolet detector 9. The controller 25 operates the ultraviolet ray emitter 10 at set timing, and detects the presence of abnormality and the contamination in the ultraviolet detector 9 and the ultraviolet ray emitter 10, and contamination in transparent glass 16, based on the presence of the detection of the ultraviolet ray by the ultraviolet detector 9. The controller 25 confirms the presence of the ultraviolet ray by the ultraviolet detector 9 by closing the shutter 11, when the ultraviolet ray is detected by the ultraviolet detector 9 under the condition where the ultraviolet ray emitter 10 is not operated, and determines discriminatingly the presence of the flame in the flue or self-discharge of the ultraviolet detector 9. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flue flame detection system for detecting a flame in a flue (exhaust duct) provided from the upper part of a cooker to the outdoors, and consequently a fire caused thereby.

  In a food factory or the like, a flue is provided from the upper part of the cooker to the outside in order to discharge smoke emitted from the cooker such as a fryer to the outside. Since oil and dirt from the cooker adhere to the flue, the flame generated from the cooker may move into the flue and cause a fire. Moreover, even if there was a flame in the flue, it was difficult to notice from the cooking room side, and the damage was likely to increase.

In such a case, use of a temperature detection type fire alarm can be considered. However, for example, in the case of charcoal grilling, the temperature inside the flue changes depending on the cooker and cooking method, such as the inside of the flue becomes hot even during normal use, so it is difficult to set the temperature. The fire alarm did not go to the flue. In addition, as disclosed in the following patent documents, a device has been proposed in which a damper is provided in the flue that can be opened and closed, and the damper is closed when a flame is detected in the flue by a flame sensor.
Utility Model Registration No. 2606514 (paragraph numbers 0022-0024) JP 2000-146171 A (paragraph numbers 0019,0027)

  However, the conventional apparatus is easy to break down or malfunction due to temperature change or contamination in the flue. Moreover, even if such a failure or contamination occurs, it cannot be self-diagnosed. In addition, all of the conventional devices use temperature or visible light for flame detection, and are easily malfunctioned by insertion of sunlight or illumination light.

  The problem to be solved by the present invention is to provide a flue flame detection system capable of accurately and reliably detecting a flame in a flue with a simple configuration and control, and capable of self-diagnosis of a component failure and dirt. .

  The present invention has been made to solve the above-described problems. The invention according to claim 1 is directed to an ultraviolet detector as a flame sensor, an ultraviolet light emitter that emits ultraviolet light, and an ultraviolet ray emitted from the ultraviolet light emitter. A flue flame detection system comprising: a controller for controlling the presence or absence of light emission and monitoring the presence or absence of reception of ultraviolet rays by the ultraviolet detector.

  According to the first aspect of the present invention, by using ultraviolet rays, it is possible to accurately detect the presence or absence of a flame regardless of the state of the flame and minimizing the influence of sunlight or illumination light. it can. Furthermore, by providing an ultraviolet light emitter, it is possible to detect flames in the flue while performing self-diagnosis of component failures and dirt from the correspondence between the ultraviolet light emitted by the ultraviolet light emitter and the detection of ultraviolet light by the ultraviolet light detector. It is.

  According to a second aspect of the present invention, the controller operates the ultraviolet light emitter at a set timing, while the ultraviolet light detector and / or the ultraviolet light emitter is based on whether or not the ultraviolet light is detected by the ultraviolet light detector. The flue flame detection system according to claim 1, wherein the presence or absence of contamination or the presence or absence of dirt is detected.

  According to the second aspect of the present invention, in the case where the ultraviolet ray detector does not detect the ultraviolet ray even though the ultraviolet ray emitter is instructed to emit the ultraviolet ray, Perceived to be due to defects or dirt.

  According to a third aspect of the present invention, the ultraviolet detector is provided separately from the flue through a transparent glass that transmits ultraviolet rays, and detects ultraviolet rays from the ultraviolet light emitter through the transparent glass. Air is flowed between the transparent glass and the flue, and the controller operates the ultraviolet light emitter at a set timing, while the ultraviolet light detector detects the ultraviolet light. 2. The flue flame detection system according to claim 1, wherein the presence or absence of an abnormality of the ultraviolet detector and / or the ultraviolet light emitter, or the presence or absence of contamination of the transparent glass is detected based on the presence or absence of the transparent glass. .

  According to the third aspect of the present invention, the ultraviolet detector is isolated from the flue through the transparent glass, and the cooling of the transparent glass and the prevention of dirt from adhering to the transparent glass can be achieved by the air flow. If the ultraviolet detector does not detect the ultraviolet ray even though the ultraviolet ray emitter is instructed to emit the ultraviolet ray, the ultraviolet ray emitter or the ultraviolet ray detector is defective or the transparent glass is dirty. It is grasped as the cause.

  Invention of Claim 4 is further equipped with the shutter which opens and closes the optical path of the ultraviolet-ray from the flame in the flue to the said ultraviolet detector, The smoke of any one of Claims 1-3 characterized by the above-mentioned. This is a road flame detection system.

  When ultraviolet rays are detected by an ultraviolet detector, there is usually either a flame in the flue or an ultraviolet ray emitted from the ultraviolet emitter, but in addition to this, malfunction due to self-discharge of the ultraviolet detector etc. Can be considered. However, according to the fourth aspect of the present invention, it is possible to switch whether the ultraviolet ray from the flame in the flue can be received by the ultraviolet ray detector by opening and closing the shutter. Therefore, when the ultraviolet ray detector detects ultraviolet rays while the ultraviolet ray emitter is stopped, it is possible to determine whether the ultraviolet ray detector is malfunctioning by opening and closing the shutter.

  The invention according to claim 5 further includes a shutter that opens and closes an optical path of ultraviolet rays from a flame in the flue to the ultraviolet detector and ultraviolet rays from the ultraviolet emitter to the ultraviolet detector, and the controller When the ultraviolet ray detector is not activated but the ultraviolet ray detector detects the ultraviolet ray, the shutter is closed to check whether the ultraviolet ray detector has detected the ultraviolet ray. The flue flame detection system according to any one of claims 1 to 3.

  If the UV detector detects the UV even though it has not been commanded to emit UV, either there is a flame in the flue or the UV detector malfunctions. It is. However, according to the fifth aspect of the present invention, when the ultraviolet ray detector is not operated but the ultraviolet ray is detected by the ultraviolet ray detector, the shutter is closed to cause the flame in the flue. It is possible to accurately determine whether it is ultraviolet light. In other words, when the UV detector still detects UV even though the shutter is closed, it can be understood that the UV detector has malfunctioned. Conversely, when the shutter is closed, the UV detector no longer detects UV. If this is the case, it can be understood that the ultraviolet ray is due to the flame in the flue.

  Further, in the invention described in claim 6, the flue is provided with dampers for opening and closing the flue, and the ultraviolet detector, the ultraviolet light emitter, the shutter, The controller is provided, and the controller at each location is connected to a common control panel, and the control panel is connected to a flame in the flue by the ultraviolet detector at any of the locations. 6. The flue flame detection system according to claim 4, wherein the dampers at all locations are closed when the detection is detected.

  According to the sixth aspect of the present invention, when a flame (fire) is detected in the flue at any location, the dampers at all locations are closed via the control panel, Propagation and burning can be prevented.

  According to the flue flame detection system of the present invention, the flame in the flue can be accurately and reliably detected with a simple configuration and control. In addition, it is possible to make a self-diagnosis about component failures and dirt.

Next, an embodiment of the present invention will be described.
The flue flame detection system of the present embodiment detects a flame and a fire in a flue (exhaust duct) in a food factory or the like, notifies that fact, closes a damper provided in the flue, or cooks It is a system that forcibly stops. The flue has one end portion or a midway portion opened above the various cookers such as a fryer and a stove via a range hood, and the other end portion opened outdoors.

  Usually, a blower as an attracting fan is provided at the end of the flue on the outdoor side. By operating this blower, odors and smoke generated by cooking can be discharged to the outside through the flue. The flue is provided with at least one range hood. However, smoke from a plurality of range hoods may be discharged to the outside through a common flue.

  In the middle of the flue, a damper is provided so that an internal passage constituting the flue can be opened and closed. Typically, this damper is comprised from the board | plate material which can change a rotation stop position, and naturally, it is normally used in the open state. The dampers are preferably installed at a plurality of locations at intervals along the flue. In particular, when a plurality of range hoods are provided, a plurality of dampers are provided correspondingly. A flame detection device is provided corresponding to the installation position of each damper. The flame detection device includes an ultraviolet detector, an ultraviolet light emitter, a shutter, and a controller.

  The ultraviolet detector is a flame sensor that detects the presence or absence of a flame in the flue based on whether or not ultraviolet rays are received. That is, the ultraviolet detector detects ultraviolet rays generated from the flame. The ultraviolet detector typically comprises an ultraviolet photoelectric tube, and discharge occurs between the electrodes when the ultraviolet ray hits. Therefore, the presence or absence of discharge can detect the presence or absence of ultraviolet rays and flames.

  The ultraviolet detector is installed in the flue or provided with an opening in a side wall constituting the flue so that ultraviolet rays from the flame in the flue can be received through the opening. At that time, the ultraviolet ray detector is disposed separately from the flue through a transparent glass that transmits ultraviolet rays so that dirt does not adhere to the ultraviolet ray detector due to smoke passing through the flue. Further, the transparent glass is preferably subjected to air purge. That is, it is preferable to prevent cooling of the transparent glass and adhesion of dirt to the transparent glass by flowing air from the outside toward the inside of the flue from the transparent glass side.

  In this embodiment, an ultraviolet light emitting fluorescent tube that generates ultraviolet light by discharge is used as the ultraviolet light emitter. The ultraviolet light emitter is provided at a position where the emitted ultraviolet light reaches the ultraviolet detector. The UV detector and the UV light emitter may be provided at the facing position penetrating the flue in the width direction, but only one opening is formed in the side wall of the flue, and the UV detector and the UV light emission are formed in the opening. It is preferable to install both of them.

  Similarly to the ultraviolet detector, the ultraviolet light emitter is preferably arranged separately from the flue through a transparent glass that transmits ultraviolet light, and it is preferable to cool the transparent glass and prevent contamination by air purge. Separation from the flue by this transparent glass can be done separately for each UV detector and UV emitter by using two transparent glasses, or both can be done with a single transparent glass. Also good.

  Among the ultraviolet rays from the flame in the flue to the ultraviolet detector and the ultraviolet rays from the ultraviolet emitter to the ultraviolet detector, at least the former ultraviolet optical path is provided with a shutter so that the optical path can be opened and closed midway. . In this embodiment, the optical paths of both the ultraviolet rays from the flame in the flue to the ultraviolet detector and the ultraviolet rays from the ultraviolet emitter to the ultraviolet detector can be opened and closed with one shutter. This shutter is preferably provided in a region isolated from the flue by the transparent glass. The shutter is not limited to a mechanical one but can be an electro-optical one. Further, it is possible to provide a wiper that removes dirt from the transparent glass and to drive it when necessary to remove dirt.

  The controller is constituted by an electronic circuit, controls whether or not ultraviolet light is emitted by the ultraviolet light emitter, and monitors whether or not ultraviolet light is received by the ultraviolet detector. This controller causes the ultraviolet light emitter to emit ultraviolet light in pulses at a set timing, usually at a predetermined interval. And a controller detects the presence or absence of abnormality of an ultraviolet detector and / or an ultraviolet light emitter based on the presence or absence of the detection of the ultraviolet-ray by an ultraviolet detector. In other words, if the UV detector does not detect the UV even though the UV emitter is instructed to emit UV, it is detected as a failure of the UV emitter or UV detector, or the contamination of the protective glass. . At that time, in the case where the ultraviolet ray from the ultraviolet ray emitter is detected by the ultraviolet ray detector through the transparent glass, the presence or absence of the stain on the transparent glass can also be detected.

  In addition, when the ultraviolet ray detector is not activated but the ultraviolet ray detector detects the ultraviolet ray, the controller closes the shutter to accurately determine whether the ultraviolet ray is caused by the flame in the flue. Identify. In other words, when the UV detector still detects UV even though the shutter is closed, it can be detected that the UV detector has malfunctioned (self-discharge). If no more is detected, it is detected that there is a flame in the flue.

  Each controller is connected to a common control panel. When each controller detects a flame in the flue, it outputs a signal to that effect to the control panel. In principle, the control panel controls the dampers at all locations to close when a flame is detected at any location. At this time, the control panel itself may directly control the drive motor of the damper, or may control the corresponding drive motor of the damper via each controller. Further, when a flame is detected in the flue, a fire may be notified by a buzzer or a lamp instead of or in addition to closing the damper, or the cooking device may be forcibly stopped.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram showing a use state of a flue flame detection system according to a first embodiment of the present invention. Moreover, FIG. 2 is a schematic block diagram which shows the principal part of the flue flame detection system of a present Example.

  The flue flame detection system 1 of the present embodiment is provided in a flue 2 in a food factory or the like. The flue 2 is a duct that discharges smoke, odor, and the like generated by cooking to the outside from a range hood 4 disposed on the top of various cookers 3 such as a fryer and a stove. Although the range hood 4 is provided in two places in the flue 2 of the example of illustration, the number of this range hood 4 is changed suitably. A blower 5 is provided at the end of the flue 2 on the outdoor side, and air from the range hood 4 is sucked and exhausted to the outside through the flue 2 by the operation of the blower 5.

  In the flue 2, a damper 6 is provided at a position on the downstream side (outdoor side) of each range hood 4 so that the internal passage can be opened and closed. This damper 6 is comprised from the board | plate material which can change a rotation stop position. In this embodiment, the rotation shaft 7 of the damper 6 is operated by a drive motor (not shown) so that the damper 6 is disposed at either one of the open position and the closed position. And the damper 6 is normally hold | maintained in an open position so that a cooking chamber and the outdoors may be connected. By the way, the damper 6 in the illustrated example is configured to open and close the flue 2 with a single plate material, but may be configured to open and close the flue 2 with a plurality of plate materials at each location.

  A plurality of flame detection devices 8 are provided in the flue 2 in the vicinity of the installation position of each damper 6. As shown in FIG. 2, the flame detector 8 of the present embodiment includes an ultraviolet detector 9, an ultraviolet light emitter 10, a shutter 11, and the like housed in a box-shaped case 12. The case 12 is attached to the flue 2 by forming an opening 14 in the side wall 13 constituting the flue 2 and connecting the opening of the case 12 to the opening 14 via a short tube 15. A transparent glass 16 that transmits ultraviolet rays is provided in the opening of the case 12. The transparent glass 16 separates the inside of the case 12 and the inside of the flue 2, and the ultraviolet detector 9, the ultraviolet light emitter 10, the shutter 11, and the like are sealed in the case 12. The flame detection device 8 configured as described above can be sold as a unit.

  However, the ultraviolet light emitter 10 may be provided at an outer position (for example, the short tube 15) than the transparent glass 16 of the case 12, as shown by a two-dot chain line in FIG. As described above, it is possible to perform self-diagnosis on the presence or absence of dirt on the transparent glass 16.

  A plurality of small holes 17 are formed in the end portion of the short pipe 15 on the case 12 side, and air can be supplied from the small holes 17 into the flue 2. By this air flow, the transparent glass 16 is cooled and contamination of the transparent glass 16 is prevented. By the way, the air supply from the short pipe 15 into the flue 2 through the small hole 17 can be naturally performed by the differential pressure inside and outside the flue 2 by the operation of the blower 5 as an induction fan. An air source other than the blower 5 can also be used.

  The ultraviolet detector 9 housed in the case 12 is a flame sensor that detects the presence or absence of a flame in the flue 2 by the presence or absence of ultraviolet rays generated from the flame. The ultraviolet detector 9 of this embodiment is composed of an ultraviolet photoelectric tube, and detects ultraviolet rays by generating a discharge between the electrodes when the ultraviolet rays hit. Specifically, “UVtron” (registered trademark) manufactured by Hamamatsu Photonics Co., Ltd. is used. Since this sensor has sensitivity only in the ultraviolet region, it can accurately detect ultraviolet rays and thus flames.

  The ultraviolet ray detector 9 is provided at a position where the flame in the flue 2 can be detected. That is, when a flame is generated in the flue 2, the ultraviolet rays from the flame reach the ultraviolet detector 9 in the case 12 through the transparent glass 16.

  The ultraviolet light emitter 10 is not particularly limited as long as it can emit ultraviolet light, but an ultraviolet light emitting fluorescent tube having a structure that generates ultraviolet light by discharge is preferably used. The ultraviolet light emitter 10 is provided at a position where the emitted ultraviolet light reaches the ultraviolet detector 9. In the illustrated example, the ultraviolet detector 9 is provided on the bottom side of the case 12, and the ultraviolet light emitter 10 is provided downward on the opening side of the case 12. However, as described above, the ultraviolet light emitter 10 may be provided on the opposite side of the ultraviolet light detector 9 through the transparent glass 16.

  On the upper part of the ultraviolet detector 9, a shutter 11 is provided so as to be openable and closable so as to block ultraviolet rays from the flame in the flue 2 and ultraviolet rays from the ultraviolet light emitter 10. The shutter 11 according to the present embodiment is formed of a disc having a notch 18 formed in a part in the circumferential direction, and the notch 18 is detected by an ultraviolet detector by the rotation of a rotation drive shaft 19 provided at the center thereof. It is selected whether or not to place it directly above 9. At this time, the rotary drive shaft 19 is rotated by a rotary solenoid 20.

  In a state where the shutter 11 is opened, that is, in a state where the notch 18 is disposed corresponding to the ultraviolet detector 9, the ultraviolet detector 9 includes ultraviolet rays from the flame in the flue 2 and the ultraviolet light emitter 10. Both ultraviolet rays can be received. On the other hand, when the notch 18 is displaced from the ultraviolet detector 9 and the shutter 11 is closed, the ultraviolet detector 9 cannot receive ultraviolet rays from the flame in the flue 2. Furthermore, in this embodiment, the shutter 11 is disposed between the ultraviolet detector 9 and the ultraviolet light emitter 10, so that when the shutter 11 is closed, the ultraviolet detector 9 also receives ultraviolet light from the ultraviolet light emitter 10. It is assumed that no light can be received.

  The ultraviolet detector 9, ultraviolet emitter 10, and rotary solenoid 20 are connected to the controller 25. The controller 25 is composed of an electronic circuit, controls whether or not the ultraviolet light emitter 10 emits ultraviolet light, and monitors whether or not the ultraviolet light detector 9 receives light. The controller 25 controls the rotary solenoid 20 for opening and closing the shutter 11. The controller 25 can also be provided in the control panel 21 described later.

  FIG. 3 is a time chart showing the state of ultraviolet light emission by the ultraviolet light emitter 10 and the state of ultraviolet light detection by the ultraviolet light detector 9. As shown in FIG. 2A, the controller 25 controls the ultraviolet light emitter 10 to emit ultraviolet light in a pulse shape at a predetermined cycle. If the shutter 11 is open and there is no flame in the flue 2, the ultraviolet light emitted in a pulse form from the ultraviolet light emitter 10 is detected in a pulse form by the ultraviolet light detector 9. That is, the ultraviolet ray detection by the ultraviolet ray detector 9 is also in the state shown in FIG.

  However, suppose that the ultraviolet ray detector 9 cannot detect the corresponding ultraviolet ray even though the ultraviolet ray emitter 10 is operated. That is, although the ultraviolet light emitter 10 is operated in a predetermined cycle in a pulsed manner as shown in FIG. 9A, ultraviolet light is detected by the ultraviolet detector 9 as indicated by the X portion in FIG. Suppose that it is no longer. In this case, the failure of the ultraviolet detector 9 or the contamination of the protective glass on the surface thereof is the cause, but the controller 25 detects that the failure or the contamination has occurred based on the fact that the detection of ultraviolet rays has become impossible. To do.

  By the way, as described above, when the ultraviolet ray detector 9 and the ultraviolet ray emitter 10 are separately arranged on both sides of the transparent glass 16 (for example, the ultraviolet ray emitter 10 is not a solid line in FIG. 2 but a two-dot chain line). In the case of being provided at the position), it is also possible to detect the presence or absence of dirt on the transparent glass 16. In this case, the ultraviolet light emitter 10 can also be provided by being covered with an appropriate case, and a transparent glass that transmits ultraviolet light is preferably provided in the opening.

  In any case, when the controller 25 detects the abnormality or dirt, the controller 25 can output the fact to the control panel 21 (FIG. 1) to be described later and notify the fact via the control panel 21. By the way, although the controller 25 issues an operation command to the ultraviolet light emitter 10, there is a possibility that the ultraviolet light emitter 10 is not activated in the first place. Faults can be detected as well.

  On the other hand, it is assumed that the ultraviolet light is detected by the ultraviolet light detector 9 even though the ultraviolet light emitter 10 is not operated. That is, as shown in FIG. 3C, it is assumed that the ultraviolet ray detector 9 detects the ultraviolet ray regardless of the emission of the ultraviolet ray emitter. In this case, it is considered that a flame is usually generated in the flue 2, but there is still a possibility of malfunction due to the self-discharge of the ultraviolet ray detector 9. Made.

  Specifically, when the ultraviolet light is detected by the ultraviolet light detector 9 even though the ultraviolet light emitter 10 is not operated, the controller 25 operates the rotary solenoid 20 to close the shutter 11. As a result, ultraviolet rays due to flames in the flue 2 and ultraviolet rays from the ultraviolet light emitter 10 cannot reach the ultraviolet detector 9 by the shutter 11. If the ultraviolet ray is detected even when the shutter 11 is closed, the controller 25 detects this as self-discharge by the ultraviolet ray detector 9. On the other hand, in a state where the shutter 11 is closed, if the ultraviolet ray detector 9 does not detect ultraviolet rays, the controller 25 detects that there is a flame in the flue 2 and that is the case. In any case, the controller 25 can output the fact to the control panel 21 and can notify the user via the control panel 21.

  Each controller 25 is connected to a common control panel 21. The control panel 21 is provided with a fire alarm lamp 22 and a buzzer (not shown). When the control panel 21 receives a signal that detects a flame in the flue 2 from any of the controllers 25, the control panel 21 turns on the notification lamp 22 or activates a buzzer. Moreover, it controls to close the damper 6 of all the places. At this time, the control panel 21 itself may directly control the drive motor (not shown) of the damper 6, or sends a signal to each controller 25 to control the drive motor of the damper 6 from the controller 25. May be. Furthermore, the control panel 21 may stop each cooking appliance 3, or may operate a fire extinguishing apparatus (not shown). Thus, the output format by the controller 25 or the control panel 21 when a flame is detected in the flue 2 can be changed as appropriate.

  FIG. 4 is a schematic view showing a usage state of the flue flame detection system according to the second embodiment of the present invention, and shows only main parts. The flue flame detection system 1 of the second embodiment is basically the same configuration as the first embodiment. Therefore, in the following, the description will be focused on the different parts, and corresponding portions will be described with the same reference numerals.

  In the first embodiment, the ultraviolet detector 9 and the ultraviolet light emitter 10 are provided together at one end of the flue 2, but in the second embodiment, at a position facing the width direction of the flue 2. Separately provided. Therefore, in the second embodiment, two cases of the first case 23 and the second case 24 are provided with the flue 2 sandwiched in the width direction.

  Each case 23, 24 is connected to the flue 2 through a short tube 15, as in the case 12 of the first embodiment. Transparent glass that transmits ultraviolet rays is formed in the opening of each case 23, 24. 16 is provided. Each case 23 and 24 is isolated from the inside of the flue 2 by the transparent glass 16. Further, in order to cool the transparent glass 16 and prevent the dirt from adhering to the transparent glass 16, air is blown into the short tube 15 from the transparent glass 16 side into the flue 2.

  In the first case 23, the ultraviolet detector 9 is provided, and a disc-shaped shutter 11 having a notch 18 is rotatably provided by a rotary solenoid 20. On the other hand, the ultraviolet light emitter 10 is accommodated in the second case 24. The ultraviolet rays from the ultraviolet light emitter 10 can reach the ultraviolet detector 9 in the first case 23 across the flue 2. Further, by opening and closing the shutter 11, whether the ultraviolet rays from the ultraviolet light emitter 10 and the ultraviolet rays due to the flame in the flue 2 can reach the ultraviolet detector 9 can be switched.

  Similarly to the first embodiment, the flue flame detection system 1 according to the second embodiment emits pulsed ultraviolet light from the ultraviolet light emitter 10 under the control of the controller 25, while the ultraviolet detector 9 detects ultraviolet light. The presence or absence of is monitored. As in the first embodiment, it is possible to detect a failure of the ultraviolet detector 9 or the like, dirt on the transparent glass 16, etc., and also check the presence or absence of self-discharge by the ultraviolet detector 9, and the flame in the flue 2. Can be detected. When a flame is detected in the flue 2, the dampers 6 at various places are closed via the control panel 21 (FIG. 1), a lamp 22 or the like is notified, or the cooker 3 is forcibly stopped. Or a fire extinguisher (not shown) can be activated.

  The flue flame detection system 1 of the present invention is not limited to the configuration of each of the embodiments described above and can be changed as appropriate. For example, in each of the embodiments described above, the shutter 11 can switch whether or not the ultraviolet ray detector 9 can receive light of both ultraviolet rays from the ultraviolet light emitter 10 and ultraviolet rays due to flames in the flue 2. 11 should just block the ultraviolet-ray by the flame in the flue 2 at least. In this case, by opening and closing the shutter 11 without operating the ultraviolet light emitter 10, it is possible to determine whether the ultraviolet light is due to the flame in the flue 2 or the ultraviolet light due to the self-discharge of the ultraviolet detector 9.

  In each of the above embodiments, the shutter 11 is made of a disk having a notch 18 formed in part, and the shutter 11 is opened and closed by rotating the shutter 11 to change the position of the notch 18. However, the shutter 11 may be configured to simply slide a substantially rectangular plate.

  Furthermore, as a modification of the second embodiment, the second case 24 may be connected to the middle portion of the short pipe 15 that connects the first case 23 and the flue 2. That is, both the first case 23 and the second case 24 may be provided on one short pipe 15 provided in the flue 2. In this case, the ultraviolet light emitter 10 in the second case 24 is arranged toward the ultraviolet light detector 9 in the first case 23, and the ultraviolet light detector 9 is connected to the ultraviolet light from the ultraviolet light emitter 10 and the flue 2. It is possible to receive both ultraviolet rays due to the flame.

It is the schematic which shows the use condition of Example 1 of the flue flame detection system of this invention. It is a schematic block diagram which shows the principal part of the flue flame detection system of Example 1. It is a time chart which shows the state of the ultraviolet light emission by an ultraviolet light emitter, and the ultraviolet-ray detection by an ultraviolet detector in the flue flame detection system of Example 1. FIG. It is the schematic which shows the use condition of Example 2 of the flue flame detection system of this invention, and has shown only the principal part.

Explanation of symbols

1 flue flame detection system 2 flue 3 cooker 6 damper 9 UV detector (flame sensor)
DESCRIPTION OF SYMBOLS 10 Ultraviolet light emitter 11 Shutter 12 Case 15 Short tube 16 Transparent glass 17 Small hole 18 Notch 21 Control panel 25 Controller

Claims (6)

An ultraviolet detector as a flame sensor;
An ultraviolet light emitter that emits ultraviolet light;
A flue flame detection system comprising: a controller that controls whether or not ultraviolet light is emitted by the ultraviolet light emitter and that monitors whether or not ultraviolet light is received by the ultraviolet detector. The controller operates the ultraviolet light emitter at a set timing, and detects whether the ultraviolet light detector and / or the ultraviolet light emitter is abnormal or dirty based on the presence or absence of the ultraviolet light detected by the ultraviolet light detector. The flue flame detection system according to claim 1. The ultraviolet detector is provided separately from the flue through a transparent glass that transmits ultraviolet rays, and is provided so as to be able to detect ultraviolet rays from the ultraviolet light emitter through the transparent glass,
Air flows between the transparent glass and the flue,
The controller operates the ultraviolet light emitter at a set timing, and on the basis of presence / absence of ultraviolet light detected by the ultraviolet light detector, whether or not the ultraviolet light detector and / or the ultraviolet light emitter is abnormal, or the transparent glass The flue flame detection system according to claim 1, wherein presence or absence of dirt is detected. The flue flame detection system according to any one of claims 1 to 3, further comprising a shutter that opens and closes an optical path of ultraviolet rays from a flame in the flue to the ultraviolet detector. A shutter that opens and closes an optical path of ultraviolet rays from the flame in the flue to the ultraviolet detector, and ultraviolet rays from the ultraviolet emitter to the ultraviolet detector;
The controller closes the shutter when the ultraviolet detector detects the ultraviolet ray even though the ultraviolet ray emitter is not operated, and confirms whether the ultraviolet ray detector is detected by the ultraviolet detector. The flue flame detection system according to any one of claims 1 to 3, wherein: The flue is provided with a plurality of dampers for opening and closing it,
The ultraviolet detector, the ultraviolet light emitter, the shutter, and the controller are provided at each location,
The controller at each location is connected to a common control panel,
6. The control panel according to claim 4, wherein, when the flame in the flue is detected by the ultraviolet detector at any one of the respective locations, the dampers at all locations are closed. 6. Flue flame detection system.

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