JPH066944U - Combustion misfire detection device - Google Patents

Abstract

(57) [Summary] [Structure] A plurality of light guides 6 for guiding the emitted light from the burner flame, a switching device 7 for switching the guided emitted light, and a photodetector 8 for detecting the presence or absence of the emitted light. Combustion misfire detection device configured. [Effects] Combustion misfires of multiple burners can be determined in a short time by using one radiation detector and an optical guide such as an optical fiber, without installing a radiation detector for each burner. It is also possible to reduce the facility cost and maintenance cost.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a combustion misfire detection device for an industrial furnace having a plurality of burners.

[0002]

[Prior art]

 In an industrial furnace with multiple burners, if a so-called misfire occurs in which combustion is interrupted due to loss of combustion air due to blockage of individual burner air passages, temporary decrease in fuel pressure, etc. As a result, the unburned fuel is discharged into the furnace and an explosive mixture is generated. When this mixture comes into contact with the heated part of the furnace, other burner flames, etc., it causes an explosion, and primarily damages the furnace equipment, and secondarily causes gas poisoning due to gas leakage. Cause damage. Therefore, in the industrial furnace having a plurality of burners, the burner combustion state is monitored.

As a method of monitoring the burner combustion state in the furnace, a method using a radiation photodetector arranged so that the flame is contained within the field of view, a temperature inside the furnace is constantly measured, and a burnout is performed to reduce the burner temperature. Many methods have been put into practical use, such as a method of determining the burner combustion state, a method of arranging a thermometer such as a thermocouple in or near the flame, and determining the burner combustion state from the temperature decrease due to misfire.

[0004]

[Problems to be solved by the device]

 However, the method using the synchrotron radiation detector arranged so that the flame is within the field of view can determine the misfire of each burner when the multiple synchrotron radiation detectors are within the field of view. First, it is necessary to provide a radiation detector for each burner. Therefore, the number of them increases, and the equipment cost and maintenance cost increase.

In the method of constantly measuring the temperature inside the furnace and determining the burner combustion state from the temperature decrease due to misfire, when a part of a plurality of burners misfires, the decrease in the temperature inside the furnace is small It may not be possible to judge. In addition, this method requires a relatively long time from the misfire to the temperature decrease in the furnace, and it takes time to detect the temperature decrease of the thermometer due to the responsiveness of the thermometer. Requires.

A method of arranging a thermometer such as a thermocouple in the flame or in the vicinity of the flame and determining the burner combustion state from the temperature decrease due to misfire requires a large number of thermometers in the case of a plurality of burners, and the equipment cost is high. , Maintenance cost will increase. Further, since a thermocouple such as a thermocouple is provided in or near the flame, the flame damages the thermometer.

The present invention has been made to solve the above-mentioned problems, and radiates light emitted from each flame to a photodetector by a plurality of light guides, and guides it by a plurality of light guides. It is an object of the present invention to provide a combustion misfire detection device that switches radiated light from individual flames by a switching device to make it enter a photodetector, and detects the presence of radiated light by the photodetector to judge misfire. It

[0008]

[Means for Solving the Problems]

 The gist of the present invention is a combustion misfire detection that is composed of a plurality of light guides that guide the emitted light from the burner flame, a switching device that switches the guided emitted light, and a photodetector that detects the presence or absence of the emitted light. It is a device.

[0009]

[Action]

 The present invention judges the misfire of the burner by detecting the emitted light from the ultraviolet rays to the infrared rays emitted by the burner flame.

An optical fiber or the like having a function of transmitting radiant light from the flame is used as a light guide for guiding the radiant light from the burner flame. A light guide is provided for each burner, and its tip is directed toward the burner flame so that the emitted light is incident. The emitted light incident on the light guide is guided to the switching device by the light guide.

The switching device is provided between the light guide and the photodetector. With this switching device, the emitted light from the individual burners guided by the plurality of light guides is sequentially switched to the photodetector. The light is made incident and the emitted light is detected by the photo detector.

The photodetector detects the radiant light guided by the light guide, and when the radiant light from the switching device is incident, it is determined that combustion is occurring in the burner, and a signal with flame is output. send. The presence or absence of this signal determines the misfire for each burner.

[0013]

【Example】

 An embodiment of the present invention will be described below. FIG. 1 shows an embodiment of a combustion misfire detection device of the present invention, in which a burner 3 is provided on a furnace wall 1, and a tip of the burner 3 is protected by a support material 5 in a direction in which a radiant light 4 emitted from a flame 2 is incident. The guided light guide 6 is arranged on the furnace wall 1. On the other hand, the rear end of the light guide 6 is connected to the switching device 7. A photodetector 8 is arranged behind the switching device 7.

An optical fiber having flexibility is used for the light guide 6. According to this, it is possible to guide only the radiated light emitted by the burner flame to the photodetector 8 without the light existing around the optical projector 6 being scattered.

A phototube is used for the photodetector 8. The photodetector 8 may be a photodiode, a phototransistor, a pyroelectric element, a photomultiplier tube, or the like.

As shown in FIG. 2, the switching device 7 has a circular plate 10 having a hole 9 at the rear end of the circular light guides 6 through which only the light emitted from one light guide can pass. Is provided and rotated by the driving device 11, and the emitted light from the light guide 6 is sequentially passed through the opening 9, whereby the emitted light is switched and the emitted light is made incident on the photodetector 8. .

A rotary position detector 12 is installed on the disk 10 and is associated with which optical device the radiated light that is currently passing is from. In other words, it is possible to know which burner is currently determining the misfire.

In determining the burner misfire, the radiant light guided by the light guide 6 is switched by the switching device 7 and made incident on the photodetector 8, and the presence or absence of radiant light is detected. Send misfire signal 13. At this time, the light guide position signal 14 is transmitted from the rotational position detector 12. The burner misfire is judged based on the burner misfire signal 15 which is a combination of these two signals. That is, by determining the theoretical product of the light guide position signal 14 and the misfire signal 13, misfire can be determined for all burners.

[0019]

[Effect of device]

 The present invention is a combustion misfire detection device including a plurality of light guides for guiding the radiant light from a burner flame, a switching device for switching the guided radiant light, and a photodetector for detecting the presence or absence of the radiant light. Therefore, according to this device, one radiation light detector and an optical prototype such as an optical fiber can be used for a plurality of burners in a short time without installing the radiation light detectors individually. Combustion misfires of multiple burners can be determined, and equipment costs and maintenance costs can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a switching device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Furnace wall, 2 ... Flame, 3 ... Burner, 4 ... Radiant light, 5 ... Supporting material, 6 ... Light guide, 7 ... Switching device, 8 ... Photodetector, 9
… Aperture, 10… disc, 11… drive, 12… rotational position detector, 13… misfire signal, 14… light guider position signal, 15… burner misfire signal.

Claims (1)

[Scope of utility model registration request] 1. A plurality of light guides for guiding the emitted light from the burner flame, a switching device for switching the guided emitted light, and a photodetector for detecting the presence or absence of the emitted light. Combustion misfire detection device.