JPS6124916A - Imperfect burning detection device - Google Patents

Abstract

PURPOSE:To detect abnormal burning by disposing a detection circuit that detects imperfect burning condition by output signal from a photoreceptor element that catches the radiation light from a red-hot body. CONSTITUTION:Vaporized fuel is mixed with air in a hollow space between an outer flame tube 2 and an inner flame tube 3, and rises at it is burnt. As a red- hot body 6 which is disposed at the upper end of the outer tube 1 and is made with a rod in a Z-shape that consists of heat-resistant metal emits radiation light at a higher intensity than the burning flame 5 around it, the photoreceptor element 4 receives the light mainly from the red-hot body 6. When oxygen becomes defficient under such a condition, the flame intensity of burning wanes by the burning mechanism which is intrincic to the natural vaporization type burning apparatus, the calorific value to heat the red-hot body 6 deminishes. As a result, the radiation light from the red-hot body 6 decreases as the temperature of the red-hot body 6 decreases, and the spectrometric characteristics of light deviates to the side of a longer wave length. Therefore, by catching such a change by the photoreceptor element 4, an abnormal burning due to the oxygen defficiency can easily be detected even in a natural vaporization type burning apparatus.

Description

[Detailed Description of the Invention] Technical Field> The present invention detects abnormal combustion in a liquid fuel natural vaporization type combustion appliance, such as an upper-and-lower wick type kerosene stove, to notify the necessity of ventilation, etc. This invention relates to an incomplete combustion detection device for stopping the combustion.

<Prior art> When a combustion appliance is burned in a highly airtight room, the oxygen concentration decreases over time, and if the oxygen deficiency further occurs, the combustion appliance causes incomplete combustion. The increase in non-combustible gases and carbon monoxide created a dangerous atmosphere that was physiologically harmful and could even lead to death.

Therefore, in Japanese Patent Application No. 58-887, the present applicant provided a plurality of light-receiving elements with different wavelength sensitivities, and detected abnormalities in the combustion state by utilizing the fact that the color of the combustion flame changes depending on the combustion state. The method has already been applied.

That is, this method detects abnormal combustion by observing the change in the color of the combustion flame caused by a change in the air-fuel ratio, which is the ratio of fuel and oxygen, with a color sensor due to oxygen deficiency.

However, the combustion mechanism of natural vaporization combustion appliances that use liquid fuel is fundamentally different from that of forced vaporization combustion appliances. With natural vaporization, the oxygen concentration and fuel ratio do not change much even in oxygen-deficient conditions. This is because the temperature of the combustion flame decreases as the oxygen concentration decreases, and the amount of vaporized fuel decreases accordingly. Therefore, based on this, even if an oxygen-deficient state occurs, the color of the combustion flame does not change as in the forced vaporization method, but the combustion flame simply becomes smaller. For these reasons, in natural vaporization combustion appliances, it is difficult to directly monitor the flame with a color sensor and detect incomplete combustion.

Additionally, there is a method of detecting abnormal combustion conditions by detecting a decrease in the amount of light using a single light-receiving element, but in natural vaporization combustion appliances, the flame condition is unstable, and the amount of light obtained by the light-receiving element is also small and unstable. It is. This is because in the natural vaporization type, the liquid fuel is vaporized by the heat of the combustion flame itself, and it is susceptible to the condition of the wick and the surrounding atmosphere, especially the wind. For this reason, it is difficult to detect incomplete combustion using a light-receiving element that captures the light from the combustion flame in natural vaporization combustion appliances.

<Purpose> The present invention has been made in view of the above-mentioned α, and its purpose is to stabilize the amount of light incident on the light receiving element in a liquid fuel natural vaporization type combustion appliance, and to provide a highly reliable incomplete combustion device. An object of the present invention is to provide a combustion detection device.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure shows a cross-sectional view of burner B of a natural vaporization type combustion appliance having outer cylinder 1 made of gold S according to the first embodiment of the present invention.
are a mutually concentric metal outer cylinder 1 and a metal outer flame cylinder 2
It has a triple structure of an inner flame tube 3, and the vaporized combustion mixes with air in the open chamber of the outer flame tube 2 and inner flame tube 3, and rises while burning.

Therefore, a part of the tip of the combustion flame 5 appears in the upper part of the burner B. A Z-shaped rod plate incandescent body 6 made of a heat-resistant metal is fixedly installed at the upper end of the outer cylinder 1 at a position where it is heated by the combustion flame 5. Since the incandescent body 6 emits more light than the surrounding combustion flame 5, the light receiving element 4 mainly receives the light from the incandescent body 6. A in the figure is a vertical type liquid fuel suction wick. When an oxygen deficiency state occurs in this state, the combustion force of the combustion state decreases due to the combustion mechanism unique to the natural vaporization type combustion appliance, and the amount of heat that heats the incandescent body 6 decreases. Therefore, the amount of radiation light emitted from the incandescent body 6 decreases as the temperature of the incandescent body 6 decreases, and the spectral characteristics of the light also shift toward longer wavelengths. Therefore, by detecting this change with the light-receiving element 4, abnormal combustion due to an oxygen-deficient state can be relatively easily detected even in a natural vaporization type combustion appliance.

Next, a detection circuit that detects an incomplete combustion state from the output signal of the light receiving element 4 and the light receiving probe 4 will be explained using the incomplete combustion detection circuit diagram shown in FIG. 2. PDl is a photodiode with high short wavelength sensitivity; PD2 is a photodiode with high long wavelength sensitivity, and the light receiving element 4 made of this photodiode is the photodiode PDI.

Ratio of short circuit current 11.12 flowing through PD2 (12/11)
This is a color sensor that can identify colors based on the value of . The light receiving element 4, that is, the color sensor mainly receives radiation light emitted from the incandescent body 6. Further, R1 is a fixed resistor, R2 is a variable resistor, 8 is a comparator for detecting an incomplete combustion state from the output signal of the light receiving element 4, and the photodiode PD'1. ．． Short circuit current 11.12 of PD2 is connected to resistor R1,
R2 causes voltage V1. ．． V2 and convert this voltage to V2.
i and V2 are input to one input terminal and ten input terminal of comparator 8, respectively. The resistance value of the variable resistor R2 is set to a voltage V1. when the combustion appliance is in an incomplete combustion state. V2 voltage ratio (V2/
Adjust so that Vl) becomes 1. That is, the voltage ratio (V2/Vl) is set to 1 when the oxygen concentration in the room housing the combustion appliance reaches approximately 18%. Therefore, in the above detection circuit, the temperature of the incandescent body 6 is high during normal combustion, and the amount of short wavelength light is large compared to incomplete combustion, and the output voltage 1 on the photodiode PDI side is the output voltage on the photodiode PD2 side. It's more dog than v2. As the oxygen concentration decreases, the temperature of the incandescent body 6 decreases. Accordingly, the light emitted from the incandescent body 6 shifts to the longer wavelength side.

Therefore, the voltage ratio (V 2 /V 1 ) approaches 1, and when the oxygen concentration is about 18%, the magnitude relationship between v2 and 1 is reversed. At that time, the comparator 8 operates and the warning LE
Current flows through D9 and issues a warning to the user.

Incidentally, when the LED 9 is turned on, an automatic fire extinguishing device of the combustion appliance may be activated to stop the combustion state.

FIG. 3 shows the relationship between voltage ratio (V2/Vl) and oxygen concentration. In the figure, A (actual M) is the flame 5 that burns the red-hot body 6.
The color sensor (light receiving element 4
), that is, when the present invention is used. The output characteristic (point m) is when light is directly received from the combustion flame 5, that is, according to the conventional example. The former has a large range of change, but the latter has a small range of change.
It is unstable.

FIG. 4 is a sectional view of a burner 8 section showing a second embodiment of the present invention. In this embodiment, a coiled incandescent body 6 is fixedly installed on the upper part of the inner flame tube 3 of the burner B. Note that the same parts as those in FIG. 1 are designated by the same reference numerals. The coil-shaped incandescent body 6 of this embodiment has a larger radiation area than a rod-shaped one, and the amount of radiant light that can be received by the light receiving element 4 also increases. Even when the height of the combustion flame 5 fluctuates, the temperature distribution is averaged due to the heat storage effect of the coil of the incandescent body 6, and stable light is radiated. Furthermore, since it can be installed symmetrically with respect to the center of burner B, it has the effect of having less influence on combustion.

Further, in the present invention, as the incandescent body, in addition to this coil-shaped body, a net-shaped body or a hook-shaped body are also effective.

Furthermore, in the present invention, a single light-receiving element may be used as the light-receiving element, and a detection circuit may be used to detect a decrease in the amount of radiant light from the incandescent body in an abnormal combustion state. In this case, too, the abnormal combustion is detected by the incandescent body. The end result is to obtain a sufficient change in output value.

<Effects> As is clear from the above description, the present invention provides an incandescent body provided at a position heated by the combustion flame of the burner in a liquid fuel natural vaporization type combustion appliance, and a system that emits radiant light from the incandescent body. This device includes a light-receiving element that captures light, and a detection circuit that detects an incomplete combustion state from the output signal of the light-receiving element.

Therefore, according to the present invention, it is possible to stabilize the amount of light incident on the light-receiving element in the incandescent body, and to provide a highly reliable incomplete burn detection device.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the burner section in the first embodiment of the present invention, FIG. 2 is an electric circuit diagram for detecting incomplete combustion, FIG. 3 is an output characteristic diagram of the light receiving element (color sensor), and FIG. FIG. 4 is a sectional view of the burner section of the second embodiment of the present invention. A: Liquid fuel suction wick, B: Burner, PDI: Photodiode, PD2: Photodiode, R1: Fixed resistance, R
2: Variable resistance, 1: Outer tube, 2: Outer flame tube, 3: Inner flame tube, 4
: Light receiving element, 5: Combustion flame, 6: Red-hot body, 8: Comparator, 9
: Warning LED.

Claims (1)

[Claims] In a liquid fuel natural vaporization type combustion appliance, there is a red-hot body installed at a position heated by the combustion flame of the burner, a light-receiving element that captures the radiant light from the red-hot body, and incomplete combustion based on the output signal of the light-receiving element. An incomplete combustion detection device characterized by comprising a detection circuit for detecting a state.