JPS636774B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion safety device, and more particularly to a combustion safety device that can prevent oxygen deficiency accidents and carbon monoxide poisoning accidents caused by the use of combustion devices.

In recent years, as housing structures have become more airtight, ventilation in living rooms has deteriorated, leading to an increase in oxygen deficiency accidents and carbon monoxide poisoning accidents caused by open gas water heaters and indoor exhaust heaters. In order to prevent such carbon monoxide poisoning accidents, conventional methods have used the phenomenon that the pilot flame of combustion equipment lifts up when there is a lack of oxygen to detect the lifted flame with a thermocouple, and The fuel supply valve is closed in response to a change in the electromotive force of the pair, thereby cutting off the supply of fuel gas. This type of device has the advantage of having a simple structure and being inexpensive, but on the other hand, the types of gas that can be used are limited to propane gas and natural gas, and in cities that contain large amounts of hydrogen and carbon monoxide. Gas has a problem in that lift-up is difficult to occur, making it difficult to apply.

Therefore, in order to solve this problem, a solid electrolyte that generates voltage due to the difference in oxygen concentration is installed in the exhaust gas downstream of the flame, and when the flame is deficient in oxygen, the flame extends and covers the solid electrolyte, creating an oxygen-deficient state. A method to detect this has been developed and is in use. In this method, a tube-shaped stabilized zirconia coated with Japanese gold electrodes on the inner and outer surfaces is installed in the exhaust gas flow downstream of the flame.
A voltage is generated by bringing indoor air with a high oxygen content into contact with the inner surface of the solid electrolyte and with combustion exhaust gas having a low oxygen content with the outer surface. According to such a device, when there is a lack of oxygen, the flame extends, further increasing the oxygen-deficient state on the outer surface of the solid electrolyte and increasing the generated voltage.This generated voltage is detected and the control circuit is activated. It can be driven to close the safety valve. However, since this type of device has a cylindrical sensor, it has the advantage of being able to separate the rich oxygen and dilute oxygen atmosphere by itself, but on the other hand, because it is installed in the exhaust gas air stream upstream of the flame, it does not produce flames like Bunsen flames. Burners with large fluctuations have the disadvantage that the voltage output is unstable, and because they are formed into a cylindrical shape, they are relatively expensive.

SUMMARY OF THE INVENTION An object of the present invention is to provide a combustion safety device that can prevent carbon monoxide poisoning accidents caused by incomplete combustion in gas combustion equipment when there is insufficient oxygen indoors.

An embodiment of the combustion safety device according to the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 indicates a main burner, and a main fuel supply pipe 2 is connected to the main burner 1, and the end of the pipe is not shown, but is connected to a gas supply source. A gas supply valve 3 is installed on the main fuel supply pipe 2, and the gas supply valve 3 is opened and closed by, for example, a solenoid valve.

Further, an auxiliary burner 4 is arranged on the side of the main burner 1, and the auxiliary burner 4 and the gas supply valve 3
and is connected via a fuel supply branch pipe 5.

Further, above the auxiliary burner 4, a rectifying plate 6 is installed horizontally toward the main burner 1, and this rectifying plate 6 has, for example, three flame holes 7a, 7b, 7c in the horizontal direction. is drilled. Further, a sensor support plate 8 extends diagonally forward from the end of the rectifying plate 6 on the main burner 1 side, and a sensor mounting groove 9 is formed in this sensor support plate 8. A plate-shaped oxygen sensor 10 is housed and held therein. This oxygen sensor 10 is made of stabilized zirconia molded into a plate shape.
It is arranged so that a side facing the main burner 1 side and a back side 10b facing the auxiliary burner 4 side. Both surfaces of the stabilized zirconia constituting the oxygen sensor 10 are coated with electrodes such as platinum.

The oxygen sensor 1 is mounted on the front surface of the sensor support plate 8.
A side plate 12 is provided with a window 11 such that the side 10a of the side plate 10 is exposed, and the back side of this side plate 12 contains the oxygen sensor 10 and forms an exhaust path 14 as an extension of the flame hole 7c. An exhaust guide tube 15 is attached.

The output end of the oxygen sensor 10 is connected to a control device 17 via a signal line 16, and the control device 17 and the electromagnetic valve of the gas supply valve 3 are connected via a signal line 18. .

Since the combustion safety device according to the present invention is configured as described above, the fuel gas is supplied to the main burner 1 by opening the gas supply valve 3 at the start of combustion.
The fuel is supplied to the auxiliary burner 4 and ignited by an ignition device (not shown).

The flame F formed on the burner port of the main burner 1 comes into contact with the front surface 10a of the oxygen sensor 10 through the window 11, and its temperature is increased and the surface in contact with the flame F becomes oxygen-depleted. On the other hand, the flame S formed on the burner port 4a of the auxiliary burner 4 is
collides with the lower surface of the flame holes 7a and 7b to form flames. However, under normal conditions when the oxygen concentration is high, combustion is completed at flame holes 7a and 7b, and combustion is completed at flame holes 7c.
No flame will form in the area. Therefore, air with a high oxygen concentration rises in the exhaust guide tube 15 from the flame hole 7c due to natural convection, creating a state of high oxygen concentration on the back surface 10b of the oxygen sensor 10. Therefore, both surfaces 10a of the oxygen sensor 10
There is a large difference in oxygen concentration between and 10b,
Generates a large electromotive force. This large electromotive force maintains the gas supply valve 3 in an open state through the control device 17, thereby creating a continuous combustion state.

However, when the oxygen concentration in the indoor air decreases, the flame S from the auxiliary burner 4 lifts up, moves along the rectifying plate 6 toward the left in the figure, and a flame appears above the flame hole 7c. The combustion gas rises inside the exhaust guide cylinder, diluting the oxygen concentration on the surface 10b side of the oxygen sensor 10. As a result, the difference in oxygen concentration between the two surfaces 10a and 10b of the oxygen sensor 10 becomes smaller, and the electromotive force generated by the oxygen sensor 10 also becomes smaller. Therefore, the gas supply is stopped by transmitting this change in electromotive force to the control device 17 and fully closing the gas supply valve 3.

As is clear from the above description, according to the present invention, a plate-shaped oxygen sensor is disposed on one side of the main burner flame to generate an electromotive force based on the difference in oxygen concentration on both sides, and the auxiliary burner is activated when oxygen is deficient. The exhaust gas from the flame is guided to the rear side to reduce the difference in oxygen concentration, and this output change quickly cuts off the supply of fuel gas to the main burner and auxiliary burner. Carbon monoxide poisoning caused by incomplete combustion can be prevented. Furthermore, since a plate-shaped sensor is used, an inexpensive oxygen deficiency prevention safety device can be provided. Furthermore, since a system is adopted in which the electromotive force decreases when oxygen is depleted, the control device can use a single standard for opening or closing the gas supply valve, thereby simplifying the control circuit.

[Brief explanation of the drawing]

The figure is a front sectional view showing an embodiment of the combustion safety device according to the present invention. DESCRIPTION OF SYMBOLS 1... Main burner, 3... Gas supply valve, 6... Rectifier plate, 7a, 7b, 7c... Flame hole, 10... Oxygen sensor, 12... Side plate, 14... Exhaust path, 15...
...Exhaust guide pipe.

Claims (1)

[Claims] 1 In a device in which fuel gas is supplied to the main burner and the auxiliary burner via a gas supply valve,
A plate-shaped oxygen sensor that generates an electromotive force due to the difference in oxygen concentration on both sides is placed at a position exposed to the flame of the main burner, while multiple flame holes are provided at the position where the flame of the auxiliary burner collides. Place the rectifier plate,
A combustion safety device characterized in that a part of the flame hole near the main burner and the rear side of the oxygen sensor are connected through an exhaust guide tube.