JPS6131768B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is designed to reduce oxygen concentration when the oxygen concentration in the air decreases, resulting in an oxygen-deficient state, and when combustion in the main burner deteriorates due to heat exchanger fin clogging, causing incomplete combustion. Regarding combustion safety devices that prevent carbon monoxide poisoning by stopping the gas supply to the burner based on a signal from a detection element that detects a decrease in concentration, the combustion safety device is especially attached to a burner installed at the bottom of an open combustion chamber. Regarding equipment.

Conventionally, various types of burners have been proposed to detect a decrease in oxygen concentration. As a burner that can detect oxygen deficiency even in gases with high combustion speeds such as city gas, the present inventors separated a part of the outer flame that contributes to flame stability, and in case of oxygen deficiency, We proposed a method for detecting oxygen deficiency using the blow-off of the primary flame (Japanese Patent Application Laid-open No. 134137/1982).

In this way, there are pilot burners that can detect oxygen deficiency phenomena for all gas types, but in this case, the pilot burner primary air hole is the length of the pilot burner's primary air hole at the flame opening ( In other words, it is located approximately 100 mm below the bottom end of the combustion chamber, and is in a position unrelated to the flow of exhaust overflow caused by clogged fins, making it impossible to prevent incomplete combustion due to clogged fins in the heat exchanger.

In addition, as a method to deal with the case where incomplete combustion occurs due to clogging of the heat exchanger fins, exhaust gas in the heat exchanger is recirculated through a pipe from the heat exchanger and returned to the primary air of the pilot burner. A system has been proposed (Japanese Unexamined Patent Publication No. 117343/1983) that contaminates the air in the mixed gas to promote changes in the flame, detects the difference, and then stops the gas supply.

The proposed method for detecting incomplete combustion due to heat exchanger fin clogging had problems with assembly and gas conversion, as the two parts, the heat exchanger and the pilot burner, were connected by installing a bypass pipe. .

The present invention is an improvement on the former of the conventional examples described above in order to solve the above problems, and one embodiment of the present invention will be described below with reference to the drawings.

The figure shows an example of a gas instant water heater, where 1 is the pilot burner body used in the present invention, and the inner cylinder 2 is the pilot burner body used in the present invention.
The inner cylinder 2 has an inner cylinder flame hole 4 at its tip, a primary air hole 6 near the gas jet of the nozzle 5, and an inner cylinder 2 above the primary air hole 6. An outer cylinder 3 is attached so as to surround the flame hole 4. In addition, the outer cylinder 3 has an outer cylinder flame hole 7 at the tip,
An auxiliary air hole 8 is provided in the lower part below the inner cylinder flame hole 4, and around the outer cylinder 3, there is a hole in the burner body to form a passage for supplying air to the auxiliary air hole 8 and the primary air hole 6. Air inflow cylinder 10 with an inflow port 9 above
is attached. This inlet 9 is connected to the main burner 1
When the heat exchange fins 12a, which are set near 1 and installed at the top of the heat exchanger combustion chamber 12, become clogged and the combustion exhaust gas overflows from the lower end of the heat exchanger 12,
It is located in the part of the combustion exhaust gas stream. Reference numeral 13 indicates an operating knob, which controls the first valve 14 and the second valve 1.
The first valve 14 is a push type electromagnetic valve, and 17 is its electromagnetic coil. This electromagnetic coil 17 is the oxygen deficiency detection pilot burner 1.
It is connected to a thermocouple 18 for detecting the primary flame A formed in the flame hole 4 of the inner cylinder. 19 is a nozzle for the main burner, and B is a secondary flame formed in the outer cylinder flame hole 7.

In the above configuration, the first valve 14 is first opened by pushing and turning the push-and-turn knob 16, and gas is guided to the nozzle 5 of the oxygen deficiency detection pilot burner 1, and the gas ejected from the nozzle 5 is the primary air. It is mixed with the primary air sucked through the hole 6 in the inner cylinder 2. At this time, the primary air is supplied as primary air from the air inlet 9 along the inner and outer cylinders while cooling the inner and outer cylinders 2 and 3. On the other hand, auxiliary air flows in from the auxiliary air hole 8 provided in the outer cylinder 3 and is supplied to the gas mixed in the inner cylinder 2, where the igniter (not shown)
When ignited, a primary flame A is formed in the inner cylinder flame hole 4. Here again, auxiliary air flows in from the air inlet 9 along the inner and outer cylinders 2 and 3. At this time, by cooling the inner and outer cylinders 2 and 3, abnormal heating of the primary flame hole is reduced, making it difficult to back up. Next, the unburned gas in the inner cylinder flame hole 4 is ejected from the outer cylinder flame hole 7 of the outer cylinder 2, obtains air from the surroundings, that is, secondary air, and burns to form a secondary flame B.

Now, in this pilot burner that detects oxygen deficiency, which is separated into primary and secondary flames, if a thermocouple 18 is installed above the primary flame A, fresh air is supplied from the air inlet 9 during normal combustion. Since a stable flame temperature is detected, the first valve 14 remains open even if the electromagnetic coil 17 of the first valve 14 is energized and the pressing operation of the operating knob 16 is released. The shortage detection pilot burner 1 continues combustion. Thereafter, when the operating knob 16 is further turned, the second valve is opened and gas is supplied to the main burner 11, which is ignited by the secondary flame B of the oxygen deficiency detection pilot burner 1 and starts combustion.

After that, if the oxygen concentration in the room decreases for some reason, primary flame A will blow out, and
Since the electromotive force of the thermocouple 18 detecting the next flame A decreases, the excitation of the electromagnetic coil 17 is released, and the first valve 1
4 is closed, gas supply is stopped and all combustion is stopped to ensure safety.

Furthermore, even if the oxygen concentration in the room is normal, if the heat exchange fins 12a provided at the top of the heat exchanger combustion chamber 12 become clogged due to reasons such as long-term use of the appliance, the combustion The necessary air flow is from the lower end of the heat exchanger combustion chamber 12 to the fin section 12a.
The combustion exhaust gas has become polluted air with a low oxygen concentration. When supplied to the hole 7, the primary flame A shows a so-called oxygen deficiency phenomenon and blows off, and the thermocouple 1 detecting the primary flame A
Since the electromotive force of 8 decreases, the electromagnetic coil 17 is de-energized, the first valve 14 is closed, and the gas supply is stopped to ensure safety.

As explained above, according to the present invention, not only when the oxygen concentration in the room has decreased, but also when the main burner is incompletely burnt due to clogging of the heat exchanger fins, the gas supply can be stopped before such a situation occurs. It provides an extremely safe device that can be shut down.
Moreover, in order to be able to handle any kind of gas, the flame is separated into upper and lower stages to detect oxygen deficiency.The simple structure is that an air inflow cylinder is installed in the separate flame burner, which detects oxygen deficiency by separating the flame into upper and lower stages. A parallel air flow is formed to cool the inner and outer cylinders, and it is possible to take measures against the primary flame pack, and also to stop the gas supply before ∞ is generated from the main burner due to clogging of the heat exchanger fins, etc.

[Brief explanation of the drawing]

The figure is a configuration diagram of a gas instantaneous water heater equipped with a combustion safety device in one embodiment of the present invention. 1...Pilot burner body, 2...Inner cylinder, 3
...Outer cylinder, 4...Inner cylinder flame hole, 6...Primary air hole,
7... External flame hole, 8... Auxiliary air hole, 9... Air inlet, 10... Air inflow cylinder, 11... Main burner, 12... Heat exchanger combustion chamber, 13... Operation trick , 14...first valve, 15...second valve, 16
...Operation knob, 17...Electromagnetic coil, 18...
Thermocouple, A...Primary flame, B...Secondary flame.

Claims (1)

[Claims] 1. A pilot burner that separately forms a primary flame and a secondary flame, and a detection element such as a thermocouple that detects the primary flame, and the pilot burner has an inner cylinder facing vertically and an outer cylinder. It has a double configuration with a cylinder, with the upper end opening of the inner cylinder serving as the primary flame hole, and the primary air hole being provided in the middle of the inner cylinder at an appropriate distance below the primary flame hole.
Surrounding the primary flame hole with an outer cylinder so as to restrict secondary air from being supplied to the primary flame formed in the secondary flame hole,
The upper end opening of the outer cylinder, which is located an appropriate distance above the primary flame hole, is used as the secondary flame hole, and an air inflow cylinder is positioned at intervals on the outer periphery of this outer cylinder, and the lower end of the air inflow cylinder is A combustion safety device characterized in that the inner cylinder is closed on the upstream side of the primary air hole, and its upper end is opened near the secondary flame hole of the outer cylinder to serve as an air inlet to the primary flame. 2. In a combustion device that sucks indoor air and releases combustion exhaust gas indoors, a main burner is provided at the lower end opening of an open combustion chamber with both upper and lower ends open, and a pilot burner is provided near the main burner.
The combustion safety device according to claim 1, wherein the air inlet of the air inlet cylinder is set near the lower end of the combustion chamber. 3 The lower end of the outer cylinder is closed between the primary air hole and the primary flame hole of the inner cylinder, and an auxiliary air hole is provided in a part of the lower part of the outer cylinder below the primary flame hole. The combustion safety device according to item 1 or 2. 4. The combustion safety device according to any one of claims 1 to 3, wherein when the detection element detects blow-off of the primary flame, the valve of the gas supply path to the burner is closed to stop combustion.