JP3848081B2 - Combustion device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combustion apparatus used in a heater such as a fan heater, a hot water heater, and a hot water boiler, and more particularly, to a spark rod that blows an ignition spark to a fuel gas.
[0002]
[Prior art]
Conventionally, this type of vaporization type combustion apparatus is provided with a fuel injection nozzle 6 facing the inside from a side wall of a bottomed cylindrical vaporizer 1 and heating the sheathed heater 2 embedded in the vaporizer 1. The fuel sprayed in the gas is vaporized, and the vaporized gas of the fuel ejected from the flame hole 10 of the burner head 9 is converted between the spark rod 14 ′ (shown by a one-dot chain line in FIG. 3) and the burner head 9. I was ignited by high pressure discharge.
[0003]
[Problems to be solved by the invention]
However, in this prior art, the dimension A between the spark rod tip 14'a and the burner head 9 is set to the discharge limit dimension C or less, and the portion other than the spark rod tip 14'a (the straight portion 14'b) and the burner are set. The spark rod 14 'is disposed so that the dimension B' between the head 9 and the heat recovery unit 12 that is electrically conducted is separated from the discharge limit dimension C by more than the discharge limit dimension C, and discharge is performed from a portion other than the spark rod tip 14'a. Since the discharge is surely performed only from the tip of the spark rod 14 ′, the tip of the spark rod 14 ′ is consumed due to repeated discharge over a long period of use, and the dimension A between the burner head 9 However, it was separated beyond the discharge limit dimension C, and an ignition error occurred without discharging.
[0004]
The life of the parts of the spark rod 14 ′ itself due to the consumption of the tip of the spark rod 14 ′ comes earlier than the product life of the combustion device itself. This would put a burden on the user and repair shop.
[0005]
[Means for Solving the Problems]
The present invention focuses on this point and solves the above problems. In particular, in claim 1, the structure is provided so as to be electrically conductive with the burner head having a plurality of flame holes and in the vicinity of the flame holes. A spark rod that generates sparks for ignition between the auxiliary discharged part and the burner head; and an igniter that applies a high voltage to the spark rod, wherein the spark rod includes a spark rod tip and the burner head. The dimension B between the auxiliary discharge part and at least a part of the portion other than the spark rod tip is less than or equal to the discharge limit dimension C. In addition, it is arranged so as to be equal to or larger than the dimension A, and normally, discharge ignition is performed at a position of the dimension A between the spark rod tip and the burner head, and the burner head tip Said the at least part of the portion other than the spark rod end that said to allow the firing at the position of the dimension B between the auxiliary the discharge portion during exhaustion.
[0006]
As a result, even when the spark rod tip is consumed and the dimension A between the burner head and the discharge limit dimension C is greater than or equal to the discharge limit dimension C, the portion other than the spark rod tip and the burner head can be electrically connected. Since the dimension B between the discharge part and the discharge target part is set to be equal to or less than the discharge limit dimension C, the auxiliary discharge part can be discharged and ignited from a part other than the tip of the spark rod.
[0007]
According to a second aspect of the present invention, a vaporizer for vaporizing liquid fuel is provided on the upstream side of the burner head, and the auxiliary discharged part is connected to the vaporizer so as to be able to conduct heat, and heat is emitted from a combustion flame to the vaporizer. It was configured with a heat recovery unit that recovered.
[0008]
Thereby, since the heat recovery unit is used as the auxiliary discharged part, it is not necessary to newly provide the auxiliary discharged part.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment according to the present invention will be described with reference to the drawings.
[0010]
Reference numeral 1 denotes a bottomed cylindrical vaporizer. Reference numeral 2 denotes a sheathed heater for heating the vaporizer 1 to a temperature at which liquid fuel can be vaporized. The sheathed heater is embedded in the upper part of the vaporizer 1 in a substantially annular shape. Reference numeral 3 denotes a combustion fan that blows air to the burner case 4 and supplies primary combustion air and secondary combustion air, and is vaporized from a venturi-shaped primary air intake 5 that is opened in the side wall of the vaporizer 1 in the burner case 4. Combustion primary air is supplied into the vessel 1 and secondary air is ejected from around the vaporizer 1 on the upper surface of the burner case 4. Reference numeral 6 denotes a fuel injection nozzle provided to the inside of the carburetor 1 through the combustion primary air intake 5. Reference numeral 7 denotes a fuel pump that pumps fuel to the fuel injection nozzle 6. An oil receiving tray 8 receives fuel from a fuel tank (not shown) so as to be maintained at a constant liquid level.
[0011]
A burner head 9 is mounted on and fixed to the upper portion of the carburetor 1, and a plurality of flame holes 10 are opened on the side wall of the burner head 9, and the inner periphery of the side wall is in close contact with the burner head 9. A rectifying net 11 is provided. Reference numeral 12 denotes a ring-shaped heat recovery section (auxiliary discharge target section) standing upright on the outer periphery of the burner head 9 and recovering the combustion heat by conducting it to the vaporizer 1 and recovering it. The input of is reduced. A temperature sensor 13 is attached to the outer periphery of the carburetor 1 to detect the temperature of the carburetor 1 and is connected to a control device (not shown) to determine whether the carburetor 1 has reached a temperature at which fuel can be vaporized. To detect. The burner head 9, the heat recovery part 12, the burner case 4, and the vaporizer 1 are electrically connected without being insulated.
[0012]
Reference numeral 14 denotes a spark rod which is ignited by being driven by a control device when the temperature of the carburetor 1 reaches a temperature at which fuel can be vaporized. The spark rod is electrically insulated from the burner case 4 via an insulator 15. In addition, the igniter ground 17 connected to the igniter 16 that generates a high voltage is connected to the burner case 4 that is electrically connected to the burner head 9.
[0013]
The spark rod 14 has its linear portion 14a spaced apart from the heat recovery portion 12 by a dimension B that is equal to or less than the discharge limit C, and extends on the heat recovery portion 12 toward the flame hole, with the tip portion 14b facing obliquely downward. The dimension A between the tip 14b and the burner head 9 is set to be shorter than the dimension B between the heat recovery part 12 and the straight part 14a of the spark rod 14. .
[0014]
Here, the relationship between the discharge distance and the discharge voltage is proportional as shown in FIG. 2, and the discharge voltage in this embodiment is about 18 kV. As a specific example, the spark rod tip 14b and the burner are illustrated. The shortest dimension A between the head 9 is 4 mm, the shortest dimension B between the spark rod straight part 14b and the heat recovery part 12 is 7 mm, and the discharge limit dimension C of this embodiment is 10 mm.
[0015]
Here, reference numeral 14 'shown in FIG. 3 by a one-dot chain line is a conventional spark rod as described in the section of the conventional example, and the specific dimensions of this conventional example are illustrated. The shortest dimension A between the head 9 is 4 mm, and the shortest dimension B between the spark rod linear portion 14 ′ b and the heat recovery unit 12 is 15 mm, which is larger than 10 mm of the discharge limit dimension C.
[0016]
Next, after the preheating is started and the sheathed heater 2 is turned on, when the temperature sensor 13 attached to the carburetor 1 detects that the fuel vaporization temperature has been reached, the control device detects the combustion fan 3 and The drive of the fuel pump 7 is started, and the fuel injected into the carburetor 1 from the fuel injection nozzle 6 collides with the inner surface of the carburetor 1 and is vaporized to become a mixed gas mixed with the combustion air and from the flame hole 10 to the burner head. 9 is ejected outward, and the igniter 16 is driven to ignite by a discharge spark at a position of a dimension A between the tip 14a of the spark rod 14 and the burner head 9, which is the shortest dimension.
[0017]
When the device is used for a long period of time, the spark rod 14 is shortened as shown by a one-dot chain line in FIG. When the shortest dimension A between the spark rod tip 14b and the burner head 9 becomes longer than the shortest dimension B between the spark rod straight part 14a and the heat recovery part 12, the spark rod straight part 14a and It is discharged and ignited at the position of the shortest dimension B between it and the heat recovery unit 12.
[0018]
Thus, even if the tip 14b of the spark rod 14 is consumed and shortened and no discharge occurs at the position of the shortest dimension A between the spark rod tip 14b and the burner head 9, the spark rod linear portion 14a and heat recovery are performed. Since the discharge is performed at the position of the shortest dimension B with respect to the portion 12, the life of the spark rod 14 itself is significantly extended and lengthened, and the durability up to the product life of the combustor itself can be ensured. This saves time and does not place an extra burden on the user.
[0019]
【The invention's effect】
As described above, according to the present invention, even if the tip of the spark rod is consumed and exceeds the discharge limit distance, the discharge is ignited at other portions, so the life of the spark rod itself is significantly extended and lengthened. , The durability of the combustor itself up to the end of its product life can be ensured, the labor of replacing parts can be saved, and the service call caused by poor ignition due to the consumption of the spark rod can be eliminated. It is what you have.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.
FIG. 2 is a diagram showing a relationship between a discharge distance and a discharge voltage in the same embodiment.
FIG. 3 is a diagram for explaining a difference between the same embodiment and a conventional example.
[Explanation of symbols]
1 Vaporizer 9 Burner head 12 Heat recovery part (auxiliary discharge part)
14 Spark rod 14a Spark rod linear portion 14b Spark rod tip 16 Igniter

Claims (2)

A burner head having a plurality of flame holes, an auxiliary discharged part provided to be conductive with the burner head in the vicinity of the flame hole, and a spark rod for generating an ignition spark between the burner head, An igniter that applies a high voltage to the spark rod, and the spark rod is arranged such that a dimension A between the spark rod tip and the burner head is equal to or less than a discharge limit dimension C, and other than the spark rod tip The dimension B between at least a part of the auxiliary discharge part and the auxiliary discharged part is arranged so as to be not more than the discharge limit dimension C and not less than the dimension A. Usually, the spark rod tip part and the burner head Discharge ignition at a position of dimension A between, and at least a part of the portion other than the spark rod tip when the burner head tip is consumed and the auxiliary discharge target portion Combustion apparatus being characterized in that to allow the firing at the position of the dimension B between. A heat recovery unit that includes a vaporizer that vaporizes liquid fuel upstream of the burner head, and that is connected to the auxiliary discharger so that heat can be transferred to the vaporizer and recovers heat from a combustion flame to the vaporizer. The combustion apparatus according to claim 1, which is configured.

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