JPH05256417A - Combustion device - Google Patents

Abstract

PURPOSE:To decrease the generation of CO and smell caused by blow-off in burning. CONSTITUTION:A mixing chamber 26 is formed so that the upstream side near a carburetor 21 is deep, and shallow as growing further apart from the carburetor 21. The bottom surface of a terminal portion of a burner head 25 is blocked off with the mixing chamber 26. Accordingly, the speed of premixed gas blown out from the terminal portion of the burner head 25 can be controlled to reduce blow-off of flames.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention uses a liquid fuel as a fuel,
The present invention relates to a combustion device used for a water heater, a heater, etc.

[0002]

2. Description of the Related Art Conventionally, a combustion apparatus of this type has a structure as shown in FIG. As shown in the figure, reference numeral 1 denotes a vaporizer in which a heater 3 is embedded, a vaporization chamber 4 is provided inside, and a heat receiving fin 2 for receiving combustion heat on the burner head 5 side is provided. Reference numeral 5 is a burner head in which primary flame ports 16 and secondary ports 15 are alternately arranged and are connected to the lower side surface of the carburetor 1. A mixing chamber 6 forms a flow path through which the premixed gas flows from the vaporization chamber 4 to the burner head 5, and a flow diverter 7 is fixed inside the igniter 14 at a position slightly on the carburetor side. A fuel nozzle 8 is located in the primary air passage 12, and its tip faces the inside of the vaporization chamber 4. A fuel pump 9 is connected to the fuel tank 10 on the suction side and to the fuel nozzle 8 on the discharge side. A blower fan 11 is connected to the primary air flow path 12 on the discharge side. A secondary air passage 13 is connected to the blower fan 11 on the inlet side (not shown) and communicates with the secondary port 15 on the outlet side. The lower surface of the secondary port 15 is closed and a large number of small holes are provided on the upper surface. The lower surface of the primary flame port 16 is open and communicates with the space inside the mixing chamber 6, and the upper surface is provided with a large number of small holes.

In the above structure, when the heater 3 is energized and the vaporizer 11 reaches a predetermined temperature, the fuel pump 9 and the blower fan 11 are operated, and the fuel in the fuel tank 10 is fed from the fuel nozzle into the vaporization chamber 4 and The primary air is the primary air passage 12
And is supplied to the inside of the vaporization chamber 4. The fuel contacts the inner wall of the vaporizer 1 heated by the heater 3, vaporizes and mixes with the primary air in the vaporization chamber 4, becomes a premixed gas, and passes from the lower portion of the vaporization chamber to the inside of the mixing chamber 6 to pass through the primary chamber. It is ejected from a small hole into the combustion chamber 17 through the opening at the lower end of the flame port 16 and is ignited by the igniter 14 to start combustion. The secondary air passes from the secondary air passage 13 through the inside of the secondary port 15 and is ejected from the small holes on the upper surface to promote combustion.

[0004]

However, in the above-mentioned conventional structure, the deflector 7 for diverting the flow of the premixed gas is provided, but the burner head 5 has the uniform depth of the mixing chamber 6. As shown by the broken line in FIG. 5, the ejection speed of the premixed gas ejected from the primary flame port 16 of the burner head is high at the end portion of the burner head, and flame blowout occurs.
There was a problem that odor was generated.

The present invention solves the above-mentioned problems by adjusting the passage area in the mixing chamber so as to adjust the ejection speed of the premixed gas from the primary flame port to eject the premixed gas at the burner head end portion. It is intended to suppress CO and reduce CO and odor.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is configured such that the shape of a mixing chamber is deep on the carburetor side and shallow as it goes away from the carburetor, and the lower surface of the terminal end of the burner head is closed. It is the one.

[0007]

According to the present invention, the premixed gas supplied from the vaporizer is gradually increased in the flow passage resistance of the mixing chamber in the process of flowing into the primary flame opening of the burner head through the mixing chamber. Therefore, the ejection speed from the primary flame port becomes almost uniform.
Since the lower part is closed in the vicinity of the terminal end of the burner head, the supply amount of the premixed gas is suppressed and the ejection speed is reduced. Therefore, the blow-off of flame is suppressed, and the generation of CO and the generation of odor are reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1 and FIG. 2, 21 is a vaporizer and is a heater 23.
Is provided, and a vaporization chamber 24 is provided inside, and a heat receiving fin 22 for receiving combustion heat is provided on the burner head 25 side. Reference numeral 25 is a burner head in which primary flame ports 36 and secondary ports 35 are alternately arranged, and are connected to the lower side surface of the carburetor 21. Reference numeral 26 denotes a mixing chamber which forms a flow path through which the premixed gas flows from the vaporizing chamber 24 to the burner head 25. The closer to the vaporizer 21, the deeper, and the shallower as the distance from the vaporizer 21 increases. The lower surface of the burner head 25 is closed. 28 is a fuel nozzle 1
It is located in the next air passage 32, and its tip faces the inside of the vaporization chamber 24. A fuel pump 29 is connected to the inside of the fuel tank 30 on the suction side and to the fuel nozzle 28 on the discharge side. A blower fan 31 is connected to the primary air passage 32 on the discharge side.
A secondary air passage 33 is connected to the blower fan 31 on the inlet side (not shown) and communicates with the secondary port 35 on the outlet side. The lower surface of the secondary port 35 is closed and a large number of small holes are provided on the upper surface. The lower surface of the primary flame port 36 is open and communicates with the space inside the mixing chamber 36, and the upper surface is provided with a large number of small holes.

In the above structure, when the heater 23 is energized and the vaporizer 21 reaches a predetermined temperature, the fuel pump 29 and the blower fan 21 are operated, and the fuel in the fuel tank 30 is transferred from the combustion nozzle into the vaporization chamber 24 and The primary air is supplied into the vaporization chamber 24 through the primary air passage 32. The fuel comes into contact with the inner wall of the vaporizer 21 heated by the heater 23, vaporizes and mixes with the primary air in the vaporization chamber 24 to become a premixed gas, and passes from the lower portion of the vaporization chamber to the interior of the mixing chamber 26, where it passes through the primary flame. The igniter 3 is ejected from the small hole into the combustion chamber 37 through the opening at the lower end of the mouth 36.
It is ignited by 4 and starts combustion. Secondary air passes from the secondary air passage 33 through the inside of the secondary port 35 and is ejected from the small holes on the upper surface to promote combustion. The heat source for vaporizing the fuel is all supplied by the heater 23 until the combustion is started, but when the combustion is started, the heat receiving fins 22 are heated by the combustion flame, and most of them are supplied by the combustion heat with a small electric power. The vaporization and combustion of fuel can be continued.

At this time, the premixed gas supplied from the lower end of the vaporization chamber 24 into the mixing chamber 26 flows through the inside of the mixing chamber 26 from the upstream side to the downstream side and into the primary flame port 36 communicating with the upper side. Also flows out into the combustion chamber 37 through a small hole opened on the upper surface of the primary flame port 36, but if the depth of the mixing chamber 26 is uniform, the primary flame hole 3 is generated due to the dynamic pressure due to the flow velocity of the premixed gas.
The amount of gas flowing in 6 is small on the upstream side (vaporizer side) and large on the downstream side, resulting in non-uniform combustion flame. Further, the amount of jetting at the end portion of the burner head 25 increases, and the flame is easily blown off, which causes CO and odor.

According to the configuration of the present invention, since the mixing chamber 26 gradually becomes shallower from the upstream side to the downstream side, the resistance applied to the flow of the premixed gas gradually increases, and
The amount of the premixed gas flowing through the secondary flame hole 36 increases, and the downstream side is suppressed, so that it can be made substantially uniform. In addition, the lower surface of the end portion of the burner head 25 is connected to the end portion 27 of the mixing chamber.
By closing at 1, the amount of supply to the end portion of the primary flame port 36 becomes smaller than the other portions, and the distribution becomes as shown by the solid line in FIG. Therefore, the flame blow-off phenomenon that is likely to occur at the end portion of the burner head 25 due to the lower temperature than other portions is suppressed, and the generation of CO and odor due to incomplete combustion can be reduced.

The lower surface of the end of the burner head 25 can be closed by a separate component, but the number of components can be reduced by using a part 27 of the mixing chamber 26.

[0013]

As described above, according to the combustion apparatus of the present invention, the following effects can be obtained. (1) By making the shape of the mixing chamber deeper on the carburetor side and shallower as it goes away from the carburetor, the distribution of the ejection speed of the premixed gas from the primary flame mouth portion becomes substantially uniform, and the flame can be made uniform. (2) With the configuration in which the lower surface of the terminal end portion of the burner head is closed, the ejection amount of the premixed gas at the terminal end portion of the burner head is suppressed, and the generation of CO and odor due to blown flame can be reduced.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part of a combustion apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the device.

FIG. 3 is a cross-sectional view of a conventional combustion device.

FIG. 4 is a cross-sectional view of the device.

FIG. 5 is a comparison diagram of jet velocity distributions of premixed gas jetted from the primary flame nozzle in the present invention and the conventional combustion apparatus.

[Explanation of symbols]

 21 vaporizer 23 heater 25 burner head 26 mixing chamber

Claims (1)

[Claims] 1. A vaporizer for vaporizing fuel, a burner head connected to a lower side wall of the vaporizer, and a gas passage from the vaporizer to the burner head formed under the burner head. A bottom mixing chamber, the depth of the mixing chamber is deeper near the bottom of the carburetor and becomes shallower as it moves away from the carburetor, and the lower surface of the terminal end of the burner head is closed. Combustion device.