JPS5855286Y2 - Forced vaporization burner fire backflow prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that prevents the flame of a forced vaporization burner that forcibly vaporizes and burns liquid fuel from flowing back into the secondary air passage used for combustion.

In a conventional forced vaporization burner, as illustrated in FIG. 1, a secondary air supply passage 3 is formed between a carburetor 1 constituting the burner body and a combustion tube 2 surrounding it. Then, the vaporizer 1 is preheated with the heater 4, and the vaporization chamber 5 is heated with the heat.
The liquid fuel supplied to the vaporizer 1 is forcibly vaporized, and the vaporized fuel and primary air supplied from the air chamber 6 formed at the bottom of the vaporizer 1 are transferred from the vaporization chamber 5 to the nozzle hole 7.
The mixture of fuel and primary air collides with the equalizing plate 9 covering the upper surface of the mixing chamber 8 and is blown out from the burner plates 1 and 10 to form the carburetor 1. Secondary air is supplied from the passage 11 formed in the center and the passage 3 to stably burn the air-fuel mixture, and a part of this combustion heat is recovered by the heat recovery section 12 provided at the upper end of the carburetor 1. was used as a vaporization heat source, and vaporization and combustion of the liquid fuel was continued even after the heater 4 was stopped.

However, the outer circumferential surface of the carburetor 1 and the inner surface of the combustion tube 2 are not formed of smooth surfaces, and vortices may occur in the secondary air flowing through the passage 3 formed between the two. , between the upper end of the carburetor 1 and the combustion tube 2, that is, because the secondary air discharge port is formed relatively large, the flame flows along the outer peripheral surface of the carburetor 1 into the passage 3. Sometimes there was reflux.

If the flame flows backward in this way, the reverse flow of flame also heats the vaporizer, causing abnormal heating of the vaporizer 1, and the heat receiving surface of the heat recovery section 12, which reaches the highest temperature, is melted and damaged, preventing the desired heat receiving from occurring. There was a drawback that the function was lost and flame backflow was more likely to occur as the heat recovery section 12 was eroded.

The purpose of the present invention is to overcome these conventional drawbacks and protect the vaporizer by preventing flame from flowing backwards by increasing the flow velocity of secondary air while having an extremely simple configuration. It is.

Hereinafter, the present invention will be explained in detail with reference to an illustrated embodiment.

Fig. 2 shows an embodiment of the present invention, in which 20 is a vaporizer constituting the main body of the burner, in which a heater 21 is embedded and fixed, and a fuel nozzle (not shown) is exposed inside the vaporizer. A chamber 22 is formed.

23 is a mixing chamber formed above the vaporization chamber 22, and the compartment 2
2.23 are formed in communication via a nozzle hole 24.

Reference numeral 25 denotes a uniform plate with a large number of small holes, which is connected to the mixing chamber 23.
A burner plate 26 having an air-fuel mixture outlet is superimposed on the upper surface of this uniform plate 25.

27 is a combustion tube that covers the outer periphery of the carburetor 20, and an annular passage 28 formed between the combustion tube 27 and the carburetor 20 is connected to an air chamber 29 formed at the bottom of the carburetor 20. This allows air supplied from the air pipe 30 to flow out and be supplied above the vaporizer 20 from the passage 28 .

The air chamber 29 is also formed in communication with a central passage 31 that runs vertically through the center of the vaporization chamber 22 and the carburetor 20, and allows primary air to flow into the vaporization chamber 22 while at the same time supplying secondary air from the central passage 31. It is possible to do so.

Furthermore, a heat recovery section 3 is formed at the outlet of the annular passage 28 from the end surface of the combustion tube 27 to the outer periphery of the upper end of the carburetor 20.
In the forced vaporization burner having the above configuration, a ring-shaped partition plate 33 hanging down toward the outer circumferential surface of the fuel cell 2 is provided, and the air outlet is narrowed by this partition plate 33. The fuel is vaporized in the vaporization chamber 22 and ejected into the mixing chamber 23 from the injection hole 24 together with the primary air that has flowed in from the air chamber 29 .

The air-fuel mixture injected into the mixing chamber 23 collides with the uniform plate 25 to be further mixed, and is blown out from the burner plate 26 under the rectifying action of the uniform plate 25, and is ignited by an ignition device (not shown).

Further, the secondary air flowing from the air chamber 29 into the annular passage 28 and the central passage 31 flows through these passages 28 .
31 and joins with the burning air-fuel mixture to promote its combustion.

When such secondary air is supplied, a vortex is generated in the annular passage 28 due to the shapes of the carburetor 20 and the combustion tube 27, and the burner plate 26 is caused by this vortex.
The flame formed above tries to flow back, but the outlet of the passage 28 is constricted by the partition plate 33 as described above.

For this purpose, a heat recovery section 3 formed at the upper end of the vaporizer 20
Since the secondary air passes above 2 at high speed and forms a so-called convection flow, the narrowing of the air outlet by the partition plate 33 prevents the flame from flowing back into the passage 28.

Therefore, there is no risk that the heat recovery section 32 will fall into an overheated state, and an accident of melting and damage of the heat recovery section 32 can be prevented.

Although there is a possibility that the secondary air may form a vortex inside the central passage 31, an air plate 34 is provided at the upper end of this passage 31 to rectify the secondary air and prevent the backflow of the flame. Therefore, flame does not flow back into this passage 31.

By the way, the forced vaporization burner 35 with such a configuration is
It is incorporated into the water heater etc. illustrated in FIG.

In FIG. 3, 36 is a hot water tank covered with a cover 37 and a heat insulating layer 38, and a water supply pipe 41 equipped with a water supply valve 39 and a pressure reducing valve 40 is connected to the bottom of the tank, and the water supplied from this pipe 41 is is brought into contact with the bottom surface of the tank 36 heated by the burner 35 to produce hot water, and this hot water is guided from a safety valve 42 provided at the top of the tank 36 to a hot water supply pipe 43 branched out, and a faucet 45 equipped with a hot water supply valve 44.
It is recommended that you take it out.

46 is a fuel pipe that supplies fuel to the forced vaporization burner 35, and 47 is an exhaust pipe of the burner 35.

As described above, in the present invention, in order to supply secondary air, the heat recovery section has an annular passage formed by the carburetor and the combustion tube, and the outlet is formed from the end of the combustion tube to the upper end of the vaporizer. Although it has an extremely simple configuration of constricting with a ring-shaped partition plate that hangs down toward the outer circumferential surface of the flame, it can significantly increase the flow velocity of secondary air flowing into the flame part, without significantly impairing the secondary air supply characteristics. Since it is possible to prevent the flame from flowing back into the passage without causing the flame to flow back into the passage, there is no risk of the vaporizer becoming overheated, and in particular, it is possible to prevent the surface of the heat recovery section, etc., which reaches the maximum temperature, from being melted and damaged. The durability of this type of forced vaporization burner can be increased.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main parts of a conventional forced vaporization burner, FIG. 2 is a sectional view of the main parts of an embodiment of the forced vaporization burner equipped with a flame backflow prevention device according to the present invention, and FIG. The figure is a schematic cross-sectional view of a water heater to which the present invention is applied. 20... vaporizer, 22... vaporization chamber, 2
3... Mixing chamber, 26... Burner plate l~, 27... Combustion cylinder, 28... Annular passage, 32... Heat recovery section, 33...
・Partition board.

Claims (1)

[Scope of utility model registration request] A burner plate that forms a vaporization chamber and a mixing chamber inside a vaporizer forming a burner body, and mixes the liquid fuel vaporized in the vaporization chamber with primary air in the mixing chamber to form the upper surface of the vaporizer. In a forced vaporization burner in which secondary air for combustion is blown upward from a burner plate from an annular passage formed between a vaporizer and a combustion tube, the upper end of the vaporizer is 1. A flame backflow prevention device for a forced vaporization burner, characterized in that a ring-shaped partition plate facing the outer circumferential surface of a heat recovery section formed in the section is suspended from an end section of the combustion tube.