JPH0360006B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a combustor used in a heater or the like.

Conventional technology In recent years, home heating appliances that utilize combustion heat have been developed to gasify liquid fuel and burn it inside a box case, using a convection blower installed at the rear, due to increasing awareness of ease of use, comfort, and energy savings. Warm air type devices that blow hot air to heat the room are becoming mainstream. Even for hot air type combustion engines, increasing awareness of indoor pollution has led to demands for cleaner combustion exhaust gas, and various combustion methods have been developed and improved.

An example of a conventional combustor will be described below with reference to the drawings.

In FIG. 3, reference numeral 1 denotes a vaporization cylinder that vaporizes fuel, premixes it with combustion air, and supplies it to the combustion section, and a burner body 2 is placed on the top. The burner body 2 is formed with a narrow part 3 integrally drawn at the bottom and a plurality of elongated flame holes 4 forming combustion parts 5 on the side wall. Reference numeral 6 denotes a pressure equalizing plate disposed in the burner body 2 so as to cover the narrow part 3, and has a plurality of small holes 6.
It has a. Reference numeral 7 designates a perforated cylinder provided in close contact with the outer peripheral side wall of the burner body 2, stretched so as to cover the plurality of flame holes 4, and made of wire mesh or a porous material. 8 is a burner cap that closes the upper end opening of the burner body 2. The porous tube 7 stretched over the outer peripheral wall of the burner body 2 has its lower end covered with the flange portion 1a of the vaporizing tube 1, and its upper end covered with the bent edge 8a of the burner cap 8.
It has come to be supported in close contact with the Reference numeral 9 denotes a sheathed heater embedded in the upper part of the vaporization cylinder 1, which is configured to maintain the temperature of the vaporization cylinder 1 above a certain constant temperature. Numeral 10 is a bolt/nut that fixes the burner cap 8 to the burner body 2. Reference numeral 11 denotes a burner ring disposed in a ring shape from below around the burner body 2 so as to cover the combustion part 5. A pore 11a (burner ring) is provided below the burner ring 11 so that air flows between the burner body 2 and the burner ring 11. 11 is a bottomless cylinder, an opening is provided at the bottom of the ring. 12 is a burner case disposed to cover the carburetor 1 from below; 13 is a combustion tube disposed above the burner case 12 to cover the combustion section 5; A secondary air hole 13a is provided for supplying secondary air. A portion of the air from a convection blower (not shown) that supplies warm air to the outer periphery of the combustion tube 13 is semi-forced from the secondary air hole 13a of the combustion tube 13. It's summery. 14 is a nozzle for supplying fuel, and 15 is an air pipe for supplying primary combustion air.

In the above configuration, fuel injected into the vaporization cylinder 1 by a pump or the like is heated to a high temperature by a sheathed heater 9. It is vaporized in the vaporization cylinder 1 and premixed with combustion air sent into the vaporization cylinder 1 by a blower or the like. This premixed vaporized gas enters the burner body 2 through the narrow part 3 of the burner body 2 and the small hole 6a of the pressure equalizing plate 6, and enters the burner body 2 through the flame hole 4 in the outer peripheral wall.
More gushing. In addition, this premixed vaporized gas is almost uniformly mixed during its passage, and when an ignition means such as a discharge spark of an ignition electrode is provided near the flame hole 4, combustion starts and the burner body 2
A flame is formed in the flame hole 4. And this flame
The combustion occurs while being supplied with secondary air as shown by arrow a from the secondary air hole 13a of the combustion tube 13, and is protected by the burner ring 11 from being affected by the direct wind (arrow b) from the secondary air hole 13a. ing. The generated combustion exhaust gas then flows upward to the combustion tube 13, mixes with the indoor air flow from the convection blower, and is discharged forward as warm air for heating.

Problems to be Solved by the Invention However, the conventional configuration described above has the following problems. That is, the secondary air to the combustion section 5 is supplied to the flame hole of the burner body 2 through the secondary air hole 13a of the combustion tube 13 by the blowing pressure of the convection blower and the combustion draft, and through the air hole 11a below the burner ring 11. 4 and the other from the periphery from above the burner ring 11.

When combustion is high, the former and latter secondary air supplies are required as combustion air, but when combustion is low, combustion is completed only with the former secondary air supply, and the latter secondary air supply makes almost no contribution as combustion air. In many cases, the flame was disturbed instead, and if too much secondary air was supplied in the former case, it could cool or disturb the flame, resulting in incomplete combustion and the production of large amounts of toxic carbon monoxide. . Therefore, if the combustion section 5 is covered too much with the burner ring 11 in order to make the flame difficult to disturb during low combustion, there is a problem that during high combustion, secondary air becomes insufficient and incomplete combustion occurs.

Also, during high combustion, the burner ring 11 itself is heated to a high temperature in terms of calorific value, and it does not cool down even if the flame comes into contact with it, so there is no problem, but during low combustion, the temperature of the burner ring 11 itself is low in terms of calorific value, and if the flame touches it, it will cool down. This tends to cause incomplete combustion. Therefore, even if you increase the amount of secondary air passing through the pores 11a of the burner ring 11 to prevent the flame from spreading too much, the secondary air may cause the flame to is easily cooled and disturbed. Therefore, if the height of the burner ring 11 is lowered so that even if the flame extends, it will be located above the upper end of the burner ring 11, the flame will be disturbed by the secondary air supplied from above around the burner ring 11. This causes incomplete combustion. The problem is that it is extremely difficult to supply secondary air in a well-balanced manner from high combustion to low combustion to achieve complete combustion without cooling or disturbing the flame.

The present invention was made in view of the above-mentioned problems, and aims at stabilizing combustion and cleaning combustion exhaust gas.

Means for Solving the Problems In order to solve the above problems, the combustor of the present invention has the following features:
A burner ring is provided to cover the combustion section, and a shielding plate is provided between the air circulation section at the bottom of the burner ring and the secondary air hole of the combustion cylinder.

Effect The present invention has the above-described configuration, so that the secondary air hole supplied from the secondary air hole of the combustion cylinder once collides with the shielding plate and is weakened, and then flows along the inner wall of the combustion cylinder, and is combusted according to the combustion draft. Only the amount necessary for this purpose is drawn to and supplied to the combustion section. Therefore, during high combustion, sufficient secondary air is supplied, and
During low combustion, there is no need to cool or disturb the flame, resulting in stable combustion from high combustion to low combustion, and the exhaust gas is clean.

Embodiment A combustor according to an embodiment of the present invention will be described below with reference to the drawings.The same parts as in the conventional example will be given the same numbers and explanations will be omitted, and only the different parts will be explained. In the figure, 16 is a ring-shaped shielding plate provided between the burner ring 11 and the secondary air hole 13a of the combustion tube 13, which is placed on the burner case 12 and is integrated with the burner ring 11. It is connected to. The upper end of this shielding plate 16 is formed at approximately the same height as the bottom wall of the burner ring 11.

Therefore, according to the above configuration, the secondary air supplied from the secondary air hole 13a of the combustion section 13 once collides with the shielding plate 16, its force is weakened, and the combustion tube 1
3, but some of it flows along the inner wall of the burner ring 11 due to the combustion draft.
A part of the fuel is supplied to the combustion section 5 from around the upper part of the burner ring 11.

When the combustion is high, the combustion draft is strong, so a large amount of secondary air is drawn to the combustion section 5, and when the combustion is low, the combustion draft is weak, so the secondary air is not drawn to the combustion section 5 so much and rises as it is. Put it away. In other words, during high combustion, burner ring 1
A large amount of secondary air is supplied to the combustion section 5 from the upper periphery of the pores 11a and the burner ring 11 and is used effectively. Also, during combustion, burner ring 1
Only the secondary air supplied through the pores 11a of 1 is supplied to the combustion part 5 according to the combustion draft,
The rest flows upward along the inner wall of the combustion tube 13 as it is, and complete combustion occurs without cooling or turbulence of the flame. Furthermore, since excess secondary air is isolated from the combustion section 5, the generation of nitrogen oxides due to combustion heat can be reduced accordingly.

Effects of the Invention As described above, according to the present invention, secondary air is supplied to the combustion section according to the combustion draft,
It is possible to prevent secondary air shortage during high combustion and flame turbulence and cooling during low combustion. That is,
Secondary air can be supplied in a well-balanced manner from high combustion to low combustion to achieve complete combustion.
Not only CO/CO2 but also the production of nitrogen oxides due to the heat of combustion can be reduced, the cleanliness of exhaust gas will be greatly improved, and combustion will be stable over a long period of time. be.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view of a main part of a combustor according to an embodiment of the present invention, FIG. 2 is a sectional view of the entire combustor, and FIG. 3 is a sectional view showing a conventional combustor. DESCRIPTION OF SYMBOLS 1... Carburizer tube, 2... Burner body, 5... Combustion part, 11... Burner ring, 11a... Stomata,
12... Burner case, 13... Combustion tube, 13a
...Secondary air hole.

Claims (1)

[Claims] 1. A vaporization tube that vaporizes fuel, premixes the vaporized gas and combustion air, and supplies the mixture to the combustion section, a burner body that is placed on top of the vaporization tube and has a combustion section on its outer circumferential wall, and A burner case arranged to cover the cylinder from below, a burner ring that covers the combustion part in a ring shape from below around the burner body and has an air circulation part such as a pore in the bottom wall, and a combustion part in the upper part of the burner case. a combustion tube which covers the burner ring and has a secondary air hole for combustion in the vicinity of the combustion section, and a shielding plate is provided between the air circulation part of the burner ring and the secondary air hole of the combustion tube, The shielding plate is set in a position in the combustor such that air flowing in from the secondary air cylinder of the combustion tube flows bypassing the shielding plate.