JPH0684117U - Combustion device - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a combustion device capable of reducing NOx, effectively preventing blow-off of a lean flame, and performing stable combustion. [Structure] Main flame mouth part (13) that forms rich flame and main flame mouth part
Secondary flame mouths (19) on both sides of (13) that form a lean flame
A burner comprising a burner consisting of (19), wherein the main flame opening surface (13a) of the main flame opening portion (13) is a secondary flame opening surface of the auxiliary flame opening portion (19).
It is characterized by being placed lower than (19a). In addition, a rising portion (23) below the step between the main flame surface and the auxiliary flame surface is provided at a part or the entire length at the outer edge portion along the longitudinal direction of the burner of each sub flame opening (19). With such a configuration, it is possible to reliably prevent the lean flame from blowing off while reducing the amount of NOx.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a combustion device capable of achieving low NOx, effectively preventing blowout of a lean flame, and performing stable combustion.

[0002]

[Prior art]

 Conventionally, one form of a low NOx burner combustion device is shown in FIG. As shown in the figure, such a combustion device includes a first air-fuel mixture chamber 53 provided in a burner body 52 having a first flame port portion 51 and wall plates 54 on both sides of the first air-fuel mixture chamber 53. A second air-fuel mixture chamber 56 having the configured second flame port portion 55, and a air-fuel mixture passage provided in the burner main body 52 that communicates the first air-fuel mixture chamber 53 and the second air-fuel mixture chamber 56. 57, a flame holding plate 58 for stabilizing the base of the flame provided between the first flame mouth portion 51 and the second flame mouth portion 55, and the second air-fuel mixture chamber 56 in the wall plate 54. It has an air intake 59 for setting the secondary air ratio.

In such a configuration, a rich flame having a low oxygen concentration is formed on the first flame port portion 51. Further, the large amount of air sucked from the air intake 59 and the air-fuel mixture supplied from the air-fuel mixture passage 57 become a lean air-fuel mixture within the combustible limit inside the second air-fuel mixture chamber 56, and the second flame port It spilled out of the part 55 and was burned by being affected by the thermal effect of the rich flame, forming a lean flame with high oxygen concentration. For the rich flame and the lean flame, the flame base was stabilized by the flame holding plate 58, and the rich and lean combustion was realized as a whole to reduce the generation of NOx.

[0004]

[Problems to be solved by the device]

 However, in the above-described combustion device, the lean flame from the second flame port 55 contains a large amount of air, so the NOx reduction effect is promoted, but on the other hand, the so-called flame disappears away from the flame port. It was supposed to be easy to cause blowout.

An object of the present invention is to provide a combustion device that can solve the above problems.

[0006]

[Means for Solving the Problems]

 The present invention is a combustion apparatus having a burner including a main flame mouth portion forming a rich flame and auxiliary flame mouth portions forming a lean flame on both sides of the main flame mouth portion. The present invention relates to a combustion device characterized in that the main flame mouth surface of the above is arranged lower than the sub flame mouth surface of the sub flame mouth part.

The present invention is also the above-mentioned structure, wherein the flame slit forming the secondary flame port extends to an end having a step with the main flame port side, and each secondary flame port. It is also characterized in that the outer edge of the section along the longitudinal direction of the burner is provided with a rising portion below the step between the main flame surface and the sub-flame surface over a part or the entire length.

Further, in the present invention, in a burner having auxiliary flame openings forming a lean flame on both sides of a main flame opening forming a rich flame, a gap between adjacent burners is set to about the full width of the burner. The present invention relates to a combustion device characterized by being set to 1/5 or less.

[0009]

【Example】

 A combustion apparatus A according to the present invention will be specifically described below with reference to examples.

1 to 3, a plurality of burner main bodies 10 are installed in parallel in a lower portion of a combustion apparatus A, and each burner main body 10 has a first mixing unit between both side walls 14 and 14. An air chamber 11 is formed, and a main flame opening 13 having a large number of flame opening slits 12 is provided on the upper surface of the burner body 10.

On both side walls 14, 14 of the burner body 10, a plurality of air-fuel mixture passages 15, 15 are provided at intervals in the longitudinal direction.

Auxiliary side walls 16 and 16 are arranged on both sides of the side walls 14 and 14 of the burner body 10 at parallel intervals. Two air-fuel mixture chambers 17 are formed.

Further, an auxiliary flame port portion 19 having a large number of flame port slits 18 is provided on the upper portion of the second air-fuel mixture chamber 17.

In addition, to explain other configurations in the illustrated embodiment, 20 is a mixture gas supply passage which is provided below the burner head 21 and communicates with the first mixture chamber 11, and 22 is a fuel gas. It is a supply pipe.

The present invention is characterized in that, in the basic structure of the burner main body 10 described above, the structure of the burner main body 10 is capable of not only reducing NOx but also reliably preventing the blowout of a lean flame. To do.

That is, in the present invention, as is most apparent from FIG. 3, the main flame opening surface 13a of the main flame opening portion 13 is arranged lower than the auxiliary flame opening surface 19a of the auxiliary flame opening portion 19 by a. .

Therefore, the main flame that emerges when the air-fuel mixture that flows upward from the flame slit 12 of the main flame port 13 is ignited has a spindle shape, and the main flame port surface 13 a of the main flame port 13 has a diameter Although it is small, it bulges out to the outermost side in the secondary flame opening surface 19a of the secondary flame opening portion 19 and becomes a large diameter.

Therefore, even if the gas is thinned as much as possible for the purpose of reducing NOx, the outside air of the lean air-fuel mixture from the auxiliary flame opening 19a to the auxiliary flame opening surface 19a is discharged from the main flame opening 13a. A part of the combustion gas can be replenished to the auxiliary flame port portion 19, and blow-off can be effectively prevented.

Further, in this embodiment, as shown in FIGS. 1 and 2, the flame opening slit 18 forming the secondary flame opening 19 extends to an end portion having a step with the main flame opening 13 side. Therefore, a part of the combustion gas can be replenished from the main flame opening 13 to the auxiliary flame opening 19 more reliably, and blowout can be prevented more effectively.

Further, in the present embodiment, as shown in FIGS. 1 and 2, the main flame mouth surface 13a and the sub flame mouth surface 19a are formed at the outer edge portions along the burner longitudinal direction of the respective sub flame mouth portions 19, 19. It is also characterized in that the rising portion 23 having a height b 1 less than or equal to the step difference is provided in part or over the entire length.

With such a configuration, the influence of the secondary air flowing between the burner main bodies 10, 10 on the lean flame on the auxiliary flame ports 19, 19 is prevented as much as possible, and the blow-off by the secondary air is prevented on this surface. Can also be prevented.

Further, in this embodiment, as shown in FIGS. 1 and 3, the gap G between the burner main bodies 10, 10 adjacent to each other is set to about 1/5 or less of the entire width W of the burner.

That is, as shown in FIG. 4, when the gap G is excessively large, the amount of the tertiary air becomes excessively large, so that the amount of the secondary air from the flame slit 18 of the auxiliary flame port 19 is increased. Fewer, less CO, but more NOx.

On the other hand, as shown in FIG. 4, when the gap G is made excessively small, the amount of tertiary air becomes excessively small, so that the amount of secondary air from the flame slit 18 of the auxiliary flame orifice 19 is increased. As a result, NOx will decrease, but CO will increase.

Therefore, in this embodiment, the gap G between the burner bodies 10 and 10 is set to an appropriate value to appropriately adjust the amount of secondary air from the flame slit 18 of the auxiliary flame port 19. Therefore, the amount of NOx will be reduced as much as possible without increasing the amount of CO.

Specifically, when the widths c, d, e of the main flame surface 13a and both auxiliary flame surfaces 19a, 19a are respectively 5 mm, the burner overall width W is 15 mm, so the burner body 10, The interval G between 10 is about 1/5, which is 3 mm or less, preferably 0.5 mm or more.

FIG. 5 shows a modified example of the above-described embodiment. In this modified example, the flame port slit 18 provided in the secondary flame port portion 19 is substantially the same as the primary flame port surface 13a and the secondary flame port. The burner body 10 can be easily manufactured because it is provided only on the auxiliary flame port surface 19a without extending to the step portion with the surface 19a.

Further, in FIG. 6, the burner body 10 has the main flame mouth surface 13 a of the main flame mouth portion 13 and the auxiliary flame mouth surface 19 a of the auxiliary flame mouth portion 19 flush with each other. And the gap G between the adjacent burner body 10 is set to 1/5 or less of the total width W of the burner to reduce NOx and CO as in the above-mentioned embodiment.

[0029]

[Effect of device]

 The present invention is a combustion apparatus having a burner including a main flame mouth portion forming a rich flame and auxiliary flame mouth portions forming a lean flame on both sides of the main flame mouth portion. The main flame mouth surface of is located lower than the sub flame mouth surface of the sub flame mouth part. Further, the outer edge portion along the longitudinal direction of the burner of each sub-flame opening is provided with a rising portion equal to or less than the step between the main flame opening surface and the sub-flame opening surface over part or the entire length. With this configuration, it is possible to reliably prevent the lean flame from blowing off while reducing the NOx amount.

Further, in a burner having sub-flame openings forming a lean flame on both sides of a main-flame opening forming a rich flame, a gap between adjacent burners is set to about 1/5 or less of the entire width of the burner. is doing. With such a configuration, the NOx amount can be reduced as much as possible without increasing the CO amount.

[0031]

[Brief description of drawings]

FIG. 1 is an overall perspective view of a burner body which is a main part of a combustion apparatus according to the present invention.

FIG. 2 is a cross-sectional perspective view of the relevant part.

FIG. 3 is a cross-sectional explanatory view showing the dimensional relationship of each part of the burner body.

FIG. 4 is a graph showing the relationship between the gap between burner bodies and the amounts of NOx and CO generated.

FIG. 5 is an explanatory diagram of a modification of the combustion device.

FIG. 6 is an explanatory diagram of a modification of the combustion device.

FIG. 7 is an explanatory view of a main part of a conventional combustion device.

[Explanation of symbols]

 A Combustion device 10 Burner body 12 Flame slit 13 Main flame 13a Main flame surface 18 Flame slit 19 Sub flame 19a Sub flame 23 Standing part

Claims (4)

[Scope of utility model registration request] Claim: What is claimed is: 1. A main flame mouth portion (13) forming a rich flame, and an auxiliary flame mouth portion (1) formed on both sides of the main flame mouth portion (13) to form a lean flame.
9) A combustion device equipped with a burner consisting of (19), wherein the main flame opening surface (13a) of the main flame opening portion (13) is separated from the auxiliary flame opening surface (19a) of the auxiliary flame opening portion (19). Combustion device characterized by being placed low. 2. A flame mouth slit (18) forming an auxiliary flame mouth portion (19).
2. The combustion apparatus according to claim 1, wherein the extension extends to an end portion having a step difference from the main flame mouth portion (13) side. 3. A rising portion (23) below the step between the main flame surface (13a) and the auxiliary flame surface (19a) is provided at the outer edge of each of the secondary flame openings (19) along the longitudinal direction of the burner. The combustion apparatus according to claim 1, wherein the combustion apparatus is provided over a part or the entire length. 4. A combustion apparatus comprising a burner having auxiliary flame openings (19) (19) forming a lean flame on both sides of a main flame opening (13) forming a rich flame. Combustion device characterized in that the gap (G) between them is about 1/5 or less of the full width of the burner.