JP3220768B2 - Burner device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion cylinder provided concentrically at a radial interval in a cylindrical case projecting into a heating furnace, and a combustion cylinder extending along a central axis of the combustion cylinder. A main burner opening to the rear area, an annular air supply passage formed between the main burner and the cylindrical case and communicating with the combustion cylinder, and an annular air supply passage formed between the combustion cylinder and the cylindrical case. The present invention relates to a burner device having an annular secondary air passage communicating with an air supply passage.

[0002]

2. Description of the Related Art Such a burner device is disclosed in JP-B-63-663.
It is known from Japanese Patent Publication No. 3806, and the amount of NOx generated is reduced by making the secondary air flow passing through the secondary air passage asymmetrical with respect to the central axis of the burner device (deviation). For this purpose, a shielding plate projecting into the secondary air passage is provided at the tip of the combustion cylinder, or the combustion cylinder is provided eccentrically in the cylindrical case. However, in the former case where the tip of the combustion cylinder is narrowed to form a nozzle, it is impossible to provide a shielding plate, and the shielding plate may be exposed to high temperatures and deformed or burnt out. In the latter case, the structure for supporting eccentricity becomes complicated.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a burner device capable of imparting a drift to secondary air with a simple structure.

[0004]

According to the present invention, there is provided, in accordance with the present invention, a shield provided in an annular secondary air passage to close a portion of an arc.

[0005]

According to the present invention, the annular secondary air passage is blocked by a shield in a part of the circular arc area, so that a secondary flow is imparted to the secondary air, and the eccentricity causes shading at the tip of the nozzle of the combustion cylinder. The amount of NOx generated can be reduced by performing the secondary combustion. Further, since the shield is provided in the secondary air passage and is cooled by the secondary air, there is no risk of deformation or burning. In addition, since this shield is configured as a bracket for receiving weight, it can also have a function of supporting the combustion cylinder on the cylindrical case.

[0006]

FIG. 1 shows an example of a regenerative burner device.
A combustion tube 3 protruding into the heating furnace 1 and concentrically surrounded at a radial interval by a cylindrical case 2 connected to the end of the radiant tube is made of metal or ceramic and distributed on the peripheral wall thereof. It has a plurality of holes 4, the tip of which is narrowed to form a nozzle 5. A main burner 6 penetrates the furnace wall along the central axis of the combustion tube 3 and
And has a nozzle 7 at its tip, forming a nozzle tip. Fuel gas is supplied to a rear area outside the furnace of the main burner 6 through a fuel gas connection port 8. An eccentric pilot burner 9 extends parallel to the main burner 6. An air guide tube 10 which extends rearward of the cylindrical case 2 and coaxially to the outside of the furnace is provided with an air supply chamber 12 having a combustion air connection port 11.
Open to. The annular air supply passage 13 formed between the main burner 6 and the air guide tube 10 is provided with a plurality of annular heat storage elements 14 along the axis. These heat accumulators 14 are made of, for example, ceramics and have many axial pores of about 1 mm. Around the area of the combustion tube 3 having the hole 4, a protective tube 20 made of ceramics is provided at a radial interval. An annular secondary air passage 16 formed between the combustion cylinder 3 and the cylindrical case 2 communicates with the annular air passage 13. In the rear area of the combustion tube 3, the secondary air passage 16 covers a part of an arc-shaped area, for example, 30 to 40% of the entire cross-sectional area, by the arc-shaped shield 15 (FIG. 2).
Is blocked by The shield 15 also serves as a metal fitting for supporting the combustion tube 3 in the cylindrical case 2.
A hole 23 is provided in the end wall 22 that closes the rear end of the combustion cylinder 3, and communicates the combustion cylinder 3 with the air supply passage 13.
The end wall 22 also serves to support the ends of the main burner 6 and the pilot burner 9 penetrating therethrough.

[0007] The regenerative burner device shifts from a heat storage operation to a combustion operation. The fuel gas supplied from the fuel connection port 8 and ejected from the nozzle 7 of the main burner 6 is preheated while passing from the air connection port 11 through the air supply chamber 12 to the regenerator 14 in the air guide cylinder 10 and is supplied with air. The primary air entering the combustion cylinder 3 from the passage 13 performs stable primary combustion through the pilot burner 9. A part of the primary combustion gas is injected through the hole 4 of the combustion cylinder 3 into the annular space between the combustion cylinder 3 and the protection cylinder 20, and the primary combustion is performed by the secondary air supplied from the secondary air passage 16. Then, the secondary air containing the primary combustion gas causes the primary combustion gas ejected from the nozzle 5 of the combustion cylinder 3 to undergo secondary combustion.

In this case, the shield 1 is provided in the secondary air passage 16.
Because of the presence of 5, no secondary combustion of the primary combustion gas that exits from the hole 4 and reaches between the protective cylinder 20 and the combustion cylinder 3 occurs at this point. On the other hand, in places where the shield 15 does not exist, the secondary combustion of the primary combustion gas coming out of the hole 4 is performed.
Thus, partial combustion is performed, and the amount of generated NOx is reduced.

More importantly, as shown in FIG. 3, when the primary combustion gas exiting from the nozzle 5 of the combustion cylinder undergoes secondary combustion here, due to the action of the shield 15, the zone X having a high air concentration is obtained. And a zone Y where the fuel concentration is high.
Accordingly, in the range following the end of the combustion cylinder 3, the primary combustion gas discharged from the nozzle 5 is subjected to concentration combustion, and the generation amount of NOx is reduced. Thus, the amount of generated NOx can be reduced to 30 ppm.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along a central axis of a burner device according to the present invention.

FIG. 2 is a front view of a secondary air passage having a shield.

FIG. 3 is a view for explaining combustion of a burner device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating furnace 2 Cylindrical case 3 Combustion cylinder 6 Main burner 13 Air supply passage 15 Shield 16 Secondary air passage

──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsuyuki Nakanishi 1-chome, Kawasaki-dori, Mizushima, Kurashiki-shi, Okayama Pref. 1-chome (without address) Kawasaki Steel Corporation Mizushima Works (56) References JP-A-50-150933 (JP, A) JP-A-4-90406 (JP, A) JP-A-62-134410 (JP, A) A) Japanese Utility Model Showa 51-69924 (JP, U) Japanese Utility Model Showa 61-149616 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23D 14/22 F23D 14/70 F23D 14 / 12 F23C 11/00

Claims (2)

(57) [Claims] 1. A combustion cylinder (3) provided concentrically at a radial interval in a cylindrical case (2) protruding into a heating furnace (1), and a central axis of the combustion cylinder (3). A main burner (6) extending along and opening to the rear area of the combustion cylinder; and an annular ring formed between the main burner (6) and the cylindrical case (2) and communicating with the combustion cylinder (3). An annular air supply passage (13) formed between the air supply passage (13) and the combustion tube (3) and the cylindrical case (2);
And an annular secondary air passage (1) in the rear area of the combustion tube (3).
6) A burner device, comprising: a shield (15) for closing a part of the circular arc range. 2. The burner device according to claim 1, wherein the shield (15) is also used as a bracket for supporting the rear area of the combustion tube (3) in the cylindrical case (2). .