JPH081286B2 - Heat storage burner - 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 which is concentrically provided at intervals in the radial direction in a cylinder projecting into a heating furnace and has a plurality of holes distributed on its peripheral wall. A main burner extending along the central axis and opening to the rear region of the combustion tube, a heat storage body provided in the combustion air supply passage of the main burner, and a pilot burner eccentrically provided in parallel with the main burner. The present invention relates to a heat storage type burner having.

[0002]

2. Description of the Related Art A combustion cylinder, which is concentrically provided at a radial interval in a cylindrical body protruding into a heating furnace and has a plurality of holes distributed on a peripheral wall, extends along a central axis of the combustion cylinder. And a main burner that opens to the rear area of the combustion cylinder, and through a hole in the combustion cylinder, a part of the primary combustion gas that is ejected into the annular space between the combustion cylinder and the surrounding simple body, A burner is known in which secondary air supplied to the annular space is mixed with the mixed gas to secondary-combust the remaining portion of the primary combustion ejected from the tip of the combustion cylinder.
No. 11534). In this burner, first, in the annular space between the combustion chamber and the cylinder, a part of the secondary combustion of the primary combustion gas ejected from the holes of the combustion cylinder is carried out, and further the primary combustion gas is ejected at the tip of the combustion cylinder. Since the secondary combustion is performed, in other words, the secondary combustion is performed in two stages, the secondary combustion is performed gently, the flame temperature is lowered, and accordingly, the amount of NOx generated is reduced.

Two regenerative burners, which project into the heating furnace and have a regenerator in the combustion air supply passage, are alternately operated for combustion and heat storage, and one of the regenerative burners operating for combustion causes the other by the combustion exhaust gas. It is also known to heat the heat storage body of the heat storage type burner described above and preheat the air supplied to the other heat storage type burner, which is now burning by switching, by the heat stored in the heat storage body (Japanese Patent Application Laid-Open No. HEI-2) -25421
No. 0). Thus, the heat efficiency can be improved by recovering the waste heat.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to protect the pilot burner from overheating due to high temperature combustion waste gas, and to extend its life.

[0005]

According to the present invention, in order to solve this application, at least the area of the pilot burner existing in the combustion air supply passage is surrounded by an air guide tube. Cooling air is passed through.

[0006]

As described above, according to the present invention, the pilot burner is surrounded by the air guide tube, and is cooled by the cooling air passing through the air guide tube at least during the combustion operation of the regenerative burner and during the heat storage operation. Even when the cooling air is not passed through, the air is not exposed to high-temperature combustion waste gas because of the air guide tube, so the pyro- burner, especially its electrode and the insulator, are effectively protected from overheating.

[0007]

[Embodiment] In FIG. 1, a cylindrical body 2 protruding into a heating furnace 1
The combustion cylinder 3 concentrically surrounded with a radial interval by is made of metal or ceramics, has a plurality of holes 4 distributed on its peripheral wall, and its tip is narrowed to form a nozzle 5. . The main burner 6 penetrates the furnace wall along the central axis of the combustion tube 3 and opens to the rear area of the combustion tube 3,
The tip has a nozzle 7 and forms a nozzle chip. Fuel gas is supplied to a rear region of the main burner 6 outside the furnace via a fuel gas connection port 8. Eccentrically, a pilot burner 9 extends parallel to the main burner 6. The air guide cylinder 10 which extends rearward of the cylinder 2 coaxially with the rear of the cylinder 2 includes a combustion air connection port 1
It is opened to the air supply chamber 12 having 1. The annular air supply passage 13 formed between the main burner 6 and the air guide cylinder 10 is provided with a plurality of annular heat storage bodies 14 along the axis. These heat storage bodies 14 are made of, for example, ceramics and have many axial pores of about 1 mm.
Around the area of the combustion cylinder 3 having the holes 4, protective cylinders 15 made of ceramics are provided at intervals in the radial direction.
A hole 18 is formed in the end wall 17 that closes the rear end of the combustion cylinder 3 supported in the cylindrical body 2 in the range of the rear end via the metal fitting 16.
Is provided. The end wall 17 also serves to support the tips of the main burner 6 and the pilot burner 9 which penetrate the end wall 17. The pilot burner 9 is surrounded by an air guide tube 19 in a region existing in the combustion air supply passage 13 and the air supply chamber 12, and is cooled through an air connection port 20 at an end protruding from the air supply chamber 12. Air for supply is supplied. The end wall at the tip of the air guide tube 19 surrounds the pilot burner 9 with a small annular gap 21.

In the embodiment of FIGS. 2 and 3, the air guide tube 19
The rear end ends in the air supply chamber 12, and the air supply chamber 1
The opening 22 to 2 is provided with a check valve 23 which is opened by the air flowing into the air supply passage 13 from the combustion air connection port 11. Therefore, during the combustion operation of the regenerative burner, the combustion burner 9 is cooled by the combustion air supplied to the air supply chamber 12. Since the check valve 23 is closed during the heat storage operation of the heat storage type burner, the high temperature combustion waste gas coming from the heating furnace 1 does not enter the air guide tube 19.

The pilot burner 9 shown in FIG. 4 has a tip 41 which ends in substantially the same end face as the main burner 6.
From the tip 41 of the pilot burner 9 to the rear as far as possible, from the opening 43 in the air guide tube 19 to the insulator 4
A pin electrode 45 for ignition and flame detection, which is insulated and supported by 4, slightly projects into the burner tube 42. The electrode 45 is drawn to the outside via a conductor 47 insulated by an insulator 46. The tip of the fuel gas supply pipe 48 for the pilot burner, which is concentrically provided in the burner pipe 42 and extends in the axial direction, ends before the electrode 45, and the burner pipe 4
It is supported within 2. The fuel gas supply pipe 48 for the pilot burner is connected to the fuel gas source in order to constantly maintain the pilot flame in the pyro burner 9. An annular air passage 49 formed between the fuel gas supply pipe 48 for the pilot burner and the burner pipe 42 is also connected to an air source different from the main burner 6. The air guide tube 19 described above
The air connection port 20 can also be connected to this other air source.

FIG. 5 shows such a regenerative burner 25, 2
The connection diagram of the heating device which performs waste heat recovery operation using two 5'is shown. The air conduits 26, 26 'connected to the air connection ports of the regenerative burners 25, 25' whose tips project into the heating furnace 1 are connected to the air inlet valve 28 or an exhaust fan as an air source via the air switching valve 27. 29 can be selectively connected. Similarly, heat storage type burners 25, 2
Gas conduits 3 respectively connected to 5'fuel gas connection ports
0 and 30 'can be connected to a gas source (not shown) via a gas switching valve 31 and a gas cutoff valve 32.

[0011]

In FIG. 5, the switching valves 27 and 31 are in the switching positions shown in the figure, and the regenerative burner 25 burns.
It is assumed that the heat storage type burner 25 'or the heat storage type is operating. The fuel gas supplied through the gas conduit 30 and ejected from the main burner 6 is supplied from the air conduit 26 to the regenerative burner 25 and passes through the heat storage body 14 in the air supply passage 13 to pass through the primary air holes of the end wall 17. It mixes with the primary air entering the combustion cylinder 3 from 18, and is ignited by the pilot flame of the pilot burner 9 to perform stable primary combustion in the combustion cylinder 3.
A part of the primary combustion gas is ejected into the annular space between the combustion cylinder 3 and the protection cylinder 15 through the hole 4 of the combustion cylinder, and is passed from the supply passage 13 between the combustion cylinder 3 and the cylinder body 2. Then, secondary combustion is performed by the secondary air supplied, and the secondary air containing the secondary combustion gas causes the remaining portion of the primary combustion gas ejected from the nozzle of the combustion cylinder 3 to perform secondary combustion.

The combustion gas generated by the primary combustion and the secondary combustion radiates heat in the heating furnace 1, enters the regenerative burner 25 'at a temperature of about 1000 ° C., and radiates to the heat storage body 14 in the air supply passage 13. After that, it is discharged to the outside through the exhaust fan 29 through the air conduit 26 'and the switching valve 27.

Since the pilot burner 9 is surrounded by the air guide tube 19, the regenerative burner 2 for storing heat is used.
The electrode 45 and the insulators 44, 46 in the 5'pyroto burner 9 are not exposed to the high temperature combustion waste gas coming from the heating furnace 1, and the soot or carbon particles in the combustion waste gas are not exposed to the insulator 44. It also does not reduce the insulation resistance.

After 30 seconds to 2 minutes, the switching valves 27 and 31 are switched, and the regenerative burner 25 'now burns and the regenerative burner 25 carries out regenerative operation. Regenerative burner 2
The air passing through the 5'heat storage body 14 is about 800 to 900
It is preheated to ℃ and used for primary and secondary combustion.

In the above-described embodiment, the combustion gas is blown into the heating furnace from the regenerative burner for direct heating, but it is also possible to perform the indirect heating by passing the combustion gas through the radiant tube extending into the heating furnace. In this case, as shown in FIG. 6, the cylindrical bodies 2 of both heat storage burners 25 and 25 'are
It is connected to both ends of a radiant tube 2'extending in the heating furnace 1. Since the operation of the heat storage type burner itself is the same as that of the embodiment of FIG. 5, its explanation is omitted.

[Brief description of drawings]

FIG. 1 is a sectional view taken along the axis of an embodiment of a regenerative burner according to the present invention.

FIG. 2 is a sectional view taken along the axis of another embodiment.

3 is a cross-sectional view taken along the line III-III in FIG.

FIG. 4 is a cross-sectional view taken along the axis of the main part of the pilot burner.

FIG. 5 is a connection diagram of a heating device including two regenerative burners.

FIG. 6 is a connection diagram of a heating device comprising two regenerative burners connected to a radiant tube.

[Explanation of symbols]

 1 Heating Furnace 2 Cylinder 3 Combustion Cylinder 4 Hole 6 Main Burner 9 Pilot Burner 13 Combustion Air Supply Passage 14 Heat Storage Body 19 Air Guide Tube

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location F23D 14/76 (72) Inventor Katsuyuki Nakanishi 1-chome, Mizushima Kawasaki-dori, Kurashiki City, Okayama Prefecture (No street number) Kawasaki Steel Co., Ltd. Mizushima Steel Works (72) Inventor Nikohiko Nakagawa 1-chome, Mizushima Kawasaki-dori, Mizushima Kurashiki City, Okayama Prefecture Kawasaki Steel Co., Ltd. Mizushima Steel Works

Claims (2)

[Claims] 1. A at a radial distance is provided concentrically within the cylindrical body which projects into the heating furnace (1) in (2) and multiple peripheral wall
A combustion cylinder (3) formed by distributing a number of holes (4), a main burner (6) extending along the central axis of the combustion cylinder (3) and opening to the rear region of the combustion cylinder, A heat storage body (14) provided in the combustion air supply passage (13) of the main burner (6) and a pilot burner (9) eccentrically provided in parallel with the main burner (6), The range of the pilot burner (9) existing in the combustion air supply passage (13) is the air guide tube (1
A regenerative burner, characterized in that it is surrounded by 9) and cooling air is passed through this air guide tube (19). 2. The combustion air supply passage (13) is provided with an air guide pipe (19) in the rear region thereof via a check valve (23) which is opened by air flowing into the combustion air supply passage.
2. The regenerative burner according to claim 1, characterized in that it opens into an air supply chamber (12) following the rear end of the burner.