JP2807165B2 - Oxygen burner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen burner for heating and melting an object, and more particularly, to a coke oven, a converter,
The present invention relates to a compact and high-efficiency oxygen burner capable of spraying a powdery refractory in a molten or semi-molten state to an inner wall damaged portion such as a degassing tank.

[0002]

2. Description of the Related Art Refractories of the inner walls of industrial kilns used in steelmaking plants such as coke ovens, converters, and degassing tanks are worn and deteriorated during use of the furnaces. In order to reduce the unit consumption, part of the worn and degraded parts is regularly repaired by thermal spraying of powdered refractories in the middle stage of the operation period. An oxygen burner is required to perform the thermal spray repair, and an oxygen burner as shown in FIG. 5 is generally used. It consists of burning a fuel gas (such as LNG or LPG) with a separately supplied oxygen-containing gas to melt and remove slag, metal, etc. attached to the repaired part, and then transporting the powdered refractory through the same flow path as LNG or LPG. A method is adopted in which the material is melted or semi-molten by the heat of combustion, and is sprayed to the worn portion of the furnace wall refractory to be fused. More specifically, the oxygen burner 3 shown in FIG. 5 will be described. First, fuel gas and oxygen are supplied to melt and remove slag, metal, and the like attached to the repaired portion, and then refractory powder (including some metal powder)
2 is supplied from the hopper 1 using the fuel gas 11 as a carrier gas and supplied to the oxygen burner 3. Then, the oxygen-containing gas 12 is supplied to the oxygen burner 3 by another route, and the fuel gas 11 is supplied to a burner nozzle (not shown).
And the oxygen-containing gas 12 are mixed to form the flame 4.
The high energy of the flame 4 melts the refractory powder 2,
The molten refractory is sprayed and attached to the wear portion 5 of the furnace wall refractory. FIG. 4 shows a side cross section of the oxygen burner 3,
The structure is such that fuel gas is supplied from the center of the nozzle and oxygen is supplied from the outer periphery of the nozzle, and the angle θ of the ejection hole is determined so that oxygen is discharged slightly inward to improve mixing with the fuel gas. Have been.

By the way, a degassing immersion pipe, in which an oxygen burner as described above must be inserted into a very narrow part,
Regarding repair of coke oven walls, etc., (1) the flame length is limited and it must be very short, about 200 to 300 mm; (2) collision of the refractory powder to be sprayed on the brick surface Due to the advantages of reducing the speed and reducing the rebound loss of the spray material, strict requirements are imposed on the oxygen burner used, such as the need to increase the flame width.

[0004]

However, in order to shorten the flame length with the above-described known oxygen burner, it is necessary to increase the angle θ of the hole for discharging oxygen from the outside to the inside. If the point is not stable and an appropriate θ that stabilizes the flame is selected, there is a drawback that the flame becomes longer (300 mm or more). further,
When supplying oxygen from the outside to the inside of the fuel gas flow path, an elongated jet-type flame is inevitably formed, the collision speed of the spray material against the furnace wall increases, and the rebound loss of the spray material is large The oxygen burner is suitable for use in a wide place, but is inconvenient in a narrow place.

In view of such circumstances, an object of the present invention is to provide an oxygen burner that has a short flame length and can generate a wide flame at a high temperature.

[0006]

Means for Solving the Problems In order to achieve the above object, the inventor has conducted extensive experiments and researches, and completed the present invention as a result. That is, the present invention provides a burner nozzle main body having a convex end provided with a central flow path for supplying an oxygen-containing gas, and a fuel gas supply flow path provided around the central flow path and having a retreated distal end. A cylindrical burner tile extending to at least the center flow channel tip disposed on the tip end outer peripheral side of the supply flow channel, wherein the center flow channel tip is closed and a plurality of openings are provided in the circumferential direction. An oxygen burner characterized in that: The present invention is preferably the oxygen burner according to claim 1, wherein the opening of the central flow path is provided at an angle of 45 to 90 degrees with respect to the fuel gas supply flow path axis. 3. The oxygen burner according to claim 2, wherein a tip portion of the center flow path provided with the opening is a detachable cap. further,
In practical use, the present invention provides an oxygen burner according to any one of claims 1, 2, and 3, further comprising mixing means for mixing refractory powder and / or metal powder in fuel gas. is there.

[0007]

According to the present invention, an oxygen burner is provided with a burner nozzle main body having a convex end provided with a central flow path for supplying an oxygen-containing gas, and a fuel gas supply flow path provided around the central flow path and having a retreated tip. And a tubular burner tile extending to at least the center flow channel tip provided on the outer peripheral side of the tip portion of the fuel gas supply flow channel, the tip of the center flow channel being closed, and a plurality of circumferentially extending circumferential burners. Since the opening of the
A flame having a short flame length and a wide flame at a high temperature can be obtained. Further, the opening of the central flow path is provided at an angle of 45 to 90 degrees with respect to the fuel gas supply flow path axis, and the tip of the central flow path is a cap including a plurality of the openings. Therefore, the length and width of the flame can be easily changed simply by replacing the cap. Further, in the present invention,
Mixing means for mixing the refractory powder and the metal powder in the fuel gas is provided so that not only heating and melting of objects in a narrow place of work, but also easy repair of refractory spraying is possible. Become. Hereinafter, the present invention will be described in detail with reference to FIG.

First, an oxygen burner 3 according to the present invention comprises a central flow path 6 for supplying a single oxygen-containing gas 12 to a central portion,
The base body is a burner nozzle main body formed by a plurality of fuel gas supply passages 7 disposed around the center flow passage and having a tip retreated from that of the center flow passage. The burner nozzle body may be an integrally molded product made of ceramic or heat-resistant alloy material, or may be an assembled product made up of a plurality of pipes. The end of the center channel 6 for supplying the oxygen-containing gas 12 projecting from the supply channel 7 for the fuel gas 11 is closed, but the oxygen-containing gas is ejected in the circumferential direction. , A plurality of openings 8 are provided. In addition, this tip part
It may be formed, for example, by a cap 10 having a screw joint so that it can be removed. Further, a cylindrical burner tile 9 is provided on the outer peripheral portion of the leading end of the supply passage 7 for the fuel gas 11, and the burner tile 9 is located at least forward of a position equivalent to the end of the central passage 6. It has a length that can be reached.

Therefore, in the oxygen burner 3 according to the present invention,
When the oxygen-containing gas 12 discharged from the opening 8 collides with the burner tile 9, the oxygen-containing gas 12 is efficiently mixed with the fuel gas 11 discharged from the fuel gas supply flow path 7, and the mixing is uniformly promoted in the circumferential direction. Therefore, a short flame is formed. Therefore,
This oxygen burner 3 is very useful for heating and melting an object in a place where a so-called short flame is required. In addition, if the refractory powder 2 (including metal powder) is mixed with the fuel gas 11, it can be used in a narrow place. It can be widely used for refractory thermal spray repairs in Japan. The refractory powder 2 was added to the fuel gas 11.
Mixing such as may be performed between the hopper 1 and the opening of the leading end of the supply flow path 7 for the fuel gas 11, and a known means can be used.

[0010] When used for repair of refractory spraying, to reduce the collision speed against a worn part such as a furnace wall and to reduce the rebound loss of the sprayed material, the flame should be thin to wide depending on the purpose. Need to change. In the oxygen burner according to the present invention, the flame shape can be arbitrarily set by changing the angle θ of the opening 8, and the widest flame is formed at θ = 45 °, and the narrow flame is formed at θ = 90 °. Can be formed. Specifically, the caps 10 having the openings 8 having various angles θ are prepared, and the caps 10 are exchanged according to the place of use. Where θ
The reason for limiting the angle from 45 ° to 90 ° is that the burner tile 9 becomes too long in order to make θ less than 45 °,
This is because it is not suitable for an oxygen burner that is inserted into a narrow space and performs thermal spraying. When θ is set to 90 ° or more,
This is because a backflow is given to the supply flow path 7 of the fuel gas 11 and the flame is not stabilized.

Furthermore, in the oxygen burner according to the present invention, the fuel gas includes blast furnace gas, converter gas, coke oven gas,
Hydrocarbon gases such as propane and butane can be used, and oxygen, air and the like are preferable as the oxygen-containing gas.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, when the oxygen burner according to the present invention is used for thermal spray repair of refractories, the flame length, the temperature distribution investigation results (FIG. 3), the flame shape investigation results (FIG. 2), and the spraying efficiency (FIG. Table 1) will be described. FIG. 3 shows the measurement results of the temperature in the flame and the amount of unburned gas when using the conventional oxygen burner (see FIG. 4) and the oxygen burner according to the present invention (θ = 45 °). As unburned gas, unburned components (C
The total of O, CH ₄ , CmHm, and H ₂ ) is plotted. From FIG. 3, in the conventional oxygen burner, the distance at which the unburned gas disappears was 400 mm from the nozzle tip, but in the oxygen burner according to the present invention, it completely disappeared at the position of 150 mm, and the flame length was extremely short. Turned out to be shorter.

Regarding the flame temperature, all the oxygen burners reach the maximum temperature at the point where the unburned gas disappears.
Since the oxygen burner according to the present invention has a shorter frame length, heat radiation is small, and the maximum temperature is higher than that of the conventional oxygen burner by about 100 ° C., so that efficient mixing and combustion are performed. Recognize. Next, FIG. 2 is a view in which a refractory wall was set at a position 200 mm from the nozzle tip and the flow of the flame was observed. From FIG. 2, in the conventional oxygen burner, since oxygen is supplied from the outside, a sharp frame is formed, and the collision speed of the frame against the wall is 100 m / s.
However, in the oxygen burner according to the present invention, the frame shape can be considerably changed by changing θ, and θ = 90 °
The collision speed is up to 30 m / s and 10 m at θ = 45 °
/ S.

Finally, Table 1 shows the results obtained by examining the spraying efficiency of the spray material with the above two types of oxygen burners. From Table 1, it can be seen that the oxygen burner according to the present invention shortened the flame length and reduced the collision speed against the fire-resistant wall, so that the rebound loss of the sprayed material was reduced and the efficiency was greatly improved. It could be confirmed.

[0015]

Table 1 ──────────────────────────────────── Conventional method The present invention θ = 90 ° θ = 45 ° Adhesion efficiency 62% 92% 96% ────────────────────────────────────

[0016]

As described above, the following effects are obtained by adopting the present invention. (1) Since a short flame can be obtained, it is possible to easily spray the refractory powder even in a small space such as a coke oven, which was difficult in the past. (2) Since a high temperature and a wide flame shape can be obtained, the spraying material efficiency is improved. (3) As a result of (1) and (2), the repair work time and workability were improved. (4) The service life of the spray repair part can be extended because the spray is efficiently performed at a high temperature.

[Brief description of the drawings]

FIG. 1 is a view showing an example of an oxygen burner according to the present invention, wherein (a) is a side sectional view, and (b) is a view taken along the line AA of (a).

FIG. 2 is a comparison diagram of flame shapes of a conventional burner and a burner of the present invention.

FIG. 3 is a diagram showing the use results of the oxygen burner according to the present invention.

FIG. 4 is a diagram showing a side cross section of a conventional oxygen burner.

FIG. 5 is a view for explaining furnace wall repair by a thermal spray repair method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hopper 2 Refractory powder 3 Oxygen burner 4 Flame 5 Refractory wear part 6 Central flow path 7 Supply flow path 8 Opening 9 Burner tile 10 Cap 11 Fuel gas 12 Oxygen-containing gas

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Keiji Matsuda 1 Kawasaki-cho, Chuo-ku, Chiba-shi Kawasaki Steel Corporation Chiba Works (56) References Hirai 1-74422 (JP, U) Shohei Mikai 54-102731 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F23D 14/22 F23D 14/56 F23D 14/84

Claims (4)

(57) [Claims] 1. A burner nozzle body having a convex end provided with a central flow path for supplying an oxygen-containing gas and a fuel gas supply flow path provided around the central flow path and having a retreated tip.
A cylindrical burner tile extending to at least the center flow channel tip disposed on the outer peripheral side of the tip portion of the fuel gas supply flow channel, wherein the tip of the center flow channel is closed, and a plurality of openings are provided in the circumferential direction. An oxygen burner characterized by comprising: 2. The oxygen burner according to claim 1, wherein the opening of the center flow path is provided at an angle of 45 to 90 degrees with respect to the fuel gas supply flow path axis. 3. The oxygen burner according to claim 2, wherein a tip portion of the center flow path provided with the opening is a removable cap. 4. The oxygen burner according to claim 1, further comprising mixing means for mixing the refractory powder and / or the metal powder into the fuel gas.