JP2565040B2 - Tuyere for blast furnace - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a tuyere for a blast furnace,
The present invention relates to a blast furnace tuyere capable of positively burning dense shells formed in the peripheral portion of the raceway formed at the tuyere tip of the blast furnace and stagnant coke in the raceway peripheral portion.

[0002]

2. Description of the Related Art In a blast furnace for steelmaking, materials inside the furnace are heated,
A tuyere for blowing hot air into the furnace is provided for melting.

A tuyere for a blast furnace will be described with reference to the drawings. FIG. 4 is a schematic sectional view of a tuyere for a blast furnace. A plurality of tuyere 2 radially provided under the furnace wall 1 of the blast furnace is approximately
High-temperature air heated to 1200 ℃ is blown into the blast furnace 1 at a speed of 200 to 250m / sec, whereby the coke charged in the furnace is burned and the high-temperature reduction of about 2000 to 2400 ℃ is carried out. A high-temperature reducing gas is used to generate a neutral gas, and the ore charged in the blast furnace is reduced and melted.

[0004] By blowing hot air from the tuyere 2 into the blast furnace as described above, a space in which the coke swirls and burns, that is, the raceway 3 is formed in the furnace at the tip of the tuyere 2. The size and shape of this raceway 3
By appropriately controlling the flow rate of the hot air from the tuyere 2 and so on, the molten metal such as the molten metal and the molten slag flowing down from the upper part of the raceway 3 is prevented from entering the raceway 3. The gas flow in the furnace is being optimized.

[0005]

However, it is known that a dense shell 4 made of small coke, slag, metal or the like is formed in the peripheral portion of the raceway 3. This is disclosed on page 17 of "Blast Furnace Phenomena and their Analysis" published by the Iron and Steel Institute of Japan in 1979. Raceway 3 is the main cause of shell 4 formation
It is thought that the fine coke generated in the raceway 3 is trapped in the peripheral portion of the raceway 3 because the coke in the lower portion of the raceway is very slow.

[0006] In normal blast furnace operation, the formation of a dense shell 4 cannot be prevented. In this way, when the dense shell 4 is formed around the raceway 3,
Since the air permeability and liquid permeability of the peripheral portion of the raceway 3 are impaired, stable air blowing cannot be achieved. Therefore, since it takes time for the coke around the raceway to disappear, the update time of the coke around the raceway is delayed, and moreover, the update time of the coke around the furnace core is delayed. Also, the liquid permeability is deteriorated, which is not preferable in the operation of the blast furnace.

Therefore, an object of the present invention is to actively burn the dense shell formed in the peripheral portion of the raceway and the staying coke in the peripheral portion of the raceway, whereby the breathability and the ventilation of the peripheral portion of the raceway are obtained. It is to improve liquidity.

[0008]

According to the present invention, the coke in the blast furnace is burned to generate a high-temperature reducing gas, and the ore in the blast furnace is reduced and melted by the reducing gas. In a tuyere for blowing hot air into the interior thereof, at least one auxiliary air blowing hole is provided in a body portion of the tuyere, and a part of the hot air in the tuyere is blown into the blast furnace through the auxiliary air blowing hole, The feature is that the dense shell formed in the peripheral portion of the way and the staying coke in the peripheral portion of the raceway are actively burned.

Next, an embodiment of a tuyere for a blast furnace according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view showing an embodiment of a tuyere for a blast furnace of the present invention, and FIG. 2 is a sectional view taken along the line AA of FIG. As shown in FIGS. 1 and 2, the blast furnace tuyere 5 of the present invention is
At least one (in this example, six in total) auxiliary air vents 6 are provided radially. The auxiliary blower holes 6 may be radially provided all around the body of the tuyere 5, but as described above, the shell 4 formed in the peripheral portion of the raceway 3 and the staying coke in the peripheral portion of the raceway 3 are formed. From the purpose of actively burning, as described above,
It is sufficient to provide it in the lower half of the tuyere. Auxiliary ventilation hole 6
From the viewpoint of combustion of the shell 4 below the raceway 3, combustion of stagnant coke in the periphery of the raceway 3 and stability of blowing hot air from the tuyeres 5 into the blast furnace, FIG.
It is preferable to continuously incline the outlet end of the auxiliary blower hole 6 so that it is closer to the tip of the tuyere 5 than the inlet end, as shown in FIG.

As described above, by providing the auxiliary blower holes 6 in the tuyere 5, a part of the hot air blown into the tuyere 5 is blown into the furnace from the auxiliary blower holes 6, so that the raceway 3 It is possible to actively burn the staying coke in the peripheral portion of the shell 4 and the raceway 3 formed in the peripheral portion. Therefore, stable air blowing can be achieved, and as a result, the disappearance time of the coke around the raceway is shortened, the update time of the coke around the raceway is shortened, and the update time of the coke around the furnace core is shortened. Therefore, the air permeability and liquid permeability of the furnace core are also improved.

To blow a part of the hot air blown into the tuyere 5 to the lower part of the raceway 3, as shown in FIG. The pipe 7 may be inserted.

[0012]

As described above, according to the present invention, the dense shell formed in the peripheral portion of the raceway and the staying coke in the peripheral portion of the raceway are formed by a part of the hot air blown into the tuyere. Can be actively burned. Therefore, stable air blowing can be achieved, and as a result, the disappearance time of the coke around the raceway is shortened, the update time of the coke around the raceway is shortened, and the update time of the coke around the furnace core is shortened. Therefore, useful effects such as improvement of air permeability and liquid permeability of the furnace core are brought about.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing one embodiment of a tuyere for a blast furnace of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a schematic cross-sectional view showing another embodiment of the tuyere for blast furnace of the present invention.

FIG. 4 is a schematic sectional view showing a conventional tuyere for a blast furnace.

[Explanation of symbols]

1: Blast furnace wall, 2: Tuyere, 3: Raceway, 4: Shell, 5: Tuyere of the present invention, 6: Auxiliary blower opening, 7: Pipe.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akio Shimomura 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Inside Nippon Steel Tube Co., Ltd. (56) Reference JP-A-5-117734 (JP, A) JP-A-55 -38407 (JP, A)

Claims (3)

(57) [Claims] 1. A blade for blowing hot air into the blast furnace in order to burn high temperature reducing gas by burning coke in the blast furnace and reduce or melt the ore in the blast furnace by the reducing gas. In the mouth, at least one auxiliary air blowing hole is provided in the body portion of the tuyere, and a part of the hot air in the tuyere is blown into the blast furnace through the auxiliary air blowing hole to form a peripheral portion of the raceway. A tuyere for a blast furnace, which is characterized in that a dense shell and the staying coke around the raceway are actively burned. 2. The tuyere for a blast furnace according to claim 1, wherein the auxiliary air blowing hole is provided in a lower half portion of a body portion of the tuyere. 3. The tuyere for a blast furnace according to claim 1 or 2, wherein the auxiliary air blowing hole is inclined so that its outlet end is closer to the tip of the tuyere than the inlet end. .