JPH0583691U - Peripheral structure of electric furnace gas injection nozzle - Google Patents

Abstract

(57) [Summary] [Object] The present invention aims to significantly reduce refractory cost and replacement / repair time in the peripheral structure of the electric furnace gas blowing nozzle. [Composition] A gas conduit that extends downward is provided at the lower end of the wind box of the gas blowing nozzle, and lower bricks are stacked so as to surround the gas conduit. An irregular shape is provided between the lower brick and the gas conduit. The structure is such that the refractory is filled and solidified, and the upper bricks are stacked on the lower bricks and fitted into the gas blowing nozzle.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a peripheral structure of a gas blowing nozzle mounted on a bottom refractory of an electric furnace.

[0002]

[Prior Art]

 In the furnace bottom refractory structure of the electric furnace, as shown in FIG. 3, a tuyere receiving brick 1 is embedded with a wind case 10 of a gas blowing nozzle. The conduit 5 is welded. A gas blowing nozzle 2 is attached to the tuyere pipe 11, a receiving brick 3 is stacked around the gas blowing nozzle 2, and a peripheral brick 14 is stacked around the receiving brick 3. 12 is a perm brick, and 13 is an iron skin. The furnace bottom refractory configured in this way gradually melts from the top during electric furnace operation. In particular, when the gas blowing nozzle 2 and its surrounding refractories are melted more by the stir flow of molten steel generated by gas blowing, and when the melting level 9 is reached, the gas blowing nozzle 2 and the receiving brick 3 And the surrounding bricks 14 were being replaced. At this time, since the tuyere pipe 11 is welded to the wind box 10 and the wind box 10 is embedded in the tuyere receiving brick 1, the tuyere receiving brick 1 and the wind box 10 which are not melted are also replaced at the same time. Was there.

[0003]

[Problems to be solved by the device]

 For this reason, conventionally, there has been a problem that the cost becomes high and it takes a long time to replace them. An object of the present invention is to prevent the waste of materials in the replacement work of the bottom refractory of the electric furnace and to improve the work efficiency.

[0004]

[Means for Solving the Problems]

 The present invention relates to a peripheral structure of a gas blowing nozzle mounted on a furnace bottom refractory of an electric furnace as a means for solving the above-mentioned problems, and is directed downward to the lower end of the gas box of the gas blowing nozzle. Connect the extended gas conduits, stack the lower receiving bricks so as to surround the gas conduits, and fill the unfixed refractory between the lower receiving bricks and the gas conduits to solidify and solidify the upper receiving bricks. It is intended to provide a peripheral structure of an electric furnace gas blowing nozzle, which is fitted with a gas blowing nozzle and is piled on a lower receiving brick.

[0005]

[Action]

 Since a gas conduit extending downward was connected to the lower end of the wind box of the gas blowing nozzle, and the irregular refractory was filled around the conduit, the irregular refractory was collapsed to separate the wind box and the gas guide tube. The separation allows the gas blowing nozzle to be easily removed, and the gas conduit and tuyere receiving brick need not be replaced. Therefore, the cost can be reduced and the replacement / repair time can be shortened.

[0006]

Embodiment 1 FIGS. 1 and 2 show the peripheral structure of a gas blowing nozzle according to the present invention. In the figure, a gas blowing nozzle 2 is a nozzle for blowing a gas such as nitrogen, argon, oxygen or LPG into the molten steel for stirring or refining the molten steel in the electric furnace. The tuyere pipe 11 is connected to the wind box 10, and a gas conduit 5 extending downward is connected to the lower end of the wind box 10. The lower receiving bricks 7 are stacked on the tuyere receiving bricks 1 so as to surround the gas conduit 5, and the irregular refractory 4 is filled and solidified between the lower receiving bricks 7 and the gas conduit 5. . The gas conduits 5 and 5 are connected to each other via a joint 8 and are supported by the tuyere receiving brick 1. An upper receiving brick 6 is fitted into the gas blowing nozzle 2 and is stacked on the lower receiving brick 7, and peripheral bricks 14 are stacked around the upper receiving brick 6. 12 is a perm brick, and 13 is an iron skin.

It is desirable that the gas blowing nozzle 2 and the upper receiving brick 6 have small melting loss due to the operation of the electric furnace and can be easily disassembled. For this reason, they are preferably made of magnesia or a refractory containing carbon therein. In addition, in FIG. 2, the upper brick 6 is integrated, but when the brick is large, it may be divided. The length of the gas blowing nozzle 2 varies depending on the nozzle material and the target life, but about 100 to 400 mm is suitable. Table 1 shows an example of the component composition and physical properties of the tuyere receiving brick 1, the upper receiving brick 6, and the lower receiving brick 7 that compose the refractory.

Molten stainless steel was melted in the electric furnace configured as described above. At this time, an inert gas is blown into the molten steel through the gas conduit 5 to stir the molten steel, whereby the dissolution rate is improved and (Cr ₂ O ₃ ) in the slag is reduced. By repeating such operation of the electric furnace, the gas blowing nozzle 2, the upper receiving brick 6 and the peripheral bricks 14 are melted from the surface. When the melting loss reaches the level 9, the gas blowing nozzle 2, the upper receiving brick 6 and the peripheral brick 14 are replaced.

The gas blowing nozzle 2 is replaced by removing the melt-damaged upper receiving bricks 6 and peripheral bricks 14, and then filling a part of the plurality of lower receiving bricks 7 and the gas conduit 5. The irregular shaped refractory 4 is removed with a small hand. Next, the portion of the joint 8 of the gas conduit 5 is cut, and the cut portion is shaped with a hand glider or the like. Next, the joint 8 is attached to this cut portion, the gas conduit 5 of the new gas blowing nozzle 2 is inserted into the joint 8, and the gas conduits 5 and 5 are welded together. Next, the amorphous refractory material 4 is filled between the gas conduit 5 and the lower brick 7 with a hand or the like and solidified. Next, a new lower receiving brick 7 is stacked on the portion where the lower receiving brick 7 is removed, an upper receiving brick 6 is stacked on the new lower receiving brick 7, and a peripheral brick 14 is stacked on the outer side thereof.

[0010]

[Table 1] (* At 1400 ℃)

[0011]

[Effect of the device]

 According to the present invention, in the peripheral structure of the electric furnace gas blowing nozzle, the gas blowing nozzle is provided with a downwardly extending gas conduit connected, and an amorphous refractory is filled around the gas conduit. It became easier to disconnect and connect the blowing conduit and replace the nozzle. This eliminates the need to replace tuyere receiving bricks and gas conduits, reducing refractory costs and halving replacement and repair times.

[Brief description of drawings]

1 is a vertical cross-sectional view showing the peripheral structure of an electric furnace furnace gas injection nozzle according to the present invention;

FIG. 2 is a plan view of FIG.

FIG. 3 is a vertical cross-sectional view showing a peripheral structure of a conventional electric furnace furnace gas blowing nozzle.

[Explanation of symbols]

 1 Tuyere Receiving Brick 2 Gas Injecting Nozzle 3 Receiving Brick 4 Unshaped Refractory 5 Gas Conduit 6 Upper Receiving Brick 7 Lower Receiving Brick 8 Joint for Connecting Pipe 9 Corrosion Level 10 Wind Turbine 11 Tuyere 12 Permanent Brick 13 Iron skin 14 surrounding bricks

Front page continuation (72) Inventor Tadashi Imoto 3434 Shimada, Hikari City, Yamaguchi Prefecture Inside the Nippon Steel Corporation Hikari Steel Works (72) Inventor Fukuyoshi Isomura 1-1, Higashihama-cho, Hachimansai-ku, Kitakyushu, Fukuoka Prefecture Kurosaki Kiln Industry Co., Ltd. (72) Inventor Toshihiro Koyama 1-1, Higashihama-cho, Hachimannishi-ku, Kitakyushu, Fukuoka Kurosaki Ceramics Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A peripheral structure of a gas blowing nozzle mounted on a furnace bottom refractory of an electric furnace, wherein a gas conduit (5) extending downward is provided at a lower end of a wind box (10) of the gas blowing nozzle. Connected, the lower receiving brick (7) is stacked so as to surround the gas conduit (5), and the irregular refractory (4) is filled between the lower receiving brick (7) and the gas conduit (5). A peripheral structure for an electric furnace gas blowing nozzle, characterized in that the upper receiving brick (6) is fitted into the gas blowing nozzle (2) and is solidified and stacked on the lower receiving brick (7).