JP3265148B2 - Blast furnace water-cooled slag gutter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled slag gutter used in a blast furnace or the like.

[0002]

2. Description of the Related Art In normal blast furnace operation, hot metal from a blast furnace is periodically tapped into a gutter and separated into hot metal and slag by a skin mer damper. Hot metal is received by, for example, a torpedo car via a hot metal decanter. On the other hand, the slag flows through the slag gutter and is discharged, for example, into slag via a hot iron pot.

[0003] The slag discharged from the taphole of the blast furnace is 15
Since the molten material is a high-temperature molten material of 00 ° C. or more, the refractory of the slag gutter through which the slag flows undergoes thermal influence or chemical erosion.
Therefore, the improvement of the slag erosion resistance of the slag gutter is a major problem in reducing the unit consumption of the gutter material and the amount of work for updating the gutter material.

A conventional blast furnace slag gutter generally comprises a refractory brick forming both side walls and a gutter bottom, and a gutter material provided on the inside of the refractory brick on the both side walls and the gutter bottom. Met. In addition, as a new technology of the slag gutter structure,
No. 33287, Japanese Utility Model Publication No. 61-29716,
There is a technique described in Japanese Utility Model Laid-Open No. 2-51244.

[0005] These techniques are based on a molten metal gutter in which a cooling pipe is built in a high heat conductive refractory brick disposed on the inner wall of a steel shell forming a gutter, or a hollow U-shaped cooling as shown in FIG. A plurality of pipes are arranged in the gutter longitudinal direction, and a water-cooled smelter gutter for passing water into the U-shaped pipe, or a plurality of casting blocks connected in the longitudinal direction forming both side walls of the slag gutter, It consists of a cooling pipe buried inside, a refractory brick forming a bottom of the slag gutter, and an irregular refractory material applied to an upper layer of the refractory brick, and furthermore, a flow rate difference between a water supply amount and a drainage amount of the cooling pipe. A water-cooled slag gutter provided with a flow meter for monitoring the flow rate and an alarm transmitter for issuing an alarm when the flow rate difference is abnormal is disclosed.

[0006]

Renewal of the tub material in the conventional slag gutter is performed when the gutter material provided inside the slag gutter is eroded by the slag and reduced to a certain thickness. The slag flowing through the slag gutter in contact with the gutter material has a high temperature exceeding 1500 ° C, and a small amount of hot metal is mixed in the slag. Even though the erosion of the gutter material progressed, the gutter material had to be renewed usually every two weeks. High quality gutters are expensive and their consumption is high, which can increase the cost of hot metal production in blast furnaces.

[0007] Renewal of the gutter material is performed by removing the remaining gutter material with a breaker or the like, thereafter filling the new gutter material, shaping it into a shape suitable for a gutter, and compacting it. It was a work in a gutter, and there was a problem as a so-called 3K work. There was a strong demand for avoiding such work and reducing work costs.

[0008] The following problems are envisaged when the techniques described in the respective publications, which are the new techniques of the slag gutter structure described above, are implemented. In the prior art, the gutter wall has a two-layer structure of a gutter material and a refractory material, and since the main material of the gutter wall does not use a thermally and chemically stable material such as a steel plate, the gutter material suddenly becomes There is a danger that the internal cooling pipe is melted and destroyed due to local melting and the like, causing a steam explosion.

Further, although the gutter material constructed on the inner wall of the molten metal gutter has a reduced wear rate due to the cooling effect of the cooling water in the cooling pipe, if the gutter material is melted or worn even partially, , Remove the remaining gutter material each time with a breaker, etc.
After that, new gutter material must be filled, and reduction of gutter material unit consumption and gutter material renewal work cannot be expected much. Furthermore, the cooling pipe group which constitutes a gutter groove consisting of a gutter bottom and a rising side wall and buried inside receives a sudden and enormous heat load from the slag in the early stage of operation, so that the cooling pipe group is Damage due to high heat, deterioration due to carburization from tub material,
There is a risk of causing thermal deformation due to rapid temperature changes.

Further, it is known that a small amount of molten pig iron called flowing pig iron always flows into the slag and flows out. The danger of an explosion cannot be ignored. Also, inside the casting block on both sides of the above technology,
The technology of casting a cooling pipe is extremely difficult in cast steel due to problems such as carburization and welding between the cooling pipe and the cast steel, whereas the manufacturing technology has been established for cast iron. Therefore, it is assumed to be a cast iron block. Since the inner surface of the cast iron block is in direct contact with the slag, there is a similar problem in use as described above. In addition, the melting point of cast iron is about 1150 ° C, which is lower than that of steel at about 1530 ° C.
There is a possibility that the above problems will be further promoted.

The present invention has been made in view of the above-mentioned problems, and the gutter wall is formed integrally with the cooling wall of the gutter wall main material by appropriately combining a steel slab, a cooling pipe insertion stave, and an irregular refractory layer. An object of the present invention is to provide a structure of a slag gutter which is improved in slag erosion properties, enhances safety against steam explosion and the like, and is compact and has good maintainability such as replacement.

[0012]

In order to achieve the above-mentioned object, a blast furnace water-cooled slag gutter of the present invention comprises a smelt gutter branched from a tapping large gutter of a blast furnace, which cools an outer side wall of the slag gutter. A cast iron stave having a cooling pipe through which water flows therein is provided, and the inside of the cast iron stave is integrally formed as a steel slab by bringing both surfaces into surface contact. The inner surface of the steel slab was lined with irregular-shaped refractories.

[0013] A steel bar is fixed to the outer surface of the steel slab, and the steel bar is cast on the steel slab as a base to form a cast iron stave. In the smelter gutter branched from the tapping gutter of the blast furnace, the side wall of the slag gutter is formed of a steel slab, and an irregular refractory layer is provided in surface contact with the outside of the slab. That a cooling pipe for inflow of air is installed. The steel slab is provided with a semi-circular groove for semi-installing the cooling pipe.

[0014]

According to the present invention, if the main material of the gutter wall is made of steel slab, its melting point is about 1530 ° C., which is about 400 ° C. higher than about 1150 ° C. of cast iron, and therefore hardly melts. In addition, since the thermal conductivity is high, the main member of the gutter wall is easily cooled, the operating surface temperature can be kept low, and it is difficult to melt.

Since the side of the side in contact with the slag is made of steel slab, the heat conductivity is good and a cooling effect from the outer surface is directly obtained, and the temperature of the inner surface of the steel slab does not rise. In another example, in the case of an irregular refractory applied to the surface in contact with the slag, the heat load from the slag is insulated /
The temperature of the slag side surface of the main material of the gutter wall from 1218 ° C to 6
The temperature is lowered by about 600 ° C. to 25 ° C. (when the thickness of the amorphous refractory layer is 50 mm). Therefore, the slag gutter can be protected from initial troubles such as deformation and breakage.

After the amorphous refractory layer is eroded by the slag and the amorphous refractory layer is thinned, a cooled and solidified slag adhesion layer is formed on the working surface of the amorphous refractory layer. Since the slag adhesion layer is effective for heat insulation, the temperature of the operating surface of the main gutter wall material can be kept low. Therefore, the amorphous refractory layer is protected by the slag adhesion layer and can be used for a long period of time, so that the basic unit of the gutter material is reduced. As a result of the above, the slag gutter has improved smelt erosion resistance on the side wall of the gutter, which can enhance safety, and also facilitates maintenance such as replacement.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a sectional view showing an example of a water-cooled slag gutter according to the present invention. As shown in FIG. 1, the water-cooled slag gutter of the present invention is composed of a cast iron stave 3 provided inside a water-cooled pipe forming the outside of both side walls and a steel slab 2 of a gutter wall main material directly in contact with the slag on the inner surface side. The gutter member 5 made of a refractory material forming the gutter bottom is sandwiched between the side walls.

The water cooling side wall 1 forming both side walls is divided into appropriate lengths in the longitudinal direction of the slag gutter, and for example, water is forced to flow through a cooling pipe 9 built in the cast iron stave 3. Cool the slag gutter from the outside. The cooling pipes 9 are connected by connecting pipes behind the respective divided positions of the cast iron staves 3 so that the slag gutter can be cooled in an integrated manner.

FIG. 2 shows a water-cooled slag gutter according to the first embodiment of the present invention. The outer sides of both side walls are composed of cast iron staves 3 and are divided into appropriate lengths in the longitudinal direction of the slag gutters. To cool. The cooling pipe 9 is connected to the rear side of each divided position of the cast iron stave 3 by a connecting pipe so that the smelter gutter can be cooled in an integrated manner.

A steel slab 2 is disposed on the inner wall side in contact with the slag, and is welded to a cast iron stave 3 to form a water-cooled side wall 1. In this case, a steel bar 8 is cast inside the cast iron stave 3 while being fixed by welding with a steel slab, and corresponds to the third embodiment of the present invention. The role of the steel bar 8 is to facilitate the integration (adhesion) between the steel slab 2 and the cast iron stave, to connect the two, and to generate a gap even when a difference in thermal expansion between the two occurs. It is to be connected firmly not to be. The cooling pipe 9 is preferably provided with a coating on its outer surface to prevent deterioration due to erosion, carburization or the like, and thermal deformation due to a rapid temperature change.

FIG. 3 shows an embodiment of the second aspect of the water-cooled side wall 1. The structure on the slag side has an irregular refractory 4 on the surface in contact with the slag inside the steel slab 2 of FIG. It has a lined structure, and the rest is the same as FIG.

FIG. 4 shows a fourth embodiment of the present invention. The structure of the slag side is the same as that of FIG. The outside of the side wall on the anti-slag side is formed of a high-thermal-conductivity irregular-shaped refractory 13, and a semicircular groove for embedding the cooling pipe 9 in the steel slab 2 is cut in the longitudinal direction of the gutter. The cooling pipe 9 is embedded in the semi-circular groove with a heat-resistant and high-thermal-conductivity material 12, for example, a carbon paste densely interposed therebetween, and is fixed by a cooling pipe holding member 15. Further, a frame metal member 14 is welded to the steel slab 2, and the frame metal member 14 is filled with a highly heat-conductive irregular-shaped refractory material 13 so that the cooling pipe 9 is built therein.

FIG. 5 shows an embodiment according to claim 5 of the present invention, in which the structure on the slag side is lined with an irregular refractory 4 on the surface in contact with the slag inside the steel slab 2 of FIG. The other structure is the same as that of FIG. In addition, when slag and hot metal can be reliably separated and a metal component such as granular iron does not flow into the slag gutter, a steel slab can be applied to the bottom of the gutter.

[0024]

According to the water-cooled slag gutter of the present invention, the main material of the gutter side wall is made of steel slab, and the anti-slag side of the main material of the gutter wall is subjected to water cooling by a cooling layer having a cooling pipe. In addition, it is possible to provide a highly safe structure of a slag gutter which solves problems such as deformation and breakage of a water-cooled slag gutter, thereby realizing a reduction in the unit consumption of the gutter material and a reduction in the amount of work for updating the gutter material.

The water-cooled slag gutter according to the present invention exhibits the following excellent effects. When the main material of the gutter side wall is made of steel slab, its melting point is about 15
At 30 ° C., it is about 400 ° C. higher than about 1150 ° C. of cast iron, so that it is difficult to melt. In addition, since the thermal conductivity is high, it is easy to be cooled, the operating surface temperature can be kept low, and it is difficult to melt. In addition, if an amorphous refractory is applied to the side in contact with the slag, the heat load from the slag is insulated and reduced in the early stage of operation, and the slag side surface temperature of the main material of the gutter side wall is changed from 1218 ° C. to 625 ° C. When the thickness of the refractory layer is 50 mm), the temperature is reduced by about 600 ° C. Therefore, the slag gutter can be protected from initial troubles such as deformation and erosion.

When the slag cools and solidifies the inner working surface and solidifies the slag adhesion layer, the slag adhesion layer is effective for heat insulation, so that the temperature of the operating surface of the main material of the gutter side wall can be kept low. In addition, it can be used for a long time because it is protected by the slag adhesion layer, and the basic unit of the gutter material is reduced. The gutter side wall can be made compact by appropriately selecting the gutter side wall main material layer, the cooling layer, and the amorphous refractory layer and integrally forming the gutter side wall. As a result, the safety of the slag gutter is improved, and the maintainability such as replacement is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a water-cooled slag gutter according to the present invention.

FIG. 2 is an enlarged sectional view of one side wall showing a part of the first and third embodiments of the present invention.

FIG. 3 is an enlarged sectional view of one side wall showing a part of the second and third embodiments of the present invention.

FIG. 4 is an enlarged sectional view of one side wall showing a part of the fourth and sixth embodiments of the present invention.

FIG. 5 is an enlarged sectional view of one side wall showing a part of the fifth and sixth embodiments of the present invention.

FIG. 6 is a bird's-eye view showing an example of a conventional slag gutter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water-cooled side wall 2 Steel slab 3 Cast iron stave 4 Irregular refractory 5 Gutter material 8 Steel bar 9 Cooling pipe 12 Heat-resistant and high-thermal-conductive material 13 High-thermal-conductivity irregular-shaped refractory material 14 Frame hardware 15 Cooling pipe presser

Continuing on the front page (72) Inventor Akira Takahashi 1 Nishinosu, Oita, Oita City, Oita Prefecture Nippon Steel Corporation Oita Works (72) Inventor Hiroyuki Takao 46-59 Ohara Nakahara, Tobata-ku, Kitakyushu-shi, Fukuoka New Japan-made (72) Inventor Toshiyuki Seto 46-59 Ohara Nakahara, Tobata-ku, Kitakyushu-shi, Fukuoka Prefecture Nippon Steel Corporation Machinery & Plant Business Department (58) Field surveyed (Int.Cl. ⁷ , DB name) C21B 7/14 303 F27D 3/14

Claims (6)

(57) [Claims] In a smelter gutter branched from a tapping gutter of a blast furnace, the outside of the side wall of the slag gutter is a cast iron stave provided with a cooling pipe through which cooling water flows, and the cast iron stave is provided. A blast furnace water-cooled slag gutter, the inside of which is integrally formed as a steel slab with both surfaces in surface contact. 2. A blast furnace water-cooled slag gutter according to claim 1, wherein the inner surface of the steel slab is lined with an irregular refractory. 3. The steel bar is fixed to an outer surface of a steel slab, and the steel bar is cast on the steel slab as a base to form a cast iron stave. Blast furnace water-cooled slag gutter. 4. A smelt gutter branched from a tapping gutter of a blast furnace, wherein a side wall of the slag gutter is formed of a steel slab,
A blast furnace water-cooled slag gutter, characterized in that an irregular refractory layer is provided in surface contact with the outside thereof, and a cooling pipe through which cooling water flows is provided in the contact surface between the two. 5. The blast furnace water-cooled slag gutter according to claim 4, wherein the inner surface of the steel slab is formed of a refractory. 6. The blast furnace water-cooled slag gutter according to claim 4, wherein the steel slab is provided with a semicircular groove for half-inside the cooling pipe.