JP2004010936A - Converter lining structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a converter lining structure for consistently preventing detachment of a lining brick for a long period of time even when any differential inflation is generated between a converter shell and the lining brick, or even when the converter lining structure is subjected to an impact of a work for removing metals deposited on a nose part. <P>SOLUTION: In this lining structure of a tapered nose part of a converter 1, a hole 5 is formed in both sides of a lining brick 3, a metal pin 6 is inserted in the holes to connect the adjacent lining bricks via the metal pin. The position of the hole 5 is behind an intermediate part of the brick, and the diameter and the depth of the hole are preferably 10-15 mm and 25-50 mm, respectively. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a converter lining structure, and more particularly to a lining structure of a converter furnace port narrowing portion.
[0002]
[Prior art]
In a converter used in a steel making process, pure oxygen is blown upward or downward from hot metal to mainly perform decarburization and refining of the hot metal. In this oxygen blowing, a large amount of oxygen is used, and the molten metal and slag are vigorously stirred, causing a phenomenon of projecting from the converter furnace mouth (referred to as "spitting" and "slopping", respectively), and decarburization at the same time. Exhaust gas with high CO concentration is generated in large quantities by refining. For the purpose of preventing the spitting and the slopping and efficiently collecting the exhaust gas, the converter furnace opening has a reduced drawing shape.
[0003]
The lining of the furnace port drawing portion is constituted by a lining consisting of a permanent brick of 100 to 150 mm inside the converter steel shell and a brick of 400 to 600 mm inside (also called "work brick"). . Permanent bricks are fixed with metal because the lining thickness is thin and easy to fall off. However, lining bricks are not held by a sufficient fixing method, and are usually held by the tapering force of the bricks in the circumferential direction.
[0004]
However, since there is a difference in the amount of expansion between the brick and the iron shell, the difference in the amount of expansion causes the brick to be pressed into the iron shell and cause a crack in the brick, or conversely, a gap occurs between the brick and the brick, Ingots are inserted into these gaps and bricks may be damaged. In particular, since the furnace port narrowing portion is located at the upper part of the converter, heat does not easily reach the brick and the brick squeezing force is weak, and the above-mentioned gap is easily generated due to the effect of the brick's own weight when the converter tilts. In addition, there is adhesion of blown metal and slag at the furnace mouth during blowing, and it is usually necessary to remove large metal jigs suspended with a crane or the like against the furnace mouth to remove these deposits. Is being done. Due to this removal work, the lining of the furnace opening narrowed portion is subjected to an impact and loosened, and the brick of the narrowed portion is facilitated to fall off.
[0005]
As described above, the furnace port drawing portion has an overhanging structure, so that once the bricks fall out, the whole expands. Therefore, it is necessary to frequently perform repair work such as spraying, but this repair work is a hot work under high temperature, and performing it frequently requires a high work load and lowers the operation rate of operation. It is not preferable.
[0006]
To solve this problem, Japanese Patent Application Laid-Open No. 5-279719 has been proposed. In the same publication, steel members such as a steel plate and a steel material are buried in the lining bricks in advance, and the steel members of the adjacent lining bricks are welded to connect the lining bricks to each other to prevent the lining bricks from falling off. . Further, instead of welding, a structure in which a notch groove is provided in a lining brick, and a cotter member is fitted in the notch groove has been proposed.
[0007]
[Problems to be solved by the invention]
However, in the countermeasure proposed in Japanese Patent Application Laid-Open No. 5-279719, it is necessary to perform a welding operation at the time of brick construction, which complicates the brick construction operation. Furthermore, even if the bricks are integrated by welding steel members, the joint between the brick, which is a fragile portion, and the steel members may be peeled off due to the expansion and contraction of the bricks due to the heat history, and the bricks may be extended for a long time. It is difficult to keep the lining bricks integrated. On the other hand, when the notch groove is installed, the welding work becomes unnecessary, but the installation of the notch groove not only reduces the strength of the brick, but also causes stress concentration on the brick and promotes wear of the brick itself. Let it.
[0008]
The present invention has been made in view of the above circumstances, and an object thereof is that even if a difference in expansion occurs between the converter steel shell and the lining brick, the impact of the work of removing the slab metal adhered to the furnace mouth portion can be obtained. An object of the present invention is to provide a lining structure capable of stably preventing falling of a lining brick for a long period of time even if the lining brick is received.
[0009]
[Means for Solving the Problems]
A converter lining structure according to the first invention of the present application for solving the above-mentioned problem is a lining structure of a converter mouth opening narrowing portion, in which holes are provided on both side surfaces of a lining brick, and a metal pin is provided in the hole. The converter lining according to the second invention is characterized in that the adjacent lining bricks are connected to each other via the metal pin, and the position of the hole is in the middle of the lining brick in the first invention. The hole has a diameter of 10 to 15 mm and a depth of 25 to 50 mm on the rear side of the portion.
[0010]
According to the converter lining structure of the above configuration, the lining brick has a ring-shaped integrated structure, and is loosened due to the thermal history of the converter, the tilting of the converter, and the impact of the furnace port adhering matter removing work. Even if cracks occur, the falling off of the lining brick can be stably prevented. Also, since the inside brick is prevented from falling off only by installing holes with an inner diameter of about 10 to 15 mm and a depth of about 25 to 50 mm on both side surfaces behind the intermediate part, the degree of stress concentration of the inside brick is Extremely few, it is possible to prevent the destruction and wear of the brick due to the installation of the holes. Further, since the metal pin and the lining brick are not restrained from each other, the lining brick can freely expand and contract according to the temperature history, and no restraint stress is generated due to the installation of the metal pin.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 to 4 are views showing one example of an embodiment of the present invention. FIG. 1 is a schematic cross-sectional view of a lining structure of a converter opening portion according to the present invention, and FIG. 1 is a partial sectional view taken along the line XX ', FIG. 3 is a detailed view of a portion A in FIG. 2, and FIG. 4 is a perspective view of a lining brick constituting the lining structure of the present invention.
[0012]
As shown in these figures, the lining structure of the converter furnace opening narrowed portion according to the present invention is configured such that adjacent bricks 4 are inserted through metal pins 6 inserted into holes 5 provided on both sides of the bricks 4. Are connected to each other, and the lining brick 4 is disposed inside the permanent lining brick 3. The permanent upholstered brick 3 is arranged inside the steel shell 2 of the converter 1.
[0013]
Holes 5 are previously installed on both sides of the lining brick 4 before use. The position of the hole 5 is a fixed position determined so as to coincide between the adjacent lining bricks 4. Even if the lining brick 4 is consumed by the oxygen blowing of the hot metal, the lining brick 4 is connected by the metal pins 6 for a long period of time. It is preferable to be on the brick 3 side. The holes 5 are formed when the lining brick 4 is manufactured.
[0014]
The diameter of the hole 5 is about 5 to 20 mm, preferably 10 to 15 mm, and the depth is about 15 to 60 mm, preferably 25 to 50 mm. When the diameter is less than 5 mm, the diameter of the metal pin 6 to be inserted becomes too small, and the strength for holding the lining brick 4 is insufficient. On the other hand, when the diameter exceeds 20 mm, the strength of the lining brick 4 is reduced and the lining brick 4 is stressed. It is not preferable because it causes concentration and causes damage to the lining brick 4. If the depth is less than 15 mm, the metal pin 6 may fall out of the hole 5 due to the shrinkage of the lining brick 4, while if it exceeds 60 mm, the strength of the lining brick 4 is reduced.
[0015]
Since the metal pin 6 is exposed to a high-temperature oxidizing atmosphere, it is preferable to use a material having high high-temperature strength and being hardly oxidized, such as stainless steel. The diameter of the metal pin 6 may be smaller than the diameter of the hole 5 by about 2 to 3 mm, and the length thereof may be shorter by about 5 to 10 mm than the length obtained by doubling the depth of the hole 5.
[0016]
When the converter 1 is being built, the lining bricks 4 are set inside the permanent lining bricks 3 while the metal pins 6 are inserted into the holes 5, and the lining bricks 4 are formed in an annular shape along the periphery of the steel shell 2. connect. In this case, no joint material such as mortar is required for the lining brick 4. In FIG. 1, the metal pins 6 are arranged over the bricks 4 at all stages of the furnace port narrowing portion. However, the metal pins 6 may be arranged only on the furnace port side where they are most likely to fall off. Further, the metal pins 6 may be arranged every other stage or every other stage.
[0017]
By adopting the lining structure of the converter furnace opening as described above, even if the lining brick 4 becomes loose due to the expansion difference between the steel shell 2 and the lining brick 4 or the tilting of the converter 1, the lining brick 4 comes out. -It can prevent falling off. Therefore, the lining brick 4 can be arranged at a predetermined position until the end of the furnace life until the lining brick 4 is worn down to the vicinity of the position where the hole 5 is provided. Further, since the adjacent bricks 4 are connected to each other by an extremely simple method, the bricks 4 can be applied in a short time which is not inferior to the conventional method. Further, since the permanent brick 3 can be constructed without any damage, even if the inner brick 4 is worn, the permanent brick 3 has no damaged portion, so that it is possible to prevent the steel shell 2 from being melted and damaged. it can.
[0018]
【Example】
An example in which the present invention is implemented in a 250-ton converter will be described. As shown in FIG. 1, a fired brick of MgO was installed as a permanent brick inside the steel shell of the converter furnace opening narrowed portion, and a non-fired brick of MgO-carbon was installed as an inner brick inside the brick. The lining thickness is 150 mm for permanent bricks and 540 mm for lining bricks. For the permanent bricks and the interior bricks, empty joints were used in which no joints were used.
[0019]
The shape of the lining brick used was 150 mm in height, 540 mm in length, and a taper with a width of 140 mm to 150 mm. Both sides of this brick had a diameter of 12 mm and a depth of 400 mm from the brick working surface side. A hole having a length of 30 mm was previously set, and a lining brick of all stages of the furnace port drawing portion was placed in this hole while inserting a stainless steel metal pin having a diameter of 9 mm and a length of 50 mm.
[0020]
When this converter was used for decarburization and refining of hot metal, the lining bricks were prevented from falling out and falling from the start of operation until 4000 heat blowing, and the amount of repair material sprayed on the narrowed part of the furnace mouth during the entire use period of the converter was reduced. It could be reduced to 30% or less of the conventional one. Also, by reducing the number of spray repair work, the converter operation rate was improved. Incidentally, when the lining brick is held by the conventional tapering force between the bricks in the circumferential direction, the lining brick has fallen off by 1000 to 2000 heat.
[0021]
【The invention's effect】
According to the present invention, the lining structure of the converter furnace opening narrowed portion is provided with holes on both sides of the lining brick, metal pins are inserted into the holes, and the adjacent lining bricks are connected via the metal pins. Because of the connected structure, even if the lining brick is loosened due to the difference in expansion between the steel shell and the lining brick or the tilting of the converter, the lining brick is also loosened due to the impact of the work to remove the metal attached to the furnace mouth. Even if it occurs, it is possible to stably prevent the lining brick from falling out or falling off. As a result, it is possible to greatly reduce the frequency of repair work such as spraying repair of the furnace port narrowing portion, and not only a reduction in repair cost but also an industrially beneficial effect such as an improvement in converter operation rate is brought about.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a lining structure of a converter furnace port drawing portion according to the present invention.
FIG. 2 is a partial cross-sectional view taken along line XX ′ of FIG.
FIG. 3 is a detailed view of a portion A in FIG. 2;
FIG. 4 is a perspective view of a lining brick constituting the lining structure of the present invention.
[Explanation of symbols]
1 Converter 2 Steel 3 Permanent brick 4 Lining brick 5 Hole 6 Metal pin

Claims (2)

It is a lining structure of a converter furnace opening narrowed part, in which holes are provided on both side surfaces of the lining bricks, metal pins are inserted into the holes, and adjacent lining bricks are connected to each other through the metal pins. Converter lining structure. 2. The converter lining structure according to claim 1, wherein the hole is located rearward of an intermediate portion of the lining brick, and has a diameter of 10 to 15 mm and a depth of 25 to 50 mm. 3.

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