JP2004082190A - Continuous casting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continuously cast a cast slab having a fixed cross section drawn while pouring molten metal by solving such problems that a flange for supporting a refractory in the conventional tundish with a cover, is deformed with the heat and the refractory is broken and fallen down caused by heat-deformation etc. <P>SOLUTION: This continuous casting apparatus is provided with a bottom steel plate 13 for holding the refractory arranged at the outer peripheral ridge of the tundish cover 10 so as to hold a monolithic refractory 15 lined on the bottom surface, and a cooling means for cooling the steel plate. Thus, the bottom steel plate for holding the refractory, heated and deformed with radiating heat etc., from the molten metal, is cooled with the cooling means to prevent the deformation caused by the rising of the temperature. Further, the breakage and the fall-down of the bottom steel plate for holding the monolithic refractory held with the bottom steel plate caused by the deformation can be prevented and the repair of a heat-damaged part is reduced and the interruption of the work can be reduced, and the productivity can be improved. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a continuous casting apparatus used in a steel mill, a smelter, or the like, and used for producing a slab having a constant cross section by withdrawing the molten metal while pouring it.
[0002]
[Prior art]
2. Description of the Related Art In a steel mill or the like, a continuous casting apparatus has been conventionally used in which a molten metal made of molten steel or the like is poured while being drawn, and a round, square, pipe, or plate-shaped slab having a constant cross section is continuously manufactured.
According to this continuous casting apparatus, it is possible to produce a slab that has been homogenized in the longitudinal direction, and there is no shrinkage cavities in the center, and it is used for the production of slabs of aluminum, copper alloy, cast iron, steel, etc. It is widely used, and particularly in the case of steel aluminum, it is frequently used in the production of slabs and billets.
[0003]
Among such continuous casting apparatuses, in a continuous casting apparatus such as a thin slab, the floating separation of inclusions contained in molten steel supplied from a ladle or the like into a tundish main body and the separation into a plurality of continuous casting molds are performed. For the purpose of smoothing the distribution of molten steel, there is a tundish cover provided at the upper part of the tundish main body to prevent the temperature of the molten steel from lowering and to block radiation heat radiation from the molten steel to the periphery.
[0004]
FIG. 4 is a plan view showing an example of such a tundish with a cover, which is conventionally used, and FIG. 5 is a cross-sectional view taken along a line CC shown in FIG.
In the figure, reference numeral 30 denotes a tundish main body for distributing the supplied molten steel to a mold, and reference numeral 40 denotes a tundish cover.
[0005]
In the tundish main body 30, a refractory material holding metal piece 32a protrudes from an inner surface side of a dish-shaped steel plate structure 32 provided with a flange 31 for holding a refractory material projecting from the outside toward the inside at the upper edge. The inner surface of the dish-shaped steel plate structure 32 is sprayed and hardened by the refractory material holding hardware 32a, and is held by the refractory castable 33 lining the inner surface of the dish-shaped steel plate structure 32, thereby forming a refractory structure.
Reference numeral 34 denotes a hot water inlet for receiving molten steel from a ladle or the like into the tundish main body 30, reference numeral 35 denotes molten steel in the tundish main body 30 to which hot water is supplied, and reference numeral 36 denotes a continuous casting provided at the bottom of the tundish main body 30. A plurality of molten steel distribution ports for distributing molten steel to the casting mold.
[0006]
The tundish cover 40 is provided on the inner surface of the lid-type steel plate structure 42 in which the flange 41 for holding the refractory material is formed at the outer peripheral lower edge portion like the flange 31 from the outside to the inside to form the flange 41 for holding the refractory material. A metal structure 42a is protruded, and the refractory holding metal structure 42a is blown onto the inner surface of the lid-shaped steel plate structure 42, and is hardened and held by an irregular-shaped refractory castable 43 lining the inner surface to form a fire-resistant structure. ing.
Reference numeral 44 denotes a slit formed at the center in the width direction of the tundish cover 40 so as to surround the above-described hot water port 34, and reference numeral 45 denotes a heating burner for heating molten steel supplied into the tundish main body 30. It is an insertion slot.
[0007]
The tundish with a cover that constitutes the conventional continuous casting apparatus is configured as described above. However, when the tundish is used for a long time, as shown by a chain line circle portion A in the upper left corner of FIG. The portion 31 and the flange 41 on the side of the tundish cover 40 are thermally deformed from the outside to the inside as shown by the dotted line, and are also thermally deformed in the peripheral direction, which is a direction orthogonal to the sheet of FIG. The tundish cover 40 may deteriorate and the function of the tundish cover 40 may be reduced, and the refractory castables 33 and 43 lined in the vicinity thereof may be damaged and fall off due to the thermal deformation. A situation occurs in which the fire-resistant structure of the cover 40 is impaired.
[0008]
That is, the portions of the flanges 31 and 41 facing the inside of the tundish body 30 are not lined with the refractory castables 33 and 43, and the heat is directly transmitted from the molten steel 35 to these portions, thereby increasing the temperature. Since the temperature difference from the portion lined with the refractory castables 33 and 43 becomes large, thermal deformation tends to occur particularly as shown in the portion A, and the flanges 31 and 41 easily undergo thermal deformation. The retained portions of the castable refractory castables 33, 43 are not affected by the thermal deformation of the flanges 31, 41, due to the fact that the refractory holding hardware 32a, 42a is not provided near the flanges 31, 41. As a result, breakage and falling off easily occur.
[0009]
For this reason, every time the tundish body 30 and the tundish cover 40 are used for a certain period of time, the tundish body 30 and the tundish body 30 and the tundish body 30, Repair of the heat-damaged portion of the dish cover 40 has to be performed, so that the operation is interrupted and the productivity of continuous casting is impaired.
[0010]
[Problems to be solved by the invention]
The present invention solves the problems of the tundish with a cover used in the conventional continuous casting apparatus described above, in order to eliminate the thermal deformation of the tundish body and / or the tundish cover, and to blow the vicinity of the thermal deformation. The refractory material such as castables, which are hardened and lined after being hardened, are damaged by thermal deformation of the holding material consisting of flanges, etc., and prevent heat damage that will fall off and impair the fire resistance structure, An object of the present invention is to provide a continuous casting apparatus capable of reducing maintenance work such as repair of a heat-damaged portion, reducing interruption of operation due to maintenance work, and improving productivity.
[0011]
[Means for Solving the Problems]
Therefore, the first continuous casting apparatus of the present invention employs the following means.
[0012]
(1) In a continuous casting apparatus provided with a tundish with a cover comprising a tundish main body and a tundish cover provided on an upper part of the tundish main body, the tundish cover is provided along an outer peripheral edge of the tundish cover, and is lined with a bottom surface of the tundish cover. And a cooling means for cooling the refractory holding bottom steel sheet heated by heat radiation from the molten metal.
[0013]
(A) Thereby, the bottom plate for refractory holding, which is heated by radiant heat from the molten metal supplied into the tundish body distributed to the mold and deformed, the temperature rise is reduced by cooling by the cooling means, and the deformation is prevented. In addition to being able to prevent fire, the refractory castables are lined on the bottom of the tundish cover, held by the bottom plate for holding the refractory, protect the tundish cover from radiant heat, etc., and also prevent the radiant heat from dissipating around. It is possible to prevent breakage and falling off due to deformation of the object holding bottom steel plate.
[0014]
For this reason, it is not necessary to frequently repair the so-called thermally damaged portion of the tundish cover such as the deformation of the bottom plate for holding the refractory and the breakage and falling off of the refractory castable which have been required at regular intervals. The interruption of the continuous casting operation caused by the repair can be reduced, and the productivity of the continuous casting device can be improved.
[0015]
The second continuous casting apparatus of the present invention employs the following means in addition to the means (1) described above.
[0016]
(2) A cooling means is provided along the outer peripheral edge of the tundish cover over the entire circumference of the tundish cover, and a cooling medium for circulating and circulating a cooling medium for cooling the refractory holding bottom steel plate therein. It consisted of a hollow tube with a passage formed inside.
[0017]
(B) Thereby, in addition to the above (a), the refractory retaining bottom steel plate provided along the outer peripheral edge of the tundish cover is uniformly cooled by the cooling medium circulating and flowing through the hollow pipe, The deformation in the inward direction of the tundish cover can be prevented, and the deformation in the outer peripheral edge direction can also be prevented.
[0018]
For this reason, the tundish cover is placed on the tundish main body in a state in which the gap with the upper edge of the tundish main body is reduced, and it is possible to effectively prevent the radiation of the radiant heat from the molten metal to the periphery. .
[0019]
Further, a third continuous casting apparatus of the present invention employs the following means in addition to the above-mentioned means (1) or (1) and (2).
[0020]
(3) A cooling means is provided over the entire circumference along the outer peripheral edge of the tundish cover, and a square pipe having a flow path for circulating and circulating cooling water therein, and a top surface fixed to the bottom surface of the square tube. The refractory holding bottom steel plate described above, which is provided along the bottom surface of the square pipe, and the inner peripheral portion upper surface is brought into contact with the lower surface of the refractory holding bottom steel plate, and along the upper edge of the tundish body. It consisted of the flanges provided.
[0021]
(C) Accordingly, in addition to the above (a) or (a) and (b), the refractory retaining bottom steel plate provided over the entire outer periphery of the tundish cover circulates in the square pipe, The cooling water circulates evenly and effectively over the entire circumference to prevent deformation in the inward direction of the tundish cover and deformation in the outer peripheral direction. The flange provided on the upper edge of the tundish main body can be prevented from being deformed by being cooled through the refractory holding bottom steel plate which is arranged in contact with the bottom surface and is cooled by the cooling water.
[0022]
In addition, along with these deformations, the tundish body is lined on the inner side edge and held by the flange to protect the tundish body in the vicinity of the flange from direct heating from molten steel or heating by radiant heat, and further to the periphery. It is possible to prevent the refractory castable, which prevents radiation heat dissipation, from being damaged or dropped.
[0023]
For this purpose, the deformation of the bottom plate for holding the refractory and the flange of the tundish body, which were required at regular intervals in the past, and the tundish cover and the refractory castable in which the tundish body has a refractory structure accompanying these deformations. Prevents breakage, falling off, etc., and in addition to the tundish cover, repairs to the thermally damaged part of the tundish body can be reduced, and interruption of continuous casting work caused by the repair can be reduced, and productivity of the continuous casting device can be reduced. Can be improved.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a continuous casting apparatus of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view of a tundish with a cover that constitutes a continuous casting apparatus according to a first embodiment of the present invention. FIG. 2 is a partial cross-sectional view of the tundish cover taken along the line AA shown in FIG. FIG. 2 is a partial cross-sectional view of the tundish cover taken along the line BB shown in FIG. 1.
[0025]
In the figure, reference numeral 10 denotes a tundish cover which has the same structure as the conventional tundish main body 30 and constitutes a tundish with a cover of the continuous casting apparatus of the present embodiment together with the tundish main body 30.
[0026]
The tundish cover 10 is provided on the outer peripheral portion, and is provided with a cooling square tube 11 also serving as a frame provided in communication with a flow path for cooling water, and an outer peripheral portion is welded to the upper surface of the cooling square tube 11 by welding or the like. The top steel plate 12 which is fixed and integrally provided, and the flange shape which is fixed to the lower surface of the cooling square tube 11 by welding or the like and is provided so as to protrude a small distance inward from the inner peripheral end of the cooling square tube 11. A number of L-shaped lining holding metal pieces 14 protruding downward from the lower surface of the top steel sheet 12 and being fixed to the lower surface of the top steel sheet 12 by welding or the like, and a bottom steel sheet 13 for holding the refractory material. From the overhanging end of the steel plate 12 to the entire lower surface of the top steel plate 12 and hardened to form a lining layer held by the lining holding hardware 14 and an irregular refractory castable 15.
[0027]
Further, the bottom plate 13 for holding the refractory material of the tundish cover 10 is arranged so that the entire bottom surface portion overlaps the inner peripheral side of the flange 31 formed on the upper edge portion of the tundish body 30.
The cooling square pipe 11 is connected to a cooling water supply / discharge pipe (not shown), and communicates with the cooling water so as to circulate the cooling water in a flow path provided on the entire circumference of the tundish cover 10.
Reference numeral 44 denotes a slit around the molten steel receiving port, and reference numeral 45 denotes a heating burner insertion port provided in the tundish cover 10, which is formed similarly to that provided in the conventional tundish cover 40 shown in FIGS. .
[0028]
FIG. 2 is a partial cross-sectional view taken along the line AA shown in FIG. 1 as described above, and details of the overlapping state of the side edge of the tundish cover 10 excluding the slit 44 and the side edge of the tundish main body 30. FIG. 3 is a cross-sectional view taken along the line BB in FIG. 1, showing details of the overlapping state of the side edge of the tundish cover 10 at the slit 44 and the side edge of the tundish body 30, 3 shows details of a side edge of the tundish cover 10 arranged at the center of the tundish main body 30.
[0029]
As shown in FIG. 3, the irregular-shaped refractory castable 15 is sprayed and hardened on the outer surface of the cooling square tube 11 facing the molten steel receiving port 34 at the slit 44, and is lined. The refractory castable 15 which is fixed and fixed to the bottom of the square tube 11 for cooling, protrudes from both sides of the bottom surface, and is lined with the outer surface of the square tube 11 for cooling. Is prevented from deforming the bottom plate 13 for holding the refractory material.
[0030]
The tundish cover 10 of the present embodiment is configured as described above, and has a flange-like bottom plate 13 for holding a refractory material, which is fixed to the bottom surface of a cooling square tube 11 provided on the outer peripheral portion of the tundish cover 10. Are arranged so as to overlap with the flange 31 provided on the upper edge of the tundish main body 30, and the tundish cover 10 is mounted on the tundish main body 30. When the cooling water is circulated in the inside, the bottom plate 13 for holding the refractory material is cooled with water, and the flange 31 of the upper edge of the tundish body 30 overlapping with the bottom plate 13 for holding the refractory material is also cooled with water. Cooled.
[0031]
For this reason, the refractory castables 15 and 33 are not lined, but face the inside of the tundish body 30 in a bare steel plate state, and are exposed to the radiant heat of the molten steel 35. The temperature rise with the flange 31 of the upper edge of the 30 is suppressed, and even when used for a long time, the bottom plate 13 for holding the refractory material and the flange 31 of the upper edge of the tundish main body 30 due to these heat effects. Deformation is prevented.
[0032]
In addition, since the refractory material holding bottom steel plate 13 and the flange 31 are prevented from being deformed, the lower surface of the top steel plate 12, especially the vicinity of the refractory material holding bottom steel plate 13, is hardened by spraying. An amorphous refractory castable 15 that is held on the upper surface, and an amorphous refractory that is sprayed and hardened on the inner surface of the dish-shaped steel plate structure 32, particularly near the flange 31, so as to be held on the lower surface of the flange 31. Breakage and falling off of the object castable 33 can be prevented.
[0033]
Further, the deformation of the bottom plate 13 for retaining the refractory material, which is provided at a portion of the tundish 10 facing the hot water receiving port 34 and protrudes from both sides of the bottom surface of the square tube 11 for cooling, is performed inside the square tube 11 for cooling. This is effectively prevented by the flowing cooling water, and the breakage and falling off of the refractory castables 15 lining the outer surface of the cooling square tube 11 held by the refractory material holding bottom steel plate 13 are effectively prevented. Is prevented.
[0034]
As a result, it is possible to greatly reduce the thermal deformation of the tundish cover 10 and the tundish main body 30 and the maintenance work of the heat-damaged portion such as breakage and dropping which occurs in the refractory castables 15 and 33 due to the thermal deformation.
For this reason, the continuous casting operation is not interrupted by these maintenance operations, and effects such as improvement in productivity of the continuous casting apparatus can be obtained.
In the above-described embodiment, the tundish cover 10 has been described with reference to FIGS. 1 to 3. However, the present invention is not limited to such a shape, and the tundish body used is By changing the shape of the tundish cover 10 as appropriate according to the shape of the thirty, and by adopting a similar configuration, the same operation and effect can be obtained.
[0035]
【The invention's effect】
As described above, the continuous casting apparatus of the present invention is a continuous casting apparatus provided with a tundish with a cover, provided on the outer peripheral edge of the tundish cover and holding a refractory castable lined on the bottom of the tundish cover. A cooling means for cooling the bottom steel plate for holding the article and the bottom steel sheet for holding the refractory heated by the molten metal is provided.
[0036]
Thus, the refractory holding bottom steel sheet, which is heated and deformed by radiant heat from the molten metal or the like, is cooled by the cooling means, and deformation due to temperature rise is prevented.
In addition, the bottom of the refractory castable, which is held on the bottom of the tundish cover with a refractory retaining bottom steel plate, protects the tundish cover from radiant heat, etc. In addition, it is possible to prevent the falling off, and to reduce the repair of the heat damaged part such as the deformation of the refractory holding bottom steel plate, the breakage of the refractory castable, the falling off, etc. which were required at regular intervals in the past, the work interruption due to this repair is reduced, The productivity of the continuous casting device can be improved.
[0037]
Further, a cooling means is provided around the entire outer peripheral edge of the tundish cover, and circulates and circulates a cooling medium for cooling the refractory-holding bottom steel plate inside, and a hollow in which a flow path is formed inside. Pipe was provided.
[0038]
Thereby, the refractory holding bottom steel plate provided along the outer periphery of the tundish cover is uniformly cooled by the circulating and circulating cooling medium, and can be prevented from being deformed inward and outwardly. The gap between the tundish main body and the tundish body can be reduced, and the radiation of radiant heat from the molten metal to the surroundings can be effectively prevented.
[0039]
In addition, a cooling means is provided on the entire circumference along the outer peripheral edge of the tundish cover, and a square tube having a flow path for circulating and circulating cooling water is formed. The inner peripheral edge upper surface is brought into contact with the bottom surface of the refractory holding bottom steel plate and the bottom surface of the refractory holding bottom steel plate, and a flange is provided along the upper edge of the tundish body from the outside to the inside.
[0040]
As a result, the bottom steel plate for holding the refractory is cooled evenly and effectively by the cooling water circulating and circulating in the square tube, thereby preventing the inward deformation and the outer circumferential edge deformation from occurring. The flange provided on the upper edge is also cooled through the refractory retaining bottom steel plate and can be prevented from being deformed, and the refractory castable held by the flange is lined with the inner side edge of the tundish body accompanying the deformation, Dropout can be prevented.
For this reason, the deformation of the flange of the tundish body, which was required at regular intervals, and the refractory castable, which has a refractory structure due to the deformation, are prevented from being broken or dropped, and the tundish cover is added to the tundish cover. Repair of the heat-damaged portion of the main body can be reduced, work interruption due to the repair can be reduced, and productivity of the continuous casting device can be improved.
[Brief description of the drawings]
FIG. 1 is a plan view of a tundish with a cover that constitutes a continuous casting apparatus according to a first embodiment of the present invention;
2 is a partial cross-sectional view of the tundish with a cover taken along the line AA shown in FIG.
FIG. 3 is a partial cross-sectional view of the tundish with a cover taken along line BB shown in FIG. 1;
FIG. 4 is a plan view showing an example of a conventional tundish with a cover. FIG. 5 is a partial cross-sectional view of the tundish with a cover taken along line CC shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Tundish cover 11 Cooling square pipe 12 Top steel plate 13 Bottom steel plate for holding refractory material 14 Lining holding hardware 15 Irregular refractory castable 30 Tundish body 31 Flange 32 Dish-shaped steel plate structure 32a Refractory retaining hardware 33 Irregular refractory Castable 34 Receiving port 35 Molten steel 36 Molten steel distribution port 40 Tundish cover 41 Flange 42 Lid-shaped steel plate structure 42 a Refractory holding metal 43 Irregular refractory castable 44 Slit 45 Heating burner insertion port

Claims (3)

In a continuous casting apparatus having a tundish body for distributing a supplied molten metal to a mold and a tundish cover provided on an upper part of the tundish body for reducing heat radiation from the molten metal, the tundish cover is provided along an outer peripheral edge of the tundish cover. A refractory holding bottom steel plate for holding a refractory castable lined on the bottom surface of the tundish cover, and cooling means for cooling the refractory holding bottom steel plate heated by heat radiation from the molten metal. A continuous casting apparatus characterized by being provided. 2. The continuous casting according to claim 1, wherein the cooling unit is a hollow tube provided around the entire outer peripheral edge of the tundish cover and circulating a cooling medium to cool the refractory holding bottom steel plate. 3. apparatus. The cooling means is provided on the entire outer peripheral edge of the tundish cover, and a square tube for circulating and circulating cooling water, and the refractory holding bottom steel plate provided with an upper surface fixed to the bottom surface of the square tube. A flange provided along an outer periphery of an upper edge of the tundish main body, and having an inner peripheral edge upper surface in contact with a lower surface of the refractory retaining bottom steel plate. The continuous casting apparatus according to claim 1 or 2.

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