Specification
Title of invention: Apparatus and method for treating molten steel
Technical field
[One]
The present invention relates to a molten steel treatment apparatus and method, and more particularly, to a molten steel treatment apparatus and method capable of controlling the level of molten steel contained in the body at the initial stage, the middle stage and the end stage of the process.
BACKGROUND ART
[2]
Turning of the continuous casting plant is a device for continuously injecting steels, for example molten steel, from a ladle into a mold. The tundish has the function of storing the molten steel for a certain period of time, maintaining the temperature, lengthening the residence time of the molten steel, and helping to separate the inclusions from each other. The tundish also has the function of continuously supplying the molten steel to the mold while continuing the continuous casting process while continuously exchanging ladders.
[3]
On the other hand, as shown in the following Patent Documents, conventionally, a method has been known in which a gas is injected into a turn-dish or a magnetic field is applied to induce an upward flow of molten steel, a molten steel is passed through slag in a droplet state, The inclusions are separated from the molten steel contained in the tundish by lifting the residence time of the molten steel by improving the shapes of the dam and the weir provided inside the dicing.
[4]
However, in the above-described conventional method, the inclusions can be separated from the molten steel in the turn-dish only when the molten steel level in the turn-dish is maintained at a certain level. It is difficult to separate the inclusions from the molten steel contained in the tundish by the above-described conventional method at the beginning, middle, and end of the process in which the molten steel level in the tundish is relatively low.
[5]
Therefore, by using the remaining molten steel of the cast steel and the tundish produced in the middle stage of the process in which the cast steel produced at the beginning of the process of supplying molten steel to the turndish is replaced and the new molten steel is supplied to the turndish, Lt; RTI ID = 0.0 & gt; finishing & lt; / RTI & gt; As a result, the slabs produced in the initial, middle, and late stages of the process are scrapped without securing the desired quality.
[6]
(Patent Document 1) KR10-2014-0085127 A
[7]
(Patent Document 2) KR10-2013-0076187 A
[8]
(Patent Document 3) KR10-2013-0127247 A
[9]
(Patent Document 4) KR10-2013-0047136 A
DETAILED DESCRIPTION OF THE INVENTION
Technical Challenge
[10]
The present invention provides a molten steel treatment apparatus and method capable of controlling the level of molten steel contained in the inside of a body by region.
[11]
The present invention provides a molten steel treating apparatus and method capable of locally raising the level of molten steel at the initial, middle, and end of the process.
[12]
The present invention provides a molten steel treatment apparatus and method capable of rapidly raising the molten steel level at the shroud nozzle side at the initial stage of the process so as to advance the injection timing of the flux.
[13]
The present invention provides a molten steel treatment apparatus and method capable of securing a residual amount in the vicinity of a ladle by moving residual molten steel to the ladle side in the middle and late stages of the process.
[14]
The present invention provides a molten steel processing apparatus and method capable of reducing inclusion indices produced during the initial, middle, and late stages of a process.
Task solution
[15]
A molten steel treatment apparatus according to an embodiment of the present invention includes: a body having an interior opened upward and a lug opening at a bottom; A fixed dam extending in a width direction of the main body and being installed in contact with both the bottom portion and longitudinal side walls of the main body; A control dam extending in the width direction of the main body; And a driving unit for supporting the control dam movably and rotatably.
[16]
And a stopper installed on both longitudinal side walls of the main body on the opposite side of the ladder from the fixed dam.
[17]
And a residual hole formed through the lower portion of the fixed dam in the longitudinal direction.
[18]
And a control unit for controlling the operation of the driving unit so that the control dam is moved in the longitudinal direction of the main body so that the inside of the main body is divided into a supply region and a discharge region and isolated from each other.
[19]
The control dam may have a width in a width direction such that the control dam is spaced apart from both longitudinal side walls of the main body at a position where the stopper is installed.
[20]
The control dam may be formed to have a width in a width direction so as to be in contact with the bottom portion of the main body and both side walls in the longitudinal direction at a position where the fixed dam is installed.
[21]
The control dam may be formed to have a width in the width direction such that both side edges in the width direction contact or overlap the stopper at the position where the stopper is installed.
[22]
And a projection protruding from a lower surface of the one side of the control dam and having a loading surface on the upper side.
[23]
The stopper may extend in the height direction of the main body and may protrude in the width direction.
[24]
A plurality of fixed dams are provided to be opposed to each other in the longitudinal direction at a central portion of the main body. A discharge area is formed on the side of the lancing hole with respect to the fixed dam, and a supply area is formed on the opposite side of the lancing hole .
[25]
A plurality of the control dam and the stopper may be installed in the supply region so as to face each other.
[26]
A molten steel treatment method according to an embodiment of the present invention is a method of treating steel comprising the steps of opening the interior upward, forming a ladder at the bottom, and installing a plurality of dams dividing the interior into a supply region and a discharge region A process of preparing a main body; Isolating the supply region from the discharge region using the plurality of dams; Supplying molten steel to the supply region; Connecting the supply region and the discharge region using the plurality of dams; And controlling the molten steel level of the discharge region by isolating the discharge region from the supply region using the plurality of dams.
[27]
The step of connecting the supply region and the discharge region may include a step of casting the slab into the molten steel in the discharge region connected to the supply region.
[28]
The process of controlling the molten steel level of the discharge region may include casting the slab from the supply region to the residual molten steel in the discharge region isolated from the supply region.
[29]
The step of controlling the molten steel level of the discharge region may include casting the slab from the supply region into the residual molten steel of the discharge region isolated and supplying the subsequent molten steel to the supply region.
[30]
Supplying the subsequent molten steel to the discharge region by connecting the supply region and the discharge region using the plurality of dams after the process of supplying the subsequent molten steel to the supply region; Isolating the discharge region from the supply region using the plurality of dams and controlling a molten steel level of the discharge region; And casting the slab from the supply region to the remaining molten steel in the discharge region isolated from the supply region.
Effects of the Invention
[31]
According to the embodiment of the present invention, the level of the molten steel contained in the main body can be controlled for each region. In addition, the level of molten steel can be locally raised at the initial, middle, and end of the process. That is, the molten steel level on the side of the shroud nozzle can be quickly raised at the initial stage of the process to advance the time for introducing the flux, and the remaining molten steel is moved to the lubrication port side in the middle and end of the process, .
[32]
From this, it is possible to reduce the index of inclusion produced in the initial stage, the middle stage and the late stage of the process.
[33]
For example, when applied to a continuous casting plant of a steelworks, the interior of the body is divided into a supply region and an exhaust region, and the feed region is isolated from the exhaust region by using a fixed dam and a control dam, Can be moved. Therefore, it is possible to raise the molten steel level of the supply region in which the shroud nozzle is located at the initial stage of the process at a faster rate than before, to advance the injection timing of the flux to the prior art, The residual molten steel can be moved, and the amount of the remaining molten metal in the vicinity of the ladle can be ensured to be equal to or higher than the minimum remaining molten metal amount.
[34]
From this, it is possible to reduce the index of inclusion produced at the initial stage, the middle stage and the end stage of the continuous casting process.
Brief Description of Drawings
[35]
1 is a view showing a molten steel processing apparatus according to an embodiment of the present invention.
[36]
2 is a view for explaining a main part of a molten steel treatment apparatus according to an embodiment of the present invention.
[37]
3 is a view for explaining a main part of a molten steel treatment apparatus according to a modification of the present invention.
[38]
4 is a view for explaining a main part of a molten steel treatment apparatus according to an embodiment of the present invention.
[39]
5 is a view for explaining a main part of a molten steel treatment apparatus according to an embodiment of the present invention.
[40]
6 is a view for explaining the operation of the molten steel treating apparatus according to the embodiment of the present invention.
[41]
7 is a view for explaining the operation of the molten steel treating apparatus according to the comparative example of the present invention.
[42]
8 is a graph for explaining casting results of a continuous casting process to which the molten steel treatment method according to the embodiment of the present invention and the comparative example is applied.
DETAILED DESCRIPTION OF THE INVENTION
[43]
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below, but may be embodied in various forms. It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS The drawings may be exaggerated or exploded to illustrate embodiments of the present invention, wherein like reference numerals refer to like elements throughout.
[44]
Hereinafter, embodiments of the present invention will be described in detail with reference to a continuous casting facility of a steelworks. However, the present invention can be applied to various equipments, processes, etc., which supply various melts to the inside and stay therein for a predetermined time,
[45]
Fig. 1 is a schematic view of a molten steel treatment apparatus according to an embodiment of the present invention, Fig. 2 (a) is a schematic view showing an enlarged main body of a molten steel treatment apparatus according to an embodiment of the present invention, Fig. 2 1 is an enlarged plan view of a main body of a molten steel treatment apparatus according to an embodiment of the present invention. 3 is an enlarged schematic view of a body of a molten steel treatment apparatus according to a modification of the present invention.
[46]
4 (a) to 4 (c) are side cross-sectional views showing the inside of the body of the molten steel treatment apparatus according to the embodiment of the present invention. 4 (a) is a side sectional view showing the main body cut in the width direction at a position where there is no stopper, Fig. 4 (b) is a side sectional view showing the main body cut in the width direction at the position where the stopper is provided, 4 (c) is a side cross-sectional view showing the main body at the position where the stopper is installed in a state in which the control dam is moved to the position where the stopper is installed, in the width direction.
[47]
5 (a) to 5 (c) are plan views showing the inside of the body of the molten steel treatment apparatus according to the embodiment of the present invention. 4 (b) is a plan view showing the main body at a position where the stopper is installed, and FIG. 4 (c) is a view showing the state where the stopper is installed Fig. 7 is a plan view showing a main body of a position where the stopper is installed in a state in which the dam is moved.
[48]
1 to 3, in the embodiment and the modification of the present invention, the control dam is tightly attached to the stopper at the lubrication port side with the stopper as the center, but the close position of the control dam with respect to the stopper is not limited to the above . For example, the control dam can be brought into close contact with the stopper on the opposite side of the louver, around the stopper. Accordingly, the control dam can more reliably control the flow of molten steel while partially dispersing the pressure due to the flow of the molten steel in the stopper, while the molten steel is continuously injected into the interior of the main body.
[49]
The molten steel treatment apparatus according to the embodiment of the present invention will be described in detail with reference to Figs. 1, 2, 4 and 5.
[50]
A molten steel treatment apparatus according to an embodiment of the present invention is provided with a transportation container 10, a first nozzle 20, a main body 30, a second nozzle 40, a mold 50, a dam unit 60, And a control unit 80. [0033] Such a molten steel treatment apparatus may be, for example, a continuous casting process in which a continuous molten steel having the same or different components as those of the previous molten steel is supplied into the main body 30 containing the previous molten steel while the carrier vessel 10 is being replaced, And a continuous casting process of the casting process.
[51]
The carrier vessel 10 may include a ladle. The conveying vessel 10 is, for example, a cylindrical vessel whose interior is opened upward, and a refractory is built up therein so that the molten steel M can be contained therein. The transport container 10 is provided movably above the main body 30 and serves to supply the molten steel M contained in the main body 30 to the main body 20. A collector nozzle (not shown) may be mounted through the lower side of the carrier container 10, and a first nozzle 20 may be connected to a lower portion of the collector nozzle.
[52]
The first nozzle 20 may include a shroud nozzle. For example, the first nozzle 20 may be movably supported by a manipulator (not shown) provided at one side of the main body 30, and may be coupled to the collector nozzle 10 at a lower side of the carrier container 10, have.
[53]
The body 30 may include a tundish. The main body 30 is a container of a predetermined shape for receiving molten steel M from the transportation container 10 at a lower side of the transportation container 10 and temporarily storing the molten steel M. The main body 30 is made of an outer wall of the main body 30, And a refractory portion 32 built inside the refractory 31. The body 30 can be symmetrically symmetrical with respect to the center in the longitudinal direction (x-axis direction), and the width in the longitudinal direction can be larger than the width in the width direction. In addition, the main body 30 may have a shape in which the central portion in the longitudinal direction protrudes to one side in the width direction (y-axis direction).
[54]
On the other hand, the width of the main body 30 in the width direction can be reduced toward the both side edges in the longitudinal direction from the central portion in the longitudinal direction. That is, the width of the main body 30 can be narrowed from the center portion to the end portion in the longitudinal direction.
[55]
The inside of the main body 30 may be opened upward, and a cover (not shown) may be mounted on the top. An injection port may be formed at the center of the cover, and the first nozzle 20 may be inserted into the injection port and connected to the inside of the main body 30. The bottom portion 33 of the main body 30 is provided with a plurality of louvers 35. The main body 30 has a plurality of left and right sides symmetrical with respect to the center in the longitudinal direction Respectively.
[56]
The opening 35 is formed in the vicinity of the widthwise opposite side walls 34a of the side walls of the main body 30 in such a manner that the molten steel M is introduced into the main body 30. [ And may be formed through the bottom portion 33 in the height direction. The second nozzle 40 may be connected to the main body 30 by being attached to the luer opening 35 at the lower side of the main body 30.
[57]
The second nozzle 40 may include a submerged entry nozzle. The second nozzle 40 is a hollow tube through which the molten steel M passes. The second nozzle 40 extends in the height direction (z-axis direction), the upper and lower portions are opened, and the inside can be protected by the refractory. The second nozzle 40 can be mounted through the louver 35 at the lower side of the main body 30 so as to supply the molten steel M contained in the main body 30 to the mold 50. A gate (not shown) of a slide structure may be provided at one side of the second nozzle 40 and a gate may adjust the opening and closing amount of the molten steel M by controlling the opening degree of the second nozzle 40.
[58]
The mold 50 has a pair of first plates facing each other spaced apart from each other in the longitudinal direction (x-axis direction) and spaced from each other in the width direction (y-axis direction) And may be a rectangular or square hollow block in which a side surface is formed by a pair of second plates and a space in which the upper and lower portions are opened and the molten steel M is first solidified therein is formed. The mold 50 is positioned to surround the lower portion of the second nozzle 40 and receives the molten steel M from the main body 30 to solidify the molten steel M and continuously draw the molten steel M.
[59]
A coolant (not shown) may be provided on the lower side of the mold 50. The cooling stand cools the casting withdrawn from the mold 50 and performs a series of molding operations. The cooling zone is provided with a plurality of segments, and the plurality of segments are continuously arranged in a predetermined direction to form a cooling zone of a curved or vertical curved shape. Each of the segments is provided with a plurality of rolls to guide the withdrawal of the strip. A nozzle is provided between each of the rolls, and the nozzle cools the casting by injecting cooling water into the casting.
[60]
Hereinafter, a dam unit according to an embodiment of the present invention will be described in detail. The dam unit 60 can be installed inside the main body 30 to control the flow of the steel, for example, molten steel M contained in the main body 30. [ The dam unit 60 may have a shape and a structure symmetrical with respect to the longitudinal direction (x-axis direction) center portion of the main body 30, respectively.
[61]
The dam unit 60 extends in the width direction (y-axis direction) of the main body 30 and extends from the center portion in the longitudinal direction of the main body 30 to the side of the lug 35, A fixed dam 61 which is installed in contact with the longitudinally opposite side walls 34a and 33b and longitudinally opposite side walls 34b of the main body 30 in the width direction of the main body 30, And a stopper 64 provided on both longitudinal side walls 34b of the main body 30 on the opposite side of the louver 35 with respect to the fixed dam 63 as a center Can be.
[62]
The fixed dam 61 is a dam made of refractory and can be formed in the shape of a plate extending in the width direction of the main body 30 and having a predetermined thickness in the longitudinal direction and a predetermined area in the width direction and height direction, 64 to the side of the louver 35 and to the lower portion of the main body 30. The fixed dam 61 can cause the molten steel M guided to the inside lower side of the main body 30 to rise by the control dam 63. [ The upper end of the fixed dam 61 may have a predetermined height from the bottom portion 33 of the main body 30 so that the upward flow of the molten steel M is easy and the flow velocity of the molten steel M can be formed at a desired flow rate. On the other hand, the upward flow of the molten steel M is relatively suppressed as the height of the fixed dam 61 increases, and the flow rate of the molten steel M relatively increases as the height decreases.
[63]
The fixed dam 61 may be provided at a central portion of the main body 30 so as to be spaced apart from each other in the longitudinal direction so as to face each other. The inside of the main body 30 can be divided into the supply region A and the discharge region B by the installation structure for partitioning the main body B into the supply region A and the discharge region B. [ For example, the supply region A may be formed on the inner side of the fixed dam 61, and the discharge region B may be formed on the outer side.
[64]
At this time, the inner side of the fixed dam 61 where the supply region A is formed may be a region on the opposite side of the discharge port 35 with the fixed dam 61 as a center. The outer side of the fixed dam 61 in which the discharge region B is formed may be a region on the side of the discharge port 35 with the fixed dam 61 as a center.
[65]
In the supply region A, a plurality of, for example, two stoppers 64 may be provided facing each other. Corresponding to this, a plurality of, for example, two control dam 63 may be installed in the supply region A, facing each other.
[66]
The immersed hole 62 is formed by penetrating the lower portion of the fixed dam 61 in the longitudinal direction and the inside thereof can be connected to the bottom portion 33 of the main body 30. The molten steel M on the inner lower side of the main body 30 can be moved from the supply region A to the discharge region B side through the dwelling hole 62. [
[67]
The control dam 63 is a dam made of refractory material and can be formed in the shape of a plate extending in the width direction of the main body 30 and having a width in the longitudinal direction and a width in the width direction and height direction. The control dam 63 is disposed in the supply area A of the main body 30 and is supported by the driving part 70 and can be moved in the longitudinal direction and in the width direction and the height direction respectively and is rotated about the axis in the height direction Can be.
[68]
The control dam 63 is provided on both longitudinal side walls 34b of the main body 30 in order to prevent structural interference with the main body 30 at the position where the stopper 64 is installed or at the time of movement and rotation in the supply area A. [ The width in the width direction is formed so as to be in contact with both the bottom portion 33 of the main body 30 and the both side walls 34b in the longitudinal direction at the position where the fixed dam 61 is installed Can be.
[69]
The control dam 63 can be moved and rotated without collision with the main body 30 in the supply region A of the main body 30 and can be moved from the supply region A side to the installation position So that it can be brought into close contact with the fixed dam 61 and both the bottom portion 33 of the main body 30 and the both longitudinal side walls 34b to isolate the supply region A from the discharge region B. [
[70]
The control dam 63 is formed to have a width in the width direction so as to be spaced apart from both longitudinal side walls 34b of the main body 30. The width of the control dam 63 is set so that both side edges in the width direction A width in the width direction can be formed so as to be contacted or overlapped.
[71]
The control dam 63 is moved from the upper part of the main body 30 to the position where the stopper 64 is provided and the upper end of the control dam 63 is pressed against the end of the molten steel M A width in the height direction may be formed such that the lower end thereof is spaced apart from the bottom portion 33 of the main body 30.
[72]
The control dam 63 is brought into close contact with the stopper 64 so as to serve as a weir and flows down into the main body 30 and flows in the molten steel M led to the discharge region B side It is possible to reduce the strength of the initial flow of the molten steel M to a desired strength.
[73]
The stopper 64 is installed on both longitudinal side walls 34b of the main body 30 at a position spaced from the fixed dam 61 toward the center in the longitudinal direction of the main body 30 and extends in the height direction of the main body 30 And may protrude in the width direction. The stopper 64 serves to seal between the control dam 63 and both longitudinal side walls 34b of the main body 30 when the control dam 63 is moved to the position where the stopper 64 is installed and closely attached thereto. The stopper 64 may be made of refractory material.
[74]
The protruding length of the stopper 64 in the width direction can be formed corresponding to the width of the control dam 63 and the distance between the control dam 63 and both longitudinal side walls 34b of the main body 30 It may be equal to or greater than the spacing.
[75]
On the other hand, the position of the stopper 64 in the longitudinal direction of the main body 30 is such that the molten steel is supplied in a steady state in a state in which the control dam 63 is closely attached to the stopper 64, Can be selected as the location.
[76]
The driving unit 70 may be, for example, a mechanical or hydraulic type driving unit provided at a predetermined position outside the main body 30. [ The driving unit 70 may be formed to support the control dam 63 movably and rotatably and more specifically may be formed to support the control dam 63 movably along the longitudinal direction of the main body 30 And can also be formed to support the control dam 63 in a tilting or rotatable manner about an axis in the height direction.
[77]
At this time, the above-described tilting is performed by controlling the angle of the control dam 63 about the axis in the height direction, and by controlling the angle of the control dam 63 to a small degree at which the control dam 63 can pass through the stopper 64 Means to control the posture of the control dam 63 by varying the angle. In addition, the above-mentioned rotation is controlled by controlling the angle of the control dam 63 about the axis in the height direction at a relatively large angle rather than a small angle at which the control dam 63 can pass through the stopper 64 It means controlling the angle of the dam 63 and controlling the posture of the control dam 63.
[78]
The drive unit 70 includes a first drive rod 71 extending in the height direction and mounted on the upper end of the control dam 63 so as to be aligned with the central portion in the width direction of the control dam 63 from above the control dam 63, A second driving rod 72 extending in the width direction and having a driving rod 71 mounted at one end in the width direction and being movably supported in a height direction, a second driving rod 72 formed to be movable in the longitudinal direction, And a fourth driving rod 74 connected to the third driving rod 73 and supporting the movement in the longitudinal direction.
[79]
On the other hand, the driving unit 70 can be formed in various configurations and systems capable of supporting the control dam 63 movably and rotatably, and is not particularly limited in the above-described configuration and method.
[80]
The control unit 80 may be configured to control the operation of the driving unit 70 in accordance with the input process pattern. The control unit 80 moves the control dam 63 in the longitudinal direction and the height direction of the main body 30 and rotates about the axis in the height direction so that the fixed dam 61 The stopper 64 can be brought into tight contact with the stopper 64 or moved toward the center of the body 30 in the longitudinal direction. These operations can be controlled differently according to the detailed process of the process. The inside of the main body 30 can be divided into the supply region A and the discharge region B and can be isolated from each other by the control of the control unit 80. The molten steel M The residual molten steel in the supply region A of the main body 30 can be pushed toward the discharge region B and moved.
[81]
Although the embodiments of the present invention have been described with reference to FIGS. 1, 2, 4, and 5, the present invention can be variously configured as follows.
[82]
Hereinafter, a molten steel treating apparatus according to a modified example of the present invention will be described with reference to Figs. 1 and 3. Fig. Since the molten steel processing apparatus according to the modified embodiment of the present invention is partially similar in structure to the molten steel processing apparatus according to the above-described embodiment of the present invention, the description of the constituent elements overlapping with the molten steel processing apparatus according to the above- And a description will be given below focusing on a component different from the embodiment of the present invention.
[83]
The dam unit 60 'of the molten steel treatment apparatus according to the modified embodiment of the present invention extends in the width direction of the main body 30 and is disposed at a position spaced from the center of the main body 30 in the longitudinal direction to the side of the run- A fixed dam 61 that is installed in contact with the bottom portion 33 and the longitudinal side walls 34b of the fixed dam 61, a residual hole 62 formed through the bottom of the fixed dam 61 in the longitudinal direction, A control dam 63 extending in the width direction of the main body 30 and a stopper 64 (not shown) provided on both longitudinal side walls 34b of the main body 30 on the opposite side of the louver 35 from the fixed dam 63 And a protrusion 65 protruding from a lower portion of one side of the control dam 63 facing the longitudinal center portion of the main body 30. The protrusion 65 protrudes from the bottom of one side of the control dam 63 and may protrude from a central portion in the width direction of the lower side of the control dam 63.
[84]
The projecting portion 65 extends in the width direction and the longitudinal direction and has an upper surface intersecting one side of the control dam 63 and extends obliquely downward from one side in the width direction of the upper surface, And a vertical surface extending perpendicularly downward from both sides in the longitudinal direction of the upper surface and joined to the upper ends of the upper surface and the widthwise ends of the inclined surfaces. The protruding portion 65 can be removed by removing a predetermined amount of slag or flux formed on the molten steel M by using the upper surface. At this time, the protruding portion 65 may be formed as a flat surface and serve as a mounting surface. In this case, slag or flux can be removed from the molten steel by stacking at least one of the slag and the flux on the mounting surface. have. Alternatively, the protrusions 65 may be configured such that the top surface is open upward and a loading space is formed therein, in which case at least one of the slag and the flux is received in the interior loading space of the protrusions 65 through the open top surface The slag or the flux can be removed from the molten steel.
[85]
6 (a) to 6 (e) are process drawings for explaining the operation of the molten steel treatment apparatus according to the embodiment of the present invention. 6 (a) is a process diagram showing the process of supplying molten steel to the supply region A isolated from the discharge region B of the main body 30, FIG. 6 (b) FIG. 4 is a process diagram showing a process in which molten steel is supplied to a supply region A isolated from the region B at a predetermined level, and then the flux F is injected and applied.
[86]
6 (c) is a process chart showing the process of casting to the molten steel in the discharge region b connected to the supply region A of the main body 30, FIG. 6 (d) At least one of the slag (not shown) and the flux (F) of the molten steel bath surface is moved to the central portion side in the longitudinal direction of the main body 30 while the molten steel in the discharge region (b) connected to the supply region (A) FIG. 6 (e) is a process drawing showing the process of completing the casting from the supply region A of the main body 30 to the residual molten steel of the discharge region B isolated, for example, residual molten steel or residue.
[87]
The operation of the molten steel treatment apparatus according to the embodiment of the present invention will be described with reference to Figs. 1 and 6 (a) to 6 (e). Here, the position and operation of the dam unit 60 will be described in detail with reference to the right side of both the left and right sides of the main body 30 in the longitudinal direction.
[88]
6 (a) and 6 (b), the control dam 63 is brought into close contact with the fixed dam 61 in the initial stage of the continuous casting process, for example, From the discharge region (B). Then, the molten steel M is injected into the main body 30. At this time, the molten steel M can be injected only into the supply region A of the main body 30, and the molten steel level can be raised quickly. Thereafter, when the molten steel level of the main body 30 becomes higher than the end level of the first nozzle 20 and the end of the first nozzle 20 is immersed in the molten steel M, the flux F ) Is quickly injected into the molten steel M and applied to the bath surface, it is possible to quickly prevent the molten steel M from being reoxidized.
[89]
Thereafter, when the molten steel M is continuously supplied and the molten steel level of the main body 30 reaches a predetermined level, the control dam 63 is moved to the stopper 64 side and raised so as to be brought into close contact with the stopper 64. During this process, a space is formed between the control dam 63 and the bottom surface 33 of the main body 30 and between the control dam 63 and the longitudinal side walls 34b of the main body 30 The molten steel M and the flux F can be moved and supplied to the discharge region B through the formed spaced spaces.
[90]
The control dam 63 can be brought into close contact with the stopper 64 on the side of the second nozzle 40 with respect to the stopper 64 or on the stopper 64 on the side of the first nozzle 20 .
[91]
On the other hand, the control dam 63 and the main body (not shown) are controlled in such a manner that the control dam 63 is tilted or rotated at a predetermined angle around the axis in the height direction before the control dam 63 is moved toward the stopper 64, The molten steel M and the flux F can be moved more smoothly by adjusting the size of the spacing space formed between the longitudinal side walls 34b of the first and second plates 30 and 30.
[92]
Then, casting is started when the molten steel M supplied to the discharge region B reaches a predetermined level. The molten steel of the main body 30 is maintained at a working level while the molten steel M in the discharge region B connected to the supply region A is being cast as shown in FIG. . At this time, the control dam 63 serves as, for example, a weir in the upper region of the main body 30, and guides the flow strength of the molten steel M to the bottom of the main body 30 Control by intensity.
[93]
Thereafter, while the supply of molten steel M to the main body 30 is completed and the molten steel level of the main body 30 is lowered, as shown in Fig. 6 (d), the control dam 63 is moved to the first nozzle 20 . At this time, the control dam 63 can be moved in such a manner that the control dam 63 passes between the stoppers 64 in a state where the control dam 63 is tilted or rotated at a predetermined angle around the axis in the height direction. The control dam 63 can be easily moved through the stopper 64 without being structurally interfered with the stopper 64 from inside the main body 30. [ During this process, the slag or flux formed on the molten steel (M) can be moved toward the central portion of the main body 30, and the molten steel in the relatively clean state located in the lower portion of the main body 30, . At this time, the slag and the flux moved toward the central portion of the main body 30 can be removed from the molten steel M by being mounted on the upper surface of the protruding portion 65 protruding from one side of the control dam 63.
[94]
6 (e), the control dam 63 is fixed to the fixed dam (not shown) at the middle or end of the continuous casting process in which the molten steel level in the main body 30 gradually decreases to reach a predetermined level, The molten steel in the supply region A can be moved to the discharge region B and then the control dam 63 is brought into close contact with the fixed dam 61 to move the molten steel It is possible to isolate the discharge region B from the supply region A. [ Thereby, the molten steel level h B on the discharge region B side can be made higher than the molten steel level h A on the supply region A side . Then, the casting proceeds from the supply region A to the remaining molten steel in the isolated discharge region B.
[95]
By making the molten steel level of the discharge region B higher than the molten steel level of the supply region A in the middle or at the end of the continuous casting process, it is possible to secure the height of the remaining molten steel in the vicinity of the pouring port at or above the height at which the slag is prevented from being introduced And the quality of the cast steel produced in the middle or end of the process can be improved.
[96]
7 (a) to 7 (d) are process drawings showing the operation of a molten steel treatment apparatus according to a comparative example of the present invention. 6 and 7, the operation of the molten steel treating apparatus according to the comparative example of the present invention will be described in comparison with the operation of the molten steel treating apparatus according to the embodiment of the present invention.
[97]
7A to 7D show a molten steel treatment apparatus according to a comparative example of the present invention in which a lower dam 91 and an upper dam 92 are provided inside the main body 30, An upper dam 92 is fixedly installed on the upper side of the main body 30 at a position spaced from the first nozzle 20 toward the second nozzle 40 as in a conventional dam structure And a lower dam 91 is fixedly installed on the lower side of the main body 30 at a position spaced from the upper dam 92 to the second nozzle 40 side.
[98]
In the comparative example of the present invention, the continuous casting process for finishing the process from the beginning of the continuous casting process (see FIGS. 7 (a) and 7 (b)) in which molten steel starts to be supplied into the main body 30 The molten steel level of the main body 30 is the same throughout the entire region of the main body 30 until the last period (see Figs. 7 (c) and 7 (d) The molten steel level h ' A and the molten steel level h' B on the second nozzle 40 side are formed at the same height. As described above, in the comparative example of the present invention, the molten steel level on the side of the first nozzle 20 and the molten steel level on the side of the second nozzle 40 can not be locally adjusted. Particularly, I can not.
[99]
As described above, in the comparative example of the present invention, since the positions of the dams are fixed in the main body, the initial and end flow and molten steel level of the continuous casting process can not be controlled in a desired manner. That is, since the molten steel enters the entire interior of the main body 30 at the time of opening the first nozzle 20, the increase of the molten steel level is delayed as compared with the case of the embodiment of the present invention, The re-oxidation of the molten steel due to the contact of the molten steel can not be suppressed or prevented. In addition, the molten steel level is lowered throughout the entirety of the main body 30 at the end of the continuous casting process, so that it is relatively difficult to maintain the minimum residual amount, resulting in a decrease in the actual rate of molten steel.
[100]
On the other hand, in the embodiment of the present invention, as described above, the molten steel levels can be controlled differently for each of the supply region A and the discharge region B of the main body 30, In addition, it is possible to secure the residual amount in the vicinity of the ladle at the middle or end of the process to a minimum residual amount, thereby ensuring the quality of the cast steel and the yield rate.
[101]
8 is a graph showing inclusion indices casting the continuous casting process to which the molten steel treatment method according to the embodiment of the present invention and the comparative example is applied.
[102]
In this case, the inclusion index in FIG. 8 means the oxygen content contained in the produced cast steel. In the initial stage of the continuous casting process, a cast steel cast as molten steel at the time of first charge (Ch) is prepared, And analyzing the oxygen content of the specimen and quantifying the result. The method of analyzing the oxygen content in the cast steel and deriving it as an inclusion index is a well-known technique, and thus a detailed description thereof will be omitted.
[103]
8, the inclusion index of the cast steel produced in the continuous casting process of the molten steel treatment apparatus according to the embodiment of the present invention is larger than that of the cast inclusion index produced in the continuous casting process of the molten steel treatment apparatus according to the comparative example of the present invention As shown in Fig. This is because in the embodiment of the present invention, the molten steel level in the supply region is rapidly raised at the beginning of the continuous casting process, and the reoxidization of the molten steel can be suppressed or prevented as the injection timing of the flux is advanced. On the other hand, in the comparative example of the present invention, since the initial rising speed of the molten steel level is slower than that in the embodiment of the present invention, the time of applying the flux is also slow, and therefore, Because it can not be suppressed.
[104]
Hereinafter, a molten steel treatment method to which the molten steel treatment apparatus according to the embodiment of the present invention is applied will be described with reference to Figs. 1 to 6. Fig. Hereinafter, duplicate contents of the molten steel treatment apparatus according to the embodiment of the present invention or modifications thereof will be omitted or briefly explained.
[105]
A method of treating molten steel according to an embodiment of the present invention includes a step of providing a main body provided with a plurality of dams having an interior opened upwardly, a bottomed portion formed with a ladder and dividing the interior into a supply region and a discharge region, A process of supplying molten steel to the supply region, a process of connecting the supply region and the discharge region by using a plurality of dams, a process of supplying the discharge region by using a plurality of dams, And controlling the molten steel level in the discharge area.
[106]
A main body 30 provided with a plurality of dams for dividing the inside into a supply region A and a discharge region B . The control unit 80 controls the driving unit 70 so that the control dam 63 is brought into close contact with the fixed dam 61 to isolate the supply area A from the discharge area B.
[107]
Thereafter, the transport container 10 is positioned above the supply region A of the main body 30, and molten steel is supplied into the supply region A of the main body 30. [ Thus, the molten steel M can be supplied only to the supply region A, and the molten steel level can be raised quickly.
[108]
In other words, the injection space of the initial molten steel can be reduced by using the control dam 63, so that the molten steel level can be reached to the lower end of the first nozzle 20 at a smaller amount than before.
[109]
When the molten steel level rises and becomes higher than the end level of the first nozzle 20, the flux F is evenly applied to the molten steel bath surface to quickly prevent molten steel from being reoxidized. At this time, since the initial application area of ​​the flux (F) can be made smaller than before, the molten steel bath surface can be protected in a shorter time.
[110]
As described above, according to the application timing of the flux F, the molten steel in a clean state in which the reformation of the reformation reaction is suppressed can be supplied to the discharge region B, and the oxidized inclusions are mixed Therefore, the quality of the initial cast steel can be secured.
[111]
Thereafter, when the molten steel level rises and reaches a predetermined height, the control dam 63 is lifted and moved to release the close contact with the fixed dam 61, thereby connecting the supply region A and the discharge region B . Thereafter, the control dam 63 is brought into close contact with the stopper 64 to guide the flow of molten steel to the lower side of the main body 30. When the molten steel supplied to the discharge region B reaches a certain level, And the casting of the cast steel is started with the molten steel of the discharge region (B) connected with the casting.
[112]
The control dam 63 can be brought into close contact with the stopper 64 on the side of the second nozzle 40 with respect to the stopper 64 or on the stopper 64 on the side of the first nozzle 20 .
[113]
Thereafter, the casting is continuously performed while maintaining the molten steel in the steady state at the molten steel level (working level) in the main body 30.
[114]
When the supply of molten steel to the main body 30 is completed, the molten steel level of the main body 30 becomes lower as the casting proceeds. During this process, the control dam 63 is moved to the first nozzle 20 side to move the slag to the longitudinal center portion of the main body 30, and the molten steel in the clean state under the main body 30 to the discharge region B side . Thereafter, the slag collected in the central portion of the main body 30 can be removed from the molten steel bath surface and removed by a certain amount in such a manner that the slag is stacked on the protruding portion 65 formed on the lower portion of the control dam 63. Thus, it is possible to effectively suppress or prevent the slag from moving toward the laden port side of the main body 30 and flowing into the ladder port.
[115]
When molten steel supply to the main body 30 is completed, the molten steel level of the main body 30 becomes lower as the casting progresses, so that the residual molten steel amount in the main body 30 reaches the minimum residual molten amount. During this process, the control dam 63 is moved to the fixed dam 61 side while being lowered to a predetermined height and the molten steel in the supply region A is moved to the discharge region B side to lower the molten steel level in the discharge region B Then, the control dam 63 is brought into close contact with the fixed dam 61 to isolate the discharge area B from the supply area in a state where the molten steel level is raised.
[116]
Thereafter, the remaining molten steel of the isolated discharge region B from the supply region A is continuously supplied to the mold and cast into the cast steel. When the molten steel level of the discharge region B reaches the molten steel level at the lowest remaining molten amount, The casting process is completed.
[117]
As described above, the molten steel level in the discharge region B can be easily raised before the residual molten steel amount in the main body 30 reaches the minimum residual molten amount. Therefore, in the embodiment of the present invention, it is possible to suppress or prevent the slag flow into the lubrication port 35, thereby ensuring the quality of the cast steel, and continuing the continuous casting as the molten steel level is increased. The amount of residual water in the main body 30 can be reduced at the end point.
[118]
Although the molten steel treatment method according to the embodiment of the present invention has been described in detail above, the present invention can be variously configured including the following modifications. Hereinafter, a method of treating molten steel according to a modification of the present invention will be described.
[119]
A molten steel treatment method according to a modification of the present invention is a molten steel treatment method applicable to a continuous casting process or a continuous casting process of a bimetal type, for example, in which the interior is opened upward, the ladder is formed at the bottom, A process of providing a main body provided with a plurality of dams divided into discharge areas, a process of isolating the supply area from the discharge area using a plurality of dams, a process of supplying molten steel to the supply area, Isolating the discharge region from the supply region using a plurality of dams and controlling the level of the molten steel in the discharge region.
[120]
Here, the process of controlling the molten steel level of the discharge region includes the steps of casting the billet from the supply region into residual molten steel in the isolated discharge region and supplying the subsequent molten steel to the supply region, A step of supplying the subsequent molten steel to the discharge region by using a plurality of dams to isolate the discharge region from the supply region and controlling the molten steel level in the discharge region, And the like.
[121]
A main body 30 provided with a plurality of dams for dividing the inside into a supply region A and a discharge region B . The control unit 80 controls the driving unit 70 so that the control dam 63 is brought into close contact with the fixed dam 61 to isolate the supply area A from the discharge area B.
[122]
Thereafter, the transport container 10 is positioned above the supply region A of the main body 30, and molten steel is supplied into the supply region A of the main body 30. [ Thus, the molten steel M can be supplied only to the supply region A, and the molten steel level can be raised quickly.
[123]
In other words, the injection space of the initial molten steel can be reduced by using the control dam 63, so that the molten steel level can be reached to the lower end of the first nozzle 20 at a smaller amount than before.
[124]
When the molten steel level rises and becomes higher than the end level of the first nozzle 20, the flux F is evenly applied to the molten steel bath surface to quickly prevent molten steel from being reoxidized. At this time, since the initial application area of ​​the flux (F) can be made smaller than before, the molten steel bath surface can be protected in a shorter time.
[125]
Thereafter, when the molten steel level rises and reaches a predetermined height, the control dam 63 is lifted and moved to release the close contact with the fixed dam 61, thereby connecting the supply region A and the discharge region B . Thereafter, the control dam 63 is brought into close contact with the stopper 64 on the first nozzle 20 side or in close contact with the stopper 64 on the side of the second nozzle 40, And when the molten steel supplied to the discharge region B reaches a certain level, the casting of the casting begins with the molten steel in the discharge region B connected to the supply region A.
[126]
At this time, since the pure molten steel in which the reoxidation reaction is inhibited is supplied to the discharge region B as the coating time of the flux (F) is advanced, the oxidized inclusions are mixed into the slab produced at the beginning of the continuous casting process The quality of the initial casting can be secured.
[127]
Thereafter, the casting is continuously performed while maintaining the molten steel in the steady state at the molten steel level (working level) in the main body 30.
[128]
When the supply of molten steel to the main body 30 is completed, the molten steel level of the main body 30 becomes lower as the casting proceeds. During this process, the control dam 63 is moved to the first nozzle 20 side to move the slag to the longitudinal center portion of the main body 30, and the molten steel in the clean state under the main body 30 to the discharge region B side . Thereafter, the slag collected in the central portion of the main body 30 can be removed from the molten steel bath surface and removed by a certain amount in such a manner that the slag is stacked on the protruding portion 65 formed on the lower portion of the control dam 63. Thus, it is possible to effectively suppress or prevent the slag from moving toward the laden port side of the main body 30 and flowing into the ladder port.
[129]
When molten steel supply to the main body 30 is completed, the molten steel level of the main body 30 becomes lower as the casting progresses, so that the residual molten steel amount in the main body 30 reaches the minimum residual molten amount. During this process, the control dam 63 is moved to the fixed dam 61 side while being lowered to a predetermined height and the molten steel in the supply region A is moved to the discharge region B side to lower the molten steel level in the discharge region B Then, the control dam 63 is brought into close contact with the fixed dam 61 to isolate the discharge area B from the supply area in a state where the molten steel level is raised.
[130]
Thereafter, the residual molten steel of the isolated discharge region B from the supply region A is continuously supplied to the mold, and the subsequent molten steel is supplied to the supply region B while the casting is continued. At this time, the subsequent molten steel may be molten steel having the same composition as that of the previous molten steel remaining in the discharge region (B), and may be a molten steel of a different grade from the previous molten steel remaining in the discharge region (B).
[131]
Thereafter, when the molten steel level of the succeeding molten steel in the supply region A rises to reach a predetermined height, the control dam 63 is lifted and moved to release the close contact with the fixed dam 61, And the discharge region (B). Accordingly, the subsequent molten steel contained in the supply region A can be supplied to the discharge region B. [ Thereafter, the control dam 63 is brought into close contact with the stopper 64 to guide the flow of the molten steel to the lower side of the main body 30, and the molten steel of the discharge region B connected to the supply region A is continuously .
[132]
When the supply of the subsequent molten steel to the main body 30 is completed, the molten steel level of the main body 30 is lowered as the casting proceeds. During this process, the control dam 63 is moved to the first nozzle 20 side to move the slag to the longitudinal center portion of the main body 30, and the molten steel in the clean state under the main body 30 to the discharge region B side . Thereafter, the slag collected in the central portion of the main body 30 can be removed from the molten steel bath surface and removed by a certain amount in such a manner that the slag is stacked on the protruding portion 65 formed on the lower portion of the control dam 63. Thus, it is possible to effectively suppress or prevent the slag from moving toward the laden port side of the main body 30 and flowing into the ladder port.
[133]
When the subsequent molten steel supply to the main body 30 is completed, the molten steel level of the main body 30 is further lowered as the casting progresses, so that the residual molten steel amount in the main body 30 reaches the lowest residual molten amount. During this process, the control dam 63 is moved to the fixed dam 61 side in a state of being lowered to a predetermined height and the molten steel in the supply region A is moved to the discharge region B side, The control dam 63 is brought into close contact with the fixed dam 61 to isolate the discharge region B from the supply region in a state where the molten steel level is raised.
[134]
Thereafter, the residual molten steel of the isolated discharge region B from the supply region A is continuously supplied to the mold and cast into a cast slab, and the molten steel level of the remaining molten steel remaining in the discharge region B is reduced to the lowermost molten steel Level is reached, the continuous casting process is completed.
[135]
As described above, in the embodiment of the present invention, it is possible to prevent the delay of the injection of flux at the initial stage of the continuous casting process, thereby minimizing the exposure of the molten steel taken in the body to the atmosphere, Thus, the quality of the initial casting can be effectively improved. Further, the molten steel level can be locally increased in order to prevent the slag from being introduced by the vortex formed in the vicinity of the ladder at the end of the process, and the minimum remaining amount of molten steel remaining in the main body at the end of the continuous casting process can be reduced Can be. In the case of this continuous casting process, the mixing portion can be reduced.
[136]
As described above, in the embodiment of the present invention, the quality of the cast steel can be ensured at the beginning and end of the continuous casting process while smoothly performing the continuous casting process, and the rate of occurrence of the failure can be ensured. In addition, the mixed portion of the cast steel can be minimized during the continuous casting process.
[137]
It should be noted that the above-described embodiments of the present invention are for the purpose of illustrating the present invention and not for the purpose of limitation of the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims and their equivalents. It will be possible.
Claim range
[Claim 1]
A fixed dam which extends in a width direction of the main body and which is installed in contact with both the bottom portion and the longitudinal side walls of the main body, Extended control dam; And a driving unit for movably and rotatably supporting the control dam.
[Claim 2]
The molten steel treatment apparatus according to claim 1, further comprising a stopper provided on both longitudinal side walls of the main body on the opposite side of the laden orifice with respect to the fixed dam.
[Claim 3]
The molten steel treatment apparatus according to claim 1, further comprising: a residual hole formed in a longitudinal direction of the lower portion of the fixed dam.
[Claim 4]
The apparatus for processing molten steel according to claim 1, wherein the control dam is moved in the longitudinal direction of the main body to control the operation of the driving unit so that the inside of the main body is separated into a supply region and an exhaust region.
[Claim 5]
The molten steel treatment apparatus according to claim 2, wherein the control dam has a width in a width direction so as to be spaced apart from both longitudinal side walls of the main body at a position where the stopper is installed.
[Claim 6]
The control dam according to any one of claims 1, 2, and 5, wherein the control dam has a width in a width direction such that the control dam is in contact with both the bottom portion and both longitudinal side walls of the main body at a position where the fixed dam is installed. .
[Claim 7]
The molten steel treatment apparatus according to claim 2 or 5, wherein the control dam has a width in a width direction such that both side edges in the width direction contact or overlap the stopper at the position where the stopper is installed.
[Claim 8]
The molten steel treatment apparatus according to claim 1, further comprising: a protrusion formed on a lower surface of one side of the control dam and having a loading surface on an upper side thereof.
[Claim 9]
The molten steel treatment apparatus according to claim 2, wherein the stopper extends in the height direction of the main body and protrudes in the width direction.
[Claim 10]
[3] The apparatus according to claim 2, wherein a plurality of fixed dams are provided so as to face each other in the longitudinal direction at a central portion of the main body, a discharge area is formed on the side of the lug, Is formed.
[Claim 11]
11. The molten steel treating apparatus according to claim 10, wherein a plurality of the control dam and the stopper are provided facing each other in the supply region.
[Claim 12]
A method of treating a river, comprising the steps of: providing a main body provided with a plurality of dams, the interior of which is open to the upper side, the ladder is formed at the bottom, and the interior is divided into a supply region and an exhaust region; A process of isolating the supply region from the discharge region, supplying molten steel to the supply region, connecting the supply region and the discharge region using the plurality of dams, And controlling the molten steel level of the discharge area by isolating the discharge area from the supply area using the plurality of dams.
[Claim 13]
[12] The method of claim 12, wherein the step of connecting the supply region and the discharge region comprises casting a slab into molten steel in the discharge region connected to the supply region.
[Claim 14]
14. The method of claim 13, wherein controlling the molten steel level in the discharge region comprises casting a slab from the supply region into residual molten steel in the isolated discharge region.
[Claim 15]
[12] The method of claim 12 or 13, wherein the step of controlling the molten steel level of the discharge region comprises the step of casting the slab from the supply region into the residual molten steel of the discharge region isolated and supplying the subsequent molten steel to the supply region .
[Claim 16]
16. The method of claim 15, further comprising: connecting the supply region and the discharge region using the plurality of dams to supply the subsequent molten steel to the discharge region after a process of supplying subsequent molten steel to the supply region; Isolating the discharge region from the supply region using a dam and controlling a molten steel level of the discharge region; And casting the slab into remaining molten steel in the discharge region isolated from the supply region.