Continuous casting facility

Abstract

To provide a continuous casting facility that suppresses defective slab cutting.SOLUTION: Continuous casting facility 2 includes: a mold 8 into which a molten steel 20 is poured; an outlet 10 that guides a continuously discharged slab 21 from the mold 8; a cutting machine 12 that cuts the slab 21; a sensor that detects the cutting of the slab 21; and a controller 18 that causes the cutting machine 12 to perform a cutting operation and, when the sensor does not detect the cutting of the slab 21, causes the cutting machine 12 to perform a re-cutting operation. Preferably, the continuous casting facility 2 further includes a basket 14 that moves together with a leading edge of the slab 21 and supports a steel billet 22 obtained by cutting the cast slab 21. The sensor detects a moving speed of the basket 14 or a load applied to the basket 14.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present specification discloses a continuous casting system. [Background technology]

[0002] Continuous casting equipment is used to manufacture steel billets such as slabs and blooms. In continuous casting equipment, billets are continuously obtained from molten steel. These billets are then cut to a specified length to obtain billets. Gas cutting machines are used to cut the billets. Gas cutting machines cut the billets using the heat of a flame.

[0003] Patent Document 1 discloses a cutting control method for a gas cutting machine. In this method, a camera is used to monitor the state of the flame during cutting when cutting a slab. Cutting defects are judged from the state of the flame. When cutting defects are judged during cutting of the slab, the gas cutting machine is returned and re-cuts the slab from the returned position. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-150262 Summary of the Invention [Problem to be solved by the invention]

[0005] In the cutting control method of Patent Document 1, cutting defects are determined from the state of the flame. With this method, cutting defects may occur due to welding after cutting.

[0006] The applicant's intention is to provide a continuous casting facility that suppresses defective cutting of a slab. [Means for solving the problem]

[0007] The continuous casting equipment disclosed in this specification includes a mold into which molten steel is poured, a discharge passage that guides the strand that is continuously discharged from the mold, a cutting machine that cuts the strand, a sensor that detects the cut of the strand, and a controller that causes the cutting machine to perform a cutting operation and, when the sensor does not detect the cut of the strand, causes the cutting machine to perform a re-cutting operation.

[0008] Preferably, the continuous casting facility further comprises a basket that moves together with the tip end of the cast strip being discharged and supports a steel strip obtained by cutting the cast strip. The sensor detects the moving speed of the basket.

[0009] Preferably, the continuous casting facility further comprises a basket that moves together with the tip end of the cast strip being discharged and supports a steel strip obtained by cutting the cast strip. The sensor detects a load applied to the basket. Effect of the Invention

[0010] The continuous casting equipment includes a sensor for detecting the cutting of the slab. The continuous casting equipment has excellent accuracy in detecting defective cutting of the slab. The continuous casting equipment includes a controller for causing the cutter to perform a re-cutting operation. The continuous casting equipment suppresses defective cutting of the slab. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is an explanatory diagram of a continuous casting facility according to one embodiment. [Diagram 2] FIG. 2 is an explanatory diagram of a gas cutter and a basket provided in the continuous casting facility of FIG. [Diagram 3] FIG. 3A is an explanatory diagram showing the use state of the continuous casting equipment of FIG. 1, FIG. 3B is an explanatory diagram showing another use state, FIG. 3C is an explanatory diagram showing yet another use state, and FIG. 3D is an explanatory diagram showing yet another use state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, preferred embodiments will be described in detail with reference to the drawings as appropriate.

[0013] 1 shows a continuous casting equipment 2. The continuous casting equipment 2 includes a ladle 4, a tundish 6, a mold 8, a discharge passage 10, a gas cutter 12, a basket 14, a conveyor 16, and a controller 18.

[0014] 1 shows molten steel 20, a slab 21, and a billet 22. The slab 21 is obtained from the molten steel 20. The billet 22 is obtained from the slab 21. The billet 22 is, for example, a slab, a bloom, or a billet.

[0015] The ladle 4 has a gate 4A at the bottom. The ladle 4 is located above a tundish 6. Molten steel 20 is poured into the ladle 4. The molten steel 20 is poured into the tundish 6 from the gate 4A.

[0016] The tundish 6 has three gates 6A. The tundish 6 is located above three molds 8. A mold 8 is located below each of the gates 6A. Molten steel 20 is poured into the mold 8 from the gates 6A. The number of gates 6A and the number of molds 8 may be one, two, or even four or more.

[0017] Each mold 8 has a pouring spout 8A and a discharge spout 8B. A number of guides 10A are located below the discharge spouts 8B. The multiple guides 10A form a discharge passage 10. The molds 8 are located above the discharge passages 10. Molten steel 20 is poured into the pouring spouts 8A of the molds 8. The molds 8 form the molten steel 20 into a predetermined cross-sectional shape while cooling it. In this manner, a slab 21 is obtained from the molten steel 20. The slab 21 is discharged from the discharge spout 8B of the molds 8. The slab 21 is guided by the discharge passage 10 and extends downward.

[0018] The gas cutter 12 is located below the discharge passage 10. The gas cutter 12 has a blowpipe 12A. The slab 21 is partially melted by the heat of the flame blown out of the blowpipe 12A. The molten steel is forced out to the opposite side of the gas cutter 12 by the gas flow. The gas cutter 12 is moved in synchronization with the movement of the tip 21A of the slab 21 and is further moved in a straight line horizontally relative to the slab 21, thereby cutting the slab 21. In this manner, the slab 21 is cut, and a steel slab 22 is obtained from the slab 21.

[0019] The basket 14 is located below the gas cutting machine 12. The basket 14 is movable in the vertical direction. The basket 14 descends while supporting the steel piece 22. The basket 14 and the steel piece 22 shown by the two-dot chain line in FIG. 1 represent the position where the conveyor 16 receives the steel piece 22. The basket 14 descends to the position where the conveyor 16 receives the steel piece 22.

[0020] The conveyor 16 receives the steel pieces 22 from the basket 14. The conveyor 16 transports the steel pieces 22 to the next process. The controller 18 is capable of controlling the conveyor 16.

[0021] 1 shows a mold 8, a discharge passage 10, a gas cutter 12, a basket 14, and a conveyor 16 corresponding to one of the three gates 6A of the tundish 6. Although the mold 8, the discharge passage 10, the gas cutter 12, the basket 14, and the conveyor 16 are also arranged corresponding to the other two gates 6A, only the mold 8 is shown here.

[0022] 2 shows the elevator 24 and the elevator 25. The continuous casting equipment 2 includes the elevator 24 and the elevator 25. The basket 14 is attached to the elevator 24. The gas cutting machine 12 is attached to the elevator 25.

[0023] The elevator 24 includes a drum 26 , a motor 28 , a sensor 30 , a movable pulley 32 , a wire 34 , a fixed pulley 36 , a fixed pulley 38 , a weight 40 , a wire 42 , and a fixed pulley 44 .

[0024] The drum 26 is rotatable. The drum 26 has a rotation shaft 26A. The rotation shaft 26A is connected to a drive shaft of a motor 28. The sensor 30 is capable of detecting the number of rotations of the motor 28.

[0025] The movable pulley 32 is attached to the basket 14. The movable pulley 32 is rotatable. A wire 34, one end of which is fixed, is hung on the movable pulley 32. The positions of the fixed pulleys 36 and 38 are fixed. The fixed pulleys 36 and 38 are each rotatable. The wire 34 is further hung on the fixed pulleys 36 and 38. The other end of the wire 34 is wound around the drum 26. One end of a wire 42 is wound around the drum 26. One end of the wire 42 and the other end of the wire 34 are wound in opposite directions in the circumferential direction of the drum 26. The position of the fixed pulley 44 is fixed. The fixed pulley 44 is rotatable. The wire 42 is hung on the fixed pulley 44. A weight 40 is attached to the other end of the wire 42.

[0026] In this elevator 24, when the drum 26 rotates in one direction, the wire 34 is wound around the drum 26. This causes the basket 14 to rise. On the other hand, the wire 42 is unwound from the drum 26. This causes the weight 40 to fall.

[0027] When the drum 26 rotates in the other direction, the wire 34 is unwound from the drum 26. This causes the basket 14 to descend. Meanwhile, the wire 42 is wound onto the drum 26. This causes the weight 40 to ascend.

[0028] The elevator 25 has a movable base 46 and rails 48. The rails 48 extend in the vertical direction. The movable base 46 is movable along the rails 48. The gas cutting machine 12 is attached to the movable base 46. This allows the gas cutting machine 12 to move in the vertical direction.

[0029] The controller 18 is capable of controlling the gas cutting machine 12, the elevator 24 (the motor 28), and the elevator 25 (the moving platform 46). The controller 18 is also capable of receiving a detection signal from the sensor 30.

[0030] FIG. 3A shows a slab 21, a gas cutter 12, and a basket 14. In FIG. 3A, the basket 14 is empty after the slab 22 has been transferred to the conveyor 16 from the basket 14 shown by the two-dot chain line in FIG. 1, and is positioned away from the slab 21. In FIG. 3B, a portion of the slab 21 has been cut off. The basket 14 supports the tip portion 21A of the slab 21. In FIG. 3C, the slab 21 has been cut off, and the slab 22 has been obtained. The basket 14 supports the slab 22. In FIG. 3D, the basket 14 is positioned away from the slab 21 and supports the slab 22.

[0031] Hereinafter, a method for cutting the slab 21 in the continuous casting equipment 2 will be described with reference to Figs.

[0032] As shown in Fig. 1, a slab 21 obtained from molten steel 20 extends downward along the discharge path 10. The basket 14 is positioned below and away from the slab 21. Here, the basket 14 is in an empty state after delivering the slab 22 to the conveyor 16 at the position of the basket 14 shown by the two-dot chain line in Fig. 1.

[0033] The controller 18 controls the elevator 24 to raise the basket 14 (see FIG. 2). The basket 14 rises toward the tip 21A of the slab 21. The controller 18 controls the elevator 25 to lower the gas cutter 12 (see FIG. 2). The gas cutter 12 descends in accordance with the speed at which the slab 21 extends downward. In this manner, the continuous casting equipment 2 is brought into use as shown in FIG. 3A.

[0034] The controller 18 operates the gas cutter 12. The gas cutter 12 cuts the slab 21 with the heat of a flame. The gas cutter 12 cuts the slab 21 while moving downward in accordance with the speed at which the slab 21 extends downward. Meanwhile, the raised basket 14 supports the tip portion 21A of the slab 21. The basket 14 descends while supporting the tip portion 21A of the slab 21. In this manner, the continuous casting equipment 2 is brought into use as shown in FIG. 3B.

[0035] The slab 21 is cut by the gas cutter 12 to obtain a billet 22. The billet 22 is supported by the basket 14. In this manner, the continuous casting equipment 2 is brought into use as shown in FIG. 3C. When the slab 21 is completely cut, the weight of the billet 22 is applied to the basket 14. When the weight of the billet 22 is applied, the descending speed of the basket 14 increases. The sensor 30 detects an increase in the rotation speed of the motor 28. The sensor 30 transmits this detection signal to the controller 18. By receiving this detection signal, the controller 18 determines that cutting of the billet 21 is complete.

[0036] The controller 18 further increases the descending speed of the basket 14 by the elevator 24. The steel billet 22 is supported by the basket 14 and separates from the billet 21. In this manner, the continuous casting equipment 2 is brought into a ready-to-use state as shown in FIG. 3D.

[0037] Furthermore, the controller 18 controls the elevator 24 to lower the basket 14 to a position where the conveyor 16 receives the steel pieces 22 (see the basket 14 and the steel pieces 22 shown by the two-dot chain lines in FIG. 1). The controller 18 controls the conveyor 16 to receive the steel pieces 22 from the basket 14. The controller 18 controls the conveyor 16 to convey the steel pieces 22 to the next process.

[0038] In this cutting method, as described above, the basket 14 descends while supporting the tip portion 21A of the slab 21. The billet 22 obtained by cutting the billet 21 is supported by the basket 14. The basket 14 bears the weight of the billet 22. On the other hand, if the billet 21 is not cut sufficiently, the load received by the basket 14 is reduced. An increase in the descending speed of the basket 14 is suppressed. The sensor 30 cannot detect a predetermined increase in the rotation speed of the motor 28. The controller 18 cannot receive a detection signal from the sensor 30. The controller 18 cannot determine when cutting of the billet 21 is complete.

[0039] In this continuous casting equipment 2, the controller 18 causes the gas cutting machine 12 to perform a cutting operation of the slab 21. When the controller 18 cannot receive a detection signal from the sensor 30 even after the gas cutting machine 12 has completed the cutting operation, the controller 18 causes the gas cutting machine 12 to perform the cutting operation again.

[0040] In the continuous casting equipment 2, the internal temperature of the slab 21 is high. The slab 21 is cut by a gas cutter 12. Depending on the material of the slab 21, after cutting by the gas cutter 12, some of the steel melted by the gas flame may not flow out from the cut part by the gas flow, and some of the steel may remain. This remaining steel may solidify after being cut by the gas cutter 12, and the slab 22 may adhere to the slab 21, resulting in poor cutting, in which the cut slab 22 is not separated.

[0041] In this continuous casting equipment 2, the sensor 30 detects the cutting of the billet 21. The controller 18 causes the gas cutter 12 to perform a cutting operation, and when the sensor 30 does not detect the cutting of the billet 21, causes the gas cutter 12 to perform the cutting operation again. This allows the continuous casting equipment 2 to separate the billet 22 more reliably.

[0042] In this continuous casting equipment 2, the controller 18 determines the completion of cutting of the slab 21. The controller 18 causes the gas cutter 12 to perform a re-cutting operation. This continuous casting equipment 2 reduces the burden on the operator of constantly monitoring for the presence or absence of cutting defects and of operating the re-cutting operation when a cutting defect occurs. In particular, in the case of the continuous casting equipment 2, which is equipped with a large number of molds 8, discharge passages 10, gas cutters 12, and baskets 14, the operator's burden of monitoring and the burden of the re-cutting operation can be significantly reduced.

[0043] The continuous casting equipment 2 may further include a connector that switches the connection between the drive shaft of the motor 28 and the rotating shaft 26A of the drum 26. For example, the connector connects the drive shaft of the motor 28 and the rotating shaft 26A of the drum 26 when the drum 26 is driven by the motor 28. The connector disconnects the drive shaft of the motor 28 from the rotating shaft 26A of the drum 26 when the drum 26 is not driven. By disconnecting the drive shaft of the motor 28 from the rotating shaft 26A of the drum 26, the basket 14 can easily descend in accordance with the descent of the tip portion 21A of the cast slab 21. From this viewpoint, the continuous casting equipment 2 preferably includes a connector that switches the connection between the drive shaft of the motor 28 and the rotating shaft 26A of the drum 26.

[0044] Also, when poor cutting of the slab 21 occurs, it is possible for an operator to manually make the gas cutting machine 12 perform a re-cutting operation. However, when poor cutting of the slab 21 occurs in two or more gas cutting machines 12, it is not easy to make each of the gas cutting machines 12 perform a re-cutting operation. In such a case, the operator has to manually reduce the casting speed of the slab 21 in order to make two or more gas cutting machines 12 perform a re-cutting operation. In contrast, in the continuous casting equipment 2, the controller 18 determines the completion of cutting of the slab 21 and makes the gas cutting machine 12 perform a re-cutting operation. As a result, when the continuous casting equipment 2 includes two or more gas cutting machines 12, it is possible to suppress a decrease in productivity.

[0045] In this continuous casting equipment 2, the sensor 30 detects an increase in the rotation speed of the motor 28. As a result, the sensor 30 detects the descending speed of the basket 14. Note that in this continuous casting equipment 2, the basket 14 is descending, and the sensor 30 detects the descending speed of the basket 14, but this is not limited to this. It is sufficient for the sensor 30 to detect the speed in the moving direction of the basket 14 (moving speed).

[0046] Many of the motors 28 are originally equipped with a sensor 30 for detecting the number of revolutions. In such a motor 28, there is no need to provide a new sensor 30. This continuous casting equipment 2 can detect breakage of the slab 21 at low cost.

[0047] In the continuous casting equipment 2, the sensor 30 only needs to detect the descending speed of the basket 14. The sensor 30 is not limited to a sensor that detects the rotation speed of the motor 28. The sensor 30 may detect the number of rotations of the drum 26 or the rotating shaft 26A. The sensor 30 may also detect the moving speed of the weight 40.

[0048] Furthermore, in the continuous casting equipment 2, another sensor may be used that detects the load applied to the basket 14 instead of or in addition to the descent speed of the basket 14. Similarly, in the continuous casting equipment 2, another sensor may be used that detects the value of the current or voltage of the motor 28 that changes as the basket 14 supports the steel billet 22.

[0049] In addition, although this continuous casting equipment 2 is a vertical type that extends the slab 21 downward without bending it, it may be a curved type that extends the slab by bending it horizontally. In that case, the sensor 30 only needs to detect the horizontal moving speed of the basket 14. [Industrial Applicability]

[0050] The continuous casting equipment described above can be widely applied to continuous casting. [Explanation of symbols]

[0051] 2. Continuous casting equipment 8. Mold 10...Exhaust channel 12 Gas cutting machine (cutting machine) 14. Basket 18. Controller 20 Molten steel 21... Cast piece 21A...Tip 22...steel billet 30 Sensor

Claims

1. The mould into which the molten steel is poured, a discharge passage for guiding the cast strip continuously discharged from the mold; a cutting machine for cutting the slab; a sensor for detecting the cutting of the slab; And, a controller that causes the cutter to perform a cutting operation and, when the sensor does not detect the cut of the cast piece, causes the cutter to perform a re-cutting operation; A continuous casting facility equipped with

2. a basket that moves together with the tip end of the cast piece being discharged and supports a steel piece obtained by cutting the cast piece; The continuous casting facility of claim 1 , wherein the sensor detects a speed of movement of the basket.

3. a basket that moves together with the tip end of the cast piece being discharged and supports a steel piece obtained by cutting the cast piece; The continuous casting facility according to claim 1 or 2, wherein the sensor detects a load applied to the basket.

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