KR20130046739A - Gas control device for sealing nozzle and method therefor - Google Patents

Abstract

PURPOSE: A gas control device for sealing a nozzle and a control method thereof are provided to reduce gas injection amount when a vibration detecting sensor detects transverse vibration. CONSTITUTION: A gas control device for sealing a nozzle comprises a gas injection part(110), a vibration detecting sensor(130), and a controller. The gas injection part injects inert gas to a part where a collector nozzle(11) and a shroud nozzle(15) are coupled. The vibration detecting sensor detects the transverse vibration of the shroud nozzle. When the vibration detecting sensor detects the transverse vibration, the controller determines that the naked molten metal is formed on the surface of molten metal a tundish(20) and reduces the injected amount of the gas injected by the gas injection part. The vibration detecting sensor is mounted on an arm(101) of a nozzle operator(100) for supporting the shroud nozzle. [Reference numerals] (110) Gas injection part; (150) Controller

Description

GAS CONTROL DEVICE FOR SEALING NOZZLE AND METHOD THEREFOR}

The present invention relates to the control of the gas for sealing when the surface of the tundish is exposed (floor), and more particularly, the nozzle sealing gas for adjusting the injection amount of the nozzle sealing gas when the molten gas is generated around the shroud nozzle immersed in the molten steel in the tundish. It relates to a control device and a method thereof.

The continuous casting machine is a machine that is produced in the steel making furnace, receives the molten steel transferred to the ladle by the tundish, and supplies it to the mold for the continuous casting machine to produce the cast steel of a certain size.

The continuous casting machine includes a ladle for storing molten steel, a playing mold for cooling the tundish and the molten steel discharged from the tundish for the first time to form a casting cast having a predetermined shape, and the casting cast formed in the mold connected to the mold. It includes a plurality of pinch rolls.

In other words, the molten steel tapping out of the ladle and tundish is formed as a cast piece having a predetermined width, thickness and shape in a mold and is transferred through a pinch roll, and the cast piece transferred through the pinch roll is cut by a cutter. It is made of slabs (Slab), Bloom (Bloom), Billet (Billet) and the like having a predetermined shape.

Related prior art is Korean Patent Publication No. 2002-16251 (published: 2002. 03. 04).

The present invention provides a nozzle sealing gas control apparatus and a method thereof, by reducing the amount of injection of nozzle sealing gas when a molten metal is generated around a shroud nozzle immersed in molten steel in a tundish.

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above.

The nozzle control gas control device of the present invention for realizing the above object is a gas injection unit for injecting the sealing inert gas to the portion of the collector nozzle and the shroud nozzle combined; A vibration sensor for sensing vibration generated in the transverse direction in the shroud nozzle; And a controller configured to control the amount of gas injected through the gas injection unit to determine that low temperature is generated on the hot water surface of the tundish when the lateral vibration is detected through the vibration detection sensor.

The vibration sensor may be mounted on the arm of the nozzle operator for supporting the shroud nozzle.

According to another aspect of the present invention, there is provided a method for controlling a nozzle sealing gas, the method comprising: injecting an inert gas for sealing into a portion in which a collector nozzle and a shroud nozzle are combined; Sensing vibration generated in the transverse direction in the shroud nozzle; And when the lateral vibration of the shroud nozzle is sensed, determining that the hot water is generated on the hot water surface of the tundish to reduce the injection amount of the inert gas for sealing.

According to the present invention configured as described above by adjusting the injection amount of the nozzle sealing argon gas automatically according to whether or not exposed to the surface of the tundish, and reduces the phenomenon of exposure to the trough in the tundish, and accidents due to exposure to the surface There is an advantage that can be prevented in advance. In addition, there is an advantage that can be quickly coped with the occurrence of tung in the tundish to contribute to maintaining and improving the cleanliness of the molten steel and the quality of the steel.

1 is a conceptual diagram showing a continuous casting machine related to the flow of molten steel according to the present invention.
2 is a view showing a nozzle and a gas control apparatus for nozzle sealing according to an embodiment of the present invention.
3 is a view specifically illustrating a nozzle coupling part of FIG. 2.
Figure 4 is a photograph showing the state of slaughter around the nozzle in the tundish.
5 is a flowchart illustrating a sealing gas control process according to an exemplary embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like elements in the figures are denoted by the same reference numerals wherever possible. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

1 is a conceptual diagram showing a continuous casting machine according to an embodiment of the present invention mainly on the flow of molten steel.

Continuous casting is a casting process in which a molten metal is continuously cast into a bottomless mold while continuously drawing a steel ingot or steel ingot. Continuous casting is used to make long products of simple cross-section, such as square, rectangular or round, and mainly slabs, blooms or billets, which are materials for rolling.

The continuous casting machine may include a ladle 10 and a tundish 20, a mold 30, secondary cooling bands 60 and 65, a pinch roll 70, and a cutter 90, as shown .

The tundish 20 is a container that receives the molten metal from the ladle 10 and supplies the molten metal to the mold 30. Ladle 10 is provided in a pair, alternately receives molten steel to supply to the tundish 20. In the tundish 20, the supply rate of the molten metal flowing into the mold 30 is controlled, the molten metal is distributed to each mold 30, the molten metal is stored, and the slag and the nonmetallic inclusions are separated.

The mold 30 is typically made of water-cooled copper and allows the molten steel to be primary cooled. The mold 30 has a pair of structurally opposed faces open to form a hollow portion for receiving molten steel. In the case of manufacturing a slab, the mold 30 includes a pair of barriers and a pair of end walls connecting the barriers. Here, the short wall has a smaller area than the barrier. The walls of the mold 30, mainly short walls, may be rotated away from or close to each other to have a certain level of taper.

The mold 30 serves to form a strong solidification angle or solidified shell 81 so that the cast steel drawn from the mold maintains a certain shape and a molten metal which is still less solidified does not flow out. Do it. The water-cooled structure includes a method of using a copper pipe, a method of drilling a water cooling groove in the copper block, and a method of assembling a copper pipe having a water cooling groove.

The mold 30 is oscillated to prevent the molten steel from adhering to the wall of the mold, and powder to prevent burning and to reduce friction between the mold 30 and the solidification shell 81 during oscillation. Lubricants such as Powder are used. The powder is added to the molten metal in the mold to become slag, as well as lubrication of the mold 30 and the solidified shell, as well as preventing oxidation and nitrification of the molten metal in the mold, keeping warm, and absorbing non-metallic inclusions floating on the surface of the molten metal. do.

The secondary cooling zones 60 and 65 further cool the molten steel primarily cooled in the mold 30. The primary cooled molten steel is directly cooled by the spray means 65 for spraying water while maintaining the solidification angle by the support roll 60 not to be deformed. The solidification of the cast steel is mostly made by the secondary cooling.

The drawing device adopts a multidrive method using a pair of pinch rolls 70 and the like so as to pull out the cast pieces without slipping. The pinch roll 70 pulls the solidified tip of the molten steel in the casting direction, thereby allowing the molten steel passing through the mold 30 to continuously move in the casting direction.

Continuously produced cast pieces are cut to a certain size by a predetermined cutter (not shown).

That is, the molten steel M flows to the tundish 20 in the state accommodated in the ladle 10. For this flow, the ladle 10 is provided with a shroud nozzle 15 extending toward the tundish 20. The shroud nozzle 15 extends to be submerged in the molten steel in the tundish 20 so that the molten steel M is not exposed to air and oxidized and nitrified.

The molten steel M in the tundish 20 flows into the mold by a submerged entry nozzle 25 extending into the mold. The immersion nozzle 25 is disposed in the center of the mold 30 so that the flow of molten steel M discharged from both discharge ports of the immersion nozzle 25 can be symmetrical. The start, discharge speed, and stop of the discharge of the molten steel M through the immersion nozzle 25 are determined by a stopper 21 installed in the tundish 20 in response to the immersion nozzle 25. Specifically, the stopper 21 may be vertically moved along the same line as the immersion nozzle 25 to open and close the inlet of the immersion nozzle 25.

The molten steel M in the mold starts to solidify from the part in contact with the wall surface of the mold 30. This is because heat is more likely to be lost by the mold 30 in which the periphery is cooled rather than the center of the molten steel M. By the way that the periphery is first solidified, the back portion along the casting direction of the casting cast piece 80 forms a shape in which the non-solidified molten steel 82 is wrapped in the solidified shell 81.

As the pinch roll 70 pulls the front end portion 83 of the completely cast solid cast steel 80, the unsolidified molten steel 82 moves together with the solidified shell 81 in the casting direction. The uncondensed molten steel 82 is cooled by the spray means 65 for spraying the cooling water in the above movement process. This causes the thickness of the non-solidified molten steel 82 in the playing cast 80 to gradually decrease. When the cast steel 80 reaches a point 85, the cast steel 80 is filled with the solidification shell 81 of the entire thickness. The solidified cast piece 80 is cut to a certain size at the cutting point 91 is divided into slabs (P) such as slabs.

2 is a view showing a gas control apparatus for a nozzle and a nozzle sealing according to an embodiment of the present invention, the control apparatus includes a gas injection unit 110, vibration detection sensor 130 and controller 150, and the like. .

The gas injection unit 110 is a portion in which the collector nozzle 11 and the shroud nozzle 15 are in contact with each other, and blows an inert gas for sealing such as argon (Ar). The coupling portion of the collector nozzle 11 and the shroud nozzle 15 is, for example, a porous ring 17-1 made of alumina inside the upper end of the base material of the shroud nozzle 15 as shown in FIG. 3. And insert it, and the mortar 18 is used to combine with the metal case 19. In addition, air is blown out from the outside by forming a gas pool 17-2 in the porous ring 17-1 and blowing argon gas through the gas inlet 16. It is suppressed to flow in.

That is, when argon gas is blown through the gas inlet 16 during the molten steel injection in the above structure, the argon gas passes through the gas pool 17-2 and through the pores of the porous ring 17-1. By the force discharged out along the inclined surface of the collector nozzle 11 in contact with the ()) air is not introduced between the gap between the porous ring 17-1 and the collector nozzle 11 to prevent reoxidation of molten steel.

The vibration sensor 130 is mounted on the arm 101 of the nozzle operator 100 supporting the shroud nozzle 15 to sense the vibration generated in the transverse direction in the shroud nozzle 15. Here, when the argon gas or the outside air flows through the inner hole of the shroud nozzle 15, horizontal vibration occurs in the shroud nozzle 15. In order to improve the vibration sensing ability, the shroud nozzle 15 and It is preferable that the end of the adjacent arm 101 or the outer circumferential surface of the shroud nozzle 15 is provided.

When the horizontal vibration is sensed through the vibration detecting sensor 130, the controller 150 determines that low-temperature water is generated on the hot water surface of the tundish and controls the amount of gas injected through the gas injection unit 110 to be reduced.

On the other hand, the nozzle operator 100 for holding and supporting the upper side of the shroud nozzle 15 is inserted into the collector nozzle 11 formed at the bottom of the ladle 10 by moving the shroud nozzle 15 horizontally and vertically. Fix it.

The nozzle manipulator 100 may include, for example, an arm 101, a first rotating member 103, and a second rotating member 105.

Arm 101 has a shroud nozzle 15 is fixed to one side and the other side is fixed to be rotated vertically through a rotating shaft to move the shroud nozzle 15 in a vertical direction in accordance with a predetermined operating command. Although not shown in detail, the arm 101 is rotated by a hydraulic cylinder or an air cylinder according to a command input through an input means installed in the nozzle operator 100 to move the shroud nozzle 15 vertically. Can be configured.

The first rotating member 103 is configured to be rotatably coupled to the arm 101 so as to rotate the arm 101 in the first horizontal direction through the rotating shaft. That is, when the first rotating member 103 is axially rotated, the arm 101 coupled to the first rotating member 103 is also rotated in the first horizontal direction.

The second rotating member 105 is configured to be fixedly coupled to the first rotating member 103 so as to rotate the first rotating member 103 in the second horizontal direction through the rotating shaft. That is, when the second rotating member 105 is axially rotated, the first rotating member 103 coupled to the second rotating member 105 is also rotated in the second horizontal direction.

In addition, reference numeral 107 denotes a handle for the operator to manually operate the first rotating member 103 and the second rotating member 105 of the nozzle operator 100. Of course, the first rotating member 103 and the second rotating member 105 may be configured to be automatically operated by a motor.

As shown in FIG. 2, the molten steel in the ladle 10 is adjusted to the sliding gate 13 to be pulled out through the collector nozzle 11 and the shroud nozzle 15 to the tundish 20.

The molten steel M accommodated in the ladle 10 flows to the tundish 20. The ladle 10 is provided with a shroud nozzle 15 extending toward the tundish 20 for the flow. The shroud nozzle 15 extends to be submerged in the molten steel in the tundish 20 so that the molten steel M is not exposed to air and oxidized and nitrided.

The shroud nozzle 15 plays a major role in improving the quality of the cast slab by preventing slag mixing by preventing oxidation of molten steel and preventing swirl of molten steel during continuous casting of steel.

When the molten steel is injected into the tundish 20 from the ladle 10 according to the structure of the nozzles 11 and 15 as described above, air is introduced into the gap between the shroud nozzle 15 and the collector nozzle 11, and thus is introduced. Air can deteriorate the quality of steel as it is reoxidized in contact with molten steel. In order to solve this problem, as shown in FIG. 3, the argon gas for sealing is injected into the combined portion of the collector nozzle 11 and the shroud nozzle 15.

However, due to the high temperature molten steel while passing through the shroud nozzle 15, the loss of the bonding force due to the thermal expansion difference of the metal case 19 and the thermal expansion of the dual material, or mismatching between the shroud nozzle 15 and the collector nozzle 11 (mismatching) generates a gap between the shroud nozzle 15 and the porous ring 17-1, so that argon gas or outside air is locally introduced into the inner hole of the shroud nozzle 15, and the tundish 20 with the molten steel. To enter. Therefore, the surface of the shroud nozzle 15 is severely generated due to the rise of argon gas or outside air in the tundish 20 due to buoyancy, and the local rise of the molten steel level around the shroud nozzle. Therefore, as the slag layer around the shroud nozzle is broken as shown in FIG.

This generation of molten iron causes molten steel to come into contact with air, resulting in reoxidation of the molten steel and increased powder consumption. In addition, the quality of the molten steel and nozzle clogging may deteriorate when tumble 20 is generated, and in the case of a quality stringent material, a situation in which the required characteristics may not be satisfied when the tumble is generated may occur.

Therefore, in the present invention, by detecting the horizontal vibration generated when the argon gas or the outside air is introduced through the inner hole of the shroud nozzle 15, indirectly predicts whether or not the tundish 20, the gas injection unit when predicting In addition to reducing the amount of argon gas injected through the (110) to output a warning sound according to the occurrence of the beetle.

5 is a flowchart illustrating a process for controlling gas for nozzle silencing according to an embodiment of the present invention, which will be described with reference to the accompanying drawings.

First, the gas injection unit 110 injects the argon gas for sealing into the part in which the collector nozzle 11 and the shroud nozzle 15 are coupled to each other through the gas inlet 16 (S11). At this time, due to high temperature molten steel, the coupling force due to the difference in thermal expansion of the metal case 19 and the thermal expansion of the dual material is lost, or the shroud nozzle 15 due to mismatching due to foreign matter between the collector nozzle 11 and the shroud nozzle. The gap between the porous ring 17-1 and the argon gas and the outside air may locally enter the tundish 20 together with the molten steel through the inner hole of the shroud nozzle 15. When the argon gas flows into the molten steel of the tundish 20, the trough flow in the tundish 20 is severely generated around the shroud nozzle 15 due to the injury of the argon gas and the outside air, and as a result, as shown in FIG. 4. As the slag layer around the shroud nozzles is broken, it is possible to generate ground.

On the other hand, the vibration sensor 130 mounted on the end of the arm 101 of the nozzle operator 100 supporting the shroud nozzle 15 or the top of the shroud nozzle 15 is transverse from the shroud nozzle (15) The vibration generated in the direction is sensed (S12). Here, when argon gas or outside air flows through the inner hole of the shroud nozzle 15, vibration occurs in the shroud nozzle 15 in the lateral direction, and the vibration sensor 130 detects the lateral vibration and the controller To 150.

Subsequently, when the horizontal vibration is sensed through the vibration sensor 130 (S13), the controller 150 determines that the hot water is generated on the hot water surface of the tundish. In the above generation, the controller 150 controls the gas injection unit 110 to reduce the injection amount of the argon gas for sealing. In addition, the controller 150 may output a beeping occurrence warning sound through a buzzer or a beacon (not shown) when a beetle is generated, and may instruct the replacement of the shroud nozzle 15 through a predetermined display unit (not shown). It may also be (S14). Of course, in the case of quality strict material may be instructed to convert the steel grade to ordinary steel.

Therefore, the present invention automatically adjusts the injection amount of argon gas for nozzle sealing according to whether or not the surface of the tundish is exposed, and outputs an alarm signal, thereby reducing the phenomenon of the surface of the trough in the tundish and in addition to accidents caused by exposure to the surface. It can prevent.

Argon gas control system as described above is not limited to the configuration and manner of operation of the embodiments described above. The above embodiments may be configured such that various modifications may be made by selectively combining all or part of the embodiments.

10: Ladle 11: Collector Nozzle
13: Slide Gate 15: Shroud Nozzle
16: Gas inlet 17-1: Porus ring
17-2: Gas Pool 20: Tundish
25: immersion nozzle 30: mold
40: mold oscillator 50: powder feeder
60: support roll 65: spray
70: pinch roll 80: performance cast
90: cutter 100: nozzle manipulator (manipulator)
101: arm 110: gas injection unit
130: vibration sensor 150: controller

Claims (3)

A gas injection unit for injecting an inert gas for sealing into a portion where the collector nozzle and the shroud nozzle are combined;
A vibration sensor for sensing vibration generated in the transverse direction in the shroud nozzle; And
And a controller configured to control the amount of gas injected through the gas injection unit to determine that low water is generated on the hot water surface of the tundish when the lateral vibration is sensed through the vibration detection sensor.
The method according to claim 1,
The vibration sensor is a nozzle control gas control device mounted to the arm of the nozzle operator for supporting the shroud nozzle.
Injecting an inert gas for sealing into a portion in which the collector nozzle and the shroud nozzle are combined;
Sensing vibration generated in the transverse direction in the shroud nozzle; And
And when the lateral vibration of the shroud nozzle is sensed, determining that the hot water is generated at the hot water surface of the tundish to reduce the injection amount of the inert gas for sealing.

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