JPS58221647A - Method for controlling spacing between partition wall and roll for cooling in continuous casting device for steel plate - Google Patents

Abstract

PURPOSE:To prevent the leakage of molten steel from the spacing between a partition wall for molten steel and rolls for cooling the molten steel, by detecting the torque of said rolls in a continuous casting device for a steel plate, and regulating the solidification of the molten steel in the forward end part of a barrel seal by making use of the detected signal thereof. CONSTITUTION:The rotating torque of two rolls 1, 2 for cooling under rotation is detected with a torque detector 15 in the stage of supplying molten steel 12 into the spacing between the rolls 1 and 2, cooling the same and casting a steel plate directly. The detected signal 16 is compared with the reference signal 17 for the rotating torque of the rolls 1, 2 in a comparing calculator 8, and if the difference thereof is large, the thickness of the solidified layer 13 of the molten steel formed at the forward end of the barrel sealing plate 4 of a partition wall 3 which supplied the molten steel is large; therefore, an operation signal is emitted to a burner 9 to melt the solidified layer with the burner 9. When the difference of the signals in the upper part is small, the shell 13 is thin, and is cooled with a nozzle 10 for blowing air in order to prevent the leakage of the molten steel from the sealing part 11, whereby the thickness of the shell 13 is optimized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a continuous casting apparatus for steel plates in which molten steel is solidified and drawn out as a plate from the gap between two cooling rolls arranged horizontally and in parallel. The present invention relates to a method for controlling the gap between a partition wall and a cooling roll, which automatically controls the gap between a partition wall located and storing molten steel and a seal portion between both rolls to prevent leakage of molten metal.

Conventionally, the most common method for producing steel plates is a method in which slag produced by continuous slab casting is rolled 5 to 10 times or more to produce a thin plate.

However, this method consumes a large amount of rolling energy and heating energy to maintain the temperature of the steel during the rolling operation.

In order to reduce this rolling energy and heating energy, methods of directly casting steel plates from molten steel have been considered in recent years. This method can be roughly divided into the twin roll method and the belt method.The belt method attempts to make a plate on a belt, so the belt method is based on the belt material's ability to withstand high-temperature molten steel. It is difficult to make a flat plate due to thermal distortion. On the other hand, the twin roll method attempts to make a plate by placing two rolls parallel to each other and pouring molten metal into the gap between the rolls, and does not have the drawbacks of the belt method. Moreover, it is relatively easy to manufacture.

However, in the above-mentioned twin-roll type continuous steel plate casting apparatus, a barrel seal plate 4 and a side seal are placed on one side of the roll gap between the cooling rolls 1 and 2, which are arranged vertically and horizontally in parallel, as shown in FIG. The molten steel in the partition wall 3 is collected on the surface of the cooling rolls 1 and 2. Since the molten steel is solidified to form a solidified layer and drawn out as a plate 8, molten steel does not leak from the gap between the rolls 1.2 and the barrel seal plate 4 and the gap between the rolls 1, 2 and the side seal plate 5. There is. Therefore,
It is necessary to seal such gaps.

The present invention attempts to prevent molten steel from leaking by sealing the gap between the roll and the barrel seal plate among the above-mentioned gaps, and reduces the rotational torque of the roll, which changes depending on the opening degree of the gap. The purpose is to detect and adjust the growth of a solidified layer of molten steel formed at the seal portion at the tip of the barrel seal plate, thereby controlling the gap between the partition wall and the cooling roll.

Embodiments of the present invention will be described below with reference to the drawings.

In a configuration in which a partition wall 3 consisting of a barrel seal plate 4 and a side seal plate 5 is disposed close to the gap between the cooling rolls 1 and 2 arranged vertically and in parallel in the same manner as in FIG. 1, FIG. As shown in the figure, a plurality of burners 9 and cooling air blowing nozzles 10 are arranged on the outside of the tip of the barrel seal plate 4, and the seal portion 11 II of the barrel seal plate 4 is heated by the cooling air from the cooling air blowing nozzles 10. The barrel seal plate 4 is cooled to a temperature slightly lower than the melting point.
A solidified layer 13 of the melt 1112 is formed on the tip surface of the barrel seal plate 4, and the solidified layer 14 is melted by heating the tip of the barrel seal plate 4 with the burner 9. The thickness of the coagulated layer 13 is adjusted by the operation of the spray nozzle 10, and the barrel seal plate 4 is
and the gap between rolls 1 and 2 is controlled.

The upper and lower cooling rolls 1 and 2 can be rotated by a drive motor 14, and the rotational torque of the rolls 1 and 2 can be detected by a torque detector 15 of the motor 14. It is compared with the rotational torque reference signal 17 of No. 2 in the comparator, and if there is a difference, the deviation No. 11 is input to the controller 19, and when the detection signal is larger, a command for operating the burner 9 is issued. Conversely, when the detection signal is smaller, that is, when molten steel is leaking, a command to operate the cooling air blowing nozzle 10 is issued.

20 is a coagulated layer formed along the surfaces of the cooling rolls 1 and 2, and 21 is a thermocouple.

The molten steel 12 in the partition wall 3 is cooled on the surfaces of the cooling rolls 1 and 2 by rotation of the cooling rolls 1 and 2.

It is solidified to form a solidified layer 2o, which is pulled out as a plate 8 from between the rolls 1.2 as shown in FIG.

During this time, the molten steel 12 inside the partition wall 3 leaks from the gap between the rolls 1 and 2 and the barrel seal plate 4 of the partition wall 3, that is, from the seal portion 11, and attempts to exit to the outside. In this case, it is not possible to seal the seal portion 11 between the rolls 1, 2 and the tip of the barrel seal plate 4 due to the surface tension of the molten steel and the width of the gap between the rolls 1, 2 and the barrel seal plate 4. Yes, but it cannot be maintained for long.

Therefore, in the present invention, the barrel seal plate 4 and the rolls 1 and 2 are
After maintaining a predetermined gap between them, a solidified layer 13 of molten steel is formed on the front end surface of the barrel seal plate 4, and the molten steel is formed between the solidified layer 13 and the surfaces of the rolls 1 and 2. Try to prevent leakage.

The rotational torque of the cooling rolls 1 and 2 is constantly detected by a torque detector 15, and is compared with a reference signal 17 by a comparison calculator 18.
are being compared.

Now, when the coagulated layer 13 grows too much and the rotational torque of the rolls 1 and 2 becomes large, that torque is immediately detected and compared with the reference signal 17, and the controller 19 turns on the burner 9 due to the large torque signal. A command to stop (OFF) the cooling air blowing nozzle 1o is issued. As a result, the tip of the barrel seal plate 4 is heated by the plurality of burners 9 and the coagulated layer 13 is melted, the thickness of the coagulated layer 13 is reduced, and the frictional force due to the sealing action is weakened.

Next, when the detected torque signal is smaller than the reference signal, the small torque signal causes the controller 19 to turn the burner 9 (OFF) and the cooling air blowing nozzle 10 (OFF).
N) command is issued. As a result, the barrel seal plate 4
The temperature at the tip of the solidified layer 13 is lowered by cooling air.
is grown to increase its thickness and strengthen its sealing action against molten steel.

The gap between the barrel seal plate 4 and the rolls 1 and 2 can be changed by automatically adjusting the thickness of the coagulated layer 13 of the barrel seal plate 4 depending on whether the detected torque signal is large or small. .

When the gap is changed, the result can be detected by the torque detection signal, and when there is no difference compared with the reference signal, the controller 19 controls the burner 9 and the nozzle IO.

In addition, in the embodiment, a case is illustrated in which the cooling rolls 1 and 2 are arranged above and below, the partition wall 3 is arranged horizontally, and the partition wall 3 is covered, but the invention is not limited to this. Instead, the same applies to a type in which the cooling rolls 1 and 2 are arranged horizontally and the partition wall 3 is arranged upward or downward.

As described above, according to the method of the present invention, when the rotational torque of the roll is detected and the detected torque signal is different from the reference signal, heating by the burner and cooling air blowing nozzle are performed depending on the difference. Cooling is performed to adjust the sealing effect by changing the thickness of the solidified layer of molten steel formed on the tip surface of the barrel seal plate, so that the gap between the roll and barrel seal plate can always be maintained properly and the molten steel can be prevented from leaking out.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of a continuous casting apparatus for steel plates, and FIG. 2 is an embodiment of the method of the present invention. 1.2... Cooling roll, 3... Compartment wall, 4...
Barrel seal plate, 5... Side seal plate, 9... Burner, 10... Cooling air blowing nozzle, 15... Torque detector, 18... Comparison calculator. Patent application Hitoshi Kawajima Harima Heavy Industries Co., Ltd.

Claims (1)

[Claims] 1) In a continuous steel plate casting apparatus that casts a steel plate while forming a solid layer of molten steel on the roll surface by positioning a partition wall for storing molten steel in the gap between two cooling rolls, the barrel seal of the partition wall A plurality of burners and cooling air blowing nozzles are arranged at the tip of the plate to detect the rotational torque of the roll and compare the detected torque with a reference value. If there is a difference, the burner or nozzle is activated based on the difference signal. A force method for controlling the gap between the partition wall and the cooling roll, characterized in that the thickness of the solidified layer of molten steel formed at the tip of the barrel seal plate is changed by operating the barrel seal plate, thereby changing the gap between the partition wall and the roll. .