JPH0623498A - Device for controlling supply of molten steel in continuous casting - Google Patents

Abstract

PURPOSE:To obtain a cast slab having high quality by preventing biased flow phenomenon in a sliding nozzle for continuous caster. CONSTITUTION:A ringed electromagnet 14 is arranged along the outer peripheral surface of the sliding nozzle 12. The electro-magnet is provided with a ringed yoke and plural coils disposed at a prescribed interval along the inner peripheral surface of the yoke and in these coils, three phase AC current is given. By this method, rotating magnetic field having rotating axis in the flowing direction of the molten steel is given to the molten steel, and the molten steel is rotated by making the flowing direction the rotating axis. In such a way, by supplying the molten steel into a mold while rotating, the biased flow of the molten steel can be prevented and the cast slab having high quality can be produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling molten steel supply in continuous casting.

[0002]

2. Description of the Related Art In a continuous casting machine, molten steel is supplied from a tundish through a nozzle to a mold (to supply hot water), and the slab is gradually drawn out from the mold to continuously produce slabs. There is. A so-called sliding nozzle is generally used as a nozzle in the continuous casting machine.

Here, the hot water supply to the mold will be outlined with reference to FIG.

The molten steel once stored in the tundish 11 is supplied to the mold 13 through the sliding nozzle 12. Sliding nozzle 12 is immersion nozzle 12
It has a, a sliding part 12b, and a cylinder 12c. In the illustrated example, the sliding portion 12b is divided into three layers (sliding bodies), and each sliding body is formed with a hole through which molten steel passes.

Referring to FIG. 5, a cylinder 12c is connected to a sliding body located at the center, and the central sliding body is moved left and right in the figure by driving the cylinder 12c by a solenoid (not shown).
The tip of the immersion nozzle 12a is immersed in the molten steel in the mold 13, and the molten steel is supplied into the mold through the hole formed in the side wall of the immersion nozzle 12a. By moving the central sliding body to the left and right as described above, the overlapping portions of the holes formed in each sliding body are changed. That is, the flow passage area in the sliding portion 12b changes. In this way, the amount of molten steel supplied to the mold 13 is controlled by the sliding nozzle 12 so as to keep the molten steel level in the mold within a predetermined range.

[0006]

By the way, when the amount of molten steel supplied to the mold 13 is controlled as described above,
Since the flow path of the molten steel fluctuates in the sliding nozzle 12, the molten steel does not flow uniformly in the sliding nozzle 12 and a so-called one-sided flow phenomenon occurs.

When such a one-sided flow phenomenon occurs, the flow of molten steel becomes non-uniform in the mold, causing not only non-uniformity in the shell during shell formation but also non-uniform temperature in the mold. However, there is a problem that a high quality slab cannot be cast.

An object of the present invention is to provide a molten steel supply control device capable of preventing a one-sided flow phenomenon and providing a high quality cast product.

[0009]

According to the present invention, the molten steel stored in the tundish is supplied to a mold through a nozzle and is used in a continuous casting machine for withdrawing a slab from the mold. A molten steel supply control device in continuous casting is obtained, which has an application means for applying a rotating magnetic field having a rotating direction as a rotating axis to the molten steel flowing in the nozzle. For example, the applying means is a ring-shaped electromagnet arranged along the outer peripheral surface of the nozzle, and the electromagnet includes a ring-shaped yoke and a plurality of plurality of magnets arranged at a predetermined interval along the inner peripheral surface of the yoke. And a three-phase alternating current is applied to the coil.

[0010]

In the present invention, since the rotating magnetic field having the rotating direction of the flowing direction of the molten steel is applied to the molten steel, the rotating magnetic field causes the molten steel to rotate about the rotating direction of the flowing direction.
The molten steel flows downward while rotating. as a result,
The molten steel is agitated in the nozzle, so that the one-sided flow phenomenon of the molten steel can be prevented.

[0011]

EXAMPLES The present invention will be described below with reference to examples.

With reference to FIGS. 1 to 3, the same components as those in the example shown in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted. A ring-shaped electromagnet 14 is arranged outside the immersion nozzle 12a along the outer peripheral surface thereof. The electromagnet 14 is composed of a ring-shaped yoke, a plurality of iron cores 14b arranged so as to project from the inner peripheral surfaces of the yokes 14a and 14a 'at a predetermined interval, and a coil 14c wound around the iron core 14b. Has been done (eg, 4
The individual coils 14c are arranged at intervals of 90 degrees).

The electromagnet 14 is divided into first and second yokes 14a and 14a 'in the axial direction (axial direction of the immersion nozzle), and the first and second yokes 14a and 14a'.
When assembled, the ends will be connected to each other.

The first and second yokes 14a and 14
One ends of the arms 15a and 15b are attached to a'through an insulator, respectively.
b are rotatably held by the pin member 15c. That is, the link mechanism is formed. The other end of the arms 15a and 15b is connected to the cylinder 16. As a result, when the piston of the cylinder 16 moves inward, the ring-shaped electromagnet 14 is constructed by combining the first and second yokes 14a and 14a 'as shown in FIG. 2 (a). Meanwhile, cylinder 16
2B, the electromagnet 14 moves the first and second yokes 14a and 14a as shown in FIG. 2B.
It will be separated into ´. The first and second yokes 14a and 14a ', the arms 15a and 15b, and the cylinder 16 are supported on the tundish 11 by a supporting member (not shown). Then, the first and second yokes 14a and 14a 'are connected or separated as needed (for example, when the immersion nozzle 12a is moved up and down).

Referring again to FIG. 1, when a three-phase current, for example, is sequentially applied to each of the coils 14c constituting the electromagnet 14, a rotating magnetic field is generated by this current (that is, a rotating magnetic field is generated by the principle of the induction motor). ). Since this rotating magnetic field acts on the molten steel flowing downward in the immersion nozzle 12a in a plane perpendicular to the flow direction, the rotating magnetic field exerts a rotational force about the flow direction on the molten steel. become. As a result, the molten steel rotates about the flow direction, and the molten steel is agitated in the immersion nozzle.

In this way, the molten steel is easily stirred by applying a rotational force to the molten steel, and as a result, the one-sided flow phenomenon can be prevented even when the molten steel supply amount is adjusted.

[0017]

As described above, in the present invention, since the rotating magnetic field having the rotating direction of the flowing direction of the molten steel is applied to the molten steel, the molten steel flows while rotating around the rotating direction of the rotating direction, and the molten steel flows in the nozzle. The molten steel is agitated to prevent the one-sided flow phenomenon. As a result, there is an effect that a high quality slab can be provided.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a molten steel supply control device according to the present invention.

FIG. 2 is a diagram schematically showing a drive mechanism that drives the electromagnet shown in FIG.

FIG. 3 is a diagram for explaining the configuration of the electromagnet shown in FIG.

FIG. 4 is a diagram schematically showing a molten steel supply mechanism in a continuous casting machine.

FIG. 5 is a diagram for explaining molten steel amount supply control in a continuous casting machine.

[Explanation of symbols]

 11 Tundish 12 Sliding Nozzle 13 Mold 14 Electromagnet

Claims (3)

[Claims] 1. A continuous casting machine in which molten steel stored in a tundish is supplied to a mold through a nozzle to draw out a slab from the mold. A molten steel supply control device in continuous casting, characterized in that it has an applying means for applying a rotating magnetic field having a rotating axis in the direction. 2. The molten steel supply control device according to claim 1, wherein the applying means is a ring-shaped electromagnet arranged along the outer peripheral surface of the nozzle, and the electromagnet includes a ring-shaped yoke and A molten steel supply control device in continuous casting, comprising: a plurality of coils arranged at a predetermined interval along the inner peripheral surface of the yoke, and the coils are provided with a three-phase alternating current. 3. The molten steel supply control device according to claim 2, wherein the electromagnet has first and second electromagnets in the rotation axis direction.
And is provided with a coupling / separating means for separating the first and second yokes of the electromagnet and the ring-shaped electromagnet by combining the first and second yokes. A molten steel supply control device for continuous casting.