JPH0614924Y2 - Pouring equipment in continuous casting equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pouring device for pouring molten steel from a ladle or a tundish into a mold of a continuous casting facility.

2. Description of the Related Art As shown in FIG. 9, for example, when pouring molten steel 24 into a mold 23 from a tundish 21 through a tundish nozzle 22, in order to cast a homogeneous cast piece 25, It is necessary to keep the molten metal surface 24a at a constant level at all times, so that the pouring amount from the tundish nozzle 22 is adjusted to be equal to the casting amount of the slab 25. As a means for adjusting the pouring amount, by vertically moving a rod-shaped stopper 26 suspended in the tundish 21, the opening of the inlet opening 22a of the tundish nozzle 22 is adjusted at the lower end of the stopper 26. Was.

The problem to be solved by the invention is that, in the above-mentioned configuration, particularly in the case of thin plate continuous casting, when the tundish nozzle 22 must be narrowed down by the stopper 26 because the casting amount is small, the inlet opening
The gap between the lower end 22a and the lower end of the stopper 26 becomes small, and it becomes easy for the flocs to partially close during casting for a long time. As a countermeasure, the stopper 26 is temporarily raised to fully open the tundish nozzle 22 to remove the flocs, but the molten metal level 24a in the mold 23 is raised to adversely affect the cast slab 25 during casting. It will be given.

The present invention solves the above problem, and an object of the present invention is to provide a pouring device in which the nozzle is not blocked even when used for a long time.

In order to solve the above problems, the present invention provides a pouring nozzle for pouring molten steel into a mold, an upper vertical flow path portion, a lower vertical flow path portion, and a plurality of intermediate horizontal flow paths connected to these. And a spiral intermediate flow passage part, and a force in the direction opposite to the sending direction is applied to the molten steel in these flow passage parts around the intermediate horizontal flow passage part or the spiral intermediate flow passage part. The configuration is such that an electromagnetic coil that generates a magnetic field is provided.

In the above configuration, a rotating magnetic field is generated by the electromagnetic coil, and its magnetic flux generates an eddy current in the molten steel passing through the intermediate horizontal flow path portion or the spiral intermediate flow path portion, and the direction of the magnetic flux and its current Depending on the direction, a force is generated in the direction opposite to the direction in which the molten steel is flown to inhibit the flow of the molten steel, so that the pouring amount of the pouring nozzle can be optimally adjusted without using a stopper.

Embodiment An embodiment of the present invention will be described below with reference to FIGS.

1 to 4, reference numeral 1 denotes a pouring nozzle for pouring molten steel 10 from a tundish 2 into a mold 5 having a pair of mold rolls 3 and a molten steel receiver 4, and the pouring nozzle 1 is fireproof. Of the upper vertical flow path portion 6 formed of a material, the upper end portion of which is connected to the tundish 2, the lower vertical flow path portion 7 of which the lower end portion reaches the inside of the molten steel receiver 4, and an intermediate portion between these flow path portions 6 and 7. It is composed of two horizontal intermediate flow passage portions 8a and 8b, one end of which is connected to the lower end portion of the upper vertical flow passage portion 6 and the other end thereof is connected to the upper end portion of the lower vertical flow passage portion 7. The two intermediate horizontal flow passage portions 8a and 8b are formed so as to make a round arc shape extending over approximately 360 ° on a horizontal plane.

Reference numeral 9 denotes an electromagnetic coil arranged on the outer peripheral portions of the two intermediate horizontal flow passages 8a and 8b, which form a rotating magnetic field across the intermediate horizontal flow passages 8a and 8b. , 8b generates an eddy current in the molten steel 10 and the horizontal flow path portion 8 in both middle portions
A force is generated in the direction opposite to the flow direction of a and 8b, whereby the pouring amount of the pouring nozzle 1 can be adjusted.

This basic principle will be described with reference to FIGS. 5 and 6. A pair of N and S magnets 12 is provided on the outer periphery of a ring-shaped conductor (molten steel) 11.
If A and 12B are rotated in the direction of arrow A, the magnetic flux 1 that crosses the conductor 11
Due to 3, an eddy current I is generated in the conductor 11, and when this current I crosses the magnetic flux 13 downward, the force in the same direction as the arrow A direction, which is the rotating direction of the magnets 12A and 12B, is applied by Fleming's left-hand rule. F is generated and the conductor 11 is rotated in the same direction as the magnet. Such a rotating magnetic field can be created by the same principle as an induction motor.

Next, the principle of stopping the flow of the fluid (molten steel) in this embodiment will be described.

In FIG. 7, assuming that the energy of the fluid between A and b is only the pressure head: H ₁ , this pressure head: H
Energy equal to ₁ , velocity to produce H ₂ :
V may be generated in the two horizontal flow passage portions 8a and 8b.

That is, H ₁ = P / γ P: fluid pressure, γ: specific weight of fluid If this is set equal The frequency for generating the rotating magnetic field for generating such V is calculated as follows.

Here, the relationship between the rotational speed of the rotating magnetic field: N (rpm), the number of magnetic poles arranged around the two horizontal flow passages: P ₀ , and the frequency applied to generate the magnetic field: S (Hz) Is.

In addition, radius: γ Speed in two-stage horizontal flow path: V and rotation speed:
Relationship with N Is.

By substituting V in (1) and N in (2) into (3), the frequency S to be added can be obtained.

Looking at specific examples, the head of the flow path: h = 750 mm, specific weight of molten steel: γ = 7 x 10 ³ kg
/ m ³ Radius of 2-step horizontal flow path: γ = 50 mm Number of magnetic poles: P ₀ = 6, g = 9.8 m / sec ² , However, the fluid does not rotate with the rotating magnetic field, that is, at the rotation speed: N. Therefore, the frequency S that should be actually added is equal to the value (0.01%) calculated by the above equation.
The range is ~ 10%).

If the efficiency is 1%, Becomes

The above efficiency is related to the material and temperature of the nozzle, and is largely influenced by the current flowing through the coil, which is related to the magnetic flux.

By the way, as shown in FIG. 3, the portion of the pouring nozzle 1 which constitutes the intermediate flow passage portion has a vertically divided three-part structure, and by inserting the central portion, the horizontal flow passage portion can be easily formed. The number of stages can be increased.

In addition, according to the above-described embodiment, the two-stage intermediate horizontal flow path portion 8 is provided.
Although a and 8b have an arc shape extending over approximately 360 °, they may have an arc shape exceeding 60 °, and may have a flow path extending over a plurality of rounds of three stages or more, and as another embodiment shown in FIG. Such a spiral intermediate flow path portion 14 may be used. Further, the cross-sectional shape of the flow path portion that constitutes these intermediate portions is not particularly limited.

Effect of the Invention According to the present invention as described above, since the pouring amount of the pouring nozzle can be adjusted by adjusting the frequency and the current flowing in the electromagnetic coil, the stopper that is frequently replaced due to wear as in the conventional case. Is unnecessary and economical. Further, the backflow generated when the flow rate is reduced can re-melt the flocs and wall shells in the molten steel, so that the pouring nozzle can be prevented from being blocked and the flow rate can be adjusted stably.

In addition, it is not necessary to control the stopper while monitoring the change in the flow rate due to blockage or wear, and control is extremely easy. Furthermore, since the intermediate flow path part has a horizontal flow path of multiple stages or a spiral shape, it becomes easier to receive the reverse direction force due to the magnetic field, and the force to rotate in the reverse direction with respect to the flow of molten steel is exerted. Since the outflow amount of molten steel can be effectively controlled, the outflow of molten steel can be stopped in some cases, and the control range of the molten steel flow is wide.

[Brief description of drawings]

1 to 7 show an embodiment of the present invention, and FIG.
FIG. 2 is a perspective view showing an intermediate horizontal flow passage portion formed in stages, FIG. 2 is an overall view of a pouring nozzle, and FIG. 3 is a side sectional view showing the intermediate horizontal flow passage portion formed in two stages. FIG. 4 is a view as seen in the direction of arrows I--I shown in FIG. 3, FIGS. 5 and 6 are explanatory views showing the basic principle, respectively, FIG. 7 is a schematic explanatory view showing the principle of the embodiment, and FIG. FIG. 9 is a schematic perspective view showing an intermediate flow path portion of the embodiment, and FIG. 9 is an overall view showing a conventional pouring nozzle. 1 ... Pouring nozzle, 2 ... Tundish, 5 ... Mold, 6 ... Upper vertical channel, 7 ... Lower vertical channel, 8
...... Middle horizontal flow path, 9 ...... electromagnetic coil, 10 ...... molten steel, 14 ...... spiral intermediate flow path.

Claims (2)

[Scope of utility model registration request] 1. A pouring nozzle for pouring molten steel into a mold is constituted by an upper vertical flow passage portion, a lower vertical flow passage portion, and a plurality of intermediate horizontal flow passage portions respectively connected to these, A note in continuous casting equipment characterized in that an electromagnetic coil for generating a magnetic field that gives a force in the direction opposite to the flowing direction to the molten steel in the horizontal flow passage is provided around the intermediate horizontal flow passage in multiple stages. Hot water equipment. 2. A pouring nozzle for pouring molten steel into a mold comprises an upper vertical flow path portion, a lower vertical flow path portion, and a spiral intermediate flow path portion connected to each of the upper vertical flow path portion and the lower vertical flow path portion. A pouring device in a continuous casting facility, characterized in that an electromagnetic coil for generating a magnetic field that gives a force in a direction opposite to the flow direction to the molten steel in the flow passage is provided around the intermediate flow passage.