JPH0525587B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to the flow of molten metal flowing from a molten metal container used in steel-making ingots, non-ferrous metal bloomers, converters, etc. to continuous casting equipment or other molten metal containers. This invention relates to a device that enables a stable supply of.

[Prior art]

Conventionally, sliding nozzle devices and stopper devices have been used as devices for controlling the flow rate of molten metal.

A sliding nozzle device is a mechanism that squeezes the molten metal passing through two or more plate bricks by sliding between them. In this mechanism, the pressure in the molten metal flow path below the constriction becomes negative, which tends to cause air and gas to be sucked in from the joints of each plate brick, adversely affecting the steel quality of the product.

In order to prevent such air and gas inhalation, various measures have been taken regarding the method of joining the plate bricks and the sealing of the joints, but these measures are still not perfect.

On the other hand, even when adjusting the flow rate using a stopper,
Negative pressure is generated within the molten metal flow path due to the restriction. Therefore, if there is a refractory joint in this negative pressure generating area, it is necessary to seal this joint. However, like the sliding nozzle device, this sealing structure has not yet reached the level of completely preventing air and gas from being sucked in.

In contrast to such conventional technology, Japanese Patent Application Laid-open No.
Publication No. 141365 proposes a mechanism that changes the outflow direction and flow rate by adjusting the opening of the immersion nozzle below the hot water surface. However, since this mechanism does not control the outflow force of the molten metal, it is inevitable that inclusions will be drawn in as described above. In addition, the immersion volume of the immersion portion changes as the immersion nozzle moves up and down, causing fluctuations in the molten metal level. For this reason, there is a problem in that the control of the molten metal level during casting becomes complicated.

Furthermore, JP-A-48-229 discloses a configuration in which a float with a hole is placed under the molten metal discharge hole of an immersion nozzle and the discharge hole is automatically opened and closed by raising and lowering the molten metal level. There is. However, when the hot water level is lower than the discharge hole of the immersion nozzle or when the hot water level is just touching the hot water level, air is sucked in and the contact area with the air is actively increased. In addition, stirring is performed accompanied by the generation of splash, which leads to problems such as roughening of the slab surface and the entrainment of inclusions.

[Purpose of the invention]

The present invention aims to solve these problems by completely preventing air or gas from entering the molten metal flow, and without disturbing the molten metal in the mold or changing the molten metal level. The purpose is to enable pouring of molten metal and improve steel quality.

[Structure of the invention]

The present invention relates to an immersion nozzle whose upper end is connected to a molten metal container in communication, and a box having an inner diameter larger than the outer diameter of the immersion nozzle, which surrounds the circumferential surface and the lower part thereof, and is immersed in the secondary molten metal. an outlet opened in the circumferential surface of the immersion nozzle for feeding the primary molten metal in the molten metal container into the box body, and an opening/closing body provided around the circumferential surface of the immersion nozzle including the outlet. , a discharge port opened in the peripheral wall of the opening/closing body at a position away from the outlet of the immersion nozzle and facing the secondary side molten metal, and connecting at least one of the immersion nozzle and the opening/closing body to a drive system and connecting them to each other. The outflow port can be opened and closed by the movement of the box, and the inside of the box body is used as a flow pool for the primary molten metal, so that the flow of the molten metal from the outflow port to the discharge port can be slowed down.

The second invention also provides a immersion nozzle whose upper end is connected in communication with a molten metal container and is rotatable around its axis, and a receiving container that surrounds and below the immersion nozzle and is immersed in the secondary molten metal. a support tube provided inside the receiving container to rotatably support the lower end of the immersion nozzle; and a support tube opened in the circumferential surface of the immersion nozzle for feeding the primary molten metal in the molten metal container into the receiving container. an outlet, a hole drilled in the support tube at a position aligned with the outlet by rotation of the immersion nozzle, and an outlet opened in the wall of the receiving container at a position away from the hole in the support tube. The molten metal flow from the hole of the support tube to the discharge port can be slowed down by using the inside of the receiving container as a flow pool of the primary molten metal.

〔Example〕

FIG. 1 is a schematic diagram showing an embodiment of the first invention.

In the figure, the upper end of a submerged nozzle 2 is connected to the bottom of a molten metal container 1 such as a ladle. The immersion nozzle 2 can be positioned, for example, at a level lower than the level of the secondary molten metal 3 retained in the mold of a continuous casting machine, and the immersion nozzle 2 has two immersion nozzles radially opposed to each other on the peripheral wall at the lower end.
A number of outlet ports 4 are opened.

An opening/closing body 5 for opening and closing the outlet 4 is fitted onto the outer peripheral surface of the immersion nozzle 2 so as to be slidable up and down.
This opening/closing body 5 has a hollow cylindrical shape that covers the periphery of the immersion nozzle 2, and has two holes 6 that can be aligned and unaligned with the outlet 4 of the immersion nozzle 2 by its vertical movement.
is open. Moreover, the opening/closing body 5 is the molten metal container 1
It is connected to an elevating cylinder 7 whose upper end is fixed to the bottom of the opening/closing body 5, and by operating this elevating cylinder 7, the opening/closing body 5 is moved up and down.

Furthermore, a box 8 is fixed to the bottom of the molten metal container 1 by a rod 8a, surrounding the immersion nozzle 2 and the opening/closing body 5. This box body 8 is a container with a bottom and a circular cross section, and as shown in FIG. 2, two discharge ports 8b are opened in the peripheral wall.
These molten metal discharge ports 8b are connected to the immersion nozzle 2 as shown in FIG.
The center of the opening is perpendicular to the opening axis of the outlet 4 of the opening and closing body 5 and the opening axis of the hole 6 of the opening/closing body 5. That is, the flow of the primary molten metal that passes through the immersion nozzle 2 from the molten metal container 1 and is supplied to the box body 8 from the outlet 4 and the hole 6 reaches the maximum flow when passing through the inside of the box body 8. The route will be long. By providing such a long flow path, the flow of the primary molten metal is temporarily stagnated within the box body 8 until it reaches the discharge port 8b at the final stage, thereby decelerating the flow.

In addition, in FIG. 2, in order to show the level relationship between the outlet 4, the hole 6, and the outlet 8b, these are depicted as being located in the same plane.

In the above configuration, when the lifting cylinder 7 is operated to lower the opening/closing body 5 from the state shown in FIG.
As shown in the figure, the outlet 4 and the hole 6 come to overlap. Therefore, the primary molten metal from the molten metal container 1 flows into the box 8 through the outlet 4 and hole 6, flows in the direction shown by the arrow in FIG. 3, and flows from the outlet 8b to the primary side in the mold. It is discharged into the molten metal 3.

Here, the molten metal flow path can be freely adjusted by adjusting the degree of alignment between the outlet 4 and the hole 6 through the stroke of the lifting cylinder 7 to change the flow path area. Further, the primary molten metal is not directly discharged from the immersion nozzle 2 into the secondary molten metal 3 in the mold,
The flow once accumulates in the box body 8 and is finally sent into the secondary molten metal 3 from the discharge port 8b.
Therefore, when the molten metal flows inside the box 8, its flow velocity is slowed down, and at the same time, the flow is made uniform, and the molten metal flows smoothly and is discharged to the secondary molten metal 3 in the mold. Therefore, the flow to the secondary molten metal 3 in the mold becomes stable, the secondary molten metal 3 is not violently disturbed, and fluctuations in the molten metal level are suppressed.

Note that instead of fixing the box 8 to the molten metal container 1, it may be connected to the opening/closing body 5 and raised and lowered together with the opening/closing body 5 by the lifting cylinder 7. Furthermore, instead of providing the outlet 8b in the box 8 in the peripheral wall, the outlet 8b may be provided in the bottom wall of the box 8. Even in this case, the molten metal from the immersion nozzle 2 is stagnated in the box 8 and decelerated before being discharged into the secondary molten metal 3 of the mold, so it does not disturb the secondary molten metal 3 and does not particularly flow. Since the water is directed downward, fluctuations in the side of the hot water can be effectively suppressed.

Furthermore, instead of moving the opening/closing body 5 up and down by the lifting cylinder 7, the opening/closing body 5 is rotated around the immersion nozzle 2 to align the outlet 4 and the hole 6, thereby dispensing. You may also do so.

FIG. 4 shows another example, in which the opening/closing body 5 is not provided with an outlet 6 and has a simple hollow cylindrical shape.

In this example, by raising and lowering the opening/closing body 5, it is possible to open/close the outlet 4 and change its opening area, as in the previous example, and to discharge the molten metal and set its flow rate.

FIGS. 5 and 6 are schematic diagrams showing an embodiment of the second invention.

In the figure, the immersion nozzle 2 is connected to a sliding nozzle device 15 that is installed in the bottom of the molten metal container. This immersion nozzle 2 can be rotated about its axis by an external drive mechanism (not shown). In addition, as for this drive mechanism, an electric motor is attached to the bottom of the molten metal container, a drive gear is provided on its output shaft, and this drive gear is connected to the immersion nozzle 2.
A configuration such as meshing with a driven gear provided on the circumferential surface of the gear can be adopted.

A receiving container 9 having a rectangular planar shape is provided below the molten metal container, and the receiving container 9 is immersed in the secondary molten metal 3 except for its upper end portion. The receiving container 9 is assembled below the molten metal container with a cylindrical sealing material 9a for sealing an inert gas such as argon gas, and therein is a support tube into which the immersion nozzle 2 is slidably inserted. 10 is provided, and this support tube 1
The discharge port 11 is opened at a position away from zero.

Holes 10a are formed in two places on the peripheral wall of the support tube 10,
The lower end of the immersion nozzle 2 has an outlet 2a that can be aligned with these holes 10b by rotation of the immersion nozzle 2.
is opened in the radial direction.

In this way, the stable supply device of the second invention removes the box body 8 from the configuration of the first invention and also includes the opening/closing body 5.
The flow path of the molten metal from the immersion nozzle 2 is opened and closed by the receiving container 9, which is a member corresponding to the receiving container 9, and the molten metal can be decelerated in the receiving container 9 and supplied from the discharge port 11 to the secondary molten metal 3. That is.

In the above configuration, the sliding nozzle device 1
In addition to adjusting the flow rate of the molten metal as shown in FIG. 5, it is possible to adjust the flow rate according to the degree of matching between the outlet 2a and the hole 10, and the flow rate of the molten metal can be set finely.

Further, from the outlet 2a of the immersion nozzle 2 to the support tube 1
The primary molten metal flowing into the receiving container 9 through the holes 10a is decelerated and its flow is made uniform before it heads toward the discharge port 11. Therefore, fluctuations in the molten metal level when the molten metal is discharged from the discharge port 11 to the secondary side molten metal 3 can be suppressed.

〔Effect of the invention〕

According to the present invention, since the molten metal from the molten metal container can be stably fed into the molten metal in the mold, the molten metal in the mold is not disturbed.
Therefore, fluctuations in the molten metal level can be suppressed, air and gas can be prevented from being mixed in, and the quality of the steel can be improved.

[Brief explanation of drawings]

Fig. 1 is a cutaway view of a submerged nozzle showing an embodiment of the first invention, Fig. 2 is a vertical sectional view of the main parts, Fig. 3 is a sectional view taken along the - line in Fig. 2, and Fig. 4 is FIG. 5 is a longitudinal sectional view of the main part showing another example, FIG. 5 is a schematic longitudinal sectional view of an example combined with a sliding nozzle device showing an embodiment of the second invention, and FIG. 6 is a -
FIG. 1: Molten metal container, 2: Immersion nozzle, 3: Molten metal, 4: First outlet, 5: Opening/closing cylinder, 6: Second outlet, 7: Lifting cylinder, 8: Box, 9: Receiving container, 10: Support cylinder, 11: Discharge port.

Claims (1)

[Scope of Claims] 1. An immersed nozzle whose upper end is connected in communication with a molten metal container, and a rod having an inner diameter larger than the outer diameter of the immersed nozzle, surrounding the circumferential surface and the lower part thereof, and immersed in the secondary molten metal. a box body for disposing the immersion nozzle; an outlet provided on the circumferential surface of the immersion nozzle for feeding the primary molten metal in the molten metal container into the box body; and an outlet provided around the periphery of the immersion nozzle including the outlet; an opening/closing body; and a discharge port opened in a peripheral wall of the opening/closing body at a position remote from the outlet of the immersion nozzle and facing the secondary molten metal, and connecting at least one of the immersion nozzle and the opening/closing body to a drive system. At the same time, the outflow port can be opened and closed by mutual movement, and the inside of the box body is used as a flow pool for the primary molten metal, so that the flow of the molten metal from the outflow port to the discharge port can be decelerated. A device for stably supplying a flow of molten metal from a submerged nozzle in a molten metal container. 2. An immersed nozzle whose upper end is connected in communication with a molten metal container and is rotatable around its axis; a receiving container surrounding and below the immersed nozzle and immersed in the secondary molten metal; and the inside of the receiving container. a support tube that rotatably supports the lower end of the immersion nozzle; an outlet that is opened on the circumferential surface of the immersion nozzle and sends the primary molten metal in the molten metal container to the receiving container; a hole formed in the support tube at a position aligned with the outlet by rotation of the support tube; and an outlet opened in the wall of the receiving container at a position away from the hole in the support tube, A device for stably supplying a flow of molten metal from a submerged nozzle in a molten metal container, characterized in that the interior of the molten metal container is used as a flow pool for the primary molten metal, so that the flow of the molten metal from the hole in the support cylinder to the discharge port can be decelerated.