JPS6316856A - Molten metal container provided with molten metal outflow port - Google Patents

Abstract

PURPOSE:To prevent the inclusion of slag into a casting mold by providing a perforated cylindrical gate member, vortex blocking members extending vertically in the gate member and foam forming means for regulating the flow rate of a molten metal by forming foam flow to the molten metal outflow port of a container. CONSTITUTION:The refractory cylindrical body 31 having many holes 32 and the cruciform vortex blocking members extending vertically in the cylindrical body 31 are disposed to the molten metal outflow port of a tundish 20. A molten steel passes the respective holes 32 of the cylindrical body 31 and falls along the vortex blocking members before the molten steel flows out to an immersion nozzle 22 at the time of supplying the molten steel through a sliding nozzle 21 into the casting mold 24. Gaseous Ar is blown from porous plugs 41 into the molten steel to form the curtain of the foam flow 43 around the cylindrical body 31, by which the flow rate of the outflowing molten steel is controlled. As a result, the inclusions are adsorbed to the wall of the respective holes 32 and the molten steel flows out to the nozzle 22 without generating vortexes. The inclusion of the slag into the casting mold is thereby prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a molten metal container such as a tundish or a pickaxe, and in particular, it prevents vortex generation of molten metal at the molten metal outlet, removes inclusions, and improves I-flow. The present invention relates to a molten metal container equipped with a molten metal outlet that allows the molten metal to be poured into another container while preventing the molten metal from leaking.

[Prior Art] As shown in Fig. 3, a conventional tanditshu has a brick 2 fitted in a proper position on its bottom 1.
In this receiver, a porous nozzle 3 is fitted into a brick 2. A sliding nozzle 5 is arranged at a position aligned with this nozzle 3.

This sliding nozzle 5 has a fixed platen 6 fixed to the iron shell 4 of the tundish bottom 1, and a slide 17 arranged to slide with respect to the fixed platen 16. Then, by sliding the slide plate 7 to change the relative positions of the holes in the fixed plate 6 and the holes in the slide plate 7, the molten steel flow cross-sectional area is adjusted and the amount of molten steel injected is adjusted. A cylindrical immersion nozzle 8 is attached to the slide plate 7.
The discharge port 9 of this immersion nozzle 8 is immersed in the molten steel 11 in the mold 10, and the molten steel is injected into the mold 10 while avoiding contact between the molten steel injection flow and air.

[Problems to be Solved by the Invention] However, at the final stage of casting, when the molten steel gap in the tundish decreases, vortices are generated in the molten steel in the tundish in the area directly above the molten steel outlet, and the slag on the surface of the molten steel is It gets rolled up and mixed into the molten steel in the mold. Then, this slag is captured by the solidified shell that is solidifying within the mold, causing inclusion defects in the slab. Also,
In the case of high-grade steel that requires high quality, the depth is sufficient to prevent the formation of vortices in the tundish, for example about 400+.
The injection of molten steel is stopped, leaving the molten steel of a+), and the remaining steel in the tundish is discarded. Therefore, there is a problem that the yield is low.

This invention was made in view of such circumstances, and
It is an object of the present invention to provide a molten metal container equipped with a molten metal outlet that can prevent slag in a tundish from being caught in a mold.

[Means for Solving the Problems] A molten metal container equipped with a molten metal outlet according to the present invention is provided with a molten metal outlet at the bottom, and the stored molten metal is transferred to other members through the molten metal outlet. The molten metal container to be supplied includes a weir member having a porous cylindrical shape and installed on the bottom of the container so as to surround the molten metal outlet, and a plurality of vortex flow prevention members disposed at the center of the weir member and extending in a vertical direction. and a bubble forming means for adjusting the flow rate of the molten metal flow by forming a bubble flow surrounding the weir member.

[Function] In this invention, even if the level of the molten metal in the container decreases at the end of casting, the eddy current prevention member disposed within the weir member prevents the generation of vortices. There is no risk of getting caught inside. Furthermore, the molten metal in the container passes through a number of holes in the weir member before flowing out from the molten metal outlet.

As a result, inclusions and the like in the molten metal adhere to the holes and are removed, and clean molten metal flows out. Further, by adjusting the amount of gas blown to form a bubble flow, the flow rate of the molten metal can be finely adjusted.

Therefore, it is possible to prevent fluctuations in the flow rate due to fluctuations in the hot water level in the container, etc., due to the bubble flow.

[Example] Fig. 1 is a perspective view showing the vicinity of a molten metal outlet of a molten metal container according to an embodiment of the present invention, and Fig. 2 is a side sectional view thereof. A sliding nozzle 21 is attached to the molten steel outlet at the bottom of the tundish 20, and an immersion nozzle 2 having a discharge hole 23 is attached to the sliding plate of this nozzle 21.
2 is fixedly attached. This immersion nozzle 22 is immersed in the molten steel 25 in the mold 24, and the tundish 2
The molten steel injected into the mold 24 from the mold 24 is prevented from coming into contact with the atmosphere, thereby preventing oxidation of the molten steel. On the surface of the molten steel 25,
Slag 26 is floating.

A weir member 3 is installed at the molten steel outlet at the bottom of the tandish 20.
0 is placed. The cylindrical body 31 of the weir member 30 is cylindrical and made of refractory material, and an eddy flow prevention member 33 is fixed inside the cylindrical body 31. The cylindrical body 31 is placed on the bottom of the tundish 20 with its axis aligned with the axis of the immersion nozzle 220, and has a number of holes 32 bored in its circumferential surface. The eddy current prevention member 33 is made up of four plate-shaped blades extending in the vertical direction and arranged so that adjacent blades are orthogonal to each other, and each blade intersects at the axis of the cylindrical body 31.

For example, this cylindrical body 31 has an outer diameter of 4001111, an inner diameter of 3501111, and a length of 900111. The diameter of the hole 32 is 2
011, the number of 320 holes is 160. The eddy current blocking member 33 is made up of, for example, four rectangular plates each having a length of 900 m, a thickness of 1511 mm, and are fixed to each other so that the cross section has a cross shape.

As shown in FIG. 2, around the cylindrical body 31, a plurality of porous plugs 41 (only plug 211 is shown in the figure) are arranged at appropriate lengths on the circumference of the cylindrical body 310. They are placed at intervals. These plugs 41 are connected to the piping 42
is connected to an Ar gas supply source via a plug 41.
Ar gas is blown into the molten steel in the tundish 20 through the tundish 20. The Ar gas blown into the molten steel becomes a flow of bubbles 43 and rises in the molten steel. That is, a cylindrical bubble flow surrounding the cylinder 31 is formed around the cylinder 31 .

In the molten metal container configured in this manner, molten steel in the tundish 20 is injected into the mold 24 through the discharge hole 23 of the immersion nozzle 22 . Molten steel 25 is mold 2
4, it is cooled and solidified to form a solidified shell. The slab containing unsolidified molten steel inside is pulled out from below the mold 24, and the molten steel is continuously cast. In this case, the molten steel in the tundish 20 passes through a hole 32 formed in the cylindrical body 31 of the weir member 300 before flowing out to the immersion nozzle 22. Objects are attracted to the walls of the holes 32 and removed.

The molten steel that has passed through the cylindrical body 31 descends along the surface of the vortex flow prevention member 33 and flows out from the molten steel outlet, so no vortex is generated in the molten steel when the molten steel flows out from the molten steel outlet. . Therefore, slag floating on the surface of the molten steel in the tundish is prevented from being caught up in the molten steel injection flow and mixed into the mold 24 through the immersion nozzle 22.

On the other hand, Ar gas is blown into the molten steel from the porous plug 41, and this Ar gas becomes bubbles 43 and rises in the molten steel. Therefore, a cylindrical curtain of bubble flow is formed around the cylindrical body 31. When the molten steel in the tundish 20 flows toward the molten steel outlet, the flow is obstructed by this curtain of bubble flow. Therefore,
By adjusting the flow rate of Ar gas blown into the molten steel, the flow rate of the molten steel flowing into the molten steel outlet can be adjusted.

This bubble flow allows fine adjustment of, for example, 0 to 15% of the weight when the sliding nozzle is fully opened.

The flow rate at full open is adjusted from O (fully open) to 85% by the sliding nozzle 21 as in the conventional case.

It is difficult to adjust the flow rate of molten steel to O due to bubble flow, but in the case of bubble flow, it is possible to finely adjust the flow rate than when using a sliding nozzle. It is used to compensate for weight fluctuations caused by the molten metal and to maintain a constant flow rate of molten steel injected into the mold.

Incidentally, inclusions in the molten steel in the tundish 20 can be floated and separated by such a bubble flow. Therefore,
In addition to the removal of inclusions and prevention of entrainment by the weir member 30 and the vortex flow prevention member 33, floating separation of inclusions is also promoted by the bubble flow.

Note that the cylinder 31 is not limited to a cylindrical shape, for example, each cylindrical shape, etc.
It can be made into various shapes. Furthermore, it goes without saying that the sizes of the cylindrical body and the eddy flow prevention member are not limited to those shown in the above embodiments.

[Effects of the Invention] According to the present invention, the vortex flow prevention member prevents the vortex from being generated in the molten metal flowing out from the molten metal outlet, and the entrainment of slag on the molten metal is suppressed.

Further, as the molten metal flows through the holes of the weir member, the inclusions in II adhere to the holes and are removed.

Furthermore, since the injection flow rate of the molten metal is adjusted by the bubble flow, it can be finely adjusted. This bubble flow also makes it possible to float and separate inclusions in the molten metal in the container. Therefore, even cleaner molten metal can be supplied from the molten metal container to other members.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the vicinity of the molten metal outlet of a molten metal container according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view thereof, and FIG.
The figure is a schematic diagram showing a conventional tandish. 20; tanditshu; 21; sliding nozzle;
22; Immersion nozzle, 23; Discharge hole, 3° weir member, 31;
Cylindrical body, 32; Hole, 33: Eddy flow prevention member, 41; Plug,
43: Plumbing applicant's representative Patent attorney Takehiko Suzue Figure 1-b Section 2aa Procedural amendment 1. Display of the case Japanese Patent Application No. 159754/1983 2 Name of the invention Molten metal container with molten metal outlet 3 Person making the amendment Relationship to the case Patent applicant (412) Nippon Kokan Co., Ltd. 4 Agent Chiyoda, Tokyo UBE Building 7, 3-7-2 Kasumigaseki,
Contents of the amendment (1) On page 7, line 18 of the specification, the word "therefore" is corrected to "therefore". (2) On page 10, line 5 of the specification, "43;Piping" is corrected to "42;Piping."

Claims (1)

[Claims] In a molten metal container that has a molten metal outlet at the bottom and supplies the stored molten metal to other parts through the molten metal outlet, a weir that has a porous cylindrical shape and is installed on the bottom of the container so as to surround the molten metal outlet. a member, a plurality of vortex flow prevention members disposed at the center of the weir member and extending in the vertical direction, and a bubble forming means for forming a bubble flow surrounding the weir member to adjust the flow rate of the molten metal flow. A molten metal container having a molten metal outlet.