JP3717103B2 - Plasma arc heating device for molten metal in tundish - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plasma arc heating apparatus for molten metal in a tundish that heats the molten metal in a tundish by a plasma arc.
[0002]
[Prior art]
Conventionally, as shown in the schematic cross-sectional view of the continuous casting facility in FIG. 8, the molten metal 2 after refining is poured into the tundish 8 from the ladle 1 placed on the support 3 through the nozzle 9, and the bottom of the tundish 8. In the continuous casting in which the molten metal 2 is poured into the casting mold 10 and cast from the bottom of the casting mold 10 as the slab 11, the molten metal 2 is heated in the tundish.
[0003]
As a heating device for molten metal in a tundish, Japanese Patent Application Laid-Open No. 8-111284 discloses a power supply circuit diagram of the plasma arc heating device in FIG. 9 and a sectional view of the tundish portion in FIG. 9 in FIG. The torch 5 inserted in the heating chamber 6 of the dish 8 by the torch lifting device 4 is used as a cathode, the feeding electrodes 12a and 12b are used as anodes, a voltage is applied and a plasma current is passed through the molten metal, and the molten metal and the torch tip In general, a plasma arc 7 is generated between them and the molten metal is heated by the energy. As the anode power supply circuit, two power supply electrodes 12a and 12b are arranged on the wall surface of the tundish 8, and the power supply electrodes 12a and 12b are connected by power supply electrode power supply circuits 13a and 13b, respectively. , 13b are gathered together and connected to the power source 15 by the bus bar 14a. The power supply 15 is connected to the torch 5 through a torch power supply circuit.
[0004]
[Problems to be solved by the invention]
When the surface of the molten metal in the tundish drops just before the end of casting, the refractory material that has melted from the ladle and tundish and slag due to impurities generated in the pretreatment process float on the surface of the molten metal in the tundish. ing. For this reason, in the conventional plasma arc heating apparatus, the phenomenon that the molten metal surface slag adheres to the anode surface arranged on the tundish wall surface frequently occurred. For this reason, the electrical resistance of the anode increases due to the adhesion of the slag, which is an electrical insulator, and when only a part of the anodes that are installed, the slag adheres, the current flows to the anode with a low electrical resistance. Thus, current imbalance occurs. As a result, the anode is overloaded and the power supply circuit for the power supply electrode is often burned out.
[0005]
Therefore, the present invention provides a plasma arc heating apparatus for molten metal in a tundish, which can prevent the occurrence of a situation where a power supply circuit for a power supply electrode is burned out.
[0006]
[Means for Solving the Problems]
Plasma arc heating device tundish molten metal of the present invention, the plasma torch is placed on top of the molten metal in the tundish, immersing the plurality of anodes in a molten metals in the tundish, and the plasma torch in the heating device in the tundish the molten metal for heating the molten metal by a plasma arc generated between the molten metal, said tank is disposed the anode on the wall of the dish, the anode the tundish in the wall It is characterized by being connected by.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, a plurality of anodes arranged on the wall surface of the tundish are connected to the outside of the tundish, or the anode is connected to the anode connection portion within the wall of the tundish, so that slag adheres to the anode surface and resistance Even if the current increases and the anode current is unbalanced, the current is equalized at the anode connecting portion, so that it is possible to prevent the feeding circuit from being burned out.
[0008]
【Example】
First Embodiment FIG. 1 is a power supply circuit diagram of the plasma arc heating apparatus of the first embodiment, FIG. 2 is a sectional view of the anode in the tundish of FIG. 1, and FIG. 3 is a sectional view of another embodiment of the anode in the tundish. FIG.
In FIG. 1, the same members as those shown in the power supply circuit diagram of the continuous casting equipment in FIG. 9 are given the same reference numerals, 5 is a plasma torch, 6 is a heating chamber, 8 is a tundish, 9 is a nozzle, 12a. , 12b are anodes (feeding electrodes), 13a and 13b are feeding circuits for feeding electrodes, 14 is a bus bar, and 15 is a power source.
[0009]
In the present embodiment, the anodes 12 a and 12 b are disposed to face the wall surface of the tundish 8. The anodes 12 and 12b are exposed from the wall surface of the tundish 8, as shown in FIG. In addition, as shown in FIG. 3, the anodes 12a and 12b in the tundish 8 may be provided with a plurality of exposed portions at the lower part of the tundish, the bottom part, etc., so that the molten metal surface in the tundish is lowered. However, slag adhesion to the anode can be avoided and a more stable current can be supplied.
[0010]
The anodes 12a and 12b are connected to each other by an anode connecting portion 16a outside the tundish 8, power supply electrode power supply circuits 13a and 13b are respectively connected to both sides of the anode connection portion 16a, and the power supply electrode power supply circuits 13a and 13b are connected to a power source 15. The bus bars 14a and 14b connected to are connected.
[0011]
In the present embodiment, for example, even if slag adheres to the surface of one anode 12a and the resistance increases and current concentrates and flows through the other anode 12b, the current is fed to each feeding electrode by the anode connecting portion 16a. Since the current is not evenly distributed to one of the power supply circuits 13a and 13b and excessive current flows through one power supply electrode power supply circuit 13a, the power supply circuit can be prevented from being burned out.
[0012]
Second Embodiment FIG. 4 is a power supply circuit diagram of the plasma arc heating apparatus of the second embodiment. In FIG. 4, the same members as those shown in the power supply circuit diagram of the continuous casting facility of FIG. The same reference numerals are given and description thereof is omitted.
[0013]
In the present embodiment, as in the first embodiment, the anodes 12a and 12b are arranged to face the wall surface of the tundish 8, and the anodes 12a and 12b in the tundish 8 are as shown in FIG. 2 or FIG. It is exposed from the wall surface of the tundish 8.
[0014]
The anodes 12a and 12b are connected by an anode connecting portion 16a outside the tundish 8, and a single feeding electrode feeding circuit 13a is connected to the anode connecting portion 16a, and the feeding electrode feeding circuit 13a is connected to a power source. A bus bar 14a is connected. In this embodiment, the allowable currents of the feeding electrode feeding circuit 13a and the bus bar 14a are made larger than those in the first embodiment.
[0015]
Also in the present embodiment, for example, even if slag adheres to the surface of one anode 12a and resistance increases, and current concentrates on the other anode 12b, it flows to the anode connecting portion 16a and flows to the feeding electrode feeding circuit. Since it flows to 13a, it can prevent that a feed circuit burns out. In this embodiment, the power supply circuit can be simplified because only one power supply circuit 13a for power supply electrodes and one bus bar 14a are required.
[0016]
FIG. 5 is a power supply circuit diagram of the plasma arc heating apparatus of the third embodiment, FIG. 6 is a sectional view of the anode in the tundish of FIG. 5, and FIG. 7 is a sectional view of another embodiment of the anode in the tundish. In FIG. 5, the same members as those shown in the feed circuit diagram of the continuous casting facility in FIG. 1 of the first embodiment described above in FIG.
[0017]
In this embodiment, the anodes 12a and 12b are disposed to face the wall surface of the tundish 8, and the anodes 12a and 12b in the tundish 8 are exposed from the wall surface of the tundish 8 as shown in FIG. ing.
[0018]
The anodes 12a and 12b are connected within the wall of the tundish 8 by an anode connecting portion 16b, and power supply circuits 13a and 13b for power supply electrodes are connected to the anode, respectively, and a power supply 15 is supplied to the power supply circuits 13a and 13b for power supply electrodes. One bus bar 14a connected to is connected. In the present embodiment, the allowable currents of the power supply circuits for power supply electrodes 13a and 13b and the bus bar 14a are set larger than those in the first embodiment.
[0019]
The anodes 12 a and 12 b are connected by an anode connecting portion 16 b in the wall of the tundish 8. The anodes 12a and 12b are exposed from the wall surface of the tundish 8, as shown in FIG. As shown in FIG. 7, the anodes 12a and 12b in the tundish 8 may be provided with exposed portions in the anode connecting portion 16b.
[0020]
Also in the present embodiment, even if a current flows concentratedly on one anode 12b, it flows to the anode coupling portion 16b and flows to the power supply electrode power supply circuit 13a, so that the power supply circuit can be prevented from being burned out.
[0021]
【The invention's effect】
In the present invention, since a plurality of anodes disposed on the wall surface of the tundish are connected to the outside of the tundish or the anode is connected to the anode connection portion within the wall of the tundish, it is possible to prevent a situation where the feeder circuit is burned out. Can be prevented.
[Brief description of the drawings]
FIG. 1 is a power supply circuit diagram of a plasma arc heating apparatus according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of an anode in the tundish of FIG.
FIG. 3 is a cross-sectional view of another embodiment of an anode in a tundish.
FIG. 4 is a power supply circuit diagram of a plasma arc heating apparatus according to a second embodiment of the present invention.
FIG. 5 is a power supply circuit diagram of a plasma arc heating apparatus according to a third embodiment of the present invention.
6 is a cross-sectional view of an anode in the tundish shown in FIG.
FIG. 7 is a cross-sectional view of another embodiment of an anode in a tundish.
FIG. 8 is a schematic sectional view of a conventional continuous casting facility.
9 is a power supply circuit diagram of the plasma arc heating apparatus of FIG.
10 is a cross-sectional view of the tundish portion of FIG. 9. FIG.
[Explanation of symbols]
1: Ladle 2: Molten metal 3: Support stand 4: Torch lifting device 5: Torch 6: Heating chamber 7: Plasma arc 8: Tundish 9: Nozzle 10: Mold 11: Slabs 12a, 12b: Anode (power supply electrode) )
13a, 13b: Power supply circuits for power supply electrodes 14a, 14b: Busbar 15: Power supplies 16a, 16b: Anode connection part

Claims (1)

A plasma torch is disposed above the molten metal in the tundish, a plurality of anodes are immersed in the molten metal in the tundish, and the molten metal is removed by a plasma arc generated between the plasma torch and the molten metal. In the heating apparatus for molten metal in a tundish to be heated, the anode is disposed on the wall surface of the tundish, and the anode is connected in the wall of the tundish, and the plasma arc of molten metal in the tundish is characterized in that click pressurized thermal device.

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