JPS58218362A - Metallurgical treating apparatus of molten metal - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for metallurgically treating molten metal before casting, particularly before continuous casting.

The molten steel that is poured into the transport ladle from the smelting furnace or plow vessel, in most cases the converter, has a steel quality ← of approximately 16
A temperature of 50 to 1750°C is required. In a ladle moving on guide rails, the steel, possibly still undergoing metallurgical processing, is conveyed by means of such a ladle to a continuous casting device and transferred to a distribution device. The distribution device must be at a high temperature to prevent localized solidification of the molten metal.

If the temperature inside the converter itself is about 1,700°C to prevent a temperature drop that occurs later, or because alloy steel requires a higher casting temperature, the refractory of the converter must be Linings are used under harsh conditions and undergo rapid wear.

Therefore, after the steel is poured from the converter, it is used for alloy forming and/or
or it may be necessary to carry out additional metallurgical treatments, which may include the addition of impurity removal additives as well as heating. This method is carried out using an arc generator. However, this method has the major drawback of causing significant uncontrolled nitrogen ingress in the heated parts. Attempts have been made to at least partially prevent this drawback by arranging the heating electrode in a covering device suitable for the ladle and operating at a constant temperature.On the other hand, this method ensures that no slag is present on the bath surface. , requiring costly recasting or very careful deslaging.

Another method involves heating the metal by induction. For this purpose, special ladles have been proposed which are equipped with induction heating devices in the floor or side walls.

A known heating device is a so-called canal inductor.
The inductor consists of a ladle mounted on the floor, and this inductor consists of a roughly semicircular tube, which is equipped with a coil for generating an electric field and connected to an opening in the ljl located at the bottom of the ladle. ing. The molten silkworm passing through this tube is connected to a hollow inductor (Hohl-Induktor).
) Since the electric field inside the ladle generates induction heating, it is possible to gradually raise the temperature of the entire pot by heating the ladle.゛.

The disadvantage of this device lies in particular in the unavoidable special construction, namely the fragile canal inductor part, which entails special problems with respect to the refractory lining. The reason for this is that it is easy to see that the refractory lining needs to be renewed more often than the refractory lining of the ladle itself.

Also, the alloying or carburizing of steel in previously known equipment is problematic, especially when large quantities are handled. □ The object of the present invention is to avoid the above-mentioned problems and to provide an apparatus capable of charging, heating, refining, and chemically and thermally homogenizing freshly tapped metal with additives as required. It is about providing.

The row consists of a furnace vessel closed at the top, with at least one vertically downwardly extending extension at the bottom of the vessel, and an induction heating stirring coil mounted on the vertical wall of the vessel. This is achieved by the device of the present invention which performs winding and crimping.

The tubular extension serves to introduce the molten metal present in any transport ladle into the furnace chamber and therefore has a length that takes into account the overall size of said transport ladle. This pipe shall be provided with a refractory lining.

A first preferred embodiment of the device according to the invention comprises two tubes as described above, the mechanism of action of which concerns in particular the introduction of the molten metal into the furnace chamber and the circulation of the molten metal. This corresponds to the working principle of known RH devices for vacuum processing.

In a second embodiment of the device according to the invention, it is also possible to provide only one tube through which the molten metal can be transferred into and out of the furnace vessel.

In the device according to the invention, the bottom of the device is equipped with an outer sealing ring that allows close contact with the transport ladle, as well as a pressure conduit opening in the inner space of the transport ladle, so that the inner axis of the transport ladle is When gas pressure is applied over the molten metal, an overpressure is created which can help push the molten metal upwardly through the tubular extension and into the furnace chamber.

If a thin sheet cap is provided at the end of the extension:
1. Yo, Yu □ and 7, □. A, 1 Yaya 7 After complete melting of the nib, the molten metal free of slag can be transferred into the furnace chamber.

In the device according to the invention, the molten metal is primarily heated by an induction coil, but the induction coil can also cause a stirring action.

The essential advantage achieved by the invention is that a single charge can be metallurgically processed in a relatively narrow volume in the absence of any molten slag and the melt can be heated.
．． In this case, heat loss due to radiation is minimized due to the small volume fraction.

Next, the present invention will be explained in terms of a gate with reference to the drawings. The device of the present invention shown in FIG.

2. These tubes are dimensioned so that they always reach below the slag layer when the device according to the invention is installed over the entire transport ladle 0. The transportation ladle 0 is preferably placed on an elevated platform (not shown), which eliminates the need to move the apparatus of the invention itself by J. .

The bottom of the device according to the invention is at the same time a supporting plate 3 and a supporting plate 8.
includes a sealing ring 30. A gas conduit, that is, a pressure tube 81 and a conduit 32 are buried in the support plate a, and the pressure tube 8
1 is connected to a compressor (not shown). Conduit 32 serves to introduce siphon gas or process gas.

When the transport ladle 0 is lifted until it comes into contact with the sealing ring 80, an overpressure is created on the melt by means of the pressure tube 81. If a portion of the melt is present in the furnace chamber, the molten metal can be circulated by introducing a gas stream - nitrogen, argon - through the conduit 82 into the extension l. In addition to the circulation in the path ladle/tube 1/furnace chamber/tube 2/ladle, treatment of the melt with refining gas takes place. Such treatment is particularly desirable when charging the melt with additives through the charging port 42.

Electrical induction heating of the melt takes place within the furnace chamber. For example, in a converter, carbon may contain manganese. 1) A furnace where steel is produced and heated at 1550 to 1570°C, □6°: 1 soak. . . 4゜9i32. . It's not really necessary. The situation is different when trying to manufacture chrome steel. This is because inherently higher outlet water temperatures need to be used. In the case of oxygen blowing, this tapping temperature should be achieved only by the heat of oxidation, but this inevitably results in loss of metal, and the lining is used under severe conditions. When using the apparatus of the invention, steel can be easily alloyed and heated relatively without problems.

In this case, as mentioned above, the disturbing effect of slag, which could not be avoided in the past, can be eliminated.

The induction coil 50, which also provides the stirring action, is water cooled. Refrigerant supply and discharge pipes and power supply lines were not shown.

The example shown in FIGS. 2 and 3 has only one tubular extension. In this case, the refining gas is passed through the extension into the melt as shown in FIG.

On the other hand, in the example shown in FIG. 8, a gas permeable body 60 can be fitted to the bottom of the furnace vessel; such means introduce inert gas into the melt from the bottom of the converter. It is known because the steel manufacturing method introduced in

As shown in these drawings, a vacuum connecting pipe 41 is provided in the upper part of the furnace vessel so that metal can be vacuum-processed. Creating a vacuum is also done to help introduce metal, so
The metal can be introduced by overpressure and/or underpressure and gas siphon action, the electromagnetic forces of the coil also contributing to the movement of the melt.

[Brief explanation of the drawing]

1, 2 and 8 are sectional views of the first, second and third examples of the apparatus of the present invention, respectively. 0...Transportation ladle 1,2...Tubular extension (
Pipe) 8...Support plate 80...Sealing ring 81...Pressure pipe 82...Conduit 41...
Vacuum connecting pipe 42...Charging port 50...Induction coil (induction heating/stirring coil) 60...Gas permeable structure Figure N

Claims (1)

[Scope of Claims] 1. An apparatus for metallurgically treating molten metal before casting, in particular before continuous casting, comprising a furnace vessel closed at the top, at least one vertically extending downwardly extending furnace vessel at the bottom of said furnace vessel. 1. An apparatus for metallurgical processing of molten metal, characterized in that the vertical wall of the furnace vessel is surrounded by an induction heating stirring coil. 2. Apparatus according to claim 1, wherein the bottom of the λ furnace vessel is provided with a sealing ring adapted to the upper edge of the transport ladle. & The device according to claim 1 or 2, wherein the gas pressure conduit opening in the inner space of the transport ladle is buried in the bottom of the furnace vessel. The apparatus according to any one of claims 1 to 8, wherein a vacuum connecting pipe is attached to the upper part of the unfurnished container. The apparatus according to any one of claims 1 to 4, wherein a charging port for introducing a solid substance is attached to the upper part of the furnace vessel. 6. The device according to claim 1, wherein a gas inlet tube opening inside the tubular extension is buried in the bottom of the furnace vessel. Claims 1 to 4 cover the outlet of the extension with a thin sheet cap that completely dissolves after penetrating the slag layer.
Apparatus according to any one of clauses 6 to 6. & Apparatus according to any one of claims 1 to 7, characterized in that a gas-permeable structure for introducing gas into the melt is embedded in the bottom of the furnace vessel.