JPS6031002Y2 - Immersion nozzle for continuous casting - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an immersion nozzle for continuous casting that generates resistance heat when energized.

If the immersion nozzle is not sufficiently preheated before use, it will not be able to withstand the thermal shock when molten metal passes through the nozzle, and cracks will occur.

Conventionally, this preheating is performed by a heating device installed at a location remote from the point of use, and gas is generally used as the heat source.

Heating with gas has the drawbacks that it takes time to raise the temperature and that heating cannot be continued after the nozzle is moved to the place of use.

With the method of heating the nozzle by energizing it and using its resistance heat generation, it does not take much time to raise the temperature, and since the nozzle can be heated at the location where it is used, there is no need to move the nozzle, and the nozzle continues to be heated until just before use. It has advantages over gas heating, such as:

For this reason, practical application is progressing.

It is desirable for the immersion nozzle to be heated to a temperature that is as uniform as possible from the top end to the bottom end of the nozzle, both from the standpoint of heat spalling resistance and from the standpoint of preventing deposits inside the nozzle.

However, when the nozzle is heated to a high temperature, the metal conductive terminal in contact with the nozzle is oxidized or melted by the heat of the nozzle.

In order to prevent this oxidation, melting, etc., if a cooling device is attached to the terminal, the nozzle portion in contact with the terminal is cooled and does not reach a high temperature, resulting in a temperature difference with other portions of the nozzle.

This invention ameliorates these drawbacks.

That is, as shown in the illustrated example, the metal terminal 2 is protected by providing a heat-resistant intermediate body 3 with good conductivity between the nozzle body 1 made of an electrical resistance heating element and the annular metal terminal 2. It was designed to do so.

In the figure, 4 is a heat insulating material provided on the nozzle body 1, 5 is an ammeter, and E is a power source.

The intermediate body 3 can be easily attached by, for example, assembling arc-shaped bodies as shown in FIG. 2 and tightening them with the outer terminals 2.

It is not that this intermediate 3 does not generate resistance heat at all;
Any material that generates significantly less resistance heat than the nozzle body 1 may be used.

Examples of materials suitable for this purpose include refractories such as carbonaceous materials and silicon carbide materials as shown in Table 1.

This intermediate body 3 also has a heat insulating effect and serves to protect the terminals and uniformly heat the nozzle body 1.

Example When the intermediate 3 having the composition shown in the previous table was used between the nozzle body 1 and the terminal 2, the temperature of the nozzle could be uniformly raised to 1400°C, and at this time, the surface temperature of the intermediate 3 was Approximately 8
The iron terminal could be used at and outside 00'C without melting or damage.

(Dimensions of the intermediate body: inner diameter of approximately 150 m, outer diameter of approximately 230 mm, width of approximately 80 m)

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, with FIG. 1 being a longitudinal sectional view and FIG. 2 being a cross sectional view of the main part. 1...Immersion nozzle body, 2...Metal terminal, 3...Intermediate body, 4...Insulating material,
5... Ammeter, E... Power supply.

Claims (1)

[Scope of utility model registration request] A immersed nozzle for continuous casting, comprising an intermediate body 3 made of a heat-resistant material with good conductivity between a immersed nozzle main body 1 made of an electric resistance heating element and a metal terminal 2.