JPH0343931B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for heating molten steel in a tundish.

The injection temperature of molten steel in continuous casting equipment drops by about 20°C at the start and end of injection due to heat dissipated during injection, so to prevent molten steel from clogging in the nozzle, the injection start temperature must be increased by that amount. As a result, wear and tear on refractories increases and high-temperature operations are forced in upstream processes. In addition, the instability of the injection temperature has a large negative effect on the quality of the steel ingot, and has been a major obstacle in recent technological trends toward higher purity steel.

In order to eliminate these drawbacks, it has been considered to heat molten steel in a tundish, and in particular electric induction heating, which has less oxidation and other harmful effects, is being considered.

However, with induction heating, the heating coil must be installed inside the iron shell of the tundish, and each tundish needs to have a built-in heating coil, which is costly, and there is no need to deal with any problems that occur in the heating coil section. This work is extremely difficult, the cost of refractories for the channels through which molten steel passes is extremely high, and continuous use requires residual molten metal and heating to prevent temperature changes. There are many inconveniences mentioned above, and a complete solution has not yet been achieved.

The present invention eliminates all of these drawbacks, and provides a heating device with an extremely innovative structure that is extremely easy to handle, can be used commonly for each tundish, and enables heating with high thermal efficiency.

The present invention will be explained in detail below with reference to the drawings showing embodiments.

FIG. 1 is a longitudinal sectional view showing the device of the present invention inserted into a tundish. A tundish 2 is arranged above a mold 1 of continuous casting equipment, and a molten steel heating device is applied to the molten steel 3 held in the tundish 2. The guiding head 4 is inserted and immersed.

The structure of the induction head 4, as shown in the cross-sectional view of FIG.
is wound around an iron core, and is configured to generate a magnetic field by passing current through the coil. These iron core 5 and coil 6 are made of refractory material 7
This prevents direct contact with molten steel and thermal effects.

The iron core 5 is formed in a square shape, and a molten steel channel 8 is provided in the inner part surrounded by the square shape, and a molten steel channel 8 is provided with a hole in the refractory material 7. An induced current is generated, causing heating and stirring.

The coil 6 is air-cooled, and the lower end 6a of the coil can be placed at a position lower than the hot water level 3a.

A guide head attaching/detaching device 9 is installed on the upper part of the guide head 4.
It is constructed so that it can be removed when not needed and immersed when needed.

In addition, FIG. 3 is a schematic perspective view of the guiding head.
4 and 5 are plan sectional views showing an example of the arrangement of the guiding head in the tundish. FIG. 4 shows an example in which the molten steel channel is arranged parallel to the longitudinal direction of the tundish, and FIG. This is an example in which the tundish is arranged perpendicularly to the longitudinal direction of the tundish.

In addition, two heating devices are installed per tundish.
Of course, it is possible to install more than one.

FIG. 6 is a cross-sectional view showing an example of the method of installing the device shown in FIG. 2 in a tundish. This is a type that prevents molten steel from flowing around the outer periphery of the induction head 4.
In this type, all the molten steel flows through the molten steel channel 8.

FIG. 7 is a cross-sectional view showing another embodiment, in which the iron core is a U-shaped iron core 11, and the molten steel in the molten steel channel 12 is heated by utilizing magnetic flux concentration at the end of the iron core. It's getting old.

FIG. 8 shows still another embodiment, in which the iron core is an I-shaped iron core 13, and when two or more iron cores are connected, they can be integrated into one body via a breakout 14 or the like. I can do it.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal cross-sectional view showing the heating device of the present invention inserted into a tundish, FIG. 2 is a cross-sectional view, and FIG. 3 is a schematic perspective view. , FIGS. 4 and 5 are plan sectional views showing examples of the arrangement of the guiding head,
6, 7 and 8 are cross-sectional views showing other embodiments of the heating device of the present invention. In the figure, 1 is the mold, 2 is the tandate, and 3
is the molten steel, 3a is the hot water level, 4 is the induction head, 5 is the iron core, 6 is the coil, 6a is the lower end of the coil, 7 is the refractory, 8 is the molten steel channel, 9 is the induction head attachment/detachment device, 10 is the filler, 11 is a U-shaped iron core, 12 is a molten steel channel, 13 is an I-shaped iron core, and 14 is a continuous material.

Claims (1)

[Claims] 1. A molten steel heating device for a tundish for continuous steel casting equipment, which has an induction head configured separately from the tundish so that it can be inserted into the tundish from above and extracted from the tundish above, and the induction head consists of an iron core that generates induced magnetism, an induction coil to excite the iron core, and a refractory lining to protect them from molten steel.Furthermore, the lower part of the iron core is A molten steel heating device in a tundish, characterized in that the molten steel heating device is set to be located below the molten steel surface, and has a molten steel distribution channel between the iron cores in the lower portion.