JPS59185556A - Heater for molten steel in tundish - Google Patents

Abstract

PURPOSE:To provide a titled heater which permits easy handling and improves thermal efficiency by inserting an induction head lined with refractories into a tundish from above, and forming a flow channel for a molten steel in the part below the iron core of the induction head. CONSTITUTION:An induction head 4 of a heater for molten steel is immersed in the molten steel 3 in a tundish 2. The iron core 5 of the head 4 is extended to below the surface 3a of the molten steel 3. An induction coil 6 is wound on a part of the core 5 and is lined with refractories 7 to prevent direct contact with the steel 3 and the thermal influence. The core 5 is formed into a square shape and a flow channel 8 is opened in the refractories 7 in the inside part of the core. The coil 6 is designed to be cooled by water cooling, etc. and is disposed to position the bottom end 6a of the coil 6 flush with the surface 3a or above the same. The heating with high efficiency is accomplished by such device.

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 the continuous casting machine VC is determined by the heat dissipated during injection V (due to the temperature drop of about 20°C at the start and end of injection, in order to prevent molten steel from clogging in the nozzle, it is necessary to start injection by that amount) In addition to the temperature, 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 the recent technical trend of VC, which is directed toward higher purity steel.

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

However, with induction heating, the heating coil must be installed inside the iron shell of the tundish, and each tundish must have a built-in YC heating coil, which is a big cost burden, and if a trouble occurs from the heating coil, it is difficult to deal with it. This work is extremely difficult, and the cost of refractories for the channels through which molten steel passes is extremely high.Continuous use requires residual molten metal and heating to prevent temperature changes. There are many inconveniences mentioned above, and VC has not been developed as a complete solution.

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 in common with each tundish VC, and is capable of heating with high thermal efficiency.

Hereinafter, the present invention will be explained in detail with reference to drawings showing embodiments.

Figure +1 is a longitudinal cross-sectional view showing the device of the present invention inserted into the tundish, where the tundish 2 is placed above the mold 1 of the continuous casting equipment, and the tundish 2 is placed above the mold 1 of the continuous casting equipment.
Molten steel held within 3! /C The induction head 4 of the molten steel heating device is inserted and immersed.

An induction coil 6 is wound around a part of the iron core, and is configured to generate a magnetic field by passing current through the coil yc. These iron core 5 and coil 6 are lined with refractory material 7Vc to prevent direct contact with molten steel and thermal influence.

The iron core 5 is formed into a 1C shape, and the inner part VC surrounded by the yc shape is made of refractory material. A VC-opened molten steel channel 8 is provided, and the molten steel channel 8 receives the magnetic field generated by the coil 6 and generates an induced current to heat and stir the molten steel.

The coil 6 is cooled by air cooling or water cooling, and in the case of an air cooling structure, the lower end 6-a of the coil 6 can be placed at a position lower than the hot water level.

On the other hand, in the case of a water-cooled structure, the RC is usually capable of applying a large power load and is suitable for large-scale equipment, but in that case, the lower end 6a of the water-cooled structure coil is
The rc is placed at the same level as or above the rc, making it a safe arrangement against steam explosions in the event of water leakage.

A guide head attaching/detaching device 9 is provided on the upper part of the guide head 4, and is configured so that it can be removed when unnecessary and can be immersed when necessary.

Note that Figure 3 is a schematic perspective view of the guiding head, Figure 4 is
Fig. 5 is a plan sectional view showing an example of the arrangement of the guiding head in the tundish, Fig. 4 is an example in which the molten steel channel is arranged parallel to the longitudinal direction of the tundish, and Fig. 5 is a plan view showing an example of the arrangement of the guiding head in the tundish. This is an example in which they are arranged perpendicular to the

Furthermore, it is natural that more than one TFC may be installed per one heating device.

Figure 6 is a cross-sectional view showing an example of the method of installing the device shown in Figure 2 in a tundish. This is a type in which the flow of molten steel on the outer periphery of the guiding head 4 is prevented, and in this type, all of the molten steel flows through the molten steel channel 8.

The off view is a cross-sectional view showing another embodiment, in which the iron core is an I-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 has become.

,! Figure tF8 shows yet another embodiment, in which the iron core is an I-shaped iron core 13, and when two or more are connected,
(can be integrated and configured via a permanent object 14 or the like.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, in which Figure 1 is a longitudinal sectional view showing the state in which the heating device of the present invention is inserted into the tundish VC, Figure 2 is a cross-sectional view, and Figure 3 is a schematic perspective view. Figures 4 and 5 are plan sectional views showing examples of the arrangement of the induction head, and Figures 6, 7 and 8 are cross sectional views showing other embodiments of the heating device of the present invention. In the figure, 1 is a mold, 2 is a tanditshu, 3 is a molten steel,
3a is the hot water surface, 4 is the induction head, and 5 is the iron core. 6 is a coil, 6a is the lower end of the coil, and 7 is a refractory. 8 is a welding channel, and 9 is a guide head attachment/detachment device. 10 is a filler, 11 is a ( ]-shaped iron core, 12 is a molten steel channel, 13 is an I-shaped iron core, and 14 is a permanent material.Representative patent attorney: Masa Akisawa, 2 Mitsugai

Claims (2)

[Claims] (1) A molten steel heating device for a tundish for continuous steel casting equipment, which is separated from the tundish so that it can be inserted into the tundish from above and extracted above the tundish, and protect the tundish from the molten steel. The lower part of the iron core consists of a refractory lining. A method for heating molten steel in a tundish, characterized in that when the induction head is inserted into the tundish, it is positioned below the surface of the molten steel, and there is a molten steel flow channel between the iron cores in the lower part. Device. (2) The induction coil has a water-cooled structure, and