JPH0612695B2 - Slab material induction heating device - Google Patents

Description

TECHNICAL FIELD The present invention relates to induction of a slab material for induction heating the slab material to a uniform temperature in a step before supplying the metal slab material to a hot rolling mill. The present invention relates to a heating device.

[Conventional technology]

3 and 4 show, for example, US Pat. No. 3,485,983.
(Dec.23.1969) shows the conventional induction heating device for slab material, in the figure, the heating coil (1) surrounds the side circumference of the slab material (2), inside the heating coil (1) Is fitted with fireproof insulation (3). Further, a ceiling refractory heat insulating material (4) is arranged inside the furnace lid (5). (6) is a slab support base. Note that (2a) shows the slab end. FIG. 5 shows a case where a slab material having a shorter slab length than the slab material shown in FIG. 4 is heated.

The heating coil (1) is wound around the rectangle formed by the longest side and the shortest side of the slab material (2) so that it is parallel to the long side, and the winding axis is vertical. Has been done.
A fireproof heat insulating material (3) is attached to the inside of the heating coil (1). Furthermore, a ceiling fireproof heat insulating material (4) is attached to the furnace lid (5) at the upper part. With the above configuration, the slab material (2) can be supported from the rectangular opening at the bottom of the heating coil (1) to the slab support base.
It is placed on the upper part of (6), enters the inside of the heating coil (1), and is statically heated. After heating, the slab support (6) descends, and the slab material (2) is taken out of the heating coil (1). When an alternating current is applied to the heating coil (1) surrounding the slab material (2),
An induced current flows on the surface of the slab material (2), and heat is mainly generated from the outer surface of the slab in the layer of current penetration depth (δ). Heat is supplied from the (δ) layer to the inside of the slab material by heat conduction, but heat is radiated from the slab surface to the refractory insulation materials (3) and (4) outside the slab material (2). Occur. This Slab Material (2)
Part of the heat radiated from the surface of the refractory insulation (3) (4) is absorbed by the refractory insulation (3) (4), the rest returns to the slab material (2), and then the refractory insulation again. It is radiated to the materials (3) and (4) and affects each other. For induction heating so that the temperature of the slab material (2) becomes uniform, the material and thickness of the fireproof insulation material around the slab material (2) and the relative positional relationship between the slab material shape and the surrounding fireproof insulation material Is an important factor. In the case of this example, the material of the fireproof insulation (3) (4) is the same material and thickness at every position, so the important elements are the shape of the slab material (2) and the surrounding fireproof insulation (3). It is a relative positional relationship with (4).

On the other hand, in the manufacturing method of the slab material (2), which is a pre-process of the slab material (2) to be induction heated, continuous casting is often used. In continuous casting, the slab thickness (the shortest side of the slab) and the width of the slab (the second longest side of the slab) are constantly cast from a nozzle, and the length of the regular slab (one of the slabs is The longest side is generally cut and sent to the induction heating process, but if a lot of slabs is continuously cast and cut to length, the end of the lot is longer than the length of slab. Short slab material can be made.

As shown in Fig. 5, when the short slab material (2) is put into the heating coil (1), the end portion of the short slab material (2) is
The distance between (2a) and the refractory heat insulating material (3) is clearly larger than that of the slab material with a fixed length. In this way, when the distance between the slab material end (2a) and the refractory insulation (3) increases, the refractory insulation that receives heat radiated from the surface of the slab material end (2a)
(3) Since the area of (4) is increased, the amount of heat absorbed by the fireproof heat insulating material (3) is large. Therefore, when the slab material (2) having a shorter slab length than the standard length material is heated, the temperature of the slab end portion (2a) is lowered.

[Problems to be solved by the invention]

Since the conventional induction heating device for slab materials is configured as described above, when induction heating is applied to a slab material that is shorter than the standard length, the heat-receiving area of the refractory insulation increases and the heat from the end of the slab material increases. There is a problem that the radiation amount is increased and the temperature of the slab end portion is lowered.

The present invention has been made to solve the above problems, and an object thereof is to obtain an induction heating device for a slab material in which the temperature of the slab end does not drop even when the length of the slab material changes. And

[Means for solving problems]

The slab material induction heating device according to the present invention is provided with a movable refractory heat insulating material that is movable in the slab length direction according to the length of the slab, facing both ends or one end of the longest side of the slab material. Has been.

[Action]

In the present invention, when the length of the slab material changes,
By moving the movable refractory insulation so that it is always a fixed distance from the slab end, the area of the refractory insulation that receives the heat radiated from the slab end surface is always about the same size, and the slab end Prevent temperature drop.

〔Example〕

1 and 2 show an embodiment of the present invention, in which a pair of movable refractory heat insulating materials (7) are respectively supported by support rods (8) and arranged in a heating coil (1), The upper end of the support rod (8) is connected to the carriage (9) provided on the upper part of the furnace lid (5). Trolley
Wheels (10) are provided on (9) and can move on rails (11) in the left-right direction in the figure.

In addition, the same reference numerals as those in FIGS. 3 to 5 denote the same parts.

With the above configuration, the support rod (8), the carriage (9), and the wheel (10) are located at positions facing both ends of the longest side of the slab material (2).
The movable fireproof heat insulating material (7) is movable by such means as to adjust the distance between the end portion (2a) of the slab material (2) and the movable fireproof heat insulating material (7) to be substantially constant. In this way, the heat from the slab end surface is always received by the refractory insulating material having the same area.

In the above example, the movable refractory heat insulating material (7) was provided at both ends of the slab material (2), but this is the center of the longest side of the slab material (2) and the heating coil (1). It was provided because the slab material (2) was supplied to the heating coil (1) with the center of the slab material (2) aligned with the center of the slab material (2) at a certain position from one end of the heating coil (1). If the slab material (2) is supplied to the heating coil (1) so that one side end comes, if the slab length changes, it is sufficient to move only the movable refractory heat insulating material provided on one side as in the above example. Has a great effect.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, even when the slab material length is changed, the movable refractory heat insulating material is moved to a position where a certain distance is taken from the slab end, and then static heating is performed. Therefore, it is possible to prevent the temperature of the end portion of the slab from lowering and to obtain uniform induction heating of the slab.

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment of the present invention, and FIG.
Sectional drawing in the plane which follows the II-II line of a figure, FIG. 3 is a sectional side view of the conventional induction heating apparatus of the slab material, FIG. 4 is IV of FIG.
FIG. 5 is a cross-sectional view taken along a plane along the line IV, and FIG. 5 is a view corresponding to FIG. 4 in the case of a short slab material. (1) …… Heating coil, (2) …… Slab material, (2a) …… Slab end, (3) …… Fireproof insulation, (4) …… Ceiling insulation, (5)…
… Furnace lid, (6) …… Slab support, (7) …… Movable fireproof insulation, (8) …… Support rod, (9) …… Bogie, (10) …… Wheels, (11)
……rail. In each figure, the same reference numerals indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masato Koide Inventor Masato Koide 1-chome, Mizushima Kawasaki-dori, Kurashiki City, Okayama Prefecture (no address) Inside the Mizushima Works, Kawasaki Steel Co., Ltd. (72) Mitsumasa Tsukada 8 Tsukaguchi Honcho, Amagasaki City, Hyogo Prefecture 1-chome Sanritsu Electric Co., Ltd. Itami Works

Claims (2)

[Claims] 1. A heating coil which surrounds a rectangle having the longest side and the shortest side of a slab material to be heated and which is wound in parallel with the longest side and has a winding axis line in a vertical direction. An induction heating apparatus for slab material, comprising: a movable refractory heat insulating material that is provided so as to face at least one of both ends of the longest side thereof and that can move in the length direction corresponding to the length of the slab material. . 2. A trolley which travels on a rail disposed above the furnace lid above the heating coil, a support rod whose upper end is connected to the trolley and extends into the inside of the heating coil, and this support rod. The induction heating device for slab material according to claim 1, further comprising a movable refractory heat insulating material supported by the.