JP2001110557A - Induction heating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction heating apparatus in which invasion of water and oxide scale are prevented by eliminating the gap between side cover and refractory insulating material, the influence of radiation heat from the heated material is prevented, and the durability of the side cover is improved to decrease exchanging. SOLUTION: The induction heating apparatus achieves induction heating by passing the material 3 through the C-shape iron core 1 which its open legs are wound with the heating coil 2. The side cover 9 having outside heat resisting board 11 is attached to the side surface surrounding the heating coil 2, with a magnetic shield board 10 in between. The mounting board 4 composed of electric insulating material having concave shape cross section, is provided to the heated side of heating coil 2, as its periphery to cover and to adhere to the edge of the heat insulating board 11. The water cooling pipe 5 is plumbed and mounted to the outside of the mounting board 4 along the cross section shape. The heat insulating board 8 is formed by burrying the cooling pipe 5 into the fire resisting material 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating coil of an inductor for induction heating a material to be continuously conveyed.
The present invention relates to an improvement in a structure for preventing a material to be heated from radiant heat.

[0002]

2. Description of the Related Art Generally, in a hot rolling line for steel, a plate-shaped material to be heated (slab) heated in advance to a high temperature in a heating furnace is continuously processed into a thin plate by passing through a rolling mill. . When a thin plate is rolled by such a steel hot rolling line, the temperature of the plate-like material heated by the heating furnace decreases while traveling on the line. Once the temperature is raised, the edge is cooled during running, so the edge is heated by an edge heater that heats the edge locally, and the whole is brought to a substantially uniform temperature state. I have.

In the edge heater, an induction heating device is used in which a heating coil is wound around each of open legs of a C-shaped iron core, and a material to be heated is passed between the heating coils to perform induction heating. The inductor of this induction heating device is shown in FIG.
As shown in FIG. 5, a heating coil 2 was formed by winding a water-cooled copper tube around the outer periphery of the leg of the C-shaped iron core 1, and the heating coil 2 was formed of an electric insulating plate on the surface side of the heating coil 2 facing the material 3 to be heated. Mounting plate 4
, A water-cooled pipe 5 is supported, and the water-cooled pipe 5 is buried in a refractory insulating material 6 to form a heat insulating plate 8.
The heating coil 2 is protected from the radiant heat of the material 3 to be heated.

The side surface of the heating coil 2 is a side cover 9.
Is surrounded by This side cover 9 is a magnetic shield plate 1
0 and the heat-resistant plate 11 are combined. The magnetic shield plate 10 has a structure in which a water-cooled pipe 13 is joined to the inner surface of a copper plate 12.
4. The end of the stainless steel plate 14 on the side of the material 3 to be heated is bent into an L shape, and a plurality of slits 15 are formed therein as shown in FIG. To prevent induction heating of the ends.

Since the heating coil 2 is disposed close to the material 3 to be induction-heated to about 1200 ° C., the magnetic shield plate 10 and the heat-resistant plate 11 constituting the side cover 9 are kept at a high temperature for a long period of time. Receive radiant heat. When the thermal expansion and contraction are repeated over a long period as described above, the heat-resistant plate 11 is gradually deformed so as to be wavy.
As shown in (B), a gap 16 between the heat insulating plate 8 and the heat-resistant plate 11 opens. Thus, the gap 16 with the heat insulating plate 8
Is opened, the slits 15 are formed, so that water and oxide scale enter from inside, and the heating coil 2 is directly exposed to radiant heat. As a result,
There is a possibility that the insulation coating of the heating coil 2 may be burned out or a water leak accident of the cooling hose may occur, leading to a short circuit accident.

[0006]

SUMMARY OF THE INVENTION The present invention eliminates the above-mentioned disadvantages, eliminates the gap between the side cover and the refractory insulating material, prevents intrusion of water and oxide scale, and reduces the radiant heat from the material to be heated. It is an object of the present invention to provide an induction heating device that prevents the influence and further improves the durability of the side cover to reduce the frequency of replacement.

[0007]

According to a first aspect of the present invention, there is provided an induction heating apparatus in which a heating coil is wound around each of the open legs of a C-shaped iron core, and a material to be heated is passed through the heating coil to perform induction heating. In the induction heating apparatus, a side cover surrounding the heating coil is provided with a side cover provided with a heat-resistant plate on the outside via a magnetic shield plate, and the heating coil has a concave cross section formed of an electrically insulating material on the side of the material to be heated. The mounting plate is covered so that the upper part of the corner is located at the end of the heat-resistant plate, and a water-cooled pipe is piped and supported outside the mounting plate along its cross-sectional shape. The heat insulating plate is formed by being buried.

According to a second aspect of the present invention, the induction heating apparatus is characterized in that a copper plate is used as the magnetic shield plate, a stainless steel plate is used as the heat-resistant plate, and a resin laminate plate is used as the mounting plate. Further, the induction heating device according to claim 3 is characterized in that a heat insulating plate formed by providing a refractory insulating material on a surface of a mounting plate having a concave cross section to which a water cooling pipe is mounted has a divided structure. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIG.
This will be described in detail with reference to FIG. The inductor of this induction heating device has a heating coil 2 formed by winding a water-cooled copper tube around the outer periphery of a leg of a C-shaped iron core 1, and a mounting plate 4 is provided on the surface side of the heating coil 2 facing the material 3 to be heated. Is provided. The mounting plate 4 is formed of an electrical insulating material such as an epoxy resin laminate, and has a concave cross section. On the outer side of the mounting plate 4 facing the material to be heated 3, a water-cooled pipe 5, which is a meandering pipe, is supported along the concave cross section of the mounting plate 4.
A refractory insulating material 6 such as castable cement is provided on the surface of the mounting plate 4, and a water-cooled pipe 5 supported by the mounting plate 4 is embedded in the refractory insulating material 6 to form a heat insulating plate 8.

The side surface of the heating coil 2 is surrounded by a side cover 9 in which a magnetic shield plate 10 and a heat-resistant plate 11 are combined. The magnetic shield plate 10 has a structure in which a water-cooled pipe 13 is joined to an inner surface of a copper plate 12, and the heat-resistant plate 11 is formed of a stainless steel plate 14. It is formed longer. Mounting plate 4 provided with heat insulating plate 8 having a concave cross section on the surface
Is separately prepared in advance, and is placed on the heated material 3 side of the heating coil 2, the upper corner thereof is placed on the outside of the end of the magnetic shield plate 10, and is closely attached to the end of the heat-resistant plate 11. Install as follows.

[0011] The inductor of the induction heating apparatus having the above-described configuration is arranged close to the material to be heated 3 that is being conveyed along the line, and receives radiant heat from the material to be heated 3 that is induction-heated to about 1200 ° C. In this case, since the heated material 3 side of the heating coil 2 is covered with the heat insulating plate 8 in which the water cooling pipe 5 is embedded, heat can be shut off. Further, since the water-cooled heat insulating plate 8 is formed to have a concave cross section on the corner side where the magnetic flux passes through and the radiant heat from the material to be heated 3 is received, the influence of heat can be prevented. The heat-resistant plate 11 is in close contact with the peripheral edge of the mounting plate 4 and
And the heating coil 2 side is shielded to the end by the magnetic shield plate 10, so that the influence of induction heating due to the passage of magnetic flux and radiation heat from the material to be heated 3 can be reduced. .

For this reason, in comparison with the conventional structure in which the corner portion of the inductor is covered by the heat-resistant plate 11 provided with the slit 15, the corner portion of the present invention having the greatest heat influence is constituted by the heat insulating plate 8. Therefore, there is no gap even when used for a long time, and the durability can be improved.

FIG. 2 shows another embodiment of the present invention. The mounting plates 4 and 4 have a two-part structure, and meandering water cooling pipes 5 and 5 are supported on the surface thereof. The surface is provided with refractory insulating materials 6, 6 such as castable cement,
The heat insulating plates 8 have a divided structure. This is 2
Since the heat insulating plates 8 and 8 having the divided structure are formed separately and attached to the C-shaped iron core 1, manufacturing and replacement work are easy.

In the above description, the case where the heat insulating plate 8 has a two-part structure has been described.

[0015]

As described above, claim 1 according to the present invention.
According to the induction heating device described, since the corner portion having the largest heat influence is constituted by a water-cooled heat insulating plate, a gap is not generated even when used for a long time, and water and oxide scale are prevented from entering. In addition, the influence of radiant heat from the material to be heated can be prevented, the durability of the side cover can be improved, and the frequency of replacement can be reduced.

In the induction heating device according to the present invention, since the copper plate is used as the magnetic shield plate, it is excellent in the magnetic shield effect, has good thermal conductivity, and is cooled by the water cooling pipe to protect the heating coil. Can be. Further, since a stainless steel plate is used as the heat-resistant plate, it is hardly deformed even by high-temperature radiant heat. In addition, by using a resin laminate plate as the mounting plate, it is possible to improve the electrical insulating property and to improve the supporting strength of the water-cooled pipe and the fire-resistant insulating material. Further, in the induction heating device according to the third aspect, since the heat insulating plate has a divided structure, manufacture and replacement work are easy.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an induction heating device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a heat insulating plate having a divided structure according to another embodiment of the present invention.

FIG. 3 is a sectional view showing a conventional induction heating device.

4 (A) is a perspective view showing a corner portion of the induction heating device of FIG. 3, and FIG. 4 (B) is a perspective view showing a corner portion where a gap is formed due to thermal deformation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 C-shaped iron core 2 Heating coil 3 Material to be heated 4 Mounting plate 5 Water cooling pipe 6 Fireproof insulating material 8 Heat insulating plate 9 Side cover 10 Magnetic shield plate 11 Heat resistant plate 12 Copper plate 13 Water cooling pipe 14 Stainless steel plate 15 Slit 16 Gap

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tetsuji Doizaki 1-1-1, Shibaura, Minato-ku, Tokyo F-term in Toshiba head office (reference) 3K059 AA10 AB19 AC10 AD03 AD30 AD34 AD40 CD44 CD52 CD73 CD77

Claims (3)

[Claims] 1. An induction heating apparatus in which a heating coil is wound around each of open leg portions of a C-shaped iron core, and a material to be heated is passed therethrough for induction heating, wherein a magnetic shield plate is provided on a side surface surrounding the heating coil. A side cover provided with a heat-resistant plate on the outside is attached, and a mounting plate having a concave cross section formed of an electrical insulating material is provided on the heated material side of the heating coil, and a corner upper portion thereof is located at an end of the heat-resistant plate. An induction heating apparatus characterized in that a water-cooled pipe is piped and supported outside the mounting plate along its cross-sectional shape, and the water-cooled pipe is embedded in a refractory insulating material to form a heat insulating plate. . 2. The induction heating apparatus according to claim 1, wherein a copper plate is used as the magnetic shield plate, a stainless steel plate is used as the heat-resistant plate, and a resin laminate plate is used as the mounting plate. 3. The induction heating apparatus according to claim 1, wherein a heat insulating plate formed by providing a refractory insulating material on a surface of the mounting plate having a concave cross section to which the water cooling pipe is mounted has a divided structure.