JPH0610067A - Electric heating device for metal strip coil - Google Patents

Abstract

(57) [Summary] [Objective] To propose an electric heating device for a metal strip coil which is simple in terms of equipment, and is excellent in uniformity and rapid heating. Structure: The electrodes 2 are arranged so that they can be pressed against both end faces of a coil 4, and a heat-generating auxiliary electrode 3 and a flexible metal cushion are interposed between the coil end face and the electrodes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric heating apparatus for a metal strip coil for rapidly and uniformly raising the temperature by directly energizing the coil used for annealing, hot rolling, warm rolling and the like. .

[0002]

2. Description of the Related Art As a heating method in a coil state, a radiant heating method of covering a coil with a lid and heating the outside with a gas burner is performed, as established by batch annealing and box annealing. ing. However, there is a large difference between the heating rate and the heating rate, and as a method for improving this, JP-A-2-88719, JP-A-2-43321, JP-A-2-43320, and JP-A-2-149623. There is known a method in which electrodes are connected to the outer end and the inner end of a coil and electrically heated as shown in the publication.

[0003]

However, in this electric heating method, in order to increase the resistance of the coil by energizing in the longitudinal direction of the strip, an insulating material or a heat insulating material is sandwiched between the plates, and a spacer is used. There is a problem in that it has a complicated structure in terms of equipment such as installing a pole and passing a plate around it, and also requires work such as winding after heating is completed.

An object of the present invention is to solve the above-mentioned problems and to provide an electric heating device which is simple in terms of equipment and which is excellent in uniformity and rapid heating property.

[0005]

DISCLOSURE OF THE INVENTION The present invention is a device for directly energizing a coil of a metal strip to heat the coil itself as a heating element, by disposing electrodes on both end faces of the coil so that they can be pressed against each other. The present invention relates to an electric heating device for a metal strip coil, characterized in that an exothermic auxiliary electrode is interposed between the end face and the electrode. Further, the present invention directly energizes the metal strip coil to heat the coil itself as a heating element. In the apparatus described above, an electric heating device for a metal strip coil is also characterized in that electrodes are arranged so as to be pressed against both end faces of the coil, and a flexible metal cushion is interposed between the coil end face and the electrode. is there.
It is desirable that a flexible metal cushion be interposed between the coil end surface and the heat-generating auxiliary electrode, and further that the electrodes be radially divided or concentrically divided and arranged.

The exothermic auxiliary electrode which can be used in the present invention is not particularly limited, but carbon, iron-chromium heating element, iron-chromium-nickel heating element and the like are preferable. In addition, as the flexible metal cushion, the conductor wires are bundled into a band shape.

[0007]

In the present invention, since both ends of the metal strip coil are sandwiched by the exothermic auxiliary electrodes to conduct electric heating, external heating supplied from the auxiliary electrodes is added to the resistance heat of the strip itself, resulting in a rapid and uniform temperature rise. Becomes Furthermore, in the present invention, the heat-generating conductor and the flexible metal cushion are interposed between the coil and the electrode, so that the current can be uniformly applied from the electrode to the coil and the heat-generating auxiliary electrode to the coil. As a result, almost uniform heating and heating can be achieved over the entire coil. That is, since the structure is such that power is supplied from the entire end surface, the low temperature portion in the coil has a small electric resistance,
The temperature unevenness is reduced by selectively passing the current through this portion.

Further, in the present invention, the electrodes are radially or concentrically arranged in multiple divisions, so that even if the flatness of the end face of the coil is poor, the electrodes can be contacted evenly, which contributes to uniform heating of the coil. be able to.

[0009]

FIG. 1 is a sectional view of an electric heating apparatus for a metal strip coil showing an embodiment of the present invention. In this case, the coil 4 is placed on the upper end of the carbon heating element 3 placed on the electrode 2, and the carbon heating element 3 and the electrode 2 are set on the upper end of the coil. An electrode pressing weight 6 is placed on the upper part 2 to maintain good contact between the coil end, the heating element and the electrode surface. In addition, 1 is a power supply device.

By the way, using the apparatus shown in FIG.
0.5mm, outer diameter 1300mm, inner diameter 500mm, width 1000mm, weight 9t
Fig. 2 shows the result of heating and heating the coil at 200 kw / h.
Shown in. Also, as a comparative example, without using a heat-generating conductor,
FIG. 2 shows a case where a copper alloy electrode having good electric conductivity is used and only the heat generated in the coil is used.

FIG. 3 is a sectional view of a metal strip coil electric heating apparatus showing another embodiment of the present invention. In this case, the coil 4 is placed up-end on the electrode 2 via a metal cushion 5. A metal cushion 5 is placed on the upper end of the coil, and an electrode 2 and an electrode pressing weight 6 are placed on the metal cushion 5. The weight 6 is not always necessary when the weight of the electrode 2 is sufficiently heavy.

FIG. 4 is a sectional view showing another embodiment of the present invention. In this embodiment, a metal cushion 5 is further interposed between the heating element 3 and the coil 4 in the embodiment shown in FIG. 1 to further improve the conformity between the end surface of the coil and the electrode surface. FIG. 5 is a sectional view showing another embodiment of the present invention. In this case, the metal cushion 5 which is also concentrically divided into three parts is held by the electrode 2 which is formed by concentrically dividing the coil 4 placed at the down end into three parts. A cylinder 7 and a piston 8 supported by a cylinder support wall 9 are mounted on the back surface of the electrode 2, and each electrode 2 can be pressed against the coil end surface with a predetermined load.

The coil of the above-mentioned embodiment in which the temperature rising curve of FIG. 2 was sampled was heated to 700 ° C. by the heating apparatus shown in FIG. 1 and the temperature difference on the circumference of the coil was measured to be 260 ° C. When the same coil was heated to 700 ° C by the heating device shown in Fig. 4, the temperature was 70 ° C.

[0014]

According to the present invention, when a coil is directly energized and heated, a heating device or a metal cushion is inserted between the electrode and the coil to rapidly press the electrode against the coil end face with simple equipment. And it became possible to heat uniformly.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a heating device showing an embodiment of the present invention.

FIG. 2 is a diagram showing a temperature raising effect using the device of the present invention.

FIG. 3 is a vertical cross-sectional view of a heating device showing another embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view of a heating device showing another embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view of a heating device showing another embodiment of the present invention.

[Explanation of symbols]

 1 Power Supply Device 2 Electrode 3 Exothermic Auxiliary Electrode 4 Coil 5 Metal Cushion 6 Electrode Pressing Weight 7 Cylinder 8 Piston 9 Cylinder Support Wall

Claims (4)

[Claims] 1. A coil of a metal strip is directly energized,
In a device that heats the coil itself as a heating element, the electrodes are arranged so that they can be pressed against both end faces of the coil,
An electric heating device for a metal strip coil, wherein an exothermic auxiliary electrode is interposed between the coil end surface and the electrode. 2. A coil of metal strip is energized directly,
In a device that heats the coil itself as a heating element, the electrodes are arranged so that they can be pressed against both end faces of the coil,
An electric heating apparatus for a metal strip coil, characterized in that a flexible metal cushion is interposed between the coil end surface and the electrode. 3. An electric heating apparatus for a metal strip coil according to claim 1, further comprising a flexible metal cushion interposed between the coil end surface and the exothermic auxiliary electrode. 4. An electric heating device for a metal strip coil according to claim 1, 2 or 3, wherein the electrodes are radially and concentrically divided.