JPS6137754B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an inductor coil device for a plane heating type induction heating device that heats objects to be heated, such as slabs, hot bars, or strips in steel rolling lines, by the electromagnetic induction action of the inductor coil. It is related to.

FIGS. 1A and 1B are a front sectional view and a side sectional view showing a conventional inductor coil device of this type of induction heating device, and 1 is a laminated layer constructed by laminating approximately E-shaped silicon steel plates to a predetermined thickness. As shown in FIG. 1B, water-cooled copper plates 2 are interposed at predetermined intervals between the laminated cores 1 for cooling the heat generated within the laminated core. Further, an inductor coil 3 is wound around the central leg portion 1a of the laminated core 1 a predetermined number of times.
It consists of a hollow copper tube whose outer surface is insulated and which allows cooling water to flow inside. Reference numeral 4 denotes heat-resistant concrete in which the laminated core 1 and the inductor coil 3 are buried so as to enclose them. This is provided to protect the laminated core 1 and the inductor coil 3 from heat.

Note that the above-mentioned induction coil device has an object to be heated 5
Although we have described the case in which the inductor coil device is placed facing each other with a predetermined gap only on the upper surface, generally speaking, a single inductor coil device configured as described above is used not only on the upper and lower surfaces of the object to be heated 5 but also on the object to be heated 5. They are also arranged on both sides of the object 5 to simultaneously inductively heat the object 5 from its surroundings. Then, the alternating magnetic velocity generated by passing a predetermined alternating current through the inductor coil 3 of each induction coil device passes through the closed circuit passing through the laminated iron core 1 and the heated object 5, The temperature of the object to be heated increases due to the Joule heat caused by the eddy current generated within the object to be heated. In addition,
At this time, the temperature also rises in the laminated iron core 1 due to Joule heat, but this is cooled by the water-cooled copper plate 2. Note that the surface temperature of the object to be heated 5 at this time is approximately 1250°C, and the surface temperature of the heat-resistant concrete 4 reaches 1150°C to 1200°C. The thickness of the thin facing portion 4a of the heat-resistant concrete 4 interposed between the object to be heated 5 and the laminated core 1 facing the object to be heated 5 has a large influence on the electrical efficiency of the inductor coil 3. For,
The temperature gradient in the thin facing portion 4a of the heat-resistant concrete 4 with a thickness of 10 m/m reaches several 100 degrees Celsius.

Therefore, as a material for this heat-resistant concrete 4, fire-resistant castable, which has good spalling resistance, is widely used, but even then, the object to be heated 5 is first conveyed to the position of the inductor coil 3. When the feed speed of the object to be heated 5 is intermittent, the temperature of the thin opposing portion 4a of the heat-resistant concrete 4 changes rapidly. This is because the heat-resistant concrete 4 in contact with the inductor coil 3 made of a hollow copper tube through which cooling water flows and the water-cooled copper plate 2 is partially cooled. If the temperature difference in the heat-resistant concrete 4 becomes large in some areas due to this reason, cracks are likely to occur particularly in the thin facing portion 4a, and pieces of concrete will peel and fall off, causing damage to the inductor coil 3 and laminated iron core 1. will be exposed. Therefore, induction coil devices placed on the bottom or side surfaces of the object to be heated 5 are not affected so much, but those placed on the top surface of the object to be heated 5 are affected by the inductor coil 3 and the laminated layers. The iron core 1 will directly receive high-temperature radiant heat from the heated object 5, and the insulating layer on the outer surface of the inductor coil 3 and the laminated core 1 will often be dielectrically broken down in a relatively short period of time due to the heat. It was.

This invention was made with attention to this point, and a mesh body made of a heat-resistant and non-magnetic material is buried in a thin part of heat-resistant concrete in which an inductor coil and a laminated core are buried, facing the object to be heated. An object of the present invention is to provide an induction heating device which prevents concrete pieces from peeling off.

That is, FIGS. 2A and 2B are a front cross-sectional view and a side cross-sectional view showing one embodiment of the present invention, and the same reference numerals as those in the above-mentioned conventional system (FIG. 1) refer to the same constituent members, so explanations thereof will be omitted. do.

Reference numeral 6 denotes a net-like body made of a heat-resistant and non-magnetic material buried in a thin facing part 4a of the heat-resistant concrete 4, in which the laminated iron core 1 and the inductor coil 3 are buried in predetermined positions, and the object to be heated 5. is provided to prevent concrete pieces from peeling off and falling off even if a crack occurs in the thin opposing portion 4a of the heat-resistant concrete 4. Incidentally, as this net-like body 6, for example, a stainless steel fiber such as a commercially available "NAS fiber" may be used.

Therefore, according to the present invention, even if a crack occurs in the thin facing portion 4a of the heat-resistant concrete 4 due to a partially large temperature difference, the presence of the net 6 prevents the concrete piece from peeling off and falling off. , as in the past, inductor coil 3 and laminated iron core 1
Therefore, the inductor coil and the laminated core are not directly exposed to the high-temperature radiant heat of the heated object 5 and the insulating layers are not broken down in a short period of time. It is effective.

[Brief explanation of the drawing]

1A and 1B are a front sectional view and a side sectional view showing a conventional induction heating device, and FIGS. 2A and 2B are a front sectional view and a side sectional view showing an embodiment of the present invention. In the drawings, 1 is a laminated iron core, 2 is a water-cooled copper plate, 3 is an inductor coil, 4 is heat-resistant concrete, 4a is a thin facing part, 5 is an object to be heated, and 6 is a mesh body. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. An induction heating device characterized in that a mesh body is buried in a thin part facing an object to be heated of heat-resistant concrete in which a laminated iron core and an inductor coil are buried in predetermined positions. 2. The induction heating device according to claim 1, wherein a wire mesh made of a heat-resistant and non-magnetic material is used as the mesh body. 3. The induction heating device according to claim 1, wherein the thin facing portion has a thickness of about 10 m/m. 4. The induction heating device according to claim 1, wherein a stainless steel fiber such as "NAS fiber" is used as the mesh body.