JPS6041607B2 - induction heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an induction heating device, particularly to a structure of an induction heating device suitable for graphitization.

FIG. 1 is a plan view of a conventional induction heating apparatus for graphitization, and FIG. 2 is a sectional view thereof.

In Figures 1 and 2, 1 is an object to be heated consisting of a fired product of carbon to be graphitized by induction heating, 2 is an induction heating coil molded with refractory cement for heating the object 1, and 3 is an induction heating coil molded with refractory cement. A heat insulating layer 4 made of carbon powder is a hearth made of refractory bricks that supports the induction heating device main body 5. A conventional induction heating device for graphitization is configured as described above.

In this configuration, when an alternating current is passed through the induction heating coil 2, an eddy current flows through the heated object 1 made of a fired carbon product, the temperature of the fired carbon product is raised by Joule heat, and the heated object 1 and the induction heating coil 2 are heated. A temperature difference occurs between the hearth 4 and the furnace top 51, and a heat flow flows from the object to be heated 1 to the hearth 4, the coil 2, and the furnace top 51, resulting in heat loss. 7A-good-fu J-yu bruises C police; huge ■■■゛、ri、
Akichi ht-li Small 'IN Large L, uses insulation materials such as carbon black and charcoal powder. These heat insulating materials can sufficiently withstand the maximum heat treatment temperature (approximately 30,000C) of the object to be heated, but the temperature of the object to be heated is approximately 2,000℃.
When the temperature exceeds 1, the electrical resistance of the heat insulating material in contact with the heated object 1 decreases significantly, and the heat insulating layer 3 becomes a good conductive material.
1 ■ Eddy current flows, resulting in power loss. Therefore, with conventional products, the temperature could generally only be raised to 2900° C. with an OKWH of 6 per 9 carbon fired products. In addition, after the heat treatment is completed, it is left to cool, but due to its low thermal conductivity, the temperature at which the graphitized carbon can be taken out is approximately 400℃.
It takes 5 to 10 days to cool the heated material to a temperature at which carbon does not oxidize in the air, which has the drawback that it is not possible to increase the rotation rate of the operation. This invention was made in order to eliminate the drawbacks of the above-mentioned products, and the heat insulating layer 3 is
It is an object of the present invention to provide an induction heating device having a heat insulating layer which is divided into layers and has heat resistance, low eddy current loss, and short cooling time.

An embodiment of this invention will be described below. FIG. 3 is a plan view of an induction heating device for graphitization according to the present invention, and FIG. 4 is a sectional view thereof. In the figure, 1, 2, and 4 are exactly the same as the conventional one. 3a is thickness 5~15C77Z
The first insulation layer 3b is made of carbon powder packed with carbon dioxide, and the second insulation layer 3b is made of a mixture of carbon powder and silica powder.
It is a heat insulating layer.

The induction heating device for graphitization according to the present invention is configured as described above, and a more specific example will be described below. Example 1 In the induction heating apparatus for graphitization configured as described above, carbon black was used as the first heat insulating layer 3a, and the thickness was 10 cm, and the second heat insulating layer 3b was made with a particle size of 1.
50 parts by weight of petroleum coke powder, 25% by weight of 00 mesh or less, 75% by weight of 100 mesh to 32 mesh, purity 9
5% or more, particle size 100 mesh to 32 mesh silica grains 5
A total of 1 (1) parts of saliva is mixed sufficiently uniformly, and the electrical resistivity is 1Ω or more at a pressure of 1k91cIt, on average 1
It was packed in a furnace with a diameter of 5 cm.

Note that the first heat insulating layer 3a is formed in the upper part 52 of the object to be heated 1.
is 15α, and the second heat insulating layer 3b is 20C! In the lower part 53 of the Ttl heated object 1, the first heat insulating layer 3a had a thickness of 5 cwt, and the second heat insulating layer 3b had a thickness of 30 cm. In the above configuration, when the induction heating coil 2 is connected to a high frequency AC power source and heated, the object to be heated consisting of a fired carbon product 1k
The amount of electricity per unit 9 is 3.5KWH, and the temperature of heated object 1 is 3.
It took 72 hours to reach 000'C and cool down to 400'C. Example 2 The first heat insulating layer 3a had the same structure as in Example 1, except that a heat insulating material made of charcoal powder thinner than 32 mesh was used, and when heated in the same manner, it was made of a carbon fired product. The temperature of the fired product reached 3000'C with an electric power consumption of 4KWH per 1K9 of the object to be heated, and it took several hours to cool it down to 400C.

Further, in Examples 1 and 2 above, there was no damage to the refractory cement used in the induction heating coil 2. It should be noted that the above embodiments are merely specific examples for facilitating understanding of the present invention, and it goes without saying that various modifications and changes are possible. Of course, its use is not necessarily limited to graphitizing carbon materials. As explained above, this invention eliminates the drawbacks of the conventional technology by providing a first heat insulating layer made of carbon and a second heat insulating layer made of carbon and silica that surrounds the first heat insulating layer. At the same time,
This has the effect of significantly reducing the electricity consumption rate and improving the operational turnover rate.

[Brief explanation of drawings]

FIG. 1 is a plan view of a conventional induction heating device, and FIG. 2 is a sectional view thereof. FIG. 3 is a plan view showing an induction heating device according to an embodiment of the present invention, and FIG. 4 is a sectional view thereof. In the figure, 1...
...Heated object, 3a...First heat insulating layer, 3b.
...Indicates the second heat insulating layer.

Claims (1)

[Claims] 1. It is characterized by comprising a first heat insulating layer made of carbon that surrounds the object to be heated, and a second heat insulating layer made of silica stone and carbon that surrounds the first heat insulating layer. Induction heating device.