JPH0574918B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a closed type induction heating apparatus that heats an induction heating furnace by filling it with an atmospheric gas such as nitrogen.

[Conventional technology]

As an example of the prior art, FIG. 4 shows the configuration of an apparatus disclosed in Japanese Utility Model Publication No. 53-39687. In the figure, 1 is a heating coil for inductively heating the material to be heated 14, and 2 is an iron core that forms an external magnetic path for the magnetic flux generated by passing an alternating current through the heating coil 1. This prevents the furnace frame 4 from overheating due to This iron core 2 is fixed to a furnace frame 4 by an iron core fixture 3. The heating coil 1 described above is fixed to the furnace frame 4 by coil support fittings 16 and 16', and one or more sheets of thin cloth-like flexible sealing material 5 are disposed inside the heating coil 1, and the upper and lower ends of the furnace frame 4 are fixed to the heating coil 1. It is fixed in the section.

Further inside this sealing material 5, a fireproof heat insulating layer 8 forming a furnace wall is provided, and above the furnace frame 4 is provided a furnace lid 6 having a fireproof heat insulating layer 8' disposed inside. There is. Further, the furnace lid 6 is equipped with an exhaust port 9 and a valve 10 for discharging the air inside the furnace, and the contact portion with the upper part of the furnace frame 4 is sand-sealed with seal sand 7. Reference numeral 11 indicates a supply port for supplying atmospheric gas into the furnace, and reference numeral 12 indicates a foundation for fixing the furnace frame 4.

The object to be heated 14 is loaded from below by the object support stand 13 . When the heated object support stand 13 rises to a predetermined position, the end of the sealing material 5 supported by the reinforcing plate 15 sinks into the sealing sand 7 provided on the heated object support stand 13, and the inside of the furnace is exposed to the outside. completely sealed from

[Problem that the invention seeks to solve]

In the conventional closed type induction heating furnace, as described above, the sealing material 5 is provided between the upper and lower ends of the furnace frame 4 protected from leakage magnetic flux by the iron core 2, and the sealing material 5 is provided between the upper and lower ends of the furnace frame 4 and the furnace lid 6.
and the heated object support stand 13 are sealed with sealing sand 7. However, in order to prevent the heating coil 1 from heating the seal fixing parts at the upper and lower ends of the furnace frame 4 and peeling off the seals at the fixing parts, the iron core 2 must be made quite long (generally by the inner radius of the coil). ), and the upper and lower ends of the furnace frame 4 must be disposed outside of the coil 1, so the outer surface of the sealing material 5 placed between the coil 1 and the upper and lower ends of the furnace frame 4 is exposed to the support structure over a considerable distance. Moreover, there was a problem that the seal could be broken due to the internal pressure of the atmospheric gas. Further, the furnace lid 6 must be removed frequently for internal inspection, but the furnace lid 6 itself requires a considerable weight for sand sealing, which is inconvenient and requires a crane.

The present invention has been made to solve the above-mentioned problems by preventing damage to the sealing material and reducing the weight of the furnace lid.

[Means for solving problems]

The present invention has been made to achieve the above object, and includes a support for a heated object that supports an object to be heated, an induction heating coil, a refractory heat insulating layer forming a furnace wall, and a connection between the refractory heat insulating layer and the induction heating coil. In a closed induction heating device consisting of a sealing material provided in between and fixed to the upper and lower ends of the furnace frame to maintain airtightness inside the furnace, an iron core, a furnace core, a furnace frame, an exhaust port, an intake port, etc., the above-mentioned A hollow shorting ring made of non-magnetic metal and configured to allow cooling water to flow inside is arranged at an appropriate insulation interval from the upper and lower ends of the induction heating coil, and the upper surface of the upper shorting ring of these shorting rings is Provided is a closed induction heating device, characterized in that a furnace lid made of a thin non-magnetic metal plate is installed through a gasket, and the upper end of the sealing material is fixed to the inner surface of the upper short circuit ring with an adhesive. It is something to do.

[Effect]

In the present invention, short-circuiting rings made of non-magnetic metal are provided at the upper and lower ends of the heating coil at an appropriate insulated distance apart from each other, and are hollow and configured to allow cooling water to flow inside. A furnace cover made of a thin non-magnetic metal plate is installed, and the part that is inserted into the furnace through a gasket is lined with ceramic fiber, and an organic-based adhesive with excellent sealing properties is applied to the inner surface of the upper short-circuit ring. The upper end of the sealing material was glued using the heat shield, and the part of the sealing material between the fireproof insulation layer and the heating coil that had no support was shortened, reducing the weight of the furnace cover and increasing the durability of the sealing material. Ru.

〔Example〕

Embodiments of the present invention will be described with reference to FIGS. 1 to 3. Figure 1 is a block diagram of the device according to the present invention, Figure 2 is an enlarged view of part A in Figure 1, and Figure 3 is B in Figure 1.
It is an enlarged view of a part. In the figure, 1-4, 7-
14 and 16' are similar to the prior art device described above. Reference numeral 17 denotes a shorting ring made of non-magnetic metal and having a hollow rectangular cross section, into which cooling water flows. This shorting ring 17 is arranged at the upper and lower ends of the coil 1, and 18 is a furnace cover made of a non-magnetic metal thin plate.

In FIG. 2, 19 is a ceramic fiber insulation material fixed to the furnace cover 18 with ceramic bolts 25, and 20 is a packing made of sponge rubber adhered to the upper surface of the upper shorting ring 17. A sealing material 5 is bonded to the side surface with an adhesive to prevent ventilation. 22 is a cotton-like ceramic fiber that fills the space between the refractory heat insulating material 8 and the furnace lid 18 and protects the gasket 20 from insulation; 23 is a candy insulating bolt that engages the short circuit ring 17 and the furnace lid 18; The furnace cover 18 and the shorting ring 17 are insulated by an insulating washer tube 24. Although not shown, the winding of the coil 1 and the shorting ring 17 are fixed to each other by studs and concrete.

In FIG. 3, the lower end of the cloth-like sealing material 5 is sealed on the upper surface of the bottom plate 4a of the furnace frame 4 by applying silicone rubber putty 26. Further, a sealing plate 4b is provided at the lower part of the bottom plate 4a, and it sinks into the sealing sand 7 of the heated object support stand 13 to perform gas sealing.

In the closed induction heating device configured as described above, a loop current flows through the shorting ring 17, so that most of the magnetic flux is blocked from passing through.
In addition, since the shorting ring 17 is rectangular and water-cooled, there is a sponge rubber cord packing 20 on the top surface.
A complete gas seal can be achieved between the furnace lid 18 and the short-circuit ring 17 by simply gluing the furnace lid 18 and pressing it lightly with the furnace lid 18 made of a non-magnetic metal thin plate. The sponge rubber cord used for the packing 20 has a minimum compressive stress for sealing that is much smaller than that of a rubber plate, so sealing is possible only with the own weight of the furnace lid 18, and the insulating bolts 23 are mainly used to prevent the furnace lid 18 from slipping. It fulfills the role of Further, even if the flatness of the upper surface of the shortening ring 17 is poor, the seal will not break because the amount of compression of the sponge rubber cord is large. Furthermore, when the sealing material 5 receives internal pressure, the cap between the upper shorting ring 17 and the upper end of the coil 1 is several tens of mm, and the distance between the lower shorting ring 17 and the bottom plate 4a can be brought close to the insulation limit. The part without it is extremely short and can withstand pressure sufficiently. Further, since the inner diameter surface of the shorting ring 17 is flat and water-cooled, the seal 5 using the adhesive 21 can be reliably fixed to the inner side of the upper shorting ring 17. Furthermore, the ceramic fibers 19 of the furnace lid 18 are inserted along the inner wall of the furnace inner wall refractory insulation material 8, and the gap is closed with the cotton-like ceramic fibers 22, so that the sponge packing 20 can be protected from the hot air inside the furnace. can. Note that the end of the lower sealing material 5 is sealed with silicone rubber putty 26, but if a mortar-like backup material is used behind it, the reliability will be further increased.

In the above embodiment, a sponge rubber cord is used for the packing 20, but a rubber plate or an O-ring may also be used.
Also, the shape of the shorting ring 17 is preferably square, but
Other cross sections may be used as long as the packing receiving cotton on the upper surface and the surface to which the sealing material 5 is fixed can be obtained on the inner diameter surface. In addition, as a sealing material, fluorine film,
Heat-resistant films, heat-resistant papers, and heat-resistant sheets such as polyamide synthetic paper, polyimide film, asbestos rubber mixture sheets, silicone rubber-impregnated glass cloth, and fluorine resin-coated glass cloth are used. Furthermore, the furnace lid 18 may be divided into parts to make it portable, and the divided surfaces may be sealed with heat-resistant putty, mortar, or the like.

〔Effect of the invention〕

As described above, according to the present invention, damage to the sealing material that maintains airtightness inside the furnace can be prevented. Furthermore, the weight of the furnace lid can be reduced, which also makes it possible to improve the maintainability of the furnace.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a closed induction heating device according to an embodiment of the present invention, Fig. 2 is an enlarged view of section A in Fig. 1, Fig. 3 is an enlarged view of section B in Fig. 1, and Fig. 4 is a conventional FIG. 2 is a configuration diagram of a closed type induction heating device. In the figure, 1: coil, 2: iron core, 3: iron core fixture, 4: furnace body, 5: sealing material, 7: sealing sand, 8: fireproof insulation layer, 9: outlet, 10: valve, 11: supply Mouth, 12: Foundation, 13: Support stand,
14: Heated material, 15: Reinforcement plate, 16: Coil support fitting, 17: Short circuit ring, 18: Furnace lid, 19:
Ceramic fiber, 23: Insulating bolt, 24:
Insulating tube washer, 25: ceramic bolt, 26: silicone putty. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. An object support stand that supports an object to be heated, an induction heating coil, a refractory insulation layer forming a furnace wall, and an upper and lower portion of the furnace frame provided between the refractory insulation layer and the induction heating coil. In a closed type induction heating device consisting of a sealing material that maintains airtightness inside the furnace by being fixed to the ends, an iron core, a reactor core, a furnace frame, an exhaust port, an intake port, etc., the upper and lower ends of the induction heating coil and Hollow short-circuit rings made of non-magnetic metal and configured to allow cooling water to flow inside are arranged at appropriate insulating intervals. A closed type induction heating device, characterized in that a furnace cover made of a thin plate is installed, and the upper end of the sealing material is fixed to the inner surface of the upper shorting ring with an adhesive. 2. The closed type induction heating device according to claim 1, wherein the packing is a rubber-coated sponge cord.