JPH041677Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial field of application" The present invention is a melting method that performs melting by directly applying current to the object to be melted to generate resistance heat, and which has a melt flow nozzle in the electrode part. It is about the road.

[Conventional technology and its problems]

Figure 2 shows a conventional example of a melting furnace.
A pair of facing electrodes 3 and 4 facing inward is provided on the side wall portion 2 of the housing, and an object G to be melted between the facing electrodes 3 and 4, for example, silicate glass in a partially molten state, is heated by an external single-phase AC power source 10. Electricity is applied directly to the object G to be melted, and the entire object G is brought into a molten state by the resistance heat generation of the object G itself. This example has advantages such as high heat generation efficiency and the ability to downsize the melting furnace.

However, in the example in FIG.
A phenomenon occurs in which current concentrates and flows in areas where the resistance value decreases between This part becomes the heat generating part A as shown by the chain line in FIG. Therefore,
A part separated from the heat generating part A, for example, tank 1
Heat transfer deteriorates near the bottom of the tank 1, making uniform melting impossible. There was a problem in that the melt was damaged and it became difficult to take the melt out of the tank.

``Purpose of the present invention'' The present invention effectively solves these problems, and also aims to homogenize the melt by generating frequent convection in the tank, and to reduce the temperature difference of the melt. The purpose is to improve the fluidity of the molten material by removing the molten material from the vicinity of the heat generation source.

"Means for Achieving the Objectives" In order to achieve each of the above objectives, the present invention provides a pair of opposing electrodes facing inward on the side walls of the tank, and a pair of opposing electrodes that are located below the opposing electrodes and narrowed at the bottom of the side walls. A lower electrode is disposed at the bottom of the inclined inner surface, and a flow nozzle is provided in a part of the lower electrode to cause the melt to flow down, and between the opposing electrode and the lower electrode. The molten body is made to resistively heat up when energized.

"Example" Hereinafter, an example of the melting furnace of the present invention will be described based on FIG. 1.

On both side walls 2 of the tank 1 of the melting furnace, there are counter electrodes 3, 4 for energizing the object G to be melted, such as silicate glass.
are provided in the same manner as in the conventional example, but the counter electrodes 3,
The side wall portion 2 at the lower position of the tank 1 is narrowed to have a V-shaped cross section to form an inclined inner surface 5, and the bottom of the inclined inner surface 5, that is, the bottom wall of the tank 1, is provided with a wall between the counter electrodes 3 and 4. a lower electrode 6 that applies a potential difference between
Further, a downstream nozzle 7 is integrally provided in a part of the lower electrode 6, and a hole 8 of the downstream nozzle 7 is formed to penetrate the inside and outside of the tank 1. . And each of these electrodes 3,
4 and 6 are connected to a three-phase AC power source 9 to be energized.

In the melting furnace configured as described above, when the three-phase AC power source 9 is energized in the operating state, as shown by the chain line in FIG. Since the two heat generating parts B and C generated between the electrodes 3 and 4 and the lower electrode 6 are added, upward flow occurs from three places. Further, since the inclined inner surface 5 is formed near the heat generating parts B and C between the opposing electrodes 3 and 4 and the lower electrode 6, so-called dead space is eliminated. For this reason, as is clear from Fig. 1, heat is generated in almost the entire area of the tank 1, and the stirring action inside the tank becomes frequent based on the convection by the heat generating parts A, B, and C, and the molten state This results in homogenization of the melted object.

On the other hand, the lower electrode 6 is located at the lower apex of the inverted triangular heating parts A, B, and C, where the object G to be melted is frequently melted, and the fluidity of the molten material in this vicinity is low. , is always high during operation of the melting furnace, and the melting object G is in the hole 8 of the downstream nozzle 7.
Even when the molten material is stuck, the layer 1 of the molten material may be melted quickly when the operation starts
It is possible to greatly reduce restrictions when taking out the product. Furthermore, the downstream nozzle 7
Since the lower electrode 6 is embedded so as to penetrate through the wall of the tank 1, it can be provided in a dual-purpose state.

In the embodiment shown in FIG. 1, a three-phase AC power supply 9 is used to generate resistance heat, but as long as a potential difference can be applied, a power source with a phase shift or a different frequency may be used. Further, the inclined inner surface may have a double slope or a single slope at the lower part of the counter electrode, or may have a tapered sloped inner surface.

"Effects of the Invention" As explained above, the melting furnace of the present invention can provide the following excellent effects.

(a) An inclined inner surface with a narrowed lower part is formed below the opposing electrode, and a lower electrode is arranged at the bottom of the inclined inner surface. is formed, and based on this similarity to the internal shape of the tank, it is possible to cause convection of the melt throughout the tank, making it possible to homogenize the melt and reducing the occurrence of temperature differences. .

(b) Since the flow nozzle is provided at the lower apex of the inverted triangular heat generating part to take out the molten material, the molten material is taken out of the tank by utilizing its high fluidity. There are fewer restrictions when taking out.

(c) By using both the lower electrode and the downstream nozzle, the structure can be simplified and heat transfer can be improved.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing an embodiment of the melting furnace of the present invention, and FIG. 2 is a front sectional view showing a conventional example of the melting furnace. G... Melting object, 1... Tank, 2... Side wall part,
3... Counter electrode, 4... Counter electrode, 5... Inclined inner surface, 6... Lower electrode, 7... Downflow nozzle, 8...
Hole, 9...Three-phase AC power supply.

Claims (1)

[Scope of utility model registration request] A pair of opposing electrodes 3 and 4 facing inward are provided on the side wall 2 of the tank 1, and an inclined inner surface 5 with a narrowed lower part of the side wall is formed below the opposing electrodes, and a lower portion is formed at the bottom of the inclined inner surface. An electrode 6 is disposed, and a flow nozzle 7 is provided on a part of the lower electrode to cause the melt to flow down, and the melt is heated by resistance by passing current between the opposing electrode and the lower electrode. A melting furnace.