JPH047155Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a melting furnace that performs melting by directly applying electricity to an object to be melted to generate resistance heat.

"Conventional technology and its problems" Figure 2 shows a conventional example of a melting furnace.
A pair of opposing electrodes 3 and 4 facing inward is provided on the side wall portion 2 of the housing, and an external single-phase AC power source 8 is used to melt a melting object G between the opposing electrodes 3 and 4, for example, borosilicate in a partially molten state. Apply electricity directly to the glass to melt the object G
It melts everything by its own resistance heat generation. 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 in the area where the resistance value decreases between This part becomes the heat generating part A as shown by the chain line in Figure 2, and the range of resistance heat generation is concentrated in this part, and the heat transfer to the bottom of layer 1 becomes poor, making it impossible to achieve uniform melting. There was a problem.

``Purpose of the present invention'' The present invention effectively solves these problems and, in particular, aims to homogenize the melt by generating frequent convection within the layer, and to reduce the temperature difference of the melt. The purpose is to do the following.

"Means for Achieving the Objectives" In order to achieve each of the above objectives, the present invention provides a counter electrode for energizing the object to be melted on the side wall of the tank, and an inclined inner surface of the side wall at a position below the counter electrode. The melting furnace is equipped with a lower electrode that applies a potential difference between the opposing electrode and the opposing electrode near the bottom of the inclined inner surface. Heat generation due to current flow between the electrodes and heat generation due to current flow between the other opposing electrode and the lower electrode are added at two locations, causing convection in the vicinity. Further, since the side wall between the counter electrode and the lower electrode has an inclined inner surface, the formation of a dead space is eliminated and the convection of the melt is carried out smoothly.

"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, counter electrodes 3 and 4 for energizing the object G to be melted such as borosilicate glass are provided, as in the conventional example, but below the counter electrodes 3 and 4. The side wall portion 2 at this position is narrowed to have a V-shaped cross section to form an inclined inner surface 5, and counter electrodes 3, 4 are provided near the bottom of the inclined inner surface 5.
It has a structure in which a lower electrode 6 is disposed to provide a potential difference between the two. And each of these electrodes 3,
4 and 6 are connected to a three-phase AC power source 7 to be energized.

In the melting furnace configured as described above, when electricity is supplied from the three-phase AC power source 7 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, an upward flow is generated 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.

In the embodiment shown in FIG. 1, the three-phase AC power supply 7 is used to generate resistance heat, but as long as it can provide a potential difference, it may be possible to use a power source with a phase shift or a different frequency. 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) Since the inclined inner surface of the side wall portion is provided below the opposing electrode, and the lower electrode is arranged near the bottom of the inclined inner surface, heat generated by current flow between the opposing electrodes can be disposed between one side of the opposing electrode and the lower Heat generation due to current flow between the electrodes and heat generation due to current flow between the other opposing electrode and the lower electrode are added in two places, and the heat generating part inside the tank is expanded into an inverted triangular shape, causing melting to occur throughout the tank. By causing convection of the material, it is possible to homogenize the molten material and to reduce the occurrence of temperature differences.

(b) By forming the side wall between the counter electrode and the lower electrode with an inclined inner surface, the formation of dead space is eliminated, and the occurrence of the phenomenon of molten material staying in the middle of convection is suppressed, and the melting object is It can be efficiently made into a melt.

[Brief explanation of drawings]

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... Three-phase AC power supply.

Claims (1)

[Scope of utility model registration request] A counter electrode for energizing the object to be melted is provided on the side wall of the tank, an inclined inner surface of the side wall is provided below the counter electrode, and a potential difference is applied between the counter electrode and the bottom of the inclined inner surface. A melting furnace characterized by being provided with a lower electrode.