JP4442049B2 - Glass melting furnace - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a glass melting furnace used when vitrifying a highly radioactive waste liquid.
[0002]
[Prior art]
The high radioactive waste liquid generated in the nuclear facility is melted by the glass melting furnace of the high radioactive waste liquid glass solidification facility, treated as a glass solid, and then stored in the radioactive waste storage facility.
[0003]
In the above-mentioned glass solidification facility, when the raw glass is melted inside the glass melting furnace, the high radioactive waste liquid is mixed, and the molten glass mixed with this high radioactive waste liquid is injected into the solidification container to solidify the molten glass. Thus, a vitrified body is formed.
[0004]
FIG. 3 is a longitudinal front view showing an example of a conventional glass melting furnace, FIG. 4 is a longitudinal side view of FIG. 3, and in FIGS. 3 and 4, 2 is a melting furnace body, and the melting furnace body 2 is disposed inside. It is comprised with the corrosion-resistant firebrick 2a so that the fusion | melting space 1 may be formed.
[0005]
On the left and right sides of the upper and lower middle part of the melting furnace body 2, a main electrode 3 is provided to face the inner end of the melting furnace body 2, and its inner end protrudes into the melting space 1. The bottom electrode 5 is provided, and its inner end protrudes into the melting space 1. 3 and 4, 6 is a raw material supply port for supplying raw glass, high radioactive waste liquid, etc. provided at the upper part of the melting furnace body 2, 7 is a waste gas take-out pipe, 8 is a waste gas treatment device, 9 is The auxiliary electrode 10 is a glass outlet for taking out the glass formed on the furnace bottom 4, 11 is a heater for heating the glass outlet 10, and G is molten glass.
[0006]
It is known that a high amount of radioactive waste liquid supplied to the glass melting furnace contains a trace amount of platinum group elements such as ruthenium (Ru), rhodium (Rh) and palladium (Pd). Platinum group elements are used in the production of nuclear reactor fuel rods due to their high temperature resistance and excellent spreadability. Therefore, platinum group elements are mixed in the highly radioactive liquid waste from cutting and melting spent fuel rods. ing.
[0007]
[Problems to be solved by the invention]
In order to melt the glass in the melting furnace main body 2, the glass is melted by Joule heat by energizing between the opposing main electrodes 3 and 3. However, when the high radioactive waste liquid is melted by mixing with the glass inside the melting furnace main body 2, the platinum group element contained in the high radioactive waste liquid is not taken into the molten glass G but settles in the melting furnace main body 2, There is a tendency to deposit near the bottom 4.
[0008]
On the other hand, in order to allow the molten glass to flow down from the glass outlet 10, current is passed between the main electrode 3 and the bottom electrode 5 to heat the glass temperature of the furnace bottom 4 to a predetermined temperature or higher. However, when the platinum group element is deposited on the bottom of the furnace, the platinum group element has conductivity, so that the current from the main electrode 3 flows to the platinum group element and does not generate heat, and the glass temperature of the furnace bottom 4 reaches the predetermined temperature. As a result, there is a problem that the rise of the molten glass G from the glass outlet 10 is hindered.
[0009]
An object of the present invention is to solve such problems and to provide a glass melting furnace capable of heating the molten glass at the bottom of the furnace to a predetermined temperature without being affected by the platinum group elements. Is.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a melting furnace main body in which a melting space is formed, a glass outlet provided in the furnace bottom of the melting furnace main body, and a main electrode provided in an intermediate portion of the melting space. And a glass melting furnace provided with an electrode rod for high-frequency induction heating in a melting space immediately above the furnace bottom, in a glass melting furnace provided with a bottom electrode provided at the furnace bottom To do.
[0011]
In the above glass melting furnace, a high-frequency current is passed through an electrode rod for high-frequency induction heating so that the vicinity of the furnace bottom is high-frequency induction heated, and the glass at the bottom of the furnace is heated to a predetermined temperature so that both platinum group elements can be removed from the glass outlet. Can flow down.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
FIG. 1 is a longitudinal sectional front view showing an example of an embodiment of the present invention, and FIG. 2 is a plan view of FIG. 1. The same parts as those in FIGS.
[0014]
As shown in FIGS. 1 and 2, in the glass melting furnace of the present invention, an electrode rod 12 for high-frequency induction heating is placed in the melting space 1 immediately above the furnace bottom 4 of the melting furnace body 2 (immediately above the bottom electrode 5). Provided. One or a plurality of electrode rods 12 for high-frequency induction heating may be used, and the cross-sectional shape may be any of a cylindrical shape with a hollow center, a solid circular shape, or a square shape.
[0015]
Next, the operation of the present invention will be described.
[0016]
When the molten glass G is energized between the main electrode 3 and the bottom electrode 5 to raise the molten glass G in the furnace bottom 4 to a predetermined temperature and the molten glass G flows down from the glass outlet 10 and is taken out at the same time, When a high-frequency current is supplied to the molten metal 12, the molten glass G containing the platinum group element 13 deposited in the vicinity of the furnace bottom 4 is heated by high-frequency induction heating of the current flowing through the electrode rod 12 to maintain a fluid state, and the platinum group element 13 is melted. Without being deposited together with the glass G, it flows down from the glass outlet 10 and is taken out.
[0017]
【The invention's effect】
The present invention effectively heats the molten glass containing the platinum group element to be deposited near the bottom of the furnace by high-frequency induction heating of the current flowing through the electrode rod and keeps it in a fluid state without depositing the platinum group element. There is an effect that it can be taken out from the glass outlet together with the molten glass.
[Brief description of the drawings]
FIG. 1 is a longitudinal front view showing an example of an embodiment of the present invention.
2 is a plan view of FIG. 1. FIG.
FIG. 3 is a longitudinal front view showing an example of a conventional glass melting furnace.
4 is a vertical side view of FIG. 3. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Melting space 2 Melting furnace main body 3 Main electrode 4 Furnace bottom 5 Bottom electrode 10 Glass outlet 12 Electrode rod

Claims (1)

A melting furnace body in which a melting space is formed, a glass outlet provided in a furnace bottom portion of the melting furnace body, a main electrode provided in an intermediate portion of the melting space, and a furnace bottom portion A glass melting furnace comprising a bottom electrode, wherein a high frequency induction heating electrode rod is provided in a melting space immediately above the furnace bottom.

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