JP2002236197A - Stirrer for glass fusion furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To agitate fused glass to preclude platinum group elements from being accumulated in the vicinity of a furnace bottom part. SOLUTION: An air blow pipe 12 having an air port 13 is arranged in the vicinity of a bottom electrode 5, in a glass fusion furnace provided with a fusion furnace main body 2 with a fusion space 1 formed in its inside, a glass take-out port 10 provided in the furnace bottom part 4 of the main body 2, a main electrode 3 arranged in an intermediate part of the fusion space 1, and the bottom electrode 5 provided in the bottom part 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass melting furnace stirring apparatus used for vitrifying highly radioactive waste liquid.

[0002]

2. Description of the Related Art Highly radioactive liquid waste generated in nuclear facilities is melted by a glass melting furnace of a highly radioactive liquid waste vitrification facility, treated as vitrified material, and stored in a radioactive waste storage facility.

[0003] In the above-mentioned vitrification facility, highly radioactive waste liquid is mixed when raw glass is melted inside a glass melting furnace, and the molten glass mixed with this highly radioactive waste liquid is poured into a solidification vessel, and the molten glass is melted. By solidifying,
Manufactures vitrified products.

FIG. 4 is a vertical front view showing an example of a conventional glass melting furnace, and FIG. 5 is a vertical side view of FIG.
In the figure, reference numeral 2 denotes a melting furnace main body, and the melting furnace main body 2 is made of a corrosion-resistant refractory brick 2a so as to form a melting space 1 therein.

A main electrode 3 is provided on the left and right sides of the upper and lower middle portions of the melting furnace body 2 so as to face each other.
A bottom electrode 5 is provided on the narrowed furnace bottom 4 below the melting space 1, and an inner end of the bottom electrode 5 projects into the melting space 1. 4 and 5, reference numeral 6 denotes a raw material supply port provided at an upper portion of the melting furnace main body 2 for supplying raw glass, highly radioactive waste liquid, etc., 7 denotes a waste gas outlet pipe, 8 denotes a waste gas treatment device, and 9 denotes a waste gas treatment device. Auxiliary electrodes 10 used when it is necessary to heat the upper part of the melting space 1 are glass outlets formed on the furnace bottom 4 for taking out molten glass.
1 is a heater for heating the glass outlet 10, and G is molten glass.

It is known that a platinum group element such as ruthenium (Ru), rhodium (Rh) and palladium (Pd) is mixed in the radioactive waste liquid supplied to the glass melting furnace. Platinum group elements are used in the production of nuclear fuel rods due to their high temperature resistance and excellent spreadability. are doing.

[0007]

The raw glass supplied to the melting space 1 of the melting furnace main body 2 together with the highly radioactive waste liquid is:
It is melted by Joule's heat when electricity is supplied between the main electrodes 3 and 3 arranged opposite to each other.

However, when the highly radioactive waste liquid is mixed with the molten glass G and melted, the platinum group elements contained in the highly radioactive waste liquid are not taken in by the molten glass G and settle down in the melting furnace main body 2 to form the furnace bottom. There is a tendency to deposit around 4.

In order to make the molten glass flow down and out of the glass outlet 10, electricity is supplied between the main electrode 3 and the bottom electrode 5 so that the glass temperature of the furnace bottom 4 is heated to a predetermined temperature or higher. However, when the platinum group element is deposited on the furnace bottom 4, the platinum group element has conductivity, so that the main electrode 3
Current does not reach the bottom electrode 5 and the furnace bottom 4
Has a problem that the temperature of the glass does not rise to a predetermined temperature, which causes a problem in taking out the molten glass G from the glass outlet 10.

An object of the present invention is to provide a glass melting furnace stirring apparatus which solves such a problem and stirs molten glass so that platinum group elements are not deposited near the bottom of the furnace. .

[0011]

In order to achieve the above object, a glass melting furnace stirrer according to claim 1 includes a melting furnace body having a melting space formed therein, and a glass provided at a furnace bottom of the melting furnace body. In a glass melting furnace having an outlet, a main electrode provided at an intermediate portion of the melting space, and a bottom electrode provided at the bottom of the furnace, an air blowing pipe having an air outlet near the bottom electrode It is characterized by having provided.

A second aspect of the present invention is characterized in that an auxiliary electrode having an air blowing passage penetrating therethrough is provided near the bottom electrode.

According to a third aspect of the present invention, in the glass melting furnace stirring apparatus, an air outlet is opened in the bottom electrode.

According to a fourth aspect of the present invention, in the glass melting furnace stirring device, an auxiliary electrode having an air blowing passage formed therein is provided immediately above the bottom electrode, and an air outlet is opened in the bottom electrode. And

According to a first aspect of the present invention, there is provided a glass melting furnace, wherein air supplied from an air blowing pipe is blown out from an air outlet provided near a bottom electrode to stir the molten glass. The stirrer heats the molten glass at the bottom of the furnace by the auxiliary electrode, and also stirs the molten glass by air blown out from the air blowing passage of the auxiliary electrode. The air blows out from the air outlet of the bottom electrode to stir the molten glass immediately above the bottom electrode. The molten glass is stirred by both the air and the molten glass, and the stirring of the molten glass according to the above claims prevents the platinum group element from being deposited near the furnace bottom.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional front view showing an example of the embodiment of the present invention, and the same parts as those in FIGS. 4 and 5 are denoted by the same reference numerals.

In the glass melting furnace shown in FIG. 1, an air blowing pipe 12 penetrating through the inside and outside of the furnace bottom 4 is provided at the furnace bottom 4 of the melting furnace main body 2. The air blowing pipe 12 is buried so that the thin pipe penetrates the refractory brick 2a. The inner end of the air blowing tube 12 has an air outlet 13 immediately above the bottom electrode 5 near the bottom electrode 5. The air blowing tube 12 is connected to the bottom electrode 5 as shown in FIG.
May be provided symmetrically on both sides, four may be provided radially around the bottom electrode 5, or only one may be provided.

The air supplied from the outer end of the air blowing pipe 12 is blown into the molten glass G from the air blowing port 13 near the bottom electrode 5 through the air blowing pipe 12. Even if the temperature of the air supplied from the outer end of the air blowing pipe 12 is low, the temperature of the air is increased by the heat of the melting furnace main body 2 while passing through the air blowing pipe 12 and the air blowing port 13 Is blown into the molten glass G from the
Temperature does not drop.

Since the molten glass G is agitated by the air blown out from the air outlet 13, the platinum group element contained in the highly radioactive waste liquid does not deposit near the furnace bottom 4 and the molten glass G And mixed with molten glass G
At the same time, it flows down from the glass outlet 10 to the outside of the melting furnace body 2 and is taken out. Therefore, the temperature of the molten glass G in the vicinity of the furnace bottom 4 due to the deposition of the platinum group element does not decrease, so that the melting ability can be improved and the glass outlet 10 can be improved.
The molten glass G can be taken out from the container reliably.

FIG. 2 is a longitudinal sectional front view showing another example of the embodiment of the present invention, and the same parts as those in FIG. 1 are denoted by the same reference numerals.

The glass melting furnace shown in FIG. 2 is provided with an air blowing tube 12 having an air blowing port 13 immediately above the bottom electrode 5 as in the embodiment shown in FIG. The auxiliary electrode 14 is provided on the upper part. Also, two auxiliary electrodes 14 are provided symmetrically on both sides of the bottom electrode 5, four auxiliary electrodes 14 are provided radially around the bottom electrode 5,
Alternatively, a mode in which only one is provided may be adopted.

The auxiliary electrode 14 has an air blowing passage 15 penetrating therethrough, and an outer end of the air blowing passage 15 is connected to a compressed air source (not shown) provided outside the melting furnace main body 2. An inner end of the air blowing passage 15 forms an air outlet 16 above and near the bottom electrode 5.

In the embodiment shown in FIG. 2, the air supplied from the outer ends of the air blowing pipe 12 and the air blowing passage 15 passes through the air blowing pipe 12 and the air outlet 13 near the bottom electrode 5. Blows into the molten glass G from
Air is also blown into the molten glass G from the air outlet 16 through the air blowing passage 15 penetrating the auxiliary electrode 14. Therefore, the molten glass G is efficiently stirred, and the platinum group element contained in the highly radioactive waste liquid flows down from the glass outlet 10 to the outside of the melting furnace main body 2 together with the molten glass G without being deposited near the furnace bottom 4. Taken out.

FIG. 3 is a longitudinal sectional front view showing still another example of the embodiment of the present invention, and the same parts as those in FIG. 2 are denoted by the same reference numerals.

In the glass melting furnace shown in FIG.
Penetrates through the refractory brick 2 a and enters the bottom electrode 5, is bent upward in the bottom electrode 5, and the air outlet 13 ′ is open at the upper surface of the bottom electrode 5. The air outlet 16 at the inner end of the air blowing passage 15 penetrating the inside of the auxiliary electrode 14 is open at a position close to immediately above the bottom electrode 5.

In the embodiment shown in FIG. 3, the air supplied to the air blowing tube 12 blows upward from the air blowing port 13 'on the upper surface of the bottom electrode 5 into the molten glass G, and the air blowing is performed. The air supplied to the passage 15 is blown into the molten glass G from an air outlet 16 near immediately above the bottom electrode 5, and the molten glass G immediately above the bottom electrode 5 is uniformly stirred. The platinum group element that is present does not accumulate near the furnace bottom 4 and flows out of the melting furnace body 2 through the glass outlet 10 together with the molten glass G and is taken out.

[0028]

According to the first aspect of the present invention, since the air supplied from the air blowing pipe blows out from the air blowing port provided near the bottom electrode to stir the molten glass, it is contained in the highly radioactive waste liquid. The platinum group element does not accumulate near the furnace bottom, and flows out of the melting furnace body out of the glass outlet together with the molten glass and is taken out. In addition, the melting ability of the glass melting furnace can be improved, and the molten glass can be reliably taken out from the glass outlet.

According to the second aspect of the present invention, the molten glass in the furnace bottom is heated by the auxiliary electrode and the molten glass is stirred by the air blown out from the air blowing passage of the auxiliary electrode. The group III elements flow out of the melting furnace body without being deposited near the furnace bottom and are taken out.There is no drop in the temperature of the molten glass near the furnace bottom, and the effect of further improving the melting capacity of the glass melting furnace is obtained. is there.

According to a third aspect of the present invention, the platinum group element contained in the highly radioactive waste liquid is discharged near the furnace bottom in order to efficiently stir the molten glass immediately above the bottom electrode by blowing air from the air outlet of the bottom electrode. The molten glass flows out of the body of the melting furnace without being deposited and is taken out. The temperature of the molten glass near the furnace bottom does not decrease, and the melting ability of the glass melting furnace can be further improved.

According to a fourth aspect of the present invention, the molten glass is agitated by both the air blown from the air blowing passage of the auxiliary electrode and the air blown from the air blowing port of the bottom electrode.
The platinum group elements contained in the highly radioactive waste liquid flow out of the melting furnace body without being deposited near the furnace bottom and are taken out.There is no drop in the temperature of the molten glass near the furnace bottom, and the melting capacity of the glass melting furnace Is extremely high.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view showing an example of an embodiment of the present invention.

FIG. 2 is a longitudinal sectional front view showing another example of the embodiment of the present invention.

FIG. 3 is a longitudinal sectional front view showing still another example of the embodiment of the present invention.

FIG. 4 is a vertical sectional front view showing an example of a conventional glass melting furnace.

FIG. 5 is a vertical sectional side view of FIG. 4;

[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 Air blowing pipe 13, 13 'Air blowing port 14 Auxiliary electrode 15 Air blowing passage

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Claims (4)

[Claims] 1. A melting furnace body having a melting space formed therein, a glass outlet provided at a furnace bottom of the melting furnace body, a main electrode provided at an intermediate portion of the melting space, A glass melting furnace comprising: a glass melting furnace having a bottom electrode provided at a bottom; and an air blowing pipe having an air blowing port provided near the bottom electrode. 2. A stirrer for a glass melting furnace according to claim 1, wherein an auxiliary electrode through which an air blowing passage penetrates is provided near the bottom electrode. 3. The glass melting furnace stirring device according to claim 1, wherein an air outlet is opened in the bottom electrode. 4. The glass according to claim 1, wherein an auxiliary electrode having an air blowing passage formed therein is provided immediately above the bottom electrode, and an air outlet is opened in the bottom electrode. Melting furnace stirrer.