JP4389367B2 - Residual glass cutting method for glass melting furnace - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a glass melting furnace used for vitrifying high-level radioactive liquid waste, and more particularly to a method for cutting a filamentous residual glass formed between a flow outlet of the glass melting furnace and a lower canister. It is.
[0002]
[Prior art]
The high-level radioactive liquid waste generated after reprocessing of spent nuclear fuel is difficult to dispose of as a liquid, so it is called a canister while being melted together with glass raw materials such as borosilicate glass in a glass melting furnace at a high temperature. It is planned that after being packed in a cylindrical stainless steel container and stabilized as a vitrified body, it is naturally cooled for a certain period and then disposed deep underground.
[0003]
As shown in FIG. 4, the glass melting furnace 1 used for this vitrification treatment constricts the inner bottom portion of the furnace body 2 in a funnel shape (square pyramid shape) and melts the furnace 2 in the lowermost end portion thereof. A structure having a bottom electrode 4 having a flow-down nozzle 3 for flowing glass and a pair of main electrodes 5 and 5 and an auxiliary electrode 6.6 in the interior thereof has been proposed.
[0004]
That is, after the high-level radioactive liquid waste and the glass raw material are introduced from the inlet 7 provided on the ceiling wall of the furnace body 2, the heat of the molten glass heated to a high temperature by flowing an electric current between the main electrodes 5 and 5. In response, the high-level radioactive liquid waste and the glass raw material are sufficiently melted together. Further, when a predetermined amount of the glass produced in the furnace 2 is reached, electricity is passed between the auxiliary electrodes 6 and 6 located below the bottom electrode 4 and the main electrodes 5 and 5 to lower the glass in the lower part. And the falling nozzle 3 is heated by the surrounding high-frequency heating coil 8 so that the molten glass in the furnace flows down into the canister c located in the lower part thereof and is accommodated in the inside as a glass solidified body. I have to.
[0005]
The gas generated in the melting furnace 1 is exhausted as an off-gas from the exhaust port 7a, and radioactive substances are completely collected and removed by a HEPA filter or the like (not shown) so as to be released into the atmosphere. It has become.
[0006]
In addition to the coupling device 10 for preventing radioactive material from being scattered from the flowing glass between the flowing port 9 where the flowing nozzle 3 of the glass melting furnace 1 is provided and the canister c as shown in the drawing. A glass cutter 11 is attached to the lower portion of the glass cutter 11, and the glass cutter 11 cuts and removes the filamentous residual glass formed between the flow-down port 9 and the canister c after the flow-down is completed, and then the canister c is used in the next process. It is supposed to move.
[0007]
That is, when a predetermined amount of molten glass has accumulated on the canister c side as described above, heating of the falling nozzle 3 by the high-frequency heating coil 8 is stopped and the flowing nozzle 3 is forcibly cooled by cooling air. Since the flow of the molten glass is stopped by solidifying the glass inside the glass, the flowing glass is solidified as it is after the end of the flow and is connected in a string between the flow port 9 and the canister c. It remains as residual glass with a diameter of about 0.5 mm.
[0008]
Therefore, conventionally, as shown in FIGS. 5 (1) and 5 (2), the cutter member 12 of the glass cutter 11 provided between the coupling device 10 and the canister c is traversed in the downflow path by a manipulator (not shown). After the thread-like residual glass G is forcibly cut by pushing into the air, air is fed into the metal bellows 13 of the coupling device 10 as shown in FIGS. Then, by completely separating it from the canister c, the injection of the molten glass into the canister c is completed. In the figure, reference numeral 14 denotes a sampling container accommodated in the glass cutter 11 for taking out and sampling a part of the glass in the middle of flowing down.
[0009]
[Problems to be solved by the invention]
By the way, in such a conventional residual glass cutting method, since the cutter member 12 is made to collide with the residual glass G and this is forcibly destroyed and cut, for example, FIG. As shown in FIG. 6, a part of the glass piece is scattered around by the momentum at the time of cutting, and is caught in the glass cutter 11, which falls to the floor surface when the next canister c is transferred and is surrounded. Or may remain so as to cross the flow path in the glass cutter 11 and become a factor of closing the flow furnace.
[0010]
Further, in such a conventional cutting method, since the residual glass G on the canister c side protrudes larger than the inlet, it is necessary to further cut and remove the protruding residual glass G by a manipulator. In addition to being bothersome, this work has the disadvantage that the manipulator is contaminated.
[0011]
Therefore, the present invention has been devised in order to effectively solve such problems, and its purpose is to reliably and satisfactorily remove the filamentous residual glass formed between the flow-down port of the glass melting furnace and the canister. A novel method for cutting residual glass in a glass melting furnace that can be cut and removed is provided.
[0012]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a method for cutting a filamentary residual glass formed vertically between a glass melting furnace and a lower canister, in a cutter casing between the canister and the downstream. A cutter member consisting of a U-shaped cutter frame is provided in a horizontally movable manner, and the cutter frame is provided with a heat ray horizontally with respect to the vertical residual glass and a plurality of the heat rays are provided above and below the height direction of the residual glass. The heat rays are heated by heating above the melting point of the residual glass, and the plurality of heat rays are brought into contact with the residual glass with a cutter frame to melt the residual glass in that portion, and the molten glass is cut into upper and lower stages. The cut glass piece is dropped vertically as it is and stored in the canister .
[0013]
As a result, the glass pieces do not scatter and get caught in the glass cutter due to the impact at the time of cutting as in the conventional method, so that the inconveniences such as contamination of the surroundings and blocking of the downflow path are surely avoided. be able to.
[0014]
Then, heat rays this multiple arrangement Subeku cutting frame in the height direction upper and lower glass The residue, provided above and below the multi-stage, the plurality of heat rays simultaneously to cut it into contact with the remaining glass in the vertical multistage Then, the residual glass can be cut and removed over a certain width in the height direction. As a result, the amount of protrusion of the residual glass on the canister side is reduced, so that the removal operation of the residual glass can be omitted, and contamination of the manipulator can be avoided in advance.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, a preferred embodiment for carrying out the present invention will be described with reference to the accompanying drawings.
[0016]
FIG.1 and FIG.2 shows one Embodiment of the glass cutter 20 of the glass melting furnace 1 applied to the method of this invention.
[0017]
As shown in the figure, the glass cutter 20 is provided inside a cutter casing 21 provided so as to communicate between the coupling device 10 extending from the flow-down port 9 of the glass melting furnace 1 and the canister c described above. The cutter member 22 is mainly composed.
[0018]
The cutter casing 21 is formed in a substantially box shape, and has through holes 23 and 24 coaxially on the upper and lower sides of the center thereof. The upper through passage 23 side is flange-coupled to the coupling device 10 side, and the lower portion The through hole 24 side is inserted so as to be fitted into the opening of the canister c, and communicates vertically between the two.
[0019]
On the other hand, the cutter member 22 includes a U-shaped cutter frame 25 located in the cutter casing 21 and a plurality of hot wires 26, 26... And an operating rod 27 that extends from the cutter frame 25 through the cutter casing 21 and extends horizontally to the outside. Are reciprocated horizontally in the cutter casing 21.
[0020]
Here, the hot wires 26, 26... Are so-called electric heater wires, and generate heat at least at a temperature higher than the melting point of the residual glass G, for example, 1000 ° C. It is supposed to be. Incidentally, reference numeral 14 in the figure denotes a sampling container provided so as to be able to appear and retract in the cutter casing 21 so as to arbitrarily collect molten glass flowing down, and the cutter frame 25 does not interfere with the sampling container 14.
[0021]
The operation rod 27 is attached so as to penetrate a bracket 29 provided outside the cutter casing 21 after penetrating the cutter casing 21. The operation rod 27 is attached at two locations of the cutter casing 21 and the bracket 29. It is in a state to be supported. Further, a coil spring 30 as an urging means is provided between the cutter casing 21 and the bracket 29 in the operation rod 27, and the operation rod 27 is urged in the retracting direction.
[0022]
In the method of the present invention using the glass cutter 20 configured as described above, first, as shown in FIG. 3 (1), the hot wire 26 at the tip of the cutter frame 25 in a state where the cutter member 22 is pulled. ... Are energized and heated to a temperature higher than the melting point of the residual glass G. Then, as shown in FIG. 2B, the operating rod 27 is pushed into the cutter casing 21 by a manipulator (not shown) to Are slowly brought into contact with the residual glass G side. Then, as shown in FIG. 3 (3), the residual glass G is simultaneously melted in the upper and lower multistages by the heat of each of the hot wires 26, 26... And the cut glass pieces are dropped vertically as they are. c.
[0023]
As a result, the cut glass pieces do not scatter in the cutter casing 21 and fall vertically and are stored in the canister c. Therefore, the scattered glass pieces remain in the glass cutter 20. In addition, it is possible to surely avoid such inconveniences that this is scattered on the floor surface and contaminates the surroundings, or gets caught in the flow path and interferes with the next glass flow.
[0024]
Further, since the residual glass G is cut and removed over a certain width in the height direction, the residual glass G on the canister c side hardly protrudes or even if it protrudes, the amount of protrusion is conventional. Since the amount is extremely small, there is no adverse effect on the subsequent operation, for example, the welding operation of the canister lid. This eliminates the need for removing the protruding residual glass G using a manipulator as in the prior art, thereby reducing the work effort and avoiding contamination of the manipulator.
[0025]
When the cutting by the cutter member 22 is completed in this way, the operating rod 27 is similarly pulled back by the manipulator to return the heat rays 26, 26... To the original position until the next cutting at that position. Since the operating rod 27 is provided with the coil spring 30 as described above, the cutter member 22 automatically returns to the original position when the operating rod 27 is released. Each pullback operation is unnecessary, and the cutting operation can be greatly reduced.
[0026]
In the present embodiment, the heat wires 26, 26... Of the cutter member 22 are vertically arranged in multiple stages, and the heat wires 26, 26. 26, 26... Are further arranged stepwise in the direction of the residual glass G so as to be melted stepwise from below or above the residual glass G, or the respective heat wires 26, 26. It is good also as a structure.
[0027]
【The invention's effect】
In short, according to the present invention, since the residual glass formed between the flow outlet of the glass melting furnace and the canister is melted and cut by heat rays, the residual glass can be cut reliably and easily, and the glass piece at the time of cutting Therefore, it is possible to prevent the surrounding contamination and blockage from being obstructed.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of a glass cutter used in the method of the present invention.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is an explanatory view showing a residual glass cutting method according to the present invention.
FIG. 4 is a longitudinal sectional view showing an example of a conventional glass melting furnace and glass solidification method.
FIG. 5 is an explanatory view showing a conventional residual glass cutting method.
6 is a cross-sectional view taken along line AA in FIG. 5 (1).
[Explanation of symbols]
9 Downstream entrance
20 Glass cutter
21 Cutter casing
22 Cutter material
25 Cutter frame
26 Hot wire
27 Operation rod
30 Coil spring G Residual glass c Canister

Claims (1)

A cutter member comprising a U-shaped cutter frame in a cutter casing between the canister and the flow outlet , in a method for cutting the filamentary residual glass formed vertically between the flow outlet of the glass melting furnace and the canister below it The cutter frame is provided with a heat wire horizontally with respect to the vertical residual glass, and a plurality of heat wires are provided above and below the residual glass in the height direction, and these heat wires are energized above the melting point of the residual glass. Heat, bring these heat rays into contact with the above-mentioned residual glass with a cutter frame, melt the residual glass in that part, and cut the molten glass into upper and lower stages, and leave the glass piece after the cutting as it is vertically A method for cutting residual glass in a glass melting furnace, wherein the glass is dropped and stored in a canister .

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