JP2001141888A - Waste melting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce processing cost by simplifying setting structure of circulation air supply piping in a melting device for melting processing especially radioactive solid waste. SOLUTION: A melting furnace 20 has a bubbling pipe 23 inserted and placed in a high frequency wave coil 11 and a melting vessel 3 placed by penetrating the melting vessel 3 and a furnace wall 9 for receiving waste R. At the tip end of the bubbling pipe 23, a tip end opening and a plurality of discharge openings are provided mutually putting intervals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for melting waste and the like, and more particularly to a waste melting apparatus suitable for melting radioactive waste.

[0002]

2. Description of the Related Art In order to facilitate storage processing of solid radioactive waste, melting processing is performed. The structure of a conventional melting furnace or melting apparatus will be described with reference to FIGS. 10 and 11. The melting vessel 3 defining the melting space of the melting furnace 1 has a bottom formed in a truncated inverted conical shape. It is connected to a nozzle 5 for discharging the melt, and is closed by a stopper 7 that can be melted. The furnace wall 9 of the melting furnace 1 is formed of a refractory material, a high-frequency coil 11 is provided through the furnace wall 9, and another high-frequency coil 13 is provided around the nozzle 5. Four straight bubbling tubes 15 and one bent tubular bubbling tube 17 are arranged along the inner surface of the melting vessel 3. The plan arrangement of the bubbling tubes 15, 17 is shown in particular in the plan view of FIG.

In order to treat radioactive waste using such a melting furnace 1, first, an inorganic radioactive waste R such as a heat insulating material, rubber, plastic, concrete or the like is charged into a melting vessel 3. . Then, an electric current is applied to the high-frequency coil 11 to heat the radioactive waste R to form a molten slag liquid S. Air is pumped from the bubbling tubes 15 and 17 to generate air bubbles B.
To the molten slag liquid S. Such bubbles B stir the molten slag liquid S to promote melting. When the supplied radioactive waste R is sufficiently melted, an electric current is applied to the high-frequency coil 13 to heat and melt the solidified molten slag in the plug 7 and the nozzle 5, and discharge the molten slag liquid S therein.

[0004]

In the above-mentioned conventional melting equipment, a large number of bubbling tubes are required to promote the melting of the molten slag liquid. Since a device for charging radioactive waste is provided above the melting furnace, it takes time and effort to attach and detach the bubbling tube.
That is, since the material to be melted is radioactive, human access is restricted, and remote control means must be used for its attachment and detachment. Was causing it. Accordingly, an object of the present invention is to provide a waste melting apparatus in which the required number of bubbling pipes or agitated air supply jet pipes is minimized to reduce the cost required for attaching and detaching the pipes.

[0005]

According to the present invention, there is provided, in accordance with the present invention, a furnace body defining a melting space for receiving waste therein, the furnace body being provided through a furnace wall of the furnace body. Waste melting device having a high-frequency coil and a stirring air supply ejection pipe provided by being inserted into the melting space,
A plurality of ejection openings are provided at the tip of the stirring air supply ejection pipe at intervals. The bottom of the melting space is formed in a truncated inverted conical shape toward the discharge port of the molten slag, and the tip of the agitating air supply jet tube is disposed along the truncated inverted conical bottom surface, and the bent portion is formed. It is preferred to form Further, it is preferable that a horizontal loop-shaped portion is formed at a central portion of the agitating air supply jet pipe, and the jet openings are formed in the horizontal loop-shaped portion in a dispersed manner.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. It is to be noted that the same portions are denoted by the same reference numerals throughout the drawings, including the drawings relating to the above-mentioned conventional technology. First, referring to FIG. 1, the melting vessel 3 defining the melting space of the melting furnace 20 is formed as a cone 21 having a truncated inverted conical bottom. The lower end of the cone 21 is connected to the vertical nozzle 5. Vertical nozzle 5
Is usually closed by a stopper 7, which is made of a material which can be melted. Below the nozzle 5, suitable equipment, not shown, such as a container for receiving molten waste, is accessible. Further, the furnace wall 9 of the melting furnace 20 is formed of a refractory material, and a high-frequency coil 11 for high-frequency induction heating is provided through the furnace wall 9, and this is connected to a power supply and a power supply control device (not shown). Similarly, another high-frequency coil 13 is provided around the nozzle 5 and penetrates the refractory material and communicates with the power supply. On the other hand, above the melting vessel 3, facilities for charging the radioactive waste R are provided so as to be close to and separated from each other (not shown).

Further, an agitating air supply jet pipe, that is, a bubbling pipe 23 extends downward along the inner surface of the melting vessel 3, and the tip extends to the cone 21. More specifically, the bubbling tube 23 has an upper vertical portion 25, an inclined portion 27 along the cone portion 21, and a bent distal end portion 29 rising from the lowermost end.
Is opened in the melting vessel 3. Although only one ejection opening 33 is shown, a plurality of ejection openings 33 may be provided at intervals. The plane arrangement of the bubbling 23 is shown in FIG.

[0010] An embodiment in which radioactive waste is melted using the melting furnace 20 having the above-described structure will be described. First, an inorganic radioactive waste R such as a heat insulating material, rubber, plastic, concrete or the like is supplied to, for example, an input facility. It is put into the melting vessel 3 via a shooter (not shown). Then, when a predetermined amount of radioactive waste R is introduced, a high-frequency current is applied to the frequency coil 11 to heat the radioactive waste R from the outside to form a molten slag liquid S. If compressed air is supplied to the bubbling tube 23 from a compressed air source (not shown), the compressed air is blown out to the molten slag liquid S as bubbles B from the ejection opening 33 and the tip end opening 31. When such bubbles B rise in the molten slag liquid S, the bubbles S stir the molten slag liquid S to promote melting. When the input radioactive waste R is sufficiently melted, a heating current is applied to the high-frequency coil 13 to melt the solidified molten slag in the plug 7 and the nozzle 5 by heating from the outside, and discharge the molten slag liquid S in the inside. I do. Although only one bubbling tube 23 is provided as described above, air is blown out from a plurality of locations separated from each other, so that the bubbles B are uniformly dispersed and rise in the molten slag liquid S, and melting is effective. Done in

Further, a modified embodiment in which the shape of the stirring air supply jet pipe is changed will be described with reference to FIGS. As can be easily understood by comparing FIGS. 4 and 1 showing the overall structure, the melting furnace 40 differs from the melting furnace 20 only in the stirring air supply jet pipe, that is, the bubbling pipe 43. The shape of the bubbling tube 43 will be described with reference to FIGS. 5 and 6. The bubbling tube 43 has an upper vertical portion 45, an inclined portion 47 along the cone portion 21, a bent tip portion 49 rising from the lowermost end, and a vertical portion. It has a horizontal loop portion 55 between 45 and the inclined portion 47, and the distal end opening 51 opens into the melting vessel 3. Further, the ejection opening 53 is formed in the upper part of the inclined portion 47 and three ejection openings 57 are formed in the horizontal loop portion 55. The plane arrangement of the ejection openings 53, 57 and the tip opening 51 is particularly clearly shown in FIG. As will be readily understood by those skilled in the art, as shown in FIG.
By arranging the tip 7 and the tip opening 51, the ejection of the bubbles B is dispersed more widely than in FIG. 3, so that the stirring performance is improved and the melting is enhanced. The shape and dimensions of the ejection openings 53 and 57 are individually set by calculation experiments so that the bubbles B are effectively dispersed.

Further, another modified embodiment will be described with reference to FIGS. As can be understood from FIG. 7 which is the overall view also in the present embodiment, the melting furnace 60 includes the melting furnace 2.
0 and 40 are different only in the shape of the bubbling tube 63. The shape of the bubbling tube 63 will be described with reference to FIG. 8B. The bubbling tube 63 includes an upper vertical portion 65, an inclined portion 67 along the cone portion 21, and a bent tip portion 69 rising from the lowermost end. And a tip opening 71 opens into the melting vessel 3. In addition, the lower part of the vertical
A plurality of stoppered openings 73 are provided. The opening 73 is vertically separated, and the opening 73 is closed by a plug 75 as shown in FIG. The stopper 75 is made of a material that melts at the melting temperature of the molten slag liquid S. The plan shape of the bubbling tube 63 is shown in FIG. Also in this melting furnace 60, the above-mentioned melting furnaces 20, 4
0, radioactive waste R is charged, and the high-frequency coil 1
1 is melted by energizing. At first, the air supplied to the bubbling tube 63 is blown out from the distal end opening 71 to become a bubble B to stir the molten slag S at the bottom of the cone portion 21. Then, as the molten slag S increases and the liquid level rises, the plugs 75 are sequentially lowered. By doing so, the stopper 75 reaches its melting temperature and is melted, and the opening 73 is opened. In this state, the bubbling tube 63
Is blown into the molten slag liquid S and is stirred to promote melting. Thus, according to the present embodiment, the stirring air is blown out to the most effective time and place to effectively promote the melting.

[0011]

As described above, according to the present invention,
Since the stirring air supply spout pipe of the melting furnace is provided with a tip opening and a spout opening that is dispersed and drilled, even if the number is minimized, the molten slag liquid of waste is effectively stirred and melted. Can be promoted, so that installation costs such as the mounting work can be reduced.

[Brief description of the drawings]

FIG. 1 is an entire vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a partially enlarged perspective view showing a main part of the embodiment.

FIG. 3 is a partial plan view corresponding to FIG. 2;

FIG. 4 is an overall sectional view showing a modified embodiment of the present invention.

FIG. 5 is a partially enlarged perspective view showing a main part of the modified embodiment.

FIG. 6 is a partial plan view corresponding to FIG.

FIG. 7 is an overall elevational sectional view showing another modified embodiment of the present invention.

FIG. 8 is a partially enlarged perspective view showing a main part of the another modified embodiment.

FIG. 9 is a partial plan view corresponding to FIG. 7;

FIG. 10 is an overall vertical sectional view showing a conventional apparatus.

FIG. 11 is a partial plan view corresponding to FIG.

[Explanation of symbols]

 3 Melting Vessel 5 Nozzle 7 Plug 9 Furnace Wall 11, 13 High-Frequency Coil 20 Melting Furnace 23 Publing Tube 25 Vertical Section 27 Inclined Section 29 Bending Tip 31 Tip Opening 33 Spouting Opening 40 Melting Furnace 43 Publing Pipe 45 Vertical Section 47 Inclined Section 49 Bending tip 51 Tip opening 53 Jet opening 55 Horizontal loop 57 Jet opening

Claims (3)

[Claims] 1. A furnace body defining a melting space for receiving waste therein, a high-frequency induction heating coil provided through a furnace wall of the furnace body, and a stirrer inserted into the melting space. In a waste melting apparatus having an air supply ejection pipe, a plurality of ejection openings are provided at an end of the stirring air supply ejection pipe at an interval from each other. 2. A bottom portion of the melting space is formed in a truncated inverted conical shape, and a tip end of the stirring air supply jet tube is disposed along the truncated inverted conical bottom surface to form a bent portion. The waste melting apparatus according to claim 1, wherein: 3. A horizontal loop-shaped portion is formed at a central portion of the stirring air supply jet pipe, and a plurality of jet openings are provided at a distance from each other in the horizontal loop-shaped portion. The waste melting apparatus according to claim 1 or 2.