JPH10132230A - Waste melting furnace and waste melting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispose incombustible article and combustible article without separating and to stably incinerate and melt it by providing an incinerating part and a molten material reservoir at a hearth of a melting furnace body, and providing a molten material output unit at the reservoir. SOLUTION: An incinerating part 7 is provided at a part directly under a waste supply port 3 so that waste 6 dumped from the port 3 is received only by the part 7, i.e., dumped waste 6 is not directly supplied to a molten material reservoir 9. And, a hearth level of the part 7 is formed higher than that of the reservoir 9 so that molten material 8 of the waste 6 incinerated and molten in the part 7 is automatically moved to the reservoir 9. Therefore, bumping generated due to abrupt burning of combustible article in the waste 6 upon dumping of the waste 6 directly in the molten material without directly dumping the waste 6 in the molten material, furnace pressure change due to the bumping can be eliminated, thereby conducting stable incinerating and melting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a waste melting furnace and a waste melting method suitable for treating solid waste generated from general industrial facilities, municipal waste, radioactive solid waste generated from nuclear facilities, and the like. Things.

[0002]

2. Description of the Related Art Solid waste generated from general industrial facilities,
Municipal garbage, radioactive miscellaneous solid waste, and the like include incombustibles such as metals and ceramics, and combustibles such as paper and resin. As a method for treating such waste, incombustibles and combustibles are separated by pretreatment, and combustibles are incinerated. In particular, radioactive incombustibles are melted in a high-frequency melting furnace to form vitrified materials. Is conventionally known. However, in this method, it is necessary to separate incombustibles and combustibles, and when handling radioactive miscellaneous solid waste, there is a danger of being exposed in the separation process.

One means for solving this problem is disclosed in Japanese Patent Application Laid-Open No. 64-6611. The apparatus described in this publication introduces a non-combustible substance and a combustible substance into a furnace equipped with a plasma torch without separation, and uses a high temperature of 10,000 to 15,000 ° C. obtained by the plasma torch to produce a combustible substance. It can incinerate materials and melt incombustibles.

[0004]

However, in the apparatus described in this publication, waste is continuously charged and incinerated.
At the time of melting, the input waste is directly injected into the molten metal in the furnace, so that the input of the waste causes bumping of the molten metal and fluctuations in the furnace pressure. For this reason, stable incineration and melting cannot be performed, and there is an undesired problem particularly when radioactive waste and harmful waste are melted.

[0005] An object of the present invention is to solve the above-mentioned problems and to provide a waste melting furnace and a waste melting method which can treat incombustibles and combustibles without separating them and can stably incinerate and melt. What you want to do.

[0006]

SUMMARY OF THE INVENTION A waste melting furnace according to the present invention comprises a melting furnace main body, a waste supply port provided at an upper portion of the melting furnace main body, and a swivelable and vertically movable movable body provided in the melting furnace main body. In a waste melting furnace comprising a heating means and an exhaust gas outlet provided in the melting furnace main body, in a hearth portion of the melting furnace main body, receiving the waste input from the waste supply port,
An incinerator for incinerating and melting the waste using the heating means, a molten metal reservoir for holding the molten material melted in the incinerator, and a molten metal tapping section provided in the molten metal reservoir are provided. It is assumed that.

Further, according to the waste melting method of the present invention, in the waste melting method using the waste melting furnace described above, the waste introduced from the waste supply port is heated by the incineration section by the heating means, preferably. It is characterized in that it is incinerated and melted using a plasma torch, and the melted melt is held in the melt reservoir, and the held melt is discharged from the tapping section.

In the waste melting furnace and the waste melting method according to the present invention, since the waste is not directly introduced into the molten metal in which the waste is incinerated and melted, there is no occurrence of bumping of the molten metal and fluctuation of the furnace pressure, and stable incineration of the waste is achieved. Melting becomes possible. Further, since the waste is preferably incinerated and melted at a time by using a plasma torch, pretreatment of the waste becomes unnecessary, and for example, it becomes possible to treat the entire drum filled with the waste.

[0009]

FIG. 1 is a view showing the structure of an example of a waste melting furnace according to the present invention. FIG. 1 (a) is a conceptual diagram viewed from the front, and FIG. The figure which looked at the downward direction from the cross section along the AA line in (a) is each shown. In the example shown in FIG. 1, a waste melting furnace 1 includes a melting furnace main body 2 and a waste supply port 3 provided at an upper portion of the melting furnace main body 2.
And a plasma torch 4 as a heating means rotatably and vertically movable at the upper part of the melting furnace main body 2 and an exhaust gas outlet 5 provided at the upper part of the melting furnace main body 2.

In this embodiment, the melting furnace main body 2 has a two-part structure in which a melting furnace upper body 2-1 and a melting furnace lower body 2-2 are fixed by flange portions of both. For example, it has a water-cooling structure in which a water-cooling jacket is provided on the outer periphery of the refractory constituting the melting furnace main body 2-1. Of course, the water jacket can be omitted if necessary. Further, a waste supply port 3, a plasma torch 4, and an exhaust gas outlet 5 are provided in the melting furnace upper main body 2-1. When the melting furnace upper body 2-1 is configured to be water-coolable, the life of the melting furnace body 2 can be extended.

The plasma torch 4 is mounted on the upper portion of the melting furnace upper body 2-1 by a ball / socket type mounting device. Therefore, the plasma torch 4 can freely rotate and move up and down. As the plasma torch 4, a conventionally known non-conductive type capable of generating plasma by the torch itself without the need for a counter electrode.
Use a transfer type. By applying a voltage to the tip of the plasma torch 4, 1
A plasma flow of 10,000 to 15,000 ° C. can be generated. Waste is incinerated and melted by this plasma flow. As described above, by using the non-transfer type plasma torch 4, the counter electrode becomes unnecessary and the configuration of the melting furnace lower body 2-2 can be simplified.

An important point in this embodiment is that the waste 6 supplied from the waste supply port 3 is received by the refractory lower body 2-2 made of a refractory, which is the hearth of the melting furnace main body 2, and receives the waste 6 therefrom. An incinerator 7 for incinerating and melting the waste 6 using the plasma torch 4 and a molten metal reservoir 9 for holding the melt 8 melted in the incinerator 7 are provided. That is the provision. Reference numeral 12 denotes a molten metal receiving mold for receiving the melt 8 discharged through the tap hole 11 of the tapping section 10.

In the present embodiment, the waste 6 introduced from the waste supply port 3 is received only by the incinerator 7, that is, the waste 6 is not directly supplied to the molten metal reservoir 9. An incineration unit 7 is provided immediately below the material supply port 3. The waste 6 incinerated and melted in the incineration unit 7
So that the molten material can automatically move to the molten metal reservoir 9.
The hearth level of the incineration unit 7 is configured to be higher than the hearth level of the molten metal storage unit 9. Therefore, since the waste is not directly injected into the molten metal, it is possible to eliminate bumping and the furnace pressure fluctuation accompanying the direct injection of the waste into the molten metal and the rapid burning of combustibles in the waste, Since stable incineration and melting can be performed, it is possible to provide an apparatus which is particularly preferable for treating radioactive waste and hazardous waste.

In this embodiment, it is not preferable that the level of the molten metal in the molten metal reservoir 9 becomes higher than the level of the incinerator 7, and that the molten metal in the molten metal reservoir 9 enters the incinerator 7.
Therefore, the level of the molten metal in the molten metal reservoir 9 is controlled by using a level meter using microwaves or ultrasonic waves or by using an image processing technique. The molten material 8 of the waste held in the molten metal reservoir 9
By opening the tap 11 of the tap, the tap 11 of the tap 10
Molten metal receiving mold 1 provided outside the waste melting furnace 1 through the
It is discharged during 2. Then, it becomes a solid in the molten metal receiving mold 12.

The opening / closing control of the tapping port 11 of the tapping section 10 is performed by blowing combustion air from below onto the tapping port 11 of the tapping section 10 to solidify the melt 8 and close the tapping port 11 of the tapping section 10 and at a predetermined time. When the melting is completed and the supply of combustion air is stopped, the solidified melt 8 is melted by using the plasma torch 4 and the tap hole 11 of the tapping section 10 is opened. The tapping section 1 using the combustion air in this way
When the opening and closing control of the tap hole 11 of 0 is performed, a complicated operation such as a tilting oxygen lance is not required, which is preferable. In addition,
When a reducing atmosphere is desired as the gas to be supplied to the tap 11 of the tapping unit 10, nitrogen gas or the like can be used instead of the combustion gas.

Further, as opening / closing control of the tapping port 11 of the other tapping section 10, a dam is provided at the tapping port 11 of the tapping section 10, the tapping port 11 of the tapping section 10 is closed, and this dam is used by the plasma torch 4. The tap hole 11 of the tapping section 10 can be opened by breaking it. A mud gun can be used as a method of making the weir. In this case, when controlling the opening and closing of the tap hole 11 of the tapping unit 10 using the combustion gas, uneven solidification of the melt 8 generated by the combustion gas or the like can be eliminated. Opening / closing control of tap hole 11 can be performed more accurately. As another tapping method, a sliding nozzle method or a high-frequency nozzle method can be used.

In this embodiment, since the molten material 8 is held in the molten metal reservoir 9 until the molten material is discharged, the ceramic component and the metal component in the molten molten material 8 can be separated. That is, due to the difference in specific gravity between the two, in the melt 8, the upper layer is a melt of the ceramic component,
The lower layer can be a melt of the metal component. If the melt 8 can be separated into two layers in the molten metal reservoir 9, the melt 8
Is discharged to the molten metal receiving mold 12 through the tap hole 11 of the tapping section 10 and solidified, the resulting solid can be separated into two layers of a ceramic component and a metal component. As described above, if the ceramic component and the metal component in the waste can be separated into two layers in the solidified body, for example, when it is necessary to measure the respective radioactivity levels of the ceramic component and the metal component, this is a preferable embodiment. .

Next, a waste melting method in the waste melting furnace 1 shown in FIG. 1 will be described. First, the waste 6 is supplied continuously or batchwise from the waste supply port 3. The input waste 6 is received by the incineration unit 7. Waste 6 from incineration unit 7
By causing the tip of the plasma torch 4 to approach to generate plasma at the tip of the plasma torch 4, the waste 6 in which combustibles and incombustibles are mixed is incinerated and melted. The melted material 8 is naturally moved to and held in the molten metal reservoir 9 by the hearth level difference between the incinerator 7 and the molten metal reservoir 9. When the level of the melt 8 in the melt reservoir 9 reaches a predetermined level, the supply of the waste 6 from the waste supply port 3 is stopped. Thereafter, the tapping port 11 of the tapping unit 10 is opened, and the melt 8 held in the melt reservoir 9 is discharged into the molten metal receiving mold 12, and one waste melting operation is completed. Then, after the melt 8 is solidified in the molten metal receiving mold 12, it is processed as a solid.

FIG. 2 is a diagram showing the configuration of another example of the waste melting furnace of the present invention. FIG. 2 (a) is a conceptual diagram viewed from the front, and FIG. ) Respectively show downward views from a cross section taken along line AA. In the example shown in FIG. 2, the same members as those in the example shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. The example shown in FIG. 2 differs from the example shown in FIG. That is, in the example shown in FIG. 2, the incineration unit 7 is configured by stacking a plurality of heat-resistant balls 21 on a hearth made of a refractory.

As the material of the heat-resistant ball 21, it is preferable to use a high melting point ceramic such as alumina, magnesia, silicon nitride, silicon carbide and the like. Heat-resistant ball 2
By using 1, the life of the lower body 2-2 of the melting furnace can be extended. In addition, since the consumed amount of the heat-resistant ball 21 due to the incineration melting using the plasma is taken into the melt 8, it does not become a secondary waste. The heat-resistant ball 21 is compensated by additionally replenishing the heat-resistant ball 21.

In the example shown in FIG.
Since the ingot may float in the molten metal, the hearth level of the incineration unit 7 is configured to be higher than the hearth level of the molten metal storage unit 9 as in the example shown in FIG. However, if the heat-resistant balls 21 do not float in the molten metal, the hearth level of the incineration unit 7 can be made the same as the hearth level of the molten metal storage unit 9. In the example shown in FIG. 2, the opening / closing control of the tap hole 11 of the tap unit 10 is performed by providing a weir 22 upstream of the tap port 11.

FIG. 3 is a view showing the configuration of still another example of the waste melting furnace according to the present invention. FIG. 3 (a) is a conceptual diagram viewed from the front, and FIG. FIG. 3A is a diagram when viewed from the cross section along the line AA in FIG. 3A, and FIG. 3C is a conceptual diagram when viewed from the side. In the example shown in FIG. 3, the same members as those in the example shown in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. The example shown in FIG. 3 differs from the example shown in FIG.
Is configured to be movable.

That is, in the example shown in FIG. 3, first, the melting furnace upper main body 2-1 is extended to the base 31, and a shutter 32 is provided in a part thereof. Then, a pair of maintenance rails 33 is provided on the base 31 at the position where the shutter 32 is provided, and the lower body 2 of the melting furnace is provided on the maintenance rails 33.
By mounting the wheel 34 rotatably provided at −2, the molten metal furnace lower body 2-2 can be moved with respect to the melting furnace upper body 2-1. In the example shown in FIG. 3, the lower furnace main body 2-2 having the incineration unit 7, the molten metal reservoir 9 and the tap hole 11 of the tapping unit 10 can be taken out from the upper furnace main body 2-1 fixed to the base 31. Because of the structure, the maintainability can be improved.

In the waste melting furnace 1 having the structure shown in FIG.
The melting furnace lower body 2-2 is set at a predetermined position in the furnace 1.
Next, the shutter 32 is closed. By performing a waste melting operation in the same manner as in the example shown in FIG. 2 with the shutter 32 closed, a solidified waste can be obtained in the molten metal receiving mold 12.

FIG. 4 is a view showing the configuration of still another example of the waste melting furnace of the present invention. FIG. 4 (a) is a conceptual diagram viewed from the front, and FIG. The figure which looked down from the cross section along the AA line in a) is shown, respectively. In the example shown in FIG. 4, the same members as those in the example shown in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. 4 is different from the example shown in FIG. 2 in that the waste supply port 3 is provided on a side surface of the melting furnace upper main body 2-1 and that the waste supply port 3 is provided on the upper side of the melting furnace upper main body 2-1 in an upward direction. Into the combustion chamber 4
1 is provided. Further, the exhaust gas outlet 5 is connected to the combustion chamber 41.
Is provided. By providing the combustion chamber 41 in the melting furnace upper main body 2-1 as in the present embodiment, the secondary combustion chamber that needs to be provided outside the exhaust gas outlet 5 in communication with the exhaust gas outlet 5 in each of the above-described embodiments. It can be unnecessary.

FIG. 5 is a view showing the configuration of still another example of the waste melting furnace according to the present invention. FIG. 5 (a) is a conceptual diagram viewed from the front, and FIG. The figure which looked down from the cross section along the AA line in a) is shown, respectively. The example shown in FIG. 5 is the lower part 2 of the melting furnace shown in FIG.
2 and the melting furnace upper main body 2 shown in FIG.
This is a combination of the first combustion chamber 41 and a description thereof is omitted here.

The present invention is not limited to the above-described embodiment, but can be variously modified and changed. For example, in the above-described embodiment, the tap hole 11 of the tapping unit 10 is provided on the hearth of the lower body 2-2 of the melting furnace, but the tap port 11 of the tapping unit 10 is provided on the side of the lower body 2-2 of the melting furnace. May be provided. In the above-described embodiment, the plasma torch 4 is used as the heating means, but another heating means such as an oxygen-rich burner can be used.

[0028]

As is clear from the above description, according to the present invention, since the waste is not directly injected into the molten metal in which the waste is incinerated and melted, there is no occurrence of bumping of the molten metal and fluctuation of the furnace pressure, and stable waste disposal. It is possible to incinerate and melt the material. In addition, since waste is incinerated and melted at once using a plasma torch,
Pretreatment of the waste is not required, and for example, it is possible to treat the entire drum filled with the waste.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an example of a waste melting furnace of the present invention.

FIG. 2 is a diagram showing the configuration of another example of the waste melting furnace of the present invention.

FIG. 3 is a diagram showing a configuration of still another example of the waste melting furnace of the present invention.

FIG. 4 is a diagram showing the configuration of still another example of the waste melting furnace of the present invention.

FIG. 5 is a view showing the configuration of still another example of the waste melting furnace of the present invention.

[Explanation of symbols]

1 waste melting furnace, 2 melting furnace body, 2-1 melting furnace upper body, 2-2 melting furnace lower body, 3 waste supply port,
4 plasma torch, 5 exhaust gas outlet, 6 waste, 7
Incineration section, 8 molten material, 9 molten metal pool section, 10 tap section, 11 tap hole, 12 melt receiving mold, 21 heat-resistant ball, 22 dam, 31 base, 32 shutter, 33
Maintenance rail, 34 wheels

Claims (11)

[Claims] 1. A melting furnace main body, a waste supply port provided in an upper part of the melting furnace main body, a heating means provided in the melting furnace main body so as to be pivotable and vertically movable, and an exhaust gas outlet provided in the melting furnace main body. An incinerator for receiving a waste introduced from the waste supply port into the hearth of the melting furnace body, and incinerating and melting the waste using the heating means. And a molten metal pool for holding a molten material melted in the incineration section, and a tapping section provided in the molten metal pool. 2. The waste melting furnace according to claim 1, wherein said heating means is a plasma torch. 3. The waste melting furnace according to claim 1, wherein the hearth level of the incineration section is higher than the hearth level of the molten metal storage section. 4. The waste melting furnace according to claim 1, wherein a heat-resistant ball is disposed in the incineration section. 5. A melting furnace lower body comprising a melting furnace upper body having a waste supply port, a heating means, and an exhaust gas outlet, an incineration section, a molten metal reservoir section, and a tapping section. The waste melting furnace according to claim 1, wherein the waste melting furnace has a two-part structure. 6. The waste melting furnace according to claim 1, wherein said melting furnace upper body has a water-cooled structure. 7. The waste melting furnace according to claim 5, wherein said melting furnace lower body is movable relative to said melting furnace upper body. 8. The waste melting furnace according to claim 1, wherein a combustion chamber is provided at an upper portion of said melting furnace main body, and said exhaust gas outlet is provided in said combustion chamber. 9. A waste melting method using a waste melting furnace according to any one of claims 1 to 8, wherein the waste supplied from the waste supply port is heated by the incineration section by the heating means. And melting the molten material by holding the molten material in the molten metal reservoir, and discharging the retained molten material from the tapping portion. 10. A tapping control of a tapping port of the tapping section, wherein combustion air is blown into the melting furnace body from the outside through the tapping port to solidify an end of the melt facing the tapping port. And stopping the supply of combustion air and stopping the supply of combustion air to melt the solidified melt using the heating means so that the melt is discharged from the tap of the tapping section. Item 10. The waste melting method according to Item 9. 11. A tapping control of a tapping port of the tapping section, a dam is provided around the tapping port to stop tapping from the tapping port, and the dam is destroyed by using the heating means.
The waste melting method according to claim 9, wherein the molten material is discharged from a tap of a tapping section.