JP2002005424A - Waste melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste melting furnace capable of restraining the blockading of a tapping hole due to the adhesion of solidified matter of molten substance even when the vicinity of the tapping hole for the batch type waste melting furnace, tapping properly the molten matter of the waste by tilting the melting furnace, is not heated by a burner or the like. SOLUTION: The waste melting furnace is constituted of a furnace body 1, a waste charging port 4 for charging the waste, a waste gas outlet port 2 as well as a tapping hole 3 and is installed so as to be capable of tapping the molten metal 10 toward a receiving vessel 5 positioned below the furnace main body 1 upon tapping the molten metal 10 through the tapping hole 3 properly by tilting the furnace body 1 after melting the waste while at least the outlet port unit 9 of the tapping hole 3 is formed of a cooling member capable of cooling the molten metal 10 upon tapping the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma arc for general waste containing various inorganic substances, metals, and organic substances, sewage sludge, municipal garbage and incinerated ash thereof, and low-level radioactive waste. A waste melting furnace that melts by a heating method such as induction heating or combustion heating and discharges molten metal from a tap hole, and in particular, waste that taps molten molten metal at a time from a tap hole by tilting the melting furnace. It relates to a melting furnace.

[0002]

2. Description of the Related Art Conventionally, general wastes including various inorganic substances, metals, and organic substances, sewage sludge, municipal garbage and incinerated ash of these substances, and various kinds of ash by plasma arc, induction heating, combustion heating, and other heating methods. A melting furnace for melting nuclear radioactive wastes and the like is a continuous melting furnace configured to continuously discharge hot water while melting these wastes (for example, Japanese Patent Publication No. 59-1984).
-24324) and after melting a certain amount of waste,
By appropriately tilting the melting furnace main body, a batch-type melting furnace configured to discharge the molten metal accumulated in the melting furnace main body at one time from a tap hole (for example, Japanese Patent Application Laid-Open No. H10-196929)
No. etc.) are provided.

[0003] In the case of the continuous melting furnace in which the molten metal is continuously discharged from the tap, in order to secure a stable tap, the molten metal near the tap is always heated by an arbitrary heating means such as a burner. In addition, it is necessary to maintain the viscosity of the molten metal so that the molten metal does not stop near the tap hole. On the other hand, in the case of a batch type melting furnace in which the latter melt is discharged by appropriately tilting the melting furnace or the like, a continuous melting furnace is used in which a certain amount of waste is melted and then the melting furnace is tilted and discharged at a time. In comparison with the conventional method, there is less need to heat the tap, so that the structure is simplified and fuel for heating the tap can be saved.

[0004]

However, in the case of a batch-type melting furnace in which the molten metal is tilted in the melting furnace to discharge the molten metal as appropriate,
When the amount of molten metal is large, the molten metal does not solidify in the vicinity of the molten metal outlet and there is no problem because the molten metal is discharged.However, the amount of molten metal decreases, and when the amount of molten metal decreases, the molten metal is cooled and solidified at the molten metal outlet. , Deposits on the tap and sticks. Therefore,
Unless solidified matter of the molten metal adhered to the tap hole is removed in this way, the tap hole may be blocked, and it may be impossible to continue the operation of the melting furnace. In addition, when pouring molten metal such as radioactive waste, it is difficult to remove solidified waste that adheres to the tap because it is not easily accessible to the furnace. Therefore, even in the case of a batch-type melting furnace, it is necessary to suppress the solidification of the molten metal at the tap hole.

Therefore, in order to suppress such a problem, even in the case of a batch-type melting furnace in which a molten material is tilted in a melting furnace and tapping is appropriately performed, as in a continuous-type melting furnace,
A melting furnace for heating the vicinity of a taphole with a burner or the like has also been proposed (JP-A-11-270815).

However, if a burner or the like is provided in the tap hole, the structure of the melting furnace becomes complicated, and a fuel or the like for heating is required, so that the manufacturing cost and running cost of the melting furnace are inevitably reduced. The melting point of the batch melting furnace.

Therefore, the present invention provides a batch type waste melting furnace in which the molten material is tilted in a melting furnace to discharge the molten metal as needed. An object of the present invention is to provide a waste melting furnace capable of suppressing blockage of a tap hole due to sticking.

[0008]

According to a first aspect of the present invention, there is provided a waste melting furnace, comprising: a waste input port for inputting waste; an exhaust gas outlet; A waste melting furnace that melts waste and then discharges molten metal from a tap hole as appropriate, wherein the tap hole discharges the molten metal toward a receiver located below the melting furnace when tapping. And at least an outlet portion of the tap hole is formed of a cooling member capable of cooling the molten metal when the molten metal is discharged. According to the above configuration, since at least the outlet portion of the tap hole is formed of the cooling member, the solidified layer formed when the amount of the molten metal discharged is reduced can be thickened. At this time, since the tap hole is formed toward the receiver located below the melting furnace, the solidified molten metal is separated from the tap port by its own weight without being fixed to the tap port and receiving the melt. It flows down toward the container, and the blockage of the tap hole can be suppressed.

Further, the waste melting furnace according to claim 2 is
The molten metal is discharged from the tap at the time of tapping by tilting the melting furnace according to claim 1. According to the above configuration, by tilting the melting furnace, the molten metal can be reliably discharged toward the receiver, and the solidified molten metal can be separated and removed by its own weight.

The waste melting furnace according to claim 3 is
The cooling member according to claim 1 or 2, wherein the cooling member has a thermal conductivity of 5%.
It is a material having high thermal conductivity of not less than W / (m · K). According to the above configuration, the tap hole has a thermal conductivity of 5 W / (m
・ K) By forming the material with a high thermal conductive material as described above, the heat dissipation of the molten metal can be enhanced at the outlet of the tap hole, and the molten metal can be cooled, the solidified layer formed can be thickened, and the solidified molten metal It can be peeled off and removed by its own weight, and the blockage of the tap hole can be suppressed.

Further, the waste melting furnace according to claim 4 is
The high thermal conductive material according to claim 3 is any one of stainless steel, cast iron, cast steel, carbon steel, copper, and carbon, or a composite material of two or more of these. According to the above configuration, stainless steel, cast iron, cast steel,
By using any one of carbon steel, copper, and carbon or a composite material of two or more of them, the thermal conductivity of the tap hole can be increased, and the surface of the tap hole can be made of a conventional refractory. The melt can be made smoother, the releasability of the melt can be improved, and the blockage of the tap hole by the melt can be suppressed.

Further, the waste melting furnace according to claim 5 is
The cooling member according to any one of claims 1 to 4 is provided with a flow path for a cooling medium. According to the configuration, by providing the cooling medium passage inside the tap hole, the molten metal can be further cooled at the tap hole, whereby the solidified layer of the molten metal can be thickened, and the releasability of the solidified layer is improved. Therefore, it is possible to more reliably suppress the blockage of the tap hole when tapping.

Further, the waste melting furnace according to claim 6 is
A guide portion for guiding the molten metal from the tap hole according to any one of claims 1 to 4 toward the receiver is provided, and the guide portion is formed by the cooling member. According to the above configuration, since the guide portion is provided from the tap hole toward the receiver, the molten metal from the tap hole can be reliably put into the receiver, and the guide portion can be formed similarly to the outlet portion of the tap hole. By using a cooling member, it is possible to prevent the molten metal from sticking to the guide portion.

Further, the waste melting furnace according to claim 7 is
The receptacle according to any one of claims 1 to 6, wherein the receptacle is provided in a tapping chamber, and the tapping chamber and the melting furnace are connected by bellows so as to be kept airtight. According to the configuration, for example, when harmful substances such as radioactive wastes are melted and discharged, it is possible to suppress scattering of the molten metal around the molten metal.

The present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a main part of a waste melting furnace according to the present invention, and FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 and 2, a waste melting furnace according to the present invention includes a furnace body 1 lined with a refractory 13 and a waste inlet 4 provided with the waste provided in the furnace body 1.
And a plasma torch 7 for melting the input waste,
Exhaust gas outlet 2 for exhausting exhaust gas generated during waste melting
And a tap 3 for discharging the molten metal 10 as a waste. The molten metal 10 from the tap 3 is located below the tap 3.
Receiving vessel 5 is provided with a tapping chamber 6 surrounding it.
It is installed in. A guide 14 is provided above the receiver 5 so that the molten metal from the tap hole 3 is reliably introduced into the receiver 5. And the tapping chamber 6 and the furnace body 1 do not hinder the tilting of the furnace body 1,
Moreover, the tapping chamber 6 and the furnace body 1 are connected by a bellows 8 so as to ensure airtightness.

The exhaust gas outlet 2 is provided so as to protrude substantially at the center of the furnace body 1, is provided on the opposite side of the furnace body 1, and is supported by a rotating shaft 16 having the same axial center and outer diameter. Part 1
2 by a lifting cylinder 15 which is pin-connected to the lower part of the furnace body 1 and the other is pin-connected to the floor side.
The furnace body 1 can be tilted freely.

The tap 3 is formed by tilting the furnace body 1.
It is provided so as to be located above the surface of the molten metal 10 so as to be in contact with the molten metal. The tap 3 is formed by extracting a part of the refractory 13 lined with the furnace body 1 and, at the time of tapping, at least the outlet portion 9 out of the portion that comes into contact with the molten metal 10 when the molten metal 10 is discharged. It is formed by a cooling member that can be cooled. This outlet part 9 is preferably inclined toward the receiver 5 side. By tilting, when the furnace body 1 is tilted, the outlet portion 9 faces more toward the receiver 5, and the molten metal 10 easily flows down, so that the molten metal 10 can be surely introduced into the receiver 5. In addition, if the tap hole 3 is formed toward the receiver 5, for example, it is provided at the bottom of the furnace body 1 and is closed by a lid or the like at times other than tapping. A structure in which the lid is opened to discharge the molten metal may be used.

Here, at least the outlet portion 9 of the tap 3
Alternatively, the cooling member forming the portion in contact with the molten metal 10 is preferably a high heat conductive material having a thermal conductivity of 5 W / (m · K) or more. Such high heat conductive materials include stainless steel, cast iron, cast steel, carbon steel, copper,
Any of carbon or a composite material of two or more of them can be used. By using such a high heat conductive material, when the amount of the molten metal 10 is reduced, the molten metal 1
0 is promoted, and the solidified layer of the molten metal 10 is formed thick. Therefore, by tilting the furnace body 1, the molten metal 10
The solidified layer has improved releasability and tends to flow down toward the receiver 5 by its own weight without sticking. In addition, any one of stainless steel, cast iron, cast steel, carbon steel, copper, and carbon or a composite material of two or more of these is different from a refractory and has a smooth surface. By tilting the furnace body 1, it tends to flow down due to its own weight.

FIG. 3 is a sectional view taken along the line BB of FIG. 1, that is, a plan sectional view of the tap hole 3 and FIG. 4 is a side view thereof. As shown in the figure, the outlet portion 9 forming the tap 3 preferably has a gutter-shaped cross section so that the molten metal 10 can easily flow down. Then, a cooling medium passage 2 that can cool the molten metal 10 flowing down through the tap hole 3 therein.
Preferably, 0 is formed. By forming the cooling medium passage 20 in this manner, even if the outlet portion 9 of the tap hole 3 is formed by a refractory as in the related art, the cooling of the molten metal 10 is performed when the molten metal 10 is reduced. Promote
The solidified layer of the melt 10 can be formed thick. Thereby, by inclining the furnace body 1, the solidified layer of the molten metal 10 becomes
Without sticking, due to its own weight, it easily flows down toward the receiver 5 side. Further, as described above, when this portion is formed of a high heat conductive material, the effect becomes more remarkable.

Returning to FIGS. 1 and 2, the receiver 5 for receiving the molten metal 10 from the tap 3 is provided with a guide portion 14 so that the molten metal 10 flowing down from the tap 3 can be reliably received.
Is provided. It is preferable that the guide portion 14 is constituted by a large guide 14a on the side facing the tap hole 3 and a small guide 14b on the surface facing the tap port 3, ie, the tap port 3 side. With such a configuration, the molten metal 10 can be reliably introduced into the receiver 5. Further, it is preferable that these guides 14a and 14b are inclined so that the opening thereof becomes smaller toward the receiver 5 so that the molten metal 10 flows down into the receiver 5 reliably. Further, it is preferable that the guide portion 14 is also formed of a high heat conductive material forming the outlet portion 9 of the tap hole 3. Furthermore, as shown in FIG. 5, it is preferable that it has a trough-shaped cross section like the tap hole 3. It is preferable that a passage 21 for a cooling medium such as air, which can cool the molten metal 10 flowing down the guide portion 14, is formed therein. By forming the cooling medium passage 21 in this manner, the guide portion 1 is made of a refractory material like the tap hole 3.
Even when the molten metal 4 is formed, when the amount of the molten metal 10 decreases, the cooling of the molten metal 10 can be promoted, and the solidified layer of the molten metal 10 can be formed thick. Further, since the guide portion 14 is inclined, the molten metal 10 does not adhere to itself,
It flows down into the receiver 5.

Further, the receiver 5 is preferably provided in a tapping chamber 6 whose periphery is closed. The tapping chamber 6 is connected to the furnace body 1 by a bellows 8. Thereby, airtightness is maintained, and the molten metal 10 does not scatter to the surroundings at the time of tapping. For example, when radioactive waste or the like is melted, peripheral devices and the like can be prevented from being contaminated by the molten metal 10. And the furnace body 1 can be tilted. The bellows 8 is preferably formed of a heat-resistant material, such as stainless steel or a heat insulating material.

The waste melting furnace according to the present invention is configured as described above. By using a cooling member that can cool the molten metal 10 when the molten metal 10 is discharged, the solidified layer of the molten metal 10 is thickened. The solidified layer can be formed, the releasability of the solidified layer is improved, and the outlet portion 9 of the tap hole 3 is formed to be inclined toward the receiver 5 side. Due to its own weight, it flows down to the receiver 5 side and does not adhere to the outlet portion 9 of the tap hole 3, that is, it is possible to prevent the tap hole 3 from being blocked. Hereinafter, a waste melting method and a tapping method by the waste melting furnace according to the present invention are shown in FIG.
This will be described with reference to FIGS.

First, waste such as general waste including various inorganic substances, metals and organic substances, sewage sludge, municipal waste and incinerated ash thereof, and low-level nuclear radioactive waste are discharged into the waste inlet 4. From the furnace body 1. Next, these wastes are melted by the plasma generated from the plasma arc torch 7 to become the molten metal 10. Exhaust gas generated during melting is exhausted out of the furnace from an exhaust gas outlet 2 which also serves as a rotation axis when the furnace body 1 tilts. This melt 10
Reaches an arbitrary amount, as shown in FIG. 6, the lift cylinder 15 tilts the exhaust gas outlet 2 and the rotation shaft 16 about the rotation center. At this time, since the furnace body 1 and the tapping chamber 6 are formed by the bellows 8, airtightness is maintained, and the molten metal 10 can be prevented from scattering around. The molten metal 10 flows down through the tap hole 3 toward the receiver 5 due to the tilting of the furnace body 1. On this occasion,
When the amount of hot water is large, the molten metal 10 is provided on the upper part of the receiver 5 and is provided on the side facing the outlet 3 of the guide part 14 provided so as to be inclined toward the receiver 5 side. Guide 14a and the guide 1 provided on the opposite side
4b ensures that it is introduced into the receiver 5. When the amount of the molten metal 10 decreases and the amount of the molten metal decreases, the molten metal 10 is easily solidified because the outlet portion 9 of the tap hole 3 is formed by the cooling member, and a thick solidified layer is formed at the outlet portion 9. Is done. Since the outlet portion 9 is formed to be inclined toward the receiver 5 side, the thick solidified layer is separated from the outlet portion 9 of the tap hole 3 by its own weight, and is directed toward the receiver 5. It will run down. Furthermore, if the outlet portion 9 is formed of a metal such as stainless steel, the surface is smooth,
The solidified layer is more easily peeled off, and the solidified layer of the molten metal 10 can be reliably prevented from sticking. Also, the guide section 14
Similarly, since the cooling member is formed of a high heat conductive material such as a stainless steel material, the same effect as the outlet portion 9 of the tap hole 3 can prevent the solidified layer of the molten metal 10 from sticking. As described above, since the molten metal 10 does not adhere to the outlet portion 9 of the tap hole 3, even in a batch type melting furnace, there is no blockage of the molten metal 10 in the tap hole 3 due to the solidified layer.
It is possible to perform stable tapping for a long time. In addition, in this embodiment, the case where the plasma arc is used as the heating means for melting the waste has been described, but the present invention is not particularly limited to this heating method, and includes induction heating, combustion heating, and the like. The present invention can be applied to a melting furnace using any heating method. In addition, as a method of disposing of the molten metal 10, not only the method using the receiver 5 as in the present embodiment but also a commonly used disposal method such as disposal in a water tank or the like can be applied.

[0024]

The waste melting furnace according to the present invention is configured as described above. According to the first aspect of the present invention, at least the outlet of the tap hole is formed by a cooling member.
The thickness of the solidified layer formed when the amount of the molten metal discharged decreases. At this time, since the tap hole is formed toward the receiver located below the melting furnace, the solidified molten metal is separated from the tap port by its own weight without being fixed to the tap port and receiving the melt. Since it flows down toward the container and the blockage of the tap hole can be suppressed, there is no need to heat the tap hole area or the like, it is not necessary to use extra energy, and the structure of the furnace is not complicated,
It is possible to obtain an effect that it is economical, for example, the production cost can be reduced, and that the stable tapping can be maintained for a long period of time.

According to the second aspect of the present invention, by inclining the melting furnace, the molten metal can be reliably discharged toward the receiver, and the solidified molten metal is separated by its own weight and removed. The effect that can be obtained can be obtained.

Further, according to the third aspect of the present invention, since the tap hole is formed of a high heat conductive material having a thermal conductivity of 5 W / (m · K) or more, the heat radiation of the molten metal at the outlet of the tap hole is enhanced. At the same time, the molten metal can be cooled, the solidified layer formed can be thickened, and the solidified molten metal can be separated and removed by its own weight, thereby obtaining an effect of suppressing blockage of the tap hole.

According to the fourth aspect of the present invention, any one of stainless steel, cast iron, cast steel, carbon steel, copper, and carbon, or a composite material of two or more of these materials is used, so that the thermal conductivity of the tap hole can be improved. Rate can be increased, and its surface can be made smooth unlike a taphole made of a conventional refractory, thereby improving the releasability of the molten metal and suppressing the blockage of the taphole by the molten metal. it can.

According to the fifth aspect of the present invention, by providing a cooling medium passage inside the tap hole, the molten metal can be further cooled at the tap hole, and thereby the solidified layer of the molten metal can be thickened. Since the releasability of the solidified layer is improved, it is possible to obtain an effect of more reliably suppressing the blockage of the tap hole at the time of tapping.

According to the sixth aspect of the present invention, since the guide portion is provided from the tap hole toward the receiver, the molten metal from the tap hole can be reliably put into the receiver, and the guide portion can be provided. Is formed of a cooling member in the same manner as the outlet portion of the tap hole, whereby an effect of preventing the molten metal from sticking to the guide portion can be obtained.

According to the invention of claim 7, for example,
When harmful substances such as radioactive wastes are melted and discharged, molten metal can be prevented from scattering around the molten metal, and an effect of preventing contamination of peripheral equipment and the like by radioactive substances can be obtained.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing one embodiment of a waste melting furnace according to the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a sectional view taken along line BB in FIG.

FIG. 4 is a front view showing a tap hole exit portion.

FIG. 5 is a perspective view showing a guide unit.

FIG. 6 is a cross-sectional view showing one embodiment of a waste melting furnace according to the present invention at the time of tapping.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Furnace body 2 Exhaust gas outlet 3 Outlet 4 Waste input port 5 Receptor 6 Outlet chamber 7 Plasma torch 8 Bellows 9 Outlet outlet 10 Melt 12 Support part 13 Refractory 14 Guide part 15 Cylinder for raising and lowering 16 Rotating shaft 20 Cooling medium Passage 21 Cooling medium passage

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F27B 3/19 F27B 3/19 3/24 3/24 F27D 3/14 F27D 3/14 Z 9/00 9/00 F Term (reference) 3K061 AA18 AA23 AB03 AC01 AC02 AC03 AC09 BA07 CA13 CA14 CA15 DA13 DB12 DB19 DB20 NB02 NB13 NB16 NB17 NB27 NB28 NC02 4K045 AA03 BA10 CA08 RA09 RB05 RB08 RB11 RC18 4K055 JA17 JA19 4K06 A17

Claims (7)

[Claims] 1. A waste melting furnace comprising: a waste input port for inputting waste; an exhaust gas outlet; and a tap hole, and after melting the waste, discharges molten metal from the tap port as appropriate. A tap hole is formed so that, at the time of tapping, the molten metal can be discharged toward a receiver located below the melting furnace, and at least an outlet portion of the tap hole cools the molten metal when the molten metal is discharged. Waste melting furnace formed with cooling members that can be. 2. By tilting the melting furnace,
The waste melting furnace according to claim 1, wherein the molten metal is poured from the tap at the time of tapping. 3. The cooling member has a thermal conductivity of 5 W / (m
The waste melting furnace according to claim 1, wherein the waste melting furnace is a highly heat-conductive material that is not less than K). 4. The high heat conductive material is a stainless steel material,
The waste melting furnace according to claim 3, wherein the waste melting furnace is any one of cast iron, cast steel, carbon steel, copper, and carbon, or a composite material of two or more of them. 5. The waste melting furnace according to claim 1, wherein the cooling member is provided with a flow path for a cooling medium. 6. The disposal according to claim 1, wherein a guide portion for guiding the molten metal from the tap hole toward the receiver is provided, and the guide portion is formed by the cooling member. Material melting furnace. 7. The receiver according to claim 1, wherein the receiver is provided in a tapping chamber, and the tapping chamber and the melting furnace are connected by bellows so as to be kept airtight.
A waste melting furnace according to any one of the above.