JPH1010293A - Melting furnace and method of supplying raw materials to melting furnace - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the occurrence of damage to a raw material supply pipe and the like constituting a supply, improve the solubility of a tangible solid raw material,
To supply a tangible solid raw material to a molten metal phase smoothly and efficiently. SOLUTION: A molten metal tank for forming a molten metal phase therein, and a tangible solid raw material which is arranged in a state of being connected to the molten metal phase of the molten metal tank and in an isolated state on a side portion of the molten metal tank is supplied. And a material supply means for removing the molten metal, a molten metal outlet for extracting the molten metal, and a slag outlet for extracting the slag.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melting furnace and a method for supplying a raw material to a melting furnace, and more particularly to a technique suitable for long-term stable supply of tangible solid raw material such as miscellaneous solid waste. .

[0002]

2. Description of the Related Art For tangible solid raw materials such as high-level radioactive liquid waste, solid waste contaminated with radioactive materials, and miscellaneous solid waste, the volume of the material is reduced by decomposition, stabilization, etc. for storage and transportation. Those that are subjected to treatment and need to be isolated from the living sphere, such as radioactive substances, are sealed in a storage container as necessary.

[0003] When the tangible solid raw material is the above-mentioned waste liquid or radioactive solid waste, for example, the raw material is sent to a melting furnace together with the glass raw material to dissolve the radioactive substance into the molten glass,
This is vitrified. As such a technique, for example, a glass melting furnace disclosed in JP-A-4-161896 and JP-A-4-169797 has been proposed.

[0004] When the tangible solid raw material contains a large amount of air like a porous material and has a large apparent volume, it is difficult to sufficiently reduce the volume of compression.
It is effective to perform the decomposition treatment using a melting furnace.
Related technologies in such a case include, for example,
No. 035899 has been proposed, applying the technology of the glass melting furnace, the tangible solid material is put into the glass melting furnace together with the molten glass, and when the tangible solid material contains glass fiber or silica gel, the glass is melted. They are trying to reduce the volume by using it as part of the solidified material.

[0005] Further, as another technique utilizing a melting furnace,
As shown in FIG. 3, a molten metal tank 2 is formed below the melting tank 1, and a raw material supply pipe 3 is attached to a ceiling portion 1 a of the molten tank 1 in a suspended state, and the raw material supply pipe 3 is Then, it is considered that the tangible solid raw material is supplied so as to be directly dropped into the molten metal phase M of the molten metal tank 2. With this technology, the processing efficiency is improved when metals such as iron are contained in the tangible solid raw material, and even when the types and amounts of the elements included in miscellaneous solid waste and the like vary widely, It is expected that the dissolution treatment can be performed relatively smoothly.

[0006]

However, the raw material supply pipe 3
Is set so as to be immersed in the molten metal phase M, the frequency of replacement of the raw material supply pipe 3 increases based on the fact that the raw material supply pipe 3 becomes severely damaged. When the tangible solid raw material is dropped using natural gravity, the tangible solid raw material can be easily supplied. However, the slag phase S is formed on the molten metal phase M based on the specific gravity difference. for,
The melting efficiency at the surface layer inside the melting tank 1 decreases, and in addition, the boundary between the slag phase S and the molten metal phase M moves depending on the amount of the tangible solid material dissolved and the metal content. Fluctuates and stable operation tends to be difficult.

The present invention aims to solve the above problems and achieve the following objects. To reduce the occurrence of damage to the raw material supply pipes and the like that constitute the supply. To improve the solubility by preheating the tangible solid raw material in the middle of the supply path. To supply the tangible solid raw material to the molten metal phase at the bottom of the melting furnace smoothly and efficiently.

[0008]

SUMMARY OF THE INVENTION In a melting furnace for forming a molten metal phase at the bottom and introducing a tangible solid raw material into the molten metal phase and guiding it to a molten state, a molten metal for forming a molten metal phase therein is formed. A tank, raw material supply means connected to the molten metal phase of the molten metal tank and separated from the side of the molten metal tank to supply a tangible solid raw material; A technique including an outlet and a slag outlet for removing slag is employed. In the raw material supply means, a raw material supply port, a raw material supply pipe for dropping the tangible solid raw material supplied from the raw material supply port,
A throat portion disposed between the lower part of the raw material supply pipe and the molten metal phase of the molten metal tank and connected to the tangible solid raw material in a molten state; The throat section is provided with a raw material heating section for heating the metal interposed therein, and as the raw material heating section, an induction heating coil is disposed and discharged from the melting tank around the raw material supply pipe and the throat section. A preheating chamber for exchanging heat with the off-gas to be provided is provided. The tangible solid raw material such as metal, concrete and plastic fragments is directly supplied from the raw material supply pipe of the raw material supply means to the molten metal phase of the molten metal tank through the throat portion on the side of the molten metal tank to be in a molten state. Be guided. When the amount of molten metal in the throat increases, the molten metal is extruded into the molten metal phase of the molten metal tank and fed into the molten metal phase. It is extracted outside from the outlet and processed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a melting furnace and a method for supplying raw materials to the melting furnace according to the present invention will be described below with reference to FIGS. 1 and 2, reference numeral 10 denotes a raw material supply unit, 20 denotes a furnace main body, and 30 denotes a melt discharge unit.

The raw material supply means 10 is arranged so as to be connected to the molten metal phase M of the melting tank 1 and is separately provided on the side of the melting tank 1 in an isolated state to form a tangible solid. A raw material supply system 11 for supplying a raw material, a raw material supply port 12 for connecting the raw material supply system 11, and a raw material supply pipe extending downward to be connected to the raw material supply port 12 and for dropping a tangible solid raw material 3, a supply cavity 13 formed inside or connected to the raw material supply pipe 3, and between the lower part of the supply cavity 13 (lower part of the raw material supply pipe 3) and the molten metal phase M in the melting tank 1. Throat portion 14 arranged to connect the tangible solid raw material to a molten state.
And

The throat section 14 is provided with a raw material heating section 15 for forming a metal phase therein. The raw material heating section 15 heats the metal phase inside the throat section 14 to a molten state, and includes an induction heating coil 15a for performing direct heating by induction heating, a raw material supply pipe 3 and a throat. A preheating chamber 16 formed in a state surrounding the periphery of the section 14 for exchanging heat with the high-temperature off-gas discharged from the melting tank 1;
An off-gas outlet 17 for discharging the heat-exchanged off-gas through the outside to the outside, and an off-gas processing system 18 connected to the off-gas outlet 17 for processing the off-gas.

In the furnace main body 20, a melting tank 1 set at an upper position and a molten metal stored in a lower part of the melting tank 1 in a connected state based on a difference in specific gravity to store a molten metal phase M
And a furnace body chamber 2 so as to surround the melting vessel 1 and the molten metal vessel 2.
1 is disposed on a ceiling portion 1a of the furnace body chamber 21.
An auxiliary heating means attachment port 22 for attaching a heating means such as a plasma torch, and a viewing window 23 for monitoring the internal state of the melting tank 1 are provided. A reaction gas supply system 24 for feeding a hydrogen-based reaction gas or nitrogen gas;
And a reactive gas supply port 25 for connecting the molten metal phase M inside the molten metal tank 2 to the molten metal phase M.

An induction heating coil 26 is provided around the partition wall of the melting tank 1 to bring the internal metal component into a high temperature state by induction heating when electricity is supplied. Between the phase G) and the supply cavity 13 in the raw material supply pipe 3, a connection port 27 for connecting them is provided.

In the melt discharge means 30, the molten metal discharge which is horizontally connected to the vicinity of the boundary between the molten metal phase M and the slag phase S in the molten tank 1 and the molten metal tank 2 is described. The tank 31 and the slag removal tank 32 are
3 are arranged in a partitioned state. The height of the partition wall 33 suppresses the flow of the molten metal phase M to the slag removal tank 32, and the slag phase S having a smaller specific gravity than the
It is set so as to be able to get over the slag removal tank 32 over the slag removal tank 3.

An auxiliary heating means attaching port 34 for attaching a heating means such as a plasma torch and the like to monitor the internal state of the molten metal extracting tank 31 and the slag extracting tank 32 are also provided on the ceiling portion of the melt extracting means 30. A viewing window 35 is provided.

A molten metal processing system 37 for performing processing such as solidifying and storing the molten metal in a state of being connected to a molten metal outlet 36 for extracting the molten metal phase M is provided below the molten metal extracting tank 31. In addition, a slag processing system 39 for performing processing such as solidifying and storing the slag is connected to a slag outlet 38 for taking out the slag phase S.

A technique for supplying a raw material to a melting furnace and a technique for extracting a molten metal will be described below.

A tangible solid material such as metal, concrete or plastic fragments is supplied to a material supply system 1 of a material supply means 10.
From 1, the raw material is supplied to the throat section 14 via the raw material supply port 12, the raw material supply pipe 3, and the supply cavity 13. At this time, when the melting furnace is in an operating state, the molten metal phase M and the slag phase S
Is formed, and a part of the molten metal enters the inside of the throat portion 14 due to the siphon phenomenon. Therefore, the tangible solid raw material is directly supplied to the molten metal phase M inside the throat portion 14 and is led to a molten state.

The throat section 14 has conditions for preheating and auxiliary heating by the raw material heating section 15, and in a normal state, the raw material supply pipe 3 and the throat section 14 use the exhaust heat of the off gas. Preheated. When it is desired to increase the internal temperature of the throat section 14 for the purpose of accelerating the dissolution of the metal in the tangible solid raw material, the induction heating coil 15a is energized, and the metal component or the molten metal inside the throat section 14 is supplied. The phase M may be forcibly heated to form a high-temperature molten metal phase M.

When the amount of the molten metal in the throat section 14 increases, the molten metal is sent to the molten metal phase M of the molten metal tank 2 so as to be extruded and merged.
The pyrolysis gas generated in the step (1) is sent to the portion of the gas phase G of the melting tank 1 via the connection port 27, and is transferred from the off gas discharge port 17 to an external off gas processing system 18 as an off gas for processing.

The molten metal phase M in the molten metal tank 2 is accumulated in the molten metal extraction tank 31 of the melt extraction means 30 based on the difference in specific gravity, and the gas is supplied from the reaction gas supply system 24 as appropriate. With the supply of iron, the iron component in the molten metal is reduced to enhance the ability to take in other metal components, and the components are homogenized in combination with the stirring effect of gas blowing. These molten metals are drawn into the molten metal processing system 37 via the molten metal outlet 36, and are sealed in a storage container in a solidified state.

In the slag phase S inside the melting tank 1,
On the basis of the specific gravity difference, the slag removal tank 3 is moved beyond the partition wall 33.
And accumulated in the slag outlet 38 as appropriate.
And is taken by the slag processing system 39 and processed.

[0023]

As described above, according to the melting furnace and the method for supplying raw materials to the melting furnace according to the present invention, the following effects are obtained. (1) A molten metal tank for forming a molten metal phase inside, a raw material supply means connected to the molten metal phase of the molten metal tank and separated from a side of the molten metal tank, By adopting a technology having a molten metal outlet for extracting metal and a slag outlet for extracting slag, the need to immerse the raw material supply pipe in the molten metal phase is eliminated, and Damage can be significantly reduced, and the life of the equipment can be extended. (2) The tangible solid raw material is not introduced into the surface layer inside the melting tank, so that the melting efficiency is prevented from lowering. In addition, the stable operation can be performed with the operating conditions of the melting furnace kept constant. (3) By disposing the raw material heating section in the throat section or the preheating chamber to perform preheating, the solubility of the tangible solid raw material in the middle of the supply path can be improved, and the efficiency of the melting furnace can be improved. (4) By connecting the molten metal phase between the throat portion and the bottom of the molten metal tank, it is possible to smoothly and efficiently supply the tangible solid raw material to the molten metal phase.

[Brief description of the drawings]

FIG. 1 is a perspective view together with a block diagram illustrating an embodiment of a melting furnace and a method of supplying raw materials to the melting furnace according to the present invention.

FIG. 2 is a front sectional view showing one embodiment of a melting furnace and a method of supplying raw materials to the melting furnace according to the present invention.

FIG. 3 is a front sectional view showing a model of a conventional melting furnace.

[Explanation of symbols]

 M molten metal phase S slag phase G gas phase 1 melting tank 2 molten metal tank 3 raw material supply pipe 10 raw material supply means 12 raw material supply port 13 supply cavity 14 throat section 15 raw material heating section 15a induction heating coil 20 furnace body section 24 reaction gas Supply system 25 Reaction gas supply port 26 Induction heating coil 27 Connection port 30 Melt removal means 31 Molten metal removal tank 32 Slag removal tank 33 Partition wall 36 Molten metal removal port 38 Slag removal port

Claims (4)

[Claims] 1. A melting furnace for forming a molten metal phase (M) at the bottom and introducing a tangible solid raw material into the molten metal phase to guide the molten metal phase into a molten state. A metal tank (2), raw material supply means (10) connected to the molten metal phase of the molten metal tank and separated from a side of the molten metal tank to supply a tangible solid raw material; A melting furnace comprising: a molten metal outlet (36) for extracting slag; and a slag outlet (38) for extracting slag. 2. A raw material supply means (10) comprising: a raw material supply port (12); a raw material supply pipe (3) for dropping a tangible solid raw material supplied from the raw material supply port; and a lower part of the raw material supply pipe. 2. The molten metal according to claim 1, further comprising a throat section (14) arranged between the molten metal phase (M) of the molten metal tank (2) and connected to the molten metal phase (M) to guide the tangible solid raw material into a molten state. Furnace. 3. A raw material heating section (1) is provided in a throat section (14).
5) is arranged, and the raw material heating unit is provided with an induction heating coil (15).
3. The melting furnace according to claim 2, comprising a). 4. A raw material supply method applied to a melting furnace for forming a molten metal phase (M) at the bottom of a molten metal tank (2) and for introducing a tangible solid raw material into the molten metal phase and leading it to a molten state. Then, the tangible solid raw material is supplied to the raw material supply means (10).
Wherein the raw material is supplied directly from the raw material supply pipe (3) to the molten metal phase through a throat (14) on the side of the molten metal tank.