JPH09229559A - Electrical melting furnace - Google Patents
Electrical melting furnaceInfo
- Publication number
- JPH09229559A JPH09229559A JP8035304A JP3530496A JPH09229559A JP H09229559 A JPH09229559 A JP H09229559A JP 8035304 A JP8035304 A JP 8035304A JP 3530496 A JP3530496 A JP 3530496A JP H09229559 A JPH09229559 A JP H09229559A
- Authority
- JP
- Japan
- Prior art keywords
- furnace
- material layer
- molten metal
- refractory material
- conductive
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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- Gasification And Melting Of Waste (AREA)
- Processing Of Solid Wastes (AREA)
- Vertical, Hearth, Or Arc Furnaces (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】都市ごみや産業廃棄物は、焼
却処理によって無害化及び減容化した上、その焼却残滓
を埋立投棄することにより処理されているが、焼却残滓
や燃焼排ガスから集塵，除去された煤塵等には、重金属
やダイオキシン等の有害物質が含まれているため、埋立
投棄後に環境汚染を生じる虞れがある上、埋立地の確保
も困難になりつつあり、実務上様々な問題を生じてい
る。そこで、近時においては、焼却残滓や煤塵等を溶融
固化することにより、その無害化と一層の減容化を図る
方策が取られている。本発明は、このような焼却残滓や
煤塵等を溶融処理するためのアーク炉等の電気溶融炉に
関するものである。BACKGROUND OF THE INVENTION Municipal solid waste and industrial waste are detoxified and reduced in volume by incineration, and the incineration residue is disposed of by landfill. However, dust is collected from the incineration residue and combustion exhaust gas. ， Since the soot and dust that have been removed contain harmful substances such as heavy metals and dioxins, there is a risk that environmental pollution will occur after landfill disposal, and securing landfill sites is becoming difficult. Is causing problems. Therefore, in recent years, measures have been taken to make the incineration residue, soot dust, etc., harmless and further reduce their volume by melting and solidifying them. The present invention relates to an electric melting furnace such as an arc furnace for melting such incineration residue and soot dust.
【０００２】[0002]
【従来の技術】従来のこの種の電気溶融炉においては、
一般に、図３又は図４に示す如く、炉の天井壁２１に貫
通支持させた主電極２３と炉の底壁２２ａ，２２ｂに設
けた炉底電極２５ａ，２５ｂとの間で溶湯２４を介して
アークを発生させることによって、焼却残滓や燃焼排ガ
スから集塵，除去された煤塵等の被溶融物を溶融処理す
るように構成されている。2. Description of the Related Art In a conventional electric melting furnace of this type,
Generally, as shown in FIG. 3 or 4, a molten metal 24 is interposed between a main electrode 23 penetratingly supported by a furnace ceiling wall 21 and furnace bottom electrodes 25a, 25b provided on furnace bottom walls 22a, 22b. By generating an arc, it is configured to melt and process a substance to be melted such as dust collected and removed from incineration residues and combustion exhaust gas.
【０００３】而して、図３に示す第１従来炉では、炉底
電極２５ａが非導電性耐火材で構成される底壁２２ａに
貫通保持させた金属製のピンや丸棒等で構成されてお
り、図４に示す第２従来炉では、炉底電極２５ｂが底壁
２２ｂで構成されている。すなわち、図４に示す如く、
底壁２２ｂを集電板２６と導電性耐火材層２７と耐食性
耐火材層２８とからなる３層構造となすと共に、耐食性
耐火材層２８にこれを貫通して導電性耐火材層２７に接
触する多数の導電部材（金属製のピンや丸棒等からな
る）２９…を埋設して、これらが全体として炉底電極２
５ｂを構成するように工夫してある。Thus, in the first conventional furnace shown in FIG. 3, the furnace bottom electrode 25a is composed of a metal pin, a round bar or the like held through the bottom wall 22a made of a non-conductive refractory material. In the second conventional furnace shown in FIG. 4, the furnace bottom electrode 25b is composed of the bottom wall 22b. That is, as shown in FIG.
The bottom wall 22b has a three-layer structure including a current collector plate 26, a conductive refractory material layer 27 and a corrosion resistant refractory material layer 28, and penetrates the corrosion resistant refractory material layer 28 to contact the conductive refractory material layer 27. A large number of conductive members (made of metal pins, round bars, etc.) 29 ...
It is devised so as to form 5b.
【０００４】[0004]
【発明が解決しようとする課題】ところで、廃棄灰を溶
融して得られる溶湯２４は、ＳｉＯ2 ，Ａｌ2 Ｏ3 ，Ｃ
ａＯ，Ｆｅ2 Ｏ3 等のスラグ成分を含む他、Ｎａ，Ｋ，
Ｃａ，Ｃｌ，ＳＯ4 ，ＣＯ3 等の塩成分やＰｂ，Ｚｎ，
Ｃｄ，Ｈｇ等の重金属等を含んでおり、極めて強い侵食
性を有する。The molten metal 24 obtained by melting waste ash is SiO 2 , Al 2 O 3 , C.
In addition to containing slag components such as aO and Fe 2 O 3 , Na, K,
Ca, Cl, SO 4 , CO 3 and other salt components, Pb, Zn,
It contains heavy metals such as Cd and Hg and has extremely strong erosion.
【０００５】したがって、第１従来炉では、炉底電極２
５ａが、溶湯２４に接触する耐火材層２２ａに、その表
面に露出する状態で貫通されているため、両者２２ａ，
２５ａ間の隙間から溶湯２４（特に、溶湯２４に含まれ
るＰｂ等の低粘性低融点金属）が滲入する虞れがあり、
電極２５ａ及び耐火材層２２ａを侵食，損傷させたり、
極端な場合には、炉底２２ａからの脱湯や電極２５ａの
脱落を生じる虞れがある。さらに、非導電性耐火材層２
２ａにひびがはいると、これに溶湯２４中の導電性金属
が侵入して、電極２５ａとの間に絶縁不良を生じる等、
炉運転上からも種々の問題が生じる。Therefore, in the first conventional furnace, the bottom electrode 2
5a is penetrated by the refractory material layer 22a which is in contact with the molten metal 24 in a state of being exposed on the surface thereof.
There is a risk that the molten metal 24 (particularly, a low-viscosity low-melting point metal such as Pb contained in the molten metal 24) may infiltrate through the gap between the 25a,
Erodes and damages the electrode 25a and the refractory layer 22a,
In an extreme case, there is a possibility that hot water may be removed from the furnace bottom 22a or the electrode 25a may be removed. Furthermore, the non-conductive refractory material layer 2
If 2a is cracked, the conductive metal in the molten metal 24 will penetrate into it and cause insulation failure with the electrode 25a.
Various problems also occur in the operation of the furnace.
【０００６】一方、第２従来炉では、溶湯２４に直接接
触する底壁上面部分２８を耐食性耐火材で構成している
ことから、溶湯２４による底壁侵食を防止でき、底壁全
体を電極２５ｂに構成していることとも相俟って、上記
した問題を生じない。しかし、導電性に優れた耐火材は
同時に熱伝導率の高いものでもあることから、底壁２２
ｂを熱伝導率の高い導電性耐火材層２７を含む積層構造
としている以上、どうしても底壁２２ｂからの放熱量が
多くなり、炉の熱効率が頗る悪くなる。また、底壁２２
ｂ上に沈降する溶融金属が、底壁２２ｂからの放熱によ
る冷却効果により、固化する虞れがある。勿論、第１従
来炉と同様に、耐火材以外の異物である導電部材２９…
が、溶湯２４が接触する耐火材層２８に、その表面に露
出した状態で埋設されているから、溶湯２４が滲入して
炉材２８や導電部材２９…を損傷させる虞れがある。On the other hand, in the second conventional furnace, since the bottom wall upper surface portion 28 which is in direct contact with the molten metal 24 is made of the corrosion resistant refractory material, the corrosion of the bottom wall by the molten metal 24 can be prevented and the entire bottom wall is covered with the electrode 25b. In combination with the configuration, the above problems do not occur. However, since the refractory material having excellent conductivity is also one having high thermal conductivity, the bottom wall 22
As long as b has a laminated structure including the conductive refractory material layer 27 having a high thermal conductivity, the amount of heat radiated from the bottom wall 22b inevitably increases, and the thermal efficiency of the furnace becomes extremely poor. Also, the bottom wall 22
The molten metal settled on b may be solidified due to the cooling effect of heat radiation from the bottom wall 22b. Of course, similar to the first conventional furnace, the conductive member 29, which is a foreign substance other than the refractory material, ...
However, since it is buried in the refractory material layer 28 with which the molten metal 24 is in contact with the refractory material layer 28 exposed on the surface thereof, the molten metal 24 may infiltrate and damage the furnace material 28 and the conductive members 29.
【０００７】本発明は、上記した問題をすべて解決し
て、長期に亘って良好な溶融処理を行いうる電気溶融炉
を提供することを目的とする。An object of the present invention is to provide an electric melting furnace which solves all the above-mentioned problems and can perform a good melting process for a long period of time.
【０００８】[0008]
【課題を解決するための手段】本発明の電気溶融炉にあ
っては、上記の目的を達成すべく、特に、炉の底壁全体
を、集電板上に形成した断熱材層と、断熱材層上に形成
された、導電性及び溶湯に対する耐侵食性に優れた導電
性耐火材層と、断熱材層に埋設されて、導電性耐火材層
と集電板とを通電可能に接続する金属製の導電体と、か
らなる炉底電極に構成しておくことを提案する。In the electric melting furnace of the present invention, in order to achieve the above-mentioned object, in particular, the entire bottom wall of the furnace is provided with a heat insulating material layer formed on a current collector and a heat insulating material. A conductive refractory layer formed on the material layer and having excellent conductivity and corrosion resistance against molten metal, and a conductive refractory layer embedded in the heat insulating material layer and electrically connected to the current collector plate It is proposed that the furnace bottom electrode is composed of a metal conductor.
【０００９】而して、炉底電極の上面部分は、侵食性の
強い高温の溶湯と接触するものの、耐侵食性に優れた導
電性耐火材層で構成されており、しかも導電性耐火材層
には第１及び第２従来炉における如き耐火材以外の異物
やこれを保持しておくための穴が全く存在しないことか
ら、溶湯中の低粘性で低融点の溶融金属が滲入するよう
なことがなく、炉底電極ないし底壁が溶湯滲入により侵
食，損傷される等の問題は生じない。Although the upper surface of the furnace bottom electrode is in contact with the high-temperature molten metal having strong erosion resistance, it is formed of a conductive refractory material layer excellent in erosion resistance, and further, the conductive refractory material layer. Since there are no foreign matters other than refractory materials and holes for holding them, as in the first and second conventional furnaces, the molten metal of low viscosity and low melting point in the molten metal may infiltrate. Therefore, there is no problem that the bottom electrode or bottom wall is eroded or damaged by the infiltration of the molten metal.
【００１０】しかも、炉底電極を構成する底壁が上下２
層構造をなし、その上層部分は熱伝導性の高い導電性耐
火材層で構成されているものの、その下層部分は断熱材
層で構成されていることから、底壁全体としての放熱
は、これを必要以上に厚くせずとも、効果的に抑制され
ることなる。In addition, the bottom wall constituting the furnace bottom electrode has two upper and lower walls.
Although it has a layered structure, the upper part of which is composed of a conductive refractory layer having high thermal conductivity, but the lower part of which is composed of a heat insulating material layer, the heat dissipation of the entire bottom wall is Even if it is not made thicker than necessary, it will be effectively suppressed.
【００１１】[0011]
【発明の実施の形態】以下、本発明の実施の形態を図１
及び図２に基づいて具体的に説明する。FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be specifically described with reference to FIG.
【００１２】図１に示す電気溶融炉である直流アーク炉
１において、２は炉壁、３は主電極、４はスタート電
極、５は炉底電極である。In a DC arc furnace 1 which is an electric melting furnace shown in FIG. 1, 2 is a furnace wall, 3 is a main electrode, 4 is a start electrode, and 5 is a furnace bottom electrode.
【００１３】炉壁２は、図１に示す如く、円筒状の周壁
６と天井壁７と後述する如く炉底電極に構成された底壁
５とからなる。周壁６には、焼却残滓等の被溶融物８ａ
の供給口９と、炉１の直径方向において被溶融物供給口
９と直対向する位置に位置する溶湯８の排出口１０と、
底壁５の上面近傍位に位置するタップホール１１と、が
穿設されている。供給口９は被溶融物８ａの供給源（図
示せず）に接続されていて、被溶融物８ａを適宜の定量
供給装置１２により炉１内に定量的に連続供給させうる
ようになっている。排出口１０は、炉１内の溶湯８を溢
流排出させると共に炉１内の排ガス８ｂを排出させるた
めのもので、水砕スラグ生成用冷却水槽等のスラグ処理
系１３ａ及び二次燃焼室等の排ガス処理系１３ｂに接続
されている。タップホール１１は、必要に応じて、底壁
５上に沈降する溶融金属を取り出すべく開口できるよう
になっている。すなわち、炉１内での溶融処理の進行に
伴い溶湯８は比重差により上下２層に分離される（比重
の軽いスラグ層と比重の重い溶融金属層とに分離され
る）が、タップホール１１を開口させることにより、溶
融金属のみを取り出しうるようになっている。なお、周
壁６及び天井壁７は、溶湯８に対する耐食性，耐熱性，
断熱性に優れた非導電性の耐火材で構成されている。As shown in FIG. 1, the furnace wall 2 is composed of a cylindrical peripheral wall 6, a ceiling wall 7 and a bottom wall 5 which constitutes a furnace bottom electrode as described later. The peripheral wall 6 has a melted material 8a such as incineration residue.
Supply port 9 of the molten metal 8 and a discharge port 10 of the molten metal 8 located directly opposite the melted material supply port 9 in the diameter direction of the furnace 1.
A tap hole 11 located near the upper surface of the bottom wall 5 is provided. The supply port 9 is connected to a supply source (not shown) of the material to be melted 8a so that the material to be melted 8a can be quantitatively continuously supplied into the furnace 1 by an appropriate quantitative supply device 12. . The discharge port 10 is for discharging the molten metal 8 in the furnace 1 to overflow and discharging the exhaust gas 8b in the furnace 1. The discharge port 10 is a slag processing system 13a such as a cooling water tank for producing water granulated slag and a secondary combustion chamber. Is connected to the exhaust gas treatment system 13b. The tap hole 11 can be opened to take out the molten metal settling on the bottom wall 5 as needed. That is, as the melting process proceeds in the furnace 1, the molten metal 8 is separated into upper and lower layers due to the difference in specific gravity (separated into a slag layer having a low specific gravity and a molten metal layer having a high specific gravity), but the tap hole 11 By opening the hole, only the molten metal can be taken out. The peripheral wall 6 and the ceiling wall 7 have corrosion resistance, heat resistance, and
It is composed of non-conductive refractory material with excellent heat insulation.
【００１４】主電極３は、図１に示す如く、炉１の中心
部に配して天井壁７に貫通支持されている。この主電極
３は、従来炉におけると同様に、炉１内の液位（溶湯８
の液面位置）に応じて昇降操作されるようになってい
る。なお、主電極３は、直流電源（図示せず）の陰極に
接続されている。As shown in FIG. 1, the main electrode 3 is disposed at the center of the furnace 1 and is supported by the ceiling wall 7 so as to penetrate therethrough. This main electrode 3 has a liquid level (molten metal 8) in the furnace 1 as in the conventional furnace.
The liquid level position of (1) is raised and lowered. The main electrode 3 is connected to the cathode of a DC power supply (not shown).
【００１５】スタート電極４は、図１に示す如く、天井
壁７に傾斜状に貫通支持されており、先端部を炉１内に
突出させない待機位置（図１実線位置）と先端部を主電
極３の先端部に近接させた状態で炉１内に垂下突出する
スタート位置（図１鎖線位置）とに亘って昇降操作され
るようになっている。なお、スタート電極４は、前記直
流電源の陽極に接続されている。また、主電極３及びス
タート電極４は中空軸状のものとされていて、その中空
部から窒素ガスを供給して、炉１内を還元雰囲気に保持
するように工夫されている。As shown in FIG. 1, the start electrode 4 is supported through the ceiling wall 7 in an inclined manner, and has a standby position (solid line position in FIG. 1) where the tip portion does not project into the furnace 1 and the tip portion is the main electrode. 3 is moved up and down to a start position (indicated by a chain line in FIG. 1) protruding downward into the furnace 1 in a state of being brought close to the tip end portion of 3. The start electrode 4 is connected to the anode of the DC power supply. Further, the main electrode 3 and the start electrode 4 are hollow shaft-shaped, and are devised so that nitrogen gas is supplied from the hollow portion to maintain the furnace 1 in a reducing atmosphere.
【００１６】炉底電極５は、図１に示す如く、炉１の底
壁全体で構成されており、集電板１５上に形成した断熱
材層１６と、断熱材層１６上に形成された導電性耐火材
１７と、断熱材層１６に埋設された導電体１８とからな
る。As shown in FIG. 1, the furnace bottom electrode 5 is composed of the entire bottom wall of the furnace 1, and is formed on the heat insulating material layer 16 formed on the current collector plate 15 and the heat insulating material layer 16. It is composed of a conductive refractory material 17 and a conductor 18 embedded in the heat insulating material layer 16.
【００１７】集電板１５は、図１に示す如く、炉壁２の
下面部に設けられた金属円板であり、前記直流電源の陽
極に接続されている。As shown in FIG. 1, the collector plate 15 is a metal disk provided on the lower surface of the furnace wall 2 and is connected to the anode of the DC power source.
【００１８】断熱材層１６は、断熱性に優れた耐火材で
構成されている。一般には、例えばハイアルミナ系の耐
火材で構成しておくことが好ましい。The heat insulating material layer 16 is made of a refractory material having excellent heat insulating properties. Generally, it is preferable to use, for example, a high alumina refractory material.
【００１９】導電性耐火材層１７は、導電性及び溶湯８
に対する耐侵食性に優れた耐火材で構成されている。特
に、耐侵食性については、溶湯８つまり被溶融物８ａの
性状を考慮することが必要である。導電性耐火材層１７
の構成材としては、このような導電性及び耐侵食性に優
れたものであれば、これを任意に選定することができる
が、一般には、カーボン系耐火材（カーボン煉瓦，カー
ボンペースト）を使用することが好ましい。The conductive refractory material layer 17 is made of conductive material and molten metal 8
It is composed of a refractory material with excellent erosion resistance to. In particular, regarding the erosion resistance, it is necessary to consider the properties of the molten metal 8, that is, the material to be melted 8a. Conductive refractory material layer 17
As a constituent material of the above, any material having excellent conductivity and erosion resistance can be arbitrarily selected, but generally, a carbon-based refractory material (carbon brick, carbon paste) is used. Preferably.
【００２０】導電体１８は、図１に示す如く、断熱材層
１６に埋設されていて、集電板１５と導電性耐火材層１
７とを通電可能に接続する金属体である。具体的には、
導電体１８は、図１及び図２（Ａ）に示す如く、複数の
金属製（例えば鉄製）のコ字形部材１８1 …を並列状に
連結してなり、該部材１８1 …の上下片で構成される一
連の上下面部１８ａ，１８ｂが導電性耐火材層１７の下
面及び集電板１５の上面に全面的ないし略全面的に接触
されている。なお、導電体１８の構成は任意であり、上
記したものの他、図２（Ｂ）〜（Ｄ）に例示するものが
考えられる。すなわち、図２（Ｂ）に示す導電体１８
は、金属製のＩ字形部材１８2 …を並列状に連結して、
該部材１８2 …の上下片で構成される一連の上下面部１
８ａ，１８ｂが導電性耐火材層１７の下面及び集電板１
５の上面に全面的ないし略全面的に接触するようになっ
ている。また、図２（Ｃ）に示す導電材１８は、金属製
のＬ字形部材１８3 …を並列状に連結して、部材１８3
…の下片で構成される一連の下面部１８ｂが集電板１５
の上面に全面的ないし略全面的に接触すると共に、部材
１８3 …の下端部が導電性耐火材層１７の下面に部分的
に接触するようになっている。また、図２（Ｄ）に示す
導電材１８は、図２（Ｃ）に示すものを上下逆にして使
用したもので、金属製の倒立Ｌ字形部材１８4 …の上片
で構成される一連の上面部１８ａが導電性耐火材層１７
の下面に全面的ないし略全面的に接触すると共に、部材
１８3 …の下端部が集電板１５の上面に部分的に接触す
るようになっている。このように、導電体１８の上下部
は、導電性耐火材層１７ないし集電板１５に全面的ない
し略全面的に接触させておいても（図２（Ａ）（Ｂ）参
照）、部分的に接触させておいても（図２（Ｃ）（Ｄ）
参照）、何れでもよく、要は、導電体１８により集電板
１５と導電性耐火材層１７とが電気的に接続されればよ
いのである。したがって、両者１５，１７間を電気的に
接続できる限りにおいて、導電体１８ないしその構成部
材１８1 ，１８2 ，１８3 ，１８4 の形状は任意であ
り、上記以外にも種々のものを使用することができる。
特に、導電体１８は、同一形状の部材１８1 ，１８2 ，
１８3 ，１８4 を連結したものとせず、異形部材を組み
合わせて構成したものでもよい。但し、導電体１８を、
導電性耐火材層１７ないし集電板１５に全面的ないし略
全面的に接触する一連の上下面部１８ａ，１８ｂを有す
るものとしておけば、導電性耐火材層１７ないし集電板
１５との間に一部隙間が生じている場合にも、両者１
５，１７間の通電性が充分に確保されることになる。換
言すれば、炉底電極５としての機能上、導電体１８と導
電性耐火材層１７ないし集電板１５との間に部分的な隙
間があっても何らの支障がなく、それだけ底壁５の施工
を容易に行いうることになる。As shown in FIG. 1, the conductor 18 is embedded in the heat insulating material layer 16, and the current collector plate 15 and the conductive refractory material layer 1 are provided.
It is a metal body that connects 7 and 7 so as to be able to conduct electricity. In particular,
Conductor 18, as shown in FIGS. 1 and FIG. 2 (A), the result was ligated made more metals (e.g., iron) a U-shaped member 18 1 ... of the parallel form, in the member 18 1 ... vertical piece A series of upper and lower surface portions 18a and 18b configured are in contact with the lower surface of the conductive refractory material layer 17 and the upper surface of the current collector plate 15 entirely or substantially entirely. The structure of the conductor 18 is arbitrary, and in addition to the above, the structures illustrated in FIGS. 2B to 2D can be considered. That is, the conductor 18 shown in FIG.
Is a metal I-shaped member 18 2 ...
A series of upper and lower surfaces 1 composed of upper and lower pieces of the member 18 2 .
8a and 18b are the lower surface of the conductive refractory material layer 17 and the collector plate 1
The upper surface of 5 is contacted with the entire surface or substantially the entire surface. Further, the conductive material 18 shown in FIG. 2 (C), by connecting the metal L-shaped member 18 3 ... in parallel form, member 18 3
... A series of lower surface portions 18b composed of lower pieces are collector plates 15
The entire lower surface of the member 18 3 comes into contact with the lower surface of the conductive refractory material layer 17, while the lower surface of the member 18 3 contacts with the upper surface thereof. Further, the conductive material 18 shown in FIG. 2 (D) is the same as that shown in FIG. 2 (C) and is used upside down, and is made up of a metal inverted L-shaped member 18 4 ... The upper surface portion 18a of the conductive refractory material layer 17
The entire lower surface of the member 18 3 comes into contact with the upper surface of the current collector plate 15 while the lower end of the member 18 3 comes into partial contact with the upper surface of the current collector plate 15. Thus, even if the upper and lower portions of the conductor 18 are brought into contact with the conductive refractory material layer 17 or the current collector plate 15 over the entire surface or substantially the entire area (see FIGS. 2A and 2B), Contact (Figs. 2 (C) and (D))
Any of them may be used, as long as the current collector plate 15 and the conductive refractory material layer 17 are electrically connected by the conductor 18. Therefore, as long as the two members 15 and 17 can be electrically connected, the conductor 18 or its constituent members 18 1 , 18 2 , 18 3 and 18 4 may have any shape. can do.
In particular, the conductor 18 is made up of members 18 1 , 18 2 having the same shape,
Instead of connecting 18 3 and 18 4 , the deformed members may be combined. However, the conductor 18 is
If the conductive refractory material layer 17 or the current collector plate 15 is provided with a series of upper and lower surfaces 18a and 18b that are in contact with the conductive refractory material layer 17 or the current collector plate 15, the space between the conductive refractory material layer 17 and the current collector plate 15 is large. Even if there is a gap, both 1
Sufficient electrical conductivity between 5 and 17 will be secured. In other words, in view of the function of the furnace bottom electrode 5, even if there is a partial gap between the conductor 18 and the conductive refractory material layer 17 or the current collector plate 15, there is no problem, and the bottom wall 5 is as much as that. The construction of can be performed easily.
【００２１】以上のように構成された直流アーク炉１に
あっては、溶融処理を開始するに当たっては、まず、主
電極３とスタート位置に下降させたスタート電極４とに
通電させて両電極３，４間にアークを発生させ、これに
より炉１内の被溶融物８ａを溶融させる（図１鎖線参
照）。これは、主電極３と炉底電極５との間に導電性の
溶湯８が介在せず、非導電性の被溶融物８ａが介在する
にすぎない運転開始状態においては、両電極３，５間に
アークを発生させ得ないからである。In the DC arc furnace 1 having the above-described structure, when starting the melting process, first, the main electrode 3 and the start electrode 4 lowered to the start position are energized so that both electrodes 3 are connected. , 4 an arc is generated, which melts the melted object 8a in the furnace 1 (see the chain line in FIG. 1). This is because the conductive molten metal 8 does not exist between the main electrode 3 and the furnace bottom electrode 5, and only the non-conductive melted material 8a intervenes. This is because an arc cannot be generated between them.
【００２２】しかる後、炉１内に溶湯８が生じると、ス
タート電極４を待機位置に上昇させた上、主電極３と炉
底電極５とに所定の電圧を印加させて両電極３，５間に
アーク（プラズマ放電）を発生させた状態で、被溶融物
８ａを定量供給装置１２により炉１内に連続供給させつ
つ、被溶融物８ａの溶融処理を開始する（図１実線参
照）。After that, when the molten metal 8 is generated in the furnace 1, the start electrode 4 is raised to the standby position, and then a predetermined voltage is applied to the main electrode 3 and the furnace bottom electrode 5, so that both electrodes 3, 5 are formed. While the arc (plasma discharge) is being generated, the melted material 8a is continuously supplied into the furnace 1 by the constant quantity supply device 12, and the melting process of the melted material 8a is started (see the solid line in FIG. 1).
【００２３】そして、主電極３と炉底電極５との間に発
生するアークによる加熱により被溶融物８ａが溶融され
るに従って、溶湯８が排出口１０からスラグ処理系１３
ａへと順次溢流排出されていくと共に、炉１内の排ガス
８ｂも排出口１０から排ガス処理系１３ｂへと排出され
ていく。Then, as the material 8a to be melted is melted by the heating by the arc generated between the main electrode 3 and the furnace bottom electrode 5, the molten metal 8 is discharged from the discharge port 10 to the slag treatment system 13
The exhaust gas 8b in the furnace 1 is exhausted to the exhaust gas processing system 13b through the exhaust port 10 as well as being sequentially overflowed and discharged to a.
【００２４】このとき、炉１の底壁５の上面部分が全面
的に導電性耐火材層１７で構成されており、この導電性
耐火材層１７が導電体１８を介して集電板１５に電気的
に接続されていることから、底壁をなす炉底電極５と主
電極３との間には良好にアークが発生されることにな
り、被溶融物８ａの溶融処理が効果的に行われることに
なる。なお、被溶融物８ａの溶融は、一般に、直流電源
から６００〜１０００ＫＷ（被溶融物１トン当たり）を
供給して、これによるアーク熱により被溶融物８ａを１
４００〜１８００℃に加熱することによって行なわれ
る。At this time, the upper surface of the bottom wall 5 of the furnace 1 is entirely constituted by the conductive refractory material layer 17, and the conductive refractory material layer 17 is applied to the collector plate 15 via the conductor 18. Since they are electrically connected, an arc is satisfactorily generated between the furnace bottom electrode 5 forming the bottom wall and the main electrode 3, so that the melted material 8a can be effectively melted. Will be seen. For melting the melted material 8a, generally, 600 to 1000 KW (per ton of melted material) is supplied from a DC power source, and the arc heat generated thereby melts the melted material 8a to 1
It is carried out by heating to 400 to 1800 ° C.
【００２５】そして、炉底電極５の上面部分は、侵食性
の強い高温の溶湯８と接触するものの、耐侵食性に優れ
た導電性耐火材層１７で構成されており、しかも導電性
耐火材層１７には第１及び第２従来炉における如き耐火
材以外の異物やこれを保持しておくための穴が全く存在
しないことから、溶湯８中の低粘性で低融点の溶融金属
が滲入するようなことがなく、炉底電極５ないし底壁が
溶湯滲入により侵食，損傷される等の問題は生じない。
したがって、炉底電極５ないし炉底（底壁）を含めた炉
１の耐久性を大幅に向上させることができる。The upper surface of the furnace bottom electrode 5 is in contact with the high-temperature molten metal 8 having strong erosion, but is formed of the conductive refractory material layer 17 having excellent erosion resistance. Since the layer 17 has no foreign matter other than the refractory material in the first and second conventional furnaces and no holes for holding the foreign matter, the low-viscosity and low-melting molten metal in the molten metal 8 permeates. Therefore, there is no problem that the furnace bottom electrode 5 or the bottom wall is corroded or damaged by the infiltration of the molten metal.
Therefore, the durability of the furnace 1 including the furnace bottom electrode 5 or the furnace bottom (bottom wall) can be significantly improved.
【００２６】しかも、炉底電極５を構成する底壁が上下
２層構造をなし、その上層部分は熱伝導性の高い導電性
耐火材層１７で構成されているものの、その下層部分は
断熱材層１６で構成されていることから、底壁全体とし
ての放熱は、これを必要以上に厚くせずとも、効果的に
抑制されることなる。したがって、第２従来炉とは炉１
の底壁全体を炉底電極５に構成している点で共通するに
も拘わらず、第２従来炉における問題（放熱による熱効
率低下，溶融金属の冷却固化等）は全く生じない。勿
論、底壁５を必要以上に厚くしておく必要がないことか
ら、炉１全体の重量化も可及的に回避することができ
る。Moreover, the bottom wall constituting the furnace bottom electrode 5 has a two-layer structure of upper and lower sides, and the upper layer portion thereof is formed of the conductive refractory material layer 17 having high thermal conductivity, but the lower layer portion thereof is the heat insulating material. Since it is composed of the layer 16, the heat radiation of the entire bottom wall is effectively suppressed without increasing the thickness more than necessary. Therefore, the second conventional furnace is the furnace 1
Despite being common in that the entire bottom wall of the above is configured as the furnace bottom electrode 5, the problems in the second conventional furnace (reduction of thermal efficiency due to heat radiation, cooling and solidification of molten metal, etc.) do not occur at all. Of course, since it is not necessary to make the bottom wall 5 thicker than necessary, it is possible to avoid weighting the entire furnace 1 as much as possible.
【００２７】なお、本発明は上記した形態に限定される
ものではなく、本発明の基本原理を逸脱しない範囲にお
いて適宜に改良，変更することができる。例えば、炉壁
２は一般に１６００〜１８００℃の高温に耐え得る耐火
材で構成されており、且つその外周面は適宜の断熱材カ
バーで被覆されているが、必要に応じて、その断熱材カ
バーを更に水冷ジャケットで囲繞するようにしてもよ
い。また、炉底電極５を冷却ファン等により空冷させる
ようにすることも可能であるが、炉底電極５が上述した
如く放熱抑制構造とされているため、かかる空冷手段を
設けることは必ずしも必要ない。The present invention is not limited to the above-mentioned embodiment, and can be appropriately improved and changed without departing from the basic principle of the present invention. For example, the furnace wall 2 is generally made of a refractory material capable of withstanding a high temperature of 1600 to 1800 ° C., and the outer peripheral surface thereof is covered with an appropriate heat insulating material cover. May be further surrounded by a water cooling jacket. It is also possible to cool the furnace bottom electrode 5 with a cooling fan or the like. However, since the furnace bottom electrode 5 has the heat dissipation suppressing structure as described above, it is not always necessary to provide such an air cooling means. .
【００２８】[0028]
【発明の効果】以上の説明からも明らかなように、本発
明の電気溶融炉にあっては、炉底電極ないし炉底が溶湯
により侵食されたり損傷されたりすることなく、その耐
久性を大幅に向上させることができる。しかも、炉底か
らの脱湯を生じず、炉底からの放熱を可及的に抑制，防
止し得て、溶融金属の固化等の問題を生じることなく、
炉の熱効率を大幅に向上させることができる。したがっ
て、本発明によれば、冒頭で述べた如き従来炉における
問題をすべて解決することができ、焼却残滓等の被溶融
物の溶融処理を、長期に亘って効率良く効果的に行なう
ことができる。As is apparent from the above description, in the electric melting furnace of the present invention, the durability of the furnace bottom electrode or the furnace bottom is greatly improved without being eroded or damaged by the molten metal. Can be improved. Moreover, without removing water from the furnace bottom, it is possible to suppress and prevent heat radiation from the furnace bottom as much as possible, without causing problems such as solidification of molten metal.
The thermal efficiency of the furnace can be greatly improved. Therefore, according to the present invention, all the problems in the conventional furnace as described at the beginning can be solved, and the melting treatment of the material to be melted such as incineration residue can be efficiently and effectively performed for a long period of time. .
【図１】本発明に係る電気溶融炉の一例を示す縦断側面
図である。FIG. 1 is a vertical side view showing an example of an electric melting furnace according to the present invention.
【図２】導電体を示す要部の斜視図である。FIG. 2 is a perspective view of a main part showing a conductor.
【図３】第１従来炉を示す縦断側面図である。FIG. 3 is a vertical sectional side view showing a first conventional furnace.
【図４】第２従来炉を示す縦断側面図である。FIG. 4 is a vertical sectional side view showing a second conventional furnace.
１…直流アーク炉（電気溶融炉）、２…炉壁、３…主電
極、５…炉底電極（炉の底壁）、８…溶湯、８ａ…被溶
融物、１５…集電板、１６…断熱材層、１７…導電性耐
火材層、１８…導電体。DESCRIPTION OF SYMBOLS 1 ... DC arc furnace (electric melting furnace), 2 ... Furnace wall, 3 ... Main electrode, 5 ... Furnace bottom electrode (furnace bottom wall), 8 ... Molten metal, 8a ... Molten material, 15 ... Current collector plate, 16 ... Insulating material layer, 17 ... Conductive refractory material layer, 18 ... Conductor.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 // Ｂ０９Ｂ 3/00 Ｂ０９Ｂ 3/00 ３０３Ｌ (72)発明者 麻生 知宣 兵庫県尼崎市金楽寺町２丁目２番33号 株 式会社タクマ内─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification number Reference number within the agency FI Technical display location // B09B 3/00 B09B 3/00 303L (72) Inventor Tomonori Aso Kinrakuji Town, Amagasaki City, Hyogo Prefecture 2-chome 2 chome In Takuma Co., Ltd.
Claims (1)
熱材層と、断熱材層上に形成された、導電性及び溶湯に
対する耐侵食性に優れた導電性耐火材層と、断熱材層に
埋設されて、導電性耐火材層と集電板とを通電可能に接
続する金属製の導電体と、からなる炉底電極に構成して
あることを特徴とする電気溶融炉。1. A heat insulating material layer formed on a current collector plate over the entire bottom wall of the furnace, and a conductive fire resistant material layer formed on the heat insulating material layer and having excellent conductivity and corrosion resistance against molten metal. , An electric melting furnace, which is embedded in a heat insulating material layer and is composed of a metal conductor that electrically connects the conductive refractory material layer and a current collector plate, and a furnace bottom electrode. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03530496A JP3393002B2 (en) | 1996-02-23 | 1996-02-23 | Electric melting furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03530496A JP3393002B2 (en) | 1996-02-23 | 1996-02-23 | Electric melting furnace |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09229559A true JPH09229559A (en) | 1997-09-05 |
| JP3393002B2 JP3393002B2 (en) | 2003-04-07 |
Family
ID=12438055
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03530496A Expired - Fee Related JP3393002B2 (en) | 1996-02-23 | 1996-02-23 | Electric melting furnace |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3393002B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004340414A (en) * | 2003-05-13 | 2004-12-02 | Ebara Corp | Melting furnace, plasma arc re-igniting method, and re-igniting bar inserting mechanism |
| JP2007292350A (en) * | 2006-04-24 | 2007-11-08 | Takuma Co Ltd | Operation control method of electric melting furnace |
-
1996
- 1996-02-23 JP JP03530496A patent/JP3393002B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004340414A (en) * | 2003-05-13 | 2004-12-02 | Ebara Corp | Melting furnace, plasma arc re-igniting method, and re-igniting bar inserting mechanism |
| JP2007292350A (en) * | 2006-04-24 | 2007-11-08 | Takuma Co Ltd | Operation control method of electric melting furnace |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3393002B2 (en) | 2003-04-07 |
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