JP4283035B2

JP4283035B2 - Melting furnace and re-ignition method of plasma arc

Info

Publication number: JP4283035B2
Application number: JP2003134962A
Authority: JP
Inventors: 泰之合田; 正実香島; 元神保; 俊郎雨宮; 隆上堀
Original assignee: Ebara Corp
Current assignee: Ebara Corp
Priority date: 2003-05-13
Filing date: 2003-05-13
Publication date: 2009-06-24
Anticipated expiration: 2023-05-13
Also published as: JP2004340414A

Description

【０００１】
【発明の属する技術分野】
この発明は、都市ごみ、下水汚泥、或いはその他の廃棄物を廃棄物焼却炉で焼却することによって発生する焼却灰等の被溶融物をプラズマアークで溶融処理する溶融炉に関し、特にプラズマアークが消滅した場合、炉体内に再着火棒を自動的に挿入し、即座にプラズマの着火再生が可能な溶融炉及びプラズマアークの再着火方法に関するものである。
【０００２】
【従来の技術】
都市ごみ、下水汚泥、或いはその他の廃棄物を廃棄物焼却炉で焼却することによって発生する焼却灰の減容化処理方法として、この焼却灰をプラズマ溶融炉等の溶融炉に投入し溶融する方法が行われている。図１は従来のこの種の溶融炉であるプラズマ溶融炉の概略構成を示す図である。プラズマ溶融炉１は炉蓋２、炉体３を具備し、炉蓋２にはプラズマトーチ４を挿入するトーチ挿入口５が設けられ、炉体３の底部には対極６が設けられている。プラズマトーチ４と対極６の間に電圧を印加し、該プラズマトーチ４と対極６の間にプラズマアーク１０を発生させ、その熱により炉体３内に投入された焼却灰７を溶融し、溶融スラグ８ａとする。溶融スラグ８ａは排出口９からオーバフローにより炉外に排出され、埋立処分、再資源化（路盤材等）に利用される。また、成形機により成形されて製品化される。なお、焼却灰７の溶融に伴って発生する排ガスＧは排ガス処理システム（図示せず）に送られ処理される（非特許文献１参照）。
【０００３】
上記構成のプラズマ溶融炉において、プラズマトーチ４と対極６の間にプラズマアークを発生させ、焼却灰７のように酸化物を主成分とする廃棄物を溶融処理するためには、溶融スラグ８ａ及びベースメタル８ｂの電気的抵抗が低く保たれなければならない。ベースメタル８ｂは温度に関わらず、液体（溶融状態）、固体であっても電気的抵抗はきわめて低い。しかし、溶融スラグ８ａは温度が高く溶融状態であるとその電気的抵抗は低いが、温度が下がり粘性が高くなるとともに電気的抵抗値は上昇し、電気伝導性が悪くなり、アークの再発生ができない。また、溶融スラグ上に酸化物等の組成が不均一な温度の低い焼却灰７が多量に投入されると、アーク電力の変動が大きく、また、プラズマアーク１０が消滅する現象が発生する。このプラズマアーク１０が消滅した場合は、ベースメタル８ｂ上を導電性のない焼却灰が覆った状態となるため、プラズマアーク１０の再発生ができないという問題があった。
【０００４】
従来、プラズマアークが消滅し再度プラズマアークを発生させる場合、例えば再着火棒１１を用意し、プラズマ溶融炉１のトーチ挿入口５から挿入ハンドルの先端に装着した再着火棒１１を挿入し、図２に示すように、対極６上に載置し、ベースメタル８ｂが安定するまで挿入ハンドルを押え、溶融部分が若干固化してきて再着火棒１１が転倒しない状態になったら、ハンドルを再着火棒から抜く。その後、再着火棒１１とプラズマトーチ４の間にプラズマアーク１０を発生させプラズマアークの再生を行っていた。この人手による再着火棒１１を炉体３内に挿入し、対極６上に載置し固定する作業は困難で煩わしいものであった。特に、プラズマアーク１０がアーク電力の変動により消滅した場合、炉体３内の溶融スラグ８ａの中に柱状の再着火棒１１を挿入し、対極６の上に配置する作業は危険を伴う極めて困難な作業であった。
【０００５】
【非特許文献１】
選鉱製錬研究所彙報第４６巻第１号１９９０年６月東北大学
【０００６】
【発明が解決しようとする課題】
本発明は上述の点に鑑みてなされたもので、人手によることなく、自動的に炉体内に再着火棒を挿入し、即座にプラズマアークの再着火ができる溶融炉及びプラズマアークの再着火方法を提供することを目的とする。
【０００７】
【課題を解決するための手段】
上記課題を解決するため請求項１に記載の本発明は、炉体、プラズマトーチ、炉体上部に設けたプラズマトーチ挿入口を具備し、該炉体内に投入された被溶融物を該プラズマトーチと炉体底部で且つプラズマトーチ挿入口に対向する位置に設けた対極の間に発生させたプラズマアークにより溶融し、該対極上にベースメタル及び該ベースメタルの上部に溶融スラグを形成する溶融炉において、再着火棒を先端に着脱可能に保持する保持部を有し、該再着火棒の先端を対極上で且つ対極上部に形成されているベースメタル中に挿入する再着火棒装着部と該再着火棒装着部と電気的に絶縁され該再着火棒装着部を上下動させる上下機構を設けた再着火棒挿入機構と、被溶融物の溶融中にプラズマアークが消滅した場合、再着火棒を再着火棒挿入機構の保持部に保持したまま該再着火棒の先端を対極上部に形成されている溶融スラグが固化する前に該溶融スラグを貫通させてベースメタル中で、且つ対極の上に挿入し、プラズマトーチと対極の間に電圧を印加し、該プラズマトーチと該再着火棒の間でプラズマアークが再生した後に該再着火棒を保持部から離脱させ、再着火棒装着部を上昇させて炉体から抜き出す制御を行う制御手段と、を設けたことを特徴とする。
【０００８】
上記のように再着火棒を先端に着脱可能に保持する保持部を有し、該再着火棒の先端を対極上で且つ対極上部に形成されているベースメタル中に挿入する再着火棒装着部と該再着火棒装着部と電気的に絶縁され該再着火棒装着部を上下動させる上下機構を設けた再着火棒挿入機構と、被溶融物の溶融中にプラズマアークが消滅した場合、再着火棒を再着火棒挿入機構の保持部に保持したまま該再着火棒の先端を対極上部に形成されている溶融スラグが固化する前に該溶融スラグを貫通させてベースメタル中で、且つ対極の上に挿入し、プラズマトーチと対極の間に電圧を印加し、該プラズマトーチと該再着火棒の間でプラズマアークが再生した後に該再着火棒を保持部から離脱させ、再着火棒装着部を上昇させて炉体から抜き出す制御を行う制御手段とを設けたので、人手によることなく、自動的に再着火棒をプラズマトーチと対極の間に挿入し、プラズマトーチと再着火棒の間でプラズマアークを発生することができる。また、再着火棒をプラズマトーチと対極の間に挿入すると、即座にプラズマトーチと再着火棒の間でプラズマアークを発生させることができるから、プラズマアークの再生が即座（短時間）にできる。
【００１１】
請求項２に記載の発明は、請求項１に記載の溶融炉において、再着火棒挿入機構は、先端に再着火棒を保持する保持部を有し、且つ軸受部材で回転自在に支持された円柱状部材と、該円柱状部材を覆う二重管とを具備することを特徴とする。
【００１２】
上記のように回転自在な円柱状部材と、該円柱状部材を覆う二重管を具備するので、二重管に冷媒を供給し、円柱状部材先端の保持部に再着火棒を保持して、円柱状部材を高温から保護しながら、再着火棒を高温の溶融炉内に挿入することができる。
【００１３】
請求項３に記載の発明は、請求項２に記載の溶融炉において、再着火棒挿入機構が具備する二重管には、冷却水を注入するための給水口と、該注入された冷却水を排出するための排水口を設けたことを特徴とする。
【００１４】
上記のように二重管に給水口及び排水口を設けたので、二重管内に冷却水を供給することにより、円柱状部材を高温雰囲気に曝すことなく、該円柱状部材先端の保持部に保持した再着火棒を、高温の溶融炉内に挿入することができる。
【００１５】
請求項４に記載の発明は、炉体、プラズマトーチ、炉体上部に設けたプラズマトーチ挿入口を具備し、該炉体内に投入された被溶融物を該プラズマトーチと炉体底部で且つプラズマトーチ挿入口に対向する位置に設けた対極の間に発生させたプラズマアークにより溶融し、該対極上にベースメタル及び該ベースメタルの上部に溶融スラグを形成する溶融炉におけるプラズマアークの再着火方法において、再着火棒を先端に着脱可能に保持する保持部を有し、該再着火棒の先端を対極上で且つ対極上部に形成されているベースメタル中に挿入する再着火棒装着部と該再着火棒装着部と電気的に絶縁され該再着火棒装着部を上下動させる上下機構を設けた再着火棒挿入機構を備え、被溶融物の溶融中にプラズマアークが消滅した場合、再着火棒を再着火棒挿入機構の保持部に保持したまま該再着火棒の先端を対極上部に形成されている溶融スラグが固化する前に該溶融スラグを貫通させてベースメタル中で、且つ対極の上に挿入し、プラズマトーチと対極の間に電圧を印加し、該プラズマトーチと該再着火棒の間でプラズマアークが再生した後に該再着火棒を保持部から離脱させ、再着火棒装着部を上昇させて炉体から抜き出すことを特徴とする。
【００１６】
上記のように再着火棒を先端に着脱可能に保持する保持部を有し、該再着火棒の先端を対極上で且つ対極上部に形成されているベースメタル中に挿入する再着火棒装着部と該再着火棒装着部と電気的に絶縁され該再着火棒装着部を上下動させる上下機構を設けた再着火棒挿入機構を備え、被溶融物の溶融中にプラズマアークが消滅した場合、再着火棒を再着火棒挿入機構の保持部に保持したまま該再着火棒の先端を対極上部に形成されている溶融スラグが固化する前に該溶融スラグを貫通させてベースメタル中で、且つ対極の上に挿入し、プラズマトーチと対極の間に電圧を印加し、該プラズマトーチと該再着火棒の間でプラズマアークが再生した後に該再着火棒を保持部から離脱させることにより、被溶融物の溶融中にプラズマアークが消滅した場合に、短時間にプラズマアークの再生が可能となる。
【００１７】
【発明の実施の形態】
以下、本発明の実施の形態例を図面に基づいて説明する。図３及び図４は本発明に係る溶融炉の概略構成例を示す図であり、図３は平面図、図４は側面図である。図３及び図４において、図１と同一符号を付した部分は同一又は相当部分を示す。溶融炉であるプラズマ溶融炉１は炉蓋２、炉体３を具備し、炉蓋２にはプラズマトーチ４を挿入するトーチ挿入口５が設けられ、炉体３の底部にはプラズマトーチ４と対向して対極（図示は省略）が設けられている。
【００１８】
２０はプラズマ溶融炉１内にトーチ挿入口５からプラズマトーチ４を挿入するプラズマトーチ挿入機構であり、該プラズマトーチ挿入機構２０は支柱２１に旋回機構２６等で旋回自在に支持された旋回台３２にブラケット３３を介して取付けられている。プラズマトーチ挿入機構２０はプラズマトーチ４の上端部を保持し、プラズマトーチを上下動させる上下動機構２２を具備している。また、プラズマ溶融炉１の炉体３の周囲には高融点物質を含む焼却灰を炉体３内に供給するための焼却灰供給装置２４が１台ないし２台又は３台設置されている。また、炉体３の周囲には排ガスや溶融スラグを排出するための排出口２５が設けられている。
【００１９】
プラズマトーチ挿入機構２０は旋回機構２６で図３のＡ位置、即ちプラズマトーチ４がトーチ挿入口５の真上に達する位置Ａと、Ｂ位置、即ちプラズマトーチ４の待機位置との間を旋回できるようになっている。また、炉蓋２に再着火棒挿入口１２が設けられており、該再着火棒挿入口１２から再着火棒挿入機構１３に装着された再着火棒１１を炉体３内に挿入できるようになっている。
【００２０】
図５及び図６は再着火棒挿入機構１３の構成を示す図で、図５は再着火棒挿入機構１３の全体構成を、図６（ａ）は再着火棒装着部の詳細構成を、図６（ｂ）、（ｃ）はそれぞれ再着火棒１１の端部を示す一部側断面図、正面図である。再着火棒挿入機構１３は該再着火棒装着部１４を具備し、該再着火棒装着部１４は円柱状部材１４−１を内管１４−２ａと外管１４−２ｂからなる二重管１４−２で覆った構造である（図７参照）。該円柱状部材１４−１は再着火棒装着部１４の先端部に設けた軸受部材１４−４に回転自在に支持され、モータ１４−３で回転するようになっている。
【００２１】
また、再着火棒装着部１４は電気絶縁部材３０及び３０を介在させ電気絶縁部材１５−１及び１５−２に取付けられ、該電気絶縁部材１５−１及び１５−２はねじ部材１６に螺合し、該ねじ部材１６をモータ１９で回転することにより、電気絶縁部材１５−１及び１５−２を介して再着火棒装着部１４は矢印Ａ方向に移動するようになっている。再着火棒装着部１４の移動量はリミットスイッチ１８−１、１８−２で検出されるようになっている。なお、再着火棒挿入機構１３は台部材３１に搭載され、該台部材３１は支柱４５、４５で支持されている（図４参照）。また図４に示すように、支柱４５、４５の途中には電気絶縁板４６、４６が介在し、再着火棒挿入機構１３は支柱４５、４５の下部と電気的に絶縁されている。
【００２２】
再着火棒１１の後端部を保持する再着火棒保持部１７は、図６（ａ）、（ｂ）、（ｃ）に示すように再着火棒１１の後端部に設けた円錐台形状凹部１１ａに設けた雌ねじ溝１１ｂに、再着火棒装着部１４の円柱状部材１４−１の先端に設けた雄ねじ溝１４−１ａを螺合させることにより、再着火棒１１を円柱状部材１４−１に装着保持できる保持機構となっている。
【００２３】
また、再着火棒１１の後端外周には四角錐台状凸部１１ｃが形成され、再着火棒装着部１４の先端部に設けた軸受部材１４−４にはこの四角錐台状凸部１１ｃが挿入される四角錐台状凹部１４−４ａが形成されており、再着火棒１１の後端部を軸受部材１４−４の四角錐台状凹部１４−４ａに押し当て、モータ１４−３を正回転させることにより円柱状部材１４−１先端の雄ねじ溝１４−１ａを再着火棒１１後端部の雌ねじ溝１１ｂにねじ込み螺合させて再着火棒１１を円柱状部材１４−１に装着する。また、モータ１４−３を逆転させることにより再着火棒１１から円柱状部材１４−１を脱着する。この装着及び脱着に際して再着火棒１１の後端部の四角錐台状凸部１１ｃは軸受部材１４−４の四角錐台状凹部１４−４ａに嵌合して再着火棒１１の回転は阻止されるから、装着及び脱着は容易に実現できる。
【００２４】
なお、モータ１４−３の回転軸と円柱状部材１４−１は電気絶縁部材３０を介在させたカップリング１４−７で連結され、モータ１４−３の回転軸と円柱状部材１４−１は電気的に絶縁されている。また、二重管１４−２も電気絶縁部材３０を介在させたブラケット１５−３を介して台部材３１に移動自在に支持されている。このようにモータ１４−３の回転軸と円柱状部材１４−１の間、及び再着火棒装着部１４の二重管１４−２と電気絶縁部材１５−１の間、モータ１４−３と電気絶縁部材１５−２の間にそれぞれ電気絶縁部材３０を介在させて再着火棒装着部１４と台部材３１の間を電気的に絶縁することにより、再着火時に再着火棒１１に発生する高電圧が台部材３１に伝わるのを阻止し、感電の危険を防止することができる。例えば、再着火棒１１と炉底対極間にほんの１Ωの抵抗があると、再着火時に最低４００Ａの電流を流すので、再着火棒１１に４００Ｖの電圧が発生する。この電圧が台部材３１に伝わり、感電の危険がある。
【００２５】
再着火棒装着部１４の円柱状部材１４−１を覆う二重管１４−２には、図７に示すように、その内外管の間の空間１４−２ａに連通する給水口１４−５と排水口１４−６が設けられ、給水口１４−５から空間１４−２ａ中に冷却水を注入し、排水口１４−６から排水することにより、再着火棒装着部１４を水冷却するようになっている。このように二重管１４−２の内管と外管の間の空間１４−２ａに冷却水を流すことにより、外からの強い輻射熱をこの冷却水で冷却し内部の昇温を防ぐことができる。また、円柱状部材１４−１を収容する内管の空間１４−２ｂに冷却空気等の冷却ガスを流すことで、再着火棒１１を把持する円柱状部材１４−１の先端部まで冷却できる。ここで冷却水による冷却と冷却ガスによる冷却を併用しているのは、冷却ガスを二重管１４−２の内管先端部から炉内に放散することにより、再着火棒１１を把持する円柱状部材１４−１をその先端部まで効果的に冷却することができると共に、冷却空気等の冷却ガスは炉内に放散しても弊害が少ないからである。なお、円柱状部材１４−１の先端部まで冷却する水冷ジャケットを形成することは構造上難しい。
【００２６】
上記構成の溶融炉において、図４に示すように、再着火棒装着部１４に、再着火棒１１を装着し、モータ１９を正回転させることにより、再着火棒１１は再着火棒挿入口１２に向って移動し、更に該再着火棒挿入口１２を通って、その先端が図８に示すように炉体３内の所定位置（対極６の真上で且つベースメタル８ｂ中の位置）に到達する。この再着火棒１１の所定位置での停止は、再着火棒装着部１４の移動量をリミットスイッチ１８−１で検出し、その検出信号を図示しない制御装置が受信したら、モータ１９を停止する信号を出力し、モータ１９を停止させる。また、再着火棒１１の先端が炉底に到達するとモータ１９の負荷電流値が増大するから、上記制御装置がモータ１９の負荷電流値を監視し、所定の電流値を越えた時モータ１９を停止する信号を出力してモータ１９を停止するようにしてもよい。
【００２７】
プラズマアーク１０を再着火させる場合は、図８に示すように、再着火棒挿入機構１３の再着火棒装着部１４で再着火棒１１を保持し、その先端を対極６上で且つベースメタル８ｂの中に保持した状態でプラズマトーチ４と対極６の間に電圧を印加し、プラズマアーク１０を発生させる。プラズマアーク１０が発生した後、モータ１４−３を逆転させることにより再着火棒１１を離脱させる。その後、モータ１９を逆転させることにより、再着火棒装着部１４は炉体３から抜け出て、炉体３外の所定位置に達したら、それをリミットスイッチ１８−２が検出し、モータ１９を停止することにより、再着火棒装着部１４は停止する。なお、再着火棒１１はプラズマアーク１０の熱により溶融し、炉体３内に形成されるベースメタル８ｂと混合される。また、ベースメタル８ｂの上にはそれより比重の軽い溶融スラグ８ａの層が形成される。
【００２８】
なお、上記再着火棒挿入機構１３において、上記のように円柱状部材１４−１、二重管１４−２は電気絶縁部材３０、３０を介して台部材３１、電気絶縁部材１５−１と電気的に絶縁され、更に円柱状部材１４−１とモータ１４−３の回転軸はカップリング１４−７の電気絶縁部材３０で電気的に絶縁されているから、図５に示すように、再着火棒１１を円柱状部材１４−１の再着火棒保持部１７に保持したままプラズマトーチ４と対極６の間に電圧を印加して、プラズマアーク１０を発生させても電気的には問題ない。
【００２９】
上記のように再着火棒装着部１４で再着火棒１１を保持したまま、プラズマアーク１０を発生させることができ、プラズマアーク１０が発生後、再着火棒１１を離脱させることができるから、即座にプラズマアーク１０を再発生させることができる。これに対して、従来のプラズマアーク１０の再生方法例では、再着火棒１１の先端部周辺の溶融部分が若干固化して再着火棒１１が転倒しない状態になったら、再着火棒１１を離脱させ、その後プラズマトーチ４と再着火棒１１の間にプラズマアーク１０を発生させるので、即座にプラズマアーク１０の再発生ができない。
【００３０】
図９及び図１０は本発明に係る溶融炉の概略構成例を示す図であり、図９は平面図、図１０は側面図である。図において、４０はプラズマトーチ挿入機構であり、該プラズマトーチ挿入機構４０は支柱２１に旋回機構２６で旋回自在に支持された旋回台３２にブラケット４１を介して取付けられている。また、プラズマトーチ挿入機構４０は、プラズマトーチ４を取付けるトーチ取付台４２を具備し、該トーチ取付台４２にプラズマトーチ４を取り付ける。
【００３１】
トーチ取付台４２は、プラズマトーチ４を上下動できるようになっている。また、前後移動機構４３を具備し、該前後移動機構４３により矢印Ｅに示すように前後に移動できるようになっており、更に左右移動機構４４を具備し、該左右移動機構４４により矢印Ｆに示すように左右に移動できるようになっている。また、プラズマトーチ挿入機構４０のトーチ取付台４２にプラズマトーチ４を取付け、旋回機構２６による図９のＡ位置とＢ位置の旋回動作、上下動機構の上下動作により、プラズマトーチ４をプラズマ溶融炉１の炉体３内に挿入できるようになっている。再着火棒挿入口１２からは、図示は省略するが、図４に示すのと同様、再着火棒挿入機構１３により、再着火棒１１を炉体３内に挿入し、所定位置に位置決めできるようになっている。
【００３２】
上記の構成の溶融炉において、再着火棒挿入機構１３により再着火棒１１を再着火棒挿入口１２から図８に示すように、炉体３内の所定位置に挿入する。その後、図９のＢ位置から旋回機構２６でプラズマトーチ挿入機構４０をＡ位置まで旋回させ、この状態で上下動機構により下降させ、プラズマトーチ４の先端を対極６の上方の所定位置まで下降させ、プラズマトーチ４と対極６の間に所定の電圧を印加し、プラズマアークを発生させる。プラズマアークの着火、再着火棒１１の脱着を行い、再着火棒挿入機構１３の再着火棒装着部１４を炉体３から抜出す。焼却灰供給装置２４から焼却灰を供給し、これを溶融する。
【００３３】
プラズマアークがアーク電力の変動等により不意に消滅し、即座にプラズマアーク１０を発生する必要がある場合は、図８に示すように、再着火棒挿入機構１３の再着火棒装着部１４に再着火棒１１を装着し、対極６上に保持した状態でプラズマトーチ４と対極６の間に電圧を印加し、プラズマアーク１０を発生させる。プラズマアーク１０が発生した後、モータ１４−３を逆転させることにより、上記のように再着火棒１１を再着火棒装着部１４の円柱状部材１４−１の先端部から脱着させる。
【００３４】
以上本発明の実施形態を説明したが、本発明は上記実施形態に限定されるものではなく、特許請求の範囲、及び明細書と図面に記載された技術的思想の範囲内において種々の変形が可能である。なお、直接明細書及び図面に記載がない何れの形状や構造や材質であっても、本願発明の作用・効果を奏する以上、本願発明の技術的思想の範囲内である。
【００３５】
【発明の効果】
以上、説明したように各請求項に記載の発明によれば、下記のような優れた効果が得られる。
【００３６】
請求項１に記載の発明によれば、再着火棒を先端に着脱可能に保持する保持部を有し、該再着火棒の先端を対極上で且つ対極上部に形成されているベースメタル中に挿入する再着火棒装着部と該再着火棒装着部と電気的に絶縁され該再着火棒装着部を上下動させる上下機構を設けた再着火棒挿入機構と、被溶融物の溶融中にプラズマアークが消滅した場合、再着火棒を再着火棒挿入機構の保持部に保持したまま該再着火棒の先端を対極上部に形成されている溶融スラグが固化する前に該溶融スラグを貫通させてベースメタル中で、且つ対極の上に挿入し、プラズマトーチと対極の間に電圧を印加し、該プラズマトーチと該再着火棒の間でプラズマアークが再生した後に該再着火棒を保持部から離脱させ、再着火棒装着部を上昇させて炉体から抜き出す制御を行う制御手段とを設けたので、人手によることなく、自動的に再着火棒をプラズマトーチと対極の間に挿入し、プラズマトーチと再着火棒の間でプラズマアークを発生することができる。また、再着火棒をプラズマトーチと対極の間に挿入すると、即座にプラズマトーチと再着火棒の間でプラズマアークを発生させることができるから、プラズマアークの再生が即座（短時間）にできる。
【００３８】
請求項２に記載の発明によれば、回転自在な円柱状部材と、該円柱状部材を覆う二重管を具備するので、二重管に冷媒を供給し、円柱状部材先端の保持部に再着火棒を保持して、円柱状部材を高温から保護しながら、再着火棒を高温の溶融炉内に挿入することができる。
【００３９】
請求項３に記載の発明によれば、二重管に給水口及び排水口を設けたので、二重管内に冷却水を供給することにより、円柱状部材を高温雰囲気に曝すことなく、該円柱状部材先端の保持部に保持した再着火棒を、高温の溶融炉内に挿入することができる。
【００４０】
請求項４に記載の発明によれば、再着火棒を先端に着脱可能に保持する保持部を有し、該再着火棒の先端を対極上で且つ対極上部に形成されているベースメタル中に挿入する再着火棒装着部と該再着火棒装着部と電気的に絶縁され該再着火棒装着部を上下動させる上下機構を設けた再着火棒挿入機構を備え、被溶融物の溶融中にプラズマアークが消滅した場合、再着火棒を再着火棒挿入機構の保持部に保持したまま該再着火棒の先端を対極上部に形成されている溶融スラグが固化する前に該溶融スラグを貫通させてベースメタル中で、且つ対極の上に挿入し、プラズマトーチと対極の間に電圧を印加し、該プラズマトーチと該再着火棒の間でプラズマアークが再生した後に該再着火棒を保持部から離脱させることにより、被溶融物の溶融中にプラズマアークが消滅した場合に、短時間にプラズマアークの再生が可能となる。
【図面の簡単な説明】
【図１】従来の溶融炉であるプラズマ溶融炉の概略構成を示す図である。
【図２】プラズマ溶融炉に再着火棒を配置しプラズマアークを発生させた状態を示す図である。
【図３】本発明に係る溶融炉の概略構成例を示す平面図である。
【図４】本発明に係る溶融炉の概略構成例を示す側面図である。
【図５】本発明に係る溶融炉に用いる再着火棒挿入機構の全体構成例を示す図である。
【図６】図６（ａ）は再着火棒挿入機構の再着火棒装着部の詳細構成を、図６（ｂ）、（ｃ）はそれぞれ再着火棒の端部を示す一部側断面図、正面図である。
【図７】再着火棒挿入機構の再着火棒装着部の断面図である。
【図８】本発明に係る溶融炉に再着火棒を配置しプラズマアークを発生させた状態を示す図である。
【図９】本発明に係る溶融炉の概略構成例を示す平面図である。
【図１０】本発明に係る溶融炉の概略構成例を示す側面図である。
【符号の説明】
１プラズマ溶融炉
２炉蓋
３炉体
４プラズマトーチ
５トーチ挿入口
６対極
７焼却灰
８ａ溶融スラグ
８ｂベースメタル
９排出口
１０プラズマアーク
１１再着火棒
１２再着火棒挿入口
１３再着火棒挿入機構
１４再着火棒装着部
１４−１円柱状部材
１４−２二重管
１４−３モータ
１４−４軸受部材
１４−５給水口
１４−６排水口
１４−７カップリング
１５−１電気絶縁部材
１５−２電気絶縁部材
１５−３ブラケット
１６ねじ部材
１７再着火棒保持部
１８−１リミットスイッチ
１８−２リミットスイッチ
１９モータ
２０プラズマトーチ挿入機構
２１支柱
２２上下動機構
２４焼却灰供給装置
２５排出口
２６旋回機構
２８トーチ取付台
３０電気絶縁部材
３１台部材
３２旋回台
３３ブラケット
４０プラズマトーチ挿入機構
４１ブラケット
４２トーチ取付台
４３前後移動機構
４４左右移動機構
４５支柱
４６電気絶縁板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a melting furnace that melts to-be-melted materials such as incineration ash generated by incineration of municipal waste, sewage sludge, or other waste in a waste incinerator, and in particular, the plasma arc disappears. In this case, a re-ignition rod is automatically inserted into the furnace, and plasma ignition regeneration is possible immediately. Melting furnace and The present invention relates to a plasma arc re-ignition method.
[0002]
[Prior art]
As a method for reducing the volume of incinerated ash generated by incineration of municipal waste, sewage sludge, or other waste in a waste incinerator, a method of melting the incinerated ash into a melting furnace such as a plasma melting furnace Has been done. FIG. 1 is a diagram showing a schematic configuration of a plasma melting furnace which is a conventional melting furnace of this type. The plasma melting furnace 1 includes a furnace lid 2 and a furnace body 3, a torch insertion port 5 for inserting a plasma torch 4 is provided in the furnace lid 2, and a counter electrode 6 is provided at the bottom of the furnace body 3. A voltage is applied between the plasma torch 4 and the counter electrode 6, a plasma arc 10 is generated between the plasma torch 4 and the counter electrode 6, and the incinerated ash 7 charged in the furnace body 3 is melted by the heat to melt Let it be slag 8a. The molten slag 8a is discharged out of the furnace by overflow from the discharge port 9, and is used for landfill disposal and recycling (roadbed material, etc.). Moreover, it is molded by a molding machine and commercialized. In addition, the exhaust gas G generated with the melting of the incineration ash 7 is sent to an exhaust gas treatment system (not shown) and processed (see Non-Patent Document 1).
[0003]
In the plasma melting furnace having the above configuration, in order to generate a plasma arc between the plasma torch 4 and the counter electrode 6 and to melt the waste mainly composed of oxides such as the incinerated ash 7, the molten slag 8a and The electric resistance of the base metal 8b must be kept low. The base metal 8b has an extremely low electrical resistance regardless of the temperature, even if it is liquid (molten state) or solid. However, when the molten slag 8a is in a molten state with a high temperature, its electrical resistance is low. However, the temperature decreases, the viscosity increases, the electrical resistance value increases, the electrical conductivity deteriorates, and the arc is regenerated. Can not. In addition, when a large amount of incinerated ash 7 having a non-uniform composition of oxide or the like on the molten slag is introduced in a large amount, the fluctuation of the arc power is large and the phenomenon that the plasma arc 10 disappears occurs. When the plasma arc 10 is extinguished, there is a problem that the plasma arc 10 cannot be regenerated because the non-conductive incineration ash is covered on the base metal 8b.
[0004]
Conventionally, when a plasma arc disappears and a plasma arc is generated again, for example, a reignition rod 11 is prepared, and a reignition rod 11 attached to the tip of an insertion handle is inserted from the torch insertion port 5 of the plasma melting furnace 1. As shown in FIG. 2, the insertion handle is placed on the counter electrode 6 until the base metal 8b is stabilized. When the molten portion is slightly solidified and the re-ignition rod 11 does not fall over, the handle is re-ignited. Unplug from. Thereafter, a plasma arc 10 was generated between the reignition rod 11 and the plasma torch 4 to regenerate the plasma arc. The manual re-ignition rod 11 was inserted into the furnace body 3 and placed on the counter electrode 6 and fixed, which was difficult and troublesome. In particular, when the plasma arc 10 is extinguished due to fluctuations in arc power, it is extremely difficult to insert the columnar reignition rod 11 into the molten slag 8a in the furnace body 3 and dispose it on the counter electrode 6 with danger. It was a difficult task.
[0005]
[Non-Patent Document 1]
Report of the Concentration Smelting Research Institute Vol.46 No.1 June 1990 Tohoku University
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned points. A re-ignition rod can be automatically inserted into the furnace body without human intervention, and a plasma arc can be immediately re-ignited. Melting furnace and An object of the present invention is to provide a method for reigniting a plasma arc.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention according to claim 1 provides a furnace body and a plasma torch. , Furnace A plasma torch insertion opening provided at the top of the body is provided, and the molten material charged into the furnace body is generated between the plasma torch and the counter electrode provided at the bottom of the furnace body and at a position facing the plasma torch insertion opening. Melted by plasma arc And forming a base metal on the counter electrode and a molten slag on top of the base metal In the melting furnace It has a holding part that is detachably held at the tip, The tip of the re-ignition rod is inserted into the base metal formed on the counter electrode and on the top of the counter electrode. A re-ignition rod mounting portion and a vertical mechanism that is electrically insulated from the re-ignition rod mounting portion and moves the re-ignition rod mounting portion up and down are provided. Re-ignition rod insertion mechanism, While melting the material to be melted If the plasma arc disappears, While holding the re-ignition rod on the holding part of the re-ignition rod insertion mechanism The tip of the re-ignition rod Vs Formed at the top Before the molten slag solidifies, the molten slag is inserted through the base metal and above the counter electrode, a voltage is applied between the plasma torch and the counter electrode, and between the plasma torch and the re-ignition rod. After the plasma arc has regenerated, The control unit is removed from the holding unit, and the re-ignition rod mounting unit is raised and removed from the furnace body. Control means and , Is provided.
[0008]
As above It has a holding part that is detachably held at the tip, The tip of the re-ignition rod is inserted into the base metal formed on the counter electrode and on the top of the counter electrode. A re-ignition rod mounting portion and a vertical mechanism that is electrically insulated from the re-ignition rod mounting portion and moves the re-ignition rod mounting portion up and down are provided. Re-ignition rod insertion mechanism, While melting the material to be melted When the plasma arc disappears Re Firing rod The re-ignition rod is held in the holding portion of the re-ignition rod insertion mechanism. tip Vs Formed at the top Before the molten slag solidifies, the molten slag is inserted through the base metal and above the counter electrode, a voltage is applied between the plasma torch and the counter electrode, and between the plasma torch and the re-ignition rod. After the plasma arc has regenerated, The control unit is removed from the holding unit, and the re-ignition rod mounting unit is raised and removed from the furnace body. Since the control means is provided, it is possible to automatically insert the re-ignition rod between the plasma torch and the counter electrode and generate a plasma arc between the plasma torch and the re-ignition rod without manual operation. Further, when the re-ignition rod is inserted between the plasma torch and the counter electrode, a plasma arc can be immediately generated between the plasma torch and the re-ignition rod, so that the plasma arc can be regenerated immediately (short time).
[0011]
Claim 2 The invention described in claim 1 In the melting furnace described above, the re-ignition rod insertion mechanism has a holding member that holds the re-ignition rod at the tip and is rotatably supported by a bearing member, and a double member that covers the columnar member. And a tube.
[0012]
As described above, a rotatable columnar member and a double tube covering the columnar member are provided, so that a refrigerant is supplied to the double tube, and a re-ignition rod is held at the holding portion at the tip of the columnar member. The re-ignition rod can be inserted into a high temperature melting furnace while protecting the cylindrical member from high temperature.
[0013]
Claim 3 The invention described in claim 2 In the melting furnace described in (1), the double pipe provided in the re-ignition rod insertion mechanism is provided with a water supply port for injecting cooling water and a drain port for discharging the injected cooling water. Features.
[0014]
Since the water supply port and the water discharge port are provided in the double pipe as described above, by supplying cooling water into the double pipe, the columnar member is not exposed to a high temperature atmosphere, and the holding part at the tip of the columnar member is provided. The held re-ignition rod can be inserted into a hot melting furnace.
[0015]
Claim 4 The invention described in (1) comprises a furnace body, a plasma torch, and a plasma torch insertion port provided in the upper part of the furnace body, and the material to be melted in the furnace body is placed in the plasma torch and the bottom of the furnace body and the plasma torch insertion port. Melting by a plasma arc generated between counter electrodes provided at a position opposite to And forming a base metal on the counter electrode and a molten slag on top of the base metal In the re-ignition method of the plasma arc in the melting furnace, It has a holding part that is detachably held at the tip, The tip of the re-ignition rod is inserted into the base metal formed on the counter electrode and on the top of the counter electrode. A re-ignition rod insertion portion and a re-ignition rod insertion mechanism provided with a vertical mechanism for moving the re-ignition rod attachment portion up and down electrically insulated from the re-ignition rod attachment portion, If the plasma arc disappears, While holding the re-ignition rod on the holding part of the re-ignition rod insertion mechanism The tip of the re-ignition rod Vs Formed at the top Before the molten slag solidifies, the molten slag is inserted through the base metal and above the counter electrode, a voltage is applied between the plasma torch and the counter electrode, and between the plasma torch and the re-ignition rod. After the plasma arc has regenerated, Detach from the holding part, raise the re-ignition rod mounting part and pull it out of the furnace body It is characterized by that.
[0016]
as mentioned above A re-ignition rod mounting portion having a holding portion for removably holding the re-ignition rod at the tip, and inserting the tip of the re-ignition rod into a base metal formed on the counter electrode and on the upper side of the counter electrode, and the re-ignition A re-ignition rod insertion mechanism that is electrically insulated from the rod mounting portion and provided with a vertical mechanism for moving the re-ignition rod mounting portion up and down is provided. If the plasma arc disappears, While holding the re-ignition rod on the holding portion of the re-ignition rod insertion mechanism, Formed at the top Before the molten slag solidifies, the molten slag is inserted through the base metal and above the counter electrode, a voltage is applied between the plasma torch and the counter electrode, and between the plasma torch and the re-ignition rod. After the plasma arc is regenerated Remove the re-ignition rod from the holder By letting go When the plasma arc disappears during melting of the material to be melted, The plasma arc can be regenerated in a short time.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 3 and 4 are diagrams showing a schematic configuration example of the melting furnace according to the present invention, FIG. 3 is a plan view, and FIG. 4 is a side view. 3 and 4, the same reference numerals as those in FIG. 1 denote the same or corresponding parts. A plasma melting furnace 1, which is a melting furnace, includes a furnace lid 2 and a furnace body 3, a torch insertion port 5 for inserting a plasma torch 4 is provided in the furnace lid 2, and a plasma torch 4 is provided at the bottom of the furnace body 3. Opposite electrodes (not shown) are provided to face each other.
[0018]
Reference numeral 20 denotes a plasma torch insertion mechanism for inserting the plasma torch 4 into the plasma melting furnace 1 from the torch insertion port 5, and the plasma torch insertion mechanism 20 is swiveled on a support column 21 by a swivel mechanism 26 and so on. Is attached via a bracket 33. The plasma torch insertion mechanism 20 includes a vertical movement mechanism 22 that holds the upper end of the plasma torch 4 and moves the plasma torch up and down. Around the furnace body 3 of the plasma melting furnace 1, one, two, or three incineration ash supply devices 24 for supplying incineration ash containing a high melting point substance into the furnace body 3 are installed. A discharge port 25 for discharging exhaust gas and molten slag is provided around the furnace body 3.
[0019]
The plasma torch insertion mechanism 20 can be rotated between the position A in FIG. 3, that is, the position A where the plasma torch 4 reaches just above the torch insertion port 5, and the position B, that is, the standby position of the plasma torch 4 by the turning mechanism 26. It is like that. Further, the re-ignition rod insertion port 12 is provided in the furnace lid 2 so that the re-ignition rod 11 mounted on the re-ignition rod insertion mechanism 13 can be inserted into the furnace body 3 from the re-ignition rod insertion port 12. It has become.
[0020]
5 and 6 are diagrams showing the configuration of the re-ignition rod insertion mechanism 13, FIG. 5 is an overall configuration of the re-ignition rod insertion mechanism 13, FIG. 6A is a detailed configuration of the re-ignition rod mounting portion, 6 (b) and 6 (c) are a partial side sectional view and a front view showing the end of the reignition rod 11, respectively. The re-ignition rod insertion mechanism 13 includes the re-ignition rod mounting portion 14, and the re-ignition rod mounting portion 14 includes a cylindrical member 14-1 and a double tube 14 including an inner tube 14-2a and an outer tube 14-2b. -2 (see FIG. 7). The columnar member 14-1 is rotatably supported by a bearing member 14-4 provided at the tip of the re-ignition rod mounting portion 14, and is rotated by a motor 14-3.
[0021]
The re-ignition rod mounting portion 14 is attached to the electrical insulation members 15-1 and 15-2 with the electrical insulation members 30 and 30 interposed therebetween, and the electrical insulation members 15-1 and 15-2 are screwed into the screw member 16. Then, by rotating the screw member 16 by the motor 19, the re-ignition rod mounting portion 14 moves in the direction of arrow A via the electrical insulating members 15-1 and 15-2. The amount of movement of the reignition rod mounting portion 14 is detected by limit switches 18-1 and 18-2. The re-ignition rod insertion mechanism 13 is mounted on a base member 31, and the base member 31 is supported by support columns 45, 45 (see FIG. 4). Further, as shown in FIG. 4, electrical insulating plates 46, 46 are interposed in the middle of the columns 45, 45, and the reignition rod insertion mechanism 13 is electrically insulated from the lower portions of the columns 45, 45.
[0022]
The reignition rod holding portion 17 that holds the rear end portion of the reignition rod 11 has a truncated cone shape provided at the rear end portion of the reignition rod 11 as shown in FIGS. 6 (a), (b), and (c). By screwing the male thread groove 14-1a provided at the tip of the cylindrical member 14-1 of the reignition rod mounting portion 14 into the female thread groove 11b provided in the recess 11a, the reignition rod 11 is connected to the cylindrical member 14-. 1 is a holding mechanism that can be attached to and held by one.
[0023]
Further, a quadrangular frustum-shaped convex portion 11 c is formed on the outer periphery of the rear end of the reignition rod 11, and this quadrangular frustum-shaped convex portion 11 c is formed on the bearing member 14-4 provided at the front end portion of the reignition rod mounting portion 14. Is formed, the rear end portion of the re-ignition rod 11 is pressed against the quadrangular frustum-shaped recess 14-4a of the bearing member 14-4, and the motor 14-3 is pressed. By rotating forward, the male thread groove 14-1a at the tip of the cylindrical member 14-1 is screwed into the female thread groove 11b at the rear end of the reignition rod 11, and the reignition rod 11 is attached to the cylindrical member 14-1. . Further, the cylindrical member 14-1 is detached from the reignition rod 11 by reversing the motor 14-3. At the time of mounting and demounting, the quadrangular frustum-shaped convex portion 11c at the rear end of the re-igniting rod 11 is fitted into the quadrangular frustum-shaped concave portion 14-4a of the bearing member 14-4 to prevent the re-igniting rod 11 from rotating. Therefore, mounting and demounting can be easily realized.
[0024]
The rotating shaft of the motor 14-3 and the columnar member 14-1 are connected by a coupling 14-7 with an electric insulating member 30 interposed therebetween. The rotating shaft of the motor 14-3 and the columnar member 14-1 are electrically connected. Is electrically insulated. The double pipe 14-2 is also movably supported by the base member 31 via a bracket 15-3 with the electrical insulating member 30 interposed. Thus, between the rotating shaft of the motor 14-3 and the cylindrical member 14-1, between the double tube 14-2 and the electrical insulating member 15-1 of the reignition rod mounting portion 14, between the motor 14-3 and the electric High voltage generated in the re-ignition rod 11 at the time of re-ignition by electrically insulating the re-ignition rod mounting portion 14 and the base member 31 with the electric insulation member 30 interposed between the insulation members 15-2. Can be prevented from being transmitted to the base member 31, and the risk of electric shock can be prevented. For example, if there is a resistance of only 1Ω between the re-ignition rod 11 and the bottom electrode of the furnace bottom, a current of at least 400 A flows at the time of re-ignition, so that a voltage of 400 V is generated in the re-ignition rod 11. This voltage is transmitted to the base member 31 and there is a risk of electric shock.
[0025]
As shown in FIG. 7, the double pipe 14-2 that covers the columnar member 14-1 of the reignition rod mounting portion 14 includes a water supply port 14-5 that communicates with a space 14-2 a between the inner and outer pipes. A drain port 14-6 is provided, and cooling water is injected into the space 14-2a from the water supply port 14-5 and drained from the drain port 14-6, so that the re-ignition rod mounting portion 14 is water cooled. It has become. In this way, by flowing the cooling water through the space 14-2a between the inner tube and the outer tube of the double tube 14-2, it is possible to cool the strong radiant heat from the outside with this cooling water and prevent the temperature rise inside. it can. Moreover, it can cool to the front-end | tip part of the cylindrical member 14-1 which hold | grips the re-ignition stick | rod 11 by flowing cooling gas, such as cooling air, in the space 14-2b of the inner tube which accommodates the cylindrical member 14-1. Here, the cooling with cooling water and the cooling with cooling gas are used together because the cooling gas is diffused from the tip of the inner pipe of the double pipe 14-2 into the furnace to hold the reignition rod 11. This is because the columnar member 14-1 can be effectively cooled to the tip thereof, and cooling gas such as cooling air is less harmful even if dissipated into the furnace. In addition, it is structurally difficult to form the water cooling jacket which cools to the front-end | tip part of the cylindrical member 14-1.
[0026]
In the melting furnace having the above-described configuration, as shown in FIG. 4, the re-ignition rod 11 is attached to the re-ignition rod mounting portion 14 and the motor 19 is rotated in the forward direction. 8 and further through the re-ignition rod insertion port 12, the tip thereof is in a predetermined position in the furnace body 3 (a position directly above the counter electrode 6 and in the base metal 8 b) as shown in FIG. 8. To reach. The stop of the re-ignition rod 11 at a predetermined position is a signal for detecting the amount of movement of the re-ignition rod mounting portion 14 with the limit switch 18-1, and when the control device (not shown) receives the detection signal, a signal for stopping the motor 19. Is output to stop the motor 19. Further, when the tip of the re-ignition rod 11 reaches the bottom of the furnace, the load current value of the motor 19 increases. Therefore, the control device monitors the load current value of the motor 19, and when the predetermined current value is exceeded, the motor 19 is turned off. A signal for stopping may be output to stop the motor 19.
[0027]
When the plasma arc 10 is re-ignited, as shown in FIG. 8, the re-ignition rod 11 is held by the re-ignition rod mounting portion 14 of the re-ignition rod insertion mechanism 13, and the tip thereof is on the counter electrode 6 and the base metal 8b. A voltage is applied between the plasma torch 4 and the counter electrode 6 in a state where the plasma arc 10 is held, and a plasma arc 10 is generated. After the plasma arc 10 is generated, the reignition rod 11 is detached by reversing the motor 14-3. Thereafter, by reversing the motor 19, the re-ignition rod mounting part 14 comes out of the furnace body 3, and when it reaches a predetermined position outside the furnace body 3, the limit switch 18-2 detects it and stops the motor 19. By doing so, the re-ignition rod mounting part 14 stops. The re-ignition rod 11 is melted by the heat of the plasma arc 10 and mixed with the base metal 8b formed in the furnace body 3. A layer of molten slag 8a having a lighter specific gravity is formed on the base metal 8b.
[0028]
In the re-ignition rod insertion mechanism 13, the cylindrical member 14-1 and the double tube 14-2 are electrically connected to the base member 31 and the electrical insulation member 15-1 via the electrical insulation members 30 and 30 as described above. Further, since the rotary shafts of the cylindrical member 14-1 and the motor 14-3 are electrically insulated by the electrical insulation member 30 of the coupling 14-7, as shown in FIG. There is no electrical problem even if the plasma arc 10 is generated by applying a voltage between the plasma torch 4 and the counter electrode 6 while the rod 11 is held by the reignition rod holding portion 17 of the cylindrical member 14-1.
[0029]
As described above, the re-ignition rod 11 can be generated while the re-ignition rod 11 is held by the re-ignition rod mounting portion 14, and after the generation of the plasma arc 10, the re-ignition rod 11 can be detached immediately. The plasma arc 10 can be regenerated. On the other hand, in the conventional method for regenerating the plasma arc 10, when the molten portion around the tip of the reignition rod 11 is slightly solidified and the reignition rod 11 does not fall down, the reignition rod 11 is detached. Then, since the plasma arc 10 is generated between the plasma torch 4 and the reignition rod 11, the plasma arc 10 cannot be immediately regenerated.
[0030]
9 and 10 are diagrams showing a schematic configuration example of the melting furnace according to the present invention, FIG. 9 is a plan view, and FIG. 10 is a side view. In the figure, reference numeral 40 denotes a plasma torch insertion mechanism, and the plasma torch insertion mechanism 40 is attached via a bracket 41 to a turntable 32 that is supported by a support 21 so as to be turnable by a turning mechanism 26. The plasma torch insertion mechanism 40 includes a torch mounting base 42 to which the plasma torch 4 is attached, and the plasma torch 4 is attached to the torch mounting base 42.
[0031]
The torch mount 42 can move the plasma torch 4 up and down. Further, it includes a back-and-forth movement mechanism 43, which can move back and forth as indicated by an arrow E by the back-and-forth movement mechanism 43, and further includes a left-right movement mechanism 44. As shown, it can move left and right. Further, the plasma torch 4 is attached to the torch mounting base 42 of the plasma torch insertion mechanism 40, and the plasma torch 4 is moved to the plasma melting furnace by the turning operation of the A and B positions in FIG. It can be inserted into one furnace body 3. Although not shown from the reignition rod insertion port 12, the reignition rod 11 can be inserted into the furnace body 3 and positioned at a predetermined position by the reignition rod insertion mechanism 13, as shown in FIG. It has become.
[0032]
In the melting furnace configured as described above, the re-ignition rod 11 is inserted into a predetermined position in the furnace body 3 by the re-ignition rod insertion mechanism 13 as shown in FIG. After that, the plasma torch insertion mechanism 40 is swung from the position B in FIG. 9 to the position A by the swiveling mechanism 26 and is lowered by the vertical movement mechanism in this state, and the tip of the plasma torch 4 is lowered to a predetermined position above the counter electrode 6. A predetermined voltage is applied between the plasma torch 4 and the counter electrode 6 to generate a plasma arc. The ignition of the plasma arc and the desorption of the re-ignition rod 11 are performed, and the re-ignition rod mounting portion 14 of the re-ignition rod insertion mechanism 13 is extracted from the furnace body 3. Incineration ash is supplied from the incineration ash supply device 24 and melted.
[0033]
If the plasma arc suddenly disappears due to fluctuations in arc power and the plasma arc 10 needs to be generated immediately, the re-ignition rod mounting portion 14 of the re-ignition rod insertion mechanism 13 is re-applied as shown in FIG. A voltage is applied between the plasma torch 4 and the counter electrode 6 with the ignition rod 11 mounted and held on the counter electrode 6 to generate a plasma arc 10. After the plasma arc 10 is generated, the re-ignition rod 11 is detached from the tip of the columnar member 14-1 of the re-ignition rod mounting portion 14 as described above by reversing the motor 14-3.
[0034]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. It should be noted that any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are exhibited.
[0035]
【The invention's effect】
As described above, according to the invention described in each claim, the following excellent effects can be obtained.
[0036]
According to the invention described in claim 1, the re-ignition rod is It has a holding part that is detachably held at the tip, The tip of the re-ignition rod is placed in the base metal formed on the counter electrode and on the top of the counter electrode. A re-ignition rod mounting portion to be inserted and a vertical mechanism that is electrically insulated from the re-ignition rod mounting portion and moves the re-ignition rod mounting portion up and down are provided. Re-ignition rod insertion mechanism, While melting the material to be melted When the plasma arc disappears Re Firing rod The re-ignition rod is held in the holding portion of the re-ignition rod insertion mechanism. tip Vs Formed at the top Before the molten slag solidifies, the molten slag is inserted through the base metal and above the counter electrode, a voltage is applied between the plasma torch and the counter electrode, and between the plasma torch and the re-ignition rod. After the plasma arc has regenerated, The control unit is removed from the holding unit, and the re-ignition rod mounting unit is raised and removed from the furnace body. Control means, so that the re-ignition rod is automatically inserted between the plasma torch and the counter electrode without human intervention. , A plasma arc can be generated between the laser torch and the re-ignition rod. Further, when the re-ignition rod is inserted between the plasma torch and the counter electrode, a plasma arc can be immediately generated between the plasma torch and the re-ignition rod, so that the plasma arc can be regenerated immediately (short time).
[0038]
Claim 2 According to the invention described in (2), since the rotatable cylindrical member and the double pipe covering the cylindrical member are provided, the refrigerant is supplied to the double pipe, and the reignition rod is attached to the holding portion at the tip of the cylindrical member. The re-ignition rod can be inserted into a high temperature melting furnace while holding the columnar member and protecting the cylindrical member from high temperature.
[0039]
Claim 3 According to the invention described in (2), since the water supply port and the water discharge port are provided in the double pipe, by supplying cooling water into the double pipe, the columnar member tip is not exposed to the high temperature atmosphere. The re-ignition rod held in the holding portion can be inserted into a high-temperature melting furnace.
[0040]
According to invention of Claim 4, A re-ignition rod mounting portion having a holding portion for removably holding the re-ignition rod at the tip, and inserting the tip of the re-ignition rod into a base metal formed on the counter electrode and on the upper side of the counter electrode, and the re-ignition A re-ignition rod insertion mechanism that is electrically insulated from the rod mounting portion and provided with a vertical mechanism for moving the re-ignition rod mounting portion up and down is provided. When the plasma arc disappears Re Firing rod The re-ignition rod is held in the holding portion of the re-ignition rod insertion mechanism. tip Vs Formed at the top Before the molten slag solidifies, the molten slag is inserted through the base metal and above the counter electrode, a voltage is applied between the plasma torch and the counter electrode, and between the plasma torch and the re-ignition rod. After the plasma arc has regenerated, From the holding part By letting go When the plasma arc disappears during melting of the material to be melted, The plasma arc can be regenerated in a short time.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a plasma melting furnace which is a conventional melting furnace.
FIG. 2 is a view showing a state where a re-ignition rod is arranged in a plasma melting furnace and a plasma arc is generated.
FIG. 3 is a plan view showing a schematic configuration example of a melting furnace according to the present invention.
FIG. 4 is a side view showing a schematic configuration example of a melting furnace according to the present invention.
FIG. 5 is a diagram showing an example of the entire configuration of a re-ignition rod insertion mechanism used in a melting furnace according to the present invention.
6A is a partial side sectional view showing a detailed configuration of a re-ignition rod mounting portion of the re-ignition rod insertion mechanism, and FIGS. 6B and 6C are partial side sectional views showing an end portion of the re-ignition rod, respectively. FIG.
FIG. 7 is a cross-sectional view of a reignition rod mounting portion of a reignition rod insertion mechanism.
FIG. 8 is a view showing a state where a re-ignition rod is arranged in the melting furnace according to the present invention to generate a plasma arc.
FIG. 9 is a plan view showing a schematic configuration example of a melting furnace according to the present invention.
FIG. 10 is a side view showing a schematic configuration example of a melting furnace according to the present invention.
[Explanation of symbols]
1 Plasma melting furnace
2 hearth
3 Furnace
4 Plasma torch
5 Torch insertion slot
6 Counter electrode
7 Incineration ash
8a Molten slag
8b base metal
9 Discharge port
10 Plasma arc
11 Re-ignition rod
12 Re-ignition rod insertion slot
13 Re-ignition rod insertion mechanism
14 Re-ignition rod mounting part
14-1 Cylindrical member
14-2 Double pipe
14-3 Motor
14-4 Bearing member
14-5 Water inlet
14-6 Drainage port
14-7 Coupling
15-1 Electrical insulation member
15-2 Electrical insulation member
15-3 Bracket
16 Screw member
17 Re-ignition rod holder
18-1 Limit switch
18-2 Limit switch
19 Motor
20 Plasma torch insertion mechanism
21 Prop
22 Vertical movement mechanism
24 Incineration ash supply equipment
25 outlet
26 Turning mechanism
28 Torch mount
30 Electrical insulation members
31 Base material
32 swivel
33 Bracket
40 Plasma torch insertion mechanism
41 Bracket
42 Torch mount
43 Forward / backward moving mechanism
44 Horizontal movement mechanism
45 prop
46 Electric insulation plate

Claims

炉体、プラズマトーチ、前記炉体上部に設けたプラズマトーチ挿入口を具備し、該炉体内に投入された被溶融物を該プラズマトーチと前記炉体底部で且つ前記プラズマトーチ挿入口に対向する位置に設けた対極の間に発生させたプラズマアークにより溶融し、該対極上にベースメタル及び該ベースメタルの上部に溶融スラグを形成する溶融炉において、
再着火棒を先端に着脱可能に保持する保持部を有し、該再着火棒の先端を前記対極上で且つ前記対極上部に形成されているベースメタル中に挿入する再着火棒装着部と該再着火棒装着部と電気的に絶縁され該再着火棒装着部を上下動させる上下機構を設けた再着火棒挿入機構と、
前記被溶融物の溶融中に前記プラズマアークが消滅した場合、前記再着火棒を前記再着火棒挿入機構の保持部に保持したまま該再着火棒の先端を前記対極上部に形成されている前記溶融スラグが固化する前に該溶融スラグを貫通させて前記ベースメタル中で、且つ前記対極の上に挿入し、前記プラズマトーチと前記対極の間に電圧を印加し、該プラズマトーチと該再着火棒の間でプラズマアークが再生した後に該再着火棒を前記保持部から離脱させ、前記再着火棒装着部を上昇させて炉体から抜き出す制御を行う制御手段と、を設けたことを特徴とする溶融炉。A furnace body, a plasma torch, and a plasma torch insertion port provided in the upper part of the furnace body are provided, and a material to be melted in the furnace body is opposed to the plasma torch insertion port at the bottom of the plasma torch and the furnace body. In a melting furnace that is melted by a plasma arc generated between counter electrodes provided at a position, and that forms a base metal on the counter electrode and a molten slag on the base metal ,
It has a holding portion for detachably holding the reignition rod tip, reignition rod mounting portion and said inserting the tip of該再ignition rod in the base metal formed on and said counter top with the pair superb A re -ignition rod insertion mechanism provided with a vertical mechanism that is electrically insulated from the re-ignition rod mounting portion and moves the re-ignition rod mounting portion up and down ;
Wherein when the plasma arc during the melting of the melt has been extinguished, the formed tip of該再ignition rod while holding the holding portion of the re-ignition rod the reignition rod insertion mechanism before Symbol counter top Before the molten slag solidifies, the molten slag is inserted through the base metal and above the counter electrode, and a voltage is applied between the plasma torch and the counter electrode, and the plasma torch and the the該再ignition rod after the plasma arc has been reproduced among the ignition rod is detached from the holding portion, characterized in that said control means for performing control of extracting from the furnace body is raised a reignition rod mounting portion, the provided A melting furnace.

請求項１に記載の溶融炉において、
前記再着火棒挿入機構は、先端に前記再着火棒を保持する保持部を有し、且つ軸受部材で回転自在に支持された円柱状部材と、該円柱状部材を覆う二重管とを具備することを特徴とする溶融炉。In the melting furnace according to claim 1 ,
The re-ignition rod insertion mechanism includes a columnar member having a holding portion that holds the re-ignition rod at a tip and rotatably supported by a bearing member, and a double tube that covers the columnar member. A melting furnace characterized by that.

請求項２に記載の溶融炉において、
前記再着火棒挿入機構が具備する前記二重管には、冷却水を注入するための給水口と、該注入された冷却水を排出するための排水口を設けたことを特徴とする溶融炉。The melting furnace according to claim 2 ,
The double furnace provided in the re-ignition rod insertion mechanism is provided with a water supply port for injecting cooling water and a drain port for discharging the injected cooling water. .

炉体、プラズマトーチ、前記炉体上部に設けたプラズマトーチ挿入口を具備し、該炉体内に投入された被溶融物を該プラズマトーチと前記炉体底部で且つ前記プラズマトーチ挿入口に対向する位置に設けた対極の間に発生させたプラズマアークにより溶融し、該対極上にベースメタル及び該ベースメタルの上部に溶融スラグを形成する溶融炉におけるプラズマアークの再着火方法において、
再着火棒を先端に着脱可能に保持する保持部を有し、該再着火棒の先端を前記対極上で且つ前記対極上部に形成されているベースメタル中に挿入する再着火棒装着部と該再着火棒装着部と電気的に絶縁され該再着火棒装着部を上下動させる上下機構を設けた再着火棒挿入機構を備え、
前記被溶融物の溶融中に前記プラズマアークが消滅した場合、前記再着火棒を前記再着火棒挿入機構の保持部に保持したまま該再着火棒の先端を前記対極上部に形成されている前記溶融スラグが固化する前に該溶融スラグを貫通させて前記ベースメタル中で、且つ前記対極の上に挿入し、前記プラズマトーチと前記対極の間に電圧を印加し、該プラズマトーチと該再着火棒の間でプラズマアークが再生した後に該再着火棒を前記保持部から離脱させ、前記再着火棒装着部を上昇させて炉体から抜き出すことを特徴とする溶融炉におけるプラズマアークの再着火方法。A furnace body, a plasma torch, and a plasma torch insertion port provided in the upper part of the furnace body are provided, and a material to be melted in the furnace body is opposed to the plasma torch insertion port at the bottom of the plasma torch and the furnace body. In a method for reigniting a plasma arc in a melting furnace, which is melted by a plasma arc generated between counter electrodes provided at a position, and a base metal is formed on the counter electrode and a molten slag is formed on top of the base metal ,
It has a holding portion for detachably holding the reignition rod tip, reignition rod mounting portion and said inserting the tip of該再ignition rod in the base metal formed on and said counter top with the pair superb A re-ignition rod insertion mechanism provided with a vertical mechanism that is electrically insulated from the re-ignition rod mounting portion and moves the re-ignition rod mounting portion up and down;
Wherein when the plasma arc during the melting of the melt has been extinguished, the formed tip of該再ignition rod while holding the holding portion of the re-ignition rod the reignition rod insertion mechanism before Symbol counter top Before the molten slag solidifies, the molten slag is inserted through the base metal and above the counter electrode, and a voltage is applied between the plasma torch and the counter electrode, and the plasma torch and the Re-ignition of the plasma arc in the melting furnace , wherein after the plasma arc is regenerated between the ignition rods, the re-ignition rod is detached from the holding portion, the re-ignition rod mounting portion is raised and extracted from the furnace body Method.