JP3591432B2

JP3591432B2 - Dismantling method of blast furnace bottom

Info

Publication number: JP3591432B2
Application number: JP2000212508A
Authority: JP
Inventors: 啓孝小島; 昌男藤田; 満木口; 博行）安原
Original assignee: JFE Steel Corp
Current assignee: JFE Steel Corp
Priority date: 2000-07-13
Filing date: 2000-07-13
Publication date: 2004-11-17
Anticipated expiration: 2020-07-13
Also published as: JP2002030313A

Description

【０００１】
【発明の属する技術分野】
本発明は、高炉炉底部の解体方法に係り、さらに詳しくは高炉を改修するため吹き卸し後、その炉底部に残存する残銑凝固物を分割することなく炉外に搬出することのできる高炉炉底部の解体方法に関するものである。
【０００２】
【従来の技術】
高炉の操業を長期間行うと、内部に設けられた煉瓦の浸食が著しく進行する。これを放置すると、高炉の上部では、耐圧容器として外周に設けられている鉄皮に亀裂が入ってガス等が噴出し、また、高炉の下部では、炉底のカーボン煉瓦が浸食され溶解物が鉄皮を溶損して流出する事故等を生じた時、ステーブ冷却水や鉄皮冷却水による水蒸気爆発を起こすこともある。このため、十数年に一度に高炉を吹き却して内部の改修を行っている。
【０００３】
高炉の改修に際しては、まず高炉炉体の炉底部を囲む外周壁の一部の鉄皮や内張りれんがをバックホー、ショベル等の建設重機で破壊して開口を設け、建設重機を炉底部内に導入する。そして、炉底部に残存しているコークスを建設重機で炉外に押し出して、除去する。その後、作業者が炉内に入り、削岩機や発破を用いて、その下に残っている銑鉄を主としてスラグあるいはコークスの混合した残銑凝固物（一枚岩のように一体化していることが多い）を砕き、炉外に搬出する必要がある。
【０００４】
残銑凝固物は崩壊性凝固物等と異なり、強固で分解することが難しく、爆破による分割作業が行われる。この爆破に先立ち、まず残銑凝固物本体に穿孔ドリルまたは酸素ランスで多数の穿孔を設け、そこにダイナマイトを詰める作業をする必要があった。このような穿孔、発破、分割する方法では、穿孔作業に長時間を要するため、工事期間が長くかかり、発破作業が他の解体作業を阻害する。また、爆発時に破砕物が飛散し危険で、騒音が著しいことから高炉周辺での作業中断を余儀なくされていた。
【０００５】
ところで、高炉の改修工事は、工事期間をできるかぎり短縮する必要があるため、炉体内の内張りれんがや残銑凝固物が完全に室温に冷却される前に、解体作業が開始され、その作業環境は、炉底部の開口と炉頂部のマンホール程度しかない場所で、かつ、粉塵の発生が多く悪環境である。また、炉壁れんがや残銑凝固物は固くて重いので開口から搬出するには、それらを小さく分割する必要がある。そのため、従来の解体作業に要する時間は非常に長く、高コスト作業となっていた。
【０００６】
また、炉体支柱にメンテナンス用に設置してあるアウトリガークレーンを使用することも知られており、高炉炉底部の鉄皮を重量５〜５０ｔの短冊状に切断して、アウトリガークレーンで撤去すると共に、高炉の炉底部側壁に設けた開口部から高炉内に存在する残銑凝固物を炉外に除去していた。さらに、例えば、特開平１０−９６００５号公報および特開平７−１９７１１２号公報に、高炉内部の改修を行う方法が開示されている。
【０００７】
特開平１０−９６００５号公報に記載された高炉炉底部の解体方法では、高炉の下部を切断し、高炉炉体を高炉支柱で懸架、固定した後に、高炉の下部の鉄皮を解体し、高炉内の残銑凝固物をワイヤ・ソーで水平に切断し、残銑凝固物を一体として水平に引き出していた。一方、特開平７−１９７１１２号公報に記載された高炉炉底の残銑凝固物の炉外搬出方法では、高炉内における周辺部の残銑凝固物と炉底耐火物の間にジャッキを設置して垂直方向に持ち上げた後、円筒状または摩擦係数の軽減物を挿入して残銑凝固物を水平方向に引き出すものであった。
【０００８】
【発明が解決しようとする課題】
しかしながら、前記従来の高炉炉底部の解体方法は、以下の問題があった。
（１）アウトリガークレーンを使用した方法では、アウトリガークレーンの吊り上げ能力が７０〜２００ｔ程度であるのに対し、高炉内の残銑凝固物には５００ｔ程度の重量を有する大型残銑凝固物もあるため残銑凝固物を２００ｔ以下の重量に分割する必要があった。また、高炉上部の解体作業と下部の残銑凝固物の除去作業が並行して行われるので、安全性を確保するため羽口部に安全天井が設置されており、これを除去後に再度設置する工程が必要となり、工期がかかっていた。
【０００９】
（２）特開平１０−９６００５号公報に記載された高炉炉底部の解体方法は、まず、れんが層の切断作業に長時間を必要とし、かつ残銑凝固物を水平方向に引き出すには、れんが切断粉の助けをかりても引き出し力として大きなものが必要で、引き出せる残銑凝固物量に制約があった。
（３）特開平７−１９７１１２号公報に記載された高炉内の残銑凝固物の炉外搬出方法も残銑凝固物を水平に引き出すものであるが、摩擦係数軽減物を利用しても前記（２）と同様に、引き出せる残銑凝固物量に制約があった。また、前記（２）、（３）においては、高炉炉体の外周に炉体支持用支柱があり、残銑凝固物を引き出す際に該支柱と干渉しないように引き出し方向を正確に導くことが必要であり、これも作業時間の延長につながっていた。
【００１０】
以上のように、アウトリガークレーンを使用した方法では、作業期間が長期間かかっており、これを特開平１０−９６００５号公報および特開平７−１９７１１２号公報に記載された方法によって短縮することができたが、まだ作業内容等に改良の余地があった。
本発明はこのような事情を考慮してなされたもので、高炉改修時における高炉の炉体冷却段階の早期に炉底部に残存する残銑凝固物を経済的に、かつ、短時間で撤去する高炉炉底部の解体方法を提供することを目的とするものである。
【００１１】
【課題を解決するための手段】
前記目的を達成するための請求項１記載の本発明は、吹き卸し後の高炉の炉体を、その炉底部に残存する残銑凝固物より高い位置で水平に切断し、この切断位置より上方の上部炉体を炉体支柱に設置した昇降手段を用いて懸架し、前記切断位置より下方にある下部炉体の少なくとも一部を全周にわたり撤去した後、前記残銑凝固物を炉外に搬出する高炉炉底部の解体方法において、前記残銑凝固物を炉外に搬出する前に、前記残銑凝固物の周辺部に沿い、かつ該残銑凝固物と炉底耐火物との間の複数箇所に空洞を堀り、該空洞部に配設したジャッキで前記残銑凝固物を持ち上げ該残銑凝固物と炉底耐火物との間に間隙を形成する段階と、該間隙に吊バンドを差し渡した後、前記炉体支柱に懸架した上部炉体を前記昇降手段を用いて下降させ、前記上部炉体の下端部に固定した吊具に前記吊バンドの両端部を接続する段階と、前記炉体支柱に懸架した上部炉体を前記残銑凝固物と共に前記昇降手段を用いて吊り上げ、前記残銑凝固物と炉底耐火物との間に作業空間を形成する段階と、該炉底耐火物上に水平移動台を引き込み配置する段階と、前記炉体支柱に懸架した上部炉体に吊具および吊バンドを介して懸架された前記残銑凝固物を前記昇降手段を用いて下降して前記水平移動台上に載置する段階と、前記上部炉体の下端部に固定した吊具を切り離した後、前記残銑凝固物を載置した前記水平移動台を炉内から炉外に移動させることを特徴とする高炉炉底部の解体方法である。
【００１２】
請求項２記載の本発明は、前記吊具は上部炉体の羽口に固定されることを特徴とする請求項１記載の高炉炉底部の解体方法である。
請求項３記載の本発明は、前記残銑凝固物と前記炉底耐火物の間に形成した作業空間下で前記炉底耐火物の表面を平坦に補修し、該補修した炉底耐火物上に複数の台車用レールを敷設した後、該台車用レール上に水平移動台を引き込み配置することを特徴とする請求項１または２記載の高炉炉底部の解体方法である。
【００１３】
請求項４記載の本発明は、前記炉底耐火物上に引き込み配置する水平移動台として、ローラを介して移動する水平移動台車またはレール上を摺動する水平移動スライド台を使用することを特徴とする請求項１、２または３記載の高炉炉底部の解体方法である。
【００１４】
【発明の実施の形態】
本発明に係る高炉炉底部の解体方法をその手順にしたがって説明する。
図１に示すように、高炉１０は外部が鉄皮で覆われており、鉄皮の内側には冷却用のステーブが取り付けられ、さらにステーブの内側には耐火レンガ等からなるれんが層を設けた構造になっている。高炉１０は下部から炉底部１１、朝顔部１２、炉胸部１３、炉口部１４の順に設置され、各部の接続部分は溶接により固着されている。高炉１０の外側には、補修等のため炉体支柱１５が組み立てられており、炉体支柱１５の上部には昇降手段の一例であるリフトジャッキ１６が複数基設置してある。
【００１５】
吹き卸された高炉１０の炉底部最下部には炉底れんが（通常、カーボンれんがを使用）１７があり、炉底れんが１７の上には銑鉄にスラグやコークスが混合、凝固して一体化した残銑凝固物１９があり、その上にはコークス、スラグ等の混合物からなる溶融凝固した崩壊物１８がある。炉底れんが１７の補修を行うためには、崩壊物１８および残銑凝固物１９を撤去する必要がある。なお、本実施の形態では崩壊物１８を予めブルドーザ等の建設重機を用いて撤去した後、残銑凝固物１９のみを吊り上げて炉底部から除去する場合について説明する。
【００１６】
吹き卸し後の高炉１０の炉体部を解体するときには、まず、炉体支柱１５に設置しておいたリフトジャッキ１６から昇降自在に垂下されたロッド２０の先端部を炉口部１４に固定して高炉１０を支持しておく。次に、炉底部１１の鉄皮を水平に切断し、切断位置Ａより下方にある下部炉体２の外周部分を炉外に撤去する。切断する高さは、少なくとも炉底部１１に残存する残銑凝固物１９より高い位置で行う。高炉１０の下部炉体２の鉄皮を除去すると、鉄皮の切断位置Ａより上方にある上部炉体１は炉体支柱１５に設置しておいたリフトジャッキ１６によって懸架される。
【００１７】
図２に示すように、下部の鉄皮を除去することによって開放された高炉１０の内部にあるれんがを図示しない建設重機で破壊し、炉底れんが１７上の炉内残留物のうち、コークス、スラグなど容易に崩すことができる崩壊物１８等は、リフトジャッキ１６を操作して上部炉体１を上昇させ、建設重機で炉体基礎の外へ排出する。炉内残留物のうち、容易に崩すことができない残銑凝固物１９が残存するが、この重量は通常３００〜５００ｔであるが、寿命の長かった高炉では炉底れんが１７の浸食領域が出銑口より下方に広がり、その浸食領域に存在する残銑凝固物１９の一部は高炉操業中にも冷却により凝固しており、炉底れんが１７の代替状態で存在する。
【００１８】
そのため、残銑凝固物１９が大きくなり、直径がほぼ炉床径に近く、５０００ｍ^３クラスの高炉では容積２５０ｍ^３程度で、重量が１３００ｔにも達する大塊を炉内から水平方向に引き出すことが必要になる。この残銑凝固物１９は建設重機によって崩壊することは困難であり、ダイナマイトを用いて発破により破壊させるしかないが、この発破作業には長時間を要するのは前述の通りである。
【００１９】
ここで、高炉１０の重量とリフトジャッキ１６の吊り上げ能力の関係について説明する。リフトジャッキ１６は、新しい炉体の据え付けにおいて、リング状に形成され、炉体冷却装置等を事前に取り付けられた上下方向に複数（例えば４個）に分割された鉄皮を炉体支柱１５内で組み立てる場合にも用いられる。例えば、内容積が約５０００ｍ^２（出銑量日産１００００ｔ）の高炉１０の据え付け鉄皮の総重量（内部のれんがを除く）は、約５５００ｔであり、高炉１０の改修に使用するリフトジャッキ１６はこれに見合った約２００ｔ／台×３０台＝約６０００ｔの吊り上げ能力を有している。一方、高炉解体時に高炉１０の炉体下部を切断して炉体上部１のみをリフトジャッキ１６により支持するときの重量は３０００〜４０００ｔになるのでリフトジャッキ１６は約２０００〜３０００ｔの余力を有していることになる。
【００２０】
本発明者らは、このリフトジャッキ１６の余力に着目し、高炉１０を解体するときにリフトジャッキ１６で残銑凝固物１９を昇降させる方法を開発した。
図３に示すように、残銑凝固物１９は炉底れんが１７の上に存在する。崩壊物１８を除去した後、図４に示すように、炉底れんが１７の表面から残銑凝固物１９の周辺部の複数箇所に空洞２１を掘り、空洞２１の箇所で残銑凝固物１９と炉底れんが１７との間に持上ジャッキ２２を設置する。この空洞２１部分は、例えばショベルカー等で容易に掘ることができる。次いで、図５に示すように、持上ジャッキ２２により残銑凝固物１９を矢印方向にジャッキアップする。このようなショベルカー等による空洞２１の掘削や、持上ジャッキ２２による残銑凝固物１９のジャッキアップは残銑凝固物１９の温度を常温まで冷却しなくてもよく、その温度が３００ ℃程度あっても作業可能であり、残銑凝固物１９の除去作業を早目に開始できる。
【００２１】
続いて、図６の（Ａ）および（Ｂ）に示すように、懸架された炉体上部の下端部に配設された羽口２３に鉄皮側吊具２４を固定する一方、残銑凝固物１９と炉底れんが１７との間に鉄板で作った残銑吊バンド２５（幅１２００ｍｍ、厚み５０ｍｍ程度）を矢印で示す水平方向に差し渡す。図７に示すように、懸架された高炉１０の炉体上部１をリフトジャッキ１６で下降させた後、鉄皮側吊具２４に残銑吊バンド２５を連結する。次に、図８に示すように、炉体上部１をリフトジャッキ１６で上昇させ、鉄皮側吊具２４と残銑吊バンド２５を介して残銑凝固物１９を吊り上げ、炉底れんが１７の上に作業空間を形成する。
【００２２】
図９、図１０に示すように炉底れんが１７の表面を凹凸のない平坦な表面に補修した後、図１１に示すように、炉底れんが１７の表面に複数本の水平移動台の走行用である炉内台車用レール２８を並行に敷設する。図１２に示すように、水平移動台２９はウインチ等を用いて炉内台車用レール２８上に簡単に取り込むことができる。水平移動台２９は、例えば、図１３〜図１５に示すように、その下部に移動用ローラ３０およびガイドローラ３１を備えた台車とすることができる。水平移動台２９の下面には、下向きに一対の支持フレーム３７を設け、これら支持フレーム３７の間にエンドレスチェン３８で連結した多数の移動用ローラ３０を備え、支持フレームの外面側にガイドローラ３１を配設したローラ構造体３９を設ける。ローラ構造体３９は市販のものを使用し、水平移動台２９の下部に間隔を置いて例えば４列取り付けてあり、溝型の炉内台車用レール２８に沿って移動するようになっている。
【００２３】
なお、炉内台車用レール28は炉底れんが17の表面を凹凸のない平坦面にした後に敷設されるので大きな荷重を受けることができ、炉底れんが17に部分的凹面があったときはモルタルで充填して平滑化してもよい。
また、水平移動台29は、図16に示すように、その下部にスライドシュー40を配設し、スライドシュー40を溝型の炉内台車用レール28に沿って摺動させるスライド台としてもよい。スライドシュー40の下面にテフロン（デュポン社の登録商標）41を張りつけ、また炉内台車用レール28の溝部の上面にステンレススチール板(SUS板)42 を取り付けて摩擦係数を小さくする。あるいは、図17に示すように、炉底れんが17の上に設けた底板43の上にレベル調整ライナー44を介してＩ型レール45を敷設し、この上を車輪を備えた台車を移動させるか、もしくは、Ｉ型レール45の上にスライド台を載せ、潤滑油を用いて滑らせるようにしてもよい。水平移動台車29は、台車タイプあるいはスライド台タイプのいずれでもよいが、高炉改修頻度が極めて少ないので、低コストで摩擦係数を小さくでき、かつ作業性のよい水平移動台29の移動構造とするのが肝要である。
【００２４】
さて、図１８に示すように、高炉１０の炉体上部１をリフトジャッキ１６で下降させ、鉄皮側吊具２４と残銑吊バンド２５を介して支持されていた残銑凝固物１９を水平移動台２９に載せる。鉄皮側吊具２４を羽口２３から切り離した後、図１９に示すように、高炉１０の炉体上部１をリフトジャッキ１６で上昇して上方に退避させる。残銑凝固物１９を支持するのに使用した鉄皮側吊具２４と残銑吊バンド２５は、水平移動台２９上に載せたままとする。炉内台車用レール２８に接続して炉外台車用レール３２がレベリングブロック４６上に配備されており、残銑凝固物１９を載せた水平移動台２９を、積荷レベル調整架構３３をセットした炉体用輸送台車３４の方に移動可能としている。
【００２５】
図２０に示すように、炉外台車用レール３２近傍に配備したセンターホールジャッキ３５を１ストローク操作する毎に固定位置を前方に変更しながら残銑凝固物１９を載せた水平移動台２９を尺取り虫のように炉内台車用レール２８から炉外台車用レール３２上に移動させて炉内から炉外へ引き出す。次に、炉体用輸送台車３４上にセットしたセンターホルジャッキ３６を操作して、図２１に示すように、炉体用輸送台車３４が備えた積荷レベル調整架構３３上に配備したセンターホールジャッキ３５を操作してレベリングブロック４６を炉体用輸送台車３４上に移動させ、これによってレベリングブロック４６に敷設した炉外台車用レール３２上の水平移動台２９と共に残銑凝固物１９を炉体用輸送台車３４の積荷レベル調整架構３３に載せる。引続き炉体用輸送台車３４を残銑凝固物置場まで移動させ、一連の高炉炉底部の解体作業を終了する。
【００２６】
【発明の効果】
以上、説明したように本発明によれば、残銑凝固物を高炉を支持している昇降手段によって昇降するので、残銑凝固物の昇降手段を別に用意しなくてもよく経済的である。上部炉体の下端部に固定した鉄皮側吊具に接続した残銑吊バンドで重量物である残銑凝固物を一体化した状態で吊り上げるので、かなりの高温状態で早期にその昇降作業および炉内から炉外への移動作業を、迅速に行うことが可能となり、高炉炉底部の解体作業の時間短縮が達成される。
【図面の簡単な説明】
【図１】本発明に係る高炉炉底部の解体方法に適用される高炉の正面図である。
【図２】本発明に係る高炉炉底部の鉄皮を除去したときの炉底部内状況を示す正面図である。
【図３】本発明に係る高炉炉底部の鉄皮を除去したときの炉底部内の残銑凝固物状況を示す正面図である。
【図４】本発明に係る高炉炉底部の鉄皮を除去して炉底部内の残銑凝固物の周辺部に掘削した複数の空洞に持上ジャッキを配置した状況を示す平面図である。
【図５】本発明に係る炉底部内の残銑凝固物を持上ジャッキにより持ち上げた状況を示す正面図である。
【図６】（Ａ）本発明に係る持上ジャッキにより持ち上げた残銑凝固物と炉底れんがとの間に残銑吊バンドを差し渡した状況を示す正面図であり、（Ｂ）羽口に鉄皮側吊具を取り付ける状況を示す部分拡大正面図である。
【図７】本発明に係る懸架された炉体上部を下降させて、羽口に固定した鉄皮側吊具に残銑吊バンドを連結した状況を示す正面図である。
【図８】本発明に係る炉体上部をリフトジャッキで上昇させ、鉄皮側吊具と残銑吊バンドを介して残銑凝固物を吊り上げ、炉底れんがの上に作業空間を形成する状況を示す正面図である。
【図９】本発明に係る炉底れんがの表層部を建設重機で整備する状況を示す正面図である。
【図１０】本発明に係る炉底れんがの表層部を凹凸のない平坦な表面に補修した状況を示す正面図である。
【図１１】本発明に係る炉底れんがの表面に炉内台車用レールを敷設する状況を示す正面図である。
【図１２】本発明に係る水平移動台を炉内台車用レール上に取り込んだ状況を示す正面図である。
【図１３】本発明に係る水平移動台の下部に設けたローラ構造体を溝型の炉内台車用レールに対応させて配設した状況を示す側面図である。
【図１４】本発明に係る水平移動台の下部に設けた移動用ローラおよびガイドローラからなるローラ構造体を溝型の炉内台車用レールに対応させて配設した状況を示す側面図である。
【図１５】本発明に係るエンドレスチェンで連結した多数の移動用ローラを内部に備え、外部にガイドローラを配設したローラ構造体を示す正面図である。
【図１６】本発明に係る水平移動台の下面に配設したスライドシューを溝型レールに対応して配設したスライド構造を示す側面図である。
【図１７】本発明に係る高炉の炉底れんがの上に敷設したＩ型レールを示す側面図である。
【図１８】本発明に係る炉体上部をリフトジャッキで下降させ、残銑吊バンドを介して支持された残銑凝固物を水平移動台に載せる状況を示す正面図である。
【図１９】本発明に係る炉体上部をリフトジャッキで上昇して退避させる一方、残銑凝固物を載せた水平移動台を、炉体用輸送台車の方に移動させる状況を示す正面図である。
【図２０】本発明に係る炉外台車用レール近傍に配備したセンターホールジャッキを操作して残銑凝固物を載せた水平移動台を炉外台車用レール上まで移動させる状況を示す正面図である。
【図２１】本発明に係る残銑凝固物を載せた水平移動台を炉外台車用レールを経由して炉体用輸送台車をセットした積荷レベル調整架構上に載せる状況を示す正面図である。
【符号の説明】
１上部炉体
２下部炉体
１０高炉
１１炉底部
１２朝顔部
１３炉胸部
１４炉口部
１５炉体支柱
１６リフトジャッキ
１７炉底れんが
１８崩壊物
１９残銑凝固物
２０ロッド
２１空洞
２２持上ジャッキ
２３羽口
２４鉄皮側吊具
２５残銑吊バンド
２６建設重機
２８炉内台車用レール
２９水平移動台
３０移動用ローラ
３１ガイドローラ
３２レベリングブロック
３３積荷レベル調整用架構
３４炉体用輸送台車
３５、３６センターホールジャッキ
３７支持フレーム
３８エンドレスチェン
３９ローラ構造体
４０スライドシュー
４１テフロン
４２ステンレススチール板
４３底板
４４レベル調整ライナー
４５Ｉ型レール
４６レベリングブロック[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for dismantling a bottom of a blast furnace, and more particularly, to a blast furnace which can be discharged outside the furnace without splitting residual iron solidified material remaining at the bottom of the blast furnace after being blown off to repair the blast furnace. It relates to the method of dismantling the bottom.
[0002]
[Prior art]
When the blast furnace is operated for a long period of time, the erosion of the bricks provided therein proceeds remarkably. If this is left undisturbed, gas will erupt in the upper part of the blast furnace as cracks will occur in the steel shell provided on the outer periphery as a pressure-resistant vessel. In the event of an accident, such as erosion of the steel shell and outflow, steam explosion due to stave cooling water or steel shell cooling water may occur. For this reason, blast furnaces are blown out once every ten years to renovate the interior.
[0003]
When refurbishing the blast furnace, firstly, a part of the outer shell surrounding the furnace bottom of the blast furnace body and the inner lining brick were destroyed by a heavy construction machine such as a backhoe or shovel to make an opening, and the heavy construction equipment was introduced into the furnace bottom. I do. Then, the coke remaining at the furnace bottom is extruded out of the furnace by a heavy construction machine and removed. After that, the worker enters the furnace, and uses a rock drill or blasting machine to collect the remaining pig iron, mainly from slag or coke, into a solidified iron solidified material (often monolithic). ) Must be crushed and taken out of the furnace.
[0004]
Residual iron solids are different from collapsible solids, etc., and are hard and difficult to decompose, and are divided by blasting. Prior to this blast, it was necessary to firstly make a large number of holes in the main body of the solidified pig iron with a drill or an oxygen lance, and to perform dynamite work there. In such a method of piercing, blasting, and dividing, a long period of time is required for the piercing operation, so that a long construction period is required, and the blasting operation hinders other dismantling operations. In addition, crushed materials were scattered during the explosion, which was dangerous, and the noise was so great that work had to be interrupted around the blast furnace.
[0005]
By the way, in the blast furnace renovation work, it is necessary to shorten the construction period as much as possible, so demolition work is started before the lining brick and residual iron solidified in the furnace are completely cooled to room temperature, and the work environment Is a place where there is only an opening at the bottom of the furnace and about a manhole at the top of the furnace, and there is a lot of dust, which is a bad environment. Furnace wall bricks and residual iron coagulates are hard and heavy, so they need to be divided into small pieces to carry them out of the opening. For this reason, the time required for the conventional dismantling work is extremely long, and the work has been expensive.
[0006]
It is also known to use an outrigger crane installed for maintenance on the furnace body column. The steel shell at the bottom of the blast furnace is cut into strips weighing 5 to 50 tons and removed with the outrigger crane. At the same time, residual iron coagulated material present in the blast furnace was removed from the furnace through an opening provided in the bottom wall of the blast furnace. Further, for example, JP-A-10-96005 and JP-A-7-197112 disclose a method for repairing the inside of a blast furnace.
[0007]
In the method of dismantling a blast furnace bottom described in Japanese Patent Application Laid-Open No. Hei 10-96005, the lower part of the blast furnace is cut, the blast furnace body is suspended and fixed with a blast furnace support, and then the iron shell at the lower part of the blast furnace is dismantled. The residual iron solidified inside was cut horizontally with a wire saw, and the residual iron solidified was pulled out horizontally as a unit. On the other hand, in the method of unloading the residual iron solidified from the blast furnace hearth described in Japanese Patent Application Laid-Open No. 7-197112, a jack is installed between the residual iron solidified in the peripheral part of the blast furnace and the furnace bottom refractory. After lifting vertically, a cylindrical or reduced friction coefficient material was inserted to pull out the residual iron solidified material horizontally.
[0008]
[Problems to be solved by the invention]
However, the conventional method of dismantling the bottom of a blast furnace has the following problems.
(1) In the method using the outrigger crane, while the lifting capacity of the outrigger crane is about 70 to 200 tons, the large amount of residual iron solidified in the blast furnace has a weight of about 500 tons. It was necessary to divide the residual iron coagulate into a weight of 200 t or less. In addition, since the work of dismantling the upper part of the blast furnace and the work of removing the residual iron coagulate in the lower part are performed in parallel, a safety ceiling is installed at the tuyere to ensure safety, and it is installed again after removing this A process was required, and a construction period was required.
[0009]
(2) The method of dismantling the bottom of a blast furnace described in Japanese Patent Application Laid-Open No. Hei 10-96005 requires a long period of time for cutting a brick layer, and a method for extracting a solidified iron residue in a horizontal direction. Even with the help of the cutting powder, a large withdrawal force was required, and the amount of residual iron solidified that could be withdrawn was limited.
(3) The method of unloading residual iron coagulated matter in a blast furnace described in Japanese Patent Application Laid-Open No. 7-197112 is also to pull out the residual iron coagulated matter horizontally. As in (2), there was a limit on the amount of residual iron solidified that could be extracted. In the above (2) and (3), there is a support for supporting the furnace body on the outer periphery of the blast furnace body, and it is possible to accurately guide the drawing direction so as not to interfere with the support when the solidified iron is drawn. Needed, which also led to an increase in working time.
[0010]
As described above, the method using the outrigger crane requires a long working period, and this can be reduced by the methods described in JP-A-10-96005 and JP-A-7-197112. However, there was still room for improvement in the work contents.
The present invention has been made in view of such circumstances, and economically removes residual iron solidified material remaining at the furnace bottom early in the furnace body cooling stage of a blast furnace during blast furnace repair, and in a short time. It is an object of the present invention to provide a method for dismantling a blast furnace bottom.
[0011]
[Means for Solving the Problems]
The present invention according to claim 1 for achieving the above object is to cut the furnace body of the blast furnace after blowing off horizontally at a position higher than the residual iron solidified material remaining at the bottom of the furnace, and above the cutting position. After suspending the upper furnace body using lifting means installed on the furnace body column and removing at least a part of the lower furnace body below the cutting position over the entire circumference, the residual iron coagulated material is taken out of the furnace. In the disassembling method of the bottom part of the blast furnace to be carried out, before carrying out the residual iron solidified material outside the furnace, along the peripheral portion of the residual iron solidified material, and between the residual iron solidified material and the furnace bottom refractory Digging cavities at a plurality of locations, lifting the residual iron solidified by jacks arranged in the hollow, forming a gap between the residual iron solidified and the furnace bottom refractory, After passing, the upper furnace body suspended on the furnace body column is lowered using the lifting means, Connecting both ends of the suspension band to the hanging fixture fixed to the lower end of the upper furnace body, and lifting the upper furnace body suspended on the furnace body support using the lifting / lowering means together with the residual iron solidified material, Forming a working space between the residual iron solidified material and the furnace bottom refractory; drawing and disposing a horizontal moving table on the furnace bottom refractory; and forming an upper furnace body suspended on the furnace body column. A step of lowering the solidified iron solids suspended via a suspending tool and a suspending band using the elevating means and placing the solidified iron on the horizontal moving table; and a suspending tool fixed to a lower end of the upper furnace body. And separating the horizontal moving table on which the residual iron solidified material is placed from inside the furnace to outside the furnace, after dismantling the blast furnace bottom.
[0012]
The present invention according to claim 2 is the method for dismantling a blast furnace bottom according to claim 1, wherein the hanging tool is fixed to a tuyere of an upper furnace body.
According to a third aspect of the present invention, the surface of the furnace bottom refractory is repaired flat under a working space formed between the residual iron solidified material and the furnace bottom refractory, and the repaired furnace bottom refractory is repaired. 3. A method for dismantling a blast furnace furnace bottom according to claim 1 or 2, wherein a plurality of bogie rails are laid on the rail, and then a horizontal moving platform is drawn in on the bogie rails.
[0013]
The present invention according to claim 4 is characterized in that a horizontal moving carriage that moves via rollers or a horizontal moving slide that slides on rails is used as the horizontal moving table that is drawn into the furnace bottom refractory. The method for dismantling a blast furnace bottom according to claim 1, 2 or 3.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
The method of dismantling the blast furnace bottom according to the present invention will be described in accordance with the procedure.
As shown in FIG. 1, the outside of the blast furnace 10 is covered with a steel shell, a cooling stave is attached inside the steel shell, and a brick layer made of a firebrick or the like is provided inside the stave. It has a structure. The blast furnace 10 is installed from the bottom in the order of the furnace bottom 11, the bosh section 12, the furnace chest 13, and the furnace opening 14, and the connection portions of the respective parts are fixed by welding. A furnace body column 15 is assembled outside the blast furnace 10 for repair or the like, and a plurality of lift jacks 16 as an example of a lifting / lowering means are installed above the furnace column 15.
[0015]
At the bottom of the bottom of the blown-out blast furnace 10, there is a bottom brick 17 (usually using carbon brick), and slag and coke are mixed with pig iron, solidified and integrated on the bottom brick 17. There is a residual iron solidified product 19, on which a melt-solidified disintegrated product 18 composed of a mixture of coke, slag and the like is provided. In order to repair the hearth brick 17, it is necessary to remove the collapsed material 18 and the residual iron solidified material 19. In the present embodiment, a case will be described in which after the collapsed material 18 is removed in advance using a heavy construction machine such as a bulldozer, only the residual iron solidified material 19 is lifted and removed from the furnace bottom.
[0016]
When disassembling the furnace part of the blast furnace 10 after the blow-off, first, the tip of the rod 20 suspended from the lift jack 16 installed on the furnace body support 15 so as to be able to move up and down is fixed to the furnace opening part 14. To support the blast furnace 10. Next, the steel shell of the furnace bottom 11 is cut horizontally, and the outer peripheral portion of the lower furnace body 2 below the cutting position A is removed out of the furnace. The cutting height is at least higher than the residual iron solidified material 19 remaining in the furnace bottom 11. When the shell of the lower furnace body 2 of the blast furnace 10 is removed, the upper furnace body 1 above the cutting position A of the steel shell is suspended by the lift jack 16 installed on the furnace body support 15.
[0017]
As shown in FIG. 2, the brick inside the opened blast furnace 10 is destroyed by a heavy construction machine (not shown) by removing a lower steel shell, and coke, The collapsed material 18 and the like, which can be easily broken down, such as slag, are lifted by operating the lift jacks 16 and discharged out of the furnace body foundation by a heavy construction machine. Of the in-furnace residue, there is residual iron coagulate 19 which cannot be easily disintegrated, and its weight is usually 300 to 500 tons. However, in a blast furnace having a long life, the erosion area of the bottom brick 17 is affected by tapping. A portion of the residual iron solidified material 19 that spreads below the mouth and exists in the erosion area is solidified by cooling even during the operation of the blast furnace, and the furnace bottom brick 17 is present as a substitute.
[0018]
Therefore, the greater the residual iron clot 19, close to almost hearth diameter in diameter, in the order of volume 250 meters ³ is a blast furnace of 5000 m ³ class, be drawn out horizontally large mass weight reaches to 1300t from the furnace Will be needed. It is difficult to disintegrate this residual iron solidified product 19 by a heavy construction machine, and it is necessary to destroy it by blasting using dynamite. However, as described above, this blasting operation requires a long time.
[0019]
Here, the relationship between the weight of the blast furnace 10 and the lifting ability of the lift jack 16 will be described. When the new furnace body is installed, the lift jack 16 is formed into a ring shape, and is divided into a plurality of (for example, four) iron skins in a vertical direction to which a furnace body cooling device or the like is attached in advance. Also used when assembling. For example, the total weight (excluding the internal brick) of the installed iron shell of the blast furnace 10 having an inner volume of about 5000 m ² (amount of tapping of 10000 t / day) is about 5500 t, and the lift jack 16 used for the renovation of the blast furnace 10 It has a lifting capacity of about 200t / unit x 30 units = about 6000t. On the other hand, when the lower part of the furnace body of the blast furnace 10 is cut at the time of dismantling the blast furnace and only the upper part 1 of the furnace body is supported by the lift jack 16, the weight becomes 3000 to 4000 t. Therefore, the lift jack 16 has a reserve of about 2000 to 3000 t. Will be.
[0020]
The present inventors have paid attention to the remaining capacity of the lift jack 16, and have developed a method of lifting and lowering the residual iron solidified material 19 with the lift jack 16 when disassembling the blast furnace 10.
As shown in FIG. 3, the solidified iron 19 is present on the bottom brick 17. After removing the debris 18, as shown in FIG. 4, cavities 21 were dug from the surface of the furnace bottom brick 17 at a plurality of locations around the periphery of the residual iron coagulate 19, and the residual iron coagulate 19 was A lifting jack 22 is installed between the furnace bottom brick 17. This cavity 21 can be easily dug by a shovel car or the like, for example. Next, as shown in FIG. 5, the remaining iron solidified material 19 is jacked up in the direction of the arrow by the lifting jack 22. Excavation of the cavity 21 by such a shovel car or jacking-up of the residual iron solidified material 19 by the lifting jack 22 does not require cooling the temperature of the residual iron solidified material 19 to room temperature. Even if there is, work is possible, and the work of removing the residual iron solidified material 19 can be started early.
[0021]
Subsequently, as shown in FIGS. 6A and 6B, the steel-shell-side hanging tool 24 is fixed to the tuyere 23 provided at the lower end of the suspended furnace body, while the remaining iron A remaining iron hanging band 25 (width of about 1200 mm, thickness of about 50 mm) made of an iron plate is inserted between the object 19 and the hearth brick 17 in a horizontal direction indicated by an arrow. As shown in FIG. 7, after lowering the furnace body upper part 1 of the suspended blast furnace 10 with the lift jack 16, the residual iron hanging band 25 is connected to the steel-side hanging tool 24. Next, as shown in FIG. 8, the furnace body upper part 1 is lifted by the lift jack 16, and the remaining iron solidified material 19 is lifted through the steel-side hanging tool 24 and the remaining iron hanging band 25, and the furnace bottom brick 17 is lifted. Form a working space on top.
[0022]
After repairing the surface of the furnace bottom brick 17 to a flat surface without irregularities as shown in FIGS. 9 and 10, as shown in FIG. Are laid in parallel with each other. As shown in FIG. 12, the horizontal moving table 29 can be easily taken in on the in-furnace bogie rail 28 using a winch or the like. As shown in FIGS. 13 to 15, for example, the horizontal moving table 29 can be a carriage provided with a moving roller 30 and a guide roller 31 at its lower part. A pair of support frames 37 are provided downward on the lower surface of the horizontal moving table 29, and a number of transfer rollers 30 connected by an endless chain 38 are provided between the support frames 37. Guide rollers 31 are provided on the outer surface side of the support frames. Is provided. The roller structure 39 is of a commercially available type, and is mounted, for example, in four rows at a lower portion of the horizontal moving table 29 so as to be moved along the groove-type furnace carriage rail 28.
[0023]
In addition, since the furnace carriage rail 28 is laid after making the surface of the bottom brick 17 a flat surface without irregularities, it can receive a large load, and when the bottom brick 17 has a partially concave surface, the mortar And smoothing.
Further, as shown in FIG. 16, the horizontal moving table 29 may be a slide table in which a slide shoe 40 is provided at a lower portion thereof, and the slide shoe 40 slides along the groove-type furnace cart rail 28. . Teflon (registered trademark of DuPont) 41 is attached to the lower surface of the slide shoe 40, and a stainless steel plate (SUS plate) 42 is attached to the upper surface of the groove of the rail 28 for the furnace carriage to reduce the coefficient of friction. Alternatively, as shown in FIG. 17, an I-type rail 45 is laid via a level adjustment liner 44 on a bottom plate 43 provided on the furnace bottom brick 17, and a bogie equipped with wheels is moved on this. Alternatively, a slide table may be placed on the I-shaped rail 45 and slid using lubricating oil. The horizontal moving trolley 29 may be either a trolley type or a slide table type.However, since the frequency of blast furnace repair is extremely low, the moving structure of the horizontal moving table 29 can be reduced at low cost and the workability is good. Is essential.
[0024]
Now, as shown in FIG. 18, the furnace body upper part 1 of the blast furnace 10 is lowered by the lift jack 16, and the residual iron solidified product 19 supported via the iron-clad suspending tool 24 and the residual iron suspending band 25 is horizontally moved. Place it on the moving table 29. After separating the steel side suspending tool 24 from the tuyere 23, as shown in FIG. 19, the furnace body upper part 1 of the blast furnace 10 is lifted by the lift jack 16 and retracted upward. The iron-clad-side hanging tool 24 and the remaining-iron hanging band 25 used to support the residual-iron coagulate 19 are left on the horizontal moving table 29. An out-of-furnace trolley rail 32 connected to the in-furnace trolley rail 28 is provided on a leveling block 46, and a horizontal moving table 29 on which the residual iron solidified material 19 is placed, and a furnace in which a load level adjusting frame 33 is set. It is possible to move toward the body transport cart 34.
[0025]
As shown in FIG. 20, each time the center hole jack 35 provided near the rail 32 for the out-of-furnace truck is operated by one stroke, the fixed position is changed to the front, and the horizontal moving table 29 on which the solidified iron 19 is placed is scaled. As described above, the trolley is moved from the in-furnace trolley rail 28 to the out-of-furnace trolley rail 32 and pulled out of the furnace. Next, the center hole jack 36 set on the furnace body transport vehicle 34 is operated, and as shown in FIG. 21, the center hole jack provided on the load level adjusting frame 33 provided in the furnace body transport vehicle 34. 35 is operated to move the leveling block 46 onto the furnace carrier trolley 34, whereby the residual iron coagulated material 19 is removed from the furnace body together with the horizontal moving platform 29 on the outer furnace rail 32 laid on the leveling block 46. The transport vehicle 34 is placed on the load level adjusting frame 33. Subsequently, the furnace body transport cart 34 is moved to the residual iron solidified material storage area, and a series of dismantling work of the blast furnace bottom is completed.
[0026]
【The invention's effect】
As described above, according to the present invention, the residual iron solidified product is raised and lowered by the elevating means supporting the blast furnace, so that there is no need to provide a separate elevating means for the residual iron solidified material, and it is economical. Since the heavy iron solidified solids are lifted in an integrated state by the residual iron hanging band connected to the steel-side hanging tool fixed to the lower end of the upper furnace body, the lifting and lowering work can be performed quickly at a considerably high temperature and The work of moving from the inside of the furnace to the outside of the furnace can be quickly performed, and the time required for dismantling the blast furnace bottom can be reduced.
[Brief description of the drawings]
FIG. 1 is a front view of a blast furnace applied to a method of dismantling a blast furnace bottom according to the present invention.
FIG. 2 is a front view showing a situation inside the furnace bottom when the steel shell of the blast furnace bottom according to the present invention is removed.
FIG. 3 is a front view showing the state of solidified iron remaining in the furnace bottom when the steel shell of the blast furnace bottom according to the present invention is removed.
FIG. 4 is a plan view showing a situation in which the iron shell on the bottom of the blast furnace according to the present invention is removed and lifting jacks are arranged in a plurality of cavities excavated in the periphery of the solidified iron remaining in the furnace bottom.
FIG. 5 is a front view showing a situation where solidified iron remaining in the furnace bottom according to the present invention is lifted by a lifting jack.
FIG. 6 (A) is a front view showing a situation in which a residual iron hanging band is inserted between the residual iron solidified material lifted by the lifting jack according to the present invention and the furnace bottom brick, and (B) tuyere It is a partial enlarged front view which shows the state which attaches a steel-shell side hanger.
FIG. 7 is a front view showing a state in which the suspended furnace body upper part according to the present invention is lowered, and a remaining iron hanging band is connected to a steel-side hanging tool fixed to the tuyere.
FIG. 8 shows a state in which the upper part of the furnace body according to the present invention is lifted by a lift jack, and the remaining iron coagulated material is lifted through the steel-side hanging tool and the remaining iron hanging band to form a work space on the furnace bottom brick. FIG.
FIG. 9 is a front view showing a state in which the surface layer of the hearth brick according to the present invention is maintained by a heavy construction machine.
FIG. 10 is a front view showing a situation in which the surface layer of the furnace bottom brick according to the present invention has been repaired to have a flat surface without irregularities.
FIG. 11 is a front view showing a situation in which a rail for a bogie in a furnace is laid on the surface of the furnace bottom brick according to the present invention.
FIG. 12 is a front view showing a state in which the horizontal moving table according to the present invention is taken in on a rail for a truck in a furnace.
FIG. 13 is a side view showing a state in which a roller structure provided at a lower portion of the horizontal moving table according to the present invention is disposed so as to correspond to a groove-type in-furnace bogie rail.
FIG. 14 is a side view showing a state in which a roller structure including a moving roller and a guide roller provided at a lower portion of the horizontal moving table according to the present invention is arranged corresponding to a groove-type furnace bogie rail. .
FIG. 15 is a front view showing a roller structure including a plurality of moving rollers connected by an endless chain according to the present invention inside and a guide roller disposed outside.
FIG. 16 is a side view showing a slide structure in which slide shoes arranged on the lower surface of the horizontal moving table according to the present invention are arranged corresponding to the groove type rails.
FIG. 17 is a side view showing an I-shaped rail laid on a bottom brick of the blast furnace according to the present invention.
FIG. 18 is a front view showing a situation in which the furnace body upper part according to the present invention is lowered by a lift jack, and the solidified iron remaining on the horizontal moving table is supported by the residual iron hanging band.
FIG. 19 is a front view showing a state in which the upper part of the furnace body according to the present invention is lifted and retracted by the lift jack, and the horizontal moving table on which the solidified iron remains is moved toward the furnace body transport vehicle. is there.
FIG. 20 is a front view showing a situation in which a center movable jack provided near the rail for out-of-furnace trolleys according to the present invention is operated to move the horizontal moving table on which the solidified iron remains on the rail for out-of-furnace trolleys. is there.
FIG. 21 is a front view showing a state in which a horizontal moving table on which the residual iron solidified product according to the present invention is mounted is placed on a load level adjusting frame on which a furnace body transport vehicle is set via a furnace outer vehicle rail. .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Upper furnace body 2 Lower furnace body 10 Blast furnace 11 Furnace bottom 12 Bosh section 13 Furnace chest 14 Furnace opening 15 Furnace column 16 Lift jack 17 Bottom brick 18 Collapsed material 19 Residual iron coagulated material 20 Rod 21 Cavity 22 Lifting jack 23 Tuyere 24 Steel-side hanging tool 25 Residual iron hanging band 26 Construction heavy equipment 28 Furnace bogie rail 29 Horizontal moving platform 30 Moving roller 31 Guide roller 32 Leveling block 33 Loading level adjusting frame 34 Furnace transport bogie 35 , 36 Center hole jack 37 Support frame 38 Endless chain 39 Roller structure 40 Slide shoe 41 Teflon 42 Stainless steel plate 43 Bottom plate 44 Level adjustment liner 45 I-type rail 46 Leveling block

Claims

The furnace body of the blast furnace after blowing off is cut horizontally at a position higher than the residual iron solidified material remaining at the bottom of the furnace, and the upper furnace body above the cutting position is installed on the furnace body column using a lifting means. Suspended, after removing at least a part of the lower furnace body below the cutting position over the entire circumference, in the dismantling method of the blast furnace furnace bottom to carry out the residual iron solidified material outside the furnace, the residual iron solidified material is removed. Before being taken out of the furnace, cavities are dug at a plurality of locations along the peripheral portion of the residual iron solidified material and between the residual iron solidified material and the furnace bottom refractory, and jacks are disposed in the hollow portion. Lifting the residual iron coagulate in the step of forming a gap between the residual iron coagulate and the furnace bottom refractory, and, after inserting a suspension band into the gap, the upper furnace body suspended on the furnace body column. The lifting band is lowered using the lifting / lowering means, and the hanging band is fixed to a hanging member fixed to a lower end portion of the upper furnace body. Connecting both ends, and lifting the upper furnace body suspended on the furnace body column using the lifting means together with the residual iron solidified material, and a work space between the residual iron solidified material and the furnace bottom refractory. Forming, drawing and disposing a horizontal moving table on the furnace bottom refractory, and removing the residual iron coagulated material suspended via a suspender and a suspension band on an upper furnace body suspended on the furnace body column. Moving down by using the lifting / lowering means and mounting on the horizontal moving table, and separating the hanging fixture fixed to a lower end portion of the upper furnace body, and then moving the horizontal movement on which the residual iron coagulate is mounted. A method for dismantling a bottom of a blast furnace, wherein the base is moved from inside the furnace to outside the furnace.

The method according to claim 1, wherein the hanging tool is fixed to a tuyere of an upper furnace body.

Under the working space formed between the solidified iron and the bottom refractory, the surface of the bottom refractory was repaired flat, and a plurality of bogie rails were laid on the repaired bottom refractory. 3. The method for dismantling a blast furnace bottom according to claim 1 or 2, wherein a horizontal moving platform is drawn and arranged on the bogie rail.

4. A horizontal moving carriage that moves via rollers or a horizontal moving slide that slides on rails is used as the horizontal moving table that is drawn into the furnace bottom refractory. A method for dismantling a blast furnace bottom according to the above.