JP3752014B2

JP3752014B2 - Blast furnace core condition estimation method

Info

Publication number: JP3752014B2
Application number: JP11219296A
Authority: JP
Inventors: 昭彦篠竹; 守政一田
Original assignee: Nippon Steel Corp
Current assignee: Nippon Steel Corp
Priority date: 1996-04-10
Filing date: 1996-04-10
Publication date: 2006-03-08
Anticipated expiration: 2016-04-10
Also published as: JPH09279207A

Description

【０００１】
【発明の属する技術分野】
本発明は、高炉の炉芯状態を検知推定する方法に関する。
【０００２】
【従来の技術】
近年の高炉の寿命は、多くの高炉において炉床部の耐火物の浸食が最大の支配要因であり、炉床部の耐火物の浸食には溶銑の流れが大きな影響を及ぼすので、局所的に溶銑流が集中して熱負荷が高くならないように操業管理されている。
操業中の高炉炉内の炉床部分には、炉芯と呼ばれるコークスの充填領域が存在し、その充填コークスの空隙部分には鉱石の還元・溶融によって生じた溶銑・溶滓がたまっている。
【０００３】
溶銑の流れは炉体の浸食プロフィルや浸食面上に生成した凝固層の形状・炉芯の下端形状・炉芯内の通液性などによって異なる。
例えば炉芯が完全に沈下して炉底に着いているときに比べ、炉芯全体が浮上して炉底との間に狭い隙間ができているときは、この隙間を溶銑が多く流れ、また、炉芯の中心部が炉底に接触して周辺部が浮いて隙間があるときは、この周辺部の隙間を通って出銑口へ向かう環状の流れができる。
【０００４】
炉底レンガには通常カーボンを主成分とする耐火物が使われているが、溶銑が多く流れる部分に相当する炉底あるいは炉床側壁部の耐火物は熱負荷を多く受ける。通常の高炉操業における操業管理は、炉床部の溶銑流を直接測定することができないため、炉底あるいは炉床側壁部の耐火物に埋設した温度計により耐火物の温度変化を監視し、温度が上昇した場合に、羽口から溶銑凝固層の生成を促進するチタン含有粉体を吹き込んだり、冷却を制御したりして温度上昇を抑制する操業アクションを採る。
【０００５】
炉床部の溶銑の流束分布を直接測定する方法はないが、流れの状態を検知する手段としては、例えば羽口から放射性元素を打ち込んで出銑口で放射強度を測定する方法が特開昭６２−１４６２０６号公報に記載されている。
【０００６】
【発明が解決しようとする課題】
通常行われている耐火物の温度を監視する方法は、耐火物や溶銑凝固層の熱伝導率等の物性値を仮定して耐火物の浸食位置あるいは凝固層の生成ラインを推定する方法であり、それ自身精度よい推定が困難である上に、炉内の溶銑流れは推定できない。
また、特開昭６２−１４６２０６号公報に記載の方法は、高炉休風直後の湯流れの状態から炉底中心部の不活性部分の多少を判断しようとするものであり、測定時期と推定する炉内状況が限定されている。
【０００７】
しかるに、炉床部の溶銑流を推定することは局所的に溶銑流が集中して耐火物が浸食されるのを防ぐように操業管理する上で重要であり、溶銑流は炉芯下端の炉底面からの浮沈状態に大きく影響される。従って、本発明は、高炉の炉芯の浮沈状態を精度良く検知推定することを課題とする。
【０００８】
【課題を解決するための手段】
本発明者らは、高炉操業時の炉床部の溶銑流れについて、模型実験による検討を行った結果、炉床部における溶銑流れは、炉芯下端の位置と形状により大きな影響を受けることを見出した。
炉芯と炉底面の位置関係としては、図１に模式的に示すように▲１▼炉芯全面が着床して空隙が存在しない場合（１−ａ図）、▲２▼炉芯の一部分が浮上している場合（１−ｂ図）、▲３▼炉芯全体が炉底面から浮上している場合（１−ｃ図）に分類できる。
【０００９】
炉芯の浮沈は湯溜まりの溶銑の浮力と上部からの炉内容物の荷重のバランスによって決まるが、近年の大型高炉では、炉内の半径方向によって荷重が異なり、壁面との応力や送風ガスによりレースウェイが形成される炉壁部の方が中心部よりも荷重が小さく、炉芯が浮上しやすい条件にあると考えられる。従って、上記▲２▼の炉芯の一部分が浮上しているというのは、炉芯中央部が着床して周辺部が浮上しているのが普通である。本発明者らは模型実験により、上記▲１▼▲２▼▲３▼の場合の湯流れについて調べた。
【００１０】
すなわち、図２に示すごとく円筒形水槽７に粒径約４ｍｍのポリプロピレン粒子を充填し、水槽上部に置いた水滴分散器８より水を滴下させて、１か所の排水口１２から排水した。
流れを調べるために、水滴分散器８に設けた穴１１を通して着色液をトレーサーとして投入し、排水口部分に設けた透過光強度測定器１３により着色液の通過を検出し、トレーサー投入から検出のピークまでの時間を測定した。
【００１１】
トレーサー投入位置として図３に示すＡ（排水口との角度９０度の周辺部）、Ｂ（排水口との角度１８０度の周辺−中央の中間部）、Ｃ（排水口との角度１８０度の周辺部）を、排水口からの水平距離がＡ，Ｂ，Ｃの順に大きくなるように選択し、炉芯形状として上記▲１▼▲２▼▲３▼を実験条件として作った。
各位置からの投入トレーサーの検出時間は、Ａ，Ｂ，Ｃから投入したトレーサーの検出時間をそれぞれｔ_A ，ｔ_B ，ｔ_C とすると、
▲１▼炉芯全面が着床して空隙が存在しない場合はｔ_A ＜ｔ_B ＜ｔ_C
▲２▼炉芯の周辺部が浮上している場合はｔ_A ＜ｔ_B ≧ｔ_C
▲３▼炉芯全体が炉底面から浮上している場合はｔ_A ≧ｔ_B
のようになった。
【００１２】
この結果は次のように解釈できる。▲１▼炉芯全面が着床して空隙が存在しない場合（図１−ａ）は、流れは充填層中を排水口へ向かって集中していくので、排水口までの距離が近いところほど速く、トレーサー投入位置が排水口から遠いほど時間がかかる。
▲２▼炉芯の周辺部が浮上している場合（図１−ｂ）は、この浮上領域に速い流れができ、Ｃから投入したトレーサーはこの速い流れの領域を経由するので排水口には速く到達するが、Ｂから投入したトレーサーは流れの遅い充填層を経由するので時間がかかる。
▲３▼炉芯全体が炉底面から浮上している場合（図１−ｃ）は、炉底の浮上領域に速い流れができ、Ｂから投入したトレーサーもこの領域経由となる。Ａから投入したトレーサーは充填層を通り抜ける距離が最も長く、排水口までの到達時間がかかる。
【００１３】
本発明は、上記炉底面と炉芯下端の位置関係による炉床部溶銑流れのパターンの違いを利用して、複数の位置から高炉炉内に打ち込んだ放射性元素等のトレーサーが、排出するまでの時間の大小から高炉炉芯の浮沈状態を推定しようとするものである。その推定結果は炉床部耐火物の損耗を防ぐための操業制御の判断に用いることができる。
【００１４】
すなわち、本発明の要旨とするところは、［１］高炉の操業中に、同一の出銑口を使用している状態において、出銑口とのなす角度が（１）７５〜１０５度にある羽口、（２）１５０〜１８０度にある羽口および、（３）（２）と同一の羽口または１５０〜１８０度にある（２）と別の羽口から炉内に挿入したパイプの先端の３箇所から順次、トレーサー物質を炉内に打ち込んで出銑された溶銑中のトレーサー物質の濃度を検出する操作を繰り返し、そのトレーサー物質打ち込みから検出濃度のピークまでの時間の順位により高炉炉芯の浮沈状態が▲１▼全面着床、▲２▼一部分浮上、▲３▼全面浮上のどのパターンかを推定する高炉炉芯状況推定方法。
【００１５】
［２］高炉の操業中に、同一の出銑口を使用している状態において、出銑口とのなす角度が（１）７５〜１０５度にある羽口、（２）１５０〜１８０度にある羽口および、（３）（２）と同一の羽口または１５０〜１８０度にある（２）と別の羽口から炉内に挿入したパイプの先端の３箇所から、それぞれ異なるトレーサー物質を炉内に打ち込んで出銑された溶銑中のトレーサー物質の濃度を検出する操作を行い、そのトレーサー物質打ち込みから検出濃度のピークまでの時間の順位により高炉炉芯の浮沈状態が▲１▼全面着床、▲２▼一部分浮上、▲３▼全面浮上のどのパターンかを推定する高炉炉芯状況推定方法。
【００１６】
［３］高炉の操業中に、同一の出銑口を使用している状態において、出銑口とのなす角度が（１）７５〜１０５度にある羽口、（２）１５０〜１８０度にある羽口および、（３）（２）と同一の羽口または１５０〜１８０度にある（２）と別の羽口から炉内に挿入したパイプの先端の３箇所のうち、２箇所は同じトレーサー物質、残りの１箇所はそれとは異なるトレーサー物質を、同時に同じトレーサー物質が２箇所から打ち込まれないように２回に分けて、炉内に打ち込んで出銑された溶銑中のトレーサー物質の濃度を検出する操作を行い、そのトレーサー物質打ち込みから検出濃度のピークまでの時間の順位により高炉炉芯の浮沈状態が▲１▼全面着床、▲２▼一部分浮上、▲３▼全面浮上のどのパターンかを推定する高炉炉芯状況推定方法。
【００１７】
［４］トレーサー物質が放射性同位元素であることを特徴とする［１］または［２］または［３］のいずれかに記載の高炉炉芯状況推定方法。
【００１８】
［５］出銑口とのなす角度が（１）７５〜１０５度にある羽口、（２）１５０〜１８０度にある羽口および、（３）（２）と同一の羽口または１５０〜１８０度にある（２）と別の羽口から炉内に挿入したパイプの先端の３箇所から打ち込んだトレーサー物質の打ち込みから検出濃度のピークまでの時間をそれぞれｔ_a ，ｔ_b ，ｔ_c とするとき、
▲１▼ｔ_a ＜ｔ_b ＜ｔ_c の時、全面が着床して空隙が存在しない
▲２▼ｔ_a ＜ｔ_b ≧ｔ_c の時、炉芯の一部が浮上している
▲３▼ｔ_a ≧ｔ_b の時、炉芯全体が炉底面から浮上している
と推定することを特徴とする［１］〜［４］のいずれかに記載の高炉炉芯状況推定方法にある。
【００１９】
【発明の実施の形態】
実際の高炉の操業においては、複数の出銑口を数時間ごとに切り替えながら操業している。本発明を実施するにあたっては、同じ出銑口を使用している状態で３回のトレーサー打ち込み・計測を行うことが必要である。いずれの回も同じトレーサー物質を使用する場合、トレーサーの打ち込みからトレーサー濃度の検出までを、信号の重複を避けるため、１回ごとに分離して測定する必要がある。
出銑時間が３回の測定をするのに十分でなければ、２回以上の出銑時に分けて同じ出銑口を使用している状態で測定を行う。異なる２種類または３種類のトレーサー物質を用いて信号を分離して計測することができるならば、同一時刻に２つまたは３つの測定が行われていてもよい。また、羽口からトレーサー物質を打ち込むには送風操業中に打ち込み可能な設備、羽口から炉内に挿入したパイプの先端からトレーサー物質を炉内に打ち込むに際しては、送風操業中に羽口からパイプを挿入できる設備を必要とする。
【００２０】
前記模型実験とのアナロジーから、トレーサー物質を打ち込む羽口の位置は、可能な限り（ａ）出銑口に対し約９０度の位置にある羽口、（ｂ）出銑口に対し約１８０度の位置にある羽口から炉内に挿入したパイプの先端、（ｃ）出銑口に対し約１８０度の位置にある羽口（（ｂ）と同じ羽口が好ましい）を選ぶことが望ましい。
かつ、出銑口からの距離の大小がａ＜ｂ＜ｃとなるように（ｂ）におけるパイプの先端の位置を決める。
【００２１】
このようにして測定したトレーサーの打ち込みから出銑口までの到達時間の大小関係から、前記模型実験で得られた結果を利用して、（ａ）、（ｂ）、（ｃ）から打ち込んだトレーサーの検出時間をそれぞれｔ_a ，ｔ_b ，ｔ_c とすると、
▲１▼ｔ_a ＜ｔ_b ＜ｔ_c の時、全面が着床して空隙が存在しない
▲２▼ｔ_a ＜ｔ_b ≧ｔ_c の時、炉芯の一部が浮上している
▲３▼ｔ_a ≧ｔ_b の時、炉芯全体が炉底面から浮上している
と推定する。なお、トレーサー物質としては例えばＣｏ⁶⁰，Ｆｅ⁵⁷，Ａｕ¹⁹⁸ 等を使うことができる。
【００２２】
【実施例】
図４は出銑口４本、羽口３０本を有する内容積３５００ｍ³ の高炉の炉床部の水平断面図であり、図５は同じ高炉の羽口レベルの断面図で、羽口の位置を示したものである。
また、図６は本発明の方法を実施した際のトレーサー物質打ち込みの位置を示す。この高炉は適宜４本の出銑口を切り替えながら操業していたが、ある時期においては角度１８０度の相対位置にある１号出銑口１４と３号出銑口１６を切り替えて操業していた。この時期において本発明の方法を実施した。
【００２３】
まず、１号出銑口を使用している状態でこの出銑口と角度９０度の位置に存するＮｏ．２３羽口１８から放射性同位元素としてＣｏ⁶⁰を打ち込み、１号出銑口の後方の樋で溶銑の放射性強度を測定した。放射性強度は図７（ａ）のように測定され、強度のピークは打ち込み後３．５時間に現れた。
この後３号出銑口に切り替えて出銑を行い、再度１号出銑口に切り替えた後、１号出銑口と角度１７４度の位置に存し、送風中にパイプを挿入できる設備を備えたＮｏ．１６羽口１９からＣｏ⁶⁰を打ち込み、１号出銑口の後方の樋で溶銑の放射性強度を測定した。放射性強度は図７（ｃ）のように測定され、強度のピークは打ち込み後３．０時間に現れた。
【００２４】
この後再び３号出銑口に切り替えて出銑を行い、再度１号出銑口に切り替えたところで今度は前の測定と同じ１号出銑口と角度１７４度の位置に存するＮｏ．１６羽口１９から内径９０ｍｍ、外径１１０ｍｍのパイプを炉内に２．５ｍ挿入してその先端からＣｏ⁶⁰を打ち込み、１号出銑口の後方の樋で溶銑の放射性強度を測定した。放射性強度は図７（ｂ）のように測定され、強度のピークは打ち込み後５．２時間に現れた。
この結果は本発明の判定方法から、ｔ_a ＝３．５時間、ｔ_b ＝５．２時間、ｔ_c ＝３．０時間すなわちｔ_a ＜ｔ_b ≧ｔ_c となり、炉芯の一部が浮上していると推定された。
【００２５】
【発明の効果】
本発明によれば、高炉炉床部の湯流れ挙動に大きく影響する炉芯の浮沈状態を検知するために、高炉の操業中に、出銑口とのなす角度が異なる２箇所の羽口および、１箇所の羽口から炉内に挿入したパイプの先端の合計３箇所から、それぞれトレーサー物質を炉内に打ち込んで出銑口された溶銑中のトレーサー濃度を検出する測定を行い、そのトレーサー物質打ち込みから検出濃度のピークまでの時間の順位により高炉炉芯の浮沈状態を▲１▼全面着床、▲２▼一部分浮上、▲３▼全面浮上の各パターンに分類して推定することができる。
従って、本発明は炉芯浮沈状態から炉床部の湯流れ状態を推定し、炉床部耐火物への負荷が大きい周辺部環状流を作りやすい炉芯一部浮上と判定された場合に、耐火物溶損を防ぐための装入物制御、冷却制御、羽口からのチタン吹き込み等のアクションを速やかに取り、耐火物の浸食を抑制して高炉寿命を長くすることができる。
【図面の簡単な説明】
【図１】高炉炉床部の炉芯状態を分類した図
【図２】高炉炉床部模型実験装置
【図３】高炉炉床部模型実験装置におけるトレーサー投入位置
【図４】高炉炉床部水平断面図（出銑口レベル）
【図５】高炉炉床部水平断面図（羽口レベル）
【図６】トレーサー打ち込みを行った位置を示す図
【図７】各位置から放射性元素を打ち込んだ後の出銑口後方の放射性強度の推移を示したもので、（ａ）はＮｏ．２３羽口から、（ｂ）はＮｏ．１６羽口から挿入したパイプの先端から、（ｃ）はＮｏ．１６羽口から夫々放射性元素を打ち込んだ後の出銑口後方の放射性強度の推移を示す図
【符号の説明】
１高炉炉体
２羽口
３出銑口
４レースウェイ
５炉芯コークス充填層
６コークフリー領域
７実験水槽
８液滴分散器
９充填粒子層
１０液面レベル
１１トレーサー投入口
１２排水口
１３トレーサー検出器
１４１号出銑口
１５２号出銑口
１６３号出銑口
１７４号出銑口
１８Ｎｏ．２３羽口
１９Ｎｏ．１６羽口
２０Ｎｏ．１６羽口より挿入したパイプの先端からのトレーサー打ち込み位置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for detecting and estimating the core state of a blast furnace.
[0002]
[Prior art]
In many blast furnaces, blast furnace refractory erosion is the most dominant factor in the life of blast furnaces in recent years, and the flow of hot metal has a major influence on refractory erosion in the hearth. The operation is managed so that hot metal flow does not concentrate and heat load increases.
In the hearth of the blast furnace furnace in operation, there is a coke filling region called a core of the core, and hot metal and hot metal produced by reduction or melting of ore are accumulated in the void portion of the filled coke.
[0003]
The hot metal flow varies depending on the erosion profile of the furnace body, the shape of the solidified layer formed on the eroded surface, the shape of the lower end of the furnace core, the liquid permeability in the furnace core, and the like.
For example, compared to when the furnace core has completely settled and arrived at the bottom of the furnace, when the entire furnace core has floated and a narrow gap is formed between it and the bottom of the furnace, a lot of molten iron flows through this gap. When the center part of the furnace core comes into contact with the furnace bottom and the peripheral part is floated and there is a gap, an annular flow can be made through the gap in the peripheral part toward the outlet.
[0004]
The refractory mainly composed of carbon is usually used for the bottom brick, but the refractory on the bottom or the side wall of the hearth corresponding to the portion where a lot of molten metal flows receives a lot of heat load. Operation management in normal blast furnace operation cannot directly measure the hot metal flow in the hearth, so the temperature change of the refractory is monitored with a thermometer embedded in the refractory on the hearth or side wall of the hearth. When the temperature rises, the titanium-containing powder that promotes the formation of the hot metal solidified layer is blown from the tuyere and the cooling action is controlled to take action to suppress the temperature rise.
[0005]
There is no method for directly measuring the flux distribution of the hot metal in the hearth, but as a means for detecting the state of the flow, for example, a method of measuring the radiation intensity at the outlet by implanting a radioactive element from the tuyere This is described in JP-A-62-146206.
[0006]
[Problems to be solved by the invention]
The usual method for monitoring the temperature of a refractory is to estimate the erosion position of the refractory or the formation line of the solidified layer, assuming physical properties such as the thermal conductivity of the refractory or molten iron solidified layer. In addition, it is difficult to estimate with high accuracy, and the hot metal flow in the furnace cannot be estimated.
In addition, the method described in Japanese Patent Application Laid-Open No. 62-146206 is intended to determine the amount of the inactive portion at the center of the furnace bottom from the state of the hot water flow immediately after the blast furnace resting wind, and is estimated as the measurement time. The situation inside the furnace is limited.
[0007]
However, it is important to estimate the hot metal flow in the hearth part in order to prevent the refractory from being eroded due to local concentration of the hot metal flow. It is greatly affected by the floating state from the bottom. Accordingly, an object of the present invention is to accurately detect and estimate the floating state of the core of the blast furnace.
[0008]
[Means for Solving the Problems]
The present inventors have conducted a model experiment on the hot metal flow in the hearth during blast furnace operation, and as a result, found that the hot metal flow in the hearth is greatly affected by the position and shape of the lower end of the core. It was.
As for the positional relationship between the furnace core and the furnace bottom, as schematically shown in FIG. 1, (1) when the entire furnace core is landed and no void exists (FIG. 1-a), (2) a part of the furnace core Can be categorized as (1) in FIG. 1-b) and (3) in the case where the entire core is levitated from the bottom of the furnace (FIG. 1-c).
[0009]
The rise and fall of the furnace core is determined by the balance between the buoyancy of the hot metal in the hot water pool and the load of the furnace contents from the top, but in recent large-scale blast furnaces, the load varies depending on the radial direction of the furnace and depends on the stress on the wall surface and the blowing gas It is considered that the furnace wall portion where the raceway is formed has a smaller load than the center portion and is in a condition where the furnace core is likely to float. Therefore, the reason why the part of the core of the above (2) is floating is that the central part of the core is landing and the peripheral part is floating. The present inventors investigated the hot water flow in the case of (1), (2), and (3) above by a model experiment.
[0010]
That is, as shown in FIG. 2, a cylindrical water tank 7 was filled with polypropylene particles having a particle diameter of about 4 mm, and water was dropped from a water drop disperser 8 placed on the upper part of the water tank, and drained from one drain outlet 12.
In order to investigate the flow, the colored liquid is introduced as a tracer through the hole 11 provided in the water droplet disperser 8, and the passage of the colored liquid is detected by the transmitted light intensity measuring device 13 provided at the drain outlet portion. The time to peak was measured.
[0011]
As shown in FIG. 3, A (periphery of an angle of 90 degrees with the drain outlet), B (periphery of an angle of 180 degrees with the drain outlet-middle part of the center), and C (an angle of 180 degrees with the drain outlet) shown in FIG. The peripheral part) was selected so that the horizontal distance from the drain outlet increased in the order of A, B, and C, and the above (1), (2), and (3) were made as experimental conditions as the furnace core shape.
The detection time of the input tracer from each position is assumed to be t _A , t _B , and t _C , respectively.
(1) t _A <t _B <t _C when the entire furnace core is landed and there is no void
(2) t _A <t _B ≧ t _C when the periphery of the furnace core is floating
(3) t _A ≧ t _B when the entire furnace core is floating from the bottom of the furnace
It became like this.
[0012]
This result can be interpreted as follows. (1) When the entire furnace core is landed and there are no voids (Fig. 1-a), the flow concentrates in the packed bed toward the drain, so the closer to the drain, the closer to the drain. The faster it takes, the longer the tracer input position is from the drain outlet.
(2) When the periphery of the furnace core is floating (Fig. 1-b), a fast flow can be made in this floating region, and the tracer introduced from C goes through this fast flow region. Although it reaches quickly, the tracer introduced from B takes time because it passes through the packed bed having a slow flow.
{Circle around (3)} When the entire furnace core is lifted from the bottom of the furnace (FIG. 1-c), a fast flow can be made in the floating area at the bottom of the furnace, and the tracer introduced from B also goes through this area. The tracer introduced from A has the longest distance passing through the packed bed and takes time to reach the drain.
[0013]
The present invention takes advantage of the difference in the pattern of the hearth part hot metal flow due to the positional relationship between the furnace bottom surface and the bottom end of the furnace core, until the tracer of radioactive elements and the like driven into the blast furnace furnace from a plurality of positions is discharged. It is intended to estimate the floating state of the blast furnace core from the time. The estimation result can be used for judgment of operation control for preventing the wear of the hearth refractory.
[0014]
That is, the gist of the present invention is as follows: [1] In the state where the same tap outlet is used during operation of the blast furnace, the angle made with the tap outlet is (1) 75 to 105 degrees. The tuyere, (2) the tuyere at 150-180 degrees, and (3) pipes inserted into the furnace from the same tuyere as (2) or (2) another tuyere at 150-180 degrees The operation to detect the concentration of the tracer substance in the molten iron that was discharged by sequentially injecting the tracer substance into the furnace from the three points at the tip was repeated, and the blast furnace furnace was ordered according to the order of time from the tracer substance injection to the peak of the detected concentration. Blast furnace core condition estimation method for estimating which pattern the core floating state is (1) full landing, (2) partial levitation, and (3) full surface floating pattern.
[0015]
[2] During operation of the blast furnace, in the state where the same tap hole is used, the angle formed by the tap hole is (1) 75-105 degrees tuyere, (2) 150-180 degrees Different tracer substances from one tuyere and (3) (2) from the same tuyere or from the tip of the pipe inserted into the furnace from another tuyere at (2) 150-180 degrees The operation to detect the concentration of tracer substance in the molten iron that was driven into the furnace and detected the concentration of the blast furnace core in the order of the time from the tracer substance injection to the peak of the detected concentration. Blast furnace core condition estimation method for estimating the pattern of floor, (2) partial levitation, and (3) full surface levitation.
[0016]
[3] During operation of the blast furnace, when using the same tap hole, the angle formed by the tap hole is (1) 75-105 degrees tuyere, (2) 150-180 degrees Two locations are the same among a certain tuyere and the tip of the pipe inserted into the furnace from the same tuyere of (3) and (2) or from 150 to 180 degrees (2) and another tuyere. The concentration of the tracer substance in the hot metal that was put into the furnace and divided into two times so that the same tracer substance was not injected from two places at the same time. According to the order of time from the placement of the tracer substance to the peak of the detected concentration, the blast furnace core rises and falls to (1) full landing, (2) partial floating, and (3) full floating pattern Estimating the blast furnace core status Law.
[0017]
[4] The blast furnace core state estimation method according to any one of [1], [2] or [3], wherein the tracer substance is a radioisotope.
[0018]
[5] The tuyere whose angle with the tap is (1) 75 to 105 degrees, (2) 150 to 180 degrees, and (3) the same tuyere as (2) or 150 to At 180 degrees (2), the time from the implantation of the tracer substance injected from three locations at the tip of the pipe inserted into the furnace from another tuyere to the peak of the detected concentration is represented by t _a , t _b , t _c , respectively. and when,
(1) When t _a <t _b <t _c , the entire surface is floored and there is no void. (2) When t _a <t _b ≧ t _c , a part of the furnace core is floating (3) In the blast furnace core condition estimation method according to any one of [1] to [4], it is estimated that when t _a ≧ t _b , the entire core is levitated from the bottom of the furnace.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
In actual blast furnace operation, operation is performed while switching several taps every few hours. In carrying out the present invention, it is necessary to drive and measure the tracer three times while using the same tap hole. When the same tracer substance is used every time, it is necessary to separately measure from the time when the tracer is driven to the detection of the tracer concentration, in order to avoid duplication of signals.
If the output time is not enough to measure 3 times, the measurement should be performed while using the same output port divided into 2 or more output times. If two or three different tracer substances can be used to separate and measure signals, two or three measurements may be made at the same time. Also, in order to drive the tracer material from the tuyere, equipment that can be driven during the blowing operation, and when placing the tracer material into the furnace from the tip of the pipe inserted into the furnace from the tuyere, the pipe from the tuyere during the blowing operation. Requires equipment that can be inserted.
[0020]
From the analogy with the model experiment, the position of the tuyere into which the tracer substance is implanted is as much as possible (a) the tuyere at about 90 degrees with respect to the spout, and (b) about 180 degrees with respect to the spout. It is desirable to select the tuyere at the tip of the pipe inserted into the furnace from the tuyere at the position (c), and the tuyere at a position of about 180 degrees with respect to the spout (preferably the same tuyere as (b)).
In addition, the position of the tip of the pipe in (b) is determined so that the distance from the spout is a <b <c.
[0021]
The tracer driven from (a), (b), (c) by using the result obtained in the model experiment from the magnitude relationship of the arrival time from the tracer driving to the tap opening measured in this way. If the detection times of t _a , t _b and t _c are respectively
(1) When t _a <t _b <t _c , the entire surface is floored and there is no void. (2) When t _a <t _b ≧ t _c , a part of the furnace core is floating (3) ▼ When t _a ≧ t _b , it is estimated that the entire core is floating from the bottom of the furnace. For example, Co ⁶⁰ , Fe ⁵⁷ , Au ¹⁹⁸ or the like can be used as the tracer substance.
[0022]
【Example】
4 is a horizontal cross-sectional view of the hearth of a blast furnace with an inner volume of 3500 m ³ having four tap holes and 30 tuyere, and FIG. Is shown.
FIG. 6 shows the position of the tracer substance driving when the method of the present invention is carried out. This blast furnace was operated while appropriately switching the four docks, but at a certain time, it switched between No. 1 dock 14 and No. 3 dock 16 at an angle of 180 degrees. It was. At this time, the method of the present invention was carried out.
[0023]
First, in the state where the No. 1 dock is used, No. 1 located at an angle of 90 degrees with this dock. Co ⁶⁰ was injected as a radioisotope from the 23 tuyere 18, and the radioactive intensity of the hot metal was measured with a ridge behind the No. 1 port. The radioactive intensity was measured as shown in FIG. 7 (a), and the intensity peak appeared 3.5 hours after implantation.
After that, after switching to No. 3 outlet and switching again to No. 1 outlet, the equipment is located at the position of 174 degrees with No. 1 outlet and can be used to insert a pipe during blowing. No. provided Co ⁶⁰ was injected from the 16 tuyere 19 and the radioactive intensity of the hot metal was measured with a spear at the back of the No. 1 spout. The radioactive intensity was measured as shown in FIG. 7 (c), and the intensity peak appeared 3.0 hours after implantation.
[0024]
After this, switching to No. 3 dock and again, and switching to No. 1 dock again, this time, No. 1 is located at the same position as No. 1 dock and 174 degrees. A pipe having an inner diameter of 90 mm and an outer diameter of 110 mm was inserted into the furnace from the 16 tuyere 19 by 2.5 m, and Co ⁶⁰ was injected from the tip of the pipe, and the radioactive intensity of the hot metal was measured with a scissors behind the No. 1 spout. The radioactive intensity was measured as shown in FIG. 7 (b), and the intensity peak appeared at 5.2 hours after implantation.
As a result, from the determination method of the present invention, t _a = 3.5 hours, t _b = 5.2 hours, t _c = 3.0 hours, that is, t _a <t _b ≧ t _c , and a part of the core is Presumed to have surfaced.
[0025]
【The invention's effect】
According to the present invention, in order to detect the rise and sink state of the furnace core that greatly affects the hot water flow behavior of the blast furnace hearth, two tuyere with different angles formed with the tap outlet during operation of the blast furnace and The tracer material is measured by detecting the tracer concentration in the hot metal discharged from each of the total three locations of the tip of the pipe inserted into the furnace from one tuyere. Based on the order of time from implantation to the peak of the detected concentration, the blast furnace core can be estimated by classifying it into the following patterns: (1) full landing, (2) partial levitation, and (3) full levitation.
Therefore, the present invention estimates the hot water flow state of the hearth part from the core floating state, and when it is determined that the core part floats easily to make a peripheral annular flow with a large load on the hearth part refractory, Actions such as charging control, cooling control, and titanium blowing from the tuyere to prevent refractory melting can be taken promptly to prevent refractory erosion and prolong the blast furnace life.
[Brief description of the drawings]
[Fig. 1] Classification of blast furnace hearth core state [Fig. 2] Blast furnace hearth model test device [Fig. 3] Tracer input position in blast furnace hearth model test device [Fig. 4] Blast furnace hearth Horizontal sectional view
[Figure 5] Horizontal sectional view of the blast furnace hearth (downhole level)
FIG. 6 is a diagram showing the positions where the tracer has been implanted. FIG. 7 shows the transition of the radioactive intensity behind the spout after the radioactive element is implanted from each position. From the 23 tuyere, (b) is No. From the tip of the pipe inserted from the 16 tuyere, (c) is No. Figure showing the transition of the radioactive intensity behind the taphole after each radioactive element is injected from the 16 tuyere.
1 Blast Furnace Furnace 2 Feather 3 Depot 4 Raceway 5 Core Coke Packing Layer 6 Coke Free Area 7 Experimental Water Tank 8 Droplet Disperser 9 Packed Particle Layer 10 Liquid Level 11 Tracer Inlet 12 Drainage Port 13 Tracer Detection No. 14 Outlet 15 No.1 Outlet 16 No.3 Outlet 17 No.4 Outlet 18 No. 23 tuyere 19 no. 16 tuyere 20 Tracer driving position from the tip of a pipe inserted from 16 tuyere

Claims

During operation of the blast furnace, when using the same tap hole, the angle between the tap hole and the tap hole is (1) 75-105 degrees tuyere, (2) 150-180 degree tuyere And (3) Tracer material is driven into the furnace sequentially from three locations at the tip of the pipe inserted into the furnace from the same tuyere as (2) or (2) and another tuyere at 150 to 180 degrees. The operation of detecting the concentration of the tracer substance in the hot metal produced in step 1 was repeated, and the rise and fall state of the core of the blast furnace core was changed according to the order of time from the placement of the tracer substance to the peak of the detected concentration. ▼ Partial levitation, ③ Blast furnace core status estimation method to estimate which pattern is floating on the entire surface.

During operation of the blast furnace, when using the same tap hole, the angle between the tap hole and the tap hole is (1) 75-105 degrees tuyere, (2) 150-180 degree tuyere (3) From the same tuyere as in (2) or from the tip of the pipe inserted into the furnace from (2) and another tuyere at 150 to 180 degrees, different tracer materials are put into the furnace. The operation of detecting the concentration of the tracer substance in the hot metal that was driven in and out was carried out, and the floating and sinking state of the blast furnace core was changed according to the order of time from the tracer substance injection to the peak of the detected concentration. 2) Blast furnace core situation estimation method for estimating which pattern is partially levitation and (3) levitation of the entire surface.

During operation of the blast furnace, when using the same tap hole, the angle between the tap hole and the tap hole is (1) 75-105 degrees tuyere, (2) 150-180 degree tuyere And (3) Of the three locations at the tip of the pipe inserted into the furnace from the same tuyere of (2) or (2) and another tuyere at 150 to 180 degrees, two are the same tracer substance, In the remaining one place, a different tracer substance is divided into two times so that the same tracer substance is not injected from two places at the same time, and the concentration of the tracer substance in the molten iron discharged from the furnace is detected. Operate and estimate the pattern of the blast furnace core from 1) full landing, 2) partial levitation, and 3) full surface floating according to the order of time from the tracer substance injection to the peak of detected concentration. Blast furnace core status estimation method.

4. The blast furnace core state estimation method according to claim 1, wherein the tracer substance is a radioisotope.

(1) The tuyere at 75 to 105 degrees, (2) The tuyere at 150 to 180 degrees, and (3) The tuyere same as (2) or 150 to 180 degrees When the times from the implantation of the tracer substance implanted from three locations at the tip of the pipe inserted into the furnace from another tuyere into a certain tuyere to the peak of the detected concentration are t _a , t _b and t _c , respectively.
(1) When t _a <t _b <t _c , the entire surface is floored and there is no void. (2) When t _a <t _b ≧ t _c , a part of the furnace core is floating (3) 5. The blast furnace core condition estimation method according to claim 1, wherein when t _a ≧ t _b , it is estimated that the entire core is levitated from the bottom surface of the furnace.