JP3731376B2 - Humidity control method of blast furnace blast by water blowing - Google Patents

Description

【０００８】
たとえば、ノズル群２ａ，…２ｅ_n から吹き込める水の量を、前記計算式(1) に従って計算した目標水吹き込み量Ｖ_W が4.0 t/h 以上、4.5 t/h 未満となれば、ノズル群２ａ，…２ｅ_n にそれぞれ対応して配置された遮断弁４ａ，…４ｅ_n のうち、前記表１に示すように遮断弁４ａ，４ｂ，４ｄを開にし、その他は閉のままとする。また、目標水吹き込み量Ｖ_W を4.5 t/h 以上5.0 t/h 未満とするときには、遮断弁４ｂ, ４ｃ, ４ｄを開にすることにより調湿に必要な水吹き込み量とする。なお、5.0 t/h 以上の場合についても同様に表１に示している。
【０００９】
このように、従来の高炉に吹き込む送風の調湿制御では、送風中に吹き込む水の量に応じ、あらかじめ設定した通りに複数の遮断弁４ａ，…４ｅ_n を開閉し、段階的に水の流量を制御するのみであったため、どうしても水吹き込み目標量Ｖw と測定した実績水吹き込み量Ｖ_W1とに、ノズル特性やノズルの劣化あるいはノズル詰まり等により生じる定常偏差ΔＶ_W が生じることになるので、その偏差を解消するために、目標送風湿度Ｍ_svをあらかじめ水吹き込み制御器16に入力しておく。
【００１０】
一方、高炉冷風管１に配設した送風流量計14および湿分計15を用いて、高炉冷風管１内を流れる水吹き込み前の送風流量ＢＶおよび送風湿分Ｍ_pvをそぞれ測定し、測定した送風流量ＢＶと湿分Ｍ_PVとを水吹き込み制御器16に入力する。水吹き込み制御器16では、測定した送風流量ＢＶおよび送風湿分Ｍ_PV並びに予め入力してある目標送風湿度Ｍ_SVとから、計算式(1) を用いて目標水吹き込み量Ｖ_W を計算する。そして、水吹き込み制御器16から目標水吹き込み量Ｖ_W を水流量調節器11に入力する一方、吹き込み水配管５に配設した水流量計６により測定した実績水流量Ｖ_W1を水流量調節器11に入力する。
【００１１】
水流量調節器11では、目標水吹き込み量Ｖ_W と測定した実績水吹き込み量Ｖ_W1とから水量の過不足を水吹き込み量偏差ΔＶ_W として演算し、この水吹き込み量偏差ΔＶ_W を補うためみ必要な水圧力偏差ΔＰ_W として水圧力調節器12に入力する。一方、吹き込み水配管５に配設した水圧力計10により測定した実績水圧力Ｐ_W を圧力調節器12に入力する。水圧力調節器12では、入力された水圧力偏差ΔＰ_W および水圧力計10により測定した実績水圧力Ｐ_W に基づいて、新たな水圧力設定値Ｐ_W0を定め、この水圧力設定値Ｐ_W0を吹き込み水配管５に配設した水圧力調節弁13に入力する。
【００１２】
水圧力調節弁13では、入力された新たな水圧力設定値Ｐ_W0にしたがって、水タンク９から水昇圧ポンプ８を介して吹き込み水配管５に供給される水の吐出圧力を調整する。これによって、吹き込み水配管５から供給される水吹き込み量偏差ΔＶ_W を補うことにより、各ノズル群２ａ，…２ｅ_n から選択されたノズル群に供給する水の過不足を補償する。このように、送風機から熱風炉に至る高炉冷風管１に配設した複数のノズル群２ａ，…２ｅ_n と遮断弁４ａ，…４ｅ_n とを組み合わせて水吹き込みを行う調湿制御に加え、各ノズル群２ａ，…２ｅ_n のノズル特性変化等から生じる目標水吹き込み量Ｖ_W と測定した実績水吹き込み量Ｖ_W1との偏差を、水昇圧ポンプ８の吐出圧力の調整により補償する一連のカスケード制御ループを構成する。
【００１３】
【発明が解決しようとする課題】
しかしながら、前述したように目標水吹き込み量に応じて所定の遮断弁を開閉する固定の設定をもつ方法では、定常的な目標水吹き込み量における特定の遮断弁の開閉動作の回数は増加する一方で、大流量を吹き込むための遮断弁はまったく動作するチャンスがないのである。
【００１４】
そのことを目標水吹き込み量を4.5 〜6.0 t/h で操業している場合を例にして具体的に説明すると、図６に示すように、時刻ｔ₁ で1.5 t/h の目標水吹き込み量に対して遮断弁４ａ，４ｂが開となり、ついで時刻ｔ₂ の目標水吹き込み量4.0 t/h に対してさらに遮断弁４ｄが開、時刻ｔ₃ の目標水吹き込み量4.5 t/h に対して遮断弁４ａが閉、遮断弁４ｃが開、時刻ｔ₄ で目標水吹き込み量が5.0 t/h になったので遮断弁４ｂ，４ｃ，４ｄが閉になって遮断弁４ｅ₁ が開（１回目の動作）となりその後目標水吹き込み量が5.2 t/h 一定状態なので遮断弁４ｅ₁ １個のみで制御される。しかし、時刻ｔ₅ で目標水吹き込み量が5.0 t/h 以下になる傾向なので、遮断弁４ｅ₁ を閉（２回目の動作）、遮断弁４ｂ，４ｃ，４ｄを開にする。さらに時刻ｔ₆ で目標水吹き込み量が再び5.0 t/h 以上になる傾向なので遮断弁４ｂ，４ｃ，４ｄを閉、遮断弁４ｅ₁ を開（３回目の動作）とする。引き続き、時刻ｔ₇ で再び目標水吹き込み量が5.0 t/h 以下になるので遮断弁４ｂ，４ｃ，４ｄを開、遮断弁４ｅ₁ を閉（４回目の動作）とする。さらに、時刻ｔ₈ での目標水吹き込み量5.0 t/h 越えに対して時刻ｔ₆ と同様に遮断弁４ｂ，４ｃ，４ｄを閉、遮断弁４ｅ₁ を開（５回目の動作）とし、時刻ｔ₉ での目標水吹き込み量5.0 t/h 以下に対して時刻ｔ₅ あるいは時刻ｔ₇ と同様に、遮断弁４ｅ₁ を閉（６回目の動作）、遮断弁４ｂ，４ｃ，４ｄを開にする。
【００１５】
このように、遮断弁４ｅ₁ は水吹き込み制御器16からの目標に従って開閉動作を行うがこの遮断弁４ｅ₁ と同じ量の水を吹き込む能力（以下、同一能力という）を有する他の遮断弁４ｅ₂ ，…４ｅ_n はまったく動作することがない。このような定常的な制御状態においては遮断弁４ｅ₁ というような特定の遮断弁のみに開閉動作が集中することになるから、その遮断弁は残された同一能力の遮断弁に比較して早期に動作限界に到達して劣化摩耗に至るため、流量制御の精度を損なうことになって信頼性がなり、早期に部品交換などの修理を要するという問題が生じることになる。
【００１６】
本発明は、上記のような従来例の有する課題を解決すべくなされたものであって、特定の遮断弁のみに開閉動作が集中することなく同一能力を有する遮断弁の開閉動作回数の均一化を図ることにより、遮断弁の信頼性を長期的に保持することの可能な水吹き込みによる高炉送風の調湿方法を提供することを目的とする。
【００１７】
【課題を解決するための手段】
前記目的を達成するための本発明は、送風機から熱風炉に至る間の高炉冷風管に、ノズル群から水を吹き込むことにより高炉への送風を調湿する際に、調湿量の最小変化分に見合う水吹き込み量をもつノズル群と、前記吹き込み量以上の水吹き込み量をもつノズル群との複数組のノズル群を設け、かつ該ノズル群の水導管に遮断弁を取り付け、前記各ノズル群のうち目標水吹き込み量に応じ選択したノズル群のみに当該遮断弁を開閉して通水して水の吹き込み量を段階的に制御するとともに、前記目標水吹き込み量と測定した実績水吹き込み量との偏差を、前記複数組のノズル群に水を供給する水昇圧ポンプから吐出される水の圧力を調整するカスケード制御により補償するようにした水吹き込みによる高炉送風への調湿方法において、所定量の水吹き込み指令に対して通水量が同一とされる複数の遮断弁の開閉動作の回数を監視して、動作回数の少ない遮断弁から順に開閉動作させるようにすることを特徴とする水吹き込みによる高炉送風の調湿方法である。
【００１８】
また、本発明は、送風機から熱風炉に至る間の高炉冷風管に、ノズル群から水を吹き込むことにより高炉への送風を調湿する際に、調湿量の最小変化分に見合う水吹き込み量をもつノズル群と、前記吹き込み量以上の水吹き込み量をもつノズル群との複数組のノズル群を設け、かつ該ノズル群の水導管に遮断弁を取り付け、前記各ノズル群のうち目標水吹き込み量に応じ選択したノズル群のみに当該遮断弁を開閉して通水して水の吹き込み量を段階的に制御するとともに、前記目標水吹き込み量と測定した実績水吹き込み量との偏差を、前記複数組のノズル群に水を供給する水昇圧ポンプから吐出される水の圧力を調整するカスケード制御により補償するようにした高炉送風への水吹き込みによる調湿方法において、通水量が同一とされる遮断弁にあらかじめ優先順位を与えておき、所定量の水吹き込み指令に対して優先順位の高い遮断弁から順次開閉動作させるとともに、所定時間経過ごとに前記優先順位を１つずつ繰り下げて変更することを特徴とする水吹き込みによる高炉送風の調湿方法である。
【００１９】
【発明の実施の形態】
以下に本発明の好適な実施の形態について、図面を参照しながら具体的に説明する。図１は本発明の高炉調湿送風設備を示す模式的に示す概要図であり、図２は本発明の要部を示す概念図である。なお、図中において従来例と同一の部材については同一符号を付して説明を省略する。
【００２０】
図１に示すように、同一能力（いずれも5.0 t/h ；前出表１参照）を有する遮断弁４ｅ₁ ，…４ｅ_n のそれぞれに、開動作でオン、閉動作でオフすることにより遮断弁の動作を検知するリミットスイッチ17ｅ₁ ，…17ｅ_n が取り付けられる。そして、リミットスイッチ17ｅ₁ ，…17ｅ_n の検出信号は、図２に示すように、それぞれ回線18ｅ₁ ，…18ｅ_n を介してカウンタ19ｅ₁ ，…19ｅ_n に入力されて、それぞれの動作回数がカウントされる。これらのカウンタ19ｅ₁ ，…19ｅ_n でカウントされた遮断弁４ｅ₁ ，…４ｅ_n の動作回数は、回線20ｅ₁ ，…20ｅ_n を介して各遮断弁に開閉動作の指令を出力する水吹き込み制御器16に入力されて、水吹き込み制御器16において同一能力を有する遮断弁間で比較される。そして、次回の動作のチャンスには、動作回数の少ない遮断弁を優先的に開閉動作をさせるのである。
【００２１】
このようにして、開閉動作の回数をカウントアップして同一能力を有する遮断弁間で比較することにより、特定の遮断弁に偏ることなく全部の遮断弁を動作させることができるとともに、その動作回数の均一化を図ることができることになる。
なお、上記の例は動作回数をカウントアップする方法であるが、本発明はこれに限るものではなく、同一能力を有する遮断弁にあらかじめ優先順位を与えておき、その順位に従って遮断弁を動作させるようにしてもよい。すなわち、上記の例と同様に同一能力を有する遮断弁４ｅ₁ ，…４ｅ_n を用いる場合、最初の遮断弁４ｅ₁ に優先順位として“１”を与え、遮断弁４ｅ₂ に“２”を与え、以下同様にして最後に遮断弁４ｅ_n に“ｎ”を与えてその順位で所定時間ずつ開閉動作を行わせるのである。これらの遮断弁が動作する優先順位を所定の時間ごとに変更していくことにより、たとえば優先順位“１”の遮断弁４ｅ₁ を開閉動作（前出表１の状態）した所定時間の経過後は、優先順位を１つ繰り下げて、表２に示すように優先順位“２”が与えられた遮断弁４ｅ₂ を所定時間の間開閉動作させる。このように順次優先順位を繰り下げることによって各遮断弁の動作回数の均一化を図ることができる。
【００２２】
【表２】

【００２３】
ここで、優先順位の繰り下げとは、優先順位“１”の遮断弁４ｅ₁ →優先順位“２”の遮断弁４ｅ₁ →優先順位“３”の遮断弁４ｅ₁ →・・・→優先順位“ｎ”の遮断弁４ｅ_n のことであるが、特定時間の経過に伴って優先順位を変更して遮断弁４ｅ₁ に“ｎ”、遮断弁４ｅ₂ に“１”、以下同様にして最後に遮断弁４ｅ_n に“ｎ−１”をそれぞれ与えるように変更していき、ｎ回優先順位を変更した後、再度最初の遮断弁４ｅ₁ に“１”の優先順位を与えるようにしても同じ操作を行うことができる。
【００２４】
【実施例】
〔実施例１〕 前出図１に示す本発明の水吹き込み調湿設備を用いて水吹き込み量4.5 〜6.0 t/h で操業した。その際、比較を容易にするために水吹き込み量の変化は前出図６と同じパターンとした。そのときの各遮断弁の動作のタイムチャートを図３に示した。
【００２５】
まず、時刻ｔ₁ で1.5 t/h の目標水吹き込み量に対して遮断弁４ａ，４ｂを開とし、ついで時刻ｔ₂ の目標水吹き込み量4.0 t/h に対してさらに遮断弁４ｄを開、時刻ｔ₃ の目標水吹き込み量4.5 t/h に対して遮断弁４ａを閉、遮断弁４ｃを開とした。時刻ｔ₄ で目標水吹き込み量が5.0 t/h になったので遮断弁４ｂ，４ｃ，４ｄを閉にした。同時に、5.0 t/h の能力を有する遮断弁を開にする必要があるが、ここで、遮断弁４ｅ₁ ，…４ｅ_n の動作回数を比較し、動作回数０である最初の遮断弁４ｅ₁ を選択して開（遮断弁４ｅ₁ ；１回目の動作）とした。時刻ｔ₅ で目標水吹き込み量が5.0 t/h 以下になったのに対応して、遮断弁４ｅ₁ を閉（遮断弁４ｅ₁ ；２回目の動作）にし、遮断弁４ｂ，４ｃ，４ｄを開にした。
【００２６】
ついで、時刻ｔ₆ で目標水吹き込み量が再び5.0 t/h 以上になったので、遮断弁４ｂ，４ｃ，４ｄを閉にした。同時に、5.0 t/h の能力を有する遮断弁を開にする際に、再度遮断弁４ｅ₁ ，…４ｅ_n を比較し、動作回数０である最初の遮断弁４ｅ₂ を選択して開（遮断弁４ｅ₂ ；１回目の動作）とした。引き続き、時刻ｔ₇ で再び目標水吹き込み量が5.0 t/h 以下になったので遮断弁４ｂ，４ｃ，４ｄを開、遮断弁４ｅ₂ を閉（遮断弁４ｅ₂ ；２回目の動作）とした。
【００２７】
さらに、時刻ｔ₈ での目標水吹き込み量5.0 t/h 以上に対して遮断弁４ｂ，４ｃ，４ｄを閉にし、開にする5.0 t/h の能力を有する遮断弁の中から動作回数０である最初の遮断弁４ｅ₃ を選択して開（遮断弁４ｅ₃ ；１回目の動作）とした。引き続き、時刻ｔ₉ で再び目標水吹き込み量が5.0 t/h 以下に対して遮断弁４ｂ，４ｃ，４ｄを開、遮断弁４ｅ₃ を閉（遮断弁４ｅ₃ ；２回目の動作）とした。
【００２８】
以下、目標水吹き込み量が5.0 t/h 以上および5.0 t/h 以下になる都度、順次同一能力を有する遮断弁４ｅ₁ ，…４ｅ_n の開閉動作の回数を比較して動作回数の少ない遮断弁を選択して開閉させることにより、同一能力を有する遮断弁４ｅ₁ ，…４ｅ_n の動作回数を均一にすることができる。
〔実施例２〕 同一能力を有する遮断弁４ｅ₁ ，…４ｅ_n にあらかじめ優先順位を付けた切り換え方式を採用した本発明の水吹き込み調湿設備を用いて水吹き込み量4.5 〜6.0 t/h で操業した。その際、比較を容易にするために水吹き込み量の変化は前出図６と同じパターンとした。
【００２９】
図４はそのときの各遮断弁の動作のタイムチャートの一例を示したものであるが、これは、最初の遮断弁４ｅ₁ に優先順位として“１”を与え、遮断弁４ｅ₂ に“２”を与え、以下同様にして最後に遮断弁４ｅ_n に“ｎ”を与えて、24時間ごとに優先順位を１つずつ繰り下げて開閉動作を行うようにした。
すなわち、図示のように、時刻ｔ₁ で1.5 t/h の目標水吹き込み量に対して遮断弁４ａ，４ｂを開にし、ついで時刻ｔ₂ の目標水吹き込み量4.0 t/h に対してさらに遮断弁４ｄを開、時刻ｔ₃ の目標水吹き込み量4.5 t/h に対して遮断弁４ａを閉、遮断弁４ｃを開とした。そして、時刻ｔ₄ で目標水吹き込み量が5.0 t/h になったので遮断弁４ｂ，４ｃ，４ｄを閉にし、5.0 t/h の能力を有する遮断弁のうち優先順位が“１”の遮断弁４ｅ₁ を開にし、その後目標水吹き込み量が5.2 t/h 一定状態なので遮断弁４ｅ₁ １個のみで制御した。時刻ｔ₅ で目標水吹き込み量が5.0 t/h 以下になったので、遮断弁４ｅ₁ を閉にし、遮断弁４ｂ，４ｃ，４ｄを開にした。さらに時刻ｔ₆ で目標水吹き込み量が再び5.0 t/h 以上になったので遮断弁４ｂ，４ｃ，４ｄを閉、遮断弁４ｅ₁ を開にし、時刻ｔ₇ で再び目標水吹き込み量が5.0 t/h 以下になったので遮断弁４ｂ，４ｃ，４ｄを開、遮断弁４ｅ₁ を閉にした。
【００３０】
時刻ｔ₈ で24時間が経過したので、優先順位を“１”から１つ繰り下げて“２”にして遮断弁４ｅ₂ を選択して備えた。そして、時刻ｔ₉ での目標水吹き込み量5.0 t/h 以上に対して遮断弁４ｂ，４ｃ，４ｄを閉、遮断弁４ｅ₂ を開とし、時刻ｔ₁₀での目標水吹き込み量5.0 t/h 以下に対応して、遮断弁４ｅ₂ を閉、遮断弁４ｂ，４ｃ，４ｄを開とした。このようにして、目標水吹き込み量が5.0 t/h 以上および5.0 t/h 以下になる都度、順次同一能力の遮断弁４ｅ₁ ，…４ｅ_n の優先順位を一つずつ繰り下げて選択して開閉させることにより、同一能力の遮断弁４ｅ₁ ，…４ｅ_n の動作回数を均一にすることができる。
【００３１】
【発明の効果】
以上説明したように、本発明よれば、同一能力の遮断弁の開閉動作回数を監視して動作回数の少ない遮断弁を選択するか、あるいはあらかじめ与えた優先順位に基づいて開閉させて所定時間の経過後優先順位を１つずつ繰り下げるようにして、遮断弁の開閉動作回数を均一にすることができるので、特定の遮断弁の早期劣化を防止することができるとともに、非稼働の遮断弁のさび付き等の動作不良発生を予防することができ、これによって設備として長期的な安定稼働を図ることが可能である。
【図面の簡単な説明】
【図１】本発明の水吹き込み調湿設備を示す模式的に示す概要図である。
【図２】本発明の要部を示す概念図である。
【図３】本発明を用いた遮断弁の動作の一例を示すタイムチャートである。
【図４】本発明を用いた遮断弁の動作の他の例を示すタイムチャートである。
【図５】水吹き込み調湿設備の従来例を示す概要図である。
【図６】従来例における遮断弁の動作を示すタイムチャートである。
【符号の説明】
１ 高炉冷風管
２ ノズル
３ 水導管
４ 遮断弁
５ 吹き込み水配管
６ 水流量計
７ 水流量調節弁
８ 水昇圧ポンプ
９ 水タンク
10 水圧力計
11 水流量調節器
12 水圧力調節器
13 水圧力調節弁
14 送風流量計
15 湿分計
16 水吹き込み制御器
17 リミットスイッチ
18 回線
19 カウンタ
20 回線[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a humidity control method for blast furnace air blowing by blowing water into a cold air pipe between a blower and a hot stove so that the air to the blast furnace is conditioned by blowing water from a plurality of nozzle groups. .
[0002]
[Prior art]
Water is blown from the nozzle group into the blast furnace cold wind tube from the blower to the hot stove to adjust the moisture in the blower from the tuyere provided on the bottom wall of the blast furnace at the bottom of the blast furnace. Therefore, humidity control air blowing is performed to adjust the air flow to the blast furnace. Since there is a change in moisture in the atmosphere, operational fluctuation factors are reduced by keeping the moisture value constant by means of humidity control air blowing. There are two types of humidity-controlled airflow: dry airflow that reduces moisture during airflow and airflow that increases humidity. The purpose of dry air blow is to reduce coke consumption by removing the negative heat of decomposition of moisture before the tuyere.
[0003]
In addition, the humidified blast controls the furnace heat by adjusting the theoretical combustion temperature and the oxidation zone in front of the tuyere to maintain the melting zone temperature at a constant temperature, and further by the reaction in the furnace by the decomposed gas. The purpose is to make the operation highly efficient. Since the increase in moisture increases the reaction between coke and moisture in the furnace, it promotes the reduction of ore in the furnace and has the effect of suppressing these cases when shelves or slips are likely to occur in the blast furnace.
[0004]
Conventionally, as a blast furnace humidifying air blowing method, steam has been mainly blown into a blast furnace cold wind tube from a blower to a hot stove. However, since the energy cost for producing water vapor is high, a method of mist-blowing liquid water (hereinafter simply referred to as water) with low cost as a substitute for water vapor is often used. Among these water blowing facilities, as disclosed in Japanese Patent Application Laid-Open No. 9-263810, which has already been filed by the present applicant, uses a water blowing humidity control device comprising a combination of a plurality of shut-off valves and nozzles. Yes. The outline of the water blowing humidity control equipment is shown in FIG.
[0005]
In FIG. 5, nozzle groups 2a, 2b, 2c having a water blowing rate (0.5 t / h) commensurate with the minimum change in humidity control amount and the nozzle group in the blast furnace cold wind tube 1 from the blower (not shown) to the hot stove. water blown amount or more nozzle groups 2d, 2e _1, installing a plurality of nozzle groups and ... 2e _n. Nozzles constituting each nozzle group, one water conduit 3a, respectively, 3b, 3c, 3d, 3e _1, ... are connected to 3e _n, each water conduit 3a, ... each shut-off valve 4a in the middle of 3e _n , 4b, 4c, 4d, 4e 1, ... provided 4e _n, and can control the water flow alone respectively. Each water conduit 3a, ... 3e _n is connected to a blowing water piping 5 in one, the blowing water pipe 5 water flow meter 6, the water flow rate control valve 7, the water tank 9 via a water booster pump 8 Connected.
[0006]
In the water blowing humidity control equipment described above, first, a target water blowing amount V _W0 blown into the blast furnace cold air pipe 1 necessary for humidity conditioning is calculated according to the following calculation formula (1).
_{V W = {(M SV -M} PV) × BV × 60} / 1000000 .................. (1)
V _W : Target water blowing rate (t / h)
M _SV : Target ventilation humidity (g / Nm ³ )
_MPV : Brewing moisture before water blowing (g / Nm ³ )
BV: Air flow rate (Nm ³ )
Shut-off valve 4a, ... the method of opening and closing combinations of 4e _n, for example, in as shown in Table 1, nozzle groups 2a with a blowing amount of water to meet the minimum change of the humidity amount (0.5t / h), 2b, 2c the water blown amount or more (2.5 t / h) of the nozzle groups 2d, 2e _1, out of ... 2e _n, and passed through only the nozzle groups used for blowing water, stepwise controlling the blowing amount of water and And air conditioning.
[0007]
[Table 1]

[0008]
For example, nozzle groups 2a, ... the amount of Fukikomeru water from 2e _n, the equation (1) target water blown amount V _W calculated according to the 4.0 t / h or higher, if less than 4.5 t / h, the nozzle groups 2a, ... 2e _n the shut-off valve 4a disposed to correspond, among ... 4e _n, and shut-off valve 4a, as shown in table 1, 4b, and 4d to open, the other is kept closed. When the target water blowing amount V _W is 4.5 t / h or more and less than 5.0 t / h, the shutoff valves 4b, 4c and 4d are opened to obtain the water blowing amount necessary for humidity control. The case of 5.0 t / h or more is also shown in Table 1.
[0009]
Thus, in the humidity adjustment of blast blown in a conventional blast furnace, depending on the amount of water blown into the blast, a plurality of shut-off valve 4a as a preset, ... open and close the 4e _n, stepwise water flow Therefore, a steady deviation ΔV _W caused by nozzle characteristics, nozzle deterioration, nozzle clogging, etc. is inevitably generated between the target water injection amount Vw and the measured water injection amount V _W1. In order to eliminate the deviation, the target blowing humidity M _sv is input to the water blowing controller 16 in advance.
[0010]
On the other hand, by using the air flow meter 14 and the moisture meter 15 disposed in the blast furnace cold air tube 1, the air flow BV and the air flow rate M _pv before the water blowing flowing in the blast furnace cold air tube 1 are measured, respectively. the a measured blower flow BV and moisture M _PV input to the water blowing controller 16. The water blowing controller 16 calculates the target water blowing amount V _W by using the calculation formula (1) from the measured blowing flow rate BV, the blowing moisture M _PV and the target blowing humidity M _SV inputted in advance. Then, the target water blowing amount V _W is input from the water blowing controller 16 to the water flow controller 11, while the actual water flow V _W1 measured by the water flow meter 6 disposed in the blowing water pipe 5 is used as the water flow controller. Enter in 11.
[0011]
The water flow controller 11 calculates the excess or deficiency of the water amount as the water injection amount deviation ΔV _W from the target water injection amount V _W and the measured actual water injection amount V _W1 , in order to compensate for this water injection amount deviation ΔV _W. The required water pressure deviation ΔP _W is input to the water pressure controller 12. On the other hand, the actual water pressure P _W measured by the water pressure gauge 10 disposed in the blowing water pipe 5 is input to the pressure regulator 12. The water pressure regulator 12 determines a new water pressure set value P _W0 based on the input water pressure deviation ΔP _W and the actual water pressure P _W measured by the water pressure gauge 10, and this water pressure set value P _W0 Is input to a water pressure control valve 13 disposed in the water pipe 5.
[0012]
The water pressure control valve 13 adjusts the discharge pressure of water supplied from the water tank 9 to the blow-in water pipe 5 through the water booster pump 8 in accordance with the input new water pressure set value P _W0 . Thus, by compensating the water blowing amount deviation [Delta] V _W supplied from blowing water piping 5, the nozzle groups 2a, to compensate for the excess and deficiency of water supplied to the nozzle group selected from ... 2e _n. Thus, a plurality of nozzle groups 2a which is arranged in the blast furnace cold pipe 1 leading to the hot air oven from the blower, ... 2e _n and shut-off valve 4a, ... in combination with 4e _n addition to performing humidity adjustment blowing water, the nozzle groups 2a, ... the deviation between the actual water blowing amount V _W1 and the measured target water blowing amount V _W resulting from nozzle property change of 2e _n, a series of cascade control to compensate by adjusting the discharge pressure of the water booster pump 8 Construct a loop.
[0013]
[Problems to be solved by the invention]
However, in the method having the fixed setting for opening and closing the predetermined shutoff valve according to the target water blowing amount as described above, the number of times of opening and closing the specific shutoff valve at the steady target water blowing amount increases. The shut-off valve for blowing a large flow rate has no chance to operate at all.
[0014]
This will be specifically explained by taking the case where the target water blowing rate is 4.5 to 6.0 t / h as an example. As shown in FIG. 6, the target water blowing rate of 1.5 t / h at time t ₁ is shown. relative shut-off valve 4a, 4b is opened, then further shutoff valve 4d is opened with respect to the target water blown quantity 4.0 t / h of time t _2, the time t ₃ of the target water blowing amount 4.5 t / h with respect to shut-off valve 4a is closed, shut-off valve 4c is opened, shut-off valves at time t ₄ since the amount of blowing target water became 5.0 t / h 4b, 4c, the shut-off valve 4d is in the closed 4e ₁ is open (first After that, since the target water blowing rate is constant at 5.2 t / h, it is controlled by only _one shutoff valve 4e ₁ . However, since at time t ₅ trend blowing amount target water is below 5.0 t / h, the shut-off valve 4e ₁ closed (second operation), shut-off valves 4b, 4c, the 4d to open. Shutoff valve 4b since the amount of blowing target water tendency to become more again 5.0 t / h at a further time t _6, 4c, 4d to be closed, the shut-off valve 4e ₁ opens (the third operation). Subsequently, shut-off valve 4b since the amount of blowing again target water at time t ₇ is below 5.0 t / h, 4c, and 4d open, the shut-off valve 4e ₁ in the closed (fourth operation). Further, the target water blown quantity 5.0 t / h Similarly shutoff valve 4b and the time t ₆ against over at time t _8, 4c, and 4d were closed, the shut-off valve 4e ₁ opens (the fifth operation), time Like the target water blowing amount 5.0 t / h time t ₅ or the time t ₇ for the following in t _9, the shut-off valve 4e ₁ closed (sixth operation), shut-off valves 4b, 4c, 4d to open To do.
[0015]
Thus, shut-off valves 4e ₁ is the ability to blow the same amount of water but the opening and closing operation according to the target and the shut-off valve 4e ₁ from the water blowing controller 16 (hereinafter, referred to as the same capacity) other shutoff valves 4e having _2, ... 4e _n have not to work at all. In such a steady control state, since the opening / closing operation is concentrated only on a specific shut-off valve such as the shut-off valve 4e ₁ , the shut-off valve is earlier than the remaining shut-off valve having the same capacity. When the operation limit is reached and deterioration wear occurs, the accuracy of the flow rate control is deteriorated and reliability is increased, and there is a problem that repair such as parts replacement is required at an early stage.
[0016]
The present invention has been made to solve the above-described problems of the conventional example, and the number of opening / closing operations of the shut-off valve having the same capability is made uniform without concentrating the opening / closing operation only on the specific shut-off valve. Therefore, an object of the present invention is to provide a humidity control method for blast furnace blast by water blowing, which can maintain the reliability of the shut-off valve for a long time.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a minimum amount of change in the amount of humidity control when adjusting the air sent to the blast furnace by blowing water from the nozzle group into the blast furnace cold air pipe between the blower and the hot air furnace. A plurality of nozzle groups including a nozzle group having a water blowing amount suitable for the nozzle and a nozzle group having a water blowing amount equal to or greater than the blowing amount, and a shutoff valve is attached to the water conduit of the nozzle group, And opening and closing the shut-off valve only to the nozzle group selected according to the target water blowing amount to control the water blowing amount in stages, and the target water blowing amount and the measured water blowing amount measured In the humidity control method for blast furnace air blowing by water blowing, which is compensated by cascade control for adjusting the pressure of water discharged from a water booster pump that supplies water to the plurality of nozzle groups, By monitoring the number of opening / closing operations of a plurality of shut-off valves that have the same water flow rate with respect to the water blowing command, the shut-off valves are operated in order from the least shut-off valve. This is a method of conditioning the blast furnace blast.
[0018]
In addition, the present invention provides a water blowing amount suitable for the minimum change in the amount of humidity control when adjusting the air sent to the blast furnace by blowing water from the nozzle group into the blast furnace cold wind tube between the blower and the hot stove. A plurality of nozzle groups, each having a nozzle group having a water blowing amount equal to or greater than the blowing amount, and a shutoff valve attached to the water conduit of the nozzle group, Opening and closing the shut-off valve only to the nozzle group selected according to the amount to control the amount of water blown in stages, and the deviation between the target water blow amount and the measured actual water blow amount, In a humidity control method using water blowing into a blast furnace blast, which is compensated by cascade control for adjusting the pressure of water discharged from a water booster pump that supplies water to a plurality of nozzle groups, the water flow rate is made the same Blocking Priorities are given to the valves in advance, and opening and closing operations are sequentially performed from a shut-off valve with a higher priority with respect to a predetermined amount of water blowing command, and the priority is lowered one by one and changed every predetermined time. It is a humidity control method for blast furnace blasting by water blowing.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a schematic diagram schematically showing a blast furnace humidity control blower facility of the present invention, and FIG. 2 is a conceptual diagram showing a main part of the present invention. In the figure, the same members as those in the conventional example are designated by the same reference numerals and the description thereof is omitted.
[0020]
As shown in FIG. 1, the same capability (both 5.0 t / h; see supra Table 1) cutoff cutoff valve 4e ₁ having, ... to each 4e _n, on in opening operation, by turning off at closing limit switch 17e ₁ for detecting the operation of the valve, ... 17e _n is attached. The limit switch 17e _1, detection signals ... 17e _n, as shown in FIG. 2, each line 18e _1, ... counter 19e ₁ through 18e _n, is input to ... 19e _n, the respective operating times Be counted. These counters 19e _1, ... 19e _n shutoff valves 4e ₁ are counted in, ... number of operations 4e _n is line 20e _1, ... output water blowing control command for opening and closing the respective shutoff valves through 20e _n The water injection controller 16 compares the shut-off valves having the same capacity. In the next operation opportunity, the shut-off valve with a small number of operations is preferentially opened and closed.
[0021]
In this way, by counting up the number of open / close operations and comparing between shut-off valves having the same capacity, all the shut-off valves can be operated without biasing to a specific shut-off valve, and the number of operations Can be made uniform.
The above example is a method of counting up the number of operations. However, the present invention is not limited to this, and priorities are given in advance to shut-off valves having the same ability, and the shut-off valves are operated according to the order. You may do it. In other words, shut-off valves 4e ₁ having the same capability as in the above example, when using a ... 4e _n, given a "1" as a priority to the first shut-off valve 4e _1, giving "2" shutoff valve 4e ₂ is to carry out opening and closing operations by a predetermined time, the order given or "n" to the shut-off valve 4e _n finally in the same manner. By changing the priority order in which these shut-off valves are operated at predetermined time intervals, for example, after a predetermined time has elapsed since the shut-off valve 4e ₁ with priority "1" is opened / closed (state shown in Table 1 above). Lowers the priority by one and opens and closes the shutoff valve 4e ₂ given the priority “2” as shown in Table 2 for a predetermined time. In this way, by sequentially lowering the priority order, the number of operations of each shut-off valve can be made uniform.
[0022]
[Table 2]

[0023]
Here, the postponement of priority, the priority "1" shut-off valve 4e ₁ → priority of "2" shut-off valve 4e ₁ → priority of "3" shut-off valve 4e ₁ → ··· → priority ""it is to the shut-off valve 4e _n of the shut-off valve 4e ₁ to change the priority with the passage of a specified time" n n ", the shut-off valve 4e _2" 1 ", the last in the same manner the "n-1" to the shut-off valve 4e _n continue to change so as to provide respectively, after changing the n times priority be given a priority "1" as the first shut-off valve 4e ₁ again the same The operation can be performed.
[0024]
【Example】
[Example 1] The water blowing humidity control equipment of the present invention shown in Fig. 1 was used to operate at a water blowing rate of 4.5 to 6.0 t / h. At that time, in order to facilitate the comparison, the change in the water blowing amount was set to the same pattern as in FIG. The time chart of the operation of each shut-off valve at that time is shown in FIG.
[0025]
First, shut-off valve 4a with respect to the target water blowing amount at a time t ₁ 1.5 t / h, 4b was opened, and then further cut-off valve 4d open to the target water blown quantity 4.0 t / h of time t _2, the the shut-off valve 4a was closed, and the shut-off valve 4c opened to the target water blown quantity 4.5 t / h at time t _3. Shutoff valves 4b, 4c, and 4d was closed at time t ₄ since the amount of blowing target water became 5.0 t / h. At the same time, it is necessary to shut-off valves having the capability of 5.0 t / h in the open, where the shut-off valves 4e _1, ... compares the number of operations of 4e _n, the first shut-off valve 4e ₁ is a number of operation times 0 Was selected and opened (shutoff valve 4e ₁ ; first operation). Corresponding to the amount blown target water is below 5.0 t / h at time t _5, the shutoff valves 4e ₁ closed; the (cutoff valve 4e ₁ 2 round of operation), the shut-off valve 4b, 4c, and 4d I opened it.
[0026]
Subsequently, since the target water blowing amount became 5.0 t / h or more again at time t ₆ , the shut-off valves 4b, 4c and 4d were closed. At the same time, when the shut-off valve having a capacity of 5.0 t / h in the open, shut-off valves 4e ₁ again, ... compare 4e _n, select and open (cut off the first shut-off valve 4e ₂ is an operation number 0 Valve 4e ₂ ; first operation). Subsequently, shut-off valve 4b since the amount of blowing again target water at time t ₇ is equal to or less than 5.0 t / h, 4c, and 4d open, the shut-off valve 4e ₂ closed; was (cutoff valve 4e ₂ 2 nd operation) .
[0027]
Further, the shut-off valves 4b, 4c, 4d are closed and opened at a time t ₈ with a target water blowing rate of 5.0 t / h or more, and the shut-off valves having the ability of 5.0 t / h to open are operated 0 times. A certain first shut-off valve 4e ₃ was selected and opened (shut-off valve 4e ₃ ; first operation). Subsequently, the amount of blowing again target water at time t ₉ is shut-off valve 4b, 4c, and 4d open, the shut-off valve 4e ₃ closed for the following 5.0 t / h; and the (cutoff valve 4e ₃ 2 round of operation).
[0028]
Hereinafter, each time the amount of blowing target water is below 5.0 t / h or more and 5.0 t / h, shutoff valves 4e ₁ having a sequence identical capacity, ... 4e _n less shut-off valve by comparing the number of opening and closing operation of the number of operations of by selectively to open and close the shut-off valve 4e ₁ having the same capacity, it is possible to equalize the number of operations of ... 4e _n.
In Example 2 shutoff valves 4e ₁ having the same capacity, ... 4e with water blowing humidity facility blowing amount of water of the present invention employing a switching scheme with a pre-priority _n 4.5 ~6.0 t / h Operated. At that time, in order to facilitate the comparison, the change in the water blowing amount was set to the same pattern as in FIG.
[0029]
Figure 4 is illustrates an example of a time chart of the operation of the shut-off valve at that time, which gives the "1" as a priority to the first shut-off valve 4e _1, shutoff valves 4e ₂ to "2 "give, following the shut-off valve 4e _n last in a similar manner" giving n ", and to perform opening and closing operation shifted down one priority every 24 hours.
That is, as illustrated, the shut-off valve 4a with respect to the target water blowing amount at a time t ₁ 1.5 t / h, and 4b was opened, and then further blocked with respect to the target water blown quantity 4.0 t / h at time t ₂ the valve 4d open, the shut-off valve 4a was closed, and the shut-off valve 4c opened to the target water blown quantity 4.5 t / h at time t _3. At time t ₄ , the target water injection amount is 5.0 t / h, so the shut-off valves 4b, 4c, 4d are closed, and the shut-off valve having the ability of 5.0 t / h has the priority “1”. The valve 4e ₁ was opened, and then the target water blowing rate was constant at 5.2 t / h, so control was performed with only _one shut-off valve 4e ₁ . Since the amount of blowing target water is below 5.0 t / h at time t _5, the shutoff valves 4e ₁ are closed, and shut-off valve 4b, 4c, and 4d to open. Shutoff valve 4b since the amount of blowing target water becomes more again 5.0 t / h at a further time t _6, 4c, 4d were closed, the shut-off valves 4e ₁ in the open, the amount of blowing again target water at time t ₇ is 5.0 t Since it became less than / h, the shut-off valves 4b, 4c and 4d were opened, and the shut-off valve 4e ₁ was closed.
[0030]
Since 24 hours at time t ₈ has elapsed, with select the cutoff valve 4e ₂ to "1" one deferred to the "2" priorities. Then, the target water blown quantity 5.0 t / h or more shut-off valve 4b against at time t _9, 4c, 4d and the closed, and the shut-off valve 4e ₂ opens, the target water blowing amount at a time t ₁₀ 5.0 t / h Corresponding to the following, the shut-off valve 4e ₂ was closed and the shut-off valves 4b, 4c and 4d were opened. In this way, each time the amount of blowing target water is below 5.0 t / h or more and 5.0 t / h, shutoff valves 4e ₁ of sequential same capacity, ... select priority one by one postponement by the 4e _n closing by, can be shut-off valves 4e ₁ of the same capacity, the number of operations of ... 4e _n uniform.
[0031]
【The invention's effect】
As described above, according to the present invention, the number of opening / closing operations of a shut-off valve of the same capacity is monitored and a shut-off valve with a small number of operations is selected, or the shut-off valve is opened / closed based on a predetermined priority order for a predetermined time. Since the priority order is lowered one by one after the passage, the number of opening / closing operations of the shut-off valve can be made uniform, so that early deterioration of a specific shut-off valve can be prevented and the rust of the shut-off shut-off valve can be prevented. Occurrence of malfunction such as sticking can be prevented, and as a result, long-term stable operation can be achieved as equipment.
[Brief description of the drawings]
FIG. 1 is a schematic diagram schematically showing a water blowing humidity control apparatus of the present invention.
FIG. 2 is a conceptual diagram showing a main part of the present invention.
FIG. 3 is a time chart showing an example of the operation of the shut-off valve using the present invention.
FIG. 4 is a time chart showing another example of the operation of the shut-off valve using the present invention.
FIG. 5 is a schematic diagram showing a conventional example of a water blowing humidity control equipment.
FIG. 6 is a time chart showing the operation of the shut-off valve in the conventional example.
[Explanation of symbols]
1 Blast Furnace Cold Air Pipe 2 Nozzle 3 Water Conduit 4 Shut-off Valve 5 Blowing Water Pipe 6 Water Flow Meter 7 Water Flow Control Valve 8 Water Booster Pump 9 Water Tank
10 Water pressure gauge
11 Water flow controller
12 Water pressure regulator
13 Water pressure control valve
14 Air flow meter
15 Moisture meter
16 Water blowing controller
17 Limit switch
18 lines
19 counter
20 lines

Claims (2)

A nozzle group having a water blowing amount commensurate with the minimum amount of change in humidity control amount when adjusting the air blowing to the blast furnace by blowing water from the nozzle group into the blast furnace cold wind tube between the blower and the hot stove, Nozzles provided with a plurality of nozzle groups with a nozzle group having a water blowing amount equal to or greater than the blowing amount, and a shutoff valve attached to the water conduit of the nozzle group, selected from the nozzle groups according to the target water blowing amount While opening and closing the shut-off valve only to the group and passing water to control the amount of water blown in steps, the deviation between the target water blow amount and the measured actual water blow amount is transferred to the plurality of nozzle groups. In a humidity control method for blast furnace blasting by water blowing, which is compensated by cascade control that adjusts the pressure of water discharged from a water booster pump that supplies water, the amount of water flow for a predetermined amount of water blowing command Monitoring the number of times of the opening and closing operation of a plurality of shut-off valve that is one method the humidity control blast blowing by blowing the water, characterized in that the low cut-off valve of the number of operations to be opened and closed in sequence. A nozzle group having a water blowing amount commensurate with the minimum amount of change in humidity control amount when adjusting the air blowing to the blast furnace by blowing water from the nozzle group into the blast furnace cold wind tube between the blower and the hot stove, Nozzles provided with a plurality of nozzle groups with a nozzle group having a water blowing amount equal to or greater than the blowing amount, and a shutoff valve attached to the water conduit of the nozzle group, selected from the nozzle groups according to the target water blowing amount While opening and closing the shut-off valve only to the group and passing water to control the amount of water blown in steps, the deviation between the target water blow amount and the measured actual water blow amount is transferred to the plurality of nozzle groups. In a humidity control method for blast furnace blasting by water blowing, which is compensated by cascade control that adjusts the pressure of water discharged from a water booster pump that supplies water, a shut-off valve that has the same amount of water flow is provided in advance. Priorities are given, and a shut-off valve with a high priority is sequentially opened and closed with respect to a predetermined amount of water blowing command, and the priority is lowered and changed one by one every predetermined time. Blast furnace air conditioning method by water blowing.

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