JP3959991B2 - Method for treating alkaline degreasing solution of metal strip - Google Patents

Method for treating alkaline degreasing solution of metal strip Download PDF

Info

Publication number
JP3959991B2
JP3959991B2 JP2001202068A JP2001202068A JP3959991B2 JP 3959991 B2 JP3959991 B2 JP 3959991B2 JP 2001202068 A JP2001202068 A JP 2001202068A JP 2001202068 A JP2001202068 A JP 2001202068A JP 3959991 B2 JP3959991 B2 JP 3959991B2
Authority
JP
Japan
Prior art keywords
degreasing
degreasing liquid
soap
liquid
amount
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP2001202068A
Other languages
Japanese (ja)
Other versions
JP2003013267A (en
Inventor
克彦 加藤
浩治 川島
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Steel Corp
Original Assignee
JFE Steel Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by JFE Steel Corp filed Critical JFE Steel Corp
Priority to JP2001202068A priority Critical patent/JP3959991B2/en
Publication of JP2003013267A publication Critical patent/JP2003013267A/en
Application granted granted Critical
Publication of JP3959991B2 publication Critical patent/JP3959991B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/10—Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working

Landscapes

  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)

Description

【０００１】
【発明の属する技術分野】
本発明は、金属帯の脱脂に用いたアルカリ性脱脂液の処理方法に関し、特に、アルカリ性脱脂液中の石鹸分の除去率に優れ、省エネルギーを達成することが可能な金属帯のアルカリ性脱脂液の処理方法に関する。
【０００２】
【従来の技術】
従来、鋼帯など金属帯の連続処理ラインにおいては、金属帯を連続的に供給しつつ、圧延、熱処理、あるいはめっきなどの表面処理が行われている。
上記した連続処理ラインとしては、例えば、鋼帯の連続熱間圧延ライン、連続冷間圧延ライン、連続焼鈍ライン、連続溶融亜鉛めっきラインなどが代表的なものであり、これらのラインに、鋼帯表面の圧延油などに起因する汚れを除去するためにアルカリ性脱脂液（以下、脱脂液とも記す）を用いた脱脂設備が付設されている。
【０００３】
図６に、従来の鋼帯など金属帯の脱脂設備のフローシートを示す。
なお、図６において、１は金属帯（鋼帯）浸漬方式の脱脂槽（アルカリ洗浄装置）、２は脱脂液循環槽である脱脂液貯槽、３は冷却器、６は析出石鹸分離除去装置（以下、分離除去装置とも記す）、7a、7bはアルカリ性脱脂液（：脱脂液）、８は蒸気配管（蛇管）、8aは蒸気、９は冷却水供給配管、9aは冷却水、9Pは冷却水供給配管９に付設されたポンプ、11は脱脂液抜き出し配管、12は脱脂液処理用配管、13、14は脱脂液戻り配管、18は冷却器３出側脱脂液の液温測定・記録計、ｆは金属帯（鋼帯）の搬送方向、Ｍ（Ｓ）は金属帯（鋼帯）、Ｖは弁を示す。
【０００４】
図６に示す冷却器３、分離除去装置６は、下記のように構成されている。
冷却器３ ：脱脂液と冷却水との間接熱交換による冷却器
分離除去装置６：濾布を用いた濾過器
すなわち、図６に示す金属帯の脱脂設備においては、脱脂反応（けん化反応）を促進するため、例えば脱脂槽１の脱脂液7a中に蛇管形式の蒸気配管８を浸漬し、脱脂液7aの液温を70〜80℃程度に昇温して鋼帯Ｓなど金属帯Ｍの脱脂が行われる。
【０００５】
また、脱脂槽１から脱脂液を抜き出し、脱脂液貯槽（脱脂液循環槽）２を経由して冷却器３に送液し、脱脂液と冷却水とを間接熱交換させ、脱脂液を冷却する。
冷却器３で冷却した脱脂液は、冷却によって析出した石鹸を析出石鹸分離除去装置（：分離除去装置）６で分離除去し、処理後の脱脂液を脱脂液貯槽２を経由して脱脂槽１に再循環する。
【０００６】
上記した脱脂液の冷却器３による冷却時の液温の制御方法としては、冷却器３出側の脱脂液の液温の測定結果に基づいて、冷却水の流量あるいはさらに冷却水の水温を制御する制御方法が用いられている。
しかしながら、上記した方法の場合、石鹸分の除去率が必ずしも十分でなく、下記(1) 、(2) の問題が生じる。
【０００７】
(1) 脱脂液の発泡による作業環境上の問題および生産性の低下：
脱脂液中の石鹸分の濃度が高い場合、脱脂液の表面張力が低下し、発泡現象が生じる。
特に、脱脂槽における鋼帯など金属帯の走行速度が速い場合、金属帯（鋼帯）が槽内の脱脂液を攪拌し激しく発泡する。
【０００８】
また、脱脂法として電解脱脂を用い、脱脂速度の面から電流密度を上げる場合、激しく発泡する。
発泡が生じた場合、脱脂槽から泡が溢れて周辺部を汚染し、作業環境を悪化させると共に、操業を阻害し、生産性が低下する。
(2) アルカリ原単位の増加：
上記した発泡が生じた場合、脱脂槽からアルカリが流出するため、金属帯（鋼帯）単位処理量当たりのアルカリ原単位が増加し、薬剤消費量が増加する。
【０００９】
上記した問題に対処するため、従来、例えば前記した冷却器３における冷却水の流量を多めに設定するか、あるいは冷却水の水温を低めに設定する必要があり、省エネルギー上問題があるばかりでなく、操業条件によっては、前記した発泡が避けられず、作業環境、生産性およびアルカリ原単位の面で問題があった。
【００１０】
【発明が解決しようとする課題】
本発明は、前記した従来技術の問題点を解決し、脱脂液中石鹸分の除去率に優れ、省エネルギーを達成することが可能な金属帯のアルカリ性脱脂液の処理方法を提供することを目的とする。
【００１１】
【課題を解決するための手段】
【００１２】
本発明は、金属帯の脱脂槽で使用後のアルカリ性脱脂液の少なくとも一部を抜き出し、冷却器で冷却後、該アルカリ性脱脂液中に析出した石鹸を分離除去装置で分離除去し、得られたアルカリ性脱脂液を前記脱脂槽に再循環する金属帯のアルカリ性脱脂液の処理方法であって、前記冷却器と分離除去装置との間のアルカリ性脱脂液中の析出石鹸量および／または析出石鹸粒子の粒径の測定結果に基づいて、前記冷却器におけるアルカリ性脱脂液の冷却温度を制御することを特徴とする金属帯のアルカリ性脱脂液の処理方法である。
【００１３】
本発明においては、前記析出石鹸量の指標として、前記分離除去装置出側のアルカリ性脱脂液または該アルカリ性脱脂液の測定用試料に光を入射したときの脱脂液からの散乱光の光量の関数である析出石鹸量を用いることが好ましい。
【００１６】
【発明の実施の形態】
以下、第１の参考例、本発明、第２の参考例の順に、さらに詳細に説明する。
〔第１の参考例：〕
第１の参考例は、アルカリ性脱脂液中に析出した石鹸の分離除去装置における分離除去量に基づいて、冷却器におけるアルカリ性脱脂液の冷却温度を制御する金属帯のアルカリ性脱脂液の処理方法である。
【００１７】
前記した第１の参考例においては、前記分離除去装置として、装置内空間が脱脂液で満たされた流通式かつ濾過式の分離除去装置を用いると共に、該分離除去装置の前後の脱脂液の圧力差（圧力損失）：ΔＰを測定し、前記石鹸の分離除去量の指標として、単位時間当たりのΔＰの変化量を用いることが好ましい。
図１に、第１の参考例の金属帯のアルカリ性脱脂液の処理方法に係わる金属帯の脱脂設備の一例を、フローシートによって示す。
【００１８】
図１において、9Pr はモータ回転数制御方式のポンプ、20は分離除去装置６の前後の脱脂液の圧力差（圧力損失）：ΔＰの測定装置（以下、ΔＰ測定装置とも記す）、21は脱脂液流量測定装置、22は演算・制御装置、23は制御信号を示し、その他の符号は前記した図６と同様の内容を示す。
なお、図１は、析出石鹸分離除去装置６の濾過器により析出石鹸の分離が行われ、析出石鹸分離除去装置に付設された演算・制御装置22によって冷却器３における脱脂液の冷却温度が制御されている状態を示す。
【００１９】
図１に示す金属帯の脱脂設備においては、前記した図６の脱脂設備と同様の方法で鋼帯Ｓなど金属帯Ｍの脱脂が行われる。
また、脱脂槽１から脱脂液を抜き出し、脱脂液貯槽（脱脂液循環槽）２を経由して冷却器３に送液し、脱脂液と冷却水とを間接熱交換させ、脱脂液を冷却する。
【００２０】
冷却器３で冷却した脱脂液は、冷却によって析出した石鹸を分離除去装置６で分離除去し、処理後の脱脂液を脱脂液貯槽２を経由して脱脂槽１に再循環する。
なお、図１に示す分離除去装置６は、装置（濾過器）内空間が脱脂液で満たされた流通式の分離除去装置であり、分離除去装置の前後の脱脂液の圧力差（圧力損失）：ΔＰを測定し、分離除去装置６における析出石鹸の分離除去量の指標として、単位時間当たりのΔＰの変化量（以下、単にΔＰの変化量とも記す）を用い、下記の方法で脱脂液の冷却器３による液温の制御を行う。
【００２１】
すなわち、脱脂液が流通している分離除去装置（濾過器）６の前後の脱脂液の圧力差（圧力損失）：ΔＰを、ΔＰ測定装置20で経時的、好ましくは連続的に測定し、分離除去装置６における石鹸の分離除去量を知る。
すなわち、上記したΔＰの単位時間当たりの増加量が基準値よりも大きい場合は、石鹸の分離除去量が多いと判定する。
【００２２】
一方、分離除去装置６を流通している脱脂液の流量が、基準流量に対して増加もしくは減少した場合は、濾布に堆積した石鹸量が同じ場合でも、その分ΔＰは大もしくは小となる。
そのため、脱脂液流量測定装置21によって、分離除去装置６を流通している脱脂液の流量を測定する。
【００２３】
ΔＰ測定装置20によるΔＰ測定結果の信号および脱脂液流量測定装置21による脱脂液流量測定結果の信号は、演算・制御装置22へ伝送される。
演算・制御装置22においては、予め求めたΔＰの変化量と単位時間当たりに濾布に堆積した石鹸量と脱脂液流量との関係式から、単位時間当たりに濾布に堆積した石鹸量（：単位時間当たりの石鹸の分離除去量、以下、単に石鹸の分離除去量とも記す）を演算し、石鹸の分離除去量に対応した出力信号23をモータ回転数制御方式のポンプ9Pr のモータあるいはさらに冷却水の温度調節装置（図示しない）へ伝送し、モータ回転数制御方式のポンプ9Pr のモータの回転数の制御による冷却水供給配管９の冷却水9aの流量の調節、あるいはさらに冷却水9aの水温の調節の制御を行う。
【００２４】
すなわち、前記した脱脂液の圧力損失：ΔＰの単位時間当たりの増加量が基準値に対して少なく、分離除去装置6aにおける石鹸の分離除去量が基準値に対して少ない場合は、脱脂液中の石鹸分の析出量が少ないと判定し、例えば、下記(1) 、（２）の制御を行う。
(1) ΔＰの単位時間当たりの増加量が基準値に対して小の場合：
前記制御を行い、冷却水9aの流量を増加する。
【００２５】
(2) ΔＰの単位時間当たりの増加量が基準値に対してかなり小の場合：
前記制御を行い、冷却水9aの流量の増加に加え、冷却水9aの水温も低下する。
上記した制御は、演算された石鹸の分離除去量の基準値に対する偏差に応じて適宜選択でき、予め、演算・制御装置にその選択基準を記憶させておくことによって、自動的に選択することもできる。
【００２６】
上記した分離除去装置６における石鹸の分離除去量に基づく脱脂液冷却温度の制御方式によれば、下記(1) 〜(3) の優れた効果が得られる。
(1) 脱脂液の石鹸分除去率の向上：
後記の実施例で示されるように、上記した制御を行うことによって、前記した図６に示す従来の冷却器３出側の脱脂液の液温の測定結果に基づく制御に対して、脱脂液の石鹸分除去率が向上する。
【００２７】
(2) ポンプ等における消費電力の低減：
脱脂液の液温を過剰に低下させることがないため、ポンプ9Pr (9P)のモータあるいはさらに冷却水の温度低下に要する消費電力が低減できる。
(3) 脱脂槽の脱脂液昇温エネルギーの削減：
脱脂液の液温を過剰に低下させることがないため、脱脂液貯槽２を経由して脱脂槽１に再循環される脱脂液の温度低下がその分少なくなり、蒸気など脱脂槽１の脱脂液昇温に必要なエネルギーを削減することができる。
【００２８】
以上、第１の参考例について述べたが、第１の参考例における分離除去装置としては、濾過式の分離除去装置に限定されることはなく、遠心分離機、沈降分離器などその他の分離除去装置を用いることもできる。
また、前記した第１の参考例の好適態様における濾過式の分離除去装置における濾材としては、濾布に限定されることはなく金網などその他の濾材を用いることもできる。
【００２９】
〔本発明：〕
本発明の要旨は、アルカリ性脱脂液の冷却器と分離除去装置との間のアルカリ性脱脂液中の析出石鹸量および／または析出石鹸粒子の粒径の測定結果に基づいて、冷却器におけるアルカリ性脱脂液の冷却温度を制御する金属帯のアルカリ性脱脂液の処理方法である。
【００３０】
本発明においては、析出石鹸量の指標として、分離除去装置出側のアルカリ性脱脂液または該アルカリ性脱脂液の測定用試料に光を入射し、該脱脂液からの散乱光の光量を測定し、散乱光の光量の関数である析出石鹸量を用いることが好ましい。
これは、析出石鹸量は、脱脂液に光を入射したときの脱脂液からの散乱光の光量の関数として求めることができるためである。
【００３１】
図２に、本発明の金属帯のアルカリ性脱脂液の処理方法に係わる金属帯の脱脂設備の一例を、フローシートによって示す。
図２において、30は脱脂液中の析出石鹸量測定装置または脱脂液中の析出石鹸粒子の粒径測定装置、31は制御装置、32は制御信号を示し、その他の符号は前記した図１、図６と同様の内容を示す。
【００３２】
なお、析出石鹸量測定装置または析出石鹸粒子の粒径測定装置30は、冷却器３と分離除去装置６との間を送液される脱脂液中の析出石鹸量または析出石鹸粒子の粒径を測定する。
図２に示す金属帯の脱脂設備においては、前記した図６の脱脂設備と同様の方法で鋼帯Ｓなど金属帯Ｍの脱脂が行われる。
【００３３】
また、脱脂槽１から脱脂液を抜き出し、脱脂液貯槽（脱脂液循環槽）２を経由して冷却器３に送液し、脱脂液と冷却水とを間接熱交換させ、脱脂液を冷却する。
冷却器３で冷却した脱脂液は、冷却によって析出した石鹸を分離除去装置６で分離除去し、処理後の脱脂液を脱脂液貯槽２を経由して脱脂槽１に再循環する。
【００３４】
上記した脱脂液の冷却器３による冷却時の液温の制御方法としては、下記の制御方法を用いる。
（アルカリ性脱脂液中の析出石鹸量の測定結果に基づく制御：）
析出石鹸量の測定装置としては、特に制限はないが、好ましくは光源と受光器（：散乱光光量測定装置）とから構成される濁度計を用いる。
【００３５】
濁度計としては、透過光濁度計、散乱光濁度計または積分球濁度計のいずれを用いてもよい。
なお、濁度計の試料槽としては、冷却器３出側配管から脱脂液が連続的に試料槽に流入し、上記出側配管に戻る流通式の試料槽（以下、脱脂液測定用フローセルとも記す）を用いることが好ましい。
【００３６】
また、冷却器３出側配管中の脱脂液の液温測定装置、測定系雰囲気温度制御装置を設け、脱脂液測定用フローセル、脱脂液サンプルの供給配管および戻り配管それぞれの周囲の雰囲気温度が冷却器３出側の脱脂液液温と等しくなるように測定系を構成することが好ましい。
なお、本発明においては、直接、冷却器３出側配管中の脱脂液に光を入射し、脱脂液からの散乱光の光量の測定結果に基づき析出石鹸量を求めてもよい。
【００３７】
本制御においては、冷却器３出側配管の脱脂液中の析出石鹸量を例えば前記した濁度計である析出石鹸量測定装置30で測定する。
なお、前記したように、析出石鹸量は、脱脂液からの散乱光の光量の関数として求めることができる。
濁度計の光量の測定結果などに基づく析出石鹸量の測定結果の信号は、制御装置31へ伝送される。
【００３８】
制御装置31においては、析出石鹸量に対応した出力信号32をモータ回転数制御方式のポンプ9Pr のモータあるいはさらに冷却水の温度調節装置（図示しない）へ伝送し、モータ回転数制御方式のポンプ9Pr のモータの回転数の制御による冷却水供給配管９の冷却水9aの流量の調節、あるいはさらに冷却水9aの水温の調節の制御を行う。
【００３９】
すなわち、例えば、下記(1) 、(2) の制御を行う。
(1) 冷却器３出側配管中の脱脂液の析出石鹸量が基準値に対して少ない場合：
前記制御を行い、冷却水9aの流量を増加する。
(2) 冷却器３出側配管中の脱脂液の析出石鹸量が基準値に対してかなり少ない場合：
前記制御を行い、冷却水9aの流量の増加に加え、冷却水9aの水温も低下する。
【００４０】
上記した制御は、析出石鹸量の測定結果に基づき適宜選択でき、予め、制御装置にその選択基準を記憶させておくことによって、自動的に選択することもできる。
上記した析出石鹸量の測定結果に基づく脱脂液冷却温度の制御方式によれば、前記した図１に示す制御方式と同様の理由で下記(1) 〜(3) の優れた効果が得られる。
【００４１】
(1) 脱脂液の石鹸分除去率の向上
(2) ポンプ等における消費電力の低減
(3) 脱脂槽の脱脂液昇温エネルギーの削減
（アルカリ性脱脂液中の析出石鹸粒子の粒径の測定結果に基づく制御：）
析出石鹸粒子の粒径の測定装置としては、特に制限はないが、好ましくはレーザ回折・散乱式粒度分布測定装置を用いる。
【００４２】
なお、測定装置としては、冷却器３出側配管から脱脂液が連続的にレーザ回折・散乱式粒度分布測定装置のフローセルに流入し、前記出側配管に戻る流通式の測定装置を用いることが好ましい。
また、冷却器３出側配管中の脱脂液の液温測定装置、測定系雰囲気温度制御装置を設け、上記したフローセル、脱脂液サンプルの供給配管および戻り配管それぞれの周囲の雰囲気温度が冷却器３出側の脱脂液液温と等しくなるように測定系を構成することが好ましい。
【００４３】
本制御においては、冷却器３出側配管の脱脂液中の析出石鹸粒子の粒径を、例えば上記したレーザ回折・散乱式粒度分布測定装置である析出石鹸粒子の粒径測定装置30で測定する。
なお、粒径としては、50％累積平均粒径などを用いることができる。
析出石鹸粒子の粒径測定結果の信号は、制御装置31へ伝送される。
【００４４】
制御装置31においては、析出石鹸粒子の粒径に対応した出力信号32をモータ回転数制御方式のポンプ9Pr のモータあるいはさらに冷却水の温度調節装置（図示しない）へ伝送し、モータ回転数制御方式のポンプ9Pr のモータの回転数の制御による冷却水供給配管９の冷却水9aの流量の調節、あるいはさらに冷却水9aの水温の調節の制御を行う。
【００４５】
すなわち、アルカリ性脱脂液の冷却器３と分離除去装置６との間を流通するアルカリ性脱脂液中の析出石鹸粒子の粒径（50％累積平均粒径）が基準値に対して小さい場合は、アルカリ性脱脂液の冷却が不十分であると判定し、例えば、下記(1) 、(2) の制御を行う。
(1) 冷却器３出側配管中の脱脂液の析出石鹸粒子の粒径（50％累積平均粒径）が基準値に対して小さい場合：
前記制御を行い、冷却水9aの流量を増加する。
【００４６】
(2) 冷却器３（後段冷却器５）出側配管中の脱脂液の析出石鹸粒子の粒径（50％累積平均粒径）が基準値に対してかなり小さい場合：
前記制御を行い、冷却水9aの流量の増加に加え、冷却水9aの水温も低下する。
上記した制御は、析出石鹸粒子の粒径測定結果に基づき適宜選択でき、予め、制御装置にその選択基準を記憶させておくことによって、自動的に選択することもできる。
【００４７】
上記した析出石鹸粒子の粒径測定結果に基づく脱脂液冷却温度の制御方式によれば、前記した図１に示す制御方式と同様の理由で下記(1) 〜(3) の優れた効果が得られる。
(1) 脱脂液の石鹸分除去率の向上
(2) ポンプ等における消費電力の低減
(3) 脱脂槽の脱脂液昇温エネルギーの削減
以上、本発明について述べたが、本発明における分離除去装置としては、濾過式の分離除去装置に限定されることはなく、遠心分離機、沈降分離器などその他の方式の分離除去装置を用いることもできる。
【００４８】
〔第２の参考例：〕
第２の参考例は、アルカリ性脱脂液の分離除去装置出側のアルカリ性脱脂液の石鹸含有量の測定結果に基づいて、冷却器におけるアルカリ性脱脂液の冷却温度を制御する金属帯のアルカリ性脱脂液の処理方法である。
前記した第２の参考例においては、前記石鹸含有量の指標として、分離除去装置出側のアルカリ性脱脂液または該アルカリ性脱脂液の測定用試料に光を入射し、脱脂液からの散乱光の光量を測定し、散乱光の光量の関数である石鹸含有量を用いることが好ましい（第２の参考例の第１の好適態様）。
【００４９】
これは、上記した石鹸含有量は、上記した脱脂液または脱脂液の測定用試料に光を入射したときの脱脂液からの散乱光の光量の関数として求めることができるためである。
上記した第２の参考例の第１の好適態様における脱脂液からの散乱光の光量の測定装置としては特に制限はないが、前記した本発明と同様に、好ましくは光源と受光器（：散乱光光量測定装置）とから構成される濁度計を用いる。
【００５０】
濁度計としては、透過光濁度計、散乱光濁度計または積分球濁度計のいずれを用いてもよい。
また、前記した第２の参考例においては、前記石鹸含有量の指標として、分離除去装置６出側のアルカリ性脱脂液の測定用試料を所定温度まで冷却した後の析出石鹸量の測定結果を用いることも好ましい（第２の参考例の第２の好適態様）。
【００５１】
また、この場合の析出石鹸量の指標としては、冷却後のアルカリ性脱脂液の測定用試料に光を入射し、脱脂液からの散乱光の光量を測定し、散乱光の光量の関数である析出石鹸量を用いることが好ましい。
これは、上記した析出石鹸量は、冷却後のアルカリ性脱脂液の測定用試料に光を入射したときの脱脂液からの散乱光の光量の関数として求めることができるためである。
【００５２】
上記した第２の参考例の第２の好適態様における析出石鹸量の測定装置としては、特に制限はないが、前記した本発明と同様に、好ましくは光源と受光器（：散乱光光量測定装置）とから構成される濁度計を用いる。
濁度計としては、透過光濁度計、散乱光濁度計または積分球濁度計のいずれを用いてもよい。
【００５３】
図３に、第２の参考例の金属帯のアルカリ性脱脂液の処理方法に係わる金属帯の脱脂設備の一例を、フローシートによって示す。
図３において、40は脱脂液（：アルカリ性脱脂液）の石鹸含有量測定装置、41は制御装置、42は制御信号を示し、その他の符号は前記した図１、図６と同様の内容を示す。
【００５４】
なお、図３に示す金属帯の脱脂設備においては、石鹸含有量測定装置40として、濁度計を用いている。
図３に示す金属帯の脱脂設備においては、前記した図６の脱脂設備と同様の方法で鋼帯Ｓなど金属帯Ｍの脱脂が行われる。
また、脱脂槽１から脱脂液を抜き出し、脱脂液貯槽（脱脂液循環槽）２を経由して冷却器３に送液し、脱脂液と冷却水とを間接熱交換させ、脱脂液を冷却する。
【００５５】
冷却器３で冷却した脱脂液は、冷却によって析出した石鹸を分離除去装置６で分離除去し、処理後の脱脂液を脱脂液貯槽２を経由して脱脂槽１に再循環する。
上記した脱脂液の冷却器３による冷却時の液温の制御方法としては、下記の制御方法を用いる。
すなわち、本制御においては、先ず、分離除去装置６出側配管の脱脂液中の石鹸含有量を、例えば前記した濁度計である石鹸含有量測定装置40で測定する。
【００５６】
濁度計の散乱光光量の測定結果などに基づく石鹸含有量の測定結果の信号は、制御装置41へ伝送される。
制御装置41においては、石鹸含有量に対応した出力信号42をモータ回転数制御方式のポンプ9Pr のモータあるいはさらに冷却水の温度調節装置（図示しない）へ伝送し、モータ回転数制御方式のポンプ9Pr のモータの回転数の制御による冷却水供給配管９の冷却水9aの流量の調節、あるいはさらに冷却水9aの水温の調節の制御を行う。
【００５７】
すなわち、分離除去装置６出側のアルカリ性脱脂液の石鹸含有量が基準値に対して多い場合は、アルカリ性脱脂液の冷却が不十分であると判定し、例えば、下記(1) 、(2) の制御を行う。
(1) 石鹸含有量が基準値に対して多い場合：
前記制御を行い、冷却水9aの流量を増加する。
【００５８】
(2) 石鹸含有量が基準値に対してかなり多い場合：
前記制御を行い、冷却水9aの流量の増加に加え、冷却水9aの水温も低下する。
上記した制御は、石鹸含有量測定結果に基づき適宜選択でき、予め、制御装置41にその選択基準を記憶させておくことによって、自動的に選択することもできる。
【００５９】
上記した分離除去装置６出側のアルカリ性脱脂液の石鹸含有量の測定結果に基づく脱脂液冷却温度の制御方式によれば、前記した図１に示す制御方式と同様の理由で下記(1) 〜(3) の優れた効果が得られる。
(1) 脱脂液の石鹸分除去率の向上
(2) ポンプ等における消費電力の低減
(3) 脱脂槽の脱脂液昇温エネルギーの削減
図４に、第２の参考例の金属帯のアルカリ性脱脂液の処理方法に係わる金属帯の脱脂設備の他の一例を、フローシートによって示す。
【００６０】
図４において、50は脱脂液（：アルカリ性脱脂液）の石鹸含有量測定装置、50a は測定用脱脂液冷却器、50b は濁度計、51は制御装置、52は制御信号を示し、その他の符号は前記した図１、図６と同様の内容を示す。
すなわち、図４に示す石鹸含有量測定装置50は、測定用脱脂液冷却器50a と濁度計50b とから構成される液流通式の測定装置である。
【００６１】
図４に示す金属帯の脱脂設備においては、前記した図６の脱脂設備と同様の方法で鋼帯Ｓなど金属帯Ｍの脱脂が行われる。
また、脱脂槽１から脱脂液を抜き出し、脱脂液貯槽（脱脂液循環槽）２を経由して冷却器３に送液し、脱脂液と冷却水とを間接熱交換させ、脱脂液を冷却する。
【００６２】
冷却器３で冷却した脱脂液は、冷却によって析出した石鹸を分離除去装置６で分離除去し、処理後の脱脂液を脱脂液貯槽２を経由して脱脂槽１に再循環する。
上記した脱脂液の冷却器３による冷却時の液温の制御方法としては、下記の制御方法を用いる。
すなわち、本制御においては、先ず、分離除去装置６出側配管の脱脂液中の石鹸含有量を、例えば前記した測定用脱脂液冷却器50a および濁度計50b から構成される石鹸含有量測定装置50で測定する。
【００６３】
なお、上記した測定用脱脂液冷却器50a における測定用脱脂液の冷却温度は、少なくとも冷却器３出側配管中の脱脂液の液温未満とし、対象とする脱脂液に応じて予め実験的に求めることができる。
分離除去装置６出側配管から分流された測定用脱脂液中の溶解石鹸分は、測定用脱脂液冷却器50a 中で析出し、析出石鹸粒子を含んだ測定用脱脂液は、濁度計50b の脱脂液測定用フローセルを流通する過程で濁度が測定される。
【００６４】
濁度計の散乱光光量の測定結果などに基づく石鹸含有量の測定結果の信号は、制御装置51へ伝送される。
制御装置51においては、石鹸含有量に対応した出力信号52をモータ回転数制御方式のポンプ9Pr のモータあるいはさらに冷却水の温度調節装置（図示しない）へ伝送し、モータ回転数制御方式のポンプ9Pr のモータの回転数の制御による冷却水供給配管９の冷却水9aの流量の調節、あるいはさらに冷却水9aの水温の調節の制御を行う。
【００６５】
すなわち、分離除去装置６出側のアルカリ性脱脂液の石鹸含有量が基準値に対して多い場合は、アルカリ性脱脂液の冷却が不十分であると判定し、例えば、下記(1) 、(2) の制御を行う。
(1) 石鹸含有量が基準値に対して多い場合：
前記制御を行い、冷却水9aの流量を増加する。
【００６６】
(2) 石鹸含有量が基準値に対してかなり多い場合：
前記制御を行い、冷却水9aの流量の増加に加え、冷却水9aの水温も低下する。
上記した制御は、石鹸含有量測定結果に基づき適宜選択でき、予め、制御装置51にその選択基準を記憶させておくことによって、自動的に選択することもできる。
【００６７】
上記した分離除去装置６出側のアルカリ性脱脂液の石鹸含有量の測定結果に基づく脱脂液冷却温度の制御方式によれば、前記した図１に示す制御方式と同様の理由で下記(1) 〜(3) の優れた効果が得られる。
(1) 脱脂液の石鹸分除去率の向上
(2) ポンプ等における消費電力の低減
(3) 脱脂槽の脱脂液昇温エネルギーの削減
以上、第２の参考例について述べたが、第２の参考例における分離除去装置としては、濾過式の分離除去装置に限定されることはなく、遠心分離機、沈降分離器などその他の方式の分離除去装置を用いることもできる。
【００６８】
【実施例】
以下、実施例に基づいて本発明をさらに具体的に説明する。
（参考例１）
前記した図１に示す金属帯の脱脂設備を用い、下記試験条件下で、冷間圧延で得られた鋼帯の脱脂を行った。
【００６９】
（試験条件：）
圧延油：植物油
脱脂槽１：鋼帯浸漬通板方式
脱脂液（アルカリ洗浄液）：（苛性ソーダ、無機リン酸ソーダ、エチレンジアミン四酢酸二ナトリウム、ポリオキシエチレンラウリルエーテル）を含有する金属用洗浄剤の３％水溶液
脱脂槽１の脱脂液液温：80℃
分離除去装置６：濾布式濾過器
すなわち、図１に示す金属帯の脱脂設備において、脱脂槽１に鋼帯Ｓを浸漬通板し脱脂を行った。
【００７０】
また、脱脂槽１から脱脂液を抜き出し、脱脂液貯槽（脱脂液循環槽）２を経由して冷却器３に送液し、脱脂液と冷却水とを間接熱交換させ、脱脂液を冷却した。
冷却器３で冷却した脱脂液は、冷却によって析出した石鹸を分離除去装置６で分離除去し、処理後の脱脂液を脱脂液貯槽２を経由して脱脂槽１に再循環した。
【００７１】
また、上記した脱脂液の冷却器３による冷却時の液温の制御方法としては、分離除去装置６の前後の脱脂液の圧力差（圧力損失）：ΔＰを測定し、石鹸の分離除去量の指標として、単位時間当たりのΔＰの変化量（：ΔＰの変化量）を用い、下記の方法で制御を行った。
すなわち、脱脂液が流通している分離除去装置（濾過器）６の前後の脱脂液の圧力差（圧力損失）：ΔＰを、ΔＰ測定装置20で経時的に測定した。
【００７２】
また、脱脂液流量測定装置21によって、分離除去装置６を流通している脱脂液の流量を測定した。
ΔＰ測定装置20によるΔＰ測定結果の信号および脱脂液流量測定装置21による脱脂液流量測定結果の信号を、演算・制御装置22へ伝送した。
演算・制御装置22においては、予め求めたΔＰの変化量と単位時間当たりに濾布に堆積した石鹸量と脱脂液流量との関係式から、単位時間当たりに濾布に堆積した石鹸量（：単位時間当たりの石鹸の分離除去量）を演算し、得られた演算結果に基づき、下記の制御を行った。
【００７３】
なお、下記冷却水9aの流量の調節に加え、冷却水9aの水温の調節を行うか否かは、石鹸の分離除去量の演算結果と、予め演算・制御装置に記憶させた選択基準に基づき自動的に選択する方式を採用し、脱脂液の冷却度を石鹸の分離除去量に反比例させる形の制御を行った。
すなわち、モータ回転数制御方式のポンプ9Pr のモータの回転数の制御による冷却水供給配管９の冷却水9aの流量の調節、あるいはさらに冷却水9aの水温の調節を行う制御である。
【００７４】
さらに、上記試験時に、冷却器３出側配管および分離除去装置６出側配管から脱脂液の試料を採取した。
また、採取したそれぞれの脱脂液の試料を、液温：10℃に冷却後、濾過し、乾燥後の濾過残渣の質量から、下記式(1) に基づいて石鹸分除去率を求めた。
石鹸分除去率＝｛（Ａ−Ｂ）／Ａ｝×100 （％）………(1)
なお、上記式中、
Ａ：冷却器３出側の脱脂液試料についての、単位液量当たりの乾燥濾過残渣の質量
Ｂ：分離除去装置６出側の脱脂液試料についての、単位液量当たりの乾燥濾過残渣の質量
図５に、得られた石鹸分除去率の測定結果を、後記する比較例１による石鹸分除去率と対比して示す。
【００７５】
図５に示すように、参考例１によれば石鹸分除去率が90％と高除去率が得られ、その結果、脱脂槽１および脱脂液貯槽（脱脂液循環槽）２のいずれにおいても泡の発生に伴う脱脂液の槽外への溢流は生じなかった。
（本発明例）
前記した図２に示す金属帯の脱脂設備を用い、参考例１における制御に代えて、冷却器３と分離除去装置６との間の脱脂液中の析出石鹸量の測定結果に基づき脱脂液の冷却温度を制御した以外は参考例１と同様の方法、条件で冷間圧延で得られた鋼帯の脱脂を行った。
【００７６】
析出石鹸量の測定法としては、前記した濁度計を用い、下記制御方法で脱脂液の冷却温度を制御した。
すなわち、冷却器３出側配管の脱脂液中の析出石鹸量を、析出石鹸量測定装置30である濁度計で測定した。
濁度計の散乱光光量の測定結果の信号は、制御装置31へ伝送し、制御装置31においては、散乱光光量の関数である析出石鹸量に対応した出力信号32をモータ回転数制御方式のポンプ9Pr のモータあるいはさらに冷却水の温度調節装置（図示しない）へ伝送し、下記の制御を行った。
【００７７】
なお、下記冷却水9aの流量の調節に加え、冷却水9aの水温の調節を行うか否かは、析出石鹸量の測定結果と、予め制御装置31に記憶させた選択基準に基づき自動的に選択する方式を採用し、脱脂液の冷却度を析出石鹸量に反比例させる形の制御を行った。
すなわち、モータ回転数制御方式のポンプ9Pr のモータの回転数の制御による冷却水供給配管９の冷却水9aの流量の調節、あるいはさらに冷却水の温度調節器の制御による冷却水9aの水温の調節を行う制御である。
【００７８】
さらに、上記試験時に、冷却器３出側配管および分離除去装置６出側配管から脱脂液の試料を採取し、前記した参考例１と同様の方法で、石鹸分除去率を求めた。
その結果、本発明例においては石鹸分除去率が93％と高除去率が得られ、脱脂槽１および脱脂液貯槽（脱脂液循環槽）２のいずれにおいても泡の発生に伴う脱脂液の槽外への溢流は生じなかった。
【００７９】
（参考例２）
前記した図３に示す金属帯の脱脂設備を用い、参考例１における制御に代えて、分離除去装置６出側の脱脂液中の石鹸含有量の測定結果に基づき脱脂液の冷却温度を制御した以外は参考例１と同様の方法、条件で冷間圧延で得られた鋼帯の脱脂を行った。
【００８０】
上記した石鹸含有量は、前記した濁度計である石鹸含有量測定装置40で測定し、下記制御方法で脱脂液の冷却温度を制御した。
すなわち、濁度計の散乱光光量の測定結果の信号を、制御装置41へ伝送し、制御装置41においては、散乱光光量の関数である石鹸含有量に対応した出力信号42をモータ回転数制御方式のポンプ9Pr のモータあるいはさらに冷却水の温度調節装置（図示しない）へ伝送し、下記の制御を行った。
【００８１】
下記冷却水9aの流量の調節に加え、冷却水9aの水温の調節を行うか否かは、石鹸含有量の測定結果と、予め制御装置41に記憶させた選択基準に基づき自動的に選択する方式を採用し、脱脂液の冷却度を石鹸含有量に比例させる形の制御を行った。
すなわち、モータ回転数制御方式のポンプ9Pr のモータの回転数の制御による冷却水供給配管９の冷却水9aの流量の調節、あるいはさらに冷却水9aの水温の調節を行う制御である。
【００８２】
さらに、上記試験時に、冷却器３出側配管および分離除去装置６出側配管から脱脂液の試料を採取し、前記した参考例１と同様の方法で、石鹸分除去率を求めた。
その結果、本参考例２においては石鹸分除去率が92％と高除去率が得られ、脱脂槽１および脱脂液貯槽（脱脂液循環槽）２のいずれにおいても泡の発生に伴う脱脂液の槽外への溢流は生じなかった。
【００８３】
（比較例１）
前記した図６に示す従来の金属帯の脱脂設備を用い、参考例１における制御に代えて、冷却器３出側の脱脂液液温が20℃一定となるように制御した以外は参考例１と同様の方法、条件で冷間圧延で得られた鋼帯の脱脂を行った。
また、参考例１と同様の方法で、石鹸分除去率を求めた。
【００８４】
図５に、得られた石鹸分除去率の測定結果を示す。
本比較例においては、石鹸分除去率が80％であり、脱脂槽１および脱脂液貯槽（脱脂液循環槽）２における泡の発生に伴う脱脂液の槽外への溢流を回避することは困難であった。
（比較例２）
前記した図６に示す従来の金属帯の脱脂設備を用い、参考例１における制御に代えて、冷却器３出側の脱脂液液温が10℃一定となるように制御した以外は参考例１と同様の方法、条件で冷間圧延で得られた鋼帯の脱脂を行った。
【００８５】
また、参考例１と同様の方法で、石鹸分除去率を求めた。
その結果、本比較例においては、石鹸分除去率が85％であり、脱脂槽１および脱脂液貯槽（脱脂液循環槽）２における泡の発生に伴う脱脂液の槽外への溢流を完全に回避することは困難であった。
以上、本発明例、参考例および比較例について述べたが、得られた試験結果を表１に一括して示す。
【００８６】
また、表１に、本発明例、参考例および比較例における下記式(2) で定義されるエネルギー消費量を、比較例１のエネルギー消費量を100 として相対値で示す。
なお、ここでエネルギー消費量は、冷却水9aの流量、水温を調節するために用いられる設備の消費電力と、脱脂液の昇温に要するエネルギーの和である。
表１に示されるように、本発明によれば、石鹸分除去率が向上し、脱脂槽および脱脂液貯槽（脱脂液循環槽）における泡の発生に伴う脱脂液の槽外への溢流を防止することができると共に、脱脂設備におけるエネルギー消費量を削減することが可能となった。
【００８７】
【表１】

Figure 0003959991
【００８８】
【発明の効果】
本発明によれば、脱脂液中石鹸分の除去率に優れ、脱脂槽などにおける泡の発生に伴う脱脂液の槽外への溢流を防止し、省エネルギーを達成できる金属帯のアルカリ性脱脂液の処理方法を提供することが可能となった。
【図面の簡単な説明】
【図１】 第１の参考例に係わる金属帯の脱脂設備の一例を示すフローシートである。
【図２】 本発明に係わる金属帯の脱脂設備の一例を示すフローシートである。
【図３】 第２の参考例に係わる金属帯の脱脂設備の一例を示すフローシートである。
【図４】 第２の参考例に係わる金属帯の脱脂設備の他の一例を示すフローシートである。
【図５】 石鹸分除去率を示すグラフである。
【図６】 従来の金属帯の脱脂設備を示すフローシートである。
【符号の説明】
１ 金属帯（鋼帯）浸漬方式の脱脂槽（アルカリ洗浄装置）
２ 脱脂液貯槽（：脱脂液循環槽）
３ 冷却器
６ 分離除去装置（：析出石鹸分離除去装置）
7a、7b アルカリ性脱脂液（：脱脂液）
８ 蒸気配管
8a 蒸気
９ 冷却水供給配管
9a 冷却水
9P ポンプ
9Pr モータ回転数制御方式のポンプ
11 脱脂液抜き出し配管
12 脱脂液処理用配管
13、14 脱脂液戻り配管
18 液温測定・記録計
20 脱脂液圧力損失（ΔＰ）測定装置（：ΔＰ測定装置）
21 脱脂液流量測定装置
22 演算・制御装置
23、32、42、52 制御信号
30 析出石鹸量測定装置または析出石鹸粒子の粒径測定装置
31、41、51 制御装置
40、50 石鹸含有量測定装置
50a 測定用脱脂液冷却器
50b 濁度計
ｆ 金属帯（鋼帯）の搬送方向
Ｍ（Ｓ） 金属帯（鋼帯）
Ｖ 弁[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for treating an alkaline degreasing solution used for degreasing a metal strip, and in particular, a treatment of an alkaline degreasing solution for a metal strip that is excellent in the removal rate of soap in the alkaline degreasing solution and can achieve energy saving. Regarding the method.
[0002]
[Prior art]
Conventionally, in a continuous treatment line for a metal strip such as a steel strip, surface treatment such as rolling, heat treatment, or plating is performed while continuously supplying the metal strip.
Typical examples of the above-described continuous treatment line include a continuous hot rolling line, a continuous cold rolling line, a continuous annealing line, and a continuous hot dip galvanizing line for steel strips. A degreasing facility using an alkaline degreasing liquid (hereinafter also referred to as a degreasing liquid) is attached to remove dirt caused by rolling oil on the surface.
[0003]
In FIG. 6, the flow sheet of the degreasing equipment of metal strips, such as the conventional steel strip, is shown.
In FIG. 6, 1 is a metal strip (steel strip) immersion type degreasing tank (alkali cleaning apparatus), 2 is a degreasing liquid storage tank that is a degreasing liquid circulation tank, 3 is a cooler, and 6 is a separated soap separating and removing apparatus ( 7a and 7b are alkaline degreasing liquid (: degreasing liquid), 8 is a steam pipe (conduit), 8a is steam, 9 is a cooling water supply pipe, 9a is cooling water, and 9P is cooling water. Pump attached to supply pipe 9, 11 is degreasing liquid extraction pipe, 12 is degreasing liquid processing pipe, 13 and 14 is degreasing liquid return pipe, 18 is cooler 3 outlet side degreasing liquid temperature measuring / recording meter, f is a metal strip (steel strip) conveying direction, M (S) is a metal strip (steel strip), and V is a valve.
[0004]
The cooler 3 and the separation / removal device 6 shown in FIG. 6 are configured as follows.
Cooler 3: Cooler by indirect heat exchange between degreasing liquid and cooling water
Separation and removal device 6: Filter using filter cloth
That is, in the metal strip degreasing equipment shown in FIG. 6, in order to promote a degreasing reaction (saponification reaction), for example, a serpentine-type steam pipe 8 is immersed in the degreasing liquid 7a of the degreasing tank 1 to remove the degreasing liquid 7a. The temperature is raised to about 70 to 80 ° C. and the metal strip M such as the steel strip S is degreased.
[0005]
Further, the degreasing liquid is extracted from the degreasing tank 1 and sent to the cooler 3 through the degreasing liquid storage tank (degreasing liquid circulation tank) 2 to indirectly heat-exchange the degreasing liquid and the cooling water to cool the degreasing liquid. .
The degreasing liquid cooled by the cooler 3 separates and removes the soap precipitated by cooling with a precipitated soap separation and removal device (: separation / removal device) 6, and the degreasing liquid after the treatment passes through the degreasing liquid storage tank 2 to the degreasing tank 1. Recirculate to
[0006]
As a method of controlling the liquid temperature during cooling by the degreasing liquid cooler 3 described above, the flow rate of the cooling water or further the cooling water temperature is controlled based on the measurement result of the liquid temperature of the degreasing liquid on the outlet side of the cooler 3. A control method is used.
However, in the case of the above method, the removal rate of soap is not always sufficient, and the following problems (1) and (2) occur.
[0007]
(1) Work environment problems and reduced productivity due to foaming of degreasing liquid:
When the concentration of soap in the degreasing liquid is high, the surface tension of the degreasing liquid is lowered and a foaming phenomenon occurs.
In particular, when the traveling speed of a metal strip such as a steel strip in a degreasing tank is fast, the metal strip (steel strip) stirs the degreasing liquid in the tank and foams vigorously.
[0008]
In addition, when electrolytic degreasing is used as a degreasing method and the current density is increased in terms of degreasing speed, foaming is intense.
When foaming occurs, foam overflows from the degreasing tank, contaminates the surrounding area, worsens the working environment, hinders operation, and decreases productivity.
(2) Increase in alkali basic unit:
When the above-mentioned foaming occurs, the alkali flows out from the degreasing tank, so that the alkali basic unit per unit treatment amount of the metal strip (steel strip) increases and the chemical consumption increases.
[0009]
In order to deal with the above-described problems, conventionally, for example, it is necessary to set a flow rate of the cooling water in the cooler 3 higher, or to set a lower cooling water temperature. Depending on the operating conditions, the above-mentioned foaming is unavoidable, and there are problems in terms of working environment, productivity, and alkali basic unit.
[0010]
[Problems to be solved by the invention]
An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a method for treating an alkaline degreasing solution for a metal strip that is excellent in the removal rate of soap in the degreasing solution and can achieve energy saving. To do.
[0011]
[Means for solving the problems]]
[0012]
  BookThe invention extracts at least part of the alkaline degreasing liquid after use in a metal strip degreasing tank, cools it with a cooler, separates and removes the soap deposited in the alkaline degreasing liquid with a separation and removal device, and obtains the alkaline A method for treating an alkaline degreasing solution for a metal strip in which a degreasing solution is recirculated to the degreasing tank, wherein the amount of precipitated soap and / or precipitated soap particles in the alkaline degreasing solution between the cooler and the separation / removal device It is the processing method of the alkaline degreasing liquid of the metal strip characterized by controlling the cooling temperature of the alkaline degreasing liquid in the said cooler based on the measurement result of a diameter.
[0013]
  BookIn the present invention, as an index of the amount of the precipitated soap, it is a function of the amount of scattered light from the degreasing liquid when light is incident on the alkaline degreasing liquid on the outlet side of the separation / removal device or the measurement sample of the alkaline degreasing liquid. It is preferable to use the amount of precipitated soap.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
  Less thanThe second1'sReference example,BookInvention, No.2ofReference exampleThis will be described in more detail in the order of.
  [FirstReference example:]
  First1'sReference exampleIs a method for treating an alkaline degreasing solution for a metal strip, which controls the cooling temperature of the alkaline degreasing solution in the cooler based on the separation and removal amount of the soap deposited in the alkaline degreasing solution.
[0017]
  First mentionedReference exampleIn the above, as the separation and removal device, a flow-type and filtration type separation and removal device in which the inner space of the device is filled with a degreasing solution is used, and the pressure difference (pressure loss) between the degreasing solution before and after the separation and removal device: ΔP It is preferable to use the amount of change in ΔP per unit time as an indicator of the amount of separation and removal of soap.
  In FIG.First reference exampleAn example of the degreasing equipment for the metal strip relating to the method for treating the alkaline degreasing solution for the metal strip is shown by a flow sheet.
[0018]
In FIG. 1, 9PrIs a motor speed control type pump, 20 is a pressure difference (pressure loss) of the degreasing liquid before and after the separation and removal device 6: ΔP measuring device (hereinafter also referred to as ΔP measuring device), 21 is a degreasing liquid flow measuring device, Reference numeral 22 denotes an arithmetic / control device, 23 denotes a control signal, and other symbols denote the same contents as those in FIG.
In FIG. 1, the separated soap is separated by the filter of the separated soap separating and removing device 6, and the cooling temperature of the degreasing liquid in the cooler 3 is controlled by the arithmetic / control device 22 attached to the separated soap separating and removing device. The state that has been done.
[0019]
In the metal strip degreasing equipment shown in FIG. 1, the metal strip M such as the steel strip S is degreased by the same method as the above-described degreasing equipment shown in FIG.
Further, the degreasing liquid is extracted from the degreasing tank 1 and sent to the cooler 3 through the degreasing liquid storage tank (degreasing liquid circulation tank) 2 to indirectly heat-exchange the degreasing liquid and the cooling water to cool the degreasing liquid. .
[0020]
The degreasing liquid cooled by the cooler 3 separates and removes the soap precipitated by cooling by the separation / removal device 6, and recirculates the treated degreasing liquid to the degreasing tank 1 via the degreasing liquid storage tank 2.
The separation / removal device 6 shown in FIG. 1 is a flow-type separation / removal device in which the inner space of the device (filter) is filled with the degreasing liquid, and the pressure difference (pressure loss) between the degreasing liquid before and after the separation / removal apparatus. : ΔP was measured, and the amount of change in ΔP per unit time (hereinafter, also simply referred to as the amount of change in ΔP) was used as an index of the separation and removal amount of the precipitated soap in the separation / removal device 6, and The liquid temperature is controlled by the cooler 3.
[0021]
That is, the pressure difference (pressure loss): ΔP of the degreasing liquid before and after the separation / removal device (filter) 6 in which the degreasing liquid is circulating is measured with the ΔP measuring device 20 over time, preferably continuously. Know the amount of soap separated and removed by the removing device 6.
That is, when the amount of increase of ΔP per unit time is larger than the reference value, it is determined that the amount of soap separation and removal is large.
[0022]
On the other hand, when the flow rate of the degreasing liquid flowing through the separation / removal device 6 is increased or decreased with respect to the reference flow rate, even if the amount of soap deposited on the filter cloth is the same, ΔP is increased or decreased accordingly. .
Therefore, the flow rate of the degreasing liquid flowing through the separation / removal device 6 is measured by the degreasing liquid flow rate measuring device 21.
[0023]
The signal of the ΔP measurement result by the ΔP measuring device 20 and the signal of the degreasing liquid flow rate measurement result by the degreasing liquid flow measuring device 21 are transmitted to the arithmetic / control device 22.
In the arithmetic / control unit 22, the amount of soap deposited on the filter cloth per unit time (:) is calculated from the relational expression between the amount of change of ΔP obtained in advance, the amount of soap deposited on the filter cloth per unit time, and the degreasing liquid flow rate. Calculates the amount of soap separation / removal per unit time (hereinafter also referred to simply as soap separation / removal amount), and outputs an output signal 23 corresponding to the soap separation / removal amount of the motor 9P pump 9P.rThe motor 9p or the cooling water temperature control device (not shown) is transmitted to the motor rotation speed control pump 9PrThe flow rate of the cooling water 9a in the cooling water supply pipe 9 is adjusted by controlling the number of rotations of the motor, or the adjustment of the water temperature of the cooling water 9a is further controlled.
[0024]
That is, when the amount of increase in the pressure loss: ΔP per unit time of the degreasing liquid described above is small with respect to the reference value and the separation / removal amount of soap in the separation / removal device 6a is small with respect to the reference value, It is determined that the amount of soap deposited is small, and, for example, the following controls (1) and (2) are performed.
(1) When the increase in ΔP per unit time is small compared to the reference value:
The above control is performed to increase the flow rate of the cooling water 9a.
[0025]
(2) When the amount of increase in ΔP per unit time is considerably smaller than the reference value:
The above control is performed, and in addition to the increase in the flow rate of the cooling water 9a, the water temperature of the cooling water 9a also decreases.
The above control can be selected as appropriate according to the deviation of the calculated soap separation and removal amount from the reference value, and can be automatically selected by storing the selection criterion in advance in the calculation / control device. it can.
[0026]
According to the control method of the degreasing liquid cooling temperature based on the amount of soap separated and removed in the separation and removal apparatus 6 described above, the following excellent effects (1) to (3) can be obtained.
(1) Improved soap removal rate of degreasing solution:
As shown in the examples described later, by performing the above-described control, the control of the degreasing liquid is compared with the control based on the measurement result of the temperature of the degreasing liquid on the outlet side of the conventional cooler 3 shown in FIG. The soap removal rate is improved.
[0027]
(2) Reduction of power consumption in pumps, etc .:
Since the temperature of the degreasing liquid is not reduced excessively, the pump 9PrThe power consumption required for lowering the temperature of the motor (9P) or further cooling water can be reduced.
(3) Reduction of degreasing liquid heating energy in the degreasing tank:
Since the liquid temperature of the degreasing liquid is not excessively decreased, the temperature decrease of the degreasing liquid recirculated to the degreasing tank 1 via the degreasing liquid storage tank 2 is reduced, and the degreasing liquid of the degreasing tank 1 such as steam is reduced. Energy required for temperature rise can be reduced.
[0028]
  1stReference exampleThe first mentionedReference exampleThe separation / removal device is not limited to a filtration-type separation / removal device, and other separation / removal devices such as a centrifugal separator and a sedimentation separator can also be used.
  In addition, the first mentionedReference exampleThe filter medium in the filtration type separation / removal apparatus in the preferred embodiment is not limited to the filter cloth, and other filter medium such as a wire mesh can also be used.
[0029]
  [Bookinvention:〕
  BookThe gist of the invention is that the alkaline degreasing liquid in the cooler is based on the measurement result of the amount of precipitated soap and / or the particle size of the precipitated soap particles in the alkaline degreasing liquid between the alkaline degreasing liquid cooler and the separation and removal device. It is the processing method of the alkaline degreasing liquid of the metal strip which controls cooling temperature.
[0030]
  BookIn the invention, as an index of the amount of soap deposited, light is incident on the alkaline degreasing liquid on the separation / removal device exit side or the measurement sample of the alkaline degreasing liquid, the amount of scattered light from the degreasing liquid is measured, and the scattered light It is preferable to use a precipitated soap amount that is a function of the amount of light.
  This is because the amount of precipitated soap can be obtained as a function of the amount of scattered light from the degreasing liquid when light enters the degreasing liquid.
[0031]
In FIG. 2, an example of the degreasing equipment of the metal strip which concerns on the processing method of the alkaline degreasing liquid of the metal strip of this invention is shown with a flow sheet.
In FIG. 2, 30 is a measuring device for the amount of precipitated soap in the degreasing liquid or a particle size measuring device for the precipitated soap particles in the degreasing solution, 31 is a control device, 32 is a control signal, and the other symbols are those shown in FIG. The same content as FIG. 6 is shown.
[0032]
The precipitated soap amount measuring device or the precipitated soap particle particle size measuring device 30 determines the amount of precipitated soap or the particle size of the precipitated soap particles in the degreasing liquid fed between the cooler 3 and the separation / removal device 6. taking measurement.
In the metal strip degreasing equipment shown in FIG. 2, the metal strip M such as the steel strip S is degreased by the same method as the above-described degreasing equipment shown in FIG.
[0033]
Further, the degreasing liquid is extracted from the degreasing tank 1 and sent to the cooler 3 through the degreasing liquid storage tank (degreasing liquid circulation tank) 2 to indirectly heat-exchange the degreasing liquid and the cooling water to cool the degreasing liquid. .
The degreasing liquid cooled by the cooler 3 separates and removes the soap precipitated by cooling by the separation / removal device 6, and recirculates the treated degreasing liquid to the degreasing tank 1 via the degreasing liquid storage tank 2.
[0034]
The following control method is used as a method for controlling the liquid temperature during cooling by the cooler 3 of the degreasing liquid described above.
(Control based on the measurement result of the amount of soap deposited in alkaline degreasing solution :)
Although there is no restriction | limiting in particular as a measuring apparatus of the amount of precipitated soaps, Preferably the turbidimeter comprised from a light source and a light receiver (: scattered light light quantity measuring apparatus) is used.
[0035]
As the turbidimeter, any of a transmitted light turbidimeter, a scattered light turbidimeter, or an integrating sphere turbidimeter may be used.
In addition, as a sample tank of the turbidimeter, a degreasing liquid continuously flows into the sample tank from the outlet pipe of the cooler 3 and returns to the outlet pipe (hereinafter referred to as a degreasing liquid measurement flow cell). It is preferable to use
[0036]
Also, a device for measuring the temperature of the degreasing liquid in the outlet side piping of the cooler 3 and a measuring system atmosphere temperature control device are provided, and the ambient temperature around each of the degreasing liquid measurement flow cell, the degreasing liquid sample supply piping and the return piping is cooled. The measurement system is preferably configured to be equal to the temperature of the degreasing liquid on the outlet side of the vessel 3.
In the present invention, light may be directly incident on the degreasing liquid in the outlet side pipe of the cooler 3, and the amount of precipitated soap may be obtained based on the measurement result of the amount of scattered light from the degreasing liquid.
[0037]
In this control, the amount of precipitated soap in the degreasing liquid of the outlet side piping of the cooler 3 is measured by the amount of precipitated soap measuring device 30 which is, for example, the turbidimeter described above.
As described above, the amount of precipitated soap can be obtained as a function of the amount of scattered light from the degreasing liquid.
A signal of the measurement result of the amount of precipitated soap based on the measurement result of the light amount of the turbidimeter is transmitted to the control device 31.
[0038]
In the control device 31, the output signal 32 corresponding to the amount of precipitated soap is sent to the motor rotation speed control type pump 9P.rThe motor 9p or the cooling water temperature control device (not shown) is transmitted to the motor rotation speed control pump 9PrThe flow rate of the cooling water 9a in the cooling water supply pipe 9 is adjusted by controlling the number of rotations of the motor, or the adjustment of the water temperature of the cooling water 9a is further controlled.
[0039]
That is, for example, the following controls (1) and (2) are performed.
(1) When the amount of soap deposited in the degreasing liquid in the outlet side of the cooler 3 is less than the reference value:
The above control is performed to increase the flow rate of the cooling water 9a.
(2) When the amount of soap deposited in the degreasing liquid in the outlet side of the cooler 3 is considerably smaller than the reference value:
The above control is performed, and in addition to the increase in the flow rate of the cooling water 9a, the water temperature of the cooling water 9a also decreases.
[0040]
The above-described control can be appropriately selected based on the measurement result of the amount of precipitated soap, and can be automatically selected by storing the selection criteria in the control device in advance.
According to the control method of the degreasing liquid cooling temperature based on the measurement result of the amount of precipitated soap, the following excellent effects (1) to (3) can be obtained for the same reason as the control method shown in FIG.
[0041]
(1) Improved soap removal rate of degreasing liquid
(2) Reduction of power consumption in pumps
(3) Reduction of degreasing liquid heating energy in the degreasing tank
(Control based on the measurement result of the particle size of the precipitated soap particles in the alkaline degreasing solution :)
Although there is no restriction | limiting in particular as a measuring apparatus of the particle size of precipitated soap particle, Preferably a laser diffraction and a scattering type particle size distribution measuring apparatus is used.
[0042]
In addition, as a measuring device, the degreasing liquid continuously flows into the flow cell of the laser diffraction / scattering type particle size distribution measuring device from the outlet side piping of the cooler 3 and uses a flow type measuring device that returns to the outlet side piping. preferable.
Further, a device for measuring the temperature of the degreasing liquid in the outlet side piping of the cooler 3 and a measuring system ambient temperature control device are provided, and the ambient temperature around each of the flow cell, the supply piping for the degreasing solution sample, and the return piping is set in the cooler 3. It is preferable to configure the measurement system so as to be equal to the temperature of the degreasing liquid on the outlet side.
[0043]
In this control, the particle size of the precipitated soap particles in the degreased liquid of the outlet side pipe of the cooler 3 is measured by, for example, the particle size measuring device 30 of the precipitated soap particles, which is the laser diffraction / scattering particle size distribution measuring device described above. .
As the particle size, a 50% cumulative average particle size or the like can be used.
A signal of the particle size measurement result of the precipitated soap particles is transmitted to the control device 31.
[0044]
In the control device 31, the output signal 32 corresponding to the particle size of the precipitated soap particles is sent to the motor 9P pump 9P.rThe motor 9p or the cooling water temperature control device (not shown) is transmitted to the motor rotation speed control pump 9PrThe flow rate of the cooling water 9a in the cooling water supply pipe 9 is adjusted by controlling the number of rotations of the motor, or the adjustment of the water temperature of the cooling water 9a is further controlled.
[0045]
That is, when the particle size (50% cumulative average particle size) of the precipitated soap particles in the alkaline degreasing liquid flowing between the alkaline degreasing liquid cooler 3 and the separation / removal device 6 is smaller than the reference value, the alkaline degreasing liquid is alkaline. It is determined that the degreasing liquid is not sufficiently cooled, and, for example, the following controls (1) and (2) are performed.
(1) When the particle size (50% cumulative average particle size) of the soap particles precipitated in the degreasing liquid in the outlet of the cooler 3 is smaller than the reference value:
The above control is performed to increase the flow rate of the cooling water 9a.
[0046]
(2) When the particle size (50% cumulative average particle size) of the precipitated soap particles of the degreasing liquid in the outlet 3 of the cooler 3 (second stage cooler 5) is considerably smaller than the reference value:
The above control is performed, and in addition to the increase in the flow rate of the cooling water 9a, the water temperature of the cooling water 9a also decreases.
The above-described control can be appropriately selected based on the particle size measurement result of the precipitated soap particles, and can also be automatically selected by previously storing the selection criteria in the control device.
[0047]
  According to the control method of the degreasing liquid cooling temperature based on the particle size measurement result of the precipitated soap particles described above, the following excellent effects (1) to (3) are obtained for the same reason as the control method shown in FIG. It is done.
  (1) Improved soap removal rate of degreasing liquid
  (2) Reduction of power consumption in pumps
  (3) Reduction of degreasing liquid heating energy in the degreasing tank
  more than,BookHaving described the invention,BookThe separation / removal device in the invention is not limited to the filtration-type separation / removal device, and other types of separation / removal devices such as a centrifugal separator and a sedimentation separator can also be used.
[0048]
  [No.2ofReference example:]
  SecondofReference exampleIs a method for treating an alkaline degreasing solution for a metal strip that controls the cooling temperature of the alkaline degreasing solution in the cooler based on the measurement result of the soap content of the alkaline degreasing solution on the outlet side of the separation and removal device of the alkaline degreasing solution.
  First mentioned2ofReference exampleIn the above, as an index of the soap content, light is incident on the alkaline degreasing liquid on the separation / removal device exit side or the measurement sample of the alkaline degreasing liquid, the amount of scattered light from the degreasing liquid is measured, and the scattered light is measured. It is preferable to use a soap content that is a function of the amount of light.2ofReference exampleFirst preferred embodiment).
[0049]
  This is because the above-described soap content can be obtained as a function of the amount of scattered light from the degreasing liquid when light is incident on the above-described degreasing liquid or the measurement sample of the degreasing liquid.
  No. mentioned above2ofReference exampleAlthough there is no restriction | limiting in particular as a measuring apparatus of the light quantity of the scattered light from the degreasing liquid in the 1st suitable aspect of above, As mentioned aboveBookSimilar to the invention, a turbidimeter preferably comprising a light source and a light receiver (: scattered light quantity measuring device) is used.
[0050]
  As the turbidimeter, any of a transmitted light turbidimeter, a scattered light turbidimeter, or an integrating sphere turbidimeter may be used.
  Also, the first mentioned2ofReference exampleIn the above, it is also preferable to use the measurement result of the amount of soap deposited after cooling the measurement sample of the alkaline degreasing liquid on the outlet side of the separation / removal device 6 to a predetermined temperature as the index of the soap content (No. 1).2ofReference exampleSecond preferred embodiment).
[0051]
Further, as an index of the amount of soap deposited in this case, light is incident on the measurement sample of the alkaline degreasing liquid after cooling, the amount of scattered light from the degreasing liquid is measured, and the precipitation is a function of the amount of scattered light. It is preferable to use a soap amount.
This is because the amount of precipitated soap described above can be obtained as a function of the amount of scattered light from the degreasing liquid when light is incident on the measurement sample of the alkaline degreasing liquid after cooling.
[0052]
  No. mentioned above2ofReference exampleThere is no particular limitation on the measuring device for the amount of precipitated soap in the second preferred embodiment of the present invention.BookSimilar to the invention, a turbidimeter preferably comprising a light source and a light receiver (: scattered light quantity measuring device) is used.
  As the turbidimeter, any of a transmitted light turbidimeter, a scattered light turbidimeter, or an integrating sphere turbidimeter may be used.
[0053]
  In FIG.Second reference exampleAn example of the degreasing equipment for the metal strip relating to the method for treating the alkaline degreasing solution for the metal strip is shown by a flow sheet.
  In FIG. 3, 40 is a soap content measuring device of a degreasing liquid (: alkaline degreasing liquid), 41 is a control device, 42 is a control signal, and other symbols are the same as those shown in FIGS. .
[0054]
In the metal strip degreasing equipment shown in FIG. 3, a turbidimeter is used as the soap content measuring device 40.
In the metal strip degreasing facility shown in FIG. 3, the metal strip M such as the steel strip S is degreased by the same method as the degreasing facility shown in FIG.
Further, the degreasing liquid is extracted from the degreasing tank 1 and sent to the cooler 3 through the degreasing liquid storage tank (degreasing liquid circulation tank) 2 to indirectly heat-exchange the degreasing liquid and the cooling water to cool the degreasing liquid. .
[0055]
The degreasing liquid cooled by the cooler 3 separates and removes the soap precipitated by cooling by the separation / removal device 6, and recirculates the treated degreasing liquid to the degreasing tank 1 via the degreasing liquid storage tank 2.
The following control method is used as a method for controlling the liquid temperature during cooling by the cooler 3 of the degreasing liquid described above.
That is, in this control, first, the soap content in the degreasing liquid of the separation / removal device 6 outlet piping is measured by the soap content measuring device 40 which is, for example, the turbidimeter described above.
[0056]
A signal of the measurement result of the soap content based on the measurement result of the amount of scattered light of the turbidimeter is transmitted to the control device 41.
In the control device 41, the output signal 42 corresponding to the soap content is sent to the motor 9P pump 9P.rThe motor 9p or the cooling water temperature control device (not shown) is transmitted to the motor rotation speed control pump 9PrThe flow rate of the cooling water 9a in the cooling water supply pipe 9 is adjusted by controlling the number of rotations of the motor, or the adjustment of the water temperature of the cooling water 9a is further controlled.
[0057]
That is, when the soap content of the alkaline degreasing liquid on the outlet side of the separation / removal device 6 is larger than the reference value, it is determined that the alkaline degreasing liquid is not sufficiently cooled. For example, the following (1), (2) Control.
(1) When the soap content is higher than the standard value:
The above control is performed to increase the flow rate of the cooling water 9a.
[0058]
(2) When the soap content is much higher than the standard value:
The above control is performed, and in addition to the increase in the flow rate of the cooling water 9a, the water temperature of the cooling water 9a also decreases.
The above-described control can be appropriately selected based on the soap content measurement result, and can be automatically selected by storing the selection criteria in the control device 41 in advance.
[0059]
  According to the control method of the degreasing liquid cooling temperature based on the measurement result of the soap content of the alkaline degreasing liquid on the outlet side of the separation / removal device 6 described above, the following (1) to (1) to the control method shown in FIG. The excellent effect (3) can be obtained.
  (1) Improved soap removal rate of degreasing liquid
  (2) Reduction of power consumption in pumps
  (3) Reduction of degreasing liquid heating energy in the degreasing tank
  In FIG.Second reference exampleAnother example of the degreasing equipment for the metal strip relating to the method for treating the alkaline degreasing solution for the metal strip is shown by a flow sheet.
[0060]
In FIG. 4, 50 is a soap content measuring device of a degreasing liquid (: alkaline degreasing liquid), 50a is a measuring degreasing liquid cooler, 50b is a turbidimeter, 51 is a control device, 52 is a control signal, The reference numerals indicate the same contents as those shown in FIGS.
That is, the soap content measuring device 50 shown in FIG. 4 is a liquid flow type measuring device composed of a measuring degreasing liquid cooler 50a and a turbidimeter 50b.
[0061]
In the metal strip degreasing facility shown in FIG. 4, the metal strip M such as the steel strip S is degreased by the same method as the above-described degreasing facility of FIG.
Further, the degreasing liquid is extracted from the degreasing tank 1 and sent to the cooler 3 through the degreasing liquid storage tank (degreasing liquid circulation tank) 2 to indirectly heat-exchange the degreasing liquid and the cooling water to cool the degreasing liquid. .
[0062]
The degreasing liquid cooled by the cooler 3 separates and removes the soap precipitated by cooling by the separation / removal device 6, and recirculates the treated degreasing liquid to the degreasing tank 1 via the degreasing liquid storage tank 2.
The following control method is used as a method for controlling the liquid temperature during cooling by the cooler 3 of the degreasing liquid described above.
That is, in this control, first, the soap content in the degreasing liquid of the separation / removal device 6 outlet pipe is determined by, for example, a soap content measuring apparatus comprising the above-described measuring degreasing liquid cooler 50a and turbidimeter 50b. Measure at 50.
[0063]
The cooling temperature of the measurement degreasing liquid in the above-described measurement degreasing liquid cooler 50a is at least lower than the temperature of the degreasing liquid in the outlet side piping of the cooler 3, and experimentally beforehand according to the target degreasing liquid. Can be sought.
Separation and removal device 6 Dissolved soap in the measurement degreasing liquid separated from the outlet piping is deposited in the measurement degreasing liquid cooler 50a, and the measurement degreasing liquid containing the precipitated soap particles is a turbidimeter 50b. Turbidity is measured in the process of flowing through the flow cell for measuring the degreasing liquid.
[0064]
A signal of the measurement result of the soap content based on the measurement result of the amount of scattered light of the turbidimeter is transmitted to the control device 51.
In the control device 51, the output signal 52 corresponding to the soap content is sent to the motor 9P pump 9P.rThe motor 9p or the cooling water temperature control device (not shown) is transmitted to the motor rotation speed control pump 9PrThe flow rate of the cooling water 9a in the cooling water supply pipe 9 is adjusted by controlling the number of rotations of the motor, or the adjustment of the water temperature of the cooling water 9a is further controlled.
[0065]
That is, when the soap content of the alkaline degreasing liquid on the outlet side of the separation / removal device 6 is larger than the reference value, it is determined that the alkaline degreasing liquid is not sufficiently cooled. For example, the following (1), (2) Control.
(1) When the soap content is higher than the standard value:
The above control is performed to increase the flow rate of the cooling water 9a.
[0066]
(2) When the soap content is much higher than the standard value:
The above control is performed, and in addition to the increase in the flow rate of the cooling water 9a, the water temperature of the cooling water 9a also decreases.
The above-described control can be selected as appropriate based on the soap content measurement result, and can be automatically selected by storing the selection criteria in the control device 51 in advance.
[0067]
  According to the control method of the degreasing liquid cooling temperature based on the measurement result of the soap content of the alkaline degreasing liquid on the outlet side of the separation / removal device 6 described above, the following (1) to (1) to the control method shown in FIG. The excellent effect (3) can be obtained.
  (1) Improved soap removal rate of degreasing liquid
  (2) Reduction of power consumption in pumps
  (3) Reduction of degreasing liquid heating energy in the degreasing tank
  No.2ofReference exampleSaid2ofReference exampleThe separation / removal device is not limited to a filtration-type separation / removal device, and other types of separation / removal devices such as a centrifugal separator and a sedimentation separator can also be used.
[0068]
【Example】
  Hereinafter, the present invention will be described more specifically based on examples.
  (referenceExample 1)
  The steel strip obtained by cold rolling was degreased using the metal strip degreasing equipment shown in FIG. 1 under the following test conditions.
[0069]
(Test conditions:)
Rolling oil: vegetable oil
Degreasing tank 1: Steel strip immersion plate method
Degreasing solution (alkali cleaning solution): 3% aqueous solution of metal cleaning agent containing (caustic soda, inorganic sodium phosphate, disodium ethylenediaminetetraacetate, polyoxyethylene lauryl ether)
Degreasing liquid temperature of degreasing tank 1: 80 ° C
Separation and removal device 6: filter cloth filter
That is, in the degreasing equipment for the metal strip shown in FIG. 1, the steel strip S was immersed in the degreasing tank 1 for degreasing.
[0070]
Moreover, the degreasing liquid is extracted from the degreasing tank 1 and sent to the cooler 3 via the degreasing liquid storage tank (degreasing liquid circulation tank) 2 to indirectly heat-exchange the degreasing liquid and the cooling water to cool the degreasing liquid. .
The degreasing liquid cooled by the cooler 3 was separated and removed by the separation / removal device 6 with the soap deposited by cooling, and the treated degreasing liquid was recirculated to the degreasing tank 1 via the degreasing liquid storage tank 2.
[0071]
Moreover, as a method of controlling the liquid temperature at the time of cooling with the cooler 3 of the degreasing liquid described above, the pressure difference (pressure loss): ΔP of the degreasing liquid before and after the separation and removal device 6 is measured, and the amount of soap separated and removed As an index, the change amount of ΔP per unit time (: change amount of ΔP) was used, and control was performed by the following method.
That is, the pressure difference (pressure loss): ΔP of the degreasing solution before and after the separation / removal device (filter) 6 in which the degreasing solution is circulating was measured with the ΔP measuring device 20 over time.
[0072]
Moreover, the flow rate of the degreasing liquid flowing through the separation / removal device 6 was measured by the degreasing liquid flow rate measuring device 21.
The signal of the ΔP measurement result by the ΔP measuring device 20 and the signal of the degreasing liquid flow rate measurement result by the degreasing liquid flow measuring device 21 were transmitted to the calculation / control device 22.
In the arithmetic / control unit 22, the amount of soap deposited on the filter cloth per unit time (: :) from the relational expression between the amount of change of ΔP obtained in advance, the amount of soap deposited on the filter cloth per unit time and the degreasing liquid flow rate: The amount of soap separated and removed per unit time) was calculated, and the following control was performed based on the obtained calculation result.
[0073]
In addition to the adjustment of the flow rate of the cooling water 9a described below, whether or not to adjust the water temperature of the cooling water 9a is based on the calculation result of the soap separation and removal amount and the selection criteria stored in advance in the calculation / control device. An automatic selection method was adopted to control the degree of cooling of the degreasing liquid in inverse proportion to the amount of soap separated and removed.
That is, the motor rotation speed control pump 9PrThis is control for adjusting the flow rate of the cooling water 9a in the cooling water supply pipe 9 by controlling the number of rotations of the motor, or further adjusting the water temperature of the cooling water 9a.
[0074]
Furthermore, a sample of the degreasing liquid was collected from the cooler 3 outlet pipe and the separation / removal device 6 outlet pipe during the test.
Further, each sample of the degreasing liquid collected was cooled to a liquid temperature of 10 ° C., filtered, and the soap removal rate was determined from the mass of the filtered residue after drying based on the following formula (1).
Soap content removal rate = {(A−B) / A} × 100 (%) (1)
In the above formula,
A: Mass of dry filtration residue per unit liquid amount for the degreasing liquid sample on the outlet side of the cooler 3
B: Mass of the dry filtration residue per unit liquid amount for the degreasing liquid sample on the outlet side of the separation / removal device 6
In FIG. 5, the measurement result of the obtained soap removal rate is shown in comparison with the soap removal rate according to Comparative Example 1 described later.
[0075]
  As shown in FIG.Reference example 1According to the above, a high removal rate of 90% is obtained with the soap content. As a result, in both the degreasing tank 1 and the degreasing liquid storage tank (degreasing liquid circulation tank) 2, the degreasing liquid accompanying the generation of bubbles is removed from the tank. No overflow occurred.
  (Example of the present invention)
  Using the metal strip degreasing equipment shown in FIG.referenceIn place of the control in Example 1, except that the cooling temperature of the degreasing liquid was controlled based on the measurement result of the amount of soap deposited in the degreasing liquid between the cooler 3 and the separation / removal device 6.referenceThe steel strip obtained by cold rolling was degreased by the same method and conditions as in Example 1.
[0076]
As a method for measuring the amount of soap deposited, the turbidimeter described above was used, and the cooling temperature of the degreasing liquid was controlled by the following control method.
That is, the amount of soap precipitated in the degreasing liquid of the outlet side of the cooler 3 was measured with a turbidimeter which is a device 30 for measuring the amount of soap deposited.
A signal of the measurement result of the amount of scattered light of the turbidimeter is transmitted to the control device 31, and the control device 31 outputs an output signal 32 corresponding to the amount of precipitated soap, which is a function of the amount of scattered light, of the motor rotation speed control method. Pump 9PrWere transmitted to a motor or a cooling water temperature control device (not shown), and the following control was performed.
[0077]
In addition to the adjustment of the flow rate of the cooling water 9a described below, whether or not to adjust the water temperature of the cooling water 9a is automatically determined based on the measurement result of the amount of precipitated soap and the selection criteria stored in advance in the control device 31. The method of selection was adopted to control the degree of cooling of the degreasing liquid in inverse proportion to the amount of soap deposited.
That is, the motor rotation speed control pump 9PrIn this control, the flow rate of the cooling water 9a in the cooling water supply pipe 9 is adjusted by controlling the number of rotations of the motor, or the water temperature of the cooling water 9a is adjusted by controlling the temperature controller of the cooling water.
[0078]
  Furthermore, at the time of the above test, a sample of the degreasing liquid was collected from the cooler 3 outlet side pipe and the separation / removal device 6 outlet side pipe, as described above.referenceThe soap removal rate was determined in the same manner as in Example 1.
  As a result, the bookinventionIn the example, a high removal rate with a soap content of 93% was obtained, and overflowing of the defatted liquid to the outside of the defatted liquid accompanying the generation of bubbles in both the defatted tank 1 and the defatted liquid storage tank (degreasing liquid circulation tank) 2 Did not occur.
[0079]
  (referenceExample2)
  Using the metal strip degreasing equipment shown in FIG.referenceIn place of the control in Example 1, except that the cooling temperature of the degreasing liquid was controlled based on the measurement result of the soap content in the degreasing liquid on the outlet side of the separation / removal device 6referenceThe steel strip obtained by cold rolling was degreased by the same method and conditions as in Example 1.
[0080]
The soap content described above was measured with the soap content measuring device 40 which is the turbidimeter described above, and the cooling temperature of the degreasing liquid was controlled by the following control method.
That is, the signal of the measurement result of the amount of scattered light of the turbidimeter is transmitted to the control device 41, and the control device 41 controls the motor rotation speed of the output signal 42 corresponding to the soap content that is a function of the amount of scattered light. System pump 9PrWere transmitted to a motor or a cooling water temperature control device (not shown) and the following control was performed.
[0081]
In addition to the adjustment of the flow rate of the cooling water 9a below, whether or not to adjust the water temperature of the cooling water 9a is automatically selected based on the measurement result of the soap content and the selection criteria stored in the control device 41 in advance. A system was adopted to control the degree of cooling of the degreasing liquid in proportion to the soap content.
That is, the motor speed control type pump 9PrThis is control for adjusting the flow rate of the cooling water 9a in the cooling water supply pipe 9 by controlling the number of rotations of the motor, or further adjusting the water temperature of the cooling water 9a.
[0082]
  Furthermore, at the time of the above test, a sample of the degreasing liquid was collected from the cooler 3 outlet side pipe and the separation / removal device 6 outlet side pipe,referenceThe soap removal rate was determined in the same manner as in Example 1.
  As a result, the bookreferenceExample2Soap removal rate is as high as 92%, and in both the degreasing tank 1 and the degreasing liquid storage tank (degreasing liquid circulation tank) 2 Did not occur.
[0083]
  (Comparative Example 1)
  Using the conventional metal strip degreasing equipment shown in FIG.referenceInstead of the control in Example 1, except that the temperature of the degreasing liquid on the outlet side of the cooler 3 is controlled to be constant at 20 ° C.referenceThe steel strip obtained by cold rolling was degreased by the same method and conditions as in Example 1.
  Also,referenceThe soap removal rate was determined in the same manner as in Example 1.
[0084]
  In FIG. 5, the measurement result of the obtained soap content removal rate is shown.
  In this comparative example, the soap removal rate is 80%, and it is possible to avoid overflow of the degreasing liquid to the outside due to the generation of bubbles in the degreasing tank 1 and the degreasing liquid storage tank (degreasing liquid circulation tank) 2. It was difficult.
  (Comparative Example 2)
  Using the conventional metal strip degreasing equipment shown in FIG.referenceIn place of the control in Example 1, except that the temperature of the degreasing liquid on the outlet side of the cooler 3 is controlled to be constant at 10 ° C.referenceThe steel strip obtained by cold rolling was degreased by the same method and conditions as in Example 1.
[0085]
  Also,referenceThe soap removal rate was determined in the same manner as in Example 1.
  As a result, in this comparative example, the soap removal rate is 85%, and the overflow of the defatted liquid to the outside of the defatted tank 1 and the defatted liquid storage tank (degreasing liquid circulation tank) 2 due to the generation of bubbles is completely completed. It was difficult to avoid.
  more than,Examples of the present invention, referenceExamples and comparative examples were described, but the test results obtained are collectively shown in Table 1.
[0086]
  In Table 1,Examples of the present invention, referenceIn the examples and comparative examples, the energy consumption defined by the following formula (2) is shown as a relative value with the energy consumption of Comparative Example 1 as 100.
  Here, the energy consumption is the sum of the power consumption of the equipment used for adjusting the flow rate and the water temperature of the cooling water 9a and the energy required for raising the temperature of the degreasing liquid.
  As shown in Table 1, according to the present invention, the soap removal rate is improved, and the overflow of the degreasing liquid to the outside of the tank due to the generation of bubbles in the degreasing tank and the degreasing liquid storage tank (degreasing liquid circulation tank) is prevented. It can be prevented and energy consumption in the degreasing equipment can be reduced.
[0087]
[Table 1]
Figure 0003959991
[0088]
【The invention's effect】
According to the present invention, the removal rate of soap in the degreasing liquid is excellent, the overflow of the degreasing liquid outside the tank due to the generation of bubbles in the degreasing tank and the like is prevented, and energy saving can be achieved. It became possible to provide a processing method.
[Brief description of the drawings]
[Figure 1]First reference exampleIt is a flow sheet which shows an example of the degreasing equipment of the metal strip concerning.
FIG. 2 is a flow sheet showing an example of a metal strip degreasing facility according to the present invention.
[Fig. 3]Second reference exampleIt is a flow sheet which shows an example of the degreasing equipment of the metal strip concerning.
[Fig. 4]Second reference exampleOf metal strip degreasing equipmentotherIt is a flow sheet which shows an example.
FIG. 5 is a graph showing a soap removal rate.
FIG. 6 is a flow sheet showing a conventional metal strip degreasing facility.
[Explanation of symbols]
  1 Metal strip (steel strip) immersion type degreasing tank (alkali cleaning device)
  2 Degreasing liquid storage tank (: Degreasing liquid circulation tank)
  3 Cooler
  6 Separation and removal equipment (: Precipitated soap separation and removal equipment)
  7a, 7b Alkaline degreasing liquid (: Degreasing liquid)
  8 Steam piping
  8a steam
  9 Cooling water supply piping
  9a Cooling water
  9P pump
  9Pr  Motor speed control type pump
  11 Piping for removing degreasing liquid
  12 Degreasing treatment pipe
  13, 14 Degreasing liquid return piping
  18 Liquid temperature measurement / recording meter
  20 Degreasing liquid pressure loss (ΔP) measuring device (: ΔP measuring device)
  21 Degreasing liquid flow measuring device
  22 Computing and control devices
  23, 32, 42, 52 Control signal
  30 Precipitated soap amount measuring device or particle size measuring device of precipitated soap particles
  31, 41, 51 Control device
  40, 50 Soap content measuring device
  50a Degreasing liquid cooler for measurement
  50b Turbidimeter
  f Transport direction of metal strip (steel strip)
  M (S) Metal strip (steel strip)
  V valve

Claims (1)

金属帯の脱脂槽で使用後のアルカリ性脱脂液の少なくとも一部を抜き出し、冷却器で冷却後、該アルカリ性脱脂液中に析出した石鹸を分離除去装置で分離除去し、得られたアルカリ性脱脂液を前記脱脂槽に再循環する金属帯のアルカリ性脱脂液の処理方法であって、前記冷却器と分離除去装置との間のアルカリ性脱脂液中の析出石鹸量および／または析出石鹸粒子の粒径の測定結果に基づいて、前記冷却器におけるアルカリ性脱脂液の冷却温度を制御することを特徴とする金属帯のアルカリ性脱脂液の処理方法。  Extract at least part of the alkaline degreasing liquid after use in a metal strip degreasing tank, cool it with a cooler, separate and remove the soap deposited in the alkaline degreasing liquid with a separation and removal device, and remove the resulting alkaline degreasing liquid. A method for treating an alkaline degreasing solution for a metal strip recirculated to the degreasing tank, wherein the amount of precipitated soap and / or the particle size of the precipitated soap particles in the alkaline degreasing solution between the cooler and the separation / removal device is measured. Based on a result, the cooling temperature of the alkaline degreasing liquid in the said cooler is controlled, The processing method of the alkaline degreasing liquid of the metal strip characterized by the above-mentioned.
JP2001202068A 2001-07-03 2001-07-03 Method for treating alkaline degreasing solution of metal strip Expired - Fee Related JP3959991B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2001202068A JP3959991B2 (en) 2001-07-03 2001-07-03 Method for treating alkaline degreasing solution of metal strip

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2001202068A JP3959991B2 (en) 2001-07-03 2001-07-03 Method for treating alkaline degreasing solution of metal strip

Publications (2)

Publication Number Publication Date
JP2003013267A JP2003013267A (en) 2003-01-15
JP3959991B2 true JP3959991B2 (en) 2007-08-15

Family

ID=19038935

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2001202068A Expired - Fee Related JP3959991B2 (en) 2001-07-03 2001-07-03 Method for treating alkaline degreasing solution of metal strip

Country Status (1)

Country Link
JP (1) JP3959991B2 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4828964B2 (en) * 2006-03-03 2011-11-30 日新製鋼株式会社 Stainless steel strip cleaning equipment

Also Published As

Publication number Publication date
JP2003013267A (en) 2003-01-15

Similar Documents

Publication Publication Date Title
CN110594569A (en) Monitoring control device for roller lubricating system
JP3959991B2 (en) Method for treating alkaline degreasing solution of metal strip
US4576677A (en) Method and apparatus for regenerating an ammoniacal etching solution
CN220520684U (en) Plating bath liquid temperature control device
JPH108274A (en) Surface treating device for strip by liquid
KR101086315B1 (en) Automation method for water quality management of open circulation cooling water
JP4424517B2 (en) PROCESSING DEVICE AND SEMICONDUCTOR DEVICE MANUFACTURING METHOD
JP4471131B2 (en) PROCESSING DEVICE AND SEMICONDUCTOR DEVICE MANUFACTURING METHOD
JP4062419B2 (en) Processing apparatus and method for manufacturing semiconductor device
JP3881924B2 (en) Pickling equipment for stainless steel and pickling solution control method for the equipment
JP3891277B2 (en) Processing apparatus and method for manufacturing semiconductor device
JP2838372B2 (en) Coolant concentration measuring device and coolant adjusting system using the same
JP4143235B2 (en) Copper chloride etchant electrolytic regeneration system
JPH08155510A (en) Method for feeding cold rolling oil
JP4062418B2 (en) Processing apparatus and method for manufacturing semiconductor device
KR102019684B1 (en) Method of reusing for cutting oil
JPH06246330A (en) Method and device for circulating water-soluble rolling liquid
CN217264955U (en) Mother liquor cooling oil removing tank after waste liquid evaporation
JP3673808B2 (en) Water scale prevention method
CN218435988U (en) Plating bath and electroplating device
CN110158006A (en) A kind of final water-cooling system for continuous annealing hot galvanizing double-purpose production line
JPH0824933A (en) Method and device for feeding rolling oil
RU2811349C1 (en) System for electrolytic etching of strip steel
JPH05237537A (en) Manufacture of cold rolled steel strip having excellent surface cleanliness
JP2007194647A (en) Treatment device, and method of manufacturing semiconductor device

Legal Events

Date Code Title Description
A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20041005

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20060912

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20061108

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20070424

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20070507

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110525

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120525

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120525

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130525

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20140525

Year of fee payment: 7

LAPS Cancellation because of no payment of annual fees