JP2004018898A

JP2004018898A - Method and device for concentrating plating solution

Info

Publication number: JP2004018898A
Application number: JP2002172534A
Authority: JP
Inventors: Koichi Yagishita; 柳下　幸一; Tadashi Fukuda; 福田　正; Shinji Matsuoka; 松岡　信次; Hideo Amakusa; 天草　英夫; Norio Nomura; 野村　記生
Original assignee: FEDERATION OF ELECTRO PLATING INDUSTRY ASSOCIATION JAPAN
Current assignee: FEDERATION OF ELECTRO PLATING INDUSTRY ASSOCIATION JAPAN
Priority date: 2002-06-13
Filing date: 2002-06-13
Publication date: 2004-01-22
Anticipated expiration: 2022-06-13
Also published as: JP3940320B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for concentrating a diluted plating solution wherein concentration can easily be managed and troubles such as precipitation of components (crystals, etc.) caused by excessive concentration are inhibited, and to provide a device for concentration of the plating solution which enables such concentration. <P>SOLUTION: In the method for concentrating the plating solution, water is removed through concentration treatment by heating the diluted plating solution. The concentration treatment is terminated as soon as electric conductivity of the liquid to be concentrated reaches a predetermined value. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、ニッケルめっき浴、クロムめっき浴などに用いられるめっき液の濃縮技術に関する。
【０００２】
【従来の技術】
近年、環境保全技術は循環型社会の理念に沿って開発が進められている。このような循環型社会の基本はリサイクルであり、リサイクルが１００％達成されたゼロエミッション（廃棄物ゼロ）が理想とされている。
【０００３】
本発明が属する技術分野である表面処理、めっき加工においては、めっき浴槽から汲み出され、水洗槽等で希釈され、回収されためっき液を濃縮し、再度使用可能とする、めっき液の濃縮処理が行われている。
【０００４】
このような希釈されためっき液の濃縮に際しては、濃度管理は殆ど行われておらず、近似的に装置の濃縮時間などで推定し、運転されている。
しかし、ニッケルめっき液のように濃縮しすぎると、ホウ酸、ニッケル塩などの結晶等が析出して濃縮操作に支障を来たす種類の浴液では、管理体制が不充分な工場では採用できない状況にあった。
【０００５】
このように、希釈されためっき液の濃縮において、濃度管理を簡便に行うことができ、過濃縮などによる成分（結晶等）の析出などの不都合が生じないめっき液濃縮方法、及び、そのような濃縮を可能とするめっき液濃縮装置が求められていた。
【０００６】
【発明が解決しようとする課題】
本発明は、上記した従来の問題点を改善する、すなわち、希釈されためっき液の濃縮において、濃度管理を簡便に行うことができ、過濃縮などによる成分（結晶等）の析出などの不都合が生じないめっき液濃縮方法、及び、そのような濃縮を可能とするめっき液濃縮装置を提供することを目的とする。
【０００７】
【課題を解決するための手段】
本発明のめっき液濃縮装置は上記課題を解決するため、請求項１に記載の通り、希釈されためっき液を加熱・蒸発による濃縮処理により水分を除去して濃縮するめっき液濃縮方法において、被濃縮液の電気伝導度が所定値となったら濃縮処理を終了するめっき液濃縮方法であり、このような構成により、常に安定しためっき液の濃縮が可能となり、過濃縮による成分（結晶等）の析出などの問題の発生を未然に防ぐことが可能となる。
【０００８】
また、本発明のめっき液濃縮装置は上記課題を解決するため、請求項２に記載の通り、希釈されためっき液から水分を蒸発除去して濃縮するめっき液濃縮装置であって、被濃縮液を加熱し水分を蒸発させて濃縮処理をおこなう加熱・蒸発手段、及び、被濃縮液の電気伝導度を測定する電気伝導度測定手段を備えためっき液濃縮装置であり、このような構成により、常に安定しためっき液の濃縮処理が可能となり、過濃縮による成分（結晶等）の析出などの問題の発生を未然に防ぐことが可能となる。
【０００９】
さらに、このめっき液濃縮装置が、濃縮処理終了後に濃縮処理済みの被濃縮液を装置外に払い出す払い出し手段と、該払い出し後にめっき液濃縮装置内に希釈されためっき液を新たな被濃縮液として導入する、被濃縮液導入手段とを備えることにより、バッチ的ではなるものの連続的な処理が容易になる。
【００１０】
また、上記被濃縮液の電気伝導度が所定の範囲に達したときに濃縮処理を終了させる濃縮処理終了手段を備えることにより、連続無人運転が可能となる。
また、上記めっき液濃縮装置において、加熱・蒸発手段が、被濃縮液を加熱する加熱部、加熱された被濃縮液から水分を蒸発させる蒸発部、及び、加熱部と蒸発部との間に被濃縮液を強制的に循環させる被濃縮液循環手段を備え、さらに、被濃縮液導入手段によりめっき液濃縮装置内に希釈されためっき液が導入された後、装置運転終了後での装置内部での被濃縮液からの成分の析出を防ぐために、上記被濃縮液循環手段によって、上記加熱部と蒸発部との間に被濃縮液を強制的に循環させる析出防止運転を行い、次いで、めっき装置自体の運転を終了させる運転終了手段を有するものであれば、めっき液濃縮装置の運転を自動終了させることが可能となり、かつ、その後の停止期間中にも加熱・蒸発手段でのめっき液成分（結晶等）の析出が防止されるので、運転再開時にも、装置内の掃除や析出成分の除去などを必要とせずに行うことができる。
【００１１】
【発明の実施の形態】
めっき工場で実際に使用されている光沢ニッケルめっき液を原液として４種類採取し、それぞれを蒸留水により希釈したときの、電気伝導度の変化を東亜電波工業社製電気伝導率計ＣＭ−２Ａにより調べた。結果を原液ごとに記号を代えて図１に示す。
【００１２】
なお、これらめっき液（原液）は表１に示される組成になるよう調製されていたものであるが、実際に使用されていたものであるため、細かい組成、夾雑物等、また、選択された光沢剤の種類・配合量に違いがあり、そのために若干の電気伝導度の違いが生じていると考えられる。
【００１３】
【表１】

【００１４】
図１より、図１のような希釈倍率と電気伝導度との関係を各めっき液ごとに予め調べておくことにより、希釈されためっき液の希釈倍率を知ることができることが判る。また、上記では蒸留水を用いたが、めっき液の洗浄に用いられる工業用水を用いた場合でも同様の結果が得られた。
【００１５】
ここで、上記３種類のめっき液原液について、それぞれ適宜希釈した後、実験装置により、電気伝導度を測定しながら原液レベルに電気伝導度が復帰するまで加熱・濃縮を行ったところ、いずれの場合においてもニッケル濃度を目標とする濃度に対して±５ｇ／Ｌ以内に濃縮することができ、また、そのままめっき浴として用いることができる組成になることが確認された。
【００１６】
上記はニッケルめっき浴について述べたが、硬質クロムめっき液（サージェント浴）についても同様に、希釈時の電気伝導度への影響を調べた。結果を図２に示す。
【００１７】
図２により、クロムめっき液についても、ニッケルめっき液同様に、原液の電気伝導度と希釈液の電気伝導度とが判れば希釈倍率を知ることができることが判る。
【００１８】
実際にクロムめっき液についても、一旦希釈した後、電気伝導度が原液と同一レベルになるまで濃縮を行ったところ、原液同様にクロムめっきに用いることができる溶液とすることができた。
【００１９】
このような知見をもとに次に示すめっき液濃縮装置を設計した。
図３に本発明に係るめっき液濃縮装置の一例のブロック図を示す。
【００２０】
この例では被濃縮液を加熱し水分を蒸発させる加熱・蒸発手段Ａにより、希釈されためっき液（被濃縮液）は濃縮されるが、その濃縮の開始と共に電気伝導度測定手段Ｂは被濃縮液の電気伝導度の測定を開始し、濃縮処理終了手段Ｃはその被濃縮液の電気伝導度が所定の範囲（所定値）となったときに、加熱・蒸発手段Ａに対して加熱・蒸発処理（濃縮処理）を終了させる。
【００２１】
次いで濃縮処理終了後に払い出し手段Ｄにより濃縮処理済みの被濃縮液を装置外に払い出し、払い出し終了後、被濃縮液導入手段Ｅがめっき液濃縮装置内に希釈されためっき液を新たな被濃縮液として導入する。
【００２２】
被濃縮液の導入後、運転終了手段Ｆに運転終了指示がスイッチ、タイマーなどによって入力されていない場合には加熱・蒸発手段Ａが濃縮処理を再開し、次いで上記サイクルが繰り返される。
【００２３】
なお、この例では加熱・蒸発手段Ａが、被濃縮液を加熱する加熱部Ａ１、加熱された被濃縮液から水分を蒸発させる蒸発部Ａ２、及び、該加熱部と蒸発部との間に被濃縮液を強制的に循環させる被濃縮液循環手段Ａ３を備えていて、被濃縮液導入手段Ｅによりめっき液濃縮装置内に希釈されためっき液が導入されたときに、運転終了手段Ｆに運転終了指示が与えられていた場合には、装置運転終了後での装置内部での被濃縮液からの成分の析出を防ぐために、上記被濃縮液循環手段Ａ３によって、上記加熱部と蒸発部との間に被濃縮液を強制的に循環させる析出防止運転を行い、次いで、めっき液濃縮装置自体の運転を終了させるようになっている。
【００２４】
このようなめっき液濃縮装置の具体例について、詳細に説明する。
まず、本発明に係るめっき液濃縮装置の主要部について、モデル的に図４に示す。
【００２５】
図中符号１は蒸発部を示し、この蒸発部１には濃縮を要する希釈されためっき液（被濃縮液）が導入される。
【００２６】
蒸発部１には上下２つの連通通路２ａ、２ｂにより熱交換部２が接続され、蒸発部１から熱交換部２に供給された被濃縮液は熱交換部２に供給される水蒸気等の熱媒２ｃにより加熱され、蒸発部１に戻るようになっている。熱交換部２は蒸発部１と共に加熱・蒸発手段を構成している。
【００２７】
蒸発部１底部と熱交換部２底部とは、また循環ポンプ３ａを有する配管３により接続されていて、強制的に被濃縮液が循環するようになっていて、この配管３には電気伝導度測定手段として電気伝導度計３ｂが配されており、被濃縮液の電気伝導度が測定される。この配管３の蒸発部１底部側には電磁弁付きの排出バルブ１ａが設けられていて、濃縮終了液タンク（図示しない）に接続されている。
【００２８】
蒸発部１には上下２つの連通通路４ａ及び４ｂにより接続された液面計４が接続され、蒸発部１の液面の高さを高、中、低の三段階で把握できるようになっている。
【００２９】
蒸発部１の被濃縮液の液面上方には、被濃縮液を蒸発部１内に導入するための電磁弁式の被濃縮液導入バルブ１ｂ、さらにその上方に気化された水蒸気中のミストを除去するためのミスト除去部１ｃが設けられ、ミスト除去部上方には圧力計１ｄ及び系を常圧に戻すときに開放される電磁弁式の真空解除弁１ｅが設けられて、さらに連通通路５ａを介してコンデンサ部５に接続されている。
【００３０】
コンデンサ部５には熱交換器５ｂが設けられ、冷媒（水等）５ｄにより冷却されていて、蒸発部１上部から連通通路５ａを通ってコンデンサ部５に供給される水蒸気はこの熱交換器５ｂにより冷却されて凝結し、コンデンサ部５下部にドレンとなって溜まるようになっている。
【００３１】
コンデンサ部５底部には、電磁弁付きの排出バルブ５ｃが設けられていて、ドレンタンク（図示しない）に接続されている。なお、ドレンタンクに回収された水はめっき工程の水洗水などに再利用される。
【００３２】
コンデンサ部５はさらに配管６ａを介して真空ポンプ６が接続され、これら、蒸発部１、熱交換部２、液面計４、コンデンサ部５及びこれらを接続する通路は減圧可能となっていて、蒸発部１での濃縮が比較的低温で行われるようになっている。
【００３３】
次いで、本発明に係るめっき液濃縮装置の制御部をも含めた全体図（モデル図）を図５（ａ）に示す。
【００３４】
図中符号７は制御用マイコン（ＭＰＵ）であり、入力ポートＩ１〜Ｉ４（符号Ｐｉ１〜Ｐｉ３）、出力ポートＯ１〜Ｏ８（符号Ｐｏ１〜Ｐｏ８）、演算回路ＣＰＵ７ｃｐ、タイマや各種変数収納用揮発メモリＲＡＭ７ｒａ、及び、プログラムや各種定数格納用不揮発メモリＲＯＭ７ｒｏを有する。
【００３５】
不揮発メモリＲＯＭ７ｒｏには図５（ｂ）に示すように、濃縮処理終了判定用の電気伝導度値ｋ（原液の電気伝導度値あるいは許容できる希釈率（例えば希釈倍率が１以下）での電気伝導度値の値）、運転終了指令スイッチＳｗが操作されたかどうかの情報（初期値は０、操作された場合には１）、及び、装置運転終了後での装置内部での被濃縮液からの成分の析出を防ぐために、被濃縮液循環手段によって、上記加熱部と蒸発部との間に被濃縮液を強制的に循環させる析出防止運転を行うためのタイマＴが格納されている。
【００３６】
Ａ／Ｄ変換機能を有する入力ポートＩ１は電気伝導度計３ｂに、入力ポートＩ２およびＩ３は共に液面計に、また、入力ポートＩ１は運転終了指令スイッチＳｗにそれぞれ接続されている。
【００３７】
ＭＰＵ７は、これら入力ポートＩ２およびＩ３の値により、蒸発部１内の液面が高位置（入力ポートＩ１及びＩ２への入力は共に「ｏｎ」）、中位置（入力ポートＩ１及びＩ２への入力はそれぞれ「ｏｆｆ」及び「ｏｎ」）、あるいは下位置（入力ポートＩ１及びＩ２への入力は共に「ｏｆｆ」）のいずれかにあるかを知ることができる。
【００３８】
また、運転終了指令スイッチＳｗは装置の運転者が操作することにより、後述するＲＡＭ７ｒａのＳｖ（初期値は０）に「１」を格納することができ、このめっき液濃縮装置の運転を終了することができる。
【００３９】
一方、出力ポートＯ１は真空解除弁１ｅに接続され、出力ポートＯ１に「ｏｎ」信号が出力されると真空解除弁１ｅが開放され装置内部と外部とが連通状態になり、出力ポートＯ１に「ｏｆｆ」信号が出力されると真空解除弁１ｅが閉鎖され、装置内部は減圧可能となる。
【００４０】
出力ポートＯ２はコンデンサ５の底部に設けられた排出バルブ５ｃに接続され、出力ポートＯ２に「ｏｎ」信号が出力されると排出バルブ５ｃが開放されコンデンサ５内のドレンは外部に排出され、出力ポートＯ２に「ｏｆｆ」信号が出力されると排出バルブ５ｃは閉鎖される。
【００４１】
出力ポートＯ３は蒸発部１底部に設けられた排出バルブ１ａに接続され、出力ポートＯ３に「ｏｎ」信号が出力されると排出バルブ１ａが開放され蒸発部１内の濃縮処理済みの液は外部に排出され、出力ポートＯ３に「ｏｆｆ」信号が出力されると排出バルブ５ｃは閉鎖される。
【００４２】
出力ポートＯ４は蒸発部１液面上に設けられた被濃縮液導入バルブ１ｂに接続され、出力ポートＯ４に「ｏｎ」信号が出力されると被濃縮液導入バルブ１ｂが開放され蒸発部１内部に被濃縮液が外部から導入され、出力ポートＯ４に「ｏｆｆ」信号が出力されると被濃縮液導入バルブ１ｂは閉鎖され、被濃縮液の外部からの導入が終了する。
【００４３】
出力ポートＯ５は真空ポンプ６に接続され、出力ポートＯ５に「ｏｎ」信号が出力されると真空ポンプ６が稼働し、装置内の減圧が開始され、出力ポートＯ５に「ｏｆｆ」信号が出力されると真空ポンプ６が停止する。
【００４４】
出力ポートＯ６はコンデンサ５の冷媒５ｄの制御機構（電磁弁等から構成される。図示しない）に接続され、出力ポートＯ６に「ｏｎ」信号が出力されると冷媒５ｄがコンデンサ５に供給され、出力ポートＯ６に「ｏｆｆ」信号が出力されるとコンデンサ５への冷媒５ｄの供給が停止する。
【００４５】
出力ポートＯ７は熱交換部２の熱媒２ｃの制御機構（電磁弁等から構成される。図示しない）に接続され、出力ポートＯ７に「ｏｎ」信号が出力されると熱媒２ｃが熱交換部２ｃに供給され、出力ポートＯ７に「ｏｆｆ」信号が出力されると熱交換部２ｃへの熱媒２ｃの供給が停止する。
【００４６】
出力ポートＯ８は蒸発部１底部と熱交換部２底部とを連結する配管３に設けられた循環ポンプ３ａに接続され、出力ポートＯ８に「ｏｎ」信号が出力されると循環ポンプ３ａが稼働し、出力ポートＯ８に「ｏｆｆ」信号が出力されると循環ポンプ３ａが停止する。
【００４７】
このような本発明のめっき液濃縮装置はそのＭＰＵ７内ＲＯＭ７ｒｏに記憶されたプログラムにより図６に示すフローチャートにしたがって運転される。
ＲＯＭ７ｒｏには、プログラム以外に析出防止運転を行う時間ｔ（通常１０分〜１５分程度）が記憶されている。
【００４８】
以下、蒸発部１内に被濃縮液が既に仕込まれていて、真空解除弁１ｅ、コンデンサ５底部の排出バルブ５ｃ、蒸発部１底部の排出バルブ１ａ、被濃縮液導入バルブ１ｂが閉鎖されている状態から運転される場合について説明する。（なお、下記説明は本発明に係る装置動作の大まかな流れを説明するものであって、実際の装置でノウハウ的に必要とされる事項、例えば１つのステップでの弁の開閉、ポンプの稼働・停止同士間の微妙な時差設定等は省略してあるが、これら微妙な調整はＲＡＭ７ｒａのその他のタイマやＲＯＭ７ｒｏに適宜記憶される定数を併用するプログラムの修正等で容易に対応できる）
【００４９】
装置運転開始後、ステップＳ１で出力ポートＯ５、Ｏ６、Ｏ７及びＯ８に信号「ｏｎ」が出力され、真空ポンプ６及び循環ポンプ３がそれぞれ稼働して装置内が減圧状態に保たれるともに配管３内に被濃縮液が強制的に流され、コンデンサ５に冷媒５ｄが、熱交換部２へは熱媒２ｃがそれぞれ供給され、濃縮処理が開始する。
【００５０】
ステップＳ２で電気伝導度計３ｂに接続された入力ポートＩ１からの値Ｉ１がチェックされ、この値Ｉ１が予めめっき液原液を基準に定め、ＲＯＭ３ｒｏに記憶された値ｋと比較され、充分な濃縮が行われたとされる所定の範囲に入っているかどうかが調べられる。
【００５１】
濃縮が充分であればステップＳ３に進み、不充分であればステップＳ２を繰り返す。
ステップＳ３で、出力ポートＯ５、Ｏ６、Ｏ７及びＯ８に信号「ｏｆｆ」が出力され、真空ポンプ６及び循環ポンプ３がそれぞれ停止し、コンデンサ５への冷媒５ｄの供給、及び、熱交換部２への熱媒２ｃの供給がそれぞれ停止される。
【００５２】
次いでステップＳ４で出力ポートＯ１、Ｏ２及びＯ３に信号「ｏｎ」が出力され、真空解除弁１ｅが開放されて装置内の減圧が解除されると共にコンデンサ５の排出バルブ５が開放されコンデンサ５内部のドレンが排出され、さらに、蒸発部１から濃縮処理済みの液が排出される。
【００５３】
ステップＳ５で入力ポートＩ２の値がチェックされ、その値が「ｏｆｆ」である、すなわち蒸発部１内の液面が下位置以下であることが確認されるまでステップＳ５が繰り返され、確認された場合にはステップＳ６に進む。
【００５４】
ステップＳ６では出力ポートＯ３に信号「ｏｆｆ」が出力され、蒸発部１底部の排出バルブ１ａが閉鎖され、次いでステップＳ７で出力ポートＯ４に信号「ｏｎ」が出力されて被濃縮液導入バルブ１ｂが開放され蒸発部１に新たな被濃縮液の導入が開始される。
【００５５】
ステップＳ８で入力ポートＩ３の値がチェックされ、蒸発部１内の被濃縮液の液面が液面計３でチェックされ高位置となった、すなわち入力ポートＩ３の値が「ｏｎ」となるまでステップＳ８が繰り返され、新たな被濃縮液の導入が継続される。
【００５６】
新たな被濃縮液の導入の結果が所定の液面高さまで達した後ステップＳ９で出力ポートＯ４に信号「ｏｆｆ」が出力されて、新たな被濃縮液の導入が終了する。
【００５７】
ステップＳ１０で、運転終了指令スイッチＳｗが操作されていたかどうかの情報（初期値は０、操作された場合には１）が格納されたＲＡＭ７ｒａ内変数Ｓｖが調べられ、操作されていない場合、すなわちＳｖの値が０のときにはステップＳ１１に進み、操作されていた場合、すなわちＳＶの値が１のときにはステップＳ２０に進む。
【００５８】
ステップＳ１１では出力ポートＯ１及びＯ２に信号「ｏｆｆ」が出力されて、真空解除弁１ｅ及びコンデンサ５の排出バルブ５ｃが閉鎖され、次いで、ステップＳ１に戻り、上記ステップＳ１〜Ｓ１０が順次繰り返される。
【００５９】
一方、ステップＳ２０では出力ポートＯ８に信号「ｏｎ」が出力されて循環ポンプ３ａが動作開始して、装置運転終了後での装置内部での被濃縮液からの成分の析出を防ぐために、上記加熱部と蒸発部との間に被濃縮液を強制的に循環させる析出防止運転が開始される。
【００６０】
ステップＳ２１でタイマＴがリセット後スタートし、このタイマＴの値が予めＲＯＭ７ｒｏ内に格納されたｔの値に達する迄ステップＳ２２が繰り返されて析出防止運転が継続し、タイマＴの値がｔの値に達した後、ステップＳ２３で出力ポート０１、０２及びＯ８に信号「ｏｆｆ」が出力されて真空解除弁１ｅ及び排出バルブ５ｃが閉じられるとともに循環ポンプ３ａが停止し、装置の運転が終了する。
【００６１】
このような本発明に係る装置において、蒸発部１及び熱交換部２が加熱・蒸発手段Ａに、電気伝導度計３ｂが電気伝導度測定手段Ｂに、ＭＰＵ７の一部の機能が濃縮処理（加熱・蒸発処理）に、排出バルブ１ａが払い出し手段Ｄに、被濃縮液導入バルブ１ｂが被濃縮液導入手段Ｅに、それぞれ該当することが判る。
【００６２】
また、上記加熱・蒸発手段が、被濃縮液を加熱する加熱部Ａ１として熱交換部２、加熱された被濃縮液から水分を蒸発させる蒸発部Ａ２として蒸発部１、及び、該加熱部である熱交換部２と蒸発部１との間に被濃縮液を強制的に循環させる被濃縮液循環手段Ａ３として蒸発部１底部と熱交換部２底部とを接続する循環ポンプ３ａを有する配管３を備え、さらに、被濃縮液導入手段Ｅによりめっき液濃縮装置内に希釈されためっき液が導入された後、装置運転終了後での装置内部での被濃縮液からの成分の析出（特に加熱部及びその付近で生じやすい）を防ぐために、上記被濃縮液循環手段Ａ３によって、上記加熱部Ａ１と蒸発部Ａ２との間に被濃縮液を強制的に循環させる析出防止運転を行い、次いで、めっき液濃縮装置自体の運転を終了させる運転終了手段ＦにはＭＰＵ７の一部の機能及びスイッチＳｗがそれぞれ該当する。
【００６３】
【発明の効果】
本発明のめっき液濃縮装置は希釈されためっき液を加熱による濃縮処理により水分を蒸発させて濃縮するめっき液濃縮方法において、被濃縮液の電気伝導度が所定値となったら濃縮処理を終了するめっき液濃縮方法であり、このような構成により、常に安定しためっき液の濃縮が可能となり、過濃縮による成分（結晶等）の析出などの問題の発生を未然に防ぐことが可能となる。
【００６４】
また、本発明のめっき液濃縮装置は希釈されためっき液から水分を蒸発除去して濃縮するめっき液濃縮装置であって、被濃縮液を加熱し水分を蒸発させて濃縮処理をおこなう加熱・蒸発手段、及び、被濃縮液の電気伝導度を測定する電気伝導度測定手段を備えためっき液濃縮装置であり、このような構成により、常に安定しためっき液の濃縮が可能となり、過濃縮による成分（結晶等）の析出などの問題の発生を未然に防ぐことが可能となる優れためっき液濃縮装置である。
【図面の簡単な説明】
【図１】４種類のニッケルめっき液原液を希釈したときの、その電気伝導度の変化を調べた結果を示す図である。
【図２】クロムめっき液原液を希釈したときの、その電気伝導度の変化を調べた結果を示す図である。
【図３】本発明に係るめっき液濃縮装置のブロック図である。
【図４】本発明に係るめっき液濃縮装置の一例の主要部を示すモデル図である。
【図５】本発明に係るめっき液濃縮装置の一例の制御部を併せて記載した主モデル図である。
【図６】図５の装置の動作の一例のフローチャート図である。
【符号の説明】
１　蒸発部
１ｂ　被濃縮液導入バルブ
１ｃ　ミスト除去部
１ｄ　圧力計
１ｅ　真空解除弁
２　熱交換部
２ａ、２ｂ　蒸発部１と熱交換部２とを接続する連通通路
３　配管
３ａ　循環ポンプ
３ｂ　電気伝導度計
４　液面計
４ａ、４ｂ　蒸発部１と液面計４とを接続する連通通路
５　　コンデンサ部
５ａ　連通通路
５ｂ　熱交換器
５ｃ　排出バルブ
６　　真空ポンプ
６ａ　配管
７　　制御用マイコン（ＭＰＵ）
Ｐｉ１〜Ｐｉ３　　入力ポートＩ１〜Ｉ３
Ｐｏ１〜Ｐｏ８　　出力ポートＯ１〜Ｏ８
７ｃｐ　演算回路ＣＰＵ
７ｒａ　ＲＡＭ
７ｒｏ　ＲＯＭ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for concentrating a plating solution used in a nickel plating bath, a chromium plating bath, or the like.
[0002]
[Prior art]
In recent years, environmental protection technology has been developed in accordance with the concept of a recycling-oriented society. Recycling is the basis of such a recycling-based society, and zero emission (zero waste) in which 100% recycling is achieved is ideal.
[0003]
In the surface treatment and plating which are the technical fields to which the present invention belongs, the plating solution concentrated from the plating bath, diluted in a water washing tank and the like, and concentrated to make it usable again. Has been done.
[0004]
At the time of concentration of such a diluted plating solution, concentration control is hardly performed, and operation is performed by estimating approximately the concentration time of the apparatus.
However, if the concentration is too high like nickel plating solution, crystals of boric acid, nickel salt, etc. will precipitate out, which will hinder the concentration operation. there were.
[0005]
As described above, in the concentration of the diluted plating solution, the concentration can be easily controlled, and a plating solution concentration method that does not cause inconvenience such as precipitation of components (crystals or the like) due to overconcentration or the like, There has been a demand for a plating solution concentrating device that enables concentration.
[0006]
[Problems to be solved by the invention]
The present invention improves the above-mentioned conventional problems, that is, concentration of diluted plating solution can be easily controlled, and disadvantages such as precipitation of components (crystals and the like) due to overconcentration and the like can be avoided. It is an object of the present invention to provide a plating solution concentrating method that does not generate a plating solution and a plating solution concentrating apparatus that enables such concentration.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a plating solution concentrating apparatus of the present invention, as described in claim 1, comprises a plating solution concentrating method for concentrating a diluted plating solution by removing water by a concentration treatment by heating and evaporating. This is a plating solution concentrating method in which the concentration process is terminated when the electric conductivity of the concentrated solution reaches a predetermined value. With such a configuration, the plating solution can always be stably concentrated, and components (crystals and the like) due to overconcentration can be reduced. It is possible to prevent problems such as precipitation from occurring.
[0008]
In order to solve the above-mentioned problems, a plating solution concentrating apparatus of the present invention is a plating solution concentrating apparatus for evaporating and removing water from a diluted plating solution and concentrating the plating solution, wherein Heating and evaporating means for heating and evaporating water to perform a concentration process, and a plating solution concentrating apparatus equipped with an electric conductivity measuring means for measuring the electric conductivity of the liquid to be concentrated, with such a configuration, It is possible to always perform a stable concentration treatment of the plating solution, and it is possible to prevent problems such as precipitation of components (crystals and the like) due to overconcentration.
[0009]
Further, the plating solution concentrating device discharges the concentrated solution after the concentration process to the outside of the device after the concentration process is completed, and the plating solution diluted in the plating solution concentrating device after the dispensing is used as a new concentrated solution. By providing the liquid to be concentrated introduction means, which is introduced as a batch, continuous processing is facilitated though it is batchwise.
[0010]
In addition, the provision of the concentration processing termination means for terminating the concentration processing when the electric conductivity of the liquid to be concentrated reaches the predetermined range enables continuous unmanned operation.
Further, in the plating solution concentrating apparatus, the heating / evaporating means includes a heating unit for heating the liquid to be concentrated, an evaporation unit for evaporating water from the heated liquid to be concentrated, and a coating unit between the heating unit and the evaporation unit. A concentrated liquid circulating means for forcibly circulating the concentrated liquid is provided, and further, after the diluted plating liquid is introduced into the plating liquid concentrating device by the concentrated liquid introducing means, inside the apparatus after the operation of the apparatus is completed. In order to prevent the deposition of components from the concentrated liquid, the concentrated liquid circulating means performs a precipitation preventing operation of forcibly circulating the concentrated liquid between the heating unit and the evaporating unit, and then performs a plating operation. If there is an operation ending means for ending the operation of itself, the operation of the plating solution concentrating device can be automatically stopped, and the plating solution component ( Precipitation of crystals, etc.) Since is prevented, even when resuming operation can be performed without requiring such removal of cleaning and deposition component in the device.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Four kinds of bright nickel plating solution actually used in a plating factory were collected as stock solutions, and the change in electric conductivity when each was diluted with distilled water was measured by an electric conductivity meter CM-2A manufactured by Toa Denpa Kogyo Co., Ltd. Examined. The results are shown in FIG. 1 with different symbols for each stock solution.
[0012]
Although these plating solutions (stock solutions) were prepared to have the compositions shown in Table 1, since they were actually used, they had fine compositions, impurities, etc. It is considered that there is a difference in the type and blending amount of the brightener, which causes a slight difference in electric conductivity.
[0013]
[Table 1]

[0014]
From FIG. 1, it is understood that the dilution ratio of the diluted plating solution can be known by previously examining the relationship between the dilution ratio and the electric conductivity as shown in FIG. 1 for each plating solution. Although distilled water was used in the above description, similar results were obtained when industrial water used for washing the plating solution was used.
[0015]
Here, the above three kinds of plating solution stock solutions were appropriately diluted, and then heated and concentrated by an experimental apparatus while measuring the electric conductivity until the electric conductivity returned to the stock solution level. It was also confirmed that the composition could be concentrated within ± 5 g / L with respect to the target concentration, and that the composition could be used as a plating bath as it was.
[0016]
Although the above description has been made with respect to the nickel plating bath, the influence of the hard chromium plating solution (Surgent bath) on the electric conductivity at the time of dilution was similarly examined. FIG. 2 shows the results.
[0017]
FIG. 2 shows that the dilution ratio can be determined for the chromium plating solution as well as the nickel plating solution if the electric conductivity of the stock solution and the electric conductivity of the diluting solution are known.
[0018]
Actually, the chromium plating solution was once diluted and then concentrated until the electric conductivity became the same level as that of the undiluted solution. As a result, a solution which could be used for chromium plating like the undiluted solution could be obtained.
[0019]
Based on such knowledge, the following plating solution concentrating device was designed.
FIG. 3 shows a block diagram of an example of the plating solution concentrating apparatus according to the present invention.
[0020]
In this example, the diluted plating solution (liquid to be concentrated) is concentrated by the heating / evaporating means A which heats the liquid to be concentrated and evaporates the water. The measurement of the electric conductivity of the liquid starts, and the concentration ending means C heats and evaporates the heating and evaporating means A when the electric conductivity of the liquid to be concentrated falls within a predetermined range (predetermined value). The processing (concentration processing) is terminated.
[0021]
Then, after the concentration process is completed, the concentrated solution to be concentrated is discharged to the outside of the apparatus by the dispensing unit D, and after the dispensing is completed, the concentrated solution introduction unit E transfers the plating solution diluted into the plating solution concentrating device to a new concentrated solution. Introduce as.
[0022]
After the introduction of the liquid to be concentrated, if an operation end instruction has not been input to the operation end means F by a switch, a timer, or the like, the heating / evaporation means A restarts the concentration process, and then the above cycle is repeated.
[0023]
In this example, the heating / evaporation means A includes a heating section A1 for heating the liquid to be concentrated, an evaporation section A2 for evaporating water from the heated liquid to be concentrated, and a heating section A1 between the heating section and the evaporation section. A concentrated liquid circulating means A3 for forcibly circulating the concentrated liquid is provided, and when the diluted plating liquid is introduced into the plating liquid concentrating apparatus by the concentrated liquid introducing means E, the operation is terminated by the operation ending means F. When the end instruction has been given, in order to prevent the precipitation of components from the liquid to be concentrated inside the apparatus after the operation of the apparatus is completed, the concentrated liquid circulating means A3 connects the heating section and the evaporating section to each other. In the meantime, a precipitation preventing operation for forcibly circulating the liquid to be concentrated is performed, and then the operation of the plating solution concentrating apparatus itself is terminated.
[0024]
A specific example of such a plating solution concentrating device will be described in detail.
First, FIG. 4 schematically shows a main part of a plating solution concentrating apparatus according to the present invention.
[0025]
In the drawing, reference numeral 1 denotes an evaporating section, into which a diluted plating solution (concentrated liquid) requiring concentration is introduced.
[0026]
A heat exchange section 2 is connected to the evaporator section 1 by two upper and lower communication passages 2a and 2b. The liquid to be concentrated supplied from the evaporator section 1 to the heat exchange section 2 is heated by steam or the like supplied to the heat exchange section 2. It is heated by the medium 2c and returns to the evaporating section 1. The heat exchanging section 2 constitutes a heating / evaporating means together with the evaporating section 1.
[0027]
The bottom of the evaporating section 1 and the bottom of the heat exchanging section 2 are connected by a pipe 3 having a circulating pump 3a so that the liquid to be concentrated is circulated forcibly. An electric conductivity meter 3b is provided as a measuring means, and the electric conductivity of the liquid to be concentrated is measured. A discharge valve 1a with a solenoid valve is provided on the bottom side of the evaporating section 1 of the pipe 3, and is connected to a concentrated liquid tank (not shown).
[0028]
The evaporator 1 is connected to a liquid level gauge 4 connected by two upper and lower communication passages 4a and 4b, so that the liquid level of the evaporator 1 can be grasped in three stages of high, medium and low. I have.
[0029]
Above the liquid surface of the liquid to be concentrated in the evaporating section 1, a concentrated liquid introducing valve 1 b of a solenoid valve type for introducing the liquid to be concentrated into the evaporating section 1, and further, mist in the vaporized vapor is further above. A mist removing unit 1c for removing the mist is provided, and a pressure gauge 1d and a solenoid valve type vacuum release valve 1e which is opened when the system is returned to normal pressure are provided above the mist removing unit. Is connected to the capacitor section 5 via the.
[0030]
The condenser section 5 is provided with a heat exchanger 5b, which is cooled by a refrigerant (water or the like) 5d and supplied to the condenser section 5 from the upper portion of the evaporator section 1 through the communication passage 5a. Then, it is cooled and condensed, and drains and accumulates in the lower part of the condenser portion 5.
[0031]
A discharge valve 5c with an electromagnetic valve is provided at the bottom of the condenser section 5, and is connected to a drain tank (not shown). The water collected in the drain tank is reused for washing water in the plating step.
[0032]
The condenser section 5 is further connected to a vacuum pump 6 via a pipe 6a, and the evaporating section 1, the heat exchange section 2, the liquid level gauge 4, the condenser section 5 and a passage connecting these can be decompressed. The concentration in the evaporating section 1 is performed at a relatively low temperature.
[0033]
Next, FIG. 5A shows an overall view (model diagram) including the control unit of the plating solution concentrating apparatus according to the present invention.
[0034]
In the figure, reference numeral 7 denotes a control microcomputer (MPU), which includes input ports I1 to I4 (reference signs Pi1 to Pi3), output ports O1 to O8 (reference signs Po1 to Po8), an arithmetic circuit CPU 7cp, a timer and a volatile memory for storing various variables. It has a RAM 7ra and a non-volatile memory ROM 7ro for storing programs and various constants.
[0035]
As shown in FIG. 5B, the non-volatile memory ROM 7ro stores an electric conductivity value k (an electric conductivity value of an undiluted solution or an electric conductivity at an allowable dilution rate (for example, dilution ratio is 1 or less)) for judging completion of the concentration process. (The value of the degree value), information as to whether or not the operation end command switch Sw has been operated (the initial value is 0, 1 when operated), and information from the liquid to be concentrated inside the apparatus after the operation of the apparatus has been completed. In order to prevent precipitation of components, a timer T for performing a precipitation prevention operation of forcibly circulating the concentrated liquid between the heating section and the evaporating section by the concentrated liquid circulating means is stored.
[0036]
The input port I1 having the A / D conversion function is connected to the electric conductivity meter 3b, the input ports I2 and I3 are both connected to the liquid level meter, and the input port I1 is connected to the operation end command switch Sw.
[0037]
According to the values of these input ports I2 and I3, the MPU 7 sets the liquid level in the evaporating section 1 to a high position (inputs to the input ports I1 and I2 are both "on") and a middle position (inputs to the input ports I1 and I2). Can be known as “off” and “on” respectively) or in the lower position (the inputs to the input ports I1 and I2 are both “off”).
[0038]
The operation end command switch Sw can store "1" in Sv (initial value: 0) of the RAM 7ra, which will be described later, by operating the apparatus driver, and terminates the operation of the plating solution concentrating apparatus. be able to.
[0039]
On the other hand, the output port O1 is connected to the vacuum release valve 1e, and when an "on" signal is output to the output port O1, the vacuum release valve 1e is opened to establish a communication state between the inside and the outside of the apparatus. When the "off" signal is output, the vacuum release valve 1e is closed, and the inside of the apparatus can be depressurized.
[0040]
The output port O2 is connected to a discharge valve 5c provided at the bottom of the condenser 5. When an "on" signal is output to the output port O2, the discharge valve 5c is opened and the drain in the condenser 5 is discharged to the outside. When the "off" signal is output to the port O2, the discharge valve 5c is closed.
[0041]
The output port O3 is connected to a discharge valve 1a provided at the bottom of the evaporator 1, and when an "on" signal is output to the output port O3, the discharge valve 1a is opened, and the concentrated liquid in the evaporator 1 is discharged to the outside. When the "off" signal is output to the output port O3, the discharge valve 5c is closed.
[0042]
The output port O4 is connected to the concentrated liquid introduction valve 1b provided on the liquid level of the evaporating section 1. When an "on" signal is output to the output port O4, the concentrated liquid introducing valve 1b is opened and the inside of the evaporating section 1 is opened. When the “concentrated liquid” is introduced from the outside and the “off” signal is output to the output port O4, the concentrated liquid introduction valve 1b is closed, and the introduction of the concentrated liquid from the outside ends.
[0043]
The output port O5 is connected to the vacuum pump 6, and when the "on" signal is output to the output port O5, the vacuum pump 6 is activated, the pressure in the apparatus is started, and the "off" signal is output to the output port O5. Then, the vacuum pump 6 stops.
[0044]
The output port O6 is connected to a control mechanism (including an electromagnetic valve or the like, not shown) for controlling the refrigerant 5d of the condenser 5, and when an “on” signal is output to the output port O6, the refrigerant 5d is supplied to the condenser 5, When the "off" signal is output to the output port O6, the supply of the refrigerant 5d to the condenser 5 is stopped.
[0045]
The output port O7 is connected to a control mechanism (including an electromagnetic valve or the like, not shown) for controlling the heat medium 2c of the heat exchange unit 2, and when an "on" signal is output to the output port O7, the heat medium 2c exchanges heat. When the “off” signal is output to the output port O7 and supplied to the unit 2c, the supply of the heat medium 2c to the heat exchange unit 2c is stopped.
[0046]
The output port O8 is connected to a circulation pump 3a provided in the pipe 3 connecting the bottom of the evaporating section 1 and the bottom of the heat exchange section 2. When an "on" signal is output to the output port O8, the circulation pump 3a operates. When the "off" signal is output to the output port O8, the circulation pump 3a stops.
[0047]
Such a plating solution concentrating apparatus of the present invention is operated according to a flowchart shown in FIG. 6 by a program stored in the ROM 7ro in the MPU 7.
The ROM 7ro stores a time t (usually about 10 to 15 minutes) for performing the precipitation prevention operation in addition to the program.
[0048]
Hereinafter, the liquid to be concentrated is already charged in the evaporating section 1, and the vacuum release valve 1e, the discharge valve 5c at the bottom of the condenser 5, the discharge valve 1a at the bottom of the evaporator 1, and the valve 1b for introducing the concentrated liquid are closed. A case where the vehicle is driven from the state will be described. (Note that the following description is intended to explain the general flow of the operation of the apparatus according to the present invention, and to know what is required in an actual apparatus in terms of know-how, for example, opening and closing a valve in one step, operating a pump. -Although the delicate time difference setting between the stops and the like are omitted, these delicate adjustments can be easily dealt with by modifying other timers of the RAM 7ra or a program using the constants appropriately stored in the ROM 7ro.
[0049]
After the start of the operation of the apparatus, a signal "on" is output to the output ports O5, O6, O7 and O8 in step S1, the vacuum pump 6 and the circulation pump 3 are operated to keep the inside of the apparatus in a reduced pressure state and the piping 3 The liquid to be concentrated is forcibly flowed into the inside, the refrigerant 5 d is supplied to the condenser 5, and the heat medium 2 c is supplied to the heat exchange unit 2, and the concentration process is started.
[0050]
In step S2, the value I1 from the input port I1 connected to the electric conductivity meter 3b is checked, and this value I1 is determined in advance with reference to the undiluted plating solution, and is compared with the value k stored in the ROM 3ro for sufficient concentration. It is checked whether it is within a predetermined range where it is assumed that the operation has been performed.
[0051]
If the concentration is sufficient, the process proceeds to step S3. If the concentration is insufficient, step S2 is repeated.
In step S3, the signal “off” is output to the output ports O5, O6, O7, and O8, the vacuum pump 6 and the circulation pump 3 are stopped, respectively, to supply the refrigerant 5d to the condenser 5, and to the heat exchange unit 2. The supply of the heat medium 2c is stopped.
[0052]
Next, in step S4, a signal "on" is output to the output ports O1, O2, and O3, the vacuum release valve 1e is opened to release the pressure reduction in the apparatus, and the discharge valve 5 of the condenser 5 is opened to open the inside of the condenser 5. The drain is discharged, and the liquid after the concentration treatment is discharged from the evaporating section 1.
[0053]
In step S5, the value of the input port I2 is checked, and step S5 is repeated until it is confirmed that the value is "off", that is, that the liquid level in the evaporator 1 is below the lower position. In this case, the process proceeds to step S6.
[0054]
In step S6, the signal "off" is output to the output port O3, the discharge valve 1a at the bottom of the evaporator 1 is closed, and then in step S7, the signal "on" is output to the output port O4, and the concentrated liquid introduction valve 1b is opened. It is opened and the introduction of a new liquid to be concentrated into the evaporating section 1 is started.
[0055]
In step S8, the value of the input port I3 is checked, and the liquid level of the liquid to be concentrated in the evaporating section 1 is checked by the liquid level gauge 3 to reach a high position, that is, until the value of the input port I3 becomes "on". Step S8 is repeated, and introduction of a new liquid to be concentrated is continued.
[0056]
After the result of the introduction of the new liquid to be concentrated reaches the predetermined liquid level, a signal “off” is output to the output port O4 in step S9, and the introduction of the new liquid to be concentrated is completed.
[0057]
In step S10, the variable Sv in the RAM 7ra storing information as to whether or not the operation end command switch Sw has been operated (the initial value is 0, and 1 if the operation has been performed) is checked. When the value of SV is 0, the process proceeds to step S11. When the operation has been performed, that is, when the value of SV is 1, the process proceeds to step S20.
[0058]
In step S11, a signal "off" is output to the output ports O1 and O2, and the vacuum release valve 1e and the discharge valve 5c of the condenser 5 are closed. Then, the process returns to step S1, and the above steps S1 to S10 are sequentially repeated.
[0059]
On the other hand, in step S20, the signal "on" is output to the output port O8, and the circulation pump 3a starts operating. In order to prevent the deposition of components from the liquid to be concentrated inside the apparatus after the operation of the apparatus, the heating is performed. A precipitation prevention operation for forcibly circulating the liquid to be concentrated between the section and the evaporation section is started.
[0060]
In step S21, after the timer T is reset and started, the step S22 is repeated until the value of the timer T reaches the value of t stored in advance in the ROM 7ro, and the deposition prevention operation is continued. After reaching the value, the signal "off" is output to the output ports 01, 02 and O8 in step S23, the vacuum release valve 1e and the discharge valve 5c are closed, the circulation pump 3a is stopped, and the operation of the apparatus is ended. .
[0061]
In such an apparatus according to the present invention, the evaporating unit 1 and the heat exchanging unit 2 are used for the heating / evaporating means A, the electric conductivity meter 3b is used for the electric conductivity measuring means B, and a part of the function of the MPU 7 is concentrated ( It can be seen that the discharge valve 1a corresponds to the discharging means D and the concentrated liquid introduction valve 1b corresponds to the concentrated liquid introduction means E during the heating / evaporation process.
[0062]
The heating / evaporating means is the heat exchange unit 2 as the heating unit A1 for heating the liquid to be concentrated, the evaporating unit 1 as the evaporation unit A2 for evaporating water from the heated liquid to be concentrated, and the heating unit. A pipe 3 having a circulation pump 3a connecting the bottom of the evaporator 1 and the bottom of the heat exchanger 2 as a concentrated liquid circulating means A3 for forcibly circulating the liquid to be concentrated between the heat exchanger 2 and the evaporator 1. Further, after the diluted plating solution is introduced into the plating solution concentrating apparatus by the concentrated solution introducing means E, precipitation of components from the concentrated solution inside the apparatus after the operation of the apparatus is completed (particularly the heating unit And the vicinity thereof), the concentrated liquid circulating means A3 performs a deposition preventing operation in which the concentrated liquid is forcibly circulated between the heating section A1 and the evaporating section A2. The operation of the liquid concentrator itself is terminated. That operation termination means F Some features and switches Sw of MPU7 corresponds respectively.
[0063]
【The invention's effect】
In the plating solution concentrating apparatus of the present invention, in the plating solution concentrating method in which the diluted plating solution is concentrated by evaporating water by a concentration process by heating, the concentration process ends when the electric conductivity of the solution to be concentrated reaches a predetermined value. This is a plating solution concentration method. With such a configuration, it is possible to always stably concentrate the plating solution, and it is possible to prevent problems such as precipitation of components (crystals and the like) due to overconcentration.
[0064]
Further, the plating solution concentrating device of the present invention is a plating solution concentrating device for evaporating and removing water from a diluted plating solution and concentrating the solution. Means, and a plating solution concentrating device provided with an electric conductivity measuring means for measuring the electric conductivity of the solution to be concentrated, by such a configuration, it is possible to always stable plating solution concentration, components due to overconcentration It is an excellent plating solution concentrating device that can prevent problems such as precipitation of (crystals and the like) from occurring.
[Brief description of the drawings]
FIG. 1 is a diagram showing the results of examining changes in electric conductivity when four types of undiluted nickel plating solutions are diluted.
FIG. 2 is a diagram showing a result of examining a change in electric conductivity when a chrome plating solution stock solution is diluted.
FIG. 3 is a block diagram of a plating solution concentrating apparatus according to the present invention.
FIG. 4 is a model diagram showing a main part of an example of a plating solution concentrating apparatus according to the present invention.
FIG. 5 is a main model diagram additionally illustrating a control unit of an example of a plating solution concentrating apparatus according to the present invention.
FIG. 6 is a flowchart illustrating an example of the operation of the apparatus in FIG. 5;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Evaporation part 1b Concentrated liquid introduction valve 1c Mist removal part 1d Pressure gauge 1e Vacuum release valve 2 Heat exchange part 2a, 2b Communication passage 3 connecting evaporation part 1 and heat exchange part 2 Pipe 3a Circulation pump 3b Electric conductivity Total 4 Level gauges 4a, 4b Communication path 5 connecting evaporating section 1 and level gauge 4 Capacitor section 5a Communication path 5b Heat exchanger 5c Discharge valve 6 Vacuum pump 6a Pipe 7 Control microcomputer (MPU)
Pi1 to Pi3 input ports I1 to I3
Po1 to Po8 Output ports O1 to O8
7 cp arithmetic circuit CPU
7ra RAM
7ro ROM

Claims

A plating solution concentrating method for concentrating a diluted plating solution by removing water by a concentration process by heating, wherein the concentration process is terminated when the electric conductivity of the solution to be concentrated reaches a predetermined value. Method.

A plating solution concentrating device for evaporating and removing water from a diluted plating solution and concentrating the plating solution,
A heating and evaporating means for heating the liquid to be concentrated and evaporating water to perform a concentration treatment, and
A plating solution concentrating device comprising an electric conductivity measuring means for measuring electric conductivity of a liquid to be concentrated.

Discharging means for discharging the concentrated liquid after concentration processing to the outside of the apparatus after completion of the concentration processing,
3. The plating solution concentrating device according to claim 2, further comprising a concentrated solution introducing means for introducing the diluted plating solution into the plating solution concentrating device as a new concentrated solution after the dispensing.

The plating solution concentrating apparatus according to claim 2 or 3, further comprising a concentration processing ending means for terminating the concentration processing when the electric conductivity of the liquid to be concentrated reaches a predetermined range.

The heating / evaporating means includes a heating section for heating the liquid to be concentrated, an evaporation section for evaporating water from the heated liquid to be concentrated, and a forced circulation of the liquid to be concentrated between the heating section and the evaporation section. The liquid to be concentrated is provided with a circulating means,
After the diluted plating solution is introduced into the plating solution concentrating apparatus by the concentrated solution introducing means, the above-mentioned concentrated solution circulation is performed to prevent precipitation of components from the concentrated solution inside the apparatus after the apparatus operation is completed. Means for performing a deposition preventing operation for forcibly circulating the liquid to be concentrated between the heating section and the evaporating section, and then terminating the operation of the plating solution concentrating apparatus itself. Item 6. A plating solution concentrating device according to any one of Items 4.