JP2004506895A

JP2004506895A - Method and apparatus for continuous ion monitoring of aqueous solution

Info

Publication number: JP2004506895A
Application number: JP2002519929A
Authority: JP
Inventors: カーソン，ウィリアム，　ダブリュ．; グレベニク，オレグ，　ヴィ．; スサ，トーマス，　ジェー．
Original assignee: イオニックス，インコーポレーテッド
Priority date: 2000-08-11
Filing date: 2001-08-10
Publication date: 2004-03-04
Also published as: WO2002014850A1; WO2002014850A9; AU2002212957A1; EP1322943A1; CN1444729A

Abstract

高純度の水溶液流のｐＨを連続的にモニタリングするのに必要なカチオン導電率、アニオン導電率、および温度のデータを連続的に発生させるための電気分解方法および装置が開示される。導電率測定のために水試料を調整するのに使用するカチオン交換材料とアニオン交換材料は、カチオン交換材料を横切ってアノードとカソードの間にＤＣ電圧を印加することで、アノードで生じる水素イオンがカチオン交換材料を通って移動し、事前に吸着したカチオンと置換し、これら置換されたカチオンが電場の影響下でカソードへと移動することによって連続的に再生されるか、またはアニオン交換材料を横切ってアノードとカソードの間にＤＣ電圧を印加することで、カソードで生じる水酸イオンがアニオン交換材料を再生する。その後、温度補正されたカチオン導電率および温度補正されたアニオン導電率が試料のｐＨを算出するために試料の比導電率の測定と共に使用される。An electrolysis method and apparatus for continuously generating the cation conductivity, anion conductivity, and temperature data required to continuously monitor the pH of a high purity aqueous solution stream is disclosed. The cation exchange and anion exchange materials used to prepare the water sample for conductivity measurements are based on the application of a DC voltage across the cation exchange material between the anode and cathode, causing the hydrogen ions generated at the anode to It migrates through the cation exchange material and displaces the pre-adsorbed cations, and these displaced cations are continuously regenerated by moving to the cathode under the influence of the electric field or traverse the anion exchange material By applying a DC voltage between the anode and the cathode, hydroxyl ions generated at the cathode regenerate the anion exchange material. Thereafter, the temperature corrected cation conductivity and the temperature corrected anion conductivity are used together with the measurement of the specific conductivity of the sample to calculate the pH of the sample.

Description

【０００１】
（発明の分野）
本発明は、水の中のイオン種の導電率の測定および「カチオン導電率」と「アニオン導電率」の改善された導電率測定に関する。「カチオン導電率」という用語は、試料中のカチオンの実質的に全てが水素イオンで置換された試料の導電率と定義される。「アニオン導電率」という用語は、試料中のアニオンの実質的に全てが水酸イオンで置換された試料の導電率と定義される。試料の比導電率、カチオン導電率、およびアニオン導電率の温度補正された測定法を用いれば、高純度の水のｐＨを正確に算出することができる。
【０００２】
（発明の背景）
カチオン導電率の測定のために水を調整する従来の方法は通常、カチオン樹脂が最初にＨ＋型であるカチオン樹脂イオン交換カラムに試料を通過させる工程を含む。試料がカチオン樹脂カラムを通過するとき、試料中のカチオンの本質的に全てが樹脂の交換部位に吸着され、それによって交換部位から水素イオンが試料中に放出される。しかしながら、この処理は、試料中に元から存在する塩の酸を含む試料を生じる。これらの酸は標準的な導電率測定器で測定した場合、元の塩を含む試料の導電率よりもはるかに高い導電率を有する。同様の方式で、試料がＯＨ型のアニオン交換樹脂を通過して試料中のアニオンが水酸イオンで置換されると、この処理は試料中に元から存在する塩の塩基を含む試料を生じる。これらの塩基は元の塩基を含む試料の導電率よりも高い導電率を有する。
【０００３】
カチオン導電率およびアニオン導電率は、検査する水のイオン純度の指標を与えるために大切な測定値である。現代の発電プラントでは、イオン純度について高圧スチームボイラ内に流れる水を連続的にモニタし、ボイラ管壁、スチームタービンやコンデンサの腐食を防止するように処理しなければならない。システムの様々な部分から来る試料の流れは比導電率とカチオン導電率とについてモニタしなければならない。カチオン導電率について流れをモニタすることができる時間の長さは、試料を処理するのに使用されるカチオン交換カラムまたは試料流のサイズ、試料流の流速、および水の中に存在するカチオンの数によって決まる。試料流が同じ速度で流れている状態で、カチオン交換カラムの容積が大きくなるにつれて、酸で置換して再生しなければならない頻度は少なくなる。しかし、カチオン交換カラムのサイズが増大すると測定の時間遅延が大きくなる。もちろん、もし測定の時間遅延を少なくするために試料流の流速を上げると、カラムを置換またはもう一度再生する必要性の頻度が増す。
【０００４】
水溶液のイオンモニタリングのための従来の装置と方法の上記の制限および欠陥の全てとは言わないまでも大部分は、本発明による水溶液の連続的イオンモニタリング方法および装置によって克服されるか、あるいは少なくとも相当改善される。本発明の他の目的および利点は以下の説明で明らかになるであろう。本発明はしたがって、限定されるものではないが、いくつかの工程と様々な構成部品を含む装置とそれに関係する方法、およびそのような工程と構成部品の１つまたは複数の他の各々との関係および順序を含むものであって、以下の説明および付随する図面で例証される。ここに説明する装置と方法の様々な変更と多様性は当業者にとって明らかであり、そのような変更および多様性の全ては本発明の範囲内と考えられる。特に、本発明は、かかる目的でこれまで使用されている従来のイオン交換カラムのコストと複雑さを解消しながら所望の高速応答時間を供給するものである。
【０００５】
（発明の概要）
本発明は、イオン交換材料の連続的な電気化学的再生を用いた水溶液流のモニタリングに関する。カチオン導電率の測定は、よく知られている温度補正技術と共に従来の導電率セルを使用して、流れの中の実質的に全てのカチオンを吸着し、それらを水素イオンと置換するカチオン交換材料を通過させるか、さもなければそれに接触させた試料流に対して行なわれる。本発明によると、このカチオン交換材料は、カチオン交換材料の一方の部分と接触するカチオン交換膜もしくは両極性膜によってカチオン交換材料から分離されるアノード区画のような隣接する水素イオン源で発生される水素イオンの通過によって連続的に再生される。本発明によると、カチオン交換材料の他方の部分はＤＣ電圧勾配の影響下で移動させられるカチオン交換材料によってカチオンが本来吸着されるカソード区画を隔離するカチオン交換膜と接触して維持される。
【０００６】
類似した方式で、アニオン導電率の測定は、温度補正技術と共に従来の導電率セルを使用して、流れの中の本質的に全てのアニオンを吸着し、それらを水酸イオンと置換するアニオン交換材料を通過させるか、さもなければそれに接触させた試料流に対して行なわれる。本発明によると、このアニオン交換材料は、アニオン交換材料の一方の部分と接触するアニオン交換膜もしくは両極性膜によってアニオン交換材料から分離されるカソード区画のような隣接する水酸イオン源で発生される水酸イオンの通過によって連続的に再生される。本発明によると、アニオン交換材料の他方の部分はＤＣ電圧勾配の影響下で移動させられるアニオン交換材料によってアニオンが本来吸着されるアノード区画を隔離するアニオン交換膜と接触して維持される。
【０００７】
「微弱な」もしくは緩衝イオンを含まない比較的純粋な水については、モニタすべき試料流のｐＨを高度に正確に測定するための計算に、本発明によって測定される温度補正された比導電率、温度補正されたカチオン導電率および温度補正されたアニオン導電率を使用することができる。高純度の水のｐＨを測定するこの方法はまた、高純度の水について使用するときに従来のｐＨ測定で問題となっていた安定性が向上し、ドリフトがなくなり、さらに汚染もなくなるという利点をも有する。
【０００８】
本発明はまた、試料のカチオン導電率をモニタするための後述するカチオン交換ユニットの独立の使用方法、ならびに試料のアニオン導電率をモニタするための後述するアニオン交換ユニットの独立の使用方法をも包含するものである。
【０００９】
（好ましい実施形態の詳細な説明）
本発明は、ＤＣ電流を印可してイオン交換材料を連続的に再生することによる水溶液の連続的モニタリングを実行する新たな考え方を基本にしている。
【００１０】
高純度の水についての高度に正確なｐＨ測定は、本発明の装置と方法とを利用した比導電率、カチオン導電率およびアニオン導電率の温度補正された測定値から算出することができる。本発明の好ましい一実施形態においては、カチオン導電率試料の流れとアニオン導電率試料の流れを処理し、その導電率を測定する。概して、カチオン導電率試料流の場合には、導電率計を作動させた後に、流れの一部もしくは全てがアノード（陽）電極を通過して流れ、その後、流体導管手段によってカソードを通過して廃棄へと導かれる。アノードで、前に測定した試料流に由来する水の電気分解によって水素イオンが発生し、ＤＣ電圧の影響下でこれらの水素イオンがカチオン交換膜を通ってカチオン交換材料へと移動し、そこで試料流中から吸着された他のカチオンを置換することによってカチオン交換材料を再生する。これら置換されたカチオンはその後、ＤＣ電圧の影響下でカチオン交換膜を通ってカソード（陰）電極へと移動し、アノード区画からカソード区画を通って流れる廃棄の流れに入る。
【００１１】
同様に、アニオン導電率試料流の場合には、導電率計を作動させた後に、流れの一部もしくは全てがカソード（陰）電極を通過して流れ、その後、配管によってアノードを通過して廃棄へと導かれる。カソードで、水の電気分解によって水酸イオンが発生し、これらの水酸イオンがＤＣ電圧の影響下でアニオン交換材料へと移動し、そこで試料流中から吸着された他のアニオンを置換することによってアニオン交換材料を再生する。これら置換されたアニオンはその後、ＤＣ電圧の影響下でアノード（陽）電極へと移動し、カソード区画からアノード区画を通って流れる廃棄の流れに入る。
【００１２】
図１に図式的に描いたように、本発明によるイオン交換ユニットを構成するための一つの好ましい実施形態では、電極１７０、１７１は、イオン交換材料１７２であるバルクからそのバルク材料の電荷と同じ電荷を有するイオン交換膜１７３によって物理的に分離されている。膜１７３と容器の壁とは区画１７４を形成しており、該区画１７４中には電極１７０が含まれ、該区画を通って事前に測定した試料が流れて電気分解のための水を供給し、かつ電極から生じる気泡を払拭している。電極がカチオン交換膜１７３と接触していること、または区画１７４が膜の電荷と同じ電荷を有するイオン交換材料で充填されていることが好ましい。
【００１３】
本発明によるイオン交換ユニットを構成するための別の好ましい実施形態では、図２Ａ、２Ｂに図式的に描いたように、イオン交換膜のみをイオン交換材料として使用する。この場合には、イオン交換膜１８０の平坦なシートが２枚の電気的絶縁性プレート１８１の間に、プレート周縁の穴１８８を通したボルトによってクランプされている。試料流のために入口手段１８２が設けられており、試料流はイオン交換膜１８０に接触している通路１８３内を流れ、出口手段１８４を通って導電率計へと至る。カチオン導電率の場合には、膜１８０はカチオン交換膜であり、アノード１８５は水の電気分解によって水素イオンを発生して膜１８０を連続的に再生する。これら水素イオンはＤＣ電圧の影響下で膜を通ってカソード１８６に向かって移動する。試料流中の実質的に全てのカチオンは膜に由来する水素イオンで交換される。これらのカチオンは膜を通ってカソード路の流れの中へと移動し、出口手段１８７を通って廃棄される。この好ましい実施形態では、試料流の流れの全体としての方向は水素イオンの移動方向に対して向流となっている。この好ましい実施形態でも同様に、アノード路およびカソード路は、膜の各試料流路側とは反対の側にある。図２Ａ、２Ｂに示したイオン交換ユニットの動作についての説明はアニオン導電率の場合に当てはまる。
【００１４】
図３には、本発明による連続的イオンモニタリングシステムの一つの形式が、並列構成にある本発明による２つのイオン交換ユニットを使用して図式的に描かれている。本システムは、流体導管によって導電率計２０１に接続されている試料流体入口２００を含んでおり、導電率計は試料流の導電率と温度の双方を連続的に測定するためのメカニズムを含んでいる。導電率計の出口から、流体導管２０２によって、試料は、通常はＴ分岐もしくはバルブである分流器２１０へと流れ、この分流器はさらに流体導管２２０、２２１によって、本発明の連続的再生カチオン交換容器２３０の入口と、本発明の連続的再生アニオン交換容器２４０の入口とにそれぞれ接続されている。各々の交換容器内では、後述する電極２３１、２３２（容器２３０）および電極２３３、２３４（容器２４０）は、それらの間に配置された各カチオンもしくはアニオンイオン交換材料でにより互いに隔てられている。イオン交換材料は、ビーズ、粒子、繊維、スクリーン、または膜の形であることができる。カチオン導電率試料部分がカチオン交換材料を通過する際に、実質的に全てのカチオンはカチオン交換材料によって吸着され、水素イオンで置換される。アニオン導電率試料部分がアニオン交換材料を通過する際に、実質的に全てのアニオンはアニオン交換材料によって吸着され、水酸イオンで置換される。このように処理された各試料部分は２つの交換器から流出し、流体導管２４１、２４２によって、処理された各試料流部分の導電率と温度の双方を連続的に測定するメカニズムを各々有する導電率計２５０、２５１をそれぞれ通過する。導電率計の電気的出力は計算システム２６５へと送られ、そこで連続的に発生する導電率と温度とのデータから試料流のｐＨが自動的に計算される。
【００１５】
本発明によるカチオン交換ユニットは独立したカソード無しで構成することもでき、その場合には、ユニットのアノード要素を利用して、電場がユニットを横切るように形成され、かつ置換されたカチオンの除去のために、廃棄流路がユニットのカソード側となるべき側に沿って設けられることが条件になる。同様に、本発明によるアニオン交換ユニットは、独立したアノード無しで構成することもできる。
【００１６】
したがって、図３に示した本発明の実施形態の変形としては、カチオン交換器のカソード要素を除去し、アニオン交換器のアノード要素を除去し、カチオン交換器区画をアニオン交換器区画と背中合わせに配置することで、カチオン交換ユニットとアニオン交換ユニットを単一ユニットに集約することも可能である。
【００１７】
試料ｐＨは以下の式体系を利用して、本発明により得られる導電率のデータから算出することが可能である。
ｋ＝２５℃における導電率
Ｌ＝２５℃における等価イオン導電率
Ｃ＝濃度
下付き文字　　　　　　　　　　　　　上付き文字
Ｈ＝水素イオン　　　　　　　　　　　Ｓ＝比導電率
ＯＨ＝水酸イオン　　　　　　　　　　ＡＣ＝アニオン導電率
Ａ＝全ての他のアニオン　　　　　　　ＣＣ＝カチオン導電率
Ｍ＝全ての他のカチオン
式
Ｋ^Ｓ＝１／１０００（Ｃ_Ｈ ^ＳＬ_Ｈ＋Ｃ_Ａ ^ＳＬ_Ａ＋Ｃ_Ｍ ^ＳＬ_Ｍ＋Ｃ_ＯＨ ^ＳＬ_ＯＨ）
ｋ^ＣＣ＝１／１０００（Ｃ_Ｈ ^ＣＣＬ_Ｈ＋Ｃ_Ａ ^ＣＣＬ_Ａ＋Ｃ_ＯＨ ^ＣＣＬ_ＯＨ）
ｋ^ＡＣ＝１／１０００（Ｃ_Ｈ ^ＡＣＬ_Ｈ＋Ｃ_Ｍ ^ＡＣＬ_Ｍ＋Ｃ_ＯＨ ^ＡＣＬ_ＯＨ）
電荷平衡
Ｃ_Ｈ ^Ｓ＋Ｃ_Ｍ ^Ｓ＝Ｃ_Ａ ^Ｓ＋Ｃ_ＯＨ ^Ｓ
Ｃ_Ｈ ^ＣＣ＝Ｃ_Ａ ^ＣＣ＋Ｃ_ＯＨ ^ＣＣ
Ｃ_ＯＨ ^ＡＣ＝Ｃ_Ｈ ^ＡＣ＋Ｃ_Ｍ ^ＡＣ
【００１８】
カチオン交換カラムを通過することでアニオン濃度は変化せず、アニオン交換カラムを通過することでカチオン濃度は変化しないので、
Ｃ_Ａ ^ＣＣ＝Ｃ_Ａ ^Ｓ
Ｃ_Ｍ ^ＡＣ＝Ｃ_Ｍ ^Ｓ
放出される水素イオンは樹脂によって吸着される他のカチオンと等量であるので、
Ｃ_Ｈ ^ＣＣ＝Ｃ_Ｈ ^Ｓ＋Ｃ_Ｍ ^Ｓ
放出される水酸イオンは樹脂によって吸着される他のアニオンと等量であるので、
Ｃ_ＯＨ ^ＡＣ＝Ｃ_Ａ ^Ｓ＋Ｃ_ＯＨ ^Ｓ
２５℃においては、水の解離定数、Ｋ_Ｗ＝Ｃ_ＨＣ_ＯＨおよび−ｌｏｇＫ_Ｗ＝−ｌｏｇＣ_Ｈ−ｌｏｇＣ_ＯＨ＝１４である。
【００１９】
強塩基と強酸との塩について、コンピュータプログラムを利用してこの式体系を解くことで実際のｐＨまたは極めて近いｐＨの近似を得ることができる。検査する流れの中に弱塩基と弱酸との塩が存在する場合には、試料流のｐＨの算出には他の分析から収集される追加の情報が必要とされる。例えば、本技術分野で知られているような総合無機炭素分析装置（Ｔｏｔａｌ　Ｉｎｏｒｇａｎｉｃ　Ｃａｒｂｏｎ　ａｎａｌｙｚｅｒ）は、試料中に存在する炭酸水素塩（弱酸）の濃度を与え、それによりｐＨの算出を可能にすることができる。
【００２０】
本発明の範囲から逸脱することなくその他の変形および変更が上述の装置、処理および方法についてなし得ることは当業者にとって明白であろう。上述した全ての事項は例示的であって限定的意味でないと解釈されるべきである。
【図面の簡単な説明】
【図１】本発明の第１の実施形態によるイオン交換ユニットの図式的な断面図であり、イオン交換材料が、電極を含んでいるか電極と接しているイオン交換膜の壁の間に配されている。
【図２Ａ】それぞれ、本発明の他の実施形態によるイオン交換ユニットの概略的平面図および断面図であり、イオン交換膜がイオン交換材料としても使用されている。
【図２Ｂ】それぞれ、本発明の他の実施形態によるイオン交換ユニットの概略的平面図および断面図であり、イオン交換膜がイオン交換材料としても使用されている。
【図３】本発明による水溶液の連続的イオンモニタリングシステムを説明する概略的処理フロー図であり、図１または２Ａ、２Ｂのイオン交換ユニットに相当するイオン交換ユニットが二つ並列構成で利用されている。[0001]
(Field of the Invention)
The present invention relates to the measurement of the conductivity of ionic species in water and to the improved measurement of "cation conductivity" and "anion conductivity". The term "cation conductivity" is defined as the conductivity of a sample in which substantially all of the cations in the sample have been replaced by hydrogen ions. The term "anion conductivity" is defined as the conductivity of a sample in which substantially all of the anions in the sample have been replaced with hydroxide ions. By using a temperature-corrected measurement method of the specific conductivity, cation conductivity, and anion conductivity of a sample, the pH of high-purity water can be accurately calculated.
[0002]
(Background of the Invention)
Conventional methods of conditioning water for measurement of cation conductivity usually involve passing the sample first through a cation resin ion exchange column where the cation resin is in the H + form. As the sample passes through the cation resin column, essentially all of the cations in the sample are adsorbed to the exchange sites on the resin, thereby releasing hydrogen ions from the exchange sites into the sample. However, this treatment results in a sample containing the acid of the salt originally present in the sample. These acids have a conductivity much higher than that of the sample containing the original salt, as measured with a standard conductivity meter. In a similar manner, when the sample passes through an anion exchange resin of the OH type and the anions in the sample are replaced with hydroxide ions, this treatment results in a sample containing the base of the salt originally present in the sample. These bases have a higher conductivity than the sample containing the original base.
[0003]
Cation conductivity and anion conductivity are important measurements to give an indication of the ionic purity of the water under test. In modern power plants, the water flowing in the high-pressure steam boiler must be continuously monitored for ionic purity and treated to prevent corrosion of boiler tube walls, steam turbines and condensers. Sample flows coming from various parts of the system must be monitored for specific and cationic conductivity. The length of time the flow can be monitored for cation conductivity depends on the size of the cation exchange column or sample stream used to process the sample, the flow rate of the sample stream, and the number of cations present in the water. Depends on With the sample stream flowing at the same speed, as the volume of the cation exchange column increases, the frequency of replacement with acid and regeneration is reduced. However, as the size of the cation exchange column increases, the time delay of the measurement increases. Of course, if the flow rate of the sample stream is increased to reduce the time delay of the measurement, the need to replace or regenerate the column will increase.
[0004]
Most, if not all, of the above-mentioned limitations and deficiencies of conventional devices and methods for ion monitoring of aqueous solutions are overcome, or at least overcome, by the method and apparatus for continuous ion monitoring of aqueous solutions according to the present invention. It is considerably improved. Other objects and advantages of the present invention will become apparent from the following description. The present invention is therefore, but is not limited to, an apparatus comprising a number of steps and various components and methods associated therewith, and the use of each and every other one or more of such steps and components. It includes relationships and sequences and is illustrated in the following description and accompanying drawings. Various modifications and variations of the described devices and methods will be apparent to those skilled in the art, and all such modifications and variations are considered to be within the scope of the present invention. In particular, the present invention provides a desired fast response time while eliminating the cost and complexity of conventional ion exchange columns previously used for such purposes.
[0005]
(Summary of the Invention)
The present invention relates to the monitoring of aqueous solution streams using continuous electrochemical regeneration of ion exchange materials. The measurement of cation conductivity uses a conventional conductivity cell with well-known temperature compensation techniques to adsorb substantially all cations in the stream and replace them with hydrogen ions. Or otherwise on the sample stream contacted with it. According to the present invention, the cation exchange material is generated in an adjacent source of hydrogen ions, such as an anode compartment separated from the cation exchange material by a cation exchange membrane or an ambipolar membrane that contacts one portion of the cation exchange material. It is continuously regenerated by passing hydrogen ions. According to the invention, the other part of the cation exchange material is maintained in contact with a cation exchange membrane that separates the cathode compartment where cations are originally adsorbed by the cation exchange material moved under the influence of a DC voltage gradient.
[0006]
In a similar manner, the measurement of anion conductivity is based on anion exchange using a conventional conductivity cell with temperature compensation techniques to adsorb essentially all anions in the stream and replace them with hydroxide ions. It is performed on the sample stream passed through or otherwise in contact with the material. According to the present invention, the anion exchange material is generated in an adjacent source of hydroxyl ions, such as a cathode compartment separated from the anion exchange material by an anion exchange membrane or an ambipolar membrane in contact with one portion of the anion exchange material. Is continuously regenerated by the passage of hydroxyl ions. According to the invention, the other part of the anion exchange material is maintained in contact with an anion exchange membrane that separates the anode compartment where the anions are originally adsorbed by the anion exchange material displaced under the influence of the DC voltage gradient.
[0007]
For relatively "weak" or relatively pure water without buffer ions, the temperature-corrected specific conductivity measured by the present invention is used in calculations to determine the pH of the sample stream to be monitored with high accuracy. Temperature-corrected cation conductivity and temperature-corrected anion conductivity can be used. This method of measuring the pH of high-purity water also has the advantage of improving stability, eliminating drift and eliminating contamination, which has been a problem with conventional pH measurements when used with high-purity water. Also have.
[0008]
The invention also encompasses the independent use of a cation exchange unit described below for monitoring the cation conductivity of the sample, and the independent use of the anion exchange unit described below for monitoring the anion conductivity of the sample. Is what you do.
[0009]
(Detailed description of preferred embodiments)
The invention is based on a new concept of performing continuous monitoring of an aqueous solution by continuously regenerating an ion exchange material by applying a DC current.
[0010]
Highly accurate pH measurements for high purity water can be calculated from temperature corrected measurements of specific, cationic and anionic conductivity utilizing the devices and methods of the present invention. In one preferred embodiment of the present invention, the flow of the cationic conductivity sample and the flow of the anion conductivity sample are treated and the conductivity is measured. Generally, in the case of a cationic conductivity sample stream, after operating the conductivity meter, some or all of the flow will flow through the anode (positive) electrode and then through the cathode by fluid conduit means. Guided to disposal. At the anode, hydrogen ions are generated by the electrolysis of water from the previously measured sample stream, and under the influence of the DC voltage, these hydrogen ions move through the cation exchange membrane to the cation exchange material, where the sample Regenerate the cation exchange material by displacing other cations adsorbed from the stream. These displaced cations then migrate under the influence of the DC voltage through the cation exchange membrane to the cathode (negative) electrode and enter the waste stream flowing from the anode compartment through the cathode compartment.
[0011]
Similarly, in the case of an anion conductivity sample stream, after operating the conductivity meter, some or all of the stream will flow past the cathode (negative) electrode and then be passed through the anode via piping to waste. It is led to. At the cathode, the electrolysis of water generates hydroxyl ions, which migrate under the influence of the DC voltage to the anion exchange material, where they displace other anions adsorbed from the sample stream. To regenerate the anion exchange material. These displaced anions then migrate to the anode (positive) electrode under the influence of the DC voltage and enter the waste stream flowing from the cathode compartment through the anode compartment.
[0012]
As schematically depicted in FIG. 1, in one preferred embodiment for constructing an ion exchange unit according to the present invention, the electrodes 170, 171 are charged from the bulk, which is the ion exchange material 172, with the charge of the bulk material. They are physically separated by an ion exchange membrane 173 having a charge. The membrane 173 and the wall of the container form a compartment 174, which contains an electrode 170, through which a previously measured sample flows to supply water for electrolysis. In addition, air bubbles generated from the electrodes are wiped off. Preferably, the electrode is in contact with the cation exchange membrane 173 or the compartment 174 is filled with an ion exchange material having the same charge as that of the membrane.
[0013]
In another preferred embodiment for constructing an ion exchange unit according to the invention, only the ion exchange membrane is used as the ion exchange material, as schematically depicted in FIGS. 2A, 2B. In this case, a flat sheet of the ion exchange membrane 180 is clamped between the two electrically insulating plates 181 by bolts passing through holes 188 in the peripheral edge of the plate. An inlet means 182 is provided for the sample stream, which flows in a passage 183 in contact with the ion exchange membrane 180 and through the outlet means 184 to the conductivity meter. In the case of cation conductivity, the membrane 180 is a cation exchange membrane, and the anode 185 generates hydrogen ions by electrolysis of water to continuously regenerate the membrane 180. These hydrogen ions move through the membrane toward the cathode 186 under the influence of the DC voltage. Substantially all of the cations in the sample stream are exchanged for hydrogen ions from the membrane. These cations move through the membrane into the flow of the cathode channel and are discarded through outlet means 187. In this preferred embodiment, the overall direction of the sample flow is countercurrent to the direction of movement of the hydrogen ions. Similarly, in this preferred embodiment, the anode and cathode paths are on opposite sides of the membrane from each sample flow path side. The description of the operation of the ion exchange unit shown in FIGS. 2A and 2B applies to the case of anion conductivity.
[0014]
FIG. 3 schematically illustrates one type of continuous ion monitoring system according to the invention, using two ion exchange units according to the invention in a parallel configuration. The system includes a sample fluid inlet 200 connected by a fluid conduit to a conductivity meter 201, which includes a mechanism for continuously measuring both the conductivity and the temperature of the sample stream. I have. From the conductivity meter outlet, the sample flows by means of a fluid conduit 202 to a flow divider 210, which is typically a T-branch or valve, which is further connected by a fluid conduit 220, 221 with the continuous regeneration cation exchange of the invention The inlet of the vessel 230 and the inlet of the continuous regeneration anion exchange vessel 240 of the present invention are connected to each other. In each exchange container, electrodes 231 and 232 (container 230) and electrodes 233 and 234 (container 240) described below are separated from each other by each cation or anion ion exchange material disposed therebetween. The ion exchange material can be in the form of beads, particles, fibers, screens, or membranes. As the cation conductivity sample portion passes through the cation exchange material, substantially all of the cations are adsorbed by the cation exchange material and displaced by hydrogen ions. As the anion conductivity sample portion passes through the anion exchange material, substantially all of the anions are adsorbed by the anion exchange material and replaced by hydroxyl ions. Each sample portion treated in this way exits the two exchangers and is connected by a fluid conduit 241, 242, each having a mechanism for continuously measuring both the conductivity and the temperature of each treated sample flow portion. It passes through rate meters 250 and 251 respectively. The electrical output of the conductivity meter is sent to a calculation system 265 where the pH of the sample stream is automatically calculated from the continuously occurring conductivity and temperature data.
[0015]
The cation exchange unit according to the invention can also be constructed without a separate cathode, in which case an electric field is formed across the unit and the removal of displaced cations is effected, utilizing the anode element of the unit. Therefore, it is a condition that the waste flow path is provided along the side to be the cathode side of the unit. Similarly, the anion exchange unit according to the invention can be constructed without a separate anode.
[0016]
Thus, a variation of the embodiment of the invention shown in FIG. 3 includes removing the cathode element of the cation exchanger, removing the anode element of the anion exchanger, and placing the cation exchanger section back to back with the anion exchanger section. By doing so, it is also possible to combine the cation exchange unit and the anion exchange unit into a single unit.
[0017]
The sample pH can be calculated from the conductivity data obtained by the present invention using the following formula system.
k = conductivity at 25 ° C. L = equivalent ionic conductivity at 25 ° C. C = concentration subscript superscript H = hydrogen ion S = specific conductivity OH = hydroxyl ion AC = anion conductivity A = all other Anion CC = Cation conductivity M = All other cation formulas K ^S = 1/1000 (C _H ^S L _H + C _A ^S _{A A A} + C _M ^S L _M + C _O ^{S S} L _OH )
^{_{^{_{k CC = 1/1000 (C}}}} H CC L H + C A CC L A + C OH CC L OH)
^{_{^{_{k AC = 1/1000 (C}}}} H AC L H + C M AC L M + C OH AC L OH)
The charge balancing _{^{_{^{_{^{C H S + C M S =}}}}}} C A S + C OH S
_{^{_{^{_{C H CC = C A CC +}}}}} C OH CC
C _OH ^AC = _CH ^AC + _CM ^AC
[0018]
Since the anion concentration does not change by passing through the cation exchange column, and the cation concentration does not change by passing through the anion exchange column,
C _A ^CC = C _A ^S
_C _^M ^AC = C _M ^S
Since the released hydrogen ions are equivalent to other cations adsorbed by the resin,
_{^{_{^{_{C H CC = C H S +}}}}} C M S
Since the released hydroxyl ions are equivalent to other anions adsorbed by the resin,
_{^{_{^{_{C OH AC = C A S +}}}}} C OH S
In 25 ° C., the dissociation constant of _water, K _W = _{C H} C _OH and _{_{_{-logK W = -logC H -logC OH =}}} 14.
[0019]
For a salt between a strong base and a strong acid, a computer program can be used to solve this equation system to obtain an approximation of the actual or very close pH. If a salt of a weak base and a weak acid is present in the stream to be tested, calculating the pH of the sample stream requires additional information gathered from other analyses. For example, a Total Inorganic Carbon analyzer, as known in the art, provides the concentration of bicarbonate (weak acid) present in a sample, thereby enabling the calculation of pH. be able to.
[0020]
It will be apparent to those skilled in the art that other variations and modifications can be made to the above-described devices, processes and methods without departing from the scope of the invention. All of the above is to be construed as illustrative and not restrictive.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an ion exchange unit according to a first embodiment of the present invention, wherein an ion exchange material is disposed between walls of an ion exchange membrane containing or in contact with an electrode. ing.
2A and 2B are a schematic plan view and a sectional view, respectively, of an ion exchange unit according to another embodiment of the present invention, wherein an ion exchange membrane is also used as an ion exchange material.
2A and 2B are a schematic plan view and a sectional view, respectively, of an ion exchange unit according to another embodiment of the present invention, wherein an ion exchange membrane is also used as an ion exchange material.
FIG. 3 is a schematic process flow diagram illustrating a continuous ion monitoring system for an aqueous solution according to the present invention, in which two ion exchange units corresponding to the ion exchange units of FIG. I have.

Claims

An apparatus for measuring the ionic purity of an aqueous sample,
A conductivity meter for measuring the conductivity and temperature of the sample;
A cation exchange element for exchanging cations present in the cation portion of the sample with hydrogen ions as the cation portion of the sample passes in contact therewith;
A conductivity meter for measuring the conductivity and temperature of the cation moiety after contacting the cation exchange element;
A cation exchange element regeneration system for continuously regenerating the cation exchange element by replacing cations removed from the cation portion with new hydrogen ions generated by electrolysis of water;
An anion exchange element for exchanging anions present in the anion portion of the sample with hydroxide ions when the anion portion of the sample passes in contact therewith;
A conductivity meter for measuring the conductivity and temperature of the anion portion after contact with the anion exchange element; and replacing the anions removed from the anion portion with new hydroxyl ions generated by electrolysis of water. An apparatus for measuring the ionic purity of an aqueous sample, comprising an anion exchange element regeneration system for continuously regenerating an anion exchange element by means of a method.

Cation exchange element regeneration system
An anode compartment including an anode, an anode compartment inlet end, and an anode compartment outlet end;
A cathode compartment including a cathode, a cathode compartment inlet end, and a cathode compartment outlet end;
DC power supply;
At least one cation exchange membrane arranged to form a cation membrane compartment, wherein the cation membrane compartment has a cation membrane compartment inlet and a cation membrane compartment outlet; and within the cation membrane compartment The apparatus of claim 1 including a cation exchange material disposed.

Anion exchange element regeneration system
An anode compartment including an anode, an anode compartment inlet end, and an anode compartment outlet end;
A cathode compartment including a cathode, a cathode compartment inlet end, and a cathode compartment outlet end;
DC power supply;
At least one anion exchange membrane arranged to form an anion membrane compartment, wherein the anion membrane compartment has an anion membrane compartment inlet and an anion membrane compartment outlet; and The device of claim 1, comprising an anion exchange material disposed.

Cation exchange element regeneration system,
Two electrically insulating flat plate elements, the first of which includes a fluid inlet and fluid outlet pair and a sample flow channel disposed therebetween along one surface thereof; A second one of the planar elements comprising two pairs of fluid inlets and fluid outlets, each having an electrode track therebetween along one side thereof;
An anode included in one of the electrode tracks and a cathode included in the other of the electrode tracks; and a cation exchange membrane disposed between the two planar elements, the anode and cathode being disposed along one surface thereof. The apparatus of claim 1 including a cation exchange membrane in contact and in contact with the sample flow path along an opposite surface.

The anion exchange element regeneration system,
Two electrically insulating flat plate elements, the first of which includes a fluid inlet and fluid outlet pair and a sample flow channel disposed therebetween along one surface thereof; A second one of the planar elements comprising two pairs of fluid inlets and fluid outlets, each having an electrode track therebetween along one side thereof;
An anode included in one of the electrode tracks and a cathode included in the other of the electrode tracks; and an anion exchange membrane disposed between the two planar elements, the anode and cathode being disposed along one surface thereof. 2. The apparatus of claim 1 including an anion exchange membrane in contact and in contact with the sample flow path along an opposite surface.

3. The apparatus of claim 2, wherein the anode compartment and the cathode compartment are filled with a cation exchange material.

The apparatus of claim 3, wherein the anode compartment and the cathode compartment are filled with an anion exchange material.

3. The device of claim 2, wherein the anode and the cathode are in contact with a cation exchange material.

The device of claim 3, wherein the anode and the cathode are in contact with the anion exchange material.

A system for measuring ionic purity of a flowing aqueous sample,
Means for measuring the conductivity and temperature of the flowing sample stream;
Means for splitting the flowing sample stream into two substantially equal split sample streams;
Means for continuously exchanging cations in one split sample stream with hydrogen ions and continuously exchanging anions in the other split sample stream with hydroxide ions;
Means for measuring both the conductivity and temperature of each split sample stream following continuous ion exchange; and the temperature and conductivity of the original sample stream and the two split ion-exchanged sample streams to determine the sample flow. A system for measuring the ionic purity of a flowing aqueous sample, comprising a means for calculating pH.

A method for measuring the ionic purity of an aqueous sample,
Measuring the conductivity and temperature of the sample;
Continuously exchanging cations in the cation portion of the sample with hydrogen ions by contacting the cations with a cation exchange element;
Continuously regenerating the cation exchange element with new hydrogen ions;
Measuring the conductivity and temperature of the cation portion of the sample removed from contact with the cation exchange element;
Continuously exchanging anions in the anion portion of the sample with hydroxyl ions by contacting the anions with an anion exchange element;
Continuously regenerating the anion exchange element with new hydroxyl ions;
A method for measuring the conductivity and temperature of the anion portion of a sample removed from contact with the anion exchange element; and a method for measuring the ionic purity of the sample based on the conductivity and temperature measurements .

Exchange of cations with hydrogen ions and continuous regeneration of the cation exchange elements,
Anode compartment means having an anode, an inlet end, and an outlet end;
Cathode compartment means having a cathode, an inlet end, and an outlet end;
DC power supply;
Two cation exchange membranes arranged to form a compartment therebetween, the cation exchange membrane having compartments having inlet and outlet means; and being disposed within the compartment between the membranes. 12. The method of claim 11, wherein the method is performed using a cation exchange material.

Exchange of anions with hydroxide ions and continuous regeneration of the anion exchange elements,
Anode compartment means having an anode, an inlet end, and an outlet end;
Cathode compartment means having a cathode, an inlet end, and an outlet end;
DC power supply;
Two anion exchange membranes arranged to form a compartment between them, the compartment having an inlet means and an outlet means; and an anion exchange membrane arranged in the compartment between the membranes 12. The method of claim 11, wherein the method is performed using an anion exchange material.

Exchange of cations with hydrogen ions and continuous regeneration of the cation exchange elements,
Two electrically insulating plates, a first plate having an inlet, an outlet, and a sample flow path disposed between the inlet and the outlet on one side of the plate; Has an inlet, an outlet, and a passage including an anode between the inlet and the outlet, and a passage including an inlet and an outlet and a cathode between the inlet and the outlet on the same side of the plate. And a cation exchange membrane disposed between the two plates, one side of which has contact with the anode and the cathode and the other side has contact with the sample flow path. The method according to claim 11, wherein the method is performed using a cation exchange membrane having the cation exchange membrane.

Exchange of anions with hydroxide ions and continuous regeneration of the anion exchange elements,
Two electrically insulating plates, a first plate having an inlet, an outlet and a sample flow path disposed between the inlet and the outlet on one side thereof; A plate having an inlet, an outlet, and a passage containing an anode between the inlet and outlet, and having a passage containing an inlet and outlet and a cathode between the inlet and outlet on the same side of the plate; An anion exchange membrane disposed between two plates, the anion exchange membrane having contact with an anode and a cathode on one side and contact with a sample flow path on the other side. The method according to claim 11, which is performed using an exchange membrane.

13. The method of claim 12, wherein the anode compartment and the cathode compartment are filled with a cation exchange material.

14. The method of claim 13, wherein the anode compartment and the cathode compartment are filled with an anion exchange material.

13. The method of claim 12, wherein the anode compartment and the cathode compartment are in contact with a cation exchange membrane.

14. The method of claim 13, wherein the anode compartment and the cathode compartment are in contact with an anion exchange membrane.

A method for measuring the ionic purity of an aqueous sample,
Measuring the conductivity and temperature of the sample stream;
Splitting the sample stream into two substantially equal split sample streams;
Continuously exchanging cations in one split sample stream for hydrogen ions and continuously exchanging anions for the other sample stream for hydroxide ions;
Measuring both conductivity and temperature of each split sample stream following continuous ion exchange;
A method for measuring the ionic purity of an aqueous sample, comprising calculating the pH of a sample stream using the temperature and conductivity of the original sample stream and the two ion-exchanged split sample streams.

An apparatus for measuring the cation conductivity of an aqueous sample,
A cation exchange element for exchanging cations present in the sample with hydrogen ions as the sample passes in contact with the cation exchange element;
A conductivity meter for measuring the conductivity and temperature of the sample after contact with the cation exchange element; and by replacing the cations removed from the cation portion with new hydrogen ions generated by electrolysis of water An apparatus for measuring the cation conductivity of an aqueous sample, comprising a cation exchange element regeneration system for continuously regenerating a cation exchange element.

Cation exchange element regeneration system
An anode compartment including an anode, an anode compartment inlet end, and an anode compartment outlet end;
A cathode compartment including a cathode, a cathode compartment inlet end, and a cathode compartment outlet end;
DC power supply;
At least one cation exchange membrane arranged to form a cation membrane compartment, the cation exchange membrane having a cation membrane compartment inlet and a cation membrane compartment outlet; and a cation exchange material disposed within the cation membrane compartment. 22. The device of claim 21 comprising:

23. The device of claim 22, wherein the anode compartment and the cathode compartment are filled with a cation exchange material.

23. The device of claim 22, wherein the anode and cathode are in contact with a cation exchange membrane.

The cation exchange element regeneration system further
Two electrically insulating flat plate elements, the first of which includes a fluid inlet and fluid outlet pair and a sample flow path disposed therebetween along one surface thereof; A second element comprising two pairs of fluid inlets and fluid outlets, each of which has an electrode track between them along one side thereof;
An anode included in one of the electrode tracks and a cathode included in the other of the electrode tracks; and a cation exchange membrane disposed between the two plate elements, the membrane being disposed along one surface of the membrane. 22. The apparatus of claim 21 including a cation exchange membrane in contact with the anode and cathode and in contact with the sample flow path along opposite sides of the membrane.

An aqueous sample anion conductivity measuring device,
An anion exchange element for exchanging anions present in the sample for hydroxyl ions as the sample passes in contact therewith;
A conductivity meter for measuring the conductivity and temperature of the sample after contact with the anion exchange element; and by replacing the anions removed from the anion portion with new hydroxyl ions generated by electrolysis of water An apparatus for measuring anion conductivity of an aqueous sample, comprising an anion exchange element regeneration system for continuously regenerating anion exchange elements.

Anion exchange element regeneration system
An anode compartment including an anode, an anode compartment inlet end, and an anode compartment outlet end;
A cathode compartment including a cathode, a cathode compartment inlet end, and a cathode compartment outlet end;
DC power supply;
At least one anion exchange membrane arranged to form an anion membrane compartment, the anion exchange membrane having an anion membrane compartment inlet and an anion membrane compartment outlet; and an anion disposed within the anion membrane compartment 27. The device of claim 26, comprising a replacement material.

28. The device of claim 27, wherein the anode compartment and the cathode compartment are filled with an anion exchange material.

28. The device of claim 27, wherein the anode and the cathode are in contact with an anion exchange material.

The anion exchange element regeneration system
Two electrically insulating flat plate elements, the first of which includes a fluid inlet and fluid outlet pair and a sample flow path disposed therebetween along one surface thereof; A second element comprising two pairs of fluid inlets and fluid outlets, each of which has an electrode track between them along one side thereof;
An anode included in one of the electrode paths and a cathode included in the other of the electrode paths; and an anion exchange membrane disposed between the two plate elements, the anode and the anode being disposed along one surface thereof. 27. The device of claim 26, comprising an anion exchange membrane in contact with the cathode and in contact with the sample flow path along an opposite surface.

A method for measuring the cation conductivity of an aqueous sample,
Continuously exchanging cations in the sample with hydrogen ions by contacting the cations with a cation exchange element;
A method for measuring the cation conductivity of an aqueous sample, comprising the steps of continuously regenerating the cation exchange element with new hydrogen ions; and measuring the conductivity and temperature of the sample removed from contact with the cation exchange element.

Exchange of cations with hydrogen ions and continuous regeneration of the cation exchange elements,
Anode compartment means having an anode, an inlet end, and an outlet end;
Cathode compartment means having a cathode, an inlet end, and an outlet end;
DC power supply;
Two cation exchange membranes arranged to form a compartment therebetween, the cation exchange membrane having compartments having inlet and outlet means; and being disposed within the compartment between the membranes. 32. The method according to claim 31, which is performed using a cation exchange material.

Exchange of cations with hydrogen ions and continuous regeneration of the cation exchange elements,
Two electrically insulating plates, one of the plates having an inlet, an outlet and a sample flow path disposed between the inlet and the outlet on one side thereof; Has an inlet, an outlet, and a passage including an anode between the inlet and the outlet, and a passage including an inlet and an outlet and a cathode between the inlet and the outlet on the same side of the plate. And a cation exchange membrane disposed between the two plates, the cation exchange membrane having contact on one side with the anode and cathode and contact on the opposite side with the sample flow path. 32. The method according to claim 31, wherein the method is performed using a cation exchange membrane.

A method for measuring anionic conductivity of an aqueous sample,
Continuously exchanging the anions in the sample with hydroxide ions by contacting the anions with an anion exchange element;
Continuously regenerating the anion exchange element with new hydroxyl ions; and measuring the anion conductivity of the aqueous sample comprising measuring the conductivity and temperature of the anion portion of the sample removed from contact with the anion exchange element Method.

Exchange of anions with hydroxide ions and continuous regeneration of the anion exchange elements,
Anode compartment means having an anode, an inlet end, and an outlet end;
Cathode compartment means having a cathode, an inlet end, and an outlet end;
DC power supply;
Using two anion exchange membranes arranged to form a compartment therebetween, the anion exchange membrane having inlet means and outlet means; and an anion exchange material arranged in the compartment between the membranes 35. The method of claim 34, wherein the method is performed.

Exchange of anions with hydroxide ions and continuous regeneration of the anion exchange elements,
Two electrically insulating plates, one of the plates having an inlet, an outlet and a sample flow path disposed between the inlet and the outlet on one side thereof; Has an inlet, an outlet, and a passage containing the anode between the inlet and the outlet, and has a passage containing the inlet and the outlet and the cathode between the inlet and the outlet on the same side of the plate. A plate; and an anion exchange membrane disposed between the two plates, the anion exchange membrane having contact with the anode and cathode on one side and contact with the sample flow path on the other side. 35. The method of claim 34, wherein the method is performed using a membrane.