JP4828012B2

JP4828012B2 - Disinfection water generation method and apparatus

Info

Publication number: JP4828012B2
Application number: JP2000140974A
Authority: JP
Inventors: 猛柴田; 利雄五津; 均毛利; 清隆志摩
Original assignee: DKK TOA Corp
Current assignee: DKK TOA Corp
Priority date: 2000-05-12
Filing date: 2000-05-12
Publication date: 2011-11-30
Anticipated expiration: 2020-05-12
Also published as: JP2001321778A

Description

【０００１】
【発明の属する技術分野】
本発明は、一般には、食品加工、農水産業、医療など様々な分野における各種機器或いは食料品を汚染する微生物を殺菌、消毒するために利用することができる殺菌水の生成方法及び装置に関し、特に、殺菌剤として用いられる次亜塩素酸ナトリウムを活性化し、殺菌力を増強させる殺菌水生成方法及び装置に関するものである。
【０００２】
【従来の技術】
従来、例えば医療分野において、血液透析用機器の殺菌、消毒のために、次亜塩素酸ナトリウム（ＮａＯＣｌ）水溶液が用いられている。通常、次亜塩素酸ナトリウムは６ｗ／ｗ％程度の濃度で提供され、この原液を使用時に５００〜１０００ｐｐｍの濃度に希釈して殺菌水として使用する。
【０００３】
しかし、このような次亜塩素酸ナトリウム含有殺菌水によって各種機器などを殺菌、消毒した後には、次亜塩素酸ナトリウムが残留しないように、十分に清水にて洗浄する必要があり、次亜塩素酸ナトリウムを含む機器洗浄廃液が環境中に排出されることとなる。従って、上述のように５００〜１０００ｐｐｍといった高濃度にて次亜塩素酸ナトリウムを含む殺菌水が多量に用いられると、環境に与える影響が大きいという問題があった。又、次亜塩素酸ナトリウムを高濃度で含む洗浄廃液が活性汚泥法を用いた排水処理施設に導入されるならば、汚泥（微生物）に相当のダメージを与え、処理不能となることさえあり得る。
【０００４】
一方、上記問題点に鑑み、近年、次亜塩素酸ナトリウム含有殺菌水の殺菌力を増強させて、次亜塩素酸ナトリウムの使用量を削減することができる装置が提案された（特開平１０−１８２３２５号公報）。又、例えば血液透析機器の洗浄、消毒方法として、次亜塩素酸ナトリウム及び酢酸を含む次亜塩素酸ナトリウム活性水を使用する方法の殺菌、消毒能力が実証されている（例えば“次亜塩素酸ナトリウム活性水の洗浄・消毒効果”、「機能水医療研究会第１巻第２号」、１０１頁〜１０４頁（１９９９））。
【０００５】
即ち、次亜塩素酸ナトリウムを含む殺菌水が示す殺菌力の主成分は次亜塩素酸（ＨＯＣｌ）であり、且つ殺菌水中の次亜塩素酸（ＨＯＣｌ）の存在率が殺菌水のｐＨに依存することが明らかにされた。図５は、次亜塩素酸ナトリウム含有殺菌水中の、ｐＨによる次亜塩素酸の存在率を示している。図５から理解されるように、次亜塩素酸ナトリウム自体は強アルカリ性であり、ｐＨの低下に伴って約ｐＨ４．５まで次亜塩素酸（ＨＣｌＯ）の含有量が増大する。又、約ｐＨ３．０より低くなり過ぎても次亜塩素酸（ＨＣｌＯ）の含有量は減少する。
【０００６】
つまり、次亜塩素酸ナトリウムを単に水で希釈した従来の殺菌水は強アルカリ性（約ｐＨ８．５〜ｐＨ１０）であり、殺菌水中に５００ｐｐｍ〜１０００ｐｐｍといった高濃度にて次亜塩素酸ナトリウムを希釈しても、含有次亜塩素酸ナトリウムのわずか５％程度しか殺菌力の強い次亜塩素酸（ＨＣｌＯ）として存在していない。
【０００７】
そこで、上記の次亜塩素酸ナトリウムの殺菌力増強装置（特開平１０−１８２３２５号公報）では、次亜塩素酸ナトリウム含有殺菌水のｐＨをｐＨ３．０〜６．０の範囲に調整する。これにより、殺菌水に含まれる次亜塩素酸ナトリウムのほぼ１００％が殺菌に有効な次亜塩素酸（ＨＣｌＯ）として存在できるので、強力な殺菌力を得るために必要とされる次亜塩素酸ナトリウムの量を低減させ、例えば１０〜２０ｐｐｍまで次亜塩素酸ナトリウムの濃度を低下させることができる。以下、この原理を用いて調製される次亜塩素酸ナトリウム含有殺菌水を、「次亜塩素酸ナトリウム活性水」或いは単に「活性水」と呼ぶ。
【０００８】
【発明が解決しようとする課題】
上述のように次亜塩素酸ナトリウムの濃度を希薄にし、且つ殺菌力を強化した次亜塩素酸ナトリウム活性水を調製するためには、活性水の次亜塩素酸ナトリウム濃度及びｐＨを、所望の設定値に正確に合わせることが不可欠であり、これによって初めて強力な殺菌力が保証される。又、必要以上に次亜塩素酸ナトリウムが添加されることがあれば、上述のように消毒、殺菌廃液が環境中に排出されたときに問題となる。
【０００９】
従来、活性水の次亜塩素酸ナトリウム濃度及びｐＨを調製する方法として、次亜塩素酸ナトリウム及び／又は酸の希釈用原水の流量を検出して、この流量に対して所定の割合で次亜塩素酸ナトリウムや酸を添加する方法がある。
【００１０】
しかし、このような方法では、例えば次亜塩素酸ナトリウムや酸の原液が無くなった場合（使い切ったとき）や、次亜塩素酸ナトリウムや酸を供給するための薬液ポンプに異常が生じた場合などには、次亜塩素酸ナトリウム濃度及びｐＨが設定値に適合しなくなる。薬液ポンプの異常としては、機械的な故障（ダイアフラムの破損など）或いは電気的な故障（ヒューズ切れなど）が考えられる。又、ダイアフラム式のポンプにエアロックが発生したり、或いは薬液配管チューブがはずれるなどの不具合が生じることも考えられる。更に、活性水の次亜塩素酸濃度及びｐＨが設定値から外れる原因としては、希釈用原水の不足、断水などが生じることも考えられる。
【００１１】
従って、このような様々な事象に対処し、常に所定の次亜塩素酸ナトリウム濃度及びｐＨを維持して、常に強い殺菌力を備えた次亜塩素酸ナトリウム活性水を調製するために、或いは所望の活性水が得られない恐れがある場合に活性水の調製を停止させたり、警報を発するために、次亜塩素酸ナトリウムの濃度及びｐＨを監視し、又次亜塩素酸ナトリウム及び酸の添加量を調整して信頼性を増すことが非常に重要である。
【００１２】
活性水の次亜塩素酸ナトリウム濃度を検出する方法としては、所謂、ポーラログラフを利用した次亜塩素酸濃度検出センサ（残留塩素濃度検出器）を用いることが考えられる。例えば、この次亜塩素酸濃度計の指示を見ながら次亜塩素酸ナトリウムの濃度が所定値になるまで手動にて次亜塩素酸ナトリウムの注入量を調整したり、或いは次亜塩素酸濃度計の検出値を用いて自動にて調整することにより行うことができる。又、活性水のｐＨは、ｐＨ計を用いて検出し、その検出値から酸の添加量を調整することが考えられる。
【００１３】
しかしながら、ポーラログラフを利用した次亜塩素酸濃度検出センサは比較的高価であり、又検出精度を維持するためには、電極のメンテナンスなど保守のための費用もかかり操作も煩雑となる。又、周知のように、ｐＨ計は定期的に標準校正を行う必要があり、ｐＨの検出精度を維持するためには、この標準校正を頻繁に行わなければならず、操作が煩雑となる。このように、次亜塩素酸濃度検出センサやｐＨ計を使用する方法では、コスト、センサの保守、信頼性の点で問題がある。
【００１４】
又、例えば次亜塩素酸ナトリウム活性水を食品加工分野における機器の消毒、殺菌に用いるような場合には、通常のガラス電極を使用したｐＨ計を使用すると、ガラス電極が破損した際に食品にガラスの破片が混入する恐れがあり問題である。尚、ガラス電極を用いない、所謂、メトキシー電極型のｐＨ計もあるが、活性水に含まれる次亜塩素酸は強力な酸化剤であるので使用に適さない。
【００１５】
このように、安全、低コスト且つ簡便に活性水の次亜塩素酸濃度及びｐＨを監視でき、常に正確に所定の濃度及びｐＨの活性水を調製し得る方法及び装置が望まれる。
【００１６】
更に、このような方法及び装置はまた、広範囲の希釈用原水の使用に適用し得ることが望まれる。即ち、例えば血液透析機器の殺菌、消毒に用いる次亜塩素酸ナトリウム活性水の調製には、希釈用原水として実質的に溶存イオンを含まない逆浸透水（Ｒ／Ｏ水）を用いる必要がある。逆浸透水生成（Ｒ／Ｏ）装置は、比較的高価であり、更には膜や樹脂の交換などのランニングコストもかかる。しかし、例えば、食品加工、農水産、畜産分野における、製造ライン、配管、タンクなどの機器或いは食料品の殺菌や消毒、半導体基板の殺菌など工業生産分野における殺菌や消毒、廃棄物処理や下水処理分野における殺菌や消毒、或いはプール水の殺菌の用途には、希釈用原水として水道水、井戸水などを使用することができ、これにより大幅にコストを削減することができる。
【００１７】
又、水道水や井戸水に加えて、海水を希釈用原水として用いることが望まれる場合がある。即ち、水産分野において、魚洗浄や解凍などに使用する海水を、殺菌力の強い次亜塩素酸ナトリウム活性水とすることにより、例えば海水に含まれる有害微生物（例えば食中毒の原因となり得る腸炎ビブリオ菌など）の殺菌、繁殖防止、洗浄の効果が得られ、同時に、希釈用原水が海水であるので、魚の変色などの弊害を防止することができる。
【００１８】
従って、本発明の目的は、安全、低コスト且つ簡便に、常に所望の次亜塩素酸ナトリウム濃度及びｐＨの殺菌水を得ることが可能な殺菌水生成方法及び装置を提供することである。
【００１９】
又、本発明の他の目的は、特に、殺菌水を調製するための希釈用原水として、逆浸透水（Ｒ／Ｏ水）、水道水、井戸水或いは海水などの広範囲の希釈用原水を使用することができ、しかも安全、低コスト且つ簡便に、常に所望の次亜塩素酸ナトリウム濃度及びｐＨの殺菌水を得ることが可能な殺菌水生成方法及び装置を提供することである。
【００２０】
【課題を解決するための手段】
上記目的は本発明に係る殺菌水生成方法及び装置にて達成される。要約すれば、本発明の第１の態様によると、一定流量で流動する原水に次亜塩素酸ナトリウムを添加して希釈混合することで次亜塩素酸ナトリウム希釈液を生成すると共に、一定流量で流動する原水に酸を添加して希釈混合することで酸希釈液を生成し、生成した前記次亜塩素酸ナトリウム希釈液と前記酸希釈液とを混合することで所望の次亜塩素酸ナトリウム濃度及びｐＨの殺菌水を生成する殺菌水生成方法であって；次亜塩素酸ナトリウム水溶液の濃度と電気伝導率との相関から、所望の濃度の次亜塩素酸ナトリウム水溶液における次亜塩素酸ナトリウムの添加による電気伝導率の増加分を第１の所定値と定めること；前記次亜塩素酸ナトリウム希釈液の濃度が所望の濃度となるように予め調整された添加量にて次亜塩素酸ナトリウムを前記一定流量で流動する原水に添加して希釈混合することで前記次亜塩素酸ナトリウム希釈液を得ること；酸水溶液の濃度と電気伝導率との相関から、所望の濃度の酸水溶液における酸の添加による電気伝導率の増加分を第２の所定値と定めること；前記酸希釈液の濃度が所望の濃度となるように予め調整された添加量にて酸を前記一定流量で流動する原水に添加して希釈混合することで前記酸希釈液を得ること；前記次亜塩素酸ナトリウム希釈液の電気伝導率（ｄ１）、前記酸希釈液の電気伝導率（ｄ２）、及び原水の電気伝導率（ｄ３）を測定すること；前記次亜塩素酸ナトリウム希釈液と原水の電気伝導率の差である第１の電気伝導率差（ｄ１−ｄ３）、及び前記酸希釈液と原水の電気伝導率の差である第２の電気伝導率差（ｄ２−ｄ３）を求めること；前記第１の電気伝導率差（ｄ１−ｄ３）と前記第１の所定値とを比較して、前記第１の電気伝導率差（ｄ１−ｄ３）が前記第１の所定値から外れて所定時間経過した場合に、前記次亜塩素酸ナトリウム希釈液の濃度が所望の濃度から外れて正常な殺菌水を生成できないことを判断して、所定の警報を発するか、所定の情報表示を行うか、又は原水の供給を停止すること；前記第２の電気伝導率差（ｄ２−ｄ３）と前記第２の所定値とを比較して、前記第２の電気伝導率差（ｄ２−ｄ３）が前記第２の所定値から外れて所定時間経過した場合に、前記酸希釈液の濃度が所望の濃度から外れて正常な殺菌水を生成できないことを判断して、所定の警報を発するか、所定の情報表示を行うか、又は原水の供給を停止すること；前記次亜塩素酸ナトリウム希釈液と前記酸希釈液とを混合して殺菌水を得ること；を含むことを特徴とする殺菌水生成方法が提供される。
【００２２】
本発明の第１の態様において、一実施態様によると、前記原水の電気伝導率（ｄ３）を測定する代わりに、原水の電気伝導率（ｄ３）として一定値を用いる。
【００２５】
本発明の第２の態様によると、原水に次亜塩素酸ナトリウム及び酸を添加して所望の次亜塩素酸ナトリウム濃度及びｐＨの殺菌水を生成する殺菌水生成装置であって、原水を供給する原水供給流路と、原水に次亜塩素酸ナトリウムを添加、混合して次亜塩素酸ナトリウム希釈液を得るための、前記原水供給流路から分岐した第１の希釈混合流路であって、当該第１の希釈混合流路中を流動する原水の流量を一定に維持する第１の流量規制手段と、当該第１の希釈混合流路中を流動する原水に次亜塩素酸ナトリウムを添加する第１の添加手段と、次亜塩素酸ナトリウムが添加された後の液を混合攪拌する第１の混合器と、を備え、前記第１の添加手段は、前記次亜塩素酸ナトリウム希釈液の濃度が所望の濃度となるように予め調整された添加量にて次亜塩素酸ナトリウムを前記一定流量で流動する原水に添加する第１の希釈混合流路と、原水に酸を添加、混合して酸希釈液を得るための、前記原水供給流路から分岐した第２の希釈混合流路であって、当該第２の希釈混合流路中を流動する原水の流量を一定に維持する第２の流量規制手段と、当該第２の希釈混合流路中を流動する原水に酸を添加する第２の添加手段と、酸が添加された後の液を混合攪拌する第２の混合器と、を備え、前記第２の添加手段は、前記酸希釈液の濃度が所望の濃度となるように予め調整された添加量にて酸を前記一定流量で流動する原水に添加する第２の希釈混合流路と、前記次亜塩素酸ナトリウム希釈液と前記酸希釈液とを混合するための、前記第１、第２の希釈混合流路からの液が合流し導かれる混合流路であって、前記第１の希釈混合流路からの液と前記第２の希釈混合流路からの液を混合攪拌する第３の混合器を備えた混合流路と、前記第１の希釈混合流路の、前記第１の混合器の下流側に設けられ、前記次亜塩素酸ナトリウム希釈液の電気伝導率（ｄ１）を測定する第１の電気伝導率測定手段と、前記第２の希釈混合流路の、前記第２の混合器の下流側に設けられ、前記酸希釈液の電気伝導率（ｄ２）を測定する第２の電気伝導率測定手段と、前記原水供給流路に設けられ、原水の電気伝導率（ｄ３）を測定する第３の電気伝導率測定手段と、前記第１、第２及び第３の電気伝導率測定手段からの信号に基づく処理を行う制御手段であって；次亜塩素酸ナトリウム水溶液の濃度と電気伝導率との相関から定められた、所望の濃度の次亜塩素酸ナトリウム水溶液における次亜塩素酸ナトリウムの添加による電気伝導率の増加分が第１の所定値として記憶され、酸水溶液の濃度と電気伝導率との相関から定められた、所望の濃度の酸水溶液における酸の添加による電気伝導率の増加分が第２の所定値として記憶されており；前記次亜塩素酸ナトリウム希釈液と原水の電気伝導率の差である第１の電気伝導率差（ｄ１−ｄ３）、及び前記酸希釈液と原水の電気伝導率の差である第２の電気伝導率差（ｄ２−ｄ３）を求める処理；前記第１の電気伝導率差（ｄ１−ｄ３）と前記第１の所定値とを比較して、前記第１の電気伝導率差（ｄ１−ｄ３）が前記第１の所定値から外れて所定時間経過した場合に、前記次亜塩素酸ナトリウム希釈液の濃度が所望の濃度から外れて正常な殺菌水を生成できないことを判断する処理；及び前記第２の電気伝導率差（ｄ２−ｄ３）と前記第２の所定値とを比較して、前記第２の電気伝導率差（ｄ２−ｄ３）が前記第２の所定値から外れて所定時間経過した場合に、前記酸希釈液の濃度が所望の濃度から外れて正常な殺菌水を生成できないことを判断する処理を行う制御手段と、を有することを特徴とする殺菌水生成装置が提供される。
【００２６】
本発明の第２の態様において、一実施態様によると、装置は更に、予め求められた原水の電気伝導率の所定値を前記制御手段に入力する電気伝導率入力手段を有し、前記制御手段は、原水の電気伝導率（ｄ３）として前記第３の電気伝導率測定手段からの信号の代わりに、前記電気伝導率入力手段から入力された信号を利用する。
【００２８】
本発明の第２の態様において、他の実施態様によると、前記制御手段は、前記正常な殺菌水が生成できないことを判断した場合に、所定の警報を発する処理、所定の情報表示を行う処理、又は原水の供給を停止させる処理を行う。
【００２９】
上記各本発明の一実施態様によると、原水は、水道水、井戸水、海水又は逆浸透水（Ｒ／Ｏ水）である。
【００３０】
又、上記各本発明の一実施態様によると、好ましくは、前記殺菌水の次亜塩素酸ナトリウム濃度は０．５ｐｐｍ〜１０００ｐｐｍの範囲とされ、ｐＨはｐＨ３．０〜７．５の範囲とされる。
【００３１】
【発明の実施の形態】
以下、本発明に係る殺菌水生成方法及び装置を図面に則して更に詳しく説明する。
【００３２】
本実施例では、本発明の殺菌水生成方法及び装置は、希釈用原水として水道水を用いるとして説明する。図１は、本発明の殺菌水生成方法を具現化する装置の一実施例の概略構成を示す。
【００３３】
先ず、本実施例の殺菌水生成装置（活性水生成装置）の基本構成について説明する。図１に示すように、本実施例の殺菌水生成装置１００は、希釈用原水の供給口１から装置内に水道水を取り込み、次亜塩素酸ナトリウムが活性化されて殺菌力が増強した殺菌水（次亜塩素酸ナトリウム活性水）を調製し、取出口１３から装置外に取り出すことができる。本実施例によれば、詳しくは後述するように、次亜塩素酸ナトリウム及び酸は、各々単独で希釈用原水に希釈混合され、その後この次亜塩素酸ナトリウム希釈液流と酸希釈液流とを混合することによって次亜塩素酸ナトリウム活性水を得る。本実施例によれば、連続的に希釈用原水を供給して連続的に活性水を生成することができる。又、例えば、取出口１３に活性水の貯留槽（図示せず）を接続し、これに活性水を貯留して用いるような場合に、貯留槽内の活性水が所定レベル以下となる毎に活性水の生成を開始するなど、活性水を間欠的に生成するように制御することもできる。
【００３４】
装置１００が備えた原水供給手段としての原水供給流路Ｌ１は、供給口１を介して一般の水道水供給管の蛇口（図示せず）などに接続される。原水供給流路Ｌ１には電磁弁１４が設けられ、この電磁弁１４の開閉によって原水の供給が制御される。電磁弁１４の開閉は、通常、装置操作部２４における使用者の操作などに従った制御手段２０の指示により行われる。又、詳しくは後述するように、制御手段２０が装置異常を検知した場合には電磁弁１４が閉じられ、希釈用原水の供給が停止される。更に、原水供給流路Ｌ１の供給口１と電磁弁１４との間に、圧力スイッチ１５を設けることができる。これにより、供給口１付近に所定の圧力がかかっている場合に装置が作動するようにでき、断水や水量不足時には、後述の次亜塩素酸ナトリウムや酸が供給されない構成とすることができる。
【００３５】
原水供給流路Ｌ１の下流側は、第１、第２の方向へと分岐され、それぞれ原水流量規制手段としての第１、第２の定流量弁２、３を介して、第１、第２の希釈混合手段としての次亜塩素酸ナトリウム希釈混合流路（第１の希釈混合流路）Ｌ２、酸希釈混合流路（第２の希釈混合流路）Ｌ３へと水道水が供給される。本実施例では、第１、第２の定流量弁２、３は、第１の希釈混合流路Ｌ２及び第２の希釈混合流路Ｌ３に等流量の希釈用原水を供給する。
【００３６】
第１の希釈混合流路Ｌ２への原水の供給は、第１の定流量弁２により一定流量に維持される。第１の希釈混合流路Ｌ２には、第１の定流量弁２の下流に位置して第１の注入部６が設けられている。この第１の注入部６において、次亜塩素酸ナトリウム添加手段として、第１の原液タンク４から第１のポンプ５を介して、次亜塩素酸ナトリウム原液が希釈用原水流中に注入される。第１のポンプ５は、詳しくは後述するように制御手段２０の制御により作動し、次亜塩素酸ナトリウムの注入量が調整される。本実施例では、次亜塩素酸ナトリウム原液の濃度は６ｗ／ｗ％であり、そのｐＨは１２．４である。
【００３７】
希釈用原水中に注入された次亜塩素酸ナトリウムは、第１の注入部６より下流に設けられた第１の混合器７にて十分に希釈用原水と攪拌混合される。
【００３８】
又、原水供給路Ｌ１から酸希釈流路Ｌ３への希釈用原水の供給量は、第２の定流量弁３によって一定流量に維持される。第２の希釈混合流路Ｌ３には、第２の定流量弁３の下流に位置して、第２の注入部１０が設けられている。この第２の注入部１０において、酸添加手段として、第２の原液タンク８から第２のポンプ９を介して、酸原液が希釈用原水の液流中に注入される。第２のポンプ９は、第１のポンプ５と同様、後述のように制御手段２０の制御によって作動し、酸の注入量が調整される。
【００３９】
本実施例では、酸原液として、濃度３０ｗ／ｗ％の酢酸を用いた。ｐＨ調整用の酸としては、価格及び無毒性であるという点で酢酸が好ましいが、本発明はこれに限定されるものではなく、活性水のｐＨ調整の目的に適合する任意の酸から適宜選択することすることができる。例えば、酢酸の代わりにクエン酸、塩酸、或いは酢酸と塩酸の混合酸を用いることができる。
【００４０】
希釈用原水中に注入された酢酸は、第２の注入部１０より下流に設けられた第２の混合器１１にて十分に希釈用原水と攪拌混合される。
【００４１】
混合器７、１１を通過した次亜塩素酸ナトリウム希釈液流、及び酸希釈液流は、更に下流側にて合流し、両希釈液の混合手段としての混合流路Ｌ４に導入され、第３の混合器１２において十分に攪拌混合される。
【００４２】
第１、第２及び第３の混合器７、１１、１２としては、それぞれ十分な攪拌能力を備えた任意の混合器とすることができる。例えば、適当な攪拌子や水流を妨げる邪魔板部材などの攪拌手段を備えたものを用いることができる。
【００４３】
前述のように、原水中に添加した次亜塩素酸ナトリウムがほぼ１００％殺菌力の強い次亜塩素酸（ＨＣｌＯ）として存在するためには、ｐＨ３．０〜７．５の範囲であることが好ましく、より好ましくは、ｐＨ３．０〜６．５、最も好ましくはｐＨ４．０〜５．０である。
【００４４】
又、活性水のｐＨを上述の範囲内とすることによって、次亜塩素酸ナトリウムは比較的低濃度にて有効な殺菌、消毒力を発揮することができる。環境に対する次亜塩素酸ナトリウムの影響を考えれば、次亜塩素酸ナトリウムはより低濃度であることが好ましいが、活性水の殺菌力は次亜塩素酸ナトリウムの濃度が高い方が強い。従って、次亜塩素酸ナトリウムの濃度は、所望の殺菌力、又環境への影響に鑑みて適宜選択することができる。好ましくは、次亜塩素酸ナトリウム濃度は０．５ｐｐｍ〜１０００ｐｐｍである。
【００４５】
本実施例では、上述のように各々単独で希釈用原水中に希釈混合された次亜塩素酸ナトリウム希釈液と酸希釈液とを混合することによって、最終的に生成される活性水の次亜塩素酸ナトリウム濃度が１０ｐｐｍ、ｐＨが５．０となるように設定されている。
【００４６】
次に、殺菌水の次亜塩素酸ナトリウムの濃度及びｐＨの調整方法について更に説明する。上述のように、活性水の次亜塩素酸ナトリウム濃度及びｐＨを監視し、常に適正な値となるようにすることは、強力な殺菌力を発揮するために極めて重要である。
【００４７】
先ず、本発明の原理を説明すると、図２は、水道水（２００ｍＬ）に添加した次亜塩素酸ナトリウム（６ｗ／ｗ％）の量（μＬ）と、その次亜塩素酸ナトリウム希釈液の電気伝導率［μＳ／ｃｍ；×１０^-4Ｓ／ｍ］（約１７℃）の関係の一例を示している。電気伝導率は、電気伝導率センサ（東亜電波製：ＣＰ９１６Ａ）を用いて測定した。図示の通り、水道水への次亜塩素酸ナトリウムの添加量、即ち、濃度と次亜塩素酸ナトリウム希釈液の電気伝導率とには一定の相関があることが分かる。同様に、図３は、水道水（２００ｍＬ）に添加した酢酸水溶液（５Ｍ）の量と、その酸希釈液の電気伝導率［μＳ／ｃｍ；×１０^-4Ｓ／ｍ］（約１５℃）との関係の一例を示す。次亜塩素酸ナトリウム希釈液と同様、水道水への酢酸の添加量、即ち、酸濃度と酸希釈液の電気伝導率とには一定の相関があることが分かる。
【００４８】
又、次亜塩素酸ナトリウム希釈液と酸希釈液とを混合して生成される活性水のｐＨは、（１）希釈用原水のｐＨ、及びバッファーアクション（２）次亜塩素酸ナトリウムの添加量、（３）酸添加量の３つを含むパラメータによって決定される。図４は、次亜塩素酸ナトリウムを３０ｐｐｍの濃度にて含む水道水（２００ｍＬ）、即ち、次亜塩素酸ナトリウム希釈液に添加した酢酸水溶液（５Ｍ）の量（μＬ）と、混合液のｐＨとの関係の一例を示している。図示の通り、所定の希釈用原水に所定の濃度で次亜塩素酸ナトリウムが希釈された次亜塩素酸ナトリウム希釈液への酸の添加量、即ち、濃度と、最終的に生成される活性水のｐＨとには一定の相関がある。
【００４９】
このように、次亜塩素酸ナトリウム希釈液の濃度と電気伝導率との相関を求めておくことによって、第１の希釈混合流路Ｌ２にて生成される次亜塩素酸ナトリウム希釈液の電気伝導率値から、その次亜塩素酸ナトリウム濃度を検知することができる。同様に、酸希釈液の濃度と電気伝導率との相関を求めておくことによって、第２の希釈混合流路Ｌ３にて生成される酸希釈液の電気伝導率から、その酸濃度を検知することができる。
【００５０】
最終的に、第１、第２の希釈混合流路Ｌ２、Ｌ３からの次亜塩素酸ナトリウム希釈液と酸希釈液が、所定の割合（流量）にて混合流路Ｌ４に導かれて混合されることで活性水は調製される。従って、第１の希釈混合流路Ｌ２における次亜塩素酸ナトリウム希釈液の濃度と第２の希釈混合流路Ｌ３における酸希釈液の濃度を監視することによって、最終的に調製される活性水の次亜塩素酸濃度及び酸濃度を監視することができる。そして、上述のように、次亜塩素酸ナトリウムを含む溶液中の酸濃度と、この溶液のｐＨとには一定の相関があるので、調製される活性水の酸濃度を所定値とすることによって、そのｐＨを所定値とすることができる。
【００５１】
しかしながら、本実施例のように希釈用原水として水道水用いる場合、その水質は、時間経過（例えば季節変化や朝夕の差）、場所、地域によって一定せず、多くの場合その電気伝導率も大きく変化する。一般に、水道水の電気伝導率は２００〜２５０［μＳ／ｃｍ；×１０^-4Ｓ／ｍ］程度であるが、この電気伝導率が場合によっては１４０〜２５０［μＳ／ｃｍ；×１０^-4Ｓ／ｍ］の範囲で大きく変動することがある。
【００５２】
このように電気伝導率の一定しない希釈用原水を利用する場合には、希釈用原水の電気伝導率変動と共に次亜塩素酸ナトリウム希釈液と酸希釈液の電気伝導率も大きく変動し、次亜塩素酸ナトリウム濃度、酸濃度自体の変動を監視することができなくなる。
【００５３】
そこで、本発明によれば、次亜塩素酸ナトリウム希釈液及び酸希釈液の電気伝導率に加えて、原水の電気伝導率をも利用し、詳しくは後述するように原水の電気伝導率変動を差し引くことによって常に正確に次亜塩素酸ナトリウム、酸濃度を検知できる構成とする。
【００５４】
上述のような原理に従い、本発明によれば、先ず、次亜塩素酸ナトリウム希釈液の電気伝導率（ｄ１）と、酸希釈液の電気伝導率（ｄ２）に対応した信号を制御手段２０に入力する第１、第２の電気伝導率測定手段を設ける。本実施例では、第１の電気伝導率測定手段として、第１の希釈混合流路Ｌ２に備えられた第１の混合器７の下流側に第１の電気伝導率センサＤ１を配置する。又、第２の電気伝導率測定手段として、第２の希釈混合流路Ｌ３に備えられた第２の混合器１１の下流側に第２の電気伝導率センサＤ２を配置する。
【００５５】
第１の電気伝導率センサＤ１は、第１の混合器７内で希釈混合された次亜塩素酸ナトリウム希釈液の電気伝導率（ｄ１）を検出し、対応する信号を制御手段２０に送信する。又、第２の電気伝導率センサＤ２は、第２の混合器１１内で希釈混合された酸希釈液の電気伝導率（ｄ２）を検出し、対応する信号を制御手段２０に送信する。
【００５６】
更に、本発明によれば、希釈用原水の電気伝導率（ｄ３）を制御手段２０に入力する第３の電気伝導率測定手段をも設ける。本実施例では、第３の電気伝導率測定手段として、原水供給流路Ｌ１の電磁弁１４の下流側に第３の電気伝導率センサＤ３を配置する。第３の電気伝導率センサＤ３は、希釈用原水の電気伝導率（ｄ３）を検出し、対応する信号を制御手段２０に送信する。
【００５７】
第１、第２及び第３の電気伝導率センサＤ１、Ｄ２、Ｄ３としては、限定するものではないが、東亜電波製ＣＰ９１６Ａを好適に使用することができる。尚、各電気伝導率センサＤ１、Ｄ２、Ｄ３の出力を所定の要領で増幅し、或いはＡ／Ｄ変換して制御手段２０に入力し得ることは当業者には明らかである。次亜塩素酸ナトリウム希釈水の電気伝導率（ｄ１）、酸希釈液の電気伝導率（ｄ２）及び原水の電気伝導率（ｄ３）に応じた信号とは、これらの電気伝導率（ｄ１、ｄ２、ｄ３）に応じて制御手段２０に入力される任意の形態の信号を包含する。
【００５８】
本実施例によれば、制御手段２０には、予め求められた次亜塩素酸ナトリウム希釈液の電気伝導率ｄ１と希釈用原水の電気伝導率ｄ３の差（ｄ１−ｄ３）と、次亜塩素酸ナトリウム濃度との関係に基づいて、所定の次亜塩素酸ナトリウム濃度の活性水を調製するための次亜塩素酸ナトリウム希釈液の濃度に相当する電気伝導率（ｄ１−ｄ３）が設定されている。
【００５９】
同様に、制御手段２０には、予め求められた酸希釈液の電気伝導率ｄ２と希釈用原水の電気伝導率ｄ３の差（ｄ２−ｄ３）と、酸濃度との関係に基づいて、所定のｐＨの活性水を調製するための酸希釈液の濃度に相当する電気伝導率（ｄ２−ｄ３）が設定されている。
【００６０】
尚、所定の次亜塩素酸ナトリウム濃度及びｐＨの活性水を調製するための電気伝導率差（ｄ１−ｄ３）、（ｄ２−ｄ３）の設定値を複数設け、例えば装置操作部２４にて適宜選択することにより、次亜塩素酸ナトリウムの濃度及びｐＨの異なる複数種類の活性水を生成できる構成とすることもできる。
【００６１】
又、例えば、制御手段２０が内蔵する記憶手段２１に、電気伝導率（ｄ１−ｄ３）と次亜塩素酸ナトリウム濃度との関係、電気伝導率（ｄ２−ｄ３）と酸濃度との関係をテーブルや数式などとして記憶させることによって、例えば０．５ｐｐｍ〜１０００ｐｐｍの次亜塩素酸ナトリウム濃度、ｐＨ３．０〜ｐＨ７．５の範囲の活性水を任意に選択し、対応する次亜塩素酸ナトリウム希釈液と酸希釈液の濃度を監視することができる。
【００６２】
更に、例えば、装置１００の使用現場にて次亜塩素酸ナトリウムの濃度及びｐＨを次亜塩素酸濃度検出センサやｐＨ計を用いて測定しながら、第１、第２のポンプ５、９を作動を制御して次亜塩素酸ナトリウムの添加量及び酸の添加量を手動にて調整し、目的の活性水が得られた時点での電気伝導率差（ｄ１−ｄ３）、（ｄ２−ｄ３）を設定、記憶させる構成とすることもできる。
【００６３】
活性水の生成に際して、制御手段２０は、入力された次亜塩素酸ナトリウム希釈水の電気伝導率（ｄ１）から希釈用原水の電気伝導率（ｄ３）を差し引いた電気伝導率（ｄ１−ｄ３）を設定値と比較することによって、次亜塩素酸ナトリウム希釈液の次亜塩素酸ナトリウム濃度を常に監視することができる。又、制御手段２０は、入力された酸希釈液の電気伝導率（ｄ２）から希釈用原水の電気伝導率（ｄ３）を差し引いた電気伝導率（ｄ２−ｄ３）を設定値と比較することによって、酸希釈液の酸濃度を常に監視することができる。
【００６４】
このように、次亜塩素酸ナトリウム希釈液の電気伝導率（ｄ１）と希釈用原水の電気伝導率（ｄ３）との差に相当する信号、又酸希釈液の電気伝導率（ｄ２）と希釈用原水の電気伝導率（ｄ３）との差に相当する信号を用いることによって、次亜塩素酸ナトリウム、及び酸の濃度変動のみに起因する電気伝導率変動を抽出して監視することができる。
【００６５】
本実施例によれば、制御手段２０は、上述のようにして監視している次亜塩素酸ナトリウムの濃度、或は酸の濃度が設定値となるように、即ち、連続的に第１、第２、第３の電気伝導率センサＤ１、Ｄ２、Ｄ３によって検出される電気伝導率ｄ１、ｄ３に基づいて検知される電気伝導率差（ｄ１−ｄ３）、及び電気伝導率差（ｄ２−ｄ３）が予め設定された所定値となるように、第１のポンプ５、及び第２のポンプ９の動作を制御し、第１の原液タンク４からの次亜塩素酸ナトリウム添加量、及び第２の原液タンク８からの酸添加量を調整する。
【００６６】
より具体的には、本実施例の殺菌水生成装置１００は、次亜塩素酸ナトリウム濃度１０ｐｐｍ、ｐＨ５．０の活性水を、約２０Ｌ／分の供給量にて調製することができる。第１及び第２の定流量弁２、３は、それぞれ等流量（約１０Ｌ／分）にて、第１の希釈混合流路Ｌ２、第２の希釈混合流路Ｌ３に希釈用原水を供給する。従って、第１のポンプ５は、第１の電気伝導率センサＤ１の位置で検出される次亜塩素酸ナトリウム濃度が２０ｐｐｍとなるように、次亜塩素酸ナトリウム原液を注入する。又、酢酸は、終濃度０．０５〜０．１ｗ／ｗ％、即ち、第２の電気伝導率センサＤ２の位置にて０．１〜０．２ｗ／ｗ％となるよう酢酸を注入することによって、活性水のｐＨをｐＨ５．０とする。
【００６７】
又、本発明によれば、所定の濃度の活性水を生成できない恐れのある場合に、警報や所定の情報表示など、所定の装置異常時動作を行うことよって、使用者に正常に活性水が生成されないことを報知することができる。又、このような場合に活性水の生成動作自体を停止させることもできる。
【００６８】
本実施例では、制御手段２０は、上述のようにして監視している次亜塩素酸ナトリウムの濃度、或は酸の濃度が設定値から外れ、即ち、電気伝導率差（ｄ１−ｄ３）及び電気伝導率（ｄ２−ｄ３）が予め設定された所定値から外れ、所定時間経過した場合に、警報装置２３によって所定の警報を発する。又、同時に、制御手段２０は電磁弁１４を閉じることによって、希釈用原水の供給を停止させる。更に、表示手段２２に装置が正常の作動していないことを使用者に知らせる情報を表示することもできる。
【００６９】
尚、上述のように、生成される活性水のｐＨは希釈原水のｐＨやバッファーアクションといったパラメータによっても変動する。例えば水道水のｐＨ及びバッファーアクションを含む水質は、時間経過（季節変化など）、場所、地域によって変化する。本発明者らの検討によると、或る特定の使用現場にて装置１００を使用する場合、水道水のｐＨ及びバッファーアクションの変化は短期間に活性水のｐＨを変動させるほどの影響は示さない。しかし、所望により、装置１００の使用現場において、定期的にｐＨ計を用いて活性水のｐＨをチェックし、活性水のｐＨと電気伝導率差（ｄ２−ｄ３）の設定値の関係、或いは記憶手段２１に記憶した電気伝導率差（ｄ２―ｄ３）と酸希釈液の酸濃度との関係を適宜補正することができる。
【００７０】
上述のように、本発明によれば、希釈用原水の電気伝導率変動に拘わらず、常に次亜塩素酸ナトリウム、酸自体の濃度変動を監視することが可能なので、例えば時間経過により水道水など希釈用原水の水質が変化し、その電気伝導率が大きく変化するような場合にも、次亜塩素酸ナトリウム及び酸の添加量を自動的に調整し、常に所定の次亜塩素酸ナトリウム濃度及びｐＨの活性水を得ることが可能である。又、所定の活性水が生成できない恐れのある場合に警報を発したり、活性水の生成動作を停止することにより、常に強力な殺菌力を有する活性水を生成することができ、更には必要以上の次亜塩素酸ナトリウムが使用されることによる、環境に与える影響やコストなどの問題も回避できる。
【００７１】
又、本発明によれば、次亜塩素酸ナトリウム、酸をそれぞれ希釈混合した液の電気伝導率から、希釈用原水自体の電気伝導率は差し引かれるので、電気伝導率が約１．０［μＳ／ｃｍ；×１０^-4Ｓ／ｍ］の逆浸透水（Ｒ／Ｏ水）、電気伝導率が約２５０［μＳ／ｃｍ；×１０^-4Ｓ／ｍ］の水道水、電気伝導率が約２０［ｍＳ／ｃｍ；×１０^-1Ｓ／ｍ］の海水などの広範囲の希釈用原水を、その電気伝導率の変動に拘わらず使用することができる。これにより、本発明に従う方法及び装置は、希釈用原水として逆浸透水（Ｒ／Ｏ水）を必要とする血液透析機器の殺菌から、例えばカット野菜の洗浄などの食品加工分野における洗浄、殺菌、更には水産分野における魚の洗浄、殺菌まで、広範囲の分野にて使用される活性水の調製に適用することができる。
【００７２】
尚、上記実施例では、装置１００は水道水供給管に直接接続されるものとして説明したが、希釈用原水として例えば逆浸透水（Ｒ／Ｏ水）を用いる場合は、原水供給手段として逆浸透水生成装置を介して供給口１を水道水供給管に接続したり、或は逆浸透水貯留槽から逆浸透水を供給口１に供給する構成とすることができる。又、希釈用原水として海水を用いる場合には、原水供給手段として、海水供給装置に供給口１を接続したり、或は海水貯留槽に供給口１を接続する構成とすることもできる。
【００７３】
又、例えば上記の電気伝導率センサ（東亜電波製ＣＰ９１６Ａ）など、一般に電気伝導率センサは金属及びプラスチックを用いて作製されるため、本発明によれば、ガラス電極を用いたｐＨ計を使用する場合のように、ガラス電極の破損によりその破片が活性水中に混入するという危険はない。又、一般に電気伝導率センサの校正周期は８０ヶ月程度と相当長くできるので、取り扱いが簡易であり、常に正確な検出が可能である。又、次亜塩素酸濃度センサ（残留塩素濃度検出器）のように定期的に電極部品を交換する必要もないので、保守の手間、コストも格段に軽減する。
【００７４】
上述の実施例では、希釈用原水の電気伝導率（ｄ３）を制御手段に入力する手段として、殺菌水の生成時に希釈用原水の電気伝導率を検出する電気伝導率センサｄ３を使用したが、別法として、例えば血液透析用機器の殺菌、消毒に用いる活性水を調製する場合など、希釈用原水として逆浸透水（Ｒ／Ｏ水）のように水質が一定であることが分かっている場合には、電気伝導率入力手段として、例えば、装置１００の操作部２４から希釈用原水の電気伝導率ｄ３の一定値を入力することによって、対応する信号を制御手段２０に入力することができる。この場合、制御手段２０は上述の実施例における第３の電気伝導率センサＤ３の検出信号の代わりに、入力された希釈用原水の電気伝導率値ｄ３の一定値を使用することが可能とされる。尚、予め記憶手段２１に複数種類の希釈用原水の電気伝導率ｄ３を記憶させ、適宜選択して用いることもできる。
【００７５】
【発明の効果】
以上説明したように、本発明によると、安全、低コスト且つ簡便に、常に所望の次亜塩素酸ナトリウム濃度及びｐＨの殺菌水を得ることができる。又、殺菌水を調製するための希釈用原水として、逆浸透水（Ｒ／Ｏ水）、水道水、井戸水或いは海水などの広範囲の希釈用原水を使用することができ、しかも安全、低コスト且つ簡便に、常に所望の次亜塩素酸ナトリウム濃度及びｐＨの殺菌水を得ることが可能である。
【図面の簡単な説明】
【図１】本発明に係る次亜塩素酸ナトリウム活性水の調製方法を具現化する装置の一実施例を示す概略構成図である。
【図２】水道水への次亜塩素酸ナトリウム添加量と電気伝導率の関係の一例を示すグラフ図である。
【図３】水道水への酢酸添加量と電気伝導率の関係の一例を示すグラフ図である。
【図４】次亜塩素酸ナトリウム水溶液への酢酸添加量とｐＨの関係の一例を示すグラフ図である。
【図５】ｐＨによる次亜塩素酸存在率を説明するためのグラフ図である。
【符号の説明】
１供給口
２第１の定流量弁
３第２の定流量弁
４第１の原液タンク（次亜塩素酸ナトリウム原液タンク）
５第１のポンプ
６第１の注入部
７第１の混合器
８第２の原液タンク（酸原液タンク）
９第２のポンプ
１０第２の注入部
１１第２の混合器
１２第３の混合器
１３取出口
１４電磁弁
１５圧力スイッチ
２０制御手段
２１記憶手段
２２表示手段
２３警報装置
２４装置操作部（電気伝導率入力手段）
１００殺菌水生成装置（次亜塩素酸ナトリウム活性水生成装置）
Ｄ１、Ｄ２、Ｄ３電気伝導率センサ（電気伝導率測定手段）
Ｌ１原水供給流路
Ｌ２第１の希釈混合流路（次亜塩素酸ナトリウム希釈混合流路）
Ｌ３第２の希釈混合流路（酸希釈混合流路）
Ｌ４混合流路[0001]
BACKGROUND OF THE INVENTION
The present invention generally relates to a method and an apparatus for producing sterilized water that can be used to sterilize and disinfect microorganisms that contaminate various devices or foodstuffs in various fields such as food processing, agriculture and fisheries, and medicine. The present invention relates to a method and apparatus for producing sterilized water that activates sodium hypochlorite used as a sterilizer and enhances sterilization power.
[0002]
[Prior art]
Conventionally, for example, in the medical field, a sodium hypochlorite (NaOCl) aqueous solution has been used for sterilization and disinfection of hemodialysis equipment. Usually, sodium hypochlorite is provided at a concentration of about 6 w / w%, and this stock solution is diluted to a concentration of 500 to 1000 ppm when used and used as sterilizing water.
[0003]
However, after sterilizing and disinfecting various devices with such sodium hypochlorite-containing sterilizing water, it is necessary to wash with clean water sufficiently so that sodium hypochlorite does not remain. Equipment cleaning waste liquid containing sodium acid will be discharged into the environment. Accordingly, when a large amount of sterilized water containing sodium hypochlorite at a high concentration of 500 to 1000 ppm as described above is used, there is a problem that the influence on the environment is large. In addition, if cleaning waste liquid containing sodium hypochlorite at a high concentration is introduced into a wastewater treatment facility using the activated sludge method, it may cause considerable damage to the sludge (microorganisms) and even make the treatment impossible. .
[0004]
On the other hand, in view of the above problems, in recent years, there has been proposed an apparatus capable of enhancing the sterilizing power of sodium hypochlorite-containing sterilizing water and reducing the amount of sodium hypochlorite used (Japanese Patent Laid-Open No. 10-2010). 182325). Further, for example, as a method for cleaning and disinfecting hemodialysis equipment, the disinfection and disinfection ability of a method using sodium hypochlorite activated water containing sodium hypochlorite and acetic acid has been demonstrated (for example, “hypochlorous acid” “Cleaning and disinfection effect of sodium active water”, “Functional Water Medical Research Group Vol. 1, No. 2,” pages 101-104 (1999)).
[0005]
That is, the main component of the sterilizing power exhibited by the sterilizing water containing sodium hypochlorite is hypochlorous acid (HOCl), and the abundance of hypochlorous acid (HOCl) in the sterilizing water depends on the pH of the sterilizing water. It was revealed that FIG. 5 shows the abundance of hypochlorous acid according to pH in the sterilized water containing sodium hypochlorite. As understood from FIG. 5, sodium hypochlorite itself is strongly alkaline, and the content of hypochlorous acid (HClO) increases to about pH 4.5 as the pH decreases. Moreover, even if it becomes lower than about pH3.0 too much, the content of hypochlorous acid (HClO) will decrease.
[0006]
In other words, conventional sterilized water obtained by simply diluting sodium hypochlorite with water is strongly alkaline (about pH 8.5 to pH 10), and dilutes sodium hypochlorite at a high concentration of 500 ppm to 1000 ppm in the sterilized water. However, only about 5% of the contained sodium hypochlorite is present as hypochlorous acid (HClO) having a strong sterilizing power.
[0007]
Therefore, in the above-mentioned sodium hypochlorite sterilizing power enhancing device (Japanese Patent Laid-Open No. 10-182325), the pH of the sodium hypochlorite-containing sterilizing water is adjusted to a range of pH 3.0 to 6.0. As a result, almost 100% of sodium hypochlorite contained in the sterilized water can exist as hypochlorous acid (HClO) effective for sterilization, so hypochlorous acid required to obtain a strong sterilizing power The amount of sodium can be reduced, for example the concentration of sodium hypochlorite can be reduced to 10-20 ppm. Hereinafter, sodium hypochlorite-containing sterilized water prepared using this principle is referred to as “sodium hypochlorite active water” or simply “active water”.
[0008]
[Problems to be solved by the invention]
In order to prepare sodium hypochlorite active water having a dilute sodium hypochlorite concentration and enhanced bactericidal activity as described above, the sodium hypochlorite concentration and pH of the active water are set to a desired value. It is indispensable to precisely match the set value, which ensures a strong sterilizing power for the first time. Further, if sodium hypochlorite is added more than necessary, it becomes a problem when the disinfecting and sterilizing waste liquid is discharged into the environment as described above.
[0009]
Conventionally, as a method for adjusting the concentration and pH of sodium hypochlorite in active water, the flow rate of raw water for diluting sodium hypochlorite and / or acid is detected, and hyponitrogen is added at a predetermined ratio to this flow rate. There is a method of adding sodium chlorate or acid.
[0010]
However, in this method, for example, when sodium hypochlorite or acid stock solution is exhausted (when it is used up), or when an abnormality occurs in the chemical pump for supplying sodium hypochlorite or acid, etc. In this case, the sodium hypochlorite concentration and pH do not meet the set values. As an abnormality of the chemical pump, a mechanical failure (diaphragm breakage, etc.) or an electrical failure (fuse blowout, etc.) can be considered. It is also conceivable that problems such as an air lock occurring in the diaphragm type pump or a disconnection of the chemical solution piping tube may occur. Furthermore, as a cause of the hypochlorous acid concentration and pH of the active water deviating from the set values, it is conceivable that the raw water for dilution is insufficient, the water is cut off, or the like.
[0011]
Therefore, in order to cope with such various events, always maintain a predetermined sodium hypochlorite concentration and pH, and to prepare sodium hypochlorite active water with always strong bactericidal power, or desired In order to stop the preparation of the active water or to give an alarm when there is a risk that the active water may not be obtained, monitor the concentration and pH of sodium hypochlorite and add sodium hypochlorite and acid. It is very important to adjust the amount to increase reliability.
[0012]
As a method for detecting the sodium hypochlorite concentration of active water, a so-called hypochlorous acid concentration detection sensor (residual chlorine concentration detector) using a polarograph may be used. For example, while referring to the instructions of this hypochlorous acid concentration meter, the injection amount of sodium hypochlorite is manually adjusted until the sodium hypochlorite concentration reaches a predetermined value, or the hypochlorous acid concentration meter This can be done by automatically adjusting using the detected value. Further, it is conceivable that the pH of the active water is detected using a pH meter, and the amount of acid added is adjusted based on the detected value.
[0013]
However, a hypochlorous acid concentration detection sensor using a polarograph is relatively expensive, and in order to maintain detection accuracy, maintenance costs such as electrode maintenance are required and the operation becomes complicated. Further, as is well known, it is necessary to periodically perform standard calibration of the pH meter, and in order to maintain the pH detection accuracy, this standard calibration must be frequently performed, and the operation becomes complicated. Thus, the method using a hypochlorous acid concentration detection sensor and a pH meter has problems in terms of cost, sensor maintenance, and reliability.
[0014]
For example, when sodium hypochlorite activated water is used for disinfection and sterilization of equipment in the food processing field, a pH meter using a normal glass electrode is used. It is a problem that glass fragments may be mixed. There is also a so-called methoxy electrode type pH meter that does not use a glass electrode, but hypochlorous acid contained in active water is a strong oxidizing agent and is not suitable for use.
[0015]
Thus, a method and an apparatus that can monitor the hypochlorous acid concentration and pH of active water safely and easily at low cost and simply and can always prepare active water of a predetermined concentration and pH are desired.
[0016]
In addition, it is desirable that such methods and apparatus are also applicable to the use of a wide range of dilution raw water. That is, for example, for preparation of sodium hypochlorite active water used for sterilization and disinfection of hemodialysis equipment, it is necessary to use reverse osmosis water (R / O water) substantially free of dissolved ions as raw water for dilution. . A reverse osmosis water generation (R / O) apparatus is relatively expensive, and further requires running costs such as replacement of a membrane and resin. However, for example, sterilization and disinfection in industrial production fields such as sterilization and disinfection of equipment such as production lines, pipes and tanks in food processing, agriculture and fisheries, livestock, and food products, sterilization of semiconductor substrates, waste treatment and sewage treatment In the field of sterilization and disinfection, or pool water sterilization, tap water, well water, and the like can be used as dilution raw water, thereby greatly reducing costs.
[0017]
In addition to tap water and well water, it may be desired to use seawater as dilution raw water. That is, in the fisheries field, seawater used for fish washing and thawing is made of sodium hypochlorite active water with strong sterilizing power, for example, harmful microorganisms contained in seawater (for example, Vibrio parahaemolyticus that can cause food poisoning) And the like, and the effects of sterilization, breeding prevention, and washing can be obtained, and at the same time, the raw water for dilution is seawater, so that adverse effects such as discoloration of fish can be prevented.
[0018]
Accordingly, an object of the present invention is to provide a method and an apparatus for producing sterilized water capable of always obtaining sterilized water having a desired sodium hypochlorite concentration and pH in a safe, low-cost and simple manner.
[0019]
Another object of the present invention is to use a wide range of dilution raw water such as reverse osmosis water (R / O water), tap water, well water or seawater, in particular, as dilution raw water for preparing sterilizing water. It is another object of the present invention to provide a method and apparatus for producing sterilized water that can be obtained safely, at low cost and easily, and can always obtain sterilized water having a desired sodium hypochlorite concentration and pH.
[0020]
[Means for Solving the Problems]
The above object is achieved by the method and apparatus for producing sterilized water according to the present invention. In summary, according to the first aspect of the present invention, Flow at a constant flow rate Sodium hypochlorite in raw water The Add Diluted and mixed to produce a sodium hypochlorite diluted solution, added acid to the raw water flowing at a constant flow rate and diluted and mixed to produce an acid diluted solution, and the generated sodium hypochlorite diluted Desired by mixing the solution with the acid diluent A sterilizing water production method for producing sterilizing water having a sodium hypochlorite concentration and pH of From the correlation between the concentration of the sodium hypochlorite aqueous solution and the electrical conductivity, the increase in electrical conductivity due to the addition of sodium hypochlorite in the sodium hypochlorite aqueous solution having the desired concentration is determined as the first predetermined value. A pre-adjusted addition amount so that the concentration of the sodium hypochlorite diluted solution becomes a desired concentration Sodium hypochlorite Flow at the constant flow rate In raw water Add Dilution mixing To Obtaining a sodium hypochlorite dilution; From the correlation between the concentration of the acid aqueous solution and the electric conductivity, the increase in the electric conductivity due to the addition of the acid in the acid aqueous solution of the desired concentration is determined as the second predetermined value; the concentration of the acid dilution solution is the desired concentration In addition amount adjusted in advance to become Acid Flow at the constant flow rate In raw water Add Dilution mixing To Obtaining an acid dilution; measuring the electrical conductivity (d1) of the sodium hypochlorite dilution, the electrical conductivity (d2) of the acid dilution, and the electrical conductivity (d3) of the raw water; A first electrical conductivity difference (d1-d3) that is a difference in electrical conductivity between the sodium hypochlorite diluted solution and the raw water, and a second electrical conductivity that is a difference in electrical conductivity between the acid diluted solution and the raw water. Determining the rate difference (d2-d3); and the first conductivity difference (d1-d3) and Said Compared with a first predetermined value, the first electrical conductivity difference (d1-d3) is Said When a predetermined time has elapsed from the first predetermined value, the concentration of the sodium hypochlorite diluted solution is Desired concentration Judged that normal sterilizing water cannot be generated. To issue a predetermined warning, display a predetermined information, or stop the supply of raw water The second electrical conductivity difference (d2−d3) and Said Compared with a second predetermined value, the second electrical conductivity difference (d2-d3) is Said When the predetermined time has elapsed after deviating from the second predetermined value, the concentration of the acid diluent is Desired concentration Judged that normal sterilizing water cannot be generated. To issue a predetermined warning, display a predetermined information, or stop the supply of raw water Providing a sterilizing water by mixing the sodium hypochlorite diluted solution and the acid diluted solution to obtain sterilized water.
[0022]
In the first aspect of the present invention, one According to an embodiment, Instead of measuring the electrical conductivity (d3) of the raw water, Raw water electrical conductivity (d3) As a constant value Is used.
[0025]
According to the second aspect of the present invention, sodium hypochlorite and an acid are added to raw water. Desired A sterilizing water generating device for generating sterilizing water having a sodium hypochlorite concentration and pH of , Raw water supply flow path for supplying raw water and , A first diluting and mixing channel branched from the raw water supply channel for adding sodium hypochlorite to raw water and mixing to obtain a diluted sodium hypochlorite solution; First flow rate regulating means for maintaining a constant flow rate of the raw water flowing in the first dilution mixing channel; First addition means for adding sodium hypochlorite to the raw water flowing in the first dilution mixing channel, and a first mixer for mixing and stirring the liquid after the sodium hypochlorite has been added When , With The first addition means adds sodium hypochlorite to the raw water flowing at the constant flow rate in an addition amount adjusted in advance so that the concentration of the sodium hypochlorite diluted solution becomes a desired concentration. Do A first dilution and mixing channel; , A second dilution mixing channel branched from the raw water supply channel for adding an acid to the raw water and mixing to obtain an acid diluted solution, A second flow rate regulating means for maintaining a constant flow rate of the raw water flowing in the second dilution mixing channel; A second addition means for adding an acid to the raw water flowing in the second dilution and mixing flow path; a second mixer for mixing and stirring the liquid after the acid has been added; , With The second addition means adds the acid to the raw water flowing at the constant flow rate in an addition amount adjusted in advance so that the concentration of the acid diluent becomes a desired concentration. A second dilution and mixing channel; , A mixing flow path for mixing and guiding the liquid from the first and second dilution mixing flow paths for mixing the sodium hypochlorite dilution liquid and the acid dilution liquid, wherein A mixing flow path comprising a third mixer for mixing and stirring the liquid from the dilution mixing flow path and the liquid from the second dilution mixing flow path; , A first electric conductivity measuring means provided on the downstream side of the first mixer in the first diluting and mixing channel and measuring the electric conductivity (d1) of the sodium hypochlorite diluted solution; , A second electric conductivity measuring means provided on a downstream side of the second mixer in the second diluting / mixing channel and measuring the electric conductivity (d2) of the acid diluted solution; , A third electrical conductivity measuring means for measuring the electrical conductivity (d3) of the raw water provided in the raw water supply channel; , Control means for performing processing based on signals from the first, second and third electrical conductivity measuring means; An increase in electrical conductivity due to the addition of sodium hypochlorite in a sodium hypochlorite aqueous solution having a desired concentration determined from the correlation between the concentration of the sodium hypochlorite aqueous solution and the electrical conductivity is the first. An increase in electrical conductivity due to the addition of acid in an aqueous acid solution having a desired concentration, which is stored as a predetermined value and determined from the correlation between the concentration of the aqueous acid solution and the electrical conductivity, is stored as a second predetermined value. ; A first electric conductivity difference (d1-d3) that is a difference in electric conductivity between the sodium hypochlorite diluted solution and the raw water, and a second electric value that is a difference in electric conductivity between the acid diluted solution and the raw water. A process for obtaining a conductivity difference (d2-d3); the first conductivity difference (d1-d3) and Said Compared with a first predetermined value, the first electrical conductivity difference (d1-d3) is Said When a predetermined time has elapsed from the first predetermined value, the concentration of the sodium hypochlorite diluted solution is Desired concentration A process of judging that normal sterilizing water cannot be generated by deviating from the above; and the second electrical conductivity difference (d2-d3) and Said Compared with a second predetermined value, the second electrical conductivity difference (d2-d3) is Said When the predetermined time has elapsed after deviating from the second predetermined value, the concentration of the acid diluent is Desired concentration Control means for performing a process of judging that normal sterilizing water cannot be generated by deviating from , There is provided a sterilizing water generator characterized by comprising:
[0026]
In a second aspect of the invention, one According to an embodiment, the apparatus further comprises electrical conductivity input means for inputting a predetermined value of the electrical conductivity of raw water determined in advance to the control means. ,in front The control means uses the signal inputted from the electric conductivity input means instead of the signal from the third electric conductivity measuring means as the electric conductivity (d3) of the raw water.
[0028]
In the second aspect of the present invention, according to another embodiment, the control means comprises: When it is determined that the normal sterilizing water cannot be generated , Predetermined alarm Processing to issue , Predetermined information display Processing , Or Raw water of Supply The Stop Processing I do.
[0029]
According to one embodiment of each of the present invention, the raw water is tap water, well water, seawater or reverse osmosis water (R / O water).
[0030]
Further, according to each embodiment of the present invention, preferably, the sodium hypochlorite concentration of the sterilizing water is in the range of 0.5 ppm to 1000 ppm, and the pH is in the range of pH 3.0 to 7.5. The
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the method and apparatus for producing sterilizing water according to the present invention will be described in more detail with reference to the drawings.
[0032]
In the present embodiment, the sterilizing water generating method and apparatus of the present invention will be described on the assumption that tap water is used as the dilution raw water. FIG. 1 shows a schematic configuration of an embodiment of an apparatus embodying the sterilizing water generating method of the present invention.
[0033]
First, the basic structure of the sterilizing water production | generation apparatus (active water production | generation apparatus) of a present Example is demonstrated. As shown in FIG. 1, the sterilizing water generating apparatus 100 of the present embodiment takes in tap water from the dilution raw water supply port 1 into the apparatus and activates sodium hypochlorite to enhance the sterilizing power. Water (sodium hypochlorite activated water) can be prepared and taken out from the apparatus through the outlet 13. According to this example, as will be described in detail later, sodium hypochlorite and acid are each diluted and mixed with the raw water for dilution, and then this sodium hypochlorite diluted acid stream and acid diluted liquid stream To obtain sodium hypochlorite activated water. According to this embodiment, the raw water for dilution can be continuously supplied to generate active water continuously. Also, for example, when an active water storage tank (not shown) is connected to the outlet 13, and the active water is stored and used in this, every time the active water in the storage tank falls below a predetermined level, It can also be controlled to generate active water intermittently, such as starting generation of active water.
[0034]
The raw water supply flow path L1 as the raw water supply means provided in the apparatus 100 is connected to a faucet (not shown) of a general tap water supply pipe through the supply port 1. An electromagnetic valve 14 is provided in the raw water supply flow path L1, and supply of the raw water is controlled by opening and closing the electromagnetic valve 14. The solenoid valve 14 is normally opened and closed by a user's operation in the device operation unit 24, etc. In This is performed according to the instruction of the control means 20 according to the instruction. As will be described in detail later, when the control means 20 detects an apparatus abnormality, the electromagnetic valve 14 is closed and the supply of the raw water for dilution is stopped. Furthermore, a pressure switch 15 can be provided between the supply port 1 of the raw water supply flow path L1 and the electromagnetic valve 14. Accordingly, the apparatus can be operated when a predetermined pressure is applied in the vicinity of the supply port 1, and a configuration in which sodium hypochlorite and an acid to be described later are not supplied when water is shut off or the amount of water is insufficient can be obtained.
[0035]
The downstream side of the raw water supply flow path L1 is branched in the first and second directions, and the first and second constant flow valves 2 and 3 as the raw water flow regulating means are respectively provided through the first and second constant flow valves 2 and 3. The tap water is supplied to the sodium hypochlorite dilution mixing channel (first dilution mixing channel) L2 and the acid dilution mixing channel (second dilution mixing channel) L3 as the dilution mixing means. In the present embodiment, the first and second constant flow valves 2 and 3 supply the equal dilution raw water to the first dilution mixing flow path L2 and the second dilution mixing flow path L3.
[0036]
The supply of raw water to the first dilution / mixing flow path L <b> 2 is maintained at a constant flow rate by the first constant flow valve 2. The first diluting / mixing flow path L <b> 2 is provided with a first injection unit 6 located downstream of the first constant flow valve 2. In the first injection section 6, sodium hypochlorite stock solution is injected from the first stock solution tank 4 into the dilution raw water stream through the first pump 5 as sodium hypochlorite addition means. . As will be described in detail later, the first pump 5 is operated by the control of the control means 20, and the injection amount of sodium hypochlorite is adjusted. In this example, the concentration of the sodium hypochlorite stock solution is 6 w / w%, and the pH is 12.4.
[0037]
The sodium hypochlorite injected into the dilution raw water is sufficiently mixed with the dilution raw water in the first mixer 7 provided downstream from the first injection unit 6.
[0038]
The supply amount of the raw water for dilution from the raw water supply passage L1 to the acid dilution passage L3 is maintained at a constant flow rate by the second constant flow valve 3. In the second dilution / mixing flow path L3, a second injection unit 10 is provided downstream of the second constant flow valve 3. In the second injection unit 10, as the acid addition means, the acid stock solution is injected from the second stock solution tank 8 through the second pump 9 into the dilution raw water stream. Similar to the first pump 5, the second pump 9 operates under the control of the control means 20 as will be described later, and the acid injection amount is adjusted.
[0039]
In this example, acetic acid having a concentration of 30 w / w% was used as the acid stock solution. The acid for adjusting the pH is preferably acetic acid in terms of cost and non-toxicity, but the present invention is not limited to this, and is appropriately selected from any acids that meet the purpose of adjusting the pH of the active water. Can be For example, citric acid, hydrochloric acid, or a mixed acid of acetic acid and hydrochloric acid can be used instead of acetic acid.
[0040]
The acetic acid injected into the dilution raw water is sufficiently agitated and mixed with the dilution raw water in the second mixer 11 provided downstream from the second injection unit 10.
[0041]
The dilute sodium hypochlorite stream and the dilute acid stream that have passed through the mixers 7 and 11 are further merged on the downstream side and introduced into the mixing flow path L4 as a mixing means for both diluting liquids. The mixer 12 is sufficiently stirred and mixed.
[0042]
The first, second and third mixers 7, 11, 12 can be arbitrary mixers each having a sufficient stirring ability. For example, a suitable stirrer or one provided with stirring means such as a baffle plate member that blocks the water flow can be used.
[0043]
As described above, in order for sodium hypochlorite added to the raw water to exist as hypochlorous acid (HClO) having almost 100% sterilizing power, the pH may be in the range of 3.0 to 7.5. More preferably, it is pH 3.0-6.5, and most preferably pH 4.0-5.0.
[0044]
Moreover, sodium hypochlorite can exhibit effective disinfection and disinfection power at a relatively low concentration by setting the pH of the active water within the above range. Considering the influence of sodium hypochlorite on the environment, it is preferable that sodium hypochlorite has a lower concentration, but the sterilizing power of active water is stronger when the concentration of sodium hypochlorite is higher. Therefore, the concentration of sodium hypochlorite can be selected as appropriate in view of the desired bactericidal power and the influence on the environment. Preferably, the sodium hypochlorite concentration is 0.5 ppm to 1000 ppm.
[0045]
In the present embodiment, the sodium hypochlorite diluted solution and the acid diluted solution, which are each independently diluted in the dilution raw water as described above, are mixed with the acid diluted solution. The sodium chlorate concentration is set to 10 ppm and the pH is set to 5.0.
[0046]
Next, a method for adjusting the concentration and pH of sodium hypochlorite of sterilized water will be further described. As described above, it is extremely important to monitor the sodium hypochlorite concentration and pH of the active water so as to always have an appropriate value in order to exert a strong sterilizing power.
[0047]
First, the principle of the present invention will be described. FIG. 2 shows the amount (μL) of sodium hypochlorite (6 w / w%) added to tap water (200 mL) and the electric power of the diluted sodium hypochlorite solution. Conductivity [μS / cm; × 10 ^-Four S / m] (about 17 ° C.). The electric conductivity was measured using an electric conductivity sensor (manufactured by Toa Radio: CP916A). As shown in the figure, it can be seen that there is a certain correlation between the amount of sodium hypochlorite added to tap water, that is, the concentration and the electrical conductivity of the diluted sodium hypochlorite solution. Similarly, FIG. 3 shows the amount of acetic acid aqueous solution (5M) added to tap water (200 mL) and the electric conductivity of the acid diluted solution [μS / cm; × 10 ^-Four S / m] (about 15 ° C.). As with the sodium hypochlorite diluted solution, it can be seen that there is a certain correlation between the amount of acetic acid added to tap water, that is, the acid concentration and the electrical conductivity of the acid diluted solution.
[0048]
The pH of the active water produced by mixing the sodium hypochlorite diluted solution and the acid diluted solution is as follows: (1) pH of raw water for dilution and buffer action (2) Amount of sodium hypochlorite added , (3) determined by parameters including three of the acid addition amount. FIG. 4 shows the amount of tap water (200 mL) containing sodium hypochlorite at a concentration of 30 ppm, that is, the amount (μL) of acetic acid aqueous solution (5 M) added to the sodium hypochlorite diluted solution, and the pH of the mixed solution. An example of the relationship is shown. As shown in the figure, the amount of acid added to the sodium hypochlorite diluted solution obtained by diluting sodium hypochlorite at a predetermined concentration in a predetermined raw water for dilution, that is, the concentration, and finally generated active water. There is a certain correlation with the pH.
[0049]
In this way, by obtaining the correlation between the concentration of the sodium hypochlorite diluted solution and the electric conductivity, the electric conduction of the sodium hypochlorite diluted solution generated in the first dilution mixing channel L2 is obtained. The sodium hypochlorite concentration can be detected from the rate value. Similarly, the acid concentration is detected from the electrical conductivity of the acid diluted solution generated in the second dilution mixing channel L3 by obtaining the correlation between the concentration of the acid diluted solution and the electrical conductivity. be able to.
[0050]
Finally, the sodium hypochlorite diluted solution and the acid diluted solution from the first and second diluted and mixed flow channels L2 and L3 are guided to the mixing flow channel L4 and mixed at a predetermined ratio (flow rate). Thus, the active water is prepared. Therefore, by monitoring the concentration of the sodium hypochlorite dilution in the first dilution mixing channel L2 and the concentration of the acid dilution in the second dilution mixing channel L3, the activated water finally prepared Hypochlorous acid concentration and acid concentration can be monitored. As described above, since there is a certain correlation between the acid concentration in the solution containing sodium hypochlorite and the pH of this solution, the acid concentration of the prepared active water is set to a predetermined value. The pH can be set to a predetermined value.
[0051]
However, when tap water is used as dilution raw water as in this embodiment, the quality of the water is not constant depending on the passage of time (for example, seasonal change or difference between morning and evening), location, and region, and in many cases the electrical conductivity is also large. Change. Generally, the electric conductivity of tap water is 200 to 250 [μS / cm; × 10 ^-Four S / m] or so, but the electrical conductivity is 140 to 250 [μS / cm; ^-Four S / m] may vary greatly.
[0052]
When diluting raw water having a constant electric conductivity is used in this way, the electric conductivity of the sodium hypochlorite diluted solution and the acid diluted solution varies greatly along with the variation in the electric conductivity of the diluting raw water. Changes in sodium chlorate concentration and acid concentration itself cannot be monitored.
[0053]
Therefore, according to the present invention, in addition to the electrical conductivity of the sodium hypochlorite diluted solution and the acid diluted solution, the electrical conductivity of the raw water is also used. By subtracting, it is possible to always accurately detect sodium hypochlorite and acid concentration.
[0054]
In accordance with the principle as described above, according to the present invention, first, signals corresponding to the electric conductivity (d1) of the sodium hypochlorite diluted solution and the electric conductivity (d2) of the acid diluted solution are sent to the control means 20. First and second electric conductivity measuring means for inputting are provided. In the present embodiment, the first electrical conductivity sensor D1 is disposed on the downstream side of the first mixer 7 provided in the first dilution / mixing flow path L2 as the first electrical conductivity measuring means. Further, as the second electric conductivity measuring means, the second electric conductivity sensor D2 is arranged on the downstream side of the second mixer 11 provided in the second diluting / mixing flow path L3.
[0055]
The first electrical conductivity sensor D 1 detects the electrical conductivity (d 1) of the diluted sodium hypochlorite solution diluted in the first mixer 7 and transmits a corresponding signal to the control means 20. . The second electrical conductivity sensor D 2 detects the electrical conductivity (d 2) of the acid diluted solution diluted and mixed in the second mixer 11, and transmits a corresponding signal to the control means 20.
[0056]
Furthermore, according to the present invention, the third electrical conductivity measuring means for inputting the electrical conductivity (d3) of the raw water for dilution to the control means 20 is also provided. In the present embodiment, a third electrical conductivity sensor D3 is disposed on the downstream side of the electromagnetic valve 14 in the raw water supply flow path L1 as the third electrical conductivity measuring means. The third electrical conductivity sensor D3 detects the electrical conductivity (d3) of the raw water for dilution and transmits a corresponding signal to the control means 20.
[0057]
Although it does not limit as 1st, 2nd and 3rd electrical conductivity sensors D1, D2, and D3, CP916A by Toa electric wave can be used conveniently. It will be apparent to those skilled in the art that the outputs of the electric conductivity sensors D1, D2, and D3 can be amplified in a predetermined manner or A / D converted and input to the control means 20. Electricity of sodium hypochlorite diluted water transmission The signal according to the electric conductivity (d1), the electric conductivity (d2) of the acid diluent and the electric conductivity (d3) of the raw water is sent to the control means 20 according to these electric conductivities (d1, d2, d3). Includes any form of input signal.
[0058]
According to the present embodiment, the control means 20 includes the electric conductivity d1 of the sodium hypochlorite diluted solution obtained in advance and the electricity of the dilution raw water. transmission Based on the relationship between the difference in the rate d3 (d1-d3) and the sodium hypochlorite concentration, the concentration of the sodium hypochlorite diluted solution for preparing active water having a predetermined sodium hypochlorite concentration Corresponding electrical conductivity (d1-d3) is set.
[0059]
Similarly, the control means 20 determines a predetermined value based on the relationship between the acid concentration and the difference (d2−d3) between the electric conductivity d2 of the acid diluent obtained in advance and the electric conductivity d3 of the raw water for dilution. The electric conductivity (d2-d3) corresponding to the concentration of the acid diluent for preparing the pH-active water is set.
[0060]
A plurality of set values of electrical conductivity differences (d1-d3) and (d2-d3) for preparing active water having a predetermined sodium hypochlorite concentration and pH are provided. By selecting, it can also be set as the structure which can produce | generate several types of active water from which the density | concentration and pH of sodium hypochlorite differ.
[0061]
Further, for example, the storage means 21 incorporated in the control means 20 is a table showing the relationship between the electrical conductivity (d1-d3) and the sodium hypochlorite concentration, and the relationship between the electrical conductivity (d2-d3) and the acid concentration. For example, an active water having a sodium hypochlorite concentration of 0.5 ppm to 1000 ppm and a pH of 3.0 to pH 7.5 is arbitrarily selected and stored as a corresponding sodium hypochlorite diluted solution. And the concentration of acid diluent can be monitored.
[0062]
Further, for example, the first and second pumps 5 and 9 are operated while measuring the concentration and pH of sodium hypochlorite using a hypochlorous acid concentration detection sensor or pH meter at the site where the apparatus 100 is used. The amount of sodium hypochlorite added and the amount of acid added are adjusted manually to control the difference in electrical conductivity when the desired active water is obtained (d1-d3), (d2-d3) Can be set and stored.
[0063]
When generating the active water, the control means 20 outputs the electric power of the input sodium hypochlorite diluted water. transmission By comparing the electric conductivity (d1-d3) obtained by subtracting the electric conductivity (d3) of the raw water for dilution from the rate (d1) with the set value, the sodium hypochlorite concentration of the diluted sodium hypochlorite solution is calculated. Can always be monitored. Further, the control means 20 compares the electric conductivity (d2-d3) obtained by subtracting the electric conductivity (d3) of the raw water for dilution from the electric conductivity (d2) of the input acid diluted solution by comparing with the set value. The acid concentration of the acid diluent can be monitored constantly.
[0064]
Thus, the signal corresponding to the difference between the electrical conductivity (d1) of the sodium hypochlorite diluted solution and the electrical conductivity (d3) of the raw water for dilution, or the electrical conductivity (d2) of the acid diluted solution and the dilution By using a signal corresponding to the difference from the electrical conductivity (d3) of the raw water, it is possible to extract and monitor the electrical conductivity fluctuation caused only by the sodium hypochlorite and acid concentration fluctuations.
[0065]
According to this embodiment, the control means 20 is configured so that the concentration of sodium hypochlorite or the acid concentration monitored as described above becomes the set value, that is, the first, Detected by second and third conductivity sensors D1, D2, D3 Is The first pump 5 so that the electric conductivity difference (d1-d3) detected based on the electric conductivity d1, d3 and the electric conductivity difference (d2-d3) are set to predetermined values. And the operation of the second pump 9 is controlled to adjust the sodium hypochlorite addition amount from the first stock solution tank 4 and the acid addition amount from the second stock solution tank 8.
[0066]
More specifically, the sterilizing water generator 100 of this embodiment can prepare active water having a sodium hypochlorite concentration of 10 ppm and a pH of 5.0 at a supply rate of about 20 L / min. The first and second constant flow valves 2 and 3 supply the dilution raw water to the first dilution mixing flow path L2 and the second dilution mixing flow path L3 at equal flow rates (about 10 L / min), respectively. . Accordingly, the first pump 5 injects the sodium hypochlorite stock solution so that the sodium hypochlorite concentration detected at the position of the first electrical conductivity sensor D1 is 20 ppm. Also, acetic acid should be injected so that the final concentration is 0.05 to 0.1 w / w%, that is, 0.1 to 0.2 w / w% at the position of the second electrical conductivity sensor D2. To bring the pH of the active water to pH 5.0.
[0067]
In addition, according to the present invention, when there is a possibility that activated water having a predetermined concentration cannot be generated, by performing a predetermined apparatus malfunction operation such as an alarm or a predetermined information display, the user can normally receive activated water. It can be notified that it is not generated. In such a case, the active water generating operation itself can be stopped.
[0068]
In this embodiment, the control means 20 detects that the sodium hypochlorite concentration or acid concentration monitored as described above deviates from the set value, that is, the conductivity difference (d1-d3) and When the electric conductivity (d2-d3) deviates from a predetermined value set in advance and a predetermined time elapses, the alarm device 23 issues a predetermined alarm. At the same time, the control means 20 closes the electromagnetic valve 14 to stop the supply of the dilution raw water. Furthermore, information for notifying the user that the apparatus is not operating normally can be displayed on the display means 22.
[0069]
As described above, the pH of the generated active water varies depending on parameters such as the pH of the diluted raw water and the buffer action. For example, the pH of tap water and the water quality including buffer action vary with time (seasonal change, etc.), location, and region. According to the study by the present inventors, when the device 100 is used at a specific use site, changes in the pH of the tap water and the buffer action do not show the effect of changing the pH of the active water in a short time. . However, if desired, at the site where the apparatus 100 is used, the pH of the active water is periodically checked using a pH meter, and the relationship between the pH of the active water and the set value of the electrical conductivity difference (d2−d3), or storage. The relationship between the electrical conductivity difference (d2-d3) stored in the means 21 and the acid concentration of the acid diluent can be corrected as appropriate.
[0070]
As described above, according to the present invention, it is possible to always monitor the concentration variation of sodium hypochlorite and the acid itself regardless of the variation in the electrical conductivity of the raw water for dilution. Even when the quality of the raw water for dilution changes and its electrical conductivity changes greatly, the amount of sodium hypochlorite and acid added is automatically adjusted to always maintain the prescribed sodium hypochlorite concentration and It is possible to obtain active water at pH. Moreover, when there is a possibility that the predetermined active water cannot be generated, it is possible to always generate active water having strong sterilizing power by issuing an alarm or stopping the operation of generating the active water, and more than necessary. Problems such as environmental impacts and costs due to the use of sodium hypochlorite can be avoided.
[0071]
Further, according to the present invention, since the electric conductivity of the raw water for dilution itself is subtracted from the electric conductivity of the solution obtained by diluting and mixing sodium hypochlorite and acid, the electric conductivity is about 1.0 [μS. / Cm; x10 ^-Four S / m] reverse osmosis water (R / O water), electric conductivity of about 250 [μS / cm; × 10 ^-Four S / m] tap water, electrical conductivity of about 20 [mS / cm; × 10 ^-1 A wide range of dilution raw water such as S / m] seawater can be used regardless of variations in its electrical conductivity. Thereby, the method and apparatus according to the present invention can be used for sterilization of hemodialysis equipment that requires reverse osmosis water (R / O water) as raw water for dilution, for example, washing and sterilization in the food processing field such as washing of cut vegetables. Furthermore, it can be applied to the preparation of active water used in a wide range of fields from fish cleaning and sterilization in the fishery field.
[0072]
In the above embodiment, the apparatus 100 has been described as being directly connected to a tap water supply pipe. However, for example, when reverse osmosis water (R / O water) is used as dilution raw water, reverse osmosis is used as raw water supply means. The supply port 1 can be connected to a tap water supply pipe via a water generator, or reverse osmosis water can be supplied to the supply port 1 from a reverse osmosis water storage tank. When seawater is used as the raw water for dilution, the supply port 1 can be connected to a seawater supply device or the supply port 1 can be connected to a seawater storage tank as raw water supply means.
[0073]
In addition, since the electrical conductivity sensor such as the above-described electrical conductivity sensor (CP916A manufactured by Toa Radio) is generally manufactured using metal and plastic, the pH meter using the glass electrode is used according to the present invention. As in the case, there is no danger that the broken pieces are mixed into the active water due to the breakage of the glass electrode. In general, the calibration cycle of the electrical conductivity sensor can be as long as about 80 months, so that handling is simple and accurate detection is always possible. Further, since there is no need to periodically replace the electrode parts unlike a hypochlorous acid concentration sensor (residual chlorine concentration detector), maintenance labor and cost can be greatly reduced.
[0074]
In the above-described embodiment, the electric conductivity sensor d3 that detects the electric conductivity of the raw water for dilution when generating the sterilizing water is used as a means for inputting the electric conductivity (d3) of the raw water for dilution to the control means. As another method, for example, when preparing active water used for sterilization and disinfection of hemodialysis equipment, when the water quality is known to be constant as reverse osmosis water (R / O water) as raw water for dilution For example, by inputting a constant value of the electric conductivity d3 of the raw water for dilution from the operation unit 24 of the apparatus 100 as the electric conductivity input means, a corresponding signal can be input to the control means 20. In this case, the control means 20 uses the electric power of the input dilution raw water instead of the detection signal of the third electric conductivity sensor D3 in the above-described embodiment. transmission It is possible to use a constant value of the rate value d3. It should be noted that the electrical conductivity d3 of a plurality of types of raw water for dilution can be stored in advance in the storage means 21, and can be appropriately selected and used.
[0075]
【The invention's effect】
As explained above, according to the present invention, , Cheap It is possible to obtain sterilized water having a desired sodium hypochlorite concentration and pH at all times at a low cost and in a simple manner. Moreover, as raw water for dilution for preparing sterilizing water, a wide range of raw water for dilution such as reverse osmosis water (R / O water), tap water, well water or seawater can be used, and it is safe, low cost and It is possible to easily obtain sterilized water having a desired sodium hypochlorite concentration and pH at all times.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of an apparatus embodying a method for preparing sodium hypochlorite activated water according to the present invention.
FIG. 2 is a graph showing an example of the relationship between the amount of sodium hypochlorite added to tap water and the electrical conductivity.
FIG. 3 is a graph showing an example of the relationship between the amount of acetic acid added to tap water and electrical conductivity.
FIG. 4 is a graph showing an example of the relationship between the amount of acetic acid added to an aqueous sodium hypochlorite solution and pH.
FIG. 5 is a graph for explaining the abundance ratio of hypochlorous acid according to pH.
[Explanation of symbols]
1 Supply port
2 First constant flow valve
3 Second constant flow valve
4 First stock solution tank (Sodium hypochlorite stock solution tank)
5 First pump
6 First injection part
7 First mixer
8 Second stock solution tank (acid stock solution tank)
9 Second pump
10 Second injection part
11 Second mixer
12 Third mixer
13 Exit
14 Solenoid valve
15 Pressure switch
20 Control means
21 Memory means
22 Display means
23 Alarm device
24 Device operation part (electrical conductivity input means)
100 Bactericidal water generator (sodium hypochlorite active water generator)
D1, D2, D3 Electrical conductivity sensor (electrical conductivity measuring means)
L1 Raw water supply channel
L2 first dilution mixing channel (sodium hypochlorite dilution mixing channel)
L3 Second dilution mixing channel (acid dilution mixing channel)
L4 mixing channel

Claims

And it generates sodium hypochlorite diluted solution by diluting mixed by adding sodium hypochlorite in the raw water flowing at a constant flow rate, mixing dilution by adding an acid to the raw water flowing at a constant flow rate In the method for producing sterilized water , an acid diluted solution is produced by mixing the produced sodium hypochlorite diluted solution and the acid diluted solution to produce sterilized water having a desired sodium hypochlorite concentration and pH. There,
From the correlation between the concentration of the sodium hypochlorite aqueous solution and the electrical conductivity, the increase in electrical conductivity due to the addition of sodium hypochlorite in the sodium hypochlorite aqueous solution having the desired concentration is determined as the first predetermined value. thing,
Wherein in the concentration of the sodium hypochlorite diluted solution is mixed and diluted by adding the desired sodium hypochlorite at preconditioned amount such that the concentration raw water flowing by the constant flow rate following Obtaining a sodium chlorite dilution,
From the correlation between the concentration of the aqueous acid solution and the electric conductivity, the increase in the electric conductivity due to the addition of the acid in the aqueous acid solution having the desired concentration is determined as the second predetermined value,
Obtaining the acid dilution by adding and diluting the acid to the raw water flowing at the constant flow rate in an addition amount adjusted in advance so that the concentration of the acid dilution becomes a desired concentration ;
Measuring the electrical conductivity (d1) of the sodium hypochlorite diluted solution, the electrical conductivity (d2) of the acid diluted solution, and the electrical conductivity (d3) of raw water,
A first electric conductivity difference (d1-d3) that is a difference in electric conductivity between the sodium hypochlorite diluted solution and the raw water, and a second electric value that is a difference in electric conductivity between the acid diluted solution and the raw water. Obtaining a conductivity difference (d2-d3);
By comparing the first of said first predetermined value and electric conductivity difference (d1-d3), a predetermined first electric conductivity difference (d1-d3) is disengaged from said first predetermined value Whether the concentration of the sodium hypochlorite diluted solution deviates from the desired concentration and normal sterilizing water cannot be generated when time elapses, and a predetermined alarm is issued or predetermined information is displayed Or stop supplying raw water ,
And comparing the second electrical conductivity difference between (d2-d3) and the second predetermined value, the predetermined second electric conductivity difference (d2-d3) is disengaged from said second predetermined value When the time elapses, it is determined that the concentration of the acid dilution solution deviates from the desired concentration and normal sterilizing water cannot be generated , and a predetermined alarm is issued, predetermined information is displayed, or raw water is generated . Stopping the supply ,
Mixing the sodium hypochlorite diluent and the acid diluent to obtain sterilized water;
A method for producing sterilized water, comprising:

The method for producing sterilized water according to claim 1, wherein a constant value is used as the electric conductivity (d3) of the raw water instead of measuring the electric conductivity (d3) of the raw water.

The raw water is tap water, well water, seawater, or reverse osmosis water (R / O water), The sterilizing water production method according to claim 1 or 2 characterized by things.

The concentration of sodium hypochlorite in sterilized water is in the range of 0.5 ppm to 1000 ppm, and the pH is in the range of pH 3.0 to 7.5. Method.

A sterilizing water generating device that adds sodium hypochlorite and acid to raw water to generate sterilizing water having a desired sodium hypochlorite concentration and pH,
A raw water supply channel for supplying raw water;
A first dilution mixing channel branched from the raw water supply channel for adding sodium hypochlorite to raw water and mixing to obtain a sodium hypochlorite diluted solution, the first dilution mixing First flow rate regulating means for maintaining a constant flow rate of raw water flowing in the flow path, and first addition means for adding sodium hypochlorite to the raw water flowing in the first dilution mixing flow path comprises a first mixer for liquid mixing stirring after being added sodium hypochlorite, wherein the first adding means, the concentration of the sodium hypochlorite diluent and the desired concentration A first diluting / mixing channel for adding sodium hypochlorite to the raw water flowing at the constant flow rate in an amount adjusted in advance ,
A second dilution mixing channel branched from the raw water supply channel for adding an acid to the raw water and mixing to obtain an acid diluted solution, the raw water flowing in the second dilution mixing channel Mixing and stirring the second flow rate regulating means for maintaining the flow rate constant, the second addition means for adding acid to the raw water flowing in the second dilution and mixing flow path, and the liquid after the acid has been added comprising a second mixer for the said second addition means, the raw water concentration of the acid diluent flows acid at preconditioned amount such that the desired concentration in the constant flow rate A second dilution mixing channel to be added to
A mixing flow path for mixing and guiding the liquid from the first and second dilution mixing flow paths for mixing the sodium hypochlorite dilution liquid and the acid dilution liquid, wherein A mixing flow path comprising a third mixer for mixing and stirring the liquid from the dilution mixing flow path and the liquid from the second dilution mixing flow path;
A first electric conductivity measuring means provided on the downstream side of the first mixer in the first diluting and mixing channel and measuring the electric conductivity (d1) of the sodium hypochlorite diluted solution; ,
A second electric conductivity measuring means for measuring the electric conductivity (d2) of the acid diluted solution provided on the downstream side of the second mixer in the second dilution mixing channel;
A third electrical conductivity measuring means provided in the raw water supply channel for measuring the electrical conductivity (d3) of the raw water;
Control means for performing processing based on signals from the first, second, and third electrical conductivity measuring means ; a desired value determined from the correlation between the concentration of the sodium hypochlorite aqueous solution and the electrical conductivity The increase in the electrical conductivity due to the addition of sodium hypochlorite in the sodium hypochlorite aqueous solution with the concentration of is stored as the first predetermined value and determined from the correlation between the concentration of the acid aqueous solution and the electrical conductivity. An increase in electrical conductivity due to addition of acid in an acid aqueous solution having a desired concentration is stored as a second predetermined value; a first difference which is a difference in electrical conductivity between the sodium hypochlorite diluted solution and raw water A process for obtaining a difference in electric conductivity (d1-d3) and a second electric conductivity difference (d2-d3), which is a difference in electric conductivity between the acid diluted solution and the raw water; d1-d3) and said first predetermined value In comparison, when the first electric conductivity difference (d1-d3) a predetermined time has elapsed deviates from the first predetermined value, the concentration of the sodium hypochlorite diluted solution deviates from the desired concentration Te is determined that it can not produce a normal sterilizing water treatment; and the second electrical conductivity difference (d2-d3) and by comparing the second predetermined value, said second electric conductivity difference ( d2-d3) said when the second out of a predetermined value elapses a predetermined time, control means for the concentration of the acid diluent performs processing for determining that can not generate normal sterile water deviates from a desired concentration When,
A sterilizing water generator characterized by comprising:

Furthermore, it has an electrical conductivity input means for inputting a predetermined value of the electrical conductivity of raw water obtained in advance to the control means, and the control means has the third electrical conductivity as the electrical conductivity (d3) of the raw water. 6. The sterilizing water generator according to claim 5, wherein a signal input from the electrical conductivity input unit is used instead of a signal from the rate measuring unit.

When it is determined that the normal sterilizing water cannot be generated, the control means performs a process for issuing a predetermined alarm, a process for displaying predetermined information, or a process for stopping the supply of raw water. The sterilizing water generator according to claim 5 or 6.

The raw water is tap water, well water, seawater, or reverse osmosis water (R / O water), The sterilizing water generator according to any one of claims 5 to 7.

The sterilized water according to any one of claims 5 to 8, wherein the concentration of sodium hypochlorite in the sterilized water is in the range of 0.5 ppm to 1000 ppm, and the pH is in the range of pH 3.0 to 7.5. Generator.