JP3701012B2

JP3701012B2 - Reverse osmosis apparatus with automatic reverse osmosis membrane cleaning mechanism, and method for producing pure water using the apparatus

Info

Publication number: JP3701012B2
Application number: JP2001188930A
Authority: JP
Inventors: 成泰金; 邦彦山中
Original assignee: JMS Co Ltd
Current assignee: JMS Co Ltd
Priority date: 2001-06-22
Filing date: 2001-06-22
Publication date: 2005-09-28
Anticipated expiration: 2021-06-22
Also published as: JP2003001072A

Description

【０００１】
【発明が属する技術分野】
本発明は、原水に含有されたコロイド、難溶性塩類やバクテリアなどの不純物が逆浸透膜の表面に濃縮・蓄積されて、製造された純水（逆浸透水）の水質が悪化すること、逆浸透膜面への不純物の付着、沈殿等の結果、逆浸透膜の透水性能が経時的に低下することを防ぐことを自動的に可能とした逆浸透装置および該装置を使用した逆浸透方法による純水の製造法に関するものである。
【０００２】
【従来の技術】
従来の逆浸透装置では逆浸透膜にコロイド、難溶性塩類やバクテリアなどの不純物が膜面に濃縮されたり、沈着することにより、製造される純水（逆浸水）の純度（導電率・微粒子数・エンドキシン濃度など）が悪化したり、透水性能の経時劣化により耐久性に問題があった。
膜の目詰まりにより透水性能が低下した場合、逆浸透膜モジュールを分離し、薬液循環ラインを形成し、アルカリないし酸性洗浄剤を逆浸透膜の原水流入側に流し込むと言う煩雑な操作を必要とした。
また、前記のような薬液洗浄後は逆浸透膜に残留する前記洗浄に使用した薬液を水洗除去するために大量の水を必要とした。
さらに、前記薬液洗浄自体によって逆浸透膜を化学的に劣化させ、逆浸透膜自体の透水性は回復しても水質は回復しないこともある。このような場合には、高価な逆浸透膜の交換が必要で維持管理コストが増大すると言う課題があった。
【０００３】
また、従来、逆浸透水（ＲＯ水、ｒｅｖｅｒｓｅｏｓｍｏｓｅｄｗａｔｅｒ、また、以下、純水とも呼ぶ。）の製造は、図５に示すような間欠運転逆浸透水製造システムが行われていた。このシステムにおいては、逆浸透装置Ｃから、濃縮水を除去すると共に、製造される純水（以下、逆浸透水とも言う）を純水タンクに貯留し、該純水タンクが純水で一杯になるとレベルスイッチで検知して制御系ｆにより原水を逆浸透装置に供給するポンプの運転を中止し、逆に純水タンクの貯水量が低下するとレベルスイッチで検知して制御系ｆにより前記原水供給ポンプの運転を再開し、純水の製造を行うものが提案されていた。
【０００４】
【発明が解決しようとする課題】
逆浸透装置による純水造水時、濃縮水循環ラインを取り付ける事で純水の回収率を著しく向上させる事が可能であるが、反面、逆浸透膜に不純物の蓄積が増加する問題が発生する。これら課題を解決するために、本出願人は、逆浸透装置の使用中に自動的な純水洗浄工程を組み込むことにより原水中の不純物の逆浸透膜表面の濃縮や沈着殿形成を防止し、（１）導電率、微粒子数、エンドトキシン濃度などでモニターされる水質を向上させる、純水の製造効率を向上させる、（２）逆浸透膜の透水性能を保持し耐用年数を延長させる、（３）煩雑で膜の化学劣化を起こす薬液洗浄を不溶とする、もしくは頻度を減じる、（４）膜面でのバクテリアの繁殖を低減するなどの課題を解決した逆浸透膜自動洗浄機構付逆浸透装置、および純水の製造法を提案している（特願平１１−３３０３２０）。本発明は、前記特願平１１−３３０３２０の発明の逆浸透膜自動洗浄機構付逆浸透装に、貯留された純水を該純水が使用されるクライアント装置に供給するための供給ポンプが故障した場合であっても、ユースポイント、あるいはクライアント装置に純水を供給することが可能な機能を付加した逆浸透膜自動洗浄機構付逆浸透装を提供することにある。
【０００５】
【課題を解決するための手段】
本発明の第１は、逆浸透装置の原水負荷側に、該装置の運転中に逆浸透装置の逆浸透膜を純水により洗浄するための純水再循環機構を設け、かつ、前記純水供給ラインと、前記純水還流ラインまたは前記調整バルブの上流側の前記循環ラインとの間にバイパスラインを設け、かつ前記循環ラインに装着された流量調節部材の調節によって、前記純水貯留容器から流出した純水の少なくとも一部を前記純水供給ラインに送液可能なことを特徴とする自動洗浄機構付逆浸透装置を提供することにより、前記のような問題あるいは課題を解決したことにある。
【０００６】
すなわち、本発明の逆浸透装置は、原水を逆浸透装置に供給する原水負荷ライン、原水負荷ラインの逆浸透装置の上流側に設けた原水または純水を高圧にするために使用する手段（以下、液体加圧化手段とも言う）、逆浸透膜を通過した純水と逆浸透膜を素通りした濃縮水に原水を分離する逆浸透膜を有する逆浸透装置、一端を逆浸透装置に接続し、他端を前記原水負荷ラインに接続して再循環ループラインを形成する素通りライン（濃縮水ライン）、前記素通りライン（濃縮水ライン）から分岐して形成された排水ライン、前記原水負荷ラインと素通りライン（濃縮水ライン）とで形成された再循環ループライン、逆浸透装置で製造された純水の貯留容器、該純水貯留容器より貯留された純水を該純水が使用されるユースポイントあるいは外部クライアント装置に供給するための供給手段を配置した純水供給ライン、逆浸透装置で分離された純水の一部を原水負荷ラインに循環する純水還流ライン、純水を純水タンクに供給する純水ラインおよび前記前記純水ラインから分岐する初期抜水ライン、前記純水還流ラインから分岐した純水を直接（純水）貯留容器に戻す循環ライン、該循環ラインに装着された流量調節部材、を少なくとも有して構成され、かつ原水の製造中において逆浸透装置の逆浸透膜を純水により清浄化できる自動洗浄機構付逆浸透装置において、前記純水供給ラインと、前記純水還流ラインまたは前記調整バルブの上流側の前記循環ラインとの間にバイパスラインを設け、かつ前記循環ラインに装着された流量調節部材の調節によって、前記純水貯留容器から流出した純水の少なくとも一部を前記純水供給ラインに送液可能なことを特徴とする自動洗浄機構付逆浸透装置にある。
【０００７】
本発明の逆浸透装置の一つの特徴は、連続運転を行いながら純水の使用量に対して造水量が優位な時間帯、いいかえると純水タンクの貯水量が多くタンク内液面が高位の状態の時間帯に純水タンク中の余剰の純水を逆浸透膜モジュールヘ還流し、該モジュールの洗浄を行う構成にある。つまり連続運転中に間欠的に洗浄工程を挿入する構成の装置にある。余剰の純水を洗浄に利用することにより、純水タンクが溢水に至ることも回避できることにある。
逆浸透装置において、膜機能の低下は、通常、膜自体の強度劣化でなく膜面に異物の沈着による劣化であるが、本発明の逆浸透装置では、前記のような単純な機構によって逆浸透膜面への優れた洗浄効果が得ら、その結果、純水の製造効率が格段に向上し、且つ逆浸透膜の性能が長期に維持される。
【０００８】
前記「純水タンクの貯水量が多くタンク内液面が高位の状態の時間帯」とは、仮に純水の貯留量が低下しても、該純水を使用するユースポイントあるいは外部クライアント装置への逆浸透水の供給量が不足するという問題が生じないような貯留量を指す。これは、例えば図１のレベルスイッチαの位置に液面がある状態（この状態をタンク内液面が高位の状態とも言う）である、これに対して、例えば図１のレベルスイッチβの位置に液面がある状態（この状態をタンク内液面が低位の状態とも言う）あるいは前記レベルスイッチβの位置より低い位置に液面がある状態では、ユースポイント（使用する箇所）への逆浸透水の供給量が不足するというような問題が生じ、純水タンク中の純水を使用して前記のような逆浸透膜モジュールの洗浄を行うことはできない。
【０００９】
本発明の逆浸透装置の他の特徴は、前記循環ラインに装着された流量調節部材の調節によって、前記純水貯留容器から流出した純水の少なくとも一部を前記純水供給ラインに送液可能な逆浸透装置であるから、純水貯留装置に貯留された純水を該純水が使用されるユースポイント（使用する箇所）、あるいはクライアント装置に供給するための供給ポンプが故障した場合であっても、クライアント装置に純水を供給することが可能な点にある。
また、本発明において以下に述べるような種種の実施態様をとることによって、さらに有用なものとすることができる。即ち、前記バイパスラインと前記純水供給ラインとの結合部位が前記供給手段の上流側であることを特徴とする前記の逆浸透装置である。
或いは、供給ラインが少なくとも２つの並列な関係に配置された純水供給ラインを有し、かつ、前記バイパスラインと前記純水供給ラインとの結合部位の上流側で前記バイパスラインが分岐して並列な関係に配置された前記純水供給ラインのそれぞれに結合し、また、前記分岐したバイパスにそれぞれ流量調節部材を設けられたことを特徴とする前記の逆浸透装置である。
或いは、前記バイパスラインが前記純水還流ラインに結合する位置と前記循環ラインが前記純水還流ラインに結合する位置が、前記純水還流ラインの同一位置であることを特徴とする前記の逆浸透装置。
【００１０】
本発明の純水の製造法は、具体的には、前記の逆浸透装置を使用して、最初に原水を逆浸透装置に供給する原水負荷ライン、初期抜水ライン、排水ラインに連結する素通りライン（濃縮水ライン）および排水ラインを開状態、純水ラインを開閉任意選択とし、その他のラインを開または閉状態で液体加圧化手段を作動させて逆浸透操作を行い、該操作によって製造された純水を該純水が使用されるユースポイントあるいは外部クライアント装置に供給するとともに、初期抜水ラインから抜水し、該抜水された純水の濃度を検査し、その濃度が一定以上に良くなった段階で、下記（１）〜（３）の各工程を連続して少なくとも１回以上行い純水を製造し、該生成された純水を製造することを特徴とする純水の製造法である。
【００１１】
（１）純水製造工程
原水負荷ライン、排水ラインに連結する素通りライン（濃縮水ライン）ライン、排水ラインおよびを純水ライン開状態、再循環ループラインは開閉任意選択とし、その他のラインを開または閉状態で原水を供給し、液体加圧化手段を作動させ原水を高圧化し逆浸透装置に送り純水を製造する工程。
（２）純水置換洗浄工程
前記（１）の純水製造工程により製造された純水の貯留量が貯留容器のあらかじめ定められた液面位置に達した状態になった場合（Ａ）、あるいは純水の液面が貯留容器の一定レベル以上にある純水の貯留量で、製造された純水の純度を検知し、その純度が一定以下に悪化した状態になった場合（Ｂ）、前記（Ａ）あるいは（Ｂ）の状態を検知して原水の供給を停止し、かつ純水ラインを開閉任意選択とし、排水ラインに連結する素通りライン（濃縮水ライン）および排水ラインを開状態で逆浸透装置に純水還流ラインから純水を供給して素通り（濃縮水）ライン中および逆浸透装置中の濃縮水を排出しつつ純水に置換する工程。
（３）高速洗浄工程
前記（２）の工程による純水の置換状態で、原水負荷ラインからの原水の供給を停止状態、再循環ループラインを開状態、および排水ラインを閉状態として液体加圧化手段の作動下で純水を高流量で再循環ループライン中を再循環させて逆浸透装置の逆浸透膜を高速洗浄した後、この不純物を洗い流した洗浄水を排水ラインに連結する素通りライン（濃縮水ライン）、排水ラインおよび純水還流ラインのみを開状態、純水ラインを開閉任意選択とし、その他のラインを閉状態として液体加圧化手段の作動下に新たな純水を注入して排水ラインから排出する工程。
本発明で言う原水としては、例えば水道水、井戸水等を使用できる。
【００１２】
以下、本発明の逆浸透装置および該逆浸透装置を使用した純水の製造法を図面に基づいて詳細に説明する。ただし、本発明は、これら実施態様のものに限定されるものではない。
図１は、本発明の自動洗浄機構付逆浸透装置を構成する構成部材および該装置内の配管フローを示した図である。
図１の逆浸透装置Ｃに原水負荷ライン６を通して原水を供給する。
原水は高圧で逆浸透することにより、逆浸透膜を通過した純水と逆浸透膜を素通りした濃縮水に分離される。逆浸透膜に反撥され膜を透過せずに素通りした濃縮水は、素通りライン（濃縮水ライン）７により逆浸透装置Ｃから取り出される。
原水負荷ライン６には、その入口側には原水の供給量を調節するための弁１、好ましくは電磁弁を設け、また、該弁１と逆浸透装置Ｃの間に原水または純水などを加圧するため液体加圧手段（本図のものは高圧ポンプＡ）を設ける。
原水は前記原水負荷ライン６より導入され、前記ポンプＡで加圧され高圧（以下、通水圧力とも言う）下で逆浸透装置Ｃ内に導入される。
前記純水の作成量は、膜の透水性、膜間圧力差（通水圧力）、原水の浸透圧、および原水の素通りラインの通過量と純水取り出し量の割合（すなわち回収率）に依存する。
【００１３】
一般に、逆浸透装置Ｃから得られる純水の純度は原水の通水圧力（透過水量）や純水の回収率で変化する。また、純水の純度は通水圧力（膜間圧力差）に応じて動的に変動すること、また、圧変化による揺さぶりが逆浸透内のシール部の閉鎖不全を起こして原水中の成分がリークすることにより純水の水質が劣化しうることから通水圧力は高圧かつ一定圧に保ち変動を避けるのが好ましい。
通水圧力としては、通常５ｋｇ／ｃｍ２〜２０ｋｇ／ｃｍ２程度の圧力が採用されるが、逆浸透装置Ｃに負荷する圧力は高圧かつ一定圧であることが好ましい。
【００１４】
逆浸透膜に掛かる圧力を一定にするため排水・濃縮循環・純水還流ライン電磁弁と注入ホ゜ンフ゜は重要な役割を果たす。すなわち、図において、排水用と濃縮水循環ラインの電磁弁並列に２個取り付けたのは、逆浸透膜に流入する流量を一定もしくは、変動を最小にし、高圧ホ゜ンフ゜にはいる圧力をより一定にする目的からである。さらに吐出流量を一定にする事で逆浸透膜にかかる圧力をより一定にする。
【００１５】
前記素通りライン（濃縮水ライン）７は高圧ポンプＡの上流側（図１のＦ地点）で原水負荷ライン６に接続し、再循環ループライン８を形成する。再循環ループライン８を構成する素通りライン（濃縮水ライン）７の途中に排液ライン９を設ける。排液ライン９上に排水用の電磁弁４と４ａを並列に設けた。該電磁弁４と４ａは１個でも良いが、下記実施例に記載する複数の洗浄操作を可能にしたり、また流量調節を容易にし、逆浸透膜に流入する流量を一定にするため複数個が好ましい。
【００１６】
排水ライン９上には前記排水弁に加えて、万が一の閉鎖回路の過負荷対策として該排水弁に並列に圧抜き安全弁Ｄを設けても良い。
前記再循環ループライン８を形成する際には、素通りライン（濃縮水ライン）７には、該ラインが原水負荷ライン６に接続する地点より手前側に電磁弁３ａと３ｂを設けるのが好ましい。或いは電磁弁３ａや３ｂを設けたラインに並列となるように、別の弁無しのラインを設けてもよい。また、これらの電磁弁は、１個であっても良いが、前記排水用の弁４ａと４と同様に下記実施例に記載する複数の洗浄操作を可能にしたり、また流量調節を容易にし、逆浸透膜に流入する流量を一定にするため複数個が好ましい。
【００１７】
逆浸透装置Ｃから純水が取り出され、逆浸透装置Ｃからの純水の取り出し制御する電磁弁２を有する純水ライン１０を通って純水タンクに貯留される。該純水ライン１０には、逆浸透装置Ｃから純水が取り出された純水が一定の純度を有するかどうか監視する部材を設けても良い。また、純水ライン１０の電磁弁の上流部に分岐を設け始動時に停滞水を排出する初期抜水ラインとし（図示せず）、初期抜水ラインの開閉を調節する電磁弁を設ける。
原水タンクから取り出された純水を原水負荷ライン６に還流させる純水還流ライン１１が原水負荷ライン６の高圧ポンプＡの上流側に結合される（図１のＦ地点）。素通り（濃縮）ライン７が原水負荷ライン６に結合するＦ点と純水還流ライン１１が原水負荷ライン６に結合するＦ点とは同一地点であることが配管を単純化する観点から好ましい、前者と後者のＦ点の位置は異なっていても良い。この場合、清浄な純水が流れる後者を前者よりも上流に配する方が原水ラインの６の洗浄性にやや優れる。
【００１８】
前記純水還流ライン１１には、逆流を防止し原水負荷ラインへの還流を容易とし、純水還流ラインの停滞部分の距離を短縮するため、さらに原水ラインの圧力と同等の圧力を供給するために注入ポンプＢを設けるのが好ましい。また、注入ポンプＢの上流側には、電磁弁５および５ａが閉鎖している間の流出路を確保するために、ポンプＢを通過した純水の一部を純水タンクに還流するラインを設ける。
前記純水還流ライン１１には前記注入ポンプＢと前記Ｆ点の間に電磁弁である５ａと５が設けられており、該５ａと５も１個であっても良いが、上述の電磁弁と同様に下記実施例に記載する複数の洗浄操作が可能としたり、流量調節を容易にするため複数個が好ましい（この製造法を第１の製造法と言う）。
前記の記載では弁として、並列に配した電磁弁を使用しているが、本発明の装置で使用する弁は電磁弁に限定されるものではないし、また並列に配した電磁弁の代わりに流量調節バルブを使用しても良いし、また、上述のように、複数個でなく１個であっても良い。
さらに、前記純水還流ライン１１からは、直接に純水を純水貯留容器に戻す循環ライン１６が分岐し、かつ、該循環ライン１６には、下記のように純水還流ライン１１からの純水を純水供給ライン１５に送ることが可能なように、流量調節部材１９、例えば流量調節弁が設けられる。
循環ライン１６に設けられる前記流量調節部材１９は任意に流量を調節できるような弁（バルブ）が望ましい。
【００１９】
また、前記純水貯留タンクには、該タンクに貯留された純水を該純水が使用されるユースポイントあるいは外部クライアント装置に供給するための供給ポンプＥ、Ｆを配置した純水供給ライン１５が接続され、該純水供給ライン１５より純水がユースポイントあるいは外部クライアント装置に供給される。
【００２０】
前記純水供給ライン１５と前記純水還流ライン１１の間にバイパスライン１４を設け、かつ循環ライン１６に設けた前記流量調節部材１９によって、純水タンクに戻る液の流量を絞ることにより、前記純水還流ライン１１から純水をバイパスライン１４を介して純水供給ラインに純水を送り、ユースポイント、あるいはクライアント装置に供給するための供給ポンプE、Fが故障した場合であっても、純水のユースポイント、あるいはクライアント装置に純水を供給することがポンプBにより、バイパスライン１４を介して可能となる。
本図の態様のものにおいては、前記バイパスライン１４が前記純水還流ライン１１に結合する位置と前記循環ライン１６が前記純水還流ライン１１に結合する位置は、前記純水還流ライン１１と同一位置であるが、前記バイパスライン１４が前記純水還流ライン１１に結合する位置と前記循環ライン１６が前記純水還流ライン１１に結合する位置は、必ずしも純水還流ライン１１の同一位置である必要はなく、例えば、図３に示すように前記バイパスライン１４が前記純水還流ライン１１に結合する位置が前記純水還流ライン１１の上流側にあり、前記循環ライン１６が前記純水還流ライン１１に結合する位置が前記純水還流ライン１１の下流側にあるような態様のものであってもよい。
【００２１】
本発明の純水の製造法の別の実施態様としては、前記第１の製造法において、純水製造工程、純水置換洗浄工程あるいは高速洗浄工程によりタンクの純水液面が中位の状態になった場合、原水負荷ライン６、純水還流ライン１１、排水ライン９および再循環ループライン８を開状態、また、純水ライン１０は開状態で逆浸透を連続して行うことを特徴とする請求項９〜１１のいずれかに記載の純水の製造法が挙げられる（この製造法は請求項１２に対応し、以下、製造法２とも言う）。
この場合、純水タンクの水位が上がるか下がるかは排水ラインから排出される排水量と原水の供給量の大小関係、および純水のユースポイント（使用する箇所）での使用量によって決まる。
【００２２】
本発明の純水の製造法のさらに別の実施態様としては、高速洗浄後、排水ライン９、再循環ループライン８、純水ライン１０および純水還流ライン１１を開状態として、純水による膜洗浄は、一部は排水しながら、一部は再循環しながら行うことを特徴とする請求項９〜１０のいずれかに記載の純水製造法が挙げられる（この製造法は請求項１１に対応し、以下、製造法３とも言う）。
前記製造法２と３においては、逆浸透膜モジュールの純水側を停滞させると、汚染が発生する可能性があるという理由から、電磁弁２を開状態で実施することが望ましい。
前記製造法２および３の場合も、前記製造法１の場合と同様、本発明の逆浸透装置を使用すれば、純水のユースポイント、あるいはクライアント装置に純水を供給することがバイパスライン１４を介して可能となる。
【００２３】
以下、本発明の実施例を示す。
【実施例】
実施例１
図に基づいて本発明を具体的に説明する。
（１）初期抜水工程
図１において、最初に原水を逆浸透装置に供給する原水負荷ライン６、初期抜水ライン（図示せず）、および排水ライン９を開状態、その他のラインを開または閉状態で液体加圧化手段を作動させて逆浸透操作を行い、該操作によって製造された純水の初期抜水を行う（ただし、本発明において、この初期抜水工程は、絶対に必要な要件ではない）。この初期抜水によって得られた純水の濃度が一定濃度以上、例えば導電率が原水の５％以下の純度になった後、純水製造工程に移行する。
【００２４】
（２）純水製造工程および純水置換洗浄工程
初期抜水を行った後、純水の製造を行う。
純水の製造は、まず、高圧ポンプＡの作動下で、電磁弁１・２・４と４ａの一方が開状態、他の弁が閉状態で最大となるので、この状態で純水の製造が行われ、製造された純水は貯留タンクに貯留される。貯留タンクが満水状態となると、レベルスイッチが作動し、図２に示すように電磁弁４・４ａ・５・５ａを開状態とし、その他の電磁弁を開状態とし、逆浸透装置の逆浸透膜モジュール中および素通りライン（濃縮水）ライン７中の濃縮水が純水で置換・洗浄される。この置換・洗浄操作によって、逆浸透膜表面に沈着沈殿したコロイド、難溶性塩類、バクテリア等を取り除き、膜の濾過効率を改善する。
【００２５】
また、前記純水置換操作の開始は、逆浸透装置から取り出される純水の純度が一定純度以下になると行われるようにしても良い。ただし、この純水の純度を検知して行う前記純水置換操作の開始は、純水タンク液面の位置の検知と併用しながら行うのが好ましい。すなわち、純水タンク液面の位置があるレベル以下になっている場合に、純水の純度の検知結果のみに基づいて前記純水置換操作の開始行った場合、純水の使用量が供給量を上回り、さらに純水タンクの液面が低下し、渇水警報が作動する可能性がある。
この段階において、ライン中の流量は、
ｐ＝ｕ＝ｖ＝ｑ＋ｒ＝ｘ＋ｙの関係を満足する。
【００２６】
図２の工程で、電磁弁２を開状態とし純水を製造しながら逆浸透膜モジュール中および素通りライン（濃縮水）ライン７中の濃縮水を純水で置換することもできる。純水の使用量が多く、純水製造の中止時間に余裕がない場合には好都合である（請求項１２に対応）。この場合、ライン中の流量は
ｐ＝ｑ＋ｒ＝ｕ＝ｖ＋ｚ、およびｖ＝ｘ＋ｙの関係を満足する。
【００２７】
次に図３に示すように、高圧ポンプＡおよび供給ポンプＢの作動下で、電磁弁３・３ａを開状態にし、他の電磁弁を閉状態にすることで純水は逆浸透装置の再循環ループライン８内で高流量に循環し膜を高速洗浄する。電磁弁２を開状態で洗浄と同時に純水製造を平行して行ってもよい。この場合電磁弁５ａないし５は開状態としなければならない。還流する純水量は電磁弁５ａおよび５の開閉状態により規定され、還流量が純水製造量と等しい。
この段階において、ライン中の流量は、
ｕ＝ｑ＋ｒ＋ｓ＋ｔ＝ｖ＋ｚ、ｖ＝ｓ＋ｔ、およびｚ＝ｐ＝ｑ＋ｒの関係を満足する。
次に、一定時間経過し十分な洗浄が達成された後かもしくは純水タンクレベルが低下した時点で、図２に示すように、電磁弁４・４ａ・５・５ａを開状態とし、その他の電磁弁は閉状態として、新たな純水を注入して、素通り（濃縮水）ライン７および再循環ループライン８内を再循環して不純物を洗い流した水をシングルバスにて洗浄、排水する。電磁弁２は開状態でもよい。この工程で純水タンクレベルが低下しレベルスイッチが作動した時点、もしくは、不純物を洗い流した水を新たな純水で排水した時点で最初の純水製造状態に戻る。
以上のような工程を繰り重しながら逆浸透膜に不純物が蓄積する前に洗浄除去を効率的に行うことで水質と膜の性能を維持し、併せて配管、逆浸透膜および純水タンク中のバクテリア等の繁殖を防ぐ。
【００２８】
前記のようにして製造された純水は、正常時には、純水タンクから、バイパスライン１４が結合する地点より上流側で２つのラインに分岐した純水供給ライン１５を経て、純水供給ライン１５の下流側のラインに設けた送液ポンプE、Fによって、ユースポイントあるいは外部クライアント装置へ純水を送液出来る。
【００２９】
実施例２
前記図３の工程の後で、純水タンク液面が中間位にある時は、図４の工程で高圧ポンプＡおよび供給ポンプＢの作動下に電磁弁３ａ、４ａ、５ａを開状態とし、その他の電磁弁を閉状態にする制御で純水による膜洗浄は、一部は排水しながら、また、一部は再循環することで膜の不純物を洗浄除去することができる。
さらに、電磁弁２を開状態でさらに一部は純水を製造しながら行うことができる（請求項１１に対応）。この制御において、ライン中の流量は、
ｕ＝ｖ＋ｚ、ｐ＝ｑ、ｕ＝ｑ＋ｓおよびｖ＝ｓ＋ｘの関係を満足する。
本実施例の場合も、実施例１の場合と同様に製造された純水は、バイパスライン１４から、純水供給ライン１５へ純水の供給を続けることが出来る。
【００３０】
実施例３
前記実施料の電磁弁１を開とした純水製造工程下のバリエーションとして、例えば電磁弁４ａおよび４を開、３ａを開、３を閉とすると濃縮水の流れは排水が相対的に増加し、回収率が低下する。逆に３ａおよび３を開、４ａを開、４を閉とすると回収率は向上し純水製造に有利となる。３ａおよび３を開、４ａおよび４を閉とするとさらに回収率は向上する。また、電磁弁１を開の状態で、電磁弁５ａ、５を全開もしくは半開、全閉鎖にするとそれぞれ純水の還流割合が低下する。純水の還流量を増やしタンク内の逆浸透水を再度逆浸透することにより純水タンクの清浄化が達成される。
この場合、ライン中の流量は、
ｕ＝ｗ＋ｐ＋ｓ＋ｔ＝ｖ＋ｚ、ｐ＝ｑ＋ｒおよびｖ＝ｓ＋ｔ＋ｘ＋ｙの関係を満足する。
このような弁の開閉状態を組み合わせることにより、純水の製造と膜洗浄を同時に行うことができる。
ただし、電磁弁の開閉状態の組み合わせは前記のようなものに限定されるものではなく、純水の製造と純水による膜洗浄を同時に行うことができるものであれば良い。
なお、図１〜４において、全部塗り潰し状態の弁は閉状態、半塗り潰し状態の弁は開閉任意選択、塗り潰されていない状態の弁は開状態をそれぞれ示す。
【００３１】
【表１】

○はポンプが動作あるいは弁が開状態にあることを示す。
×はポンプが停止あるいは弁が閉状態にあることを示す。
三角はポンプが動作あるいは停止、弁が開あるいは閉状態の任意であることを示す。
【００３２】
【効果】
発明に係る逆浸透装置および該装置を使用した純水の製造法によると、純水による逆浸透膜への優れた洗浄効果により逆浸透膜の性能が長期に維持され、さらに純水の水質も従来の装置に比べ優れている。また、純水の製造効率も格段に改善される。逆浸透膜の交換頻度や薬液洗浄の頻度が減少することにより、保守にかかる費用も格段に少ない。大量の純水の安定供給を必要とする血液透析治療のための透析用水の供給手段として応用できる。
また、ユースポイントあるいは外部クライアント装置に純水を供給するラインに設けた供給ポンプが故障で停止、あるいはなんらかの理由で該供給ポンプが駆動不能な状態になった場合でも、ユースポイントあるいは外部クライアント装置への純水の供給を継続できる。
【図面の簡単な説明】
【図１】逆浸透膜自動製造機構付逆浸透装置の各部品取り付け配置および配管フローを説明した図である。
【図２】逆浸透膜をシングルバス洗浄するフロー図である。
【図３】逆浸透膜を純水で再循環洗浄するフロー図である。
【図４】逆浸透膜を純水で再循環洗浄し、一部を排水するとともに純水製造も平行して実施できるフロー図である。
【図５】従来例の間欠運転型ＲＯシステムフロー図である。
【符号の説明】
Ａ高圧ポンプ
Ｂ供給ポンプ
Ｃ逆浸透装置
Ｄ安全弁
Ｅユースポイントあるいは該純水が使用される外部クライアント装置に供給するための供給ポンプ
Ｆユースポイントあるいは該純水が使用される外部クライアント装置に供給するための供給ポンプ
α レベルスイッチ
β レベルスイッチ
ｐ純水タンクからの再循環量
ｑ弁を通過する流量
ｑ弁を通過する流量
ｒ弁を通過する流量
ｓ弁を通過する流量
ｔ弁を通過する流量
ｕポンプを通過する流量
ｖ流量
ｗポンプを通過する流量
ｘ弁を通過する流量
ｙ弁を通過する流量
ｚ弁を通過する流量
１電磁弁
２電磁弁
３電磁弁
３ａ電磁弁
４電磁弁
４ａ電磁弁
５電磁弁
５ａ電磁弁
６原水負荷ライン
７素通り（濃縮水）ライン
８再循環ループライン
９排水ライン
１０純水（逆浸透水）ライン
１１純水還流ライン
１２三方電磁弁
１３初期抜水ライン
１４純水供給ラインと前記純水還流ラインの間のバイパスライン
１５ユースポイントあるいは外部クライアント装置への純水供給ライン
１６循環ライン
１７流量調節弁
１８流量調節弁
１９流量調節弁[0001]
[Technical field to which the invention belongs]
In the present invention, impurities such as colloids, sparingly soluble salts and bacteria contained in raw water are concentrated and accumulated on the surface of the reverse osmosis membrane, and the quality of the produced pure water (reverse osmosis water) deteriorates. According to a reverse osmosis device that automatically prevents the water permeation performance of a reverse osmosis membrane from decreasing over time as a result of adhesion, precipitation, etc. of impurities on the osmosis membrane surface, and a reverse osmosis method using the device The present invention relates to a method for producing pure water.
[0002]
[Prior art]
In conventional reverse osmosis equipment, the purity (conductivity, number of fine particles) of pure water (reverse immersion water) produced by condensing or depositing colloids, poorly soluble salts, bacteria and other impurities on the membrane surface・ Endotoxin concentration etc.) deteriorated and water permeability performance deteriorated over time.
When the water permeability is reduced due to clogging of the membrane, the reverse osmosis membrane module is separated, a chemical circulation line is formed, and the complicated operation of pouring an alkali or acidic detergent into the raw water inflow side of the reverse osmosis membrane is required. did.
In addition, a large amount of water was required after washing with the chemical solution as described above in order to wash away the chemical solution used in the washing remaining on the reverse osmosis membrane.
Furthermore, even if the reverse osmosis membrane is chemically deteriorated by the chemical cleaning itself and the water permeability of the reverse osmosis membrane itself is recovered, the water quality may not be recovered. In such a case, there has been a problem that an expensive reverse osmosis membrane needs to be replaced and maintenance costs increase.
[0003]
Conventionally, reverse osmosis water (RO water, reverse osmosed water, hereinafter also referred to as pure water) has been manufactured by an intermittent operation reverse osmosis water production system as shown in FIG. In this system, the concentrated water is removed from the reverse osmosis device C, and the produced pure water (hereinafter also referred to as reverse osmosis water) is stored in a pure water tank, and the pure water tank is filled with pure water. Then, the operation of the pump that supplies the raw water to the reverse osmosis device by the control system f is stopped by the level switch, and conversely, when the amount of water stored in the pure water tank decreases, the control system f detects that the raw water is supplied. The one that resumed the operation of the pump and produced pure water was proposed.
[0004]
[Problems to be solved by the invention]
Concentrated water circulation during reverse osmosis water purification line Although it is possible to remarkably improve the recovery rate of pure water by attaching, the problem of increasing the accumulation of impurities in the reverse osmosis membrane occurs. In order to solve these problems, the present applicant prevents the concentration of the reverse osmosis membrane surface of impurities in the raw water and the formation of deposits by incorporating an automatic pure water washing process during the use of the reverse osmosis apparatus, (1) Improve the water quality monitored by conductivity, fine particle count, endotoxin concentration, etc., improve the production efficiency of pure water, (2) maintain the water permeability of the reverse osmosis membrane and extend the service life, (3 ) Reverse osmosis equipment with automatic reverse osmosis membrane cleaning system that solves problems such as insoluble or reduced frequency of chemical cleaning that causes chemical degradation of the membrane, and (4) reduced bacterial growth on the membrane surface And a method for producing pure water (Japanese Patent Application No. 11-330320). According to the present invention, the supply pump for supplying the stored pure water to the reverse osmosis device with the reverse osmosis membrane automatic cleaning mechanism of the invention of the aforementioned Japanese Patent Application No. 11-330320 fails. Even in such a case, the object is to provide a reverse osmosis device with a reverse osmosis membrane automatic cleaning mechanism to which a function that can supply pure water to a use point or a client device is added.
[0005]
[Means for Solving the Problems]
According to a first aspect of the present invention, a pure water recirculation mechanism is provided on the raw water load side of the reverse osmosis device to clean the reverse osmosis membrane of the reverse osmosis device with pure water during operation of the device, and the pure water By providing a bypass line between the supply line and the pure water recirculation line or the circulation line upstream of the regulating valve, and adjusting the flow rate adjusting member attached to the circulation line, the pure water storage container By providing a reverse osmosis device with an automatic cleaning mechanism characterized in that at least part of the pure water that has flowed out can be sent to the pure water supply line, the problem or problem as described above has been solved. .
[0006]
That is, the reverse osmosis device of the present invention is a raw water load line for supplying raw water to the reverse osmosis device, means for increasing the pressure of raw water or pure water provided on the upstream side of the reverse osmosis device of the raw water load line (hereinafter referred to as “high pressure”). , Also referred to as liquid pressurizing means), a reverse osmosis device having a reverse osmosis membrane that separates raw water into pure water that has passed through the reverse osmosis membrane and concentrated water that has passed through the reverse osmosis membrane, one end connected to the reverse osmosis device, A flow line (concentrated water line) that connects the other end to the raw water load line to form a recirculation loop line, a drainage line formed by branching from the flow line (enriched water line), and a flow through the raw water load line A recirculation loop line formed with a line (concentrated water line), a pure water storage container manufactured by a reverse osmosis device, and a point of use where the pure water is used from the pure water stored in the pure water storage container Or A pure water supply line with supply means for supplying water to the client device, a pure water recirculation line that circulates a portion of the pure water separated by the reverse osmosis device to the raw water load line, and a supply of pure water to the pure water tank A deionized water line, an initial drain line branched from the pure water line, a circulation line for returning pure water branched from the pure water reflux line directly to the (pure water) storage container, and a flow rate control attached to the circulation line A reverse osmosis device with an automatic washing mechanism, wherein the reverse osmosis membrane of the reverse osmosis device can be purified with pure water during the production of raw water. From the pure water storage container, a bypass line is provided between the line and the circulation line upstream of the regulating valve, and the flow rate adjusting member attached to the circulation line is adjusted. At least a portion of the pure water out is the pure water supply line reverse osmosis device with automatic cleaning mechanism, wherein the possible sent to.
[0007]
One feature of the reverse osmosis device of the present invention is a time zone in which the amount of water produced is superior to the amount of pure water used during continuous operation, in other words, the amount of water stored in the pure water tank is large and the liquid level in the tank is high. In the state time zone, excess pure water in the pure water tank is returned to the reverse osmosis membrane module, and the module is washed. In other words, the apparatus is configured to insert the cleaning process intermittently during continuous operation. By using excess pure water for cleaning, the pure water tank can be prevented from overflowing.
In the reverse osmosis device, the decrease in membrane function is usually not due to the strength deterioration of the membrane itself but due to the deposition of foreign matter on the membrane surface. In the reverse osmosis device of the present invention, reverse osmosis is performed by the simple mechanism as described above. As a result of obtaining an excellent cleaning effect on the membrane surface, the production efficiency of pure water is remarkably improved, and the performance of the reverse osmosis membrane is maintained for a long time.
[0008]
The “time zone in which the amount of water stored in the pure water tank is large and the liquid level in the tank is high” means that even if the amount of pure water stored decreases, the point of use or the external client device that uses the pure water is used. The amount of storage that does not cause the problem of insufficient supply of reverse osmosis water. This is, for example, a state in which the liquid level is at the position of the level switch α in FIG. 1 (this state is also referred to as a state in which the liquid level in the tank is high). In contrast, for example, the position of the level switch β in FIG. When there is a liquid level in the tank (this state is also referred to as a low liquid level in the tank) or in a state where the liquid level is lower than the level switch β, reverse osmosis to the point of use (where to use) There arises a problem that the supply amount of water is insufficient, and the reverse osmosis membrane module cannot be cleaned using pure water in the pure water tank.
[0009]
Another feature of the reverse osmosis device of the present invention is that at least a part of pure water flowing out of the pure water storage container can be sent to the pure water supply line by adjusting a flow rate adjusting member mounted on the circulation line. Since this is a reverse osmosis device, the use point where the pure water is stored in the pure water storage device (where it is used) or the supply pump for supplying the client device has failed. However, pure water can be supplied to the client device.
Further, the present invention can be further useful by adopting various embodiments as described below. That is, in the reverse osmosis device, the coupling site between the bypass line and the pure water supply line is upstream of the supply means.
Alternatively, the supply line has at least two pure water supply lines arranged in parallel, and the bypass line branches in parallel at the upstream side of the connecting portion between the bypass line and the pure water supply line. The reverse osmosis device according to the present invention is characterized in that a flow rate adjusting member is provided in each of the branched bypasses, which is coupled to each of the pure water supply lines arranged in a proper relationship.
Alternatively, the reverse osmosis is characterized in that the position where the bypass line is coupled to the pure water reflux line and the position where the circulation line is coupled to the pure water reflux line are the same position of the pure water reflux line. apparatus.
[0010]
Specifically, the pure water production method of the present invention uses the reverse osmosis device described above, and first connects the raw water load line, the initial drainage line, and the drainage line for supplying raw water to the reverse osmosis device. Manufacture by reverse osmosis operation by operating the liquid pressurizing means with the line (concentrated water line) and drainage line open, the pure water line open / close optional and the other lines open or closed The purified water is supplied to a point of use where the pure water is used or an external client device, drained from the initial drain line, the concentration of the drained pure water is inspected, and the concentration is above a certain level. The pure water is characterized by producing pure water by continuously performing at least once each of the following steps (1) to (3) at the stage of improving the quality, and producing the produced pure water. It is a manufacturing method.
[0011]
(1) Pure water production process
The raw water load line, the passage line (concentrated water line) connected to the drainage line, the drainage line and the pure water line are open, the recirculation loop line is optional to open and close, and other lines are open or closed to supply raw water Then, the liquid pressurizing means is operated to increase the pressure of the raw water and send it to the reverse osmosis device to produce pure water.
(2) Pure water replacement cleaning process
When the amount of pure water produced by the pure water production process (1) reaches the predetermined liquid level of the storage container (A), or the liquid level of pure water is the storage container When the purity of the produced pure water is detected with the amount of pure water stored above a certain level of (B), when the purity has deteriorated below a certain level (B), (A) or (B) The raw water supply is stopped by detecting the condition, and the pure water line is optionally opened and closed. The drainage line is connected to the drainage line (concentrated water line) and the drainage line is opened to the reverse osmosis unit from the pure water return line. A step of supplying pure water and replacing it with pure water while discharging the concentrated water in the flow-through (concentrated water) line and the reverse osmosis apparatus.
(3) High-speed cleaning process
Under the operation of the liquid pressurizing means, with the supply of raw water from the raw water load line stopped, the recirculation loop line opened, and the drainage line closed with pure water replaced by the step (2) After recirculating pure water through the recirculation loop line at a high flow rate and washing the reverse osmosis membrane of the reverse osmosis unit at high speed, a flow-through line (concentrated water line) that connects the wash water that has washed away this impurity to the drainage line, Only the drainage line and pure water recirculation line are open, the pure water line can be opened and closed arbitrarily, and the other lines are closed, and new pure water is injected under the operation of the liquid pressurizing means and discharged from the drain line. Process.
As raw water as referred to in the present invention, for example, tap water, well water and the like can be used.
[0012]
Hereinafter, a reverse osmosis device of the present invention and a method for producing pure water using the reverse osmosis device will be described in detail with reference to the drawings. However, the present invention is not limited to these embodiments.
FIG. 1 is a view showing constituent members constituting a reverse osmosis device with an automatic cleaning mechanism of the present invention and a piping flow in the device.
Raw water is supplied through the raw water load line 6 to the reverse osmosis device C of FIG.
The raw water is separated into pure water that has passed through the reverse osmosis membrane and concentrated water that has passed through the reverse osmosis membrane by reverse osmosis at high pressure. Concentrated water which is repelled by the reverse osmosis membrane and passes through the membrane without passing through the membrane is taken out from the reverse osmosis device C by a passage line (concentrated water line) 7.
The raw water load line 6 is provided with a valve 1 for adjusting the supply amount of raw water, preferably a solenoid valve, on the inlet side, and raw water or pure water is supplied between the valve 1 and the reverse osmosis device C. In order to pressurize, a liquid pressurizing means (the high-pressure pump A in this figure) is provided.
Raw water is introduced from the raw water load line 6, pressurized by the pump A, and introduced into the reverse osmosis device C under high pressure (hereinafter also referred to as water flow pressure).
The amount of pure water produced depends on the water permeability of the membrane, the pressure difference between the membranes (water flow pressure), the osmotic pressure of the raw water, and the ratio of the raw water passage line and the amount of pure water taken out (that is, the recovery rate). To do.
[0013]
In general, the purity of pure water obtained from the reverse osmosis device C varies depending on the water pressure (permeated water amount) of raw water and the recovery rate of pure water. In addition, the purity of pure water changes dynamically according to the water flow pressure (transmembrane pressure difference), and the shaking caused by the pressure change causes the closure failure of the seal part in reverse osmosis, causing the components in the raw water to Since the quality of pure water can deteriorate due to leakage, it is preferable to keep the water flow pressure at a high and constant pressure to avoid fluctuations.
As the water flow pressure, a pressure of about 5 kg / cm 2 to 20 kg / cm 2 is usually employed, but the pressure applied to the reverse osmosis device C is preferably high and constant.
[0014]
Drainage / concentration circulation / pure water recirculation to keep the pressure applied to the reverse osmosis membrane constant line Solenoid valve and injection Phone Plays an important role. That is, in the figure, for drainage and concentrated water circulation line The two solenoid valves are installed in parallel because the flow rate flowing into the reverse osmosis membrane is constant or the fluctuation is minimized and the pressure is high. Phone This is for the purpose of making the pressure to enter more constant. Further, by making the discharge flow rate constant, the pressure applied to the reverse osmosis membrane is made more constant.
[0015]
The passing line (concentrated water line) 7 is connected to the raw water load line 6 on the upstream side of the high-pressure pump A (point F in FIG. 1) to form a recirculation loop line 8. A drain line 9 is provided in the middle of a passage line (concentrated water line) 7 constituting the recirculation loop line 8. Solenoid valves 4 and 4a for drainage are provided in parallel on the drainage line 9. The electromagnetic valves 4 and 4a may be one, but a plurality of electromagnetic valves 4 and 4a may be used to enable a plurality of washing operations described in the following examples, to facilitate flow rate adjustment, and to keep the flow rate flowing into the reverse osmosis membrane constant. preferable.
[0016]
In addition to the drain valve, a pressure relief safety valve D may be provided on the drain line 9 in parallel with the drain valve as a measure against overload of the closed circuit.
When the recirculation loop line 8 is formed, it is preferable that the passing-through line (concentrated water line) 7 is provided with solenoid valves 3 a and 3 b before the point where the line is connected to the raw water load line 6. Alternatively, another line without a valve may be provided so as to be in parallel with the line provided with the electromagnetic valves 3a and 3b. In addition, the number of these solenoid valves may be one, but the plurality of washing operations described in the following examples can be performed similarly to the drainage valves 4a and 4, and the flow rate can be easily adjusted. A plurality is preferable in order to make the flow rate flowing into the reverse osmosis membrane constant.
[0017]
Pure water is taken out from the reverse osmosis device C and stored in a pure water tank through a pure water line 10 having an electromagnetic valve 2 that controls the removal of pure water from the reverse osmosis device C. The pure water line 10 may be provided with a member for monitoring whether or not the pure water from which the pure water is taken out from the reverse osmosis device C has a certain purity. In addition, a branch is provided upstream of the solenoid valve of the pure water line 10 as an initial drain line for discharging stagnant water at the start (not shown), and an electromagnetic valve for adjusting the opening and closing of the initial drain line is provided.
A pure water recirculation line 11 for recirculating pure water taken out from the raw water tank to the raw water load line 6 is coupled to the upstream side of the high-pressure pump A of the raw water load line 6 (point F in FIG. 1). From the viewpoint of simplifying the piping, it is preferable that the point F where the passage (concentration) line 7 is coupled to the raw water load line 6 and the point F where the pure water reflux line 11 is coupled to the raw water load line 6 are preferable. The position of the latter F point may be different. In this case, it is somewhat superior in the washability of the raw water line 6 that the latter in which clean pure water flows is arranged upstream of the former.
[0018]
The pure water reflux line 11 is supplied with a pressure equal to the pressure of the raw water line in order to prevent back flow and facilitate return to the raw water load line, to shorten the distance of the stagnant portion of the pure water reflux line. It is preferable to provide an infusion pump B. Further, on the upstream side of the injection pump B, a line for returning a part of the pure water that has passed through the pump B to the pure water tank is provided in order to secure an outflow path while the solenoid valves 5 and 5a are closed. Provide.
The pure water reflux line 11 is provided with solenoid valves 5a and 5 between the injection pump B and the point F. The solenoid valve 5a and 5 may be one. Similarly, a plurality of cleaning operations described in the following examples are possible, and a plurality of cleaning operations are preferable in order to easily adjust the flow rate (this manufacturing method is referred to as a first manufacturing method).
In the above description, a solenoid valve arranged in parallel is used as a valve. However, the valve used in the device of the present invention is not limited to a solenoid valve, and a flow rate is used instead of a solenoid valve arranged in parallel. A regulating valve may be used, and as described above, one may be used instead of a plurality.
Further, a circulation line 16 for returning pure water to the pure water storage container directly branches from the pure water reflux line 11, and the circulation line 16 includes pure water from the pure water reflux line 11 as described below. A flow rate adjusting member 19, for example, a flow rate adjusting valve is provided so that water can be sent to the pure water supply line 15.
The flow rate adjusting member 19 provided in the circulation line 16 is preferably a valve (valve) that can arbitrarily adjust the flow rate.
[0019]
The pure water storage tank is provided with a pure water supply line 15 provided with supply pumps E and F for supplying the pure water stored in the tank to a use point where the pure water is used or an external client device. And pure water is supplied from the pure water supply line 15 to a use point or an external client device.
[0020]
By providing a bypass line 14 between the pure water supply line 15 and the pure water reflux line 11, and by reducing the flow rate of the liquid returning to the pure water tank by the flow rate adjusting member 19 provided in the circulation line 16, Even if the supply pumps E and F for sending pure water from the pure water recirculation line 11 to the pure water supply line via the bypass line 14 and supplying the pure water to the use point or the client device break down, A pure water use point or pure water can be supplied to the client device by the pump B via the bypass line 14.
In the embodiment of this figure, the position where the bypass line 14 is coupled to the pure water reflux line 11 and the position where the circulation line 16 is coupled to the pure water reflux line 11 are the same as the pure water reflux line 11. The position where the bypass line 14 is coupled to the pure water reflux line 11 and the position where the circulation line 16 is coupled to the pure water reflux line 11 are not necessarily the same position as the pure water reflux line 11. For example, as shown in FIG. 3, the position where the bypass line 14 is coupled to the pure water reflux line 11 is on the upstream side of the pure water reflux line 11, and the circulation line 16 is connected to the pure water reflux line 11. It is also possible to adopt a mode in which the position where it is coupled to is on the downstream side of the pure water reflux line 11.
[0021]
In another embodiment of the pure water production method of the present invention, in the first production method, the pure water liquid level of the tank is in a middle state by the pure water production step, the pure water replacement washing step or the high-speed washing step. The raw water load line 6, the pure water recirculation line 11, the drainage line 9, and the recirculation loop line 8 are open, and the pure water line 10 is continuously open and reverse osmosis is continuously performed. A method for producing pure water according to any one of claims 9 to 11 is mentioned (this production method corresponds to claim 12 and is hereinafter also referred to as production method 2).
In this case, whether the level of the pure water tank rises or falls depends on the magnitude relationship between the amount of drainage discharged from the drainage line and the amount of raw water supplied, and the amount used at the point of use of pure water (where it is used).
[0022]
As still another embodiment of the pure water production method of the present invention, a membrane made of pure water is opened after the high-speed washing, with the drain line 9, the recirculation loop line 8, the pure water line 10 and the pure water reflux line 11 being opened. The pure water production method according to any one of claims 9 to 10, wherein the washing is performed while partly draining and partly recirculating (this production method is described in claim 11). Correspondingly, hereinafter also referred to as production method 3).
In the

manufacturing methods

2 and 3, it is desirable that the solenoid valve 2 is opened in the open state because the contamination may occur if the pure water side of the reverse osmosis membrane module is stagnated.
In the

production methods

2 and 3, as in the case of the production method 1, if the reverse osmosis device of the present invention is used, it is possible to supply pure water to the use point of pure water or to the client device by the bypass line 14. It becomes possible through.
[0023]
Examples of the present invention will be described below.
【Example】
Example 1
The present invention will be specifically described with reference to the drawings.
(1) Initial drainage process
In FIG. 1, the raw water load line 6 for initially supplying raw water to the reverse osmosis device, the initial drainage line (not shown), and the drainage line 9 are opened, and the other lines are opened or closed for liquid pressurization. The reverse osmosis operation is performed by operating the means, and the initial drainage of pure water produced by the operation is performed (however, in the present invention, the initial drainage step is not an absolutely necessary requirement). After the concentration of pure water obtained by this initial drainage becomes a certain concentration or more, for example, the conductivity is 5% or less of the raw water, the process proceeds to the pure water production process.
[0024]
(2) Pure water production process and pure water replacement cleaning process
After the initial drainage, pure water is produced.
In the production of pure water, first, under the operation of the high-pressure pump A, one of the

solenoid valves

1, 2, 4 and 4a is in the open state and the other valve is in the closed state. The produced pure water is stored in a storage tank. When the storage tank is full, the level switch is activated, the

electromagnetic valves

4, 4a, 5, 5a are opened as shown in FIG. 2, the other electromagnetic valves are opened, and the reverse osmosis membrane of the reverse osmosis device The concentrated water in the module and in the passage line (concentrated water) line 7 is replaced and washed with pure water. This replacement / washing operation removes colloids, sparingly soluble salts, bacteria, etc. deposited and precipitated on the reverse osmosis membrane surface, and improves the filtration efficiency of the membrane.
[0025]
In addition, the pure water replacement operation may be started when the purity of pure water taken out from the reverse osmosis apparatus is equal to or lower than a certain level. However, the start of the pure water replacement operation performed by detecting the purity of the pure water is preferably performed in combination with the detection of the position of the pure water tank liquid level. That is, when the pure water tank liquid level is below a certain level and the pure water replacement operation is started based only on the pure water purity detection result, the amount of pure water used is the supply amount. There is a possibility that the water level of the pure water tank will drop and the drought warning will be activated.
At this stage, the flow rate in the line is
The relationship of p = u = v = q + r = x + y is satisfied.
[0026]
In the step of FIG. 2, the concentrated water in the reverse osmosis membrane module and the passage line (concentrated water) line 7 can be replaced with pure water while the electromagnetic valve 2 is opened and pure water is produced. It is convenient when the amount of pure water used is large and there is no allowance for the stop time of pure water production (corresponding to claim 12). In this case, the flow rate in the line is
The relations p = q + r = u = v + z and v = x + y are satisfied.
[0027]
Next, as shown in FIG. 3, under the operation of the high pressure pump A and the supply pump B, the pure water is returned to the reverse osmosis device by opening the

solenoid valves

3 and 3a and closing the other solenoid valves. A high flow rate is circulated in the circulation loop line 8 to clean the membrane at high speed. The pure water production may be performed in parallel with the cleaning while the electromagnetic valve 2 is opened. In this case, the solenoid valves 5a to 5 must be opened. The amount of pure water to be refluxed is defined by the open / close state of the solenoid valves 5a and 5, and the amount of reflux is equal to the amount of pure water produced.
At this stage, the flow rate in the line is
The relationships u = q + r + s + t = v + z, v = s + t, and z = p = q + r are satisfied.
Next, after a certain time has passed and sufficient cleaning has been achieved or when the pure water tank level has dropped, as shown in FIG. 2, the

solenoid valves

4, 4a, 5, 5a are opened, The solenoid valve is closed, injecting fresh pure water, recirculating through the passage (concentrated water) line 7 and the recirculation loop line 8 to wash and drain the water that has washed away impurities in a single bath. The electromagnetic valve 2 may be in an open state. In this step, when the level of the pure water tank is lowered and the level switch is activated, or when the water from which impurities have been washed away is drained with new pure water, the first pure water production state is restored.
Maintaining water quality and membrane performance by performing washing and removal efficiently before impurities accumulate in the reverse osmosis membrane while repeating the above processes, and also in the piping, reverse osmosis membrane and pure water tank Prevent the growth of bacteria.
[0028]
The pure water produced as described above normally passes through the pure water supply line 15 branched from the pure water tank into two lines upstream from the point where the bypass line 14 is joined. Pure water can be sent to a point of use or an external client device by liquid feed pumps E and F provided on the downstream side of the line.
[0029]
Example 2
After the step of FIG. 3, when the pure water tank liquid level is in an intermediate position, the

solenoid valves

3a, 4a, 5a are opened under the operation of the high pressure pump A and the supply pump B in the step of FIG. By controlling the other solenoid valves to be closed, the membrane cleaning with pure water can remove and remove impurities from the membrane by partially draining and recirculating partially.
Furthermore, it can be performed while the electromagnetic valve 2 is opened and a part of the pure water is produced (corresponding to claim 11). In this control, the flow rate in the line is
The relationship of u = v + z, p = q, u = q + s and v = s + x is satisfied.
Also in the case of the present embodiment, the pure water produced in the same manner as in the first embodiment can continue to be supplied from the bypass line 14 to the pure water supply line 15.
[0030]
Example 3
As a variation under the pure water production process in which the solenoid valve 1 of the above fee is opened, for example, when the solenoid valves 4a and 4 are opened, 3a is opened, and 3 is closed, the flow of concentrated water is relatively increased. , The recovery rate decreases. Conversely, when 3a and 3 are opened, 4a is opened, and 4 is closed, the recovery rate is improved, which is advantageous for producing pure water. When 3a and 3 are opened and 4a and 4 are closed, the recovery rate is further improved. Further, when the electromagnetic valve 1 is opened and the electromagnetic valves 5a and 5 are fully opened, half-opened, and fully closed, the reflux ratio of pure water decreases. Purification of the pure water tank is achieved by increasing the reflux amount of pure water and reverse osmosis of reverse osmosis water in the tank again.
In this case, the flow rate in the line is
The relationship of u = w + p + s + t = v + z, p = q + r and v = s + t + x + y is satisfied.
By combining such valve open / closed states, it is possible to simultaneously produce pure water and clean the membrane.
However, the combination of the open / close states of the solenoid valves is not limited to the above, and any combination may be used as long as the production of pure water and the membrane cleaning with pure water can be performed simultaneously.
In FIGS. 1 to 4, a valve that is completely filled indicates a closed state, a valve that is semi-filled is arbitrarily opened and closed, and a valve that is not filled indicates an open state.
[0031]
[Table 1]

○ indicates that the pump is operating or the valve is open.
X indicates that the pump is stopped or the valve is closed.
The triangle indicates that the pump is operating or stopped and the valve is open or closed.
[0032]
【effect】
According to the reverse osmosis device according to the invention and the method for producing pure water using the device, the performance of the reverse osmosis membrane is maintained for a long time due to the excellent cleaning effect on the reverse osmosis membrane by pure water, and the quality of the pure water is also improved. It is superior to conventional devices. In addition, the production efficiency of pure water is greatly improved. Since the frequency of replacement of the reverse osmosis membrane and the frequency of chemical cleaning are reduced, the maintenance cost is remarkably low. It can be applied as a means for supplying dialysis water for hemodialysis treatment that requires a stable supply of a large amount of pure water.
Even if a supply pump provided in a line for supplying pure water to a use point or an external client device stops due to a failure, or for some reason, the supply pump cannot be driven, the use point or an external client device The supply of pure water can be continued.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram for explaining each component mounting arrangement and piping flow of a reverse osmosis device with a reverse osmosis membrane automatic manufacturing mechanism.
FIG. 2 is a flowchart for single bath cleaning of a reverse osmosis membrane.
FIG. 3 is a flowchart for recirculating and washing a reverse osmosis membrane with pure water.
FIG. 4 is a flow chart in which a reverse osmosis membrane is recirculated and washed with pure water, a part of the reverse osmosis membrane is drained, and pure water production can be performed in parallel.
FIG. 5 is a flowchart of a conventional intermittent operation RO system.
[Explanation of symbols]
A High pressure pump
B Supply pump
C Reverse osmosis equipment
D Safety valve
E Use point or supply pump for supplying to the external client device where the pure water is used
F Use point or supply pump for supplying to the external client device where the pure water is used
α level switch
β level switch
p Recirculation volume from pure water tank
q Flow through valve
q Flow through valve
r Flow through valve
s Flow through valve
t Flow through valve
u Flow through the pump
v Flow rate
w Flow through the pump
x Flow through valve
y Flow through valve
z Flow through valve
1 Solenoid valve
2 Solenoid valve
3 Solenoid valve
3a Solenoid valve
4 Solenoid valve
4a Solenoid valve
5 Solenoid valve
5a Solenoid valve
6 Raw water load line
7 Through (concentrated water) line
8 Recirculation loop line
9 Drainage line
10 Pure water (reverse osmosis water) line
11 Pure water reflux line
12 Three-way solenoid valve
13 Initial drainage line
14 Bypass line between pure water supply line and pure water recirculation line
15 Pure water supply line to point of use or external client device
16 Circulation line
17 Flow control valve
18 Flow control valve
19 Flow control valve

Claims

Raw water load line for supplying raw water to the reverse osmosis device, means used for increasing the pressure of raw water or pure water provided upstream of the reverse osmosis device of the raw water load line (hereinafter also referred to as liquid pressurizing means), A reverse osmosis device having a reverse osmosis membrane that separates raw water into pure water that has passed through the reverse osmosis membrane and concentrated water that has passed through the reverse osmosis membrane, one end connected to the reverse osmosis device, and the other end connected to the raw water load line Formed by a passage line (concentrated water line) forming a recirculation loop line, a drainage line formed by branching from the passage line (concentrated water line), the raw water load line and a passage line (concentrated water line). A recirculation loop line, a pure water storage container manufactured by a reverse osmosis device, and supply pure water stored in the pure water storage container to a use point where the pure water is used or to an external client device A pure water supply line in which a supply means is disposed, a pure water recirculation line for circulating a part of pure water separated by a reverse osmosis device to a raw water load line, a pure water line for supplying pure water to a pure water tank, and the aforementioned An initial drainage line that branches off from the pure water line, a circulation line that branches off from the pure water reflux line, and returns a part of the pure water flowing to the pure water reflux line directly to the pure water storage container, is attached to the circulation line A reverse osmosis device with an automatic washing mechanism, wherein the reverse osmosis membrane of the reverse osmosis device can be cleaned with pure water during the production of raw water. A bypass line is provided between the water reflux line or the circulation line upstream of the regulating valve, and the flow rate adjusting member attached to the circulation line is adjusted to flow out of the pure water storage container. It at least a portion of the pure water can be fed to the pure water supply line automatic cleaning mechanism with reverse osmosis device according to claim.

The reverse osmosis device according to claim 1, wherein a flow rate adjusting means is provided on the drainage line, the recirculation loop line, and the pure water reflux line.

The reverse osmosis device according to claim 1, wherein at least one of the flow rate control means is a flow rate control valve.

The reverse osmosis device according to any one of claims 1 to 3, wherein at least one of the flow rate adjusting means is a plurality of parallel valves.

The reverse osmosis device according to any one of claims 1 to 4, wherein the initial drainage line has a valve for opening and closing the line.

The reverse osmosis device according to any one of claims 1 to 5, wherein a passage line (concentrated water line) and a pure water reflux line are connected to the raw water load line on the upstream side of the high-pressure pump.

The reverse osmosis device according to claim 6, wherein the passage line (concentrated water line) and the pure water recirculation line are connected to the same point of the raw water load line (this point is also referred to as point F hereinafter).

Control the time for performing the pure water replacement and the washing process in advance to a certain fixed time, and if the liquid level of the storage container falls below a certain level even within this time, control to immediately shift to the pure water production process The reverse osmosis device according to any one of claims 1 to 7, further comprising means.

The reverse osmosis device according to any one of claims 1 to 8, wherein a flow rate adjusting member is provided in the bypass line.

The reverse osmosis device according to any one of claims 1 to 9, wherein a coupling site between the bypass line and the pure water supply line is upstream of the supply means.

The supply line has a pure water supply line arranged in at least two parallel relations, and the bypass line branches in parallel at the upstream side of the connecting portion between the bypass line and the pure water supply line, and is in a parallel relation The reverse osmosis device according to any one of claims 1 to 10, wherein a flow rate adjusting member is provided for each of the pure water supply lines arranged in the pipe and the branched bypasses.

The position where the bypass line is coupled to the pure water reflux line and the position where the circulation line is coupled to the pure water reflux line are the same position of the pure water reflux line. The reverse osmosis device according to any one of the above.

The position where the bypass line is coupled to the pure water reflux line, the located upstream of pure water reflux line, and, downstream of the pure water reflux line position where the circulation line is coupled to the pure water return line The reverse osmosis device according to any one of claims 1 to 11, wherein the reverse osmosis device is provided.

Using the reverse osmosis device according to any one of claims 1 to 13, a raw water load line for initially supplying raw water to the reverse osmosis device, an initial drainage line, a passage line connected to a drainage line (concentrated water line) Open the drainage line, open and close the recirculation loop line, and open or close the other lines to operate the liquid pressurizing means to perform the reverse osmosis operation, and remove the pure water produced by the operation. After draining from the initial drain line, the concentration of the drained pure water is inspected, and at the stage where the concentration becomes better than a certain level, the following steps (1) to (3) are continuously performed at least. A method for producing pure water, comprising producing pure water by performing at least once, and supplying pure water to a use point or an external client device during or after production of pure water.
(1) Pure water production process Raw water load line, passage line (concentrated water line) line connected to the drainage line, drainage line and the pure water line open state, recirculation loop line can be opened and closed arbitrarily, and other lines opened Alternatively, the raw water is supplied in a closed state, and the liquid pressurizing means is operated to increase the pressure of the raw water and send it to the reverse osmosis device to produce pure water.
(2) Pure water replacement cleaning process When the amount of pure water produced by the pure water production process of (1) reaches a predetermined high liquid level position of the storage container (A) Or, when the purity of the produced pure water is detected by the amount of pure water stored with a pure water level above a certain level in the storage container, and the purity deteriorates below a certain level (B) The state of (A) or (B) is detected, the supply of raw water is stopped, the pure water line is optionally opened and closed, and the passage line (concentrated water line) connected to the drainage line and the drainage line are opened. Then, with the recirculation loop line (valves 3a and 3) opened or closed, pure water is supplied to the reverse osmosis device from the pure water reflux line, and the concentrated water in the flow-through (concentrated water) line and the reverse osmosis device is discharged. While replacing with pure water.
(3) High-speed washing process In the pure water replacement state in the step (2), liquid pressurization is performed with the raw water supply from the raw water load line stopped, the recirculation loop line opened, and the drain line closed. Under normal operation, pure water is recirculated through the recirculation loop line at a high flow rate and the reverse osmosis membrane of the reverse osmosis unit is washed at high speed, and then the wash water that has washed away these impurities is connected to the drainage line. (Concentrated water line), drainage line and pure water recirculation line only open, pure water line can be opened and closed arbitrarily, and other lines are opened or closed to supply new pure water under the operation of the liquid pressurizing means. The process of injecting and discharging from the drainage line.

The pure water replacement cleaning step and the high-speed cleaning step are performed for a predetermined period of time that can be arbitrarily set for the pure water replacement cleaning and cleaning step, and the liquid level of the tank is determined in advance even within this time. The method for producing pure water according to claim 14, wherein when the liquid level becomes lower than the lower level, the process is immediately shifted to a pure water production process.

After high-speed cleaning, the drainage line, recirculation loop line, pure water line, and pure water reflux line are opened, and membrane cleaning with pure water is performed while partly draining and partly recirculating. The method for producing pure water according to claim 14 or 15.

When the pure water level of the tank is between the predetermined low and high levels in the pure water production process, pure water replacement cleaning process or high-speed cleaning process, the raw water load line, pure water reflux line, drainage line and recirculation The method for producing pure water according to any one of claims 14 to 16, wherein reverse osmosis is continuously performed with the loop line open and the pure water line open.

18. The method according to claim 14, wherein at least a part of the pure water flowing out of the pure water storage container is sent to the pure water supply line by adjustment of a flow rate adjusting member attached to the circulation line. The manufacturing method of the pure water of crab.