JP2004216263A - Hollow fiber membrane filter and its operation method - Google Patents

Hollow fiber membrane filter and its operation method Download PDF

Info

Publication number
JP2004216263A
JP2004216263A JP2003006050A JP2003006050A JP2004216263A JP 2004216263 A JP2004216263 A JP 2004216263A JP 2003006050 A JP2003006050 A JP 2003006050A JP 2003006050 A JP2003006050 A JP 2003006050A JP 2004216263 A JP2004216263 A JP 2004216263A
Authority
JP
Japan
Prior art keywords
housing
hollow fiber
fiber membrane
air
treated water
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2003006050A
Other languages
Japanese (ja)
Other versions
JP4211400B2 (en
Inventor
Yasuo Ochi
Masaaki Taguchi
正明 田口
康夫 越智
Original Assignee
Miura Co Ltd
三浦工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Miura Co Ltd, 三浦工業株式会社 filed Critical Miura Co Ltd
Priority to JP2003006050A priority Critical patent/JP4211400B2/en
Publication of JP2004216263A publication Critical patent/JP2004216263A/en
Application granted granted Critical
Publication of JP4211400B2 publication Critical patent/JP4211400B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hollow fiber membrane filter by which removed stain or particles are prevented from re-sticking to a membrane surface to positively discharge the removed stain or the particles after effective back washing. <P>SOLUTION: The hollow fiber membrane comprises: a housing 2 housing a hollow fiber membrane 3; a raw water supply conduit 7; an overflow conduit 15; a treatment water conduit 17; A drainage conduit 9; and a back wash air supply conduit 19. The treatment water conduit 17 derives treatment water obtained by filtering raw water through the hollow fiber membrane 3 from the housing 2 and is openably provided with a treatment water outlet valve 18. The back wash air supply conduit 19 is connected to the treatment water conduit 17 at the housing 2 side remote from the treatment water outlet valve 18. In a state retaining the treatment water in the treatment water conduit 17 by closing the treatment water outlet valve 18, pressure by air is applied plural times to the retaining section to conduct air push back washing returning the treatment water in the retaining section through the hollow fiber membrane 3 to the raw water side. Draining the treatment water to the drainage conduit 9 from the housing 2 is accompanied by bubbling. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【0001】
【発明の属する技術分野】
本発明は、中空糸膜ろ過装置とその運転方法に関するものである。
【0002】
【従来の技術】
中空糸膜ろ過装置は、原水中のバクテリア(細菌類)や、鉄分などの微細な懸濁物質類(SS)を除去するために、原水を中空糸膜でろ過して処理水を得るものである。この中空糸膜ろ過装置では、ろ過に伴って、中空糸膜に汚れや粒子が付着するため、長期的に通水流量を確保して使用するには、運転中、定期的に中空糸膜を洗浄して、目詰まりの防止を図る必要がある。
【0003】
このような中空糸膜の洗浄方法として、従来、ろ過とは逆方向に、処理水側から原水側に液体を戻して洗浄する逆洗や、中空糸膜を気泡で揺らして洗浄するバブリングなどが知られている。また、下記特許文献1に開示されるように、処理水に気体による圧力を加えて、処理水を原水側に戻して洗浄する方法も知られている。
【0004】
【特許文献1】
特開平10−286441号公報
【0005】
【発明が解決しようとする課題】
しかしながら、従来の中空糸膜ろ過装置は、逆洗がろ過運転後に1回行われるのみで、しかも定常的な一定圧力をかけるだけであった。そのため、汚れの付着度合いによっては、逆洗不足が発生し、早期目詰まりの可能性があった。また、洗浄により中空糸膜から汚れや粒子を除去できても、その汚れや粒子をうまくハウジング外へ排出できないことで、膜面へ再付着するおそれもあった。
【0006】
本発明は、上記事情に鑑みてなされたものであり、その主たる目的は、効果的な逆洗が可能で、また逆洗やバブリングなどで除去された汚れや粒子を、膜面へ再付着することを防止しつつ、確実にハウジング外へ排出可能な中空糸膜ろ過装置とその運転方法を提供することにある。
【0007】
【課題を解決するための手段】
上記目的を達成するために、本発明の中空糸膜ろ過装置は、下記構成要件(A)から(E)を備えることを特徴とする。
(A)中空糸膜が収容されたハウジング。
(B)ハウジングに原水を供給可能とされた原水供給管路。
(C)原水を中空糸膜にてろ過して得られる処理水をハウジングから導出する処理水管路。
(D)ハウジングの下部から原水を排出可能な排水管路。
(E)ハウジングの下部において原水供給管路若しくは排水管路又はハウジングに接続され、ハウジングから排水管路への排水時に、ハウジング下部からハウジング内に気泡を噴出可能に、エアを供給するバブリングエア供給管路。
【0008】
この構成によれば、排水工程において、バブリングしながらハウジング内の水を排水(ブロー)することができる。排水時のバブリングは、浮遊物質の再付着を防止する。
【0009】
また、本発明の中空糸膜ろ過装置は、下記構成要件(A)から(E)を備えることを特徴とする。
(A)中空糸膜が収容されたハウジング。
(B)ハウジングに原水を供給可能とされた原水供給管路。
(C)原水を中空糸膜にてろ過して得られる処理水をハウジングから導出すると共に、処理水出口弁が開閉可能に設けられた処理水管路。
(D)ハウジングの下部から原水を排出可能な排水管路。
(E)処理水出口弁よりハウジング側の処理水管路、又はハウジングの処理水部に接続され、処理水出口弁を閉じて、処理水管路又はハウジングの処理水部に処理水を滞留させた状態で、その滞留部にエアによる圧力を複数回かけることで、中空糸膜を介して滞留部の処理水を原水側に戻すエア押し逆洗を行う逆洗エア供給管路。
【0010】
この構成によれば、エアによる圧力で、ろ過処理時とは逆方向に、処理水を原水側に戻して、中空糸膜表面に付着した汚れを剥離させる逆洗が行われる。本明細書において、このような逆洗を、「エア押し逆洗」と呼ぶことにする。このエア押し逆洗によれば、液体を用いた通常のポンプ逆洗に比べ、ポンプやその駆動源が不要で、さらには逆洗水タンクも不要となる。しかも、このエア押し逆洗を単発ではなく複数回かけることで、逆洗用処理水の流れに変化を持たせることができる。つまり、エアによる加圧が複数回なされることで、各回の逆洗開始時に、逆洗用処理水にエアによる衝撃力が加わり、中空糸膜の効果的洗浄が期待される。
【0011】
そして、好ましくは上記構成に加えて、前記逆洗エア供給管路には、エア押し弁が開閉可能に設けられ、逆洗エア供給管路は、エア押し弁よりハウジング側の圧力が、エア押し弁よりコンプレッサ側の圧力と等しくなる前に、開閉操作が複数回行われて、前記エア押し逆洗がなされることを特徴とする中空糸膜ろ過装置である。
【0012】
この構成の場合、エア押し弁よりハウジング側の圧力が、エア押し弁よりコンプレッサ側の圧力と等しくなる前に、エア押し弁の開閉操作を複数回行うだけで、複数回のエア押し逆洗が容易に実行される。エア押し波状逆洗により、中空糸膜面からの付着物剥離状況が向上することは、上述したとおりである。
【0013】
また、本発明は、中空糸膜が収容されたハウジング内に原水を供給する水張り工程、中空糸膜にて原水をろ過して処理水を得るろ過工程、中空糸膜の洗浄工程、ハウジング内からの排水工程が順次に行われる中空糸膜ろ過装置の運転方法であって、排水工程は、ハウジング下部から気泡を噴出させつつ行われることを特徴とする。この構成の場合、排水時のバブリングは、浮遊物質の再付着を防止する。
【0014】
また本発明は、下記(イ)から(ホ)の各工程を備えることを特徴とする中空糸膜ろ過装置の運転方法である。
(イ)中空糸膜が収容されたハウジング内に原水を供給する水張り工程。
(ロ)ハウジングに供給された原水を中空糸膜にてろ過して処理水を得るろ過工程。
(ハ)ハウジングからの原水のオーバーフロー管路を開く一方、ハウジングからの処理水管路を閉じた状態で、ハウジング上部の処理水滞留部にエアによる圧力をかけることで、中空糸膜を介して滞留部の処理水を原水側に戻して、オーバーフロー管路から排水することで、中空糸膜を洗浄するエア押し逆洗工程。
(ニ)ハウジングの下部から気泡を噴出させて中空糸膜を洗浄するバブリング工程。
(ホ)ハウジングの下部から気泡を噴出させつつハウジングから排水する排水工程。
【0015】
この構成の場合も、特にエア押し逆洗工程、バブリング工程に続く排水工程においてバブリングを行うことで、浮遊物質の除去と、再付着防止が図られ、中空糸膜の洗浄効果が向上する。そして、エア押し逆洗工程において、エア押し逆洗を複数回行えば、中空糸膜面からの付着物剥離効果が一層向上する。
【0016】
【発明の実施の形態】
以下、本発明の中空糸膜ろ過装置とその運転方法について、実施例に基づき更に詳細に説明する。なお、本発明の中空糸膜ろ過装置とその運転方法は、下記実施例に限定されるものではなく、その発明の趣旨を逸脱しない範囲で適宜に変更可能なことは言うまでもない。
【0017】
図1は、本発明の中空糸膜ろ過装置の一実施例の主要部を示す概略図である。なお、本実施例の装置は、後述するように、より具体的には図3から図6に示すような構造であるが、図1ではその主要部を概略的に示した。
【0018】
この図に示すように、中空糸膜ろ過装置は、1以上の中空糸膜モジュール1を主要部として備える。各中空糸膜モジュール1は、ボックス状のハウジング2内に、中空糸膜3が収容されてなる。本実施例では、ハウジング2は、略円筒状のハウジング本体4の上部開口に、ハウジング蓋体5が着脱可能に設けられている。そして、ハウジング本体4とハウジング蓋体5との間には、仕切板6を介して上下に区分けされ、その仕切板6には、例えば数千本の中空糸膜3の束が、吊り下げられた状態で保持される。本実施例では、中空糸膜3は、下端部がフリーの状態で保持されている。なお、中空糸膜3の構成は、特に問わないが、本実施例では例えば、ろ過精度0.02μmの高精度中空糸膜が使用される。
【0019】
ハウジング2は、仕切板6より下方、つまりハウジング本体4側が原水側とされ、仕切板6より上方、つまりハウジング蓋体5側が処理水側とされる。すなわち、ハウジング2に供給された原水は、中空糸膜3を介してろ過され、ハウジング2上部へ処理水として導出可能とされる。
【0020】
ハウジング2の下端部には、原水供給管路7、バブリングエア供給管路8、及び排水管路9が接続される。これら管路7〜9は、それぞれ個別にハウジング2に接続してもよいが、本実施例ではハウジング2へは原水供給管路7のみを接続し、その原水供給管路7にバブリングエア供給管路8や排水管路9を接続して、原水供給管路7の先端部を他の管路8,9としても共通的に使用している。
【0021】
つまり、ハウジング2の下端部には原水供給管路7が接続されており、その原水供給管路7には、原水ポンプ10からの原水が原水入口弁11を介して、ハウジング2へ供給可能とされている。そして、その原水入口弁11よりハウジング2側の原水供給管路7に、排水管路9が接続される。この排水管路9には、排水弁12が開閉可能に設けられている。さらに、ハウジング2下部の原水供給管路7には、ハウジング2に近接した位置に、バブリングエア供給管路8が接続されている。このバブリングエア供給管路8には、バブリング弁13が開閉可能に設けられており、コンプレッサ14からの加圧エアの連通の有無が切り替えられる。
【0022】
このような構成であるから、原水入口弁11を閉じて排水弁12を開けると、ハウジング2内の水を排出することができる一方、原水入口弁11を開いて排水弁12を閉じると、原水ポンプ10からハウジング2内に原水の供給が可能とされる。しかも、原水供給時や排水時に、バブリング弁13を開けてコンプレッサ14から加圧エアを送り込むと、そのエアはハウジング2内の中空糸膜3を揺らしてバブリングを行うことができる。さらに、原水入口弁11と排水弁12を閉じて、バブリング弁13を開けてコンプレッサ14からエアを送り込むと、一般的なバブリングを行うこともできる。なお、ハウジング2からの排水は、重力による自然落下を利用して排水できるように配管している。
【0023】
原水側のハウジング本体4の上部には、ハウジング2に過剰に供給された水をオーバーフローさせて、排水するオーバーフロー管路15が接続されている。このオーバーフロー管路15には、オーバーフロー弁16が開閉可能に設けられている。このオーバーフロー弁16は、本実施例では中空糸膜3の洗浄時、つまり後述するエア押し逆洗工程、バブリング工程、排水工程、及び水張り工程からなる再生時に開かれる。
【0024】
処理水側のハウジング蓋体5の上部には、中空糸膜3でろ過された処理水を導出するための処理水管路17が接続されている。この処理水管路17には、処理水出口弁18が開閉可能に設けられている。また、処理水管路17には、処理水出口弁18より上流側(ハウジング2側)に、逆洗エア供給管路19が接続されている。この逆洗エア供給管路19には、エア押し弁20が開閉可能に設けられており、コンプレッサ14からの加圧エアの連通の有無が切り替えられる。なお本実施例では、逆洗エア供給管路19を処理水管路17に接続しているが、逆洗エア供給管路19は、ハウジング蓋体5に直接に接続するようにしてもよい。
【0025】
このような構成であるから、原水入口弁11と処理水出口弁18を開いて、その他の弁を閉じておけば、原水供給管路7からハウジング2内に供給された原水は、中空糸膜3でろ過されて、処理水として処理水管路17から導出することができる。また、ろ過終了時に、処理水出口弁18を閉じると、その処理水出口弁18より上流側において、処理水管路17とハウジング蓋体5には、処理水が滞留されることになる。そして、その状態で、オーバーフロー弁16を開いた状態でエア押し弁20を開くと、逆洗エア供給管路19からの加圧エアが、前記滞留部の処理水に作用して、処理水が原水側に押し戻されてオーバーフロー管路15へ排出されるというエア押し逆洗を行うことができる。そして、本実施例のろ過装置では、このエア押し逆洗のエアは、複数回に亘り、衝撃的に加えられる。
【0026】
以下、本実施例の中空糸膜ろ過装置とその運転方法について、より具体的に説明する。
図2は、本実施例の中空糸膜ろ過装置の運転方法を示す流れ図である。また、図3から図6は、本実施例の中空糸膜ろ過装置の使用状態を示す図であり、図3は水張り(補水)工程、図4はエア押し逆洗工程、図5はバブリング工程、図6は排水(ブロー)工程を示している。なお、各図において、太い実線は水の流れを示し、破線は空気の流れを示している。また、黒く塗りつぶされた弁体は、閉じた状態を示し、白い弁体は、開いている状態を示している。
【0027】
本実施例の中空糸膜ろ過装置は、典型的には、図2に示すような工程を繰り返して、運転が行われる。つまり、水張り工程、ろ過工程、エア押し逆洗工程、バブリング工程、排水工程が順次に行われる。各工程の詳細は、後述するが、ろ過工程では原水をろ過し、そのろ過工程でろ過した汚れや粒子は、他の工程(エア押し逆洗工程、バブリング工程、排水工程、水張り工程)で、中空糸膜から剥離されハウジング外に排出され、洗浄・再生されることになる。なお、本実施例においては、中空糸膜に外圧をかけて原水を全量ろ過(外圧全量ろ過)する中空糸膜ろ過装置とされている。
【0028】
図3は、本実施例の中空糸膜ろ過装置の具体的構成を示す図であり、水張り工程を示している。なお、図において、二点鎖線で囲んだ本体ユニットが、中空糸膜ろ過装置の本体である。
【0029】
本実施例では、中空糸膜モジュール1が4本使用されているが、この本数は適宜に変更されることは言うまでもない。各中空糸膜モジュール1のハウジング2には、原水タンク21から原水供給管路7を介して原水が供給される。原水タンク21には、原水タンクレベルスイッチ22が設けられている。原水タンク21の原水は、原水ポンプ10にて原水供給管路7へ送り出され、原水流量調節弁23、原水入口弁11を介した後、分岐して各ハウジング2へ供給される。原水入口弁11よりハウジング2側の原水供給管路7には、排水管路9が接続されており、その排水管路9には、排水弁12が設けられている。
【0030】
各ハウジング2への原水供給管路7には、ハウジング2側の位置に、バブリングエア供給管路8が接続される。バブリングエア供給管路8は、コンプレッサ14からの加圧エアが通され、その加圧エアは、バブリング弁13を介して、原水供給管路7ひいてはハウジング2内に供給可能とされる。なお、図において、符号24は、バブリング流量計である。本実施例のバブリング流量計24は、フロート指示式瞬間流量計であり、バブリングエア流量を測定し、エアが規定量流れているかを目視するためのものである。
【0031】
各ハウジング2には、原水側のオーバーフロー水を排出するために、オーバーフロー管路15が接続されている。オーバーフロー管路15は、オーバーフロー弁16を介して排水管路9に接続される。その際、排水弁12より下流側に接続される。なお、図において、符号25は、エア導入弁である。このエア導入弁25は、排水時にハウジング2内に空気を導入し、ハウジング2内を大気圧として排水できるようにするためのものである。
【0032】
各ハウジング2の上部には、処理水を導出するために、処理水管路17が接続されている。処理水管路17は、処理水出口弁18を介して処理水タンク26に接続されている。処理水タンク26には、その処理水量を把握する処理水タンクレベルスイッチ27が設けられている。
【0033】
さらに、処理水管路17には、処理水出口弁18より上流側に、逆洗エア供給管路19が接続される。この逆洗エア供給管路19は、ハウジング2上部の処理水部に直接的に接続してもよいが、本実施例では処理水管路17に接続している。逆洗エア供給管路19は、途中で分岐しており、一方は、エア抜き弁28を介して排水管路9に接続され、他方は、エア押し弁20を介してコンプレッサ14に接続される。
【0034】
本実施例の中空糸膜ろ過装置には、その本体内にエアタンク29が設けられており、そのエアタンク29にコンプレッサ14からの空気を貯留しておくことができる。逆洗エア供給管路19は、エアタンク29からの空気を、エアフィルタ30、レギュレータ31、エア圧力スイッチ32,33、エア押し弁20を介して、処理水管路17側に放出可能とされている。なお、この逆洗エア供給管路19は、エア圧力スイッチ33の部分で分岐して、バブリングエア供給管路8と接続される。つまり、両エア供給管路8,19は、基端部において共通化され、途中で分岐して、一方がバブリングエア供給管路8、他方が逆洗エア供給管路19とされる。
【0035】
エア押し逆洗のために、逆洗エア供給管路19から処理水管路17へ加圧エアが供給される。このエアの圧力は、適宜に設定されるが、本実施例では、例えば中空糸膜の耐圧が3kg/cm程度で、通常運転時の膜内外の最大通水差圧は1〜1.5 kg/cm程度であるため、逆洗用エア圧力として2kg/cm程度が採用される。そのエアを安定して供給するために、ろ過装置本体には上述したエアタンク29が備えられている。このエアタンク29内には、上記逆洗用エア圧力よりも高い圧力でエアが貯留しておく。本実施例では、例えば5kg/cmにてエアをエアタンク29に貯留する。なお、その場合、コンプレッサ14としては、例えば5〜8kg/cmの出力のものが使用され、既設コンプレッサが使用可能で、専用コンプレッサを新たに設置する必要がない。
【0036】
逆洗用エアのエアタンク29への貯留によって、エア源の小規模化が図られ、設置スペースの低減も図ることができる。また、後述の洗浄方法にも起因して、洗浄工程の省エネルギー化を図ることもできる。
【0037】
エアタンク29に貯留された高圧のエアは、エアフィルタ30などを介した後、レギュレータ(減圧弁)31で2kg/cmに減圧されて、エア押し弁20の側へ送られる。その中途には、低圧用と高圧用の二つのエア圧力スイッチ32,33が設けられており、レギュレータ31の圧力調整不良を検出する。例えば、2kg/cmより高圧の場合には、中空糸膜を損傷するおそれがあるので、ろ過装置を停止させ、2kg/cmより低圧の場合には、エア押し逆洗による洗浄不良のおそれがあるので、警報を出すことが考えられる。
【0038】
前述したように、本実施例のろ過装置では、2kg/cmの加圧エアを用いて、装置内部の処理水をろ過時の通水方向と逆方向(中空糸膜の内側から外側)に押し流して、中空糸膜のエア押し逆洗がなされる。逆洗用エア圧力は2kg/cmであるが、エアタンク29の容量を小さくするために、エアタンク29内の貯留空気圧は5kg/cm程度としている。装置内部の処理水量が14L程度である場合には、本来は、2kg/cmの空気容量が14L必要になるが、エアタンク29のエア圧を約2〜3倍の5kg/cmとすることで、エアタンク29のタンク容量は約半分の7L程度にすることができる。
【0039】
なお、エアタンク29へのエアの貯留は、逆洗時以外の運転時間(ろ過工程など)で行うため、貯留時間を別途設ける必要はない。また、コンプレッサ14からのエア供給量は、既設のバブリングエア供給用としての120L/min程度のものを使用できる。そして、その場合でも、エアタンク29への貯留時間は30秒程度となり、頻繁な逆洗にも対応できる。
【0040】
さて、以上のような構成の中空糸膜ろ過装置は、まず図3に示すように、ハウジング2内への水張り工程が実施される。これには、バブリング弁13、排水弁12を閉じた状態で、原水入口弁11を開いて、原水ポンプ10からの原水を原水供給管路7を介してハウジング2へ送り込めばよい。
【0041】
水張り時には、処理水管路17の処理水出口弁18は閉めておく。また、逆洗エア供給管路19のエア押し弁20を閉める一方、オーバーフロー管路15のオーバーフロー弁16は開けておく。エア抜きをしないと、ハウジング2の原水部にエアが存在したままとなり、ろ過面積を少なくしてしまうことになるが、オーバーフロー弁16を開けておくことで、ハウジング2の原水部のエア抜きが行われる。また、エア抜き弁28を開け、処理水管路17内にある前回実施したエア押し逆洗の残留エアを排出する。
【0042】
このように、原水入口弁11、エア抜き弁28、オーバーフロー弁16を開けた状態で、原水ポンプ10を運転して、中空糸膜モジュール1のハウジング2内の空気を抜きながら、ハウジング2内に原水を供給する。ハウジング2内が満水になると、オーバーフロー管路15から原水のオーバーフロー水が排水される。
【0043】
上記水張り工程において、オーバーフロー弁16及びエア抜き弁28を閉じる一方、処理水出口弁18を開くことで、ろ過工程に移行する。このろ過工程では、原水供給管路7から中空糸膜モジュール1に原水を加圧給水し、中空糸膜の外側から内側に原水を通過させる。これにより、原水中の細菌・懸濁物質類は中空糸膜の外側で捕捉される。つまり、原水は、中空糸膜でろ過され、ろ過水は処理水として処理水管路17から導出される。なお、ろ過開始直後の一定時間だけは、エア抜き弁28やオーバーフロー弁16を開けておくことで、ハウジング2内の急激な圧力上昇の防止と、処理水管路17のエア溜まりが除去される。
【0044】
一定時間ろ過した後は、エア押し逆洗工程(エア押しによる処理水逆通水逆洗)がなされる。前記ろ過工程における通水を停止すると、ろ過された処理水はハウジング2上部の処理水部に貯留するが、その処理水部より下流地点に設けた処理水出口弁18を閉止し、閉止時点と処理水部との間に、エアによる圧力をかけて流すと、その圧力により処理水が中空糸内側より外側に流れて、その処理水の流れにより中空糸外側に付着している浮遊物質などの汚れが剥離される。
【0045】
具体的には、エア押し逆洗工程は、図4に示すように、原水入口弁11と処理水出口弁18を閉じる一方、エア押し弁20とオーバーフロー弁16を開けて実施される。処理水出口弁18を閉じることで、処理水出口弁18よりハウジング2側の処理水管路17や、ハウジング2の処理水側には、処理水が滞留する。その状態で、エア押し弁20を開くと、加圧エアが中空糸膜モジュール1の処理水側に供給される。これにより、エア圧で処理水が原水側に押し出され、ハウジング2内の水の一部がオーバーフロー管路15より排出される。
【0046】
本実施例のろ過装置では、このエア押し逆洗工程に特徴を出したので、この点について次に説明する。いま仮に、エア押し弁20を開けたまま放置しておくと、時間の経過に伴い、エア押し弁20よりハウジング2側の圧力も逆洗用エア圧力2kg/cmに近づく。例えば、2秒程度で逆洗用エア圧力2kg/cmに到達してしまい、前記滞留部の処理水も原水側に戻されてしまう。しかし、本実施例のろ過装置では、そのような逆洗用エア圧力2kg/cmに到達する前に、エア押し弁20を複数回、断続的に開閉するよう制御される。例えば0.5秒程度だけエア押し弁20を開いてすぐに閉じた後、1秒後に再び開けるパルス状の動作を2回、或いはそれ以上繰り返す。エア押し波状逆洗により、加圧エア噴出時の衝撃力で、中空糸膜面からの付着物剥離状況が向上する。
【0047】
ところで、ろ過装置のコンパクト化と洗浄効果を考慮した場合、前記滞留する処理水部の体積は、中空糸膜モジュール1の処理水側のモジュール保有水量に対し、最大2倍の水量以内にするのが好ましい。ここで、「処理水側のモジュール保有水量」とは、中空糸膜内部にある処理水のみをいい、処理水の滞留水量はこれ以外として2倍以内の水量とするということである。例えば、モジュール保有水量が約0.1Lの場合には、処理水部の体積を0.2L以下にするのがよい。なお、後述するように、次工程にバブリングを行うことで、少量の逆洗水でも洗浄効果が期待される。
【0048】
次に、図5に示すように、エア押し弁20を閉じる一方、バブリング弁13とオーバーフロー弁16を開いた状態で、バブリングエア供給管路8からハウジング2内にエアを噴出して、バブリング工程を実施する。バブリングにより中空糸膜を揺動させ、中空糸膜同士の隙間や膜表面に付着した汚れが除去される。
【0049】
なお、コンパクト化のために、エア押し逆洗工程の前記処理水部(滞留部)を小さくすると、剥離された浮遊物質は中空糸外面近傍に存在したままであるが、中空糸束下部より中空糸全体にバブリングを行うと、中空糸外面近傍から離れて原水部に広がることになる。仮に、この広がりがなければ、次工程のブローを行っても、中空糸外面に浮遊物質が再付着し、洗浄の効率が低下してしまうが、このバブリングを行うことで、そのような不都合が防止される。
【0050】
最後に、図6に示すように、逆洗やバブリングにより中空糸膜から除去した汚れを装置外に排出するために、排水弁12を開いて、ハウジング2内の水を排水(ブロー)する排水工程が実施される。その際、バブリング弁13を開いて、バブリングエア供給管路8からのエアをハウジング2内に送り込んでバブリングを行いつつ、排水がなされる。このブローにより、浮遊物質の再付着が防止される。そして、中空糸外面への付着状態から、上記エア押し逆洗工程やバブリング工程により原水部に広がった浮遊物質を、ハウジング原水部から効果的に排出することができる。
【0051】
なお、オーバーフロー弁16を開けておくことで、バブリングのエア抜きがなされる。このような排水工程の後には、ハウジング2内に水を供給し、オーバーフローさせる水張り工程に戻される。補水時にバブリングを追加することで、浮遊物質の排出効果を高め、中空糸膜を再洗浄し膜洗浄効果を向上させる。しかも、補水時のオーバーフローは、再付着した浮遊物質を流し出すのに効果的である。
【0052】
【発明の効果】
以上詳述したように、本発明の中空糸膜ろ過装置によれば、圧力変化を伴う複数回のエア押し逆洗にて、中空糸膜を効果的に洗浄することができる。また、排水時にバブリングを付加することで、膜面へ再付着を防止しつつ汚れや粒子を確実にハウジング外へ排出することができる。
【図面の簡単な説明】
【図1】本発明の中空糸膜ろ過装置の一実施例の主要部を示す概略図である。
【図2】図1の中空糸膜ろ過装置の運転工程の一例を示す流れ図である。
【図3】図1の中空糸膜ろ過装置の使用状態を示す図であり、水張り工程を示している。
【図4】図1の中空糸膜ろ過装置の使用状態を示す図であり、エア押し逆洗工程を示している。
【図5】図1の中空糸膜ろ過装置の使用状態を示す図であり、バブリング工程を示している。
【図6】図1の中空糸膜ろ過装置の使用状態を示す図であり、排水工程を示している。
【符号の説明】
2 ハウジング
3 中空糸膜
7 原水供給管路
8 バブリングエア供給管路
9 排水管路
15 オーバーフロー管路
17 処理水管路
18 処理水出口弁
19 逆洗エア供給管路
20 エア押し弁
28 エア抜き弁
[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hollow fiber membrane filtration device and a method for operating the same.
[0002]
[Prior art]
The hollow fiber membrane filtration device is used to obtain treated water by filtering raw water through a hollow fiber membrane in order to remove bacteria (bacteria) and fine suspended substances (SS) such as iron in raw water. is there. In this hollow fiber membrane filtration device, dirt and particles adhere to the hollow fiber membrane during filtration. It is necessary to wash to prevent clogging.
[0003]
Conventional methods for washing such hollow fiber membranes include backwashing, in which the liquid is returned from the treated water side to the raw water side in the opposite direction to the filtration, and washing, and bubbling, in which the hollow fiber membrane is shaken with air bubbles and washed, and the like. Are known. Further, as disclosed in Patent Literature 1 below, there is also known a method of applying a gas pressure to treated water and returning the treated water to the raw water side for cleaning.
[0004]
[Patent Document 1]
JP-A-10-286441
[0005]
[Problems to be solved by the invention]
However, in the conventional hollow fiber membrane filtration device, the backwash is performed only once after the filtration operation, and only a constant constant pressure is applied. For this reason, depending on the degree of adhesion of dirt, insufficient backwashing occurs, and there is a possibility of early clogging. Further, even if dirt and particles can be removed from the hollow fiber membrane by washing, the dirt and particles cannot be discharged to the outside of the housing well, and there is a possibility that the dirt and particles may be reattached to the membrane surface.
[0006]
The present invention has been made in view of the above circumstances, and its main purpose is to enable effective backwashing, and to reattach dirt and particles removed by backwashing or bubbling to the film surface. It is an object of the present invention to provide a hollow fiber membrane filtration device capable of reliably discharging the outside of the housing while preventing such a situation, and an operation method thereof.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the hollow fiber membrane filtration device of the present invention is provided with the following constituent features (A) to (E).
(A) Housing housing hollow fiber membrane.
(B) A raw water supply pipe capable of supplying raw water to the housing.
(C) A treated water pipe for extracting treated water obtained by filtering raw water through a hollow fiber membrane from a housing.
(D) A drainage pipe capable of discharging raw water from the lower part of the housing.
(E) a bubbling air supply which is connected to a raw water supply pipe or a drain pipe or a housing at a lower part of the housing and supplies air so that bubbles can be ejected from the lower part of the housing into the housing when draining from the housing to the drain pipe; Pipeline.
[0008]
According to this configuration, in the draining step, the water in the housing can be drained (blown) while bubbling. Bubbling during drainage prevents suspended solids from re-adhering.
[0009]
Further, the hollow fiber membrane filtration device of the present invention is characterized by having the following constituent requirements (A) to (E).
(A) Housing housing hollow fiber membrane.
(B) A raw water supply pipe capable of supplying raw water to the housing.
(C) A treated water pipe in which treated water obtained by filtering raw water through a hollow fiber membrane is led out of a housing, and a treated water outlet valve is provided so as to be openable and closable.
(D) A drainage pipe capable of discharging raw water from the lower part of the housing.
(E) A state in which the treated water is connected to the treated water pipe on the housing side or the treated water section of the housing from the treated water outlet valve, the treated water outlet valve is closed, and the treated water is retained in the treated water pipe or the treated water section of the housing. A backwash air supply line for performing air-pressed backwashing by returning the treated water in the staying portion to the raw water side through the hollow fiber membrane by applying a plurality of times of air pressure to the staying portion.
[0010]
According to this configuration, backwashing is performed in which the treated water is returned to the raw water side by the pressure of air in a direction opposite to that at the time of the filtration treatment, and the dirt attached to the surface of the hollow fiber membrane is removed. In the present specification, such backwashing is referred to as “air-pushed backwashing”. According to the air-pushed backwashing, a pump and its driving source are not required, and a backwashing water tank is not required as compared with a normal pump backwashing using a liquid. Moreover, by applying the air-push backwash not a single time but a plurality of times, the flow of the backwashing treatment water can be changed. In other words, by performing the pressurization with air a plurality of times, at the start of each backwash, the impact force of the air is applied to the backwashing treatment water, and effective cleaning of the hollow fiber membrane is expected.
[0011]
Preferably, in addition to the above configuration, an air push valve is provided in the backwash air supply line so as to be openable and closable, and the pressure on the housing side of the backwash air supply line is higher than that of the air push valve. The hollow fiber membrane filtration device is characterized in that the opening and closing operation is performed a plurality of times before the pressure becomes equal to the pressure on the compressor side from the valve, and the air pushing backwash is performed.
[0012]
In this configuration, before the pressure on the housing side from the air push valve becomes equal to the pressure on the compressor side from the air push valve, the air push valve can be opened and closed several times to perform multiple air push backwashes. Easy to implement. As described above, the situation of the adhered matter peeling off from the hollow fiber membrane surface is improved by the air pushing wavy backwashing.
[0013]
Further, the present invention provides a water filling step of supplying raw water into a housing containing a hollow fiber membrane, a filtration step of filtering raw water with a hollow fiber membrane to obtain treated water, a washing step of a hollow fiber membrane, The method of operating a hollow fiber membrane filtration device, wherein the draining step is sequentially performed, wherein the draining step is performed while jetting air bubbles from a lower portion of the housing. In this configuration, bubbling during drainage prevents re-adherence of suspended matter.
[0014]
Further, the present invention is a method for operating a hollow fiber membrane filtration device, comprising the following steps (a) to (e).
(A) A water filling step of supplying raw water into the housing in which the hollow fiber membrane is housed.
(B) A filtration step in which raw water supplied to the housing is filtered through a hollow fiber membrane to obtain treated water.
(C) While the overflow pipe of the raw water from the housing is opened and the treated water pipe from the housing is closed, pressure is applied to the treated water retaining section on the upper part of the housing by air, thereby retaining the treated water via the hollow fiber membrane. An air-pressed backwashing step of washing the hollow fiber membrane by returning the treated water of the section to the raw water side and draining it from the overflow conduit.
(D) A bubbling step of blowing air bubbles from a lower part of the housing to wash the hollow fiber membrane.
(E) A draining process in which air bubbles are ejected from the lower part of the housing and drained from the housing.
[0015]
Also in the case of this configuration, by performing bubbling in the draining step following the air pushing backwashing step and the bubbling step, removal of suspended substances and prevention of reattachment are achieved, and the effect of cleaning the hollow fiber membrane is improved. Then, in the air-pushed backwashing step, if the air-pushed backwash is performed a plurality of times, the effect of removing adhering matter from the hollow fiber membrane surface is further improved.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the hollow fiber membrane filtration device of the present invention and the operation method thereof will be described in more detail based on examples. In addition, the hollow fiber membrane filtration device of the present invention and the operation method thereof are not limited to the following examples, and it is needless to say that they can be appropriately changed without departing from the spirit of the invention.
[0017]
FIG. 1 is a schematic view showing a main part of one embodiment of the hollow fiber membrane filtration device of the present invention. The device of the present embodiment has a structure as shown in FIGS. 3 to 6 more specifically, as will be described later, but FIG. 1 schematically shows a main part thereof.
[0018]
As shown in this figure, the hollow fiber membrane filtration device includes one or more hollow fiber membrane modules 1 as a main part. Each hollow fiber membrane module 1 has a hollow fiber membrane 3 housed in a box-shaped housing 2. In this embodiment, the housing 2 has a housing lid 5 detachably provided at an upper opening of a substantially cylindrical housing body 4. The housing body 4 and the housing lid 5 are vertically divided via a partition plate 6, and a bundle of, for example, thousands of hollow fiber membranes 3 is suspended on the partition plate 6. It is held in the state that it was. In this embodiment, the lower end of the hollow fiber membrane 3 is held free. The configuration of the hollow fiber membrane 3 is not particularly limited, but in the present embodiment, for example, a high-precision hollow fiber membrane having a filtration accuracy of 0.02 μm is used.
[0019]
The housing 2 has a raw water side below the partition plate 6, that is, the housing body 4 side, and a treated water side above the partition plate 6, ie, the housing lid 5 side. That is, the raw water supplied to the housing 2 is filtered through the hollow fiber membrane 3 and can be led out to the upper part of the housing 2 as treated water.
[0020]
A raw water supply pipe 7, a bubbling air supply pipe 8, and a drain pipe 9 are connected to a lower end of the housing 2. Although these pipes 7 to 9 may be individually connected to the housing 2, in this embodiment, only the raw water supply pipe 7 is connected to the housing 2, and the bubbling air supply pipe is connected to the raw water supply pipe 7. The line 8 and the drainage line 9 are connected, and the distal end of the raw water supply line 7 is commonly used as the other lines 8 and 9.
[0021]
That is, the raw water supply pipe 7 is connected to the lower end of the housing 2, and the raw water from the raw water pump 10 can be supplied to the housing 2 via the raw water inlet valve 11 to the raw water supply pipe 7. Have been. Then, a drain pipe 9 is connected to the raw water supply pipe 7 on the housing 2 side from the raw water inlet valve 11. The drain pipe 9 is provided with a drain valve 12 that can be opened and closed. Further, a bubbling air supply line 8 is connected to the raw water supply line 7 at the lower part of the housing 2 at a position close to the housing 2. A bubbling valve 13 is provided in the bubbling air supply pipe 8 so as to be openable and closable, and the presence or absence of communication of pressurized air from the compressor 14 is switched.
[0022]
With such a configuration, when the raw water inlet valve 11 is closed and the drain valve 12 is opened, the water in the housing 2 can be discharged. On the other hand, when the raw water inlet valve 11 is opened and the drain valve 12 is closed, the raw water is closed. Raw water can be supplied from the pump 10 into the housing 2. In addition, when the bubbling valve 13 is opened and pressurized air is sent from the compressor 14 when supplying or discharging the raw water, the air can shake the hollow fiber membrane 3 in the housing 2 to perform bubbling. Further, when the raw water inlet valve 11 and the drain valve 12 are closed, the bubbling valve 13 is opened, and air is sent from the compressor 14, general bubbling can be performed. In addition, the drainage from the housing 2 is piped so as to be able to drain using the natural fall due to gravity.
[0023]
An overflow pipe 15 for overflowing and draining water excessively supplied to the housing 2 is connected to an upper portion of the housing body 4 on the raw water side. An overflow valve 16 is provided in the overflow pipe 15 so as to be openable and closable. In this embodiment, the overflow valve 16 is opened at the time of cleaning the hollow fiber membrane 3, that is, at the time of regeneration including an air pushing backwashing step, a bubbling step, a draining step, and a water filling step to be described later.
[0024]
A treated water pipeline 17 for extracting treated water filtered by the hollow fiber membrane 3 is connected to an upper portion of the housing lid 5 on the treated water side. The treated water pipe 17 is provided with a treated water outlet valve 18 so as to be openable and closable. A backwash air supply pipe 19 is connected to the treated water pipe 17 on the upstream side (the housing 2 side) of the treated water outlet valve 18. An air push valve 20 is provided in the backwash air supply pipe 19 so as to be openable and closable, and the presence or absence of communication of pressurized air from the compressor 14 is switched. In this embodiment, the backwash air supply pipe 19 is connected to the treated water pipe 17, but the backwash air supply pipe 19 may be directly connected to the housing lid 5.
[0025]
With this configuration, if the raw water inlet valve 11 and the treated water outlet valve 18 are opened and the other valves are closed, the raw water supplied from the raw water supply pipe 7 into the housing 2 will be hollow fiber membrane. The water is filtered at 3 and can be led out of the treated water line 17 as treated water. When the treated water outlet valve 18 is closed at the end of the filtration, the treated water stays in the treated water pipe 17 and the housing lid 5 on the upstream side of the treated water outlet valve 18. Then, in this state, when the air push valve 20 is opened with the overflow valve 16 opened, the pressurized air from the backwash air supply pipe 19 acts on the treated water in the stagnation portion, and the treated water is It is possible to perform an air-push backwash in which the water is pushed back to the raw water side and discharged to the overflow pipe 15. Then, in the filtration device of the present embodiment, the air of the air pushing and backwashing is impulsively applied a plurality of times.
[0026]
Hereinafter, the hollow fiber membrane filtration device of the present embodiment and the operation method thereof will be described more specifically.
FIG. 2 is a flowchart showing an operation method of the hollow fiber membrane filtration device of the present embodiment. 3 to 6 are views showing the use state of the hollow fiber membrane filtration device of this embodiment. FIG. 3 shows a water filling (water refilling) step, FIG. 4 shows an air pushing backwashing step, and FIG. 5 shows a bubbling step. FIG. 6 shows a drainage (blow) process. In each figure, a thick solid line indicates a flow of water, and a broken line indicates a flow of air. Further, a valve element painted black indicates a closed state, and a white valve element indicates an open state.
[0027]
Typically, the operation of the hollow fiber membrane filtration device of the present embodiment is performed by repeating the steps shown in FIG. That is, a water filling step, a filtration step, an air pushing backwashing step, a bubbling step, and a draining step are sequentially performed. Although details of each step will be described later, in the filtration step, the raw water is filtered, and the dirt and particles filtered in the filtration step are subjected to other steps (air pushing backwashing step, bubbling step, drainage step, water filling step), It is peeled off from the hollow fiber membrane, discharged out of the housing, and washed and regenerated. In the present embodiment, a hollow fiber membrane filtration device that applies external pressure to the hollow fiber membrane and filters the entire amount of raw water (external pressure total filtration) is used.
[0028]
FIG. 3 is a diagram showing a specific configuration of the hollow fiber membrane filtration device of the present embodiment, and shows a water filling process. In addition, in the figure, the main unit surrounded by the two-dot chain line is the main body of the hollow fiber membrane filtration device.
[0029]
In the present embodiment, four hollow fiber membrane modules 1 are used, but it is needless to say that this number is appropriately changed. Raw water is supplied to the housing 2 of each hollow fiber membrane module 1 from a raw water tank 21 via a raw water supply pipe 7. The raw water tank 21 is provided with a raw water tank level switch 22. The raw water in the raw water tank 21 is sent out to the raw water supply line 7 by the raw water pump 10, and is branched and supplied to each housing 2 after passing through the raw water flow control valve 23 and the raw water inlet valve 11. A drain pipe 9 is connected to the raw water supply pipe 7 on the housing 2 side from the raw water inlet valve 11, and the drain pipe 9 is provided with a drain valve 12.
[0030]
A bubbling air supply line 8 is connected to the raw water supply line 7 to each housing 2 at a position on the housing 2 side. Pressurized air from the compressor 14 is passed through the bubbling air supply line 8, and the pressurized air can be supplied to the raw water supply line 7 and the housing 2 via the bubbling valve 13. In the drawings, reference numeral 24 denotes a bubbling flow meter. The bubbling flow meter 24 of the present embodiment is a float indicating type instantaneous flow meter for measuring a bubbling air flow rate and visually checking whether a predetermined amount of air is flowing.
[0031]
An overflow pipe 15 is connected to each housing 2 in order to discharge overflow water on the raw water side. The overflow pipe 15 is connected to the drain pipe 9 via an overflow valve 16. At this time, it is connected downstream from the drain valve 12. In the drawings, reference numeral 25 denotes an air introduction valve. The air introduction valve 25 is for introducing air into the housing 2 at the time of drainage so that the inside of the housing 2 can be drained at atmospheric pressure.
[0032]
A treated water pipe 17 is connected to an upper portion of each housing 2 to discharge treated water. The treated water pipe 17 is connected to a treated water tank 26 via a treated water outlet valve 18. The treated water tank 26 is provided with a treated water tank level switch 27 for grasping the treated water amount.
[0033]
Further, a backwash air supply pipe 19 is connected to the treated water pipe 17 on the upstream side of the treated water outlet valve 18. The backwash air supply pipe 19 may be directly connected to the treated water section on the upper part of the housing 2, but is connected to the treated water pipe 17 in this embodiment. The backwash air supply pipe 19 is branched in the middle, one is connected to the drain pipe 9 via an air release valve 28, and the other is connected to the compressor 14 via an air push valve 20. .
[0034]
An air tank 29 is provided in the main body of the hollow fiber membrane filtration device of the present embodiment, and air from the compressor 14 can be stored in the air tank 29. The backwash air supply line 19 can discharge air from the air tank 29 to the treated water line 17 via the air filter 30, the regulator 31, the air pressure switches 32 and 33, and the air push valve 20. . The backwash air supply line 19 branches off at the air pressure switch 33 and is connected to the bubbling air supply line 8. In other words, the two air supply pipes 8 and 19 are shared at the base end, branch off in the middle, and one is the bubbling air supply pipe 8 and the other is the backwash air supply pipe 19.
[0035]
Pressurized air is supplied from the backwash air supply line 19 to the treated water line 17 for air pushing backwashing. The pressure of the air is appropriately set. In this embodiment, for example, the pressure resistance of the hollow fiber membrane is 3 kg / cm. 2 The maximum differential pressure between the inside and outside of the membrane during normal operation is 1 to 1.5 kg / cm. 2 About 2 kg / cm 2 The degree is adopted. In order to stably supply the air, the filtration device body is provided with the above-described air tank 29. Air is stored in the air tank 29 at a pressure higher than the backwash air pressure. In this embodiment, for example, 5 kg / cm 2 To store the air in the air tank 29. In this case, as the compressor 14, for example, 5 to 8 kg / cm 2 The existing compressor can be used and there is no need to newly install a dedicated compressor.
[0036]
By storing the backwash air in the air tank 29, the size of the air source can be reduced, and the installation space can be reduced. In addition, energy saving in the cleaning step can be achieved due to the cleaning method described later.
[0037]
The high-pressure air stored in the air tank 29 passes through an air filter 30 and the like, and is then supplied to a regulator (pressure reducing valve) 31 at 2 kg / cm. 2 And sent to the air push valve 20 side. On the way, two air pressure switches 32 and 33 for low pressure and high pressure are provided, and a pressure adjustment failure of the regulator 31 is detected. For example, 2kg / cm 2 If the pressure is higher, there is a risk of damaging the hollow fiber membrane. 2 In the case of a lower pressure, there is a possibility that cleaning may be defective due to back-washing with air, so that an alarm may be issued.
[0038]
As described above, in the filtration device of the present embodiment, 2 kg / cm 2 By using the pressurized air described above, the treated water inside the device is flushed in the direction opposite to the direction of water flow during filtration (from inside to outside of the hollow fiber membrane), and the hollow fiber membrane is subjected to air-push backwash. Backwash air pressure is 2kg / cm 2 However, in order to reduce the capacity of the air tank 29, the stored air pressure in the air tank 29 is 5 kg / cm. 2 About. When the amount of treated water inside the device is about 14 L, it should be 2 kg / cm 2 The air pressure of the air tank 29 is increased by about 2 to 3 times to 5 kg / cm. 2 By doing so, the tank capacity of the air tank 29 can be reduced to about 7 L, which is about half.
[0039]
In addition, since the air is stored in the air tank 29 during an operation time (such as a filtration step) other than the time of the backwash, there is no need to separately provide a storage time. Further, the air supply amount from the compressor 14 can be about 120 L / min for the existing bubbling air supply. And even in that case, the storage time in the air tank 29 is about 30 seconds, which can cope with frequent backwashing.
[0040]
Now, in the hollow fiber membrane filtration device configured as described above, first, as shown in FIG. 3, a step of filling the housing 2 with water is performed. To do this, with the bubbling valve 13 and the drain valve 12 closed, the raw water inlet valve 11 is opened, and the raw water from the raw water pump 10 may be sent to the housing 2 via the raw water supply pipe 7.
[0041]
At the time of filling, the treated water outlet valve 18 of the treated water line 17 is closed. Further, the air push valve 20 of the backwash air supply line 19 is closed, while the overflow valve 16 of the overflow line 15 is opened. If the air is not evacuated, the air remains in the raw water portion of the housing 2 and the filtration area is reduced. However, by opening the overflow valve 16, the air bleeding of the raw water portion of the housing 2 can be performed. Done. In addition, the air release valve 28 is opened, and the residual air from the previous air pushing backwashing in the treated water pipe 17 is discharged.
[0042]
In this way, with the raw water inlet valve 11, the air release valve 28, and the overflow valve 16 opened, the raw water pump 10 is operated to remove air from the housing 2 of the hollow fiber membrane module 1, Supply raw water. When the inside of the housing 2 becomes full, the overflow water of the raw water is drained from the overflow pipe 15.
[0043]
In the above-mentioned water filling step, the overflow valve 16 and the air release valve 28 are closed, while the treated water outlet valve 18 is opened, thereby shifting to the filtration step. In this filtration step, raw water is supplied under pressure from the raw water supply pipe 7 to the hollow fiber membrane module 1 so that the raw water passes from the outside to the inside of the hollow fiber membrane. As a result, bacteria and suspended matter in the raw water are captured outside the hollow fiber membrane. That is, the raw water is filtered by the hollow fiber membrane, and the filtered water is led out of the treated water pipe 17 as treated water. By opening the air bleed valve 28 and the overflow valve 16 only for a certain period immediately after the start of filtration, a rapid pressure increase in the housing 2 can be prevented and the air pool in the treated water pipe 17 is removed.
[0044]
After the filtration for a certain period of time, an air pushing backwashing step (backwashing of treated water by water pushing backwater) is performed. When the flow of water in the filtration step is stopped, the filtered treated water is stored in the treated water portion in the upper part of the housing 2, and the treated water outlet valve 18 provided at a point downstream from the treated water portion is closed. When air pressure is applied between the treated water section and the treated water section, the treated water flows from the inside of the hollow fiber to the outside due to the pressure. Dirt is removed.
[0045]
Specifically, the air pushing backwashing step is performed by closing the raw water inlet valve 11 and the treated water outlet valve 18 and opening the air pushing valve 20 and the overflow valve 16 as shown in FIG. By closing the treated water outlet valve 18, the treated water stays in the treated water pipe 17 on the housing 2 side of the treated water outlet valve 18 or on the treated water side of the housing 2. When the air push valve 20 is opened in this state, pressurized air is supplied to the treated water side of the hollow fiber membrane module 1. As a result, the treated water is pushed out to the raw water side by the air pressure, and a part of the water in the housing 2 is discharged from the overflow pipe 15.
[0046]
The filtering apparatus of the present embodiment is characterized by the air pushing backwashing step, and this point will be described below. If the air push valve 20 is left open while it is open, the pressure on the housing 2 side from the air push valve 20 also increases with the passage of time to a backwash air pressure of 2 kg / cm. 2 Approach. For example, the air pressure for backwashing is 2 kg / cm in about 2 seconds. 2 And the treated water in the stagnation section is also returned to the raw water side. However, in the filtration device of the present embodiment, such an air pressure for back washing is 2 kg / cm. 2 Is controlled so that the air push valve 20 is opened and closed intermittently a plurality of times. For example, the pulse-like operation of opening the air push valve 20 for about 0.5 second, closing it immediately, and then opening it again one second later is repeated twice or more. By the air-push wavy backwash, the state of detachment of the adhered matter from the hollow fiber membrane surface is improved by the impact force at the time of blowing the pressurized air.
[0047]
By the way, in consideration of the compactness and the cleaning effect of the filtration device, the volume of the retained treated water portion is set to be at most twice the amount of water held by the module on the treated water side of the hollow fiber membrane module 1. Is preferred. Here, “the amount of water possessed by the module on the treated water side” means only treated water inside the hollow fiber membrane, and the amount of retained water of treated water is set to within twice as much as the rest. For example, when the amount of water retained in the module is about 0.1 L, the volume of the treated water section is preferably set to 0.2 L or less. As will be described later, by performing bubbling in the next step, a cleaning effect can be expected even with a small amount of backwash water.
[0048]
Next, as shown in FIG. 5, while the air push valve 20 is closed, while the bubbling valve 13 and the overflow valve 16 are opened, air is jetted from the bubbling air supply pipe 8 into the housing 2 to perform a bubbling step. Is carried out. The hollow fiber membrane is swung by bubbling, and the dirt attached to the gap between the hollow fiber membranes and the membrane surface is removed.
[0049]
When the treated water portion (residence portion) in the air-pushed backwashing step is reduced for compactness, the separated suspended substance remains in the vicinity of the outer surface of the hollow fiber, but becomes hollow from the lower portion of the hollow fiber bundle. When bubbling is performed on the entire yarn, the yarn is spread from the vicinity of the outer surface of the hollow fiber to the raw water portion. If this spread did not occur, even if the next process was blown, the suspended solids would reattach to the outer surface of the hollow fiber and the efficiency of washing would be reduced. Is prevented.
[0050]
Finally, as shown in FIG. 6, in order to discharge dirt removed from the hollow fiber membrane by backwashing or bubbling to the outside of the apparatus, the drain valve 12 is opened, and the water in the housing 2 is drained (blown). A process is performed. At this time, the bubbling valve 13 is opened, and the air from the bubbling air supply pipe 8 is sent into the housing 2 to perform bubbling while draining. This blowing prevents the re-adhesion of suspended matter. Then, from the state of attachment to the outer surface of the hollow fiber, the suspended matter spread to the raw water portion by the air pushing backwashing step or the bubbling step can be effectively discharged from the housing raw water portion.
[0051]
By opening the overflow valve 16, air is removed from the bubbling. After such a drainage step, the water is supplied into the housing 2 and returned to a water filling step for overflowing. By adding bubbling at the time of water replenishment, the effect of discharging suspended substances is enhanced, and the hollow fiber membrane is washed again to improve the membrane washing effect. Moreover, the overflow at the time of water replenishment is effective for draining out the re-attached suspended solids.
[0052]
【The invention's effect】
As described in detail above, according to the hollow fiber membrane filtration device of the present invention, the hollow fiber membrane can be effectively cleaned by a plurality of air-pressed backwashes with pressure changes. In addition, by adding bubbling at the time of drainage, dirt and particles can be reliably discharged to the outside of the housing while preventing re-adhesion to the membrane surface.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a main part of one embodiment of a hollow fiber membrane filtration device of the present invention.
FIG. 2 is a flowchart showing an example of an operation process of the hollow fiber membrane filtration device in FIG.
FIG. 3 is a view showing a use state of the hollow fiber membrane filtration device of FIG. 1, showing a water filling step.
FIG. 4 is a view showing a use state of the hollow fiber membrane filtration device of FIG. 1, showing an air-pressed backwashing step.
FIG. 5 is a view showing a use state of the hollow fiber membrane filtration device in FIG. 1, showing a bubbling step.
FIG. 6 is a view showing a use state of the hollow fiber membrane filtration device of FIG. 1, showing a drainage step.
[Explanation of symbols]
2 Housing
3 Hollow fiber membrane
7 Raw water supply pipeline
8 Bubbling air supply line
9 drainage pipeline
15 Overflow pipeline
17 Treatment water pipeline
18 Treated water outlet valve
19 Backwash air supply line
20 Air push valve
28 Air release valve

Claims (6)

  1. 中空糸膜が収容されたハウジングと、
    ハウジングに原水を供給可能とされた原水供給管路と、
    原水を中空糸膜にてろ過して得られる処理水をハウジングから導出する処理水管路と、
    ハウジングの下部から原水を排出可能な排水管路と、
    ハウジングの下部において原水供給管路若しくは排水管路又はハウジングに接続され、ハウジングから排水管路への排水時に、ハウジング下部からハウジング内に気泡を噴出可能に、エアを供給するバブリングエア供給管路と
    を備えることを特徴とする中空糸膜ろ過装置。
    A housing containing the hollow fiber membrane,
    A raw water supply pipe capable of supplying raw water to the housing,
    A treated water pipe for drawing treated water obtained by filtering raw water through a hollow fiber membrane from a housing,
    A drain pipe that can discharge raw water from the lower part of the housing,
    A bubbling air supply line connected to the raw water supply line or the drainage line or the housing at the lower part of the housing, and for supplying air so that air bubbles can be ejected from the lower part of the housing into the housing at the time of drainage from the housing to the drainage line; A hollow fiber membrane filtration device comprising:
  2. 中空糸膜が収容されたハウジングと、
    ハウジングに原水を供給可能とされた原水供給管路と、
    原水を中空糸膜にてろ過して得られる処理水をハウジングから導出すると共に、処理水出口弁が開閉可能に設けられた処理水管路と、
    ハウジングの下部から原水を排出可能な排水管路と、
    処理水出口弁よりハウジング側の処理水管路、又はハウジングの処理水部に接続され、処理水出口弁を閉じて、処理水管路又はハウジングの処理水部に処理水を滞留させた状態で、その滞留部にエアによる圧力を複数回かけることで、中空糸膜を介して滞留部の処理水を原水側に戻すエア押し逆洗を行う逆洗エア供給管路と
    を備えることを特徴とする中空糸膜ろ過装置、又は請求項1に記載の中空糸膜ろ過装置。
    A housing containing the hollow fiber membrane,
    A raw water supply pipe capable of supplying raw water to the housing,
    A treated water pipe provided with a treated water outlet valve that can be opened and closed while extracting treated water obtained by filtering raw water through a hollow fiber membrane, and
    A drain pipe that can discharge raw water from the lower part of the housing,
    The treated water outlet valve is connected to the treated water pipe on the housing side from the treated water outlet valve, or the treated water section of the housing, the treated water outlet valve is closed, and the treated water is retained in the treated water pipe or the treated water section of the housing. A backwash air supply pipe for performing air-push backwash for returning the treated water of the stay portion to the raw water side through the hollow fiber membrane by applying pressure by air to the stay portion a plurality of times; A fiber membrane filtration device, or the hollow fiber membrane filtration device according to claim 1.
  3. 前記逆洗エア供給管路には、エア押し弁が開閉可能に設けられ、
    逆洗エア供給管路は、エア押し弁よりハウジング側の圧力が、エア押し弁よりコンプレッサ側の圧力と等しくなる前に、開閉操作が複数回行われて、前記エア押し逆洗がなされる
    ことを特徴とする請求項2に記載の中空糸膜ろ過装置。
    In the backwash air supply pipe, an air push valve is provided so as to be openable and closable,
    Before and after the pressure on the housing side from the air push valve becomes equal to the pressure on the compressor side from the air push valve, the backwash air supply pipeline is opened and closed a plurality of times to perform the air push backwash. The hollow fiber membrane filtration device according to claim 2, wherein:
  4. 中空糸膜が収容されたハウジング内に原水を供給する水張り工程、中空糸膜にて原水をろ過して処理水を得るろ過工程、中空糸膜の洗浄工程、ハウジング内からの排水工程が順次に行われる中空糸膜ろ過装置の運転方法であって、
    排水工程は、ハウジング下部から気泡を噴出させつつ行われる
    ことを特徴とする中空糸膜ろ過装置の運転方法。
    A water filling step of supplying raw water into the housing containing the hollow fiber membrane, a filtration step of filtering the raw water through the hollow fiber membrane to obtain treated water, a washing step of the hollow fiber membrane, and a draining step from the housing are sequentially performed. A method of operating a hollow fiber membrane filtration device to be performed,
    The method for operating a hollow fiber membrane filtration device, wherein the draining step is performed while bubbles are ejected from a lower portion of the housing.
  5. 中空糸膜が収容されたハウジング内に原水を供給する水張り工程、
    ハウジングに供給された原水を中空糸膜にてろ過して処理水を得るろ過工程、ハウジングからの原水のオーバーフロー管路を開く一方、ハウジングからの処理水管路を閉じた状態で、ハウジング上部の処理水滞留部にエアによる圧力をかけることで、中空糸膜を介して滞留部の処理水を原水側に戻して、オーバーフロー管路から排水することで、中空糸膜を洗浄するエア押し逆洗工程、
    ハウジングの下部から気泡を噴出させて中空糸膜を洗浄するバブリング工程、
    ハウジングの下部から気泡を噴出させつつハウジングから排水する排水工程
    を備えることを特徴とする中空糸膜ろ過装置の運転方法。
    A water filling process for supplying raw water into the housing in which the hollow fiber membrane is housed,
    Filtration step of filtering raw water supplied to the housing with a hollow fiber membrane to obtain treated water, processing of the upper part of the housing while closing the treated water pipe from the housing while opening the overflow pipe of the raw water from the housing An air-pressed backwashing step of washing the hollow fiber membrane by applying pressure from the air to the water accumulation section to return the treated water in the accumulation section to the raw water side via the hollow fiber membrane and draining it from the overflow conduit. ,
    A bubbling step of washing the hollow fiber membrane by ejecting air bubbles from the lower part of the housing,
    A method for operating a hollow fiber membrane filtration device, comprising a draining step of discharging air from a housing while ejecting air bubbles from a lower part of the housing.
  6. 前記エア押し逆洗工程は、前記処理水滞留部へのエアによる圧力付加が複数回に亘ってなされる
    ことを特徴とする請求項5に記載の中空糸膜ろ過装置の運転方法。
    The method for operating a hollow fiber membrane filtration device according to claim 5, wherein in the air pushing backwashing step, pressure application by air to the treated water retaining portion is performed a plurality of times.
JP2003006050A 2003-01-14 2003-01-14 Operation method of hollow fiber membrane filtration device Active JP4211400B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2003006050A JP4211400B2 (en) 2003-01-14 2003-01-14 Operation method of hollow fiber membrane filtration device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2003006050A JP4211400B2 (en) 2003-01-14 2003-01-14 Operation method of hollow fiber membrane filtration device

Publications (2)

Publication Number Publication Date
JP2004216263A true JP2004216263A (en) 2004-08-05
JP4211400B2 JP4211400B2 (en) 2009-01-21

Family

ID=32896552

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2003006050A Active JP4211400B2 (en) 2003-01-14 2003-01-14 Operation method of hollow fiber membrane filtration device

Country Status (1)

Country Link
JP (1) JP4211400B2 (en)

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010501340A (en) * 2006-08-31 2010-01-21 シーメンス・ウォーター・テクノロジーズ・コーポレーション Low pressure backwash
US8377305B2 (en) 2004-09-15 2013-02-19 Siemens Industry, Inc. Continuously variable aeration
US8382981B2 (en) 2008-07-24 2013-02-26 Siemens Industry, Inc. Frame system for membrane filtration modules
JP2013063367A (en) * 2011-09-15 2013-04-11 Toshiba Corp Membrane filter apparatus, operation method, and damage detection device
US8496828B2 (en) 2004-12-24 2013-07-30 Siemens Industry, Inc. Cleaning in membrane filtration systems
US8506806B2 (en) 2004-09-14 2013-08-13 Siemens Industry, Inc. Methods and apparatus for removing solids from a membrane module
US8512568B2 (en) 2001-08-09 2013-08-20 Siemens Industry, Inc. Method of cleaning membrane modules
US8518256B2 (en) 2001-04-04 2013-08-27 Siemens Industry, Inc. Membrane module
US8623202B2 (en) 2007-04-02 2014-01-07 Siemens Water Technologies Llc Infiltration/inflow control for membrane bioreactor
US8622222B2 (en) 2007-05-29 2014-01-07 Siemens Water Technologies Llc Membrane cleaning with pulsed airlift pump
US8758621B2 (en) 2004-03-26 2014-06-24 Evoqua Water Technologies Llc Process and apparatus for purifying impure water using microfiltration or ultrafiltration in combination with reverse osmosis
US8758622B2 (en) 2004-12-24 2014-06-24 Evoqua Water Technologies Llc Simple gas scouring method and apparatus
WO2014104558A1 (en) * 2012-12-29 2014-07-03 제일모직 주식회사 Pressure hollow fiber membrane module, and backwashing method using same
US8790515B2 (en) 2004-09-07 2014-07-29 Evoqua Water Technologies Llc Reduction of backwash liquid waste
US8808540B2 (en) 2003-11-14 2014-08-19 Evoqua Water Technologies Llc Module cleaning method
US8858796B2 (en) 2005-08-22 2014-10-14 Evoqua Water Technologies Llc Assembly for water filtration using a tube manifold to minimise backwash
US8956464B2 (en) 2009-06-11 2015-02-17 Evoqua Water Technologies Llc Method of cleaning membranes
US9022224B2 (en) 2010-09-24 2015-05-05 Evoqua Water Technologies Llc Fluid control manifold for membrane filtration system
US9533261B2 (en) 2012-06-28 2017-01-03 Evoqua Water Technologies Llc Potting method
US9604166B2 (en) 2011-09-30 2017-03-28 Evoqua Water Technologies Llc Manifold arrangement
US9675938B2 (en) 2005-04-29 2017-06-13 Evoqua Water Technologies Llc Chemical clean for membrane filter
US9764288B2 (en) 2007-04-04 2017-09-19 Evoqua Water Technologies Llc Membrane module protection
US9764289B2 (en) 2012-09-26 2017-09-19 Evoqua Water Technologies Llc Membrane securement device
US9815027B2 (en) 2012-09-27 2017-11-14 Evoqua Water Technologies Llc Gas scouring apparatus for immersed membranes
US9914097B2 (en) 2010-04-30 2018-03-13 Evoqua Water Technologies Llc Fluid flow distribution device
US9925499B2 (en) 2011-09-30 2018-03-27 Evoqua Water Technologies Llc Isolation valve with seal for end cap of a filtration system
US9962865B2 (en) 2012-09-26 2018-05-08 Evoqua Water Technologies Llc Membrane potting methods
US10322375B2 (en) 2015-07-14 2019-06-18 Evoqua Water Technologies Llc Aeration device for filtration system
US10427102B2 (en) 2013-10-02 2019-10-01 Evoqua Water Technologies Llc Method and device for repairing a membrane filtration module

Cited By (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8518256B2 (en) 2001-04-04 2013-08-27 Siemens Industry, Inc. Membrane module
US8512568B2 (en) 2001-08-09 2013-08-20 Siemens Industry, Inc. Method of cleaning membrane modules
US8808540B2 (en) 2003-11-14 2014-08-19 Evoqua Water Technologies Llc Module cleaning method
US8758621B2 (en) 2004-03-26 2014-06-24 Evoqua Water Technologies Llc Process and apparatus for purifying impure water using microfiltration or ultrafiltration in combination with reverse osmosis
US8790515B2 (en) 2004-09-07 2014-07-29 Evoqua Water Technologies Llc Reduction of backwash liquid waste
US8506806B2 (en) 2004-09-14 2013-08-13 Siemens Industry, Inc. Methods and apparatus for removing solids from a membrane module
US8377305B2 (en) 2004-09-15 2013-02-19 Siemens Industry, Inc. Continuously variable aeration
US8496828B2 (en) 2004-12-24 2013-07-30 Siemens Industry, Inc. Cleaning in membrane filtration systems
US8758622B2 (en) 2004-12-24 2014-06-24 Evoqua Water Technologies Llc Simple gas scouring method and apparatus
US9675938B2 (en) 2005-04-29 2017-06-13 Evoqua Water Technologies Llc Chemical clean for membrane filter
US8894858B1 (en) 2005-08-22 2014-11-25 Evoqua Water Technologies Llc Method and assembly for water filtration using a tube manifold to minimize backwash
US8858796B2 (en) 2005-08-22 2014-10-14 Evoqua Water Technologies Llc Assembly for water filtration using a tube manifold to minimise backwash
JP2010501340A (en) * 2006-08-31 2010-01-21 シーメンス・ウォーター・テクノロジーズ・コーポレーション Low pressure backwash
US8623202B2 (en) 2007-04-02 2014-01-07 Siemens Water Technologies Llc Infiltration/inflow control for membrane bioreactor
US9764288B2 (en) 2007-04-04 2017-09-19 Evoqua Water Technologies Llc Membrane module protection
US8622222B2 (en) 2007-05-29 2014-01-07 Siemens Water Technologies Llc Membrane cleaning with pulsed airlift pump
US8840783B2 (en) 2007-05-29 2014-09-23 Evoqua Water Technologies Llc Water treatment membrane cleaning with pulsed airlift pump
US9573824B2 (en) 2007-05-29 2017-02-21 Evoqua Water Technologies Llc Membrane cleaning with pulsed airlift pump
US9206057B2 (en) 2007-05-29 2015-12-08 Evoqua Water Technologies Llc Membrane cleaning with pulsed airlift pump
US10507431B2 (en) 2007-05-29 2019-12-17 Evoqua Water Technologies Llc Membrane cleaning with pulsed airlift pump
US9023206B2 (en) 2008-07-24 2015-05-05 Evoqua Water Technologies Llc Frame system for membrane filtration modules
US8382981B2 (en) 2008-07-24 2013-02-26 Siemens Industry, Inc. Frame system for membrane filtration modules
US8956464B2 (en) 2009-06-11 2015-02-17 Evoqua Water Technologies Llc Method of cleaning membranes
US10441920B2 (en) 2010-04-30 2019-10-15 Evoqua Water Technologies Llc Fluid flow distribution device
US9914097B2 (en) 2010-04-30 2018-03-13 Evoqua Water Technologies Llc Fluid flow distribution device
US9630147B2 (en) 2010-09-24 2017-04-25 Evoqua Water Technologies Llc Fluid control manifold for membrane filtration system
US9022224B2 (en) 2010-09-24 2015-05-05 Evoqua Water Technologies Llc Fluid control manifold for membrane filtration system
JP2013063367A (en) * 2011-09-15 2013-04-11 Toshiba Corp Membrane filter apparatus, operation method, and damage detection device
US9604166B2 (en) 2011-09-30 2017-03-28 Evoqua Water Technologies Llc Manifold arrangement
US10391432B2 (en) 2011-09-30 2019-08-27 Evoqua Water Technologies Llc Manifold arrangement
US9925499B2 (en) 2011-09-30 2018-03-27 Evoqua Water Technologies Llc Isolation valve with seal for end cap of a filtration system
US9533261B2 (en) 2012-06-28 2017-01-03 Evoqua Water Technologies Llc Potting method
US9764289B2 (en) 2012-09-26 2017-09-19 Evoqua Water Technologies Llc Membrane securement device
US9962865B2 (en) 2012-09-26 2018-05-08 Evoqua Water Technologies Llc Membrane potting methods
US9815027B2 (en) 2012-09-27 2017-11-14 Evoqua Water Technologies Llc Gas scouring apparatus for immersed membranes
US10159937B2 (en) 2012-12-29 2018-12-25 Lotte Advanced Materials Co., Ltd. Pressurized hollow fiber membrane module and backwashing method using same
WO2014104558A1 (en) * 2012-12-29 2014-07-03 제일모직 주식회사 Pressure hollow fiber membrane module, and backwashing method using same
CN104918685A (en) * 2012-12-29 2015-09-16 第一毛织株式会社 Pressure hollow fiber membrane module, and backwashing method using same
US10427102B2 (en) 2013-10-02 2019-10-01 Evoqua Water Technologies Llc Method and device for repairing a membrane filtration module
US10322375B2 (en) 2015-07-14 2019-06-18 Evoqua Water Technologies Llc Aeration device for filtration system

Also Published As

Publication number Publication date
JP4211400B2 (en) 2009-01-21

Similar Documents

Publication Publication Date Title
JP4838248B2 (en) Reduction of backwash liquid waste
JP4975950B2 (en) Membrane module cleaning method
JP4896025B2 (en) Method and apparatus for removing solids from membrane modules
TWI544971B (en) Method of operating process liquid supply device,process liquid supply device,and storage medium
JP4382275B2 (en) Membrane module cleaning method
CN1265867C (en) High solids module
AU2008101317A4 (en) Cleaning method for simple filtration systems
EP1680210B1 (en) Improved method of cleaning membrane modules
US8758622B2 (en) Simple gas scouring method and apparatus
JP4920990B2 (en) Separation membrane cleaning method
JP2904564B2 (en) Method of scrubbing filtration tower using hollow fiber membrane
RU2432323C2 (en) Equipment with bioreactor and membrane filter for water treatment
CN101511455B (en) Low pressure backwash
KR20070097425A (en) Modular filtration system
KR20060080584A (en) Backwash
WO2003059495A1 (en) Methods for improving filtration performance of hollow fiber membranes
JP2000237548A (en) Hollow fiber membrane type heat storage tank water purifying device
JPH088980B2 (en) Filter cleaning
JP2763262B2 (en) Backwashing method of ceramic membrane
JP2000317276A (en) Filtering device
JP3583201B2 (en) Cleaning method for separation membrane module
WO1996029142A1 (en) Method of desalinating saline water and apparatus therefor
WO2001066238A1 (en) Method of producing purified water
JP4042967B2 (en) Filtration device backwash method
JPH07289860A (en) Cleaning method of hollow fiber membrane module

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20050808

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20070712

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20070731

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20070921

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

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20081007

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20081020

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

Free format text: PAYMENT UNTIL: 20111107

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Ref document number: 4211400

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

Free format text: JAPANESE INTERMEDIATE CODE: R150

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

Free format text: PAYMENT UNTIL: 20111107

Year of fee payment: 3

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

Free format text: PAYMENT UNTIL: 20121107

Year of fee payment: 4

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

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

Free format text: PAYMENT UNTIL: 20131107

Year of fee payment: 5

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250