JP3697719B2

JP3697719B2 - Water purifier and method for cleaning porous filtration membrane in water purifier

Info

Publication number: JP3697719B2
Application number: JP11316294A
Authority: JP
Inventors: 秀雄岩田; 幹夫品川; 恵施今西
Original assignee: Matsushita Electric Works Ltd
Current assignee: Panasonic Electric Works Co Ltd
Priority date: 1994-05-26
Filing date: 1994-05-26
Publication date: 2005-09-21
Anticipated expiration: 2020-09-21
Also published as: JPH07313973A

Description

【０００１】
【産業上の利用分野】
本発明は、多孔質ろ過膜を利用して水をろ過する浄水器及び浄水器における多孔質ろ過膜の洗浄方法に関するものである。
【０００２】
【従来の技術】
従来から中空糸膜のような多孔質ろ過膜を用いた浄水器が知られている。この多孔質ろ過膜で原水をろ過してろ過水を得るのであるが、多孔性ろ過膜が詰まって流量が減少するという問題がある。これに対する対策としては例えば、特開平５ー２３６６７号公報などに示されるように、ろ過時と逆方向から洗浄水を多孔質ろ過膜に流して詰まりを解除し、流量を改善するという方法を取っていた。しかしながら、上記のような逆流洗浄においては、多孔質ろ過膜の目が詰まっていない所の方が詰まっている所よりも抵抗が少ないため、詰まっていない部分が選択的に逆流洗浄が行われることになり、逆洗の効率が低いという本質的な欠点があった。これを避けるためにはかなりの量のろ過水を逆方向に流す必要があった。また、逆方向に原水を流すと原水に含まれている異物が多孔質ろ過膜の下流側の面において目詰まりし、このため洗浄効果が劣り、逆洗に当たっては原水をろ過したろ過水を使用する必要があり、多孔質ろ過膜でいったんろ過したろ過水を貯めておいて使うことになり、装置が複雑になるという問題があった。
【０００３】
更に、従来にあっては、通常多孔質ろ過膜は活性炭より下流側に置かれているため活性炭に水中の有機物や無機物が付着し、活性炭の本来の吸着性能が衰える前に活性炭表面がそのような物質で覆われてしまって活性炭の寿命が短いという問題があった。
【０００４】
【発明が解決しようとする課題】
本発明は上記の従来例の問題点に鑑みて発明したものであって、その目的とするところは、多孔質ろ過膜が目詰まりした場合における多孔質ろ過膜の洗浄が簡単且つ確実に行え、装置の長寿命化がはかれる浄水器及び浄水器における多孔質ろ過膜の洗浄方法を提供するにある。
【０００５】
【課題を解決するための手段】
上記のような従来例の問題点を解決して本発明の目的を達成するため、本発明の浄水器は、原水入口１からハウジング２内に供給された原水をハウジング２内に内装した多孔質ろ過膜３によりろ過してろ過水出口４より排出する浄水器において、多孔質ろ過膜３の上流側の面を洗浄するために多孔質ろ過膜３の上流側においてハウジング２内に洗浄液を供給するための洗浄液供給口５を設けると共に多孔質ろ過膜３の上流側の面を洗浄した後の
洗浄液を多孔質ろ過膜３の上流側においてハウジング２外に排出するための排出口６を設け、洗浄液供給口５側及び排出口６側の夫々にろ過運転時には閉じられて洗浄時には開かれる開閉弁１４、１５、を設け、原水入口１側及びろ過水出口４側の夫々にろ過運転時には開かれて洗浄時には閉じられる開閉弁１３を設け、多孔質ろ過膜３の下流側において空気を送り込むための空気送り込み手段１０を設けて成ることを特徴とするものである。
【０００６】
ここで、洗浄液が原水であったり、洗浄液が温水であったり、洗浄液が界面活性剤であったり、あるいは、洗浄液が希塩酸等の酸や水酸化ナトリウム水溶液、あるいは水の電気分解による酸性水やアルカリ水のうちのいずれかであったりするのが好ましい。また、多孔質ろ過膜３の洗浄に当たり、多孔質ろ過膜３を振動又は揺動させる手段を設けて成る構成とすることも好ましい。
【０００７】
そして、振動又は揺動させる手段が超音波発生手段７であったり、振動又は揺動させる手段がカルマン渦発生手段８であったり、振動又は揺動させる手段が流体素子９であったりするのが好ましい。また、振動又は揺動の際に多孔質ろ過膜３相互が擦れ合うことができる距離を持っていることも好ましい。
【０００８】
また、多孔質ろ過膜３の下流側に活性炭ろ過部１１を設けて成ることも好ましい。また、活性炭ろ過部１１の外周部に多孔質ろ過膜３を配置して成ることも好ましい。
【０００９】
また、本発明の浄水器における多孔質ろ過膜３の洗浄方法は、原水入口１からハウジング２内に供給された原水をハウジング２内に内装した多孔質ろ過膜３によりろ過してろ過水出口４より排出する浄水器における多孔質ろ過膜３の洗浄方法であって、原水を多孔質ろ過膜３によってろ過するろ過運転を止めた後、ハウジング２内に洗浄液を供給して多孔質ろ過膜３の上流側の面を洗浄し、該多孔質ろ過膜３の洗浄時に、多孔質ろ過膜３の下流側からの空気の逆流による洗浄を同時に行い、該多孔質ろ過膜３の上流側の面を洗浄した後の洗浄液を多孔質ろ過膜３の上流側からハウジング２外に排出することを特徴とするものである。
【００１０】
また、前回の多孔質ろ過膜３の洗浄直後の多孔質ろ過膜３を通過する原水の通過流量の約半分程度の流量に低下した時点で、多孔質ろ過膜３の再洗浄を行うことも好ましい。また、多孔質ろ過膜３によるろ過運転を行った後一定時間経過してから多孔質ろ過膜３の洗浄をすることも好ましい。
【００１１】
【作用】
しかして本発明によれば、多孔質ろ過膜３の上流側の面を洗浄するために多孔質ろ過膜３の上流側においてハウジング２内に洗浄液を供給するための洗浄液供給口５を設けると共に多孔質ろ過膜３の上流側の面を洗浄した後の洗浄液を多孔質ろ過膜３の上流側においてハウジング２外に排出するための排出口６を設けるので、多孔質ろ過膜３が目詰まりして洗浄する際、多孔質ろ過膜３の上流側においてハウジング２内に供給した洗浄液により、多孔質ろ過膜３の上流側の面を洗浄することで、多孔質ろ過膜３の上流側の面を洗浄し、目詰まり物質を除去して多孔質ろ過膜３の上流側からハウジング２外に排出できることになり、この結果、中空糸膜のような多孔質ろ過膜３の上流側の面に主として付着して目詰まりしている目詰まり物質を効率的に洗浄して除去できるようになったものであり、また、洗浄した目詰まり物質を多孔質ろ過膜３を通して排出することがなく、また、従来のように逆洗するものにおいては多孔質ろ過膜３の下流側の面が目詰まりしないようにろ過水を使用しているが、本発明によれば、多孔質ろ過膜３の上流側の面を洗浄して上流側から排出することでろ過水を洗浄液として使用する必要がなくなったものである。また、多孔質ろ過膜３の下流側において空気を送り込むための空気送り込み手段１０を設けることで、多孔質ろ過膜３の上流側の面を洗浄液により洗浄するのに加えてバブリングによって
も洗浄され、効果的に洗浄できることになる。
【００１２】
そして、洗浄液が原水であると、従来のようにろ過水を洗浄液とするものに比べてろ過水を貯めて逆洗するための複雑な装置が必要でなく、装置の構成を簡略化できるものである。また、洗浄液が温水であると、多孔質ろ過膜３の洗浄効率が向上することになる。
【００１３】
また、洗浄液が界面活性剤であると、油脂分の洗浄が効果的にできる。また、洗浄液が希塩酸等の酸や水酸化ナトリウム水溶液、あるいは水の電気分解による酸性水やアルカリ水のうちのいずれかであると、酸を使うことで主として無機の成分の溶解除去による洗浄ができ、また、アルカリを使うことで主として有機成分を溶解除去することができる。
【００１４】
また、多孔質ろ過膜３の洗浄に当たり、多孔質ろ過膜３を振動又は揺動させる手段を設けることで、多孔質ろ過膜３の上流側の面を洗浄するに当たり、振動又は揺動させて洗浄効果を向上させることができるものである。また、振動又は揺動させる手段が超音波発生手段７であると、簡単な構成で多孔質ろ過膜３を振動又は揺動させることができる。
【００１５】
また、振動又は揺動させる手段がカルマン渦発生手段８であると、洗浄液の供給口の位置設定等の簡単な構成で多孔質ろ過膜３を振動又は揺動させることができる。また、振動又は揺動させる手段が流体素子９であると、簡単な構成で多孔質ろ過膜３を振動又は揺動させることができる。
【００１６】
また、振動又は揺動の際に多孔質ろ過膜３相互が擦れ合うことができる距離を持っていると、多孔質ろ過膜３を振動又は揺動させた際に隣合う多孔質ろ過膜３の上流側の面同士が擦れ合って多孔質ろ過膜３の上流側の面に付着している異物を払い落とすことになり、効果的に洗浄できることになる。
【００１７】
また、多孔質ろ過膜３の下流側に活性炭ろ過部１１を設けてあると、多孔質ろ過膜３により原水中の有機物や無機物がろ過され、活性炭ろ過部１１の表面に原水中の有機物や無機物が付着して、活性炭本来の吸着性能を損なわないようにできる。
【００１８】
また、活性炭ろ過部１１の外周部に多孔質ろ過膜３を配置してあることで、多孔質ろ過膜３が外側に位置しており、この結果、多孔質ろ過膜３の洗浄がしやすいことになる。
【００１９】
また、本発明の浄水器における多孔質ろ過膜の洗浄方法によれば、原水入口１からハウジング２内に供給された原水をハウジング２内に内装した多孔質ろ過膜３によりろ過してろ過水出口４より排出する浄水器における多孔質ろ過膜３の洗浄方法であって、原水を多孔質ろ過膜３によってろ過するろ過運転を止めた後、ハウジング２内に洗浄液を供給して多孔質ろ過膜３の上流側の面を洗浄し、該多孔質ろ過膜３の上流側の面を洗浄した後の洗浄液を多孔質ろ過膜３の上流側からハウジング２外に排出することで、簡単に多孔質ろ過膜３の上流側の面を洗浄液で洗浄して多孔質ろ過膜３の上流側から排出できるものである。また、多孔質ろ過膜３の洗浄時に、多孔質ろ過膜３の下流側からの水又は空気の逆流による洗浄を同時に行うことで、多孔質ろ過膜３の上流側の面を洗浄液によりろ過する際、下流側からも多孔質ろ過膜３の上流側の面を閉塞している閉塞物を多孔質ろ過膜３から離そうとする流れを形成し、より効果的な洗浄ができるものである。
【００２０】
また、洗浄をあまり頻繁に行うと却って性能回復度合いが低くなることが実験的に知られており、これは洗浄により除去できない非常に小さい粒子等が頻繁な洗浄により常に膜の表面に付き蓄積していくことになるからであると考えらえている。そこで、前回の多孔質ろ過膜３の洗浄直後の多孔質ろ過膜３を通過する原水の通過流量の約半分程度の流量に低下した時点で、多孔質ろ過膜３の再洗浄を行うというような頻度の低い洗浄にすると、
非常に小さな粒子は先に膜に付いた大きな粒子がフィルターとなって、これに捕捉された状態となり、洗浄時に多孔質ろ過膜３の上流側の面に付着している大きな粒子と一緒に除去されることになる。
【００２１】
また、多孔質ろ過膜３によるろ過運転を行った後一定時間経過してから多孔質ろ過膜３の洗浄をすることで、多孔質ろ過膜３によるろ過運転を行って一定時間が経過するまでの間、多孔質ろ過膜３の内部と外部の間にろ過物質の濃度差ができ、流れを止めた時に逆浸透して性能回復を図ることができ、この逆浸透して性能回復を図った時点で洗浄を行うことでより洗浄効果を高めることができるものである。
【００２２】
【実施例】
以下本発明を添付図面に示す実施例に基づいて詳述する。図１、図２には本発明の浄水器の一例が示してある。２は浄水器のハウジングであり、内部に多孔質ろ過膜３が内装してあり、ハウジング２に設けた原水入口１からハウジング２内に原水を供給し、ハウジング２内に内装した多孔質ろ過膜３によりろ過し、ハウジング２に設けたろ過水出口４からろ過水を排出するようになっている。つまり、図１において矢印Ａ方向から原水を供給し、多孔質ろ過膜３によりろ過し、ろ過水を矢印Ｂ方向に排出するのである。
【００２３】
上記の浄水器のハウジング２には多孔質ろ過膜３の上流側においてハウジング２内に洗浄液を供給するための洗浄液供給口５が設けてあり、更に、多孔質ろ過膜３の上流側の面を洗浄した後の洗浄液を多孔質ろ過膜３の上流側においてハウジング２外に排出するための排出口６が設けてある。ここで、添付図面に示す実施例においては図２に示すようにハウジング２に内装する多孔質ろ過膜３は中空糸膜よりなり、膜単体３ａをそれぞれＵ字状にして両端を束ねてポッティングして構成してある。そして、ハウジング２内に内装した場合、ポッティング部１２はハウジング２内を仕切る仕切りとなり、Ｕ字状部分が上流側に位置し、ポッティング部１２が下流側に位置するように内装される。
【００２４】
原水入口１側には開閉弁１３が設けてあり、洗浄液供給口５側及び排出口６側にもそれぞれ開閉弁１４、１５が設けてある。しかして、ろ過運転するには開閉弁１４、１５を閉じた状態で開閉弁１３を開くと、原水入口１から原水が供給され、多孔質ろ過膜３でろ過され、ろ過水出口４からろ過水が排出される。そして、ろ過運転により多孔質ろ過膜３の上流側には原水に含まれている微細粒子が付着して目詰まりがしていく。そこで、本発明においては、多孔質ろ過膜３が目詰まりすると、多孔質ろ過膜３を洗浄して性能回復を行うものである。この場合、開閉弁１３を閉じた状態で、開閉弁１４、１５を開き、洗浄液供給口５からハウジング２内の多孔質ろ過膜３の上流側に洗浄液を供給し、この洗浄液により多孔質ろ過膜３の上流側の面を洗浄し、洗浄後の洗浄液を多孔質ろ過膜３の上流側において排出口６からハウジング２外に排出するのである。つまり、図１において矢印Ｃ方向から洗浄液を供給し、多孔質ろ過膜３の上流側の面を洗浄した後、排出口６から矢印Ｄのように排出するのである。この場合、ろ過水出口４側にも開閉弁を設けて、上記洗浄時に開閉弁を閉じるようにしてもよい。このように多孔質ろ過膜３の上流側の面を洗浄することで、ろ過運転の際に主として多孔質ろ過膜３の上流側の面に付着した粒子を効果的に洗浄して排出することができることになる。この場合、洗浄液を高速で多孔質ろ過膜３に噴射する構成とすることで、洗浄液の運動エネルギーにより多孔質ろ過膜３の上流側の面に付着した付着物を高速、高効率で洗浄できることになる。
【００２５】
ここで、多孔質ろ過膜３を洗浄するに当たっては、多孔質ろ過膜３の下流側から逆洗浄する従来のもののように多孔質ろ過膜３の下流側の面に異物が付着するのを防止するためにいったんろ過したろ過水を使用するというようなことが必要でなく、ろ過前の原水を直接使用することができる。つまり、浄水器でろ過の対象としている原水をそのままま洗浄液として使用することができて、この場合には、従来のようにいったんろ過したろ過水を
溜めて逆洗浄のために流すという複雑な構造が必要でなく、構造が簡略化されることになる。
【００２６】
洗浄水としては上記の原水にのみ限定されず、温水（原水を加熱して温水としたものでよい）を用いると、洗浄効果がより向上するものである。また、洗浄液として界面活性剤を用いることもできる。この場合には、多孔質ろ過膜３に油脂分が付着している場合に効果的に洗浄できるものである。また、洗浄液として希塩酸等の酸を用いることもできる。酸を用いた場合には多孔質ろ過膜３に付着した無機の成分の溶解除去が効果的にできるものである。また、洗浄液として水酸化ナトリウム水溶液等のアルカリを用いることもできる。アルカリを用いた場合には多孔質ろ過膜３に付着した有機成分の溶解除去が効果的にできるものである。
【００２７】
ここで、洗浄水として使用する酸やアルカリとしては電気分解により得られる酸性水やアルカリ水であってもよい。この場合には図９のように洗浄液供給口５の上流側にアルカリイオン整水器と称されるイオン整水器１６を接続し、イオン整水器１６により生成した酸性水又はアルカリ水のいずれかを洗浄液として洗浄液供給口５側に供給するようにしてもよい。
【００２８】
そして本発明においては、多孔質ろ過膜３の上流側に洗浄液を供給して多孔質ろ過膜３の上流側の面を洗浄し、洗浄後の洗浄液を多孔質ろ過膜３の上流側において排出するようにするに当たり、図６に示すように多孔質ろ過膜３の下流側において空気を送り込むための空気送り込み手段１０を設けている。空気の動きにより多孔質ろ過膜３の上流側の面に付着している付着物を下流側から上流側に向けて離そうとする流れが発生し、効果的に洗浄できることになる。
【００２９】
ところで、上記のように多孔質ろ過膜３の上流側に洗浄液を供給して多孔質ろ過膜３の上流側の面を洗浄し、洗浄後の洗浄液を多孔質ろ過膜３の上流側において排出するようにするに当たり、洗浄時に多孔質ろ過膜３を振動又は揺動させる手段を設けるとより効果的な洗浄ができる。図１においては略円柱状に束ねた多孔質ろ過膜３の径方向に洗浄液供給口５が開口しており、このような位置関係とすることで、洗浄液供給口５から供給された洗浄液のうち多孔質ろ過膜３の外周に沿って流れる流れがカルマン渦を発生させ、このことにより多孔質ろ過膜３が振動又は揺動することになる。したがって、この実施例では略円柱状に束ねた多孔質ろ過膜３の径方向に開口した洗浄液供給口５の構造そのものがカルマン渦発生手段８となっている。
【００３０】
図３に示す実施例では、洗浄液供給口５に振動又は揺動させるための手段として流体素子９を設けた例が示してある。流体素子９は図４に示すようなもので、入口１７から流入した洗浄液が発振型の流体素子９内で発振し、出口１８ａと出口１８ｂとに別れてハウジング２内の多孔質ろ過膜３の上流側に流入し、これにより多孔質ろ過膜３を振動又は揺動させながら洗浄するのである。
【００３１】
また、振動又は揺動させる手段として図５に示すように超音波発生手段７を用いてもよい。このものにおいては、洗浄時に超音波発生手段７により超音波を発生させて振動又は揺動させながら洗浄をするのである。ここで、多孔質ろ過膜３を振動や揺動しながら洗浄液により多孔質ろ過膜３の上流側の面を洗浄する際、多孔質ろ過膜３を構成している膜単体３ａが隣りの膜単体３ａと適当なある一定の距離Ｘ（図２に示す）を保つようにしてある。この距離Ｘは振動又は揺動手段により多孔質ろ過膜３を振動させて洗浄する際、多孔質ろ過膜３相互が擦れ合うことができる距離とする。ここで、あまり距離Ｘが短いとかえって擦れ合う効果が小さくなるため、振動又は揺動させる方法と膜の剛性により上記距離Ｘを求める。そして、上記のように振動又は揺動手段により多孔質ろ過膜３を振動又は揺
動させて洗浄する際、多孔質ろ過膜３相互が擦れ合う構成とすることで、多孔質ろ過膜３の上流側の面に付着している粒子が剥離し、洗浄効果をより確実なものとする。
【００３２】
また、図１乃至図６、図８の実施例においては浄水器のハウジング２内に多孔質ろ過膜３のみを内装したものの例を示しているが、図１乃至図６、図８では図示を省略しているがハウジング２内に更に活性炭ろ過部１１を内装してもよい。この場合、多孔質ろ過膜３の上流側に活性端炭ろ過部１１を配置してもよいが、多孔質ろ過膜３の下流側に活性炭ろ過部１１を設けてもよい。多孔質ろ過膜３の下流側に活性炭ろ過部１１を設けると、原水中のごみは多孔質ろ過膜３でろ過されて活性炭ろ過部１１の表面に原水中の有機物や無機物のごみが付着して、活性炭本来の吸着性能を損なわないようできて、活性炭本来の吸着性能の劣化が非常に少なくなる。この場合、活性炭ろ過部１１を多孔質ろ過膜３の上流側に配置する場合に比べて多孔質ろ過膜３の目詰まりが早まることは避けられないが、この多孔質ろ過膜３の目詰まりの洗浄による性能回復は、すでに述べたように多孔質ろ過膜３の上流側に洗浄液を供給して多孔質ろ過膜３の上流側の面を洗浄し、洗浄後の洗浄液を多孔質ろ過膜３の上流側において排出するようにすることで、簡単且つ確実に洗浄して性能回復ができるのである。
【００３３】
ここで、多孔質ろ過膜３と活性炭ろ過部１１とを併用するに当たり、図７に示すように活性炭ろ過部１１の外周部に多孔質ろ過膜３を配置した構成とすると、多孔質ろ過膜３が外側に位置することになるので、多孔質ろ過膜３の洗浄がしやすくなる。図７において矢印は原水の流れる方向を示している。ところで、本発明における浄水器の多孔質ろ過膜３の洗浄方法は、すでに述べたように、原水を多孔質ろ過膜３によるろ過するろ過運転を止めた後、ハウジング２内に洗浄液を供給して多孔質ろ過膜３の上流側の面を洗浄し、該多孔質ろ過膜３の上流側の面を洗浄した後の洗浄液を多孔質ろ過膜３の上流側からハウジング２外に排出するのであるが、この洗浄に当たり、前回の多孔質ろ過膜３の洗浄直後の多孔質ろ過膜３を通過する原水の通過流量の約半分程度の流量に低下した時点で、多孔質ろ過膜３の再洗浄を行うようにするのが好ましい。すなわち、本発明者の実験によれば、洗浄をあまり頻繁に行うと却って性能回復度合いが低くなることが確認されている。これは、洗浄により除去できない非常に小さな粒子等が頻繁な洗浄により常に多孔質ろ過膜３の上流側の面に付着して蓄積していくことになるからであると考えられる。一方、頻度の低い洗浄では非常に小さな粒子は先に多孔質ろ過膜３の上流側の面に付着した大きな粒子がフィルターとなってこれに捕捉され、このため、多孔質ろ過膜３の上流側の面を洗浄液で洗浄する際に大きな粒子に捕捉された非常に小さな粒子が一緒に除去されることになり、却って洗浄効果が高くなると考えられる。この結果に鑑み、洗浄頻度の目安として、前回の多孔質ろ過膜３の洗浄直後の多孔質ろ過膜３を通過する原水の通過流量の約半分程度の流量に低下した時点で、多孔質ろ過膜３の再洗浄を行うことによりろ過寿命を長くすることができるのである。
【００３４】
また、通常、多孔質ろ過膜３によりろ過を行う場合、ろ過を中断するとろ過性能が回復し、連続的に使うように寿命が長くなることが実験的に確認されている。これは、多孔質ろ過膜３の内部と外部の間にろ過物質の濃度差ができ、流れを止めた時に逆浸透してくるからである。このことにより多孔質ろ過膜３の洗浄のタイミングとしては多孔質ろ過膜３によるろ過運転を行った直後ではなく、例えば、次にろ過しようとする直前に洗浄をすることで、ろ過運転後における逆浸透のための時間を稼ぎ性能回復を図る構造とすると、洗浄効果の高い浄水器を得ることができる。この場合、多孔質ろ過膜３の洗浄のタイミングとして多孔質ろ過膜３によるろ過運転が終わってから一定時間経過してから多孔質ろ過膜３の洗浄をするようにしてもよい。
【００３５】
そして本発明は、原水を多孔質ろ過膜３によってろ過するろ過運転を止めた後、ハウジング２内に洗浄液を供給して多孔質ろ過膜３の上流側の面を洗浄し、該多孔質ろ過膜３の
上流側の面を洗浄した後の洗浄液を多孔質ろ過膜３の上流側からハウジング２外に排出するという洗浄方法において、多孔質ろ過膜３の洗浄時に、多孔質ろ過膜３の下流側からの空気の逆流による洗浄を同時に行うことで、多孔質ろ過膜３の上流側の面を上流側で洗浄液による洗浄するのに加え、多孔質ろ過膜３の下流側から上流側への逆流を併用して、多孔質ろ過膜３の目詰まりを効果的に無くすことができることになる。
【００３６】
【発明の効果】
本発明の請求項１記載の発明にあっては、原水入口からハウジング内に供給された原水をハウジング内に内装した多孔質ろ過膜によりろ過してろ過水出口より排出する浄水器において、多孔質ろ過膜の上流側の面を洗浄するために多孔質ろ過膜の上流側においてハウジング内に洗浄液を供給するための洗浄液供給口を設けると共に多孔質ろ過膜の上流側の面を洗浄した後の洗浄液を多孔質ろ過膜の上流側においてハウジング外に排出するための排出口を設け、洗浄液供給口側及び排出口側の夫々にろ過運転時には閉じられて洗浄時には開かれる開閉弁を設け、原水入口側及びろ過水出口側の夫々にろ過運転時には開かれて洗浄時には閉じられる開閉弁を設けてあるので、多孔質ろ過膜の上流側の面に主として付着している目詰まり物質を上流側における洗浄で効率的に除去できるものであり、また多孔質ろ過膜の下流側において空気を送り込むための空気送り込み手段を設けてあるので、多孔質ろ過膜の上流側の面を洗浄液により洗浄するのに加えてバブリングによっても洗浄され、両者の相乗的な洗浄効果により効果的に洗浄できるものであり、特に、下流側から多孔質ろ過膜を通って上流側に空気が流れることで、上流側の面に付着している付着物を剥離し、上流側において洗浄液により効果的に洗い流すことができる。また、洗浄した目詰まり物質を多孔質ろ過膜を通して排出することがなくて除去した目詰まり物質が再び多孔質ろ過膜に目詰まりするというおそれがなく、また、従来のように逆洗するものに比べて洗浄液としてろ過水を使用する必要がないものである。
【００３７】
また、請求項２記載の発明にあっては、請求項１記載の発明の効果に加えて、洗浄液が原水であるから、従来のようにろ過水を洗浄液とするものに比べてろ過水を貯めて逆洗するための複雑な装置が必要でなく、装置の構成を簡略化できるものである。また、請求項３記載の発明にあっては、請求項１記載の発明の効果に加えて、洗浄液が温水であるから、多孔質ろ過膜の洗浄効率が向上するものである。
【００３８】
また、請求項４記載の発明にあっては、請求項１記載の発明の効果に加えて、洗浄液が界面活性剤であると、油脂分の洗浄が効果的にできるものである。また、請求項５記載の発明にあっては、請求項１記載の発明の効果に加えて、洗浄液が希塩酸等の酸や水酸化ナトリウム水溶液、あるいは水の電気分解による酸性水やアルカリ水のうちのいずれかであると、酸を使うことで主として無機の成分の溶解除去による洗浄ができ、また、アルカリを使うことで主として有機成分を溶解除去することができるものであり、また、電気分解による酸性水やアルカリ水であると、イオン整水器を接続する構成により簡単に酸性水やアルカリ水を供給できるものである。
【００３９】
また、請求項６記載の発明にあっては、請求項１記載の発明の効果に加えて、多孔質ろ過膜の洗浄に当たり、多孔質ろ過膜を振動又は揺動させる手段を設けてあるので、洗浄液により多孔質ろ過膜の上流側の面を洗浄する際に、多孔質ろ過膜を振動又は揺動させながら洗浄することで、上流側の面に付着した付着物を剥離して洗い流すことができ、効果的な洗浄ができるものである。
【００４０】
また、請求項７記載の発明にあっては、請求項６記載の発明の効果に加えて、振動又は揺動させる手段が超音波発生手段であるから簡単な構成で多孔質ろ過膜を振動又は揺動させることができるものである。また、請求項８記載の発明にあっては、請求項６記載の発明の効果に加えて、振動又は揺動させる手段がカルマン渦発生手段であるから、洗浄液の
供給口の位置設定等の簡単な構成で多孔質ろ過膜を振動又は揺動させることができるものである。
【００４１】
また、請求項９記載の発明にあっては、請求項６記載の発明の効果に加えて、振動又は揺動させる手段が流体素子であるから、簡単な構成で多孔質ろ過膜を振動又は揺動させることができるものである。また、請求項１０記載の発明にあっては、請求項６乃至９のいずれかに記載の発明の効果に加えて、振動又は揺動の際に多孔質ろ過膜相互が擦れ合うことができる距離を持っているので、多孔質ろ過膜を振動又は揺動させた際に隣合う多孔質ろ過膜の上流側の面同士が擦れ合って多孔質ろ過膜の上流側の面に付着している異物を効果的に払い落とすことになり、より効果的に洗浄できるものである。
【００４２】
また、請求項１１記載の発明にあっては、請求項１記載の発明の効果に加えて、多孔質ろ過膜の下流側に活性炭ろ過部を設けてあるので、多孔質ろ過膜により原水中の有機物や無機物がろ過され、活性炭ろ過部の表面に原水中の有機物や無機物が付着して、活性炭本来の吸着性能を損なわないようにでき、多孔質ろ過膜の上流側に付着した付着物は洗浄液により効果的に洗浄して簡単に再生できるものである。
【００４３】
また、請求項１２記載の発明にあっては、請求項１記載の発明の効果に加えて、活性炭ろ過部の外周部に多孔質ろ過膜を配置してあるので、多孔質ろ過膜が外側に位置することになって多孔質ろ過膜の洗浄がしやすいものである。
【００４４】
また、請求項１３記載の発明にあっては、原水入口からハウジング内に供給された原水をハウジング内に内装した多孔質ろ過膜によりろ過してろ過水出口より排出する浄水器における多孔質ろ過膜の洗浄方法であって、原水を多孔質ろ過膜によってろ過するろ過運転を止めた後、ハウジング内に洗浄液を供給して多孔質ろ過膜の上流側の面を洗浄し、該多孔質ろ過膜の上流側の面を洗浄した後の洗浄液を多孔質ろ過膜の上流側からハウジング外に排出するので、簡単な方法で多孔質ろ過膜の上流側の面を洗浄できて再生でき、また、多孔質ろ過膜の洗浄時に、多孔質ろ過膜の下流側からの空気の逆流による洗浄を同時に行うので、多孔質ろ過膜の上流側の面を洗浄液によりろ過する際、下流側からも多孔質ろ過膜の上流側の面を閉塞している閉塞物を多孔質ろ過膜から離そうとする流れを形成し、より効果的な洗浄ができるものである。
【００４５】
また、請求項１４記載の発明にあっては、請求項１３記載の発明の効果に加えて、前回の多孔質ろ過膜の洗浄直後の多孔質ろ過膜を通過する原水の通過流量の約半分程度の流量に低下した時点で、多孔質ろ過膜の再洗浄を行うので、すでに述べたように、非常に小さい粒子を先に膜に付着している大きな粒子をフィルターとして捕捉でき、洗浄の際に非常に小さい粒子を大きな粒子と共に洗浄できるものである。
【００４６】
また、請求項１５記載の発明にあっては、請求項１３記載の発明の効果に加えて、多孔質ろ過膜によるろ過運転を行った後一定時間経過してから多孔質ろ過膜の洗浄をするので、多孔質ろ過膜によるろ過運転を行って一定時間が経過するまでの間、多孔質ろ過膜の内部と外部の間にろ過物質の濃度差ができ、流れを止めた時に逆浸透して性能回復を図ることができ、この逆浸透して性能回復を図った時点で洗浄を行うことでより洗浄効果を高めることができるものである。
【図面の簡単な説明】
【図１】本発明の浄水器の一実施例の概略構成図である。
【図２】同上の概略断面図である。
【図３】本発明の他の実施例の概略構成図である。
【図４】同上に用いる流体素子の断面図である。
【図５】本発明の更に他の実施例の概略断面図である。
【図６】本発明の概略断面図である。
【図７】本発明の活性炭ろ過部の外周部に多孔質ろ過膜を配置した実施例を示す一部破断した概略斜視図である。
【図８】本発明の更に他の実施例の概略断面図である。
【符号の説明】
１原水入口
２ハウジング
３多孔質ろ過膜
４ろ過水出口
５洗浄液供給口
６排出口
７超音波発生手段
８カルマン渦発生手段
９流体素子
１０空気送り込み手段
１１活性炭ろ過部[0001]
[Industrial application fields]
  The present invention relates to a water purifier that filters water using a porous filtration membrane and a method for cleaning a porous filtration membrane in a water purifier.
[0002]
[Prior art]
  Conventionally, a water purifier using a porous filtration membrane such as a hollow fiber membrane is known. Although raw water is filtered with this porous filtration membrane to obtain filtered water, there is a problem that the porous filtration membrane is clogged and the flow rate is reduced. As a countermeasure against this, for example, as disclosed in Japanese Patent Application Laid-Open No. 5-23667, etc., a method of improving the flow rate by flowing the washing water through the porous filtration membrane from the opposite direction to the time of filtration to release the clogging. It was. However, in the backwashing as described above, the portion where the porous filtration membrane is not clogged has less resistance than the clogged portion, so that the backwashing is selectively performed on the clogged portion. Thus, there is an essential drawback that the efficiency of backwashing is low. In order to avoid this, it was necessary to flow a considerable amount of filtered water in the reverse direction. In addition, if the raw water is flowed in the opposite direction, foreign substances contained in the raw water are clogged on the downstream side of the porous filtration membrane, and therefore the cleaning effect is inferior, and filtered water obtained by filtering the raw water is used for backwashing. Therefore, the filtered water once filtered by the porous filtration membrane is stored and used, and there is a problem that the apparatus becomes complicated.
[0003]
  Furthermore, conventionally, since the porous filtration membrane is usually placed downstream of the activated carbon, organic and inorganic substances in the water adhere to the activated carbon, and the activated carbon surface does not deteriorate before the original adsorption performance of the activated carbon deteriorates. There is a problem that the activated carbon has a short life because it is covered with a new material.
[0004]
[Problems to be solved by the invention]
  The present invention was invented in view of the problems of the above-described conventional example, and the object of the present invention is to easily and reliably perform cleaning of the porous filtration membrane when the porous filtration membrane is clogged, It is in providing the washing | cleaning method of the porous filter membrane in a water purifier and water purifier with which lifetime improvement of an apparatus is achieved.
[0005]
[Means for Solving the Problems]
  In order to solve the problems of the conventional example as described above and achieve the object of the present invention, the water purifier of the present invention is a porous material in which raw water supplied from the raw water inlet 1 into the housing 2 is housed in the housing 2. In the water purifier that is filtered by the filtration membrane 3 and discharged from the filtrate outlet 4, the cleaning liquid is supplied into the housing 2 on the upstream side of the porous filtration membrane 3 in order to wash the upstream surface of the porous filtration membrane 3. After providing the cleaning liquid supply port 5 for cleaning the upstream surface of the porous filtration membrane 3
A discharge port 6 for discharging the cleaning liquid to the outside of the housing 2 on the upstream side of the porous filtration membrane 3 is provided,On the cleaning liquid supply port 5 side and the discharge port 6 side, on-off valves 14 and 15 that are closed during the filtration operation and opened during the cleaning operation are provided, and the raw water inlet 1 side and the filtrate outlet 4 side are opened during the filtration operation. An on-off valve 13 that is closed during cleaning is provided, and an air feeding means 10 is provided for feeding air downstream of the porous filtration membrane 3.It is characterized by comprising.
[0006]
  Here, the cleaning liquid is raw water, the cleaning liquid is warm water, the cleaning liquid is a surfactant, or the cleaning liquid is an acid such as dilute hydrochloric acid, an aqueous solution of sodium hydroxide, or acidic water or alkali by electrolysis of water. It is preferably any of water. In addition, it is also preferable to provide a means for vibrating or swinging the porous filtration membrane 3 when cleaning the porous filtration membrane 3.
[0007]
  The means for vibrating or swinging is the ultrasonic wave generating means 7, the means for vibrating or swinging is the Karman vortex generating means 8, or the means for vibrating or swinging is the fluid element 9. preferable. It is also preferable that the porous filtration membranes 3 have a distance that can rub against each other during vibration or swinging..
[0008]
  Also,It is also preferable that the activated carbon filtration part 11 is provided on the downstream side of the porous filtration membrane 3. Moreover, it is also preferable to arrange the porous filtration membrane 3 on the outer peripheral part of the activated carbon filtration part 11.
[0009]
  Further, the method for cleaning the porous filtration membrane 3 in the water purifier of the present invention is the filtration of the raw water supplied from the raw water inlet 1 into the housing 2 by the porous filtration membrane 3 built in the housing 2 and the filtered water outlet 4. This is a method for cleaning the porous filtration membrane 3 in the water purifier that discharges more water. After stopping the filtration operation of filtering raw water through the porous filtration membrane 3, the cleaning liquid is supplied into the housing 2 and the porous filtration membrane 3 Clean the upstream surface,At the time of washing the porous filtration membrane 3, washing is performed simultaneously with the backflow of air from the downstream side of the porous filtration membrane 3,The cleaning liquid after cleaning the upstream surface of the porous filtration membrane 3 is discharged out of the housing 2 from the upstream side of the porous filtration membrane 3.
[0010]
  It is also preferable to re-clean the porous filtration membrane 3 when the flow rate is reduced to about half the flow rate of the raw water passing through the porous filtration membrane 3 immediately after the previous cleaning of the porous filtration membrane 3. . It is also preferable to wash the porous filtration membrane 3 after a certain time has elapsed after the filtration operation with the porous filtration membrane 3..
[0011]
[Action]
  Thus, according to the present invention, the cleaning liquid supply port 5 for supplying the cleaning liquid into the housing 2 is provided on the upstream side of the porous filtration membrane 3 in order to clean the surface on the upstream side of the porous filtration membrane 3, and the porous filtration membrane 3 is porous. Since the discharge port 6 for discharging the cleaning liquid after cleaning the upstream surface of the mass filtration membrane 3 to the outside of the housing 2 on the upstream side of the porous filtration membrane 3 is provided, the porous filtration membrane 3 is clogged. When cleaning, the upstream surface of the porous filtration membrane 3 is cleaned by cleaning the upstream surface of the porous filtration membrane 3 with the cleaning liquid supplied into the housing 2 on the upstream side of the porous filtration membrane 3. Thus, the clogging substance can be removed and discharged from the upstream side of the porous filtration membrane 3 to the outside of the housing 2, and as a result, it adheres mainly to the upstream side surface of the porous filtration membrane 3 such as a hollow fiber membrane. Clogging substances that are clogged It can be removed by washing efficiently, and the clogged substance that has been washed is not discharged through the porous filtration membrane 3, and is porous in the case of backwashing as in the prior art. Although filtered water is used so that the downstream surface of the filtration membrane 3 is not clogged, according to the present invention, the upstream surface of the porous filtration membrane 3 is washed and discharged from the upstream side. It is no longer necessary to use filtered water as a cleaning liquid.Further, by providing an air feeding means 10 for feeding air on the downstream side of the porous filtration membrane 3, in addition to washing the upstream surface of the porous filtration membrane 3 with the washing liquid, bubbling is performed.
Will also be cleaned and effectively cleaned.
[0012]
  And if the cleaning liquid is raw water, it is not necessary to use a complicated device for storing the filtered water and backwashing compared to the conventional method using the filtered water as the cleaning liquid, and the configuration of the apparatus can be simplified. is there. Moreover, the cleaning efficiency of the porous filtration membrane 3 will improve that a washing | cleaning liquid is warm water.
[0013]
  Further, when the cleaning liquid is a surfactant, the oil and fat can be effectively cleaned. In addition, if the cleaning liquid is an acid such as dilute hydrochloric acid, an aqueous sodium hydroxide solution, or acidic water or alkaline water obtained by electrolysis of water, cleaning can be performed mainly by dissolving and removing inorganic components by using an acid. Moreover, organic components can be dissolved and removed mainly by using alkali.
[0014]
  Further, when the porous filtration membrane 3 is washed, a means for vibrating or swinging the porous filtration membrane 3 is provided so that the upstream surface of the porous filtration membrane 3 is washed by vibrating or shaking. The effect can be improved. Further, when the means for vibrating or rocking is the ultrasonic wave generating means 7, the porous filtration membrane 3 can be vibrated or rocked with a simple configuration.
[0015]
  Further, if the means for vibrating or swinging is the Karman vortex generating means 8, the porous filtration membrane 3 can be vibrated or rocked with a simple configuration such as setting the position of the supply port of the cleaning liquid. If the fluid element 9 is a means for vibrating or rocking, the porous filtration membrane 3 can be vibrated or rocked with a simple configuration.
[0016]
  Further, if the porous filtration membrane 3 has a distance that can be rubbed with each other during vibration or swinging, the upstream of the adjacent porous filtration membrane 3 when the porous filtration membrane 3 is vibrated or swinged. The foreign surfaces adhering to the upstream side surface of the porous filtration membrane 3 by rubbing each other side will be wiped off, and cleaning can be performed effectively..
[0017]
  Also,When the activated carbon filtration unit 11 is provided on the downstream side of the porous filtration membrane 3, organic matter and inorganic matter in the raw water are filtered by the porous filtration membrane 3, and the organic matter and inorganic matter in the raw water adhere to the surface of the activated carbon filtration unit 11. Thus, the original adsorption performance of the activated carbon can be maintained.
[0018]
  In addition, since the porous filtration membrane 3 is arranged on the outer peripheral portion of the activated carbon filtration portion 11, the porous filtration membrane 3 is located on the outside, and as a result, the porous filtration membrane 3 can be easily washed. become.
[0019]
  In addition, according to the method for cleaning a porous filtration membrane in the water purifier of the present invention, the raw water supplied from the raw water inlet 1 into the housing 2 is filtered by the porous filtration membrane 3 built in the housing 2 and filtered water outlet. 4 is a method for cleaning the porous filtration membrane 3 in the water purifier discharged from the water purifier 4. After stopping the filtration operation of filtering the raw water through the porous filtration membrane 3, the cleaning liquid is supplied into the housing 2 to supply the porous filtration membrane 3. The upstream surface of the porous filtration membrane 3 is washed, and the washing liquid after washing the upstream surface of the porous filtration membrane 3 is discharged from the upstream side of the porous filtration membrane 3 to the outside of the housing 2, thereby easily performing the porous filtration. The upstream surface of the membrane 3 can be washed with a cleaning liquid and discharged from the upstream side of the porous filtration membrane 3.Further, when the porous filtration membrane 3 is cleaned, the upstream side of the porous filtration membrane 3 is filtered with the cleaning liquid by simultaneously performing the cleaning by the backflow of water or air from the downstream side of the porous filtration membrane 3. Further, a flow that attempts to separate the blockage closing the surface on the upstream side of the porous filtration membrane 3 from the downstream side of the porous filtration membrane 3 is formed, and more effective cleaning can be performed.
[0020]
  In addition, it has been experimentally known that if the cleaning is performed too frequently, the degree of performance recovery is low. This is because very small particles that cannot be removed by cleaning always accumulate on the surface of the film by frequent cleaning. I think it is because it will be followed. Therefore, when the flow rate of the raw water passing through the porous filtration membrane 3 immediately after the previous cleaning of the porous filtration membrane 3 is reduced to about half the flow rate, the porous filtration membrane 3 is rewashed. Infrequent cleaning
Very small particles are filtered by the large particles attached to the membrane first, and are removed together with the large particles adhering to the upstream surface of the porous filtration membrane 3 during cleaning. Will be.
[0021]
  In addition, by washing the porous filtration membrane 3 after a certain time has elapsed after performing the filtration operation with the porous filtration membrane 3, the filtration operation with the porous filtration membrane 3 is performed until a certain time elapses. During this time, there is a difference in the concentration of the filtration material between the inside and the outside of the porous filtration membrane 3, and when the flow is stopped, reverse osmosis can be performed to restore the performance. The cleaning effect can be enhanced by washing with.
[0022]
【Example】
  Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings. 1 and 2 show an example of the water purifier of the present invention. Reference numeral 2 denotes a water purifier housing, and a porous filtration membrane 3 is internally provided therein. Raw water is supplied into the housing 2 from a raw water inlet 1 provided in the housing 2, and the porous filtration membrane is provided in the housing 2. The filtrate is filtered by 3 and the filtrate is discharged from a filtrate outlet 4 provided in the housing 2. That is, in FIG. 1, raw water is supplied from the direction of arrow A, filtered by the porous filtration membrane 3, and the filtered water is discharged in the direction of arrow B.
[0023]
  aboveWater purifierThe housing 2 is provided with a cleaning liquid supply port 5 for supplying a cleaning liquid into the housing 2 on the upstream side of the porous filtration membrane 3, and further, after cleaning the upstream surface of the porous filtration membrane 3. A discharge port 6 for discharging the cleaning liquid to the outside of the housing 2 on the upstream side of the porous filtration membrane 3 is provided. Here, in the embodiment shown in the accompanying drawings, as shown in FIG. 2, the porous filtration membrane 3 housed in the housing 2 is made of a hollow fiber membrane, and each membrane 3a is U-shaped and bundled at both ends and potted. Configured. When the interior of the housing 2 is installed, the potting portion 12 serves as a partition for partitioning the interior of the housing 2, and the interior of the potting portion 12 is positioned on the upstream side and the potting portion 12 is positioned on the downstream side.
[0024]
  An open / close valve 13 is provided on the raw water inlet 1 side, and open / close valves 14 and 15 are provided on the cleaning liquid supply port 5 side and the discharge port 6 side, respectively. In order to perform the filtration operation, when the on-off valve 13 is opened with the on-off valves 14 and 15 closed, raw water is supplied from the raw water inlet 1, filtered through the porous filtration membrane 3, and filtered water from the filtrate outlet 4. Is discharged. And the fine particle contained in raw | natural water adheres to the upstream side of the porous filtration membrane 3 by filtration operation, and clogging continues. Therefore, in the present invention, when the porous filtration membrane 3 is clogged, the performance is recovered by washing the porous filtration membrane 3. In this case, with the on-off valve 13 closed, the on-off valves 14 and 15 are opened, the cleaning liquid is supplied from the cleaning liquid supply port 5 to the upstream side of the porous filtration membrane 3 in the housing 2, and the porous filtration membrane is supplied by this cleaning liquid. 3 is cleaned, and the cleaning liquid after cleaning is discharged out of the housing 2 from the discharge port 6 on the upstream side of the porous filtration membrane 3. That is, in FIG. 1, the cleaning liquid is supplied from the direction of arrow C, the surface on the upstream side of the porous filtration membrane 3 is cleaned, and then discharged from the discharge port 6 as indicated by arrow D. In this case, an on-off valve may be provided on the filtered water outlet 4 side so that the on-off valve is closed during the cleaning. By washing the upstream surface of the porous filtration membrane 3 in this way, particles adhering mainly to the upstream surface of the porous filtration membrane 3 during the filtration operation can be effectively washed and discharged. It will be possible. In this case, by adopting a configuration in which the cleaning liquid is jetted onto the porous filtration membrane 3 at a high speed, it is possible to clean the deposits adhering to the upstream surface of the porous filtration membrane 3 at a high speed and with high efficiency by the kinetic energy of the cleaning liquid. Become.
[0025]
  Here, when the porous filtration membrane 3 is washed, it is possible to prevent foreign matters from adhering to the downstream surface of the porous filtration membrane 3 as in the conventional case of back washing from the downstream side of the porous filtration membrane 3. Therefore, it is not necessary to use filtered water once filtered, and raw water before filtration can be used directly. In other words, the raw water that is subject to filtration by the water purifier can be used as it is as the washing liquid. In this case, the filtered water once filtered as in the past is used.
A complicated structure of storing and flowing for backwashing is not necessary, and the structure is simplified.
[0026]
  The cleaning water is not limited to the above raw water, and the use of warm water (which may be heated to heat the raw water) improves the cleaning effect. Further, a surfactant can be used as the cleaning liquid. In this case, it is possible to effectively wash when the fat and oil are adhered to the porous filtration membrane 3. An acid such as dilute hydrochloric acid can also be used as the cleaning liquid. When an acid is used, the inorganic component adhering to the porous filtration membrane 3 can be effectively dissolved and removed. Moreover, alkalis, such as sodium hydroxide aqueous solution, can also be used as a washing | cleaning liquid. When alkali is used, the organic component adhering to the porous membrane 3 can be effectively dissolved and removed.
[0027]
  Here, the acid or alkali used as the washing water may be acidic water or alkaline water obtained by electrolysis. In this case, as shown in FIG. 9, an ion water conditioner 16 called an alkali ion water conditioner is connected to the upstream side of the cleaning liquid supply port 5, and either acidic water or alkaline water generated by the ion water conditioner 16 is connected. You may make it supply to the washing | cleaning-liquid supply port 5 side as a washing | cleaning liquid.
[0028]
  And in this invention, a washing | cleaning liquid is supplied to the upstream of the porous filtration membrane 3, and the porous filtration membrane 3 is supplied. In order to clean the upstream surface of the liquid and discharge the washed liquid after the cleaning on the upstream side of the porous filtration membrane 3, as shown in FIG. Air feeding means 10 is provided. Due to the movement of air, a flow is generated in which the adhering material adhering to the upstream surface of the porous filtration membrane 3 tends to be separated from the downstream side toward the upstream side, and can be effectively washed.
[0029]
  By the way, as described above, the cleaning liquid is supplied to the upstream side of the porous filtration membrane 3 to clean the surface on the upstream side of the porous filtration membrane 3, and the cleaned cleaning liquid is discharged on the upstream side of the porous filtration membrane 3. In doing so, more effective cleaning can be achieved by providing means for vibrating or swinging the porous filtration membrane 3 during cleaning. In FIG. 1, the cleaning liquid supply port 5 is opened in the radial direction of the porous filtration membrane 3 bundled in a substantially columnar shape, and with this positional relationship, the cleaning liquid supplied from the cleaning liquid supply port 5 The flow flowing along the outer periphery of the porous filtration membrane 3 generates a Karman vortex, which causes the porous filtration membrane 3 to vibrate or oscillate. Therefore, in this embodiment, the structure itself of the cleaning liquid supply port 5 opened in the radial direction of the porous filtration membrane 3 bundled in a substantially cylindrical shape is the Karman vortex generating means 8.
[0030]
  In the embodiment shown in FIG. 3, an example in which a fluid element 9 is provided as means for vibrating or swinging the cleaning liquid supply port 5 is shown. The fluid element 9 is as shown in FIG. 4, and the cleaning liquid flowing from the inlet 17 oscillates in the oscillation type fluid element 9, and is separated into the outlet 18 a and the outlet 18 b of the porous filtration membrane 3 in the housing 2. The liquid flows into the upstream side, and thus the porous filtration membrane 3 is washed while being vibrated or swung.
[0031]
  Further, as a means for vibrating or swinging, an ultrasonic wave generating means 7 may be used as shown in FIG. In this apparatus, an ultrasonic wave is generated by the ultrasonic wave generating means 7 during cleaning to vibrate or swing.While lettingIt is washed. Here, when the upstream surface of the porous filtration membrane 3 is washed with the washing liquid while vibrating or swinging the porous filtration membrane 3, the membrane single body 3a constituting the porous filtration membrane 3 is adjacent to the single membrane. 3a and an appropriate fixed distance X (shown in FIG. 2) are maintained. The distance X is a distance at which the porous filtration membranes 3 can rub against each other when the porous filtration membrane 3 is vibrated and cleaned by vibration or rocking means. Here, if the distance X is too short, the effect of rubbing is reduced. Therefore, the distance X is obtained by the method of vibrating or swinging and the rigidity of the film. Then, as described above, the porous filtration membrane 3 is vibrated or rocked by the vibrating or rocking means.
When cleaning by moving the porous filtration membrane 3, the particles adhering to the upstream surface of the porous filtration membrane 3 are peeled off to make the cleaning effect more reliable..
[0032]
  1 to FIG.6The figure8In the embodiment, an example in which only the porous filtration membrane 3 is housed in the housing 2 of the water purifier is shown.6The figure8Then, although illustration is abbreviate | omitted, you may equip the housing 2 with the activated carbon filtration part 11 further. In this case, the active end charcoal filtration unit 11 may be disposed on the upstream side of the porous filtration membrane 3, but the activated carbon filtration unit 11 may be provided on the downstream side of the porous filtration membrane 3. When the activated carbon filtration unit 11 is provided on the downstream side of the porous filtration membrane 3, the dust in the raw water is filtered by the porous filtration membrane 3, and organic or inorganic waste in the raw water adheres to the surface of the activated carbon filtration unit 11. The original adsorption performance of the activated carbon can be kept intact, and the deterioration of the original adsorption performance of the activated carbon can be greatly reduced. In this case, it is inevitable that clogging of the porous filtration membrane 3 is accelerated as compared with the case where the activated carbon filtration unit 11 is arranged on the upstream side of the porous filtration membrane 3, but the clogging of the porous filtration membrane 3 is unavoidable. As described above, the performance recovery by the cleaning is performed by supplying the cleaning liquid to the upstream side of the porous filtration membrane 3 to clean the upstream surface of the porous filtration membrane 3, and washing the cleaned liquid after the cleaning of the porous filtration membrane 3. By discharging on the upstream side, the performance can be recovered simply and reliably.
[0033]
  Here, in using the porous filtration membrane 3 and the activated carbon filtration part 11 together,7When the porous filtration membrane 3 is arranged on the outer peripheral portion of the activated carbon filtration portion 11 as shown in FIG. 3, the porous filtration membrane 3 is located on the outside, so that the porous filtration membrane 3 can be easily cleaned. . Figure7The arrow indicates the direction in which the raw water flows. By the way, the washing | cleaning method of the porous filter membrane 3 of the water purifier in this invention supplies the washing | cleaning liquid in the housing 2, after stopping the filtration operation which filters raw | natural water with the porous filtration membrane 3 as already stated. The upstream surface of the porous filtration membrane 3 is washed, and the washing liquid after washing the upstream surface of the porous filtration membrane 3 is discharged out of the housing 2 from the upstream side of the porous filtration membrane 3. In this cleaning, the porous filtration membrane 3 is rewashed when the flow rate drops to about half of the flow rate of the raw water passing through the porous filtration membrane 3 immediately after the previous porous filtration membrane 3 washing. It is preferable to do so. That is, according to the experiment of the present inventor, it is confirmed that the degree of performance recovery is lowered when cleaning is performed too frequently. This is probably because very small particles that cannot be removed by washing always adhere to and accumulate on the upstream surface of the porous filtration membrane 3 by frequent washing. On the other hand, in the case of infrequent cleaning, very small particles are captured by the large particles adhering to the upstream side surface of the porous filtration membrane 3 in advance, and thus the upstream side of the porous filtration membrane 3. It is considered that the very small particles trapped by the large particles are removed together when the surface is cleaned with the cleaning liquid, and the cleaning effect is enhanced. In view of this result, as a measure of the cleaning frequency, when the flow rate is reduced to about half of the flow rate of the raw water passing through the porous filtration membrane 3 immediately after the previous porous filtration membrane 3 was washed, the porous filtration membrane By performing the re-washing of 3, the filtration life can be extended.
[0034]
  Moreover, normally, when filtering with the porous filtration membrane 3, it has been experimentally confirmed that when the filtration is interrupted, the filtration performance is recovered and the life is prolonged so that it can be used continuously. This is because there is a difference in the concentration of the filtration material between the inside and the outside of the porous filtration membrane 3, and reverse osmosis occurs when the flow is stopped. As a result, the cleaning timing of the porous filtration membrane 3 is not immediately after the filtration operation by the porous filtration membrane 3 but is performed immediately before the next filtration, for example, so that the reverse of the filtration operation after the filtration operation is performed. If it is made the structure which earns time for infiltration and aims at performance recovery, a water purifier with a high washing effect can be obtained. In this case, the porous filtration membrane 3 may be washed after a predetermined time has passed since the filtration operation by the porous filtration membrane 3 is finished as the timing of washing the porous filtration membrane 3.
[0035]
  AndThe present inventionIsThen, after the filtration operation of filtering the raw water through the porous filtration membrane 3 is stopped, the cleaning liquid is supplied into the housing 2 to clean the upstream surface of the porous filtration membrane 3.
In the cleaning method of discharging the cleaning liquid after cleaning the upstream surface from the upstream side of the porous filtration membrane 3 to the outside of the housing 2, the cleaning liquid from the downstream side of the porous filtration membrane 3 is washed when the porous filtration membrane 3 is cleaned.airSimultaneous cleaning with reverse flowBy doingIn addition to cleaning the upstream surface of the porous filtration membrane 3 with the cleaning liquid upstream, the porous filtration membrane 3 is clogged by using a reverse flow from the downstream side to the upstream side of the porous filtration membrane 3 together. Can be effectively eliminated.
[0036]
【The invention's effect】
  In the invention described in claim 1 of the present invention, in the water purifier for filtering the raw water supplied from the raw water inlet into the housing through the porous filtration membrane built in the housing and discharging the raw water from the filtered water outlet, A cleaning liquid after cleaning the upstream surface of the porous filtration membrane while providing a cleaning liquid supply port for supplying the cleaning liquid into the housing on the upstream side of the porous filtration membrane in order to clean the upstream surface of the filtration membrane A discharge port is provided on the upstream side of the porous filtration membrane to discharge it from the housing.In addition, an opening / closing valve that is closed during filtration operation and opened during cleaning is provided on each of the cleaning liquid supply port side and the discharge port side, and that is opened during filtration operation and closed during cleaning on each of the raw water inlet side and the filtrate outlet side. ProvidedTherefore, clogging substances mainly adhering to the upstream surface of the porous filtration membrane can be efficiently removed by washing on the upstream side,In addition, since air feeding means for feeding air is provided on the downstream side of the porous filtration membrane, the surface on the upstream side of the porous filtration membrane is washed with a cleaning liquid, and is also washed by bubbling. Can be effectively cleaned by the effective cleaning effect, especially from the downstream side. By allowing air to flow upstream through the porous filtration membrane, the adhering material adhering to the upstream surface can be peeled off, and can be effectively washed away with the cleaning liquid on the upstream side.In addition, there is no risk that the clogged material that has been removed without being discharged through the porous filtration membrane will clog the porous filtration membrane again, and it will be backwashed as before. In comparison, it is not necessary to use filtered water as a cleaning liquid.
[0037]
  Further, in the invention described in claim 2, in addition to the effect of the invention described in claim 1, since the cleaning liquid is raw water, the filtered water is stored as compared with the conventional case using the filtered water as the cleaning liquid. Therefore, a complicated apparatus for backwashing is not necessary, and the configuration of the apparatus can be simplified. In addition, in the invention described in claim 3, in addition to the effect of the invention described in claim 1, since the cleaning liquid is warm water, the cleaning efficiency of the porous filtration membrane is improved.
[0038]
  Further, in the invention described in claim 4, in addition to the effect of the invention described in claim 1, when the cleaning liquid is a surfactant, the oil and fat can be effectively cleaned. Further, in the invention according to claim 5, in addition to the effect of the invention according to claim 1, the washing liquid is an acid such as dilute hydrochloric acid, an aqueous solution of sodium hydroxide, or acidic water or alkaline water by electrolysis of water. Any of the above can be washed by dissolving and removing mainly inorganic components by using an acid, and by dissolving and removing mainly organic components by using an alkali, and by electrolysis In the case of acidic water or alkaline water, acidic water or alkaline water can be easily supplied by a configuration in which an ion water conditioner is connected.
[0039]
  In addition, in the invention according to claim 6, in addition to the effect of the invention according to claim 1, in cleaning the porous filtration membrane, means for vibrating or oscillating the porous filtration membrane is provided. When cleaning the upstream surface of the porous filtration membrane with the cleaning liquid, the adhered material adhering to the upstream surface can be removed and washed away by washing while vibrating or shaking the porous filtration membrane. Effective cleaning is possible.
[0040]
  In addition, in the invention described in claim 7, in addition to the effect of the invention described in claim 6, since the means for vibrating or swinging is an ultrasonic wave generating means, the porous filtration membrane is vibrated with a simple configuration. It can be swung. Further, in the invention described in claim 8, in addition to the effect of the invention described in claim 6, since the means for vibrating or swinging is the Karman vortex generating means,
The porous filtration membrane can be vibrated or oscillated with a simple configuration such as setting the position of the supply port.
[0041]
  In addition, in the invention according to claim 9, in addition to the effect of the invention according to claim 6, the means for vibrating or swinging is a fluid element, so that the porous filtration membrane is vibrated or shaken with a simple configuration. It can be moved. In addition, in the invention according to claim 10, in addition to the effect of the invention according to any one of claims 6 to 9, the distance that the porous filtration membranes can rub against each other during vibration or swinging is set. Therefore, when the porous filtration membrane is vibrated or swung, the upstream surfaces of the adjacent porous filtration membranes rub against each other to remove foreign substances adhering to the upstream surface of the porous filtration membrane. It will be effectively wiped off and can be cleaned more effectively.
[0042]
  Also,Claim 11In the described invention, in addition to the effect of the invention described in claim 1, since the activated carbon filtration section is provided on the downstream side of the porous filtration membrane, organic substances and inorganic substances in the raw water are filtered by the porous filtration membrane. In addition, organic and inorganic substances in the raw water adhere to the surface of the activated carbon filtration part so that the original adsorption performance of the activated carbon is not impaired, and the adhering substance adhering to the upstream side of the porous filtration membrane is effectively washed with the cleaning liquid. And can be played easily.
[0043]
  Claims12In the described invention, in addition to the effect of the invention described in claim 1, since the porous filtration membrane is arranged on the outer peripheral portion of the activated carbon filtration portion, the porous filtration membrane is located outside. Therefore, it is easy to clean the porous filtration membrane.
[0044]
  Claims13In the described invention, there is provided a method for cleaning a porous filtration membrane in a water purifier in which raw water supplied from the raw water inlet into the housing is filtered by a porous filtration membrane built in the housing and discharged from the filtered water outlet. Then, after the filtration operation of filtering the raw water through the porous filtration membrane is stopped, the cleaning liquid is supplied into the housing to clean the upstream surface of the porous filtration membrane, and the upstream surface of the porous filtration membrane is cleaned. Since the cleaning liquid after cleaning is discharged from the upstream side of the porous filtration membrane to the outside of the housing, the surface on the upstream side of the porous filtration membrane can be cleaned and regenerated by a simple method.In addition, when cleaning the porous filtration membrane, since the cleaning by the backflow of air from the downstream side of the porous filtration membrane is performed at the same time, when filtering the upstream surface of the porous filtration membrane with the cleaning liquid, A flow that attempts to separate the blockage blocking the upstream surface of the porous filtration membrane from the porous filtration membrane is formed, and more effective cleaning can be performed.
[0045]
  Claims14In the described invention, the claims13In addition to the effects of the described invention, when the flow rate of the raw water passing through the porous filtration membrane immediately after washing the porous filtration membrane is reduced to about half the flow rate of the raw water, the porous filtration membrane is washed again. Because, as already mentioned, very small particlesTheLarge particles previously attached to the film can be captured as a filter, and very small particles can be washed together with large particles during washing.
[0046]
  Claims15In the described invention, the claims13In addition to the effects of the described invention, since the porous filtration membrane is washed after a certain time has elapsed after performing the filtration operation with the porous filtration membrane, the filtration operation with the porous filtration membrane is performed for a certain time. In the meantime, there is a difference in the concentration of the filtration material between the inside and outside of the porous filtration membrane, and when the flow is stopped, reverse osmosis can be achieved to restore performance. The cleaning effect can be enhanced by cleaning at the time.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an embodiment of a water purifier according to the present invention.
FIG. 2 is a schematic sectional view of the above.
FIG. 3 is a schematic configuration diagram of another embodiment of the present invention.
FIG. 4 is a cross-sectional view of a fluidic device used for the above.
FIG. 5 is a schematic cross-sectional view of still another embodiment of the present invention.
[Fig. 6]It is a schematic sectional drawing of this invention.
[Fig. 7]It is the schematic perspective view which fractured | ruptured partially which shows the Example which has arrange | positioned the porous filtration membrane in the outer peripheral part of the activated carbon filtration part of this invention.
[Fig. 8]It is a schematic sectional drawing of other Example of this invention.
[Explanation of symbols]
1 Raw water entrance
2 Housing
3 Porous filtration membrane
4 Filtrated water outlet
5 Cleaning liquid supply port
6 outlet
7 Ultrasonic wave generation means
8 Karman vortex generation means
9 Fluid element
10 Air feeding means
11 Activated carbon filtration section

Claims

In order to clean the upstream surface of the porous filtration membrane in a water purifier that filters the raw water supplied from the raw water inlet into the housing through the porous filtration membrane built in the housing and discharges it from the filtered water outlet. A cleaning liquid supply port for supplying a cleaning liquid into the housing is provided on the upstream side of the filtration membrane, and the cleaning liquid after cleaning the upstream surface of the porous filtration membrane is discharged out of the housing on the upstream side of the porous filtration membrane. And an opening / closing valve that is closed at the time of filtration operation and opened at the time of cleaning, and opened at the time of filtration operation at the raw water inlet side and the filtrate water outlet side, respectively. A water purifier comprising an on-off valve that is closed at the time of washing, and an air feeding means for feeding air downstream of the porous filtration membrane .

The water purifier according to claim 1, wherein the cleaning liquid is raw water.

The water purifier according to claim 1, wherein the cleaning liquid is warm water.

The water purifier according to claim 1, wherein the cleaning liquid is a surfactant.

The water purifier according to claim 1, wherein the cleaning liquid is one of an acid such as dilute hydrochloric acid, an aqueous sodium hydroxide solution, or acidic water or alkaline water obtained by electrolysis of water.

The water purifier according to claim 1, further comprising means for vibrating or swinging the porous filtration membrane in cleaning the porous filtration membrane.

The water purifier according to claim 6, wherein the means for vibrating or swinging is an ultrasonic wave generating means.

The water purifier according to claim 6, wherein the means for vibrating or swinging is Karman vortex generating means.

The water purifier according to claim 6, wherein the means for vibrating or swinging is a fluid element.

The water purifier according to any one of claims 6 to 9, wherein the water purifier has a distance that allows the porous filtration membranes to rub against each other during vibration or swinging.

The water purifier according to claim 1, wherein an activated carbon filtration part is provided on the downstream side of the porous filtration membrane.

A porous filtration membrane is placed on the outer periphery of the activated carbon filtration part.
The water purifier according to claim 1.

A method for cleaning a porous filtration membrane in a water purifier that filters raw water supplied from a raw water inlet into a housing through a porous filtration membrane built in the housing and discharges the raw water from the filtered water outlet. After the filtration operation is stopped, the cleaning liquid is supplied into the housing to clean the upstream surface of the porous filtration membrane, and the air from the downstream side of the porous filtration membrane is washed when the porous filtration membrane is washed. The porous filtration membrane in the water purifier is characterized by discharging the cleaning liquid after washing the upstream side of the porous filtration membrane from the upstream side of the porous filtration membrane to the outside of the housing. Cleaning method.

The porous filtration membrane is rewashed when the flow rate is reduced to about half of the flow rate of raw water passing through the porous filtration membrane immediately after the previous washing of the porous filtration membrane. The washing | cleaning method of the porous filtration membrane in the water purifier of description.

The method for washing a porous filtration membrane in a water purifier according to claim 13, wherein the porous filtration membrane is washed after a predetermined time has elapsed after the filtration operation with the porous filtration membrane.