JP3807676B2

JP3807676B2 - Ion exchange membrane electrolytic cell

Info

Publication number: JP3807676B2
Application number: JP2003041267A
Authority: JP
Inventors: 眞二片山; 勝森; 雅和亀田
Original assignee: Chlorine Engineers Corp Ltd
Current assignee: ThyssenKrupp Nucera Japan Ltd
Priority date: 2002-02-20
Filing date: 2003-02-19
Publication date: 2006-08-09
Anticipated expiration: 2023-02-19
Also published as: JP2003313690A

Description

【０００１】
【発明の属する技術分野】
本発明はイオン交換膜電解槽に関するものであり、とくに複極式フィルタープレス型イオン交換膜電解槽に関するものである。
【０００２】
【従来の技術】
複極式のフィルタープレス型イオン交換膜電解槽は、陽極室隔壁と陰極室隔壁とを機械的および電気的に接合した電解槽ユニットをイオン交換膜を介して多数積層したものが用いられている。
【０００３】
図８は、従来のイオン交換膜電解槽を説明する図である。
図８（Ａ）は、複極式イオン交換膜電解槽の電解槽ユニットの陽極室側から見た図であり、図８（Ｂ）は、断面図であり、図８（Ａ）においてＡ−Ａで切断した断面図である。
単位電解槽５１の陽極室５２および陰極室５３を形成する、陽極室隔壁５４および陰極室隔壁５５には、それぞれ所定の間隔で陽極リブ５６、および陰極リブ５７が接合され、陽極リブ５６には陽極５８が取り付けられている。また、陰極リブ５７には、陰極５９が取り付けられている。
【０００４】
イオン交換膜電解槽は、縦方向には１ｍ余の高さを有し、また横方向にも２ｍ余の幅を有しているので、電気分解を効率的に行なうためには、電極室内での電解液の濃度分布を小さくすることが求められている。電極室内での濃度分布を小さくするためには、電解液の循環用のポンプを外部に配置して電解液を循環する方法もあるが、電気分解によって発生する気体の浮力を利用して内部循環を行う方法は、循環用ポンプを必要としない方法である。そして、内部循環を円滑に進めるために電極室内に内部循環用の部材を配置することが提案されている。
ところが、陽極リブ、陰極リブとは別に電極室内に内部循環用の部材を配置することは電解槽の構成に必要な部材を多く必要とし、また内部循環の性能も不充分なものであった。
【０００５】
図９は、従来の他の構造のイオン交換膜電解槽を説明する図である。
図９（Ａ）は、複極型イオン交換膜電解槽の単位電解槽の陽極室側から見た図であり、図９（Ｂ）は、隔壁板の斜視図である。
図９に示す電解槽は、本出願人が特開平５−９７７４号公報等において提案した複極式イオン交換膜電解槽である。
電解槽ユニット５１の陽極室５２および陰極室を形成する陽極室隔壁５４および陰極室隔壁に同様の形状の凹凸部を形成して、凹凸部によって陽極室隔壁５４と陰極室隔壁が互いにかみ合って一体化され、凹部６０に沿って電極で発生した気体と電解液との気液混相流体が上昇するとともに、電極室内に設けた電解液循環路形成部材６１と陽極室隔壁５４との間を電解液が下降することによって電解槽内での内部循環を行ったものである。この電解槽においては、電解液循環路が電解液循環路形成部材と、凹凸状の隔壁との間に形成される空間であるために、電解液の循環の面において改良の余地があった。
【０００６】
【発明が解決しようとする課題】
本発明は、イオン交換膜電解槽において、陽極室および陰極室内での発生気体の上昇および気体を分離した後に下降流を利用した電解液の内部循環が良好で、電気分解効率が良好で、剛性が大きなイオン交換膜電解槽を提供することを課題とするものである。
【０００７】
【課題を解決するための手段】
本発明の課題は、イオン交換膜電解槽において、平板状の陽極室隔壁と平板状の陰極室隔壁とが接合され、少なくとも一方の隔壁に、帯状の接合部を形成して接合され、隣接する接合部の間には電極を接合した凸条部を設けた板状の電極保持部材を有し、該電極保持部材の接合部と凸条部の間がそれぞれ一つの平面で結合されて、該電極保持部材の電極面側の空間は電極室内の流体の上昇流路を形成し、その反対側の空間は、電極室の上部で気体を分離した電解液の下降流路を形成し、陽極保持部材、陰極保持部材のいずれか一方がバネ性の部材から形成され、バネ性の部材が隔壁との接合部側とは反対側へ突出した少なくとも三個の凸条部を有し、凸条部のうち押圧した際の変位量が最も大きな凸条部は、一部を切り欠くことによって形成されており、該変位量が最も大きな凸条部の最大開角度を開角度とする凸条部保護部材が変位量が最も大きな凸条部に結合されているイオン交換膜電解槽によって解決することができる。
【０００９】
凸条部のうち押圧した際に変位量が最も大きな凸条部に電極を接合した前記のイオン交換膜電解槽である。
変位量が最も大きな凸条部は、凸条部の一部を切り欠くことによって形成した前記のイオン交換膜電解槽である。
接合部に近接する凸条部に電極が接触する際に、変位量が最も大きな凸条部の開角度を最大開角度とする凸条部保護部材が変位量の最も大きな凸条部に結合されている前記のイオン交換膜電解槽である。
変位量が最も大きな凸条部に接合した電極を隔壁側へ押圧した場合に、接合部に隣接する凸条部によって電極の移動が制限を受ける前記のイオン交換膜電解槽である。
【００１０】
このように、凸条部に電極を接合すると共に、凸条部に開角度を制限する部材を設けることによって対向する電極との間の電極間距離を所定の大きさに設定することを可能とすると共に、圧力変動によって対極室側から押圧した場合にも、凸条部の開角度が制限されて、大きく変形することを防止することができる。
【００１１】
【発明の実施の形態】
本発明のイオン交換膜電解槽は、陽極室と陰極室とを区画する隔壁をそれぞれ平板状とし、平板状の各隔壁に隔壁との間に帯状の接合部を形成して接合され、隣接する接合部の間には電極を接合した凸条部を設けた板状の電極保持部材を設けたので、電極保持部材は電極を保持する単位電解槽の構造部材としての作用を果たして電解槽の剛性を高めるとともに、電解液の循環路が電極室の全面にわたり配置されるので、電極室内での電解液の循環をより十分なものとして電解効率を高めたものである。
【００１２】
以下に、図面を参照して本発明を説明する。
図１は、本発明のイオン交換膜電解槽の一実施例を説明する図である。
図１（Ａ）は、複数個の電解槽ユニットを積層したイオン交換膜電解槽の断面を説明する図であり、図１（Ｂ）は、陽極室側から電解槽ユニットを見た図である。また、図１（Ｂ）において、Ａ−Ａ線で切断した断面図を図１（Ｃ）に示す。
図１（Ａ）に示すように、イオン交換膜電解槽１は複数の複極式の電解槽ユニット２のフランジ面３にガスケット４を配置し、イオン交換膜５を介して積層して組み立てられており、一方の端部には陰極室側のみを有する陰極室ユニット２Ａを有し、他方の端部には陽極室側のみを有する陽極室ユニット２Ｂを有している。
電解槽ユニット２の陽極室６には、陽極室隔壁８から間隔を設けて陽極１５が配置されている。陰極室７には、陰極室隔壁９から間隔を設けて陰極２０が配置されており、陰極室側隔壁９とイオン交換膜５の間に陰極室７が形成されている。
【００１３】
また、陽極室６、陰極室７の上部には、それぞれ陽極室側気液分離室３０、陰極室側気液分離室３７が設けられている。
イオン交換膜電解槽の複極式の電解槽ユニット２は、陽極室６と陰極室７とから構成されており、陽極室６および陰極室７は、それぞれ平板状の陽極室隔壁８と陰極室隔壁９が電気的および機械的に接合一体化されている。
【００１４】
陽極室隔壁８には、陽極保持部材１０が帯状の接合部１１を形成して接合されており、帯状の接合部１１において陽極室隔壁８と陽極保持部材１０が密着して接合されている。両者は、連続的な溶接部によって接合されていなくても、両者を密着した状態で多数のスポット溶接部１２によって接合することによって陽極保持部材１０と陽極室隔壁８とが密着し、両者の導電接続と陽極保持部材１０と陽極室隔壁８の間で形成される空間が反対側の空間と分離されていればよい。
陽極保持部材１０の隣接する帯状の接合部１１の間には凸条部１３が形成され、凸条部１３と帯状の接合部１１の間は平面部１４で結合されている。また、凸状部１３には、陽極１５が複数の個所において接合されており、陽極１５の保持と陽極１５への電気分解電流の通電が行なわれている。
【００１５】
凸条部１３は、頂部に電極を接合することができる幅を有していれば十分であり、金属板に角を設けて折り曲げ加工して形成された凸条部であっても、電極保持部材が隔壁に平行な平面であっても良い。陽極保持部材を別個の部材として作製しても、プレス成形によって複数個が連結した部材を作製しても良く、あるいは陽極室隔壁に配置するすべての陽極保持部材を、一枚の金属板を成形して製造したものであっても良い。
また、接合部１１と凸状部１３とが平面部１４で結合されている場合には、断面形状がトラス型となり、薄板で作製した陽極室の剛性を高めることができる。
【００１６】
陽極保持部材１０、陽極室隔壁８および隣接する帯状の接合部１１によって形成される空間には、陽極液循環通路１６が形成され、陽極保持部材１０の陽極１５面側の空間を上昇した気液混合流体が陽極室の上部で気液分離した電解液の一部は陽極液排出口１９から流出する。また、その他の部分は陽極液循環通路１６を下降し、陽極電極室の下部において陽極面側の空間へ流出し、電解槽ユニットに設けた陽極液供給管１７から供給されて陽極液噴出口１８から陽極室内へ噴出する陽極液とともに混合されて陽極１５において電気分解を受ける。
【００１７】
一方、陰極室７には、図１（Ｃ）に示すように、陰極２０が陰極室隔壁９に接合された陰極保持部材２１に取り付けられ、陰極室隔壁９と陰極保持部材２１との間に陰極液循環通路２２が形成されている。
陰極室隔壁９に接合した陰極保持部材２１はバネ性の部材であり、陰極保持部材２１は、陰極液循環通路２２の流通方向に直角の面で切断した断面図は、左右対称であって、陰極２０を取り付けた凸条部２３の両側の帯状の接合部２４において陰極室隔壁９と接合されているとともに、接合部２４に隣接して接合部側凸条部２５が設けられており、陰極２０を取り付けた凸条部２３が両側の接合部側凸条部２５に比べて対極面側に突出している。また、バネ性の部材であるので陰極２０とイオン交換膜面との間隔を所定の大きさに保持することができる。
【００１８】
本発明のイオン交換膜電解槽は、陽極室と陰極室とを区画する隔壁をそれぞれ平板状とし、平板状の各隔壁に隔壁との間に帯状の接合部を形成し、隣接する接合部の間には電極を接合した凸条部を設けた板状の電極保持部材を設けたので、電解液の循環路を隔壁の全面にわたり配置することができるので電極室内での電解液の循環が十分に行われる剛性の大きな電解槽とすることができる。
また、図１（Ｃ）に示したように、陽極室隔壁８と陽極保持部材１０との接合部１１の背面側の陰極室隔壁９に陰極保持部材２１との接合部２４を設けることが好ましい。これによって陽極側から陰極側への電流の通電経路を短くすることができるので好ましい。
【００１９】
図２は、本発明のイオン交換膜電解槽の電解液循環機構の一例を説明する図である。
図２（Ａ）は、図１（Ａ）において、Ｂ−Ｂ線での断面を説明する図であり、電解槽の上部に設けた気液分離室を説明する図である。
陽極室の電気分解領域よりも上部には陽極側気液分離室３０を有しており、陽極側気液分離室３０の陽極室隔壁８側には、電気分解領域と陽極側気液分離室３０とを連通する隔壁側通路３１を有している。陽極側気液分離室３０内を部分的に上下に分離する断面がＬ字状の第一区画部材３２が配置され、また第１区画部材とは、陽極側気液分離室内での高さが異なる位置から隔壁側から延びて陽極側気液分離室３０内を部分的に上下に分離する断面がＬ字状の第二区画部材３３が配置されており、第一区画部材３２と第二区画部材３３の間には上下に連通路３４が形成されている。
【００２０】
電気分解によって発生した気泡を含有した気液混相流体は、陽極保持部材１０と陽極１５との間に形成された空間を上昇し、隔壁側通路３１および連通路３４から陽極側気液分離室３０へと流入し、発生気体を分離した電解液は陽極保持部材の上端部を越えて陽極室隔壁と陽極保持部材によって形成された陽極液循環通路１６を陽極室の下方へと下降する。
【００２１】
陽極側気液分離室３０に設ける第一区画部材３２および第二区画部材３３は、陽極室の構造体を構成する陽極室枠体の一部を兼ねたものとしても良く、また陽極側気液分離室３０内部に仕切り板３５を設けるとともに、仕切り板３５を陽極室枠体を兼ねた第一区画部材３２および第二区画部材３３に接合することにより、単位電解槽を積層して電解槽を組み立てる際に単位電解槽の荷重による変形を防止し、剛性の大きな電解槽とすることができる。
【００２２】
また、陰極室の電気分解領域の上部には、陰極側気液分離室３７が設けられており、陰極２０と陰極保持部材２１によって形成された空間を上昇した気液混相流体は、気体を分離した後に、陰極保持部材２１と陰極室隔壁９とによって形成された、陰極液循環通路２０を陰極室の下方へ下降する。
陰極側気液分離室３７の内部にも、陰極室の構造体を構成する陰極室枠体３８の一部を設け、陰極室枠体３８に仕切り板３９を所定の間隔で設けることによって、陰極室枠体３８の電解槽を積層した際の荷重による変形を防止し、剛性の大きな電解槽とすることができる。
【００２３】
図２（Ｂ）は、図１（Ａ）において、Ｃ−Ｃ線での断面を説明する図であり、電解槽の下部の電解液の循環機構を説明する図である。
また、電解槽の下部の陽極保持部材１０には下降液噴出口４０が設けられており、気液分離室で気体を分離して陽極保持部材１０と陽極室隔壁８とによって形成された陽極液循環通路１２を下降した陽極液が下降液噴出口４０から電極室内へ噴出し、陽極液供給管に連結された陽極室の下部に設けた陽極液供給通路４１を通じて陽極液噴出口１８から陽極室内へ噴出する陽極液をとともに混合されて陽極１１面において電気分解を受ける。
【００２４】
同様に、陰極室の下部には、陰極保持部材２１の下部の開口部から下降した陰極液が噴出するとともに、陰極液供給管に連結した陰極液供給通路４２を通じて陰極液噴出口４３から陰極室内へ噴出する陰極液とともに、陰極２０において電気分解を受ける。
また、電解槽ユニット２の下部には、電解槽の機械的な構造を保持し、電解槽の剛性を保つ電解槽枠体４４を有している。
【００２５】
なお、以上の説明では、電極室内での気泡の影響、および電解液の濃度分布の影響を受けやすい陽極室において、より気液分離性能と電解液の循環性能に優れた気液分離室を設ける例について説明をしたが、陰極側気液分離室においても陽極側気液分離室と同様の構造の気液分離室を設けても良い。
【００２６】
図３は、本発明のイオン交換膜電解槽の他の実施例を説明する図である。
図３（Ａ）は、陽極室側から電解槽ユニットを見た図である。また、図３（Ａ）において、Ａ−Ａ線で切断した断面図を図３（Ｂ）に示す。
電解槽ユニット２は、陽極室６と陰極室７とから構成されており、陽極室６および陰極室７は、それぞれ平板状の陽極室隔壁８と陰極室隔壁９が電気的、および機械的に接合一体化されている。
陽極室隔壁８には、陽極保持部材１０が帯状の接合部１１を形成して接合されている。帯状の接合部１１において陽極室隔壁８と陽極保持部材１０が密着して接合されている。陽極保持部材１０は、接合部１１に接続された縦方向部１０Ａと、縦方向部に直角に交わる陽極室隔壁８に平行な横方向部１０Ｂとから構成されており、横方向部１０Ｂには凸条部１３が形成され、凸条部１３には陽極１５が複数の個所において接合されており、陽極保持部材１０を通じた陽極１５の保持と陽極１５への電気分解電流の通電が行なわれる。
【００２７】
凸条部１３は、頂部に電極を接合することができる幅を有しておれば十分であり、図３（Ｂ）に示すように金属板を山型に加工する際に形成された頂部であっても、あるいは頂部が平坦な形状を有しているものであっても良い。陽極室隔壁８と陽極保持部材１０は、帯状の接合部によって陽極液循環通路１６を形成している。
図３で示す形状の陽極保持部材１０は、接合部に連なる縦方向部１０Ａの高さ、あるいは角度を変化させることによって、陽極液循環通路１６の断面積を調整することが容易であり、陽極室の断面積に占める陽極液循環通路１６の断面積を任意の割合とすることができる。
【００２８】
また、平板状の陽極室隔壁８の全幅に均一に陽極保持部材１０に接合し、陽極保持部材１０の凸状部１３に陽極１５を接合することにより陽極室内での循環を均一なものとするとともに、強度が大きな電解槽とすることができる。
陽極保持部材１０の陽極１５面側の空間を上昇した気液混合流体が陽極室の上部で気液分離した電解液が、陽極液循環通路１６を下降し、電極室の下部において電極面側の空間へ流出し、電解槽に設けた陽極液供給管１７から供給されて、陽極液噴出口１８から電極室内へ噴出する陽極液とともに陽極１５において電気分解を受ける。
【００２９】
陰極室７には、図１（Ｂ）で示したものと同様に、陰極２０が陰極室隔壁９に接合された陰極保持部材２１に取り付けられ、陰極室隔壁９と陰極保持部材２１との間に陰極液循環通路２２が形成されている。
陰極室隔壁９に接合した陰極保持部材２１はバネ状の部材であり、陰極保持部材２１は、陰極液循環通路２２の流通方向に直角の面で切断した断面図は、左右対称であって、陰極２０を取り付けた凸条部２３の両側の帯状の接合部２４において陰極室隔壁９と接合されているとともに、接合部２４に隣接して接合部側凸条部２５が設けられており、陰極２０を取り付けた凸条部２３が両側の凸条部２５に比べて大きく対極面側に突出しており、陰極２０とイオン交換膜面との距離を小さく保持する作用を果たしている。
【００３０】
図４は、本発明のイオン交換膜電解槽の電解液循環機構の他の例を説明する図である。
図４（Ａ）は、図３（Ａ）において、Ｂ−Ｂ線での断面を説明する図であり、電解槽の上部に設けた気液分離室の他の例を説明する図である。
陽極室の電気分解領域よりも上部には陽極側気液分離室３０を有しており、陽極側気液分離室３０の陽極室隔壁８側には、電気分解領域と陽極側気液分離室３０とを連通する隔壁側通路３１を有し、陽極面側から延びて隔壁側通路３１の壁面を形成する部材と接合された陽極側気液分離室３０内を上下に分離する区画部材３６を有している。
【００３１】
電気分解によって発生した気泡を含有した気液混相流体は、陽極保持部材１０と陽極１５との間に形成された空間を上昇し、隔壁側通路３１から陽極側気液分離室３０へと流入し、発生気体を分離した電解液は陽極保持部材の上端部を越えて陽極室隔壁と陽極保持部材によって形成された陽極液循環通路１６を陽極室の下方へと下降する。
【００３２】
陽極側気液分離室３０に設ける区画部材３６は、陽極室の構造体を構成する陽極室枠体の一部を兼ねたものとしても良く、また陽極側気液分離室３０内部に仕切り板３５を設けるとともに、仕切り板３５を陽極室枠体を兼ねた区画部材３６に接合することにより、単位電解槽を積層して電解槽を組み立てる際に単位電解槽の荷重による変形を防止し、剛性の大きな電解槽とすることができる。
【００３３】
また、陰極室の電気分解領域の上部には、陰極側気液分離室３７が設けられており、陰極２０と陰極保持部材２１によって形成された空間を上昇した気液混相流体は、気体を分離した後に陰極保持部材２１と陰極室隔壁９とによって形成された陰極液循環通路２２を陰極室の下方へ下降する。
陰極側気液分離室３７の内部にも、陰極室の構造体を構成する陰極室枠体３８の一部を設け、陰極室枠体３８に仕切り板３９を所定の間隔で設けることによって、陰極室枠体３８の電解槽を積層した際の荷重による変形を防止し、剛性の大きな電解槽とすることができる。
【００３４】
また、図４（Ｂ）に、図３（Ａ）における、Ｃ−Ｃ線での断面を説明する図を示すように、電解槽の下部の陽極保持部材１０には下降液噴出口４０が設けられており、陽極液は気液分離室で気体を分離し陽極保持部材１０と陽極室隔壁８とによって形成された陽極液循環通路１６を下降し、下降液噴出口４０から電極室内へ噴出して電解槽の下部に設けた陽極液供給通路４１から供給されて陽極液噴出口１８から陽極室内へ噴出する陽極液とともに混合されて陽極１５において電気分解を受ける。
【００３５】
同様に、陰極室７の下部には、陰極保持部材２１の下部の開口部から下降した陰極液が噴出するとともに、陰極液供給通路４２を通じて供給されて陰極液噴出口４３から陰極室内へ噴出する陰極液とともに、陰極２０において電気分解を受ける。
また、イオン交換膜電解槽１の下部には、電解槽の機械的な構造を保持し、電解槽の剛性を保つ電解槽枠体４４を有している。
【００３６】
図５は、本発明のイオン交換膜電解槽の他の実施例を説明する図である。
図５（Ａ）は、陽極室側から電解槽ユニットを見た図である。また、図５（Ａ）において、Ａ−Ａ線で切断した断面図を図５（Ｂ）に示す。
イオン交換膜電解槽の複極式の電解槽ユニット２は、陽極室６と陰極室７とから構成されており、陽極室６および陰極室７は、それぞれ平板状の陽極室隔壁８と陰極室隔壁９が電気的および機械的に接合一体化されている。
【００３７】
陽極室隔壁８には、陽極保持部材１０が帯状の接合部１１を形成して接合されており、帯状の接合部１１において陽極室隔壁８と陽極保持部材１０が密着して接合されている。両者は連続した溶接部によって溶接されて接合されていなくても良い。すなわち両者を密着した状態で多数のスポット溶接部１２によって接合することによって陽極保持部材１０と陽極室隔壁８とが密着し、両者の導電接続と陽極保持部材１０と陽極室隔壁８の間で形成される空間が反対側の空間と分離されている。
【００３８】
陽極保持部材１０の隣接する帯状の接合部１１の間には凸条部１３が形成され、凸条部１３と帯状の接合部１１の間は平面部１４で結合されている。また、凸状部１３には、陽極１５が複数の個所において接合されており、陽極１５の保持と陽極への電気分解電流の通電が行なわれている。
【００３９】
凸条部１３は、頂部に電極を接合することができる幅を有しておれば十分であり、金属板を三角形状に折り曲げ加工することによって形成された凸条部であっても、隔壁に平行な面を有する凸条部であっても良い。陽極保持部材を別個の部材として作製しても、プレス成形によって複数個が連結した部材を作製しても良く、あるいは陽極室隔壁に配置するすべての陽極保持部材を、一枚の金属板のプレス成型によって製造したものであっても良い。
【００４０】
また、陰極室７の陰極保持部材２１は、隣接する接合部２４の間には少なくとも三個の、隔壁との接合部とは反対側へ突出した凸条部を形成した可撓性の電極支持部材を有し、該凸条部のうち陰極室隔壁方向への押圧時の変位量が最も大きな凸条部２３に電極が接合されており、接合部側凸条部２５が接合部２４とは９０度近傍の角度をなしている。
【００４１】
これにより、電解槽の運転時に何らかの原因で陰極室側の圧力が低くなり、イオン交換膜が陽極室側から陰極側へ押し付けられた場合にも、陰極２０は凸状部２３よりも変位量が小さな接合部側凸状部２５おいても保持されることとなり、陰極２０あるいは陰極保持部材２１が回復しがたい変形を生じることを防止することができる。
【００４２】
図６は、図５で示した押圧時の陰極の挙動を説明する図である。
電解槽の運転中の圧力異常時に陽極室側の圧力が陰極室側の圧力に比べて大きくなると、イオン交換膜によって陰極面に作用する圧力によって、陰極保持部材２１が陰極室隔壁９側へ変位するが、陰極保持部材２１の陰極室隔壁９とは反対側へ突出した凸条部のうち陰極室隔壁側への変位量が最も大きな凸条部２３に陰極２０が接合されているので、図６（Ａ）に示すように、陰極２０が陰極室隔壁９側へ押圧力Ｆで押圧された場合には、接合部の両側に位置する接合部側凸条部２５は、押圧時の変位量が小さいので、陰極を接合した凸条部の開角度θが大きくなり、陰極２０が陰極室隔壁９側へ変位する。
【００４３】
そして、図６（Ｂ）に示すように、接合部側凸条部２５の高さ、および変位量と、陰極２０を接合した凸条部２３の変位量、陰極を接合した凸条部の両側に形成した陰極室隔壁側へ向かって突出した凹条部２６の大きさを調整することによって、陰極面が接合部側凸条部２５に接した際に、同時に凹条部２６の先端が陰極室隔壁９に接触するように設定することによって陰極に加わる圧力を多数の接触点で分散するようにすることができる。
【００４４】
また、陰極保持部材に陰極を接合した凸条部の変位量は、陰極保持部材の他の部分に比べて押圧時の変形を大きくするためには、凸条部２３の一部、もしくは全部の厚みを小さくしたり、図６（Ｃ）に、陰極保持部材の斜視図を示すように、凸条方向に沿って横長の孔２７を形成する等の方法によって実現することができる。
【００４５】
その結果、押圧された場合には凸条部は比較的小さな圧力によって開角度θが大きくなり陰極隔壁方向へ変形するものとなる。
小さな押圧力によって変位する凸条部に装着した陰極は、通常の電解槽の運転時には、陰極面に近接して配置してもイオン交換膜面を大きな圧力で押圧してイオン交換膜に損傷を及ぼす等の怖れはなく、安定した運転が可能となる。
【００４６】
図７は、本発明のイオン交換膜電解槽の他の実施例を説明する図である。
図７（Ａ）は、陽極室側から電解槽ユニットを見た図である。また、図７（Ｂ）において、Ａ−Ａ線で切断した断面図を図７（Ｂ）に示す。
イオン交換膜電解槽の複極式の電解槽ユニット２は、陽極室６と陰極室７とから構成されており、陽極室６および陰極室７は、それぞれ平板状の陽極室隔壁８と陰極室隔壁９が電気的および機械的に接合一体化されている。
【００４７】
陽極室隔壁８には、陽極保持部材１０が帯状の接合部１１を形成して接合されており、帯状の接合部１１において陽極室隔壁８と陽極保持部材１０が密着して接合されている。両者は線状の溶接部によって溶接されて接合されていなくても、両者を密着した状態で多数のスポット溶接部１２において接合することによって陽極保持部材１０と陽極室隔壁８とが密着し、両者の導電接続と陽極保持部材１０と陽極室隔壁８の間で形成される空間が反対側の空間と分離されていればよい。
陽極保持部材１０の隣接する帯状の接合部１１の間には凸条部１３が形成され、凸条部１３と帯状の接合部１１の間は平面部１４で結合されている。また、凸状部１３には、陽極１５が複数の個所において接合されており、陽極１５の保持と陽極への電解電流の通電が行なわれている。
【００４８】
また、陰極室７の陰極保持部材２１は、隣接する接合部２４の間には少なくとも三個の、隔壁との接合部側とは反対側へ突出した凸条部を形成した可撓性の電極支持部材を有し、該凸条部のうち陰極室隔壁方向への押圧時の変位量が最も大きな凸条部２３には、凸条の方向に横長の開口部を間隔を設けて形成し、凸条部２３の変位を大きくするとともに、凸条部保護部材２８を配置したものである。凸条部保護部材２８を設けることによって、陰極保持部材２１の変位量を大きくするために凸条部２３の厚みを薄くしたり、凸条に沿って開口部を設けたことによって、凸条部２３への陰極２０の溶接個所が不確実となることを防止することができる。
【００４９】
また、凸条部保護部材２８の開角度θは、陰極が接合部側凸条部２５と接触する凸条部の最大開角度とすることが好ましい。この様にすることによって、押圧されて凸条部が開いた場合にも、凸条部が大きく変形することを防止する。また、凸条部保護部材は、陰極保持部材に比べて厚みが大きく、剛性が大きな材料で作製することにより、陰極に異常に大きな圧力が加わった際に凸条部が大きく変形することを制限し、陰極の変形を防止する作用をより大きなものとすることができる。
【００５０】
また、接合部２４と接合部側凸条部２５を結ぶ面が陰極室隔壁となす角度は、９０度以上、１００度以下とすることが好ましく、これによって接合部側凸条部２５は陰極が押圧された場合に陰極保持部材の変形を小さくすることができ、陰極２０あるいは陰極保持部材２１が回復しがたい変形を生じることを防止することができる。
【００５１】
本発明のイオン交換膜電解槽は、上記した陽極室と陰極室を有する複極式の電解槽ユニットの複数個を積層し、両端部には、陰極室のみを有する陰極側端部電解槽と陽極室のみを有する陽極側端部電解槽を積層することによって作製することができる。
【００５２】
本発明のイオン交換膜電解槽の陽極室隔壁には、チタン、タンタル、ジルコニウム等の薄膜形成性金属あるいはこれらの合金を用いることができる。陽極には、チタン、タンタル、ジルコニウム等の薄膜形成性金属あるいはこれらの合金の表面に、白金族金属、白金族金属の酸化物を含有する電極触媒物質の被覆を形成した陽極を用いることができる。
【００５３】
また、陰極室隔壁には、ニッケル、ニッケル合金等を用いることができ、陰極には、ニッケル、ニッケル合金の多孔体、網状体、エキスパンデッドメタル、あるいはこれらを基体として、表面に白金族金属含有層、ラネーニッケル含有層、活性炭含有ニッケル層等の電極触媒物質の被覆を形成し、水素過電圧を低下させたものを用いることができる。また、陰極液循環通路形成部材は、陰極室隔壁と同一の材料を用いることができる。
【００５４】
また、陽極保持部材、陰極保持部材は、それぞれ陽極室隔壁、陰極室隔壁と同一の材料を用いて作製することができ、個別に作製した陽極保持部材、陰極保持部材を、陽極室隔壁、陰極室隔壁に接合したものでも、あるいは複数個の陽極保持部材、陰極保持部材、あるいはすべての陽極保持部材、陰極保持部材を一体にプレス成形によって作製して、それぞれ陽極室隔壁、陰極室隔壁に接合しても良い。
【００５５】
本発明のイオン交換膜電解槽をアルカリ金属ハロゲン化物の水溶液の電気分解、例えば食塩水の電気分解に用いる場合には、陽極室には、飽和食塩水を供給し、陰極室には水または希薄水酸化ナトリウム水溶液を供給し、所定の分解率で電気分解を行った後に電解槽から取り出される。
また、食塩水のイオン交換膜電解槽による電気分解においては、陰極室の圧力を陽極室の圧力よりも高く保持して電気分解が行われ、イオン交換膜は陽極に密着した状態で運転が行われるが、陰極保持部材はバネ性の部材であって変位量が大きな凸条部に陰極が接合されているので、陰極をイオン交換膜面に所定の距離に近づけて電気分解をすることができることができる。
【発明の効果】
本発明のイオン交換膜電解槽によれば、平板状の陽極室隔壁と陰極室隔壁を帯状の接合部を形成して接合され、隣接する接合部の間には電極を接合した凸条部を有する板状の電極保持部材を設けたので、電極保持部材の電極面側の空間は電極室内の流体の上昇流路を形成し、隔壁側の空間は電極室内の流体の下降通路を電極室内の全面に形成したので、電解液の循環を効率的に行うことが可能であるとともに、電極保持部材を全面に配置したので、剛性の大きなイオン交換膜電解槽を得ることができる。
【図面の簡単な説明】
【図１】図１は、本発明のイオン交換膜電解槽の一実施例を説明する図である。
【図２】図２は、本発明のイオン交換膜電解槽の電解液循環機構の一例を説明する図である。
【図３】図３は、本発明のイオン交換膜電解槽の他の実施例を説明する図である。
【図４】図４は、本発明のイオン交換膜電解槽の電解液循環機構の他の例を説明する図である。
【図５】図５は、本発明のイオン交換膜電解槽の他の実施例を説明する図である。
【図６】図６は、図５で示した押圧時の陰極の挙動を説明する図である。
【図７】図７は、本発明のイオン交換膜電解槽の他の実施例を説明する図である。
【図８】図８は、従来のイオン交換膜電解槽を説明する図である。
【図９】図９は、従来の他の構造のイオン交換膜電解槽を説明する図である。
【符号の説明】
１…イオン交換膜電解槽、２…電解槽ユニット、２Ａ…陰極室ユニット、２Ｂ…陽極室ユニット、３…フランジ面、４…ガスケット、５…イオン交換膜、６…陽極室、７…陰極室、８…陽極室隔壁、９…陰極室隔壁、１０…陽極保持部材、１０Ａ…縦方向部、１０Ｂ…横方向部、１１…接合部、１２…スポット溶接部、１３…凸条部、１４…平面部、１５…陽極、１６…陽極液循環通路、１７…陽極液供給管、１８…陽極液噴出口、１９…陽極液排出口、２０…陰極、２１…陰極保持部材、２２…陰極液循環通路、２３…凸条部、２４…接合部、２５…接合部側凸条部、２６…凹条部、２７…横長の孔、２８…凸条部保護部材、３０…陽極室側気液分離室、３１…隔壁側通路、３２…第一区画部材、３３…第二区画部材、３４…連通路、３５…仕切り板、３６…区画部材、３７…陰極室側気液分離室、３８…陰極室枠体、３９…仕切り板、４０…下降液噴出口、４１…陽極液供給通路、４２…陰極液供給通路、４３…陰極液噴出口、４４…電解槽枠体、Ｆ…押圧力、θ…開角度[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ion exchange membrane electrolytic cell, and more particularly to a bipolar filter press type ion exchange membrane electrolytic cell.
[0002]
[Prior art]
A bipolar filter-press type ion exchange membrane electrolytic cell is used in which a large number of electrolytic cell units in which an anode chamber partition wall and a cathode chamber partition wall are mechanically and electrically joined are laminated via an ion exchange membrane. .
[0003]
FIG. 8 is a diagram for explaining a conventional ion exchange membrane electrolytic cell.
FIG. 8 (A) is a view as seen from the anode chamber side of the electrolytic cell unit of the bipolar ion exchange membrane electrolytic cell, FIG. 8 (B) is a cross-sectional view, and FIG. It is sectional drawing cut | disconnected by A. FIG.
An anode rib 56 and a cathode rib 57 are bonded to the anode chamber partition wall 54 and the cathode chamber partition wall 55 forming the anode chamber 52 and the cathode chamber 53 of the unit electrolytic cell 51 at predetermined intervals, respectively. An anode 58 is attached. A cathode 59 is attached to the cathode rib 57.
[0004]
Since the ion exchange membrane electrolytic cell has a height of about 1 m in the vertical direction and a width of about 2 m in the horizontal direction, in order to perform electrolysis efficiently, It is required to reduce the concentration distribution of the electrolyte. In order to reduce the concentration distribution in the electrode chamber, there is a method to circulate the electrolyte solution by arranging a pump for circulating the electrolyte solution. However, the internal circulation is performed using the buoyancy of the gas generated by electrolysis. This is a method that does not require a circulation pump. In order to facilitate the internal circulation, it has been proposed to arrange an internal circulation member in the electrode chamber.
However, disposing an internal circulation member in the electrode chamber separately from the anode rib and the cathode rib requires many members necessary for the construction of the electrolytic cell, and the internal circulation performance is insufficient.
[0005]
FIG. 9 is a diagram illustrating an ion exchange membrane electrolytic cell having another conventional structure.
FIG. 9A is a view seen from the anode chamber side of the unit cell of the bipolar ion exchange membrane electrolytic cell, and FIG. 9B is a perspective view of the partition plate.
The electrolytic cell shown in FIG. 9 is a bipolar ion exchange membrane electrolytic cell proposed by the present applicant in Japanese Patent Laid-Open No. 5-9774.
The anode chamber partition wall 54 and the cathode chamber partition wall forming the anode chamber 52 and the cathode chamber of the electrolytic cell unit 51 are formed with uneven portions having the same shape, and the anode chamber partition wall 54 and the cathode chamber partition wall are meshed with each other by the uneven portion. The gas-liquid mixed phase fluid of the gas and the electrolyte generated at the electrode along the recess 60 rises, and the electrolyte between the electrolyte circulation path forming member 61 and the anode chamber partition wall 54 provided in the electrode chamber The internal circulation in the electrolytic cell is carried out by lowering. In this electrolytic cell, since the electrolyte circulation path is a space formed between the electrolyte circulation path forming member and the uneven partition wall, there is room for improvement in terms of electrolyte circulation.
[0006]
[Problems to be solved by the invention]
In the ion exchange membrane electrolytic cell, the present invention provides a good rise in the generated gas in the anode chamber and the cathode chamber and good internal circulation of the electrolyte using the downflow after separating the gas, good electrolysis efficiency, and rigidity. An object of the present invention is to provide a large ion exchange membrane electrolytic cell.
[0007]
[Means for Solving the Problems]
An object of the present invention is to provide a plate-like anode chamber partition and a plate-like cathode chamber partition which are joined in an ion exchange membrane electrolytic cell, and are joined to each other by forming a strip-like joint on at least one partition. There is a plate-like electrode holding member provided with a protruding strip portion to which an electrode is bonded between the bonding portions, and the bonding portion of the electrode holding member and the protruding strip portion are respectively coupled with one plane, The space on the electrode surface side of the electrode holding member forms an ascending flow path for the fluid in the electrode chamber, and the space on the opposite side forms a descending flow path for the electrolyte that separates the gas in the upper part of the electrode chamber, and holds the anode Either the member or the cathode holding member is formed of a spring-like member, and the spring-like member has at least three ridges projecting to the side opposite to the joint side with the partition wall, The protrusion with the largest displacement when pressed is formed by cutting out a part. The ridge protection member having the maximum opening angle of the ridge having the largest displacement as the opening angle is solved by an ion exchange membrane electrolytic cell in which the ridge having the largest displacement is coupled. Can do.
[0009]
It is the said ion exchange membrane electrolytic cell which joined the electrode to the protruding item | line part with the largest displacement amount when pressing among protruding item | lines.
The protruding portion having the largest displacement is the ion exchange membrane electrolytic cell formed by cutting out a part of the protruding portion.
When the electrode comes into contact with the protruding portion adjacent to the joint, the protruding portion protection member having the maximum opening angle of the protruding portion with the largest displacement amount is coupled to the protruding portion with the largest displacement amount. It is the said ion exchange membrane electrolytic cell.
In the ion exchange membrane electrolytic cell, the movement of the electrode is restricted by the convex portion adjacent to the joint portion when the electrode joined to the convex portion having the largest displacement amount is pressed toward the partition wall.
[0010]
In this way, it is possible to set the distance between the electrodes to a predetermined size by joining the electrodes to the ridges and providing a member that limits the opening angle on the ridges. In addition, even when pressed from the counter electrode chamber side due to pressure fluctuations, the opening angle of the ridges is limited, and it is possible to prevent large deformation.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In the ion exchange membrane electrolytic cell of the present invention, the partition walls partitioning the anode chamber and the cathode chamber are each formed in a flat plate shape, and each flat plate partition wall is bonded by forming a band-shaped joint between the partition walls. Since the plate-like electrode holding member provided with the protruding strip portion to which the electrode is joined is provided between the joint portions, the electrode holding member serves as a structural member of the unit electrolytic cell for holding the electrode, and the rigidity of the electrolytic cell. In addition, since the circulation path of the electrolytic solution is disposed over the entire surface of the electrode chamber, the electrolytic efficiency is enhanced by making the circulation of the electrolytic solution in the electrode chamber more satisfactory.
[0012]
The present invention will be described below with reference to the drawings.
FIG. 1 is a view for explaining an embodiment of the ion exchange membrane electrolytic cell of the present invention.
FIG. 1A is a diagram for explaining a cross section of an ion exchange membrane electrolytic cell in which a plurality of electrolytic cell units are stacked, and FIG. 1B is a diagram of the electrolytic cell unit viewed from the anode chamber side. . In addition, a cross-sectional view taken along line AA in FIG. 1B is illustrated in FIG.
As shown in FIG. 1A, the ion exchange membrane electrolytic cell 1 is assembled by arranging gaskets 4 on the flange surfaces 3 of a plurality of bipolar electrolytic cell units 2 and laminating them through the ion exchange membrane 5. One end portion includes a cathode chamber unit 2A having only the cathode chamber side, and the other end portion includes an anode chamber unit 2B having only the anode chamber side.
An anode 15 is disposed in the anode chamber 6 of the electrolytic cell unit 2 at a distance from the anode chamber partition wall 8. In the cathode chamber 7, a cathode 20 is arranged at a distance from the cathode chamber partition wall 9, and the cathode chamber 7 is formed between the cathode chamber side partition wall 9 and the ion exchange membrane 5.
[0013]
An anode chamber side gas-liquid separation chamber 30 and a cathode chamber side gas-liquid separation chamber 37 are provided above the anode chamber 6 and the cathode chamber 7, respectively.
The bipolar electrolytic cell unit 2 of the ion exchange membrane electrolytic cell is composed of an anode chamber 6 and a cathode chamber 7, and the anode chamber 6 and the cathode chamber 7 are respectively a plate-like anode chamber partition wall 8 and a cathode chamber. The partition wall 9 is joined and integrated electrically and mechanically.
[0014]
An anode holding member 10 is bonded to the anode chamber partition wall 8 by forming a band-shaped joint portion 11, and the anode chamber partition wall 8 and the anode holding member 10 are closely bonded to each other at the band-shaped joint portion 11. Even if they are not joined by a continuous welded portion, the anode holding member 10 and the anode chamber partition 8 are brought into close contact with each other by joining them with a large number of spot welded portions 12 in close contact with each other. The space formed between the connection and anode holding member 10 and the anode chamber partition wall 8 may be separated from the opposite space.
A protruding strip portion 13 is formed between the adjacent strip-shaped joint portions 11 of the anode holding member 10, and the convex strip portion 13 and the strip-shaped joint portion 11 are joined by a flat portion 14. Further, the anode 15 is joined to the convex portion 13 at a plurality of locations, and the anode 15 is held and the electrolysis current is supplied to the anode 15.
[0015]
It is sufficient that the ridge 13 has a width that allows the electrode to be joined to the top, and even if the ridge is formed by bending a metal plate with a corner, the electrode holding The member may be a plane parallel to the partition wall. The anode holding member may be manufactured as a separate member, a plurality of members connected by press molding may be manufactured, or a single metal plate may be formed for all anode holding members arranged in the anode chamber partition wall. And may be manufactured.
Moreover, when the junction part 11 and the convex-shaped part 13 are couple | bonded by the plane part 14, a cross-sectional shape becomes a truss type, and the rigidity of the anode chamber produced with the thin plate can be improved.
[0016]
An anolyte circulation passage 16 is formed in the space formed by the anode holding member 10, the anode chamber partition wall 8, and the adjacent band-shaped joint portion 11, and the gas-liquid that has moved up the space on the anode 15 surface side of the anode holding member 10. A part of the electrolytic solution obtained by gas-liquid separation of the mixed fluid in the upper part of the anode chamber flows out from the anode solution discharge port 19. Further, the other part descends the anolyte circulation passage 16 and flows out into the space on the anode surface side in the lower part of the anode electrode chamber, and is supplied from the anolyte supply pipe 17 provided in the electrolytic cell unit and is supplied with the anolyte outlet 18. And mixed with the anolyte sprayed into the anode chamber and undergoes electrolysis at the anode 15.
[0017]
On the other hand, in the cathode chamber 7, as shown in FIG. 1C, a cathode 20 is attached to a cathode holding member 21 joined to the cathode chamber partition wall 9, and between the cathode chamber partition wall 9 and the cathode holding member 21. A catholyte circulation passage 22 is formed.
The cathode holding member 21 joined to the cathode chamber partition wall 9 is a spring member, and the cathode holding member 21 is symmetrical in cross section taken along a plane perpendicular to the flow direction of the catholyte circulation passage 22. The strip-shaped joint portions 24 on both sides of the ridge portion 23 to which the cathode 20 is attached are joined to the cathode chamber partition wall 9, and a joint portion-side ridge portion 25 is provided adjacent to the joint portion 24. The ridge portion 23 to which 20 is attached protrudes to the counter electrode surface side as compared to the joint-side ridge portions 25 on both sides. Further, since it is a spring member, the distance between the cathode 20 and the ion exchange membrane surface can be maintained at a predetermined size.
[0018]
In the ion exchange membrane electrolytic cell of the present invention, the partition walls partitioning the anode chamber and the cathode chamber are each formed in a flat plate shape, and a strip-shaped junction is formed between the partition walls on each of the flat partition walls. Since a plate-like electrode holding member provided with protruding strips joined with electrodes is provided between the electrodes, the electrolyte circulation path can be arranged over the entire surface of the partition wall, so that the electrolyte is sufficiently circulated in the electrode chamber. It is possible to provide a highly rigid electrolytic cell.
Further, as shown in FIG. 1C, it is preferable to provide a junction 24 with the cathode holding member 21 in the cathode chamber partition 9 on the back side of the junction 11 between the anode chamber partition 8 and the anode holding member 10. . This is preferable because the current supply path from the anode side to the cathode side can be shortened.
[0019]
FIG. 2 is a diagram illustrating an example of an electrolyte solution circulation mechanism of the ion exchange membrane electrolytic cell of the present invention.
FIG. 2A is a view for explaining a cross section taken along line BB in FIG. 1A, and is a view for explaining a gas-liquid separation chamber provided in the upper part of the electrolytic cell.
The anode side gas-liquid separation chamber 30 is provided above the electrolysis region of the anode chamber, and the electrolysis region and the anode-side gas-liquid separation chamber are disposed on the anode chamber partition wall 8 side of the anode side gas-liquid separation chamber 30. 30 has a partition wall side passage 31 communicating with 30. A first partition member 32 having an L-shaped cross section that partially separates the inside of the anode side gas-liquid separation chamber 30 vertically is disposed, and the first partition member has a height in the anode-side gas-liquid separation chamber. A second partition member 33 having an L-shaped section extending from the partition side and partially separating the anode-side gas-liquid separation chamber 30 in the vertical direction is disposed from the different positions. A communication path 34 is formed between the members 33 in the vertical direction.
[0020]
The gas-liquid mixed phase fluid containing bubbles generated by electrolysis rises in the space formed between the anode holding member 10 and the anode 15, and passes through the partition-side passage 31 and the communication passage 34 to the anode-side gas-liquid separation chamber 30. The electrolyte that has flowed into and separated the generated gas passes over the upper end of the anode holding member and descends below the anode chamber through the anolyte circulation passage 16 formed by the anode chamber partition and the anode holding member.
[0021]
The first partition member 32 and the second partition member 33 provided in the anode side gas-liquid separation chamber 30 may also serve as a part of the anode chamber frame constituting the structure of the anode chamber. A partition plate 35 is provided inside the separation chamber 30, and the partition plate 35 is joined to the first partition member 32 and the second partition member 33 that also serve as the anode chamber frame, thereby stacking the unit electrolytic cells to form the electrolytic cell. When assembled, the unit electrolytic cell can be prevented from being deformed by a load, and a highly electrolytic cell can be obtained.
[0022]
In addition, a cathode side gas-liquid separation chamber 37 is provided above the electrolysis region of the cathode chamber, and the gas-liquid mixed phase fluid rising in the space formed by the cathode 20 and the cathode holding member 21 separates the gas. After that, the catholyte circulation passage 20 formed by the cathode holding member 21 and the cathode chamber partition wall 9 is lowered to the lower side of the cathode chamber.
A part of the cathode chamber frame 38 constituting the structure of the cathode chamber is also provided inside the cathode side gas-liquid separation chamber 37, and the partition plate 39 is provided at a predetermined interval on the cathode chamber frame 38, thereby providing a cathode. It is possible to prevent deformation due to a load when the electrolytic cells of the chamber frame 38 are stacked, and to obtain a highly rigid electrolytic cell.
[0023]
FIG. 2B is a view for explaining a cross section taken along line CC in FIG. 1A, and is a view for explaining an electrolyte solution circulation mechanism at the lower part of the electrolytic cell.
Further, the anode holding member 10 at the lower part of the electrolytic cell is provided with a descending liquid jet 40, and an anolyte formed by the anode holding member 10 and the anode chamber partition 8 by separating the gas in the gas-liquid separation chamber. The anolyte descending the circulation passage 12 is ejected from the descending liquid outlet 40 into the electrode chamber, and from the anolyte outlet 18 through the anolyte supply passage 41 provided below the anode chamber connected to the anolyte supply pipe. The anolyte spouted out is mixed together and electrolyzed on the surface of the anode 11.
[0024]
Similarly, the catholyte descending from the opening at the bottom of the cathode holding member 21 is ejected to the lower part of the cathode chamber, and from the catholyte outlet 43 through the catholyte supply passage 42 connected to the catholyte supply pipe. It undergoes electrolysis at the cathode 20 together with the catholyte spouted out.
Further, below the electrolytic cell unit 2, there is an electrolytic cell frame 44 that maintains the mechanical structure of the electrolytic cell and maintains the rigidity of the electrolytic cell.
[0025]
In the above description, a gas-liquid separation chamber having better gas-liquid separation performance and electrolyte circulation performance is provided in the anode chamber that is easily affected by bubbles in the electrode chamber and the concentration distribution of the electrolyte. Although an example has been described, a gas-liquid separation chamber having the same structure as that of the anode-side gas-liquid separation chamber may be provided in the cathode-side gas-liquid separation chamber.
[0026]
FIG. 3 is a view for explaining another embodiment of the ion exchange membrane electrolytic cell of the present invention.
FIG. 3A is a view of the electrolytic cell unit viewed from the anode chamber side. 3A is a cross-sectional view taken along line AA in FIG.
The electrolytic cell unit 2 is composed of an anode chamber 6 and a cathode chamber 7, and the anode chamber 6 and the cathode chamber 7 are electrically and mechanically composed of a flat anode chamber partition wall 8 and a cathode chamber partition wall 9, respectively. Bonded and integrated.
An anode holding member 10 is joined to the anode chamber partition wall 8 by forming a band-like joining portion 11. The anode chamber partition wall 8 and the anode holding member 10 are in close contact with each other at the band-shaped joint portion 11. The anode holding member 10 is composed of a longitudinal portion 10A connected to the joining portion 11 and a transverse portion 10B parallel to the anode chamber partition wall 8 that intersects the longitudinal portion at a right angle. A protruding portion 13 is formed, and an anode 15 is bonded to the protruding portion 13 at a plurality of locations, and the anode 15 is held through the anode holding member 10 and electrolysis current is supplied to the anode 15.
[0027]
It is sufficient that the ridge 13 has a width that allows the electrode to be joined to the top, and the top formed when the metal plate is processed into a chevron as shown in FIG. Or the top may have a flat shape. The anode chamber partition wall 8 and the anode holding member 10 form an anolyte circulation passage 16 by a band-shaped joint.
The anode holding member 10 having the shape shown in FIG. 3 can easily adjust the cross-sectional area of the anolyte circulation passage 16 by changing the height or angle of the longitudinal portion 10A connected to the joint portion. The cross-sectional area of the anolyte circulation passage 16 occupying the cross-sectional area of the chamber can be set to an arbitrary ratio.
[0028]
Further, the anode holding member 10 is uniformly bonded to the entire width of the flat anode chamber partition wall 8, and the anode 15 is bonded to the convex portion 13 of the anode holding member 10, whereby the circulation in the anode chamber is made uniform. At the same time, the electrolytic cell can have a high strength.
The electrolytic solution obtained by gas-liquid separation of the gas-liquid mixed fluid that has risen in the space on the anode 15 surface side of the anode holding member 10 in the upper part of the anode chamber descends the anolyte circulation passage 16, and is on the electrode surface side in the lower part of the electrode chamber. It flows into the space, is supplied from the anolyte supply pipe 17 provided in the electrolytic cell, and is electrolyzed in the anode 15 together with the anolyte that is ejected from the anolyte outlet 18 into the electrode chamber.
[0029]
In the cathode chamber 7, a cathode 20 is attached to a cathode holding member 21 joined to the cathode chamber partition wall 9, as shown in FIG. 1B, and between the cathode chamber partition wall 9 and the cathode holding member 21. A catholyte circulation passage 22 is formed in the upper part.
The cathode holding member 21 joined to the cathode chamber partition wall 9 is a spring-like member, and the cathode holding member 21 is symmetrical in cross section taken along a plane perpendicular to the flow direction of the catholyte circulation passage 22. The strip-shaped joint portions 24 on both sides of the ridge portion 23 to which the cathode 20 is attached are joined to the cathode chamber partition wall 9, and a joint portion-side ridge portion 25 is provided adjacent to the joint portion 24. The ridges 23 to which the ridges 20 are attached project larger toward the counter electrode side than the ridges 25 on both sides, and serve to keep the distance between the cathode 20 and the ion exchange membrane surface small.
[0030]
FIG. 4 is a diagram for explaining another example of the electrolyte circulation mechanism of the ion exchange membrane electrolytic cell of the present invention.
FIG. 4A is a view for explaining a cross section taken along line BB in FIG. 3A, and is a view for explaining another example of the gas-liquid separation chamber provided in the upper part of the electrolytic cell.
The anode side gas-liquid separation chamber 30 is provided above the electrolysis region of the anode chamber, and the electrolysis region and the anode-side gas-liquid separation chamber are disposed on the anode chamber partition wall 8 side of the anode side gas-liquid separation chamber 30. A partition member 36 that has a partition-side passage 31 that communicates with 30 and that separates the inside of the anode-side gas-liquid separation chamber 30 that is joined to a member that extends from the anode surface side and forms the wall surface of the partition-side passage 31. Have.
[0031]
The gas-liquid mixed phase fluid containing bubbles generated by the electrolysis rises in the space formed between the anode holding member 10 and the anode 15 and flows into the anode-side gas-liquid separation chamber 30 from the partition-side passage 31. The electrolytic solution from which the generated gas has been separated passes over the upper end portion of the anode holding member and descends below the anode chamber through the anolyte circulation passage 16 formed by the anode chamber partition and the anode holding member.
[0032]
The partition member 36 provided in the anode-side gas / liquid separation chamber 30 may also serve as a part of the anode chamber frame constituting the structure of the anode chamber, and the partition plate 35 is provided inside the anode-side gas / liquid separation chamber 30. In addition, the partition plate 35 is joined to the partition member 36 that also serves as the anode chamber frame, thereby preventing deformation due to the load of the unit cell when the unit cells are stacked and the cell is assembled. A large electrolytic cell can be obtained.
[0033]
In addition, a cathode side gas-liquid separation chamber 37 is provided above the electrolysis region of the cathode chamber, and the gas-liquid mixed phase fluid rising in the space formed by the cathode 20 and the cathode holding member 21 separates the gas. After that, the catholyte circulation passage 22 formed by the cathode holding member 21 and the cathode chamber partition wall 9 is lowered to the lower side of the cathode chamber.
A part of the cathode chamber frame 38 constituting the structure of the cathode chamber is also provided inside the cathode side gas-liquid separation chamber 37, and the partition plate 39 is provided at a predetermined interval on the cathode chamber frame 38, thereby providing a cathode. It is possible to prevent deformation due to a load when the electrolytic cells of the chamber frame 38 are stacked, and to obtain a highly rigid electrolytic cell.
[0034]
Further, as shown in FIG. 4B, a view for explaining a cross section taken along the line CC in FIG. 3A is provided, the anode holding member 10 at the lower part of the electrolytic cell is provided with a descending liquid jet 40. The anolyte separates the gas in the gas-liquid separation chamber, descends the anolyte circulation passage 16 formed by the anode holding member 10 and the anode chamber partition wall 8, and is ejected from the descending liquid outlet 40 into the electrode chamber. Then, it is mixed with the anolyte supplied from the anolyte supply passage 41 provided in the lower part of the electrolytic cell and ejected from the anolyte outlet 18 into the anode chamber, and undergoes electrolysis at the anode 15.
[0035]
Similarly, the catholyte descending from the lower opening of the cathode holding member 21 is ejected to the lower part of the cathode chamber 7, and supplied through the catholyte supply passage 42 to be ejected from the catholyte outlet 43 into the cathode chamber. Along with the catholyte, it undergoes electrolysis at the cathode 20.
Further, below the ion exchange membrane electrolytic cell 1, there is an electrolytic cell frame 44 that maintains the mechanical structure of the electrolytic cell and maintains the rigidity of the electrolytic cell.
[0036]
FIG. 5 is a view for explaining another embodiment of the ion exchange membrane electrolytic cell of the present invention.
FIG. 5A shows the electrolytic cell unit viewed from the anode chamber side. FIG. 5B is a cross-sectional view taken along line AA in FIG.
The bipolar electrolytic cell unit 2 of the ion exchange membrane electrolytic cell is composed of an anode chamber 6 and a cathode chamber 7, and the anode chamber 6 and the cathode chamber 7 are respectively a plate-like anode chamber partition wall 8 and a cathode chamber. The partition wall 9 is joined and integrated electrically and mechanically.
[0037]
An anode holding member 10 is bonded to the anode chamber partition wall 8 by forming a band-shaped joint portion 11, and the anode chamber partition wall 8 and the anode holding member 10 are closely bonded to each other at the band-shaped joint portion 11. Both may not be welded and joined by a continuous weld. In other words, the anode holding member 10 and the anode chamber partition 8 are brought into close contact with each other by joining with a large number of spot welds 12 in a state where they are in close contact, and the conductive connection between them and the anode holding member 10 and the anode chamber partition 8 are formed. Space is separated from the opposite space.
[0038]
A protruding strip portion 13 is formed between the adjacent strip-shaped joint portions 11 of the anode holding member 10, and the convex strip portion 13 and the strip-shaped joint portion 11 are joined by a flat portion 14. In addition, the anode 15 is joined to the convex portion 13 at a plurality of locations, and the anode 15 is held and electrolysis current is supplied to the anode.
[0039]
It is sufficient for the ridge 13 to have a width that can join the electrode to the top, and even if it is a ridge formed by bending a metal plate into a triangular shape, It may be a ridge having parallel surfaces. The anode holding member may be manufactured as a separate member, a plurality of members connected by press molding may be manufactured, or all the anode holding members arranged in the anode chamber partition wall may be pressed with a single metal plate. It may be manufactured by molding.
[0040]
Further, the cathode holding member 21 of the cathode chamber 7 is a flexible electrode support in which at least three protruding ridges projecting to the side opposite to the junction with the partition wall are formed between the adjacent junctions 24. An electrode is joined to the ridge 23 having the largest amount of displacement when pressed in the direction toward the cathode chamber partition, and the joint-side ridge 25 is the joint 24. The angle is in the vicinity of 90 degrees.
[0041]
Thereby, the pressure on the cathode chamber side is lowered for some reason during the operation of the electrolytic cell, and even when the ion exchange membrane is pressed from the anode chamber side to the cathode side, the cathode 20 is displaced more than the convex portion 23. Even the small joint-side convex portion 25 is held, and it is possible to prevent the cathode 20 or the cathode holding member 21 from being deformed that cannot be recovered.
[0042]
FIG. 6 is a diagram for explaining the behavior of the cathode during pressing shown in FIG.
When the pressure on the anode chamber side becomes larger than the pressure on the cathode chamber side when the pressure is abnormal during operation of the electrolytic cell, the cathode holding member 21 is displaced toward the cathode chamber partition wall 9 due to the pressure acting on the cathode surface by the ion exchange membrane. However, since the cathode 20 is joined to the protruding portion 23 having the largest displacement amount to the cathode chamber partition side among the protruding portions protruding to the opposite side of the cathode chamber partition 9 of the cathode holding member 21, FIG. As shown in FIG. 6A, when the cathode 20 is pressed to the cathode chamber partition wall 9 side by the pressing force F, the joint-side convex strips 25 located on both sides of the joint portion are displaced by the amount of pressing. Is small, the open angle θ of the protruding portion where the cathode is joined is increased, and the cathode 20 is displaced toward the cathode chamber partition wall 9 side.
[0043]
Then, as shown in FIG. 6B, the height and displacement amount of the joint-side ridge portion 25, the displacement amount of the ridge portion 23 to which the cathode 20 is joined, and both sides of the ridge portion to which the cathode is joined. By adjusting the size of the concave portion 26 projecting toward the cathode chamber partition wall formed on the cathode side, when the cathode surface comes into contact with the joint-side convex portion 25, the tip of the concave portion 26 is simultaneously By setting so as to contact the chamber partition wall 9, the pressure applied to the cathode can be dispersed at a large number of contact points.
[0044]
In addition, the displacement amount of the ridge portion in which the cathode is joined to the cathode holding member is set to be a part or all of the ridge portion 23 in order to increase the deformation at the time of pressing compared to other portions of the cathode holding member. It can be realized by reducing the thickness, or by forming a horizontally long hole 27 along the protruding stripe direction as shown in the perspective view of the cathode holding member in FIG.
[0045]
As a result, when pressed, the ridge is increased in opening angle θ by a relatively small pressure and deformed in the direction of the cathode partition.
The cathode mounted on the ridge that is displaced by a small pressing force may damage the ion exchange membrane by pressing the ion exchange membrane surface with a large pressure even if it is placed close to the cathode surface during normal electrolytic cell operation. There is no fear of impact and stable operation is possible.
[0046]
FIG. 7 is a view for explaining another embodiment of the ion exchange membrane electrolytic cell of the present invention.
FIG. 7A shows the electrolytic cell unit viewed from the anode chamber side. FIG. 7B shows a cross-sectional view taken along line AA in FIG. 7B.
The bipolar electrolytic cell unit 2 of the ion exchange membrane electrolytic cell is composed of an anode chamber 6 and a cathode chamber 7, and the anode chamber 6 and the cathode chamber 7 are respectively a plate-like anode chamber partition wall 8 and a cathode chamber. The partition wall 9 is joined and integrated electrically and mechanically.
[0047]
An anode holding member 10 is bonded to the anode chamber partition wall 8 by forming a band-shaped joint portion 11, and the anode chamber partition wall 8 and the anode holding member 10 are closely bonded to each other at the band-shaped joint portion 11. Even if they are not welded and joined together by a linear welded part, the anode holding member 10 and the anode chamber partition wall 8 are brought into close contact with each other by joining at a large number of spot welded parts 12 in close contact with each other. The space formed between the conductive connection, the anode holding member 10 and the anode chamber partition wall 8 may be separated from the space on the opposite side.
A protruding strip portion 13 is formed between the adjacent strip-shaped joint portions 11 of the anode holding member 10, and the convex strip portion 13 and the strip-shaped joint portion 11 are joined by a flat portion 14. Moreover, the anode 15 is joined to the convex portion 13 at a plurality of locations, and the anode 15 is held and an electrolytic current is supplied to the anode.
[0048]
Further, the cathode holding member 21 of the cathode chamber 7 is a flexible electrode in which at least three protruding ridges projecting to the opposite side to the side of the junction with the partition wall are formed between the adjacent junctions 24. A protrusion having a support member and having a largest amount of displacement when pressed in the cathode chamber partition direction among the protrusions is formed with a laterally elongated opening in the direction of the protrusions. While increasing the displacement of the ridge 23, the ridge protection member 28 is disposed. By providing the ridge protection member 28, the thickness of the ridge 23 is reduced in order to increase the amount of displacement of the cathode holding member 21, or the opening is provided along the ridge. It is possible to prevent the welding portion of the cathode 20 to 23 from becoming uncertain.
[0049]
Moreover, it is preferable that the opening angle θ of the protruding portion protection member 28 be the maximum opening angle of the protruding portion where the cathode contacts the bonding portion side protruding portion 25. By doing in this way, even if it presses and a ridge part opens, it prevents that a ridge part deform | transforms greatly. In addition, the ridge protection member is made of a material that is thicker and more rigid than the cathode holding member, thereby restricting the ridge from being greatly deformed when an abnormally large pressure is applied to the cathode. In addition, the effect of preventing the deformation of the cathode can be further increased.
[0050]
The angle formed by the surface connecting the joint 24 and the joint-side ridge 25 with the cathode chamber partition wall is preferably 90 degrees or more and 100 degrees or less. When pressed, the deformation of the cathode holding member can be reduced, and the cathode 20 or the cathode holding member 21 can be prevented from being deformed that cannot be recovered.
[0051]
The ion exchange membrane electrolytic cell of the present invention comprises a plurality of bipolar electrode units each having the above-described anode chamber and cathode chamber, and a cathode side end electrolytic cell having only a cathode chamber at both ends. It can be produced by stacking anode side end electrolytic cells having only an anode chamber.
[0052]
A thin film forming metal such as titanium, tantalum or zirconium or an alloy thereof can be used for the anode chamber partition wall of the ion exchange membrane electrolytic cell of the present invention. As the anode, an anode in which a coating of an electrocatalytic substance containing a platinum group metal or an oxide of a platinum group metal is formed on the surface of a thin film forming metal such as titanium, tantalum or zirconium or an alloy thereof can be used. .
[0053]
In addition, nickel, nickel alloy, or the like can be used for the cathode chamber partition wall, and the cathode is made of nickel, a porous body of nickel alloy, a net-like body, an expanded metal, or a platinum group metal on the surface thereof. A coating in which an electrode catalyst material such as a containing layer, a Raney nickel-containing layer, an activated carbon-containing nickel layer, or the like is formed and the hydrogen overvoltage is reduced can be used. Moreover, the same material as the cathode chamber partition can be used for the catholyte circulation passage forming member.
[0054]
The anode holding member and the cathode holding member can be manufactured using the same material as the anode chamber partition and the cathode chamber partition, respectively. Even those bonded to the chamber partition walls, or a plurality of anode holding members, cathode holding members, or all anode holding members and cathode holding members are integrally manufactured by press molding, and bonded to the anode chamber partition walls and the cathode chamber partition walls, respectively. You may do it.
[0055]
When the ion exchange membrane electrolytic cell of the present invention is used for electrolysis of an aqueous solution of an alkali metal halide, for example, electrolysis of brine, saturated saline is supplied to the anode chamber, and water or dilute is supplied to the cathode chamber. A sodium hydroxide aqueous solution is supplied, electrolyzed at a predetermined decomposition rate, and then taken out from the electrolytic cell.
Also, in the electrolysis using saline ion exchange membrane electrolytic cell, the electrolysis is performed with the pressure in the cathode chamber kept higher than the pressure in the anode chamber, and the ion exchange membrane is operated in close contact with the anode. However, since the cathode holding member is a spring-like member and the cathode is bonded to the protruding portion having a large displacement, the cathode can be electrolyzed close to a predetermined distance on the surface of the ion exchange membrane. Can do.
【The invention's effect】
According to the ion exchange membrane electrolytic cell of the present invention, the plate-like anode chamber partition and the cathode chamber partition are joined by forming a strip-like joint, and the protruding strip part joining the electrodes is provided between the adjacent joints. Since the electrode holding member having a plate shape is provided, the space on the electrode surface side of the electrode holding member forms an ascending flow path for fluid in the electrode chamber, and the space on the partition wall serves as a descending passage for fluid in the electrode chamber. Since it is formed on the entire surface, it is possible to efficiently circulate the electrolytic solution, and since the electrode holding member is disposed on the entire surface, a highly rigid ion exchange membrane electrolytic cell can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining an embodiment of an ion exchange membrane electrolytic cell of the present invention.
FIG. 2 is a diagram for explaining an example of an electrolyte circulation mechanism of the ion exchange membrane electrolytic cell of the present invention.
FIG. 3 is a view for explaining another embodiment of the ion exchange membrane electrolytic cell of the present invention.
FIG. 4 is a diagram for explaining another example of the electrolyte circulation mechanism of the ion exchange membrane electrolytic cell of the present invention.
FIG. 5 is a view for explaining another embodiment of the ion exchange membrane electrolytic cell of the present invention.
6 is a diagram for explaining the behavior of the cathode during pressing shown in FIG. 5. FIG.
FIG. 7 is a view for explaining another embodiment of the ion exchange membrane electrolytic cell of the present invention.
FIG. 8 is a diagram illustrating a conventional ion exchange membrane electrolytic cell.
FIG. 9 is a diagram for explaining an ion exchange membrane electrolytic cell having another conventional structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Ion exchange membrane electrolytic cell, 2 ... Electrolytic cell unit, 2A ... Cathode chamber unit, 2B ... Anode chamber unit, 3 ... Flange surface, 4 ... Gasket, 5 ... Ion exchange membrane, 6 ... Anode chamber, 7 ... Cathode chamber 8 ... Anode chamber partition wall, 9 ... Cathode chamber partition wall, 10 ... Anode holding member, 10A ... Vertical portion, 10B ... Horizontal portion, 11 ... Joint portion, 12 ... Spot welded portion, 13 ... Round strip portion, 14 ... Flat part, 15 ... anode, 16 ... anolyte circulation passage, 17 ... anolyte supply pipe, 18 ... anolyte outlet, 19 ... anolyte outlet, 20 ... cathode, 21 ... cathode holding member, 22 ... catholyte circulation A passage, 23 ... a convex strip, 24 ... a joint, 25 ... a joint side convex strip, 26 ... a concave strip, 27 ... a horizontally long hole, 28 ... a convex strip protection member, 30 ... an anode chamber side gas-liquid separation Chamber 31, partition wall side passage 32, first partition member 33 33 second partition member 34 34 communication passage 35 Partition plate, 36 ... partition member, 37 ... cathode chamber side gas-liquid separation chamber, 38 ... cathode chamber frame, 39 ... partition plate, 40 ... descending liquid outlet, 41 ... anolyte supply passage, 42 ... catholyte supply passage 43 ... Cathode outlet, 44 ... Electrolyzer frame, F ... Pressing force, θ ... Open angle

Claims

In an ion exchange membrane electrolytic cell, a plate-like anode chamber partition and a plate-like cathode chamber partition are joined, and at least one partition is joined by forming a strip-like joint, and between adjacent joints An electrode surface of the electrode holding member having a plate-like electrode holding member provided with a protruding strip portion to which the electrodes are bonded, wherein the bonding portion of the electrode holding member and the protruding strip portion are respectively coupled with one plane. The space on the side forms an ascending flow path for the fluid in the electrode chamber, and the space on the opposite side forms a descending flow path for the electrolyte separated from the gas in the upper part of the electrode chamber, and the anode holding member and the cathode holding member Either one is formed from a spring-like member, and the spring-like member has at least three ridges protruding to the opposite side of the joint with the partition wall, and when the ridge is pressed The protruding portion having the largest displacement is formed by cutting out a part of the protruding portion. Ion exchange membrane electrolyzer, characterized in that the amount is convex portion protection member for the maximum opening angle of the greatest ridge in the open angular amount displacement is coupled to the most significant ridges.

2. The structure according to claim 1, wherein when the electrode joined to the protruding portion having the largest displacement is pressed toward the partition wall, the movement of the electrode is restricted by the protruding portion adjacent to the joining portion. Ion exchange membrane electrolytic cell.

3. The ion exchange membrane electrolytic cell according to claim 2, wherein the maximum opening angle of the protruding portion having the largest displacement amount is an angle at which the electrode contacts with the protruding portion adjacent to the connecting portion. .