JP3655948B2

JP3655948B2 - Water storage device

Info

Publication number: JP3655948B2
Application number: JP21156695A
Authority: JP
Inventors: 博司小山
Original assignee: 博司小山
Priority date: 1995-08-21
Filing date: 1995-08-21
Publication date: 2005-06-02
Anticipated expiration: 2015-08-21
Also published as: JPH0958786A

Description

【０００１】
【発明の属する技術分野】
本発明は貯水装置に関し、特に震災時の応急給水を目的とした公共用の貯水装置に関する。
【０００２】
【従来の技術】
大地震等の災害が発生した場合、水道施設の破壊や停電等により水道水の供給が停止する可能性は非常に大きい。そのため、非常用の飲料水の確保および応急給水対策は常日頃から確立しておくことが必要であるが、平成７年１月に起きた阪神大震災でははからずもこの事前の応急給水対策が十分でない、または十分機能しなかったということが立証された。
【０００３】
災害救助法によれば、災害時の応急給水は、本来的に都道府県および市町村の責務とされ、一定規模の震災対策用貯水施設が各地で設置され始めている。そして震災時にはこの震災対策用貯水施設や浄水場・給水所を拠点として直接または車両輸送により住民に給水するようになっている。
【０００４】
このような公共用の震災対策用貯水施設における貯水装置の構造については、震災時にも確実に水が貯留されかつ確実に給水できること、貯留水を清浄に保ち水質基準に適合させるために水が常時適切に流入し、流出する形式であることが求められる。
【０００５】
ここで、図５を用いて東京都などに設置されている震災対策用の貯水装置の一例を説明する。貯水装置３０は比較的大規模な公園の地下に設置されており、貯水容量は例えば１，５００ｍ³ であり、半径２ｋｍの範囲内に一か所このような貯水装置３０を設けることが目標とされている。
【０００６】
まず、その構成について説明すると、貯水装置３０は水道の配水本管２１から水を導入する導入管２２と、導入管２２から導入される水を貯留する給水槽２４と給水槽２４に導入された水をポンプＰ１により配水本管２１に強制的に排出する排出管２３と、災害時に給水槽２４に貯留された水をポンプＰ２により汲み上げて給水するための給水管２６と、給水管２６に取りつけられた水の取り出し口２７と、ポンプＰ２を作動させるための自家発電設備２５を備えている。
【０００７】
次にこの貯水装置３０の貯水と給水のしくみについて説明する。
【０００８】
平常時には、配水本管２１を流れる水は水圧により導入管２２に導かれ、給水槽２４に流し込まれる。一方、ポンプＰ１を常時作動させることにより、いったん給水槽２４に流れ込んだ水は強制的に排出管２３より配水本管２１に戻される。このようにして、常時給水槽２４の水を循環させて水質を確保するようにしている。
【０００９】
一方、災害時断水が起きると、自家発電設備２５を稼働させポンプＰ２を作動させることによって給水槽２４に貯留されている水を給水管２６を介して汲み上げ取り出し口２７から給水を行う。
【００１０】
以上のように構成されているので、貯水装置３０は上に述べた公共用の震災対策用貯水施設における貯水装置の構造について一応基準を満たしている。
【００１１】
【発明が解決しようとする課題】
しかしながら、貯水装置３０は貯水容量としては十分であっても、災害時の応急給水については問題がある。阪神大震災において、人員が確保できなかったり道路の寸断や破壊により車両輸送による住民への給水が十分に機能しなかったのは記憶に新しい。例え貯水容量は十分であっても、貯水装置３０の恩恵を受けられるのは貯水装置３０のある場所まで歩いていける近隣の住民等に限られてしまうおそれが大きい。
【００１２】
また、災害時に給水を行うに際しては、水は地下に貯留されているので自家発電設備２５を稼働させなければポンプＰ２で水を汲み出せない。災害時には住民だけでなく地方公共団体の職員もまた被災者であるので、確実に自家発電設備２５やポンプＰ２を稼働させる人員が確保できるか問題である。
【００１３】
さらに、貯水装置３０はメンテナンスの点でも問題がある。大規模な給水槽を地下に設けてしまうと、例えば給水槽２４のどこかで漏水が起こってもそれを点検する方法がない。現にこのような地下貯水槽での漏水はしばしば起こる現象である。また、自家発電設備２５やポンプＰ２は常日頃から点検を行っていないと、いざ災害時になって故障で稼働できないことも考えられる。
【００１４】
本発明者は、公共用の震災対策用貯水施設を設置するに際し、大規模な地下貯水施設で広域的に住民の飲料水をカバーしようとする考え方を根本的に考え直さなければ以上のような問題は解決しないと考える。
【００１５】
すなわち、災害時の給水が動力の助けを借りないでも簡便に行うことができると共に日頃のメンテナンスも楽な比較的小規模な貯水装置を公園や学校、病院などの公共施設に多数設けることによって、災害時の応急給水の機能を十分発揮させることができるのである。本発明の目的は、このような多数の公共施設に設置することを目的とした比較的小規模でかつメンテナンスも楽な貯水装置を提供することである。
【００１６】
【課題を解決するための手段】
請求項１に記載の貯水装置は、地上にほぼ水平に配列された複数個の貯水槽と、地下の１次側水道配水管から第１番目の貯水槽の最上部に水を導入する導水管と、各貯水槽の上部と、隣接して設置されている貯水槽の最上部を順次に接続している流水管と、前記各貯水槽の最低部とそれぞれ接続されており必要により水を取り出すための取り出し口を設けた取り出し管と、前記接続している流水管の最後部の貯水槽の上部と地下の２次側水道配水管とを接続している第１の戻し管と、前記取り出し管と地下の２次側水道配水管とを接続している第２の戻し管とを有し、前記第１の戻り管の最高部が前記各貯水槽の最上部よりも高所にあるようにし、前記第１の戻り管の前記最高部には配管内と配管外との圧力により開閉する空気入り切り弁がもうけられ、前記第２の戻り管の最高部を前記各貯水槽の最上部より高所にあるように設け、前記第２の戻り管の前記最高部には前記空気入り切り弁が設けられ、各貯水槽の最上部には前記空気入り切り弁が設けられていることを特徴とする。
【００１７】
請求項２に記載の貯水装置は、地上にほぼ水平に配列された複数個の貯水槽と、地下の１次側水道配水管に接続するとともに、各貯水槽の最上部にそれぞれ接続して１次側の水道水を導入する導水管と、前記各貯水槽の最低部にそれぞれ接続されて、必要により水を取り出すための取り出し口を設けた取り出し管と、前記導水管の端末と地下の２次側水道配水管とを接続している第１の戻し管と、前記取り出し管と地下の２次側水道配水管とを接続している第２の戻し管とを有し、前記第２の戻し管の最高部を前記各貯水槽の最上部より上にあるように設け、前記第２の戻り管の前記最高部には前記空気入り切り弁が設けられ、各貯水槽の最上部には前記空気入り切り弁が設けられていることを特徴とする。
【００１８】
請求項３に記載の貯水装置は、ほぼ垂直に積み重ねた状態に配列された複数個の貯水槽と、地下の１次側水道配水管に接続するとともに、前記各貯水槽の最上部にそれぞれ接続して１次側の水道水を導入する導水管と、前記最下層の貯水槽の下に配置された、必要により水を取り出すための取り出し口を設けた取り出し管と、前記各貯水槽の最下部と前記取り出し管とを接続する導出管と、前記取り出し管と地下の２次側水道配水管とを接続している戻し管とを有し、前記戻し管の最高部を１番上に位置する貯水槽の最上部より高所にあるように設けるとともに、前記戻り管の前記最高部には前記空気入り切り弁を設け、各貯水槽の最上部には前記空気入り切り弁が設けられていることを特徴とする。
【００１９】
請求項４に記載の貯水装置は、水平に配列され、かつ多段に積み重ねた状態に配列された複数個の貯水槽と、地下の１次側水道配水管に接続するとともに、前記各貯水槽の最上部にそれぞれ接続されて１次側の水道水を導入する導水管と、前記最下層の貯水槽の下に配置されて、必要により水を取り出すための取り出し口を設けた取り出し管と、前記各貯水槽の最下部と前記取り出し管とを接続する導出管と、前記取り出し管と地下の２次側水道配水管とを接続している戻し管とを有し、前記戻し管の最高部を１番上に位置する貯水槽の最上部より高所にあるように設けるともに、前記戻り管の前記最高部には前記空気入り切り弁を設け、各貯水槽の最上部には前記空気入り切り弁が設けられていることを特徴とする。
【００２０】
したがって、平常時は、１次側水道管からの供給圧力によって、水道水は各貯水槽の最上部から導入され、最低部および上部から導出される。水は上記供給圧力により各貯水槽内で常時循環し滞留することなく取り出し管または上部出口に押し出される。したがって水道水として必要な水質を確保できる。取り出し管から押し出された水は接続している戻し管へ押し込まれ、戻し管を上方へ向かって流れる。戻し管の最高部が各貯水槽の最上部よりも高くしてあるので、水は１次側水道管からの供給圧力によって、一旦配管系の最高場所に押し上げられてから２次側水道配水管に排出することになる。断水が起きたときに、２次側の配水管の圧力が下がっても水が前記配管系の最高部を越えて貯水槽から流出することがなく確実に貯水できる。空気入り切り弁を最高部に設けることによりサイフォン現象を防ぎ、サイフォンによる貯水槽の水の流出も防ぐことができる。
【００２１】
請求項５および６に記載の貯水装置は、所望の数の貯水槽を縦にも横にも配列することができるので、設置場所に適した容量、形状の貯水装置に構成できる。
【００２２】
また、貯水槽の最上部に空気の入り切り弁を設けることにより、満水時には貯水槽に密閉状態を作り出し水を衛生的に保つとともに、断水時には各貯水槽の最低部から自然落下により水を取り出す時にスムースに水を取り出すことができる。
【００２３】
【発明の実施の形態】
以下、本発明による実施の形態について図面を参照して説明する。
【００２４】
図１は本発明による貯水装置１の第１の実施の形態を示す断面図である。貯水装置１は地上にほぼ水平に配列された貯水槽４、４′、４″を備え、地下に配設された水道の配水管の途中に組み込まれるようになっている。貯水装置１は、導入管３によって１次側配水管１１から水を取り込み、各貯水槽４、４′、４″と流水管５を経て第１の戻し管６を通るルートと、各貯水槽４、４′、４″、取り出し管７を経て第２の戻し管６ａを通るルートと、の２つのルートによって２次側配水管１１ａに水を排出するようになっている。
【００２５】
各貯水槽４、４′、４″は最上部に設けられた導入口１２から水を取り込み、最低部に設けられた各取り出し口１３にそれぞれ接続された取り出し管７を経由して第２の戻し管６ａと、最下流側の貯水槽４″の上部に設けられた流水口１４に接続された流水管５を経由し第１の戻し管６とから水を２次側配水管に排出するようになっている。他の貯水槽４、４′の流水管５の一端は貯水槽４、４′の流水口１４に接続され、他端は隣に設置される貯水槽４′、および４″の導入口１２に接続されている。上述のように貯水槽４″の流水口１４には第１の戻し管６が接続されている。第１の戻し管６は水を一旦各貯水槽４、４′、４″の最上部またはそれより高い位置に引き上げるために、各貯水槽の最上部より高い位置において折り返すように配管された後、地下の２次側配水管１１ａに接続されている。
【００２６】
取り出し管７は各貯水槽４、４′、４″の取り出し口１３に共通に接続されている。このようにして、各貯水槽４、４′、４″は水平に接続されている。また、各貯水槽４、４′、４″の導入口１２の上部には空気の入り切り弁１０がそれぞれ設けられている。
【００２７】
導入管３の途中には逆止弁２が設けられ、取り出し管７には給水弁７ａが設けられている。また、第１の戻し管６と第２の戻し管６ａの最上部にも空気の入り切り弁１０が設けられている。
【００２８】
各貯水槽４、４′、４″や第１の戻し管６と第２の戻し管６ａの最上部に設けられた空気の入り切り弁１０は、水が満杯の時は水圧により弁が閉じて外気を遮断し、断水になり水圧が下がると弁が開いて空気が流入するようになっている。空気の入り切り弁１０はこのように水が満杯のときに密閉状態を作り出すことにより、外部からのほこりや細菌の侵入を防止し、水を衛生的に保つことを可能にすると共に、断水時に貯水装置１の下部から自然落下による水の取り出しを行う時に空気の流入によりスムースな取り出しを可能にする。また、第２の戻し管６ａの最上部に設けられた空気の入り切り弁１０は断水時に第２の戻し管６ａ内の水が２次側配水管１１ａ内にサイフォン現象により引き込まれてしまうことを防止する（なお、空気の入り切り弁１０の具体的な構成の一例については本出願人による特願平６−７８７２６５号明細書参照）。
【００２９】
次に貯水装置１の平常時および断水時の動作について説明する。
【００３０】
平常時は、１次側配水管１１の水は水圧によって導入管３中を押し上げられ逆止弁２を通った後導入口１２から最初の貯水槽４に導入され、貯水槽４内を一巡した後、上部に設けられた流水口１４から流水管５へ導かれるルートと、最低部に設けられた取り出し口１３から取り出し管７へ導かれるルートに別れて最初の貯水槽４から流出する。
【００３１】
最初の貯水槽４から流水管５に導かれた水は次の貯水槽４′の導入口１２から貯水槽４′に流入し、再び流水管５と取り出し管７との２つのルートに別れて流出し、同様のことを繰り返しながら最後の貯水槽４″に流入する。最後の貯水槽４″から第１の戻し管６に導出された水は第１の戻し管６によって一旦貯水槽４、４′、４″の最上部またはそれより高い位置に引き上げられた後、２次側配水管１１ａに排出される。一方、貯水槽４、４′、４″から取り出し管７に導出された水は第２の戻し管６ａによって貯水槽４、４′、４″の最上部またはそれより高い位置に引き上げられた後、２次側配水管１１ａに排出される。
【００３２】
各貯水槽４、４′、４″から流出する水は流水管５と取り出し管７の２つのルートに別れて流出するため、各貯水槽４、４′、４″内で水が滞留することがなく水質を清浄に保つことができる。
【００３３】
一方、断水が起きると、１次側配水管１１内の水圧は急激に失われ、それに引きずられるようにして導入管３内の水も１次側配水管１１へ戻ろうとする動きに変わるが、その圧力変化により逆止弁２が閉じるので１次側配水管１１への逆流を防ぐことができる。しかし、その他の管内や各貯水槽４、４′、４″内の水が自然落下により取り出し管７を通じて２次側配水管１１ａへ流出しようとする動きは変わらない。
【００３４】
そこで、貯水装置１ではその水の流出を防止するために、貯水槽の上部に接続する第１の戻し管と、取り出し管７に接続する第２の戻し管とは、いずれも貯水槽４、４′、４″の最上部またはそれより高い位置まで配管を一旦引き上げてから２次側配水管に接続している。それによって断水時に貯水装置１の中に水を閉じ込め、貯留した水の流出を防止することができるのである。第１および第２の戻し管６、６ａの最上部に設けられた空気入り切り弁１０の作用により、水がサイフォン現象により２次側配水管１１ａ内に引き込まれることはない。
【００３５】
断水時に貯水装置１より給水を行う場合は、動力を用いなくても給水弁７ａを開くだけで自然落下により各貯水槽４、４′、４″に貯留された水を取り出すことができる。また、給水弁７ａを開くと、同時に各貯水槽４、４′、４″の最上部に取りつけられた空気の入り切り弁１０が開くので各貯水槽４、４′、４″内に空気が流入し、給水弁７ａからの水の取り出しがスムースに行える。
【００３６】
一方、断水が終わり通水が再開されると、１次側配水管１１から水圧により水が導入管３中を逆止弁２を開きながら上昇して、貯水槽４、４′、４″の順に水が供給されていくが、この時各貯水槽４、４′、４″の最上部に取りつけられた空気の入り切り弁１０の働きにより、各貯水槽４、４′、４″内の空気は余さず外部に排出され、水が満杯になると同時に空気の入り切り弁１０が完全に閉じて元の密閉状態が再び保たれることになる。
【００３７】
図２は図１に示した貯水装置１の変形例である。図２において図１と同じ参照番号を用いた場合は図１と同じ構成要素を表しているので説明を省略し、図１と異なる部分を中心に説明する。
【００３８】
図２に示す貯水装置１は地上にほぼ水平に接続した貯水槽４、４′、４″を導入管３と第１の戻し管６および第２の戻し管６ａとの間で上下３段に配列したものであり、このように所望の数の貯水槽を縦にも横にも配列することにより、無数の貯水槽群を構成することが可能である。したがって、その設置場所の広さによっては、何百トン、あるいは何千トンもの水を貯留することも可能である。
【００３９】
また、図２に示した貯水装置１では、第２の戻し管６ａの最上部に貯水槽４ａを設けている。貯水槽４ａは貯留した水が２次側配水管１１ａにそのまま流出しないように貯水装置１内に閉じ込めるために設けるものであるが、貯水槽４ａはまた、水道水に混入した砂等の混入物を取り除いて２次側配水管１１ａに水を排出する機能を有する。そして、排出管９の排出弁９ａを開くことにより、混入物を排出させることができる。もちろん貯水槽４ａ自体としても水を貯留することができるので、最終的には貯水槽４ａ内の水を排出弁９ａを開くことにより飲料水として利用することも可能である。
【００４０】
図３は本発明による貯水装置の第２の実施の形態を示す断面図である。図３において図１と同じ参照番号は図１と同じ構成要素を表しているので説明を省略し、図１と異なる部分を中心に説明する。
【００４１】
貯水装置１は地上にほぼ水平に配列された貯水槽４、４′、４″を備え、地下に配設された水道の配水管の途中に組み込まれるようになっている。貯水装置１において、導入管３によって１次側配水管１１から取り込まれた水は、各貯水槽４、４′、４″の最上部に共通に接続された導入管３からそれぞれの貯水槽内に導かれ、各貯水槽４、４′、４″の最低部から取り出し管７を経て第２の戻し管６ａを通るルートと、各貯水槽４、４′、４″内に取り込まれずにそのまま導入管３を経て第１の戻し管６を通るルートと、の２つのルートによって２次側配水管１１ａに排出されるようになっている。
【００４２】
取り出し管７に導入された水は第２の戻し管６ａに導かれ、貯水槽４、４′、４″の最上部またはそれより高い位置まで一旦引き上げられた後２次側配水管１１ａに排出されるので、断水時に、貯留した水の２次側配水管１１ａへの流出を防止することができる。空気の入り切り弁１０の作用は図１を用いて説明したものと同様である。
【００４３】
また、図３に示した貯水装置１では、地上にほぼ水平に配列された貯水槽４、４′、４″の最上部から各々水を取り込み、最低部から流出させるようにしているので水が各貯水槽内で滞留をすることがなく、水質を清浄に保つことができる。
【００４４】
なお、図３において、第１の戻し管６を設けずに、導入管３を貯水槽４″に接続する部位でとどめ、第２の戻し管６ａのみによって地下の２次側配水管１１ａに水を排出するようにしてもよい。
【００４５】
図４は本発明による貯水装置の第３の実施の形態を示す断面図である。図４において図１と同じ参照番号は図１と同じ構成要素を表しているので説明を省略し、図１と異なる部分を中心に説明する。
【００４６】
貯水装置１は地上に縦に配列された貯水槽４、４′、４″を備え、地下に配設された水道の配水管の途中に組み込まれるようになっている。導入管３は１次側配水管１１から水を取り込み、各貯水槽４、４′、４″の最上部からそれぞれの貯水槽内に水を導入する。貯水槽４、４′に導入された水は各貯水槽４、４′の最低部から導出管１５に導出され、さらに導出管１５に接続された取り出し管７に導入される。また、貯水槽４″に導入された水は貯水槽４″の最低部から直接取り出し管７に導入される。取り出し管７に導入された水は戻し管８に導かれ、最も高い位置にある貯水槽４と同じまたはそれより高い位置まで一旦引き上げられた後２次側配水管１１ａに排出される。
【００４７】
図４に示した貯水装置１では、縦に配列された貯水槽４、４′、４″の各々の最上部から水を取り込み、最低部から流出させるようにしているので水が各貯水槽内で滞留をすることがなく、水質を清浄に保つことができる。また、戻し管８に導入された水は一旦貯水槽４、４′、４″の最上部またはそれより高い位置まで引き上げられてから２次側配水管１１ａに排出するようにしているので、断水時に貯留した水の流出を防止することができる。空気の入り切り弁１０の作用は図１を用いて説明したものと同様である。
【００４８】
図３に示した貯水装置１の変形例として、地上に水平に配列した貯水槽４、４′、４″を配水管の途中に上下に複数段配列させ、また、図４に示した貯水装置１の変形例として、縦に配列した貯水槽４、４′、４″を配水管の途中に複数水平に並列させるようにすれば、無数の貯水槽群を構成することが可能である。また、戻し管６ａまたは戻し管８の最上部にさらに貯水槽を設けてもよい。
【００４９】
なお、図１〜図４に示した貯水槽４、４′、４″は球形であるが、本発明による貯水装置に設けられる貯水槽は球形には限られず、円筒形、角型等種々の形状が考えられる。また、図１〜図４に示した貯水槽の数は３個であるが、本発明による貯水装置に設けられる貯水槽の数は３個に限られず、所望の数の貯水槽を接続すればよい。
【００５０】
【発明の効果】
本発明による貯水装置は以上説明したように構成されているので、次に列記するような効果を奏する。
（１）水道の配水管内の水を自然水圧により地上に設置した貯水槽まで押し上げて貯留するので、水の貯留や取り出しにポンプ等の動力を必要としない。従って、維持管理が簡単で経済的であると同時に、停電などが原因で機能しなくなることはない。
（２）断水になっても貯水槽内の水は一滴たりとも水道本管に逆流しない。
（３）所望の数の貯水槽を縦にも横にも接続できるので、設置場所に適した形状および貯水容量の貯水装置にすることができる。
（４）貯水装置を地上に設置するようにしたので、漏水等の不具合が生じても点検が容易である。また、複数の貯水槽で構成されているので、一部の貯水槽に不具合が生じてもその部位の系統のみを止めて修理を行うことができ、貯水装置全体が機能しなくなることがない。
（５）平常時には貯水装置内で水は常時循環し滞留することがないので水道水として必要な水質を確保できる。
【図面の簡単な説明】
【図１】本発明による貯水装置の第１の実施の形態を示す図である。
【図２】図１に示した貯水装置の変形例を示す図である。
【図３】本発明による貯水装置の第２の実施の形態を示す図である。
【図４】本発明による貯水装置の第３の実施の形態を示す図である。
【図５】従来の貯水装置の一例を示した図である。
【符号の説明】
１貯水装置
２逆止弁
３導入管
４、４′、４″ 貯水槽
５流水管
６第１の戻し管
６ａ第２の戻し管
７取り出し管
７ａ給水弁
９排出管
９ａ排出弁
８戻し管
１０空気の入り切り弁
１１１次側配水管
１１ａ２次側配水管
１２導入口
１３取り出し口
１４流水口
２１配水本管
２２導入管
２３排出管
２４給水槽
２５自家発電設備
２６給水管
２７取り出し口
３０貯水装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water storage device, and more particularly to a public water storage device intended for emergency water supply in the event of an earthquake.
[0002]
[Prior art]
When a disaster such as a major earthquake occurs, there is a great possibility that the supply of tap water will be stopped due to destruction of water supply facilities or power outages. For this reason, it is necessary to establish emergency drinking water and emergency water supply measures on a regular basis. However, this emergency water supply measure is not sufficient in the Great Hanshin Earthquake that occurred in January 1995. Or it was proved that it did not work well.
[0003]
According to the Disaster Relief Act, emergency water supply in the event of a disaster is essentially the responsibility of prefectures and municipalities, and a certain scale of earthquake-preserving water storage facilities has begun to be installed in various places. In the event of an earthquake disaster, water is supplied to the residents directly or by vehicle transport using the water storage facilities, water treatment plants, and water supply stations for earthquake countermeasures.
[0004]
With regard to the structure of the water storage system in such public earthquake disaster-preserving water storage facilities, water can be reliably stored and supplied even during an earthquake, and water must be stored in order to keep the stored water clean and conform to water quality standards. Is required to be in the form of proper inflow and outflow at all times.
[0005]
Here, an example of the water storage device for earthquake disaster countermeasures installed in Tokyo etc. is demonstrated using FIG. The water storage device 30 is installed in the basement of a relatively large park, and the water storage capacity is 1,500 m ³ , for example, and the goal is to install such a water storage device 30 in a radius of 2 km. Has been.
[0006]
First, the configuration will be described. The water storage device 30 was introduced into the introduction pipe 22 for introducing water from the water distribution main pipe 21, the water supply tank 24 for storing the water introduced from the introduction pipe 22, and the water supply tank 24. A discharge pipe 23 for forcibly discharging water to the water distribution main 21 by the pump P1, a water supply pipe 26 for pumping the water stored in the water supply tank 24 in the event of a disaster by the pump P2, and a water supply pipe 26 And a private power generation facility 25 for operating the pump P2.
[0007]
Next, the water storage and water supply mechanism of the water storage device 30 will be described.
[0008]
Under normal circumstances, water flowing through the water distribution main pipe 21 is guided to the introduction pipe 22 by water pressure and poured into the water supply tank 24. On the other hand, by always operating the pump P1, the water once flowing into the water supply tank 24 is forcibly returned to the distribution main pipe 21 through the discharge pipe 23. In this way, the water in the water tank 24 is constantly circulated to ensure water quality.
[0009]
On the other hand, when a water outage occurs during a disaster, the private power generation facility 25 is operated and the pump P2 is operated to pump water stored in the water supply tank 24 through the water supply pipe 26 and supply water from the outlet 27.
[0010]
Since it is configured as described above, the water storage device 30 satisfies the standard for the structure of the water storage device in the public earthquake disaster countermeasure water storage facility described above.
[0011]
[Problems to be solved by the invention]
However, even if the water storage device 30 has a sufficient water storage capacity, there is a problem with emergency water supply in the event of a disaster. In the Great Hanshin Earthquake, it is new to the memory that people could not be secured or water supply to residents by vehicle transportation did not function sufficiently due to cuts and destruction of roads. Even if the water storage capacity is sufficient, it is highly likely that the benefit of the water storage device 30 is limited to nearby residents who can walk to the place where the water storage device 30 is located.
[0012]
In addition, when water is supplied in the event of a disaster, the water is stored underground, so that the pump P2 cannot pump out the water unless the private power generation facility 25 is operated. In the event of a disaster, not only residents but also staff of local public organizations are also affected by the disaster, so it is a problem whether it is possible to ensure personnel who can operate the private power generation facility 25 and the pump P2.
[0013]
Furthermore, the water storage device 30 has a problem in terms of maintenance. If a large-scale water tank is provided in the basement, there is no way to check even if water leaks somewhere in the water tank 24, for example. In fact, leakage in such underground reservoirs is a frequent phenomenon. In addition, if the private power generation facility 25 and the pump P2 are not inspected on a regular basis, it may be possible that they cannot operate due to a failure at the time of a disaster.
[0014]
The present inventor, when installing a water storage facility for earthquake disaster countermeasures for public use, has to rethink the idea of covering a large area of the underground water storage facility with residents' drinking water over a wide area. I think the problem will not be solved.
[0015]
In other words, by providing a large number of relatively small water storage devices in public facilities such as parks, schools, and hospitals, water supply at the time of disaster can be easily performed without the help of power, and daily maintenance is easy, The function of emergency water supply at the time of a disaster can be fully demonstrated. An object of the present invention is to provide a water storage device that is relatively small and easy to maintain for the purpose of being installed in such a large number of public facilities.
[0016]
[Means for Solving the Problems]
Aqueduct water storage apparatus according to claim 1, for introducing a plurality pieces of water tanks which are substantially horizontally arranged on the ground, the water on top of the first reservoir from the primary side water distribution pipes underground And the upper part of each water tank, the water pipe that sequentially connects the uppermost part of the water tanks installed adjacent to each other, and the lowest part of each of the water tanks are connected to each other, and water is taken out if necessary. A take-out pipe provided with a take-out port, a first return pipe connecting the upper part of the water storage tank at the end of the connected water pipe and the underground secondary water pipe, and the take-out A second return pipe connecting the pipe and the underground secondary water pipe, and the highest part of the first return pipe is higher than the uppermost part of each water storage tank And the pneumatic return valve that opens and closes by the pressure inside and outside the pipe at the highest part of the first return pipe. Received, the highest part of the second return pipe is provided to be higher than the uppermost part of each water storage tank, the pneumatic return valve is provided at the highest part of the second return pipe, The pneumatic shutoff valve is provided at the uppermost part of the water storage tank.
[0017]
The water storage device according to claim 2 is connected to a plurality of water tanks arranged substantially horizontally on the ground and a primary water supply pipe in the basement, and connected to the top of each water tank. A water guide pipe for introducing tap water on the next side, a take-out pipe connected to the lowest part of each of the water storage tanks and provided with a take-out port for taking out water if necessary; A first return pipe connecting a secondary side water pipe, and a second return pipe connecting the take-out pipe and an underground secondary side water pipe. The highest part of the return pipe is provided so as to be above the uppermost part of each of the water tanks, the pneumatic shut-off valve is provided at the highest part of the second return pipe, and the uppermost part of each water tank is provided with the above-mentioned A pneumatic shut-off valve is provided .
[0018]
The water storage device according to claim 3 is connected to a plurality of water tanks arranged in a substantially vertically stacked state and a primary water supply pipe in the underground, and connected to the uppermost part of each water tank. And a water conduit for introducing the tap water on the primary side, a take-out pipe provided under the lowermost water tank, and a take-out port for taking out water if necessary, and A lead-out pipe connecting the lower part and the take-out pipe, and a return pipe connecting the take-out pipe and the underground secondary water supply pipe, the highest part of the return pipe being located at the top The uppermost part of the water storage tank is provided at a higher position, the highest part of the return pipe is provided with the pneumatic cut-off valve, and the uppermost part of each water tank is provided with the pneumatic cut-off valve. It is characterized by.
[0019]
The water storage device according to claim 4 is connected to a plurality of water tanks arranged horizontally and stacked in a multi-stage, and a primary water supply pipe in the underground, A water guide pipe connected to the uppermost part to introduce primary side tap water, a take-out pipe disposed under the lowermost water tank, and provided with a take-out port for taking out water if necessary; A lead-out pipe that connects the lowest part of each water tank and the take-out pipe; and a return pipe that connects the take-out pipe and the underground secondary water supply pipe. The uppermost reservoir of the uppermost water tank is provided at a higher position, the highest part of the return pipe is provided with the pneumatic shutoff valve, and the uppermost part of each reservoir is provided with the pneumatic shutoff valve. It is provided.
[0020]
Therefore, in normal times , tap water is introduced from the uppermost part of each water tank and led out from the lowest part and the upper part by the supply pressure from the primary side water pipe . The water is constantly circulated in each water tank by the supply pressure and is pushed out to the take-out pipe or the upper outlet without staying there . Therefore , it is possible to secure the water quality necessary for tap water. The water pushed out from the take-out pipe is pushed into the connected return pipe and flows upward through the return pipe. Since the highest part of the return pipe is higher than the uppermost part of each water tank, the water is once pushed up to the highest place of the piping system by the supply pressure from the primary side water pipe, and then the secondary side water pipe. Will be discharged . When a water break occurs, water can be reliably stored without flowing out of the water storage tank beyond the highest part of the piping system even if the pressure of the secondary distribution pipe drops. The siphon phenomenon can be prevented by providing the pneumatic shut-off valve at the highest portion, and the outflow of water from the water storage tank by the siphon can also be prevented.
[0021]
Since the desired number of water storage tanks can be arranged both vertically and horizontally, the water storage device according to claims 5 and 6 can be configured as a water storage device having a capacity and shape suitable for the installation location.
[0022]
In addition, by providing an air on / off valve at the top of the water tank, when the water is full, the water tank is sealed to keep the water hygienic, and when water is shut off, when water is taken out from the lowest part of each water tank by natural fall Water can be taken out smoothly.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0024]
FIG. 1 is a cross-sectional view showing a first embodiment of a water storage device 1 according to the present invention. The water storage device 1 includes water storage tanks 4, 4 ′, 4 ″ arranged almost horizontally on the ground, and is incorporated in the middle of a water distribution pipe disposed in the basement. The water is taken in from the primary side water distribution pipe 11 by the introduction pipe 3, the route passing through the first return pipe 6 through the water storage tanks 4, 4 ′, 4 ″ and the flowing water pipe 5, and the water storage tanks 4, 4 ′, Water is discharged to the secondary side water distribution pipe 11a through two routes, 4 ″ and a route passing through the second return pipe 6a via the take-out pipe 7.
[0025]
Each of the water storage tanks 4, 4 ′, 4 ″ takes in water from the introduction port 12 provided at the uppermost part, and passes through the extraction pipes 7 connected to the respective extraction outlets 13 provided at the lowest part, so that the second Water is discharged from the first return pipe 6 to the secondary water distribution pipe via the return pipe 6a and the flow pipe 5 connected to the water flow port 14 provided at the upper part of the water tank 4 ″ on the most downstream side. It is like that. One end of the water pipe 5 of the other water storage tank 4, 4 ′ is connected to the water flow inlet 14 of the water storage tank 4, 4 ′, and the other end is connected to the water storage tank 4 ′ adjacent to the water storage tank 4 ′ and the inlet 12 of 4 ″. As described above, the first return pipe 6 is connected to the water inlet 14 of the water storage tank 4 ″. The first return pipe 6 once the water each reservoir 4, 4 ', 4 at the top or pulling because it higher position of "plumbed to wrap at higher than the upper end position of each reservoir Afterwards, it is connected to the underground secondary water pipe 11a.
[0026]
The take-out pipe 7 is connected in common to the take-out port 13 of each water tank 4, 4 ', 4 ". In this way, each water tank 4, 4', 4" is connected horizontally. In addition, an air on / off valve 10 is provided above the inlet 12 of each of the water storage tanks 4, 4 ′, 4 ″.
[0027]
A check valve 2 is provided in the middle of the introduction pipe 3, and a water supply valve 7 a is provided in the extraction pipe 7. An air on / off valve 10 is also provided at the top of the first return pipe 6 and the second return pipe 6a.
[0028]
The air on / off valve 10 provided at the top of each of the water tanks 4, 4 ', 4 "and the first return pipe 6 and the second return pipe 6a is closed by water pressure when the water is full. When the outside air is shut off and the water pressure drops and the water pressure drops, the valve opens and the air flows in. The air on / off valve 10 thus creates a sealed state when the water is full, thereby creating a sealed state from the outside. Prevents dust and bacteria from entering, keeps the water hygienic, and enables smooth removal by inflow of air when water is removed from the lower part of the water storage device 1 when water is shut off. In addition, the air on / off valve 10 provided at the uppermost part of the second return pipe 6a causes water in the second return pipe 6a to be drawn into the secondary water distribution pipe 11a due to siphoning when the water is shut off. (In addition, air Ri reference Japanese Patent Application No. 6-787265 specification of the applicant is an example of a specific configuration of the cut valve 10).
[0029]
Next, the operation of the water storage device 1 during normal times and when water is shut off will be described.
[0030]
Under normal conditions, the water in the primary side distribution pipe 11 is pushed up in the introduction pipe 3 by water pressure, passes through the check valve 2, and then introduced into the first water storage tank 4 from the introduction port 12. Thereafter, the water flows out from the first water tank 4 separately from the route led from the water flow port 14 provided at the top to the water pipe 5 and the route led from the take-out port 13 provided at the lowest part to the take-out tube 7.
[0031]
The water introduced from the first water storage tank 4 to the water flow pipe 5 flows into the water storage tank 4 ′ from the introduction port 12 of the next water storage tank 4 ′, and is divided again into two routes of the water flow pipe 5 and the extraction pipe 7. It flows out and flows into the last water tank 4 ″ while repeating the same. The water led out from the last water tank 4 ″ to the first return pipe 6 is temporarily stored in the water tank 4, by the first return pipe 6. After being pulled up to the top of 4 ′, 4 ″ or higher, it is discharged to the secondary water distribution pipe 11a. On the other hand, the water led out from the water tank 4, 4 ′, 4 ″ to the take-out pipe 7 Is raised by the second return pipe 6a to the uppermost part of the water storage tank 4, 4 ', 4 "or higher, and then discharged to the secondary side water distribution pipe 11a.
[0032]
Since water flowing out from each water tank 4, 4 ′, 4 ″ flows out into two routes of the water flow pipe 5 and take-out pipe 7, the water stays in each water tank 4, 4 ′, 4 ″. The water quality can be kept clean.
[0033]
On the other hand, when the water break occurs, the water pressure in the primary side water distribution pipe 11 is suddenly lost, and the water in the introduction pipe 3 is changed to move toward the primary side water distribution pipe 11 by being dragged by it. Since the check valve 2 is closed by the pressure change, it is possible to prevent the backflow to the primary side water distribution pipe 11. However, the movement in which the water in the other pipes and the water storage tanks 4, 4 ′, 4 ″ attempts to flow out to the secondary side water distribution pipe 11a through the take-out pipe 7 by natural fall does not change.
[0034]
Therefore, in the water storage device 1, in order to prevent the outflow of the water, the first return pipe connected to the upper part of the water storage tank and the second return pipe connected to the take-out pipe 7 are both the water storage tank 4, The pipe is once pulled up to the top of 4 ′, 4 ″ or higher, and then connected to the secondary side water distribution pipe. By this , water is confined in the water storage device 1 when water is shut off, and the stored water flows out. Due to the action of the pneumatic shut-off valve 10 provided at the uppermost part of the first and second return pipes 6 and 6a , water is drawn into the secondary water distribution pipe 11a by siphon phenomenon. There is nothing.
[0035]
When water is supplied from the water storage device 1 when the water is shut off, the water stored in each of the water storage tanks 4, 4 ′, 4 ″ can be taken out by natural fall only by opening the water supply valve 7a without using power. When the water supply valve 7a is opened, the air on / off valve 10 attached to the top of each water tank 4, 4 ', 4 "is opened at the same time, so that air flows into each water tank 4, 4', 4". The water can be taken out from the water supply valve 7a smoothly.
[0036]
On the other hand, when the water shutoff is finished and the water flow is resumed, the water rises from the primary side distribution pipe 11 by the water pressure through the introduction pipe 3 while opening the check valve 2, and the water tanks 4, 4 ', 4 " Water is supplied in order, and at this time, the air in each reservoir 4, 4 ', 4 "is operated by the action of an air on / off valve 10 attached to the top of each reservoir 4, 4', 4". As a result, the air is completely exhausted, and at the same time, the air on / off valve 10 is completely closed and the original sealed state is maintained again.
[0037]
FIG. 2 is a modification of the water storage device 1 shown in FIG. 2, when the same reference numerals as those in FIG. 1 are used, the same components as those in FIG.
[0038]
In the water storage device 1 shown in FIG. 2, the water storage tanks 4, 4 'and 4 "connected substantially horizontally on the ground are arranged in three upper and lower stages between the introduction pipe 3, the first return pipe 6 and the second return pipe 6a. By arranging a desired number of water tanks vertically and horizontally in this way, it is possible to configure an infinite number of water tank groups. Can store hundreds or thousands of tons of water.
[0039]
Moreover, in the water storage apparatus 1 shown in FIG. 2, the water storage tank 4a is provided in the uppermost part of the 2nd return pipe 6a. The water storage tank 4a is provided for confining the stored water in the water storage device 1 so that the stored water does not flow into the secondary water distribution pipe 11a as it is, but the water storage tank 4a is also a contaminant such as sand mixed in tap water. Is removed and water is discharged to the secondary side water distribution pipe 11a. Then, the contaminants can be discharged by opening the discharge valve 9a of the discharge pipe 9. Of course, since the water can be stored as the water tank 4a itself, the water in the water tank 4a can be finally used as drinking water by opening the discharge valve 9a.
[0040]
FIG. 3 is a sectional view showing a second embodiment of the water storage device according to the present invention. In FIG. 3, the same reference numerals as those in FIG. 1 represent the same components as those in FIG.
[0041]
The water storage device 1 includes water storage tanks 4, 4 ′, 4 ″ arranged substantially horizontally on the ground, and is incorporated in the middle of a water distribution pipe disposed in the basement. The water taken in from the primary side water distribution pipe 11 by the introduction pipe 3 is guided into the respective water tanks from the introduction pipes 3 commonly connected to the uppermost parts of the respective water tanks 4, 4 ′, 4 ″. The route passing through the second return pipe 6a from the lowest part of the water tanks 4, 4 'and 4 "through the take-out pipe 7 and the inlet pipe 3 without being taken into the water tanks 4, 4' and 4". It is discharged to the secondary side water distribution pipe 11a through two routes: a route passing through the first return pipe 6.
[0042]
The water introduced into the take-out pipe 7 is guided to the second return pipe 6a, and once pulled up to the top of the water storage tanks 4, 4 ', 4 "or higher, it is discharged to the secondary side water distribution pipe 11a. Therefore, it is possible to prevent the stored water from flowing out to the secondary side water distribution pipe 11a when the water is shut off, and the operation of the air on / off valve 10 is the same as that described with reference to FIG.
[0043]
Further, in the water storage device 1 shown in FIG. 3, water is taken in from the uppermost part of the water storage tanks 4, 4 ', 4 "arranged almost horizontally on the ground and flows out from the lowest part. The water quality can be kept clean without staying in each water tank.
[0044]
In FIG. 3, the first return pipe 6 is not provided, but the introduction pipe 3 is kept at a portion connected to the water storage tank 4 ″, and water is supplied to the underground secondary side water distribution pipe 11a only by the second return pipe 6a. May be discharged.
[0045]
FIG. 4 is a sectional view showing a third embodiment of the water storage device according to the present invention. 4, the same reference numerals as those in FIG. 1 represent the same components as those in FIG. 1, and thus the description thereof will be omitted.
[0046]
The water storage device 1 includes water storage tanks 4, 4 ', 4 "arranged vertically on the ground, and is incorporated in the middle of a water distribution pipe arranged underground. The introduction pipe 3 is a primary. Water is taken in from the side water distribution pipes 11 and water is introduced into the respective water storage tanks from the uppermost part of the respective water storage tanks 4, 4 ′, 4 ″. The water introduced into the water storage tanks 4, 4 ′ is led out from the lowest part of each water tank 4, 4 ′ to the lead-out pipe 15 and further introduced into the take-out pipe 7 connected to the lead-out pipe 15. The water introduced into the water storage tank 4 ″ is directly introduced into the take-out pipe 7 from the lowest part of the water storage tank 4 ″. The water introduced into the take-out pipe 7 is guided to the return pipe 8, and is once pulled up to the same or higher position as the water tank 4 at the highest position, and then discharged to the secondary water distribution pipe 11a.
[0047]
In the water storage device 1 shown in FIG. 4, water is taken in from the uppermost part of each of the vertically arranged water storage tanks 4, 4 ′, 4 ″ and flows out from the lowest part. In this case, the water quality can be kept clean without any stagnation, and the water introduced into the return pipe 8 is once pulled up to the top of the water tanks 4, 4 ', 4 "or higher. Since the water is discharged to the secondary side water distribution pipe 11a, the outflow of water stored at the time of water outage can be prevented. The operation of the air on / off valve 10 is the same as that described with reference to FIG.
[0048]
As a modification of the water storage device 1 shown in FIG. 3, water storage tanks 4, 4 ′, 4 ″ arranged horizontally on the ground are arranged in a plurality of stages in the middle of the water distribution pipe, and the water storage device shown in FIG. As a modification of the first embodiment, an infinite number of water tank groups can be configured by arranging a plurality of water tanks 4, 4 ′, 4 ″ arranged vertically in parallel in the middle of the water distribution pipe. Further, a water storage tank may be further provided at the uppermost portion of the return pipe 6a or the return pipe 8.
[0049]
1 to 4 have a spherical shape, the water tank provided in the water storage device according to the present invention is not limited to a spherical shape, and various types such as a cylindrical shape and a square shape can be used. 1 to 4 is three, the number of water tanks provided in the water storage device according to the present invention is not limited to three, and a desired number of water tanks What is necessary is just to connect a tank.
[0050]
【The invention's effect】
Since the water storage device according to the present invention is configured as described above, the following effects can be obtained.
(1) Since the water in the distribution pipe of the water supply is pushed up and stored up to a water tank installed on the ground by natural water pressure, power such as a pump is not required for storing and taking out water. Therefore, it is easy and economical to maintain, and at the same time, it will not fail due to a power failure.
(2) Even if water is cut off, even a single drop of water in the reservoir will not flow back to the water main.
(3) Since a desired number of water storage tanks can be connected both vertically and horizontally, a water storage device having a shape suitable for the installation location and a water storage capacity can be obtained.
(4) Since the water storage device is installed on the ground, it is easy to check even if a malfunction such as water leakage occurs. Moreover, since it consists of a plurality of water storage tanks, even if some of the water storage tanks are defective, it is possible to stop and repair only the part of the system, and the entire water storage apparatus will not fail.
(5) Since water does not circulate and stay in the water storage device at normal times, the water quality necessary for tap water can be ensured.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment of a water storage device according to the present invention.
FIG. 2 is a diagram showing a modification of the water storage device shown in FIG.
FIG. 3 is a diagram showing a second embodiment of a water storage device according to the present invention.
FIG. 4 is a diagram showing a third embodiment of a water storage device according to the present invention.
FIG. 5 is a diagram showing an example of a conventional water storage device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Water storage apparatus 2 Check valve 3 Introducing pipe 4, 4 ', 4 "Water storage tank 5 Flowing water pipe 6 1st return pipe 6a 2nd return pipe 7 Extraction pipe 7a Water supply valve 9 Discharge pipe 9a Drain valve 8 Return pipe 10 Air inlet / outlet valve 11 Primary side water pipe 11a Secondary side water pipe 12 Inlet 13 Outlet 14 Flow outlet 21 Water main 22 Inlet pipe 23 Discharge pipe 24 Water tank 25 Private power generation facility 26 Water supply pipe 27 Outlet 30 Storage water apparatus

Claims

A plurality of water tanks arranged almost horizontally on the ground;
A water conduit that introduces water from the underground primary water pipe to the top of the first water tank,
A water pipe that sequentially connects the uppermost part of each water tank and the uppermost part of the water tank installed next to the water tank;
A take-out pipe connected to the lowest part of each water tank and provided with a take-out port for taking out water if necessary;
A first return pipe connecting the upper part of the water tank at the end of the connected water pipe and the underground secondary side water pipe;
A second return pipe connecting the take-out pipe and the secondary side water pipe;
The highest part of the first return pipe is located higher than the uppermost part of each water tank, and the highest part of the first return pipe is opened and closed by the pressure inside and outside the pipe. On / off valve is provided,
The highest part of the second return pipe is provided to be higher than the uppermost part of each water storage tank, and the pneumatic shut-off valve is provided at the highest part of the second return pipe. A water storage device.

A plurality of water tanks arranged almost horizontally on the ground;
A water conduit that connects to the primary water supply pipe in the basement and introduces the tap water on the primary side by connecting to the top of each water tank,
A take-out pipe connected to the lowest part of each of the water storage tanks and provided with a take-out port for taking out water if necessary;
A first return pipe connecting the terminal of the conduit pipe and the underground secondary side water pipe;
A second return pipe connecting the take-out pipe and the underground secondary water supply pipe;
The highest part of the second return pipe is provided to be above the uppermost part of each water tank, and the pneumatic shut-off valve is provided at the highest part of the second return pipe,
The water storage device, wherein the pneumatic shut-off valve is provided at the top of each water tank.

A plurality of water tanks arranged in a substantially vertically stacked state;
A water conduit that connects to the primary water supply pipe in the basement and introduces the tap water on the primary side by connecting to the top of each water tank,
A take-out pipe disposed under the lowermost water tank, provided with a take-out port for taking out water if necessary,
A lead-out pipe connecting the lowest part of each water tank and the take-out pipe;
A return pipe connecting the take-out pipe and the underground secondary water supply pipe;
The highest part of the return pipe is provided to be higher than the uppermost part of the water storage tank located at the top, and the pneumatic cut-off valve is provided at the highest part of the return pipe,
The water storage device, wherein the pneumatic shut-off valve is provided at the top of each water tank.

A plurality of water tanks arranged horizontally and stacked in multiple stages;
A conduit pipe connected to the underground primary water pipe, and connected to the uppermost part of each of the water storage tanks to introduce primary tap water;
A take-out pipe disposed below the lowermost water storage tank and provided with a take-out port for taking out water if necessary;
A lead-out pipe connecting the lowest part of each water tank and the take-out pipe;
A return pipe connecting the take-out pipe and the underground secondary water supply pipe;
While providing the highest part of the return pipe to be higher than the uppermost part of the water storage tank located at the top, the highest part of the return pipe is provided with the pneumatic cut-off valve,
The water storage device, wherein the pneumatic shut-off valve is provided at the top of each water tank.

A plurality of water tanks arranged horizontally and stacked in multiple stages;
A water conduit that introduces water from the underground primary water pipe to the top of the first water tank in each stage;
For each stage, a water pipe that sequentially connects the upper part of each water tank and the uppermost part of the water tank installed next to the water tank,
A take-out pipe disposed below the lowest water tank, connected to the lowest part of each water tank, and provided with a take-out port for taking out water if necessary,
A first return pipe connecting the upper part of each of the water tanks arranged at the end of each stage and an underground secondary side water pipe,
A second return pipe connecting the take-out pipe and the underground secondary water supply pipe;
The highest part of the first return pipe is located higher than the uppermost part of each water tank, and the highest part of the first return pipe is opened and closed by the pressure inside and outside the pipe. On / off valve is provided,
The highest part of the second return pipe is provided to be higher than the uppermost part of each water storage tank, and the pneumatic cut-off valve is provided at the highest part of the second return pipe. A water storage device.

In the vicinity of the front of the second return pipe, at the same height as the uppermost water tank, another water storage tank provided with the pneumatic shut-off valve is provided at the uppermost part, and the return pipe side of the return pipe was connected to the top of the water tank is connected to the highest portion of the back of the top of the outlet of the reservoir tube, the water storage apparatus according to claim 5 in which a hole taken up in the lowest part of the reservoir.