JP4048559B2

JP4048559B2 - U-shaped air lift pump pipe and septic tank

Info

Publication number: JP4048559B2
Application number: JP2002213997A
Authority: JP
Inventors: 裕二小泉; 淳日比野; 信義片貝; 宏山下
Original assignee: 株式会社日立ハウステック
Priority date: 2002-02-05
Filing date: 2002-07-23
Publication date: 2008-02-20
Anticipated expiration: 2022-07-23
Also published as: JP2003300085A

Description

【０００１】
【発明の属する技術分野】
本発明は、家庭等から排出される屎尿やその他の生活排水（単に、汚水ともいう）を処理する汚水浄化槽と、その汚水浄化槽に付設するエアリフトポンプ管に関するものである。
【０００２】
【従来の技術】
図１１に、汚水浄化槽に備える従来のエアリフトポンプ管の一例を示した（例えば、実開平４−１１８１９９号公報参照）。エアリフトポンプ管は、液中に水没・立設して使用されるものであり、上部に液吸込口１０のある液吸込管２と上部に液排出口５のある揚水管３とが略Ｕ字状に接続され、この略Ｕ字状管の揚水管側の底部よりやや上に、空気供給管４の下端開口部９が揚水管３から分岐するように接続され、この空気供給管４の上端開口部８から空気を吹き込む構造となっている。また、揚水管３上部の液排出口５には、移送量を調整する調整マス１３が備えられ、過剰に揚水した場合は、余剰水を元の槽内へ戻す切欠部が取り付けられている。なお、図１１中、実線矢印は液流を示し、点線矢印は空気流を示す。
エアリフトポンプ管による揚水は次のようにして行われる。空気供給管４の上端開口部８から入った空気が、その下端開口部（分岐部）９から揚水管３内に吐出すると、その空気は空気泡となって液と共に揚水管３内を上昇する。Ｕ字状管の底部で揚水管３に接続された液吸込管２では、液吸込管２外の槽内液が液吸込口１０から吸い込まれ、Ｕ字状管の底部を経て、揚水される。この際、押し上げられた揚水は液排出口５から調整マス１３に至る。調整マス１３では、過剰分の揚水を切欠部から溢れ出させ、必要分だけを行先へ移送させる。
【０００３】
【発明が解決しようとする課題】
しかし、エアリフトポンプ管は、上記したように汚水の移送に用いるため、運転を続けると、液吸込管２や揚水管３の管内壁に汚水中の汚泥が付着・堆積し、遂には堆積物が抵抗となって揚水が困難となる。そのため、管内壁に少々の汚泥が付着・堆積しても問題を生じないように、従来は管径が大きめの液吸込管２及び揚水管３（例えば、内径が４０ｍｍ〜６０ｍｍ）を使用し、必要量以上に揚水した後に調整マス等の調整装置で余剰液を元に戻したのである。
【０００４】
本発明は、従来よりも液吸込管や揚水管の管径を小さくでき、汚泥の付着・堆積が少なく、あるいは、調整マス等の調整装置を必要としないエアリフトポンプ管を提供することを課題とするものである。
【０００５】
【課題を解決するための手段】
上記課題を達成するため本発明者らは種々検討した結果、運転中に液吸込管及び揚水管のいずれの管内壁も、空気供給管から吐出する空気と汚水とが混ざった気液混合流体で自動的に洗浄する構造のエアリフトポンプ管を着想することができ、本発明を完成するに至った。すなわち、本発明のエアリフトポンプ管は、上部に液排出口５を有して立設する揚水管３と、上部に開口部８を有する空気供給管４とが、直接に又は接続部材（６ａ，６ｂ）を介して、底部で繋がって略Ｕ字状管を形成してなり、その揚水管側では、前記底部より上の位置で、上端に液吸込口１０を有する液吸込管２が、直接に又は接続部材（６ｃ）を介して、立ち上がるように分岐しており、前記液吸込管２の液吸込口１０の高さ位置は、前記揚水管３の液排出口５の高さ位置よりも低い位置に形成されているエアリフトポンプ管１である。
【０００６】
ここで、液吸込管２の液吸込口１０の周りには、好ましくは、阻流部材１４を設ける。スカムと呼ばれる浮上性固形物１５が液吸込口１０に集積して液吸込みの効率が低下するのを防ぐためである。
【０００７】
また、揚水管３、空気供給管４及び液吸込管２の各々の内径は、好ましくは、いずれも５〜２０ｍｍの範囲とする。少ない空気量で必要な量の汚水を揚水するためである。
また、これら三つの管の内径は同じとすることが好ましい。接続部における段差を無くし、流体（汚水、空気又はこれらの混合した気液混合流体）の流れをスムーズにするほか、エアリフトポンプ管を構成する管及び接続部材の種類を増やさないためである。
【０００８】
本発明は、上記エアリフトポンプ管を利用し、これを槽内に配置した汚水浄化槽にも関するものである。
このような汚水浄化槽として好ましいものは、上流側から、流量調整機能を有する嫌気処理槽（流量調整槽）２２、好気処理槽２３、濾過槽２４及び消毒槽２５を備える汚水浄化槽である。この流量調整機能を有する嫌気処理槽（流量調整槽）２２及び濾過槽２３のいずれかの槽又は両槽の一画に、上記エアリフトポンプ管を各々立てるようにして設ける。
【０００９】
【作用】
従来例のエアリフトポンプ管（図１１）においては、揚水管３下部から枝分かれする（空気供給管４への）分岐部９は、液吸込管２と揚水管３との接続部、すなわち、略Ｕ字状管の底部１２よりも高い位置にあるので、気液混合流体は液吸込管２側へは入り込めず、したがって、その管内壁に付着・堆積した堆積物や汚泥を落とせない。
【００１０】
一方、本発明のエアリフトポンプ管１（例えば、図１）においては、上端に液吸込口１０をもつ液吸込管２が、略Ｕ字状管の底部１２の少し上（揚水管３側）から立ち上がるように分岐しているので、空気供給管４からの空気又はこの空気と汚水とが混ざった気液混合流体の一部は液吸込管２内にも回り込んで、その管内を上昇し、管内壁に付着した汚泥を落とすことができる。
【００１１】
特に、流量調整機能がある汚水浄化槽の流量調整槽（例えば、流量調整槽２２）に、本発明のエアリフトポンプ管１を配置すると、槽内の水位が最低水位（Ｌ．Ｗ．Ｌ）に近いときに、空気泡・汚水混じりの気液混合流体が揚水管３内を上下に激しく流動し、管内壁に付着した汚泥を剥離させる（図２参照）。また、空気供給管４からの空気の一部が液吸込管２の上方へも押し出されるので、その液吸込管２の管内壁に付着した汚泥の剥離又は洗浄も起こる。このように、揚水管３の管内ばかりではなく液吸込管２の管内においても汚泥の剥離（すなわち、洗浄）が起こる。エアリフトポンプ管の管内径を従来よりも小さくできる理由である。
【００１２】
【発明の実施の形態】
以下、図面を参照して、本発明を具体的に説明する。
図１は、本発明の一例のエアリフトポンプ管１で、槽内液が最高水位にあるときの断面図を示す。
図示したように、エアリフトポンプ管１は、上部に液排出口５を有する揚水管３と空気を供給する空気供給管４とが底部１２で繋がって略Ｕ字状管を形成してなり、その揚水管３側では底部１２よりやや上の位置で液吸込管２が上方に向かって分岐しており、その上端は開口された液吸込口１０である。立設して使用される。なお、図１中の実線矢印は液流を示し、点線矢印は空気流を示す（以下の図２〜図７においても同じ）。
【００１３】
図２は、槽内液が最低水位にあるときのエアリフトポンプ管１の縦断面図である。図１及び図２を用い、流量調整機能がある槽（流量調整槽）２２におけるエアリフトポンプ（エアリフトポンプ管とブロアとを組み合わせてなるもの）の運転を説明する。
エアリフトポンプ管１がある流量調整槽２２では、槽内の水位が最高水位と最低水位との間で変動するように液吸込口１０の位置を予め決める。先ず、ブロアからの空気は、空気供給管４から連続的に供給する。水位が最低水位より高い位置にあるときは、槽内液は揚水され液排出口５から所定の行先へ移る。このとき、移った槽内液（揚水量）よりも流入した汚水量のほうが多いと、その差分だけ蓄積し、水位は徐々に上昇し、場合によっては最高水位にまで高まる。
【００１４】
一方、流量調整槽２２に汚水が流入しない時間が続くと、水位は徐々に低下して最低水位まで下がり、液吸込口１０へ吸い込まれる汚水は殆どなくなり、槽内液の揚水は殆どゼロとなる（図２）。そうすると、揚水管３と液吸込管２の内部の圧力バランスが崩れ、空気供給管４から流入した空気は時々液吸込管２に流れて、液吸込管２を空気で洗浄する形となる。また、揚水管３側では、空気泡の比率の高い気液混合流体が揚水管３内を上下に激しく動き（両端に矢をもつ矢印で示す）、管内壁を洗浄する形となる。こうして、液吸込管２の内壁や揚水管３の内壁に付着した汚泥は剥離し、汚泥の堆積は避けられる。
【００１５】
図３及び図４は、本発明の第２例のエアリフトポンプ管で、液吸込口の周りに中空円筒状の阻流部材１４を設けたエアリフトポンプ管の例である。流量調整槽２２には、ある程度の時間が経過すると、スカムと呼ばれる浮上性の汚泥塊や油分であるオイルボール（油塊）等の浮上性固形物１５が出現する。この浮上性固形物１５は液吸込口１０付近に集積し、液の吸い込み効率を低下させる。阻流部材１４は、液吸込口１０に、浮上性固形物が集積するのを防止する。
【００１６】
図５は、本発明の第３例のエアリフトポンプ管１で、阻流部材１４内のメンテナンス性を考慮し、液吸込口１０を中空円筒状の阻流部材１４の側壁に設けた。こうすることによって、阻流部材１４内に付着した汚泥などを清掃で除き易くなる。なお、阻流部材１４は中空円筒状の代わりに、中空角筒状であってもよい。
【００１７】
図６は、本発明の第４例のエアリフトポンプ管で、図５のエアリフトポンプ管の変形である。浮上する固形物が阻流部材１４内に侵入しないように、中空角筒状の阻流部材１４下部の相対する二辺を図のように折り曲げ、一方の下端を他方の下端よりも下方に長く張り出させている。
また、液吸込口１０付近の液吸込管２は、最低水位（Ｌ．Ｗ．Ｌ）に近いときに、空気泡が抜け易いように傾斜させて接続している。これにより、液吸込管２の管内は効率よく洗浄される。
【００１８】
図７は上記エアリフトポンプ管を備える汚水浄化槽の概略構成図、図８は図７のＡ―Ａ矢視における断面図である。次に、これらの図を参照して本発明の汚水浄化槽について説明する。
【００１９】
汚水浄化槽２０は、上流側から、汚水中の沈降性固形物を重力下に沈降させ、そのあとの（上）液を次槽にオーバーフローさせる第一槽２１と、オーバーフローしてきた液を貯留させ、次槽へ液を定量的に移送させる第二槽２２と、移流してきた液を生物学的に好気処理する第三槽２３と、汚泥（浮遊性懸濁物質、ＳＳともいう）を濾過し、その濾液を次槽へ移流させる第四槽２４と、液を消毒処理する第五槽２５とに区画され、これらの槽は仕切壁２６、２７、２８、２９によってそれぞれ仕切られている。また、第一槽２１は汚水中の沈降性固形物を重力下に沈降させる沈降分離室２１ａ及び沈降させた固形物を貯留させ濃縮させる汚泥濃縮室２１ｂとの二室に分かれている。
【００２０】
各槽を機能面からみると、第一槽２１は沈殿分離槽、第二槽２２は流量調整槽、第三槽２３は好気処理槽、第四槽２４は濾過槽、第五槽２５は消毒槽と呼ぶこともできる。また、第一槽２１及び第二槽２２は嫌気的生物分解機能も有する。この嫌気的生物分解機能を更に高めるため、充填材（濾材、濾床）を充填した嫌気濾床槽又は嫌気処理槽とすることもできる。
【００２１】
沈降分離室２１ａでは、槽内液面よりも高い位置の壁部に汚水導入管４３を設け、その反対側の仕切壁２６には流量調整槽２２（第二槽）へ移流させる移流開口４４を設けている。また、沈降分離室２１ａを囲んで対峙する仕切壁３０、３１（図８）の下部には、汚水導入管４３側の壁面から移流開口４４の仕切壁２６に亘って開口部３２を設けている。
【００２２】
沈降分離室２１ａ内の液面付近には、汚水流入時の液流れを抑制する傾斜したバッフル板３３を汚水導入管４３側に設けている。
【００２３】
汚水導入管４３から沈降分離室２１ａに流入した汚水は、バッフル板３３を潜り抜けた後、略水平流となって移流開口４４に向って移流する。この間、水平流の流速よりも速い沈降速度をもつ固形物は、沈降分離室２１ａ下部の開口部３２を通過し、汚泥濃縮室２１ｂの底部に至り蓄積する。
【００２４】
汚泥濃縮室２１ｂでは、流入汚水の液流によって乱されることが少ないので、沈降した固形物は高濃度で蓄積し汚泥化する。汚泥化した固形物は、時間の経過とともに徐々に嫌気化して一部はスカムとなり、汚泥濃縮室２１ｂ上部の液面付近に浮上してくる。このとき、仕切壁３０の下端は仕切壁３１の下端よりも下方に長く且つ水平方向に張り出ているので、浮上したスカムが沈降分離室２１ａ下部の開口部３２から沈降分離室２１ａ内に入ることを阻止する。
【００２５】
流量調整槽２２（第二槽）では、次槽の好気処理槽（第三槽）２３へ槽内液を移送するエアリフトポンプ管（ブロワ３５と接続）１を配置し、汚水浄化槽２０へ流入する汚水量の変動を吸収する。すなわち、次槽への槽内液の移送は、エアリフトポンプ管１を介した平均化した移送である。
【００２６】
ここで、エアリフトポンプ管１で移送される液量が、移流開口４４からの流入量よりも多いとその差だけ槽内液は蓄積し、水位は最低水位から最高水位に向かう。逆の場合は、水位は最高水位から最低水位に向かう。最低水位になると、エアリフトポンプ管１では槽内液が揚水されず、空気は液吸込口１０からも吐出する（いわゆる、空運転）。
【００２７】
なお、図では示していないが、流量調整槽２２内には、汚泥や微生物が付着する濾材又は接触材等の充填材を配することもでき、その場合、充填材の上部を大気に露出（散水濾床の機能）させることができる。
【００２８】
好気処理槽（第三槽）２３では、好気的微生物によって液中の有機物を分解除去する。槽内には、通常、微生物の保持・増殖に好適な微生物担体（微生物付着材、接触材）を充填し、濾床（好気濾床、微生物反応用）３４を形成させる。濾床３４は、微生物担体が固定された固定床であっても、液とともに流動する流動床であってもよい。この際、好気的条件を維持させるためにブロワ３５から散気部材３７を通して空気を吐出する。
【００２９】
好気処理槽２３へ流れ込んだ液は、槽内の濾床３４を下向流で流れる。濾床３４で有機物が生物分解されると、その一部は汚泥に転換され、汚泥は増え、一部の汚泥は槽底部に集まる。集まった汚泥を槽底部から（エアリフトポンプを用いて）沈降分離室２１ａに移送させることもできるが、図７の場合では、発生する汚泥量は少ないので、移流管３８を介してこれを次槽の濾過槽（第四槽）２４へ移流させる。ここで、移流管３８は上端が開放し、下端が閉じている管状のものであり、この管の途中に移流口を設けている。なお、流れ込んだ液を好気処理槽２３の濾床内に下向流で流すのではなく、上向流で流してもよい。
【００３０】
濾過槽（第四槽）２４では、移流液中の汚泥を濾過し、その濾液を次槽へ移流させる。汚泥を濾過・捕捉するため、濾過槽２４内には濾材を充填した濾床（濾過用）４０が形成されている。濾床４０内を流れる流の方向は、図７に示すように下向流である。
【００３１】
濾床４０に捕捉された汚泥は蓄積すると閉塞等が起こるため、定期的に逆洗が必要となる。所定の時刻になると、タイマー５４が働いてブロワ３６が稼動し、逆洗管５３及びエアリフトポンプ管（逆洗排液返送用）１１の両方に空気を送り、逆洗する。この逆洗は、流量調整槽２２の水位が最低水位のときに行うのがよい。逆洗排液はエアリフトポンプ管１１を用いて第一槽２１へ返送する。このとき、効率よく逆洗するためには、濾過槽２４内の水位が底部に下がるまで、すなわち、濾過槽２４内の液の全量を返送するのがよい。水位が底部に下がったとき、底部で繋がったエアリフトポンプ管１１では、揚水管及び液吸込管内は気液混合流体が激しく上下し、管内壁に付着している汚泥を剥離させる。
【００３２】
消毒槽（第五槽）２５では、消毒薬によって大腸菌や細菌等を殺菌消毒する。消毒後の処理液は、放流口４１から汚水浄化槽外へ排出する。
【００３３】
汚水浄化槽２０には、槽内の保守点検及び清掃を容易に行うことができるように、槽上部にマンホールが設けてあり、そのマンホールにはマンホールカバー４２が取り付けられている。
【００３４】
次に、実験例を示す。用いたエアリフトポンプ管の寸法は図９の通り。液吸込管２、揚水管３及び空気供給管４は、いずれも塩化ビニル製（内径１３ｍｍ、ＶＰ１３）で、これらの管の接続には塩化ビニル製継手（エルボ６ａ，６ｂ、チーズ６ｃ）を用いた。
このエアリフトポンプ管を、図７に示すような５人槽規模の汚水浄化槽の流量調整槽２２に配置した。ここで、流量調整槽２２における水位は最高水位で１，４００ｍｍとし、最低水位で１，２００ｍｍ（すなわち、両者の水位差は２００ｍｍ。最高水位から揚水管３の液排出口５までの水位差と同じ。）とし、エアリフトポンプ管の下端から槽底部までは７００ｍｍとし、また、最高水位から揚水管３の液排出口５までの高さを２００ｍｍとした。空気供給管４にはブロワ３５から５Ｌ／ｍｉｎの送気量で連続供給し、汚水導入管４３から合併汚水を流入させ、長期の連続運転試験を実施した。
【００３５】
図１０に、流量調整槽２２の水位（Ｈ）とエアリフトポンプ管の揚水量（Ｑ）との関係、いわゆるＱ−Ｈ特性を示した。初期値、２ヶ月後及び４ヶ月後のいずれにおいてもＱ−Ｈ特性は安定しており、流量調整機能は維持されていた。また、内径１３ｍｍのエアリフトポンプ管内には汚泥の蓄積や詰まりも見られなかった。
【００３６】
【発明の効果】
本発明のエアリフトポンプ管は、構造が簡単であり、管内壁において汚泥の付着や堆積が起こりにくい。また、管径を従来よりも小さくでき、調整マス等の調整装置を要しない。維持管理における付着物除去等の煩わしい作業からも解放される。
エアリフトポンプ管の管内径を５ｍｍ以上２０ｍｍ以下の範囲とすれば、使用材料が少なくて済むので経済的であり、また、平面視におけるエアリフトポンプ管の占有面積を小さくすることができる。また、揚水能力の少ない送気量で済むため、ブロワの使用電力を減らすことができる。
本発明のエアリフトポンプ管を利用した流量調整機能を有する汚水浄化槽によれば、流量変動の大きい汚水を平均化して移流させることができるので、安定した汚水処理を行うことができる。
【図面の簡単な説明】
【図１】本発明の第１例のエアリフトポンプ管で、槽内液が最高水位にあるときの縦断面図。図中の実線矢印は液流を示し、点線矢印は空気流を示す。
【図２】槽内液が最低水位にあるときの同縦断面図。
【図３】本発明の第２例のエアリフトポンプ管（液吸込口の周りに阻流部材が形成されているもの）で、槽内液が最高水位にあるときの縦断面図。
【図４】槽内液が最低水位にあるときの同縦断面図。
【図５】本発明の第３例のエアリフトポンプ管で、槽内液が最高水位にあるときの縦断面図。
【図６】本発明の第４例のエアリフトポンプ管で、槽内液が最低水位にあるときの縦断面図。
【図７】本発明の一例の汚水浄化槽の概略構成図。
【図８】図７のＡ―Ａ矢視における断面図。
【図９】試験に用いたエアリフトポンプ管の正面図。
【図１０】揚水量Ｑと水位Ｈとをプロットしたグラフ（Ｑ−Ｈ特性）。
【図１１】従来例のエアリフトポンプ管の縦断面図。
【符号の説明】
１：エアリフトポンプ管２：液吸込管
３：揚水管４：空気供給管
５：（揚水管の）液排出口６ａ，６ｂ，６ｃ：接続部材
８：空気供給管の上端開口部
９：空気供給管の下端開口部（分岐部）
１０：液吸込口１１：エアリフトポンプ管（逆洗排液返送用）
１２：底部１３：調整マス
１４：阻流部材（円筒状）１５：スカム（浮上性固形物）
２０：汚水浄化槽
２１：第一槽２１ａ：沈降分離室２１ｂ：汚泥濃縮室
２２：第二槽（流量調整槽）２３：第三槽（好気処理槽）
２４：第四槽（濾過槽）２５：第五槽（消毒槽）
２６：仕切壁２７：仕切壁
２８：仕切壁２９：仕切壁
３０：仕切壁３１：仕切壁
３２：開口部３３：バッフル板
３４：濾床３５：ブロワ
３６：ブロワ３７：散気部材
３８：移流管４０：濾床
４１：放流口４２：マンホールカバー
４３：汚水導入管４４：移流開口
５３：逆洗管５４：タイマー[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sewage septic tank for treating manure discharged from homes and the like and other domestic wastewater (also simply referred to as sewage), and an air lift pump pipe attached to the sewage septic tank.
[0002]
[Prior art]
FIG. 11 shows an example of a conventional air lift pump pipe provided in a sewage septic tank (see, for example, Japanese Utility Model Laid-Open No. 4-118199). The air lift pump pipe is used by being submerged and standing in the liquid. The liquid suction pipe 2 having the liquid suction port 10 on the upper side and the pumping pipe 3 having the liquid discharge port 5 on the upper side are substantially U-shaped. The lower end opening 9 of the air supply pipe 4 is connected so as to branch from the pumping pipe 3 slightly above the bottom of the substantially U-shaped pipe on the pumping pipe side, and the upper end of the air supply pipe 4 is connected. Air is blown from the opening 8. Further, the liquid discharge port 5 at the upper part of the pumping pipe 3 is provided with an adjusting mass 13 for adjusting the transfer amount, and a notch portion for attaching excess water to the original tank when the water is pumped excessively is attached. In FIG. 11, the solid line arrow indicates the liquid flow, and the dotted line arrow indicates the air flow.
Pumping by the air lift pump pipe is performed as follows. When the air that has entered from the upper end opening 8 of the air supply pipe 4 is discharged from the lower end opening (branch) 9 into the pumping pipe 3, the air becomes air bubbles and rises in the pumping pipe 3 together with the liquid. . In the liquid suction pipe 2 connected to the pumping pipe 3 at the bottom of the U-shaped pipe, the liquid in the tank outside the liquid suction pipe 2 is sucked from the liquid suction port 10 and pumped through the bottom of the U-shaped pipe. . At this time, the pumped water pushed up reaches the adjustment mass 13 from the liquid discharge port 5. In the adjustment mass 13, the excessive amount of pumped water overflows from the notch, and only the necessary amount is transferred to the destination.
[0003]
[Problems to be solved by the invention]
However, since the air lift pump pipe is used for the transfer of sewage as described above, if the operation is continued, sludge in the sewage adheres to and accumulates on the inner walls of the liquid suction pipe 2 and the pumping pipe 3, and finally the deposits are formed. It becomes resistance and pumping becomes difficult. Therefore, conventionally, the liquid suction pipe 2 and the pumping pipe 3 (for example, the inner diameter is 40 mm to 60 mm) having a larger pipe diameter are used so that no problem occurs even if a little sludge adheres to and accumulates on the inner wall of the pipe. After pumping up more than the necessary amount, the excess liquid was returned to the original with an adjusting device such as an adjusting mass.
[0004]
It is an object of the present invention to provide an air lift pump pipe that can make the pipe diameter of a liquid suction pipe and a pumping pipe smaller than before, less adherence and accumulation of sludge, or does not require an adjustment device such as an adjustment mass. To do.
[0005]
[Means for Solving the Problems]
As a result of various studies conducted by the present inventors to achieve the above-described problems, the inner walls of both the liquid suction pipe and the pumping pipe are a gas-liquid mixed fluid in which air discharged from the air supply pipe and sewage are mixed during operation. An air lift pump pipe having a structure for automatic cleaning can be conceived, and the present invention has been completed. That is, in the air lift pump pipe of the present invention, the pumping pipe 3 standing with the liquid discharge port 5 in the upper part and the air supply pipe 4 having the opening 8 in the upper part are directly or connected to the connecting members (6a, 6b) is connected to the bottom part to form a substantially U-shaped pipe, and on the pumping pipe side, the liquid suction pipe 2 having the liquid suction port 10 at the upper end is located directly above the bottom part. Or through a connecting member (6c), the liquid suction port 2 of the liquid suction pipe 2 has a height position higher than that of the liquid discharge port 5 of the pumping pipe 3. The air lift pump pipe 1 is formed at a low position.
[0006]
Here, a baffle member 14 is preferably provided around the liquid suction port 10 of the liquid suction pipe 2. This is to prevent the floating solid material 15 called scum from accumulating in the liquid suction port 10 and reducing the efficiency of liquid suction.
[0007]
The inner diameters of the pumping pipe 3, the air supply pipe 4, and the liquid suction pipe 2 are preferably all in the range of 5 to 20 mm. This is because the required amount of sewage is pumped with a small amount of air.
The inner diameters of these three tubes are preferably the same. This is because the step in the connecting portion is eliminated and the flow of fluid (sewage, air, or a mixed gas-liquid mixture thereof) is made smooth, and the types of pipes and connecting members constituting the air lift pump pipe are not increased.
[0008]
The present invention also relates to a sewage septic tank using the above-described air lift pump pipe and disposed in the tank.
What is preferable as such a sewage septic tank is a sewage septic tank provided with an anaerobic treatment tank (flow rate adjustment tank) 22, an aerobic treatment tank 23, a filtration tank 24, and a disinfection tank 25 having a flow rate adjusting function from the upstream side. The air lift pump pipes are respectively provided so as to stand in one of the anaerobic treatment tank (flow rate adjustment tank) 22 and the filtration tank 23 having the flow rate adjustment function or in one tank.
[0009]
[Action]
In the air lift pump pipe (FIG. 11) of the conventional example, the branch part 9 (to the air supply pipe 4) branches from the lower part of the pumping pipe 3 is a connection part between the liquid suction pipe 2 and the pumping pipe 3, that is, approximately U Since the gas-liquid mixed fluid cannot enter the liquid suction pipe 2 side because it is at a position higher than the bottom portion 12 of the letter-shaped pipe, deposits and sludge adhering to and accumulating on the inner wall of the pipe cannot be dropped.
[0010]
On the other hand, in the air lift pump pipe 1 of the present invention (for example, FIG. 1), the liquid suction pipe 2 having the liquid suction port 10 at the upper end is slightly above the bottom 12 of the substantially U-shaped pipe (from the pumping pipe 3 side). Since it branches to rise, a part of the air-liquid mixed fluid in which the air from the air supply pipe 4 or this air and sewage is mixed also enters the liquid suction pipe 2 and rises in the pipe, Sludge adhered to the inner wall of the pipe can be removed.
[0011]
In particular, when the air lift pump pipe 1 of the present invention is arranged in a flow rate adjustment tank (for example, the flow rate adjustment tank 22) of a sewage purification tank having a flow rate adjustment function, the water level in the tank is close to the lowest water level (LWL). Sometimes, the gas-liquid mixed fluid containing air bubbles and sewage flows vigorously up and down in the pumping pipe 3 to peel off the sludge adhering to the inner wall of the pipe (see FIG. 2). Further, since a part of the air from the air supply pipe 4 is pushed out above the liquid suction pipe 2, the sludge adhered to the inner wall of the liquid suction pipe 2 is also peeled off or washed. In this manner, sludge is peeled off (that is, washed) not only in the pumped water pipe 3 but also in the liquid suction pipe 2. This is the reason why the inner diameter of the air lift pump pipe can be made smaller than before.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described with reference to the drawings.
FIG. 1 is a cross-sectional view of an air lift pump pipe 1 according to an example of the present invention when the liquid in the tank is at the highest water level.
As shown in the figure, the air lift pump pipe 1 is formed by connecting a pumping pipe 3 having a liquid discharge port 5 at an upper part and an air supply pipe 4 for supplying air at a bottom part 12 to form a substantially U-shaped pipe. On the pumping pipe 3 side, the liquid suction pipe 2 branches upward at a position slightly above the bottom 12, and the upper end of the liquid suction pipe 2 is an open liquid suction port 10. Used standing up. In addition, the solid line arrow in FIG. 1 shows a liquid flow, and a dotted line arrow shows an air flow (the same also in the following FIGS. 2-7).
[0013]
FIG. 2 is a longitudinal sectional view of the air lift pump pipe 1 when the liquid in the tank is at the lowest water level. The operation of an air lift pump (combined with an air lift pump pipe and a blower) in a tank (flow rate adjusting tank) 22 having a flow rate adjusting function will be described with reference to FIGS.
In the flow rate adjusting tank 22 having the air lift pump pipe 1, the position of the liquid suction port 10 is determined in advance so that the water level in the tank varies between the highest water level and the lowest water level. First, air from the blower is continuously supplied from the air supply pipe 4. When the water level is higher than the lowest water level, the liquid in the tank is pumped and moves from the liquid discharge port 5 to a predetermined destination. At this time, if the amount of sewage that flows in is larger than the transferred liquid in the tank (the amount of pumped water), only the difference is accumulated, the water level gradually rises, and in some cases increases to the maximum water level.
[0014]
On the other hand, if the time during which sewage does not flow into the flow rate adjusting tank 22 continues, the water level gradually decreases to the lowest water level, almost no sewage is sucked into the liquid suction port 10, and the pumping of the liquid in the tank becomes almost zero. (FIG. 2). If it does so, the pressure balance inside the pumping-up pipe 3 and the liquid suction pipe 2 will collapse | crumble, and the air which flowed in from the air supply pipe 4 will flow into the liquid suction pipe 2 occasionally, and will become the form which wash | cleans the liquid suction pipe 2 with air. On the pumping pipe 3 side, the gas-liquid mixed fluid having a high ratio of air bubbles moves violently up and down in the pumping pipe 3 (indicated by arrows having arrows at both ends) to clean the inner wall of the pipe. In this way, the sludge adhering to the inner wall of the liquid suction pipe 2 and the inner wall of the pumping pipe 3 is peeled off, and accumulation of sludge is avoided.
[0015]
3 and 4 are examples of an air lift pump pipe according to a second example of the present invention, in which a hollow cylindrical blocking member 14 is provided around a liquid suction port. When a certain amount of time has elapsed in the flow rate adjustment tank 22, a floating solid material 15 such as a floating sludge block called scum or an oil ball (oil block) that is an oil component appears. The floatable solid material 15 accumulates in the vicinity of the liquid suction port 10 and reduces the liquid suction efficiency. The baffle member 14 prevents floating solids from accumulating at the liquid suction port 10.
[0016]
FIG. 5 shows a third example of the air lift pump pipe 1 according to the present invention. In consideration of maintainability in the baffle member 14, the liquid suction port 10 is provided on the side wall of the hollow baffle baffle member 14. By doing so, it becomes easy to remove sludge and the like adhering in the baffle member 14 by cleaning. The baffle member 14 may be a hollow rectangular tube instead of a hollow cylinder.
[0017]
FIG. 6 shows an air lift pump pipe of a fourth example of the present invention, which is a modification of the air lift pump pipe of FIG. The two opposite sides of the hollow rectangular tube-shaped baffle member 14 are bent as shown in the figure so that the solid matter that floats does not enter the baffle member 14, and one lower end is longer downward than the other lower end. It is overhanging.
Further, the liquid suction pipe 2 in the vicinity of the liquid suction port 10 is connected so as to be inclined so that air bubbles can be easily removed when it is close to the lowest water level (LWL). Thereby, the inside of the liquid suction pipe 2 is efficiently cleaned.
[0018]
FIG. 7 is a schematic configuration diagram of a sewage septic tank provided with the air lift pump pipe, and FIG. 8 is a cross-sectional view taken along line AA of FIG. Next, the sewage septic tank of the present invention will be described with reference to these drawings.
[0019]
From the upstream side, the sewage septic tank 20 sinks sedimentary solids in the sewage under gravity, and stores the first tank 21 that overflows the subsequent (upper) liquid to the next tank, and the overflowed liquid. The second tank 22 for quantitatively transferring the liquid to the next tank, the third tank 23 for biologically aerobically treating the transferred liquid, and sludge (also called suspended suspended matter, SS) are filtered. The filtrate is divided into a fourth tank 24 for transferring the filtrate to the next tank and a fifth tank 25 for disinfecting the liquid, and these tanks are partitioned by partition walls 26, 27, 28 and 29, respectively. The first tank 21 is divided into two chambers: a sedimentation separation chamber 21a for sedimenting sedimentary solids in sewage under gravity and a sludge concentration chamber 21b for storing and concentrating the sedimented solids.
[0020]
Looking at each tank from the functional aspect, the first tank 21 is a precipitation separation tank, the second tank 22 is a flow rate adjustment tank, the third tank 23 is an aerobic treatment tank, the fourth tank 24 is a filtration tank, and the fifth tank 25 is It can also be called a disinfection tank. The first tank 21 and the second tank 22 also have an anaerobic biodegradation function. In order to further enhance the anaerobic biodegradation function, an anaerobic filter bed tank or an anaerobic treatment tank filled with a filler (filter medium, filter bed) can be used.
[0021]
In the sedimentation / separation chamber 21a, a sewage introduction pipe 43 is provided in a wall portion at a position higher than the liquid level in the tank, and an advection opening 44 for advancing to the flow rate adjustment tank 22 (second tank) is provided in the partition wall 26 on the opposite side. Provided. An opening 32 is provided below the partition walls 30 and 31 (FIG. 8) facing and surrounding the sedimentation separation chamber 21a from the wall surface on the sewage introduction pipe 43 side to the partition wall 26 of the advection opening 44. .
[0022]
In the vicinity of the liquid surface in the sedimentation separation chamber 21a, an inclined baffle plate 33 that suppresses the liquid flow when sewage flows is provided on the sewage introduction pipe 43 side.
[0023]
The sewage flowing into the sedimentation separation chamber 21 a from the sewage introduction pipe 43 passes through the baffle plate 33 and then becomes a substantially horizontal flow and moves toward the convection opening 44. During this time, the solid matter having a sedimentation speed faster than the horizontal flow rate passes through the opening 32 at the bottom of the sedimentation separation chamber 21a and reaches the bottom of the sludge concentration chamber 21b and accumulates.
[0024]
In the sludge concentrating chamber 21b, since it is rarely disturbed by the liquid flow of the inflowing sewage, the settled solid matter accumulates at a high concentration and becomes sludge. The sludge solidified material gradually becomes anaerobic over time, and part of it becomes scum, and emerges near the liquid surface above the sludge concentrating chamber 21b. At this time, since the lower end of the partition wall 30 is longer than the lower end of the partition wall 31 and protrudes in the horizontal direction, the floated scum enters the sedimentation separation chamber 21a from the opening 32 below the sedimentation separation chamber 21a. Stop that.
[0025]
In the flow rate adjusting tank 22 (second tank), an air lift pump pipe (connected to the blower 35) 1 for transferring the liquid in the tank to the aerobic treatment tank (third tank) 23 of the next tank is arranged and flows into the sewage purification tank 20 Absorb fluctuations in the amount of sewage. That is, the transfer of the liquid in the tank to the next tank is an averaged transfer through the air lift pump pipe 1.
[0026]
Here, if the amount of liquid transferred by the air lift pump pipe 1 is larger than the amount of inflow from the advection opening 44, the liquid in the tank accumulates by the difference, and the water level moves from the lowest level to the highest level. In the opposite case, the water level goes from the highest water level to the lowest water level. When the water level reaches the lowest level, the liquid in the tank is not pumped by the air lift pump pipe 1, and the air is also discharged from the liquid suction port 10 (so-called idle operation).
[0027]
Although not shown in the figure, a filler such as a filter medium or a contact material to which sludge and microorganisms adhere can be disposed in the flow rate adjusting tank 22, and in this case, the upper part of the filler is exposed to the atmosphere ( Function of watering filter bed).
[0028]
In the aerobic treatment tank (third tank) 23, organic substances in the liquid are decomposed and removed by aerobic microorganisms. The tank is usually filled with a microbial carrier (microbe adhesion material, contact material) suitable for holding and growing microorganisms, and a filter bed (aerobic filter bed, for microbial reaction) 34 is formed. The filter bed 34 may be a fixed bed to which a microorganism carrier is fixed or a fluidized bed that flows together with the liquid. At this time, air is discharged from the blower 35 through the diffuser member 37 in order to maintain the aerobic condition.
[0029]
The liquid flowing into the aerobic treatment tank 23 flows downward through the filter bed 34 in the tank. When organic matter is biodegraded in the filter bed 34, a part thereof is converted into sludge, the sludge increases, and a part of the sludge collects at the bottom of the tank. The collected sludge can be transferred from the bottom of the tank (using an air lift pump) to the settling separation chamber 21a. However, in the case of FIG. 7, the amount of generated sludge is small, so this is transferred to the next tank via the advection pipe 38. To the filtration tank (fourth tank) 24. Here, the advection tube 38 is a tubular tube having an open upper end and a closed lower end, and a transfer port is provided in the middle of the tube. The liquid that has flowed in may be flowed in the upward flow instead of flowing in the filter bed of the aerobic treatment tank 23.
[0030]
In the filtration tank (fourth tank) 24, the sludge in the advection liquid is filtered, and the filtrate is transferred to the next tank. In order to filter and capture sludge, a filter bed (for filtration) 40 filled with a filter medium is formed in the filtration tank 24. The direction of the flow flowing through the filter bed 40 is a downward flow as shown in FIG.
[0031]
When the sludge trapped in the filter bed 40 accumulates, clogging or the like occurs, so regular backwashing is necessary. At a predetermined time, the timer 54 is activated and the blower 36 is operated to send air to both the backwash pipe 53 and the air lift pump pipe (for backwash drainage return) 11 for backwashing. This backwashing is preferably performed when the water level of the flow rate adjusting tank 22 is the lowest water level. The backwash drainage liquid is returned to the first tank 21 using the air lift pump pipe 11. At this time, in order to backwash efficiently, it is preferable to return the entire amount of the liquid in the filtration tank 24 until the water level in the filtration tank 24 drops to the bottom. When the water level drops to the bottom, in the air lift pump pipe 11 connected at the bottom, the gas-liquid mixed fluid moves up and down vigorously in the pumping pipe and the liquid suction pipe, and the sludge adhering to the inner wall of the pipe is peeled off.
[0032]
In the disinfection tank (fifth tank) 25, Escherichia coli, bacteria, and the like are sterilized and disinfected with a disinfectant. The treated liquid after disinfection is discharged out of the sewage septic tank from the outlet 41.
[0033]
The sewage septic tank 20 is provided with a manhole at the upper part of the tank so that maintenance and cleaning in the tank can be easily performed, and a manhole cover 42 is attached to the manhole.
[0034]
Next, an experimental example is shown. The dimensions of the used air lift pump pipe are as shown in FIG. The liquid suction pipe 2, the pumping pipe 3 and the air supply pipe 4 are all made of vinyl chloride (inner diameter 13 mm, VP13), and joints made of vinyl chloride (elbows 6a, 6b, cheese 6c) are used for connecting these pipes. It was.
This air lift pump pipe was disposed in a flow rate adjustment tank 22 of a five-person tank-scale sewage purification tank as shown in FIG. Here, the water level in the flow control tank 22 is 1,400 mm at the highest water level and 1,200 mm at the lowest water level (that is, the water level difference between them is 200 mm. The water level difference from the highest water level to the liquid outlet 5 of the pumping pipe 3 is And the height from the lower end of the air lift pump pipe to the bottom of the tank is 700 mm, and the height from the highest water level to the liquid discharge port 5 of the pumping pipe 3 is 200 mm. The air supply pipe 4 was continuously supplied from the blower 35 at an air supply rate of 5 L / min, and the combined sewage was introduced from the sewage introduction pipe 43 to conduct a long-term continuous operation test.
[0035]
FIG. 10 shows the relationship between the water level (H) of the flow rate adjusting tank 22 and the pumped amount (Q) of the air lift pump pipe, so-called QH characteristics. The QH characteristics were stable both at the initial value, after 2 months, and after 4 months, and the flow rate adjustment function was maintained. In addition, no accumulation or clogging of sludge was observed in the air lift pump pipe having an inner diameter of 13 mm.
[0036]
【The invention's effect】
The air lift pump pipe of the present invention has a simple structure, and sludge adheres and accumulates on the inner wall of the pipe. Moreover, the pipe diameter can be made smaller than before, and an adjusting device such as an adjusting mass is not required. It is also free from troublesome work such as removal of deposits in maintenance.
If the inner diameter of the air lift pump pipe is in the range of 5 mm or more and 20 mm or less, it is economical because less material is used, and the area occupied by the air lift pump pipe in plan view can be reduced. Moreover, since the air supply capacity with a small pumping capacity is sufficient, the power consumption of the blower can be reduced.
According to the sewage septic tank having a flow rate adjusting function using the air lift pump pipe of the present invention, sewage having a large flow rate fluctuation can be averaged and transferred, so that stable sewage treatment can be performed.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of the air lift pump pipe of the first example of the present invention when the liquid in the tank is at the highest water level. A solid line arrow in the figure indicates a liquid flow, and a dotted line arrow indicates an air flow.
FIG. 2 is a longitudinal sectional view when the liquid in the tank is at the lowest water level.
FIG. 3 is a longitudinal sectional view of the air lift pump pipe (with a baffle member formed around the liquid suction port) of the second example of the present invention when the liquid in the tank is at the highest water level.
FIG. 4 is a longitudinal sectional view when the liquid in the tank is at the lowest water level.
FIG. 5 is a longitudinal sectional view of the air lift pump pipe of the third example of the present invention when the liquid in the tank is at the highest water level.
FIG. 6 is a longitudinal sectional view of the fourth example of the air lift pump pipe of the present invention when the liquid in the tank is at the lowest water level.
FIG. 7 is a schematic configuration diagram of a sewage septic tank according to an example of the present invention.
8 is a cross-sectional view taken along the line AA in FIG.
FIG. 9 is a front view of an air lift pump pipe used in the test.
FIG. 10 is a graph (QH characteristics) in which the amount of pumped water Q and the water level H are plotted.
FIG. 11 is a longitudinal sectional view of a conventional air lift pump pipe.
[Explanation of symbols]
1: Air lift pump pipe 2: Liquid suction pipe 3: Pumping pipe 4: Air supply pipe 5: Liquid discharge port (of the pumping pipe) 6a, 6b, 6c: Connection member 8: Upper end opening of the air supply pipe 9: Air supply Pipe lower end opening (branch)
10: Liquid suction port 11: Air lift pump pipe (for backwash drainage return)
12: Bottom 13: Adjustment mass 14: Block member (cylindrical) 15: Scum (floating solid)
20: Sewage purification tank 21: First tank 21a: Sedimentation separation chamber 21b: Sludge concentration chamber 22: Second tank (flow rate adjustment tank) 23: Third tank (aerobic treatment tank)
24: Fourth tank (filtration tank) 25: Fifth tank (disinfection tank)
26: Partition wall 27: Partition wall 28: Partition wall 29: Partition wall 30: Partition wall 31: Partition wall 32: Opening 33: Baffle plate 34: Filter bed 35: Blower 36: Blower 37: Aeration member 38: Advection Pipe 40: Filter bed 41: Discharge port 42: Manhole cover 43: Sewage introduction pipe 44: Advection opening 53: Backwash pipe 54: Timer

Claims

上部に液排出口を有する揚水管と、上部に開口部を有する空気供給管とが、直接に又は接続部材を介して、底部で繋がって略Ｕ字状管を形成してなり、
その揚水管側では、前記底部より上の位置で、上端に液吸入口を有する液吸入管が、直接に又は接続部材を介して、立ち上がるように分岐しており、
前記液吸込管の液吸込口の位置は、前記揚水管の液排出口の位置よりも低い位置に形成されているエアリフトポンプ管。A pumping pipe having a liquid outlet at the top and an air supply pipe having an opening at the top are connected at the bottom directly or via a connecting member to form a substantially U-shaped pipe,
On the pumping pipe side, at a position above the bottom , a liquid suction pipe having a liquid suction port at the upper end is branched so as to stand up directly or via a connecting member,
The position of the liquid suction port of the liquid suction pipe is an air lift pump pipe formed at a position lower than the position of the liquid discharge port of the water pumping pipe.

更に、液吸込管の液吸込口には阻流部材が形成されている、請求項１のエアリフトポンプ管。 Furthermore, the air lift pump pipe | tube of Claim 1 in which the baffle member is formed in the liquid suction inlet of a liquid suction pipe | tube.

揚水管、空気供給管及び液吸込管の内径はいずれも５ｍｍ以上２０ｍｍ以下である、請求項１又は２のエアリフトポンプ管。 The air lift pump pipe according to claim 1 or 2, wherein an inner diameter of each of the pumping pipe, the air supply pipe, and the liquid suction pipe is 5 mm or more and 20 mm or less.

請求項１〜３のいずれかのエアリフトポンプ管を備える汚水浄化槽。 A sewage septic tank comprising the air lift pump pipe according to claim 1.

上流側から、流量調整機能を有する嫌気処理槽、好気処理槽、濾過槽及び消毒槽を備える汚水浄化槽であって、前記嫌気処理槽及び濾過槽の少なくとも一槽に、請求項１〜３のいずれかのエアリフトポンプ管が付設されている汚水浄化槽。 From an upstream side, an anaerobic treatment tank having a flow adjustment function, an aerobic treatment tank, a filtration tank, and a sterilization tank, comprising at least one of the anaerobic treatment tank and the filtration tank, A sewage septic tank equipped with one of the air lift pump pipes.