JP3716926B2

JP3716926B2 - Air cleaning method

Info

Publication number: JP3716926B2
Application number: JP2002024290A
Authority: JP
Inventors: 功寺田; 智美濃部; 稔久岡部
Original assignee: Nichias Corp
Current assignee: Nichias Corp
Priority date: 2002-01-31
Filing date: 2002-01-31
Publication date: 2005-11-16
Anticipated expiration: 2022-01-31
Also published as: JP2003222363A

Description

【０００１】
【発明の属する技術分野】
本発明は、空気中の化学汚染物質を水で洗浄して清浄にする空気清浄方法に関するものである。さらに詳しくは、半導体や液晶デバイスの製造工場、製薬工場やライフサイエンス関連設備等のクリーンルームに供給する空気の空気清浄方法に関するものである。
【０００２】
【従来の技術】
半導体や液晶デバイスの製造工場、製薬工場やライフサイエンス関連設備等では、製品歩留りを向上し、或いは品質確保するために、従来の微粒子状の汚染物質に加え、ガス状化学汚染物質をも除去することが望まれている。このような化学汚染物質としては、例えば、ナトリウム、カリウム、カルシウム、ホウ素等の無機質の金属元素、フッ素イオン、塩化物イオン、硝酸イオン、亜硝酸イオン、硫酸イオン、亜硫酸イオン等のアニオン類やアンモニウムイオン等のカチオン類等が挙げられる。従来の微粒子状の汚染物質は、ＵＬＰＡフィルター等の集塵フィルターで除去できるが、これらの化学汚染物質は、ＵＬＰＡフィルター等では除去できない。
【０００３】
このため、空気中の化学汚染物質は、従来より、所謂、水シャワーと呼ばれる水滴のシャワーを用いる方法や化学成分を吸着除去できるケミカルフィルターを用いる方法により除去される。ここで、前者の水シャワーを用いる方法は、化学汚染物質を含む空気を水滴の噴霧により取り除く方法である。
【０００４】
【発明が解決しようとする課題】
しかしながら、前者の水シャワーを用いた方法は、被処理空気と水との接触効率が悪いために化学汚染物質の除去効率が低い。このため、水シャワー装置からなる加湿手段の奥行きは数ｍ程度も必要となり、広大な設置スペースを要すると共に、圧力損失も大きくなるという問題があった。また、水シャワーの処理水としては、通常高価な脱イオン水（ＤＩＷ）が用いられているが、処理水量も多く必要となるためコストが高くなるという問題があった。さらに、低コスト化のためにＤＩＷは、通常循環使用されているが、一旦吸収した化学汚染物質の再気散が生じ易いという問題があった。一方、後者のケミカルフィルターを用いた方法は、ケミカルフィルター自体が高価であり、しかも吸着能力に寿命があるため、コストが高くなるという問題があった。
【０００５】
従って、本発明の目的は、空気中の化学汚染物質の除去効率が高く、処理装置がコンパクトで、圧力損失が小さく、低コストな空気清浄方法を提供することにある。
【０００６】
【課題を解決するための手段】
かかる実情において、本発明者らは鋭意検討を行った結果、加湿手段又は凝縮手段の一方又は両方に、金属製斜行ハニカムを用い、該金属製斜行ハニカムの前面開口部から空気を導入すると共に、上面開口部から水を供給すれば、金属製斜行ハニカムに導入される空気と供給される水とが効率よく接触して、加湿手段においては効率よく空気中の湿度を上昇させることができる。また、凝縮手段においては、ガス状化学汚染物質が凝縮水中に効率よく取り込まれて除去されることを見出し、本発明を完成するに至った。
【０００７】
すなわち、本発明の請求項１記載の発明は、一方向に向かって伝播する波形形状を有する厚さ１０〜２００μｍの金属製波形シートが複数積層されてハニカム形状を呈し、積層される金属製波形シートは、波の伝播方向が一枚おきに斜めに交差するように積層され、且つ、二層おきのシートの波の伝播方向がそれぞれ略同一方向になるように配置され、また、金属製波形状シートに平行な面に対して垂直な４面で切断して直方体を形成し、該切断面が金属製波形状シートの波の伝播方向と平行でなく、且つ、垂直でもない厚さ１００〜１０００ｍｍの金属製斜行ハニカムを用い、その前後両面と上下両面とが開口して配置された金属製斜行ハニカムの前面開口部から化学汚染物質を含む空気を導入すると共に、上面開口部から水を供給することで、前記金属製斜行ハニカム内で前記空気を加湿させ、得られる過剰な水分に化学汚染物質の少なくとも一部を取り込むことで、空気中から化学汚染物質を除去することを特徴としている。
【０００８】
本発明の請求項２記載の発明は、一方向に向かって伝播する波形形状を有する厚さ１０〜２００μｍの金属製波形シートが複数積層されてハニカム形状を呈し、積層される金属製波形シートは、波の伝播方向が一枚おきに斜めに交差するように積層され、且つ、二層おきのシートの波の伝播方向がそれぞれ略同一方向になるように配置され、また、金属製波形状シートに平行な面に対して垂直な４面で切断して直方体を形成し、該切断面が金属製波形状シートの波の伝播方向と平行でなく、且つ、垂直でもない厚さ１００〜１０００ｍｍの金属製斜行ハニカムを用い、その前後両面と上下両面とが開口して配置された金属製斜行ハニカムの前面開口部から化学汚染物質を含む空気を導入すると共に、上面開口部から水を供給することで、前記金属製斜行ハニカム内で前記空気を除湿させ、得られる凝縮水に化学汚染物質の少なくとも一部を取り込むことで、空気中から化学汚染物質を除去することを特徴としている。
【０００９】
本発明の請求項３記載の発明は、化学汚染物質を含む空気を導入すると共に、該空気と水とを接触することで、前記空気を加湿させ、得られる過剰な水分に化学汚染物質の少なくとも一部を取り込むことで、空気中から化学汚染物質を除去する加湿工程と、化学汚染物質を含む空気を導入させ、該空気と水とを接触することで、前記空気を除湿し、得られる凝縮水に化学汚染物質の少なくとも一部を取り込むことで、空気中から化学汚染物質を除去する除湿工程とを有する空気洗浄方法であって、加湿工程で使用する加湿手段、及び除湿手段で使用する凝縮手段として、一方向に向かって伝播する波形形状を有する厚さ１０〜２００μｍの金属製波形シートが複数積層されてハニカム形状を呈し、積層される金属製波形シートは、波の伝播方向が一枚おきに斜めに交差するように積層され、且つ、二層おきのシートの波の伝播方向がそれぞれ略同一方向になるように配置され、また、金属製波形状シートに平行な面に対して垂直な４面で切断して直方体を形成し、該切断面が金属製波形状シートの波の伝播方向と平行でなく、且つ、垂直でもない厚さ１００〜１０００ｍｍの金属製斜行ハニカムを用い、その前後両面と上下両面とが開口して配置された金属製斜行ハニカムを前記両手段の一方又は両方に使用することを特徴としている。
【００１０】
本発明の請求項４記載の発明は、一方向に向かって伝播する波形形状を有する厚さ１０〜２００μｍの金属製波形シートが複数積層されてハニカム形状を呈し、積層される金属製波形シートは、波の伝播方向が一枚おきに斜めに交差するように積層され、且つ、二層おきのシートの波の伝播方向がそれぞれ略同一方向になるように配置され、また、金属製波形状シートに平行な面に対して垂直な４面で切断して直方体を形成し、該切断面が金属製波形状シートの波の伝播方向と平行でなく、且つ、垂直でもない厚さ１００〜１０００ｍｍの金属製斜行ハニカムを用い、その前後両面と上下両面とが開口して配置された金属製斜行ハニカムの前面開口部から化学汚染物質を含む空気を導入すると共に、上面開口部から水を供給し、前記金属製斜行ハニカムの前段部内で前記空気を加湿させ、得られる過剰な水分に化学汚染物質の少なくとも一部を取り込むことで、空気中から化学汚染物質を除去し、次いで前記金属製斜行ハニカムの後段部内で前記空気を除湿させ、得られる凝縮水に化学汚染物質の少なくとも一部を取り込むことで、空気中から化学汚染物質を除去することを特徴としている。
【００１１】
【発明の実施の形態】
本発明において、加湿手段とは、被処理空気への水分の供給手段及び適宜、水分の回収手段や温度調整手段を備えることにより、被処理空気を所定の湿度まで加湿すると共に、過剰な水分を得る手段である。該加湿手段は、被処理空気を加湿すると共に、被処理空気中に含まれるガス状化学汚染物質の少なくとも一部を該余分な水分中に取り込んで除去するものである。
【００１２】
凝縮手段とは、被処理空気と接触可能な低温部及び水分の回収手段を備えることにより、被処理空気を所定の湿度まで除湿すると共に、除湿の際に生じた凝縮水を得る手段である。該凝縮手段は、被処理空気中の化学汚染物質又は前記加湿手段で除去されなかった化学汚染物質を除湿の際に生じる凝縮水に可能な限り取り込んで除去するものである。
【００１３】
本発明において、化学汚染物質としては、高性能（ＵＬＰＡ）フィルターの編み目を通過するような微細な化学物質を意味し、例えば、ナトリウム、カリウム、カルシウム、ホウ素等の無機質の金属元素、フッ素イオン、塩化物イオン、硝酸イオン、亜硝酸イオン、硫酸イオン、亜硫酸イオン等のアニオン類やアンモニウムイオン等のカチオン類等が挙げられる。
【００１４】
本発明では、上記加湿手段又は凝縮手段の一方又は両方に、前後両面と上下両面とが開口した配置された金属製斜行ハニカムを用いる。該金属製斜行ハニカムを図１を参照して説明する。ここで、金属製斜行ハニカム１とは、一方向に向かって伝播する波形形状を有する金属製波形シート２，３（以下、「金属製コルゲート状シート」ともいう）が複数積層されてハニカム形状を呈するものであって、積層される金属製コルゲート状シート２，３は、波の伝播方向が一枚おきに斜めに交差するように積層され、且つ、二層おきのシートの波の伝播方向がそれぞれ略同一方向になるように配置されたハニカム状体である。
【００１５】
該金属製斜行ハニカム１は、金属製コルゲート状シート２，３に平行な面に対して垂直な４面１０１〜１０４で切断して直方体を形成し、該切断面が金属製コルゲート状シート２，３の波の伝播方向と平行でなく、且つ、垂直でもないようにした場合、該直方体を切断面の１つ１０４を下面にし、金属製コルゲート状シート２，３の最外層１０５，１０６をそれぞれ左右面にして載置すると、切断面である前後両面１０２，１０３及び上下両面１０１，１０４の４面は、全てハニカムセルが開口し、左右面１０５，１０６は金属製コルゲート状シート２，３で閉じられた構造を有するものである。また、該切断面の、例えば、前後両面１０２，１０３は、斜め上方向に延設されるセルと斜め下方向に延設されるセルとが一層おきに形成される。斜め上方向に延設されるセルの前後両面から見た場合の空気の流入、流出方向（水平方向）に対する斜め角度（図中、符号Ｘ）は、通常１５〜４５度、好ましくは２５〜３５度の範囲内にする。上記斜め角度が該範囲内にあると、流下速度が適度の範囲となり接触効率が向上するため好ましい。
【００１６】
上記金属製斜行ハニカム１において、積層された金属製コルゲート状シート２，３の一層おきの波の伝播方向が互いに交差する角度（図中、符号Ｙ）は、通常３０〜９０度、好ましくは２５〜３５度である。このような金属製コルゲート状シート２，３を互いに上記角度範囲内で交差するように積層すると、上記のように斜め角度（Ｘ）を上記の１５〜４５度とした場合に、被処理空気及び水がハニカムセルと実質的に接触する面積が大きくなるため、被処理空気と水との接触、すなわち、加湿手段においては被処理空気の加湿の効率、また、凝縮手段においては、被処理空気中の水分の凝縮による除湿の効率が高くなるため好ましい。つまり、後述するように、本発明において、被処理空気は金属製斜行ハニカム１の前面開口部１０３から導入され、水は上面開口部１０１から例えば、給水ダクト４により供給され金属製斜行ハニカム１の金属製コルゲート状シート２，３に表面を下方に流下するため、被処理空気の通気方向と浸透壁面の水の流下方向とが適度の角度を保持し、接触効率が高くなる。
【００１７】
本発明に用いられる金属製斜行ハニカム１のセルの高さ、すなわち、波の山と谷間の寸法を示すセルの山高寸法は、通常１．５〜８ｍｍ、好ましくは２．０〜５ｍｍである。セル寸法が１．５ｍｍ未満であると製造が困難であり、圧力損失が大きくなるため好ましくない。また、セル寸法が８ｍｍを越えると、ガス状化学汚染物質の除去効率が低下するため好ましくない。
【００１８】
金属製斜行ハニカム１の金属製コルゲート状シート２，３の状態におけるセルの幅、すなわち、セルピッチは通常２．５〜１２．０ｍｍ、好ましくは３．０〜１０．０ｍｍである。また、金属製斜行ハニカム１の前面開口部と後面開口部との間の寸法、すなわち、金属製斜行ハニカム１の厚さ（ｔ）は、特に制限されないが、通常１００〜１０００ｍｍ、好ましくは２００〜８００ｍｍである。また、梅雨時のように湿度が高い時期に、１台のハニカムで化学汚染物質の除去と除湿とを行う場合には、除湿を十分に行うために８００ｍｍ程度の厚いものを使用した方がよい。該厚さが１００ｍｍ未満であると、ＮＯ₂ ^-等の除去効率が低下するため好ましくなく、厚さが１０００ｍｍを越えると、化学汚染物質の除去効率がこれ以上向上せず、圧力損失が大きくなるため好ましくない。なお、本発明において、金属製斜行ハニカム１の厚さは、該金属製斜行ハニカム１を複数枚使用する場合には、この合計の厚さが上記範囲内のものであればよい。例えば、厚さが３００ｍｍの金属製斜行ハニカムを用いる場合には、厚さが１００ｍｍの金属製斜行ハニカムを３枚厚さ方向に重ねて合計の厚さを３００ｍｍとしてもよい。なお、従来加湿手段として用いられていた水シャワーは、装置の奥行きが数ｍ程度必要であるが、本発明に係る金属製斜行ハニカムを加湿手段として用いると、金属製斜行ハニカム自体の厚さはせいぜい４００ｍｍ程度であるため、装置の設置スペースを大幅に小さくすることができる。このような大幅な省スペース化は半導体製造工場等の合理化の要求を満足する。さらに、水を循環するポンプの動力は、従来の水シャワーのものと比較すると格段に少なく、大幅な省エネルギー化をも図ることができる。
【００１９】
本発明で使用される金属製斜行ハニカムの材質は強度、化学的安定性等が金属ハニカム担体に要求される条件を満たすものであればよく、特に限定されないが、例えばステンレス、アルミニウム、銅等が挙げられる。
厚さは１０〜２００μｍで、１０μｍより薄いと強度や加工性が悪く、２００μｍを超えると重い、しかも圧力損失が大きいという問題がある。好ましい厚さは、３０〜１００μｍである。
【００２０】
本発明で用いられる金属製コルゲート状シート２，３は、平板状金属箔をコルゲート加工してなるものであり、金属箔の面内の一方向に波が進行するように凹凸が形成されたものである。ここでコルゲート加工とは、平板状物を波形状物に加工することを意味する。
【００２１】
金属製コルゲート状シート２，３に成形する方法としては、径方向に振幅する波形の凹凸が表面に形成された複数の歯車間に平板状シートを通すような公知のコルゲーターを用いる方法が挙げられる。得られた金属製コルゲート状シート２，３から上記金属製斜行ハニカム１を成形する方法としては、例えば、まず、上記金属製コルゲート状シート２，３を縦１００ｍｍ（成形後の厚み寸法）×横３００ｍｍ程度の矩形の裁断型に対し、波の伝播方向が矩形型の一辺に対して１５〜４５度になるように配置して裁断して矩形のコルゲート状シートを作製し、次いで、得られた矩形のコルゲート状シートを１枚おきの波の伝播方向が斜交するように配置し、これらを積層する方法が挙げられる。なお、このようにして製造した場合、上記裁断型の縦の長さが金属製斜行ハニカム１枚の厚さとなる。このため、例えば、加湿手段や凝縮手段に必要な金属製斜行ハニカムの厚さ、すなわち、金属製斜行ハニカムの前面開口部と後面開口部との間の寸法を３００ｍｍとする場合には、縦１００ｍｍの裁断型で作製した厚さ１００ｍｍの金属製斜行ハニカムを厚さ方向に３枚重ねて使用すればよい。
【００２２】
本発明において、上記金属製斜行ハニカムが上記加湿手段又は上記凝縮手段の一方又は両方に用いられる場合、金属製斜行ハニカムは前後両面と上下両面とが開口するように配置される。金属製斜行ハニカムをこのように配置することにより、金属製斜行ハニカムの前面開口部から被処理空気を導入すると共に、上面開口部から水を供給することが可能になり、被処理空気と水との接触が被処理空気の通気方向と水の流下方向とが直交するようになる。このため、加湿手段又は凝縮手段として、金属製斜行ハニカムを用いると、被処理空気と水との接触効率が従来の水シャワーを用いた加湿手段や冷却器を用いた凝縮手段に比べて高くなり、被処理空気中に含まれる化学汚染物質を効率よく除去することができ、装置の奥行きを大幅に小さくすることができる。
【００２３】
金属製斜行ハニカムが加湿手段又は凝縮手段に用いられる場合、該金属製斜行ハニカムを用いた具体的な加湿手段又は凝縮手段としては、例えば、前後両面と上下両面とが開口するように配置される金属製斜行ハニカムと、該金属製斜行ハニカムの上面開口部から水を供給する給水部と、金属製斜行ハニカムを流下した水分を回収する水回収部と、給水部に供給する水の温度を調節する加熱器又は熱交換機等とからなるものが挙げられる。流下した水分を回収しない場合、水回収部の代わりに、水放出部を設けてもよい。なお、金属製斜行ハニカムが加湿手段及び凝縮手段の両方に用いられる場合、加湿手段及び凝縮手段の態様は同様であるが、除湿手段に供給する水の水温を加湿手段に供給する水の水温よりも低くすればよい。加湿手段及び凝縮手段に供給する水の水温は、適宜定めればよい。
【００２４】
本発明において、金属製斜行ハニカムの使用形態としては、具体的には、金属製斜行ハニカムが加湿手段及び凝縮手段の両方に用いられる第１の実施形態、金属製斜行ハニカムが加湿手段のみに用いられる第２の実施形態、金属製斜行ハニカムが凝縮手段のみに用いられる第３の実施形態、１台の金属製斜行ハニカムにおいて、加湿手段と凝縮手段とを順次行う第４の実施形態が挙げられる。
【００２５】
第１の実施形態は、加湿手段及び凝縮手段の両方に、水と被処理空気との接触効率のため金属製斜行ハニカムを用いるため、最も化学汚染物質の除去効率が高く、装置の設置面積及び使用水量が少なくて済み、圧力損失が小さいため好ましい。また、加湿手段及び凝縮手段の両方に供給する水としては、加湿手段及び凝縮手段の両方共に、又は少なくとも凝縮手段に供給する水は脱イオン水を用いると被処理空気の汚染が少ないため好ましい。ただし、加湿手段と凝縮手段がそれぞれ独立している場合には、加湿手段及び凝縮手段に供給する水は、凝縮手段に供給される水の汚染がなるべく生じないように独立した系とすることで互いに混合しないようにすることが好ましい。また、加湿手段に供給する水は、市水又は工業用水を用いると低コスト化できるため好ましい。上記脱イオン水としては、特に制限されず、例えば、市水又は工業用水を前処理した後、イオン交換樹脂で処理した処理水を用いることができる。
【００２６】
次に、第１の実施形態における作用を説明する。まず、被処理空気は、ダクトを通してブロアー等により加湿工程に供される。加湿工程では、被処理空気は、所定の温度に加温され、且つ、金属製斜行ハニカムの上部から水が供給されて、該金属製斜行ハニカムをゆっくりと流下してセル全体が水膜壁構造になっている金属製斜行ハニカムのセルの表面と接触する。この際、被処理空気は膜面から蒸発する水分により加湿されると共に、一方では被処理空気中の化学汚染物質の一部が水中に吸収される。この結果、被処理空気から化学汚染物質がある程度除去される。
【００２７】
加湿工程終了後、加湿された被処理空気は凝縮工程に供給される。凝縮工程では、被処理空気は、前記加湿工程よりも低温にされた金属製斜行ハニカムのセルの表面で冷却されて空気中の水分が凝縮し、この際に空気中に前記加湿工程で除去されずに残存する化学汚染物質が略凝縮水に取り込まれ流下水と共に回収され、被処理空気中から化学汚染物質が除去される。上記の加湿工程における水の温度、及び凝縮工程における水の温度、前者が後者よりも高いものであればよく、所望の湿度又は温度の空気が得られるように、適宜調整すればよい。凝縮工程終了後は、そのまま、又は適宜湿度や温度を調整してクリーンルーム等に用いられる清浄空気として使用される。
【００２８】
なお、クリーンルーム内は、通常、温度が２３℃前後、相対湿度が４０〜５０％程度に調節されるため、クリーンルーム用の浄化空気を調製する場合、加湿工程及び凝縮工程の条件は、上記凝縮工程後に得られる浄化空気は、２３℃前後に適宜加熱された際に上記範囲内の相対湿度になるように設定される。この際に用いられる加熱手段又は加湿手段としては特に限定されず、電熱器や温水による加温器等の公知のものを用いることができる。このようにして得られた２３℃前後、且つ、相対湿度が４０〜５０％程度の浄化空気クリーンルーム用空気として用いられる。
【００２９】
本発明の第１の実施形態によれば、金属製斜行ハニカムを構成する波形状の金属板表面を流下する水で加湿又は凝縮するために、循環使用等により化学汚染物質を含むようになった循環水を用いる場合でも、該循環水から化学汚染物質が再気散することがほとんどない。すなわち、従来の方法では、汚染物質を含む水をシャワー状で噴霧するため、ミストが空気に取り込まれて化学汚染物質の再飛散を引き起こしていた。これに対して、本発明の方法では、表面積の大きなハニカム表面の水のみが蒸発し、一度水に取り込まれた化学汚染物質は、水側に残るので、汚染物質の再飛散は起こりにくいと考えられる。このため、金属製斜行ハニカムを加湿手段に用いる場合には、上記のように脱イオン水のみならず市水や工業用水を用いることができる。また、化学汚染物質の除去効率が高いため、公知の水シャワー等では１〜２程度必要であった液ガス比を０．１程度とすることができる。また、加湿工程や凝縮工程に用いられる水を循環使用する場合に、使用する水量が少なくて済み、この結果、ポンプ容量等が小さくて済む。
【００３０】
本発明の第２の実施形態は、加湿手段のみに、水と被処理空気との接触効率のため金属製斜行ハニカムを用いるものであり、従来公知の水シヤワー等の加湿手段に比べて、第１の実施形態において、加湿手段に金属製斜行ハニカムを用いた効果と同様の効果を奏することができる。本例は、冬場の乾燥空気を被処理空気とする場合に好適である。また、本例では、加湿手段のみで被処理空気中の化学汚染物質を除去できるが、凝縮手段として、公知の冷却器を使用して、加湿後の空気を除湿してもよい。
【００３１】
本発明の第３の実施形態は、凝縮手段のみに、水と被処理空気との接触効率の良い金属製斜行ハニカムを用いるものであり、従来公知の冷却器等を用いる凝縮手段に比べて、第１の実施形態において、凝縮手段に金属製斜行ハニカム用いた効果と同様の効果を奏することができる。また、この実施形態においては、凝縮手段が金属製斜行ハニカムを用いており、被処理空気と水との接触効率が高く、化学汚染物質の除去効率が高いため、凝縮手段のみでもある程度のガス状化学汚染物質の除去が可能であり、加湿手段を設けずに設備に掛かるコストを低減することができる。特に梅雨時から夏場にかけては空気が高温高湿であり、そのまま被処理空気として供給できるため、本実施の形態は特に有効である。本例では、凝縮手段のみで被処理空気中の化学汚染物を除去できるが、さらに、加湿手段として、公知の加湿器を使用し、その後、上記金属製斜行ハニカムで除湿してもよい。
【００３２】
本発明の第４の実施形態は、１台の金属製斜行ハニカムにおいて、加湿工程と凝縮工程を順次行うものである。すなわち、被処理空気は、ダクトを通してブロアー等により金属製斜行ハニカムの前面の開口部に供給される。金属製斜行ハニカムの前段側は加湿部となり、被処理空気は所定の湿度まで加湿され、該金属製斜行ハニカム内で飽和状態にまで加湿されると、次いで、通過する金属製斜行ハニカムの後段部では、所定の湿度まで除湿されることとなる。このため、前記加湿部で該空気中の化学汚染物質の一部が過剰な水分に取り込まれると共に、前記除湿部により、前記加湿部で除去されずに残存する化学汚染物質が凝縮水に取り込まれて除去される。
【００３３】
上記の本発明に係る空気清浄方法は、例えば、半導体や液晶デバイスの製造工場、製薬工場、ライフサイエンス関連施設等のクリーンルームに供給する空気の空気清浄方法として用いることができる。また、特に、半導体や液晶デバイスの製造工場において、当該方法に使用される金属製斜行ハニカムの大きさは、例えば、縦１０００〜５０００ｍｍ、横１０００〜５０００ｍｍ、厚さ１００〜１０００ｍｍのものが使用できる。
【００３４】
【実施例】
次に、実施例を挙げて本発明をさらに具体的に説明するが、本発明はこれに限定されるものではない。
【００３５】
（実施例１〜１０、比較例１〜３）
表１〜３に示す仕様の加湿手段及び凝縮手段を有する空気清浄装置を作製し、これらをそれぞれ表４〜６に示す条件で処理した結果、それぞれ表７〜９に示す結果が得られた。また、得られた浄化空気を表１０〜１２に示す条件で加熱してクリーンルーム用の浄化空気を得た。結果を表１０〜１２に示す。なお、実施例５〜９は、加湿ゾーンを設けずに被処理空気を直接に凝縮ゾーンに供給するものである。さらに、金属製斜行ハニカムは、表１〜３に記載のＳＵＳ製コルゲート状シートが１層おきに交差し、且つ、セルの斜め角度が空気の流入方向に対して３０度であるものを用いた。また、加湿手段で用いられる水と凝縮手段で用いられる水とはそれぞれ独立した系とし、実施例４と比較例２については、それぞれの水は循環使用し、実施例１〜３、５〜１１及び比較例１、３については１パスとした。補給水は、循環水中の汚染物質が所定濃度以下になるように供給した。例えば、循環水中のアンモニアイオン濃度は、実施例３では１００ｐｐｂ、実施例４では５００ｐｐｂである。水中のアンモニアイオン濃度が５００ｐｐｂを越えると、従来の水シャワーではアンモニアの気散が起こり、その吸収除去率は著しく低下する（比較例２）。表中、「エアオッシャー」は水シャワーのことである。
【００３６】
【表１】

【００３７】
【表２】

【００３８】
【表３】

【００３９】
【表４】

【００４０】
【表５】

【００４１】
【表６】

【００４２】
【表７】

【００４３】
【表８】

【００４４】
【表９】

【００４５】
【表１０】

【００４６】
【表１１】

【００４７】
【表１２】

【００４８】
【発明の効果】
本発明に係る空気清浄方法は、以下のような効果を奏する。
（１）ガス状化学汚染物質の除去効率が高い。
（２）安価な金属製斜行ハニカムの使用により、空気清浄装置全体がコンパクトになるため、省資源であると共に、処理コストを大幅に低減できる。
（３）使用する脱イオン水の量が少なくて済むため、脱イオン水の製造コストやポンプ搬送能力を削減できる。
（４）処理する空気が空気清浄装置を通過する際の圧力損失が小さいため送風動力を低減できる。
（５）金属製斜行ハニカムを構成する波形状の金属板の上を流下する水と処理空気とを接触させるため、表面積の大きなハニカム表面の水だけが蒸発し、一度水に取り込まれてしまった化学汚染物質は水側に残るので、化学汚染物質の再飛散は起こり難い。このため、被処理空気を再汚染する恐れが少ない。
（６）斜行ハニカムが金属製であるため、壁の強度を強くできるので、該金属製斜行ハニカムの壁を薄くできる。
（７）ハニカムの壁を薄くできるので、圧力損失を小さくできる。
（８）耐水性や流水による耐摩耗性を含めた耐久性に優れる。
（９）空気と水の接触を金属製斜行ハニカムを介して行うため、使用する金属板からのパーティクルが空気に混入することがないので、クリーンルームへ送る空気の清浄化に好適である。
（１０）空気と水の接触を金属製斜行ハニカムを介して行うため、使用する金属板からのアウトガスが空気に混入することがないのでクリーンルームへ送る空気の清浄化に好適である。
（１１）空気と水の接触を金属製斜行ハニカムを介して行うため、かびや藻類の発生がない。
【図面の簡単な説明】
【図１】本発明の空気清浄方法で使用する金属製斜行ハニカムを説明する図である。
【符号の説明】
１金属製斜行ハニカム
１３加湿手段
２３凝縮手段
１０１，１０４上下両面
１０２，１０３前後両面[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air cleaning method for cleaning chemical contaminants in the air by washing with water. More specifically, the present invention relates to a method for purifying air supplied to clean rooms such as semiconductor and liquid crystal device manufacturing factories, pharmaceutical factories and life science-related facilities.
[0002]
[Prior art]
Semiconductor and liquid crystal device manufacturing factories, pharmaceutical factories, life science-related facilities, etc. remove gaseous chemical pollutants in addition to conventional particulate pollutants in order to improve product yield and ensure quality. It is hoped that. Examples of such chemical pollutants include inorganic metal elements such as sodium, potassium, calcium and boron, anions such as fluorine ion, chloride ion, nitrate ion, nitrite ion, sulfate ion and sulfite ion, and ammonium. And cations such as ions. Conventional particulate contaminants can be removed with a dust collection filter such as an ULPA filter, but these chemical contaminants cannot be removed with an ULPA filter or the like.
[0003]
For this reason, chemical pollutants in the air are conventionally removed by a method using a so-called water shower called a water shower or a method using a chemical filter capable of adsorbing and removing chemical components. Here, the former method using a water shower is a method of removing air containing chemical contaminants by spraying water droplets.
[0004]
[Problems to be solved by the invention]
However, the former method using a water shower has low contact efficiency between the air to be treated and water, and therefore has low chemical contaminant removal efficiency. For this reason, the depth of the humidifying means comprising the water shower device is required to be about several meters, which requires a large installation space and a large pressure loss. Moreover, although expensive deionized water (DIW) is usually used as the treated water for the water shower, there is a problem that the cost increases because a large amount of treated water is required. Furthermore, although DIW is normally used in order to reduce the cost, there is a problem that chemical contaminants once absorbed easily re-evaporate. On the other hand, the latter method using a chemical filter has a problem in that the chemical filter itself is expensive and the adsorption capacity has a long lifetime, which increases the cost.
[0005]
Accordingly, it is an object of the present invention to provide an air cleaning method that has a high efficiency of removing chemical contaminants in the air, a compact processing apparatus, low pressure loss, and low cost.
[0006]
[Means for Solving the Problems]
Under such circumstances, as a result of intensive studies, the present inventors have used a metal skewed honeycomb as one or both of the humidifying means and the condensing means, and introduced air from the front opening of the metal skewed honeycomb. At the same time, if water is supplied from the opening on the upper surface, the air introduced into the metal skew honeycomb and the supplied water are in efficient contact with each other, and the humidifier can efficiently increase the humidity in the air. it can. Further, in the condensing means, it has been found that gaseous chemical pollutants are efficiently taken in and removed from the condensed water, and the present invention has been completed.
[0007]
  That is, the invention according to claim 1 of the present invention isA plurality of metal corrugated sheets having a corrugated shape propagating in one direction and having a thickness of 10 to 200 μm are stacked to form a honeycomb shape. 4 planes that are stacked so as to intersect with each other, and the wave propagation directions of every two layers are substantially the same, and are perpendicular to the plane parallel to the metal corrugated sheet A rectangular parallelepiped is formed by cutting with a metal skew honeycomb having a thickness of 100 to 1000 mm whose cut surface is not parallel to and perpendicular to the wave propagation direction of the metal corrugated sheet,By introducing air containing chemical contaminants from the front opening of the metal skew honeycomb arranged with both the front and rear surfaces and the upper and lower surfaces opened, and supplying water from the upper surface opening,In the metal skew honeycombThe air is humidified, and chemical contaminants are removed from the air by incorporating at least a part of the chemical contaminants into the obtained excess moisture.
[0008]
  The invention according to claim 2 of the present invention isA plurality of metal corrugated sheets having a corrugated shape propagating in one direction and having a thickness of 10 to 200 μm are stacked to form a honeycomb shape. 4 planes that are stacked so as to intersect with each other, and the wave propagation directions of every two layers are substantially the same, and are perpendicular to the plane parallel to the metal corrugated sheet A rectangular parallelepiped is formed by cutting with a metal skew honeycomb having a thickness of 100 to 1000 mm whose cut surface is not parallel to and perpendicular to the wave propagation direction of the metal corrugated sheet,By introducing air containing chemical contaminants from the front opening of the metal skew honeycomb arranged with both the front and rear surfaces and the upper and lower surfaces opened, and supplying water from the upper surface opening,In the metal skew honeycombThe air is dehumidified, and at least part of the chemical pollutant is taken into the resulting condensed water, thereby removing the chemical pollutant from the air.
[0009]
  The invention according to claim 3 of the present invention introduces air containing a chemical pollutant, and humidifies the air by bringing the air and water into contact with each other. Humidification process that removes chemical pollutants from the air by incorporating a part, air containing chemical pollutants is introduced, and the air is dehumidified by contacting the air with water, resulting in condensation A dehumidifying step for removing chemical pollutants from the air by taking at least a part of the chemical pollutants into water, a humidifying means used in the humidifying step, and a condensation used in the dehumidifying means As a meansA plurality of metal corrugated sheets having a corrugated shape propagating in one direction and having a thickness of 10 to 200 μm are stacked to form a honeycomb shape. 4 planes that are stacked so as to intersect with each other, and the wave propagation directions of every two layers are substantially the same, and are perpendicular to the plane parallel to the metal corrugated sheet A rectangular parallelepiped is formed by cutting with a metal skew honeycomb having a thickness of 100 to 1000 mm whose cut surface is not parallel to and perpendicular to the wave propagation direction of the metal corrugated sheet,A metal skew honeycomb in which both front and rear surfaces and upper and lower surfaces are opened is used for one or both of the means.
[0010]
  The invention according to claim 4 of the present invention isA plurality of metal corrugated sheets having a corrugated shape propagating in one direction and having a thickness of 10 to 200 μm are stacked to form a honeycomb shape. 4 planes that are stacked so as to intersect with each other, and the wave propagation directions of every two layers are substantially the same, and are perpendicular to the plane parallel to the metal corrugated sheet A rectangular parallelepiped is formed by cutting with a metal skew honeycomb having a thickness of 100 to 1000 mm whose cut surface is not parallel to and perpendicular to the wave propagation direction of the metal corrugated sheet,Air containing chemical contaminants is introduced from the front opening of the metal skewed honeycomb arranged with both the front and rear surfaces and the upper and lower surfaces opened, and water is supplied from the upper surface opening, Front partInsideThe air is humidified by removing at least part of the chemical pollutant into the resulting excess moisture, thereby removing the chemical pollutant from the air,In the latter part of the metal skew honeycombThe air is dehumidified, and at least part of the chemical pollutant is taken into the resulting condensed water, thereby removing the chemical pollutant from the air.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the humidifying means includes a means for supplying moisture to the air to be treated and, as appropriate, a means for collecting moisture and a temperature adjusting means, thereby humidifying the air to be treated to a predetermined humidity and removing excessive moisture. It is a means to obtain. The humidifying means humidifies the air to be treated, and takes in and removes at least a part of the gaseous chemical pollutants contained in the air to be treated in the excess moisture.
[0012]
The condensing means is a means for dehumidifying the air to be treated to a predetermined humidity and obtaining condensed water generated at the time of dehumidification by providing a low temperature part that can contact the air to be treated and a means for collecting moisture. The condensing means removes chemical contaminants in the air to be treated or chemical contaminants that have not been removed by the humidifying means as much as possible into the condensed water generated during dehumidification.
[0013]
In the present invention, the chemical pollutant means a fine chemical substance that passes through the stitch of a high performance (ULPA) filter, for example, an inorganic metal element such as sodium, potassium, calcium, boron, fluorine ion, Examples thereof include anions such as chloride ion, nitrate ion, nitrite ion, sulfate ion and sulfite ion, and cations such as ammonium ion.
[0014]
In the present invention, a metal skew honeycomb in which both front and rear surfaces and upper and lower surfaces are opened is used for one or both of the humidifying means and the condensing means. The metal skew honeycomb will be described with reference to FIG. Here, the metal skew honeycomb 1 is a honeycomb shape in which a plurality of metal corrugated sheets 2 and 3 (hereinafter also referred to as “metal corrugated sheets”) having a corrugated shape propagating in one direction are laminated. The metal

corrugated sheets

2 and 3 to be laminated are laminated so that the wave propagation direction obliquely intersects every other sheet, and the wave propagation direction of every other layer sheet Are honeycomb-like bodies arranged so as to be in substantially the same direction.
[0015]
The metal skew honeycomb 1 is cut along four planes 101 to 104 perpendicular to the plane parallel to the metal

corrugated sheets

2 and 3 to form a rectangular parallelepiped, and the cut plane is the metal corrugated sheet 2. , 3 is not parallel to the wave propagation direction and is not vertical, the rectangular parallelepiped has one of the cut surfaces 104 as the lower surface, and the

outermost layers

105, 106 of the metal

corrugated sheets

2, 3 are When placed on the left and right sides, the honeycomb cells are opened on all four sides of the front and

rear sides

102 and 103 and the upper and

lower sides

101 and 104, which are cut surfaces, and the left and

right sides

105 and 106 are made of metal

corrugated sheets

2, 3 It has a closed structure. For example, the front and

rear surfaces

102 and 103 of the cut surface are formed with cells extending obliquely upward and cells extending obliquely downward. The oblique angle (symbol X in the figure) with respect to the inflow and outflow direction (horizontal direction) of air when viewed from the front and rear surfaces of the cell extending obliquely upward is usually 15 to 45 degrees, preferably 25 to 35. Within the range of degrees. It is preferable that the oblique angle is within this range because the flow velocity is in an appropriate range and the contact efficiency is improved.
[0016]
In the metal skew honeycomb 1, the angle (in the figure, Y) in which the wave propagation directions of every other layer of the laminated metal corrugated

sheets

2 and 3 intersect each other is usually 30 to 90 degrees, preferably It is 25 to 35 degrees. When such metal corrugated

sheets

2 and 3 are laminated so as to intersect each other within the above angle range, when the oblique angle (X) is set to 15 to 45 degrees as described above, the air to be treated and Since the area where water substantially contacts the honeycomb cell is increased, the contact between the air to be treated and water, that is, the humidifying efficiency of humidifying the air to be treated, and the condensation means being in the air to be treated. This is preferable because the efficiency of dehumidification due to the condensation of moisture is increased. That is, as will be described later, in the present invention, the air to be treated is introduced from the front opening 103 of the metal skewed honeycomb 1 and the water is supplied from the upper surface opening 101 by, for example, the water supply duct 4. Since the surface of the metal corrugated

sheets

2 and 3 flows downward, the air flowing direction of the air to be treated and the water flowing direction of the permeation wall surface maintain an appropriate angle, and the contact efficiency is increased.
[0017]
The height of the cell of the metal skew honeycomb 1 used in the present invention, that is, the height of the cell indicating the dimension between the crest and trough of the wave is usually 1.5 to 8 mm, preferably 2.0 to 5 mm. . If the cell size is less than 1.5 mm, the production is difficult and the pressure loss increases, which is not preferable. On the other hand, if the cell size exceeds 8 mm, the removal efficiency of gaseous chemical contaminants is not preferable.
[0018]
The cell width in the state of the metal corrugated

sheets

2 and 3 of the metal skew honeycomb 1, that is, the cell pitch is usually 2.5 to 12.0 mm, preferably 3.0 to 10.0 mm. Further, the dimension between the front opening and the rear opening of the metal skew honeycomb 1, that is, the thickness (t) of the metal skew honeycomb 1 is not particularly limited, but is usually 100 to 1000 mm, preferably 200-800 mm. Also, when removing and dehumidifying chemical pollutants with a single honeycomb during periods of high humidity, such as during the rainy season, it is better to use a thick one with a thickness of about 800 mm for sufficient dehumidification. . If the thickness is less than 100 mm, NO₂ ^-The thickness is more than 1000 mm, which is not preferable because the removal efficiency of chemical contaminants is not further improved and the pressure loss increases. In the present invention, the thickness of the metal skewed honeycomb 1 may be such that the total thickness is within the above range when a plurality of the metal skewed honeycombs 1 are used. For example, when a metal skew honeycomb having a thickness of 300 mm is used, three metal skew honeycombs having a thickness of 100 mm may be stacked in the thickness direction so that the total thickness is 300 mm. The water shower conventionally used as the humidifying means requires a depth of about several meters, but when the metal skew honeycomb according to the present invention is used as the humidifying means, the thickness of the metal skew honeycomb itself is increased. Since it is about 400 mm at most, the installation space of the apparatus can be greatly reduced. Such a large space saving satisfies the demand for rationalization of semiconductor manufacturing factories and the like. Furthermore, the power of the pump that circulates water is much less than that of a conventional water shower, and a significant energy saving can be achieved.
[0019]
The material of the metal skew honeycomb used in the present invention is not particularly limited as long as the strength, chemical stability, and the like satisfy the conditions required for the metal honeycomb carrier. For example, stainless steel, aluminum, copper, etc. Is mentioned.
The thickness is 10 to 200 μm, and if it is thinner than 10 μm, the strength and workability are poor, and if it exceeds 200 μm, there is a problem that it is heavy and the pressure loss is large. A preferable thickness is 30 to 100 μm.
[0020]
The metal corrugated

sheets

2 and 3 used in the present invention are obtained by corrugating a flat metal foil, and are provided with irregularities so that the wave travels in one direction within the surface of the metal foil. It is. Here, corrugating means that a flat plate is processed into a corrugated object.
[0021]
Examples of the method for forming the metal corrugated

sheets

2 and 3 include a method using a known corrugator in which a flat sheet is passed between a plurality of gears having corrugated irregularities that oscillate in the radial direction. . As a method for forming the metal skewed honeycomb 1 from the obtained metal corrugated

sheets

2 and 3, for example, first, the metal corrugated

sheets

2 and 3 are vertically 100 mm (thickness dimension after forming) × A rectangular corrugated sheet is produced by arranging and cutting a rectangular cutting mold having a width of about 300 mm so that the wave propagation direction is 15 to 45 degrees with respect to one side of the rectangular shape. A method in which the rectangular corrugated sheets are arranged so that the propagation direction of every other wave is oblique, and these are laminated is mentioned. In addition, when manufactured in this way, the vertical length of the cutting die is the thickness of one metal skew honeycomb. Therefore, for example, when the thickness of the metal skew honeycomb required for the humidifying means and the condensation means, that is, when the dimension between the front opening and the rear opening of the metal skew honeycomb is 300 mm, What is necessary is just to use the metal skew honeycomb of thickness 100mm produced with the cutting type | mold with a length of 100 mm in the thickness direction.
[0022]
In the present invention, when the metal skew honeycomb is used for one or both of the humidifying means and the condensing means, the metal skew honeycomb is disposed so that both front and rear surfaces and upper and lower surfaces are opened. By arranging the metal skew honeycomb in this way, it becomes possible to introduce the air to be treated from the front opening of the metal skew honeycomb and to supply water from the top opening. As for the contact with water, the direction of ventilation of the air to be treated and the direction of water flow are perpendicular to each other. For this reason, when a metal skew honeycomb is used as the humidifying means or the condensing means, the contact efficiency between the air to be treated and the water is higher than the humidifying means using a conventional water shower or the condensing means using a cooler. Thus, chemical contaminants contained in the air to be treated can be efficiently removed, and the depth of the apparatus can be greatly reduced.
[0023]
When the metal skew honeycomb is used for the humidifying means or the condensation means, the specific humidification means or the condensation means using the metal skew honeycomb is, for example, arranged so that both the front and rear surfaces and the upper and lower surfaces are opened. A metal skewed honeycomb, a water supply portion for supplying water from an upper surface opening of the metal skew honeycomb, a water recovery portion for collecting water flowing down the metal skew honeycomb, and a water supply portion What consists of a heater or a heat exchanger etc. which adjust the temperature of water is mentioned. In the case where the flowed-down water is not collected, a water discharge unit may be provided instead of the water collection unit. When the metal skew honeycomb is used for both the humidifying means and the condensing means, the modes of the humidifying means and the condensing means are the same, but the water temperature of the water supplied to the dehumidifying means is the water temperature of the water supplied to the humidifying means. Lower than that. What is necessary is just to determine suitably the water temperature of the water supplied to a humidification means and a condensation means.
[0024]
In the present invention, as the usage form of the metal skew honeycomb, specifically, the first embodiment in which the metal skew honeycomb is used for both the humidifying means and the condensing means, and the metal skew honeycomb is the humidifying means. The second embodiment used only for the third embodiment, the third embodiment in which the metal skew honeycomb is used only for the condensation means, and the fourth embodiment in which the humidification means and the condensation means are sequentially performed in one metal skew honeycomb. Embodiments are mentioned.
[0025]
In the first embodiment, a metal skew honeycomb is used for both the humidifying means and the condensing means for the contact efficiency between water and the air to be treated. Therefore, the removal efficiency of chemical contaminants is the highest, and the installation area of the apparatus Further, it is preferable because the amount of water used is small and the pressure loss is small. As water supplied to both the humidifying means and the condensing means, it is preferable to use both dehumidifying means and condensing means, or at least water supplied to the condensing means, since deionized water is less contaminated. However, if the humidifying means and the condensing means are independent of each other, the water supplied to the humidifying means and the condensing means should be an independent system so that the water supplied to the condensing means is not contaminated as much as possible. It is preferable not to mix with each other. Moreover, since the water supplied to a humidification means can reduce cost when using city water or industrial water, it is preferable. The deionized water is not particularly limited, and for example, treated water treated with an ion exchange resin after pretreatment of city water or industrial water can be used.
[0026]
Next, the operation in the first embodiment will be described. First, the air to be treated is subjected to a humidification process by a blower or the like through a duct. In the humidification step, the air to be treated is heated to a predetermined temperature, and water is supplied from the upper part of the metal skew honeycomb, and slowly flows down the metal skew honeycomb so that the entire cell becomes a water film. It contacts the surface of the cell of the metal slanted honeycomb having a wall structure. At this time, the air to be treated is humidified by the water evaporated from the film surface, and on the other hand, a part of the chemical contaminants in the air to be treated is absorbed into the water. As a result, chemical contaminants are removed to some extent from the air to be treated.
[0027]
After the humidification process, the humidified air to be treated is supplied to the condensation process. In the condensation process, the air to be treated is cooled on the surfaces of the cells of the metal slanted honeycomb that has been cooled to a temperature lower than that in the humidification process, and moisture in the air is condensed. At this time, the air is removed in the humidification process. The remaining chemical pollutant is taken into substantially condensed water and collected together with the flowing water, and the chemical pollutant is removed from the air to be treated. The temperature of water in the humidification step, the temperature of water in the condensation step, and the former need only be higher than the latter, and may be appropriately adjusted so as to obtain air having a desired humidity or temperature. After the condensing step is finished, it is used as it is or as clean air used in a clean room or the like by appropriately adjusting the humidity and temperature.
[0028]
In the clean room, the temperature is usually adjusted to around 23 ° C. and the relative humidity is adjusted to about 40 to 50%. Therefore, when preparing clean air for clean room, the conditions of the humidifying step and the condensing step are the above condensing steps. The purified air obtained later is set so as to have a relative humidity within the above range when appropriately heated to around 23 ° C. The heating means or humidifying means used at this time is not particularly limited, and a known one such as an electric heater or a warmer using warm water can be used. The purified air is used as clean room air having a temperature of about 23 ° C. and a relative humidity of about 40 to 50%.
[0029]
According to the first embodiment of the present invention, in order to humidify or condense with water flowing down the surface of the corrugated metal plate constituting the metal skew honeycomb, chemical contaminants are contained by circulation use or the like. Even when the circulating water is used, chemical pollutants are hardly re-aired from the circulating water. That is, in the conventional method, since water containing a pollutant is sprayed in the form of a shower, the mist is taken into the air and causes chemical contaminants to re-scatter. On the other hand, in the method of the present invention, only the water on the honeycomb surface having a large surface area evaporates, and the chemical pollutant once taken into the water remains on the water side. It is done. For this reason, when using a metal skew honeycomb for a humidification means, not only deionized water but city water and industrial water can be used as mentioned above. In addition, since the removal efficiency of chemical pollutants is high, the liquid / gas ratio that is required in the known water shower or the like can be about 0.1. In addition, when the water used in the humidification process and the condensation process is circulated and used, the amount of water to be used is small, and as a result, the pump capacity and the like can be small.
[0030]
The second embodiment of the present invention uses a metal skew honeycomb for the contact efficiency between water and air to be treated only in the humidifying means, compared with the humidifying means such as a conventionally known water shower, In the first embodiment, the same effect as that obtained by using a metal skew honeycomb as the humidifying means can be obtained. This example is suitable when dry air in winter is treated air. In this example, chemical pollutants in the air to be treated can be removed only by the humidifying means, but the humidified air may be dehumidified using a known cooler as the condensing means.
[0031]
The third embodiment of the present invention uses a metal skew honeycomb having good contact efficiency between water and air to be treated only for the condensing means, compared to the condensing means using a conventionally known cooler or the like. In the first embodiment, the same effect as that obtained by using the metal skew honeycomb as the condensing means can be obtained. In this embodiment, the condensing means uses a metal skew honeycomb, and the contact efficiency between the air to be treated and water is high, and the removal efficiency of chemical contaminants is high. The chemical pollutant can be removed, and the cost for the equipment can be reduced without providing the humidifying means. In particular, this embodiment is particularly effective since the air is hot and humid from the rainy season to the summer and can be supplied as it is. In this example, chemical contaminants in the air to be treated can be removed only by the condensing means, but further, a known humidifier may be used as the humidifying means, and then dehumidified by the metal skew honeycomb.
[0032]
In the fourth embodiment of the present invention, a humidifying step and a condensing step are sequentially performed in one metal skew honeycomb. That is, the air to be treated is supplied to the opening on the front surface of the metal skew honeycomb through a duct by a blower or the like. The front side of the metal skew honeycomb is a humidified portion, and the air to be treated is humidified to a predetermined humidity, and when it is humidified to a saturated state in the metal skew honeycomb, the metal skew honeycomb that passes next In the subsequent stage, the moisture is dehumidified to a predetermined humidity. For this reason, a part of the chemical pollutants in the air is taken into excess moisture by the humidifying unit, and the chemical pollutants remaining without being removed by the humidifying unit are taken into the condensed water by the dehumidifying unit. Removed.
[0033]
The above-described air cleaning method according to the present invention can be used, for example, as a method for cleaning air supplied to clean rooms such as semiconductor and liquid crystal device manufacturing factories, pharmaceutical factories, and life science related facilities. In particular, in a semiconductor or liquid crystal device manufacturing factory, the size of the metal skew honeycomb used in the method is, for example, 1000 to 5000 mm in length, 1000 to 5000 mm in width, and 100 to 1000 mm in thickness. it can.
[0034]
【Example】
Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.
[0035]
(Examples 1-10, Comparative Examples 1-3)
As a result of producing air purifiers having humidifying means and condensing means having the specifications shown in Tables 1 to 3 and treating them under the conditions shown in Tables 4 to 6, the results shown in Tables 7 to 9 were obtained, respectively. Moreover, the obtained purified air was heated under the conditions shown in Tables 10 to 12 to obtain purified air for a clean room. The results are shown in Tables 10-12. In Examples 5 to 9, the air to be treated is directly supplied to the condensation zone without providing the humidification zone. Further, the metal skew honeycomb used is one in which the SUS corrugated sheets described in Tables 1 to 3 intersect every other layer, and the oblique angle of the cell is 30 degrees with respect to the air inflow direction. It was. In addition, the water used in the humidifying means and the water used in the condensing means are independent from each other. For Example 4 and Comparative Example 2, each water is circulated and used in Examples 1-3, 5-11. For Comparative Examples 1 and 3, one pass was used. The make-up water was supplied so that the pollutants in the circulating water had a predetermined concentration or less. For example, the ammonia ion concentration in the circulating water is 100 ppb in Example 3 and 500 ppb in Example 4. When the ammonia ion concentration in water exceeds 500 ppb, ammonia is diffused in the conventional water shower, and the absorption and removal rate thereof is significantly reduced (Comparative Example 2). In the table, “Air Osher” means a water shower.
[0036]
[Table 1]

[0037]
[Table 2]

[0038]
[Table 3]

[0039]
[Table 4]

[0040]
[Table 5]

[0041]
[Table 6]

[0042]
[Table 7]

[0043]
[Table 8]

[0044]
[Table 9]

[0045]
[Table 10]

[0046]
[Table 11]

[0047]
[Table 12]

[0048]
【The invention's effect】
The air cleaning method according to the present invention has the following effects.
(1) The removal efficiency of gaseous chemical pollutants is high.
(2) The use of an inexpensive metal skew honeycomb makes the entire air purifier compact, which saves resources and significantly reduces the processing cost.
(3) Since the amount of deionized water to be used is small, the production cost of deionized water and the pump conveyance capacity can be reduced.
(4) Since the pressure loss when the air to be processed passes through the air cleaning device is small, the blast power can be reduced.
(5) Since the water flowing down on the corrugated metal plate constituting the metal skew honeycomb is brought into contact with the treated air, only the water on the honeycomb surface with a large surface area evaporates and is once taken into the water. Since chemical pollutants remain on the water side, re-scattering of chemical pollutants is unlikely. For this reason, there is little possibility of recontaminating to-be-processed air.
(6) Since the skew honeycomb is made of metal, the strength of the wall can be increased, and thus the wall of the metal skew honeycomb can be thinned.
(7) Since the honeycomb wall can be thinned, the pressure loss can be reduced.
(8) Excellent durability including water resistance and wear resistance due to running water.
(9) Since contact between air and water is performed through the metal skew honeycomb, particles from the metal plate to be used are not mixed into the air, which is suitable for cleaning air to be sent to a clean room.
(10) Since the contact between air and water is performed through the metal skew honeycomb, the outgas from the metal plate to be used is not mixed into the air, which is suitable for cleaning the air sent to the clean room.
(11) Since the contact of air and water is performed through the metal skew honeycomb, there is no generation of mold or algae.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a metal skew honeycomb used in the air cleaning method of the present invention.
[Explanation of symbols]
1 Metal skew honeycomb
13 Humidification means
23 Condensing means
101,104 both top and bottom
102,103 front and back both sides

Claims

A plurality of metal corrugated sheets having a corrugated shape propagating in one direction and having a thickness of 10 to 200 μm are stacked to form a honeycomb shape. 4 planes that are stacked so as to intersect with each other, and the wave propagation directions of every two layers are substantially the same, and are perpendicular to the plane parallel to the metal corrugated sheet A rectangular parallelepiped is formed by cutting with a metal skew honeycomb having a thickness of 100 to 1000 mm that is not parallel to and perpendicular to the wave propagation direction of the metal corrugated sheet. In addition to introducing air containing chemical contaminants from the front opening of the metal skewed honeycomb arranged so that both the upper and lower surfaces are opened, water is supplied from the upper surface opening so that the inside of the metal skewed honeycomb in the air Is humidified by incorporating at least part of the chemical pollutants in excess water resulting, air cleaning method characterized by removing the chemical pollutants from the air.

A plurality of metal corrugated sheets having a corrugated shape propagating in one direction and having a thickness of 10 to 200 μm are stacked to form a honeycomb shape. 4 planes that are stacked so as to intersect with each other, and the wave propagation directions of every two layers are substantially the same, and are perpendicular to the plane parallel to the metal corrugated sheet A rectangular parallelepiped is formed by cutting with a metal skew honeycomb having a thickness of 100 to 1000 mm that is not parallel to and perpendicular to the wave propagation direction of the metal corrugated sheet. In addition to introducing air containing chemical contaminants from the front opening of the metal skewed honeycomb arranged so that both the upper and lower surfaces are opened, water is supplied from the upper surface opening so that the inside of the metal skewed honeycomb in the air Removal was humidified, by incorporating at least part of the chemical pollutants in the condensed water obtained, air cleaning method characterized by removing the chemical pollutants from the air.

Introducing air containing chemical pollutants, bringing the air into contact with water, humidifying the air, and taking in at least a portion of the chemical pollutants into the excess moisture obtained, thereby chemicals from the air. Humidification process for removing pollutants, introducing air containing chemical pollutants, bringing the air into contact with water, dehumidifying the air, and taking in at least a part of the chemical pollutants into the resulting condensed water A dehumidifying step for removing chemical pollutants from the air, and a waveform propagating in one direction as a humidifying means used in the humidifying step and a condensing means used in the dehumidifying means A plurality of metal corrugated sheets having a shape of 10 to 200 μm in thickness are laminated to form a honeycomb shape, and the wave propagation directions of the laminated metal corrugated sheets cross each other diagonally. Are arranged so that the wave propagation directions of every two layers are substantially the same, and cut by four planes perpendicular to the plane parallel to the metal corrugated sheet. A rectangular parallelepiped is formed, and a metal skew honeycomb having a thickness of 100 to 1000 mm, which is not parallel and perpendicular to the wave propagation direction of the metal corrugated sheet, is used, and both its front and rear surfaces and both upper and lower surfaces A method for purifying air, wherein a metal skew honeycomb having an opening is disposed in one or both of the means.

A plurality of metal corrugated sheets having a corrugated shape propagating in one direction and having a thickness of 10 to 200 μm are stacked to form a honeycomb shape. 4 planes that are stacked so as to intersect with each other, and the wave propagation directions of every two layers are substantially the same, and are perpendicular to the plane parallel to the metal corrugated sheet A rectangular parallelepiped is formed by cutting with a metal skew honeycomb having a thickness of 100 to 1000 mm that is not parallel to and perpendicular to the wave propagation direction of the metal corrugated sheet. And air containing chemical contaminants is introduced from the front opening of the metal skewed honeycomb arranged so that the upper and lower surfaces are open, and water is supplied from the upper surface opening, and the front stage of the metal skewed honeycomb wherein the inner air Is humidified by incorporating at least part of the excess water to chemical contaminants resulting to remove chemical contaminants from the air, then allowed dehumidified said air in a subsequent stage portion of said metallic oblique honeycomb, is obtained An air cleaning method, wherein chemical contaminants are removed from the air by incorporating at least part of the chemical contaminants into condensed water.