JP2003071444A - Ultrapure water making system - Google Patents
Ultrapure water making systemInfo
- Publication number
- JP2003071444A JP2003071444A JP2001267538A JP2001267538A JP2003071444A JP 2003071444 A JP2003071444 A JP 2003071444A JP 2001267538 A JP2001267538 A JP 2001267538A JP 2001267538 A JP2001267538 A JP 2001267538A JP 2003071444 A JP2003071444 A JP 2003071444A
- Authority
- JP
- Japan
- Prior art keywords
- ultrapure water
- water
- sterilizing agent
- production system
- ultrapure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Separation Using Semi-Permeable Membranes (AREA)
- Treatment Of Water By Oxidation Or Reduction (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は超純水製造装置で製
造した超純水をユースポイントに送水する超純水製造シ
ステムに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrapure water production system for sending ultrapure water produced by an ultrapure water production system to a point of use.
【0002】[0002]
【従来の技術】半導体製造等の分野における洗浄工程で
は、洗浄水として超純水が用いられている。この超純水
としては、洗浄トラブルの原因となる微粒子、有機物や
無機物を含まないことが要求され、例えば抵抗率:1
8.2MΩ・cm以上、微粒子:1個/mL以下、生
菌:1個/L以下、TOC(Total Organic Carbon):
1μg/L以下、シリカ:1μg/L以下、金属類:1
ng/L以下、イオン類:10ng/L以下であること
が要求水質となっている。2. Description of the Related Art Ultrapure water is used as cleaning water in cleaning processes in the field of semiconductor manufacturing. This ultrapure water is required to be free of fine particles, organic substances and inorganic substances that cause cleaning troubles. For example, resistivity: 1
8.2 MΩ · cm or more, fine particles: 1 piece / mL or less, viable bacteria: 1 piece / L or less, TOC (Total Organic Carbon):
1 μg / L or less, silica: 1 μg / L or less, metals: 1
The required water quality is ng / L or less and ions: 10 ng / L or less.
【0003】超純水の使用場所(ユースポイント)は、
超純水製造装置と配管(流路)で接続され、このユース
ポイントで使用されなかった残余の超純水は別の流路を
介して前記超純水製造装置に戻されることにより循環系
が形成され、全体として超純水製造システムが構成され
ている。The place of use (use point) of ultrapure water is
It is connected to the ultrapure water production system by a pipe (flow path), and the remaining ultrapure water not used at this point of use is returned to the ultrapure water production system through another flow path to form a circulation system. Formed, the ultrapure water production system is configured as a whole.
【0004】図2は、従来の超純水製造システムを示す
系統図である。この超純水製造システムは、紫外線(U
V)酸化装置4、イオン交換樹脂塔5及び限外濾過(U
F)膜分離装置6を備える超純水製造装置で製造された
超純水が、配管16を介してユースポイント7へ送られ
て該ユースポイント7でその一部が使用され、未使用の
超純水が配管17を経て原水槽1に戻され、超純水製造
装置で再び処理される循環系をなしている。FIG. 2 is a system diagram showing a conventional ultrapure water production system. This ultrapure water production system uses ultraviolet rays (U
V) Oxidizer 4, ion exchange resin tower 5 and ultrafiltration (U
F) The ultrapure water produced by the ultrapure water producing apparatus equipped with the membrane separation device 6 is sent to the use point 7 through the pipe 16 and a part of the ultrapure water is used at the use point 7 Pure water is returned to the raw water tank 1 through the pipe 17 and is treated again in the ultrapure water production system to form a circulation system.
【0005】即ち、配管11から導入された一次純水及
びユースポイント7から配管17を経て戻された未使用
の超純水は原水槽1に収容される。ここで一次純水は、
例えば、工水、井水、市水等の原水を凝集沈殿等の前処
理後、逆浸透膜分離処理、アニオン性及びカチオン性の
イオン交換樹脂による処理を順に行い、更に逆浸透膜処
理することにより得られる。原水槽1内の水は、ポンプ
2により配管12を経て熱交換器3で温度調整された
後、配管13よりUV酸化装置4に導入され有機物が除
去される。UV酸化装置4の処理水は、配管14よりイ
オン交換樹脂塔5に導入されて脱塩処理された後、配管
15よりUF膜分離装置6に導入され微粒子が除去され
る。このようにして得られた超純水は、配管16よりユ
ースポイント7に送給され、余剰の超純水が配管17よ
り原水槽1に戻される。That is, the primary pure water introduced from the pipe 11 and the unused ultrapure water returned from the use point 7 via the pipe 17 are stored in the raw water tank 1. Here, the primary pure water is
For example, raw water such as industrial water, well water, and city water is subjected to pretreatment such as coagulation sedimentation, reverse osmosis membrane separation treatment, treatment with anionic and cationic ion exchange resins, and then reverse osmosis membrane treatment. Is obtained by After the temperature of the water in the raw water tank 1 is adjusted by the pump 2 through the pipe 12 and the heat exchanger 3, the water is introduced into the UV oxidizer 4 through the pipe 13 to remove organic substances. The treated water of the UV oxidizer 4 is introduced into the ion exchange resin tower 5 through the pipe 14 and desalted, and then introduced into the UF membrane separator 6 through the pipe 15 to remove fine particles. The ultrapure water thus obtained is fed to the use point 7 through the pipe 16, and the surplus ultrapure water is returned to the raw water tank 1 through the pipe 17.
【0006】ユースポイント7は超純水の使用場所を示
し、対象物(例えば半導体)を洗浄するための洗浄装置
の他、適宜配管やノズル類等を含んでもよい。なお、ユ
ースポイント7で使用された超純水は、適宜排水として
回収される。A use point 7 indicates a place where ultrapure water is used, and may include a pipe, a nozzle, and the like, in addition to a cleaning device for cleaning an object (for example, a semiconductor). The ultrapure water used at the use point 7 is appropriately collected as waste water.
【0007】超純水製造システムにおいて、このように
絶えず超純水の循環を行っているのは、超純水製造シス
テムのポンプや熱交換器、配管等を構成する材料からの
溶出成分を除去して系内を高純度に保つことを目的とし
ている。なお、一般に超純水製造システムのポンプや熱
交換器、配管等の構成材料としてはSUS材が適用され
ている。In the ultrapure water production system, the reason why the ultrapure water is constantly circulated in this way is to remove elution components from the materials constituting the pump, heat exchanger, piping, etc. of the ultrapure water production system. The purpose is to maintain high purity inside the system. In general, a SUS material is used as a constituent material of a pump, a heat exchanger, piping, etc. of an ultrapure water production system.
【0008】超純水製造システムでは、ユースポイント
7に供給される超純水中の生菌数を上記要求水質レベル
とするために、定期的に系内の殺菌が行われる。従来、
超純水製造システムの殺菌剤としては過酸化水素水が用
いられ、一般的には次のような手順で殺菌処理が行われ
ている。
超純水製造システムの運転を停止した後、殺菌剤
(過酸化水素水)を配管18より原水槽1に添加してポ
ンプ2により超純水製造システム系内全体に循環させ
る。即ち、原水槽1、配管12及びポンプ2、熱交換器
3、配管13、UV酸化装置4、配管14、イオン交換
樹脂塔5のバイパス配管14A、配管15、UF膜分離
装置6、配管16、ユースポイント7、配管17、原水
槽1の順で循環させる(循環殺菌洗浄)。なお、殺菌剤
の添加方法としては、原水槽1のマンホールより投入す
る方法、エジェクター又は薬液ポンプを用いて添加する
方法がある。
ポンプ2を停止して、所定時間系内に殺菌剤を保持
する(浸漬殺菌洗浄)。
系内の水を配管19より排出し、原水槽1を水洗
し、更にポンプ2を起動して殺菌剤が検出されなくなる
まで超純水製造システム系内を超純水で洗浄する(押し
出し洗浄)。In the ultrapure water production system, in order to keep the number of viable bacteria in the ultrapure water supplied to the use point 7 at the required water quality level, the system is regularly sterilized. Conventionally,
Hydrogen peroxide solution is used as a sterilizing agent in the ultrapure water production system, and sterilizing treatment is generally performed by the following procedure. After stopping the operation of the ultrapure water production system, a sterilizing agent (hydrogen peroxide solution) is added to the raw water tank 1 through the pipe 18 and circulated in the entire ultrapure water production system by the pump 2. That is, the raw water tank 1, the pipe 12 and the pump 2, the heat exchanger 3, the pipe 13, the UV oxidation device 4, the pipe 14, the bypass pipe 14A of the ion exchange resin tower 5, the pipe 15, the UF membrane separation device 6, the pipe 16, The point of use 7, the pipe 17, and the raw water tank 1 are circulated in this order (circulation sterilization cleaning). As a method of adding the bactericide, there are a method of adding from the manhole of the raw water tank 1 and a method of adding using a ejector or a chemical solution pump. The pump 2 is stopped and the germicide is held in the system for a predetermined time (immersion sterilization cleaning). The water in the system is discharged from the pipe 19, the raw water tank 1 is washed, and the pump 2 is further activated to wash the inside of the ultrapure water production system with ultrapure water until no sterilizing agent is detected (extrusion washing). .
【0009】上記〜の操作の後、超純水製造システ
ムの運転を再開する。After the above operations 1 to 3, the operation of the ultrapure water production system is restarted.
【0010】[0010]
【発明が解決しようとする課題】半導体の集積度が増々
高められている現在、その洗浄に用いられる超純水につ
いても益々高純度であることが要求されており、このた
め、超純水製造システムにおいては、殺菌処理後の運転
再開時において、運転再開直後から高純度で安定な水質
を維持し得ることが望まれている。At the present time when the degree of integration of semiconductors is increasing more and more, it is required that the ultrapure water used for cleaning the semiconductor should be of even higher purity. In the system, when the operation is restarted after the sterilization treatment, it is desired that high purity and stable water quality can be maintained immediately after the restart of the operation.
【0011】しかしながら、本発明者らが殺菌処理後の
超純水の水質を調査した結果、殺菌処理後は超純水中の
金属濃度が上昇し、運転再開後も長期にわたり金属濃度
の高い状態が継続することが判明した。即ち、殺菌処理
後、超純水製造システムの運転を再開した際には、製造
される超純水中にFe,Cr,Ni等の金属が0.1〜
1ng/L程度検出され、特に、Feは運転再開後一週
間を経過しても超純水中に検出された。However, as a result of the investigation by the present inventors of the water quality of the ultrapure water after the sterilization treatment, the metal concentration in the ultrapure water increases after the sterilization treatment, and the metal concentration in the ultrapure water remains high for a long period after the restart of the operation. Was found to continue. That is, when the operation of the ultrapure water production system is restarted after the sterilization treatment, metals such as Fe, Cr, and Ni are contained in the produced ultrapure water in an amount of 0.1 to 0.1%.
About 1 ng / L was detected, and particularly Fe was detected in ultrapure water even one week after the restart of operation.
【0012】本発明は上記従来の問題点を解決し、系内
の殺菌処理後、超純水製造システムの運転を再開した際
の超純水中の金属濃度が著しく低く、運転再開直後から
高純度で安定した水質の超純水を得ることができる超純
水製造システムを提供することを目的とする。The present invention solves the above-mentioned conventional problems, and the metal concentration in the ultrapure water when the operation of the ultrapure water production system is restarted after the sterilization treatment in the system is remarkably low, and becomes high immediately after restarting the operation. It is an object of the present invention to provide an ultrapure water production system capable of obtaining ultrapure water with high purity and stable water quality.
【0013】[0013]
【課題を解決するための手段】本発明の超純水製造シス
テムは、一次純水の貯水用の原水槽と、該原水槽内の水
が導入されて超純水を製造する、少なくとも膜分離手段
を有する超純水製造装置と、該超純水製造装置により製
造された超純水をユースポイントへ送水する送水手段
と、該ユースポイントを通過した未使用の超純水を前記
原水槽へ戻す返送手段とを有する超純水製造システムに
おいて、前記膜分離手段の1次側に殺菌剤を供給すると
共に、該返送手段から殺菌剤を含む水を排出させて、該
膜分離手段及び前記送水手段を殺菌する手段を備えたこ
とを特徴とする。The ultrapure water production system of the present invention comprises a raw water tank for storing primary pure water, and water in the raw water tank is introduced to produce ultrapure water. At least membrane separation. Means for supplying ultrapure water having means, water supply means for supplying ultrapure water produced by the apparatus for use with ultrapure water to a point of use, and unused ultrapure water that has passed the point of use to the raw water tank In an ultrapure water production system having a returning means for returning, a sterilizing agent is supplied to the primary side of the membrane separating means, and water containing the sterilizing agent is discharged from the returning means, the membrane separating means and the water feeding means. It is characterized by comprising means for sterilizing the means.
【0014】本発明者らは、従来の超純水製造システム
において、殺菌処理後の運転再開時に超純水中の金属濃
度が上昇し、金属濃度の高い状態が継続する原因を調べ
た結果、この原因は、循環殺菌洗浄中に超純水製造シス
テムのポンプや熱交換器、配管等の構成材料から溶出す
る金属や、停止中の予備ポンプ等に滞留していた金属が
過酸化水素等の殺菌剤により酸化されて微粒子化し、こ
れが超純水製造装置の最後段に設置されている分離膜手
段で捕捉されて分離膜を汚染し、その後、押し出し洗浄
で系内の過酸化水素が排出された後に、超純水中に再溶
解することによることを知見した。In the conventional ultrapure water production system, the present inventors have investigated the cause of the fact that the metal concentration in ultrapure water rises when the operation is restarted after the sterilization treatment and the high metal concentration continues. The cause of this is that metal that elutes from constituent materials such as pumps, heat exchangers, and piping of the ultrapure water production system during circulation sterilization cleaning, and metal that has accumulated in the standby pump that is stopped are hydrogen peroxide and the like. Oxidized by the bactericide and made into fine particles, which are captured by the separation membrane means installed at the final stage of the ultrapure water production system to contaminate the separation membrane, and then hydrogen peroxide in the system is discharged by extrusion washing. After that, it was found to be redissolved in ultrapure water.
【0015】ところで、超純水製造システムにおける殺
菌処理の目的は、主に超純水製造装置の膜分離手段から
ユースポイントに至る流路における菌の増殖を防止する
ことにある。即ち、超純水製造システムの超純水製造装
置において、通常最後段に設けられているUF膜分離装
置等の膜分離手段では、水中の菌体を確実に除去するこ
とができ、一方で、超純水製造装置には一次純水中に含
まれる菌体が常に流入していることを考慮した場合、原
水槽から超純水製造装置の膜分離手段までの経路につい
ての殺菌はさほど重要ではなく、膜分離手段以降のユー
スポイントに至る流路について殺菌を行うことができれ
ば良い。By the way, the purpose of the sterilization treatment in the ultrapure water production system is mainly to prevent the growth of bacteria in the flow path from the membrane separation means of the ultrapure water production apparatus to the point of use. That is, in an ultrapure water production system of an ultrapure water production system, a membrane separation means such as a UF membrane separation device usually provided at the last stage can reliably remove bacterial cells in water. Considering that the bacterial cells contained in the primary pure water constantly flow into the ultrapure water production system, sterilization of the route from the raw water tank to the membrane separation means of the ultrapure water production system is not so important. Instead, it suffices to be able to sterilize the flow path to the use point after the membrane separation means.
【0016】本発明の超純水製造システムでは、超純水
製造装置の膜分離手段の1次側に殺菌剤を供給すると共
に、ユースポイントから未使用の超純水を原水槽に戻す
返送手段から殺菌剤を含む水を排出させて、膜分離手段
と膜分離手段からユースポイントへ超純水を送水する送
水手段を殺菌する手段を有し、殺菌処理に当っては、殺
菌剤を膜分離手段の入口から導入して、当該膜分離手段
以降の送水手段及び返送配管の上流側のみを殺菌し、従
来の超純水製造システムのように、膜分離手段の前段の
配管や熱交換器、ポンプ等に殺菌剤を循環させない。In the ultrapure water production system of the present invention, a sterilizing agent is supplied to the primary side of the membrane separation means of the ultrapure water production apparatus, and a return means for returning unused ultrapure water from the point of use to the raw water tank. It has a means to sterilize the water containing the disinfectant from the membrane, and the means for sterilizing the membrane separation means and the water supply means for sending ultrapure water from the membrane separation means to the use point. Introduced from the inlet of the means, only the upstream side of the water supply means and the return pipe after the membrane separation means is sterilized, like the conventional ultrapure water production system, the pipe and heat exchanger in the preceding stage of the membrane separation means, Do not circulate the germicide in the pump, etc.
【0017】このため、この膜分離手段の前段における
殺菌処理中の金属の溶出が防止され、この溶出した金属
が膜分離手段を汚染し、その後超純水製造システムの運
転再開時に再溶解することによる超純水中の金属濃度の
上昇の問題は解決される。Therefore, the elution of the metal during the sterilization treatment in the preceding stage of the membrane separation means is prevented, the eluted metal contaminates the membrane separation means, and then is redissolved when the operation of the ultrapure water production system is restarted. The problem of increasing the metal concentration in ultrapure water due to is solved.
【0018】本発明においては、膜分離手段に殺菌剤を
供給する手段として、殺菌剤を蓄える殺菌剤貯槽と、該
殺菌剤貯槽内の殺菌剤を前記膜分離手段の1次側に導く
殺菌剤導入手段と、前記返送手段から排出された殺菌剤
を含む水を該殺菌剤貯槽へ戻す殺菌剤返送手段とを有す
ることが好ましく、これにより、殺菌剤貯槽から殺菌剤
を膜分離手段の入口側に導入し、膜分離手段以降の超純
水製造装置、ユースポイントへの超純水の送水手段、未
使用の超純水の返送配管及び殺菌剤貯槽に循環させて、
効率的な殺菌処理を行うことができる。In the present invention, as a means for supplying the sterilizing agent to the membrane separating means, a sterilizing agent storage tank for storing the sterilizing agent and a sterilizing agent for guiding the sterilizing agent in the sterilizing agent storage tank to the primary side of the membrane separating means. It is preferable to have an introducing means and a bactericide returning means for returning the water containing the bactericide discharged from the returning means to the bactericide storage tank, whereby the bactericide is supplied from the bactericide storage tank to the inlet side of the membrane separating means. The ultrapure water production device after the membrane separation means, the means for feeding ultrapure water to the point of use, the return pipe for unused ultrapure water and the germicide storage tank are circulated.
Efficient sterilization treatment can be performed.
【0019】また、この場合において、殺菌剤導入手段
は、前記殺菌剤貯槽内の殺菌剤を送液するためのポンプ
を備えており、該ポンプの接液部が非金属材料よりなる
ことが好ましく、これにより、殺菌処理中にポンプから
金属が溶出することを防止して、運転再開時の超純水の
金属濃度をより一層低く抑えることができる。In this case, the sterilizing agent introducing means is provided with a pump for feeding the sterilizing agent in the sterilizing agent storage tank, and the liquid contact portion of the pump is preferably made of a non-metallic material. As a result, it is possible to prevent the metal from being eluted from the pump during the sterilization process and to further suppress the metal concentration of the ultrapure water when the operation is restarted.
【0020】[0020]
【発明の実施の形態】以下に図面を参照して本発明の超
純水製造システムの実施の形態を詳細に説明する。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an ultrapure water production system of the present invention will be described in detail below with reference to the drawings.
【0021】図1は本発明の超純水製造システムの実施
の形態を示す系統図である。図1において、図2に示す
部材と同一機能を奏する部材には同一符号を付してあ
る。FIG. 1 is a system diagram showing an embodiment of the ultrapure water production system of the present invention. In FIG. 1, members having the same functions as those shown in FIG. 2 are designated by the same reference numerals.
【0022】この超純水製造システムでは、殺菌処理時
に、殺菌剤貯槽20内の殺菌剤含有水をポンプ21によ
ってUF膜分離装置6の入口側に導入すると共に、返送
配管17から殺菌剤を含む水を配管23より殺菌剤貯槽
20に導入するように構成している。In this ultrapure water producing system, the sterilizing agent-containing water in the sterilizing agent storage tank 20 is introduced into the inlet side of the UF membrane separation device 6 by the pump 21 and the sterilizing agent is contained from the return pipe 17 during the sterilizing treatment. Water is introduced into the germicide storage tank 20 through the pipe 23.
【0023】この実施の形態では、配管22の吐出側先
端は、配管15のUF膜分離装置6の入口近傍に設けら
れた殺菌剤導入口に接続されている。また、配管23の
流入側先端は、配管17に接続されている。In this embodiment, the discharge-side end of the pipe 22 is connected to the bactericide introducing port provided in the vicinity of the inlet of the UF membrane separation device 6 of the pipe 15. Further, the inflow side tip of the pipe 23 is connected to the pipe 17.
【0024】配管17のうち配管23の接続部よりも下
流側に開閉バルブV1が設けられると共に、配管23に
開閉バルブV2が設けられている。超純水製造運転時に
は、バルブV1を開、バルブV2を閉とし、また殺菌処
理時には、バルブV1を閉、バルブV2を開とする。な
お、配管23のバルブV2よりも殺菌剤貯槽20側には
押し出し洗浄排水の排出用の配管24が分岐しており、
該配管24に開閉バルブV3が設けられている。このバ
ルブV3は押し出し洗浄排水の排水時にのみ開とされ
る。An opening / closing valve V 1 is provided on the downstream side of the connection portion of the piping 23 in the piping 17, and an opening / closing valve V 2 is provided in the piping 23. The valve V 1 is opened and the valve V 2 is closed during the ultrapure water production operation, and the valve V 1 is closed and the valve V 2 is opened during the sterilization process. In addition, a pipe 24 for discharging the extruded cleaning drainage is branched to the sterilizing agent storage tank 20 side of the valve V 2 of the pipe 23,
An on-off valve V 3 is provided in the pipe 24. This valve V 3 is opened only when the extrusion cleaning waste water is discharged.
【0025】図1の超純水製造システムのその他の構成
は図2と同一である。この超純水製造システムの超純水
製造運転は、図2に示す従来の超純水製造システムと同
様に実施される。The other structure of the ultrapure water production system of FIG. 1 is the same as that of FIG. The ultrapure water production operation of this ultrapure water production system is carried out in the same manner as the conventional ultrapure water production system shown in FIG.
【0026】殺菌処理に当っては、上記の通りバルブV
1を閉、バルブV2を開とし、原水槽1への一次純水の
流入を停止すると共にポンプ2を停止させる。そして、
ポンプ21を起動させて殺菌剤貯槽20内の殺菌剤含有
水を配管22、UF膜分離装置6、配管16、ユースポ
イント7、配管17、配管23を経て殺菌剤貯槽20に
戻す循環殺菌洗浄を行う。この循環殺菌洗浄を所定時間
行った後は、ポンプ21を停止して所定時間保持する浸
漬殺菌洗浄を行う。In the sterilization process, the valve V is used as described above.
1 is closed and the valve V 2 is opened to stop the inflow of primary pure water into the raw water tank 1 and stop the pump 2. And
Circulating sterilization cleaning in which the pump 21 is activated to return the sterilizing agent-containing water in the sterilizing agent storage tank 20 to the sterilizing agent storage tank 20 via the pipe 22, the UF membrane separation device 6, the pipe 16, the use point 7, the pipe 17, and the pipe 23. To do. After the circulation sterilization cleaning is performed for a predetermined time, the pump 21 is stopped and the immersion sterilization cleaning is performed for a predetermined time.
【0027】その後、ポンプ21を停止し、バルブV3
を開とすると共に、ポンプ2を起動して押し出し洗浄を
行う。押し出し洗浄排水は配管24から排出される。押
し出し洗浄は、配管24から排出される押し出し洗浄排
水中に殺菌剤が検出されなくなるまで行う。Thereafter, the pump 21 is stopped and the valve V 3
Is opened and the pump 2 is activated to perform extrusion cleaning. The extrusion cleaning wastewater is discharged from the pipe 24. The extrusion cleaning is performed until no sterilizing agent is detected in the extrusion cleaning drainage discharged from the pipe 24.
【0028】押し出し洗浄後は、バルブV1を開、バル
ブV2,V3を閉に戻し、通常の超純水製造運転を再開
する。After the extrusion cleaning, the valve V 1 is opened and the valves V 2 and V 3 are returned to the closed state, and the normal ultrapure water production operation is restarted.
【0029】図1の超純水製造システムでは、殺菌処理
時において、UF膜分離装置6には、殺菌剤貯槽20、
ポンプ21、配管22、UF膜分離装置6、配管16、
ユースポイント7及び配管17を循環する殺菌剤含有水
が通水され、この殺菌剤はポンプ2、熱交換器3や超純
水製造装置の上流側の配管を通ることはないため、これ
らの配管や機器からの金属の溶出に起因するUF膜分離
装置6の膜汚染は防止される。このため、殺菌処理後の
超純水製造運転の再開直後から、高純度の超純水を安定
に製造することができる。In the ultrapure water production system of FIG. 1, during the sterilization process, the UF membrane separation device 6 has a bactericide storage tank 20,
Pump 21, piping 22, UF membrane separation device 6, piping 16,
The sterilizing agent-containing water that circulates through the use point 7 and the pipe 17 is passed through, and the sterilizing agent does not pass through the pump 2, the heat exchanger 3, and the pipes on the upstream side of the ultrapure water producing apparatus. Membrane contamination of the UF membrane separation device 6 due to elution of metal from the equipment is prevented. Therefore, high-purity ultrapure water can be stably produced immediately after the restart of the ultrapure water production operation after the sterilization treatment.
【0030】この殺菌処理時のUF膜分離装置6の金属
汚染を防止する観点から、UF膜分離装置6の入口側に
設けられる前記殺菌剤導入口(配管22の接続部)は、
配管15上のUF膜分離装置6の入口近傍であることが
好ましい。また、超純水製造装置には、膜分離手段への
原水導入圧力を確保するために、膜分離手段の前段にブ
ースターポンプを設けたものがあるが、この場合には、
ブースターポンプの吐出口と膜分離手段の入口との間に
殺菌剤導入口を設けることが好ましい。From the viewpoint of preventing metal contamination of the UF membrane separation device 6 during this sterilization treatment, the sterilizing agent introduction port (connection part of the pipe 22) provided on the inlet side of the UF membrane separation device 6 is
It is preferable to be near the inlet of the UF membrane separation device 6 on the pipe 15. Further, in an ultrapure water production apparatus, there is one in which a booster pump is provided in front of the membrane separation means in order to secure the raw water introduction pressure to the membrane separation means.
It is preferable to provide a sterilizing agent inlet between the discharge port of the booster pump and the inlet of the membrane separating means.
【0031】同様に、UF膜分離装置6の金属汚染を防
止する観点から、殺菌剤の循環系路の接液面は非金属材
料で構成されることが好ましく、特に、殺菌剤ポンプ2
1については、接液面が四フッ化樹脂、高密度ポリエチ
レン、ポリブテン、塩化ビニル、PVDF(ポリフッ化
ビニリデン)、ポリプロピレン等の非金属材料で構成さ
れていることが好ましい。また、殺菌剤の導入配管2
2、返送配管23についても、接液面がこれらの非金属
材料よりなるものを用いても良い。Similarly, from the viewpoint of preventing metal contamination of the UF membrane separation device 6, it is preferable that the liquid contact surface of the circulation path of the disinfectant is made of a non-metal material, and particularly, the disinfectant pump 2
Regarding No. 1, it is preferable that the liquid contact surface is made of a non-metal material such as tetrafluororesin, high-density polyethylene, polybutene, vinyl chloride, PVDF (polyvinylidene fluoride), and polypropylene. In addition, the disinfectant introduction pipe 2
2, the return pipe 23 may have a liquid contact surface made of these non-metallic materials.
【0032】本発明において、殺菌剤としては一般に過
酸化水素水を用いることができ、循環殺菌洗浄時におい
て、0.1〜1重量%濃度程度の過酸化水素水を上記殺
菌剤循環系路に循環させることが好ましい。In the present invention, hydrogen peroxide solution can be generally used as the sterilizing agent, and hydrogen peroxide solution having a concentration of about 0.1 to 1% by weight is introduced into the sterilizing agent circulation system during circulation sterilization cleaning. It is preferable to circulate.
【0033】なお、図1の超純水製造システムは本発明
の実施の形態の一例を示すものであって、本発明はその
要旨を超えない限り何ら図示のものに限定されるもので
はない。The ultrapure water production system of FIG. 1 shows an example of an embodiment of the present invention, and the present invention is not limited to the illustrated one unless it exceeds the gist.
【0034】例えば、殺菌剤貯槽20、殺菌剤ポンプ2
1、配管22,23等の殺菌剤を循環させるための手段
は必ずしも必要とされず、UF膜分離装置6の入口側の
殺菌剤導入口から導入した殺菌剤をUF膜分離装置6、
配管16、ユースポイント7及び配管17に通水した
後、配管17の途中に設けた排出口から排出し、一過性
で殺菌洗浄しても良く、この場合であっても殺菌処理時
のUF膜分離装置6の分離膜の金属汚染を防止して、殺
菌処理後超純水製造システムの運転再開直後から、高純
度の超純水を安定に製造することができる。For example, the germicide storage tank 20 and the germicide pump 2
1, a means for circulating the sterilizing agent such as the pipes 22 and 23 is not necessarily required, and the sterilizing agent introduced from the sterilizing agent introducing port on the inlet side of the UF membrane separating apparatus 6 is supplied to the UF membrane separating apparatus 6,
After water is passed through the pipe 16, the use point 7 and the pipe 17, the water may be discharged from a discharge port provided in the middle of the pipe 17 and temporarily sterilized and washed. Even in this case, the UF at the time of sterilization treatment It is possible to prevent metal contamination of the separation membrane of the membrane separation device 6 and to stably produce high-purity ultrapure water immediately after restarting the operation of the ultrapure water production system after sterilization.
【0035】また、超純水製造装置の構成としても何ら
図示のものに限定されるものではなく、膜分離手段とし
ては、UF膜分離装置の他、精密濾過膜分離装置や逆浸
透膜分離装置或いはこれらを組み合わせて用いても良
い。いずれの場合においても膜分離手段の入口側に殺菌
剤導入口を設けるが、一般的には、超純水製造装置の最
後段に設けられる微粒子除去用の膜分離手段の入口側に
殺菌剤導入口を設けることが好ましい。The structure of the ultrapure water producing apparatus is not limited to the one shown in the figure. Means for separating the membrane include a UF membrane separating apparatus, a microfiltration membrane separating apparatus and a reverse osmosis membrane separating apparatus. Alternatively, these may be used in combination. In any case, a bactericide introducing port is provided on the inlet side of the membrane separating means, but generally, the sterilizing agent is introduced on the inlet side of the membrane separating means for removing fine particles provided at the final stage of the ultrapure water production apparatus. It is preferable to provide a mouth.
【0036】[0036]
【実施例】以下に実施例及び比較例を挙げて本発明をよ
り具体的に説明する。EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples below.
【0037】実施例1
図1に示す本発明の超純水製造システムにおいて、殺菌
処理後の超純水中の金属濃度を調べる実験を行った。Example 1 In the ultrapure water production system of the present invention shown in FIG. 1, an experiment was conducted to check the metal concentration in ultrapure water after sterilization.
【0038】なお、殺菌剤としては過酸化水素を用い、
循環中の系内の過酸化水素濃度が1重量%となる濃度で
用いた。Hydrogen peroxide was used as a bactericide,
It was used at a concentration such that the hydrogen peroxide concentration in the system during circulation was 1% by weight.
【0039】原水槽1への一次純水の導入及びポンプ2
の作動を停止した後、バルブV1閉、バルブV2開と
し、殺菌剤貯槽20の殺菌剤含有水をポンプ21により
配管22を経てUF膜分離装置6の入口側に導入し、U
F膜分離装置6、配管16、ユースポイント7、配管1
7、配管23及び殺菌剤貯槽20の循環系に30分間、
8L/分で循環させた後、ポンプ21を停止して120
分間浸漬した。なお、ポンプ21としては、接液部がポ
リプロピレンで構成されているものを用いた。Introduction of primary pure water into raw water tank 1 and pump 2
The valve V 1 is closed and the valve V 2 is opened after the operation of No. 1 is stopped, and the disinfectant-containing water in the disinfectant storage tank 20 is introduced into the inlet side of the UF membrane separation device 6 by the pump 21 through the pipe 22 and U
F membrane separation device 6, piping 16, point of use 7, piping 1
7, 30 minutes in the circulation system of the pipe 23 and the germicide storage tank 20,
After circulating at 8 L / min, the pump 21 is stopped and 120
Soaked for a minute. As the pump 21, a pump whose liquid contact part was made of polypropylene was used.
【0040】その後、ポンプ21を停止し、バルブV3
を開とし、一次純水の導入を再開すると共にポンプP2
を作動させて、20L/分で通水することにより、系内
の殺菌剤を押し出し洗浄し、70分の押し出し洗浄後、
洗浄排水中に過酸化水素が検出されなくなった時点で超
純水製造システムの運転を再開した。運転再開後、得ら
れた超純水中の金属濃度の経時変化を調べ、結果を表1
に示した。Thereafter, the pump 21 is stopped and the valve V 3
Open, restart the introduction of primary pure water, and pump P 2
Is activated and water is passed at 20 L / min to extrude and wash the disinfectant in the system, and after extruding and washing for 70 min,
The operation of the ultrapure water production system was restarted when hydrogen peroxide was no longer detected in the cleaning wastewater. After the operation was restarted, the change with time of the metal concentration in the obtained ultrapure water was examined, and the results are shown in Table 1.
It was shown to.
【0041】比較例1
図2に示す従来の超純水製造システムにおいて、殺菌処
理後の超純水中の金属濃度を調べる実験を行った。Comparative Example 1 In the conventional ultrapure water production system shown in FIG. 2, an experiment was conducted to examine the metal concentration in ultrapure water after sterilization.
【0042】なお、殺菌剤としては過酸化水素を用い、
循環中の系内の過酸化水素濃度が1重量%となる濃度で
用いた。Hydrogen peroxide was used as a bactericide,
It was used at a concentration such that the hydrogen peroxide concentration in the system during circulation was 1% by weight.
【0043】原水槽1への一次純水の導入及びポンプ2
の作動を停止した後、原水槽1に殺菌剤を添加し、再び
ポンプ2を作動させて、超純水製造システムの系内全体
に殺菌剤を30分間、8L/分で循環させた後、ポンプ
2を停止して120分間浸漬した。Introduction of primary pure water into raw water tank 1 and pump 2
After stopping the operation of, the sterilizing agent was added to the raw water tank 1, the pump 2 was operated again, and the sterilizing agent was circulated in the entire system of the ultrapure water production system for 30 minutes at 8 L / min. The pump 2 was stopped and it was immersed for 120 minutes.
【0044】その後、一次純水の導入を再開し、20L
/分で通水することにより、系内の殺菌剤を押し出し洗
浄し、120分の押し出し洗浄後、洗浄排水中に過酸化
水素が検出されなくなった時点で超純水製造システムの
運転を再開した。運転再開後、得られた超純水中の金属
濃度の経時変化を調べ、結果を表1に示した。After that, the introduction of primary pure water was restarted, and 20 L
The sterilizing agent in the system was extruded and washed by passing water at a flow rate of / min, and after the extruded washing for 120 minutes, the operation of the ultrapure water production system was restarted when hydrogen peroxide was not detected in the washing wastewater. . After the operation was restarted, the change with time of the metal concentration in the obtained ultrapure water was examined, and the results are shown in Table 1.
【0045】[0045]
【表1】 [Table 1]
【0046】表1より明らかなように、従来の超純水製
造システムでは、殺菌処理後の運転再開後にFe,C
r,Niが検出され、特にFeは一週間後においても
0.1ng/L検出され、殺菌処理による純度低下の問
題がある。これに対して、本発明の超純水製造システム
によれば、殺菌処理後の運転再開直後から金属は検出さ
れず、超純水の水質を高純度に安定化させることができ
ることがわかる。As is clear from Table 1, in the conventional ultrapure water production system, Fe and C were added after restarting the operation after the sterilization treatment.
r and Ni are detected, and particularly 0.1 ng / L of Fe is detected even after one week, and there is a problem of deterioration in purity due to sterilization. On the other hand, according to the ultrapure water production system of the present invention, no metal is detected immediately after the restart of the operation after the sterilization treatment, and the water quality of the ultrapure water can be stabilized to high purity.
【0047】なお、図1に示す如く、殺菌剤貯槽と殺菌
剤ポンプを用いて殺菌剤の循環系を形成し、殺菌剤を循
環させる代りに、UF膜分離装置6の入口から殺菌剤を
導入し、返送配管17から殺菌剤を排出することによ
り、殺菌剤を一過式に通水し、その後浸漬殺菌及び押し
出し洗浄したこと以外は実施例1と同様にして殺菌処理
を行ったところ、実施例1と同様に、運転再開後、得ら
れた超純水中には金属は検出されなかった。As shown in FIG. 1, instead of forming a circulation system of the disinfectant using the disinfectant storage tank and the disinfectant pump and circulating the disinfectant, the disinfectant is introduced from the inlet of the UF membrane separation device 6. Then, the sterilizing treatment was carried out in the same manner as in Example 1 except that the sterilizing agent was passed through the return pipe 17 to pass water through the sterilizing agent in a transient manner, and then immersion sterilization and extrusion cleaning were performed. As in Example 1, no metal was detected in the obtained ultrapure water after the operation was restarted.
【0048】[0048]
【発明の効果】以上詳述した通り、本発明の超純水製造
システムによれば、系内の殺菌処理後、超純水製造シス
テムの運転を再開した際の超純水中の金属濃度が著しく
低く、運転再開直後から高純度で安定した水質の超純水
を得ることができる。As described in detail above, according to the ultrapure water production system of the present invention, the metal concentration in the ultrapure water when the operation of the ultrapure water production system is restarted after the sterilization treatment in the system is completed. It is possible to obtain ultrapure water of extremely high purity and stable water quality immediately after the operation is restarted.
【0049】このため、本発明によれば、今後益々高め
られる傾向にある半導体洗浄用超純水の水質要求に十分
に対応することが可能となる。Therefore, according to the present invention, it becomes possible to sufficiently meet the water quality requirement of the ultrapure water for semiconductor cleaning, which tends to be further increased in the future.
【図1】本発明の超純水製造システムの実施の形態を示
す系統図である。FIG. 1 is a system diagram showing an embodiment of an ultrapure water production system of the present invention.
【図2】従来の超純水製造システムを示す系統図であ
る。FIG. 2 is a system diagram showing a conventional ultrapure water production system.
1 原水槽 2 ポンプ 3 熱交換器 4 UV酸化装置 5 イオン交換樹脂塔 6 UF膜分離装置 7 ユースポイント 20 殺菌剤貯槽 21 ポンプ 1 raw water tank 2 pumps 3 heat exchanger 4 UV oxidizer 5 Ion exchange resin tower 6 UF membrane separator 7 Use points 20 Disinfectant storage tank 21 pumps
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 FI テーマコート゛(参考) C02F 1/50 540 C02F 1/50 540B 550 550C 560 560C 560D 1/72 1/72 Z Fターム(参考) 4D006 GA07 KA02 KB04 KB11 KC21 KD06 KD22 PA01 PC02 4D050 AA05 AB06 BB01 BB09 BC09 BD03 BD06 CA08 CA09 CA12─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. 7 Identification code FI theme code (reference) C02F 1/50 540 C02F 1/50 540B 550 550C 560 560C 560D 1/72 1/72 Z F term (reference) 4D006 GA07 KA02 KB04 KB11 KC21 KD06 KD22 PA01 PC02 4D050 AA05 AB06 BB01 BB09 BC09 BD03 BD06 CA08 CA09 CA12
Claims (3)
とも膜分離手段を有する超純水製造装置と、 該超純水製造装置により製造された超純水をユースポイ
ントへ送水する送水手段と、 該ユースポイントを通過した未使用の超純水を前記原水
槽へ戻す返送手段とを有する超純水製造システムにおい
て、 前記膜分離手段の1次側に殺菌剤を供給すると共に、該
返送手段から殺菌剤を含む水を排出させて、該膜分離手
段及び前記送水手段を殺菌する手段を備えたことを特徴
とする超純水製造システム。1. A raw water tank for storing primary pure water, an ultrapure water production apparatus having at least a membrane separation means for producing ultrapure water by introducing water in the raw water tank, and the ultrapure water In the ultrapure water production system having a water supply means for sending the ultrapure water produced by the production apparatus to the use point, and a return means for returning the unused ultrapure water that has passed through the use point to the raw water tank, A means for sterilizing the membrane separating means and the water feeding means by supplying a sterilizing agent to the primary side of the membrane separating means and discharging water containing the sterilizing agent from the returning means. Pure water production system.
菌剤を供給する手段として、 殺菌剤を蓄える殺菌剤貯槽と、 該殺菌剤貯槽内の殺菌剤を前記膜分離手段の1次側に導
く殺菌剤導入手段と、 前記返送手段から排出された殺菌剤を含む水を該殺菌剤
貯槽へ戻す殺菌剤返送手段とを有することを特徴とする
超純水製造システム。2. The disinfectant storage tank for storing a disinfectant as a means for supplying a disinfectant to the membrane separating means, and the disinfectant in the disinfectant storage tank on the primary side of the membrane separating means according to claim 1. An ultrapure water production system comprising: a sterilizing agent introducing means for guiding the sterilizing agent and means for returning the water containing the sterilizing agent discharged from the returning means to the sterilizing agent storage tank.
は、 前記殺菌剤貯槽内の殺菌剤を送液するためのポンプを備
えており、 該ポンプの接液部が非金属材料よりなることを特徴とす
る超純水製造システム。3. The disinfectant introducing means according to claim 2, further comprising a pump for delivering the disinfectant in the disinfectant storage tank, wherein the liquid contact portion of the pump is made of a non-metallic material. An ultrapure water production system characterized by.
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