JP7743555B2

JP7743555B2 - Water treatment system and method for operating same

Info

Publication number: JP7743555B2
Application number: JP2024025560A
Authority: JP
Inventors: 貴充栗田
Original assignee: Organo Corp
Current assignee: Organo Corp
Priority date: 2024-02-22
Filing date: 2024-02-22
Publication date: 2025-09-24
Anticipated expiration: 2044-02-22
Also published as: WO2025177861A1; JP2025128712A

Description

本発明は、水処理システムおよびその運転方法に関する。 The present invention relates to a water treatment system and an operating method thereof.

従来から、医薬品製造などに使用される純水（精製水や注射用水など）を製造する装置として、工業用水、井水、市水などの原水を透過水と濃縮水とに分離する膜分離装置と、膜分離装置からの透過水をイオン交換体に通水することで脱イオン水（純水）を製造する電気式脱イオン水製造装置とを組み合わせたものが知られている。このような純水製造装置では、医薬品製造などに使用される純水を製造するという性質上、日本薬局方の要求を担保するために、例えば６０℃以上の熱水を系内に通水することで系内の生菌数を低減させる殺菌処理が定期的に行われている。 Conventionally, known systems for producing pure water (such as purified water and water for injection) for use in pharmaceutical manufacturing and other applications include a combination of a membrane separation device that separates raw water, such as industrial water, well water, or city water, into permeate and concentrate, and an electrodeionization water production system that produces deionized water (pure water) by passing the permeate from the membrane separation device through an ion exchanger. Due to the nature of these water production systems, which produce pure water for use in pharmaceutical manufacturing and other applications, a sterilization process is periodically carried out to reduce the number of viable bacteria in the system by passing hot water (for example, 60°C or higher) through the system to ensure compliance with the requirements of the Japanese Pharmacopoeia.

上述した純水製造装置の殺菌方法として、膜分離装置と電気式脱イオン水製造装置に一括して熱水を通水して殺菌する方法が知られている（例えば、特許文献１参照）。この方法では、熱水を膜分離装置と電気式脱イオン水製造装置に順次供給した後に原水タンクに還流させることで、循環する熱水により系全体が一括して殺菌される。これにより、膜分離装置と電気式脱イオン水製造装置を個別に殺菌する場合に比べて、水使用量や工程数が削減され、より効率的な殺菌処理が可能になる。 A known method for sterilizing the above-mentioned pure water production system is to pass hot water through the membrane separation system and electrodeionized water production system simultaneously (see, for example, Patent Document 1). In this method, hot water is sequentially supplied to the membrane separation system and electrodeionized water production system, and then returned to the raw water tank, so that the entire system is sterilized simultaneously by the circulating hot water. This reduces the amount of water used and the number of steps compared to sterilizing the membrane separation system and electrodeionized water production system separately, enabling a more efficient sterilization process.

特開２０１９－１０７６１７号公報Japanese Patent Application Laid-Open No. 2019-107617

ところで、純水製造装置には、多くの場合、膜分離装置に供給される原水の前処理を行う前処理手段として、原水中の残留塩素を除去する活性炭ろ過器が設けられているが、活性炭ろ過器内では生菌が発生しやすくなるため、より高頻度で殺菌処理を実行することが求められる。しかしながら、上述したように系全体を一括して殺菌する方法では、殺菌処理を実行するタイミングを決定するにあたり、熱や圧力によるダメージを受けやすい膜分離装置や電気式脱イオン水製造装置の都合が優先されるのが一般的である。そのため、活性炭ろ過器にとっては、殺菌処理の頻度が十分ではない可能性があり、その場合、活性炭ろ過器内に生菌が繁殖する可能性がある。同様のことは、原水が滞留する原水タンクにも該当する。 Incidentally, pure water production systems often include an activated carbon filter to remove residual chlorine from raw water as a pretreatment means for pretreating the raw water supplied to the membrane separation device. However, because live bacteria are likely to grow inside the activated carbon filter, more frequent sterilization is required. However, as mentioned above, when sterilizing the entire system at once, the convenience of the membrane separation device and electrodeionized water production device, which are easily damaged by heat and pressure, is generally prioritized when deciding the timing of sterilization. As a result, the frequency of sterilization may not be sufficient for the activated carbon filter, which could lead to the proliferation of live bacteria inside the activated carbon filter. The same applies to raw water tanks where raw water stagnates.

そこで、本発明の目的は、生菌が繁殖しやすい場所に対してより高頻度で熱水による殺菌処理を実行可能な水処理システムおよびその運転方法を提供することである。 The object of the present invention is to provide a water treatment system and an operating method thereof that can perform hot water sterilization treatment more frequently in areas where live bacteria are likely to grow.

上述した目的を達成するために、本発明の水処理システムは、被処理水を貯留するタンクと、被処理水を処理して処理水を生成する水処理手段と、活性炭ろ過器を少なくとも含み、水処理手段に供給される被処理水の前処理を行う前処理手段と、タンクおよび活性炭ろ過器を経由して水処理手段に至る供給ラインと、タンクの下流側かつ活性炭ろ過器の下流側で供給ラインから分岐してタンクの上流側かつ活性炭ろ過器の上流側に戻る還流ラインと、供給ラインのうちタンクおよび還流ラインとの分岐部の間に設けられ、供給ラインを流れる被処理水を加熱する加熱手段と、を有している。一態様では、水処理システムが、水処理手段からの処理水をタンクに返送する返送ラインと、水処理システムの運転を制御する制御手段と、を有し、制御手段は、加熱手段により供給ラインを流れる被処理水が加熱されて熱水が生成されたときに、熱水の少なくとも一部を還流ラインに流入させる第１の処理を実行し、活性炭ろ過器は、供給ラインのうちタンクの上流側に設けられ、制御手段は、第１の処理において、熱水の一部を供給ラインから水処理手段を通じて返送ラインに流通させ、残りを還流ラインに流入させる。他の態様では、前処理手段が、活性炭ろ過器以外の他の前処理手段を含み、他の前処理手段は、供給ラインのうち還流ラインとの分岐部の下流側に設けられ、分岐部の上流側には設けられていない。 In order to achieve the above-mentioned objectives, the water treatment system of the present invention comprises a tank for storing water to be treated, a water treatment means for treating the water to be treated to produce treated water, a pretreatment means including at least an activated carbon filter for pretreatment of the water to be treated that is supplied to the water treatment means, a supply line that passes through the tank and the activated carbon filter to the water treatment means, a reflux line that branches off from the supply line downstream of the tank and downstream of the activated carbon filter and returns to the upstream side of the tank and upstream of the activated carbon filter, and a heating means that is provided in the supply line between the branch point with the tank and the reflux line and that heats the water to be treated flowing through the supply line. In one aspect, the water treatment system includes a return line that returns treated water from the water treatment means to the tank, and a control means that controls the operation of the water treatment system, and the control means performs a first process of causing at least a portion of the hot water to flow into the reflux line when the heating means heats the water to be treated flowing through the supply line to generate hot water, and the activated carbon filter is provided on the supply line upstream of the tank, and the control means, in the first process, causes a portion of the hot water to flow from the supply line through the water treatment means to the return line and causes the remainder to flow into the reflux line. In another aspect, the pretreatment means includes other pretreatment means other than the activated carbon filter, and the other pretreatment means is provided on the supply line downstream of a branch point with the reflux line, but not upstream of the branch point.

また、本発明の水処理システムの運転方法は、被処理水を貯留するタンクと、被処理水を処理して処理水を生成する水処理手段と、活性炭ろ過器を少なくとも含み、水処理手段に供給される被処理水の前処理を行う前処理手段と、タンクおよび活性炭ろ過器を経由して水処理手段に至る供給ラインと、を有する水処理システムの運転方法であって、タンク内の被処理水を供給ラインに流通させ、流通する被処理水を加熱して熱水を生成する工程と、熱水の少なくとも一部を、タンクの下流側かつ活性炭ろ過器の下流側で供給ラインから分岐した還流ラインを通じて、タンクおよび活性炭ろ過器に還流させる工程と、を含んでいる。一態様では、活性炭ろ過器は、供給ラインのうちタンクの上流側に設けられ、熱水の少なくとも一部を還流させる工程が、熱水の全部をタンクおよび活性炭ろ過器に還流させることで、タンクおよび活性炭ろ過器を殺菌することと、熱水の一部を活性炭ろ過器からタンクに還流させ、残りを水処理手段に供給した後、タンクに返送することで、タンクおよび活性炭ろ過器に加えて水処理手段を殺菌することとを含んでいる。他の態様では、熱水の少なくとも一部を還流させる工程が、前処理手段のうち活性炭ろ過器以外の他の前処理手段には熱水を通水しないことを含んでいる。 In addition, the operating method of the water treatment system of the present invention is a method for operating a water treatment system having a tank for storing water to be treated, a water treatment means for treating the water to be treated to produce treated water, a pretreatment means including at least an activated carbon filter for pretreatment of the water to be treated that is supplied to the water treatment means, and a supply line that passes through the tank and the activated carbon filter to the water treatment means, and includes the steps of circulating the water to be treated in the tank through the supply line and heating the circulating water to produce hot water, and returning at least a portion of the hot water to the tank and the activated carbon filter through a return line branching off from the supply line downstream of the tank and downstream of the activated carbon filter. In one aspect, the activated carbon filter is provided upstream of the tank in the supply line, and the step of returning at least a portion of the hot water includes returning all of the hot water to the tank and the activated carbon filter to sterilize the tank and the activated carbon filter, and returning a portion of the hot water from the activated carbon filter to the tank and supplying the remainder to the water treatment means and then returning it to the tank to sterilize the tank, the activated carbon filter, and the water treatment means. In another aspect, the step of returning at least a portion of the hot water includes not passing the hot water through any pretreatment means other than the activated carbon filter among the pretreatment means.

本発明によれば、生菌が繁殖しやすい場所に対してより高い頻度で熱水殺菌処理を実行することができる。 According to the present invention, hot water sterilization treatment can be performed more frequently in areas where live bacteria are likely to grow.

本発明の第１の実施形態に係る水処理システムの概略構成図である。1 is a schematic configuration diagram of a water treatment system according to a first embodiment of the present invention. 本発明の第２の実施形態に係る水処理システムの概略構成図である。FIG. 10 is a schematic configuration diagram of a water treatment system according to a second embodiment of the present invention.

以下、図面を参照して、本発明の実施の形態について説明する。本発明の水処理システムは、医薬品製造に使用される純水、具体的には精製水または注射用水を製造し、それをユースポイントに供給するものであり、被処理水として塩素を含む市水（水道水）を処理する場合に好適に用いられる。なお、本明細書において、精製水とは、常水を、イオン交換、逆浸透（ＲＯ）、限外ろ過（ＵＦ）、またはそれらの組み合わせにより精製したものを意味し、注射用水とは、精製水または適切な前処理を行った水を蒸留または超ろ過（ＲＯ／ＵＦ）で処理し、発熱性物質（エンドトキシン）試験や生菌試験に適合したものを意味する。このような精製水および注射用水としては、例えば、日本薬局方で規定されたものを例示することができる。また、本明細書において、「医薬品製造に使用される純水」とは、上述した精製水や注射用水だけでなく、それらを収容する容器または医薬品を収容する容器を洗浄する洗浄水も含む。 Embodiments of the present invention will be described below with reference to the drawings. The water treatment system of the present invention produces pure water for use in pharmaceutical manufacturing, specifically purified water or water for injection, and supplies it to a point-of-use. It is suitable for treating chlorine-containing city water (tap water) as the water to be treated. In this specification, "purified water" refers to tap water purified by ion exchange, reverse osmosis (RO), ultrafiltration (UF), or a combination thereof. "Water for injection" refers to purified water or water that has undergone appropriate pretreatment, which has been distilled or ultrafiltration (RO/UF) to pass pyrogen (endotoxin) tests and viable bacterial tests. Examples of such purified water and water for injection include those specified in the Japanese Pharmacopoeia. In this specification, "pure water used in pharmaceutical manufacturing" includes not only the purified water and water for injection described above, but also the wash water used to clean containers containing them or containers containing pharmaceuticals.

（第１の実施形態）
図１は、本発明の第１の実施形態に係る水処理システムの概略構成図である。なお、図示した水処理システムの構成は、単なる一例であり、本発明を制限するものではなく、システムの使用目的や用途、要求性能に応じて適宜変更可能であることは言うまでもない。 (First embodiment)
1 is a schematic diagram of a water treatment system according to a first embodiment of the present invention. Note that the configuration of the water treatment system shown in the figure is merely an example and does not limit the present invention, and it goes without saying that it can be appropriately changed depending on the purpose, application, and required performance of the system.

水処理システム１は、被処理水（原水）を順次処理して純水を製造する純水製造装置１０と、こうして製造された純水を循環させながら保持し、必要に応じてその一部をユースポイント２に供給する純水供給装置２０とから構成されている。 The water treatment system 1 is composed of a pure water production device 10 that sequentially treats the water to be treated (raw water) to produce pure water, and a pure water supply device 20 that circulates and stores the pure water thus produced, and supplies a portion of it to the point of use 2 as needed.

純水製造装置１０は、原水タンク１１と、膜分離装置１２と、電気式脱イオン水製造装置（以下、「ＥＤＩ装置」ともいう）１３とを有している。また、詳細は後述するが、純水製造装置１０では、医薬品製造に使用される純水を製造するという性質上、通常運転（純水製造）の合間に、熱水により系内の生菌数を低減させる殺菌処理が定期的に行われる。純水製造装置１０は、そのような熱水殺菌処理を実行する制御部（制御手段）１４をさらに有している。 The pure water production system 10 includes a raw water tank 11, a membrane separation system 12, and an electrodeionized water production system (hereinafter also referred to as an "EDI system") 13. As will be described in more detail below, the pure water production system 10, which produces pure water used in pharmaceutical manufacturing, periodically performs a sterilization process using hot water to reduce the number of viable bacteria in the system between normal operations (pure water production). The pure water production system 10 also includes a control unit (control means) 14 that executes this hot water sterilization process.

膜分離装置１２は、原水に含まれる不純物を除去して処理水を生成する装置であり、原水タンク１１から供給される原水を、不純物を含む濃縮水と不純物が除去された透過水とに分離する逆浸透膜（ＲＯ膜）を有している。膜分離装置１２の分離膜としては、後述する加熱殺菌用の熱水に対する耐熱性を有する限り、ＲＯ膜に限定されず、例えば、精密ろ過膜（ＭＦ膜）、限外ろ過膜（ＵＦ膜）、ナノろ過膜（ＮＦ膜）などを用いることができる。ただし、処理水質の向上の観点から、ＮＦ膜またはＲＯ膜を用いることが好ましく、ＲＯ膜を用いることがより好ましい。なお、膜分離装置１２は、複数のＲＯ膜を有していてもよく、それらは、直列に接続されていてもよく、並列に接続されていてもよく、直列と並列を組み合わせて接続されていてもよい。ここでいう「直列に接続される」とは、被処理水が複数のＲＯ膜で順次処理されることを意味し、隣接する２つのＲＯ膜において、上流側のＲＯ膜で分離された透過水が下流側のＲＯ膜に被処理水として供給されることを意味する。この場合、上流側のＲＯ膜で分離された透過水が下流側のＲＯ膜でさらに処理されるため、より良好な水質の処理水を得ることができる。 The membrane separation device 12 removes impurities from raw water to produce treated water. It has a reverse osmosis (RO) membrane that separates the raw water supplied from the raw water tank 11 into a concentrate containing impurities and a permeate from which the impurities have been removed. The separation membrane of the membrane separation device 12 is not limited to an RO membrane, and can be, for example, a microfiltration (MF) membrane, an ultrafiltration (UF) membrane, or a nanofiltration (NF) membrane, as long as it is heat-resistant to the hot water used for sterilization (described below). However, from the perspective of improving treated water quality, the use of an NF membrane or an RO membrane is preferred, and an RO membrane is more preferred. The membrane separation device 12 may have multiple RO membranes, which may be connected in series, in parallel, or in a combination of series and parallel. Here, "connected in series" means that the treated water is sequentially treated by multiple RO membranes, and between two adjacent RO membranes, the permeate separated by the upstream RO membrane is supplied to the downstream RO membrane as the treated water. In this case, the permeate separated by the upstream RO membrane is further treated by the downstream RO membrane, resulting in treated water of better quality.

膜分離装置１２には、膜分離装置１２に原水を供給する給水ラインＬ１と、膜分離装置１２からの透過水を流通させる透過水ラインＬ２と、膜分離装置１２からの濃縮水（以下、「ＲＯ濃縮水」ともいう）を流通させるＲＯ濃縮水ラインＬ３とが接続されている。給水ラインＬ１は、その上流側で開閉弁Ｖ１を介して原水タンク１１に接続され、原水タンク１１には、開閉弁Ｖ２を介して原水補給ラインＬ４が接続され、後述するように、必要に応じて原水が供給される。したがって、給水ラインＬ１と原水補給ラインＬ４は、原水タンク１１を経由して膜分離装置１２に至る供給ラインとして機能するとも言える。透過水ラインＬ２は、その下流側でＥＤＩ装置１３に接続され、ＲＯ濃縮水ラインＬ３は、その下流側で原水タンク１１に接続されている。また、給水ラインＬ１と原水補給ラインＬ４との間には、原水補給ラインＬ４から原水タンク１１を介さずに給水ラインＬ１に原水を供給するためのバイパスラインＬ５が設けられている。バイパスラインＬ５は、開閉弁Ｖ２の上流側で原水補給ラインＬ４から分岐し、開閉弁Ｖ１の下流側で開閉弁Ｖ３を介して給水ラインＬ１に接続されている。なお、給水ラインＬ１の開閉弁Ｖ１は、純水製造装置１０の通常運転時には常時開放され、後述する殺菌工程時に開閉される。また、バイパスラインＬ５の開閉弁Ｖ３は、純水製造装置１０の通常運転時には常時閉鎖され、後述する殺菌工程時に開閉される。 Connected to the membrane separation device 12 are a water supply line L1 that supplies raw water to the membrane separation device 12, a permeate line L2 that distributes permeate from the membrane separation device 12, and an RO concentrate line L3 that distributes concentrated water (hereinafter also referred to as "RO concentrate") from the membrane separation device 12. The water supply line L1 is connected upstream to a raw water tank 11 via an on-off valve V1, and a raw water supply line L4 is connected to the raw water tank 11 via an on-off valve V2, through which raw water is supplied as needed, as described below. Therefore, the water supply line L1 and the raw water supply line L4 can be said to function as supply lines that lead to the membrane separation device 12 via the raw water tank 11. The permeate line L2 is connected downstream to the EDI device 13, and the RO concentrate line L3 is connected downstream to the raw water tank 11. Additionally, a bypass line L5 is provided between the water supply line L1 and the raw water supply line L4 for supplying raw water from the raw water supply line L4 to the water supply line L1 without passing through the raw water tank 11. The bypass line L5 branches off from the raw water supply line L4 upstream of the on-off valve V2 and is connected to the water supply line L1 via an on-off valve V3 downstream of the on-off valve V1. The on-off valve V1 on the water supply line L1 is always open during normal operation of the pure water production system 10 and opens and closes during the sterilization process described below. The on-off valve V3 on the bypass line L5 is always closed during normal operation of the pure water production system 10 and opens and closes during the sterilization process described below.

給水ラインＬ１には、送水ポンプ１５と、熱交換器１６と、活性炭ろ過器１７と、フィルタ１８と、加圧ポンプ１９とが設けられている。なお、熱交換器１６と活性炭ろ過器１７の位置は逆であってもよい。 The water supply line L1 is equipped with a water pump 15, a heat exchanger 16, an activated carbon filter 17, a filter 18, and a pressure pump 19. Note that the positions of the heat exchanger 16 and the activated carbon filter 17 may be reversed.

送水ポンプ１５は、加圧ポンプ１９と共に、原水タンク１１に貯留された原水を膜分離装置１２に供給する機能を有し、インバータ（図示せず）によって回転数が制御されるようになっていてもよい。熱交換器１６は、季節による気温変動や機器の発熱など、様々な要因で変動する原水の温度を一定温度（例えば２５℃）に制御するために用いられるとともに、後述する殺菌工程時に加熱殺菌用の熱水を生成するための加熱手段としても用いられる。活性炭ろ過器１７は、フィルタ１８と共に、膜分離装置１２に供給される原水の前処理を行うものであり、活性炭により原水中の残留塩素を除去する機能を有している。フィルタ１８は、活性炭ろ過器１７から生じる微粉炭を捕捉して除去する機能を有している。フィルタ１８としては、上記機能を有する限り特に限定されず、例えば、ＭＦ膜やＵＦ膜を用いることができる。加圧ポンプ１９は、その回転数を制御するインバータ（図示せず）を備えていてもよく、それにより、膜分離装置１２への原水の供給圧力を調整する機能を有していてもよい。 The water supply pump 15, together with the pressure pump 19, supplies raw water stored in the raw water tank 11 to the membrane separation device 12, and its rotation speed may be controlled by an inverter (not shown). The heat exchanger 16 is used to maintain a constant temperature (e.g., 25°C) for the raw water, which fluctuates due to various factors such as seasonal temperature fluctuations and heat generated by equipment. It also serves as a heating means for generating hot water for sterilization during the sterilization process described below. The activated carbon filter 17, together with the filter 18, performs pretreatment of the raw water supplied to the membrane separation device 12 and removes residual chlorine from the raw water using activated carbon. The filter 18 captures and removes pulverized coal generated by the activated carbon filter 17. The filter 18 is not particularly limited as long as it has the above function; for example, an MF membrane or UF membrane can be used. The pressure pump 19 may be equipped with an inverter (not shown) that controls its rotation speed, thereby adjusting the pressure of the raw water supplied to the membrane separation device 12.

給水ラインＬ１のうち活性炭ろ過器１７とフィルタ１８との間には、開閉弁Ｖ４が設けられ、その上流側近傍には、開閉弁Ｖ５を介して熱水還流ラインＬ６が接続されている。熱水還流ラインＬ６は、その下流側で原水補給ラインＬ４に接続され、具体的には、原水補給ラインＬ４に設けられた開閉弁Ｖ６の下流側近傍に接続されている。したがって、熱水還流ラインＬ６は、活性炭ろ過器１７の下流側で給水ラインＬ１から分岐して原水タンク１１の上流側に戻るラインであるとも言える。純水製造装置１０の通常運転時、給水ラインＬ１の開閉弁Ｖ４は常時開放され、熱水還流ラインＬ６の開閉弁Ｖ５は常時閉鎖される。一方で、後述する殺菌工程時には、制御部１４により、開閉弁Ｖ４，Ｖ５の開閉が制御され、給水ラインＬ１から熱水還流ラインＬ６に流入する熱水の流量（ゼロを含む）が調整される。なお、開閉弁Ｖ４，Ｖ５の代わりに、給水ラインＬ１と熱水還流ラインＬ６との分岐部に三方弁が設けられていてもよい。 An on-off valve V4 is provided in the water supply line L1 between the activated carbon filter 17 and the filter 18, and a hot water reflux line L6 is connected upstream of the on-off valve V4 via an on-off valve V5. The hot water reflux line L6 is connected downstream to the raw water supply line L4, specifically, connected downstream of the on-off valve V6 provided in the raw water supply line L4. Therefore, the hot water reflux line L6 can also be considered a line that branches off from the water supply line L1 downstream of the activated carbon filter 17 and returns to the upstream side of the raw water tank 11. During normal operation of the pure water production system 10, the on-off valve V4 of the water supply line L1 is always open, and the on-off valve V5 of the hot water reflux line L6 is always closed. Meanwhile, during the sterilization process described below, the control unit 14 controls the opening and closing of the on-off valves V4 and V5 to adjust the flow rate (including zero) of hot water flowing from the water supply line L1 into the hot water reflux line L6. Instead of the on-off valves V4 and V5, a three-way valve may be provided at the branch point between the water supply line L1 and the hot water return line L6.

図示していないが、透過水ラインＬ２には、膜脱気装置や脱炭酸塔などの脱気装置が設けられていてもよい。脱気装置は、膜分離装置１２からの透過水中に溶存する酸素や二酸化炭素を除去する機能を有し、特に、ＥＤＩ装置１３に供給される被処理水中の溶存二酸化炭素濃度を低減することで、後述する脱イオン化（脱塩）処理の負荷を低減することができる。なお、脱気装置の位置は、膜分離装置１２よりも下流側の透過水ラインＬ２に限定されず、被処理水中の溶存酸素濃度を低減することで微生物の増殖を抑え、それにより、ＲＯ膜のバイオファウリングを抑制するために、膜分離装置１２の上流側であってもよい。また、図示していないが、ＲＯ濃縮水ラインＬ３には、例えば、純水製造装置１０の通常運転時にＲＯ濃縮水を外部に排出するための排水ラインが接続されている。 Although not shown, the permeate line L2 may be provided with a degassing device such as a membrane degassing device or a decarbonation tower. The degassing device has the function of removing oxygen and carbon dioxide dissolved in the permeate from the membrane separation device 12. In particular, by reducing the dissolved carbon dioxide concentration in the water being treated supplied to the EDI device 13, the load on the deionization (desalination) process, described below, can be reduced. The location of the degassing device is not limited to the permeate line L2 downstream of the membrane separation device 12; it may be located upstream of the membrane separation device 12 to reduce the dissolved oxygen concentration in the water being treated, thereby suppressing microbial growth and thereby inhibiting biofouling of the RO membrane. Furthermore, although not shown, the RO concentrate line L3 is connected to a drainage line, for example, for discharging the RO concentrate to the outside during normal operation of the pure water production system 10.

ＥＤＩ装置１３は、イオン交換体による被処理水の脱イオン化（脱塩）処理と、イオン交換体の再生処理とを同時に行う装置であり、透過水ラインＬ２を通じて膜分離装置１２から供給される透過水を処理して脱イオン水（純水）を製造するものである。ＥＤＩ装置１３には、ＥＤＩ装置１３からの純水を流通させる純水ラインＬ７と、ＥＤＩ装置１３からの濃縮水（以下、「ＥＤＩ濃縮水」ともいう）を流通させるＥＤＩ濃縮水ラインＬ８が接続されている。純水ラインＬ７は、その下流側で純水供給装置２０の後述する純水タンク２１に接続され、ＥＤＩ濃縮水ラインＬ８は、その下流側で原水タンク１１に接続されている。また、図示していないが、ＥＤＩ濃縮水ラインＬ８には、例えば、純水製造装置１０の通常運転時にＥＤＩ濃縮水を外部に排出するための排水ラインが接続されていてもよい。さらに、図示していないが、ＥＤＩ装置１３には、ＥＤＩ装置１３からの電極水を外部に排出する電極水排出ラインが接続され、電極水排出ラインには、ＥＤＩ装置１３への通電が行われない場合に電極水を原水タンク１１に返送する電極水返送ラインが接続されていてもよい。 The EDI unit 13 simultaneously deionizes (deminesalises) the water to be treated using an ion exchanger and regenerates the ion exchanger. It produces deionized water (pure water) by treating the permeate water supplied from the membrane separation unit 12 via the permeate line L2. The EDI unit 13 is connected to a pure water line L7, which distributes pure water from the EDI unit 13, and an EDI concentrated water line L8, which distributes concentrated water (hereinafter referred to as "EDI concentrated water") from the EDI unit 13. The pure water line L7 is connected downstream to a pure water tank 21 (described below) of the pure water supply unit 20, and the EDI concentrated water line L8 is connected downstream to the raw water tank 11. Although not shown, the EDI concentrated water line L8 may be connected to a drainage line, for example, for discharging the EDI concentrated water to the outside during normal operation of the pure water production system 10. Furthermore, although not shown, an electrode water discharge line that discharges electrode water from the EDI device 13 to the outside may be connected to the EDI device 13, and an electrode water return line that returns the electrode water to the raw water tank 11 when power is not applied to the EDI device 13 may be connected to the electrode water discharge line.

一例として、ＥＤＩ装置１３は、陽極および陰極と、陽極および陰極の間に配置され、カチオン交換体とアニオン交換体との少なくとも一方が充填された脱塩室と、イオン交換膜を介して脱塩室の両側に配置された一対の濃縮室とを有している。脱塩室には、透過水ラインＬ２を通じて膜分離装置１２からの透過水が被処理水として供給され、濃縮室には、同じく膜分離装置１２からの透過水が濃縮水として供給される。なお、陽極および陰極をそれぞれ収容する電極室にも、同じく膜分離装置１２からの透過水が電極水として供給される。膜分離装置１２から脱塩室に透過水が供給されると、透過水中のイオン成分は、脱塩室内のイオン交換体でイオン交換されて除去される。イオン成分が除去された透過水は、脱イオン水（純水）として、脱塩室から純水ラインＬ７を通じてＥＤＩ装置１３から排出される。このとき、脱塩室で除去されたイオン成分は、両極間に直流電圧が印加されることで発生する電位差により、イオン交換体から脱離して脱塩室に隣接する濃縮室に移動する。こうして濃縮室に移動したイオン成分は、濃縮室を流れる濃縮水に取り込まれ、ＥＤＩ濃縮水ラインＬ８を通じてＥＤＩ装置１３から排出される。一方で、脱塩室では、水解離反応（水が水素イオンと水酸化物イオンとに解離する反応）が連続的に進行しており、これら水素イオンおよび水酸化物イオンが脱塩室内のイオン交換体に保持されたイオン成分と交換されて、脱塩室内のイオン交換体が再生される。 As an example, the EDI device 13 has an anode and a cathode, a deionization compartment positioned between the anode and the cathode and filled with at least one of a cation exchanger and an anion exchanger, and a pair of concentration compartments positioned on either side of the deionization compartment via an ion exchange membrane. Permeated water from the membrane separation device 12 is supplied to the deionization compartment as treated water via the permeate line L2, and the concentration compartment is supplied with the permeated water from the membrane separation device 12 as concentrated water. The electrode compartments, which house the anode and cathode, are also supplied with the permeated water from the membrane separation device 12 as electrode water. When the permeated water is supplied from the membrane separation device 12 to the deionization compartment, the ionic components in the permeated water are removed by ion exchange in the ion exchangers in the deionization compartment. The permeated water from which the ionic components have been removed is discharged as deionized water (pure water) from the deionization compartment via the pure water line L7 and the EDI device 13. At this time, the ionic components removed in the deionization compartment are desorbed from the ion exchanger due to the potential difference generated by the application of a DC voltage between the two electrodes, and migrate to the concentrating compartment adjacent to the deionization compartment. The ionic components that have migrated to the concentrating compartment are then taken up by the concentrated water flowing through the concentrating compartment and discharged from the EDI device 13 via the EDI concentrated water line L8. Meanwhile, in the deionization compartment, a water dissociation reaction (a reaction in which water dissociates into hydrogen ions and hydroxide ions) is continuously occurring, and these hydrogen ions and hydroxide ions are exchanged for ionic components held in the ion exchanger in the deionization compartment, regenerating the ion exchanger in the deionization compartment.

純水ラインＬ７には開閉弁Ｖ７が設けられ、その上流側近傍には、開閉弁Ｖ８を介して純水返送ラインＬ９が接続されている。純水返送ラインＬ９は、その下流側で原水タンク１１に接続されている。これにより、例えば、装置起動時や運転再開時、ユースポイント２で純水の需要がない場合に純水供給装置２０の後述する純水タンク２１内の水位が変動しないときなど、純水製造装置１０内で純水の循環運転を行うこともできる。すなわち、純水ラインＬ７の開閉弁Ｖ７が閉鎖され、純水返送ラインＬ９の開閉弁Ｖ８が開放されることで、純水返送ラインＬ９を通じてＥＤＩ装置１３で製造される純水を原水タンク１１に還流させることができる。このような純水の循環運転により、純水の滞留による生菌発生を抑制することができる。なお、開閉弁Ｖ７，Ｖ８の代わりに、純水ラインＬ７と純水返送ラインＬ９との接続部に三方弁が設けられていてもよい。 An on-off valve V7 is provided on the pure water line L7, and a pure water return line L9 is connected upstream of the line via an on-off valve V8. The pure water return line L9 is connected downstream to the raw water tank 11. This allows for pure water circulation within the pure water production system 10, for example, when the system is started up or restarted, or when there is no demand for pure water at the use point 2 and the water level in the pure water tank 21 (described below) of the pure water supply system 20 remains constant. That is, by closing the on-off valve V7 on the pure water line L7 and opening the on-off valve V8 on the pure water return line L9, the pure water produced by the EDI device 13 can be returned to the raw water tank 11 via the pure water return line L9. This pure water circulation operation can suppress the growth of viable bacteria due to stagnation of pure water. Instead of the on-off valves V7 and V8, a three-way valve may be provided at the connection between the pure water line L7 and the pure water return line L9.

図示していないが、純水ラインＬ７のうち純水返送ラインＬ９との接続部の上流側には、フィルタと紫外線殺菌器とが設けられていてもよい。フィルタは、ＥＤＩ装置１３から生じる破砕樹脂を捕捉して除去する機能を有している。このようなフィルタとしては、上記機能を有する限り特に限定されず、例えば、ＭＦ膜やＵＦ膜を用いることができる。紫外線殺菌器は、純水ラインＬ７を流れる純水を紫外線照射により殺菌するために用いられる。なお、純水は不純物が少ないため、フィルタと紫外線殺菌器の位置は逆であってもよい。また、図示していないが、純水返送ラインＬ９には、必要に応じて純水を外部に排出するための排水ラインが接続されていてもよい。 Although not shown, a filter and ultraviolet sterilizer may be provided on the pure water line L7 upstream of the connection with the pure water return line L9. The filter has the function of capturing and removing crushed resin generated by the EDI device 13. Such a filter is not particularly limited as long as it has the above function, and for example, an MF membrane or UF membrane can be used. The ultraviolet sterilizer is used to sterilize the pure water flowing through the pure water line L7 by irradiating it with ultraviolet light. Note that because pure water contains few impurities, the positions of the filter and ultraviolet sterilizer may be reversed. Also, although not shown, a drainage line for discharging the pure water to the outside may be connected to the pure water return line L9 if necessary.

純水製造装置１０の通常運転時には、原水タンク１１に貯留された原水が膜分離装置１２やＥＤＩ装置１３などで順次処理され、こうして得られた純水が純水ラインＬ７を通じて純水供給装置２０に供給される採水工程が行われる。具体的には、原水タンク１１に貯留された原水は、送水ポンプ１５の作動により、給水ラインＬ１を通じて熱交換器１６に供給される。熱交換器１６において一定温度（例えば２５℃）に調節された原水は、活性炭ろ過器１７において残留塩素が除去された後、フィルタ１８において異物が除去される。こうして前処理された原水は、加圧ポンプ１９の作動により膜分離装置１２に供給され、そこで膜分離処理により透過水とＲＯ濃縮水とに分離される。透過水は、透過水ラインＬ２を通じてＥＤＩ装置１３に供給され、ＲＯ濃縮水は、ＲＯ濃縮水ラインＬ３を通じて原水タンク１１に返送されるか、または、ＲＯ濃縮水ラインＬ３から排水ライン（図示せず）を通じて外部に排出される。ＥＤＩ装置１３に供給された透過水は、脱塩処理によりイオン成分が除去された後、純水として純水ラインＬ７を通じて純水供給装置２０へと送られる。このとき、ＥＤＩ濃縮水は、その少なくとも一部が、ＥＤＩ濃縮水ラインＬ８を通じて原水タンク１１に返送されるか、または、ＥＤＩ濃縮水ラインＬ８から排水ライン（図示せず）を通じて外部に排出される。また、ＥＤＩ装置１３からの電極水は、その全てが電極水排出ライン（図示せず）を通じて外部に排出される。 During normal operation of the pure water production system 10, raw water stored in the raw water tank 11 is sequentially treated in the membrane separation device 12, EDI device 13, etc., and the resulting pure water is supplied to the pure water supply system 20 via the pure water line L7 in a water sampling process. Specifically, the raw water stored in the raw water tank 11 is supplied to the heat exchanger 16 via the water supply line L1 by the operation of the water pump 15. The raw water is adjusted to a constant temperature (e.g., 25°C) in the heat exchanger 16, where residual chlorine is removed in the activated carbon filter 17 and foreign matter is removed in the filter 18. The pre-treated raw water is supplied to the membrane separation device 12 by the operation of the pressure pump 19, where it is separated into permeate and RO concentrate by membrane separation. The permeate is supplied to the EDI device 13 via the permeate line L2, and the RO concentrate is returned to the raw water tank 11 via the RO concentrate line L3 or discharged from the RO concentrate line L3 to the outside via a drain line (not shown). The permeate supplied to the EDI device 13 is desalinated to remove ionic components, and then sent as pure water to the pure water supply device 20 via the pure water line L7. At this time, at least a portion of the EDI concentrate is returned to the raw water tank 11 via the EDI concentrate line L8 or discharged from the EDI concentrate line L8 to the outside via a drain line (not shown). All of the electrode water from the EDI device 13 is discharged to the outside via the electrode water discharge line (not shown).

原水タンク１１には、図示しない水位センサが設けられ、上述した採水工程時、その水位センサにより検出された原水タンク１１内の水位に応じて、原水補給ラインＬ４を通じて原水が供給される。具体的には、原水タンク１１内の水位が所定の下限水位以下になると、原水補給ラインＬ４の開閉弁Ｖ２，Ｖ６が開放されて原水が供給され、原水タンク１１内の水位が所定の上限水位に達すると、原水補給ラインＬ４の開閉弁Ｖ２または開閉弁Ｖ６が閉鎖されて原水の供給が停止される。 The raw water tank 11 is equipped with a water level sensor (not shown), and during the water sampling process described above, raw water is supplied through the raw water supply line L4 according to the water level in the raw water tank 11 detected by the water level sensor. Specifically, when the water level in the raw water tank 11 falls below a predetermined lower limit, the on-off valves V2 and V6 on the raw water supply line L4 are opened to supply raw water, and when the water level in the raw water tank 11 reaches a predetermined upper limit, the on-off valve V2 or on-off valve V6 on the raw water supply line L4 is closed to stop the supply of raw water.

純水供給装置２０は、純水ラインＬ７を通じて純水製造装置１０から供給される純水を貯留する純水タンク２１と、純水タンク２１内の純水を循環させる循環ラインＬ１０と、循環ラインＬ１０に設けられた循環ポンプ２２とを有している。循環ラインＬ１０には、開閉弁（図示せず）を介して送水ラインＬ１１が接続され、送水ラインＬ１１は、その下流側でユースポイント２に接続されている。これにより、純水供給装置２０は、純水を循環ラインＬ１０に沿って循環させながら保持し、必要に応じてその一部をユースポイント２に供給することができる。こうした純水の循環運転は、ユースポイント２での純水の需要の有無にかかわらず常時行われるため、循環ラインＬ１０を構成する配管内部に細菌が付着したり、バイオフィルムが成熟したりすることを抑制することができる。なお、送水ラインＬ１１の数は１つに限定されず、複数であってもよい。すなわち、純水供給装置２０は、複数のユースポイント２に純水を供給するようになっていてもよい。 The pure water supply system 20 includes a pure water tank 21 that stores pure water supplied from the pure water production system 10 via the pure water line L7, a circulation line L10 that circulates the pure water in the pure water tank 21, and a circulation pump 22 provided on the circulation line L10. A water supply line L11 is connected to the circulation line L10 via an on-off valve (not shown), and the water supply line L11 is connected downstream to the point of use 2. This allows the pure water supply system 20 to store and circulate pure water along the circulation line L10, and to supply a portion of the pure water to the point of use 2 as needed. This pure water circulation operation is performed continuously, regardless of whether there is a demand for pure water at the point of use 2, thereby preventing bacteria from adhering to the inside of the piping that makes up the circulation line L10 and preventing biofilms from maturing. The number of water supply lines L11 is not limited to one, and may be multiple. In other words, the pure water supply system 20 may supply pure water to multiple points of use 2.

純水タンク２１には、上述したように純水ラインＬ７が接続され、例えば、水位センサ（図示せず）により検知された純水タンク２１内の水位に応じて、純水製造装置１０から純水が補給される。具体的には、純水タンク２１内の水位が所定の下限水位以下になると、純水ラインＬ７の開閉弁Ｖ７が開放される（とともに、純水返送ラインＬ９の開閉弁Ｖ８が閉鎖される）ことで、純水ラインＬ７を通じて純水タンク２１に純水が補給される。そして、純水タンク２１内の水位が所定の上限水位に達すると、純水ラインＬ７の開閉弁Ｖ７が閉鎖される（とともに、純水返送ラインＬ９の開閉弁Ｖ８が開放される）ことで、純水タンク２１への純水の補給は停止される。 As described above, the pure water line L7 is connected to the pure water tank 21, and pure water is replenished from the pure water production system 10 depending on the water level in the pure water tank 21 detected, for example, by a water level sensor (not shown). Specifically, when the water level in the pure water tank 21 falls below a predetermined lower limit, the on-off valve V7 on the pure water line L7 is opened (and the on-off valve V8 on the pure water return line L9 is closed), thereby replenishing pure water to the pure water tank 21 through the pure water line L7. Then, when the water level in the pure water tank 21 reaches a predetermined upper limit, the on-off valve V7 on the pure water line L7 is closed (and the on-off valve V8 on the pure water return line L9 is opened), thereby stopping the replenishment of pure water to the pure water tank 21.

循環ラインＬ１０には、紫外線殺菌器（図示せず）と熱交換器２３が設けられている。紫外線殺菌器は、循環ラインＬ１０を流れる純水を紫外線照射により殺菌するために用いられる。熱交換器２３は、純水製造装置１０の熱交換器１６と同様に、純水供給装置２０において熱水による系内の殺菌処理を行う際に加熱殺菌用の熱水を生成するために用いられる。また、熱交換器２３は、純水ポンプ２２や紫外線殺菌器の発熱などにより、循環する純水の温度が上昇してユースポイント２での要求温度以上になってしまう場合に備えて、そのような純水の温度上昇を抑制するための冷却機能も備えている。なお、図示していないが、循環ラインＬ１０のうち熱交換器２３の下流側には、循環する純水を外部に排出するための排水ラインが接続されている。これにより、例えば、循環する純水の水質が悪化した場合に、その一部を外部に排出し、それに応じて純水製造装置１０から新たな純水を補給することで、純水の水質を回復させることができる。 The circulation line L10 is provided with an ultraviolet sterilizer (not shown) and a heat exchanger 23. The ultraviolet sterilizer is used to sterilize the pure water flowing through the circulation line L10 by irradiating it with ultraviolet light. Like the heat exchanger 16 of the pure water production system 10, the heat exchanger 23 is used to generate hot water for heated sterilization when the pure water supply system 20 performs a hot water sterilization process within the system. The heat exchanger 23 also has a cooling function to suppress a rise in the temperature of the circulating pure water in case the temperature of the circulating pure water rises above the required temperature at the point of use 2 due to heat generated by the pure water pump 22 or the ultraviolet sterilizer. Although not shown, a drainage line is connected to the circulation line L10 downstream of the heat exchanger 23 for discharging the circulating pure water to the outside. This allows the quality of the circulating pure water to be restored, for example, by discharging a portion of the circulating pure water to the outside and then replenishing it with new pure water from the pure water production system 10.

上述したように、医薬品製造に使用される純水を製造する純水製造装置１０では、通常運転の合間に、熱水により系内の生菌数を低減させる殺菌処理が制御部１４により定期的に行われる。具体的には、活性炭ろ過器１７を単独で殺菌処理する活性炭殺菌工程と、活性炭ろ過器１７だけでなく膜分離装置１２とＥＤＩ装置１３もまとめて殺菌処理する全体殺菌工程とがそれぞれ独立して定期的に行われる。以下、これら２つの殺菌工程について説明する。 As described above, in the pure water production system 10 that produces pure water used in pharmaceutical manufacturing, a sterilization process using hot water to reduce the number of viable bacteria in the system is periodically performed by the control unit 14 during normal operation. Specifically, an activated carbon sterilization process, which sterilizes the activated carbon filter 17 alone, and a total sterilization process, which sterilizes not only the activated carbon filter 17 but also the membrane separation device 12 and EDI device 13, are periodically and independently performed. These two sterilization processes are described below.

（活性炭殺菌工程）
活性炭殺菌工程は、活性炭ろ過器１７を含む系内の一部を熱水により殺菌する工程である。具体的には、原水タンク１１に貯留された原水を所定の経路で循環させつつ、熱交換器１６により６０℃以上、好ましくは８０℃以上に加熱し、一定時間保持した後、経路内の温度が膜分離装置１２による膜分離処理に適した温度になるまで冷却する工程である。なお、ここでは詳細に説明しないが、加熱殺菌用の熱水として、原水の代わりに、膜分離装置１２からの透過水やＥＤＩ装置１３からの脱イオン水（純水）を用いてもよい。 (Activated carbon sterilization process)
The activated carbon sterilization step is a step of sterilizing a part of the system including the activated carbon filter 17 with hot water. Specifically, this step involves circulating raw water stored in the raw water tank 11 through a predetermined path, heating the raw water to 60°C or higher, preferably 80°C or higher, using the heat exchanger 16, maintaining the temperature for a certain period of time, and then cooling the temperature in the path until it becomes a temperature suitable for membrane separation treatment by the membrane separation device 12. Although not described in detail here, permeated water from the membrane separation device 12 or deionized water (pure water) from the EDI device 13 may be used instead of raw water as the hot water for thermal sterilization.

活性炭殺菌工程が開始されると、好ましくは、ＥＤＩ装置１３の運転（直流電圧の印加）が停止され、その状態で膜分離装置１２からの透過水が少なくとも電極室に通水された後に、加圧ポンプ１９が停止され、ＥＤＩ装置１３への給水が停止される。これにより、ＥＤＩ装置１３において、電極室内で発生する水素ガス、塩素ガス、酸素ガスなどの酸化性ガスが残留し、イオン交換膜やイオン交換樹脂などの構成部材を劣化させるおそれを低減することができる。このときの通水量および通水時間に特に制限はないが、上述したガスの排出性の観点から、採水工程時と同程度の通水量で３０秒程度であることが好ましい。そして、給水ラインＬ１の開閉弁Ｖ４と原水補給ラインＬ４の開閉弁Ｖ６が閉鎖され、熱水還流ラインＬ６の開閉弁Ｖ５と原水補給ラインＬ４の開閉弁Ｖ２が開放される（第１の処理）ことで、給水ラインＬ１を流れる原水は、その全てが熱水還流ラインＬ６に流入し、原水補給ラインＬ４を通じて原水タンク１１に還流される。すなわち、原水タンク１１内の原水は、給水ラインＬ１、熱水還流ラインＬ６、および原水補給ラインＬ４を通じて循環される。それと同時に、熱交換器１６に熱媒体（例えば蒸気）が供給され、循環する原水が６０℃以上、好ましくは８０℃以上に加熱されて保持される。こうして、高温に保持された原水（熱水）の循環により、原水タンク１１と活性炭ろ過器１７を含む系内の一部が殺菌される。 When the activated carbon sterilization process begins, the operation of the EDI device 13 (application of DC voltage) is preferably stopped. After the permeate from the membrane separation device 12 has been passed through at least the electrode chambers in this state, the pressure pump 19 is stopped and the water supply to the EDI device 13 is halted. This reduces the risk of oxidizing gases, such as hydrogen gas, chlorine gas, and oxygen gas, generated in the electrode chambers of the EDI device 13 remaining and deteriorating components such as the ion exchange membrane and ion exchange resin. There are no particular restrictions on the amount of water passed or the time for which it is passed; however, from the perspective of the aforementioned gas dischargeability, it is preferable to pass the water at a rate similar to that used during the water sampling process for approximately 30 seconds. Then, the on-off valve V4 on the water supply line L1 and the on-off valve V6 on the raw water supply line L4 are closed, and the on-off valve V5 on the hot water return line L6 and the on-off valve V2 on the raw water supply line L4 are opened (first process). All of the raw water flowing through the water supply line L1 flows into the hot water return line L6 and is returned to the raw water tank 11 via the raw water supply line L4. In other words, the raw water in the raw water tank 11 is circulated through the water supply line L1, the hot water return line L6, and the raw water supply line L4. At the same time, a heat medium (e.g., steam) is supplied to the heat exchanger 16, and the circulating raw water is heated to and maintained at 60°C or higher, preferably 80°C or higher. In this way, the circulation of raw water (hot water) maintained at a high temperature sterilizes a portion of the system, including the raw water tank 11 and the activated carbon filter 17.

熱水の循環が一定時間行われた後、熱交換器１６への熱媒体の供給が停止され、その代わりに、熱交換器１６に冷媒（例えば冷水）が供給されることで、熱水の冷却が開始される。そして、循環する熱水が膜分離装置１２による膜分離処理に適した温度（例えば４５℃未満）にまで冷却されると、純水製造装置１０の通常運転が再開される。すなわち、給水ラインＬ１の開閉弁Ｖ４が開放され、熱水還流ラインＬ６の開閉弁Ｖ５が閉鎖されると同時に、加圧ポンプ１９が起動されることで、原水タンク１１から膜分離装置１２への原水の供給が再開される。そして、ＥＤＩ装置１３の運転も再開されることで、純水製造装置１０において通常運転が再開される。通常運転が再開されると、純水ラインＬ７の開閉弁Ｖ７が開放され、純水返送ラインＬ９の開閉弁Ｖ８が閉鎖されることで、必要に応じて、純水製造装置１０で製造された純水が純水ラインＬ７を通じて純水供給装置２０に供給される。 After the hot water has been circulated for a certain period of time, the supply of heat medium to the heat exchanger 16 is stopped, and instead, a refrigerant (e.g., cold water) is supplied to the heat exchanger 16, thereby starting to cool the hot water. When the circulating hot water is cooled to a temperature suitable for membrane separation processing by the membrane separation device 12 (e.g., below 45°C), normal operation of the pure water production system 10 resumes. Specifically, the on-off valve V4 on the water supply line L1 is opened, the on-off valve V5 on the hot water reflux line L6 is closed, and the pressure pump 19 is simultaneously started, thereby resuming the supply of raw water from the raw water tank 11 to the membrane separation device 12. Operation of the EDI device 13 is also resumed, and normal operation of the pure water production system 10 resumes. When normal operation resumes, the on-off valve V7 on the pure water line L7 is opened and the on-off valve V8 on the pure water return line L9 is closed, allowing the pure water produced in the pure water production system 10 to be supplied to the pure water supply system 20 via the pure water line L7 as needed.

（全体殺菌工程）
全体殺菌工程は、膜分離装置１２とＥＤＩ装置１３を含む系全体を熱水により殺菌する工程である。具体的には、原水タンク１１に貯留された原水を純水で置換した後、その純水を系全体に循環させつつ、熱交換器１６により６０℃以上、好ましくは８０℃以上に加熱し、一定時間保持した後、系内の温度が膜分離装置３による膜分離処理に適した温度になるまで冷却する工程である。なお、加熱殺菌用の熱水として、活性炭殺菌工程と同様に原水を用いてもよいが、殺菌処理中のＥＤＩ装置１３へのイオン負荷を考慮すると、純水を用いることが好ましい。 (Overall sterilization process)
The total sterilization step is a step of sterilizing the entire system including the membrane separation device 12 and the EDI device 13 with hot water. Specifically, after raw water stored in the raw water tank 11 is replaced with pure water, the pure water is heated to 60°C or higher, preferably 80°C or higher, by the heat exchanger 16 while circulating the pure water throughout the system, and after maintaining the temperature for a certain period of time, the system is cooled until the temperature inside the system becomes suitable for membrane separation treatment by the membrane separation device 3. As in the activated carbon sterilization step, raw water may be used as the hot water for thermal sterilization; however, in consideration of the ion load on the EDI device 13 during the sterilization treatment, pure water is preferably used.

全体殺菌工程では、まず、図示しない排水ラインを通じて原水タンク１１の水抜きが２段階で行われる。すなわち、全体殺菌工程が開始されると、原水タンク１１内の水位が所定の下限水位以下になるまでは、送水ポンプ１５と加圧ポンプ１９の運転が継続されることで、ＲＯ濃縮水ラインＬ３に接続された排水ラインを通じて、原水タンク１１に貯留されていた原水が外部に排出される。そして、水位センサ（図示せず）により原水タンク１１内の水位が所定の下限水位以下になったことが確認されると、給水ラインＬ１の開閉弁Ｖ１が閉鎖されるとともに、送水ポンプ１５と加圧ポンプ１９が停止されることで、給水ラインＬ１のうち開閉弁Ｖ１の上流側に接続された排水ラインを通じて原水の排出が行われる。なお、原水の排出は、以降の工程で原水タンク１１に純水が貯留されるため、原水タンク１１ができるだけ空になるまで行われることが好ましい。 In the total sterilization process, the raw water tank 11 is first drained in two stages through a drain line (not shown). That is, once the total sterilization process begins, the raw water stored in the raw water tank 11 is drained to the outside through a drain line connected to the RO concentrated water line L3 by continuing to operate the water supply pump 15 and the pressure pump 19 until the water level in the raw water tank 11 falls below a predetermined lower limit. Then, when a water level sensor (not shown) confirms that the water level in the raw water tank 11 has fallen below the predetermined lower limit, the on-off valve V1 on the water supply line L1 is closed, and the water supply pump 15 and the pressure pump 19 are stopped, thereby draining the raw water through a drain line connected to the upstream side of the on-off valve V1 on the water supply line L1. Note that, because pure water will be stored in the raw water tank 11 in subsequent processes, it is preferable to drain the raw water until the raw water tank 11 is as empty as possible.

こうして原水の排出が行われた後、純水製造装置１０において採水工程時と同様の純水製造が行われ、得られた純水が原水タンク１１に供給されて貯留される。具体的には、原水補給ラインＬ４の開閉弁Ｖ６とバイパスラインＬ５の開閉弁Ｖ３が開放され、原水補給ラインＬ４の開閉弁Ｖ２が閉鎖されることで、原水補給ラインＬ４から原水タンク１１を介さずにバイパスラインＬ５を通じて給水ラインＬ１に原水が供給される。そして、送水ポンプ１５と加圧ポンプ１９が起動されることで、純水製造装置１０において採水工程時と同様の純水製造が行われる。このとき、純水ラインＬ７の開閉弁Ｖ７が閉鎖され、純水返送ラインＬ９の開閉弁Ｖ８が開放されることで、ＥＤＩ装置１３からの脱イオン水（純水）は、純水ラインＬ７から純水返送ラインＬ９を通じて、原水タンク１１に供給されて貯留される。なお、ＲＯ濃縮水は、その少なくとも一部がＲＯ濃縮水ラインＬ３に接続された図示しない排水ラインを通じて外部に排出される。 After the raw water is discharged in this manner, the pure water production system 10 produces pure water in the same manner as during the water sampling process, and the resulting pure water is supplied to and stored in the raw water tank 11. Specifically, the on-off valve V6 on the raw water supply line L4 and the on-off valve V3 on the bypass line L5 are opened, and the on-off valve V2 on the raw water supply line L4 is closed, thereby supplying raw water from the raw water supply line L4 to the water supply line L1 via the bypass line L5 without passing through the raw water tank 11. The water supply pump 15 and the pressure pump 19 are then activated, and the pure water production system 10 produces pure water in the same manner as during the water sampling process. At this time, the on-off valve V7 on the pure water line L7 is closed, and the on-off valve V8 on the pure water return line L9 is opened, thereby supplying deionized water (pure water) from the EDI device 13 from the pure water line L7 through the pure water return line L9 to the raw water tank 11 and storing it there. At least a portion of the RO concentrated water is discharged to the outside through a drain line (not shown) connected to the RO concentrated water line L3.

その後、例えば、水位センサ（図示せず）により原水タンク１１内の水位が所定の上限水位に達したことが確認された時点で、ＥＤＩ装置１３の運転（直流電圧の印加）が停止される。そして、原水補給ラインＬ４の開閉弁Ｖ６とバイパスラインＬ５の開閉弁Ｖ３が閉鎖され、原水補給ラインＬ４から給水ラインＬ１への原水の供給も停止されると、給水ラインＬ１の開閉弁Ｖ１が開放され、原水タンク１１から給水ラインＬ１への純水の供給が開始される。これにより、原水タンク１１内の純水は、給水ラインＬ１と透過水ラインＬ２を通じて、膜分離装置１２とＥＤＩ装置１３に順次供給された後、純水ラインＬ７と純水返送ラインＬ９を通じて原水タンク１１に返送される。すなわち、原水タンク１１内の純水は、給水ラインＬ１、透過水ラインＬ２、純水ラインＬ７、および純水返送ラインＬ９を通じて循環される。それと同時に、熱交換器１６に熱媒体（例えば蒸気）が供給され、循環する純水が６０℃以上、好ましくは８０℃以上に加熱されて保持される。こうして、高温に保持された純水（熱水）の循環により、原水タンク１１と活性炭ろ過器１７に加え、膜分離装置１２とＥＤＩ装置１３を含む系全体が殺菌される。このとき、ＲＯ濃縮水ラインＬ３とＥＤＩ濃縮水ラインＬ８にも熱水が通水されて殺菌される。 Then, for example, when a water level sensor (not shown) confirms that the water level in the raw water tank 11 has reached a predetermined upper limit, operation of the EDI device 13 (application of DC voltage) is stopped. Then, the on-off valve V6 of the raw water supply line L4 and the on-off valve V3 of the bypass line L5 are closed, and the supply of raw water from the raw water supply line L4 to the feedwater line L1 is stopped. The on-off valve V1 of the feedwater line L1 is opened, and the supply of pure water from the raw water tank 11 to the feedwater line L1 begins. As a result, the pure water in the raw water tank 11 is sequentially supplied to the membrane separation device 12 and the EDI device 13 via the feedwater line L1 and the permeate line L2, and then returned to the raw water tank 11 via the pure water line L7 and the pure water return line L9. In other words, the pure water in the raw water tank 11 is circulated through the feedwater line L1, the permeate line L2, the pure water line L7, and the pure water return line L9. At the same time, a heat medium (e.g., steam) is supplied to the heat exchanger 16, and the circulating pure water is heated and maintained at 60°C or higher, preferably 80°C or higher. In this way, the circulation of pure water (hot water) maintained at a high temperature sterilizes the entire system, including the raw water tank 11, activated carbon filter 17, membrane separation device 12, and EDI device 13. At this time, hot water is also passed through the RO concentrated water line L3 and EDI concentrated water line L8, which are also sterilized.

なお、上述した熱水の循環時、熱水還流ラインＬ６の開閉弁Ｖ５は開放され（それに応じて、原水補給ラインＬ４の開閉弁Ｖ２も開放され）てもよく、それにより、原水補給ラインＬ４のうち熱水還流ラインＬ６との接続部よりも下流側の部分に熱水が通水されて殺菌されてもよい。あるいは、熱水還流ラインＬ６の開閉弁Ｖ５は、閉鎖されたままであってもよい。換言すると、給水ラインＬ１の開閉弁Ｖ１が開放される限り、熱水還流ラインＬ６の開閉弁Ｖ５の開閉は任意である（第２の処理）。 Note that during the circulation of hot water described above, the on-off valve V5 of the hot water return line L6 may be opened (and accordingly the on-off valve V2 of the raw water supply line L4 may also be opened), allowing hot water to flow through the portion of the raw water supply line L4 downstream of its connection with the hot water return line L6 for sterilization. Alternatively, the on-off valve V5 of the hot water return line L6 may remain closed. In other words, as long as the on-off valve V1 of the water supply line L1 is open, the on-off valve V5 of the hot water return line L6 may be opened or closed as desired (second process).

熱水の循環が一定時間行われた後、熱交換器１６への熱媒体の供給が停止され、その代わりに、熱交換器１６に冷媒（例えば冷水）が供給されることで、熱水の冷却が開始される。そして、循環する熱水が膜分離装置１２による膜分離処理に適した温度（例えば４５℃未満）にまで冷却されると、熱水還流ラインＬ６の開閉弁Ｖ５が（上述した熱水の循環時に開放されていた場合には）閉鎖され、ＥＤＩ装置１３の運転が再開されることで、純水製造装置１０の通常運転が再開される。通常運転が再開されると、純水ラインＬ７の開閉弁Ｖ７が開放され、純水返送ラインＬ９の開閉弁Ｖ８が閉鎖されることで、必要に応じて、純水製造装置１で製造された純水が純水ラインＬ７を通じて純水供給装置２０に供給される。 After the hot water has been circulated for a certain period of time, the supply of heat medium to the heat exchanger 16 is stopped, and instead, a refrigerant (e.g., cold water) is supplied to the heat exchanger 16, thereby starting to cool the hot water. When the circulating hot water is cooled to a temperature suitable for membrane separation processing by the membrane separation device 12 (e.g., below 45°C), the on-off valve V5 on the hot water reflux line L6 is closed (if it was open during the hot water circulation described above), and operation of the EDI device 13 is resumed, thereby resuming normal operation of the pure water production system 10. When normal operation resumes, the on-off valve V7 on the pure water line L7 is opened, and the on-off valve V8 on the pure water return line L9 is closed, allowing pure water produced in the pure water production system 1 to be supplied to the pure water supply device 20 via the pure water line L7 as needed.

上述した各殺菌工程での熱水の温度は、熱水の循環経路内に設けられた温度センサ（図示せず）の検出値に基づいて、例えば熱交換器１６への熱媒体の供給量が調整されることで調整される。温度センサの位置は、特に限定されないが、熱水の循環方向において熱交換器１６からできるだけ離れた位置であることが好ましく、より好ましくは、純水ラインＬ７から純水返送ラインＬ９を経て熱交換器１６の入口付近までの間である。すなわち、この位置では、放熱の影響で熱水の温度が最も低くなるため、この位置での熱水の温度が所望の殺菌温度を下回らないように調整することで、十分な殺菌効果を確保することができる。一方で、熱交換器１６の出口付近にも温度センサを設置して、熱交換器１６により生成される熱水の温度を監視してもよい。昇温過程での加熱速度は、急激な温度変化による各機器へのダメージを少なくするために、活性炭殺菌工程では、１５℃／ｍｉｎ以下であることが好ましく、全体殺菌工程では、２℃／ｍｉｎ以下であることが好ましい。降温過程での冷却速度も、急激な温度変化による影響を軽減するために、活性炭殺菌工程では、１５℃／ｍｉｎ以下であることが好ましく、全体殺菌工程では、２℃／ｍｉｎ以下であることが好ましい。なお、各殺菌工程での熱水の流量は、熱水の流通範囲が所望の殺菌温度に昇温されるまでの時間が、例えば、活性炭殺菌工程では１０～３０分程度になるように調整され、全体殺菌工程では３０～６０分程度になるように調整される。 The temperature of the hot water in each of the above-mentioned sterilization processes is adjusted, for example, by adjusting the amount of heat medium supplied to the heat exchanger 16 based on the detection value of a temperature sensor (not shown) installed in the hot water circulation path. The location of the temperature sensor is not particularly limited, but it is preferably located as far away from the heat exchanger 16 as possible in the hot water circulation direction, and more preferably between the pure water line L7 and the pure water return line L9 and near the inlet of the heat exchanger 16. In other words, at this location, the hot water temperature is lowest due to heat radiation. Therefore, sufficient sterilization effect can be ensured by adjusting the hot water temperature at this location so that it does not fall below the desired sterilization temperature. Alternatively, a temperature sensor may be installed near the outlet of the heat exchanger 16 to monitor the temperature of the hot water generated by the heat exchanger 16. To minimize damage to each device due to sudden temperature changes, the heating rate during the temperature rise process is preferably 15°C/min or less in the activated carbon sterilization process and 2°C/min or less in the overall sterilization process. To reduce the effects of sudden temperature changes, the cooling rate during the temperature drop process is preferably 15°C/min or less in the activated carbon sterilization process, and 2°C/min or less in the total sterilization process. The flow rate of hot water in each sterilization process is adjusted so that the time it takes for the hot water flow range to reach the desired sterilization temperature is, for example, approximately 10 to 30 minutes in the activated carbon sterilization process, and approximately 30 to 60 minutes in the total sterilization process.

なお、純水供給装置２０においても、上述した純水製造装置１０の殺菌工程と同時に、またはそれとは別に、熱水による殺菌処理が定期的に行われる。具体的には、循環ラインＬ１０に沿って循環する純水が、熱交換器２３により、例えば６０℃以上、好ましくは８０℃以上に加熱されることで、純水タンク２１と循環ラインＬ１０を含む純水供給装置２０の系内が殺菌される。このような熱水の循環が一定時間行われた後、熱交換器２３により、あるいは、循環する熱水の排出と純水製造装置１０からの純水の補給とを繰り返すことにより、循環する熱水が冷却され、具体的には、ユースポイント２での適正使用温度以下になるまで冷却される。なお、純水供給装置２０における熱水殺菌処理では、純水の昇温速度と熱水の降温速度に特に制限はない。 In addition, the pure water supply system 20 also periodically performs a hot water sterilization process, either simultaneously with or separately from the sterilization process of the pure water production system 10 described above. Specifically, the pure water circulating along the circulation line L10 is heated by the heat exchanger 23 to, for example, 60°C or higher, preferably 80°C or higher, thereby sterilizing the pure water supply system 20 system, including the pure water tank 21 and circulation line L10. After this hot water circulation has been performed for a certain period of time, the circulating hot water is cooled by the heat exchanger 23 or by repeatedly discharging the circulating hot water and replenishing it from the pure water production system 10; specifically, until it reaches or falls below the appropriate temperature for use at the point of use 2. In the hot water sterilization process in the pure water supply system 20, there are no particular limitations on the rate at which the pure water is heated or cooled.

一方で、純水供給装置２０では、純水製造装置１０の各殺菌工程中に熱水殺菌処理が行われない場合、純水製造装置１０からの純水の補給は停止されるものの、純水の循環運転は継続して行われ、ユースポイント２への純水の供給も継続して行われる。ただし、純水タンク２１内の水位が所定の下限水位に達すると、ユースポイント２への純水の供給は停止され、純水の滞留による生菌発生を抑制する観点から、純水の循環運転のみが継続して行われる。純水製造装置１０の殺菌工程が終了し、純水の補給が開始され、純水タンク２１内の水位が所定の水位以上になると、再びユースポイント２への純水の供給が開始される。 On the other hand, in the pure water supply device 20, if hot water sterilization treatment is not performed during each sterilization step of the pure water production device 10, the supply of pure water from the pure water production device 10 is stopped, but the pure water circulation operation continues and the supply of pure water to the point of use 2 also continues. However, when the water level in the pure water tank 21 reaches a predetermined lower limit, the supply of pure water to the point of use 2 is stopped and only the pure water circulation operation continues from the perspective of suppressing the growth of live bacteria due to stagnation of pure water. When the sterilization step of the pure water production device 10 is completed, the supply of pure water begins, and when the water level in the pure water tank 21 reaches or exceeds the predetermined level, the supply of pure water to the point of use 2 begins again.

以上、本実施形態によれば、膜分離装置１２とＥＤＩ装置１３を含む系全体を殺菌処理するのとは別に、原水タンク１１と活性炭ろ過器１７だけを個別に殺菌処理することが可能になる。これにより、純水製造装置１０内で生菌が繁殖しやすい場所、すなわち、原水が滞留する原水タンク１１や原水中の残留塩素を除去する活性炭ろ過器１７に対して、より高頻度に熱水による殺菌処理を実行することが可能になる。 As described above, according to this embodiment, it is possible to sterilize the raw water tank 11 and activated carbon filter 17 separately, in addition to sterilizing the entire system including the membrane separation device 12 and EDI device 13. This makes it possible to more frequently perform hot water sterilization treatment on areas within the pure water production system 10 where live bacteria are likely to grow, namely the raw water tank 11 where raw water stagnates and the activated carbon filter 17 which removes residual chlorine from the raw water.

純水製造装置１０の採水工程時、熱水還流ラインＬ６の開閉弁Ｖ５が常時閉鎖されるため、熱水還流ラインＬ６には、各殺菌工程時に流通した原水や純水が滞留しやすくなる。したがって、このような滞留部分を極力減らすために、熱水還流ラインＬ６の長さはできるだけ短いことが好ましく、すなわち、開閉弁Ｖ５の一次側にある部分と二次側にある部分の長さは、それぞれできるだけ短いことが好ましい。また、活性炭殺菌工程時には、給水ラインＬ１の開閉弁Ｖ４が閉鎖され、熱水還流ラインＬ６の開閉弁Ｖ５が開放されるため、給水ラインＬ１のうち熱水還流ラインＬ６との分岐部から開閉弁Ｖ４までの部分に原水が滞留しやすくなり、その滞留部分には熱水が行き渡らずに殺菌不良が発生する可能性がある。このような観点から、開閉弁Ｖ４の位置は、給水ラインＬ１のうち上記分岐部にできるだけ近い位置であることが好ましい。同様の理由から、原水補給ラインＬ４の開閉弁Ｖ６の位置は、熱水還流ラインＬ６との接続部にできるだけ近い位置であることが好ましい。 During the water sampling process of the pure water production system 10, the on-off valve V5 on the hot water reflux line L6 is constantly closed, which means that raw water and pure water circulated during each sterilization process tend to stagnate in the hot water reflux line L6. Therefore, to minimize such stagnation, it is preferable to keep the length of the hot water reflux line L6 as short as possible. That is, it is preferable to keep the lengths of the portions on the primary and secondary sides of the on-off valve V5 as short as possible. Furthermore, during the activated carbon sterilization process, the on-off valve V4 on the water supply line L1 is closed and the on-off valve V5 on the hot water reflux line L6 is open. This means that raw water tends to stagnate in the portion of the water supply line L1 from the branch with the hot water reflux line L6 to the on-off valve V4. This can result in insufficient hot water reaching the stagnant portion, potentially resulting in insufficient sterilization. From this perspective, it is preferable to position the on-off valve V4 as close as possible to the branch in the water supply line L1. For the same reason, it is preferable that the opening/closing valve V6 on the raw water supply line L4 be located as close as possible to the connection with the hot water return line L6.

なお、冒頭でも述べたように、図示した水処理システム１の構成は、あくまで一例であり、特に、純水製造装置１０の構成は、所定の水質基準（例えば、米国薬局方によれば、医薬品製造用の精製水の場合、２５℃での許容導電率が１．３μＳ／ｃｍ）を満たす純水が得られる限り、図示した構成に限定されるものではない。例えば、膜分離装置１２に加えて、原水を処理して純水（処理水）を生成する水処理手段として、ＥＤＩ装置１３の代わりに、非再生型または再生型の混床式イオン交換装置が設けられていてもよい。一方、給水ラインＬ１には、膜分離装置１２に供給される原水の前処理を行う前処理手段として、活性炭ろ過器１７やフィルタ１８に加え、原水から硬度成分（カルシウムやマグネシウムなど）を除去する軟水器が設けられていてもよい。軟水器の位置は、例えば、活性炭ろ過器１７の上流側であってもよいが、内部の充填物であるイオン交換樹脂（カチオン交換樹脂）が活性炭に比べて熱劣化しやすいため、より高頻度で行われる活性炭殺菌工程時に熱水が流通しない位置、すなわち、開閉弁Ｖ４の下流側であることが好ましい。なお、フィルタ１８の位置も特に限定されないが、同様の理由から、図示した開閉弁Ｖ４の下流側であることが好ましい。 As mentioned at the beginning, the illustrated configuration of the water treatment system 1 is merely one example. In particular, the configuration of the pure water production apparatus 10 is not limited to the illustrated configuration, as long as it produces pure water that meets predetermined water quality standards (e.g., according to the United States Pharmacopeia, the allowable conductivity at 25°C for purified water for pharmaceutical production is 1.3 μS/cm). For example, in addition to the membrane separation apparatus 12, a non-regenerative or regenerative mixed-bed ion exchange apparatus may be provided instead of the EDI apparatus 13 as a water treatment means for treating raw water to produce pure water (treated water). Meanwhile, the water supply line L1 may be provided with a water softener that removes hardness components (such as calcium and magnesium) from the raw water in addition to the activated carbon filter 17 and filter 18 as a pretreatment means for pretreatment of the raw water supplied to the membrane separation apparatus 12. The water softener may be located upstream of the activated carbon filter 17, for example. However, because the ion exchange resin (cation exchange resin) filling the water softener is more susceptible to thermal degradation than activated carbon, it is preferable to locate the water softener in a location where hot water does not flow during the activated carbon sterilization process, which is performed more frequently, i.e., downstream of the on-off valve V4. The location of the filter 18 is also not particularly limited, but for the same reason, it is preferably located downstream of the on-off valve V4 shown in the figure.

また、熱水還流ラインＬ６は、原水補給ラインＬ４にではなく、原水タンク１１に直接接続されていてもよい。その場合も、活性炭殺菌工程時に、熱水還流ラインＬ６の開閉弁Ｖ５を開放して給水ラインＬ１から原水タンク１１に熱水を還流させることで、原水タンク１１と活性炭ろ過器１７だけを個別に殺菌することができる。なお、この場合、全体殺菌工程時には、熱水還流ラインＬ６の開閉弁Ｖ５は開放されなくてもよい。給水ラインＬ１の開閉弁Ｖ４は、任意の開度に調整可能な制御弁であってもよく、例えば、全体殺菌工程時の開度が全開ではなく、所定の中間開度であってもよい。また、熱水還流ラインＬ６の開閉弁Ｖ５も、任意の開度に調整可能な制御弁であってもよく、例えば、活性炭殺菌工程時の開度が全開ではなく、所定の中間開度であってもよく、全体殺菌工程時の開度が全閉ではなく、所定の中間開度であってもよい。 The hot water reflux line L6 may be connected directly to the raw water tank 11 rather than to the raw water supply line L4. In this case, too, the raw water tank 11 and the activated carbon filter 17 can be sterilized separately by opening the on-off valve V5 of the hot water reflux line L6 and refluxing hot water from the water supply line L1 to the raw water tank 11 during the activated carbon sterilization process. In this case, the on-off valve V5 of the hot water reflux line L6 does not need to be opened during the total sterilization process. The on-off valve V4 of the water supply line L1 may be a control valve that can be adjusted to any opening degree. For example, the opening degree during the total sterilization process may not be fully open but may be a predetermined intermediate opening degree. The on-off valve V5 of the hot water reflux line L6 may also be a control valve that can be adjusted to any opening degree. For example, the opening degree during the activated carbon sterilization process may not be fully open but may be a predetermined intermediate opening degree. For example, the opening degree during the total sterilization process may not be fully closed but may be a predetermined intermediate opening degree.

（第２の実施形態）
図２は、本発明の第２の実施形態に係る水処理システムの概略構成図である。 Second Embodiment
FIG. 2 is a schematic configuration diagram of a water treatment system according to a second embodiment of the present invention.

本実施形態は、活性炭ろ過器１７が、給水ラインＬ１にではなく、原水補給ラインＬ４に設けられ、具体的には、熱水還流ラインＬ６との接続部の下流側に設けられている点で、第１の実施形態と異なっている。これに伴い、全体殺菌工程における熱水還流ラインＬ６の開閉弁Ｖ５の開閉動作も第１の実施形態と異なっている。すなわち、第１の実施形態では、全体殺菌工程時に、給水ラインＬ１の開閉弁Ｖ４が開放される一方、熱水還流ラインＬ６の開閉弁Ｖ５は場合によっては開放されなくてもよい（ただし、図１に示す構成では開放されることが好ましい）が、本実施形態では開放される（第１の処理）必要がある。これは、全体殺菌工程時に熱水還流ラインＬ６の開閉弁Ｖ５が開放されないと、給水ラインＬ１を流れる熱水が熱水還流ラインＬ６を通じて原水補給ラインＬ４に通水されず、したがって、活性炭ろ過器１７が殺菌されなくなるためである。なお、本実施形態のその他の構成は、第１の実施形態と同様であり、それにより得られる効果も、給水ラインＬ１に比べて原水補給ラインＬ４の通水量が小さいために、活性炭ろ過器１７の小型化が可能になる点を除いて、第１の実施形態と同様である。 This embodiment differs from the first embodiment in that the activated carbon filter 17 is installed not in the water supply line L1 but in the raw water supply line L4, specifically downstream of the connection with the hot water reflux line L6. Accordingly, the opening and closing operation of the on-off valve V5 of the hot water reflux line L6 during the total sterilization process also differs from that of the first embodiment. In other words, in the first embodiment, the on-off valve V4 of the water supply line L1 is opened during the total sterilization process, while the on-off valve V5 of the hot water reflux line L6 does not necessarily need to be opened in some cases (although opening is preferred in the configuration shown in FIG. 1). However, in this embodiment, it must be opened (first process). This is because if the on-off valve V5 of the hot water reflux line L6 is not opened during the total sterilization process, the hot water flowing through the water supply line L1 will not pass through the hot water reflux line L6 to the raw water supply line L4, and therefore the activated carbon filter 17 will not be sterilized. The rest of the configuration of this embodiment is the same as that of the first embodiment, and the resulting effects are also the same as those of the first embodiment, except that the activated carbon filter 17 can be made smaller because the amount of water passing through the raw water supply line L4 is smaller than that through the water supply line L1.

１水処理システム
２ユースポイント
１０純水製造装置
１１原水タンク
１２膜分離装置
１３ＥＤＩ装置
１４制御部
１５送水ポンプ
１６熱交換器
１７活性炭ろ過器
１８フィルタ
１９加圧ポンプ
２０純水供給装置
２１純水タンク
２２純水ポンプ
２３熱交換器
Ｌ１給水ライン
Ｌ２透過水ライン
Ｌ３ＲＯ濃縮水ライン
Ｌ４原水補給ライン
Ｌ５バイパスライン
Ｌ６熱水還流ライン
Ｌ７純水ライン
Ｌ８ＥＤＩ濃縮水ライン
Ｌ９純水返送ライン
Ｌ１０循環ライン
Ｌ１１送水ライン
Ｖ１～Ｖ８開閉弁 1 Water treatment system 2 Point of use 10 Pure water production device 11 Raw water tank 12 Membrane separation device 13 EDI device 14 Control unit 15 Water supply pump 16 Heat exchanger 17 Activated carbon filter 18 Filter 19 Pressure pump 20 Pure water supply device 21 Pure water tank 22 Pure water pump 23 Heat exchanger L1 Water supply line L2 Permeate line L3 RO concentrated water line L4 Raw water supply line L5 Bypass line L6 Hot water reflux line L7 Pure water line L8 EDI concentrated water line L9 Pure water return line L10 Circulation line L11 Water supply line V1 to V8 Opening and closing valve

Claims

1. A water treatment system comprising:
a tank for storing the water to be treated;
a water treatment means for treating the water to be treated to produce treated water;
a pretreatment means including at least an activated carbon filter for pretreating the water to be treated that is to be supplied to the water treatment means;
a supply line passing through the tank and the activated carbon filter to the water treatment means;
a return line branching from the supply line downstream of the tank and downstream of the activated carbon filter and returning to the upstream of the tank and upstream of the activated carbon filter;
a return line for returning treated water from the water treatment means to the tank;
a heating means provided in the supply line between the tank and the branching portion of the return line, for heating the water to be treated flowing through the supply line;
a control means for controlling the operation of the water treatment system ;
The control means executes a first process of causing at least a portion of the hot water to flow into the reflux line when the heating means heats the water to be treated flowing through the supply line to generate hot water,
the activated carbon filter is provided in the supply line upstream of the tank;
In the first treatment, the control means causes a portion of the hot water to flow from the supply line through the water treatment means to the return line, and causes the remainder to flow into the reflux line .

a tank for storing the water to be treated;
a water treatment means for treating the water to be treated to produce treated water;
a pretreatment means including at least an activated carbon filter for pretreating the water to be treated that is to be supplied to the water treatment means;
a supply line passing through the tank and the activated carbon filter to the water treatment means;
a return line branching from the supply line downstream of the tank and downstream of the activated carbon filter and returning to the upstream of the tank and upstream of the activated carbon filter;
a heating means provided in the supply line between the tank and a branching portion of the return line, for heating the water to be treated flowing through the supply line;
the pretreatment means includes a pretreatment means other than the activated carbon filter,
A water treatment system, wherein the other pretreatment means is provided downstream of a branch point of the supply line with the return line, and is not provided upstream of the branch point.

a control means for controlling the operation of the water treatment system;
The water treatment system described in claim 2, wherein the control means performs a first process in which, when the heating means heats the treated water flowing through the supply line to produce hot water, at least a portion of the hot water is flowed into the return line.

The water treatment system according to claim 3 , wherein the control means causes all of the hot water to flow into the reflux line in the first treatment.

a return line for returning treated water from the water treatment means to the tank;
the activated carbon filter is provided in the supply line upstream of the tank;
The water treatment system according to claim 3 , wherein the control means, in the first treatment, causes a portion of the hot water to flow from the supply line through the water treatment means to the return line, and causes the remainder to flow into the reflux line.

a return line for returning treated water from the water treatment means to the tank;
the activated carbon filter is provided in the supply line downstream of the tank;
The water treatment system according to claim 3 or 4 , wherein the control means executes a second treatment of circulating at least a portion of the hot water from the supply line through the water treatment means to the return line.

the pretreatment means includes a pretreatment means other than the activated carbon filter,
The water treatment system according to claim 1 , wherein the other pretreatment means is provided downstream of a branch point of the supply line with the return line, but not upstream of the branch point.

The water treatment system according to claim 1 , which is used to produce pure water for use in pharmaceutical manufacturing.

A method for operating a water treatment system comprising: a tank for storing water to be treated; water treatment means for treating the water to be treated to produce treated water; pretreatment means including at least an activated carbon filter for pretreatment of the water to be treated that is supplied to the water treatment means; and a supply line that passes through the tank and the activated carbon filter and leads to the water treatment means, the activated carbon filter being provided on the supply line upstream of the tank, the method comprising:
a step of circulating the water to be treated in the tank through the supply line and heating the circulating water to be treated to generate hot water;
and returning at least a portion of the hot water to the tank and the activated carbon filter through a return line branching from the supply line downstream of the tank and downstream of the activated carbon filter,
A method for operating a water treatment system, wherein the step of returning at least a portion of the hot water includes: returning all of the hot water to the tank and the activated carbon filter, thereby sterilizing the tank and the activated carbon filter; and returning a portion of the hot water from the activated carbon filter to the tank, supplying the remainder to the water treatment means, and then returning it to the tank, thereby sterilizing the tank, the activated carbon filter , and the water treatment means.

A method for operating a water treatment system having a tank for storing water to be treated, water treatment means for treating the water to be treated to produce treated water, pretreatment means including at least an activated carbon filter for pretreatment of the water to be treated to be supplied to the water treatment means, and a supply line that passes through the tank and the activated carbon filter and leads to the water treatment means,
a step of circulating the water to be treated in the tank through the supply line and heating the circulating water to be treated to generate hot water;
and returning at least a portion of the hot water to the tank and the activated carbon filter through a return line branching from the supply line downstream of the tank and downstream of the activated carbon filter,
A method for operating a water treatment system, wherein the step of refluxing at least a portion of the hot water includes not passing the hot water through any pretreatment means other than the activated carbon filter among the pretreatment means.

11. The method of operating a water treatment system according to claim 10 , wherein the step of returning at least a portion of the hot water includes returning all of the hot water to the tank and the activated carbon filter to sterilize the tank and the activated carbon filter.

the activated carbon filter is provided in the supply line upstream of the tank;
12. The method for operating a water treatment system according to claim 11, wherein the step of returning at least a portion of the hot water further comprises returning a portion of the hot water from the activated carbon filter to the tank and supplying the remainder to the water treatment means and then returning it to the tank , thereby sterilizing the tank, the activated carbon filter, and the water treatment means.

the activated carbon filter is provided in the supply line downstream of the tank;
11. The method for operating a water treatment system according to claim 10, further comprising the step of supplying at least a portion of the hot water to the water treatment means through the supply line and then returning it to the tank, thereby sterilizing the tank, the activated carbon filter and the water treatment means.

10. The method for operating a water treatment system according to claim 9 , wherein the step of refluxing at least a portion of the hot water includes not passing the hot water through any pretreatment means other than the activated carbon filter among the pretreatment means.