JP6801731B2 - Pure water production equipment and pure water production method - Google Patents

Pure water production equipment and pure water production method Download PDF

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JP6801731B2
JP6801731B2 JP2019062621A JP2019062621A JP6801731B2 JP 6801731 B2 JP6801731 B2 JP 6801731B2 JP 2019062621 A JP2019062621 A JP 2019062621A JP 2019062621 A JP2019062621 A JP 2019062621A JP 6801731 B2 JP6801731 B2 JP 6801731B2
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後藤　秀樹
秀樹 後藤
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
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    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
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    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
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    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
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    • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
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Description

本発明は、純水製造装置及び純水製造方法に関する。 The present invention relates to a pure water production apparatus and a pure water production method.

一般に純水製造装置には、不純物の除去を目的として、原水を透過水と濃縮水とに分離するための逆浸透膜が備えられている。逆浸透膜を透過した透過水は、更にイオン交換処理などがなされた後に、純水としてユースポイントに供給される。一方、逆浸透膜を透過しなかった濃縮水は、水の有効利用を図るために、原水に返送されて純水製造に再利用されるか、あるいは、冷却塔（クーリングタワー）等の冷却装置の冷却水として再利用される場合がある。 Generally, a pure water production apparatus is provided with a reverse osmosis membrane for separating raw water into permeated water and concentrated water for the purpose of removing impurities. The permeated water that has permeated the reverse osmosis membrane is further subjected to ion exchange treatment and the like, and then supplied to the point of use as pure water. On the other hand, the concentrated water that has not permeated the reverse osmosis membrane is returned to raw water and reused for pure water production in order to make effective use of water, or it is used in a cooling device such as a cooling tower. It may be reused as cooling water.

純水製造装置における濃縮水の再利用に関する技術として、特許文献１には、第１の逆浸透膜装置から出された濃縮水を、第２の逆浸透膜装置によって処理することで透過水とし、この透過水を原水槽に戻すことが記載されている。また、特許文献２には、中圧逆浸透によって第１の濃縮水を産出し、この第１の濃縮水を高圧逆浸透によって処理することで第２の透過水を産出し、第２の透過水を再利用することが記載されている。更に、特許文献３には、逆浸透膜処理装置によって生成される濃縮水を循環冷却水として使用する濃縮水の利用方法が記載されている。 As a technique for reusing concentrated water in a pure water production apparatus, Patent Document 1 states that concentrated water discharged from a first reverse osmosis membrane apparatus is treated with a second reverse osmosis membrane apparatus to obtain permeable water. , It is described that this permeated water is returned to the raw water tank. Further, in Patent Document 2, a first concentrated water is produced by medium pressure reverse osmosis, and a second permeated water is produced by treating the first concentrated water by high pressure reverse osmosis to produce a second permeated water. It is stated that water will be reused. Further, Patent Document 3 describes a method of using concentrated water using concentrated water generated by a reverse osmosis membrane treatment apparatus as circulating cooling water.

逆浸透膜によって生成された濃縮水には不純物が濃化されているため、カルシウムやシリカなどの成分が原水よりも高濃度で含まれる。このような濃縮水が冷却塔に供給されると、冷却塔内の配管においてカルシウムやシリカが析出して目詰まりが発生するおそれがある。そのため、純水製造装置の逆浸透膜によって生成した濃縮水を冷却塔に再利用する場合は、特許文献１〜３に記載のように、１段目の逆浸透膜によって生成された濃縮水を２段目の逆浸透膜によって処理することで不純物濃度を下げるか、あるいは、逆浸透膜における濃縮倍率を調整することで、カルシウムやシリカによる目詰まりを予防する場合がある。 Impurities are concentrated in the concentrated water produced by the reverse osmosis membrane, so that components such as calcium and silica are contained at a higher concentration than the raw water. When such concentrated water is supplied to the cooling tower, calcium and silica may precipitate in the piping inside the cooling tower to cause clogging. Therefore, when the concentrated water generated by the reverse osmosis membrane of the pure water production apparatus is reused for the cooling tower, the concentrated water generated by the first-stage reverse osmosis membrane is used as described in Patent Documents 1 to 3. Treatment with a second-stage reverse osmosis membrane may reduce the impurity concentration, or adjustment of the concentration ratio in the reverse osmosis membrane may prevent clogging due to calcium or silica.

しかし、冷却塔における冷却水の需要量と、逆浸透膜による濃縮水の生成量とは合致しない場合が多く、特に、冷却水の需要量が濃縮水の生成量を下回る場合は、余剰の濃縮水を純水製造装置から排出せざるを得ず、純水製造装置における水の有効利用が図られていなかった。 However, the demand for cooling water in the cooling tower often does not match the amount of concentrated water produced by the reverse osmosis membrane, and especially when the demand for cooling water is less than the amount of concentrated water produced, excess concentration is achieved. Water had to be discharged from the pure water production equipment, and the effective use of water in the pure water production equipment was not achieved.

特開２０１６−１３５２９号公報JP-A-2016-13529 特開２０１８−８６６４９号公報JP-A-2018-86649 特開２０１７−１０４７８７号公報JP-A-2017-104787

本発明は上記事情に鑑みてなされたものであり、逆浸透膜によって生成された濃縮水を冷却塔の冷却水として再利用する場合において、水の有効利用を可能とする純水製造装置及び純水製造方法を提供するこことを課題とする。 The present invention has been made in view of the above circumstances, and is a pure water production apparatus and pure water that enable effective use of water when the concentrated water generated by the reverse osmosis membrane is reused as cooling water for a cooling tower. The subject is to provide a water production method.

上記課題を解決するため、本発明は以下の構成を採用する。
［１］ 原水を流す原水供給路と、
前記原水供給路から供給された前記原水を、一次透過水と一次濃縮水とに分離する第１の逆浸透膜と、
前記一次濃縮水を、二次透過水と二次濃縮水とに分離する第２の逆浸透膜と、
前記二次透過水を、冷却水として冷却塔に供給する冷却水供給路と、
前記第２の逆浸透膜における前記二次透過水の生産量が、前記冷却塔における前記二次透過水の需要量を超える場合に、前記二次透過水の余剰分を前記原水供給路に返送する返送手段と、が備えられていることを特徴とする純水製造装置。
［２］ 前記返送手段は、前記二次透過水を前記原水供給路に返送する返送路と、
前記冷却水供給路に流す前記二次透過水の流量を制御する流量制御手段と、から構成されていることを特徴とする［１］に記載の純水製造装置。
［３］ 前記原水供給路の途中に配置されて前記原水を予熱する予熱手段と、
前記原水供給路の途中に配置されて予熱後の前記原水を加熱する加熱手段と、が更に備えられ、
前記予熱手段は、前記冷却水供給路を流れる前記二次透過水を高温側流体とし、前記原水を低温側流体とする熱交換器であることを特徴とする［１］または［２］に記載の純水製造装置。
［４］ 前記第１の逆浸透膜を透過した前記一次透過水が流れる一次透過水路と、
前記一次透過水路に設置され、前記一次透過水を脱炭酸処理する第１脱炭酸手段と、
前記一次透過水路の前記第１脱炭酸手段の後段に設置され、前記第１脱炭酸手段を通過後の前記一次透過水を脱イオン処理すると、が更に備えられていることを特徴とする［１］乃至［３］の何れか一項に記載の純水製造装置。
［５］ 前記返送路に、前記二次透過水を脱炭酸処理する第２脱炭酸手段が備えられている［２］乃至［４］の何れか一項に記載の純水製造装置。 In order to solve the above problems, the present invention adopts the following configuration.
[1] Raw water supply channel for flowing raw water and
A first reverse osmosis membrane that separates the raw water supplied from the raw water supply channel into primary permeated water and primary concentrated water.
A second reverse osmosis membrane that separates the primary concentrated water into secondary permeated water and secondary concentrated water.
A cooling water supply path that supplies the secondary permeated water to the cooling tower as cooling water, and
When the production amount of the secondary permeated water in the second reverse osmosis membrane exceeds the demand amount of the secondary permeated water in the cooling tower, the surplus of the secondary permeated water is returned to the raw water supply channel. A pure water production apparatus characterized in that it is provided with a return means.
[2] The return means includes a return path for returning the secondary permeated water to the raw water supply path and a return path.
The pure water production apparatus according to [1], which comprises a flow rate control means for controlling the flow rate of the secondary permeated water flowing through the cooling water supply path.
[3] A preheating means arranged in the middle of the raw water supply path to preheat the raw water, and
A heating means for heating the raw water after preheating, which is arranged in the middle of the raw water supply path, is further provided.
The preheating means according to [1] or [2], wherein the preheating means is a heat exchanger in which the secondary permeated water flowing through the cooling water supply path is a high temperature side fluid and the raw water is a low temperature side fluid. Pure water production equipment.
[4] A primary permeation channel through which the primary permeate water that has permeated the first reverse osmosis membrane flows.
A first decarboxylation means that is installed in the primary permeation channel and decarboxylates the primary permeate water.
When the primary permeated water is installed after the first decarboxylation means of the primary permeation channel and the primary permeate water after passing through the first decarboxylation means is deionized, the present invention is further provided [1]. ] To [3]. The pure water production apparatus according to any one of the items.
[5] The pure water production apparatus according to any one of [2] to [4], wherein the return path is provided with a second decarboxylation means for decarboxylating the secondary permeated water.

［６］ 原水を、第１の逆浸透膜により、一次透過水と一次濃縮水とに分離する第１の逆浸透膜分離工程と、
前記一次濃縮水を、第２の逆浸透膜により、二次透過水と二次濃縮水とに分離する第２の逆浸透膜分離工程と、
前記二次透過水を、冷却水供給路により、冷却水として冷却塔に供給するとともに、前記第２の逆浸透膜における前記二次透過水の生産量が前記冷却塔における前記二次透過水の需要量を超える場合に、前記二次透過水の余剰分を、返送手段により、前記原水として返送する二次透過水供給工程と、
が備えられていることを特徴とする純水製造方法。
［７］ 前記返送手段は、前記二次透過水を、前記原水に返送する返送路と、
前記冷却水供給路に流す前記二次透過水の流量を制御する流量制御手段とからなることを特徴とする［６］に記載の純水製造方法。
［８］ 前記第１の逆浸透膜への供給前の前記原水を予熱する予熱工程と、
予熱後の前記原水を加熱する加熱工程と、が更に備えられ、
前記予熱工程は、前記冷却水供給路を流れる前記二次透過水を高温側流体とし、前記原水を低温側流体とする熱交換器によって行うことを特徴とする［６］または［７］に記載の純水製造方法。
［９］ 前記一次透過水を、第１脱炭酸手段により、脱炭酸処理する第１脱炭酸工程と、
前記第１脱炭酸工程後の前記一次透過水を、電気脱イオン装置により、脱イオン処理する電気脱イオン工程と、が更に備えられていることを特徴とする［６］乃至［８］の何れか一項に記載の純水製造方法。
［１０］ 前記返送路を流れる前記二次透過水を、第２脱炭酸手段により、脱炭酸処理する第２脱炭酸工程が備えられている［７］乃至［９］の何れか一項に記載の純水製造方法。 [6] A first reverse osmosis membrane separation step of separating raw water into primary permeated water and primary concentrated water by a first reverse osmosis membrane.
A second reverse osmosis membrane separation step of separating the primary concentrated water into secondary permeated water and secondary concentrated water by a second reverse osmosis membrane.
The secondary permeated water is supplied to the cooling tower as cooling water through the cooling water supply path, and the production amount of the secondary permeated water in the second reverse osmosis membrane is the secondary permeated water in the cooling tower. A secondary permeated water supply step in which the surplus of the secondary permeated water is returned as raw water by a return means when the demand amount is exceeded.
A pure water production method characterized by being provided with.
[7] The return means includes a return path for returning the secondary permeated water to the raw water.
The pure water production method according to [6], which comprises a flow rate control means for controlling the flow rate of the secondary permeated water flowing through the cooling water supply path.
[8] A preheating step of preheating the raw water before supply to the first reverse osmosis membrane, and
A heating step of heating the raw water after preheating is further provided.
[6] or [7], wherein the preheating step is performed by a heat exchanger in which the secondary permeated water flowing through the cooling water supply path is used as a high temperature side fluid and the raw water is used as a low temperature side fluid. Pure water production method.
[9] In the first decarboxylation step of decarboxylating the primary permeated water by the first decarboxylation means,
Any of [6] to [8], further comprising an electrodeionization step of deionizing the primary permeated water after the first decarboxylation step with an electrodeionizer. The pure water production method according to item 1.
[10] The item according to any one of [7] to [9], which comprises a second decarboxylation step of decarboxylating the secondary permeated water flowing through the return path by a second decarboxylation means. Pure water production method.

本発明の純水製造装置によれば、第２の逆浸透膜における二次透過水の生産量が、冷却塔における二次透過水の需要量を超える場合に、二次透過水の余剰分を原水供給路に返送する返送手段が備えられているので、余剰な二次透過水を廃棄することなく有効利用することができる。 According to the pure water production apparatus of the present invention, when the production amount of the secondary permeated water in the second reverse osmosis membrane exceeds the demand amount of the secondary permeated water in the cooling tower, the surplus amount of the secondary permeated water is taken. Since a return means for returning to the raw water supply channel is provided, excess secondary permeated water can be effectively used without being discarded.

また、本発明の純水製造装置によれば、返送手段が、二次透過水を原水供給路に返送する返送路と、冷却水供給路に流す二次透過水の流量を制御する流量制御手段とから構成されているので、冷却塔への二次透過水の供給量と、原水供給路への二次透過水の返送量とを最適な割合に調整することができ、水の有効利用を図ることができる。 Further, according to the pure water production apparatus of the present invention, the return means is a flow rate control means for controlling the flow rate of the secondary permeated water flowing through the return path for returning the secondary permeated water to the raw water supply path and the cooling water supply path. Since it is composed of, the amount of secondary permeated water supplied to the cooling tower and the amount of secondary permeated water returned to the raw water supply channel can be adjusted to the optimum ratio, and effective use of water can be achieved. Can be planned.

更に、本発明の純水製造装置によれば、原水供給路の途中に原水を予熱する予熱手段及び加熱手段が配置される場合に、予熱手段を熱交換器として利用し、冷却水供給路を流れる二次透過水の熱を予熱手段によって回収することで、加熱手段におけるエネルギー消費を低減できるとともに、冷却塔に送る二次透過水を冷却することができる。 Further, according to the pure water production apparatus of the present invention, when the preheating means and the heating means for preheating the raw water are arranged in the middle of the raw water supply path, the preheating means is used as a heat exchanger to provide the cooling water supply path. By recovering the heat of the flowing secondary permeated water by the preheating means, the energy consumption in the heating means can be reduced and the secondary permeated water sent to the cooling tower can be cooled.

更にまた、本発明の純水製造装置によれば、第１の逆浸透膜を透過した一次透過水が流れる一次透過水路に、第１脱炭酸手段と電気脱イオン装置とが更に備えられているので、一次透過水の不純物量を更に低減することができ、高純度の純水を製造できる。 Furthermore, according to the pure water production apparatus of the present invention, the primary decarbonization means and the electrodeionization apparatus are further provided in the primary permeation channel through which the primary permeate water that has permeated the first reverse osmosis membrane flows. Therefore, the amount of impurities in the primary permeated water can be further reduced, and high-purity pure water can be produced.

また、本発明の純水製造装置によれば、二次透過水と原水供給路に返送する返送路に、二次透過水を脱炭酸処理する第２脱炭酸手段が備えられているので、脱炭酸処理された二次透過水を原水供給路に返送することができ、これにより原水の炭酸濃度が減少し、一次透過水路に配置した第１脱炭酸手段の負荷を軽減できる。 Further, according to the pure water production apparatus of the present invention, the secondary permeated water and the return path for returning to the raw water supply channel are provided with a second decarboxylation means for decarboxylating the secondary permeated water. The carbonated secondary permeated water can be returned to the raw water supply channel, thereby reducing the carbonic acid concentration of the raw water and reducing the load on the first decarboxylation means arranged in the primary permeated water channel.

次に、本発明の純水製造方法によれば、第２の逆浸透膜における二次透過水の生産量が、冷却塔における二次透過水の需要量を超える場合に、二次透過水の余剰分を原水供給路に返送する二次透過水供給工程が備えられているので、余剰な二次透過水を廃棄することなく有効利用することができる。 Next, according to the pure water production method of the present invention, when the production amount of the secondary permeated water in the second reverse osmosis membrane exceeds the demand amount of the secondary permeated water in the cooling tower, the secondary permeated water Since the secondary permeated water supply process for returning the surplus to the raw water supply channel is provided, the surplus secondary permeated water can be effectively used without being discarded.

また、本発明の純水製造方法によれば、返送手段が、二次透過水を原水供給路に返送する返送路と、冷却水供給路に流す二次透過水の流量を制御する流量制御手段とから構成されているので、冷却塔への二次透過水の供給量と、原水供給路への二次透過水の返送量とを最適な割合に調整することができ、水の有効利用を図ることができる。 Further, according to the pure water production method of the present invention, the return means is a flow rate control means for controlling the flow rate of the secondary permeated water flowing through the return path for returning the secondary permeated water to the raw water supply path and the cooling water supply path. Since it is composed of, the amount of secondary permeated water supplied to the cooling tower and the amount of secondary permeated water returned to the raw water supply channel can be adjusted to the optimum ratio, and effective use of water can be achieved. Can be planned.

更に、本発明の純水製造方法によれば、原水供給路の途中に原水を予熱する予熱工程及び加熱工程がなされる場合に、冷却水供給路を流れる二次透過水の熱を予熱手段によって回収するので、加熱工程におけるエネルギー消費を低減できるとともに、冷却塔に送る二次透過水を冷却することができる。 Further, according to the pure water production method of the present invention, when a preheating step and a heating step for preheating the raw water are performed in the middle of the raw water supply path, the heat of the secondary permeated water flowing through the cooling water supply path is preheated by the preheating means. Since it is recovered, energy consumption in the heating process can be reduced, and the secondary permeated water sent to the cooling tower can be cooled.

更にまた、本発明の純水製造方法によれば、第１の逆浸透膜を透過した一次透過水に対して、第１脱炭酸工程と電気脱イオン工程とを順次行うことで、一次透過水の不純物量を更に低減することができ、高純度の純水を製造できる。 Furthermore, according to the pure water production method of the present invention, the primary permeated water is subjected to the first decarbonization step and the electrodeionization step in sequence with respect to the primary permeated water that has permeated the first reverse osmosis membrane. The amount of impurities in the above can be further reduced, and high-purity pure water can be produced.

また、本発明の純水製造方法によれば、二次透過水を原水供給路に返送する際に、二次透過水に対して第２脱炭酸工程を行うので、脱炭酸処理された二次透過水を原水供給路に返送することができ、これにより原水の炭酸濃度が減少し、一次透過水路における第１脱炭酸工程の負荷を軽減できる。 Further, according to the pure water production method of the present invention, when the secondary permeated water is returned to the raw water supply channel, the secondary decarboxylation step is performed on the secondary permeated water, so that the decarboxylated secondary water is subjected to. The permeated water can be returned to the raw water supply channel, thereby reducing the carbonation concentration of the raw water and reducing the load of the first decarboxylation step in the primary permeated water channel.

図１は、本発明の第１の実施形態である純水製造装置の構成を説明する模式図。FIG. 1 is a schematic diagram illustrating a configuration of a pure water production apparatus according to a first embodiment of the present invention. 図２は、本発明の第２の実施形態である純水製造装置の構成を説明する模式図。FIG. 2 is a schematic diagram illustrating a configuration of a pure water production apparatus according to a second embodiment of the present invention. 図３は、本発明の第３の実施形態である純水製造装置の構成を説明する模式図。FIG. 3 is a schematic view illustrating the configuration of a pure water production apparatus according to a third embodiment of the present invention.

（第１の実施形態）
図１を参照して、本発明の第１の実施形態である純水製造装置及び純水製造方法を説明する。 (First Embodiment)
The pure water production apparatus and the pure water production method according to the first embodiment of the present invention will be described with reference to FIG.

まず、純水製造装置１の全体構成を説明する。本実施形態の純水製造装置１は、原水ｗ１を流す原水供給路２と、原水ｗ１を一次透過水ｗ２と一次濃縮水ｗ３に分離する第１の逆浸透膜３と、一次濃縮水ｗ３を二次透過水ｗ４と二次濃縮水ｗ５に分離する第２の逆浸透膜４と、二次透過水ｗ４を冷却水として冷却塔５に供給する冷却水供給路Ｌ８と、二次透過水ｗ４の余剰分を原水供給路２に返送する返送手段６とが備えられている。また、純水製造装置１には、一次透過水ｗ２を流す一次透過水路Ｌ３、Ｌ４と、第１脱炭酸手段３１と、電気脱イオン装置３２とが備えられている。更に、第１の逆浸透膜３と第２の逆浸透膜４との間には、一次濃縮水ｗ３を貯留する濃縮水槽８が備えられている。更にまた、濃縮水槽８と第２の逆浸透膜４との間には、一次濃縮水ｗ３の水質を調整する水質調整手段４２が備えられている。 First, the overall configuration of the pure water production apparatus 1 will be described. The pure water production apparatus 1 of the present embodiment provides a raw water supply path 2 through which the raw water w1 flows, a first reverse osmosis membrane 3 that separates the raw water w1 into a primary permeated water w2 and a primary concentrated water w3, and a primary concentrated water w3. A second reverse osmosis membrane 4 that separates the secondary permeated water w4 and the secondary concentrated water w5, a cooling water supply path L8 that supplies the secondary permeated water w4 as cooling water to the cooling tower 5, and a secondary permeated water w4. A return means 6 for returning the surplus portion of the above water to the raw water supply channel 2 is provided. Further, the pure water production apparatus 1 is provided with primary permeation channels L3 and L4 through which the primary permeation water w2 flows, a first decarboxylation means 31, and an electric deionization apparatus 32. Further, a concentrated water tank 8 for storing the primary concentrated water w3 is provided between the first reverse osmosis membrane 3 and the second reverse osmosis membrane 4. Furthermore, a water quality adjusting means 42 for adjusting the water quality of the primary concentrated water w3 is provided between the concentrated water tank 8 and the second reverse osmosis membrane 4.

また、図１に示すように、原水供給路２の前段には前処理装置４１が備えられている。前処理装置４１は、純水製造装置１に含めてもよく、含めなくてもよい。 Further, as shown in FIG. 1, a pretreatment device 41 is provided in front of the raw water supply path 2. The pretreatment device 41 may or may not be included in the pure water production device 1.

原水供給路２は、原水槽２ａと、前処理装置４１と原水槽２ａとを接続する水路Ｌ１と、原水槽２ａと第１の逆浸透膜３とを接続する水路Ｌ２とから構成されている。 The raw water supply channel 2 is composed of a raw water tank 2a, a water channel L1 connecting the pretreatment device 41 and the raw water tank 2a, and a water channel L2 connecting the raw water tank 2a and the first reverse osmosis membrane 3. ..

返送手段６は、二次透過水ｗ４を原水供給路２に返送する返送路Ｌ９と、流量制御手段７とから構成されている。流量制御手段７は、流量調整弁７ａと制御装置７ｂとから構成されている。 The return means 6 is composed of a return path L9 for returning the secondary permeated water w4 to the raw water supply path 2 and a flow rate control means 7. The flow rate control means 7 is composed of a flow rate adjusting valve 7a and a control device 7b.

また、純水製造装置１には、各装置及び各手段の間に水を流すための水路が備えられている。すなわち、原水供給路２には水路Ｌ１及び水路Ｌ２がある。また、第１の逆浸透膜３と第１脱炭酸手段３１とが一次透過水路Ｌ３によって接続され、第１脱炭酸手段３１と電気脱イオン装置３２とが一次透過水路Ｌ４によって接続されている。また、電気脱イオン装置３２と原水供給路２の原水槽２ａとが水路Ｌ１０によって接続されている。なお、水路Ｌ１０は、原水槽２ａに限らず、水路Ｌ１、Ｌ２のいずれかに接続されていてもよい。 Further, the pure water production apparatus 1 is provided with a water channel for flowing water between each apparatus and each means. That is, the raw water supply channel 2 has a water channel L1 and a water channel L2. Further, the first reverse osmosis membrane 3 and the first decarboxylation means 31 are connected by the primary permeation water channel L3, and the first decarboxylation means 31 and the electric decarboxylation device 32 are connected by the primary permeation water channel L4. Further, the electric deionization device 32 and the raw water tank 2a of the raw water supply path 2 are connected by a water channel L10. The water channel L10 is not limited to the raw water tank 2a, and may be connected to any of the water channels L1 and L2.

また、第１の逆浸透膜３と濃縮水槽８とが水路Ｌ５によって接続され、濃縮水槽８と第２の逆浸透膜４とが水路Ｌ６によって接続され、第２の逆浸透膜４と流量調整弁７ａとが水路Ｌ７によって接続され、流量調整弁７ａと冷却塔５とが冷却水供給路Ｌ８によって接続されている。更に、水路Ｌ７の途中から返送路Ｌ９が分岐している。返送路Ｌ９は原水槽２ａに接続されている。なお、返送路Ｌ９は、原水槽２ａに限らず、水路Ｌ１、Ｌ２のいずれかに接続されていてもよい。 Further, the first reverse osmosis membrane 3 and the concentrated water tank 8 are connected by a water channel L5, and the concentrated water tank 8 and the second reverse osmosis membrane 4 are connected by a water channel L6 to adjust the flow rate with the second reverse osmosis membrane 4. The valve 7a is connected by a water channel L7, and the flow control valve 7a and the cooling tower 5 are connected by a cooling water supply path L8. Further, the return path L9 branches from the middle of the water channel L7. The return path L9 is connected to the raw water tank 2a. The return channel L9 is not limited to the raw water tank 2a, and may be connected to any of the water channels L1 and L2.

次に、純水製造装置１を構成する各装置及び各手段について説明する。
前処理装置４１は、上水道水や工業用水等の原水ｗ１に対して凝集沈降、濾過、イオン交換等を行うことによって、原水ｗ１の不純物量を所定の濃度以下に低減させるものである。前処理装置４１によって処理された原水ｗ１は、水路Ｌ１によって原水槽２ａに送られる。 Next, each device and each means constituting the pure water production device 1 will be described.
The pretreatment device 41 reduces the amount of impurities in the raw water w1 to a predetermined concentration or less by performing coagulation sedimentation, filtration, ion exchange, etc. on the raw water w1 such as tap water and industrial water. The raw water w1 treated by the pretreatment device 41 is sent to the raw water tank 2a by the water channel L1.

原水槽２ａは、原水ｗ１を一時的に貯留する。また、原水槽２ａには、水路Ｌ１０及び返送路Ｌ９が接続されており、これらの水路Ｌ９、Ｌ１０から返送された水も原水ｗ１として貯留する。貯留された原水ｗ１は水路Ｌ２によって第１の逆浸透膜３に送られる。 The raw water tank 2a temporarily stores the raw water w1. Further, a water channel L10 and a return channel L9 are connected to the raw water tank 2a, and the water returned from these water channels L9 and L10 is also stored as the raw water w1. The stored raw water w1 is sent to the first reverse osmosis membrane 3 by the water channel L2.

第１の逆浸透膜３は、原水供給路２から供給された原水ｗ１を、一次透過水ｗ２と一次濃縮水ｗ３に分離させる。原水ｗ１は、第１の逆浸透膜３に通水されることによって、不純物が除去されて一次透過水ｗ２とされる。除去された不純物は一次濃縮水ｗ３に含有される。第１の逆浸透膜３は、浸透膜（メンブレン）を何層にも重ねて海苔巻き状に巻き、容器に収めたスパイラル型モジュールを好適に使用できるが、これに限定されるものではない。 The first reverse osmosis membrane 3 separates the raw water w1 supplied from the raw water supply path 2 into the primary permeated water w2 and the primary concentrated water w3. The raw water w1 is passed through the first reverse osmosis membrane 3 to remove impurities and become the primary permeated water w2. The removed impurities are contained in the primary concentrated water w3. As the first reverse osmosis membrane 3, a spiral type module in which osmosis membranes (membranes) are stacked in multiple layers and wound in a seaweed roll shape and housed in a container can be preferably used, but the first is not limited thereto.

第１の逆浸透膜３には、一次透過水ｗ２を流す一次透過水路Ｌ３と、一次濃縮水ｗ３を流す水路Ｌ５とが接続されている。 The first reverse osmosis membrane 3 is connected to a primary permeation channel L3 through which the primary permeate water w2 flows and a channel L5 through which the primary concentrated water w3 flows.

また、第１の逆浸透膜３は２つ以上直列に設けられていてもよい。第１の逆浸透膜３が２つ以上直列に設けられる場合、前段の逆浸透膜の透過水が後段の逆浸透膜の供給水となるように設けられる。 Further, two or more first reverse osmosis membranes 3 may be provided in series. When two or more first reverse osmosis membranes 3 are provided in series, the permeated water of the reverse osmosis membrane in the front stage is provided so as to supply water to the reverse osmosis membrane in the subsequent stage.

第１脱炭酸手段３１は、一次透過水ｗ２を脱炭酸処理するものである。第１脱炭酸手段３１としては、第１の逆浸透膜３を透過した一次透過水ｗ２に溶存している二酸化炭素を主に除去できるものであれば、特に限定されない。第１脱炭酸手段３１としては、例えば、中空糸膜等の脱気膜から構成される膜脱気装置や、脱炭酸塔等を用いることができる。第１脱炭酸手段３１には、一次透過水ｗ２を電気脱イオン装置３２に送る一次透過水路Ｌ４が接続されている。 The first decarboxylation means 31 decarboxylates the primary permeated water w2. The first decarboxylation means 31 is not particularly limited as long as it can mainly remove carbon dioxide dissolved in the primary permeated water w2 that has permeated the first reverse osmosis membrane 3. As the first decarboxylation means 31, for example, a membrane degassing device composed of a degassing membrane such as a hollow fiber membrane, a decarboxylation tower, or the like can be used. The first decarboxylation means 31 is connected to a primary permeation water channel L4 that sends the primary permeation water w2 to the electrodeionizer 32.

電気脱イオン装置３２は、第１脱炭酸手段３１の後段に設置されている。電気脱イオン装置３２は、一次透過水ｗ２を脱イオン処理することにより、一次透過水ｗ２に残存するイオン性物質を更に除去するためのものである。除去されたイオン性物質は濃縮水ｗ６に濃縮される。電気脱イオン装置３２は、例えば、陽極と陰極との間がアニオン交換膜とカチオン交換膜とで区画され、陽極室、陰極室、脱塩室および濃縮室が形成されてなるものが用いられる。 The electrodeionizer 32 is installed after the first decarboxylation means 31. The electrodeionizer 32 is for further removing the ionic substance remaining in the primary permeated water w2 by deionizing the primary permeated water w2. The removed ionic substance is concentrated in concentrated water w6. As the electrodeionizer 32, for example, an anode and a cathode are partitioned by an anion exchange membrane and a cation exchange membrane, and an anode chamber, a cathode chamber, a desalting chamber and a concentration chamber are formed.

また、電気脱イオン装置３２には水路Ｌ１０が接続されている。水路Ｌ１０は、濃縮水ｗ６を原水槽２ａに返送させる。更に、電気脱イオン装置３２には水路Ｌ１１が接続されている。水路Ｌ１１は、ユースポイントに接続されており、脱イオン処理された一次透過水ｗ２を純水としてユースポイントに供給させる。 Further, a water channel L10 is connected to the electric deionization device 32. The water channel L10 returns the concentrated water w6 to the raw water tank 2a. Further, a water channel L11 is connected to the electrodeionizer 32. The water channel L11 is connected to the use point, and the deionized primary permeated water w2 is supplied to the use point as pure water.

第１の逆浸透膜３に接続された水路Ｌ５の先には、濃縮水槽８が設置されている。濃縮水槽８は、一次濃縮水ｗ３を一時的に貯留する。また、濃縮水槽８には一次濃縮水ｗ３を第２の逆浸透膜４に送るための水路Ｌ６が接続されている。 A concentrated water tank 8 is installed at the end of the water channel L5 connected to the first reverse osmosis membrane 3. The concentrated water tank 8 temporarily stores the primary concentrated water w3. Further, a water channel L6 for sending the primary concentrated water w3 to the second reverse osmosis membrane 4 is connected to the concentrated water tank 8.

水路Ｌ６の途中には、一次濃縮水ｗ３の水質調整をするための水質調整手段４２が接続されている。一次濃縮水ｗ３の水質調整の主な目的は、第２の逆浸透膜４におけるスケールの析出を予防して、膜の閉塞を予防することである。そのため、水質調整手段４２では、一次濃縮水ｗ３の水質を酸性に、例えばｐＨ５．５以下に調整するとともに、スケール分散剤を添加する。ｐＨの調整は、硫酸等の添加によって行うことが好ましい。なお、水質調整手段４２は水路Ｌ６の途中に設置することに限定されず、濃縮水槽８に設置してもよい。 A water quality adjusting means 42 for adjusting the water quality of the primary concentrated water w3 is connected in the middle of the water channel L6. The main purpose of adjusting the water quality of the primary concentrated water w3 is to prevent scale precipitation in the second reverse osmosis membrane 4 and prevent membrane blockage. Therefore, in the water quality adjusting means 42, the water quality of the primary concentrated water w3 is adjusted to be acidic, for example, pH 5.5 or less, and a scale dispersant is added. The pH is preferably adjusted by adding sulfuric acid or the like. The water quality adjusting means 42 is not limited to being installed in the middle of the water channel L6, and may be installed in the concentrated water tank 8.

第２の逆浸透膜４は、水質調整手段４２によって水質調整された一次濃縮水ｗ３を、二次透過水ｗ４と二次濃縮水ｗ５に分離させる。一次濃縮水ｗ３は、第２の逆浸透膜４に通水されることによって、不純物が除去されて二次透過水ｗ４とされる。除去された不純物は二次濃縮水ｗ５に含有される。第２の逆浸透膜４は、浸透膜（メンブレン）を何層にも重ねて海苔巻き状に巻き、容器に収めたスパイラル型モジュールを好適に使用できるが、これに限定されるものではない。 The second reverse osmosis membrane 4 separates the primary concentrated water w3 whose water quality has been adjusted by the water quality adjusting means 42 into the secondary permeated water w4 and the secondary concentrated water w5. The primary concentrated water w3 is passed through the second reverse osmosis membrane 4 to remove impurities and become the secondary permeated water w4. The removed impurities are contained in the secondary concentrated water w5. As the second reverse osmosis membrane 4, a spiral type module in which osmosis membranes (membranes) are stacked in multiple layers and wrapped in a seaweed roll can be preferably used, but the second reverse osmosis membrane 4 is not limited thereto.

第２の逆浸透膜４には、二次透過水ｗ４を流す水路Ｌ７と、二次濃縮水ｗ５を流す水路Ｌ１２とが接続されている。 A water channel L7 through which the secondary permeated water w4 flows and a water channel L12 through which the secondary concentrated water w5 flows are connected to the second reverse osmosis membrane 4.

また、第２の逆浸透膜４は２つ以上直列に設けられていてもよい。第２の逆浸透膜４が２つ以上直列に設けられる場合、前段の逆浸透膜の透過水が後段の逆浸透膜の供給水となるように設けられる。 Further, two or more second reverse osmosis membranes 4 may be provided in series. When two or more second reverse osmosis membranes 4 are provided in series, the permeated water of the reverse osmosis membrane in the front stage is provided so as to supply water to the reverse osmosis membrane in the subsequent stage.

返送手段６は、水路Ｌ７の途中から分岐する返送路Ｌ９と、流量制御手段７とから構成されている。流量制御手段７は、流量調整弁７ａと制御装置７ｂとから構成されている。流量調整弁７ａは、水路Ｌ７と冷却水供給路Ｌ８との間に配置されている。冷却水供給路Ｌ８は冷却塔５に接続されており、二次透過水ｗ４を冷却塔５に供給させる。冷却塔５では、二次透過水ｗ４を冷却水として利用する。 The return means 6 is composed of a return path L9 that branches from the middle of the water channel L7 and a flow rate control means 7. The flow rate control means 7 is composed of a flow rate adjusting valve 7a and a control device 7b. The flow rate adjusting valve 7a is arranged between the water channel L7 and the cooling water supply channel L8. The cooling water supply path L8 is connected to the cooling tower 5, and the secondary permeated water w4 is supplied to the cooling tower 5. In the cooling tower 5, the secondary permeated water w4 is used as the cooling water.

流量調整弁７ａは、制御装置７ｂの指令を受けて、冷却水供給路Ｌ８における二次透過水ｗ４の流量を調整する。また、制御装置７ｂは、冷却塔５における冷却水（二次透過水ｗ４）の使用量を監視しており、二次透過水ｗ４の供給量が不足する場合は流量調整弁７ａを制御して冷却水供給路Ｌ８における二次透過水ｗ４の流量を増加させ、逆に二次透過水ｗ４の供給量が過剰な場合は流量調整弁７ａを制御して冷却水供給路Ｌ８における二次透過水ｗ４の流量を減少させる。 The flow rate adjusting valve 7a adjusts the flow rate of the secondary permeated water w4 in the cooling water supply path L8 in response to the command of the control device 7b. Further, the control device 7b monitors the usage amount of the cooling water (secondary permeated water w4) in the cooling tower 5, and controls the flow rate adjusting valve 7a when the supply amount of the secondary permeated water w4 is insufficient. The flow rate of the secondary permeated water w4 in the cooling water supply path L8 is increased, and conversely, when the supply amount of the secondary permeated water w4 is excessive, the flow rate adjusting valve 7a is controlled to control the secondary permeated water in the cooling water supply path L8. Reduce the flow rate of w4.

流量調整弁７ａ及び制御装置７ｂによる二次透過水ｗ４に対する流量制御の結果、二次透過水ｗ４に余剰が生じると、余剰分の二次透過水ｗ４は返送路Ｌ９に流され、原水供給路２の原水槽２ａに送られる。 When a surplus is generated in the secondary permeated water w4 as a result of the flow rate control for the secondary permeated water w4 by the flow rate adjusting valve 7a and the control device 7b, the surplus secondary permeated water w4 is flowed to the return path L9 and the raw water supply path. It is sent to the raw water tank 2a of 2.

次に図１を参照しつつ、本実施形態の純水製造方法について説明する。本実施形態の純水製造方法は、原水ｗ１を、第１の逆浸透膜３により、一次透過水ｗ２と一次濃縮水ｗ３とに分離する第１の逆浸透膜分離工程と、一次濃縮水ｗ３を、第２の逆浸透膜４により、二次透過水ｗ４と二次濃縮水ｗ５とに分離する第２の逆浸透膜分離工程と、二次透過水ｗ４を、冷却水として冷却塔５に供給するとともに、二次透過水ｗ４の余剰分を第１の逆浸透膜３の前段に返送する二次透過水供給工程と、を行う。また、本実施形態の純水製造方法では、一次透過水ｗ２を、第１脱炭酸手段３１により脱炭酸処理する第１脱炭酸工程と、第１脱炭酸工程後の一次透過水ｗ２を、電気脱イオン装置３２により、脱イオン処理する電気脱イオン工程とを行う。
以下、各工程について説明する。 Next, the pure water production method of the present embodiment will be described with reference to FIG. The pure water production method of the present embodiment includes a first reverse osmosis membrane separation step of separating raw water w1 into primary permeated water w2 and primary concentrated water w3 by a first reverse osmosis membrane 3, and primary concentrated water w3. In the second reverse osmosis membrane separation step of separating the secondary osmosis water w4 and the secondary concentrated water w5 by the second reverse osmosis membrane 4, and the secondary osmosis water w4 as cooling water in the cooling tower 5. A secondary permeable water supply step of supplying and returning the surplus of the secondary permeable water w4 to the previous stage of the first reverse osmosis membrane 3 is performed. Further, in the pure water production method of the present embodiment, the first decarboxylation step of decarboxylating the primary permeated water w2 by the first decarboxylation means 31 and the primary permeated water w2 after the first decarboxylation step are electrically operated. The deionization device 32 performs an electrodeionization step of deionizing.
Hereinafter, each step will be described.

まず、上水道水や工業用水等の原水ｗ１に対して前処理装置４１によって凝集沈降、濾過、イオン交換等を行うことで、原水ｗ１の不純物量を所定の濃度以下に低減させる。前処理装置４１によって処理された原水ｗ１は、水路Ｌ１によって原水槽２ａに送る。 First, the amount of impurities in the raw water w1 is reduced to a predetermined concentration or less by performing coagulation sedimentation, filtration, ion exchange, etc. on the raw water w1 such as tap water and industrial water by the pretreatment device 41. The raw water w1 treated by the pretreatment device 41 is sent to the raw water tank 2a by the water channel L1.

次に、第１の逆浸透膜分離工程では、原水供給路２の原水槽２ａから供給された原水ｗ１を、一次透過水ｗ２と一次濃縮水ｗ３に分離する。原水ｗ１は、第１の逆浸透膜３によって不純物が除去されて一次透過水ｗ２とされる。また、除去された不純物は一次濃縮水ｗ３に含有される。そして、一次透過水ｗ２は一次透過水路Ｌ３を介して第１脱炭酸手段３１に送られる。また、一次濃縮水ｗ３は水路Ｌ５を介して濃縮水槽８に送られる。 Next, in the first reverse osmosis membrane separation step, the raw water w1 supplied from the raw water tank 2a of the raw water supply path 2 is separated into the primary permeated water w2 and the primary concentrated water w3. Impurities are removed from the raw water w1 by the first reverse osmosis membrane 3 to obtain the primary permeated water w2. Further, the removed impurities are contained in the primary concentrated water w3. Then, the primary permeated water w2 is sent to the first decarboxylation means 31 via the primary permeated water channel L3. Further, the primary concentrated water w3 is sent to the concentrated water tank 8 via the water channel L5.

濃縮水槽８に送られた一次濃縮水ｗ３は、更に水路Ｌ６を介して第２の逆浸透膜４に送られるが、その前に、水質調整手段４２によって一次濃縮水ｗ３の水質を調整する。一次濃縮水ｗ３は、第１の逆浸透膜分離工程において不純物が濃縮された水であるため、カルシウム、シリカ、炭酸イオンといった不純物が比較的高い濃度で含まれており、スケールが生成しやすい水質になっている。特に、第２の逆浸透膜分離工程においてスケールが生成すると、スケールによって膜の閉塞が起きてしまう。このため、予め、一次濃縮水ｗ３の水質調整を行う。具体的には、一次濃縮水ｗ３を酸性に、例えばｐＨ５．５以下に調整するとともに、スケール分散剤を添加する。一次濃縮水ｗ３のｐＨを下げることでスケールの析出が抑制される。また、スケール分散剤を添加しておくことで、仮にスケールが生成してしまった場合でもスケールを凝集させずに膜の閉塞が防止される。なお、一次濃縮水ｗ３中でのスケール生成の可能性が低いと見込まれる場合は、一次濃縮水ｗ３の水質調整は省略してもよい。 The primary concentrated water w3 sent to the concentrated water tank 8 is further sent to the second reverse osmosis membrane 4 via the water channel L6, but before that, the water quality of the primary concentrated water w3 is adjusted by the water quality adjusting means 42. Since the primary concentrated water w3 is water in which impurities are concentrated in the first reverse osmosis membrane separation step, impurities such as calcium, silica, and carbonate ions are contained in a relatively high concentration, and the water quality is such that scale is easily generated. It has become. In particular, when scale is generated in the second reverse osmosis membrane separation step, the scale causes membrane blockage. Therefore, the water quality of the primary concentrated water w3 is adjusted in advance. Specifically, the primary concentrated water w3 is adjusted to be acidic, for example, pH 5.5 or less, and a scale dispersant is added. By lowering the pH of the primary concentrated water w3, the precipitation of scale is suppressed. Further, by adding the scale dispersant, even if the scale is generated, the scale is not aggregated and the film is prevented from being blocked. If the possibility of scale formation in the primary concentrated water w3 is expected to be low, the water quality adjustment of the primary concentrated water w3 may be omitted.

次に、第２の逆浸透膜分離工程では、一次濃縮水ｗ３を、二次透過水ｗ４と二次濃縮水ｗ５に分離する。一次濃縮水ｗ３は、第２の逆浸透膜４によって不純物が除去されて二次透過水ｗ４とされる。また、除去された不純物は二次濃縮水ｗ５に含有される。そして、二次透過水ｗ４は水路Ｌ７に送られる。一方、二次濃縮水ｗ５は水路Ｌ１２を介して純水製造装置１から排出される。 Next, in the second reverse osmosis membrane separation step, the primary concentrated water w3 is separated into the secondary permeated water w4 and the secondary concentrated water w5. Impurities are removed from the primary concentrated water w3 by the second reverse osmosis membrane 4 to obtain the secondary permeated water w4. Further, the removed impurities are contained in the secondary concentrated water w5. Then, the secondary permeated water w4 is sent to the water channel L7. On the other hand, the secondary concentrated water w5 is discharged from the pure water production apparatus 1 via the water channel L12.

第２の逆浸透膜分離工程によって一次濃縮水ｗ３から二次透過水ｗ４を分離することで、一次濃縮水ｗ３よりも不純物量が低減された二次透過水ｗ４が得られる。この二次透過水ｗ４は、不純物濃度が低くスケールが析出しにくいため、冷却塔５において冷却水として利用されたとしても、冷却塔５の配管内においてスケールを生成させることがなく、目詰まりを起こすおそれが少ない。 By separating the secondary permeated water w4 from the primary concentrated water w3 by the second reverse osmosis membrane separation step, the secondary permeated water w4 having a smaller amount of impurities than the primary concentrated water w3 can be obtained. Since the secondary permeated water w4 has a low impurity concentration and scale is difficult to precipitate, even if it is used as cooling water in the cooling tower 5, scale is not generated in the piping of the cooling tower 5 and clogging occurs. There is little risk of waking up.

次に、二次透過水供給工程では、二次透過水ｗ４を冷却水として冷却塔５に供給するとともに、二次透過水ｗ４の余剰分を返送手段６によって原水として原水槽２ａに返送する。冷却塔５における冷却水の需要量は季節変動があり、気温や水温が比較的高くなる夏期では冷却塔５における冷却水の需要量が増大し、一方、気温や水温が比較的低くなる冬期では冷却塔５における冷却水の需要量が減少する。また、二次透過水ｗ４の生産量も、様々な要因で変動し得る。このような要因として例えば、水不足による原水ｗ１の取水制限、コスト削減のための原水ｗ１の使用量の減少、環境負荷軽減のための原水ｗ１の使用量の減少などが挙げられる。そこで、第２の逆浸透膜４における二次透過水ｗ４の生産量が冷却塔５における二次透過水ｗ４の需要量を超える場合には、二次透過水ｗ４の余剰分を、返送手段６によって原水として返送することとする。 Next, in the secondary permeated water supply step, the secondary permeated water w4 is supplied to the cooling tower 5 as cooling water, and the surplus of the secondary permeated water w4 is returned to the raw water tank 2a as raw water by the return means 6. The demand for cooling water in the cooling tower 5 fluctuates seasonally, and in the summer when the temperature and water temperature are relatively high, the demand for cooling water in the cooling tower 5 increases, while in the winter when the temperature and water temperature are relatively low. The demand for cooling water in the cooling tower 5 is reduced. In addition, the production amount of the secondary permeated water w4 can also fluctuate due to various factors. Examples of such factors include restrictions on the intake of raw water w1 due to water shortage, a decrease in the amount of raw water w1 used for cost reduction, and a decrease in the amount of raw water w1 used for reducing the environmental load. Therefore, when the production amount of the secondary permeated water w4 in the second reverse osmosis membrane 4 exceeds the demand amount of the secondary permeated water w4 in the cooling tower 5, the surplus amount of the secondary permeated water w4 is returned by the returning means 6. Will be returned as raw water.

具体的には、制御装置７ｂが、冷却塔５における冷却水（二次透過水ｗ４）の使用量を監視する。二次透過水ｗ４の供給量が不足する場合は、制御装置７ｂが流量調整弁７ａを制御して冷却水供給路Ｌ８における二次透過水ｗ４の流量を増加させる。一方、二次透過水ｗ４の供給量が過剰な場合は、制御装置７ｂが流量調整弁７ａを制御して冷却水供給路Ｌ８における二次透過水ｗ４の流量を減少させる。 Specifically, the control device 7b monitors the amount of cooling water (secondary permeated water w4) used in the cooling tower 5. When the supply amount of the secondary permeated water w4 is insufficient, the control device 7b controls the flow rate adjusting valve 7a to increase the flow rate of the secondary permeated water w4 in the cooling water supply path L8. On the other hand, when the supply amount of the secondary permeated water w4 is excessive, the control device 7b controls the flow rate adjusting valve 7a to reduce the flow rate of the secondary permeated water w4 in the cooling water supply path L8.

二次透過水ｗ４の流量を減少させると、余剰の二次透過水ｗ４が発生する。この余剰の二次透過水ｗ４は、水路Ｌ７から分岐する返送路Ｌ９に流入し、原水槽２ａに送られる。返送路Ｌ９は、流量調整弁７ａよりも上流側にあるため、流量調整弁７ａが二次透過水ｗ４の流量を減少させると、二次透過水ｗ４が返送路Ｌ９にも流入するようになる。 When the flow rate of the secondary permeated water w4 is reduced, excess secondary permeated water w4 is generated. The surplus secondary permeated water w4 flows into the return channel L9 branching from the channel L7 and is sent to the raw water tank 2a. Since the return path L9 is on the upstream side of the flow rate adjusting valve 7a, when the flow rate adjusting valve 7a reduces the flow rate of the secondary permeated water w4, the secondary permeated water w4 also flows into the return path L9. ..

原水槽２ａに戻された二次透過水ｗ４は、原水ｗ１として再び第１の逆浸透膜３に送られ、第１の逆浸透膜分離工程によって処理され、一次透過水ｗ２及び一次濃縮水ｗ３が生成される。 The secondary permeated water w4 returned to the raw water tank 2a is sent to the first reverse osmosis membrane 3 again as raw water w1, treated by the first reverse osmosis membrane separation step, and the primary permeated water w2 and the primary concentrated water w3. Is generated.

次に、第１の逆浸透膜分離工程において分離された一次透過水ｗ２は、一次透過水路Ｌ３を介して第１脱炭酸手段３１に送られる。第１脱炭酸手段３１では、第１脱炭酸工程を行う。第１脱炭酸工程では、一次透過水ｗ２を脱炭酸処理することで、一次透過水ｗ２中に溶存する二酸化炭素を一次透過水ｗ２から除去する。 Next, the primary permeated water w2 separated in the first reverse osmosis membrane separation step is sent to the first decarboxylation means 31 via the primary permeated water channel L3. In the first decarboxylation means 31, the first decarboxylation step is performed. In the first decarboxylation step, carbon dioxide dissolved in the primary permeated water w2 is removed from the primary permeated water w2 by decarboxylating the primary permeated water w2.

次いで、電気脱イオン工程では、第１脱炭酸工程後の一次透過水ｗ２に対して脱イオン処理することにより、残存する不純物を更に除去する。電気脱イオン工程では、一次透過水ｗ２に対して脱イオン処理することによって、不純物が濃縮された濃縮水ｗ６が生成する。この濃縮水ｗ６は、水路Ｌ１０を介して原水槽２ａに戻され、原水ｗ１として再び第１の逆浸透膜３に送られ、第１の逆浸透膜分離工程によって処理される。一方、脱イオン処理された一次透過水ｗ２は、水路Ｌ１１を介してユースポイントに送られ、純水として利用される。 Next, in the electrodeionization step, the remaining impurities are further removed by deionizing the primary permeated water w2 after the first decarboxylation step. In the electrodeionization step, the primary permeated water w2 is deionized to produce concentrated water w6 in which impurities are concentrated. The concentrated water w6 is returned to the raw water tank 2a via the water channel L10, sent again as raw water w1 to the first reverse osmosis membrane 3, and treated by the first reverse osmosis membrane separation step. On the other hand, the deionized primary permeated water w2 is sent to the use point via the water channel L11 and used as pure water.

以上説明したように、本実施形態の純水製造装置１によれば、第２の逆浸透膜４における二次透過水ｗ４の生産量が、冷却塔５における二次透過水ｗ４の需要量を超える場合に、二次透過水ｗ４の余剰分を原水槽２ａに返送する返送手段６が備えられているので、余剰の二次透過水ｗ４を廃棄することなく有効利用することができる。 As described above, according to the pure water production apparatus 1 of the present embodiment, the production amount of the secondary permeated water w4 in the second reverse osmosis membrane 4 determines the demand amount of the secondary permeated water w4 in the cooling tower 5. When the amount exceeds the limit, the return means 6 for returning the surplus of the secondary permeated water w4 to the raw water tank 2a is provided, so that the surplus secondary permeated water w4 can be effectively used without being discarded.

また、本実施形態の純水製造装置１によれば、返送手段６が、二次透過水ｗ４を原水槽２ａに返送する返送路Ｌ９と、冷却水供給路Ｌ８に流す二次透過水ｗ４の流量を制御する流量制御手段７とから構成されているので、冷却塔５への二次透過水ｗ４の供給量と、原水槽２ａへの二次透過水ｗ４の返送量とを最適な割合に調整することができ、水の有効利用を図ることができる。 Further, according to the pure water production apparatus 1 of the present embodiment, the return means 6 has a return path L9 for returning the secondary permeated water w4 to the raw water tank 2a and a secondary permeated water w4 flowing through the cooling water supply path L8. Since it is composed of the flow rate control means 7 for controlling the flow rate, the supply amount of the secondary permeated water w4 to the cooling tower 5 and the return amount of the secondary permeated water w4 to the raw water tank 2a are set to the optimum ratio. It can be adjusted and effective use of water can be achieved.

更にまた、本実施形態の純水製造装置１によれば、第１の逆浸透膜３を透過した一次透過水ｗ２が流れる一次透過水路Ｌ３、Ｌ４に、第１脱炭酸手段３１と電気脱イオン装置３２とが更に備えられているので、一次透過水ｗ２の不純物量を更に低減することができ、高純度の純水を製造できる。 Furthermore, according to the pure water production apparatus 1 of the present embodiment, the first decarbonizing means 31 and electrodeionization are carried out in the primary permeation channels L3 and L4 through which the primary permeation water w2 that has permeated the first reverse osmosis membrane 3 flows. Since the device 32 is further provided, the amount of impurities in the primary permeated water w2 can be further reduced, and high-purity pure water can be produced.

次に、本実施形態純水製造方法によれば、第２の逆浸透膜４における二次透過水ｗ４の生産量が、冷却塔５における二次透過水ｗ４の需要量を超える場合に、二次透過水ｗ４の余剰分を原水槽２ａに返送する二次透過水供給工程が備えられているので、余剰の二次透過水ｗ４を廃棄することなく有効利用することができる。 Next, according to the pure water production method of the present embodiment, when the production amount of the secondary permeated water w4 in the second reverse osmosis membrane 4 exceeds the demand amount of the secondary permeated water w4 in the cooling tower 5, the second Since the secondary permeated water supply step of returning the surplus of the secondary permeated water w4 to the raw water tank 2a is provided, the surplus secondary permeated water w4 can be effectively used without being discarded.

また、本実施形態の純水製造方法によれば、返送手段６が、二次透過水ｗ４を原水槽２ａに返送する返送路Ｌ９と、冷却水供給路Ｌ８に流す二次透過水ｗ４の流量を制御する流量制御手段７とから構成されているので、冷却塔５への二次透過水ｗ４の供給量と、原水槽２ａへの二次透過水ｗ４の返送量とを最適な割合に調整することができ、水の有効利用を図ることができる。 Further, according to the pure water production method of the present embodiment, the return means 6 returns the secondary permeated water w4 to the raw water tank 2a, and the flow rate of the secondary permeated water w4 flowing through the cooling water supply path L8. Since it is composed of the flow rate control means 7 for controlling the above, the supply amount of the secondary permeated water w4 to the cooling tower 5 and the return amount of the secondary permeated water w4 to the raw water tank 2a are adjusted to the optimum ratio. It is possible to make effective use of water.

更にまた、本実施形態の純水製造方法によれば、第１の逆浸透膜３を透過した一次透過水ｗ２に対して、第１脱炭酸工程と電気脱イオン工程とを順次行うことで、一次透過水ｗ２の不純物量を更に低減することができ、高純度の純水を製造できる。 Furthermore, according to the pure water production method of the present embodiment, the first decarboxylation step and the electrodeionization step are sequentially performed on the primary permeated water w2 that has permeated the first reverse osmosis membrane 3. The amount of impurities in the primary permeated water w2 can be further reduced, and high-purity pure water can be produced.

特に、冷却塔５における冷却水の需要量は上述したような季節変動があり、また、二次透過水ｗ４の生産量も上述したような様々な要因で変動し得る。本実施形態の純水製造装置１及び純水製造方法では、返送手段６または二次透過水供給工程によって水の有効利用を図ることで、様々な外的要因の変動があったとしても、安定して純水を製造でき、かつ、冷却塔にも冷却水を供給できる。 In particular, the demand for cooling water in the cooling tower 5 has seasonal fluctuations as described above, and the production amount of the secondary permeated water w4 may also fluctuate due to various factors as described above. In the pure water production apparatus 1 and the pure water production method of the present embodiment, the water is effectively used by the return means 6 or the secondary permeated water supply step, so that it is stable even if various external factors fluctuate. Pure water can be produced, and cooling water can be supplied to the cooling tower.

また、二次透過水ｗ４は、上水や工業用水あるいは一次濃縮水ｗ３に比べると純度が高く、一次透過水ｗ２に比べると不純物量が多いため純度が低い。例えば、前処理後の原水ｗ１の電気伝導率は１００μＳ／ｃｍ程度であり、逆浸透膜透過後の一次透過水ｗ２は１〜１０μＳ／ｃｍ程度であり、一次濃縮水ｗ３は２００〜６００μＳ／ｃｍ程度であり、二次透過水ｗ４は１０〜４０μＳ／ｃｍ程度である。このため、冷却塔５の配管等を構成する鉄や銅等の金属に対する腐食性は、一次透過水ｗ２よりも二次透過水ｗ４の方が低くなり、二次透過水ｗ４は配管等を腐食しにくい。また、上水や工業用水は、配管等においてスケールを生成する可能性があり、一方、二次透過水ｗ４はスケール生成の可能性が低い。このため、本実施形態における二次透過水ｗ４は、冷却塔５において冷却水として好適に用いることができる。 Further, the secondary permeated water w4 has a higher purity than the clean water, industrial water or the primary concentrated water w3, and has a lower purity than the primary permeated water w2 because it has a larger amount of impurities. For example, the electric conductivity of the raw water w1 after the pretreatment is about 100 μS / cm, the primary permeated water w2 after the reverse osmosis membrane permeation is about 1 to 10 μS / cm, and the primary concentrated water w3 is 200 to 600 μS / cm. The secondary permeated water w4 is about 10 to 40 μS / cm. Therefore, the corrosiveness to metals such as iron and copper constituting the pipes of the cooling tower 5 is lower in the secondary permeated water w4 than in the primary permeated water w2, and the secondary permeated water w4 corrodes the pipes and the like. It's hard to do. Further, clean water and industrial water may generate scales in pipes and the like, while secondary permeated water w4 has a low possibility of scale generation. Therefore, the secondary permeated water w4 in the present embodiment can be suitably used as cooling water in the cooling tower 5.

また、本実施形態では、原水ｗ１よりも純度高い二次透過水ｗ４を原水槽２ａに返送するので、原水槽２ａに貯留されている原水ｗ１の不純物量を低減することが出来、これにより、純水製造装置１の負担を低減させることができる。 Further, in the present embodiment, since the secondary permeated water w4 having a purity higher than that of the raw water w1 is returned to the raw water tank 2a, the amount of impurities in the raw water w1 stored in the raw water tank 2a can be reduced. The burden on the pure water production apparatus 1 can be reduced.

（第２の実施形態）
図２を参照して、本発明の第２の実施形態である純水製造装置及び純水製造方法を説明する。本実施形態の純水製造装置１０と第１の実施形態の純水製造装置１との相違点は、本実施形態の純水製造装置１０では予熱手段と加熱手段を有する点である。以下、この相違点を中心に説明する。また、図２において、図１に示す構成要素と同一の構成要素には、図１と同一の符号を付して、その説明を省略若しくは簡素化する。 (Second Embodiment)
The pure water production apparatus and the pure water production method according to the second embodiment of the present invention will be described with reference to FIG. The difference between the pure water production apparatus 10 of the present embodiment and the pure water production apparatus 1 of the first embodiment is that the pure water production apparatus 10 of the present embodiment has a preheating means and a heating means. Hereinafter, this difference will be mainly described. Further, in FIG. 2, the same components as those shown in FIG. 1 are designated by the same reference numerals as those in FIG. 1, and the description thereof will be omitted or simplified.

本実施形態の純水製造装置１０には、原水槽２ａと第１の逆浸透膜３との間の水路Ｌ２（原水供給路２）に、予熱手段１１と加熱手段１２とが備えられている。予熱手段１１は原水ｗ１を予熱して原水ｗ１の水温を上昇させ、加熱手段１２は予熱後の原水ｗ１を更に加熱して原水の水温を更に上昇させる。 In the pure water production apparatus 10 of the present embodiment, the preheating means 11 and the heating means 12 are provided in the water channel L2 (raw water supply path 2) between the raw water tank 2a and the first reverse osmosis membrane 3. .. The preheating means 11 preheats the raw water w1 to raise the water temperature of the raw water w1, and the heating means 12 further heats the raw water w1 after the preheating to further raise the water temperature of the raw water.

予熱手段１１には、二次透過水ｗ４を流す冷却水供給路Ｌ１８が引き込まれている。予熱手段１１では、原水ｗ１と二次透過水ｗ４との間で熱交換が可能とされている。これにより予熱手段１１は、冷却水供給路Ｌ１８を流れる二次透過水ｗ４を高温側流体とし、原水ｗ１を低温側流体とする熱交換器となっている。 A cooling water supply path L18 through which the secondary permeated water w4 flows is drawn into the preheating means 11. In the preheating means 11, heat exchange is possible between the raw water w1 and the secondary permeated water w4. As a result, the preheating means 11 is a heat exchanger in which the secondary permeated water w4 flowing through the cooling water supply path L18 is used as the high temperature side fluid and the raw water w1 is used as the low temperature side fluid.

加熱手段１２は、原水ｗ１を加熱するものであり、具体的には、電気ヒータまたは各種の熱交換器を用いることができる。熱交換器としては、二次透過水ｗ４以外の高温流体、例えば燃焼ガス、加熱空気、高温の油、高温水等の流体を高温流体とし、原水ｗ１を低温流体とする熱交換器を例示できる。 The heating means 12 heats the raw water w1, and specifically, an electric heater or various heat exchangers can be used. Examples of the heat exchanger include heat exchangers in which a high-temperature fluid other than the secondary permeated water w4, for example, a fluid such as combustion gas, heated air, high-temperature oil, or high-temperature water is used as the high-temperature fluid, and raw water w1 is used as the low-temperature fluid. ..

本実施形態の純水製造方法は、第１の実施形態の場合と同様に、第１の逆浸透膜分離工程、第２の逆浸透膜分離工程及び二次透過水供給工程、第１脱炭酸工程及び電気脱イオン工程を行うことで、一次透過水ｗ２を製造してこれを純水としてユースポイントに送り、また、二次透過水ｗ４を冷却塔５に送る。 The pure water production method of the present embodiment is the same as that of the first embodiment, that is, the first reverse osmosis membrane separation step, the second reverse osmosis membrane separation step, the secondary permeated water supply step, and the first decarbonation. By performing the step and the electrodeionization step, the primary permeated water w2 is produced and sent as pure water to the use point, and the secondary permeated water w4 is sent to the cooling tower 5.

ここで、本実施形態の純水製造方法では、第２の逆浸透膜分離工程によって生成した二次透過水ｗ４を、冷却水供給路Ｌ１８によって予熱手段１１に送り、予熱手段１１において原水と熱交換した後に、再び冷却水供給路Ｌ１８によって冷却塔５に送る。これにより、原水ｗ１は予熱手段１１によって予熱される。 Here, in the pure water production method of the present embodiment, the secondary permeated water w4 generated by the second reverse osmosis membrane separation step is sent to the preheating means 11 by the cooling water supply path L18, and the raw water and heat are sent in the preheating means 11. After the replacement, the water is sent to the cooling tower 5 again by the cooling water supply path L18. As a result, the raw water w1 is preheated by the preheating means 11.

また、予熱後の原水ｗ１は、加熱手段１２によって所定の温度まで加熱される。加熱されて原水ｗ１は、第１の逆浸透膜３に供給される。 Further, the raw water w1 after preheating is heated to a predetermined temperature by the heating means 12. After being heated, the raw water w1 is supplied to the first reverse osmosis membrane 3.

このように、予熱手段１１及び加熱手段１２によって原水ｗ１を加熱することで、原水ｗ１の水温調整を行うことができる。例えば、原水ｗ１の水温が比較的低くなると、原水ｗ１の粘度が低下することで逆浸透膜における有効圧力が低下し、不純物の阻止率が低下するおそれがある。そこで、原水ｗ１を予熱及び加熱することで、有効圧力の低下を防止して不純物の阻止率を高く維持することができる。 In this way, the water temperature of the raw water w1 can be adjusted by heating the raw water w1 by the preheating means 11 and the heating means 12. For example, when the water temperature of the raw water w1 becomes relatively low, the viscosity of the raw water w1 decreases, so that the effective pressure in the reverse osmosis membrane decreases, and the inhibition rate of impurities may decrease. Therefore, by preheating and heating the raw water w1, it is possible to prevent a decrease in the effective pressure and maintain a high blocking rate of impurities.

本実施形態の純水製造方法によって、加熱手段１２によって加熱された原水ｗ１から二次透過水ｗ４が得られるが、二次透過水ｗ４は、原水ｗ１が加熱された影響により、その水温が高くなっている。そこで、比較的高水温になっている二次透過水ｗ４を予熱手段１１において原水ｗ１との間で熱交換を行うことで、熱回収が行われる。また、熱回収後の二次透過水ｗ４は、水温が比較的低くなるので、冷却塔５の冷却水として好適である。 According to the pure water production method of the present embodiment, the secondary permeated water w4 can be obtained from the raw water w1 heated by the heating means 12, but the water temperature of the secondary permeated water w4 is high due to the influence of the heating of the raw water w1. It has become. Therefore, heat recovery is performed by exchanging heat between the secondary permeated water w4, which has a relatively high water temperature, and the raw water w1 in the preheating means 11. Further, since the water temperature of the secondary permeated water w4 after heat recovery is relatively low, it is suitable as cooling water for the cooling tower 5.

以上のように、本実施形態の純水製造装置１０及び純水製造方法によれば、予熱手段１１を熱交換器として利用し、冷却水供給路Ｌ１８を流れる二次透過水の熱を回収することで、加熱手段１２におけるエネルギー消費を低減できるとともに、冷却塔５に送る二次透過水ｗ４を冷却することができる。 As described above, according to the pure water production apparatus 10 and the pure water production method of the present embodiment, the preheating means 11 is used as a heat exchanger to recover the heat of the secondary permeated water flowing through the cooling water supply path L18. As a result, the energy consumption in the heating means 12 can be reduced, and the secondary permeated water w4 sent to the cooling tower 5 can be cooled.

（第３の実施形態）
図３を参照して、本発明の第３の実施形態である純水製造装置及び純水製造方法を説明する。本実施形態の純水製造装置２０と第１または第２の実施形態の純水製造装置１、１０との相違点は、本実施形態の純水製造装置２０では返送路Ｌ９に第２脱炭酸手段を有する点である。以下、この相違点を中心に説明する。また、図３において、図１及び図２に示す構成要素と同一の構成要素には、図１及び図２と同一の符号を付して、その説明を省略若しくは簡素化する。 (Third Embodiment)
The pure water production apparatus and the pure water production method according to the third embodiment of the present invention will be described with reference to FIG. The difference between the pure water production device 20 of the present embodiment and the pure water production devices 1 and 10 of the first or second embodiment is that the pure water production device 20 of the present embodiment has a second decarboxylation in the return path L9. The point is that it has means. Hereinafter, this difference will be mainly described. Further, in FIG. 3, the same components as those shown in FIGS. 1 and 2 are designated by the same reference numerals as those in FIGS. 1 and 2, and the description thereof will be omitted or simplified.

本実施形態の純水製造装置２０には、返送路Ｌ９の途中に、第２脱炭酸手段２１を配置する。第２脱炭酸手段２１は、返送中の二次透過水ｗ４を脱炭酸処理するものである。第２脱炭酸手段２１としては、二次透過水ｗ４に溶存している二酸化炭素を主に除去できるものであれば、特に限定されない。第２脱炭酸手段２１としては、例えば、中空糸膜等の脱気膜から構成される膜脱気装置や、脱炭酸塔等を用いることができる。 In the pure water production apparatus 20 of the present embodiment, the second decarboxylation means 21 is arranged in the middle of the return path L9. The second decarboxylation means 21 decarboxylates the secondary permeated water w4 being returned. The second decarboxylation means 21 is not particularly limited as long as it can mainly remove carbon dioxide dissolved in the secondary permeated water w4. As the second decarboxylation means 21, for example, a membrane degassing device composed of a degassing membrane such as a hollow fiber membrane, a decarboxylation tower, or the like can be used.

本実施形態の純水製造方法は、第１または第２の実施形態の場合と同様に、第１の逆浸透膜分離工程、第２の逆浸透膜分離工程及び二次透過水供給工程、第１脱炭酸工程及び電気脱イオン工程を行うことで、一次透過水ｗ２を製造してこれを純水としてユースポイントに送り、また、二次透過水ｗ４を冷却塔５に送る。 The pure water production method of the present embodiment is the same as in the case of the first or second embodiment, that is, the first reverse osmosis membrane separation step, the second reverse osmosis membrane separation step, and the secondary permeated water supply step. 1 By performing the decarbonization step and the electrodeionization step, the primary permeated water w2 is produced and sent as pure water to the use point, and the secondary permeated water w4 is sent to the cooling tower 5.

ここで、本実施形態の純水製造方法では、第２の逆浸透膜分離工程によって生成した二次透過水ｗ４の余剰分を、返送路Ｌ９によって原水槽２ａに返送する際に、第２脱炭酸工程として、第２脱炭酸手段２１によって二次透過水ｗ４の脱炭酸処理を行う。脱炭酸処理された二次透過水ｗ４を原水槽２ａに返送することで、原水槽２ａに貯留されている原水ｗ１の炭酸濃度を低減される。 Here, in the pure water production method of the present embodiment, when the surplus of the secondary permeated water w4 generated by the second reverse osmosis membrane separation step is returned to the raw water tank 2a by the return path L9, the second decarboxylation is performed. As the carbonization step, the secondary permeated water w4 is decarboxylated by the second decarboxylation means 21. By returning the decarboxylated secondary permeated water w4 to the raw water tank 2a, the carbonic acid concentration of the raw water w1 stored in the raw water tank 2a is reduced.

このように、本実施形態の純水製造装置２０及び純水製造方法によれば、二次透過水ｗ４を原水槽２ａに返送する際に、二次透過水ｗ４に対して第２脱炭酸工程を行うので、脱炭酸処理された二次透過水ｗ４を原水槽２ａに返送することができ、これにより原水ｗ１の炭酸濃度が減少し、第１脱炭酸手段３１における第１脱炭酸工程の負荷を軽減できる。 As described above, according to the pure water production apparatus 20 and the pure water production method of the present embodiment, when the secondary permeated water w4 is returned to the raw water tank 2a, the secondary decarboxylation step is performed on the secondary permeated water w4. Therefore, the decarboxylated secondary permeated water w4 can be returned to the raw water tank 2a, whereby the carbonic acid concentration of the raw water w1 is reduced, and the load of the first decarboxylation step in the first decarboxylation means 31 is performed. Can be reduced.

なお、本発明の純水製造装置は図１〜図３に示されたものに限定されるものではなく、例えば、第２脱炭酸手段２１を図１の純水製造装置１に適用してもよい。 The pure water production apparatus of the present invention is not limited to that shown in FIGS. 1 to 3, and for example, even if the second decarboxylation means 21 is applied to the pure water production apparatus 1 of FIG. Good.

１、１０、２０…純水製造装置、２…原水供給路、２ａ…原水槽、３…第１の逆浸透膜、４…第２の逆浸透膜、５…冷却塔、６…返送手段、７…流量制御手段、７ａ…流量調整弁、７ｂ…制御装置、１１…熱交換器（予熱手段）、１２…加熱手段、２１…第２脱炭酸手段、３１…第１脱炭酸手段、３２…電気脱イオン装置、４１…前処理装置、Ｌ３、Ｌ４…一次透過水路、Ｌ８、Ｌ１８…冷却水供給路、Ｌ９…返送路、ｗ１…原水、ｗ２…一次透過水、ｗ３…一次濃縮水、ｗ４…二次透過水、ｗ５…二次濃縮水。 1, 10, 20 ... Pure water production equipment, 2 ... Raw water supply path, 2a ... Raw water tank, 3 ... First reverse osmosis membrane, 4 ... Second reverse osmosis membrane, 5 ... Cooling tower, 6 ... Return means, 7 ... Flow control means, 7a ... Flow control valve, 7b ... Control device, 11 ... Heat exchanger (preheating means), 12 ... Heating means, 21 ... Second decarbonization means, 31 ... First decarbonization means, 32 ... Electrodeionizer, 41 ... Pretreatment device, L3, L4 ... Primary permeated water channel, L8, L18 ... Cooling water supply channel, L9 ... Return channel, w1 ... Raw water, w2 ... Primary permeated water, w3 ... Primary concentrated water, w4 ... secondary permeated water, w5 ... secondary concentrated water.

Claims (10)

原水を流す原水供給路と、
前記原水供給路から供給された前記原水を、一次透過水と一次濃縮水とに分離する第１の逆浸透膜と、
前記一次濃縮水を、二次透過水と二次濃縮水とに分離する第２の逆浸透膜と、
前記二次透過水を、冷却水として冷却塔に供給する冷却水供給路と、
前記第２の逆浸透膜における前記二次透過水の生産量が、前記冷却塔における前記二次透過水の需要量を超える場合に、前記二次透過水の余剰分を前記原水供給路に返送する返送手段と、が備えられていることを特徴とする純水製造装置。 Raw water supply channel for flowing raw water and
A first reverse osmosis membrane that separates the raw water supplied from the raw water supply channel into primary permeated water and primary concentrated water.
A second reverse osmosis membrane that separates the primary concentrated water into secondary permeated water and secondary concentrated water.
A cooling water supply path that supplies the secondary permeated water to the cooling tower as cooling water, and
When the production amount of the secondary permeated water in the second reverse osmosis membrane exceeds the demand amount of the secondary permeated water in the cooling tower, the surplus of the secondary permeated water is returned to the raw water supply channel. A pure water production apparatus characterized in that it is provided with a return means. 前記返送手段は、前記二次透過水を前記原水供給路に返送する返送路と、
前記冷却水供給路に流す前記二次透過水の流量を制御する流量制御手段と、から構成されていることを特徴とする請求項１に記載の純水製造装置。 The return means includes a return path for returning the secondary permeated water to the raw water supply path, and a return path.
The pure water production apparatus according to claim 1, further comprising a flow rate control means for controlling the flow rate of the secondary permeated water flowing through the cooling water supply path. 前記原水供給路の途中に配置されて前記原水を予熱する予熱手段と、
前記原水供給路の途中に配置されて予熱後の前記原水を加熱する加熱手段と、が更に備えられ、
前記予熱手段は、前記冷却水供給路を流れる前記二次透過水を高温側流体とし、前記原水を低温側流体とする熱交換器であることを特徴とする請求項１または請求項２に記載の純水製造装置。 A preheating means arranged in the middle of the raw water supply channel to preheat the raw water,
A heating means for heating the raw water after preheating, which is arranged in the middle of the raw water supply path, is further provided.
The first or second aspect of the present invention, wherein the preheating means is a heat exchanger in which the secondary permeated water flowing through the cooling water supply path is a high temperature side fluid and the raw water is a low temperature side fluid. Pure water production equipment. 前記第１の逆浸透膜を透過した前記一次透過水が流れる一次透過水路と、
前記一次透過水路に設置され、前記一次透過水を脱炭酸処理する第１脱炭酸手段と、
前記一次透過水路の前記第１脱炭酸手段の後段に設置され、前記第１脱炭酸手段を通過後の前記一次透過水を脱イオン処理する電気脱イオン装置と、が更に備えられていることを特徴とする請求項１乃至請求項３の何れか一項に記載の純水製造装置。 A primary permeation channel through which the primary permeate water that has permeated the first reverse osmosis membrane flows,
A first decarboxylation means that is installed in the primary permeation channel and decarboxylates the primary permeate water.
An electric deionization device installed after the first decarboxylation means of the primary permeation channel and deionizing the primary permeation water after passing through the first decarboxylation means is further provided. The pure water production apparatus according to any one of claims 1 to 3, which is characterized. 前記返送路に、前記二次透過水を脱炭酸処理する第２脱炭酸手段が備えられている請求項２乃至請求項４の何れか一項に記載の純水製造装置。 The pure water production apparatus according to any one of claims 2 to 4, wherein the return path is provided with a second decarboxylation means for decarboxylating the secondary permeated water. 原水を、第１の逆浸透膜により、一次透過水と一次濃縮水とに分離する第１の逆浸透膜分離工程と、
前記一次濃縮水を、第２の逆浸透膜により、二次透過水と二次濃縮水とに分離する第２の逆浸透膜分離工程と、
前記二次透過水を、冷却水供給路により、冷却水として冷却塔に供給するとともに、前記第２の逆浸透膜における前記二次透過水の生産量が前記冷却塔における前記二次透過水の需要量を超える場合に、前記二次透過水の余剰分を、返送手段により、前記原水として返送する二次透過水供給工程と、
が備えられていることを特徴とする純水製造方法。 A first reverse osmosis membrane separation step of separating raw water into primary permeated water and primary concentrated water by a first reverse osmosis membrane.
A second reverse osmosis membrane separation step of separating the primary concentrated water into secondary permeated water and secondary concentrated water by a second reverse osmosis membrane.
The secondary permeated water is supplied to the cooling tower as cooling water through the cooling water supply path, and the production amount of the secondary permeated water in the second reverse osmosis membrane is the secondary permeated water in the cooling tower. A secondary permeated water supply step in which the surplus of the secondary permeated water is returned as raw water by a return means when the demand amount is exceeded.
A pure water production method characterized by being provided with. 前記返送手段は、前記二次透過水を、前記原水に返送する返送路と、
前記冷却水供給路に流す前記二次透過水の流量を制御する流量制御手段とからなることを特徴とする請求項６に記載の純水製造方法。 The return means includes a return path for returning the secondary permeated water to the raw water.
The pure water production method according to claim 6, further comprising a flow rate control means for controlling the flow rate of the secondary permeated water flowing through the cooling water supply path. 前記第１の逆浸透膜への供給前の前記原水を予熱する予熱工程と、
予熱後の前記原水を加熱する加熱工程と、が更に備えられ、
前記予熱工程は、前記冷却水供給路を流れる前記二次透過水を高温側流体とし、前記原水を低温側流体とする熱交換器によって行うことを特徴とする請求項６または請求項７に記載の純水製造方法。 A preheating step of preheating the raw water before supply to the first reverse osmosis membrane, and
A heating step of heating the raw water after preheating is further provided.
The sixth or seventh aspect of the present invention, wherein the preheating step is performed by a heat exchanger in which the secondary permeated water flowing through the cooling water supply path is used as a high temperature side fluid and the raw water is used as a low temperature side fluid. Pure water production method. 前記一次透過水を、第１脱炭酸手段により、脱炭酸処理する第１脱炭酸工程と、
前記第１脱炭酸工程後の前記一次透過水を、電気脱イオン装置により、脱イオン処理する電気脱イオン工程と、が更に備えられていることを特徴とする請求項６乃至請求項８の何れか一項に記載の純水製造方法。 In the first decarboxylation step of decarboxylating the primary permeated water by the first decarboxylation means,
The first decarboxylation step the primary permeate after, electricity by deionizer, and electrodeionization step of treating demineralized, but the claims 6 to 8, characterized in that further provided The pure water production method according to any one item. 前記返送路を流れる前記二次透過水を、第２脱炭酸手段により、脱炭酸処理する第２脱炭酸工程が備えられている請求項７乃至請求項９の何れか一項に記載の純水製造方法。 The pure water according to any one of claims 7 to 9, further comprising a second decarboxylation step of decarboxylating the secondary permeated water flowing through the return path by a second decarboxylation means. Production method.
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