Pure water production system, recovery treatment water supply apparatus, and pure water production method

Abstract

To conduct production of ultra pure water easily and continuously.SOLUTION: A pure water production system includes: a pure water production apparatus 100 for producing pure water from first water to be treated by conducting water treatment by combining a plurality of water treatment apparatuses 10-1 to 10-4; a recovery treatment water production apparatus 200 including at least any of a reverse osmosis membrane apparatus and an ion exchange apparatus for producing recovery treatment water from second water to be treated; and supply lines 40-1 to 40-4 connected respectively with a part or all of the plurality of water treatment apparatuses 10-1 to 10-4 to be able to supply the recovery treatment water produced by the recovery treatment water production apparatus 200 to the plurality of water treatment apparatuses 10-1 to 10-4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pure water production system, a recovered treated water supply device, and a pure water production method. [Background technology]

[0002] In recent years, the depletion of raw water used in ultrapure water production facilities has become a problem. To address this issue, a technology has been devised in which water produced in an ultrapure water production system and used at a point-of-use is recovered and treated, and the recovered and treated water is supplied to the ultrapure water production system (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-202587 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described above involves using a pure water production system to reuse water produced in an ultrapure water production facility and used at a point-of-use. Therefore, a pure water production system must be designed to handle the worst possible wastewater quality from the point-of-use. This creates the problem of increased costs and effort required to build and install the pure water production system.

[0005] An object of the present invention is to provide an ultrapure water production system, a recovered water treatment device, and an ultrapure water production method that can easily and continuously produce ultrapure water. [Means for solving the problem]

[0006] The pure water producing system of the present invention comprises: a pure water production system that performs water treatment by combining a plurality of water treatment systems and produces pure water from first treated water; a recovered treated water producing device that includes at least one of a reverse osmosis membrane device and an ion exchange device and produces recovered treated water from the second treated water; The apparatus has a plurality of supply lines connected to some or all of the plurality of water treatment devices, respectively, so that the recovered treated water produced by the recovered treated water producing apparatus can be supplied to the plurality of water treatment devices.

[0007] In addition, the recovered treated water supply device of the present invention is a recovered treated water producing apparatus that produces recovered treated water from second treated water and supplies it to a pure water producing apparatus that produces pure water from first treated water, by combining a plurality of water treatment devices to perform water treatment; a plurality of supply lines connected to some or all of the plurality of water treatment devices so that the recovered treated water produced by the recovered treated water producing device can be supplied to the plurality of water treatment devices; a water quality acquisition unit that acquires the water quality of the recovered treated water; a supply destination determination unit that determines a water treatment device to which the recovered treated water is to be supplied based on the water quality acquired by the water quality acquisition unit; a control unit that supplies the recovered treated water via the supply line to the water treatment device determined by the supply destination determination unit, The recovered treated water producing apparatus includes at least one of a reverse osmosis membrane device and an ion exchange device.

[0008] Further, the method for producing pure water of the present invention comprises the steps of: a pure water production system that performs water treatment by combining a plurality of water treatment systems, which produces pure water from the first water to be treated; a recovered treated water producing apparatus including at least one of a reverse osmosis membrane device and an ion exchange device, producing recovered treated water from the second treated water; Obtaining the water quality of the recovered treated water, determining a water treatment device to which the recovered treated water is to be supplied based on the acquired water quality; The recovered treated water is supplied to the determined water treatment device via a supply line connected to some or all of the water treatment devices so that the recovered treated water produced by the recovered treated water manufacturing device can be supplied to the water treatment devices. [Effects of the Invention]

[0009] In the present invention, ultrapure water can be easily produced continuously. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram showing a first embodiment of a pure water producing system according to the present invention. [Figure 2] 2 is a diagram showing an example of an internal configuration of a supply unit shown in FIG. 1. FIG. [Figure 3] 2 is a diagram illustrating an example of components included in the control device illustrated in FIG. 1. FIG. [Figure 4] 2 is a flowchart for explaining an example of a pure water producing method in the pure water producing system shown in FIG. [Figure 5] FIG. 2 is a diagram showing a second embodiment of the pure water producing system of the present invention. [Figure 6] 6 is a diagram showing an example of components included in the control device shown in FIG. 5. FIG. [Figure 7] 6 is a flowchart for explaining an example of a pure water producing method in the pure water producing system shown in FIG. 5. [Figure 8] FIG. 10 is a diagram showing a third embodiment of the pure water producing system of the present invention. [Figure 9] 9 is a diagram showing an example of components included in the control device shown in FIG. 8. FIG. [Figure 10] 9 is a flowchart for explaining an example of a pure water producing method in the pure water producing system shown in FIG. 8. [Figure 11] FIG. 10 is a diagram showing a fourth embodiment of the pure water producing system of the present invention. [Figure 12] 12 is a diagram illustrating an example of components included in the control device illustrated in FIG. 11. FIG. [Figure 13] 12 is a flowchart for explaining an example of a pure water producing method in the pure water producing system shown in FIG. [Figure 14] 1 is a diagram showing an example of application of a pure water producing system according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. (First embodiment)

[0012] Figure 1 is a diagram showing a first embodiment of a pure water producing system of the present invention. As shown in Figure 1, the pure water producing system in this embodiment has a pure water producing apparatus 100 and a recovered treated water supply apparatus 500. The recovered treated water supply apparatus 500 has a recovered treated water producing apparatus 200, a measuring instrument 210, a supply section 300, a control device 400, and a plurality of supply lines 40-1 to 40-4.

[0013] The pure water production system 100 performs water treatment by combining multiple water treatment devices 10-1 to 10-4. Raw water (first water to be treated) supplied on a main line 1, which serves as the main supply path for water to be treated, is passed through the water treatment devices 10-1 to 10-4 to produce pure water. This raw water includes river water, well water, and industrial water. The pure water production system 100 supplies the produced ultrapure water to a subsystem 110. The treated water treated in the subsystem 110 is then supplied to a point of use. Note that while FIG. 1 shows an example in which there are four water treatment devices, the number is not specified. Each of the water treatment devices 10-1 to 10-4 is a device that performs a predetermined water treatment by passing supplied water (liquid) through it. Each of the water treatment devices 10-1 to 10-4 is, for example, a filtration device such as a reverse osmosis membrane device, activated carbon, ion exchange resin, ultraviolet oxidation device, desalinated water tank, or the like. The water treatment devices 10-1 to 10-4 are connected in an arrangement (order) based on the specifications of the pure water production system 100.

[0014] The recovered treated water producing apparatus 200 produces recovered treated water from second treated water, which may be, for example, water used at a point of use such as a semiconductor factory, wastewater from other factories or facilities, or treated sewage. The second treated water may also include raw water used elsewhere. The recovered treated water producing apparatus 200 produces recovered treated water by passing the second treated water through multiple water treatment devices installed inside. The multiple water treatment devices installed in the recovered treated water producing apparatus 200 may include, for example, a reverse osmosis membrane device and an ultraviolet oxidation device and an ion exchange device installed downstream of the reverse osmosis membrane device. The recovered treated water producing apparatus 200 supplies the produced recovered water to the supply unit 300. Note that the recovered water supplied from the recovered treated water producing apparatus 200 to the supply unit 300 may be treated water treated by not only all of the multiple water treatment devices installed in the recovered treated water producing apparatus 200, but also some of the water treatment devices. Furthermore, from the viewpoint of supplying the recovered treated water to an ultrapure water production system, it is preferable that the recovered treated water production system 200 is equipped with at least one of a reverse osmosis membrane device and an ion exchange device such as an ion exchange resin tower or an electrical deionized water production system (EDI).

[0015] The measuring device 210 measures the water quality of the treated water produced by the recovered treated water producing apparatus 200. The water quality measured by the measuring device 210 is the content or percentage of TOC (Total Organic Carbon), urea, or boron contained in the recovered treated water, or the electrical conductivity. The measuring device 210 not only measures the water quality of the treated water supplied from the recovered treated water producing apparatus 200 to the supply unit 300, but may also measure the water quality of the treated water treated by any of the multiple water treatment devices provided in the recovered treated water producing apparatus 200. The measuring device 210 notifies the control device 400 of a value indicating the measured water quality. A single measuring device 210 may be provided, or multiple measuring devices 210 may be provided to measure the water quality of the treated water treated by any of the multiple water treatment devices provided in the recovered treated water producing apparatus 200. The measuring device 210 measures these water qualities online and notifies the control device 400.

[0016] The supply unit 300 supplies the recovered treated water supplied from the recovered treated water producing apparatus 200 to any one of the plurality of water treatment devices 10-1 to 10-4 of the pure water producing apparatus 100. The supply unit 300 has supply lines 40-1 to 40-4, which are piping connected to the water treatment devices 10-1 to 10-4, respectively, so that the recovered treated water supplied from the recovered treated water producing apparatus 200 can be supplied to the water treatment devices 10-1 to 10-4. FIG. 2 is a diagram showing an example of the internal configuration of the supply unit 300 shown in FIG. 1. As shown in FIG. 2, the supply unit 300 shown in FIG. 1 is provided with valves 30-1 to 30-4 on the supply lines 40-1 to 40-4, respectively. The valves 30-1 to 30-4 are control units that control the supply of recovered treated water to the water treatment devices 10-1 to 10-4 via the supply lines 40-1 to 40-4, respectively. The valve 30-1 controls the supply of recovered treated water to the water treatment device 10-1 via the supply line 40-1. Valve 30-2 controls the supply of recovered treated water to water treatment device 10-2 via supply line 40-2. Valve 30-3 controls the supply of recovered treated water to water treatment device 10-3 via supply line 40-3. Valve 30-4 controls the supply of recovered treated water to water treatment device 10-4 via supply line 40-4. Each of valves 30-1 to 30-4 opens and closes based on a control signal transmitted from control device 400.

[0017] The control device 400 controls the opening and closing of each of the valves 30-1 to 30-4 shown in Fig. 2. Fig. 3 is a diagram showing an example of components included in the control device 400 shown in Fig. 1. As shown in Fig. 3, the control device 400 shown in Fig. 1 has a water quality acquisition unit 410 and a supply destination determination unit 420. Of the components included in the control device 400 shown in Fig. 1, Fig. 3 shows only the main components related to this embodiment.

[0018] The water quality acquisition unit 410 acquires the water quality of the recovered treated water produced by the recovered treated water producing apparatus 200. Specifically, the water quality acquisition unit 410 acquires a value indicating the water quality notified by the measuring device 210. If the measuring device 210 is not provided, the water quality acquisition unit 410 may acquire a portion of the recovered treated water supplied from the recovered treated water producing apparatus 200 to the supply unit 300 and measure the water quality of the acquired portion of the recovered treated water using a water quality measuring device. The water quality acquisition unit 410 acquires at least one of the TOC value, the urea content or content rate, and the conductivity value as the water quality value. The water quality acquisition unit 410 notifies the supply destination determination unit 420 of the acquired water quality value.

[0019] The supply destination determination unit 420 determines water treatment devices 10-1 to 10-4 to which the recovered treated water from the recovered treated water producing apparatus 200 will be supplied, based on the water quality value notified by the water quality acquisition unit 410. The supply destination determination unit 420 may previously associate water quality values ​​with water treatment devices as supply destinations, and when notified of the water quality value from the water quality acquisition unit 410, determine the water treatment device associated with the notified water quality value as the supply destination of the recovered treated water. The supply destination determination unit 420 transmits control signals to each of the valves 30-1 to 30-4 to control the opening and closing of each of the valves 30-1 to 30-4 so that the recovered treated water is supplied to the determined water treatment devices 10-1 to 10-4 as supply destinations. The supply destination determination unit 420 may also issue a notification to prompt control (opening and closing control) of each of the valves 30-1 to 30-4 to supply the recovered treated water to the determined water treatment devices 10-1 to 10-4 as supply destinations. This notification may be, for example, a display prompting control of each of valves 30-1 to 30-4, or the transmission of a signal indicating this to another device. This allows the operator who receives this notification to open or close valves 30-1 to 30-4. Furthermore, supply destination determination unit 420 may notify only device identification information indicating each of the determined supply destination water treatment devices 10-1 to 10-4, or valve identification information indicating each of valves 30-1 to 30-4. Depending on the water quality value notified by water quality acquisition unit 410, supply destination determination unit 420 may decide not to supply the recovered treated water supplied from recovered treated water manufacturing apparatus 200 to any of water treatment devices 10-1 to 10-4.

[0020] The following describes a method for producing ultrapure water in the pure water producing system shown in Fig. 1. Fig. 4 is a flowchart for explaining an example of a method for producing pure water in the pure water producing system shown in Fig. 1. This process is mainly performed by the control device 400 shown in Fig. 1.

[0021] First, the quality of the recovered treated water produced by the recovered treated water producing apparatus 200 is measured (step S1). A water quality measuring device provided in the control device 400 may measure the quality of a portion of the recovered treated water supplied from the recovered treated water producing apparatus 200 to the supply unit 300, or the measuring device 210 may measure the water quality. Next, the water quality acquiring unit 410 acquires the measured water quality value (step S2). The water quality acquiring unit 410 notifies the supply destination determining unit 420 of the acquired water quality value. Then, the supply destination determining unit 420 determines the water treatment devices 10-1 to 10-4 to which the recovered treated water will be supplied based on the water quality value notified by the water quality acquiring unit 410 (step S3). Then, the supply destination determining unit 420 controls the opening and closing of the valves 30-1 to 30-4 so that the recovered treated water is supplied to the water treatment devices 10-1 to 10-4 determined as the supply destinations of the recovered treated water (step S4).

[0022] A specific example of the processing of step S4 will be described. For example, if the supply destination determination unit 420 determines water treatment device 10-1 as the supply destination of the recovered treated water, the supply destination determination unit 420 controls valve 30-1 to open and valves 30-2 to 30-4 to close. If the supply destination determination unit 420 determines water treatment device 10-2 as the supply destination of the recovered treated water, the supply destination determination unit 420 controls valve 30-2 to open and valves 30-1, 30-3, and 30-4 to close. If the supply destination determination unit 420 determines water treatment device 10-3 as the supply destination of the recovered treated water, the supply destination determination unit 420 controls valve 30-3 to open and valves 30-1, 30-2, and 30-4 to close. Furthermore, when the supply destination determination unit 420 determines the water treatment device 10-4 as the supply destination of the recovered treated water, the supply destination determination unit 420 controls the valve 30-4 to be open and the valves 30-1 to 30-3 to be closed. Note that the supply destination determination unit 420 may determine a plurality of water treatment devices as the supply destinations of the recovered treated water.

[0023] As described above, in this embodiment, the recovered treated water production system 200 supplies recovered treated water produced from water such as service water, wastewater, and sewage to one of the water treatment devices constituting the pure water production system 100. At this time, the destination water treatment device is determined based on the quality of the recovered treated water to be supplied, and the recovered treated water is supplied to the determined water treatment device. In this way, by supplying recovered treated water that has been reused from water used in other facilities or factories to the pure water production system 100, it is possible to easily and continuously produce ultrapure water via the subsystem 110. Furthermore, by supplying the recovered treated water to a water treatment device that performs a water treatment process according to the quality of the recovered treated water, the recovered treated water can be reused through a route appropriate for the water quality of the recovered treated water. (Second embodiment)

[0024] Figure 5 is a diagram showing a second embodiment of the pure water producing system of the present invention. As shown in Figure 5, the pure water producing system in this embodiment has a pure water producing apparatus 100 and a recovered treated water supply apparatus 501. The recovered treated water supply apparatus 501 has a recovered treated water producing apparatus 200, a measuring device 210, a supply section 300, a control device 401, and a plurality of supply lines 40-1 to 40-4. The pure water producing apparatus 100, the recovered treated water producing apparatus 200, the measuring device 210, the supply section 300, and the supply lines 40-1 to 40-4 are each the same as those in the first embodiment.

[0025] Control device 401 controls the opening and closing of each of valves 30-1 to 30-4 shown in FIG. 2 that are provided in supply unit 300. FIG. 6 is a diagram showing an example of components included in control device 401 shown in FIG. 5. As shown in FIG. 6, control device 401 shown in FIG. 5 has a water quality acquisition unit 411, a supply destination determination unit 421, and a supply amount calculation unit 431. In addition to the functions included in water quality acquisition unit 410 in the first embodiment, water quality acquisition unit 411 has a function of notifying supply amount calculation unit 431 of the acquired water quality value. In addition to the functions included in supply destination determination unit 420 in the first embodiment, supply destination determination unit 421 transmits a control signal to each of valves 30-1 to 30-4 to control the opening and closing of each of valves 30-1 to 30-4 based on the supply amount notified by supply amount calculation unit 431. The supply destination determination unit 421 may issue a notification urging the control (open / close control) of each of the valves 30-1 to 30-4 to supply the recovered treated water at the supply amount notified by the supply amount calculation unit 431 to the determined water treatment devices 10-1 to 10-4 as the supply destinations. This notification may be, for example, a display prompting the control of each of the valves 30-1 to 30-4 or the transmission of a signal indicating this to another device. This allows the operator who receives this notification to open or close the valves 30-1 to 30-4. The supply destination determination unit 421 may also notify only information indicating the supply amount notified by the supply amount calculation unit 431, device identification information indicating each of the determined water treatment devices 10-1 to 10-4 as the supply destinations, and valve identification information indicating each of the valves 30-1 to 30-4. Note that FIG. 6 shows only the main components related to this embodiment among the components included in the control device 401 shown in FIG. 5.

[0026] The supply amount calculation unit 431 calculates the amount of recovered treated water to be supplied by the supply unit 300 to the water treatment devices 10-1 to 10-4 based on the water quality value notified by the water quality acquisition unit 411. The supply amount calculation unit 431 may previously associate the water quality value with the amount of recovered treated water to be supplied by the supply unit 300 to the water treatment devices 10-1 to 10-4, and when notified of the water quality value by the water quality acquisition unit 410, calculate the amount of recovered treated water associated with the notified water quality value as the amount of recovered treated water to be supplied to the water treatment devices 10-1 to 10-4. Alternatively, the supply amount calculation unit 431 may use a predetermined formula to calculate the amount of recovered treated water to be supplied by the supply unit 300 to the water treatment devices 10-1 to 10-4 from the water quality value notified by the water quality acquisition unit 411. For example, the supply amount calculation unit 431 calculates a smaller amount of recovered treated water to be supplied by the supply unit 300 to the water treatment devices 10-1 to 10-4 as the water quality value notified by the water quality acquisition unit 411 indicates a worsening of the water quality. Furthermore, the supply amount calculation unit 431 may calculate the amount of recovered treated water to be supplied to the supply destination based on the water quality value notified by the water quality acquisition unit 411, taking into consideration the supply destination determined by the supply destination determination unit 421. The supply amount calculation unit 431 notifies the supply destination determination unit 421 of the calculated supply amount.

[0027] The following describes a method for producing pure water in the pure water producing system shown in Fig. 5. Fig. 7 is a flowchart for explaining an example of the method for producing pure water in the pure water producing system shown in Fig. 5. This process is mainly performed by the control device 401 shown in Fig. 5.

[0028] First, the quality of the recovered treated water produced by the recovered treated water producing apparatus 200 is measured (step S11). A water quality measuring device provided in the control device 401 may measure the quality of a portion of the recovered treated water supplied from the recovered treated water producing apparatus 200 to the supply unit 300, or the measuring device 210 may measure the water quality. Next, the water quality acquiring unit 411 acquires the measured water quality value (step S12). The water quality acquiring unit 411 notifies the supply destination determining unit 421 and the supply amount calculating unit 431 of the acquired water quality value. Then, the supply destination determining unit 421 determines the water treatment device 10-1 to 10-4 to which the recovered treated water will be supplied based on the water quality value notified by the water quality acquiring unit 411 (step S13). Furthermore, based on the water quality value notified by the water quality acquisition unit 411, the supply amount calculation unit 431 calculates the supply amount of recovered treated water to be supplied to the water treatment devices 10-1 to 10-4 determined by the supply destination determination unit 421 (step S14). The supply amount calculation unit 431 notifies the supply destination determination unit 421 of the calculated supply amount. Then, the supply destination determination unit 421 controls the opening and closing of the valves 30-1 to 30-4 so that the supply amount notified by the supply amount calculation unit 431 is supplied to the water treatment devices 10-1 to 10-4 determined as the supply destinations in step S13.

[0029] A specific example of the processing in step S15 will be described. For example, when supply destination determination unit 421 determines water treatment device 10-1 as the supply destination of the recovered treated water, supply destination determination unit 421 controls valve 30-1 to be open for a period of time that allows the supply amount notified by supply amount calculation unit 431 to be supplied, and controls valves 30-2 to 30-4 to be closed. Also, when supply destination determination unit 421 determines water treatment device 10-2 as the supply destination of the recovered treated water, supply destination determination unit 421 controls valve 30-2 to be open for a period of time that allows the supply amount notified by supply amount calculation unit 431 to be supplied, and controls valves 30-1, 30-3, and 30-4 to be closed. Furthermore, when the supply destination determination unit 421 determines water treatment device 10-3 as the supply destination of the recovered treated water, it controls valve 30-3 to be open for a period of time during which the supply amount notified by supply amount calculation unit 431 can be supplied, and controls valves 30-1, 30-2, and 30-4 to be closed. When the supply destination determination unit 421 determines water treatment device 10-4 as the supply destination of the recovered treated water, it controls valve 30-4 to be open for a period of time during which the supply amount notified by supply amount calculation unit 431 can be supplied, and controls valves 30-1 to 30-3 to be closed.

[0030] As described above, in this embodiment, the recovered treated water production system 200 supplies recovered treated water produced from water such as service water, wastewater, and sewage to one of the water treatment devices constituting the pure water production system 100. The destination water treatment device is determined based on the quality of the recovered treated water to be supplied, and the recovered treated water is supplied to the determined water treatment device. Furthermore, the amount of recovered treated water to be supplied to the destination water treatment device is calculated based on the quality of the recovered treated water to be supplied, and the calculated amount of recovered treated water is supplied to the destination water treatment device. In this way, by supplying recovered treated water that has been reused from other facilities or factories to the pure water production system 100, ultrapure water can be easily and continuously produced via the subsystem 110. Furthermore, by supplying the recovered treated water to a water treatment device that performs a water treatment process appropriate for the quality of the recovered treated water, the recovered treated water can be reused in a route and amount appropriate for the water quality of the recovered treated water. (Third embodiment)

[0031] Figure 8 is a diagram showing a third embodiment of the pure water manufacturing system of the present invention. As shown in Figure 8, the pure water manufacturing system in this embodiment has a pure water manufacturing apparatus 100 and a recovered treated water supply apparatus 502. The recovered treated water supply apparatus 502 has a recovered treated water manufacturing apparatus 200, a measuring device 210, a supply section 300, a control device 402, and a plurality of supply lines 40-1 to 40-4. The pure water manufacturing apparatus 100, the recovered treated water manufacturing apparatus 200, the measuring device 210, the supply section 300, and the supply lines 40-1 to 40-4 are each the same as those in the first embodiment.

[0032] Control device 402 controls the opening and closing of each of valves 30-1 to 30-4 shown in FIG. 2. Control device 402 also controls the operation of water treatment devices 10-1 to 10-4. FIG. 9 is a diagram showing an example of components included in control device 402 shown in FIG. 8. As shown in FIG. 9, control device 402 shown in FIG. 8 has a water quality acquisition unit 410, a supply destination determination unit 422, and an operation control unit 442. Water quality acquisition unit 410 is the same as that in the first embodiment. In addition to the functions of supply destination determination unit 420 in the first embodiment, supply destination determination unit 422 notifies operation control unit 442 of the determined water treatment devices 10-1 to 10-4 as supply destinations. Note that FIG. 9 shows only the main components related to this embodiment among the components included in control device 402 shown in FIG. 8.

[0033] The operation control unit 442 controls the operation of a water treatment device located upstream of the water treatment device determined by the supply destination determination unit 422 as the supply destination of the recovered treated water. For example, when the water treatment device determined by the supply destination determination unit 422 as the supply destination of the recovered treated water, as notified by the supply destination determination unit 422, is water treatment device 10-2, the operation control unit 442 controls the operation of water treatment device 10-1 located upstream of water treatment device 10-2. This control may start / stop the operation of the water treatment device, or may operate it intermittently. In this control, control signals for operating the water treatment devices 10-1 to 10-4 are transmitted, and the operation of the water treatment devices 10-1 to 10-4 is controlled based on the transmitted control signals. The operation control unit 442 may also control the operation of a water treatment device located upstream of the water treatment device determined by the supply destination determination unit 422 as the supply destination of the recovered treated water, based on the water quality acquired by the water quality acquisition unit 410. In this case, the operation control unit 442 determines, based on the water quality acquired by the water quality acquisition unit 410, whether it is better to stop the operation of the water treatment device located upstream of the water treatment device determined by the supply destination determination unit 422 as the supply destination of the recovered treated water, and if it determines that it is better to stop the operation, performs control to stop the operation. For example, if the water quality acquired by the water quality acquisition unit 410 is higher than a predetermined threshold, the operation control unit 442 stops the operation of the upstream water treatment device if it determines that it is better to supply the recovered treated water to the water treatment device determined by the supply destination determination unit 422 as the supply destination of the recovered treated water rather than water from the upstream water treatment device. Note that the operation control unit 442 may control the operation of multiple water treatment devices (for example, all water treatment devices located upstream of the water treatment device determined by the supply destination determination unit 422 as the supply destination of the recovered treated water).

[0034] The following describes a method for producing pure water in the pure water producing system shown in Fig. 8. Fig. 10 is a flowchart for explaining an example of the method for producing pure water in the pure water producing system shown in Fig. 8. This process is mainly performed by the control device 402 shown in Fig. 8.

[0035] First, the quality of the recovered treated water produced by the recovered treated water producing apparatus 200 is measured (step S21). A water quality measuring device provided in the control device 402 may measure the quality of a portion of the recovered treated water supplied from the recovered treated water producing apparatus 200 to the supply unit 300, or the measuring device 210 may measure the water quality. Next, the water quality acquiring unit 410 acquires the measured water quality value (step S22). The water quality acquiring unit 410 notifies the supply destination determining unit 422 of the acquired water quality value. The supply destination determining unit 422 then determines the water treatment devices 10-1 to 10-4 to which the recovered treated water will be supplied based on the water quality value notified by the water quality acquiring unit 410 (step S23). The supply destination determining unit 422 notifies the operation control unit 442 of the water treatment devices 10-1 to 10-4 determined to be the supply destinations of the recovered treated water. Then, operation control unit 442 controls the operation of the water treatment device located upstream of the water treatment device notified by supply destination determination unit 422 (step S24). The method for controlling this operation is as described above. Furthermore, supply destination determination unit 422 controls the opening and closing of valves 30-1 to 30-4 so that the recovered treated water is supplied to water treatment devices 10-1 to 10-4 determined as the supply destination in step S23 (step S25).

[0036] A specific example of the processing of step S25 will be described. For example, if the supply destination determination unit 422 determines water treatment device 10-1 as the supply destination of the recovered treated water, the supply destination determination unit 422 controls valve 30-1 to open and valves 30-2 to 30-4 to close. If the supply destination determination unit 422 determines water treatment device 10-2 as the supply destination of the recovered treated water, the supply destination determination unit 422 controls valve 30-2 to open and valves 30-1, 30-3, and 30-4 to close. If the supply destination determination unit 422 determines water treatment device 10-3 as the supply destination of the recovered treated water, the supply destination determination unit 422 controls valve 30-3 to open and valves 30-1, 30-2, and 30-4 to close. Furthermore, when the supply destination determination unit 422 determines the water treatment device 10-4 as the supply destination of the recovered treated water, the supply destination determination unit 422 controls the valve 30-4 to be open and the valves 30-1 to 30-3 to be closed.

[0037] As described above, in this embodiment, the recycled water production system 200 supplies recycled water produced from water such as service water, wastewater, and sewage to one of the water treatment devices constituting the pure water production system 100. The destination water treatment device is determined based on the quality of the recycled water to be supplied, and the recycled water is supplied to the determined water treatment device. Furthermore, the operation of a water treatment device located upstream of the destination water treatment device is controlled based on the quality of the recycled water to be supplied. In this way, by supplying recycled water reused from other facilities or factories to the pure water production system 100, ultrapure water can be easily and continuously produced via the subsystem 110. Furthermore, by supplying the recycled water to a water treatment device that performs a water treatment process appropriate for the quality of the recycled water, the recycled water can be reused through a route appropriate for the water quality of the recycled water. Furthermore, the operation of unnecessary water treatment devices can be stopped. (Fourth embodiment)

[0038] Figure 11 is a diagram showing a fourth embodiment of the pure water manufacturing system of the present invention. As shown in Figure 11, the pure water manufacturing system in this embodiment has a pure water manufacturing apparatus 100 and a recovered treated water supply apparatus 503. The recovered treated water supply apparatus 503 has a recovered treated water manufacturing apparatus 200, a measuring device 210, a supply section 300, a control device 403, and a plurality of supply lines 40-1 to 40-4. The pure water manufacturing apparatus 100, the recovered treated water manufacturing apparatus 200, the measuring device 210, the supply section 300, and the supply lines 40-1 to 40-4 are each the same as those in the first embodiment.

[0039] Control device 403 controls the opening and closing of each of valves 30-1 to 30-4 shown in Fig. 2. Fig. 12 is a diagram showing an example of components included in control device 403 shown in Fig. 11. As shown in Fig. 12, control device 403 shown in Fig. 11 has a water quality acquisition unit 410, a supply destination determination unit 423, and a supply water quality acquisition unit 453. Water quality acquisition unit 410 is the same as that in the first embodiment. Note that Fig. 12 shows only the main components related to this embodiment among the components included in control device 403 shown in Fig. 11.

[0040] The supply water quality acquiring unit 453 acquires the quality of water supplied to each of the water treatment devices 10-1 to 10-4 provided in the pure water manufacturing system 100. Here, if a measuring device for measuring water quality is provided in each of the water treatment devices 10-1 to 10-4, the quality of the water supplied to each of the water treatment devices 10-1 to 10-4 may be a value measured by the measuring device. The supply water quality acquiring unit 453 may acquire a value measured by the measuring device. Alternatively, the supply water quality acquiring unit 453 may acquire a portion of the water supplied to each of the water treatment devices 10-1 to 10-4 and measure the quality of that water. The supply water quality acquiring unit 453 notifies the supply destination determining unit 423 of the acquired water quality (value).

[0041] The supply destination determination unit 423 determines water treatment devices 10-1 to 10-4 to which the recovered treated water supplied from the recovered treated water producing apparatus 200 will be supplied, based on the water quality value notified by the water quality acquisition unit 410 and the water quality notified by the supply water quality acquisition unit 453. The supply destination determination unit 423 may previously associate each water quality value with a water treatment device as a supply destination, and when notified of the water quality value from the water quality acquisition unit 410 and the supply water quality acquisition unit 453, determine the water treatment device associated with the notified water quality value as the supply destination of the recovered treated water. The supply destination determination unit 423 transmits control signals to each of the valves 30-1 to 30-4 to control the opening and closing of each of the valves 30-1 to 30-4 so that the recovered treated water is supplied to the determined supply destination water treatment devices 10-1 to 10-4. For example, the flow rate in treatment devices 10-1 to 10-4 is measured, and supply destination determination unit 423 calculates the load amount (= flow rate × concentration) using the measured flow rate and the water quality (concentration) of water treatment devices 10-1 to 10-4 acquired by supply water quality acquisition unit 453. If the load amount including recovered water exceeds the removal amount (design value) in each treatment step in treatment devices 10-1 to 10-4, supply destination determination unit 423 determines a stage upstream of each treatment device 10-1 to 10-4 as the supply destination. Also, for urea, supply destination determination unit 423 compares the urea design value (design removal rate) in each treatment device 10-1 to 10-4 with the actual load amount, and determines the supply destination based on the result.

[0042] The following describes a method for producing pure water in the pure water producing system shown in Fig. 11. Fig. 13 is a flowchart for explaining an example of the method for producing pure water in the pure water producing system shown in Fig. 11. This process is mainly performed by the control device 403 shown in Fig. 11.

[0043] First, the quality of the recovered treated water produced by the recovered treated water producing apparatus 200 is measured (step S31). A water quality measuring device provided in the control device 403 may measure the quality of a portion of the recovered treated water supplied from the recovered treated water producing apparatus 200 to the supply unit 300, or the measuring device 210 may measure the water quality. Next, the water quality acquiring unit 410 acquires the measured water quality value (step S32). The water quality acquiring unit 410 notifies the supply destination determining unit 422 of the acquired water quality value. Furthermore, the supply water quality acquiring unit 453 acquires the water quality of the water supplied to each of the water treatment devices 10-1 to 10-4 provided in the pure water producing apparatus 100 (step S33). Either the processing of steps S31 to S32 or the processing of step S33 may be performed first.

[0044] Then, supply destination determination unit 423 determines water treatment devices 10-1 to 10-4 to which the recovered treated water will be supplied (step S34) based on the water quality value notified by water quality acquisition unit 410 and the water quality value acquired by supply water quality acquisition unit 453. Supply destination determination unit 423 controls opening and closing of valves 30-1 to 30-4 so that the recovered treated water is supplied to water treatment devices 10-1 to 10-4 determined as the supply destination in step S34 (step S35).

[0045] A specific example of the processing of step S35 will be described. For example, if the supply destination determination unit 423 determines water treatment device 10-1 as the supply destination of the recovered treated water, the supply destination determination unit 423 controls valve 30-1 to open and valves 30-2 to 30-4 to close. If the supply destination determination unit 423 determines water treatment device 10-2 as the supply destination of the recovered treated water, the supply destination determination unit 423 controls valve 30-2 to open and valves 30-1, 30-3, and 30-4 to close. If the supply destination determination unit 423 determines water treatment device 10-3 as the supply destination of the recovered treated water, the supply destination determination unit 423 controls valve 30-3 to open and valves 30-1, 30-2, and 30-4 to close. Furthermore, when the supply destination determination unit 423 determines the water treatment device 10-4 as the supply destination of the recovered treated water, the supply destination determination unit 422 controls the valve 30-4 to be open and the valves 30-1 to 30-3 to be closed.

[0046] As described above, in this embodiment, the recovered treated water production system 200 supplies recovered treated water produced from water such as service water, wastewater, and sewage to one of the water treatment devices constituting the pure water production system 100. The destination water treatment device is determined based on the quality of the recovered treated water to be supplied and the quality of the water to be supplied to the water treatment device, and the recovered treated water is supplied to the determined water treatment device. In this way, by supplying recovered treated water that has been reused from water used in other facilities or factories to the pure water production system 100, ultrapure water can be easily and continuously produced via the subsystem 110. Furthermore, by supplying the recovered treated water to a water treatment device that performs a water treatment process according to the quality of the recovered treated water and the water to be supplied to the water treatment device, the recovered treated water can be reused through a route appropriate for the quality of the recovered treated water and the water to be supplied to the water treatment device. (Application example)

[0047] Figure 14 is a diagram showing an example of an application of the ultrapure water production system of the present invention. The raw water tank 11-1, MMF (filtration device) 11-2, ACF (activated carbon filter) 11-3, filtered water tank 11-4, 2B3T (two-bed, three-tower ion exchange resin tower) 11-5, RO (reverse osmosis membrane device) 11-6, demineralized water tank 11-7, Uvox (ultraviolet oxidation device) 11-8, SBP (multi-bed countercurrent regenerative ion exchange device) 11-9, sub-tank 11-10, and subsystem 11-11 correspond to the water treatment devices shown in Figures 1, 5, and 8. These water treatment devices are arranged in series to form an ultrapure water production system. In this ultrapure water production system, raw water is passed from the raw water tank 11-1 to the subsystem 11-11 to produce ultrapure water, which is then supplied to a POU (point of use). The water flow path of the ultrapure water production system is provided with water quality measuring devices 12-1 to 12-9 for measuring water quality (e.g., TOC and urea content). The recovered water treatment system is configured by serially arranging a raw recovered water tank 21-1, an ACF (activated carbon filter) 21-2, a turbidity-removed raw water tank 21-3, a turbidity removal membrane 21-4, an RO raw water tank 21-5, an RO (reverse osmosis membrane device) 21-6, an RO treated water tank 21-7, an Uvox (ultraviolet oxidation device) 21-8, an IER (ion exchange resin) 21-9, and a recovered water treatment tank 21-10. The RO treated water tank 21-7 and the recovered water treatment tank 21-10 are each provided with water quality measuring devices 22-1 and 22-2 for measuring water quality (e.g., TOC and urea content). Valves 31-1 to 31-6 are also provided to control the supply of recovered water treated in the RO treatment tank 21-7 or the recovered treatment tank 21-10 to the raw water tank 11-1, the path between the MMF 11-2 and the ACF 11-3, the filtered water tank 11-4, the path between the 2B3T 11-5 and the RO 11-6, the desalinated water tank 11-7, and the sub-tank 11-10. Note that not all of the water tanks, filtration membrane devices, activated carbon, ultraviolet oxidation devices, ion exchange resins, and other devices constituting the ultrapure water production system and recovered water treatment system shown in Figure 14 are essential. The ultrapure water production system and recovered water treatment system shown in Figure 14 may also be provided with other components (water treatment devices) as needed.

[0048] 14, the lines from the RO treatment tank 21-7 to each of the valves 31-1 to 31-6 and the lines from the recovery treatment tank 21-10 to each of the valves 31-1 to 31-6 are separate, but the lines may also be such that treated water from the RO treatment tank 21-7 and treated water from the recovery treatment tank 21-10 join together and are supplied to each of the valves 31-1 to 31-6.Alternatively, a valve may be provided at the joining point, and the valve may be controlled so that either the treated water from the recovery treatment tank 21-10 or the treated water from the recovery treatment tank 21-10 is supplied to each of the valves 31-1 to 31-6.

[0049] Although not shown in Fig. 14, the control device 400 shown in Fig. 1, the control device 401 shown in Fig. 5, the control device 402 shown in Fig. 8, or the control device 403 shown in Fig. 11 determines a supply destination to which the recovered treated water treated in the RO treatment tank 21-7 is to be supplied based on the water quality measured by the water quality measuring device 22-1, and controls the opening and closing of the valves 31-1 to 31-6. Also, the control device 400 shown in Fig. 1, the control device 401 shown in Fig. 5, the control device 402 shown in Fig. 8, or the control device 403 shown in Fig. 11 determines a supply destination to which the recovered treated water treated in the recovery treatment tank 21-10 is to be supplied based on the water quality measured by the water quality measuring device 22-2, and controls the opening and closing of the valves 31-1 to 31-6. Note that the control device 403 determines a supply destination to which the recovered treated water is to be supplied, taking into consideration the water quality measured by the water quality measuring devices 12-1 to 12-9, and controls the opening and closing of the valves 31-1 to 31-6. The valves 31-1 to 31-6 may be opened and closed manually. If the ultrapure water production system or recovered water treatment system has multiple systems, each system may be started and stopped separately.

[0050] 14, for example, if the TOC value measured by water quality measuring instrument 22-2 is smaller than the TOC value measured by water quality measuring instrument 12-4, valves 31-1 to 31-6 may be controlled so that treated water from recovery treatment tank 21-10 is supplied to filtration water tank 11-4. At this time, if the TOC value measured by water quality measuring instrument 22-2 exceeds the upper TOC limit (design value) in the specifications of RO 11-6, valves 31-1 to 31-6 are controlled so that treated water from recovery treatment tank 21-10 is supplied from valve 31-2 to the stage preceding ACF 11-3. Furthermore, if the TOC value measured by water quality measuring instrument 22-1 is smaller than the TOC value measured by water quality measuring instrument 12-6, valves 31-1 to 31-6 may be controlled so that treated water from RO treatment tank 21-7 is supplied to desalination tank 11-7, and operation of Uvox 21-8, IER 21-9 and recovery treatment tank 21-10 may be stopped.

[0051] Although the above description has been given by allocating each function (process) to each component, this allocation is not limited to the above. Furthermore, the configuration of the components is also not limited to the above-described embodiments, which are merely examples. Furthermore, each embodiment may be combined. [Explanation of symbols]

[0052] 1. Main Line 10-1~10-4 Water treatment equipment 11-1 Raw water tank 11-2 MMF 11-3,21-2 ACF 11-4 Filtration tank 11-5 2B3T 11-6,21-6 RO 11-7 Desalination tank 11-8,21-8 Uvox 11-9 SBP 11-10 Subtank 11-11,110 Subsystem 12-1~12-9,22-1,22-2 Water quality meter 21-1 Raw water recovery tank 21-3 De-turbidity tank 21-4 Turbidity membrane 21-5 RO raw water tank 21-7 RO treatment tank 21-9 IER 21-9 Collection and treatment tank 30-1~30-4, 31-1~31-6 Valves 40-1~40-4 Supply Line 100 Pure water production equipment 200 Reclaimed treated water production equipment 210 Measuring instruments 300 Supply section 400~403 Control device 410,411 Water Quality Acquisition Department 420~423 Supply Destination Decision Department 431 Supply amount calculation section 442 Operation control section 453 Supply water quality acquisition department 500~503 Reclaimed treated water supply equipment

Claims

1. a pure water producing apparatus for producing pure water from first treated water by combining a plurality of water treatment apparatuses to perform water treatment; a recovered treated water producing apparatus including at least one of a reverse osmosis membrane device and an ion exchange device, which produces recovered treated water from the second treated water; A pure water producing system having a plurality of supply lines connected to some or all of the plurality of water treatment devices so that the recovered treated water produced by the recovered treated water producing device can be supplied to the plurality of water treatment devices.

2. 2. The pure water producing system according to claim 1, a water quality acquisition unit that acquires the water quality of the recovered treated water; a supply destination determination unit that determines a water treatment device to which the recovered treated water is to be supplied based on the water quality acquired by the water quality acquisition unit; a control unit that supplies the recovered treated water via the supply line to the water treatment device determined by the supply destination determination unit.

3. 3. The pure water producing system according to claim 2, the recovered treated water producing apparatus has the ion exchange device downstream of the reverse osmosis membrane device, the water quality acquisition unit includes a first water quality acquisition unit that acquires the water quality of the treated water from the reverse osmosis membrane device, and a second water quality acquisition unit that acquires the water quality of the treated water from the ion exchange device; The supply destination determination unit determines a water treatment device to supply at least one of the treated water from the reverse osmosis membrane device and the treated water from the ion exchange device based on at least one of the water quality acquired by the first water quality acquisition unit and the water quality acquired by the second water quality acquisition unit.

4. The pure water producing system according to claim 2 or 3, a supply water quality acquisition unit that acquires the water quality of water supplied to each of the plurality of water treatment devices from a main line through which raw water is supplied; The supply destination determination unit determines a water treatment device to which the recovered treated water is to be supplied based on the water quality acquired by the supply water quality acquisition unit and the water quality acquired by the water quality acquisition unit.

5. 4. The pure water producing system according to claim 1, A pure water producing system, wherein the second water to be treated is at least one of sewage and wastewater.

6. The pure water producing system according to claim 2 or 3, The water quality acquisition unit acquires at least one of a TOC (Total Organic Carbon) content and a urea content as the water quality of the recovered treated water.

7. 7. The pure water producing system according to claim 6, The water quality acquisition unit is a pure water production system that acquires the urea content online.

8. a recovered treated water producing apparatus which produces recovered treated water from second treated water and supplies the recovered treated water to a pure water producing apparatus which produces pure water from first treated water, by combining a plurality of water treatment devices; a plurality of supply lines connected to some or all of the plurality of water treatment devices so that the recovered treated water produced by the recovered treated water producing device can be supplied to the plurality of water treatment devices; a water quality acquisition unit that acquires the water quality of the recovered treated water; a supply destination determination unit that determines a water treatment device to which the recovered treated water is to be supplied based on the water quality acquired by the water quality acquisition unit; a control unit that supplies the recovered treated water via the supply line to the water treatment device determined by the supply destination determination unit, The recovered treated water production apparatus is a recovered treated water supply apparatus including at least one of a reverse osmosis membrane device and an ion exchange device.

9. The recovered treated water supply apparatus according to claim 8, A recovered treated water supply system having a reverse osmosis membrane device and an ultraviolet oxidation device and an ion exchange device downstream of the reverse osmosis membrane device.

10. a pure water producing apparatus for performing water treatment by combining a plurality of water treatment apparatuses, which produces pure water from the first water to be treated; a recovered treated water producing apparatus including at least one of a reverse osmosis membrane device and an ion exchange device, producing recovered treated water from the second treated water; Obtaining the water quality of the recovered treated water, determining a water treatment device to which the recovered treated water is to be supplied based on the acquired water quality; A pure water manufacturing method in which the recovered treated water produced by the recovered treated water manufacturing apparatus is supplied to the determined water treatment apparatus via a supply line connected to some or all of the water treatment apparatuses so that the recovered treated water produced by the recovered treated water manufacturing apparatus can be supplied to the water treatment apparatuses.

11. The method for producing pure water according to claim 10, The recovered treated water production apparatus further includes an ion exchange device downstream of the reverse osmosis membrane device, Obtaining the water quality of the treated water from the reverse osmosis membrane device; Obtaining the quality of the treated water from the ion exchange device; A pure water production method that determines a water treatment device to supply treated water from the reverse osmosis membrane device and treated water from the ion exchange device based on the obtained water quality of the treated water from the reverse osmosis membrane device and the obtained water quality of the treated water from the ion exchange device.

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