Water treatment system and method for operating a water treatment system

Abstract

It includes an EDI (100), a pump (200) for supplying the water to be treated to the EDI (100), a pressure gauge (300) for measuring the output pressure value of the water to be treated from the pump (200), and a control unit (400) for controlling the discharge pressure of the pump so that the output pressure value measured by the pressure gauge (300) at a predetermined timing becomes a predetermined value.

Description

Technical Field

[0001] The present invention relates to a water treatment system and an operation method of the water treatment system.

Background Art

[0002] Generally, the discharge amount of treated water discharged from a water treatment system is controlled so as to fall within a predetermined range. For example, as a control method of an electro-deionized water production device provided in a water treatment system, in order to suppress the generation of scale due to a decrease in the water supply amount, a technique is known in which control is performed while maintaining the concentrated water amount at a certain level or more by a valve (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technique described in Patent Document 1, when suppressing the amount of treated water by an electro-deionized water production device, its control mechanism is complicated.

[0005] An object of the present invention is to provide a water treatment system and an operation method of the water treatment system that can exhibit a high power saving effect with a simple control method when suppressing the discharge amount of treated water from an electro-deionized water production device.

Means for Solving the Problems

[0006] The water treatment system of the present invention includes an electro-deionized water production device, a pump for supplying raw water to the electro-deionized water production device, a pressure gauge for measuring the output pressure value of the raw water from the pump, It has a control unit that controls the discharge pressure of the pump so that the output pressure value measured by the pressure gauge becomes a predetermined value at a predetermined timing.

[0007] Moreover, the operation method of the water treatment system of the present invention is acquire the output pressure value of the treated water from the pump that supplies the treated water to the electrodialysis deionized water production device, control the discharge pressure of the pump so that the output pressure value becomes a predetermined value at a predetermined timing.

Advantages of the Invention

[0008] In the present invention, when suppressing the discharge amount of the treated water from the electrodialysis deionized water production device, a high power saving effect can be exhibited by a simple control method.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. (First Embodiment)

[0011] FIG. 1 is a diagram showing a first embodiment of the water treatment system of the present invention. As shown in FIG. 1, the water treatment system in this embodiment includes an EDI (electro-deionization water production device) 100, a pump 200, a pressure gauge 300, a control unit 400, and a DC power supply device 500. In addition, flow meters 600-1 to 600-3 are provided in the path from the EDI 100. The form shown in FIG. 1 may be provided in the primary pure water system within a water treatment system composed of a general so-called pretreatment system, a primary pure water system, and a subsystem (secondary pure water system). Further, between the pump 200 and the EDI 100, a water treatment device for performing a predetermined treatment on the water to be treated, a conductivity meter, a specific resistance meter, an on-off valve, a flow rate adjustment valve, a flow meter, etc. may be provided. Further, a conductivity meter, a specific resistance meter, an on-off valve, a flow rate adjustment valve, a flow meter, etc. may be provided at the subsequent stage of the EDI 100. When a water treatment device for performing a predetermined treatment on the water to be treated and a conductivity meter are provided between the pump 200 and the EDI 100, the position where the pressure gauge 300 is arranged is preferably immediately after the pump 200.

[0012] EDI100 is also called an electrically regenerative pure water device or a continuously regenerative pure water device. EDI100 has a desalination chamber 100-1, a concentration chamber 100-2, and an electrode chamber 100-3 partitioned by a cation exchange membrane and an anion exchange membrane. At least one of a cation exchange resin and an anion exchange resin is filled in the desalination chamber 100-1. In EDI100, a direct current flows between the anode and the cathode from a direct current power supply device 500, and while removing ions contained in the water to be treated supplied to EDI100 in the desalination chamber 100-1, the ion exchange resin is continuously regenerated. The ions removed from the water to be treated in the desalination chamber 100-1 move to the concentration chamber 100-2, are contained in the concentrated water, and are discharged. The treated water from which ions have been removed in the desalination chamber 100-1 is discharged as desalted water. The treated water discharged from each of the desalination chamber 100-1, the concentration chamber 100-2, and the electrode chamber 100-3 is supplied to the demand location via different paths. The flow meter 600-1 measures the flow rate of the desalted water discharged from the desalination chamber 100-1. The flow meter 600-2 measures the flow rate of the concentrated water discharged from the concentration chamber 100-2. The flow meter 600-3 measures the flow rate of the electrode water discharged from the electrode chamber 100-3. Note that the concentration chamber 100-2 of EDI100 also serves as the electrode chamber 100-3, and the electrode chamber 100-3 may not be provided in EDI100. When the structure of EDI100 is such that the concentration chamber 100-2 also serves as the electrode chamber 100-3, the electrode water line through which the flow meter 600-3 passes water from the electrode chamber 100-3 is omitted.

[0013] The pump 200 sucks up external water to be treated and discharges and supplies it to EDI100. The pump 200 operates based on a drive signal from the control unit 400. For example, the pump 200 rotates the motor at a rotation speed based on a drive signal from the control unit 400, sucks up the water to be treated, and discharges it.

[0014] The pressure gauge 300 measures the output pressure value of the water to be treated from the pump 200 at the discharge port of the pump 200. The pressure gauge 300 notifies the control unit 400 of the measured output pressure value.

[0015] The control unit 400 acquires the output pressure value measured by the pressure gauge 300. The control unit 400 controls the discharge pressure of the pump 200 via an inverter so that the output pressure value acquired from the pressure gauge 300 at a predetermined timing becomes a predetermined value. When the maximum capacity value of the discharge pressure of the pump 200 is set to 100%, the control unit 400 controls the discharge pressure of the pump 200 so that the pressure reduction rate is 0 to 60%. This maximum capacity value may be a value determined in advance as the specification of the pump 200, may be the maximum value that the pump 200 can discharge in the water treatment system in use, or may be the pump discharge pressure value in the normal mode other than the power saving mode. When the pump 200 has a mechanism using a motor, the control unit 400 outputs a drive signal to the pump 200 to control the rotation speed of the motor so that the output pressure value measured by the pressure gauge 300 becomes a predetermined value.

[0016] For example, when receiving an input from the outside to switch to the power saving mode, the control unit 400 acquires the output pressure value measured by the pressure gauge 300. The control unit 400 compares the acquired output pressure value with the value set as the output pressure value in the power saving mode. The control unit 400 calculates a rate of decreasing the rotation speed of the motor of the pump 200 based on the result of the comparison. The control unit 400 outputs a control signal corresponding to the calculated decrease rate to the pump 200. The method of calculating the rate of decreasing the rotation speed of the motor of the pump 200 may be, for example, a method in which the decrease rate for decreasing the output pressure value to the value set as the output pressure value in the power saving mode and the decrease rate of the rotation speed of the motor are associated in advance, and the calculation is performed based on the association. Also, the method of calculating the rate of decreasing the rotation speed of the motor of the pump 200 may be a method of decreasing the output pressure value at a certain rate and adjusting it step by step to the output pressure value corresponding to the required water volume. Thereby, power consumption can be reduced at a desired timing.

[0017] Also, for example, the control unit 400 acquires the output pressure value measured by the pressure gauge 300. The control unit 400 compares the acquired output pressure value with the pressure value corresponding to the required flow rate in the system downstream of the EDI 100. Based on the result of the comparison, the control unit 400 calculates the rate at which the rotational speed of the motor of the pump 200 is decreased. The control unit 400 outputs a control signal corresponding to the calculated decrease rate to the pump 200. The pressure value corresponding to the required flow rate at this time is obtained from the pre-set association between the required flow rate and the pressure value. The method of calculating the rate at which the rotational speed of the motor of the pump 200 is decreased may be, for example, a method in which the decrease rate for decreasing the output pressure value to the pressure value corresponding to the required flow rate and the decrease rate of the rotational speed of the motor are pre-associated and calculated based on that association. Also, the method of calculating the rate at which the rotational speed of the motor of the pump 200 is decreased may be a method in which the output pressure value is decreased at a constant rate and adjusted step by step to the output pressure value that results in the required water volume. In this way, the output of the pump 200 is controlled to an output pressure value suitable for the requirements from the downstream system. Thereby, it is possible to reduce the power consumption without producing excessive water.

[0018] Also, for example, when it comes to the time zone set to operate in the power-saving mode set in advance, such as at night or on holidays, the control unit 400 acquires the output pressure value measured by the pressure gauge 300. The control unit 400 compares the acquired output pressure value with the value set as the output pressure value in the power-saving mode. Based on the result of the comparison, the control unit 400 calculates the rate of decreasing the rotation speed of the motor of the pump 200. The control unit 400 outputs a control signal corresponding to the calculated decreasing rate to the pump 200. The method of calculating the rate of decreasing the rotation speed of the motor of the pump 200 at this time may be the same method as the method described above. In addition, at the timing of returning from the power-saving mode to the normal mode, the control unit 400 acquires the output pressure value measured by the pressure gauge 300, compares the acquired output pressure value with the value set as the output pressure value in the normal mode, and based on the result of the comparison, calculates the rate of increasing the rotation speed of the motor of the pump 200, and outputs a control signal corresponding to the calculated increasing rate to the pump 200. In this way, the control unit 400 controls the output of the pump 200 to the output pressure value corresponding to the operation mode. Thereby, it is possible to reduce the power consumption as scheduled for reducing the power consumption.

[0019] Further, for example, the control unit 400 may perform control based on the operating status of the system downstream of the EDI 100 (e.g., the number of operating lines). The control unit 400 acquires the output pressure value measured by the pressure gauge 300. The control unit 400 compares the acquired output pressure value with the pressure value corresponding to the operating status. The control unit 400 calculates the rate of decreasing the rotational speed of the motor of the pump 200 based on the result of the comparison. The control unit 400 outputs a control signal corresponding to the calculated decrease rate to the pump 200. The pressure value corresponding to the operating status at this time is obtained from the pre-set association between the operating status and the pressure value. The method of calculating the rate of decreasing the rotational speed of the motor of the pump 200 may be, for example, a method in which the decrease rate for decreasing the output pressure value to the pressure value corresponding to the operating status and the decrease rate of the rotational speed of the motor are associated in advance and calculated based on the association. Also, the method of calculating the rate of decreasing the rotational speed of the motor of the pump 200 may be a method of decreasing the output pressure value at a constant rate and adjusting it step by step to the output pressure value corresponding to the operating status. In this way, the control unit 400 controls the output of the pump 200 to an output pressure value suitable for the operating status from the downstream system. Thereby, it is possible to reduce the power consumption without producing excessive desalinated water.

[0020] Further, for example, the control unit 400 may perform control based on the water production rate upstream of the EDI 100. The control unit 400 acquires the output pressure value measured by the pressure gauge 300. The control unit 400 compares the acquired output pressure value with the pressure value corresponding to the upstream water production rate. The control unit 400 calculates the rate of decreasing the rotation speed of the motor of the pump 200 based on the result of the comparison. The control unit 400 outputs a control signal corresponding to the calculated decrease rate to the pump 200. The pressure value corresponding to the upstream water production rate at this time is obtained from the association between the preset upstream water production rate and the pressure value. The method of calculating the rate of decreasing the rotation speed of the motor of the pump 200 may be, for example, a method in which the decrease rate for decreasing the output pressure value to the pressure value corresponding to the upstream water production rate and the decrease rate of the motor rotation speed are associated in advance and calculated based on the association. Further, the method of calculating the rate of decreasing the rotation speed of the motor of the pump 200 may be a method of decreasing the output pressure value at a constant rate and gradually adjusting it to the output pressure value corresponding to the upstream water production rate. In this way, the control unit 400 controls the output of the pump 200 to an output pressure value suitable for the upstream water production rate. Thereby, it is possible to reduce power consumption without producing excessive water.

[0021] Hereinafter, the operation method of the water treatment system in the water treatment system shown in FIG. 1 will be described. FIG. 2 is a flowchart for explaining an example of the operation method of the water treatment system in the water treatment system shown in FIG. 1. Hereinafter, an example of the process when it becomes the time zone operating in the power saving mode in a preset schedule will be described.

[0022] First, the control unit 400 determines whether the current timing is the power saving mode (step S1). This determination is made based on a preset schedule and the date and time indicated by the clock. In this schedule, which operation mode, the normal mode or the power saving mode for power saving, the water treatment system is to be operated is set for each time zone and date (for example, day of the week, season, etc.).

[0023] When it is determined that the current timing is the power-saving mode, the control unit 400 acquires the output pressure value of the pump 200 measured by the pressure gauge 300 (step S2). Subsequently, the control unit 400 compares the acquired output pressure value with the value set as the output pressure value in the power-saving mode. The control unit 400 calculates the rate of decreasing the rotational speed of the motor of the pump 200 based on the result of the comparison (step S3). At this time, the control unit 400 may calculate the rate of decreasing the rotational speed of the motor of the pump 200 according to a preset target pressure value. The control unit 400 outputs a control signal corresponding to the calculated reduction rate to the pump 200 to control the discharge pressure of the pump 200 (step S4).

[0024] In this way, the control unit 400 controls the discharge pressure of the pump 200 so that the output pressure value of the pump 200 measured by the pressure gauge 300 provided at the discharge port of the pump 200 that supplies the water to be treated to the EDI 100 becomes a predetermined value. This control timing is the timing performed based on an external request, the operating status of the downstream system, the water supply amount from the upstream system, or a schedule in which the operation mode is set. Therefore, when suppressing the discharge amount of the treated water from the electro-deionized water production device in order to provide an appropriate amount of treated water, the power consumption of the pump 200 can be kept low, and a high power-saving effect can be exhibited. When there is no water intake request from the outside such as the supply destination, in order to suppress the discharge amount of the treated water from the electro-deionized water production device, it is generally performed to perform a circulation operation in the system. In this case, the water temperature rises due to the heat input to the pump. It is known that when the water temperature rises, the boron removal performance of the EDI deteriorates. On the other hand, in this embodiment, in order to suppress the discharge amount of the treated water from the electro-deionized water production device, control is performed to decrease the rotational speed of the motor of the pump 200. By this control, it is possible to avoid a decrease in the boron removal rate by continuing the operation in the normal temperature range without causing the water temperature to rise due to the heat input to the pump during circulation. (Second Embodiment)

[0025] FIG. 3 is a diagram showing a second embodiment of the water treatment system of the present invention. As shown in FIG. 3, in addition to the components of the first embodiment shown in FIG. 1, a branch path 700 and flow rate adjustment valves 800-1 to 800-3 are further provided in the water treatment system of this embodiment.

[0026] The branch path 700 is a path that branches from the path from the pump 200 to the desalination chamber 100-1, the concentration chamber 100-2, and the electrode chamber 100-3 of the EDI 100, respectively. The branch point where the branch path 700 branches is provided on the EDI 100 side rather than at the point where the pressure gauge 300 measures the output pressure value of the pump 200. The water to be treated discharged from the pump 200 is supplied to the desalination chamber 100-1, the concentration chamber 100-2, and the electrode chamber 100-3 respectively via the branch path 700. When the structure of the EDI 100 is such that the concentration chamber 100-2 also serves as the electrode chamber 100-3, the electrode water line that passes water from the flow rate adjustment valve 800-3 through the electrode chamber 100-3 to the flow meter 600-3 is omitted.

[0027] The flow rate adjustment valve 800-1 is provided in the branch path 700 that supplies the water to be treated to the desalination chamber 100-1. The flow rate adjustment valve 800-1 is a valve that adjusts the flow rate of the water to be treated supplied to the desalination chamber 100-1. Further, the flow rate adjustment valve 800-1 may be provided at the outlet of the desalination chamber 100-1. The flow rate adjustment valve 800-2 is provided in the branch path 700 that supplies the water to be treated to the concentration chamber 100-2. The flow rate adjustment valve 800-2 is a valve that adjusts the flow rate of the water to be treated supplied to the concentration chamber 100-2. Further, the flow rate adjustment valve 800-2 may be provided at the outlet of the concentration chamber 100-2. The flow rate adjustment valve 800-3 is provided in the branch path 700 that supplies the water to be treated to the electrode chamber 100-3. The flow rate adjustment valve 800-3 is a valve that adjusts the flow rate of the water to be treated supplied to the electrode chamber 100-3. Further, the flow rate adjustment valve 800-3 may be provided at the outlet of the electrode chamber 100-3.

[0028] FIG. 4 is a graph showing an example of the relationship between the reduction rate of the output pressure value of the pump 200 shown in FIG. 3 and the reduction rate of the flow rate discharged from the EDI 100. FIG. 4 shows how the flow rate of the demineralized water discharged from the demineralization chamber 100-1 and measured by the flow meter 600-1 and the flow rate of the concentrated water discharged from the concentration chamber 100-2 and measured by the flow meter 600-2 decrease at what rate according to the reduction rate of the output pressure value of the pump 200. This is the result obtained by experiments. As shown in FIG. 4, when the reduction rate of the output pressure value of the pump 200 increases, the reduction rates of the flow rates of the demineralized water and the concentrated water also increase. The ratio of the increase in the reduction rate of the flow rate to the increase in the reduction rate of the output pressure value of the pump 200 is different between the demineralized water and the concentrated water. It can be seen that the reduction rate of the flow rate of the discharged demineralized water, which is most easily affected by the flow rate of the water to be treated supplied to the EDI 100, is low compared to the reduction rate of the output pressure value of the pump 200. Therefore, if the pressure value reduction does not exceed 60% of the maximum capacity value of the pump 200 in this water treatment system, it is possible to control without monitoring the flow rate of the treated water discharged from the EDI 100.

[0029] FIG. 5 is a graph showing an example of the relationship between the reduction rate of the output pressure value of the pump 200 shown in FIG. 3 and the reduction rate of the power consumption. As shown in FIG. 5, when the reduction rate of the output pressure value of the pump 200 increases, the reduction rate of the power consumption of the pump 200 increases. At this time, it can be seen that the reduction rate of the power consumption of the pump 200 is high compared to the reduction rate of the output pressure value of the pump 200. From this, it can be seen that reducing the output pressure value of the pump 200 has a great power saving effect.

[0030] FIG. 6 is a graph showing an example of the relationship between the reduction rate of the output pressure value of the pump 200 shown in FIG. 3 and the concentration ratio in the EDI 100. The concentration ratio is the ratio of the inlet water volume of the EDI 100 to the concentrated water volume. As shown in FIG. 6, when the reduction rate of the output pressure value of the pump 200 increases, the concentration ratio remains unchanged or decreases without increasing. This is the result obtained by experiments. Therefore, it is possible to operate while maintaining or reducing the concentration ratio in the EDI 100 without controlling the supply amount of the water to be treated to the EDI 100 using the flow control valves 800-1 to 800-3. By monitoring the pump discharge pressure and reducing the output of the pump, the risk of problems (such as scale and slime) caused by an increase in the concentration ratio can be reduced.

[0031] In this way, the water to be treated from the pump 200 to the EDI 100 is branched from the main path to the branch paths, and is supplied to the desalination chamber 100-1, the concentration chamber 100-2, and the electrode chamber 100-3 through each branch path. If the supply amounts to the desalination chamber 100-1, the concentration chamber 100-2, and the electrode chamber 100-3 are adjusted in advance using the flow control valves 800-1 to 800-3 provided in the respective branch paths, then, by only controlling the output pressure value of the pump 200, the ratio of the desalinated water to the concentrated water can be changed without significantly changing, and the supply amount of the water to be treated to the EDI 100 can be changed (decreased) in the direction of reducing the concentration ratio. (Third Embodiment)

[0032] FIG. 7 is a diagram showing a third embodiment of the water treatment system of the present invention. As shown in FIG. 7, the water treatment system in this embodiment is a system in which the control unit 400 is replaced by a control unit 401 among the components of the second embodiment shown in FIG. 3.

[0033] In addition to the functions of the control unit 400 shown in FIG. 1 or FIG. 3, the control unit 401 has a function of calculating a reduction rate for reducing the current value flowing from the DC power supply device 500 to the EDI 100 based on the reduction rate of the output pressure value of the pump 200. This calculation method may be a method of calculating in advance the correlation between the reduction rate of the output pressure value of the pump 200 and the reduction rate for reducing the current value flowing from the DC power supply device 500 to the EDI 100 (for example, a relational expression or an algorithm for deriving one from the other), and using the calculated correlation to calculate the reduction rate for reducing the current value flowing from the DC power supply device 500 to the EDI 100. Or, this calculation method may be a method of associating (linking) in advance the reduction rate of the output pressure value of the pump 200 and the reduction rate for reducing the current value flowing from the DC power supply device 500 to the EDI 100, and calculating the reduction rate for reducing the current value flowing from the DC power supply device 500 to the EDI 100 based on the association. The timing of control with the reduction rate of the current value calculated by the control unit 401 may be the timing when an input indicating switching to the power saving mode is received from the outside. Also, the timing of control with the reduction rate of the current value calculated by the control unit 401 may be the timing of switching to the power saving mode in a preset schedule. Also, the timing of control with the reduction rate of the current value calculated by the control unit 401 may be the same as or different from the timing of reducing the output pressure value of the pump 200.

[0034] In this way, the control unit 401 reduces the output pressure value of the pump 200 and reduces the current value flowing from the DC power supply device 500 to the EDI 100 according to the reduction rate. Thereby, a higher power saving effect can be exhibited. Note that the control unit 401 in this embodiment may be applied to the EDI 100 in the first embodiment. (Fourth Embodiment)

[0035] FIG. 8 is a diagram showing a fourth embodiment of the water treatment system of the present invention. As shown in FIG. 8, the water treatment system in this embodiment is a system in which three sets of the EDI 100s shown in FIG. 3 are connected in parallel.

[0036] The water to be treated from the pump 200 is supplied to three EDIs 100 to 102. Also, a direct current flows from each of the DC power supply devices 500 to 502 to each of the EDIs 100 to 102. The water to be treated from the pump 200 is supplied to the desalination chamber 100-1, the concentration chamber 100-2, and the electrode chamber 100-3 of the EDI 100 through the flow rate adjustment valves 800-1 to 800-3 provided in the branch path 700, respectively. The water to be treated from the pump 200 is supplied to the desalination chamber 101-1, the concentration chamber 101-2, and the electrode chamber 101-3 of the EDI 101 through the flow rate adjustment valves 801-1 to 801-3 provided in the branch path 700, respectively. The water to be treated from the pump 200 is supplied to the desalination chamber 102-1, the concentration chamber 102-2, and the electrode chamber 102-3 of the EDI 102 through the flow rate adjustment valves 802-1 to 802-3 provided in the branch path 700, respectively. The treated water discharged from the desalination chamber 100-1 of the EDI 100, the desalination chamber 101-1 of the EDI 101, and the desalination chamber 102-1 of the EDI 102 merges and is supplied downstream as desalted water. The treated water discharged from the concentration chamber 100-2 of the EDI 100, the concentration chamber 101-2 of the EDI 101, and the concentration chamber 102-2 of the EDI 102 merges and is supplied downstream as concentrated water. The treated water discharged from the electrode chamber 100-3 of the EDI 100, the electrode chamber 101-3 of the EDI 101, and the electrode chamber 102-3 of the EDI 102 merges and is supplied downstream as electrode water. Note that the positions of the flow rate adjustment valves 800-1 to 800-3 are not limited to the upstream of the EDI 100. For example, the flow rate adjustment valve 800-1 may be provided at the outlet of the desalination chamber 100-1. Also, the flow rate adjustment valve 800-2 may be provided at the outlet of the concentration chamber 100-2. The flow rate adjustment valve 800-3 may be provided at the outlet of the electrode chamber 100-3. Also, instead of the flow rate adjustment valves 800-1 to 800-3, a flow rate adjustment valve may be provided at the upstream stage (before the branch point) or the downstream stage (confluence point) of the branch path 700. Note that when the structure of the EDI 100 is such that the concentration chamber 100-2 also serves as the electrode chamber 100-3, the electrode water line through which the flow meter 600-3 passes through the electrode chamber 100-3 from the flow rate adjustment valve 800-3 is omitted.

[0037] Thus, even in a system where a plurality of EDIs are connected in parallel, the control unit 400 only needs to perform the control on the pump 200 in the first to third embodiments, and the ratio of the demineralized water and the concentrated water discharged from each of the plurality of EDIs can be kept unchanged while the supply amount of the water to be treated to the EDI can be changed (decreased) in the direction of reducing the concentration ratio. By such a method, even in a system where a plurality of EDIs are connected in parallel or in series, excessive water production can be eliminated and power consumption can be reduced. Needless to say, the control in each form can also be performed even when the EDI 100 in the first embodiment and the EDI 100 in the second embodiment are arranged in a plurality in parallel as in the EDIs 100 to 102 in the third embodiment.

[0038] As described above, the present invention has been described with reference to the embodiments, but the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

[0039] This application claims priority based on Japanese Patent Application No. 2023-216824 filed on December 22, 2023, and incorporates the entire disclosure thereof herein.

Claims

1. An electrodeionized water production device; a pump for supplying water to be treated to the electrodeionized water production apparatus; a pressure gauge for measuring an output pressure value of the water to be treated from the pump; a control unit that controls the discharge pressure of the pump so that the output pressure value measured by the pressure gauge at a predetermined timing becomes a predetermined value.

2. 2. The water treatment system according to claim 1, a branch path branching from the path from the pump to each of a deionization compartment and a concentration compartment of the electrodeionization water production apparatus; a flow rate control valve provided in at least one of the branch paths, A water treatment system, wherein the pressure gauge is provided on the pump side relative to a branch point where the path branches into the branch path.

3. The water treatment system according to claim 1 or 2, The control unit, when receiving a predetermined input from outside, controls the discharge pressure of the pump so that the output pressure value measured by the pressure gauge becomes a predetermined value.

4. The water treatment system according to claim 1 or 2, The control unit of this water treatment system controls the discharge pressure of the pump so that the output pressure value measured by the pressure gauge becomes a predetermined value based on at least one of the required flow rate in a system downstream of the electrical deionized water production apparatus, the amount of water produced upstream of the electrical deionized water production apparatus, and the operating status of the system downstream of the electrical deionized water production apparatus.

5. The water treatment system according to claim 1 or 2, The control unit controls the discharge pressure of the pump based on a predetermined schedule so that the output pressure value measured by the pressure gauge becomes a predetermined value.

6. The water treatment system according to claim 1 or 2, The control unit controls the discharge pressure of the pump so that a pressure reduction rate is 0 to 60% when the maximum capacity value of the discharge pressure is 100%.

7. The water treatment system according to claim 1 or 2, A water treatment system comprising a plurality of the electrodeionized water production apparatuses, the plurality of electrodeionized water production apparatuses being connected in parallel or in series to one another.

8. acquiring an output pressure value of the water to be treated from a pump that supplies the water to the electrodeionization water production apparatus; A method for operating a water treatment system, comprising controlling the discharge pressure of the pump so that the output pressure value becomes a predetermined value at a predetermined timing.

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