Water treatment equipment, control device, control method, and program

Abstract

This minimizes the impact on the quality of treated water and easily maintains a constant water level in the treated water tank. [Solution] The system includes a pump 500, a water treatment device 300 that performs predetermined processing on raw water supplied from a raw water tank 200 using the pump 500, valves 600 and 610 that distribute the treated water processed by the water treatment device 300 to a treated water line 700 and a return line 710, a water level gauge 410 that measures the water level of the treated water stored in the treated water tank 400, and a control device 100 that controls the distribution ratio of the treated water line 700 and the return line 710 in the valves 600 and 610 based on the water level measured by the water level gauge 410, and controls the output of the pump 500 based on the controlled distribution ratio.

Description

Technical Field

[0001] The present invention relates to a water treatment facility, a control device, an operation control method, and a program.

Background Art

[0002] When there is a difference between the amount of treated water supplied from a water treatment device that performs predetermined treatment on raw water to a water storage tank and the amount of treated water used from the water storage tank, the amount of treated water stored in the water storage tank fluctuates. In order to reduce such fluctuations, that is, to keep the water level of the treated water in the water storage tank constant, a device that controls the rotational speed of a pump for supplying raw water to the water treatment device based on the water level of the treated water in the water storage tank has been disclosed (for example, see Patent Document 1).

[0003] In addition, based on the water level of a sub-tank that stores primary pure water obtained by treating raw water supplied from a tank using a pump, a system that controls the flow rate of the primary pure water to the sub-tank and the flow rate to a circulation line to the tank by adjusting the opening degree of a control valve has been considered (for example, see Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, even when using the apparatus described in Patent Document 1, there is a time lag between the pump and the water treatment device located downstream of the pump, which processes the water to be treated. Therefore, pump control cannot immediately affect fluctuations in water level. Furthermore, as in the system described in Patent Document 2, changing the ratio of the flow rate to the sub-tank to the flow rate to the circulation line causes fluctuations in the quality of the treated water supplied. Fluctuations in the quality of the treated water pose a significant problem for those using the treated water.

[0006] The object of the present invention is to provide a water treatment system, a control device, an operation control method, and a program that can easily maintain a constant water level of treated water stored in a treated water tank while minimizing the impact on the water quality of the treated water. [Means for solving the problem]

[0007] The water treatment equipment of the present invention is Pump and A water treatment device that performs predetermined treatment on raw water supplied from a raw water tank using the pump, A treated water line for sending the treated water treated by the water treatment device to a treated water tank, A return line for returning the treated water processed by the water treatment device to the raw water tank, a tank located upstream of the raw water tank, or a pipe through which raw water supplied from the raw water tank flows. A valve that distributes the treated water treated by the water treatment device to the treated water line and the return line, A water level measuring means for measuring the water level of the treated water stored in the aforementioned treated water tank, A ratio control unit controls the distribution ratio between the treated water line and the return line in the valve based on the water level measured by the water level measuring means, The system includes a pump control unit that controls the output of the pump based on the distribution ratio controlled by the ratio control unit.

[0008] Furthermore, the control device of the present invention is A water level acquisition unit that acquires a water level value indicating the water level of treated water stored in a treated water tank, which is supplied from the raw water tank using a pump and treated by the water treatment device, Based on the water level value acquired by the water level value acquisition unit, a ratio control unit controls the distribution ratio of valves that distribute the treated water treated by the water treatment device to a treated water line for sending water to the treated water tank and a return line for returning water to the raw water tank or a tank located upstream of the raw water tank or a pipe through which raw water supplied from the raw water tank flows. The system includes a pump control unit that controls the output of the pump based on the distribution ratio of the valves controlled by the ratio control unit.

[0009] Furthermore, the control method of the present invention is The process involves obtaining a water level value indicating the water level of the treated water stored in the treated water tank, which is supplied from the raw water tank using a pump and treated by the water treatment device. Based on the acquired water level value, a process to control the distribution ratio of valves that distribute the treated water treated by the water treatment device to a treated water line for sending water to the treated water tank and a return line for returning the treated water to the raw water tank or a tank located upstream of the raw water tank or a pipe through which raw water supplied from the raw water tank flows. The process involves controlling the output of the pump based on the distribution ratio of the controlled valves.

[0010] Furthermore, the program of the present invention, On the computer, A procedure for obtaining a water level value indicating the water level of treated water stored in a treated water tank, which is supplied from the raw water tank using a pump and treated by a water treatment device, and A procedure for controlling the distribution ratio of valves that distribute the treated water treated by the water treatment device to a treated water line for sending water to the treated water tank, and to a return line for returning the treated water to the raw water tank, or a tank located upstream of the raw water tank, or a pipe through which raw water supplied from the raw water tank flows, based on the acquired water level value, The procedure for controlling the output of the pump based on the distribution ratio of the controlled valve is to be executed. [Effects of the Invention]

[0011] In the present invention, it is possible to easily keep the water level of the treated water stored in the treatment water tank constant while suppressing the influence on the quality of the treated water.

Brief Description of the Drawings

[0012] [Figure 1] It is a diagram showing a first embodiment of the water treatment equipment according to the present invention. [Figure 2] It is a diagram showing an example of the components included in the control device shown in FIG. 1. [Figure 3] It is a diagram showing an example of the association between the water level value and the ratio (distribution ratio) used by the ratio control unit shown in FIG. 2. [Figure 4] It is a flowchart for explaining an example of the control method performed by the control device shown in FIG. 1. [Figure 5] It is a diagram showing a second embodiment of the water treatment equipment according to the present invention. [Figure 6] It is a flowchart for explaining an example of the water quality control method in the water treatment equipment shown in FIG. 5. [Figure 7] It is a diagram showing a third embodiment of the water treatment equipment according to the present invention. [Figure 8] It is a flowchart for explaining an example of the water quality control method in the water treatment equipment shown in FIG. 7. [Figure 9] It is a diagram showing a fourth embodiment of the water treatment equipment according to the present invention. [Figure 10] It is a flowchart for explaining an example of the water quality control method in the water treatment equipment shown in FIG. 9. [Figure 11] It is a diagram showing an example of a water treatment system to which the water treatment equipment of the present invention is applied.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. (First Embodiment)

[0014] Figure 1 shows a first embodiment of the water treatment equipment according to the present invention. As shown in Figure 1, the water treatment equipment according to this embodiment includes a control device 100, a raw water tank 200, a water treatment device 300, and a treated water tank 400. Furthermore, a pump 500 is provided to pump up the raw water stored in the raw water tank 200 and supply it to the water treatment device 300, and an inverter 510 is provided to control the operating speed (output) of the pump 500. In addition, a treated water line 700 is provided for sending the treated water treated by the water treatment device 300 to the treated water tank 400, and a return line 710 is provided for returning the treated water to the raw water tank 200. The return line 710 may be a line for returning the treated water treated by the water treatment device 300 to a tank located upstream of the raw water tank 200, or it may be a line for returning the treated water to a pipe through which the raw water supplied from the raw water tank 200 flows. A valve 600 is provided in the treated water line 700, and a valve 610 is provided in the return line 710. The opening degrees of valves 600 and 610 are controlled to control the distribution ratio of treated water from the water treatment device 300 to the treated water line 700 and the return line 710. Furthermore, a water level gauge 410 is provided, which is a water level measuring means for measuring the water level of the treated water stored in the treated water tank 400. The water level gauge 410 can be any instrument that can measure the water level of the treated water stored in the treated water tank 400. Valves 600 and 610 may also be implemented using three-way valves.

[0015] The water treatment device 300 performs predetermined treatment on the raw water supplied using the pump 500. The water treatment device 300 may be a device that performs a single unit operation for water treatment, or it may be a group of devices that combine multiple devices that perform unit operations. Examples of the water treatment device 300 include a reverse osmosis membrane device (RO), an electrodeionized water production device (EDI), an ultraviolet oxidation device (UV), a non-regenerative ion exchange resin tower (CP), a mixed-bed ion exchange device (SBP), a membrane degasser (MD), a combination of these devices, and a combination of these devices and a treated water tank in which the treated water is stored.

[0016] The control device 100 controls the water treatment equipment shown in Figure 1. Figure 2 shows an example of the components of the control device 100 shown in Figure 1. As shown in Figure 2, the control device 100 shown in Figure 1 has a water level acquisition unit 110, a ratio control unit 120, and a pump control unit 130. Note that Figure 2 shows only the main components of the control device 100 shown in Figure 1 that are relevant to this embodiment.

[0017] The water level acquisition unit 110 acquires the water level value, which indicates the water level measured by the water level gauge 410, from the water level gauge 410. There is no specific timing for the water level acquisition unit 110 to acquire the water level value from the water level gauge 410, but considering the need to perform control in accordance with water level fluctuations, a shorter acquisition time interval is preferable. The water level acquisition unit 110 notifies the ratio control unit 120 of the acquired water level value.

[0018] The ratio control unit 120 controls the distribution ratio of treated water from the water treatment device 300 to the treated water line 700 and the return line 710 by adjusting the opening degrees of valves 600 and 610 based on the water level values ​​notified by the water level acquisition unit 110. Specifically, the ratio control unit 120 may compare the water level values ​​notified by the water level acquisition unit 110 with a reference water level, and based on the result of this comparison, adjust the opening degrees of valves 600 and 610 to increase or decrease the ratio of treated water sent from the water treatment device 300 to the treated water line 700 compared to the reference ratio. Here, the reference water level may be a value set in advance based on the conditions for supplying treated water to the recipient, the performance of the water treatment device 300, etc. Alternatively, the reference water level may be a value calculated using a predetermined algorithm based on the operating state of the system, etc. The reference ratio may be a value set as the ratio when the water level value notified by the water level acquisition unit 110 reaches the reference water level. In this case, if the water level value notified by the water level acquisition unit 110 is higher than the reference water level, the ratio control unit 120 adjusts the opening of valves 600 and 610 to lower the ratio at which treated water processed by the water treatment device 300 is sent to the treated water line 700 compared to the reference ratio. Conversely, if the water level value notified by the water level acquisition unit 110 is lower than the reference water level, the ratio control unit 120 adjusts the opening of valves 600 and 610 to increase the ratio at which treated water processed by the water treatment device 300 is sent to the treated water line 700 compared to the reference ratio.

[0019] The ratio control unit 120 may control the opening degrees of valves 600 and 610 so that the ratio of treated water sent from the water treatment device 300 to the treated water line 700 is a ratio (distribution ratio) set in correspondence with the water level value indicated by the water level gauge 410. Figure 3 is a diagram showing an example of the correspondence between water level value and ratio (distribution ratio) used by the ratio control unit 120 shown in Figure 2. As shown in Figure 3, the water level value and the ratio (distribution ratio) to the treated water line 700 are associated on a straight line represented by a linear function in which the ratio decreases as the water level value increases. A reference water level is set for the water level value. In addition, the ratio at which the water level value becomes the reference water level on the straight line is set as the reference ratio. Using the correspondence shown in Figure 3, the ratio control unit 120 controls the opening degrees of valves 600 and 610, using the ratio associated with the water level value notified from the water level value acquisition unit 110 as the ratio to the treated water line 700. Furthermore, the ratio control unit 120 may use not only a linear function as shown in Figure 3, but also a correspondence in which the ratio decreases curvilinearly as the water level increases, or a correspondence in which the ratio decreases in steps as the water level increases.

[0020] The ratio control unit 120 notifies the pump control unit 130 of the controlled ratio (distribution ratio).

[0021] The pump control unit 130 controls the output of the pump 500 based on the ratio (distribution ratio) notified by the ratio control unit 120. Specifically, it controls the output (rotational speed) of the pump 500 by controlling the inverter 510 so that the ratio (distribution ratio) notified by the ratio control unit 120 becomes the reference ratio. For example, if the reference ratio is 95% and the ratio notified by the ratio control unit 120 is 90%, the pump control unit 130 lowers the output (rotational speed) of the pump 500 so that the ratio notified by the ratio control unit 120 becomes 95%. This is because the distribution ratio to the treated water line 700 is lower than the reference ratio, so the flow rate of treated water from the water treatment device 300 is reduced to increase the distribution ratio to the treated water line 700. Also, if the reference ratio is 95% and the ratio notified by the ratio control unit 120 is 100%, the pump control unit 130 increases the output (rotational speed) of the pump 500 so that the ratio notified by the ratio control unit 120 becomes 95%. This is because the distribution ratio to the treated water line 700 is higher than the standard ratio, so the flow rate of treated water from the water treatment device 300 is increased to lower the distribution ratio to the treated water line 700.

[0022] The control method performed by the control device 100 shown in Figure 1 will be described below. Figure 4 is a flowchart illustrating an example of the control method performed by the control device 100 shown in Figure 1. Here, we will explain using as an example a method that controls the ratio of treated water sent to the treated water line 700 based on the result of comparing the water level value acquired by the water level value acquisition unit 110 with the reference water level, as described above.

[0023] First, the water level acquisition unit 110 acquires the water level value from the water level gauge 410, which indicates the water level measured by the water level gauge 410 (step S1). Then, the ratio control unit 120 compares the water level value acquired by the water level acquisition unit 110 with the reference water level (step S2).

[0024] If the water level acquired by the water level acquisition unit 110 is higher than the reference water level, the ratio control unit 120 adjusts the opening of valves 600 and 610 to lower the ratio at which treated water treated by the water treatment device 300 is sent to the treated water line 700 from the reference ratio (step S3). Subsequently, the pump control unit 130 lowers the output (rotation speed) of the pump 500 so that the ratio notified by the ratio control unit 120 becomes the reference ratio (step S4).

[0025] On the other hand, if the water level acquired by the water level acquisition unit 110 is lower than the reference water level, the ratio control unit 120 adjusts the opening of valves 600 and 610 to increase the ratio at which treated water treated by the water treatment device 300 is sent to the treated water line 700 above the reference ratio (step S5). Subsequently, the pump control unit 130 increases the output (rotation speed) of the pump 500 so that the ratio notified by the ratio control unit 120 becomes the reference ratio (step S6).

[0026] The process described above is repeated until the water level reading from water level gauge 410 stabilizes at the reference water level, bringing the water level closer to the reference level.

[0027] In this configuration, the control device 100 controls the distribution ratio of water supplied to the treated water line 700 and water supplied to the return line 710 to the raw water tank 200, based on the water level of the treated water stored in the treated water tank 400, which is located in the treated water line 700 to which the treated water treated by the water treatment device 300 is supplied. The control device 100 then controls the output of the pump 500 that supplies the water to be treated to the water treatment device 300 so that the controlled distribution ratio approaches a standard value. In other words, the distribution ratio is controlled using valves 600 and 610 to respond immediately to fluctuations in the water level, while the pump 500 is used to control the distribution ratio so that it approaches a standard value. As a result, the effect of dilution by the returned treated water is reduced, and the water level of the treated water stored in the treated water tank can be easily kept constant while minimizing the impact on the water quality of the treated water. Furthermore, sensors such as flow meters and pressure gauges for measuring the flow rate of the treated water can be eliminated. (Second Embodiment)

[0028] Figure 5 shows a second embodiment of the water treatment equipment according to the present invention. As shown in Figure 5, the water treatment equipment according to this embodiment has a resistivity meter 311 and a DC power supply 312 added to the components of the first embodiment shown in Figure 1. Also, as shown in Figure 5, the water treatment device 300 shown in Figure 1 is replaced with an EDI 310 in this embodiment. In this embodiment, the control method performed by the control device 100 is the same as that in the first embodiment.

[0029] The EDI310 is an electrolytic deionized water production device. The EDI310 is equipped with a positive electrode and a negative electrode, and by passing an electric current between these electrodes, it produces desalinated water and concentrated water from raw water.

[0030] The resistivity meter 311 is a water quality meter that measures the resistivity of treated water (desalinated water) from the EDI 310 as a water quality measure. The resistivity meter 311 may also notify the DC power supply 312 of the measured resistivity. There is no specific timing for notification. The timing of notification may be, for example, a predetermined periodic timing, a timing based on an external instruction, or the timing when the measured resistivity reaches a preset value. In addition, a boron meter or silica meter may be provided as a water quality meter instead of the resistivity meter 311.

[0031] The DC power supply 312 acquires the resistivity measured by the resistivity meter 311. The DC power supply 312 is a water quality control unit that controls the current supplied to the EDI 310 so that the acquired resistivity falls within a predetermined range. Generally, when the flow rate of the water to be treated increases, the current supplied to the water per unit flow rate by the EDI 310 decreases. As a result, the quality of the desalinated water from the EDI 310 deteriorates (the resistivity decreases). On the other hand, when the flow rate of the water to be treated decreases, the current supplied to the water per unit flow rate by the EDI 310 increases. As a result, the quality of the desalinated water from the EDI 310 improves (the resistivity increases). By controlling the current supplied to the EDI 310 so that the resistivity measured by the resistivity meter 311 falls within a predetermined range, the water quality of the treated water (desalinated water) from the EDI 310 can be kept constant.

[0032] Alternatively, the DC power supply 312 may be divided into an element that supplies current to the EDI 310 and an element that controls that current, with the current control element included in the control device 100. In this case, the control device 100 acquires the resistivity measured by the resistivity meter 311. The control device 100 controls the current supplied to the EDI 310 so that the acquired resistivity falls within a predetermined range.

[0033] The following describes the water quality control method in the water treatment facility shown in Figure 5. Figure 6 is a flowchart illustrating an example of the water quality control method in the water treatment facility shown in Figure 5.

[0034] The resistivity meter 311 measures the resistivity of the treated water (demineralized water) from the EDI 310 (step S11). Then, the DC power supply 312 controls and supplies current to the EDI 310 so that the resistivity measured by the resistivity meter 311 falls within a predetermined range (step S12).

[0035] In this configuration, when the EDI310 is installed as a water treatment device, the resistivity of the treated water (desalination water) from the EDI310 is measured, and the supply current to the EDI310 is controlled so that the measured resistivity falls within a predetermined range. This reduces fluctuations in the water quality of the treated water due to flow rate fluctuations and helps to stabilize the water quality. (Third embodiment)

[0036] Figure 7 shows a third embodiment of the water treatment equipment according to the present invention. As shown in Figure 7, the water treatment equipment according to this embodiment has a conductivity meter 321 and a control valve 322 added to the components of the first embodiment shown in Figure 1. Also, as shown in Figure 7, the water treatment device 300 shown in Figure 1 is replaced with RO320 in this embodiment. In this embodiment, the control method performed by the control device 100 is the same as that in the first embodiment.

[0037] RO320 is a reverse osmosis membrane system. RO320 applies pressure to the supplied raw water and causes it to pass through a reverse permeable membrane, separating the raw water into permeate and concentrated water. The separated permeate is output to the treated water line 700 and the return line 710. Meanwhile, the separated concentrated water is drained into a line equipped with a control valve 322.

[0038] The conductivity meter 321 is a water quality meter that measures the conductivity of treated water (persemite) from RO320 as a water quality measure. The conductivity meter 321 may also notify the control valve 322 of the measured conductivity. There is no specific timing for notification. The timing of notification may be, for example, a predetermined periodic timing, a timing based on an external instruction, or the timing when the measured conductivity reaches a preset value. In addition, a resistivity meter may be provided instead of the conductivity meter 321 as a water quality meter.

[0039] The control valve 322 acquires the conductivity measured by the conductivity meter 321. The control valve 322 is a water quality control unit that controls the discharge of concentrated water from RO320 so that the acquired conductivity falls within a predetermined range. Specifically, the control valve 322 controls the flow rate (recovery rate) of the discharged concentrated water from RO320.

[0040] Alternatively, the control valve 322 may be divided into a valve element that opens and closes and an element that controls the opening and closing of the valve element, with the control device 100 including the element that controls the opening and closing of the valve element. In this case, the control device 100 acquires the conductivity measured by the conductivity meter 321. The control device 100 controls the opening and closing (degree of opening) of the valve element so that the acquired conductivity falls within a predetermined range.

[0041] The following describes a water quality control method for the water treatment facility shown in Figure 7. Figure 8 is a flowchart illustrating an example of a water quality control method for the water treatment facility shown in Figure 7.

[0042] The conductivity meter 321 measures the conductivity as a water quality measure of the treated water (permeate) from RO320 (step S21). Then, the control valve 322 controls the opening and closing (opening degree) of the valve so that the conductivity measured by the conductivity meter 321 falls within a predetermined range, thereby controlling the discharge of concentrated water from RO320 (step S22).

[0043] In this embodiment, when RO320 is installed as a water treatment device, the conductivity of the treated water (persemite) from RO320 is measured, and the flow rate of the concentrated water discharged from RO320 is controlled so that the measured conductivity falls within a predetermined range. This reduces fluctuations in the water quality of the treated water due to flow rate fluctuations and helps to stabilize the water quality. (Fourth embodiment)

[0044] Figure 9 shows a third embodiment of the water treatment equipment according to the present invention. As shown in Figure 9, the water treatment equipment according to this embodiment has a TOC meter 331 and a UV irradiation dose control means 332 added to the components of the first embodiment shown in Figure 1. Also, as shown in Figure 9, the water treatment device 300 shown in Figure 1 is replaced with a UV-CP 330 in this embodiment. In this embodiment, the control method performed by the control device 100 is the same as that in the first embodiment.

[0045] The UV-CP330 is a water treatment system that combines an ultraviolet oxidation device (UV) and a non-regenerative ion exchange resin tower (CP). In the ultraviolet oxidation device (UV), ultraviolet light is irradiated onto the water to be treated, and the total organic carbon (TOC) in the water is decomposed. Subsequently, in the non-regenerative ion exchange resin tower (CP), ionic components such as metal ions are removed by ion exchange treatment.

[0046] The TOC meter 331 is a water quality meter that measures the concentration of TOC (Total Organic Carbon) as a water quality measure of treated water from the UV-CP 330. The TOC meter 331 may also notify the UV irradiation dose control means 332 of the measured TOC concentration. The timing of the notification is not specifically defined. The timing of the notification may be, for example, a predetermined periodic timing, a timing based on an external instruction, or the timing when the measured TOC concentration reaches a preset value. The TOC meter 331 may be installed before the UV-CP 330. In addition, a DO meter that measures the concentration of dissolved oxygen in the water to be treated may be installed before the UV-CP 330.

[0047] The UV irradiation dose control means 332 acquires the TOC concentration measured by the TOC meter 331. The UV irradiation dose control means 332 is a water quality control unit that controls the amount of ultraviolet radiation irradiated by the UV-CP 330 onto the water to be treated so that the acquired TOC concentration falls within a predetermined range. Generally, when the flow rate of the water to be treated increases, the amount of ultraviolet radiation irradiated onto the water to be treated per unit flow rate by the UV-CP 330 (irradiation intensity) decreases. As a result, the water quality of the treated water from the UV-CP 330 deteriorates (the TOC concentration increases). On the other hand, when the flow rate of the water to be treated decreases, the amount of ultraviolet radiation irradiated onto the water to be treated per unit flow rate by the UV-CP 330 (irradiation intensity) increases. As a result, the water quality of the treated water from the UV-CP 330 improves (the TOC concentration decreases). The UV irradiation amount control means 332 controls the amount of ultraviolet light that the UV-CP330 irradiates onto the water to be treated so that the TOC concentration measured by the TOC meter 331 falls within a predetermined range, thereby maintaining a constant water quality for the treated water from the UV-CP330.

[0048] The UV irradiation dose control means 332 may also be included in the control device 100. In this case, the control device 100 acquires the TOC concentration measured by the TOC meter 331. The control device 100 controls the amount of ultraviolet light irradiated by the UV-CP 330 onto the water to be treated so that the acquired TOC concentration falls within a predetermined range.

[0049] The following describes a water quality control method for the water treatment facility shown in Figure 9. Figure 10 is a flowchart illustrating an example of a water quality control method for the water treatment facility shown in Figure 9.

[0050] The TOC meter 331 measures the TOC concentration of the treated water from the UV-CP 330 (step S31). Then, the UV irradiation amount control means 332 controls the amount of ultraviolet light that the UV-CP 330 irradiates the water to be treated with so that the TOC concentration measured by the TOC meter 331 falls within a predetermined range, and the UV-CP 330 irradiates the water to be treated with ultraviolet light (step S32).

[0051] In this embodiment, when the UV-CP330 is installed as a water treatment device, the TOC concentration of the treated water from the UV-CP330 is measured, and the amount of ultraviolet radiation emitted by the UV-CP330 is controlled so that the measured TOC concentration falls within a predetermined range, thereby irradiating the water to be treated with ultraviolet radiation. This reduces fluctuations in the water quality of the treated water due to flow fluctuations and helps to stabilize the water quality.

[0052] Figure 11 shows an example of a water treatment system to which the water treatment equipment of the present invention is applied. The water treatment system shown in Figure 11 has a pretreatment system 10, a primary pure water production system 20, and a secondary pure water production system 30, which is a so-called subsystem. The pretreatment system 10 can be a system used in a general water treatment system. The pretreatment system 10 is a water treatment equipment that removes fine particles from the supplied raw water. The primary pure water production system 20 performs predetermined treatment on the treated water treated in the pretreatment system 10 and supplies the treated water to the secondary pure water production system 30. The secondary pure water production system 30 can be a secondary pure water production system used in a general water treatment system. The secondary pure water production system 30 removes trace amounts of ions and total organic carbon that could not be removed by the primary pure water production system 20. The treated water treated in the secondary pure water production system 30 is supplied to the use point, which is the destination of the treated water.

[0053] The water treatment equipment of the present invention is applied to the primary pure water production system 20 shown in Figure 11. For example, the raw water tank 200 shown in Figure 1 may be applied to the desalination tank 21 in the primary pure water production system 20 shown in Figure 11, the water treatment device 300 shown in Figure 1 (RO320 shown in Figure 7) may be applied to the reverse osmosis membrane device 22 shown in Figure 11, and the treated water tank 400 shown in Figure 1 may be applied to the RO permeate tank 23 shown in Figure 11. Alternatively, the raw water tank 200 shown in Figure 1 may be applied to the RO permeate tank 23 in the primary pure water production system 20 shown in Figure 11, the water treatment device 300 shown in Figure 1 (EDI310 shown in Figure 5) may be applied to the EDI 24 shown in Figure 11, and the treated water tank 400 shown in Figure 1 may be applied to the EDI treated water tank 25 shown in Figure 11. Furthermore, the raw water tank 200 shown in Figure 1 may be applied to the EDI treatment tank 25 in the primary pure water production system 20 shown in Figure 11, the water treatment device 300 shown in Figure 1 (UV-CP330 shown in Figure 9) may be applied to the UV oxidation device 26 shown in Figure 11, and the treated water tank 400 shown in Figure 1 may be applied to the ultrapure water tank 31 in the secondary pure water production system 30 shown in Figure 11. These may also be applied in any combination. For example, the reverse osmosis membrane device 22, RO permeate tank 23, and EDI 24 shown in Figure 11 may be treated as a single device group, and the water treatment device 300 shown in Figure 1 may be applied to this device group. Alternatively, the reverse osmosis membrane device 22, RO permeate tank 23, EDI 24, EDI treatment tank 25, and UV oxidation device 26 shown in Figure 11 may be treated as a single device group, and the water treatment device 300 shown in Figure 1 may be applied to this device group.

[0054] The above explanation describes how each component is assigned a specific function (process), but this assignment is not limited to those described above. Furthermore, the configurations of the components described above are merely examples and are not limited to them. Also, the embodiments described above may be combined in any combination.

[0055] The processing performed by the control device 100 described above may also be performed by logic circuits created according to the purpose. Alternatively, a computer program (hereinafter referred to as "program") describing the processing content as a procedure may be recorded on a recording medium readable by the control device 100, and the program recorded on this recording medium may be read by the control device 100 and executed. A recording medium readable by the control device 100 refers to portable recording media such as floppy disks, magneto-optical disks, DVDs (Digital Versatile Discs), CDs (Compact Discs), Blu-ray Discs (Registered Trademarks), USB (Universal Serial Bus) memory, and SD cards, as well as memory such as ROM (Read Only Memory), RAM (Random Access Memory), and HDDs (Hard Disc Drives) built into the control device 100. The program recorded on this recording medium is read by a CPU (not shown) provided in the control device 100, and the same processing as described above is performed under the control of the CPU. Here, the CPU operates as a computer that executes the program read from the recording medium on which the program is recorded. [Explanation of Symbols]

[0056] 10 Pre-processing system 20 Primary pure water production system 21 Desalination tank 22 Reverse osmosis membrane equipment 23 RO permeable water tank 24,310 EDI 25 EDI treatment tanks 26 UV oxidation equipment 30 Secondary pure water production system 31 Ultrapure water tank 100 Control device 110 Water level acquisition unit 120 Ratio Control Unit 130 Pump Control Unit 200 raw water tanks 300 Water Treatment Equipment 311 Resistivity meter 312 DC power supply 320 RO 321 Conductivity meter 322 Control valve 330 UV-CP 331 TOC meter 332 UV irradiation dose control means 400 treatment tanks 410 Water level gauge 500 pumps 510 Inverter 600,610 valves 700 treated water line 710 Return Line

Claims

1. Pump and A water treatment device that performs predetermined treatment on raw water supplied from a raw water tank using the pump, A treated water line for sending the treated water treated by the water treatment device to a treated water tank, A return line for returning the treated water processed by the water treatment device to the raw water tank, a tank located upstream of the raw water tank, or a pipe through which raw water supplied from the raw water tank flows. A valve that distributes the treated water treated by the water treatment device to the treated water line and the return line, A water level measuring means for measuring the water level of the treated water stored in the aforementioned treated water tank, A ratio control unit controls the distribution ratio between the treated water line and the return line in the valve based on the water level measured by the water level measuring means, A water treatment facility comprising: a pump control unit that controls the output of the pump based on the distribution ratio controlled by the ratio control unit.

2. In the water treatment equipment described in claim 1, The ratio control unit, when the water level measured by the water level measuring means is higher than the reference water level, lowers the ratio at which treated water treated by the water treatment device is sent to the treated water line compared to the reference ratio, and when the water level measured by the water level measuring means is lower than the reference water level, raises the ratio at which treated water treated by the water treatment device is sent to the treated water line compared to the reference ratio. A water treatment facility in which the pump control unit controls the output of the pump so that the ratio controlled by the ratio control unit becomes the reference ratio.

3. In the water treatment equipment described in claim 1, The ratio control unit controls the valves according to a distribution ratio set in correspondence with the water level value measured by the water level measuring means, in a water treatment facility.

4. In the water treatment equipment described in claim 1, A water quality meter for measuring the water quality of the treated water treated by the water treatment device, A water treatment facility comprising: a water quality control unit that controls the water treatment device so that the water quality measured by the water quality meter falls within a predetermined range.

5. In the water treatment equipment described in claim 4, The water treatment apparatus is an electrolytic deionized water production apparatus, The water quality meter is a resistivity meter, The water quality control unit is a DC power supply that controls the current supplied to the electro-deionized water production apparatus, in a water treatment facility.

6. In the water treatment equipment described in claim 4, The water treatment device is a reverse osmosis membrane device. The aforementioned water quality meter is a conductivity meter, The water quality control unit is a control valve that controls the discharge of concentrated water from the reverse osmosis membrane device, in a water treatment facility.

7. In the water treatment equipment described in claim 4, The water treatment device is an ultraviolet oxidation device, The water quality meter is a TOC (Total Organic Carbon) meter. The water quality control unit is an irradiation dose control means for controlling the amount of ultraviolet radiation irradiated in the ultraviolet oxidation device, in a water treatment facility.

8. A water level acquisition unit that acquires a water level value indicating the water level of treated water stored in a treated water tank, which is supplied from the raw water tank using a pump and treated by the water treatment device, Based on the water level value acquired by the water level value acquisition unit, a ratio control unit controls the distribution ratio of valves that distribute the treated water treated by the water treatment device to a treated water line for sending water to the treated water tank and a return line for returning water to the raw water tank or a tank located upstream of the raw water tank or a pipe through which raw water supplied from the raw water tank flows. A control device comprising: a pump control unit that controls the output of the pump based on the distribution ratio of the valves controlled by the ratio control unit.

9. The process involves obtaining a water level value indicating the water level of the treated water stored in the treated water tank, which is supplied from the raw water tank using a pump and treated by the water treatment device. Based on the acquired water level value, a process to control the distribution ratio of valves that distribute the treated water treated by the water treatment device to a treated water line for sending water to the treated water tank and a return line for returning the treated water to the raw water tank or a tank located upstream of the raw water tank or a pipe through which raw water supplied from the raw water tank flows. A control method that performs a process to control the output of the pump based on the distribution ratio of the controlled valve.

10. On the computer, A procedure for obtaining the water level value indicating the water level of treated water stored in a treated water tank, which is supplied from the raw water tank using a pump and treated by a water treatment device, and A procedure for controlling the distribution ratio of valves that distribute the treated water treated by the water treatment device to a treated water line for sending water to the treated water tank, and to a return line for returning the treated water to the raw water tank, or a tank located upstream of the raw water tank, or a pipe through which raw water supplied from the raw water tank flows, based on the acquired water level value, A procedure for controlling the output of the pump based on the distribution ratio of the controlled valve, and a program for performing this procedure.

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