Water treatment system and method for operating water treatment system

Abstract

The water treatment system is provided with a membrane separation device and an ion exchange device, treats water to be treated, and is further provided with: a first pipe for simultaneously supplying a chemical solution to the membrane separation device and the ion exchange device in parallel; a first valve group (510, 530) provided in the first pipe; and a control device (600) that controls the opening and closing of the first valve groups (510, 530).

Description

Technical Field

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

[0002] In water treatment systems, in order to remove dissolved gases (CO 2 or 2 ), a degassing device with a degassing membrane is used. In addition, in order to remove ions and total organic carbon (TOC: Total Organic Carbon) contained in the water to be treated, water treatment devices such as ion exchange resins, reverse osmosis membranes, and ultrafiltration membranes are used. A water treatment system is constructed by combining multiple degassing devices and water treatment devices.

[0003] With the use of degassing membranes, organic or inorganic substances may adhere to or accumulate on the membrane surface, causing blockage, so-called fouling. If fouling occurs, the degassing performance and water permeability of the degassing device will be reduced. In order to remove the attached and accumulated organic or inorganic substances, the degassing membrane needs to be cleaned regularly. The degassing membrane is cleaned using a chemical solution such as an acid or an alkali (for example, see Patent Document 1).

[0004] In water treatment devices, regular cleaning and regeneration operations are also required. For example, in ion exchange resins, regular regeneration with a chemical solution is required. In addition, in order to restore the membrane performance reduced by fouling, membranes such as reverse osmosis membranes and ultrafiltration membranes are also cleaned using a chemical solution. In addition, a technology that uses a chemical solution used for cleaning a water treatment device to clean other water treatment devices is considered (for example, refer to Patent Document 2).

[0005] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2007-90249 Patent Document 2: Japanese Patent Application Publication No. 2016-22447 Summary of the invention

[0006] Technical problem to be solved by the invention The cleaning and regeneration of the above-mentioned devices are performed for each degassing device and water treatment device. When cleaning and regenerating the degassing device and water treatment device, the operation of the degassing device, water treatment device or the system equipped with these devices is usually stopped, and the device to be cleaned and regenerated is separated from the main line. Therefore, if cleaning and regeneration are frequently performed, there is a problem that the operating rate of the system is greatly reduced. In addition, in the technology described in Patent Document 2, the number of auxiliary equipment increases, and the structure of the system becomes complicated.

[0007] An object of the present invention is to provide a water treatment system and a method for operating the water treatment system, which can easily shorten the system operation stop time caused by the regeneration of the device.

[0008] Technical solutions for solving technical problems The water treatment system of the present invention comprises a membrane separation device and an ion exchange device. The water treatment system further comprises: a first pipe for simultaneously and in parallel supplying a chemical solution to the membrane separation device and the ion exchange device; a first valve group provided on the first pipe; and a control device for controlling opening and closing of the first valve group.

[0009] A water treatment system according to another aspect of the present invention comprises a membrane separation device and an ion exchange device. The water treatment system further comprises: a first pipe for supplying a chemical solution to the membrane separation device; a second pipe for supplying the chemical solution after passing through the membrane separation device to the ion exchange device; A first valve group is arranged on the first pipe; A second valve group is provided on the second pipe; and a control device for controlling the opening and closing of the first valve group and the opening and closing of the second valve group, The control device controls the opening and closing of the second valve group to supply the chemical solution that has passed through the membrane separation device to the ion exchange device.

[0010] In addition, the operating method of the water treatment system of the present invention is an operating method of the water treatment system including a membrane separation device and an ion exchange device. In the operating method of the water treatment system, a water passing step and a drug passing step are performed. In the water passing step, the opening and closing of valves arranged in the pipes are controlled to pass the water to be treated into the membrane separation device and the ion exchange device. In the chemical supplying step, the opening and closing of the valve is controlled based on a given timing to supply the chemical solution to the membrane separation device and the ion exchange device simultaneously and in parallel.

[0011] Effects of the Invention In the present invention, it is possible to easily shorten the system operation stop time due to the regeneration of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a diagram showing an example of the configuration of a general water treatment system.

[0013] Figure 2 It is a diagram showing a first embodiment of the water treatment system of the present invention.

[0014] Figure 3 It is used to illustrate Figure 2 Flow chart of a first example of an operating method in a water treatment system shown.

[0015] Figure 4 It is used to illustrate Figure 2 Flow chart of a second example of the operating method in the water treatment system shown.

[0016] Figure 5 It is a diagram showing a second embodiment of the water treatment system of the present invention.

[0017] Figure 6 It is used to illustrate Figure 5 Flowchart of an example of an operating method in the water treatment system shown.

[0018] Figure 7 It is a diagram showing a third embodiment of the water treatment system of the present invention.

[0019] Figure 8 It is used to illustrate Figure 7 Flowchart of an example of an operating method in the water treatment system shown.

[0020] Fig. 9 It is a diagram showing a fourth embodiment of the water treatment system of the present invention.

[0021] Fig.10 It is used to illustrate Fig. 9 Flowchart of an example of an operating method in the water treatment system shown.

[0022] Fig.11 This is a table showing the results of Example 1, Example 2, and Comparative Example. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figure 1 This is a diagram showing an example of the configuration of a general water treatment system. Figure 1The water treatment system shown has a raw water tank 100, a degassing device 200, and a water treatment device 300. The raw water tank 100 is a tank storing raw water as a liquid to be treated. The liquid stored in the raw water tank 100 is supplied from the raw water tank 100 to the degassing device 200 using, for example, a pump in the water passing process of the raw water. The degassing device 200 removes dissolved gas contained in the liquid supplied from the raw water tank 100. For example, the degassing device 200 is a membrane degassing device that uses a polymer membrane to remove dissolved gases such as dissolved oxygen and free carbon dioxide by allowing them to pass through the membrane. It should be noted that a membrane degassing device that removes free carbon dioxide is sometimes referred to as a decarbonation membrane device. The type of dissolved gas removed by the membrane degassing device in the present invention is not particularly limited. For example, the membrane degassing device in the present invention can remove dissolved gas regardless of its type, or can remove a specific type of dissolved gas. The liquid from which the dissolved gas has been removed by the degassing device 200 is supplied to the water treatment device 300 in the water passing process. The water treatment device 300 is connected in series with the degassing device 200, and is a device for removing impurities contained in the liquid supplied from the degassing device 200. The water treatment device 300 may be, for example, an ion exchange device filled with ion exchange resin. As the ion exchange resin, a cation exchange resin that removes cationic components in water and an anion exchange resin that removes anionic components in water can be used. The water treatment device 300 may also be a UF (ultrafiltration device) or a RO (reverse osmosis membrane). The liquid (treated water) treated by the water treatment device 300 is stored in a treated water tank as needed in the water passing process, or is treated by other unit operations. Such water is used as pure water, ultrapure water for the manufacture of electronic components such as semiconductors, and miscellaneous water in the factory, depending on the quality of the raw water and the purity of the treated water. It should be noted that other water treatment devices (for example, a cation exchange resin device filled with cation exchange resin, etc.) may also be configured between the raw water tank 100 and the degassing device 200.

[0024] The present invention described below relates to Figure 1 Regeneration and cleaning of components used in the water treatment system in the water passing process shown.

[0025] (First embodiment) Figure 2 1 is a diagram showing a first embodiment of the water treatment system of the present invention. Figure 2 As shown, the water treatment system in this embodiment includes a raw water tank 100, a degassing device 200 (membrane separation device), and a water treatment device 300 (ion exchange device). Figure 1The membrane separation device is the same as the device shown in the figure. Here, the membrane separation device is a device that uses a separation membrane to remove ions, TOC, SS (suspended matter), gas components, etc. in raw water. In addition, examples of separation membranes include microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, reverse osmosis membranes, degassing membranes (decarbonation membranes), etc. Further, as Figure 2 As shown, the water treatment system in this embodiment has a liquid medicine tank 400, a valve 510, a valve 520, a valve 530, a valve 540 as a plurality of opening and closing valves, and a control device 600. The valve 510 and the valve 530 constitute a first valve group. These components are connected to each other via piping. In this embodiment, the piping from the liquid medicine tank 400 to the degassing device 200 and the water treatment device 300 is the first piping. In addition, the piping from the degassing device 200 to the water treatment device 300 via the valve 520 and the valve 530 is the second piping.

[0026] The chemical liquid tank 400 is a tank storing a chemical liquid for regenerating the degassing device 200 and the water treatment device 300. When the water treatment device 300 is filled with an anion exchange resin, the chemical liquid stored in the chemical liquid tank 400 is, for example, an alkaline chemical liquid such as a sodium hydroxide solution and a potassium hydroxide solution. In addition, when the water treatment device 300 is filled with a cation exchange resin, the chemical liquid stored in the chemical liquid tank 400 is, for example, an acidic chemical liquid such as hydrochloric acid and sulfuric acid. The chemical liquid stored in the chemical liquid tank 400 is supplied from the chemical liquid tank 400 to the valve 510 and the valve 530 using, for example, a pump in the process of passing the chemical liquid. It should be noted that a method of mixing a chemical liquid such as sodium hydroxide with clear water such as RO treated water, ion exchange water, and pure water in a pipeline and then supplying it to the valve 510 and the valve 530 can also be used instead of supplying the chemical liquid stored in the chemical liquid tank 400 to 510 and 530. The chemical liquid from the chemical liquid tank 400 is supplied to the degassing device 200 and the water treatment device 300 simultaneously and in parallel via the first piping. The meaning of "simultaneously" here is not limited to the meaning of strictly the same timing with each other, and as long as the effect of the present invention can be achieved, it also includes the meaning of a difference of less than a preset time. This meaning is also the same for the embodiments described below.

[0027] The control device 600 controls the opening and closing of the valves 510, 520, 530, and 540, each of which is arranged in a path where the liquid to be treated, the treated liquid, the chemical solution, etc. flow. The control device 600 controls the opening and closing of the valves 510 and 530 in the chemical passing process so that the chemical solution supplied from the chemical solution tank 400 is supplied to the degassing device 200 and the water treatment device 300 in parallel. Specifically, the control device 600 controls the opening and closing of the valve 510 so that the liquid from the raw water tank 100 is not supplied to the degassing device 200, and the chemical solution from the chemical solution tank 400 is supplied to the degassing device 200. In addition, the control device 600 controls the opening and closing of the valve 530 so that the liquid from the valve 520 is not supplied to the water treatment device 300, and the chemical solution from the chemical solution tank 400 is supplied to the water treatment device 300. Furthermore, the control device 600 controls the opening and closing of the valve 520 so that the liquid flowing out of the degassing device 200 flows to the waste path. In addition, the control device 600 controls the opening and closing of the valve 540 so that the liquid flowing out of the water treatment device 300 flows to the waste path.

[0028] The timing of the transition from the water passing process to the drug passing process may also be a timing in accordance with a preset schedule. In addition, the timing of the transition from the water passing process to the drug passing process may also be a timing based on the difference between the pressure of the raw water side (raw water tank 100 side) of the front stage of the degassing device 200 and the pressure of the treated water side (water treatment device 300 side) of the back stage of the degassing device 200. Specifically, when the difference between the pressure of the raw water side of the degassing device 200 and the pressure of the permeation side of the degassing device 200 exceeds a given threshold, the control device 600 controls the opening and closing of the valves 510, 520, 530, and 540 in order to transition from the water passing process to the drug passing process.

[0029] The following, Figure 2 The operation method in the water treatment system shown is described. Figure 3 It is used to illustrate Figure 2 Flow chart of a first example of an operating method in a water treatment system shown.

[0030] First, in order to perform the water passing process, the control device 600 controls the opening and closing of the valve 510, the valve 520, the valve 530, and the valve 540 to pass water from the raw water tank 100 (step S1). Specifically, the control device 600 controls the opening and closing of the valve 510 so that the liquid from the raw water tank 100 is supplied to the degassing device 200. In addition, the control device 600 controls the opening and closing of the valve 520 and the valve 530 so that the liquid from the degassing device 200 is supplied to the water treatment device 300. In addition, the control device 600 controls the opening and closing of the valve 540 so that the liquid from the water treatment device 300 is supplied to the treated water tank.

[0031] The control device 600 controls the opening and closing of the valves 510, 520, 530, and 540 so that water is passed from the raw water tank 100. After the water passing process is performed, the control device 600 determines whether it is the timing to pass the chemical solution based on a preset schedule (step S2). The timing to pass the chemical solution is the timing to shift from the water passing process to the chemical passing process.

[0032] If the control device 600 determines that it is the timing to pass the chemical solution, the control device 600 controls the opening and closing of the valve 510, the valve 520, the valve 530, and the valve 540 (step S3) so that the chemical solution from the chemical solution tank 400 is supplied to the degassing device 200 and the water treatment device 300 in parallel. Specifically, the control device 600 controls the opening and closing of the valve 510 so that the liquid from the raw water tank 100 is not supplied to the degassing device 200, and the chemical solution from the chemical solution tank 400 is supplied to the degassing device 200. In addition, the control device 600 controls the opening and closing of the valve 520 so that the chemical solution from the degassing device 200 flows to the path for disposal. In addition, the control device 600 controls the opening and closing of the valve 530 so that the chemical solution from the chemical solution tank 400 is supplied to the water treatment device 300. In addition, the control device 600 controls the opening and closing of the valve 540 so that the chemical solution from the water treatment device 300 flows to the path for disposal.

[0033] Figure 4 It is used to illustrate Figure 2 Flow chart of a second example of the operating method in the water treatment system shown.

[0034] First, in order to perform the water passing process, the control device 600 controls the opening and closing of the valve 510, the valve 520, the valve 530, and the valve 540 to pass water from the raw water tank 100 (step S11). Specifically, the control device 600 controls the opening and closing of the valve 510 so that the liquid from the raw water tank 100 is supplied to the degassing device 200. In addition, the control device 600 controls the opening and closing of the valve 520 and the valve 530 so that the liquid from the degassing device 200 is supplied to the water treatment device 300. In addition, the control device 600 controls the opening and closing of the valve 540 so that the liquid from the water treatment device 300 is supplied to the treated water tank.

[0035] The control device 600 controls the opening and closing of the valves 510, 520, 530, and 540 to pass water from the raw water tank 100. After the water passing process, the control device 600 determines whether the difference (pressure difference) between the pressure on the raw water side of the degassing device 200 and the pressure on the permeate side of the degassing device 200 exceeds a given threshold value (step S12).

[0036] When the control device 600 determines that the difference (pressure difference) between the pressure on the raw water side of the degassing device 200 and the pressure on the permeate side of the degassing device 200 exceeds a given threshold value, the control device 600 controls the opening and closing of the valves 510, 520, 530, and 540 so that the chemical liquid from the chemical liquid tank 400 is supplied to the degassing device 200 and the water treatment device 300 in parallel (step S13). Specifically, the control device 600 controls the opening and closing of the valve 510 so that the liquid from the raw water tank 100 is not supplied to the degassing device 200, and the chemical liquid from the chemical liquid tank 400 is supplied to the degassing device 200. In addition, the control device 600 controls the opening and closing of the valve 520 so that the chemical liquid from the degassing device 200 flows to the path for disposal. In addition, the control device 600 controls the opening and closing of the valve 530 so that the chemical liquid from the chemical liquid tank 400 is supplied to the water treatment device 300. In addition, the control device 600 controls the opening and closing of the valve 540 so that the chemical solution from the water treatment device 300 flows to the path for disposal.

[0037] It should be noted that, when the water treatment system has a redundant structure with multiple operation trains, if the train operating in the water passing process is transferred from the water passing process to the chemical passing process, it is needless to say that the other trains are transferred to the water passing process. This also applies to the following embodiments.

[0038] Thus, in this method, in the process of introducing the chemical solution to regenerate the degassing device and the water treatment device constituting the water treatment system, the chemical solution is supplied to the degassing device and the water treatment device in parallel. Therefore, the system operation stop time caused by the regeneration of the device can be easily shortened.

[0039] It should be noted that in the process of introducing the drug solution, for example, Figure 2 The chemical tank 400 shown is provided with a valve at a position where the valve 510 and the valve 530 branch, or the path from the chemical tank 400 to the valve 530 is cut off / eliminated, so that the chemical from the chemical tank 400 is not directly supplied to the valve 530. In this case, in the process of passing the chemical, the chemical from the chemical tank 400 can also be supplied to the degassing device 200, and the chemical after passing through the degassing device 200 can be supplied to the water treatment device 300. Thereby, the amount of chemical used in the process of passing the chemical and the amount of water discharged from the chemical can be reduced.

[0040] (Second embodiment) Figure 5 2 is a diagram showing a second embodiment of the water treatment system of the present invention. Figure 5 As shown in FIG. 1 , the water treatment system in this embodiment includes a raw water tank 100, a degassing device 200, and a water treatment device 300. These are the same as those in the first embodiment. Figure 5As shown, the water treatment system in this embodiment has a liquid medicine tank 400, a valve 510, a valve 530, a valve 540 as a plurality of opening and closing valves, and a control device 601. The valve 510 and the valve 530 constitute a first valve group. It should be noted that the valve 520 of the first embodiment may also be provided. The valve 520 and the valve 530 constitute a second valve group. The valve 530 belongs to the first valve group and the second valve group. That is, the valve 530 plays two roles, the role of the first valve group and the role of the second valve group. In the case where the valve 520 is provided, after the drug passing process just begins, the control device 601 can also control the valve 520 to discharge the liquid medicine passed into the degassing device 200 to the outside of the system. Afterwards, at a given timing, the control device 601 controls the valve 520 to supply the liquid medicine passed into the degassing device 200 to the valve 530. As a given timing, for example When a preset time has passed; When the TOC value contained in the chemical solution from the degassing device 200 becomes lower than a given threshold value; When the pH value of the drug solution from the degassing device 200 becomes higher than a given threshold; When the conductivity of the chemical solution from the degassing device 200 becomes higher than a given threshold The reason for this is that, in the early stage of the drug passing process, the drug solution passed into the degassing device 200 contains a large amount of removed pollutants, which may re-contaminate the water treatment device 300. In addition, the reason for this is to prevent the drug solution diluted by the water contained in the degassing device 200 from flowing into the water treatment device 300.

[0041] The valve 510, valve 530, valve 540 and chemical tank 400 are respectively the same as those in the first embodiment. In this embodiment, the piping from the chemical tank 400 to the degassing device 200 and the water treatment device 300 is the first piping. In addition, the piping from the degassing device 200 to the water treatment device 300 via the valve 530 is the second piping.

[0042] The control device 601 controls the opening and closing of the valve 510, the valve 530, and the valve 540, each of which is provided in a path through which the liquid to be treated, the treated liquid, the chemical solution, etc. flow. The control device 601 controls the opening and closing of the valve 510 and the valve 530 in the chemical passing process so that the chemical solution supplied from the chemical solution tank 400 is supplied to the degassing device 200 and the water treatment device 300 in parallel. Specifically, the control device 601 controls the opening and closing of the valve 510 so that the liquid from the raw water tank 100 is not supplied to the degassing device 200, and the chemical solution from the chemical solution tank 400 is supplied to the degassing device 200. In addition, the control device 601 controls the opening and closing of the valve 530 so that the chemical solution from the degassing device 200 and the chemical solution from the chemical solution tank 400 are supplied to the water treatment device 300. Furthermore, the control device 601 controls the opening and closing of the valve 540 so that the liquid flowing out of the water treatment device 300 flows to the path for disposal. In this embodiment, when the valve 520 of the first embodiment is provided, the control device 601 controls the opening and closing of the valve 520 so that the liquid flowing out of the degassing device 200 is supplied to the water treatment device 300 (valve 530). At this time, the control device 601 may also control the opening and closing of the valves 520 and 530 to continue the supply of the liquid medicine from the liquid medicine tank 400 directly through the valve 530 to the water treatment device 300. In addition, if the supply amount of the liquid medicine passed through the degassing device 200 to the water treatment device 300 is sufficient, the control device 601 may also control the opening and closing of the valves 520 and 530 to cut off the supply of the liquid medicine from the liquid medicine tank 400 directly through the valve 530 to the water treatment device 300.

[0043] The timing of transition from the water passing step to the chemical passing step is the same as that in the first embodiment.

[0044] The following, Figure 5 The operation method in the water treatment system shown is described. Figure 6 It is used to illustrate Figure 5 Flowchart of an example of an operating method in the water treatment system shown.

[0045] First, in order to perform the water passing process, the control device 601 controls the opening and closing of the valve 510, the valve 530, and the valve 540 to pass water from the raw water tank 100 (step S21). Specifically, the control device 601 controls the opening and closing of the valve 510 so that the liquid from the raw water tank 100 is supplied to the degassing device 200. In addition, the control device 601 controls the opening and closing of the valve 530 so that the liquid from the degassing device 200 is supplied to the water treatment device 300. In addition, the control device 601 controls the opening and closing of the valve 540 so that the liquid from the water treatment device 300 is supplied to the equipment such as the treated water tank provided at the subsequent stage.

[0046] The control device 601 controls the opening and closing of the valves 510, 530, and 540 to pass water from the raw water tank 100. After the water passing process, the control device 601 determines whether it is the timing to pass the chemical solution based on a preset schedule (step S22). The timing to pass the chemical solution is the timing to transfer from the water passing process to the chemical passing process.

[0047] If the control device 601 determines that it is the timing to pass the chemical solution, the control device 601 controls the opening and closing of the valve 510, the valve 530, and the valve 540 (step S23) so that the chemical solution from the chemical solution tank 400 is supplied to the degassing device 200 and the water treatment device 300 in parallel. Specifically, the control device 601 controls the opening and closing of the valve 510 so that the liquid from the raw water tank 100 is not supplied to the degassing device 200, and the chemical solution from the chemical solution tank 400 is supplied to the degassing device 200. In addition, the control device 601 controls the opening and closing of the valve 530 so that the chemical solution from the degassing device 200 and the chemical solution from the chemical solution tank 400 are supplied to the water treatment device 300. In addition, the control device 601 controls the opening and closing of the valve 540 so that the chemical solution from the water treatment device 300 flows to the path for disposal. In the present embodiment, when the valve 520 of the first embodiment is provided, the control device 601 controls the opening and closing of the valve 520 so that the chemical solution flowing out of the degassing device 200 is also supplied to the water treatment device 300 (valve 530 ).

[0048] Thus, in this method, in the process of passing the chemical liquid in order to regenerate the degassing device and the water treatment device constituting the water treatment system, the chemical liquid is supplied to the degassing device and the water treatment device in parallel. Therefore, the operation stop time of the system caused by the regeneration of the device can be easily shortened. Furthermore, the chemical liquid after passing through the degassing device is supplied to the water treatment device. Thus, the amount of chemical liquid used in the chemical passing process and the amount of water discharged from the chemical liquid can be reduced. If the chemical liquid after passing through the degassing device is supplied to the water treatment device, the amount of chemical liquid supplied from the chemical liquid tank to the water treatment device can also be reduced.

[0049] (Third Embodiment) Figure 7 2 is a diagram showing a third embodiment of the water treatment system of the present invention. Figure 7 As shown in FIG. 1 , the water treatment system in this embodiment includes a raw water tank 100, a degassing device 200, and a water treatment device 300. These are the same as those in the first embodiment. Figure 7As shown, the water treatment system in this embodiment has a liquid medicine tank 400, valve 520, valve 530, valve 550, valve 560 as multiple opening and closing valves, and a control device 602. The valve 530 and valve 550 constitute a first valve group. The valve 550 and valve 560 constitute a third valve group. Valve 550 belongs to the first valve group and the third valve group. That is, valve 550 plays two roles: the role of the first valve group and the role of the third valve group. After the drug passing process just starts, the control device 602 controls valve 560 and can also discharge the liquid medicine after passing into the water treatment device 300 to the outside of the system. Afterwards, at a given timing, the control device 602 controls valve 560 to supply the liquid medicine after passing into the water treatment device 300 to valve 550. As a given timing, for example When a preset time has passed; When the TOC value contained in the chemical solution from the water treatment device 300 becomes smaller than a given threshold value; When the pH value of the chemical solution from the water treatment device 300 becomes higher than a given threshold; When the conductivity of the chemical solution from the water treatment device 300 becomes higher than a given threshold The reason for this is that, in the early stage of the drug passing process, the drug solution passed into the water treatment device 300 contains a large amount of removed pollutants, which may re-contaminate the degassing device 200. In addition, the reason for this is to prevent the drug solution diluted by the water contained in the degassing device 200 from flowing into the water treatment device 300.

[0050] The valve 520, the valve 530 and the liquid medicine tank 400 are respectively the same as those in the first embodiment. In this embodiment, the piping from the liquid medicine tank 400 to the degassing device 200 and the water treatment device 300 is the first piping. In addition, the piping from the degassing device 200 to the water treatment device 300 via the valve 520 and the valve 530 is the second piping. In addition, the piping from the water treatment device 300 to the degassing device 200 via the valve 560 and the valve 550 is the third piping.

[0051] The control device 602 controls the opening and closing of the valve 520, the valve 530, the valve 550, and the valve 560, each of which is provided in a path through which the liquid to be treated, the treated liquid, the chemical solution, etc. flow. The control device 602 controls the opening and closing of the valve 520, the valve 530, the valve 550, and the valve 560 in the chemical passing process so that the chemical solution supplied from the chemical solution tank 400 is supplied to the degassing device 200 and the water treatment device 300 in parallel. Specifically, the control device 602 controls the opening and closing of the valve 550 so that the liquid from the raw water tank 100 is not supplied to the degassing device 200, and the chemical solution from the chemical solution tank 400 is supplied to the degassing device 200. At this time, the control device 602 controls the valve 550 so that the chemical solution from the water treatment device 300 through the valve 560 is also supplied to the degassing device 200. In addition, the control device 602 controls the opening and closing of the valve 530 so that the chemical liquid from the chemical liquid tank 400 is supplied to the water treatment device 300. Further, the control device 602 controls the opening and closing of the valve 560 so that the chemical liquid flowing out of the water treatment device 300 is supplied to the valve 550. In addition, the control device 602 controls the opening and closing of the valve 520 so that the liquid flowing out of the degassing device 200 flows to the path for disposal. At this time, the control device 602 may also control the opening and closing of the valves 550 and 560 to continue the supply of the chemical liquid from the chemical liquid tank 400 directly through the valve 550 to the degassing device 200. In addition, if the supply amount of the chemical liquid passed into the water treatment device 300 to the degassing device 200 is sufficient, the control device 602 may also control the opening and closing of the valves 550 and 560 to cut off the supply of the chemical liquid from the chemical liquid tank 400 directly through the valve 550 to the degassing device 200.

[0052] The timing of transition from the water passing step to the chemical passing step is the same as that in the first embodiment.

[0053] The following, Figure 7 The operation method in the water treatment system shown is described. Figure 8 It is used to illustrate Figure 7 Flowchart of an example of an operating method in the water treatment system shown.

[0054] First, in order to perform the water passing process, the control device 602 controls the opening and closing of the valve 520, the valve 530, the valve 550, and the valve 560 to pass water from the raw water tank 100 (step S31). Specifically, the control device 602 controls the opening and closing of the valve 550 so that the liquid from the raw water tank 100 is supplied to the degassing device 200. In addition, the control device 602 controls the opening and closing of the valve 520 and the valve 530 so that the liquid from the degassing device 200 is supplied to the water treatment device 300. In addition, the control device 602 controls the opening and closing of the valve 560 so that the liquid from the water treatment device 300 is supplied to the treated water tank.

[0055] The control device 602 controls the opening and closing of the valves 520, 530, 550, and 560 to pass water from the raw water tank 100. After the water passing process, the control device 602 determines whether it is the timing to pass the chemical solution based on a preset schedule (step S32). The timing to pass the chemical solution is the timing to transfer from the water passing process to the chemical passing process.

[0056] If the control device 602 determines that it is the timing to introduce the chemical solution, the control device 602 controls the opening and closing of the valve 520, the valve 530, the valve 550, and the valve 560 (step S33) so that the chemical solution from the chemical solution tank 400 is supplied to the degassing device 200 and the water treatment device 300 in parallel, and the chemical solution from the water treatment device 300 is supplied to the degassing device 200 via the valve 550 and the valve 560. Specifically, the control device 602 controls the opening and closing of the valve 530 so that the chemical solution from the chemical solution tank 400 is supplied to the water treatment device 300. In addition, the control device 602 controls the opening and closing of the valve 560 so that the chemical solution from the water treatment device 300 is supplied to the valve 550. In addition, the control device 602 controls the opening and closing of the valve 550 so that the liquid from the raw water tank 100 is not supplied to the degassing device 200, and the chemical liquid from the chemical liquid tank 400 and the chemical liquid from the water treatment device 300 through the valve 560 are supplied to the degassing device 200. Furthermore, the control device 602 controls the opening and closing of the valve 520 so that the chemical liquid from the degassing device 200 flows to the path for disposal.

[0057] Thus, in this method, in the process of passing the chemical solution in order to regenerate the degassing device and the water treatment device constituting the water treatment system, the chemical solution is supplied to the degassing device and the water treatment device in parallel. Therefore, the operation stop time of the system caused by the regeneration of the device can be easily shortened. Furthermore, the chemical solution after passing through the water treatment device is supplied to the degassing device. Thus, the amount of chemical solution used in the chemical passing process and the amount of water discharged from the chemical solution can be reduced.

[0058] (Fourth Embodiment) Fig. 9 1 is a diagram showing a fourth embodiment of the water treatment system of the present invention. In this embodiment, the operation when the water treatment system is transferred from the water treatment process to the cleaning process is described. Fig. 9 As shown in FIG. 1 , the water treatment system in this embodiment includes a raw water tank 100, a degassing device 200, and a water treatment device 300. These are the same as those in the first embodiment. Fig. 9 As shown, the water treatment system in this embodiment includes a chemical tank 400, a plurality of on-off valves including valve 530, valve 540, valve 570, valve 580, a control device 603, and a cleaning water tank 700. In this embodiment, valve 530, valve 570, and valve 580 constitute a fourth valve group.

[0059] Valves 530, 540 and the liquid medicine tank 400 are the same as those in the first embodiment. The liquid medicine tank 400 is used in the drug passing step before the cleaning step, and is not used in the cleaning step. In this embodiment, the cleaning step after the drug passing step is used as an example. Fig. 9 4 shows the chemical tank 400. In this embodiment, the piping from the chemical tank 400 to the degassing device 200 and the water treatment device 300 is the first piping. In addition, the piping from the degassing device 200 to the water treatment device 300 via the valve 530 is the second piping. In addition, the piping from the cleaning water tank 700 to the water treatment device 300 via the degassing device 200 is the fourth piping. The piping from the valve 570 to the degassing device 200 via the valve 580 serves as both the first piping and the fourth piping. The piping from the degassing device 200 to the water treatment device 300 via the valve 530 serves as both the second piping and the fourth piping.

[0060] The cleaning water tank 700 is a tank storing liquid (cleaning water) which is used to clean the degassing device 200 and the water treatment device 300 into which the chemical solution is passed in the cleaning process. Raw water, RO treated water, ion exchange water, pure water, etc. can be used as the cleaning water. When the cleaning water is raw water, the cleaning water tank can also be used as a raw water tank.

[0061] The control device 603 controls the opening and closing of the valve 530, the valve 540, the valve 570, and the valve 580, each of which is provided in a path through which the liquid to be treated, the treated liquid, the chemical solution, the cleaning water, etc. flow. The control device 602 controls the opening and closing of the valve 530, the valve 540, the valve 570, and the valve 580 in the cleaning process after the chemical passing process so that the cleaning water supplied from the cleaning water tank 700 is supplied to the degassing device 200, and the cleaning water flowing to the degassing device 200 is supplied to the water treatment device 300. Specifically, when the chemical passing process ends and the cleaning process begins, the control device 603 controls the opening and closing of the valve 570 so that the chemical solution from the chemical solution tank 400 is not supplied to the degassing device 200 via the valve 580, and the cleaning water from the cleaning water tank 700 is supplied to the degassing device 200 via the valve 580. In addition, the control device 603 controls the opening and closing of the valve 580 so that the liquid from the raw water tank 100 is not supplied to the degassing device 200 and the cleaning water from the valve 570 is supplied to the degassing device 200. In addition, the control device 603 controls the opening and closing of the valve 530 so that the chemical liquid from the chemical liquid tank 400 is not supplied to the water treatment device 300 and the cleaning water from the degassing device 200 is supplied to the water treatment device 300. In addition, the control device 603 controls the opening and closing of the valve 540 so that the cleaning water from the water treatment device 300 flows to the path for disposal.

[0062] The timing of the transition from the drug passing step to the cleaning step may also be a timing in accordance with a preset schedule. In addition, the timing of the transition from the drug passing step to the cleaning step may also be a timing when the amount of the drug solution supplied from the drug solution tank 400 in the drug passing step reaches a preset amount.

[0063] The following, Fig. 9 The operation method in the water treatment system shown is described. Fig.10 It is used to illustrate Fig. 9 Flowchart of an example of an operating method in the water treatment system shown.

[0064] When the drug passing process is completed (step S41), the opening and closing of valves 530, 540, 570, and 580 are controlled so that the cleaning water from the cleaning water tank 700 is supplied to the degassing device 200, and the cleaning water passed to the degassing device 200 is supplied to the water treatment device 300 (step S42). Specifically, the control device 603 controls the opening and closing of valve 570 so that the chemical liquid from the chemical liquid tank 400 is not supplied to valve 580, and the cleaning water from the cleaning water tank 700 is supplied to the degassing device 200 through valve 580. In addition, the control device 603 controls the opening and closing of valve 580 so that the liquid from the raw water tank 100 is not supplied to the degassing device 200, and the cleaning water from valve 570 is supplied to the degassing device 200. In addition, the control device 603 controls the opening and closing of the valve 530 so that the chemical solution from the chemical solution tank 400 is not supplied to the water treatment device 300 and the cleaning water from the degassing device 200 is supplied to the water treatment device 300. In addition, the control device 603 controls the opening and closing of the valve 540 so that the cleaning water from the water treatment device 300 flows to the path for disposal.

[0065] It should be noted that although the entry path of the drug solution in the drug passing process in this method is described using the same entry path as that in the second embodiment, it is not limited to this. For example, the entry path of the drug solution in the first embodiment and the entry path of the drug solution in the third embodiment may also be used.

[0066] Thus, in this method, in the cleaning process performed after the process of passing the chemical solution to regenerate the degassing device and the water treatment device constituting the water treatment system, cleaning water is supplied to the degassing device, and the cleaning water after passing through the degassing device is supplied to the water treatment device. Thus, the amount of cleaning water used in the cleaning process and the amount of water discharged from the cleaning water can be reduced.

[0067] It should be noted that in the water passing process, the water treatment device 300 may also be arranged in the front stage of the degassing device 200. In the cleaning process of this structure, the cleaning water discharged from the water treatment device 300 used for cleaning the water treatment device 300 may be supplied to the degassing device 200, and the degassing device 200 may be cleaned using the supplied cleaning water. In addition, before and after the water passing process, the drug passing process, and the cleaning process, other independent processes may be performed on the degassing device 200 and the water treatment device 300. For example, a flushing process of replacing the liquid in the degassing device and the water treatment device with raw water; a process of circulating the drug solution in the degassing membrane and the separation membrane; an extrusion process of supplying water to the ion exchange resin to squeeze out the drug solution; a circulation standby process of circulating water in the device to prepare for water collection, an immersion process, etc. may be performed. In the case of performing any process, the present invention contributes to reducing the stop time of the entire system, reducing the amount of drugs in the drug water passing process, and reducing the amount of water used. In addition, in the degassing device 200 and the water treatment device 300, the direction of passing the raw water and the direction of passing the chemical solution are not particularly limited. Figure 2 In the figure, the direction of the raw water flowing into the degassing device 200 and the water treatment device 300 and the direction of the liquid medicine flowing into the degassing device 200 and the water treatment device 300 are shown as follows: Figure 2 The direction of the raw water flow and the direction of the liquid medicine flow may be opposite to each other. The direction may also be set from the outside.

[0068] [Example 1] Water flow process: The raw water from which turbidity and chlorine were removed was pre-treated in advance by a degassing membrane and an anion exchange resin device in that order to obtain treated water. As the degassing membrane, a separation membrane module manufactured by 3M was used. In addition, as the water treatment device, an anion exchange device filled with anion exchange resins AMBERJET4200 (manufactured by DuPont) and IRA96RF (manufactured by DuPont) in a ratio of 2:1 was used.

[0069] Drug-passing process: Sodium hydroxide is added to the treated water obtained from the water passing step to prepare a sodium hydroxide solution with a concentration of 1.5% as a cleaning solution. The cleaning solution is passed through the degassing membrane and the anion exchange resin device, respectively, and regenerated. After regeneration for a given time, the raw water is passed through the anion exchange resin device to clean the anion exchange resin. Then, the raw water is passed through the degassing membrane to clean the degassing membrane. After the cleaning of the degassing membrane and the anion exchange resin device is completed, transfer to the water passing step.

[0070] [Example 2] In the cleaning step, raw water is passed through the anion exchange resin, and the degassing membrane is cleaned using the water that has passed through the anion exchange resin.

[0071] [Comparative Example] The degassing membrane and the anion exchange resin are regenerated and cleaned separately.

[0072] Fig.11 TABLE 1 is a table showing the results of Example 1, Example 2 and Comparative Example. Fig.11 As shown, in the comparative example, the degassing membrane and the anion exchange resin device are regenerated and cleaned separately. Therefore, it takes a long time corresponding to the amount of individual treatment. On the other hand, in Example 1, the degassing membrane and the anion exchange resin are regenerated simultaneously with each other. Therefore, the drug passing process time can be shortened. In addition, in Example 2, by passing the water that cleaned the anion exchange resin to the degassing membrane (reuse), it is possible to achieve a shortening of the cleaning time and a reduction in the amount of cleaning water used.

[0073] In the above, each component is explained to share each function (processing), but this distribution is not limited to the above method. In addition, regarding the structure of the components, the above method is only an example and is not limited to this. In addition, the various embodiments can also be combined. In addition, the valve 510, valve 520, valve 530, valve 540, valve 550, valve 560, valve 570, and valve 580 are not limited to three-way valves, but can also be a combination of independent valves that open and close each input and output.

[0074] As mentioned above, although the present invention has been described with reference to the embodiment, the present invention is not limited to the above-mentioned embodiment. Various changes that can be understood by those skilled in the art can be made to the structure and details of the present invention within the scope of the present invention.

[0075] This application claims the benefit of priority based on Japanese patent application No. 2022-120285, filed on July 28, 2022, the disclosure of which is incorporated herein in its entirety by reference.

Claims

1. A water treatment system comprising a membrane separation device and an ion exchange device, The water treatment system also has: a first pipe for simultaneously and in parallel supplying a chemical solution to the membrane separation device and the ion exchange device; A first valve group is provided on the first pipe; and A control device controls the opening and closing of the first valve group.

2. The water treatment system according to claim 1, wherein: When the difference between the pressure at the front stage of the membrane separation device and the pressure at the rear stage of the membrane separation device exceeds a given threshold, the control device controls the opening and closing of the first valve group so that the chemical solution is supplied to the membrane separation device and the ion exchange device.

3. The water treatment system according to claim 1 or 2, wherein: The water treatment system comprises: a second pipe for supplying the chemical solution after passing through the membrane separation device to the ion exchange device; and A second valve group is provided on the second pipe. The control device controls the opening and closing of the second valve group so that the chemical solution that has passed through the membrane separation device is supplied to the ion exchange device.

4. The water treatment system according to claim 3, wherein: The control device controls opening and closing of the second valve group based on at least one of a TOC value, a pH value, and an electrical conductivity of the chemical solution after passing through the membrane separation device so as to supply the chemical solution after passing through the membrane separation device to the ion exchange device.

5. The water treatment system according to claim 1 or 2, wherein: The water treatment system comprises: a third pipe for supplying the chemical solution after passing through the ion exchange device to the membrane separation device; and A third valve group is provided on the third pipe. The control device controls the opening and closing of the third valve group so that the chemical solution that has passed through the ion exchange device is supplied to the membrane separation device.

6. The water treatment system according to claim 1 or 2, wherein: The ion exchange device is filled with anion exchange resin, and the drug solution is an alkaline liquid.

7. The water treatment system according to claim 1 or 2, wherein: The ion exchange device is filled with cation exchange resin, and the drug solution is an acidic liquid.

8. The water treatment system according to claim 1 or 2, wherein: The water treatment system comprises: a fourth pipe for supplying cleaning water to the membrane separation device and the ion exchange device; and a fourth valve group, arranged on the fourth pipe, After the supply of the chemical solution to the membrane separation device and the ion exchange device is completed, the control device controls the opening and closing of the fourth valve group so that the cleaning water is supplied to the membrane separation device and the ion exchange device.

9. A water treatment system comprising a membrane separation device and an ion exchange device, The water treatment system also has: a first pipe for supplying a chemical solution to the membrane separation device; a second pipe for supplying the chemical solution after passing through the membrane separation device to the ion exchange device; A first valve group is arranged on the first pipe; A second valve group is arranged on the second pipe; as well as a control device for controlling the opening and closing of the first valve group and the opening and closing of the second valve group, The control device controls the opening and closing of the second valve group so that the chemical solution that has passed through the membrane separation device is supplied to the ion exchange device.

10. A method for operating a water treatment system, the water treatment system comprising a membrane separation device and an ion exchange device, In the operating method of the water treatment system, a water passing step and a drug passing step are performed. In the water passing step, the opening and closing of valves arranged in the pipes are controlled to pass the water to be treated into the membrane separation device and the ion exchange device. In the chemical supplying step, the opening and closing of the valve is controlled based on a given timing to supply the chemical solution to the membrane separation device and the ion exchange device simultaneously and in parallel.

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