Ultrapure water production system and ultrapure water supply device

Abstract

The present invention comprises: a secondary pure water production device (100) which produces ultrapure water by processing primary pure water; and ultrapure water supply devices (300-1) to (300-3) which are respectively provided in supply pipes that connect the secondary pure water production device (100) and use devices (200-1) to (200-3), in each of which ultrapure water produced by the secondary pure water production device (100) is used, and which have a function of decreasing the concentration of impurities contained in the ultrapure water supplied from the secondary pure water production device (100).

Description

Ultrapure water production system and ultrapure water supply device

[0001] The present invention relates to an ultrapure water manufacturing system and an ultrapure water supply apparatus.

[0002] Ultrapure water supplied from an ultrapure water production system is pumped through a supply pipe connecting the ultrapure water production system to a point of use (hereinafter referred to as a "use point"), and then supplied to the use point. Therefore, there is a risk that the quality of the ultrapure water may be degraded due to impurities eluting from the pipe. To address this issue, a technology has been proposed that uses a type of fluororesin, such as PVDF (polyvinylidene fluoride), which has low elution, as the material for the supply pipe (see, for example, Patent Document 1).

[0003] Patent No. 7033691

[0004] Even in piping using PVDF, there is a risk of trace impurities eluting. If trace impurities elute, the quality of ultrapure water will deteriorate during the process of supplying it to the point of use. The deteriorated water quality may be lower than the required quality for ultrapure water used in cutting-edge semiconductor manufacturing. As such, the above-mentioned technology has the problem of being unable to satisfy the recent demand for even higher purity of ultrapure water (suppression of water quality deterioration).

[0005] An object of the present invention is to provide an ultrapure water manufacturing system and an ultrapure water supply apparatus that can improve the quality of ultrapure water supplied to a point of use.

[0006] The ultrapure water production system of the present invention comprises a secondary pure water production apparatus that produces ultrapure water by treating primary pure water, and an ultrapure water supply apparatus that is provided in a supply pipe connecting the secondary pure water production apparatus to a user device that uses the ultrapure water produced by the secondary pure water production apparatus and has the function of reducing the concentration of impurities contained in the ultrapure water supplied from the secondary pure water production apparatus.

[0007] The ultrapure water supply system of the present invention is also provided with a water treatment device that is provided in a supply pipe connecting a secondary pure water production system that produces ultrapure water from primary pure water and a user device that uses the ultrapure water produced by the secondary pure water production system, and that has the function of reducing the concentration of impurities contained in the ultrapure water supplied from the secondary pure water production system via the supply pipe.

[0008] In the present invention, the quality of ultrapure water supplied to a point of use can be improved.

[0009] FIG. 1 is a diagram showing a first embodiment of the ultrapure water producing system of the present invention. FIG. 2 is a diagram showing a second embodiment of the ultrapure water producing system of the present invention. FIG. 3 is a diagram showing a first example of the configuration inside the ultrapure water supply apparatus shown in FIG. 2. FIG. 4 is a diagram showing a fourth example of the configuration inside the ultrapure water supply apparatus shown in FIG. 2. FIG. 5 is a diagram showing an application example of the ultrapure water producing system of the present invention.

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings.

[0011] FIG. 1 is a diagram showing a first embodiment of an ultrapure water production system according to the present invention. As shown in FIG. 1, the ultrapure water production system according to this embodiment includes a secondary pure water production system 100, a supply pipe 210, and a circulation pipe (circulation line) 211. The supply pipe 210 supplies (transports) ultrapure water produced by the secondary pure water production system 100 to use devices 200-1 to 200-3, each of which is provided at a point-of-use. The circulation pipe (circulation line) 211 is connected to the supply pipe 210 and transports ultrapure water not used by the use devices 200-1 to 200-3 to the secondary pure water production system 100. The supply pipe 210 includes a main pipe (main line) 210A and multiple branch pipes (branch lines) 210B. The main pipe (main line) 210A is connected to the secondary pure water production system 100. Branch pipes (branch lines) 210B are pipes that branch off from main pipe 210A and are connected to each of use devices 200-1 to 200-3. Each branch pipe 210B branches off from a branch point of main pipe 210A, is connected to each of use devices 200-1 to 200-3, and supplies ultrapure water to each of use devices 200-1 to 200-3. While Fig. 1 shows an example in which the number of use devices is three, the number is not limited to three.

[0012] In this embodiment, the secondary pure water production system 100 is a subsystem that produces secondary pure water (ultrapure water) from primary pure water produced in a primary pure water production system (not shown). In this embodiment, the secondary pure water production system 100 includes a water treatment device that performs a predetermined impurity removal process on the primary pure water supplied from the primary pure water production system and the ultrapure water (circulating water, return water) that is not used in the user devices 200-1 to 200-3 and is circulated via a supply pipe 210 and a circulation pipe 211. The secondary pure water production system 100 may include multiple water treatment devices.

[0013] The use devices 200-1 to 200-3 are devices that use ultrapure water supplied from the secondary pure water production device 100 via the supply pipe 210. The use devices 200-1 to 200-3 may be devices that use ultrapure water to clean components of semiconductor devices or liquid crystal displays. The use devices 200-1 to 200-3 may also be devices that use ultrapure water to clean medical products. The use devices 200-1 to 200-3 may also be devices that use ultrapure water in the steam generator of a power generation turbine.

[0014] The piping and / or supply piping 210 used in the secondary pure water production system 100 is composed of a combination of piping made of a fluorine-based material and piping made of a material other than fluorine-based material. The fluorine-based piping also includes piping made of a material other than fluorine-based material, the liquid-contacting surface (surface that comes into contact with ultrapure water) of which is lined with a fluorine-based material (e.g., piping made of stainless steel lined with a fluororesin). Examples of fluorine-based materials include PVDF (polyvinylidene fluoride), PFA (perfluoroalkoxyalkane), and PTFE (polytetrafluoroethylene). PVDF is a material that is often used as a material for piping that delivers ultrapure water because it has low impurity elution. Examples of materials other than fluorine-based materials include PP (polypropylene), PVC (polyvinyl chloride), and PE (polyethylene). The supply piping 210 includes a supply line and branch lines. The supply line is a line that transports ultrapure water from the secondary pure water production system 100 to a branching point for supplying the ultrapure water to each of the user devices 200-1 to 200-3. The branching line is a line that branches from the branching point to supply the ultrapure water to each of the user devices 200-1 to 200-3. The ratio of the fluorine-based material piping portion to the non-fluorine-based material piping portion that constitutes the piping and / or supply piping 210 used in the secondary pure water production system 100 is not particularly specified. This ratio may be 0:100 or 100:0. For example, the piping and / or supply piping 210 used in the secondary pure water production system 100 may be composed solely of piping made of a material other than fluorine-based materials (i.e., the ratio of the fluorine-based material piping portion to the non-fluorine-based material piping portion is 0:100). Furthermore, the closer the piping is to the user devices 200-1 to 200-3, the higher the ratio of the fluorine-based material piping portion that constitutes the supply piping 210. It goes without saying that the higher the proportion of piping made of fluorine-based materials that constitutes the piping of the secondary pure water production system 100 and / or the supply piping 210, the higher the quality of the ultrapure water supplied to the use devices 200-1 to 200-3. The ratio of piping made of fluorine-based materials to piping made of materials other than fluorine-based materials may be set according to the quality of ultrapure water required by each of the use devices 200-1 to 200-3.For example, a formula for calculating the ratio of the piping portion made of a fluorine-based material to the piping portion made of a material other than a fluorine-based material may be set in advance based on the quality of the ultrapure water, and when a new supply pipe 210 is installed, a computer such as a CPU (Central Processing Unit) may use the formula to calculate the ratio of the piping portion made of a fluorine-based material to the piping portion made of a material other than a fluorine-based material based on the quality of the ultrapure water required by each of the use apparatuses 200-1 to 200-3, and prepare the supply pipe 210 according to the calculated ratio. This calculation may be performed by an administrator who manages the ultrapure water producing system.

[0015] In this manner, in this embodiment, the piping used in the secondary pure water production system 100 and / or the supply piping 210 from the secondary pure water production system 100 to the user devices 200-1 to 200-3 are constructed by combining piping made of a fluorine-based material with piping made of a material other than a fluorine-based material. Therefore, even if there is a shortage of fluorine-based material, the ultrapure water production system in this embodiment can maintain the quality of the ultrapure water produced by the secondary pure water production system 100 and supply it to the user devices 200-1 to 200-3, compared to a system in which the piping used in the secondary pure water production system 100 and / or the supply piping are constructed only of piping made of a material other than a fluorine-based material. (Second Embodiment)

[0016] Figure 2 is a diagram showing a second embodiment of the ultrapure water production system of the present invention. As shown in Figure 2, the ultrapure water production system of this embodiment includes a secondary pure water production system 100, a supply pipe 210, a circulation pipe (circulation line) 211, and ultrapure water supply systems 300-1 to 300-3. The secondary pure water production system 100, the supply pipe 210, and the circulation pipe 211 are the same as those in the first embodiment. Figure 2 shows an example in which the number of operating systems and the number of ultrapure water supply systems are three, but the number is not limited to three.

[0017] The ultrapure water supply units 300-1 to 300-3 are provided on the supply pipe 210 between the secondary pure water production system 100 and each of the use units 200-1 to 200-3. Specifically, each of the ultrapure water supply units 300-1 to 300-3 is provided on a branch line of the supply pipe 210 extending from the supply pipe 210 to each of the use units 200-1 to 200-3. The closer each of the ultrapure water supply units 300-1 to 300-3 is to each of the use units 200-1 to 200-3, the more preferable it is. As long as the quality of the treated water from the ultrapure water supply units 300-1 to 300-3 is higher than the quality of the water to be treated, the impurity removal performance of the ultrapure water supply units 300-1 to 300-3 is not particularly limited. For example, the ultrapure water supply units 300-1 to 300-3 have the function of removing trace amounts of impurities (e.g., impurities eluted from the supply pipe 210) contained in the ultrapure water supplied from the secondary pure water production system 100 via the supply pipe 210, that is, reducing the concentration of impurities and improving the quality of the ultrapure water. The ultrapure water supply units 300-1 to 300-3 remove impurities as required from the ultrapure water supplied from the secondary pure water production system 100 via the supply pipe 210 in accordance with the water quality required by each of the user devices 200-1 to 200-3. Each of the ultrapure water supply units 300-1 to 300-3 supplies, to each of the user devices 200-1 to 200-3, ultrapure water from which impurities have been removed (hereinafter referred to as ultra-ultrapure water). Impurities removed from ultrapure water by the ultrapure water supply units 300-1 to 300-3 include, for example, metals, organic matter containing TOC (Total Organic Carbon) components, dissolved oxygen, hydrogen peroxide, and fine particles. The ultrapure water supply units 300-1 to 300-3 are internally equipped with water treatment devices that perform unit operations (e.g., impurity removal) according to the required water quality of each of the use units 200-1 to 200-3. Examples of water treatment devices that may be equipped in the ultrapure water supply units 300-1 to 300-3 include an ion exchange unit for removing metal ions, a UV oxidation unit for removing organic matter containing TOC components, a degassing membrane unit for removing dissolved oxygen, and a filtration membrane unit including a microfiltration membrane or ultrafiltration membrane for removing fine particles.In this case, the ion exchange devices provided in the ultrapure water supply systems 300-1 to 300-3 have an ion exchanger such as an ion exchange resin, a monolithic ion exchanger, or an ion adsorption membrane.

[0018] The ultrapure water supply systems 300-1 to 300-3 do not need to have the same removal performance. The removal performance of each of the ultrapure water supply systems 300-1 to 300-3 corresponds to the water quality required by each of the use systems 200-1 to 200-3. For example, the ultrapure water quality required by each of the use systems 200-1 to 200-3 and the type of water treatment system capable of performing water treatment that satisfies that water quality may be associated in advance and stored in a memory unit or the like, and a computer such as a CPU may read from the memory unit or the like the type of water treatment system associated with the ultrapure water quality required by each of the use systems 200-1 to 200-3, and the read-out type of water treatment system may be provided in each of the ultrapure water supply systems 300-1 to 300-3. Alternatively, the water treatment devices provided in the ultrapure water supply devices 300-1 to 300-3 may be preset, and the quality of ultrapure water required by each of the use devices 200-1 to 200-3 may be associated with the type of water treatment device capable of performing water treatment that satisfies that water quality and stored in a memory or the like, and a computer such as a CPU may read from the memory or the like the type of water treatment device associated with the quality of ultrapure water required by each of the use devices 200-1 to 200-3, and bypass some of the water treatment devices in the ultrapure water supply devices 300-1 to 300-3 so that treatment is performed using the read-out type of water treatment device. The information associated with the type of water treatment device is not limited to the quality of ultrapure water, but may also be the purpose of use of the ultrapure water in the use devices 200-1 to 200-3. In this case, a computer such as a CPU may read out from a storage unit or the like the type of water treatment device associated with the intended use of each of the use devices 200-1 to 200-3, and provide each of the ultrapure water supply devices 300-1 to 300-3 with the read-out type of water treatment device. The type of water treatment device may be selected by an administrator who manages the ultrapure water producing system.

[0019] FIG. 3A is a diagram showing a first example of the internal configuration of the ultrapure water supply apparatus 300-1 shown in FIG. 2. As shown in FIG. 3A, the ultrapure water supply apparatus 300-1 shown in FIG. 2 is provided with valves 311, 315, and 316, a pump (boost pump) 312, an ion exchanger 313 having a monolithic ion exchanger, and a filtration membrane device 314 including a microfiltration membrane. The valve 311 is an on-off valve that controls the supply of ultrapure water from the supply pipe 210 to the ultrapure water supply apparatus 300-1. The pump 312 is a boost pump that adjusts the supply flow rate of ultrapure water from the supply pipe 210. The pump 312 sends ultrapure water to a downstream stage at a water pressure equal to or greater than the water pressure at which the ultrapure water supply apparatus 300-1 supplies the ultrapure water to the use apparatus 200-1. The pump 312 is selected such that the parts that come into contact with the ultrapure water are made of a fluororesin such as PFA or PTFE and the pulsation is below a predetermined threshold. The ion exchange device 313 having a monolithic ion exchanger is equipped with a monolithic packed column made of a fluororesin such as PTFE, packed with a monolithic ion exchanger for deionizing ultrapure water. Examples of monolithic organic porous structures include the open-cell structure disclosed in Japanese Patent Application Laid-Open Nos. 2002-306976 and 2009-62512, the bicontinuous structure disclosed in Japanese Patent Application Laid-Open No. 2009-67982, the particle aggregation structure disclosed in Japanese Patent Application Laid-Open No. 2009-7550, and the particle composite structure disclosed in Japanese Patent Application Laid-Open No. 2009-108294. Examples of the structure, material, and properties of the ion exchanger include those disclosed in Japanese Patent Application Laid-Open No. 2019-195763. Furthermore, examples of the ion exchange groups introduced into the monolithic organic porous column, the cation exchange groups introduced into the monolithic organic porous cation exchanger, and the anion exchange groups introduced into the monolithic organic porous anion exchanger include those disclosed in Japanese Patent Application Laid-Open No. 2019-195763. The monolith-packed column is washed and quality-controlled using ultrapure water or acid before being installed in the ion exchange device 313 containing the monolithic ion exchanger. The quality control involves passing ultrapure water through the washed monolith-packed column, and conducting a pre-installation inspection based on the metal concentrations of the ultrapure water in the upstream and downstream stages of the column to be evaluated.The condition for incorporation into the ion exchange device 313 having a monolithic ion exchanger is that in this pre-installation test, the elution concentration of metal ions (e.g., sodium) (the difference in metal concentration between the upstream and downstream ultrapure waters to be evaluated) is less than 0.1 ng / L, more preferably less than 0.01 ng / L, and even more preferably less than 0.001 ng / L. The filtration membrane device 314 includes a filter module filled with a microfiltration membrane (MF), an ultrafiltration membrane (UF), or the like. The filter module and / or the filled microfiltration membrane (cartridge) are cleaned and quality-controlled using ultrapure water or acid before being installed in the filtration membrane device 314. The quality control is performed by passing ultrapure water through the cleaned filter module or cartridge, and then conducting a pre-installation test based on the metal concentration of the upstream ultrapure water to be evaluated and the metal concentration of the downstream ultrapure water. A condition for incorporation into the filtration membrane device 314 is that, in this pre-installation inspection, the elution concentration of metal ions (e.g., sodium) (the difference in metal concentration between the upstream and downstream ultrapure water being evaluated) is less than 0.1 ng / L, more preferably less than 0.01 ng / L, and even more preferably less than 0.001 ng / L. Valve 315 is an on-off valve that controls the supply of ultrapure water treated by the filtration membrane device 314 to the use device 200-1. Valve 315 is controlled so that the flow rate of the ultrapure water supplied to the use device 200-1 is constant. A return pipe 317 that branches off from the branch pipe 210B and is connected to the circulation pipe 211 is provided downstream of the filtration membrane device 314. Valve 316 is provided in the return pipe 317 and is an on-off valve that controls the supply of ultrapure water treated by the filtration membrane device 314 to a return pipe (e.g., the circulation pipe 211 shown in FIG. 2) via the return pipe 317. The valve 316 is controlled to change the flow path and the flow rate, for example, when the supply to the use device 200-1 is cut off. The opening and closing of the valves 311, 315, and 316 and the adjustment of the pressure increase of the pump 312 may be performed by a control unit (not shown).

[0020] FIG. 3(B) is a diagram showing a second example of the internal configuration of the ultrapure water supply system 300-1 shown in FIG. 2. As shown in FIG. 3(B), the ultrapure water supply system 300-1 shown in FIG. 2 is provided with valves 311, 315, and 316, a pump 312, a first ion exchange system 323 having a non-regenerative ion exchange resin, and a membrane filtration system 314. The valves 311, 315, and 316, the pump 312, and the membrane filtration system 314 are the same as those shown in FIG. 3(A). The first ion exchange system 323 having a non-regenerative ion exchange resin is a packed column (ion exchanger) filled with ion exchange resin for deionizing ultrapure water. This ion exchange resin is a mixed-bed resin or a double-bed resin containing strongly acidic cations and strongly basic anions. The water flow rate (space velocity) of the first ion exchange device 323 having a non-regenerative ion exchange resin is preferably 30 (SV) or more, and more preferably 50 (SV).

[0021] FIG. 3(C) is a diagram showing a third example of the internal configuration of the ultrapure water supply system 300-1 shown in FIG. 2. As shown in FIG. 3(C), the ultrapure water supply system 300-1 shown in FIG. 2 is provided with valves 311, 315, and 316, a pump 312, a second ion exchange system 333 having a non-regenerative ion exchange resin, and a filtration membrane device 314. The valves 311, 315, and 316, the pump 312, and the filtration membrane device 314 are the same as those shown in FIG. 3(A). The second ion exchange system 333 having a non-regenerative ion exchange resin has the function of removing fine particles from ultrapure water. The second ion exchange system 333 having a non-regenerative ion exchange resin also has the function of deionizing ultrapure water. The second ion exchange system 333 having a non-regenerative ion exchange resin is a packed column (ion exchanger) filled with ion exchange resin. This ion exchange resin is a mixed-bed resin containing strongly acidic cations and strongly basic anions. The anion-to-cation ratio in the second ion exchange device 333 containing a non-regenerative ion exchange resin may be different from the anion-to-cation ratio in the first ion exchange device 323 containing a non-regenerative ion exchange resin, in that the anion-to-cation ratio is higher. The water flow rate (space velocity) of the second ion exchange device 333 containing a non-regenerative ion exchange resin is 170 to 2000 (SV). The bed height of the second ion exchange device 333 containing a non-regenerative ion exchange resin is 30 cm or more. In this configuration, the second ion exchange device 333 containing a non-regenerative ion exchange resin can remove particulates from the ultrapure water, so the filtration membrane device 314 does not need to be provided.

[0022] 3(D) is a diagram showing a fourth example of the internal configuration of the ultrapure water supply system 300-1 shown in FIG. 2. As shown in FIG. 3(D), the ultrapure water supply system 300-1 shown in FIG. 2 is provided with valves 311, 315, and 316, a pump 312, an ion exchange unit 343, and a filtration membrane device 314. The valves 311, 315, and 316, the pump 312, and the filtration membrane device 314 are the same as those shown in FIG. 3(A). The ion exchange unit 343 is a unit consisting of an ion exchange device containing a platinum group metal-supported resin (e.g., a single bed of Pd catalyst-supported resin or a combination of an anion exchanger and a Pd catalyst-supported resin) connected in series with an ion exchange device 313 having a monolithic ion exchanger or a first ion exchange device 323 having a non-regenerative ion exchange resin upstream of the ion exchange device 313 having a monolithic ion exchanger or a first ion exchange device 323 having a non-regenerative ion exchange resin. The platinum group metal-supported resin is a platinum group metal supported on an anion exchange resin as a carrier, and has the catalytic action of decomposing hydrogen peroxide into water and oxygen (2H2O2 → 2H2O + O2). Therefore, the ion exchange device installed in the ion exchange unit 343 can remove not only ionic components such as metal ions contained in the water to be treated, but also hydrogen peroxide by contacting the water to be treated with the platinum group metal-supported resin. Palladium is preferably used as the platinum group metal used in the platinum group metal-supported resin because of its excellent catalytic activity and relatively low cost. The platinum group metal-supported resin contained in the ion exchange unit 343 is a gel-type anion resin with an R-OH ratio of 95% or more. The catalyst loading capacity packed in the ion exchange unit 343 is 10 to 500 mg-catalyst / LR, more preferably 10 to 170 mg-catalyst / LR. The water flow rate (space velocity) through the platinum group metal-supported resin of the ion exchange unit 343 is 200 to 2000 (SV). The water flow rate (space velocity) through the first ion exchange device 323 having a non-regenerative ion exchange resin is preferably 30 (SV) or more, and more preferably 50 (SV).

[0023] The ion exchange resins shown in Figures 3(B) to 3(D) are purified and quality-controlled before being loaded into the ion exchange devices 323, 333 and ion exchange unit 343 containing non-regenerative ion exchange resins. For quality control, a portion of the purified ion exchange resin is loaded into a water flow column as a sample, and then ultrapure water is passed through the column. A pre-loading test is then performed based on the metal concentrations of the upstream and downstream ultrapure waters being evaluated. This pre-loading test requires that the elution concentration of metal ions (e.g., sodium) (the difference in metal concentration between the upstream and downstream ultrapure waters being evaluated) be less than 0.1 ng / L, more preferably less than 0.01 ng / L, and even more preferably less than 0.001 ng / L. This is a condition for installation in the ion exchange devices 323, 333 containing ion exchange resins. Furthermore, this pre-filling inspection may involve completely acid-decomposing the non-regenerative ion exchange resin using a microwave decomposition device, measuring the metal concentration in the decomposition solution, and then inferring the metal content of the non-regenerative ion exchange resin from the correlation between the metal content and the elution concentration. For example, when the resin incorporated into the ion exchange devices 323 and 333 is a mixed-bed resin of a cation exchange resin and an anion exchange resin, the sodium content, which is the metal content, is preferably 50 μg-Na / L or less of the mixed-bed resin. More specifically, the sodium content of the cation exchange resin (CER) used in the mixed-bed or dual-bed resin is 100 μg-Na / L or less of CER, more preferably 50 μg-Na / L or less of CER, and even more preferably 10 μg-Na / L or less of CER. The sodium content of the anion exchange resin (AER) is 50 μg-Na / L-AER or less, more preferably 30 μg-Na / L-AER or less, and even more preferably 10 μg-Na / L-AER or less. The pump 312 may be installed between the ion exchange device and the membrane filtration device 314 or after the membrane filtration device 314. In addition to the components shown in FIGS. 3(A) to 3(D), the ultrapure water supply devices 300-1 to 300-3 may also be equipped with a water treatment device, such as a UV oxidation device or a degassing membrane device, that performs a unit operation (e.g., removal of impurities) according to the required water quality of each of the use devices 200-1 to 200-3.

[0024] The ultrapure water supply systems 300-2 to 300-3 may be equipped with the components shown in Figures 3(A) to 3(D). The ultrapure water supply systems 300-1 to 300-3 may be equipped with the same components as those shown in Figures 3(A) to 3(D), or may be equipped with different components. Furthermore, depending on the quality of ultrapure water required by the use systems 200-1 to 200-3 or the purpose of use of the ultrapure water in the use systems 200-1 to 200-3, it may be possible to select which of the components shown in Figures 3(A) to 3(D) each ultrapure water supply system 300-1 to 300-3 will be equipped with. For example, the quality of ultrapure water required by each of the use apparatuses 200-1 to 200-3 may be associated with the components shown in Figures 3(A) to 3(D) and stored in a memory or the like in advance. A computer such as a CPU may then read from the memory or the like the components associated with the quality of ultrapure water required by each of the use apparatuses 200-1 to 200-3, and equip each of the ultrapure water supply apparatuses 300-1 to 300-3 with the read-out components. The information associated with the components shown in Figures 3(A) to 3(D) is not limited to the quality of ultrapure water, but may also be the purpose of use of the ultrapure water in each of the use apparatuses 200-1 to 200-3. In this case, a computer such as a CPU may read from a memory or the like the components associated with the purpose of use of each of the use apparatuses 200-1 to 200-3, and equip each of the ultrapure water supply apparatuses 300-1 to 300-3 with the read-out components. This selection of components may be performed by an administrator who manages the ultrapure water manufacturing system. The components of the ultrapure water supply systems 300-1 to 300-3 can be changed depending on the quality of ultrapure water required by each of the use systems 200-1 to 200-3 and the purpose of use of the ultrapure water in each of the use systems 200-1 to 200-3. Furthermore, it is also possible to change only some of the components of the ultrapure water supply systems 300-1 to 300-3 to other water treatment systems.

[0025] In this embodiment, ultrapure water supply units 300-1 to 300-3 that remove impurities are provided in the supply pipe 210 from the secondary pure water production system 100 to the user devices 200-1 to 200-3. Therefore, even if the quality of the ultrapure water supplied from the secondary pure water production system 100 deteriorates due to external factors such as impurities eluting from the liquid-contacting surface of the supply pipe 210 as the ultrapure water is sent through the supply pipe 210, the impurities are removed from the ultrapure water by the ultrapure water supply units 300-1 to 300-3 arranged near the user devices 200-1 to 200-3. For example, when treated water from each of the ultrapure water supply units 300-1 to 300-3 is used in each of the user devices 200-1 to 200-3, the ultrapure water supply units 300-1 to 300-3 are arranged in positions that satisfy the water quality requirements of the user devices 200-1 to 200-3. Alternatively, ultrapure water supply units 300-1 to 300-3 are disposed in the space between the secondary pure water production system 100 and the use devices 200-1 to 200-3. As a result, the quality of the ultrapure water produced by the secondary pure water production system 100 can be maintained or improved and supplied to the use devices 200-1 to 200-3. Furthermore, in this embodiment, ultrapure water supply units 300-1 to 300-3 are provided according to the water quality or purpose required by each of the use devices 200-1 to 200-3. Conventionally, it has been common to improve the quality of the ultrapure water in the secondary pure water production system 100, aiming for the highest water quality among the water qualities required by the use devices 200-1 to 200-3. However, the water quality required by the use devices 200-1 to 200-3 is not necessarily the same, and the quality of the ultrapure water for use devices that do not require high water quality has been unnecessarily improved. In this embodiment, the secondary pure water production system 100 produces ultrapure water of a certain quality, and the water quality is further improved by the ultrapure water supply systems 300-1 to 300-3 according to the water quality required by the use devices 200-1 to 200-3. As a result, the quality of the ultrapure water supplied from the secondary pure water production system 100 does not need to be the highest quality required by the use devices 200-1 to 200-3. (Application Example)

[0026] FIG. 4 is a diagram showing an example of an application of the ultrapure water production system of the present invention. As shown in FIG. 4, a secondary pure water production system 100 for producing ultrapure water from primary pure water includes a water tank (primary pure water tank) 101, a pump 102, a heat exchanger (HEX) 103, an ultraviolet oxidation device (UVox) 104, a non-regenerative ion exchange device (CP) 105, a degassing membrane device (MD) 106, and an ultrafiltration membrane device (UF) 107. The water tank 101 is a tank in which primary pure water is stored. A portion of the ultrapure water supplied from the ultrafiltration membrane device 107 is returned to the water tank 101 as circulating water via a supply pipe 210 and stored therein. The pump 102 pumps up the primary pure water and circulating water stored in the water tank 101 and supplies them to the heat exchanger 103. The primary pure water and circulating water pumped up by the pump 102 are sequentially treated in the heat exchanger 103, ultraviolet oxidation device 104, non-regenerative ion exchange device 105, degassing membrane device 106, and ultrafiltration membrane device 107, respectively, and then sent to the supply pipe 210. The treatments in the heat exchanger 103, ultraviolet oxidation device 104, non-regenerative ion exchange device 105, degassing membrane device 106, and ultrafiltration membrane device 107 may be the same as the water treatments typically performed in these devices. The ultrapure water supplied from the secondary pure water production system 100 having this configuration to each of the use devices 200-1 to 200-3 via the supply pipe 210 is subjected to impurity removal treatment in each of the ultrapure water supply devices 300-1 to 300-3, which are located near each of the use devices 200-1 to 200-3.

[0027] Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

[0028] This application claims priority based on Japanese Patent Application No. 2023-115671, filed on July 14, 2023, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. An ultrapure water production system comprising: a secondary pure water production apparatus that produces ultrapure water by treating primary pure water; and an ultrapure water supply apparatus that is provided in a supply piping that connects the secondary pure water production apparatus to a user device that uses the ultrapure water produced by the secondary pure water production apparatus and has the function of reducing the concentration of impurities contained in the ultrapure water supplied from the secondary pure water production apparatus.

2. An ultrapure water production system according to claim 1, wherein the ultrapure water supply device is provided with an ion exchange device having a granular or monolithic ion exchanger.

3. An ultrapure water production system as described in claim 2, wherein when the ion exchange device provided in the ultrapure water supply system has a monolithic ion exchanger, the ion exchange device is an ultrapure water production system in which the amount of metal elution based on the metal concentration of the ultrapure water in the upstream and downstream stages of the ion exchanger when ultrapure water is passed through the washed ion exchanger after the ion exchanger has been washed satisfies a predetermined condition.

4. An ultrapure water producing system as claimed in claim 2 or 3, wherein when the ion exchange resin used in the ion exchanger is a cation exchange resin, the Na content is 100 μg / L-CER or less, when the ion exchange resin is an anion exchange resin, the Na content is 50 μg / L-AER or less, and when the ion exchange resin is a mixed bed resin of a cation exchange resin and an anion exchange resin, the Na content is 50 μg / L-CP or less.

5. An ultrapure water production system as claimed in claim 2 or 3, wherein the ultrapure water supply device is provided with a filtration membrane device downstream of the ion exchange device, and the filtration membrane device is provided with a microfiltration membrane filter or an ultrafiltration membrane filter.

6. An ultrapure water producing system as described in claim 5, wherein the filtration membrane device provided in the ultrapure water supply device is such that, after the filtration membrane device is washed, the amount of metal elution based on the metal concentration of the ultrapure water in the upstream and downstream stages of the filtration membrane device satisfies a predetermined condition when ultrapure water is passed through the washed filtration membrane device.

7. An ultrapure water production system according to claim 2 or 3, wherein the ultrapure water supply device is provided with a boost pump.

8. An ultrapure water production system as claimed in any one of claims 1 to 3, wherein the supply piping has a main piping connected to the secondary pure water production apparatus and a branch piping branched off from the main piping and connected to the use apparatus, and the ultrapure water supply apparatus is provided on the branch piping.

9. An ultrapure water production system according to any one of claims 1 to 3, wherein the ultrapure water supply device has a return pipe for returning treated ultrapure water to the secondary pure water production device, and a valve provided on the return pipe.

10. An ultrapure water supply system having a water treatment device that is provided in a supply piping connecting a secondary pure water production apparatus that produces ultrapure water from primary pure water and a user device that uses the ultrapure water produced by the secondary pure water production apparatus, and that has the function of reducing the concentration of impurities contained in the ultrapure water supplied from the secondary pure water production apparatus through the supply piping.

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