KR20130114616A - Ultra water pure plant - Google Patents

Abstract

PURPOSE: An ultrapure water manufacturing device is provided to stably manufacture the ultrapure water of high quality, simplify maintenance management and reduce manufacturing costs. CONSTITUTION: An ultrapure water manufacturing device comprises a base peat (2), a first pure water system (12) and a second pure water system (13). The base peat stores preprocessing water in which raw water is recycled. The first pure water system includes an ion-exchange resin apparatus (103) which removes ionic components among the preprocessing water, a reverse osmosis membrane device (105) and multiple processing systems which process the preprocessing water. The second pure water system processes first pure water processed at the first pure water system and supplies to the in-use position. [Reference numerals] (AA) Raw water

Description

Ultrapure Water Manufacturing Equipment {Ultra Water Pure Plant}

The present invention relates to an ultrapure water production apparatus that enables stable production of high purity ultrapure water and facilitates operation and management, and more particularly, to an ultrapure water production apparatus suitable for the production of large-scale ultrapure water such as 2,000 m 3 / day or more.

Conventionally, ultrapure water used in the manufacturing process of semiconductors or plat pannel displays is produced by sequentially treating raw water such as river water, well water, industrial water, etc. with a pretreatment system, a primary pure water system, and a secondary pure water system. have.

In the pretreatment system, raw water is deposited using a filtration device or temperature control of the raw water is performed by a heat exchanger.

In the primary pure water system, the pretreated water is treated by a deionization apparatus using an activated carbon adsorption apparatus, an ion exchange resin, or the like, and a reverse osmosis membrane apparatus for removing ionic substances and particle components. Further, removal of carbon dioxide gas and oxygen dissolved in water by a degassing device, removal of organic matter in water by a combination of an ultraviolet irradiation device and an ion exchange polisher, and the like become primary pure water.

Primary pure water is stored in the primary pure tank and supplied to the secondary pure water system.

In the secondary pure water system, ultrapure water is removed by removing an extremely small amount of impurities in the primary pure water using an ion exchange polisher or an ultrafiltration device. The ultrapure water thus produced is supplied to a point of use (hereinafter also referred to as a point of use). In addition, the waste water used at the point of use may be recovered, and the recovered water may be used as raw water.

In such ultrapure water production equipment, the arrangement of unit devices is optimized according to the required conditions for the content and amount of raw water, the daily yield of ultrapure water to be manufactured, safety management, operation management, cost, and the like, and are installed in series along the flow path. Doing. Moreover, the method of lengthening the continuous pot life of an ion exchange resin and reducing the usage-amount of the chemical used is also proposed (refer patent document 1, 2).

In primary pure water systems, deionizers such as regenerative ion exchange resins are often used. Such deionization apparatus requires regeneration treatment at a frequency of several days to one week. In addition, the membrane treatment apparatus such as the reverse osmosis membrane apparatus, the ultraviolet irradiation apparatus and the like do not need the regeneration treatment, but, for example, replacement of the membrane module or the lamp is required at a frequency of several months to one year.

Therefore, in the primary pure water system of a large-scale ultrapure water production system, a plurality of deionizers, a membrane treatment device, an ultraviolet irradiation device, and the like are installed in parallel, respectively, and low water feet (large capacity underground reservoirs) for storing intermediate treated water are installed. Is installed in the required part of the flow path. At the time of reproduction or maintenance check, only the target device is stopped. In the meantime, in the deionization device which does not change the processing flow rate, the membrane treatment apparatus is supplied with the intermediate treated water of the low water feet downstream of the target device to the rear stage to continue the production of ultrapure water, while the temporary increase in the processing flow rate is not a problem. The method of increasing the flow volume of the apparatus which does not stop is employ | adopted.

In the second pure water system, the ultrapure water, which was not used in the POU, is returned to the primary pure water tank to keep the treatment flow rate constant, thereby preventing deterioration of water quality due to the increase and decrease of the flow rate.

In general, primary pure water systems adjust the production volume of primary pure water according to the increase or decrease of the amount of ultrapure water used in the POU. Therefore, in a small pure water production apparatus, a method of repeating the operation and stopping of the entire primary pure water system may be employed, but this method has a problem that it is difficult to improve the water quality. In addition, in a large-scale ultrapure water production system, there is a possibility that a large flow rate fluctuation at the time of operating and stopping imposes a mechanical load (water hammer) on various devices and piping and causes the device to fail.

Therefore, in general, a large-scale ultrapure water production system is provided with a pipe for refluxing the excess treated water to the front end in any device in the primary pure water system, and the treated water is refluxed when the amount of ultrapure water used in the POU is reduced. The method of adjusting the flow volume of the primary pure water obtained is employ | adopted.

At this time, the low water foot serves to suppress the influence of the water hammer.

Although optimization has been attempted for circulation lines, in terms of power consumption and water use rate, generally, short circulation pipes are used to circulate the treated water through the previous low water feet or reservoir tanks.

On the other hand, as the line width of semiconductors to be manufactured gets finer year by year, the demand for water quality becomes more stringent. For example, stable production of ultrapure ultrapure water as disclosed in Non-Patent Document 1 is required.

However, the conventional ultrapure water production system has a problem that it is difficult to satisfy such a demand for high water quality.

In addition, in recent years, the substrate size has been expanded from 200 mm wafers to 300 mm and 450 mm wafers for the purpose of mass production and manufacturing cost reduction of semiconductor products. Therefore, the use amount of ultrapure water is also increasing, and the ultrapure water production apparatus is also becoming large.

As a result, the number of devices and pipes is increased, huge water feet and the like for temporarily storing intermediate treatment water are required, and a large area is required, and the operation management and maintenance management of each processing device is complicated. It is happening.

In addition, nitrogen gas is filled in the upper space of the low water feet, and the change in the water level of the stored water increases the usage amount of the nitrogen gas. In particular, in the large-scale apparatus, the increase of the use of nitrogen gas was remarkable, and there also existed a problem that operating cost increased.

Japanese Laid-Open Patent Publication No. 2009-240891 Japanese Laid-Open Patent Publication No. 2003-190947

2010 International Technology Roadmap for Semiconductors (ITRS)

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an ultrapure water production apparatus capable of stably maintaining ultra high quality water even at the point of use and maintaining each device, and producing ultrapure water at a constant flow rate. Do it.

An object of the present invention is to provide an ultrapure water production apparatus that can easily operate and maintain and significantly reduce manufacturing costs.

The ultrapure water production apparatus of the present invention includes a low water feet for storing pretreated water in which raw water is deposited, an reverse osmosis membrane device, and an ion exchange resin device for removing ionic components from the treated water. And a primary pure water system having a plurality of processable treatment lines, and a secondary pure water system for treating and supplying primary pure water treated in the primary pure water system to a point of use.

More specifically, it is preferable that the treatment series includes at least one device selected from a membrane degassing device, an ion exchange resin device, and a reverse osmosis membrane device, respectively.

In addition, the secondary pure water system is connected to the primary pure water system through a pure water tank, it is preferable that the system consists of one or more pure water systems that can be treated independently by a pump from the pure water tank.

In the ultrapure water producing system of the present invention, the flow rate of the ultrapure water to be produced is preferably 2,000 m 3 / day or more.

It is preferable that the ultrapure water producing system of the present invention includes at least one device in which the treatment series of the primary pure water system is also selected from an ultraviolet irradiation device, a chelating resin device, and an activated carbon device.

In the ultrapure water producing system of the present invention, the ion exchange resin device is selected from a cation exchange resin device, an anion exchange resin device, a multi-layer ion exchange resin device, a mixed bed ion exchange resin device and an electric regenerative ion exchange resin device. It is preferable that it is 1 or more types of apparatuses.

In the ultrapure water producing system of the present invention, each treatment series of the primary pure water system preferably includes a cation exchange resin device, a membrane degassing device, an anion exchange resin device, and a reverse osmosis membrane device in this order.

In the ultrapure water producing system of the present invention, the secondary pure water system preferably includes at least one device selected from an ultraviolet irradiation device, a film degassing device, a polisher, and an ultrafiltration device.

It is preferable that the ultrapure water producing system of the present invention collectively performs maintenance of the devices in the stopped processing series.

According to the ultrapure water production apparatus of the present invention, it is possible to significantly suppress the fluctuation of the flow rate of the ultrapure water to be produced and to stably produce high pure water. In addition, maintenance can be simplified and manufacturing costs can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically one Embodiment of the ultrapure water manufacturing apparatus of this invention.
It is a figure which shows typically one Embodiment of the ultrapure water manufacturing apparatus of this invention.
It is a figure which shows typically one Embodiment of the ultrapure water manufacturing apparatus of this invention.
4 is a graph showing changes over time of the ultrapure water quality obtained in Example 2 and Comparative Example 1. FIG.
5 is a graph showing the change over time of the ultrapure water quality obtained in Example 2 and Comparative Example 1.
FIG. 6 is a graph showing changes over time of ultrapure water quality when the circulation line H is used in a large-scale ultrapure water system.
7 is a graph showing changes over time of ultrapure water quality when the circulation line E is used in a large-scale ultrapure water system.
8 is a view schematically showing an ultrapure water producing system used in a comparative example of the present invention.
9 is a diagram schematically showing a conventional large-scale ultrapure water device.
FIG. 10 is a diagram schematically showing a pipe for regeneration treatment in a conventional large-scale ultrapure water producing system.

The present inventors have intensively studied for the purpose of further stable production of high quality ultrapure water, which is shown in FIG. 9, which will be described later, in a large-scale ultrapure water producing apparatus having a treatment flow rate of 10,000 m 3 / day, which is a conventional circulation method. Ultrapure water (in the outlet of the ultrafiltration unit) produced in the case of circulating ultrapure water circulated from the low water feet at the front end to the front end in addition to the line E, and circulating ultrapure water through each circulation line The number of fine particles in it was measured and compared. As shown in FIG. 7, the water quality fluctuated significantly when the circulation line E was used. On the other hand, it was found that when the circulation line H was used as shown in FIG. 6, fluctuations in water quality were suppressed. In addition, fluctuations in the water quality of the degree shown in FIG. 7 were acceptable in the conventional small and medium ultrapure water production apparatus. 6 and 7, the particle number was measured using an online particle counter.

In the large-scale ultrapure water production system, the present inventors rectify and circulate intermediate treated water in low water feet in a primary pure water system, which leads to deterioration of end water quality. It was found that the fluctuations in the flow rate caused the fluctuations in the ultrapure water quality to be produced, and thus completed the apparatus of the present invention which enables the stable production of the ultrapure water. In addition, in order to manufacture a large amount of ultrapure ultrapure water, a treated water is circulated to the front end of the primary pure water system and reprocessed by using both the reverse osmosis membrane device and the ion exchange resin device. It was found that organic components remained at the end to prevent deterioration of water.

In addition, the inventors of the present invention configure the treatment series by connecting the ion exchange resin device and the reverse osmosis membrane device which require maintenance and have a large difference in operation cycles or methods in series without passing through the low water feet or the water storage tank. The present invention has been provided with a plurality of systems, and has made it possible to operate another processing system in a state in which one system is stopped. As a result of operation without stopping the whole pure water system, it was possible to suppress the influence of the fluctuation of the flow volume and the flow path in a piping to the minimum, and to suppress the fluctuation of the ultrapure water quality manufactured to a large extent.

EMBODIMENT OF THE INVENTION Below, embodiment of this invention is described in detail with reference to drawings. The present invention is not limited to the ultrapure water producing system illustrated. In addition, in the following description, FIGS. 1-3, 8-10, and an English letter show the following meanings.

MF… Precision filtration device, HEX… Heat exchanger, AC ... Activated carbon apparatus, SC1, SC2... Strong acid cation exchange resin device, DG… Deaerator, MDG… Membrane deaerator, WA... Weakly basic anion exchange resin device, SA1, SA2... Strongly basic anion exchange resin device, RO… Reverse osmosis membrane device, TOC-UV… UV irradiation device, MB... Mixed bed ion exchange resin device, ANP… Oxidant removal resin, UF ... Ultrafiltration, Polisher… Polisher, POU… Point of Use, PIT: Feet

(Configuration example of conventional ultrapure water production apparatus)

First, as an example of a conventional ultrapure water producing system, an ultrapure water producing system 90 for producing ultrapure water at a processing flow rate of 420 m 3 / hour, that is, 10,000 m 3 / day is shown in FIG. 9.

In the apparatus shown in FIG. 9, the pretreatment system 91 includes a low water feet (PIT) 93, a microfiltration (MF) apparatus 901, a sand filtration apparatus (not shown), a heat exchanger (not shown). It is configured by appropriately selecting and connecting the pipes. The pretreatment water treated in the pretreatment system 91 is stored in the storage feet 94.

The primary pure water system 92 has a heat exchanger (HEX), an activated carbon tower unit (AC) 902, and a deionization unit (SC, WA, SA, MB, etc.) at the rear end of the low water feet 94 (903). ), Degassing apparatus (MDG, etc.) 904, reverse osmosis membrane apparatus (RO) 905, ultraviolet irradiating apparatus (TOC-UV) 906, prefilter (not shown), etc. Therefore, it is comprised by piping connected via a pump or a valve.

The pretreated water becomes primary pure water treated in the primary pure water system 92 and is stored in the pure water tank 97.

In the primary pure water system 92 of the ultrapure water producing system 90 shown in FIG. 9, the activated carbon tower device 902 is configured by connecting 5 to 7 activated carbon towers in parallel. The activated carbon device tower is filled with about 10,000 L of granular or powdery activated carbon in a container having an inner diameter of 3 to 4 m and a height of 2 to 3 m.

The ion exchange resin device 903, which is widely used as a deionizer, is formed by connecting four to five ion exchange resin towers in parallel. The ion exchange resin tower is filled with various known ion exchange resins of about 6000 to 10,000 L in a vessel having an inner diameter of 2 to 3 m and a height of 2 to 3 m.

Each ion exchange resin tower depends on the amount of impurities in the treated water, design conditions, operating conditions, and the like, but requires regeneration treatment once every two to three days.

In addition, the ion exchange resin device on the upstream side of the ultraviolet irradiation device removes ions in the pre-treated or intermediate treated water. The ion exchange resin device on the downstream side of the ultraviolet irradiation device mainly produces ions generated by decomposition of organic matter in the ultraviolet irradiation device. To remove the ingredients.

As the degassing apparatus 904, the membrane degassing apparatus MDG which connected several dozen hollow fiber membrane modules in parallel is used, for example. The apparatus which provided the vacuum degassing tower which filled fillers, such as a teralette, in the container of internal diameter (phi) 3-4m x height 3-4m may be used.

The reverse osmosis membrane apparatus 905 is comprised including 4-20 units with the same number of well-known modules, respectively.

The reverse osmosis membrane device 905 does not stop the operation from the start of water supply to the exchange. When adjustment of the processing flow volume of a reverse osmosis membrane apparatus is required, the method of waiting one or two units among the said units one by one, etc. is employ | adopted. Depending on the operating conditions, etc., the module replacement cycle is about half a year to three years.

The ultraviolet irradiator 906 decomposes live bacteria, bacteria, organic matters, and the like in the water by irradiating ultraviolet rays.

The prefilter is constructed by connecting 10 to 7 bag filter modules inserted into a container made of stainless steel (SUS304) in parallel.

As described above, the ion exchange resin device 903 and the reverse osmosis membrane device 905 have a greatly different cycle and method of maintenance. In order to stably maintain the flow rate and the water quality of the ultrapure water produced, it was necessary to interpose a large reservoir feet 95 and 96 or a reservoir tank having a buffer function therebetween.

In order to adjust the production flow rate of primary pure water, if each water treatment apparatus in a primary pure water apparatus is stopped and restarted after that, it is necessary to discharge treated water until water quality stabilizes after reoperation. In particular, in the membrane treatment apparatus, a large flow rate fluctuation occurs, so that a mechanical load may be applied to the membrane. Therefore, there is a possibility that the device may break down. In order to solve these problems, in the apparatus shown in FIG. 9 as a primary pure water circulation system, a circulation line E, a circulation line F, and a circulation line G are installed, and at the time of maintenance of the water treatment device or fluctuation of ultrapure water consumption in the POU. The excess intermediate treated water was refluxed to the inlet side of each water treatment apparatus using at least one of circulation lines E, F and G. At this time, since the primary pure water is higher than or equal to a certain level, high efficiency of the piping configuration and operation management has been carried out by refluxing the intermediate treated water to a water reservoir or a water tank as close as possible.

In the conventional large-scale apparatus shown in Fig. 9, the low water feet 95 and 96 are mainly provided between the ion exchange resin apparatus 903 and the reverse osmosis membrane apparatus 905. These low water feet were necessary to obtain large quantities of high quality ultrapure water.

The secondary pure water system 93 is a system for further treating primary pure water.

In the secondary pure water system 93, the ultraviolet irradiation device 907 has a scale including four to five ultraviolet irradiation towers. The polisher 908 has about seven polisher tops. For example, the polisher column is filled with a cation exchange resin and an anion exchange resin of about 3,000 to 5,000 L in a stainless steel (SUS316) container having a column diameter of 1.5 to 2 m and a height of 1.5 to 2.5 m.

The ultrafiltration device 910 is configured by connecting 60 to 70 hollow fiber membrane modules in parallel.

High water quality also tends to be required for the treated water (primary pure water) in the primary pure water system in order to reduce the load of impurity removal to each device of the secondary pure water system (93) and extend its life.

In the apparatus shown in Fig. 9, the inside of the secondary pure water system circulates ultrapure water in the secondary system circulation line 1d in order to prevent deterioration of the ultrapure water quality, and always at a constant treatment flow rate. The pure water tank 97 is for smoothly carrying out the circulation, and its capacity is about 150 m 3.

In the primary pure water system and the secondary pure water system 93, the low water feet 95 and 96, the pure water tank 97 and each system are sealed and sealed by inert gas. When the entire ultrapure water production system or each device is enlarged in size, the consumption of these inert gases is also enormous. In addition, during the maintenance, the low water amount of the low water feet varies, so increasing the number of maintenance increases the consumption of inert gas.

(Playback processing method in conventional device)

In small and medium-sized ultrapure water production systems, recycling chemicals have been attempted during maintenance. FIG. 10 schematically shows a water treatment apparatus requiring a regeneration treatment in the primary pure water system 92 of the ultrapure water producing system shown in FIG. 9 and a pipe for reuse of the regeneration chemicals not shown in FIG. As shown. In FIG. 9, the same code | symbol as FIG. 10 has shown the same apparatus, and the illustration of other piping and water treatment apparatus is abbreviate | omitted.

In a large-scale ultrapure water production apparatus as shown in FIG. 9, a large amount of regeneration chemicals are used for regeneration of an ion exchange resin apparatus and the like. Therefore, it is also conceivable to continuously regenerate a plurality of ion exchange resin towers by reusing chemicals for regeneration, as conventionally practiced in small and medium ultrapure water production equipment. In this case, the plurality of ion exchange resin towers need to be stopped and regenerated at the same time, but the actual regeneration cycle is not the same for each ion exchange resin tower. In addition, as shown in FIG. 10, in the large-scale ultrapure water production system, many valves, a water storage tank, and a pump are provided in many places, and piping becomes complicated. Therefore, in a large-scale ultrapure water production system, it is difficult to realize a method of recycling recycled chemicals.

In addition, such a conventional large-scale ultrapure water production system uses about 30,000 L of hydrochloric acid solution and sodium hydroxide solution in one regeneration treatment. At this time, the sodium hydroxide solution requires a lot of operation such as using by heating up to 40 ℃ by steam. In the case of a mixed bed ion exchange resin device, hydrochloric acid solution or sodium hydroxide solution is used in the amount of thousands to tens of thousands of each. In the case of a mixed bed ion exchange resin tower, many processes such as backwashing the ion exchange resin prior to the regeneration treatment, separating the cation exchange resin and the anion exchange resin, and then regenerating each of them and mixing them after regeneration are performed. need.

As described above, in the ultrapure water production system as shown in FIG. 9, for example, nitrogen gas consumes 4,000 Nm 3 / day at 0.7 MPa, sodium hydroxide 11,100 kg / day, and hydrochloric acid consumes 3500 kg / day. In addition, a control system for interlocking all processes, such as adjustment of the amount of water in the low water feet 95 and 96 or the pure water tank 97, management of a device or a pump, management of regeneration chemicals, and the like, is also required.

(Ultra pure water production apparatus of the embodiment)

1 and 3 are diagrams schematically showing the ultrapure water producing apparatuses 10 and 30 of the embodiment of the present invention.

The ultrapure water producing system (10, 30) excludes the low water feet (95, 96) between the ion exchange resin device (903) and the reverse osmosis membrane device (905) in the ultrapure water producing system shown in FIG. A processing sequence that can be processed independently is configured in the above, and the processing sequences are connected in parallel. Each treatment series is constructed by connecting a water treatment device without passing through the water feet, and the primary pure water system has no water feet.

The ultrapure water producing system 10 of the present embodiment includes a pretreatment system 11, a primary pure water system 12 connected to a rear end of the pretreatment system 11 via a water storage foot 2, and the primary pure water system ( A secondary pure water system 13 connected to the rear end of the tank 12 through the pure water tank 3 is provided. Each system, the water feet, the water storage tank, and the pure water tank are connected to each other by piping through a pump P (not shown in the drawings), which allows the flow path to be changed or the flow rate to be changed as necessary.

The pretreatment system 11 is a system for purifying raw water and controlling temperature, and is configured by selecting a conventionally known precision filtration device, sand filtration device, activated carbon device, heat exchanger and the like as necessary.

The primary pure water system 12 is a system that removes ionic and nonionic components from pretreated water and makes them highly purified. The primary pure water system 12 is configured by selecting a conventionally known activated carbon device, membrane degassing device, ion exchange resin device, ultraviolet irradiation device and the like as necessary. In the primary pure water system, primary pure water having a resistivity value of 10 MPa · cm or more is produced.

The secondary pure water system 13, also called a subsystem, is a system that removes trace ions and fine particles in the primary pure water and makes the primary pure water even higher. The secondary pure water system is configured by selecting a conventionally known ultraviolet irradiation device, non-regenerated polisher, membrane degassing device, peroxide decomposition resin device, ultrafiltration device and the like as necessary. In the second pure water system, ultrapure water having a resistivity value of 18 MPa · cm or more and a TOC concentration of 1 ppb or less is produced.

In this specification, for convenience, the terms "low water feet", "water tank" or "pure tank" are distinguished by their size for convenience, but the size and shape of the low water feet, water storage tank, and pure water tank may be determined by conditions such as treatment flow rate. Therefore, the decision can be made.

In addition, the same code | symbol is attached | subjected to the apparatus which has the same function in each process series.

As raw water, surface water such as industrial water, river water or lake water, municipal water, purified water, waste water, and the like can be used.

The pretreatment system 11 of this embodiment is the same as that of a conventionally well-known thing, It does not specifically limit about the structure, It can change suitably by the quality of raw water. For example, it can be set as the structure similar to the pretreatment system 91 of the ultrapure water manufacturing apparatus 90 shown in FIG.

The treatment series A of the primary pure water system 12 of the present embodiment can be treated independently, and in the primary pure water line 1bA, the ion exchange resin device 103 and the reverse osmosis membrane 105 are low water feet or low water tanks. It is connected in series by piping without going through. The primary pure water line 1bA is connected to the pretreatment tank 2 via the pump P which can switch a flow path.

The pump P is not particularly limited as long as the pump P can switch between the processing lines to be passed through and the flow rate in each processing line. For example, as illustrated in FIG. 1, a pump P capable of switching flow rates may be provided at the front end of each processing series. Further, a pump P capable of switching both the flow path and the flow rate may be provided at the front end classified into each processing series.

The primary pure water system 12 can be treated independently and has a treatment sequence B formed by connecting the same water treatment apparatus as the treatment sequence A in the same arrangement. The processing sequence A and the processing series B are connected in parallel to the water storage feet 2 via a pump P capable of switching the flow paths, respectively. The primary pure water system 12 is configured in such a manner that a total of two or more such processing systems are connected in parallel through the pumps P, respectively. Each treatment series is a treatment sequence formed by arranging the same water treatment apparatus as treatment sequence A in the same manner.

Since the primary pure water system of the present embodiment has a configuration in which a plurality of processing sequences that can be processed independently are connected in parallel, it is possible to operate another processing sequence while the arbitrary one series is stopped. For example, in FIG. 1, the operation of the processing series B can be continued while the processing series A is stopped. At this time, by adjusting the flow rate of the treatment series B, it is possible to stably maintain the flow rate of the primary pure water flowing into the tank 3 without using a plurality of circulation pipes as in the prior art. In addition, in the primary pure water system, the intermediate treated water is not circulated to the front end without rectifying the treated water to the low water feet in accordance with the amount of ultrapure water used in the POU, and thus the ultrapure water quality obtained can be stably maintained at high water quality. In addition, when the process series A is stopped, the operation of the process series B is continued, so that it is possible to continuously operate the system without stopping the entire primary pure water system, so that the quality of the primary pure water flowing into the tank 3 can be stably maintained. . In this way, even when any one series is stopped, operation of another processing series can be continued, so that it is easy to stably maintain the ultrapure water flow rate and water quality to be produced.

When the flow rate of the water to be introduced into the ion exchange resin device 103 in the other treatment series is too large when one series is stopped, the quality of the treated water of the ion exchange resin device 103 may be lowered. . Therefore, in order to reduce the change of the flow volume of each process series, it is preferable to provide the said process sequence 3-5 series.

Each processing series is controlled to switch the flow path by the pump P. FIG. It is preferable that the rear end of the primary pure water system is provided with a means (not shown) for preventing the reverse flow of the treated water.

The ion exchange resin device 103 removes ions in the pretreated water, and an ion exchange resin device in which various known ion exchange resins are filled can be used. Examples of ion exchange resins include strong acid cation exchange resins, weakly acidic cation exchange resins, strong base anion exchange resins, weak base anion exchange resins, and chelate resins. Powder, particulate, membrane, and fibrous substrates are appropriately selected and used.

As the ion exchange resin device 103, a multi-phase ion exchange resin device in which a cation exchange resin and an anion exchange resin are charged as two different layers in the same column, and a mixed phase ion exchange resin device (MB) mixed and filled can be used. . In addition, an electrically regenerative ion exchange resin device may be used.

The chelate resin is used as a chelate forming group with metal ions or the like and containing two or more electron donating elements such as N, S, O and P. As chelate resin, an imino diacetic acid type, a polyamine type, and a glucamine type are mentioned, for example.

As a chelate resin device, glucamine type chelate resin is preferable because it can remove ionic substances, such as boron.

In the ion exchange resin device 103, when the flow rate decreases, the TOC component from the ion exchange resin may be eluted, and when the flow rate increases, the deionization efficiency may decrease. Therefore, it is preferable to make process flow volume constant.

When the treatment flow rate is 2,000 m 3 / day or more, it is preferable to use a chemical regeneration type as the ion exchange resin device 103 in order to improve the regeneration efficiency and to improve the quality of the ultrapure water obtained.

The reverse osmosis membrane device 105 removes nonionic and ionic particulate components in the pretreated water. A pump (not shown) is provided at the front end of the reverse osmosis membrane device 105. The pump can adjust the flow rate of the water to be treated. The reverse osmosis membrane apparatus 105 can use a well-known thing provided with modules, such as a polyamide type or a cellulose acetate type. Treated Water (Permeated Water) From the viewpoint of stabilizing the water quality, the treated water recovery rate in the reverse osmosis membrane device is preferably constant at a predetermined value in the range of 85 to 90%.

The permeate water of the reverse osmosis membrane device 105 is sent downstream to be further processed. The concentrated water is returned to the raw water tank or the like by piping to be reprocessed or reused as scrubber water as necessary. The reverse osmosis membrane apparatus 105 may connect two or more reverse osmosis membrane modules in series in order to increase the recovery rate of the treated water. As needed, just before the reverse osmosis membrane apparatus 105, pH of the to-be-processed water may be adjusted to 9.5 or more.

In the primary pure water line 1bA, a conventionally known water treatment apparatus such as a membrane degassing apparatus, an activated carbon apparatus, and an ultraviolet irradiation apparatus may be interposed.

As each water treatment apparatus, the water treatment apparatus which comprises the above-mentioned conventional primary pure water system can be used. In addition, the number, function, scale, and arrangement of each water treatment apparatus installed in the treatment series A can be optimized according to the quality and flow rate of the ultrapure water used in the POU.

As an activated carbon tower device, it is preferable to provide an activated carbon device tower filled with granular or powdered activated carbon. As an ultraviolet irradiation device, the device which irradiates an ultraviolet-ray about wavelength 185nm or wavelength 254nm vicinity can be used. It is preferable that the prefilter is comprised by the bag filter module of 1 micrometer of nominal diameters.

It is preferable to use piping, such as stainless steel and vinyl chloride, for the primary pure water line 1bA. The inner diameter and the length of the pipe can be appropriately designed and changed according to the flow rate or water quality of the ultrapure water produced.

The flow rate of the ultrapure water produced in the present embodiment is preferably 2,000 m 3 / day or more, particularly preferably 10,000 m 3 / day or more. If the flow rate of the ultrapure water produced is in the said range, the influence of the fluctuation | variation of the flow rate of the ultrapure water produced can be suppressed, and the quality of ultrapure water can be stably maintained at high water quality.

In each processing series, piping for connecting the processing series at arbitrary positions may be provided. This piping can be installed using seams or pumps. By using the pipe, even if the device at a later stage is temporarily stopped due to failure or the like, the operation of the ultrapure water producing system can be continued.

In the primary pure water system 12 of the present embodiment, the primary pure water is preferably produced at a resistivity value of 15 Pa · cm or more, more preferably 17 Pa · cm or more.

The secondary pure water system 13 of the present embodiment includes a heat exchanger, an ultraviolet irradiation device, a peroxide decomposition resin device, a membrane degassing device, a mixed phase ion exchange resin device, a polisher, and an ultrafiltration device from an upstream side of the secondary pure water line 1c. At least one water treatment device of the filtration device is included. Each of these water treatment apparatuses can be selected and connected in accordance with the required water quality in the POU. In addition, each device can use a conventionally well-known thing.

As the ultraviolet irradiation device, it is preferable to use an ultraviolet irradiation device having a wavelength of about 185 nm. It is preferable to use an exchange type that does not regenerate as a mixed bed ion exchange resin device, a membrane degassing device, and an ultrafiltration device. In this case, contamination of the ultrapure water produced by the chemical | medical agent for regeneration treatment etc. can be suppressed.

As a polisher, about 3000 L of oxidizing agent removal resin (brand name: ANP, product made by Nomura Microscience Co., Ltd.) is filled in a tower, and the inside wall of a tower is lined with resin, and special resin for ultra-low ion component removal, for example, MBGP ( It is preferable that the brand name, the Nomura microscience company make, etc. were filled.

It is preferable to use the polysulfone hollow fiber membrane module as an ultrafiltration apparatus.

In this embodiment, in order to prevent deterioration of the ultrapure water quality in the secondary pure water system 13, the secondary system circulation line 1d and the pure water tank 3 are provided like the conventional one, and the manufactured ultrapure water is circulated.

In addition, in order to simplify maintenance and the like, the secondary pure water system 13 may be configured in the same manner as the primary pure water system 12 in which a plurality of processing sequences in which each device is arranged in series are connected in parallel.

The resistivity value of the ultrapure water produced by the secondary pure water system in the apparatus of the present embodiment is preferably 18.2 Pa · cm or more. Moreover, the apparatus of this embodiment exhibits the effect remarkably when the flow volume of the ultrapure water manufactured is 2,000 m <3> / day or more.

(Example of the reproduction processing method in the apparatus of the embodiment)

Since the apparatus of this embodiment is comprised by connecting the several process series which can be processed independently in parallel as mentioned above, the state which stopped the water to-be-processed water to arbitrary 1 series by switching the pump P, In this case, it can be passed through to another treatment system for treatment. Therefore, the apparatus in the stopped processing series can collectively perform maintenance. The maintenance may be performed at the timing of maintenance of the water treatment apparatus having the highest maintenance frequency in the treatment series. As a result, the water treatment apparatus having a low frequency may be appropriately performed during the maintenance cycle.

As a control method of the maintenance timing of each treatment series, a conductivity meter or a resistivity meter is provided at the outlet of each treatment series to measure the conductivity, and the measurement is performed when the measured value (conductivity, etc.) exceeds a predetermined value. There is a method of performing a regeneration treatment by switching the treatment sequence into which the treatment water is introduced. There is also a method in which a timer is provided to switch the processing sequence every predetermined time and perform the regeneration process.

FIG. 2 shows a water treatment apparatus which requires a regeneration treatment in the primary pure water system 12 of the pure water production apparatus shown in FIG. 3, and a pipe for performing these chemical regeneration treatments. In FIG. 2, the same code | symbol as FIG. 3 has shown the same apparatus, and the other apparatus and piping are abbreviate | omitted illustration.

In the present embodiment, an apparatus for regenerating treatment with an acidic chemical is connected to the pure water tank 41 by a pipe 201 for introducing and discharging the chemical. In addition, an acidic solution tank 205 is provided, and the acidic solution tank 205 is connected to the inlet side of the pipe 201 by a pipe 202. The acid solution of the acid solution tank 205 is supplied from the pipe 202 and primary pure water is supplied from the pure water tank 41 through the pipe 201. The pipe 201 is interposed between a switchable pump (not shown) and a suction ejector E1 that sucks pure water, and the pipe 202 is interposed with a switchable pump (not shown).

The regeneration treatment in acidic chemicals is carried out as follows. The hydrochloric acid solution is mixed and diluted with primary pure water as described above, and passed through each cation exchange resin device from the rear end side of the primary pure water system. Specifically, this is carried out by collectively passing through the pipe 201 in the order of the strongly acidic cation exchange resin (SC2) 130 and the strongly acidic cation exchange resin (SC1) 122 of FIG. 3.

The chelate resin device 126 is connected to the pipe 201c through the valve 207 and to the pipe 203c through the valve 208, and switches between the pipe 201c and the valve 208 by switching the valve 207 and the valve 208. The pipe 203c is configured to be switchable. The pipe 201c and the pipe 203c are connected to the pipe 201 and the pipe 203 by seams or the like, respectively.

In the regeneration process of the chelate resin device 126, the valve 207 interposed in the pipe 201c is switched to pass the acidic solution through the pipe. In the middle of the pipe 201, the chelate resin device 126 may be interposed through the valve 207. In this case, the regeneration treatment can be performed collectively including the cation exchange resin described above.

The apparatus processed with basic chemical | medical agent is connected to the pure water tank 41 by the piping 203 which introduces and discharges chemical | medical agent. A basic solution tank 206 is provided as the chemical storage tank, and the basic solution tank 206 is connected to the inlet side of the pipe 203 by the pipe 204. The basic solution is supplied from the basic solution tank 206 by the pipe 204, and the primary pure water is supplied from the pure water tank 41 by the pipe 203. A pipe (not shown) that can be switched is interposed between the pipes 203 to 206, and a suction ejector E2 that sucks pure water is interposed in the pipe 206.

The regeneration treatment with the basic solution is carried out as follows. The aqueous sodium hydroxide solution is mixed with the primary pure water in the pipe 203 as described above, diluted, heated to about 40 ° C. by steam or the like, and then each anion exchange resin device from the rear end side of the primary pure water system. Pass in Specifically, piping 203 in the order of the strong basic anion exchange resin (SA2) 129, the strong basic anion exchange resin (SA1) 125, and the weakly basic anion exchange resin (WA) 124 of FIG. It is carried out by collectively passing through).

The regeneration treatment of the chelate resin device 126 is performed by switching the valve 208 interposed between the pipe 203c and passing a basic solution out of the pipe.

The chelating resin device 126 may be interposed through the valve 208 in the middle of the pipe 203. In this case, the regeneration treatment can be performed collectively including the above-described anion exchange resin.

As described above, in the ultrapure water producing system of the present embodiment, each processing series configured without intervening low water feet in the primary pure water system is configured to be independently connected in parallel so as to be treated independently, and the devices that require regeneration are collected in each processing series. The reuse of the chemicals for regeneration can be facilitated. As a result, compared with the conventional ultrapure water producing apparatus shown in FIG. 9, FIG. Moreover, piping and a pump can be reduced.

Therefore, reuse of the chemical | medical agent for regeneration can be simplified.

In addition, the use of nitrogen gas can be reduced by 20 to 40% by reducing the number of low-pitched water in the primary pure water system. As a result, the running cost can be reduced by about 10 to 20%.

In addition, if the flow rate of the ultrapure water produced is 10,000 m 3 / day, a large-scale ultra pure water system, the space of 500 m3 of low water feet, the amount of raw water 1,000 m 3 / day, the waste water 1,200 m 3 / day, the pipe route or valve according to the concentration, Joints, pumps, etc. can be reduced. In addition, the cost can be reduced.

(Example 1)

Subsequently, ultrapure water was manufactured using the apparatus of this embodiment and the conventional ultrapure water manufacturing apparatus.

The apparatus and each condition which were used by the Example and the comparative example are as follows.

Source: Atsugi-shi tap water

[Pretreatment System 11]

Precision filtration device 111: Pressurized PVDF MF module UNA-620A, manufactured by Asahi Kasei Chemicals Co., Ltd.

Heat exchanger 112: plate type heat exchanger, stainless steel, manufactured by Hisaka Seisakusho Co., Ltd.

Water storage tank 21: capacity 1m 3, made of polyethylene.

[Primary Pure Water System (12)]

Activated carbon apparatus 121: Nomura cartridge column NCC-200AC, the product made by Nomura Micro Science Corporation.

Strongly acidic cation exchange resin device 122: Duolite C255LFH, vessel diameter 300 mm, resin amount 80L, manufactured by Dow Chemical Nippon Corporation.

Membrane deaerator 123: Rikisher X-40, manufactured by Polypoea Co., Ltd.

Weakly basic anion exchange resin device 124: Duolite A378LF, vessel diameter φ300 mm, resin amount 80L, manufactured by Dow Chemical Nippon Corporation.

Strong basic anion exchange resin device 125: Duolite A113LF, vessel diameter φ300 mm, resin amount 80L, manufactured by Dow Chemical Nippon Corporation.

Chelating resin device 126: CRBT-03, container inner diameter phi 300 mm, resin amount 50L, Mitsubishi Chemical Co., Ltd. make.

Reverse osmosis membrane apparatus 127: Membrane membrane module TMG20-370, manufactured by Toray Corporation.

Ultraviolet irradiation device 128: SUV-ST, the Nippon Photo Science Co., Ltd. make.

Strong basic anion exchange resin device 129: Duolite AGP, vessel diameter φ200 mm, resin amount 32L, manufactured by Dow Chemical Nippon Corporation.

Water storage tank 31: capacity 5m <3>, polyethylene.

Storage tank 51: capacity 5 m 3, made of polyethylene.

Strong acid cationic exchange resin device 130: Duolite CGP, vessel diameter φ200 mm, resin amount 32L, manufactured by Dow Chemical Nippon Corporation.

Piping (primary pure water line) 1b: made of hard polyvinyl chloride, inner diameter of 41.6 mm.

Mixed phase ion exchange resin device 131: Nomura cartridge column NCC-200M, manufactured by Nomura Microsciences Corporation.

Tank (pure tank) 41: Capacity 10 m 3, glass fiber reinforced plastic, nitrogen filled.

[2nd Pure Water System (13)]

Heat exchanger (HEX) 132: plate type heat exchanger, made of titanium, manufactured by Hisaka Seisakusho Co., Ltd.

Ultraviolet irradiation device 133: SUV-ST, the Nippon Photo Science Co., Ltd. product.

Peroxide decomposition resin device 134: NCC-200M (ANP), the product made by Nomura microsciences.

Membrane degassing apparatus 135: Rikisher X-40, manufactured by Polypore Corporation.

Mixed phase ion exchange resin device 136: 210 L of MBSP manufactured by Nomura MicroSense Co., Ltd. is filled into a container lined with polytetrafluoroethylene and an inner diameter of 400 mm.

Ultrafiltration device 137: OLT-6036HA, manufactured by Asahi Chemical Co., Ltd ..

Piping 1c (piping downstream from the outlet of the mixing type ion exchange resin apparatus 131): Inner diameter (phi) 75 mm, Polyvinylidene fluoride (PVDF) product.

[Playback processing condition]

Hydrochloric acid container: 35% by mass (wt%) hydrochloric acid (manufactured by Asahi Glass Co., Ltd., industrial standard)

Sodium hydroxide container: 25 mass% (wt%) sodium hydroxide (manufactured by Asahi Glass Co., Ltd., industrial standard).

[Analytical device]

TOC analyzer: A-1000XP, manufactured by Anatel

Dissolved oxygen system: MOCA-3600, product made by Obispair.

Resistivity monitor: Resistivity monitor

Particle measuring instrument: Online particle counter (UDI-50, manufactured by PMS).

Silica: Atomic Absorption Spectrophotometer.

Boron: Inductively Coupled Plasma Mass Spectrometer.

Various metals (Li, Na, K, Zn, Fe, Cu, Ca, Ni, Mg, Mn, Al, Cr, Co, Ti, Mo, Ba, Pb): Inductively coupled plasma mass spectrometer.

Various ions ^{(Br -, F -, NO} 3 -, Cl -, NO 2 -, PO 4 3 -, SO 4 2 -, NH 4 +): ion chromatography apparatus.

Hydrogen peroxide: peroxide monitor (NOXIA-L, manufactured by Nomura Microscience Co., Ltd.).

(Example 1)

Ultrapure water was manufactured using the pure water manufacturing apparatus 30 shown in FIG.

As shown in FIG. 3, the ultrapure water producing system 30 used in Example 1 has a rear end of the pretreatment system 11 and the pretreatment system 11 in which the precision filtration device 111 and the heat exchanger 112 are connected in this order. The water storage tank 21 is provided. In the water storage tank 21, the treatment series 12A and the treatment series 12B of the primary pure water system are connected to the primary pure water lines 1bA and 1bB through the pumps P1 and P3 at the front end, respectively. The pumps P1 and P3 are pumps capable of changing the flow path and changing the flow rate. The treatment series 12A includes the activated carbon device 121A, the strong acid cation exchange resin device 122A, the membrane degassing device 123A, the weakly basic anion exchange resin device 124A, and the steel from the upstream side of the primary pure water line 1bA. Basic anion exchange resin device (125A), chelate resin device (126A), reverse osmosis membrane device (127A), ultraviolet irradiation device (128A), strong basic anion exchange resin device (129A) and strong acid cation exchange resin device (130A) In this order, the pipes are connected in series. The reservoir tank 31 is connected downstream of the strongly acidic cation exchange resin device 130A, and the mixed phase ion exchange resin device 131 and the pure water tank 41 are connected in this order.

The front end of the reverse osmosis membrane device 127A and the front end of the mixed-phase ion exchange resin device 131 are provided with pumps P2, P4, and P5, each of which is capable of adjusting the flow rate.

The processing series 12B is configured by connecting the same devices as the processing series 12A in series in the same order.

Downstream of the pure water tank 41 is a secondary pure water system 13 as a secondary pure water system 13 on the pipe 1c via a pump P6, a heat exchanger 132, an ultraviolet irradiation device 133, a peroxide decomposition resin device 134, and a membrane. The degassing apparatus 135, the mixed bed ion exchange resin apparatus 136, and the ultrafiltration apparatus 137 are connected in series in this order, and are subsequently connected to the POU. The pump P6 is a pump which can adjust the flow volume of the to-be-processed water. A secondary system circulation line 1d is formed between the POU and the pure water tank 41 by piping.

[Preparation of Pretreated Water]

The raw water was introduced into the microfiltration unit 111 and then passed through the heat exchanger 112. The temperature of the raw water withdrawn from the heat exchanger 112 was 25 degreeC. The pretreatment water was stored in the storage tank 21.

[Preparation of Primary Pure Water]

In the primary pure water system, only the treatment series A was used in the ultrapure water producing system 30 shown in FIG.

The pretreatment water from the water storage tank 21 was introduced into the treatment system A from the activated carbon device 121A of the treatment system 12A at a flow rate of 2.1 m 3 / hour through the pump P1. In the reverse osmosis membrane apparatus 127A, the flow rate of the water to be treated was 2.1 m 3 / hour and the treated water recovery was 90%.

The resistivity value of the treated water (treated water 1) withdrawn from the strongly acidic cation exchange resin device (130A) was measured at the outlet port side of the reservoir tank 31. The results are shown in Table 1.

The treated water stored in the storage tank 31 was introduced into the mixed-phase ion exchange resin device 131 at a flow rate of 1.9 m 3 / hour through the pump P5. In this embodiment, the mixed phase ion exchange resin device 131 is provided at the rear end of the water storage tank 31. As shown in Table 1 to be described later, the treated water 1 is of high water quality, so the mixed phase ion exchange resin device 131 may be non-regenerated. Even in the case of regeneration, unlike the ion exchange resin device of the front end, the regeneration frequency can be extended to about one month to six months.

Subsequently, the treated water (primary pure water) of the mixed bed ion exchange resin device 131 was introduced into the pure water tank 41.

[Production of Secondary Pure Water]

Subsequently, the primary pure water was introduced into the secondary pure water system 13 with a pump P6 and treated. The temperature of the treated water withdrawn from the heat exchanger 132 was 25 ° C. The recovery rate of the treated water in the ultrafiltration device 137 was 95%.

The flow rate of the prepared ultrapure water was 1.8 m 3 / hour.

The ultrapure water thus obtained was referred to as ultrapure water 1.

For ultrapure water 1 obtained in Example 1, the water quality was measured by the analyzer and the monitor described above. The results are shown in Table 1.

In Table 1, it can be seen that the treated water 1 has a specific resistivity value of 15 to 17 Pa · cm and satisfies the high water quality required in the manufacturing process of the semiconductor or the plate. In addition, general primary pure water (pure water) has a resistivity value of 10 Pa.cm or more.

In addition, since the treated water 1 is of high quality, the load of the secondary pure water system can be reduced, and the number and size of each water treatment device can be reduced.

(Example 2)

Ultrapure water was prepared using the treatment series A and the treatment series B in the apparatus of FIG. 3.

At first, the pumps P1 and P3 were switched so as to be treated using the treatment sequence A without passing the pretreatment water into the treatment sequence B. The apparatuses in the processing systems A and B used those which had been regenerated in advance.

The flow rate of the ultrapure water produced (at the outlet of the ultrafiltration device 137) was 1.9 m 3 / hour.

Based on the water quality, flow rate, and resin amount of the water to be treated, the strong acid cation exchange resin 122 undergoes a regeneration treatment, and starts to pass water. Each treatment sequence switches pumps P1 and P3 to stop the passage of water to the treatment sequence every 24 hours and start the passage of water to the other treatment sequence at the same time. While passing through one process line, the regeneration process was performed using the piping shown in FIG. 2 about the apparatus in the other process line. At this time, the regeneration chemicals are injected and injected into the pipe 201 and the pipe 203 using a pump capable of supplying the following amount, and the regeneration chemicals are mixed through the line mixer in the pipe 201 and the pipe 203. Dilution was carried out and the liquid was passed through.

The hydrochloric acid solution passed for the regeneration of the strong acid cation exchange resin device 130 and the strong acid cation exchange resin device 122 in each regeneration treatment cycle was 5 mass% in concentration, 2.9 L / min in flow rate, and 160 L in total.

The hydrochloric acid solution passed through for the regeneration of the chelating resin device 126 was 5 mass% in concentration, 1.75 L / min in flow rate, and 70 L in total.

The sodium hydroxide solution passed through for the regeneration of the strong basic anion exchange resin device (129), the strong basic anion exchange resin device (125), the chelate resin device (126), and the weakly basic anion exchange resin device (124) has a temperature of 40 ° C. , Concentration 5 mass%, flow rate 3.5L / min, total amount 120L.

The processing sequence A and the processing series B were switched to the above timings, and ultrapure water was produced for 168 hours while regenerating.

The change of the obtained ultrapure water quality with time is shown in FIG. 4 with respect to particulate water, and FIG. 5 with respect to TOC density | concentration.

(Comparative Example 1)

The apparatus shown in FIG. 8 was used. In the apparatus shown in FIG. 3, the activated carbon device 121 to the chelate resin device 126 and the reverse osmosis membrane device 127 to the strongly acidic cation exchange resin device 130 are each sub-series, and each sub-series is in parallel. It was comprised as two series. In addition, pumps P7 to P10 capable of switching flow paths and changing flow rates were interposed at the front end of each sub-series. Between the chelating resin device 126 and the pumps P8 and P10, the same storage tank 51 as the storage tank 31 was provided.

Other than that is the same as the apparatus shown in FIG.

The introduction flow rate of the water to be treated into the activated carbon device 121 was 2.1 m 3 / hour, which is the same as in Example 1.

In addition, ultrapure water was produced in the same manner as in Example 1 except that each sub-series conversion and regeneration were carried out as follows.

Ultrapure water production was carried out by switching the pumps P7 to 10 so as to pass water to one of the sub-series and stop the passage to the other. The pumps P7 and P9 were switched every 24 hours, and the introduction of the water to be treated into the sub-series that was passed through was stopped, respectively, and at the same time, water-through was started to the other sub-series. In addition, when the resistivity meter was installed at the outlet of the strongly acidic cation exchange resin device 130 and the resistivity value was lowered to less than 10 m · cm, the pumps P8 and P10 were switched to pass through the sub-series treated with the sub-series. The introduction of water was stopped, and water flow was started in the other sub-series at the same time.

While passing through one sub-series, the regeneration process of the apparatus in the other sub-series was performed.

Thus, ultrapure water production was performed for 168 hours.

The flow rate of the produced ultrapure water was 1.9 m 3 / hour.

The change of the obtained ultrapure water quality with time is shown in FIG. 4 with respect to particulate water, and FIG. 5 with respect to TOC density | concentration. 4 and 5, the solid line represents Example 2 and the dotted line represents Comparative Example 1. In FIG.

4 and 5, in Example 2, there was no change in the amount of water and the quality of water due to the switching of the run / stop series, so that the number of fine particles and the TOC concentration in ultrapure water were kept constant. On the other hand, in Comparative Example 1, the water quality of the ultrapure water obtained is varied. This is due to the variation of the treated water recovery rate due to the variation of the flow rate of the water to be treated in the membrane treatment device such as the reverse osmosis membrane device 127 or the ultrafiltration device 137 or the elution from the piping constituent member due to the variation of the flow rate in the pipe. It is considered that it is due to the fluctuation of component concentration. Ultrapure water having increased particulate water or TOC concentration may affect the yield of the product, and it is refluxed to the front end and reprocessed if necessary.

Example 3 Massive Ultrapure Water System

On the basis of the results obtained in Examples 1 and 2, the apparatus shown in Fig. 3 is a large-scale system in which the primary pure water system has five series of the same treatment series as the treatment series A, and the flow rate of the ultrapure water produced is 17,500 m 3 / day. Table 2 shows the results of designing the ultrapure water production system, calculating the chemical usage (the total value of 35 mass% hydrochloric acid and 25 mass% sodium hydroxide) and the nitrogen gas consumption.

(Comparative Example 2)

On the basis of the results obtained in Example 2 and Comparative Example 1, the conventional large-scale ultrapure water producing apparatus shown in FIG. 9, which has a flow rate of ultrapure water produced is 17,500 m 3 / day, was used, and the chemical use amount (35 mass% hydrochloric acid, 25 Table 2 shows the results of calculating the total value of mass% sodium hydroxide), nitrogen gas usage and cooling water usage.

As compared with Comparative Example 2, in Example 2, the amount of chemicals used is reduced by 6,000 kg / day. This is because the device is concentrated and series operation is performed to collectively regenerate the ion exchange resin device. The decrease in the amount of nitrogen gas used is 500 cubic meters of low-foot water.

As described above, in the ultrapure water producing system of the present invention, the primary pure water system is constituted by parallel connection of two or more processing systems which are configured without the water feet or the water storage tank, and which can be processed independently, respectively, and these treatments are performed. It is possible to stop the other processing series while operating at least one processing series of the series. Therefore, it is possible to continuously manufacture ultrapure water without stopping the entire primary pure water system, and thus it is possible to stably produce high quality ultrapure water by significantly suppressing fluctuations in the flow rate of the ultrapure water produced.

In addition, according to the ultrapure water producing system of the present invention, it does not have low water feet in the primary pure water system, and therefore does not require a circulation pipe for circulating the intermediate treated water. In the absence of these low water feet and circulation pipes, according to the ultrapure water producing apparatus of the present invention, the ultrapure water quality to be produced can be stably maintained. In addition, since the water treatment apparatuses requiring regeneration treatment or replacement are condensed in each treatment series, it is easy to collectively regenerate and replace these water treatment apparatuses, thereby simplifying maintenance. As described above, according to the ultrapure water producing system of the present invention, the manufacturing cost can be reduced.

In particular, when a large-scale ultrapure water production system having a treatment flow rate of 2,000 m 3 / day or more is used, the number of water treatment devices to be provided is increased, and the frequency of maintenance of each water treatment device and the variation of the ultrapure water usage of the POU are also increased. Even in this case, the above-described configuration can suppress variation in the flow rate of the ultrapure water produced in the ultrapure water production system of the present invention, so that the specific resistivity value is 18 Pa · cm or more, 0.05 μm or more, and the number of fine particles 200pcs./L or less High quality ultrapure water having a carbon (hereinafter also referred to as TOC) concentration of 0.5 ppb or less can be stably produced. In addition, maintenance costs can be simplified to significantly reduce manufacturing costs.

10, 20, 30, 80, 90: ultrapure water production system 11: pretreatment system
12: 1st pure water system 13: 2nd pure water system
2,21: Low water feet 3,31,41: Pure water tank
103: ion exchange resin device 105: reverse osmosis membrane device
1a, 1b, 1c: pure line 1d, E, F, G: circulation line
111: precision filtration device 112, 132: heat exchanger
121: activated carbon device 122: strong acid cation exchange resin device
123: membrane deaerator
124: weakly basic anion exchange resin device
125: strong basic anion exchange resin device
126: chelate resin device 127: reverse osmosis membrane device
128: UV irradiation device
129: strong basic anion exchange resin device
130: strong acid cation exchange resin device 131: mixed phase ion exchange resin device
133: ultraviolet irradiation device 134: oxidant removal resin device
135: membrane deaerator 136: interphase ion exchange resin device
137: ultrafiltration device P: pump

Claims (9)

Low water feet to store pretreated water in which raw water is deposited;
A primary pure water system comprising a reverse osmosis membrane device and an ion exchange resin device for removing ionic components in the pretreated water, and further comprising a plurality of treatment systems capable of independently treating the pretreated water, and
Ultra pure water production apparatus having a secondary pure water system for processing and supplying the primary pure water treated in the primary pure water system to the point of use. The method of claim 1,
And said treatment series comprises at least one device selected from a membrane degassing device, an ion exchange resin device, and a reverse osmosis membrane device, respectively. 3. The method according to claim 1 or 2,
And the secondary pure water system is connected to the primary pure water system through a pure water tank, and the ultrapure water producing system comprising at least one pure water system that can be independently processed by a pump from the pure water tank. 3. The method according to claim 1 or 2,
Ultrapure water production apparatus having a flow rate of ultrapure water is produced more than 2,000㎥ / day. 3. The method according to claim 1 or 2,
The treatment system of the primary pure water system is also characterized in that the ultrapure water production apparatus having at least one device selected from ultraviolet irradiation device, chelate resin device and activated carbon device. 3. The method according to claim 1 or 2,
And the ion exchange resin device is at least one device selected from a cation exchange resin device, an anion exchange resin device, a multi-layer ion exchange resin device, a mixed bed ion exchange resin device and an electric regenerative ion exchange resin device. 3. The method according to claim 1 or 2,
The treatment system of the primary pure water system is an ultrapure water production system comprising a cation exchange resin device, a membrane degassing device, an anion exchange resin device and a reverse osmosis membrane device in this order. 3. The method according to claim 1 or 2,
The secondary pure water system is an ultrapure water producing system comprising at least one device selected from ultraviolet irradiation device, membrane degassing device, polisher and ultrafiltration device. 3. The method according to claim 1 or 2,
An apparatus for producing ultrapure water for stopping at least one treatment sequence among the plurality of treatment sequences and collectively performing maintenance of the apparatus in the stopped treatment sequence.

Images