TWI687374B - Ultrapure water manufacturing device - Google Patents

Abstract

Provide an ultrapure water manufacturing device, which can reduce the cost of heat source to heat the ultrapure water sent to the point of use to become a warm ultrapure water heat exchanger, and can reduce the cost of cooling the pure water once . The secondary pure water from the sub-system (4) is heated by the heat exchanger (6), the heat exchanger (10) and the heat exchanger (12) and sent to the point of use. The heat source of the heat exchanger (6) is warm ultrapure water returning from the point of use. The reflux ultrapure water is cooled by the heat exchanger (6) and the heat exchanger (43), and then introduced into the sub tank (2). The first medium water heated by the heat pump (20) circulates through the heat exchanger (10). The second medium water is circulated in the evaporator 21 of the heat pump (20). A heat exchanger (26) that circulates warm water from the point of use (40) is provided in the second medium water circulation channel, and a heat exchanger (43) is provided on the upstream side of the heat exchanger (26).

Description

Ultrapure water manufacturing device

The present invention relates to an ultrapure water production device, and particularly to an ultrapure water production device that heats ultrapure water from a secondary pure water production device with a heat exchanger and supplies it as warm ultrapure water to a point of use.

As shown in FIG. 2, ultrapure water used as semiconductor cleaning water is composed of a pretreatment system 50, a primary pure water production device 60, and a secondary pure water production device (mostly referred to as a sub-system) 70. An ultrapure water manufacturing device processes raw water (industrial water, household water, well water, etc.) and manufactures it (Patent Document 1). The function of each system in FIG. 2 is as follows.

In a pretreatment system 50 made of agglomeration, pressurized floating (precipitation), filtration (membrane filtration) device, etc. (the previous example is agglomeration filtration device), the suspended matter or colloidal substance in the raw water is removed. In addition, high-molecular organics, hydrophobic organics, etc. can also be removed in this process.

Equipped with: pre-treated water tank 61, heat exchanger 65, reverse osmosis membrane treatment device (RO device) 62, ion exchange device (mixed bed type or 4 bed 5 tower type, etc.) 63, tank 63A, ion exchange The primary pure water production device 60 of the device 63B and the degassing device 64 removes ions or organic components in the raw water. In addition, the higher the temperature of water, the lower the viscosity, and the permeability of the RO membrane will increase. Therefore, as shown in FIG. 2, a heat exchanger 65 is provided in the front stage of the reverse osmosis membrane treatment device 62 to heat the water so that the temperature of the water supplied to the reverse osmosis membrane treatment device 62 becomes a predetermined temperature or more. On the primary side of the heat exchanger 65, steam as a heat source fluid is supplied. In the reverse osmosis membrane processing device 62, salts are removed, and ionic and colloidal TOC are removed. In the ion exchange devices 63 and 63B, salts and inorganic carbon (IC) are removed, and the TOC component of adsorption or ion exchange is removed by ion exchange resin. In the degassing device 64, inorganic carbon (IC) and dissolved oxygen are removed.

The primary pure water produced in the primary pure water production device 60 is sent through the pipe 69 to the secondary pure water production device 70. The secondary pure water manufacturing device 70 includes a sub tank (also referred to as a pure water tank) 71, a pump 72, a heat exchanger 73, a low-pressure ultraviolet oxidation device (UV device) 74, an ion exchange device 75, and an ultra Filter membrane (UF membrane) separation device 76. The heat exchanger 73 is used for temperature control of secondary pure water. Generally, the supply temperature of secondary pure water (normal temperature ultrapure water) is 23 to 25°C. In order to control this temperature range, the heat exchanger 73 series uses a cooler. As the cooling source of the cooler, cold water is used. The heat exchanger 73 must be placed before the ion exchange device 75. When high-temperature pure water comes into contact with ion exchange resins, TOC components will be eluted, resulting in deterioration of water quality. Therefore, it is necessary to reduce the temperature of the water to 23 to 25°C by the heat exchanger 73 and then send it to the ion exchange device 75. In order to receive the supply of cold water flowing through the cooling heat exchanger 73 from an electronic component manufacturing plant, piping equipment for this is necessary. Furthermore, in order to reduce the manufacturing cost of ultrapure water, it is desirable to reduce the amount of cold water used.

The low-pressure ultraviolet oxidation device 74 decomposes TOC into organic acids or even CO ₂ by the 185nm ultraviolet light emitted by the low-pressure ultraviolet lamp. Organic matter and CO ₂ generated by the decomposition are removed by the ion exchange device 75 in the latter stage. In the ultrafiltration membrane separation device 76, the fine particles are removed, and the outflow particles from the ion exchange resin are also removed.

The treated water of the ion exchange device 75 is divided into: ultrapure water (normal temperature ultrapure water) sent from the ultrafiltration membrane separation device 76 through the piping 81 to the use point 90, after the heat exchangers 85 and 86 are heated The ultrapure water (warm ultrapure water) sent to the use point 90 through the ultrafiltration membrane separation device 87 and the piping 88.

In the latter route, the ultrapure water from the secondary pure water production device 70 is heated to about 65 to 75° C. in the front-stage heat exchanger 85 and the rear-stage heat exchanger 86 and supplied to the point of use 90. The warm reflux water from the usage point 90 passes through the pipe 91 and circulates to the heat source side of the front-stage side heat exchanger 85. The return water system passing through the heat source side of the front-stage side heat exchanger 85 is cooled to about 30 to 40°C, and returns to the auxiliary tank 71 through the piping 92. The rear heat exchanger 86 uses steam as a heat source.

[Patent Document 1] Japanese Laid-Open Patent 2013-202581

The present invention aims to provide an ultrapure water manufacturing device that can reduce the cost of a heat source for a heat exchanger for warm ultrapure water by heating the ultrapure water sent to the point of use, and can be used for cooling once The cost of pure water is reduced.

An ultrapure water production apparatus according to one aspect of the present invention supplies heated ultrapure water to a point of use, and includes: a primary pure water production apparatus, which processes primary pure water from the primary pure water production apparatus On the other hand, a secondary pure water manufacturing device for manufacturing ultrapure water, a first heat exchanger for heating ultrapure water from the secondary pure water manufacturing device and using the return water from the point of use as a heat source A second heat exchanger that cools the reflux water of the first heat exchanger, and adds the reflux water cooled in the second heat exchanger to the reflux water return system of the primary pure water, and to the first The heating means for further heating the ultrapure water heated by the heat exchanger, the heating means includes: a third heat for circulating the ultrapure water heated in the first heat exchanger to the heated fluid flow path An exchanger, a first circulation flow path that circulates the first medium water as a heat transfer medium in the heat source fluid flow path of the third heat exchanger, and the first medium water flowing through the first circulation flow path A heated heat pump including a condenser, an evaporator, a pump, and an expansion valve. The condenser is provided in the first circulation channel to heat the first medium water. The evaporator is provided in the first The second circulation water channel circulates the second medium water, and a second heat exchanger that heats the second medium water by the heat of warm water drainage is provided in the second circulation flow path, and is further than the fourth heat exchanger. The second circulation flow path on the upstream side is provided with the aforementioned second heat exchanger.

In one aspect of the present invention, a fifth heat exchanger using steam as a heat source for heating the ultrapure water heated in the third heat exchanger is provided.

In one aspect of the present invention, the first circulation flow path is provided with a sixth heat exchanger using steam as a heat source for heating the first medium water from the condenser to the third heat exchanger.

In the ultrapure water production apparatus of the present invention, in the first heat exchanger, the ultrapure water is heated by using the heat held by the return water at the point of use. Then, the ultrapure water is further heated by the third heat exchanger using the first medium water heated by the condenser of the heat pump as a heat source fluid. The second medium water circulates through the evaporator of the heat pump. The second medium water includes a fourth heat exchanger using warm drain water as a heat source, and a second heat exchanger using return water passing through the first heat exchanger as a heat source. As a result, the cost of the heat source for heating ultrapure water that has been sent to the point of use to a predetermined temperature to become warm ultrapure water can be reduced. In addition, the reflux water passing through the first heat exchanger is further reduced in the second heat exchanger, and then added to the primary pure water. Therefore, the cold water used to cool the primary pure water is not needed, which can be reduced.

In addition, the water temperature of the reflux water at the point of use is usually 70 to 80°C, for example, about 75°C.

In the present invention, the so-called warm drainage refers to drainage used for washing at the point of use. The concentrated water of the UF membrane separation device installed just before the point of use can also be included in the warm drainage. The temperature of warm drainage is usually 60 to 75°C, for example about 65°C.

1‧‧‧ Once pure water

2‧‧‧slot

3‧‧‧Piping

4‧‧‧Subsystem

5‧‧‧Piping

5A‧‧‧Piping

5B‧‧‧UF membrane separation device

5C‧‧‧Piping

6‧‧‧ Heat exchanger

7‧‧‧ Piping

10‧‧‧ heat exchanger

11‧‧‧Piping

12‧‧‧Steam heat exchanger

13‧‧‧UF membrane separation device

14‧‧‧Piping

15‧‧‧Piping

16‧‧‧Piping

17‧‧‧Bypass piping

20‧‧‧heat pump

21‧‧‧Evaporator

22‧‧‧Pump

23‧‧‧Condenser

24‧‧‧Expansion valve

25‧‧‧Piping

26‧‧‧ Heat exchanger

27‧‧‧Piping

28‧‧‧Bypass piping

29‧‧‧Piping

30‧‧‧Piping

40‧‧‧point of use

41‧‧‧Piping

42‧‧‧Piping

43‧‧‧ Heat exchanger

44‧‧‧Piping

FIG. 1 is a system diagram of an ultrapure water production apparatus according to an embodiment.

FIG. 2 is a system diagram of the ultrapure water manufacturing apparatus of the previous example.

The ultrapure water production apparatus of the present invention includes a primary pure water production apparatus, a secondary pure water production apparatus, and a heating means for heating ultrapure water.

At the front stage of the primary pure water production device, a pretreatment device is usually provided. The pretreatment device is used for pretreatment caused by the filtration of raw water, coagulation and sedimentation, precision filtration membranes, etc., mainly to remove suspended substances. By this pretreatment, the number of fine particles in water is usually 10 ³ particles/mL or less.

Primary pure water production equipment, including: reverse osmosis (RO) membrane separation device, degassing device, regenerative ion exchange device (mixed bed type or 4 bed 5 tower type, etc.), electrical deionization device, ultraviolet (UV) irradiation Oxidation devices, such as oxidation devices, remove most of the electrolyte, fine particles, and bacteria in the pretreated water. The primary pure water production device is composed of, for example, a heat exchanger, two or more RO membrane separation devices, a mixed-bed ion exchange device, and a degassing device.

The secondary pure water manufacturing device is composed of auxiliary tank, water supply pump, cooling heat exchanger, low-pressure ultraviolet oxidation device or sterilization device and other ultraviolet irradiation devices, non-regenerative mixed bed ion exchange device or electrical deionization device, ultrafiltration (UF) Membrane separation devices or precision filtration (MF) membrane separation devices are used for membrane filtration devices. However, there are cases where a desalination device such as a membrane degassing device, RO membrane separation device, or electrical deionization device is further provided. In the secondary pure water manufacturing device, a low-pressure ultraviolet oxidation device is applied, and a mixed-bed ion exchange device is provided at the rear stage, thereby oxidizing and decomposing TOC in water with ultraviolet rays, and removing oxidative decomposition products by ion exchange. In this specification, hereinafter, the portion of the secondary pure water production device that is further to the secondary side than the secondary tank is referred to as a secondary system.

In addition, a tertiary pure water manufacturing device may be provided at a later stage of the secondary pure water manufacturing device, and the ultrapure water from the tertiary pure water manufacturing device may be heated. This tertiary pure water manufacturing device has the same structure as the secondary pure water manufacturing device, and is a person who manufactures ultra-pure water of higher purity.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a system diagram showing an ultrapure water production apparatus according to an embodiment. In addition, although the water temperature is exemplified in the following description, each water temperature is only an example, and does not limit the present invention in any way.

The primary pure water at about 25°C is introduced into the sub-system 4 through the piping 1, sub-tank 2, and piping 3 to produce ultra-pure water. The produced ultrapure water at about 25°C flows through piping 5, heat exchanger 6, piping 7, heat exchanger 10, piping 11, steam heat exchanger 12, UF membrane separator 13 and piping 14 in this order And heated to approximately 75°C by the heat exchangers 6, 10, 12 and sent to the point of use 40 through the piping 14 as warm ultrapure water. The UF membrane separation device 13 is installed just before the point of use 40 is reached.

The piping 5A is branched from the piping 5, and the ultra-pure water at normal temperature is sent to the point of use through the UF membrane separation device 5B and the piping 5C.

In the heat source fluid flow path of the heat exchanger 6, the return temperature ultrapure water (reflux water) from the point of use 40 is introduced through the pipe 41. The ultra-pure water with the return temperature passing through the heat exchanger 6 is cooled by heat exchange between the heat exchanger 43 and the second medium water of the heat pump 20, and then sent to the sub tank 2 through the pipe 44.

In the heat source fluid flow path of the heat exchanger 10, the first medium water (water as the heat transfer medium) heated by the condenser 23 of the heat pump 20 is circulated and circulated.

The heat pump 20 is configured such that a heat medium such as a chlorofluorocarbon substitute from the evaporator 21 is compressed by the pump 22 and introduced into the condenser 23, and the heat medium from the condenser 23 is introduced into the evaporator 21 through the expansion valve 24 .

The first medium water from the heat exchanger 10 at about 75°C is introduced into the condenser 23 through the piping 15 and the first medium water heated to about 80°C in the condenser 23 is sent through the piping 16 to send water to the heat exchanger 10. In addition, a part of the first medium water from the condenser 23 is sent back to the piping 15 through the bypass piping 17. The heat exchanger 10, the piping 15, the condenser 23, and the piping 16 constitute a first circulation flow path. The bypass piping 17 is provided with a flow control valve (not shown).

In order to circulate the second medium water in the heat source fluid flow path of the evaporator 21, a second circulation flow path formed by the piping 25, the heat exchanger 43, the heat exchanger 26, and the piping 27 is provided. In addition, a bypass pipe 28 is provided between the pipes 25 and 27. The bypass piping 28 is provided with a flow control valve (not shown).

In the heat source fluid flow path of the heat exchanger 26, through the piping 29, a warm drain of about 65°C at the point of use 40 is introduced. The heat-exchanged water that has been cooled by heat exchange with the second medium to a temperature of about 30 to 40°C flows out of the pipe 30 and is recovered as recovered water.

The second medium water heated to about 25°C in the heat exchangers 43 and 26 is introduced into the heat source fluid flow path of the evaporator 21, exchanges heat with the heat medium of the heat pump 20, and then cools down to about 20°C. The pipe 25 sends water to the heat exchanger 43. Part of the second medium water passes through the bypass piping 28 and flows from the piping 25 to the piping 27. The bypass piping 28 is provided with a flow control valve (not shown).

The heat exchanger 43 is provided on the second circulation flow path on the second medium water outlet side of the evaporator 21 that is upstream of the heat exchanger 26. The temperature of the return water (reflux ultrapure water) passing through the heat exchanger 6 (for example, about 32°C) is lower than the temperature of the second medium water (for example, about 20°C) which is cooled by the evaporator 21 and flows out to the piping 25. high. Therefore, the reflux water system from the heat exchanger 6 cools the heat exchanger 43 to almost the same temperature as the normal temperature ultrapure water (about 23 to 25° C.), and then flows into the sub tank 2.

As a result, there is no need for a heat exchanger (from the heat exchanger 73 in FIG. 2 described above) supplied from the sub tank 2 to the sub system 4 for cooling primary pure water. Moreover, even if the heat exchanger is installed, the amount of cold water used can be reduced.

As an operation method of the heat pump 20, for example, the input power and the circulating water flow rate of the heat pump compressor are adjusted so that the outlet temperatures of the first medium water and the second medium water are each constant. It can also make the heat pump into a multiple series to control the number of units in response to the heat load. Furthermore, as shown in the figure, the piping bypassing the heat exchanger and the flow control valve may be provided in the circulation system on the high temperature side and/or the low temperature side to perform an operation capable of controlling the inlet temperature of the heat pump.

In FIG. 1, although only the warm drain water at the use point 40 is supplied to the heat exchanger 26, the concentrated water provided in the UF membrane separation device 13 immediately before the use point may be used as the warm drain water.

In the above embodiment, the steam heat exchanger 15 is provided to heat the ultrapure water heated in the heat exchanger 10, but it may be provided in the first circulation flow path from the condenser 23 to the heat exchanger. 10 The first flowing medium water is heated. The steam heat exchanger 15 or the steam heat exchanger of the first circulation flow path may be omitted. However, in the case where the amount of ultra-pure water used in the factory increases rapidly, it is expected that the heat source of the heat pump 20 will be insufficient, so that the temperature of the ultra-pure water cannot reach a predetermined temperature. To prevent this, it is preferable to provide a steam-type heat exchanger, and steam heating can be performed as necessary.

The above-mentioned embodiment is an example of the present invention, and the present invention may be other than the illustrated embodiment.

Although the present invention has been described in detail using specific aspects, it is obvious that those skilled in the art can make various changes within the scope not departing from the gist of the present invention.

This application is based on the Japanese Patent Application 2016-179641 filed on September 14, 2016, and the entire application is incorporated herein by reference.

1‧‧‧ Once pure water

2‧‧‧slot

3‧‧‧Piping

4‧‧‧Subsystem

5‧‧‧Piping

5A‧‧‧Piping

5B‧‧‧UF membrane separation device

5C‧‧‧Piping

6‧‧‧ Heat exchanger

7‧‧‧ Piping

10‧‧‧ heat exchanger

11‧‧‧Piping

12‧‧‧Steam heat exchanger

13‧‧‧UF membrane separation device

14‧‧‧Piping

15‧‧‧Piping

16‧‧‧Piping

17‧‧‧Bypass piping

20‧‧‧heat pump

21‧‧‧Evaporator

22‧‧‧Pump

23‧‧‧Condenser

24‧‧‧Expansion valve

25‧‧‧Piping

26‧‧‧ Heat exchanger

27‧‧‧Piping

28‧‧‧Bypass piping

29‧‧‧Piping

30‧‧‧Piping

40‧‧‧point of use

41‧‧‧Piping

42‧‧‧Piping

43‧‧‧ Heat exchanger

44‧‧‧Piping

Claims (8)

An ultrapure water manufacturing device that supplies heated ultrapure water to a point of use, and has a primary pure water manufacturing device that processes primary pure water from the primary pure water manufacturing device to produce ultrapure water A secondary pure water production device, a first heat exchanger for heating ultrapure water from the secondary pure water production device and using the return water from the point of use as a heat source, including a first heat exchanger The second heat exchanger that cools the reflux water and adds the reflux water cooled in the second heat exchanger to the reflux water return system of the primary pure water, and the heated water in the first heat exchanger The heating means for further heating the ultrapure water is characterized in that the heating means includes a third heat exchanger that circulates the ultrapure water heated in the first heat exchanger to the heated fluid flow path , A first circulation flow path that circulates the first medium water as a heat transfer medium in the heat source fluid flow path of the third heat exchanger, and heats the first medium water flowing in the first circulation flow path A heat pump including a condenser, an evaporator, a pump, and an expansion valve. The condenser is provided in the first circulation channel to heat the first medium water. This evaporator is installed in the second circulation flow path where the second medium water circulates. An ultrapure water manufacturing device that supplies heated ultrapure water to a point of use, and has a primary pure water manufacturing device that processes primary pure water from the primary pure water manufacturing device to produce ultrapure water A secondary pure water production apparatus and a heating means for heating ultrapure water from the secondary pure water production apparatus, characterized in that the heating means is provided with: the ultrapure water is circulated to the heated fluid flow path A third heat exchanger, a first circulation channel that circulates the first medium water as a heat transfer medium in the heat source fluid channel of the third heat exchanger, and a first circulation channel that will flow through the first circulation channel 1. A heat pump for heating medium water. The heat pump includes a condenser, an evaporator, a pump, and an expansion valve. The condenser is provided in the first circulation flow path to heat the first medium water and the evaporator. It is provided in the second circulation flow path where the second medium water is circulated, and the second circulation flow path is provided with a fourth heat exchanger for heating the second medium water by the heat of warm drainage. An ultrapure water manufacturing device that supplies heated ultrapure water to a point of use, and has a primary pure water manufacturing device that processes primary pure water from the primary pure water manufacturing device to produce ultrapure water A secondary pure water manufacturing apparatus, a second heat exchanger that cools the return water from the point of use, and a return water return system that adds the return water cooled in the second heat exchanger to the primary pure water, and The heating means for heating the ultrapure water from the secondary pure water production device is characterized in that the heating means includes a third heat exchanger for circulating the ultrapure water to the heated fluid flow path, and The first medium water as a heat transfer medium circulates through the heat source fluid flow path of the third heat exchanger, and a heat pump that heats the first medium water flowing in the first circulation flow path The heat pump includes a condenser, an evaporator, a pump, and an expansion valve. The condenser is provided in the first circulation flow path to heat the first medium water. The evaporator is provided in the circulation with a second medium A second circulation flow path for water is provided in the second circulation flow path to heat the second The fourth heat exchanger for medium water is provided with the aforementioned second heat exchanger in the second circulation flow path upstream of the fourth heat exchanger. The ultrapure water production apparatus according to any one of claims 1 to 3, further comprising: a first section using steam as a heat source for heating the ultrapure water heated in the third heat exchanger 5 Heat exchanger. The ultrapure water production apparatus according to any one of claims 1 to 3, wherein the first circulation flow path is provided with: for heating the first medium water from the condenser to the third heat exchanger The sixth heat exchanger uses steam as a heat source. An ultrapure water manufacturing device that supplies heated ultrapure water to a point of use, and has a primary pure water manufacturing device that processes primary pure water from the primary pure water manufacturing device to produce ultrapure water A secondary pure water production device, a first heat exchanger for heating ultrapure water from the secondary pure water production device and using the return water from the point of use as a heat source, including a first heat exchanger The second heat exchanger that cools the reflux water and adds the reflux water cooled in the second heat exchanger to the reflux water return system of the primary pure water, and the heated water in the first heat exchanger Heating means for further heating of ultrapure water, The heating means includes: a third heat exchanger that circulates ultrapure water heated in the first heat exchanger to the heated fluid flow path; and a first medium water that is a heat transfer medium A first circulation flow path circulating in the heat source fluid flow path of the third heat exchanger, and a heat pump that heats the first medium water flowing in the first circulation flow path, the heat pump includes a condenser, An evaporator, a pump, and an expansion valve. The condenser is provided in the first circulation flow path to heat the first medium water. The evaporator is provided in a second circulation flow path that circulates the second medium water. This second circulation flow path is provided with a fourth heat exchanger for heating the second medium water by the heat of warm drainage, and the second circulation flow path upstream of the fourth heat exchanger is provided with the above-mentioned first 2 Heat exchanger. The ultrapure water manufacturing apparatus according to claim 6, further comprising: a fifth heat exchanger using steam as a heat source for heating the ultrapure water heated in the third heat exchanger. The ultrapure water manufacturing apparatus according to claim 6 or 7, wherein the first circulation flow path is provided with: a pair of the first from the condenser to the third heat exchanger The sixth heat exchanger uses steam as a heat source for heating the medium water.

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