TW201811682A - Ultrapure water manufacturing device - Google Patents

Abstract

Provided is an ultrapure water manufacturing device that can reduce the heat source cost of a heat exchanger, said heat exchanger being for heating ultrapure water sent from a use point to produce warm ultrapure water, said ultrapure water manufacturing device also being able to reduce costs for cooling primary pure water. Secondary pure water from a subsystem 4 is heated with a heat exchanger 6, a heat exchanger 10, and a heat exchanger 12, and is sent to a use point. A heat source of the heat exchanger 6 is returning warm ultrapure water from the use point. This returning ultrapure water is introduced into a subtank 2 after having the temperature thereof reduced with the heat exchanger 6 and a heat exchanger 43. A first medium water that has been heated with a heat pump 20 is circulated and passed through the heat exchanger 10. A second medium water is circulated to a vaporizer 21 of the heat pump 20. A heat exchanger 26 through which warm discharge water from the use point 40 is passed is positioned on the circulation flow path of the second medium water, and the heat exchanger 43 is provided further to an upstream side than the heat exchanger 26.

Description

   Ultra-pure water manufacturing device   

The present invention relates to an ultrapure water production device, and more 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 to the point of use as warm ultrapure water.

As shown in FIG. 2, ultrapure water used as semiconductor washing water is composed of a pretreatment system 50, a primary pure water production device 60, and a secondary pure water production device (referred to as a sub-system) 70. An ultrapure water manufacturing apparatus is used to process raw water (industrial water, domestic water, well water, etc.) and manufacture it (Patent Document 1). The functions of each system in Figure 2 are described below.

Removal of suspended matter or colloidal matter in raw water is performed in a pretreatment system 50 made up of an agglutination, pressure floating (precipitation), filtration (membrane filtration) device (the previous example is an agglutination filtration device). Moreover, polymer organic matter, hydrophobic organic matter, etc. can also be removed in this process.

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

The primary pure water produced by the primary pure water producing device 60 is sent to the secondary pure water producing device 70 through a pipe 69. The secondary pure water production 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 Filter membrane (UF membrane) separation device 76. The heat exchanger 73 is used for temperature control of the secondary pure water. Generally, the supply temperature of secondary pure water (normal temperature ultrapure water) is 23 ~ 25 ° C. In order to control this temperature range, the heat exchanger 73 uses a cooler. Cold water was used as a cooling source of the cooler. This heat exchanger 73 needs to be placed before the ion exchange device 75. When high temperature pure water comes into contact with ion exchange resin, TOC components will be dissolved out, resulting in deterioration of water quality. Therefore, it is necessary to cool the water temperature to 23 to 25 ° C. with the heat exchanger 73 before sending the water to the ion exchange device 75. When the cold water circulating in the cooling heat exchanger 73 is supplied from an electronic component manufacturing plant, piping equipment for this purpose is required. In addition, in order to reduce the production cost of ultrapure water, it is desirable to reduce the amount of cold water used.

The low-pressure ultraviolet oxidizing device 74 decomposes TOC into organic acids and even CO ₂ by ultraviolet rays of 185 nm emitted by a low-pressure ultraviolet lamp. Organic matter and CO ₂ generated by the decomposition are removed by an ion exchange device 75 at a later stage. In the ultrafiltration membrane separation device 76, fine particles are removed, and outflowing 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) that is sent from the ultrafiltration membrane separation device 76 through the pipe 81 to the use point 90, and is heated by the heat exchangers 85 and 86. The ultra-pure water (warm ultra-pure water) is sent to the use point 90 through the ultrafiltration membrane separation device 87 and the pipe 88.

The latter route is to heat the ultrapure water from the secondary pure water production device 70 to about 65 to 75 ° C. in the front-stage heat exchanger 85 and the rear-stage heat exchanger 86 and supply it to the use point 90. The warm return water from the use point 90 is passed through the pipe 91 to flow to the heat source side of the front-stage-side heat exchanger 85. The temperature of the return water passing through the heat source side of the front-stage heat exchanger 85 is lowered to about 30 to 40 ° C., and returns to the sub tank 71 through the pipe 92. The rear-stage heat exchanger 86 uses steam as a heat source.

[Patent Document 1] Japanese Patent Laid-Open No. 2013-202581

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

One aspect of the present invention is an ultrapure water production device that supplies heated ultrapure water to a point of use, and includes: a primary pure water production device; and a method for treating primary pure water from the primary pure water production device. A second pure water production device for producing ultrapure water, a first heat exchanger for heating the ultrapure water from the secondary pure water production device, and using the return water from the point of use as a heat source. A second heat exchanger that cools the return water of the first heat exchanger, and adds the return water cooled in the second heat exchanger to the return water return system of the primary pure water, and A heating means for further heating the ultrapure water heated in the heat exchanger, the heating means includes a third heat that circulates the ultrapure water heated in the first heat exchanger to a heated fluid flow path An exchanger, a first circulation flow path that circulates the first medium water as a heat transfer medium through a heat source fluid flow path of the third heat exchanger, and performs a first circulation of water on the first circulation flow path Heated heat pump that heats It is provided with a condenser, an evaporator, a pump, and an expansion valve. The condenser is installed in the first circulation flow path to heat the first medium water, and the evaporator is provided in the second circulation flow path to make the second The medium water is circulated, and a second heat exchanger is installed in the second circulation flow path to heat the second medium water by the heat of the warm drainage water, and the second circulation flow path is upstream of the fourth heat exchanger. The aforementioned second heat exchanger is provided.

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 that heats the first medium water from the condenser to the third heat exchanger and uses steam as a heat source.

In the ultrapure water producing apparatus of the present invention, the ultrapure water is heated in the first heat exchanger by the heat retained by the point-of-use reflux water. Then, the ultrapure water is further heated by a third heat exchanger using the first medium water heated by the condenser of the heat pump as a heat source fluid. A second medium water is circulated in the evaporator of the heat pump. The second medium water is provided with a fourth heat exchanger using warm drainage 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, it is possible to reduce the cost of heating the ultrapure water sent to the point of use to a predetermined temperature to become a heat source for the ultrapure water. In addition, since the return water passing through the first heat exchanger is further cooled in the second heat exchanger, it is added to the primary pure water. Therefore, cold water for cooling the primary pure water is not needed and can be reduced.

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

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

1‧‧‧ once pure water

2‧‧‧ auxiliary tank

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‧‧‧ side wild tube

20‧‧‧ heat pump

21‧‧‧Evaporator

22‧‧‧Pump

23‧‧‧Condenser

24‧‧‧ Expansion Valve

25‧‧‧Piping

26‧‧‧Heat exchanger

27‧‧‧Piping

28‧‧‧ side wild tube

29‧‧‧Piping

30‧‧‧Piping

40‧‧‧use points

41‧‧‧Piping

42‧‧‧Piping

43‧‧‧Heat exchanger

44‧‧‧Piping

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

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

An ultrapure water producing device of the present invention includes a primary pure water producing device, a secondary pure water producing device, and a heating means for heating ultrapure water.

A pretreatment device is usually provided at the front stage of the primary pure water production device. The pretreatment device is the pretreatment caused by the filtration, agglomeration and sedimentation of the raw water, and the precision filtration membrane. It mainly removes suspended matter. By this pretreatment, the number of fine particles in water is usually set to ¹⁰³ / 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 An oxidizing device, such as an oxidizing device, removes most of electrolytes, fine particles, germs, and the like in 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.

Secondary pure water production equipment is composed of auxiliary tanks, water supply pumps, cooling heat exchangers, low-pressure ultraviolet oxidizers, sterilizers and other ultraviolet irradiation devices, non-regenerating mixed bed ion exchange devices or electrical deionization devices, and ultrafiltration. (UF) Membrane filtration devices such as membrane separation devices or precision filtration (MF) membrane separation devices. However, there may be cases in which desalting devices such as membrane degassing devices, RO membrane separation devices, and electric deionization devices are further provided. In the secondary pure water production device, a low-pressure ultraviolet oxidation device is applied, and a mixed bed type ion exchange device is provided at the latter stage, thereby oxidizing and decomposing TOC in water with ultraviolet rays, and removing oxidative decomposition products by ion exchange. In the present specification, a portion of the secondary pure water production apparatus that is on the rear side of the sub tank is referred to as a sub system.

Further, a tertiary pure water production device may be provided at the rear stage of the secondary pure water production device, and the ultrapure water from the tertiary pure water production device may be heated. The tertiary pure water production device has the same structure as the secondary pure water production device, and is a person producing ultra-pure water with higher purity.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram showing an ultrapure water producing apparatus according to the embodiment. In addition, although the water temperature is illustrated in the following description, each water temperature is only an example, and does not limit the present invention at all.

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

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

Into the heat source fluid flow path of the heat exchanger 6, the return temperature ultrapure water (return water) from the use point 40 is introduced through the pipe 41. The return temperature ultrapure water passing through the heat exchanger 6 is reduced in temperature 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 a pipe 44.

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

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

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

The heat source fluid flow path in the heat exchanger 26 is passed through the pipe 29 to introduce warm water drainage at a use point 40 of about 65 ° C. The warm drainage, which is cooled to about 30 to 40 ° C by heat exchange with the second medium water, flows out from 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 to reduce the temperature to about 20 ° C., and then transmits. Pipe 25 sends water to heat exchanger 43. A part of the second medium water flows from the pipe 25 to the pipe 27 through the bypass pipe 28. A flow regulating valve (not shown) is provided in the bypass pipe 28.

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

As a result, there is no need for a heat exchanger (the heat exchanger 73 of FIG. 2 described above) for cooling the pure water that is supplied from the auxiliary tank 2 to the auxiliary system 4. In addition, even when the heat exchanger is installed, the amount of cold water used can be reduced.

As a method of operating the heat pump 20, for example, the input power of the heat pump compressor and the circulating water flow rate are adjusted so that the outlet temperatures of the first medium water and the second medium water become constant temperatures, respectively. It is also possible to make the heat pump a plural series to control the number of units in accordance with the heat load. Moreover, as shown in the figure, the circulation system at the high temperature side and / or the low temperature side may be provided with a pipe bypassing the heat exchanger and a flow control valve to perform an operation capable of controlling the inlet temperature of the heat pump.

In FIG. 1, although only the hot water from the use point 40 is supplied to the heat exchanger 26, the concentrated water of the UF membrane separation device 13 installed immediately before the use point may be used as the hot water.

In the above embodiment, although the steam-type heat exchanger 15 is provided to heat the ultrapure water heated in the heat exchanger 10, it may also be provided in the first circulation flow path to the heat exchanger from the condenser 23 to the heat exchanger. 10 flowing first 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 of a sharp increase in the amount of warm ultrapure water in the factory, it can be expected that the heat source of the heat pump 20 will be insufficient, so that the temperature of the pure ultrapure water cannot reach a predetermined temperature. In order to prevent this, it is preferable to provide a steam-type heat exchanger, and steam heating may be performed as necessary.

The embodiment described above is an example of the present invention, and the present invention may be in a form other than the one shown in the drawings.

Although the present invention has been described in detail using specific aspects, it is apparent that various changes can be made by those skilled in the art without departing from the spirit of the present invention.

This application is based on Japanese Patent Application No. 2016-179641 filed on September 14, 2016, and is incorporated herein by reference in its entirety.

Claims (3)

    An ultrapure water production device is a device that supplies heated ultrapure water to a point of use. The device includes a primary pure water production device and a device that processes ultrapure water from the primary pure water production 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 return water from a point of use as a heat source, the device includes a first heat exchanger that passes through the first heat exchanger A second heat exchanger cooled by the return water, adding the return water cooled in the second heat exchanger to the return water return system of the primary pure water, and heating 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 a heated fluid flow path. A first circulation flow path that circulates first medium water as a heat transfer medium in a heat source fluid flow path of the third heat exchanger, and heats the first medium water flowing in the first circulation flow path Heat pump The condenser is provided with 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 second cycle in which the second medium water is circulated. A flow path is provided in the second circulation flow path with a fourth heat exchanger for heating the second medium water by the heat of the warm drainage water, and a second circulation flow path upstream of the fourth heat exchanger. The aforementioned second heat exchanger is provided.         The ultrapure water manufacturing apparatus according to claim 1, further comprising a fifth heat exchanger that heats the ultrapure water heated in the third heat exchanger and uses steam as a heat source.         The ultrapure water production device according to claim 1 or 2, wherein the first circulation flow path is provided with steam for heating the first medium water from the condenser to the third heat exchanger, and using steam as 6th heat exchanger for heat source.