JP6149993B1 - Ultrapure water production equipment - Google Patents

Abstract

[PROBLEMS] To reduce the heat source cost of a heat exchanger for warming ultrapure water sent to a use point into warm ultrapure water, and to reduce the cost for cooling primary pure water. Provided is an ultrapure water production apparatus capable of Secondary pure water from a subsystem is heated by a heat exchanger, a heat exchanger and a heat exchanger and sent to a use point. The heat source of the heat exchanger 6 is return temperature ultrapure water from the use point. The returned 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 is circulated through the heat exchanger 10. The second medium water is circulated in the evaporator 21 of the heat pump 20. In the circulation path of the second medium water, a heat exchanger 26 through which hot waste water from the use point 40 is passed is installed, and a heat exchanger 43 is provided upstream of the heat exchanger 26. [Selection] Figure 1

Description

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

  The ultrapure water used as the semiconductor cleaning water is, as shown in FIG. 2, a pretreatment system 50, a primary pure water production apparatus 60, and a secondary pure water production apparatus (often referred to as a subsystem) 70. It is manufactured by treating raw water (industrial water, city water, well water, etc.) with an ultrapure water manufacturing apparatus composed of (Patent Document 1). In FIG. 2, the role of each system is as follows.

  In the pretreatment system 50 comprising agglomeration, pressurized flotation (precipitation), filtration (membrane filtration) apparatus, etc. (in this conventional example, agglomeration filtration apparatus), suspended substances and colloidal substances in raw water are removed. In this process, it is also possible to remove high molecular organic substances, hydrophobic organic substances, and the like.

  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 device 63B, The primary pure water production apparatus 60 including the deaeration device 64 removes ions and organic components from the raw water. In addition, as the temperature of water increases, the viscosity decreases and the permeability of the RO membrane improves. For this reason, as shown in FIG. 2, a heat exchanger 65 is installed in the preceding stage of the reverse osmosis membrane treatment device 62, and water is heated so that the temperature of the water supplied to the reverse osmosis membrane treatment device 62 becomes a predetermined temperature or higher. Steam is supplied to the primary side of the heat exchanger 65 as a heat source fluid. The reverse osmosis membrane treatment device 62 removes salts and removes ionic and colloidal TOC. The ion exchange devices 63 and 63B remove salts and inorganic carbon (IC) and remove TOC components adsorbed or ion exchanged by an ion exchange resin. In the deaerator 64, inorganic carbon (IC) and dissolved oxygen are removed.

  The primary pure water produced by the primary pure water production apparatus 60 is sent to the secondary pure water production apparatus 70 via the pipe 69. The secondary pure water production apparatus 70 includes a sub-tank (sometimes referred to as a pure water tank) 71, a pump 72, a heat exchanger 73, a low-pressure ultraviolet oxidation apparatus (UV apparatus) 74, an ion exchange apparatus 75, and a limiter. An outer filtration membrane (UF membrane) separation device 76 is provided. The heat exchanger 73 is for temperature control of secondary pure water. Generally, the supply temperature of secondary pure water (room temperature ultrapure water) is 23 to 25 ° C., and a heat exchanger 73 is a cooler for controlling the temperature range. Cold water is used as a cooling source for the cooler. This heat exchanger 73 must be placed before the ion exchange device 75. This is because when the high-temperature pure water comes into contact with the ion exchange resin, the TOC component is eluted and the water quality deteriorates. Accordingly, it is necessary that the water temperature is lowered to 23 to 25 ° C. by the heat exchanger 73 before being sent to the ion exchange device 75. In the case where the cold water passing through the cooling heat exchanger 73 is supplied from an electronic component manufacturing factory, a piping facility for that purpose is required. Moreover, in order to reduce the production cost of ultrapure water, it is desired to reduce the amount of cold water used.

In the low-pressure ultraviolet oxidizer 74, the TOC is decomposed to an organic acid and further to CO ₂ by 185 nm ultraviolet rays emitted from a low-pressure ultraviolet lamp. Organic substances and CO ₂ produced by the decomposition are removed by the ion exchange device 75 in the subsequent 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 exchanger 75 is heated by ultrapure water (room temperature ultrapure water) sent from the ultrafiltration membrane separator 76 to the use point 90 via the pipe 81 and heat exchangers 85 and 86. And ultrapure water (warm ultrapure water) sent to the use point 90 via the ultrafiltration membrane separator 87 and the pipe 88.

  In the latter line, ultrapure water from the secondary pure water production apparatus 70 is heated to about 65 to 75 ° C. by the front-stage heat exchanger 85 and the rear-stage heat exchanger 86 and supplied to the use point 90. The warm return water from this use point 90 is circulated through the pipe 91 to the heat source side of the pre-stage side heat exchanger 85. The return water that has passed through the heat source side of the pre-stage side heat exchanger 85 has been cooled to about 30 to 40 ° C. and is returned to the sub tank 71 via the pipe 92. The rear stage heat exchanger 86 uses steam as a heat source.

JP2013-202581A

  The present invention can reduce the heat source cost of the heat exchanger for heating the ultrapure water sent to the use point to make the ultrapure water, and the cost for cooling the primary pure water. An object of the present invention is to provide an ultrapure water production apparatus capable of performing the above.

  An ultrapure water production apparatus according to an aspect of the present invention includes a primary pure water production apparatus, a secondary pure water production apparatus that processes primary pure water from the primary pure water production apparatus to produce ultrapure water, A first heat exchanger for heating the ultrapure water from the secondary pure water production apparatus using the return water from the use point as a heat source, and a first heat exchanger for cooling the return water that has passed through the first heat exchanger. A return water return system that includes two heat exchangers and adds the return water cooled by the second heat exchanger to the primary pure water, and heating that further heats the ultrapure water heated by the first heat exchanger An ultrapure water production apparatus that supplies heated ultrapure water to a use point, wherein the heating means is configured to pass the ultrapure water heated by the first heat exchanger into the heated fluid channel. A third heat exchanger through which water is passed, and a first medium water as a heat transfer medium that circulates and circulates through a heat source fluid flow path of the third heat exchanger. A circulation path and a heat pump for heating the first medium water flowing through the first circulation path. The heat pump includes a condenser, an evaporator, a pump, and an expansion valve. The first medium water is installed in the first circulation channel so as to heat the evaporator, and the evaporator is installed in a second circulation channel through which the second medium water is circulated. A fourth heat exchanger for heating the second medium water by the heat of the warm waste water is installed in the path, and the second heat is provided in the second circulation channel upstream of the fourth heat exchanger. It is characterized in that an exchanger is installed.

  In one aspect of the present invention, a fifth heat exchanger using steam as a heat source for heating the ultra pure water heated by the third heat exchanger is installed.

  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 toward the third heat exchanger. Yes.

  In the ultrapure water production apparatus of the present invention, the ultrapure water is heated by the heat held by the use point return water in the first heat exchanger. The ultrapure water is further heated by a third heat exchanger that uses the first medium water heated by the condenser of the heat pump as a heat source fluid. The second medium water is circulated through the evaporator of the heat pump. The second medium water is provided with a fourth heat exchanger that uses hot wastewater as a heat source and a second heat exchanger that uses return water that has passed through the first heat exchanger as a heat source. As a result, it is possible to reduce the heat source cost of heating the ultrapure water to be sent to the use point to a predetermined temperature to obtain the warm ultrapure water. In addition, since the return water that has passed through the first heat exchanger is further cooled by the second heat exchanger and then added to the primary pure water, no cold water is required to cool the primary pure water, It can be reduced.

  In addition, the water temperature of a use point return water is 70-80 degreeC normally, for example, about 75 degreeC.

  In the present invention, warm waste water is waste water used for cleaning at a use point. Concentrated water from a UF membrane separator installed just before the use point may be included in the warm waste water. The temperature of the hot waste water is usually 60 to 75 ° C., for example, about 65 ° C.

It is a systematic diagram of the ultrapure water manufacturing apparatus concerning an embodiment. It is a systematic diagram of the ultrapure water manufacturing apparatus which concerns on a prior art example.

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

In the normal stage of the primary pure water production apparatus, a pretreatment apparatus is usually provided. In the pretreatment device, pretreatment by raw water filtration, coagulation sedimentation, microfiltration membrane or the like is performed, and suspended substances are mainly removed. By this pretreatment, the number of fine particles in water is usually 10 ³ / mL or less.

  Primary pure water production equipment includes reverse osmosis (RO) membrane separators, deaerators, regenerative ion exchangers (such as mixed bed or 4 bed 5 tower type), electrodeionizers, ultraviolet (UV) irradiation oxidizers Etc., and removes most of the electrolytes, fine particles, viable bacteria, etc. in the pretreated water. The primary pure water production apparatus is composed of, for example, a heat exchanger, two or more RO membrane separation apparatuses, a mixed bed ion exchange apparatus, and a deaeration apparatus.

  Secondary pure water production equipment includes subtanks, feed water pumps, cooling heat exchangers, low-pressure ultraviolet oxidizers or sterilizers, UV irradiation equipment, non-regenerative mixed bed ion exchange equipment or electrodeionization equipment, ultrafiltration ( (UF) Membrane filtration device such as membrane separation device or microfiltration (MF) membrane separation device, but also equipped with demineralization devices such as membrane deaeration device, RO membrane separation device, and electro-deionization device In some cases. In the secondary pure water production apparatus, a low-pressure ultraviolet oxidation apparatus is applied, and a mixed bed type ion exchange apparatus is provided at the subsequent stage, whereby TOC in water is oxidized and decomposed by ultraviolet rays, and oxidation decomposition products are removed by ion exchange. . Hereinafter, in the secondary pure water production apparatus, the downstream side of the sub tank is referred to as a subsystem.

  A tertiary pure water production apparatus may be provided after the secondary pure water production apparatus, and the ultrapure water from the tertiary pure water production apparatus may be heated. This tertiary pure water production apparatus has the same configuration as that of the secondary pure water production apparatus, and produces higher purity ultrapure water.

  Embodiments of the present invention will be described below 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 illustrated in the following description, each water temperature is an example and does not limit this invention at all.

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

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

  Return temperature ultrapure water (return water) from the use point 40 is introduced into the heat source fluid flow path of the heat exchanger 6 through the pipe 41. The return temperature ultrapure water that has passed through the heat exchanger 6 is heat-exchanged with the second medium water of the heat pump 20 by the heat exchanger 43 and cooled, and then sent to the sub tank 2 through the pipe 44.

  The first medium water (water as the 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 compresses the heat medium such as CFC substitute from the evaporator 21 by the pump 22 and introduces it into the condenser 23, and introduces the heat medium from the condenser 23 into the evaporator 21 through the expansion valve 24. It is configured.

  About 75 degreeC 1st medium water from the heat exchanger 10 is introduce | transduced into the condenser 23 via the piping 15, and the 1st medium water heated by the condenser 23 at about 80 degreeC is heat-exchanged via the piping 16. Water is sent to the vessel 10. A part of the first medium water from the condenser 23 is returned to the pipe 15 via the bypass pipe 17. The heat exchanger 10, the pipe 15, the condenser 23, and the pipe 16 constitute a first circulation channel. The bypass pipe 17 is provided with a flow rate adjustment valve (not shown).

  In order to circulate the second medium water through the heat source fluid flow path of the evaporator 21, a second circulation flow path including 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. The bypass pipe 28 is provided with a flow rate adjustment valve (not shown).

  A hot waste water of about 65 ° C. at the use point 40 is introduced into the heat source fluid flow path of the heat exchanger 26 through the pipe 29. The warm waste water that has been subjected to heat exchange with the second medium water and has fallen to about 30 to 40 ° C. flows out of the pipe 30 and is recovered as recovered water.

  The second medium water having a temperature of about 25 ° C. heated by 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 drops to about 20 ° C. The water is sent to the heat exchanger 43 through 25. A part of the second medium water flows from the pipe 25 to the pipe 27 via the bypass pipe 28. The bypass pipe 28 is provided with a flow rate adjustment valve (not shown).

  In the second circulation channel, the heat exchanger 43 is installed on the upstream side of the heat exchanger 26, that is, on the second medium water outlet side of the evaporator 21. The temperature of the return water (returned ultrapure water) that has passed through the heat exchanger 6 (for example, about 32 ° C.) is lowered by the evaporator 21 and the temperature of the second medium water that has flowed out to the pipe 25 (for example, about 20 ° C.). Higher than. Therefore, the return water from the heat exchanger 6 is lowered to a temperature substantially the same as the room temperature ultrapure water (about 23 to 25 ° C.) by the heat exchanger 43 and then flows into the sub tank 2.

  As a result, a heat exchanger (heat exchanger 73 in FIG. 2) for cooling the primary pure water supplied from the sub tank 2 to the sub system 4 becomes unnecessary. Moreover, even when this heat exchanger is installed, the amount of cold water used is 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 constant. A plurality of heat pumps may be used, and the number control may be performed according to the heat load. Further, as shown in the figure, piping for bypassing the heat exchanger and a flow rate control valve may be provided in the high-temperature side and / or low-temperature side circulation system so as to control the heat pump inlet temperature.

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

  In the above embodiment, the steam heat exchanger 15 is provided to heat the ultrapure water heated by the heat exchanger 10, but the first medium that flows from the condenser 23 toward the heat exchanger 10. You may install in a 1st circulation flow path so that water may be heated. The steam heat exchanger 15 and the steam heat exchanger of the first circulation channel may be omitted. However, when the amount of hot ultrapure water used in the factory suddenly increases, it is assumed that the heat source of the heat pump 20 is insufficient and the temperature of ultrapure water does not reach the predetermined temperature. In preparation for such a case, it is preferable to install a steam heat exchanger so that the steam can be heated if necessary.

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

2 Sub tank 4 Sub system 6, 10, 12, 26, 43 Heat exchanger 20 Heat pump 21 Evaporator 22 Pump 23 Condenser 24 Expansion valve

Claims (3)

Primary pure water production equipment,
A secondary pure water production apparatus for producing ultrapure water by treating primary pure water from the primary pure water production apparatus;
A first heat exchanger for heating the ultrapure water from the secondary pure water production apparatus using the return water from the use point as a heat source;
A return water return system that includes a second heat exchanger that cools the return water that has passed through the first heat exchanger, and that adds the return water cooled by the second heat exchanger to the primary pure water;
In the ultrapure water production apparatus that has heating means for further heating the ultrapure water heated by the first heat exchanger and supplies the heated ultrapure water to the use point,
The heating means includes
A third heat exchanger in which ultrapure water heated in the first heat exchanger is passed through the heated fluid flow path;
A first circulation passage for circulating and circulating a first medium water as a heat transfer medium in a heat source fluid passage of the third heat exchanger;
A heat pump for heating the first medium water flowing through the first circulation flow path,
The heat pump comprises a condenser, an evaporator, a pump and an expansion valve,
The condenser is installed in the first circulation channel so as to heat the first medium water,
The evaporator is installed in a second circulation channel through which the second medium water is circulated,
The second circulation channel is provided with a fourth heat exchanger for heating the second medium water by the heat of the warm waste water,
The ultrapure water production apparatus, wherein the second heat exchanger is installed in a second circulation channel upstream of the fourth heat exchanger.   2. The apparatus for producing ultrapure water according to claim 1, further comprising a fifth heat exchanger using steam as a heat source for heating the ultrapure water heated by the third heat exchanger. .   In Claim 1 or 2, the 6th heat exchanger using steam as a heat source for heating the 1st medium water which goes to the 3rd heat exchanger from the condenser is provided in the 1st circulation channel. An ultrapure water production apparatus characterized by comprising:

Images