Ultrapure water process system having water hammer mitigation function

Abstract

The present invention relates to an ultrapure water process system and, more specifically, to an ultrapure water process system having a water hammer mitigation function. The ultrapure water process system according to the present invention produces ultrapure water by sequentially transferring treated water among a pretreatment process, a pure water treatment process, and an ultrapure water treatment process along a main pipe, and is configured such that a surge tank for preventing water hammer is directly connected to the main pipe through which the treated water is transferred, the main pipe is connected to one side of the upper portion of the surge tank to introduce the treated water, and the main pipe is connected to the lower portion of the surge tank to discharge the treated water, thereby enabling first-in, first-out flow of the treated water that enters the surge tank.

Description

Ultrapure water process system equipped with water hammer mitigation function

[0001] The present invention relates to an ultrapure water process system, and more specifically, to an ultrapure water process system equipped with a water hammer mitigation function.

[0002]

[0003] Ultrapure water (UPW) refers to high-purity water that is essential in various industrial fields such as semiconductors, pharmaceuticals, and power plants. A typical ultrapure water manufacturing process, as illustrated in FIG. 1, consists mainly of a pretreatment process (20), a pure water treatment process (30), and an ultrapure water treatment process (50). The pretreatment process (20) is a step to improve the quality of raw water supplied from a water source (10), such as a water purification plant, and to increase the efficiency of subsequent processes, and mainly undergoes processes such as coagulation, sedimentation, and filtration. In this process, suspended solids, organic matter, colloids, etc., in the raw water are removed. The pure water treatment process (30) is a step to remove ionic substances from the pretreated water, mainly using a reverse osmosis (RO) system and an ion exchange resin. Through this process, the electrical conductivity of the water is significantly reduced, and most dissolved solids are removed. The pure water that has undergone the pure water treatment process (30) is temporarily stored in a pure water storage tank (40) and then supplied to the ultrapure water treatment process (50). The ultrapure water treatment process (50) is a step for producing ultra-high purity water by further purifying the pure water, and uses a mixed-bed ion exchange resin tower, an electro-deionization (EDI) device, an ultraviolet sterilizer, etc. In this process, residual ions, organic matter, microorganisms, etc. are removed to meet the quality standards of ultrapure water. The ultrapure water produced in the ultrapure water treatment process (50) is then supplied to a demand source (60).

[0004]

[0005] In these ultrapure water manufacturing processes, various treatment stages are sequentially connected along a single main pipeline. Consequently, water hammer can occur within the piping due to the opening and closing of valves or the operation and stopping of pumps in each process unit. Water hammer is a pressure wave generated by sudden changes in fluid velocity; it can cause severe damage to the piping system and degrade the performance of water treatment equipment. In the case of Electro-Deionization (EDI), a water treatment device that treats water by adsorbing impurities using resin, the shock wave caused by water hammer can lead to an uneven distribution of the resin layer responsible for absorbing impurities. This results in impurities passing through without being removed, or the resin may be damaged, allowing impurities to pass through without being removed, becoming a major cause of water quality deterioration. Furthermore, in Reverse Osmosis (RO) systems, impurities are removed by the adsorption, attachment, and accumulation of contaminants other than water molecules on the membrane. However, the shock wave from water hammer can cause impurities to pass through instantaneously or damage the membrane, allowing them to pass through and resulting in water quality degradation. As such, water hammer is a risk factor that must be avoided in most water treatment devices. In general water treatment systems, surge tanks are used to mitigate such water hammer. A surge tank is a device designed to mitigate water hammer in piping systems and is connected to a branch pipe (2) branched from the main pipe (1), as shown in FIG. 2 (a). The surge tank is filled with compressed air in its upper internal space, and the compressed air acts as the tank's primary buffering medium. When water hammer occurs, the compressed air works in conjunction with the water inside the tank to absorb pressure changes. This utilizes the compressibility of air (gas) and the incompressibility of water; when a sudden pressure change occurs, the air is compressed to absorb energy and then gradually expands, providing stable pressure to the system.This process helps the surge tank safely maintain piping pressure within a certain range, and consequently mitigates sudden pressure fluctuations within the piping system, thereby reducing or preventing damage from water hammer.

[0006]

[0007] However, as such surge tanks for mitigating water hammer are generally branched and connected to the main pipe (1) by a single branch pipe (2) as shown in FIG. 2 (a), the inflow and outflow of water into and out of the surge tank occurs only through the single branch pipe (1) as indicated by the dotted arrow. Consequently, the water flowing into the surge tank may stagnate internally or not circulate smoothly, resulting in a disadvantage where the water quality inside the surge tank deteriorates. In the ultrapure water process, since there is no significant change in the normal operating pressure of the pump, if a conventional surge tank is installed at the pump outlet, the water stored inside the surge tank is bound to remain in a stagnant state. In the ultrapure water process, stagnation of water can lead to a deterioration in water quality. Therefore, when the amount of ultrapure water used is less than the amount produced, the excess ultrapure water is discharged to a storage tank in the initial stage of ultrapure water treatment, thus preventing stagnation of ultrapure water within the process. Consequently, conventional surge tanks could not be used in the ultrapure water process because stagnation of water could lead to a deterioration in water quality. Ultrapure water must be maintained in an extremely pure state, and stagnant water poses risks such as microbial proliferation, accumulation of contaminants, or changes in electrical conductivity. Therefore, continuous circulation and flow of water are essential in ultrapure water systems.

[0008]

[0009] Against this backdrop, there is a need to develop a new system capable of effectively mitigating water hammer while taking into account the characteristics of the ultrapure water process.

[0010]

[0011] [Prior Art Literature]

[0012] (Patent Document 1) Republic of Korea Registered Patent No. 10-0868908

[0013] (Patent Document 2) Republic of Korea Published Patent No. 10-2023-0051424

[0014]

[0015] The present invention was devised to solve the problem of water hammer occurring in the conventional ultrapure water manufacturing process described above, and aims to provide a new ultrapure water process system that can maintain the quality of ultrapure water while mitigating water hammer by employing a surge tank.

[0016]

[0017] The ultrapure water process system according to the present invention for achieving the above-mentioned purpose is an ultrapure water process system that produces ultrapure water by sequentially transporting treated water along a main pipe between a pretreatment process, a pure water treatment process, and an ultrapure water treatment process, wherein a surge tank for preventing water hammer is directly connected to the main pipe through which the treated water is transported, and treated water is introduced through a connection to the main pipe at one side of the upper portion of the surge tank, and treated water is discharged through a connection to the main pipe at the lower portion of the surge tank, thereby enabling the first-in, first-out operation of the treated water introduced into the surge tank.

[0018]

[0019] Here, an inlet connected to the main pipe for the inflow of treated water is provided on one side of the upper part of the surge tank, and an outlet connected to the main pipe for the outflow of treated water is provided on the lower part of the surge tank.

[0020]

[0021] Herein, it further includes a guide pipe extending laterally from the surge tank, which is connected at one end to the inlet and at the other end extends into the interior of the surge tank, so that the treated water moves downward while rotating in a spiral and is discharged toward the outlet.

[0022]

[0023] In addition, the system further includes a degassing storage tank for temporarily storing treated water supplied from the above-mentioned pure water treatment process and for removing dissolved gases contained in the treated water. The ultrapure water treatment process not only removes various solids and foreign substances from the water but also treats electrical conductivity. In water (liquid), gases are dissolved in an amount equal to the liquid's saturation solubility (Henry's Law). If these gases are atmospheric air, then in addition to the nitrogen and oxygen contained in the air, there are trace amounts of gases that are harmful to ultrapure water. If these gases exist in a dissolved state in the ultrapure water, they act as a load that must be handled by each water treatment process and are a factor that degrades the water quality and efficiency of the water treatment. Therefore, by making the storage tank in the stage prior to ultrapure water treatment after pure water treatment into a pressure vessel structure capable of complete degassing, that is, capable of maintaining a vacuum, and by filling it with a high-purity inert gas (such as ultra-high-purity nitrogen) that can be included in ultrapure water after vacuum degassing to the required pressure and pressurizing it, gaseous impurities will no longer exist in the ultrapure water treatment process, and thus high-purity ultrapure water can be produced.

[0024]

[0025] Here, the pure storage tank is configured as a pressure tank; a vacuum pump is connected to the upper part of the pure storage tank to create a vacuum inside; a filling pipe connected to the outlet side of the pressurizing pump is connected to one side of the lower part of the pure storage tank to fill the pure storage tank with treated water after a vacuum is formed inside the pure storage tank by the vacuum pump; an exhaust valve is connected to one side of the upper part of the pure storage tank to discharge the gas remaining in the pure storage tank to the outside when the pure storage tank is filled with treated water; and a gas supply device is connected to the other side of the upper part of the pure storage tank to pressurize and fill insoluble gas. The storage tank is not a simple storage tank structure, but must be configured as a pressure vessel (Pressure Vessel, ASME SEC VIII, Div 1, or subject to inspection by the Korea Occupational Safety and Health Agency, etc.) capable of forming a vacuum close to a complete vacuum to reduce gas solubility to a level of almost 0 (ZERO), so that it does not collapse even in a vacuum state. In this way, by making the storage tank in the pre-ultrapure water treatment stage into a sealed pressure vessel and vacuum degassing, the fundamental problem caused by gas is eliminated, thereby eliminating secondary problems that may arise when dissolved gas in the ultrapure water process reacts with the treated water (ultrapure water), and by omitting or installing membrane degasifiers (MDGs) used in the ultrapure water process, the load on the degasifier can be reduced, which helps improve the quality of ultrapure water.

[0026]

[0027] In addition, an auxiliary storage tank is additionally provided on one side of the above-mentioned pure storage tank, wherein one side of the upper portion of the auxiliary storage tank is connected to the vacuum pump, and the other side of the upper portion is connected to an exhaust valve and a gas supply unit, respectively, and one side of the lower portion is connected to the main piping, and the other side of the lower portion is connected to a filling pipe connected to the outlet side of the pressure pump to fill the auxiliary storage tank with treated water after a vacuum is formed inside the auxiliary storage tank by the vacuum pump.

[0028]

[0029] According to the present invention as described above, by employing a pipe-direct surge tank capable of first-in, first-out of treated water, it has the excellent advantage of being able to maintain the quality of ultrapure water while mitigating water hammer and preventing stagnation of treated water.

[0030]

[0031] FIG. 1 is a configuration diagram of a conventional general ultrapure water process system,

[0032] FIG. 2 is a drawing comparing the connection structure (a) of a conventional general surge tank for preventing water hammer and the connection structure (b) of a surge tank according to the present invention.

[0033] FIG. 3 is a configuration diagram of an ultrapure water process system equipped with a surge tank according to a preferred embodiment of the present invention.

[0034] FIG. 4 is a configuration diagram of an ultrapure water process system equipped with a surge tank and a pure water storage tank according to another preferred embodiment of the present invention.

[0035] FIG. 5 is a detailed configuration diagram of a surge tank according to a preferred embodiment of the present invention,

[0036] Figure 6 is a diagram showing the degassing operation state of a pure water storage tank employed in an ultrapure water process system according to the present invention.

[0037]

[0038] [Explanation of the symbol]

[0039] VP: Vacuum pump

[0040] 130 : Surge tank

[0041] 140 : Pure storage tank

[0042] 150 : Auxiliary storage tank

[0043]

[0044] Hereinafter, the configuration and operation of an ultrapure water process system equipped with a water hammer mitigation function according to the present invention will be described in detail with reference to the attached drawings and preferred embodiments.

[0045]

[0046] Figure 2(b) illustrates the connection structure of a surge tank for preventing water hammer according to the present invention. The surge tank (130) is a pressure tank for preventing water hammer occurring in an ultrapure water process, and is configured such that the internal water level is maintained at a constant level by having a gas supply unit (Sn) and an exhaust valve (EV) at the top, as in a general surge tank for preventing water hammer, and by filling and exhausting compressed gas such as compressed air or nitrogen inside the surge tank. The configuration and operation of such a general surge tank are already known, so further detailed description is omitted.

[0047]

[0048] As mentioned above and illustrated in FIG. 2(a), a general surge tank is connected to the main pipe (1) by a single branch pipe (2), but the surge tank (130) according to the present invention is a first-in, first-out type surge tank directly connected to the main pipe (1). More specifically, the surge tank (130) employed in the ultrapure water process system according to the present invention is directly connected to the main pipe (1) as illustrated in FIG. 2(b), and an inlet is provided on one side of the upper part of the surge tank (130) connected to the main pipe (1) for the inflow of treated water, and an outlet is provided on the lower part of the surge tank (130) connected to the main pipe for the outflow of treated water. As a result, the treated water flowing in directly connected to the main pipe is transported in one direction, and the first-in, first-out type of treated water flowing into the surge tank (130) is configured to be configured so that the treated water flowing into the surge tank (130) is transported in one direction. Accordingly, the problem of water quality deterioration is resolved because the treated water does not stagnate inside the surge tank (130).

[0049]

[0050] Such a direct-connection first-in, first-out surge tank (130) can be installed anywhere in the main pipe (1) of the ultrapure water process. That is, the direct-connection first-in, first-out surge tank (130) can be installed between the pure water treatment process (30) and the ultrapure water treatment process (50), or it can be installed anywhere in the main pipe (1) connecting the individual units (e.g., heat exchanger, UV oxidation device, anion polisher, mixed-bed polisher, membrane degasser, ultrafiltration device, etc.) that constitute the ultrapure water treatment process (50).

[0051]

[0052] FIG. 3 illustrates a configuration diagram of an ultrapure water process system in which a direct-connected first-in, first-out surge tank (130) is installed between a pure water treatment process (30) and an ultrapure water treatment process (50) as a preferred embodiment according to the present invention. As illustrated, a pure water storage tank (140, 150) for temporarily storing manufactured pure water is provided at the downstream end of the pure water treatment process (30), and a pressure pump (110) and a surge tank (130) may be installed between the pure water storage tank (140, 150) and the ultrapure water treatment process (50).

[0053]

[0054] The above-mentioned pressure pump (110) is a pump that connects each treatment stage of the ultrapure water process and is installed in the main pipe through which the treated water is transported to pressurize and transport the treated water. By this pressure pump (110), the treated water is pressurized and transported along the main pipe, flows into the upper side of the surge tank (130), and then is discharged back into the main pipe from the lower side.

[0055]

[0056] FIGS. 4 and FIGS. 5 illustrate the structure of the surge tank (130) in more detail. As illustrated, the surge tank (130) comprises a tank body (131) having a space for receiving treated water inside, an inlet (132) provided at the upper end of the tank body (131) to receive the treated water, an outlet (133) provided at the lower end of the tank body (131) to discharge the treated water, and a guide pipe (134) extending laterally from the tank body (131), with one end connected to the inlet (132) and the other end extending into the interior of the tank body (131), so that the treated water moves downward while rotating spirally and is discharged toward the outlet (133). In addition, a pressure sensor (PT1) and a water level sensor (LT1) for detecting internal pressure and water level, and an exhaust valve (EV1) for discharging internal gas to the outside are provided at the top of the surge tank (130). Furthermore, a gas supply device (Sn), such as a compressor, a nitrogen generator, or a nitrogen cylinder, is connected to one side of the top of the surge tank (130) to supply compressed gas to the inside.

[0057]

[0058] Meanwhile, as previously mentioned, the surge tank (130) is filled with compressed gas, which may be compressed air or nitrogen. Pressure changes occur frequently inside the surge tank (130), and due to these pressure changes, gas may dissolve in the water. When compressed air is used, dissolved oxygen or carbon dioxide increases. Since dissolved gas increases the conductivity of water, and ultrapure water requires very low conductivity, the presence of dissolved gas is a factor that degrades the quality of ultrapure water. Furthermore, if the dissolved oxygen concentration increases, it becomes difficult to control the gate oxide thickness during semiconductor wafer processing, negatively affects the continuous electro-ionization (EDI) process, and promotes microbial growth, which can result in contamination of the ultrapure water system. To minimize such dissolved gas, the ultrapure water process system according to the present invention includes a pure water storage tank (140).

[0059]

[0060] The above-mentioned pure water storage tank (140) is a tank that receives and temporarily stores treated water from the pure water treatment process (30). In the past, it was a storage tank in the form of a water tank made of a general metal tank, but in the present invention, it is a low-pressure storage tank, and it is preferable to be configured as a pressure tank so that it does not easily collapse or break even with pressure changes and can prevent deformation when vacuum depressurizing for internal degassing as described later.

[0061]

[0062] The above-mentioned pure water storage tank (140) is equipped with a degassing function as mentioned above. To this end, as shown in FIG. 4, the pure water storage tank (140) is connected to a treated water supply valve (WS), a vacuum pump (VP), a water filling pipe (112), an exhaust valve (EV2), and a gas supply unit (Sn).

[0063]

[0064] Preferably, the treated water supply valve (WS) is an electric valve installed in the main pipe connected to the pure water treatment process (30) to control the supply of treated water to the pure water storage tank (140). Here, the treated water supply valve (WS) is preferably configured as a general 2-WAY valve when the pure water storage tank (140) is configured as a single tank, and as described below, is preferably configured as a 3-WAY valve when the pure water storage tanks (140, 150) are configured as multiple tanks.

[0065]

[0066] A vacuum pump (VP) discharges residual gas contained in the pure storage tank (140) for more than a set time to the outside and forms a vacuum of approximately -1 bar inside the pure storage tank (140). It is provided outside the pure storage tank (140) and connected to one side of the upper part of the pure storage tank (140) by a pipe, and a first suction shut-off valve (S1) is installed in this connecting pipe.

[0067]

[0068] The filling pipe (112) is a pipe that connects the outlet side of the pressure pump and the lower part of the pure water storage tank to refill the pure water storage tank with treated water after a vacuum is formed inside the pure water storage tank by the vacuum pump. It is obvious that a separate valve (not given a reference number) is installed in the filling pipe (112).

[0069]

[0070] The exhaust valve (EV2) is a valve that discharges gas remaining in the pure storage tank (140) to the outside when the pure storage tank (140) is filled with treated water by the treated water supply valve (WS).

[0071]

[0072] The gas supply unit (Sn) injects insoluble seal gas into the interior of the pure storage tank (140) at high pressure. The gas supply unit (Sn) that supplies compressed gas to the surge tank (130) may be used in common, or a separate, independent gas supply unit (Sn) may be used. The compressed gas supplied from the gas supply unit (Sn) to the pure storage tank (140) pressurizes the treated water filled in the pure storage tank (140) and discharges it through the main pipe connected to the bottom. Here, a first discharge control valve (S3) for controlling the discharge of treated water is provided in the main pipe at the bottom of the pure storage tank (140).

[0073]

[0074] As previously mentioned above and illustrated in FIG. 4, the pure storage tank (140) may be composed of multiple tanks. That is, an auxiliary storage tank (150) may be additionally provided on one side of the pure storage tank (140). The auxiliary storage tank (150) is configured with the same structure as the pure storage tank (140). Specifically, the lower side of the auxiliary storage tank (150) is connected to a vacuum pump (VP) by a pipe and the pipe is equipped with a second suction shut-off valve (S2), the upper side is connected to the treated water supply valve (WS) by a separate supply pipe, the lower other side is connected to the main pipe through a separate discharge pipe and the discharge pipe is equipped with a second discharge shut-off valve (S4), the upper side is equipped with an exhaust valve (EV3) and the other side is connected to a gas supply unit (Sn). In this way, when the pure storage tank (140) and the auxiliary storage tank (150) are connected in parallel, the degassing and supply operations of the treated water can be performed alternately in the two tanks, allowing the system to operate continuously without a separate waiting time.

[0075]

[0076] Below, the method of degassing and supplying treated water in the above-mentioned pure water storage tank (140) will be explained in more detail with reference to FIG. 6.

[0077]

[0078] As shown in FIG. 6(a), the lower part of the first pure water storage tank (140) is filled with pure treated water and the upper part is filled with gas, and dissolved gas remains in the pure treated water. Here, the treated water supply valve (WS), the first suction shut-off valve (S1), and the first discharge shut-off valve (S3) are in a closed (OFF) state. In this state, to degas, as shown in FIG. 6(b), the first suction shut-off valve (S1) is opened (ON) and the vacuum pump (VP) is operated so that all gas contained inside the pure water storage tank (140) or remaining in the treated water is discharged to the outside. After the remaining gas is discharged, the vacuum pump (VP) continues to operate until the internal pressure of the pure water storage tank (140) becomes -1 bar, and a vacuum is formed inside the pure water storage tank (140). Since the above-mentioned pure storage tank (140) is a pressure tank, it does not collapse or deform even when the pressure drops to -1 bar. In this way, residual gas inside the pure storage tank (140) is removed by suction and vacuum treatment of the gas inside the pure storage tank (140). When the inside of the pure storage tank (140) becomes a vacuum state, as shown in Fig. 6 (c), the vacuum pump (VP) is stopped and the first suction shut-off valve (S1) is closed (OFF), and the treated water is filled into the pure storage tank (140) through the filling pipe (112) by operating the pressure pump (110). Since the outlet pressure of the pressure pump (110) is significantly higher than that of the low-pressure pure storage tank (140, 150), filling is achieved by simply opening the valve of the filling pipe (112). At this time, the treated water is buffered inside the pure water storage tank (140), but if a small amount of oxygen remains inside the pure water storage tank (140), the exhaust valve (EV2) is opened to discharge it to the outside. Accordingly, almost no gas remains inside the pure water storage tank (140).When the treated water in the pure water storage tank (140) is filled, as shown in (d) of FIG. 5, the gas supply unit (Sn) is activated (ON) to supply insoluble compressed nitrogen gas to the upper part inside the pure water storage tank (140), and when the first discharge shut-off valve (S3) provided at the lower part of the pure water storage tank (140) is opened (ON), the treated water inside the pure water storage tank (140) is pressurized by the pressure of the compressed nitrogen and discharged into the main pipe. The treated water discharged into the main pipe is pressurized again by the pressure pump (110), passes through the surge tank (130), and is supplied to the ultrapure water treatment process (50).

[0079]

[0080] Meanwhile, since it takes a considerable amount of time for the treated water buffered in the pure storage tank (140) to be completely discharged, the same degassing operation is performed in the auxiliary storage tank (150) during this time, and after the treated water in the pure storage tank (140) is completely discharged, the degassing and buffered treated water in the auxiliary storage tank (150) is supplied to the main pipe. While the treated water in the auxiliary storage tank (150) is being discharged, degassing is performed again in the pure storage tank (140), and through this alternating degassing and treated water supply operation between the pure storage tank (140) and the auxiliary storage tank (150), the ultrapure water process system can be operated continuously without waiting time.

[0081]

[0082] Specific embodiments of the present invention have been described above. However, those skilled in the art will understand that the spirit and scope of the present invention are not limited to these specific embodiments, but that various modifications and variations are possible within the scope of the invention without altering the essence of the invention. Accordingly, the embodiments described above are provided to fully inform those skilled in the art of the scope of the invention and should be understood as illustrative in all respects and not restrictive, and the present invention is defined only by the scope of the claims.

Claims

1. In an ultrapure water process system that produces ultrapure water by sequentially transferring treated water along a main pipe between a pretreatment process, a pure water treatment process, and an ultrapure water treatment process, An ultrapure water process system characterized by a surge tank for preventing water hammer being directly connected to a main pipe through which the treated water is transported, wherein the treated water is introduced through a connection to the main pipe at one side of the upper portion of the surge tank and the treated water is discharged through a connection to the main pipe at the lower portion of the surge tank, thereby enabling the first-in, first-out of the treated water introduced into the surge tank.

2. In Paragraph 1, An ultrapure water process system characterized by having an inlet connected to a main pipe and into which treated water flows in on one side of the upper part of the surge tank, and an outlet connected to a main pipe and into which treated water flows out on the lower part of the surge tank.

3. In Paragraph 2, An ultrapure water process system characterized by including a guide pipe extending laterally from the surge tank, with one end connected to the inlet and the other end extending into the interior of the surge tank, so that the treated water moves downward while rotating in a spiral and is discharged toward the outlet.

4. In Paragraph 1 or 2, An ultrapure water process system characterized by receiving treated water from the above-mentioned pure water treatment process and temporarily storing it, and further including a pure water storage tank for degassing to remove dissolved gas contained in the treated water.

5. In Paragraph 4, The above-mentioned pure storage tank is composed of a pressure tank; A vacuum pump is connected to the upper part of the above-mentioned pure storage tank to create a vacuum inside; A filling pipe connected to the outlet side of the pressurizing pump is connected to one side of the lower part of the above-mentioned pure storage tank to fill the pure storage tank with treated water after a vacuum is formed inside the pure storage tank by the above-mentioned vacuum pump; An exhaust valve is connected to one side of the upper portion of the pure storage tank to discharge gas remaining in the pure storage tank to the outside when the pure storage tank is filled with treated water; An ultrapure water process system characterized by having a gas supply unit connected to the upper side of the above-mentioned pure water storage tank for pressurizing and filling with insoluble gas.

6. In Paragraph 5, An ultrapure water process system characterized by having an auxiliary storage tank additionally provided on one side of the above-mentioned pure water storage tank, wherein the upper side of the auxiliary storage tank is connected to the vacuum pump, and the other side of the upper side is connected to an exhaust valve and a gas supply unit, respectively, and the lower side is connected to a main pipe, and the other side of the lower side is connected to a filling pipe connected to the outlet side of the pressure pump to fill the auxiliary storage tank with treated water after a vacuum is formed inside the auxiliary storage tank by the vacuum pump.

Images