Resistivity adjustment device and resistivity adjustment method

Abstract

This invention, with its simple structure, suppresses changes in the resistivity of the liquid adjusting the specific resistance value even when the flow rate of the supplied liquid changes. This invention provides a specific resistance value adjusting device, comprising: a hollow yarn membrane module, divided into a liquid phase side region and a gas phase side region by the hollow yarn membrane; the liquid phase side region is supplied with a liquid for which the specific resistance value is to be adjusted; the gas phase side region is supplied with an adjusting gas for adjusting the specific resistance value of the liquid; a liquid supply pipe; a liquid discharge pipe; a module via pipe communicating with the liquid phase side region of the hollow yarn membrane module, the liquid supply pipe, and the liquid discharge pipe, passing through the hollow yarn membrane module; and a bypass pipe communicating with the liquid supply pipe and the liquid discharge pipe, bypassing the hollow yarn membrane module, and the bypass pipe having: a laminarization section comprising a plurality of thin tubes thinner than the module via pipe. This invention also provides a specific resistance value adjusting method.

Description

Technical Field

[0001] One aspect of the present invention relates to a resistivity adjustment device and a resistivity adjustment method for adjusting the resistivity of a liquid. Prior Technology

[0002] In semiconductor or liquid crystal manufacturing processes, ultrapure water is used to clean the substrate. In this case, if the ultrapure water has a high resistivity, static electricity is generated. This can lead to insulation breakdown or microparticle re-attachment, significantly impacting product yield. To address this problem, a method using a hydrophobic hollow fiber membrane module has been proposed. This method uses a hollow fiber membrane module to dissolve gases such as carbon dioxide or ammonia in ultrapure water. Ions are then generated through dissociation equilibrium, and the resistivity of the ultrapure water decreases as a result of these ions.

[0003] Furthermore, the flow of ultrapure water fluctuates drastically during steps such as substrate cleaning and dicing. Therefore, Patent Document 1 proposes a technique that stabilizes the resistivity even with flow rate variations. In the technique described in Patent Document 1, a hollow fiber membrane module and a bypass pipe are provided. The hollow fiber membrane module generates a small flow rate of ultrapure water with added gas, while the bypass pipe allows a large flow rate of ultrapure water to pass through. Additionally, the generated ultrapure water with added gas is combined with the ultrapure water passing through the bypass pipe. This allows for easy adjustment of the resistivity of the ultrapure water.

[0004] However, in the technology described in Patent Document 1, if the ultrapure water flow rate becomes low, the flow rate of ultrapure water supplied to the hollow fiber membrane module sometimes decreases relative to the flow rate of ultrapure water bypassing the hollow fiber membrane module, resulting in an increase in the resistivity of the ultrapure water. Therefore, Patent Document 2 proposes a technology that involves providing multiple bypass pipes and installing shut-off valves on one or more of the bypass pipes. In the technology described in Patent Document 2, if the ultrapure water flow rate decreases, some or all of the shut-off valves are closed. This prevents the situation where, when the ultrapure water flow rate becomes low, the flow rate of ultrapure water supplied to the hollow fiber membrane module decreases relative to the flow rate of ultrapure water bypassing the hollow fiber membrane module. [Existing technical documents] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent No. 3951385 [Patent Document 2] Japanese Patent Application Publication No. 2012-223725 Summary of the Invention

[0006] [The problem that the invention aims to solve]

[0007] However, the technology described in Patent Document 2 requires controlling the opening and closing of shut-off valves installed in multiple bypass pipes according to the flow rate of ultrapure water, which leads to problems such as increased complexity and cost of the device. Moreover, the technology described in Patent Document 2 also has the following problem: if the supply flow rate changes, the pressure loss in the bypass pipe changes drastically with the opening and closing of the shut-off valves.

[0008] Therefore, one aspect of the present invention is to provide a resistivity adjustment device and a resistivity adjustment method, which, with a simple structure, can suppress the change in the resistivity of the liquid being adjusted even if the flow rate of the supplied liquid changes. [Methods for solving problems]

[0009] The inventors conducted in-depth research on the aforementioned problem and discovered that in previous resistivity adjustment devices, the liquid in the bypass pipe becomes turbulent. This turbulence significantly affects the change in the resistivity of the resistivity adjustment liquid when the liquid supplied to the resistivity adjustment device changes. This is not limited to the case where ultrapure water is supplied, but also applies when various liquids other than ultrapure water are supplied. Furthermore, resistivity adjustment liquid refers to a liquid whose resistivity has been adjusted by the resistivity adjustment device.

[0010] To elaborate, the pressure loss of the liquid in the bypass pipe, where the liquid flows turbulently, is an exponential function of the liquid flow rate. On the other hand, the flow rate of the liquid supplied to the module via the hollow yarn membrane module is smaller than the flow rate of the liquid supplied to the bypass pipe that bypasses the hollow yarn membrane module. Therefore, when comparing the pressure loss of the liquid in the bypass pipe, regardless of whether the liquid flowing in the module via pipe and the hollow yarn membrane module is turbulent, the pressure loss of the liquid in both the module via pipe and the hollow yarn membrane module can be considered proportional to the liquid flow rate. That is, the tendency of pressure loss is quite different for the liquid in the bypass pipe and the liquid in the module via pipe and the hollow yarn membrane module.

[0011] Therefore, as the flow rate of the liquid supplied to the resistivity adjustment device changes, the liquid distribution ratio between the module via pipe and the bypass pipe changes (is disrupted), and the resistivity of the resistivity adjustment liquid changes. In particular, if the flow rate of the liquid supplied to the resistivity adjustment device becomes small, the liquid distribution ratio of the bypass pipe to the module via pipe becomes larger, and the resistivity of the resistivity adjustment liquid becomes higher.

[0012] Therefore, the inventors solved the aforementioned problem by making the tendency of pressure loss of the liquid in the bypass pipe close to the tendency of pressure loss of the liquid in the module through pipe and the hollow yarn membrane module.

[0013] That is, one aspect of the resistivity adjustment device of the present invention includes: a hollow yarn membrane module, which is divided into a liquid phase side region and a gas phase side region by the hollow yarn membrane, wherein the liquid phase side region is supplied with a liquid that is the object of resistivity adjustment, and the gas phase side region is supplied with an adjusting gas for adjusting the resistivity of the liquid; a liquid supply pipe; a liquid discharge pipe; a module via pipe, which is connected to the liquid phase side region, the liquid supply pipe and the liquid discharge pipe of the hollow yarn membrane module, and passes through the hollow yarn membrane module; and a bypass pipe, which is connected to the liquid supply pipe and the liquid discharge pipe, bypasses the hollow yarn membrane module, and the bypass pipe has: a laminarization section, which includes a plurality of thin tubes that are thinner than the module via pipe.

[0014] In the resistivity adjustment device, liquid is supplied to the liquid supply pipe, and adjusting gas is supplied to the gas phase side region of the hollow yarn film module. The liquid supplied to the liquid supply pipe is distributed to the module via pipe and bypass pipe, and the liquid distributed to the module via pipe is supplied to the liquid phase side region of the hollow yarn film module. In the hollow yarn film module, the adjusting gas passing through the hollow yarn film dissolves in the liquid supplied to the liquid phase side region, generating a liquid containing the adjusting gas dissolved in the liquid. The liquid containing the adjusting gas generated by the hollow yarn film module and the liquid bypassing the hollow yarn film module merge in the liquid discharge pipe to become the resistivity adjustment liquid, which is discharged from the resistivity adjustment device.

[0015] Furthermore, the bypass pipe has a laminarization section comprising multiple finer tubes than the module through pipe, thus enabling laminar flow of the liquid in the bypass pipe. In laminar flow, the pressure loss of the liquid is proportional to the flow rate. Even if it is not laminar flow, the closer the flow is from turbulent to laminar, the closer the pressure loss of the liquid is to the flow rate. On the other hand, the flow rate of the liquid supplied to the module through pipe is smaller than the flow rate of the liquid supplied to the bypass pipe. Therefore, when comparing the pressure loss of the liquid in the bypass pipe, regardless of whether the liquid flowing in the module through pipe and the hollow yarn membrane module is turbulent, the pressure loss of the liquid in the module through pipe and the hollow yarn membrane module can be considered proportional to the flow rate. That is, the tendency of the pressure loss of the liquid in the bypass pipe is close to the tendency of the pressure loss of the liquid in the module through pipe and the hollow yarn membrane module. Therefore, even if the flow rate of the liquid supplied to the resistivity adjustment device changes, the change in the liquid distribution ratio between the module through pipe and the bypass pipe can be suppressed, and the change in the resistivity of the resistivity adjustment liquid can be suppressed. In particular, even if the liquid supplied to the resistivity adjustment device is at a low flow rate, the increase in the liquid distribution ratio of the bypass pipe to the module through pipe can be suppressed, thus suppressing the increase in the resistivity of the resistivity adjustment liquid. Therefore, for a simple structure, even if the flow rate of the supplied liquid changes, the change in the resistivity of the resistivity adjustment liquid can be suppressed.

[0016] As one embodiment, the laminarization section can also be configured such that when ultrapure water is supplied as a liquid to the bypass pipe at a specified flow rate, the liquid in the laminarization section becomes laminar. In the resistivity adjustment device, by configuring the laminarization section so that the liquid becomes laminar when ultrapure water is supplied as a liquid to the bypass pipe at a specified flow rate, the laminarization section can be easily designed, and even if the flow rate of the supplied liquid changes, the change in the resistivity of the resistivity adjustment liquid can be further suppressed.

[0017] As one embodiment, the laminar fluidization section can also be configured such that when ultrapure water is supplied to the bypass pipe at a specified flow rate, the Reynolds number in the laminar fluidization section is 2300 or less. In the resistivity adjustment device, by configuring the laminar fluidization section such that the Reynolds number in the laminar fluidization section is 2300 or less when ultrapure water is supplied to the bypass pipe at a specified flow rate, the laminar fluidization section can be easily designed, and even if the flow rate of the supplied liquid changes, the change in the resistivity of the resistivity adjustment liquid can be further suppressed.

[0018] In one embodiment, the number of multiple capillary tubes can be five or more. In the resistivity adjustment device, by having five or more capillary tubes, the flow rate of the liquid in the laminar fluidization section is ensured, and the flow of the liquid in the laminar fluidization section is easily made into laminar flow.

[0019] As one embodiment, the inner diameter of each of the multiple capillary tubes can be 0.01 mm or more and 10 mm or less. In the resistivity adjustment device, by having the inner diameter of each of the multiple capillary tubes be 0.01 mm or more and 10 mm or less, the pressure loss of the liquid in the laminarization section is suppressed from becoming too large or too small, and the flow of the liquid in the laminarization section is made easier to become laminar.

[0020] In one embodiment, the length of each of the multiple capillary tubes can be 1 mm or more and 1000 mm or less. In the resistivity adjustment device, by having the length of each of the multiple capillary tubes be 1 mm or more and 1000 mm or less, the pressure loss of the liquid in the laminarization section can be suppressed from becoming too large or too small.

[0021] In one embodiment, the length of the laminarization section can be 1% or more of the length of the bypass pipe. In the resistivity adjustment device, by making the length of the laminarization section 1% or more of the length of the bypass pipe, the flow of liquid in the bypass pipe can be easily made into laminar flow.

[0022] As one embodiment, it may further include: a branch module connected to the liquid supply pipe, the module via pipe, and the bypass pipe, thereby connecting the liquid supply pipe, the module via pipe, and the bypass pipe; and a confluence module connected to the liquid discharge pipe, the module via pipe, and the bypass pipe, thereby connecting the liquid discharge pipe, the module via pipe, and the bypass pipe, with the laminarization section extending from the branch module to the confluence module. In the resistivity adjustment device, by including the branch module and the confluence module, a branch structure from the liquid supply pipe to the module via pipe and the bypass pipe, and a confluence structure from the module via pipe and the bypass pipe to the liquid discharge pipe can be easily realized. In particular, the bypass pipe has a laminarization section comprising multiple thin tubes, thus allowing easy connection between the bypass pipe and the liquid supply pipe and the liquid discharge pipe via the branch module and the confluence module. Furthermore, by extending the laminarization section from the branch module to the confluence module, the laminarization section can be easily formed, and the flow of liquid in the laminarization section can easily become laminar.

[0023] As one embodiment, it may further include: a gas supply pipe connected to the gas phase side region for supplying adjusting gas to the gas phase side region; and a gas discharge pipe connected to the gas phase side region for discharging adjusting gas from the gas phase side region. In the resistivity adjustment device, by including the gas supply pipe and the gas discharge pipe, the supply and discharge of adjusting gas to the gas phase side region of the hollow yarn film module can be easily performed.

[0024] As one embodiment, it may further include: a valve installed on the module via pipe for adjusting the liquid distribution ratio between the module via pipe and the bypass pipe. In the resistivity adjustment device, by including the valve, the liquid flow distribution ratio between the module via pipe and the bypass pipe can be easily adjusted. Furthermore, since the valve is installed on the module via pipe, laminar flow in the bypass pipe can be prevented from being obstructed by the valve.

[0025] One aspect of the resistivity adjustment device of the present invention supplies liquid to the liquid supply pipe of any of the resistivity adjustment devices and supplies adjustment gas to the gas phase side region of the hollow yarn film module, thereby adjusting the resistivity of the liquid.

[0026] In the described resistivity adjustment method, liquid is supplied to the liquid supply pipe and adjusting gas is supplied to the gas phase side region of the hollow yarn film module in the resistivity adjustment device, thereby adjusting the resistivity of the liquid. This provides a simple structure, and even changes in the flow rate of the supplied liquid can suppress changes in the resistivity of the liquid used for resistivity adjustment. [The effects of the invention]

[0027] According to one aspect of the invention, the structure is simple, and even if the flow rate of the supplied liquid changes, the change in the resistivity of the liquid adjusting the resistivity can be suppressed. Simple Explanation of the Diagram

[0028] Figure 1 is a schematic diagram of the resistivity adjustment device in the embodiment. Figure 2 is an enlarged cross-sectional view of a portion of the hollow yarn film. Figure 3 is a cross-sectional view showing a portion of the resistivity adjustment device shown in Figure 1. Figure 4 is an enlarged cross-sectional view of a portion of the bypass pipe. Figure 5 is a graph showing the measurement results of the resistivity of the liquid used for resistivity adjustment in Example 1. Figure 6 is a graph showing the measurement results of the resistivity of the liquid used to adjust the resistivity of Comparative Example 1. Figure 7 is a graph showing the measurement results of the pressure loss of the liquid in the module of Comparative Example 1 via the pipe and the bypass pipe. Implementation

[0029] The resistivity adjustment device and method of the embodiment are described in detail below with reference to the drawings. Furthermore, in all drawings, the same or equivalent parts are labeled with the same symbols, and repeated descriptions are omitted.

[0030] Figure 1 is a schematic diagram of the resistivity adjustment device according to an embodiment. As shown in Figure 1, the resistivity adjustment device 1 of this embodiment generates a liquid L1 containing adjusting gas, which is formed by dissolving adjusting gas G in liquid L. Moreover, the resistivity adjustment device 1 is a device that generates a resistivity-adjusting liquid L2 by merging liquid L with liquid L1 containing adjusting gas to adjust the resistivity of liquid L. Furthermore, liquid L1 containing adjusting gas is liquid L containing dissolved adjusting gas G, and resistivity-adjusting liquid L2 is liquid L whose resistivity has been adjusted. Therefore, sometimes liquid L1 containing adjusting gas and resistivity-adjusting liquid L2 are simply referred to as liquid L. The resistivity adjustment device 1 includes a hollow yarn film module 2, a liquid supply pipe 3, a liquid discharge pipe 4, a gas supply pipe 5, a gas discharge pipe 6, a module via pipe 7, a bypass pipe 8, a valve 9, a branch module 11, and a merging module 12.

[0031] The hollow yarn membrane module 2 is a module used to dissolve the adjusting gas G, which adjusts the resistivity value, in the liquid L, whose resistivity value is to be adjusted. The hollow yarn membrane module 2 includes multiple hollow yarn membranes 21 and a housing 22 that houses the hollow yarn membranes 21 inside.

[0032] Liquid L is the liquid whose resistivity is being adjusted. There are no particular limitations on the liquid used for L; for example, it can be pure water or ultrapure water used for cleaning semiconductors, liquid crystals, etc. Typically, the resistivity of pure water and ultrapure water is 0.1 MΩ·cm or higher. Therefore, the resistivity of liquid L can be, for example, 0.1 MΩ·cm or higher, preferably 15.0 MΩ·cm or higher, and even more preferably 17.5 MΩ·cm or higher. Furthermore, there are no particular limitations on the upper limit of the resistivity of liquid L; for example, it can be in the range of 18.248 MΩ·cm or lower.

[0033] The temperature of liquid L is not particularly limited, for example, it can be above 5°C, preferably above 10°C, more preferably above 20°C, and can be below 60°C, preferably below 40°C, more preferably below 30°C. The supply pressure of liquid L is not particularly limited, for example, it can be above 0.01 MPa, preferably above 0.1 MPa, more preferably above 0.2 MPa, and can be below 1.0 MPa, preferably below 0.4 MPa, more preferably below 0.3 MPa.

[0034] The adjusting gas G is a gas used to adjust the resistivity of liquid L. There are no particular limitations on the gas used for adjusting gas G; for example, it can be carbon dioxide or ammonia. There are no particular limitations on the temperature of the adjusting gas G; for example, it can be above 0°C, preferably above 20°C, more preferably above 25°C, and below 60°C, preferably below 50°C, more preferably below 30°C. There are no particular limitations on the supply pressure of the adjusting gas G; for example, it can be above 0.01 MPa, preferably above 0.05 MPa, and below 0.5 MPa, preferably below 0.2 MPa, more preferably below 0.15 MPa.

[0035] The hollow yarn membrane 21 is a hollow yarn-shaped membrane that allows gas to pass through but not liquid. There are no particular limitations on the material, shape, or morphology of the hollow yarn membrane 21. The outer casing 22 is a sealed container that houses the hollow yarn membrane 21. The membrane area of ​​the hollow yarn membrane module 2 can be appropriately adjusted according to the processing flow rate (the flow rate of liquid L), and is not particularly limited; for example, it can be in the range of 0.1 m² or more and 120 m² or less. When adjusting the membrane area of ​​the hollow yarn membrane module 2 to the optimal value according to the processing flow rate, for example, in the case of normal flow rate processing (e.g., 1 L / min to 120 L / min), it can be in the range of 0.1 m² or more and 4.0 m² or less; in the case of larger flow rate processing (e.g., 120 L / min to 4000 L / min), it can be in the range of 4.0 m² or more and 120 m² or less.

[0036] The hollow yarn membrane module 2 includes multiple hollow yarn membranes 21 and an outer shell 22 that houses the hollow yarn membranes 21 inside.

[0037] Figure 2 is an enlarged cross-sectional view of a portion of the hollow yarn membrane. As shown in Figure 2, the hollow yarn membrane module 2 is divided into a liquid phase region LA and a gas phase region GA by the hollow yarn membrane 21. The liquid phase region LA is the region within the hollow yarn membrane module 2 where the liquid L to be adjusted for resistivity is supplied. The gas phase region GA is the region within the hollow yarn membrane module 2 where the adjusting gas G to adjust the resistivity is supplied. Hollow yarn membrane modules 2 can be either internally perfused or externally perfused. In this embodiment, either internally perfused or externally perfused is acceptable. In the externally perfused hollow yarn membrane module 2, the inner side (inner surface side) of the hollow yarn membrane 21 becomes the gas phase region GA, and the outer side (outer surface side) of the hollow yarn membrane 21 becomes the liquid phase region LA. In the internally perfused hollow yarn membrane module 2, the inner side (inner surface side) of the hollow yarn membrane 21 becomes the liquid phase side region LA, and the outer side (outer surface side) of the hollow yarn membrane 21 becomes the gas phase side region GA. Furthermore, in the hollow yarn membrane module 2, the adjusting gas G supplied to the gas phase side region GA and passing through the hollow yarn membrane 21 dissolves in the liquid L supplied to the liquid phase side region LA, thereby generating a liquid L1 with the added adjusting gas.

[0038] As shown in Figure 1, a liquid supply port 22A, a liquid discharge port 22B, a gas supply port 22C, and a gas discharge port 22D are formed on the outer casing 22. The liquid supply port 22A is an opening in the outer casing 22 for supplying liquid L to the liquid phase region LA. The liquid discharge port 22B is an opening in the outer casing 22 for discharging liquid L1 with added conditioning gas from the liquid phase region LA. The gas supply port 22C is an opening in the outer casing 22 for supplying conditioning gas G to the gas phase region GA. The gas discharge port 22D is an opening in the outer casing 22 for discharging conditioning gas G from the gas phase region GA. Therefore, the liquid supply port 22A and the liquid discharge port 22B are connected to the liquid phase region LA. Furthermore, the gas supply port 22C and the gas discharge port 22D are connected to the gas phase region GA. The positions of the liquid supply port 22A, the liquid discharge port 22B, the gas supply port 22C, and the gas discharge port 22D on the outer casing 22 are not particularly limited.

[0039] Figure 3 is a cross-sectional view showing a portion of the resistivity adjustment device shown in Figure 1. As shown in Figures 1 and 3, the liquid supply pipe 3 is a tubular component with a flow path 3A for liquid L formed inside. Liquid L is supplied to the liquid supply pipe 3. The material, properties (hardness, elasticity, etc.), shape, and size of the liquid supply pipe 3 are not particularly limited.

[0040] The liquid discharge pipe 4 is a tubular component with a flow path 4A formed internally for the resistivity-adjusting liquid L2. The resistivity-adjusting liquid L2 is discharged from the liquid discharge pipe 4. There are no particular limitations on the material, properties (hardness, elasticity, etc.), shape, and size of the liquid discharge pipe 4.

[0041] The gas supply pipe 5 is a tubular component with an internal flow path (not shown) for adjusting gas G. The gas supply pipe 5 is connected to the gas supply port 22C and communicates with the gas phase region GA of the hollow yarn film module 2 in order to supply adjusting gas G to the gas phase region GA of the hollow yarn film module 2. The material, properties (hardness, elasticity, etc.), shape, and size of the gas supply pipe 5 are not particularly limited.

[0042] The gas discharge pipe 6 is a tubular component with an internal flow path (not shown) for adjusting gas G. The gas discharge pipe 6 is connected to the gas outlet 22D and communicates with the gas phase region GA of the hollow yarn film module 2 to discharge the adjusting gas G from the gas phase region GA of the hollow yarn film module 2. A valve 6A is installed in the gas discharge pipe 6 to open and close the flow path of the gas discharge pipe 6. By opening the valve 6A, the adjusting gas G can be discharged from the gas phase region GA of the hollow yarn film module 2. Furthermore, by closing the valve 6A, the adjusting gas G cannot be discharged from the gas phase region GA of the hollow yarn film module 2. The valve 6A can also be used to adjust the opening degree of the flow path of the gas discharge pipe 6. The material, properties (hardness, elasticity, etc.), shape, and size of the gas discharge pipe 6 are not particularly limited. Furthermore, the gas discharge pipe 6 may also be provided with a leakage section (not shown) for the adjustment gas G of the gas phase side region GA of the hollow yarn film module 2 to leak out. The adjustment gas G leaks out continuously from the leakage section.

[0043] The module is connected to the liquid phase region LA, liquid supply pipe 3, and liquid discharge pipe 4 of the hollow yarn membrane module 2 via pipe 7, and passes through the hollow yarn membrane module 2. That is, the hollow yarn membrane module 2 is positioned midway through the module via pipe 7. The module via pipe 7 has an upstream module via pipe 71 and a downstream module via pipe 72. The upstream module via pipe 71 is positioned upstream of the hollow yarn membrane module 2 in the flow direction of liquid L. The downstream module via pipe 72 is positioned downstream of the hollow yarn membrane module 2 in the flow direction of liquid L.

[0044] The upstream module via pipe 71 is a tubular component with a flow path 71A formed internally. The upstream module via pipe 71 is connected to both the liquid supply pipe 3 and the liquid phase region LA of the hollow yarn film module 2 in order to supply liquid L from the liquid supply pipe 3 to the liquid phase region LA of the hollow yarn film module 2. The upstream end of the upstream module via pipe 71 is connected to the branch module 11 to communicate with the flow path 3A of the liquid supply pipe 3. The downstream end of the upstream module via pipe 71 is connected to the liquid supply port 22A to communicate with the liquid phase region LA of the hollow yarn film module 2. The material, properties (hardness, elasticity, etc.), shape, and size of the upstream module via pipe 71 are not particularly limited. However, the cross-sectional area of ​​the flow path 71A of the upstream module via pipe 71 is preferably smaller than the cross-sectional area of ​​the flow path 3A of the liquid supply pipe 3.

[0045] The downstream module via pipe 72 is a tubular component with a flow path 72A formed internally. The downstream module via pipe 72 is connected to the liquid discharge pipe 4 and the liquid phase region LA of the hollow yarn film module 2 to discharge the liquid L1 generated by the hollow yarn film module 2 with added adjusting gas to the liquid discharge pipe 4. The upstream end of the downstream module via pipe 72 is connected to the liquid discharge port 22B to communicate with the liquid phase region LA of the hollow yarn film module 2. The downstream end of the downstream module via pipe 72 is connected to the confluence module 12 to communicate with the flow path 4A of the liquid discharge pipe 4. The material, properties (hardness, elasticity, etc.), shape, and size of the downstream module via pipe 72 are not particularly limited. However, the cross-sectional area of ​​the flow path 72A of the downstream module via pipe 72 is preferably smaller than the cross-sectional area of ​​the flow path 4A of the liquid discharge pipe 4.

[0046] Figure 4 is an enlarged cross-sectional view of a portion of the bypass pipe. As shown in Figures 1, 3, and 4, the bypass pipe 8 is connected to the liquid supply pipe 3 and the liquid discharge pipe 4, bypassing the hollow yarn membrane module 2. That is, the bypass pipe 8 is not connected to the hollow yarn membrane module 2, and the liquid L supplied to the liquid supply pipe 3 is discharged to the liquid discharge pipe 4 without passing through the hollow yarn membrane module 2. The direction of the bypass pipe 8 from the liquid supply pipe 3 to the liquid discharge pipe 4 is called the flow direction FD from the liquid supply pipe 3 to the liquid discharge pipe 4. The flow direction FD from the liquid supply pipe 3 to the liquid discharge pipe 4 is also simply referred to as the flow direction FD. The upstream end of the bypass pipe 8 (the upstream end of the flow direction FD) is connected to the branch module 11 to connect with the liquid supply pipe 3. The downstream end of the bypass pipe 8 (the downstream end of the flow direction FD) is connected to the confluence module 12 to connect with the liquid discharge pipe 4. No shut-off valve or other valves for opening and closing the bypass pipe 8 are installed on the bypass pipe 8.

[0047] The bypass pipe 8 has a laminarization section 8A and a bypass housing 8B that houses the laminarization section 8A.

[0048] The bypass housing 8B is formed in a cylindrical shape to accommodate the laminarization section 8A. The upstream end (upstream of the flow direction FD) of the bypass housing 8B is hermetically connected to the branch module 11. The downstream end (downstream of the flow direction FD) of the bypass housing 8B is hermetically connected to the confluence module 12. That is, the laminarization section 8A extends from the branch module 11 to the confluence module 12. The hermetically sealed connection of the bypass housing 8B to the branch module 11 and the confluence module 12 can be achieved, for example, by bonding, welding, fitting, or a combination thereof. The material, properties (hardness, elasticity, etc.), shape, and size of the bypass housing 8B are not particularly limited. However, the bypass housing 8B is preferably a cylindrical shape extending in a straight line.

[0049] The laminarization section 8A includes multiple capillary tubes 8C to achieve laminar flow of liquid L in the bypass pipe 8. "Achieving laminar flow" means not only setting the flow to laminar flow but also bringing the turbulent flow closer to laminar flow. Laminar flow, for example, refers to flow with a Reynolds number of 2300 or lower. Bringing the turbulent flow closer to laminar flow, for example, means reducing the Reynolds number to approach 2300. The laminarization section 8A can also be configured such that, when ultrapure water is supplied to the bypass pipe 8 at a specified flow rate as liquid L, the liquid L in the laminarization section 8A becomes laminar. Furthermore, the laminarization section 8A can also be configured such that, when ultrapure water is supplied to the bypass pipe 8 at a specified flow rate as liquid L, the Reynolds number in the laminarization section 8A is 2300 or lower, preferably 2000 or lower, and more preferably 500 or lower. These specified flow rates can be, for example, any value between 0.1 L / min and 120 L / min.

[0050] Each of the multiple capillary tubes 8C is a tubular component with a flow path 8D formed internally. Each capillary tube 8C is thinner than the module via pipe 7 (upstream module via pipe 71 and downstream module via pipe 72). That is, the cross-sectional area of ​​the flow path 8D of each of the multiple capillary tubes 8C is smaller than the cross-sectional area of ​​the flow path 71A of the upstream module via pipe 71 and the cross-sectional area of ​​the flow path 72A of the downstream module via pipe 72. The sum of the cross-sectional areas of the flow paths 8D of each of the multiple capillary tubes 8C is, for example, larger than the cross-sectional area of ​​the flow path 71A of the upstream module via pipe 71 and the cross-sectional area of ​​the flow path 72A of the downstream module via pipe 72. Each of the multiple capillary tubes 8C is formed, for example, of polymethylpentene (PMP), polypropylene (PP), polyethylene (PE), urethane, polytetrafluoroethylene (PFA), nylon, etc.

[0051] The upstream ends of the plurality of capillary tubes 8C are fixed to the bypass housing 8B or the branch module 11 by means of a first sealing part 8E. The downstream ends of the plurality of capillary tubes 8C are fixed to the bypass housing 8B or the confluence module 12 by means of a second sealing part 8G. In addition, the plurality of capillary tubes 8C extend from the branch module 11 to the confluence module 12. Furthermore, the length of the laminar fluidization section 8A and the length of the plurality of capillary tubes 8C are the length of the flow direction FD.

[0052] The first sealing portion 8E seals the multiple capillary tubes 8C and the portion of the bypass housing 8B or branch module 11 that secures the multiple capillary tubes 8C without blocking their respective flow paths 8D. That is, the first sealing portion 8E fills the spaces between the multiple capillary tubes 8C and between the multiple capillary tubes 8C and the portion of the bypass housing 8B or branch module 11 that secures the multiple capillary tubes 8C (see Figure 4). The flow paths 8D of each of the multiple capillary tubes 8C are exposed from their upstream end faces 8F and communicate with the branch module 11. Therefore, the liquid L supplied to the bypass pipe 8 is supplied from the upstream end faces 8F of each of the multiple capillary tubes 8C to their respective flow paths 8D. The first sealing portion 8E is, for example, formed of resin. Examples of resins used for the first sealing portion 8E include epoxy resin, urethane resin, UV-curable resin, and polyolefin resins such as polyethylene or polypropylene.

[0053] The second sealing portion 8G seals the multiple capillary tubes 8C and the portion of the bypass housing 8B or the merging module 12 that secures the multiple capillary tubes 8C without blocking their respective flow paths 8D. That is, the second sealing portion 8G fills the spaces between the multiple capillary tubes 8C and between the multiple capillary tubes 8C and the portion of the bypass housing 8B or the merging module 12 that secures the multiple capillary tubes 8C (see Figure 4). The flow paths 8D of each of the multiple capillary tubes 8C are exposed from their downstream end faces 8H and communicate with the merging module 12. Therefore, the liquid L supplied to the flow paths 8D of each of the multiple capillary tubes 8C is discharged from their respective downstream end faces 8H. The second sealing portion 8G is, for example, formed of resin. Examples of resins used for the second sealing portion 8G include epoxy resin, urethane resin, UV-curable resin, and polyolefin resins such as polyethylene or polypropylene.

[0054] Here, the Reynolds number Re of the liquid L flowing in each of the multiple capillary tubes 8C can be obtained by the following equation (1). In equation (1), V is the flow velocity (m / s) of the liquid L flowing in each of the multiple capillary tubes 8C, D is the inner diameter (m) of each of the multiple capillary tubes 8C, ν is the dynamic viscosity of the liquid L (m 2 / s), ρ is the density of the liquid L (kg / m 3), and μ is the viscosity of the liquid L (Pa·s). [Number 1]

[0055] As shown in equation (1), the Reynolds number Re of the liquid L flowing in each of the plurality of capillary tubes 8C varies depending on the flow velocity V of the liquid L flowing in each of the plurality of capillary tubes 8C, the inner diameter D of each of the plurality of capillary tubes 8C, the dynamic viscosity ν of the liquid L, the density ρ of the liquid L, and the viscosity μ of the liquid L. Therefore, the plurality of capillary tubes 8C may, for example, have these parameters set such that the Reynolds number of the liquid L in the laminarization section 8A is 2300 or less, preferably 1000 or less, and more preferably 500 or less.

[0056] For example, from the viewpoint of easily making the flow of liquid L in the laminar fluidization section 8A laminar, the inner diameter (diameter) of each of the plurality of capillary tubes 8C can be 10 mm or less, preferably 5 mm or less, and even more preferably 1 mm or less. On the other hand, from the viewpoint of ease of manufacturing of the laminar fluidization section 8A, the inner diameter (diameter) of each of the plurality of capillary tubes 8C can be 0.01 mm or more, preferably 0.05 mm or more, and even more preferably 0.1 mm or more. From these viewpoints, the inner diameter (diameter) of each of the plurality of capillary tubes 8C can be 0.01 mm or more and 10 mm or less, preferably 0.05 mm or more and 5 mm or less, and even more preferably 0.1 mm or more and 1 mm or less.

[0057] Here, if the inner diameter of each of the multiple capillary tubes 8C is reduced, the flow rate of the liquid flowing in the laminar fluidization section 8A will decrease. Therefore, from the viewpoint of ensuring the flow rate of the liquid in the laminar fluidization section 8A, the number of capillary tubes 8C in the laminar fluidization section 8A can be 5 or more, preferably 50 or more, and even more preferably 100 or more, and more preferably 500 or more. On the other hand, from the viewpoint of ease of manufacturing of the laminar fluidization section 8A, the number of capillary tubes 8C in the laminar fluidization section 8A can be 100,000 or less, preferably 27,000 or less, even more preferably 18,000 or less, and even more preferably 9,000 or less. In view of these points, the number of capillary tubes 8C in the laminar fluidization section 8A can be more than 5 and less than 100,000, preferably more than 50 and less than 27,000, more preferably more than 100 and less than 18,000, and even more preferably more than 500 and less than 9,000.

[0058] The pressure loss ΔPa (Pa) of the liquid L in the laminar fluidization section 8A is obtained by using Equation (2) as a Hagen-Poiseuille calculation formula. In Equation (2), Q is the flow rate (m2 / s) of the liquid L flowing in the laminar fluidization section 8A (the total of multiple capillary tubes 8C), μ is the viscosity of the liquid L (Pa·s), n is the number of multiple capillary tubes 8C, D is the inner diameter (m) of each of the multiple capillary tubes 8C, and L is the length (m) of each of the multiple capillary tubes 8C. [Number 2]

[0059] As shown in equation (2), the pressure loss ΔPa of the liquid L in the laminar fluidization section 8A varies depending on the flow rate Q of the liquid L flowing in the laminar fluidization section 8A, the viscosity μ of the liquid L, the number n of the plurality of capillary tubes 8C, the inner diameter D of each of the plurality of capillary tubes 8C, and the length L of each of the plurality of capillary tubes 8C. Therefore, for example, these parameters can be set such that the pressure loss of the liquid L in the laminar fluidization section 8A is 10 kPa or more and 1000 kPa or less.

[0060] For example, from the viewpoint that the pressure loss of the liquid in the laminar fluidization section does not become excessive, the number of capillary tubes 8C in the laminar fluidization section 8A can be 5 or more, preferably 50 or more, further preferably 100 or more, and even more preferably 500 or more. On the other hand, from the viewpoint of ease of manufacturing of the laminar fluidization section 8A, the number of capillary tubes 8C in the laminar fluidization section 8A can be 100,000 or less, preferably 27,000 or less, further preferably 18,000 or less, and even more preferably 9,000 or less. From these viewpoints, the number of capillary tubes 8C in the laminar fluidization section 8A can be 5 or more and 100,000 or less, preferably 50 or more and 27,000 or less, further preferably 100 or more and 18,000 or less, and even more preferably 500 or more and 9,000 or less.

[0061] Furthermore, from the viewpoint that the pressure loss of the liquid in the laminarization section does not become excessive, the inner diameter (diameter) of each of the plurality of capillary tubes 8C can be 0.01 mm or more, preferably 0.05 mm or more, and even more preferably 0.1 mm or more. On the other hand, from the viewpoint of ease of manufacturing of the laminarization section 8A, the inner diameter (diameter) of each of the plurality of capillary tubes 8C can be 10 mm or less, preferably 5 mm or less, and even more preferably 1 mm or less. From these viewpoints, the inner diameter (diameter) of each of the plurality of capillary tubes 8C can be 0.01 mm or more and 10 mm or less, preferably 0.05 mm or more and 5 mm or less, and even more preferably 0.1 mm or more and 1 mm or less.

[0062] Furthermore, from the viewpoint that the pressure loss of the liquid L in the laminar fluidization section does not become excessive, the length of each of the multiple capillary tubes 8C can be 1000 mm or less, preferably 500 mm or less, and even more preferably 100 mm or less. On the other hand, from the viewpoint of ease of manufacturing of the laminar fluidization section 8A, the length of each of the multiple capillary tubes 8C can be 1 mm or more, preferably 5 mm or more, and even more preferably 10 mm or more. From these viewpoints, the length of each of the multiple capillary tubes 8C can be 1 mm or more and 1000 mm or less, preferably 5 mm or more and 500 mm or less, and even more preferably 10 mm or more and 100 mm or less.

[0063] Furthermore, the laminarization of the liquid L in the bypass pipe 8 is achieved by the laminarization section 8A. Therefore, when the proportion of the laminarization section 8A in the bypass pipe 8 is large, the laminarization of the liquid L in the bypass pipe 8 is promoted. From this perspective, the length of the laminarization section 8A can be more than 1% of the length of the bypass pipe 8, preferably more than 10%, and more preferably more than 50%. On the other hand, from the perspective of ease of manufacturing of the laminarization section 8A, the length of the laminarization section 8A can be less than 100% of the length of the bypass pipe 8, preferably less than 90%, and more preferably less than 80%. From these perspectives, the length of the laminarization section 8A can be more than 1% and less than 100% of the length of the bypass pipe 8, preferably more than 10% and less than 90%, and more preferably more than 50% and less than 80%.

[0064] Valve 9 is installed on module via pipe 7 to adjust the distribution ratio of liquid L between module via pipe 7 and bypass pipe 8. Valve 9 adjusts the distribution ratio of liquid L between module via pipe 7 and bypass pipe 8, for example, by making the flow rate of liquid L supplied to module via pipe 7 (significantly) less than the flow rate of liquid L supplied to bypass pipe 8. For example, when adjusting liquid L2 to generate a specific resistance value of 1.0 MΩ·cm, the distribution ratio of liquid L between module via pipe 7 and bypass pipe 8 is approximately 1:3920 (module via pipe 7 side: bypass pipe 8 side).

[0065] Valve 9 is installed, for example, in the upstream module via pipe 71. By adjusting the opening of the flow path 71A of the upstream module via pipe 71, the flow rate of the liquid L flowing in the upstream module via pipe 71 is adjusted. Alternatively, valve 9 can be installed in the downstream module via pipe 72. By adjusting the opening of the flow path 72A of the downstream module via pipe 72, the flow rate of the liquid L1 containing the adjusting gas flowing in the downstream module via pipe 72 is adjusted. Various known valves can be used as valve 9, such as a needle valve.

[0066] Branch module 11 is connected to liquid supply pipe 3, upstream module via pipe 71, and bypass pipe 8, thus connecting liquid supply pipe 3, upstream module via pipe 71, and bypass pipe 8. Branch module 11 distributes liquid L supplied to liquid supply pipe 3 to upstream module via pipe 71 and bypass pipe 8. Branch module 11 has a flow path 11A that connects to flow path 3A of liquid supply pipe 3, flow path 71A of upstream module via pipe 71, and flow paths 8D of each of the multiple capillary tubes 8C. Flow path 11A may be divided into three branches, for example, with each branch end connected to flow path 3A of liquid supply pipe 3, flow path 71A of upstream module via pipe 71, and flow path 8D of each of the multiple capillary tubes 8C.

[0067] The merging module 12 is connected to the liquid discharge pipe 4, the downstream module via pipe 72, and the bypass pipe 8, thus connecting the liquid discharge pipe 4, the downstream module via pipe 72, and the bypass pipe 8. The merging module 12 merges the liquid L1 supplied to the downstream module via pipe 72 with the liquid L supplied to the bypass pipe 8, discharging the resistivity-adjusting liquid L2, formed by the mixture of the liquid L1 with the adjusting gas and the liquid L, into the liquid discharge pipe 4. The merging module 12 has a flow path 12A that connects to the flow path 4A of the liquid discharge pipe 4, the flow path 72A of the downstream module via pipe 72, and the respective flow paths 8D of the multiple thin tubes 8C. The flow path 12A may be divided into three branches, each branch connecting to the flow path 4A of the liquid discharge pipe 4, the flow path 72A of the downstream module via pipe 72, and the respective flow paths 8D of the multiple thin tubes 8C.

[0068] Next, the method for adjusting the resistivity of liquid L by means of resistivity adjustment device 1 will be explained.

[0069] In this method, liquid L is supplied to the liquid supply pipe 3, and adjusting gas G is supplied to the gas phase side region GA of the hollow yarn film module 2, thereby adjusting the specific resistivity of liquid L.

[0070] Specifically, liquid L is supplied to liquid supply pipe 3, and adjusting gas G is supplied to gas supply pipe 5. The liquid L supplied to liquid supply pipe 3 is then distributed in branch module 11 to upstream module via pipe 71 and bypass pipe 8. The liquid distributed to upstream module via pipe 71 is supplied to the liquid phase region LA of hollow yarn membrane module 2. Meanwhile, the adjusting gas G supplied to gas supply pipe 5 is supplied to the gas phase region GA of hollow yarn membrane module 2. The adjusting gas G supplied to gas phase region GA dissolves in liquid L supplied to liquid phase region LA by passing through hollow yarn membrane 21. This generates liquid L1, in which adjusting gas G is dissolved in liquid L and supplemented with adjusting gas. Preferably, the liquid L1 supplemented with adjusting gas is a liquid saturated with adjusting gas, in which adjusting gas G is dissolved in liquid L in a saturated state. That is, preferably, the supply pressure of the adjusting gas G and the flow rate of the liquid L distributed to the upstream module via pipe 71 are adjusted by dissolving the adjusting gas G in the liquid L in a saturated state. The so-called saturated state is not only a completely saturated state, but also includes a state close to saturation. The state close to saturation refers to the state in which the adjusting gas G is dissolved in the liquid L to such an extent that the specific resistance of the liquid L can be adjusted by using only the distribution ratio of the liquid L between the upstream module via pipe 71 and bypass pipe 8.

[0071] Subsequently, liquid L1, supplemented with adjusting gas, is discharged from the liquid phase region LA of the hollow yarn film module 2 to the downstream module via pipe 72. The liquid L1 supplemented with adjusting gas discharged from the liquid phase region LA of the hollow yarn film module 2 to the downstream module via pipe 72 merges with the liquid L distributed to the bypass pipe 8 in the merging module 12. This generates a resistivity-adjusting liquid L2 with adjusted resistivity. The generated resistivity-adjusting liquid L2 is then discharged from the liquid discharge pipe 4. Furthermore, adjusting gas G from the gas phase region GA of the hollow yarn film module 2 can also be discharged from the gas discharge pipe 6 by opening valve 6A.

[0072] Thus, in the resistivity adjustment device 1 of this embodiment, the bypass pipe 8 has a laminarization section 8A comprising a plurality of thin tubes 8C that are thinner than those in the module via pipe 7, thereby enabling the flow of liquid L in the bypass pipe 8 to become laminar. In the case of laminar flow, the pressure loss of the liquid is proportional to the flow rate of the liquid. Even if it is not laminar flow, the closer the flow is from turbulent to laminar flow, the closer the pressure loss of the liquid is to the flow rate of the liquid. On the other hand, the flow rate of liquid L supplied to the module via pipe 7 is smaller than the flow rate of liquid L supplied to the bypass pipe 8. Therefore, when comparing the pressure loss of liquid L in the bypass pipe 8, regardless of whether the liquid L flowing in the module via pipe 7 and the hollow yarn film module 2 is turbulent, the pressure loss of liquid L in the module via pipe 7 and the hollow yarn film module 2 can be considered proportional to the flow rate of liquid L. That is, the tendency of the pressure loss of liquid L in the bypass pipe 8 is close to the tendency of the pressure loss of liquid L in the module via pipe 7 and the hollow yarn film module 2. Therefore, even if the flow rate of liquid L supplied to the resistivity adjustment device 1 varies, changes in the distribution ratio of liquid L between the module via pipe 7 and the bypass pipe 8 can be suppressed, thus suppressing changes in the resistivity of the resistivity adjustment liquid. In particular, even if the flow rate of liquid L supplied to the resistivity adjustment device 1 becomes small, the increase in the distribution ratio of liquid L between the bypass pipe 8 and the module via pipe 7 can be suppressed, thereby suppressing an increase in the resistivity of the resistivity adjustment liquid L2. Thus, for a simple structure, changes in the resistivity of the resistivity adjustment liquid L2 can be suppressed even if the flow rate of the supplied liquid L varies.

[0073] Furthermore, in the resistivity adjustment device 1, the laminar fluidization section 8A is set to a laminar flow mode when ultrapure water is supplied to the bypass pipe 8 at a specified flow rate as liquid L. This allows the laminar fluidization section 8A to be easily designed, and even if the flow rate of the supplied liquid L changes, the change in resistivity of the resistivity adjustment liquid L2 can be further suppressed.

[0074] Furthermore, in the resistivity adjustment device 1, the laminar fluidization section 8A is set such that when ultrapure water is supplied to the bypass pipe 8 at a specified flow rate as liquid L, the Reynolds number in the laminar fluidization section 8A is 2300 or less. This makes it easy to design the laminar fluidization section 8A, and even if the flow rate of the supplied liquid L changes, the change in the resistivity of the resistivity adjustment liquid L2 can be further suppressed.

[0075] Furthermore, in the resistivity adjustment device 1, the number of thin tubes 8C in the laminar fluidization section 8A is 5 or more, preferably 50 or more, more preferably 100 or more, and even more preferably 500 or more, thereby ensuring the flow rate of the liquid in the laminar fluidization section and making it easy for the flow of the liquid in the laminar fluidization section to become laminar flow.

[0076] Furthermore, in the resistivity adjustment device 1, the inner diameter of each of the plurality of thin tubes 8C is 0.01 mm or more and 10 mm or less, preferably 0.05 mm or more and 5 mm or less, and even more preferably 0.1 mm or more and 1 mm or less, thereby suppressing the pressure loss of the liquid L in the laminar fluidization section 8A from becoming too large or too small, and making it easy for the flow of the liquid in the laminar fluidization section 8A to become laminar flow.

[0077] Furthermore, in the resistivity adjustment device 1, by having the length of each of the multiple thin tubes 8C be 1 mm or more and 1000 mm or less, preferably 5 mm or more and 500 mm or less, and even more preferably 10 mm or more and 100 mm or less, the pressure loss of the liquid L in the laminarization section 8A can be suppressed from becoming too large or too small.

[0078] Furthermore, in the resistivity adjustment device 1, by making the length of the laminarization section 8A at or above 1%, preferably at or above 10%, and even more preferably at or above 50%, the flow of liquid in the bypass pipe 8 can be easily made into laminar flow.

[0079] Furthermore, the resistivity adjustment device 1, by including the branch module 11 and the confluence module 12, can easily realize the branching structure from the liquid supply pipe 3 to the upstream module via the pipe 71 and the bypass pipe 8, and the confluence structure from the downstream module to the liquid discharge pipe 4 via the pipe 72 and the bypass pipe 8. In particular, the bypass pipe 8 has a laminarization section 8A containing multiple thin tubes 8C, so the bypass pipe 8 can be easily connected to the liquid supply pipe 3 and the liquid discharge pipe 4 by passing through the branch module 11 and the confluence module 12. Moreover, by extending the laminarization section 8A from the branch module 11 to the confluence module 12, the laminarization section 8A can be easily formed, and the flow of liquid L in the laminarization section 8A can easily become laminar flow.

[0080] Furthermore, the resistivity adjustment device 1 includes a gas supply pipe 5 and a gas discharge pipe 6, which allows for easy supply and discharge of adjustment gas G to the gas phase side region GA of the hollow yarn film module 2.

[0081] Furthermore, the resistivity adjustment device 1 includes a valve 9, which allows for easy adjustment of the liquid L flow distribution ratio between the module via pipe 7 and the bypass pipe 8. Moreover, since the valve 9 is installed in the module via pipe 7, it prevents the laminar flow of the bypass pipe 8 from being obstructed by the valve 9.

[0082] In this embodiment of the resistivity adjustment method, liquid L is supplied to the liquid supply pipe 3 in the resistivity adjustment device 1, and adjusting gas G is supplied to the gas phase side region GA of the hollow yarn film module 2, thereby adjusting the resistivity of liquid L. This provides a simple structure, and even if the flow rate of the supplied liquid L changes, the change in the resistivity of the resistivity adjustment liquid L2 can be suppressed.

[0083] The embodiments of the present invention have been described above, but the present invention is not limited to the described embodiments.

[0084] For example, in the embodiment described, the resistivity adjustment device 1 is described as including a gas supply pipe 5 and a gas discharge pipe 6. However, as long as the adjusting gas G can be supplied to the gas phase side region GA of the hollow yarn film module 2, the resistivity adjustment device 1 may also be configured to not include at least one of the gas supply pipe 5 and the gas discharge pipe 6.

[0085] Furthermore, in the described embodiment, the resistivity adjustment device 1 is described with valve 9 included. However, as long as the distribution ratio of liquid L between the module via pipe 7 and the bypass pipe 8 can be adjusted by means other than valve 9, the resistivity adjustment device 1 may also be provided without valve 9. Moreover, when the distribution ratio of liquid L between the module via pipe 7 and the bypass pipe 8 is not adjusted, the resistivity adjustment device 1 may also be provided without valve 9.

[0086] Furthermore, in the described embodiment, the resistivity adjustment device 1 is explained as including a branch module 11 and a merging module 12. However, as long as the liquid L supplied to the liquid supply pipe 3 can be distributed to the upstream module via pipe 71 and bypass pipe 8 by means different from the branch module 11 and merging module 12, and the liquid L1 supplied to the downstream module via pipe 72 with added adjusting gas can be merged with the liquid L supplied to the bypass pipe 8, the resistivity adjustment device 1 can also be configured to exclude at least one of the branch module 11 and merging module 12. In this case, the liquid supply pipe 3 can also be directly connected to the upstream module via pipe 71 and bypass pipe 8, and the liquid discharge pipe 4 can be directly connected to the downstream module via pipe 72 and bypass pipe 8. [Example]

[0087] The embodiments of the present invention will then be described, but the present invention is not limited to the following embodiments.

[0088] (Example 1) The resistivity adjustment device of Example 1 was fabricated. Except for the following aspects, the resistivity adjustment device of Example 1 is identical to the resistivity adjustment device 1 shown in Figures 1, 3, and 4. In the resistivity adjustment device of Example 1, SEPAREL PF-001L-NA manufactured by DIC Corporation is used as the hollow yarn film module. 9000 thin tubes with an outer diameter of 0.225 mm, an inner diameter of 0.175 mm, and a length of 110 mm are bundled together to form a laminarized layer containing multiple thin tubes. Furthermore, in the resistivity adjustment device of Example 1, the inner diameter of the liquid supply pipe is set to 10 mm, the inner diameter of the liquid discharge pipe is set to 10 mm, and the inner diameter of the module via pipes (upstream module via pipe and downstream module via pipe) is set to 4 mm.

[0089] (Comparative Example 1) A resistivity adjustment device for Comparative Example 1 was fabricated. The resistivity adjustment device for Comparative Example 1 was identical to that for Example 1, except that a tube with an outer diameter of 8 mm, an inner diameter of 6 mm, and a length of 110 mm was used as a bypass tube.

[0090] (evaluate) The following measurements were performed using the resistivity adjustment device of Example 1 and the resistivity adjustment device of Comparative Example 1, respectively. At room temperature (25°C), liquid at 25°C was supplied to the liquid supply pipe at a flow rate of 8 L, and adjusting gas at 25°C and 0.1 MPa was supplied to the gas supply pipe. The distribution ratio of the liquid through the module's via pipe and bypass pipe was adjusted by opening and closing the valve to achieve a predetermined resistivity value for the liquid used for resistivity adjustment. Ultrapure water was used as the liquid. Carbon dioxide was used as the adjusting gas. The predetermined resistivity values ​​were set to five conditions: 0.1 MΩ·cm, 0.4 MΩ·cm, 0.6 MΩ·cm, 0.8 MΩ·cm, and 1.0 MΩ·cm. Furthermore, with the valve in each resistivity value state, the flow rate of the liquid supplied to the liquid supply pipe was changed sequentially in 5-minute increments to 16 L / mm, 12 L / mm, 8 L / mm, 4 L / mm, and 1 L / mm, and the resistivity value of the liquid used for resistivity adjustment was measured. Furthermore, the pressure loss of the liquid in the bypass pipe was measured under the condition that the resistivity of the liquid was adjusted to 1.0 MΩ·cm. The measurement results of Example 1 are shown in Figure 5, and the measurement results of Comparative Example 1 are shown in Figure 6.

[0091] As shown in Figure 6, in the resistivity adjustment device of Comparative Example 1, when the resistivity of the liquid being adjusted is 0.1 MΩ·cm at a flow rate of 8 L, the change in resistivity with changes in liquid flow rate is small. However, under other flow rate conditions, the change in resistivity with changes in liquid flow rate becomes larger. In particular, the lower the liquid flow rate, the larger the change in resistivity.

[0092] In contrast, as shown in Figure 5, in the resistivity adjustment device of Embodiment 1, under any flow rate condition, the change in resistivity is small as the flow rate of the liquid changes, and even when the liquid flow rate is low, the change in resistivity is not significant.

[0093] The following measurements were performed using the resistivity adjustment device of Comparative Example 1. At room temperature (25°C), liquid at 25°C was supplied to the liquid supply pipe at a flow rate of 16 L, and adjusting gas at 25°C and 0.1 MPa was supplied to the gas supply pipe. The inner diameter and length of the bypass pipe were adjusted so that the pressure loss of the liquid in the bypass pipe was 0.09 Pa. Furthermore, at room temperature (25°C), liquid at 25°C was supplied to the liquid supply pipe at a flow rate of 8 L, and adjusting gas at 25°C and 0.1 MPa was supplied to the gas supply pipe. The liquid distribution ratio between the module via pipe and the bypass pipe was adjusted by opening and closing the valve so that the resistivity of the liquid was adjusted to 1.0 MΩ·cm. Ultrapure water was used as the liquid. Carbon dioxide was used as the adjusting gas. The pressure loss of the liquid in the module via pipe and the bypass pipe was measured by varying the flow rate of the liquid supplied to the liquid supply pipe from 16 L / mm to 0.7 L / mm. The pressure loss of the liquid in the module via pipe and bypass pipe is defined as the pressure loss of the liquid from the upstream module via pipe through the hollow yarn membrane module to the downstream module via pipe. The measurement results are shown in Figure 7. In Figure 7, the pressure loss of the liquid in the bypass pipe when the liquid in the bypass pipe is in laminar flow is illustrated as a reference.

[0094] As shown in Figure 7, in the resistivity adjustment device of Comparative Example 1, the liquid in the bypass pipe becomes turbulent, and therefore the pressure loss of the liquid in the bypass pipe is an exponential function of the liquid flow rate. On the other hand, the flow rate of the liquid supplied to the module via pipe is smaller than the flow rate of the liquid supplied to the bypass pipe. Therefore, compared to the pressure loss of the liquid in the bypass pipe, regardless of whether the liquid flowing in the module via pipe and the hollow yarn membrane module is turbulent, the pressure loss of the liquid in the module via pipe and the hollow yarn membrane module can be considered proportional to the liquid flow rate. That is, the tendency of pressure loss is very different for the liquid in the bypass pipe and the liquid in the module via pipe and the hollow yarn membrane module.

[0095] For example, when a liquid with a flow rate of 16 L / min is supplied to the bypass pipe, the pressure loss of the liquid in the bypass pipe is approximately 0.09 Pa, regardless of whether the liquid flow in the bypass pipe is turbulent or laminar. However, when a liquid with a flow rate of 7 L / min, which is less than 16 L / min, is supplied to the bypass pipe, the pressure loss of the liquid in the bypass pipe with laminar flow is approximately 0.04 Pa, compared to approximately 0.015 Pa in the bypass pipe with turbulent flow. That is, the pressure loss of the liquid in the bypass pipe is smaller when the liquid flow is turbulent compared to when the liquid flow is laminar. As a result, the liquid distribution ratio of the bypass pipe to the module via pipe becomes larger. Furthermore, when a liquid with a flow rate greater than 16 L / min is supplied to the bypass pipe, the opposite trend occurs.

[0096] Therefore, as shown in Figure 6, in the resistivity adjustment device of Comparative Example 1, it can be assumed that with the change in the flow rate of the supplied liquid, the liquid distribution ratio between the module via pipe and the bypass pipe changes (is disrupted), and the resistivity of the resistivity adjustment liquid changes. In particular, it can be assumed that if the liquid supplied to the resistivity adjustment device becomes a small flow rate, the liquid distribution ratio of the bypass pipe to the module via pipe increases, and the resistivity of the resistivity adjustment liquid increases.

[0097] In contrast, in the resistivity adjustment device of Example 1, the flow of liquid in the bypass pipe becomes laminar compared to the resistivity adjustment device of Comparative Example 1. Therefore, the pressure loss of liquid in the bypass pipe is proportional to the flow rate of liquid. That is, the pressure loss of liquid in the bypass pipe tends to be similar to the pressure loss of liquid in the module via pipe and the hollow yarn membrane module.

[0098] Therefore, as shown in Figure 5, in the resistivity adjustment device of Embodiment 1, it can be considered that even if the flow rate of the supplied liquid changes, the change in the liquid distribution ratio between the module via pipe and the bypass pipe is suppressed, thereby suppressing the change in the resistivity of the resistivity adjustment liquid. In particular, it can be considered that even if the liquid supplied to the resistivity adjustment device becomes a small flow rate, the increase in the liquid distribution ratio between the bypass pipe and the module via pipe is suppressed, thus suppressing the increase in the resistivity of the resistivity adjustment liquid.

[0099] 1: Specific resistance adjustment device 2: Hollow yarn film module 3: Liquid supply pipe 3A, 4A, 8D, 11A, 12A, 71A, 72A: Flow paths 4: Liquid discharge pipe 5: Gas supply pipe 6: Gas exhaust pipe 6A, 9: Valve 7: Module via pipe 8: Bypass pipe 8A: Laminar fluidization section 8B: Bypass housing 8C: Thin tube 8E: First sealing part 8F: Upstream side end face 8G: Second sealing part 8H: Downstream side end face 11: Branch Module 12: Merging Module 21: Hollow yarn film 22: Outer shell 22A: Liquid supply port 22B: Liquid discharge outlet 22C: Gas supply port 22D: Gas exhaust outlet 71: Upstream module via pipe 72: Downstream module via pipe FD: Flow direction G: Adjust the gas GA: Gas Phase Side Region L: Liquid L1: Liquid with added conditioning gas L2: Liquid for adjusting resistivity LA: Liquid phase side region

Claims

1. A resistivity adjustment device, comprising: A hollow yarn membrane module is divided into a liquid phase region and a gas phase region by the hollow yarn membrane. The liquid phase region is supplied with a liquid for adjusting the resistivity, and the gas phase region is supplied with an adjusting gas for adjusting the resistivity of the liquid. The module includes: a liquid supply pipe; a liquid discharge pipe; a module via pipe communicating with the liquid phase region, the liquid supply pipe, and the liquid discharge pipe of the hollow yarn membrane module, and passing through the hollow yarn membrane module; and a bypass pipe communicating with the liquid supply pipe and the liquid discharge pipe, bypassing the hollow yarn membrane module. The bypass pipe has a laminarization section comprising a plurality of thinner tubes than the module via pipe, wherein the flow rate of the liquid supplied to the module via pipe is smaller than the flow rate of the liquid supplied to the bypass pipe.

2. The resistivity adjustment device as claimed in claim 1, wherein the laminarization section is configured such that when ultrapure water is supplied as the liquid to the bypass pipe at a predetermined flow rate, the liquid in the laminarization section becomes laminar.

3. The resistivity adjustment device as described in claim 1 or claim 2, wherein the laminar fluidization section is configured such that when ultrapure water is supplied to the bypass pipe at a predetermined flow rate as the liquid, the Reynolds number in the laminar fluidization section is 2300 or less.

4. The resistivity adjustment device as described in claim 1 or claim 2, wherein the number of the plurality of thin tubes is 5 or more.

5. The resistivity adjustment device as claimed in claim 1 or claim 2, wherein the inner diameter of each of the plurality of thin tubes is 0.01 mm or more and 10 mm or less.

6. The resistivity adjustment device as claimed in claim 1 or claim 2, wherein the length of each of the plurality of thin tubes is more than 1 mm and less than 1000 mm.

7. The resistivity adjustment device as described in claim 1 or claim 2, wherein the length of the laminarization section is more than 1% of the length of the bypass tube.

8. The resistivity adjustment device as described in claim 1 or claim 2, further comprising: A branch module is connected to the liquid supply pipe, the module via pipe, and the bypass pipe, thereby connecting the liquid supply pipe, the module via pipe, and the bypass pipe; and a confluence module is connected to the liquid discharge pipe, the module via pipe, and the bypass pipe, thereby connecting the liquid discharge pipe, the module via pipe, and the bypass pipe, wherein the laminarization section extends from the branch module to the confluence module.

9. The resistivity adjustment device as described in claim 1 or claim 2, further comprising: A gas supply pipe is connected to the gas phase side region in order to supply the conditioning gas to the gas phase side region; And a gas discharge pipe, which is connected to the gas phase side region in order to discharge the adjusting gas from the gas phase side region.

10. The resistivity adjustment device as described in claim 1 or claim 2, further comprising: A valve, installed on the module via pipe, is used to adjust the liquid distribution ratio between the module via pipe and the bypass pipe.

11. A method for adjusting resistivity, comprising, in any one of claims 1 to 10, supplying the liquid to the liquid supply pipe and supplying the adjusting gas to the gas phase side region of the hollow yarn film module, thereby adjusting the resistivity of the liquid.

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