Water supply device and water supply method for hydrogen water

Abstract

The present invention provides a tap water hydrogen water supply device and tap water hydrogen water supply method that ensures that dissolved hydrogen gas does not separate as gas bubbles until the hydrogen water is used, and that hydrogen water with a predetermined concentration or higher can always be obtained, regardless of the amount of hydrogen water taken out at any given time. [Solution] A water hydrogen water supply device is provided that is directly connected to a water supply and supplies tap water from this water supply in a single pass. This water hydrogen water supply device comprises a hydrogen gas generating means that generates hydrogen gas by electrolysis, and a hydrogen gas dissolving means that has a gas separation hollow fiber membrane, and tap water is supplied inside the gas separation hollow fiber membrane, and hydrogen gas to be dissolved is supplied from the hydrogen gas generating means to the outside of the gas separation hollow fiber membrane, and the pressure of the hydrogen gas outside the gas separation hollow fiber membrane is set lower than the water pressure of the hydrogen water generated after passing through the gas separation hollow fiber membrane.

Description

[Technical Field]

[0001] The present invention relates to a water hydrogen water supply device and a water hydrogen water supply method for generating and supplying hydrogen water by dissolving hydrogen gas in tap water at a predetermined concentration or higher. In particular, the present invention relates to a water hydrogen water supply device and a water hydrogen water supply method that are suitable for generating water hydrogen water for drinking, cooking, washing the face, and bathing, by dissolving hydrogen gas in tap water at a predetermined concentration or higher for household use, and are also suitable for generating medical hydrogen water used in hemodialysis and the like. [Background technology]

[0002] Conventional hydrogen water supply devices (e.g., hydrogen water servers) that generate and supply hydrogen water produce and supply hydrogen water by first pre-treating tap water according to its intended use (e.g., activated carbon filtration), and then dissolving hydrogen gas into it.

[0003] Patent Document 1 discloses an apparatus for producing hydrogen water for hemodialysis, which involves pre-treating raw water with processes such as water softening and activated carbon filtration, then performing reverse osmosis (RO) treatment on the pre-treated water to obtain reverse osmosis water, and finally dissolving hydrogen in this reverse osmosis water by electrolysis in an electrolytic water generation unit to produce hydrogen water for medical use.

[0004] Furthermore, Patent Document 2 discloses an electrolytic water production apparatus for hemodialysis, which comprises an electrolytic water production apparatus that obtains electrolytic water by electrolyzing pre-treated water, which has been treated to soften raw water, to dissolve hydrogen, and a reverse osmosis membrane apparatus (RO apparatus) that performs reverse osmosis treatment on the obtained electrolytic water.

[0005] In the apparatus disclosed in Patent Documents 1 and 2, since hydrogen is dissolved in pre-treated water, bacteria may grow in the hydrogen dissolution apparatus, and it was necessary to periodically sterilize and clean this hydrogen dissolution apparatus.

[0006] If a tap water hydrogen water supply system is used that generates hydrogen water by dissolving hydrogen gas directly into tap water without any pretreatment, then the hydrogen gas will dissolve while retaining residual chlorine, eliminating the need for periodic sterilization and cleaning processes within the hydrogen gas dissolution system.

[0007] Patent Document 3 discloses a hydrogen water supply device in which tap water from a directly connected water supply is passed through in a single pass. This hydrogen water supply device generates hydrogen water by dissolving the supplied hydrogen gas in tap water using a gas separation hollow fiber membrane. In particular, in this hydrogen water supply device, the gas pressure of the hydrogen gas supplied to the gas separation hollow fiber membrane and the water pressure of the tap water supplied to the gas separation hollow fiber membrane when the tap water supply valve and the hydrogen water extraction valve are closed are controlled to be approximately the same pressure. This configuration ensures that hydrogen water with a predetermined concentration or higher can always be obtained, regardless of the amount of hydrogen water extracted at any given time. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Patent No. 5940689 [Patent Document 2] Patent No. 6017911 [Patent Document 3] Patent No. 6185445 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] However, the hydrogen water supply device disclosed in Patent Document 3 is a device that generates and supplies hydrogen water for drinking. Therefore, when hydrogen water is taken out of this device, dissolved gases are released due to a pressure drop such as venting to the atmosphere, causing a large amount of bubbles to float to the surface. Furthermore, in order to use such a hydrogen water supply device for supplying medical hydrogen water used in hemodialysis, etc., it is necessary to implement special measures in the raw water pretreatment process before the reverse osmosis membrane treatment device (RO device) so that dissolved hydrogen does not float to the surface as bubbles even if the water pressure of the tap hydrogen water drops when it passes through the raw water pretreatment device.

[0010] Therefore, the object of the present invention is to provide a water hydrogen water supply device and a water hydrogen water supply method that can supply tap water with a sufficient concentration of dissolved hydrogen gas when tap water is used as raw water, and in particular, to provide a water hydrogen water supply device and a water hydrogen water supply method that can always obtain hydrogen water with a predetermined concentration or higher, even when any amount of hydrogen water is taken out at any time, without the dissolved hydrogen gas separating as gas bubbles until the time the hydrogen water is used. [Means for solving the problem]

[0011] The present invention provides a water hydrogen water supply device that is directly connected to a water supply and supplies tap water from this water supply in a single pass. This water hydrogen water supply device comprises a hydrogen gas generating means that generates hydrogen gas by electrolysis, and a hydrogen gas dissolving means that has a gas separation hollow fiber membrane, and is configured such that tap water is supplied inside the gas separation hollow fiber membrane, and hydrogen gas to be dissolved is supplied from the hydrogen gas generating means to the outside of the gas separation hollow fiber membrane. In particular, in the present invention, the pressure of the hydrogen gas outside the gas separation hollow fiber membrane is set lower than the water pressure of the hydrogen water generated after passing through the gas separation hollow fiber membrane.

[0012] Because the hydrogen gas pressure outside the gas separation hollow fiber membrane is lower than the water pressure of the hydrogen water produced after passing through the membrane, the dissolved gas in the produced hydrogen water is prevented from becoming supersaturated and forming bubbles due to the drop in water pressure. In other words, by not dissolving under pressure, the generation of bubbles in the hydrogen water path can be suppressed. In this way, in order to dissolve hydrogen gas in tap water inside the gas separation hollow fiber membrane, the differential pressure of the tap water passing through the inside of the gas separation hollow fiber membrane is increased, and the negative pressure of the tap water is used to dissolve the hydrogen gas. Furthermore, by generating hydrogen gas by this electrolysis method, hydrogen gas cylinders become unnecessary, saving the trouble of replacing them and allowing for a stable supply of hydrogen gas. In addition, since hydrogen gas cylinders are not used, there is no need to employ a high-pressure gas handling supervisor or be subject to safety laws such as storage facility standards, making compliance simpler.

[0013] Preferably, the system further includes a control means for controlling the electrolysis of the hydrogen gas generating means so that the pressure of the hydrogen gas supplied to the hydrogen gas dissolution means is lower than the water pressure of the hydrogen-rich tap water produced. A configuration in which the electrolysis is controlled (on / off) by the control means to control the gas pressure results in a simple device configuration and therefore lower manufacturing costs.

[0014] It is also preferable to further include a means for removing water vapor components from the hydrogen gas generated by the hydrogen gas generation means. If water vapor components are present in the hydrogen gas, condensation will occur when the hydrogen gas comes into contact with the outer surface of the gas separation hollow fiber membrane, causing water to adhere to the surface and forming a water film. In order to dissolve hydrogen gas in tap water under these conditions, it is necessary to implement a pressurized dissolution method in which the gas pressure of the hydrogen gas is made higher than the water pressure of the hydrogen water produced after passing through the gas separation hollow fiber membrane. However, with a pressurized dissolution method, the hydrogen gas pressure is adjusted to a pressure higher than the pressure at which the tap water passes through, which carries the risk of excessive dissolution of hydrogen gas, and a subsequent pressure drop may lead to the generation of bubbles.

[0015] In this case, it is more preferable that the water vapor component removal means is configured by combining a gas-water separator and a humidity control tube.

[0016] When producing medical hydrogen water, it further includes filtration means for filtering the produced tap water hydrogen water, and the control means is configured to control the electrolysis of the hydrogen gas generation means so that the pressure of the hydrogen gas supplied to the hydrogen gas dissolution means is as low as possible than the water pressure of the tap water hydrogen water output from the filtration means. This can prevent the occurrence of a situation where bubbles are generated due to excessive dissolution of hydrogen gas due to the pressure drop caused by the resistance of the filtration means even when the filtration means is connected after the tap water hydrogen water supply device. When such bubbles are generated, in a closed system, the bubbles will remain as gas until the next pressurization, storing a lot of gas in the filtration means and thus unable to obtain the original water treatment capacity.

[0017] When producing medical hydrogen water, it further includes ion exchange means for ion-exchanging the produced tap water hydrogen water, and the control means is configured to control the electrolysis of the hydrogen gas generation means so that the pressure of the hydrogen gas supplied to the hydrogen gas dissolution means is as low as possible than the water pressure of the tap water hydrogen water output from the ion exchange means. This can prevent the occurrence of a situation where bubbles are generated due to excessive dissolution of hydrogen gas due to the pressure drop caused by the resistance of the ion exchange means even when the ion exchange means for softening hard water is connected after the tap water hydrogen water supply device. When such bubbles are generated, in a closed system, the bubbles will remain as gas until the next pressurization, storing a lot of gas in the ion exchange means and thus unable to obtain the original water treatment capacity.

[0018] According to the present invention, there is further provided a method for supplying tap water hydrogen water, which electrolyzes water to generate hydrogen gas, supplies tap water to the inside of the gas separation hollow fiber membrane and supplies hydrogen gas to be dissolved to the outside of the gas separation hollow fiber membrane, and controls the pressure of the hydrogen gas on the outside of the gas separation hollow fiber membrane to be lower than the water pressure of the generated hydrogen water after passing through the gas separation hollow fiber membrane.

[0019] Since the pressure of hydrogen gas outside the gas separation hollow fiber membrane is lower than the water pressure of the generated hydrogen-rich water after passing through the gas separation hollow fiber membrane, it is possible to prevent the dissolved gas in the generated hydrogen-rich water from becoming supersaturated due to the decrease in water pressure and forming bubbles. That is, it is possible to prevent bubbles from generating in the hydrogen-rich water path. Thus, in order to dissolve hydrogen gas in tap water inside the gas separation hollow fiber membrane, the differential pressure of tap water passing through the inside of the gas separation hollow fiber membrane is increased, and hydrogen gas is dissolved by utilizing the negative pressure during tap water passage. Also, by generating hydrogen gas through such electrolysis, a hydrogen gas cylinder becomes unnecessary, saving the labor of its replacement and enabling the supply of stable hydrogen gas. Furthermore, since a hydrogen gas cylinder is not used, there is no need to be subject to the application of safety laws such as the employment of a high-pressure gas handling supervisor and storage facility standards, making the application simple.

[0020] It is also preferable to remove the water vapor component from the generated hydrogen gas. When a water vapor component exists in the hydrogen gas, a dew condensation phenomenon appears when the hydrogen gas contacts the outer surface of the gas separation hollow fiber membrane, and water adheres to that surface to generate a water film. In order to dissolve hydrogen gas in tap water in such a state, it is necessary to implement a pressure dissolution method in which the gas pressure of the hydrogen gas is made higher than the water pressure of the generated hydrogen-rich water after passing through the gas separation hollow fiber membrane. However, according to the pressure dissolution method, since the hydrogen gas pressure needs to be adjusted higher than the tap water passage pressure, there is a risk of excessive dissolution of hydrogen gas, and when a pressure drop occurs later, there is a risk of causing the generation of bubbles.

[0021] It is also preferable to control the electrolysis so that the pressure of the supplied hydrogen gas is lower than the water pressure of the generated tap water hydrogen-rich water. Thereby, even if there is a decrease in the water pressure of the finally generated tap water hydrogen-rich water, bubbles do not generate.

Advantages of the Invention

[0022] According to the present invention, since the pressure of hydrogen gas outside the gas separation hollow fiber membrane is set lower than the water pressure of the hydrogen water produced after passing through the gas separation hollow fiber membrane, it is possible to suppress the formation of bubbles due to supersaturation of the dissolved gas in the produced hydrogen water as a result of the decrease in water pressure. In other words, by preventing dissolution under pressure, the generation of bubbles in the hydrogen water pathway can be suppressed. [Brief explanation of the drawing]

[0023] [Figure 1] This is a block diagram schematically showing the overall configuration of a water hydrogen water supply device according to one embodiment of the present invention. [Figure 2] Figure 1 shows a flowchart illustrating an example of the control program flow for the control circuit in the embodiment shown. [Figure 3] This is a block diagram schematically showing the overall configuration of a water hydrogen water supply device according to a modified embodiment of the example shown in Figure 1. [Figure 4] This is a block diagram schematically showing the overall configuration of the tap water hydrogen water supply device in Embodiment 1 of the present invention. [Figure 5] This graph shows the change in dissolved hydrogen concentration over time when hydrogen gas pressure control (on / off operation electrolysis control) is performed in Example 1. [Figure 6] This graph shows the dissolved hydrogen concentration corresponding to the hydrogen gas pressure, the saturated hydrogen concentration corresponding to the tap water pressure, the line for the observation point water pressure of 100 kPa, and the line for the saturated hydrogen concentration at a tap water pressure of 100 kPa in Example 1. [Figure 7] This graph shows the change in dissolved hydrogen concentration over time when hydrogen gas pressure control (on / off operation electrolysis control) is performed in Example 1 and Comparative Example 2, the change in dissolved hydrogen concentration over time when hydrogen gas pressure control (on / off operation electrolysis control) is performed in Example 1, and the saturated hydrogen concentration line at a tap water pressure of 100 kPa. [Figure 8] This graph shows the dissolved hydrogen concentration corresponding to the hydrogen gas pressure in Example 1, the saturated hydrogen concentration corresponding to the tap water pressure, the line for the observation point water pressure of 100 kPa, the line for the saturated hydrogen concentration at a tap water pressure of 100 kPa, and the dissolved hydrogen concentration in Comparative Example 4. [Figure 9] This graph shows the change in saturated hydrogen concentration over time when continuous operation was performed in Example 4. [Figure 10] This graph shows the change in saturated hydrogen concentration over time when water intake was repeatedly performed in Example 4, with a cycle of "30 seconds of water intake / 30 seconds of shut-off". [Modes for carrying out the invention]

[0024] Before describing embodiments of the present invention, the theory of hydrogen gas dissolution in tap water will be explained below.

[0025] Tap water is purified at a water treatment plant after being exposed to the atmosphere, then pressurized and supplied to the point of use. Before pressurization, tap water is in contact with the atmosphere at atmospheric pressure, so the solubility of oxygen and nitrogen in tap water is a partial pressure ratio of 1 part oxygen to 4 parts nitrogen, and varies depending on the water temperature. Table 1 shows the saturation concentrations of hydrogen, oxygen, and nitrogen at a water temperature of 20°C. [Table 1]

[0026] In a water treatment plant, the gas is compressed while maintaining its solubility. According to Henry's Law, this means there is room for approximately the gauge pressure of gas to dissolve. For example, at a water temperature of 20°C, the atmospheric pressure saturation solubility of hydrogen gas alone (100 kPa) is 1.62 mg / L. Calculating the amount of hydrogen gas that can dissolve, we obtain the soluble concentrations shown in Table 2. [Table 2] In typical water treatment systems, the tap water supply gauge pressure is required to be 100 kPa or higher, which means that a dissolved hydrogen concentration of 1.6 mg / L (20°C) or higher can be dissolved. Since the supplied tap water has a gauge pressure of 200 kPa or higher, it is possible to dissolve 3.2 mg / L of dissolved hydrogen. However, a method has been found to dissolve 1.6 mg / L, and stable dissolution is maintained within the supply path. Specifically, hydrogen gas is dissolved in the cavities shown in Table 2.

[0027] Regarding stable dissolution within the pathway, it was found that, similar to how the dissolved oxygen concentration of tap water does not change even when it passes through membrane filters, ion exchange resin towers, or activated carbon filtration towers, the dissolved hydrogen concentration also does not change as long as the water pressure is maintained above the dissolution pressure concentration. Therefore, a configuration was obtained for a tap water hydrogen water supply system in which hydrogen gas is dissolved under negative pressure by passing tap water through a gas separation hollow fiber membrane according to Henry's Law, and no gas bubbles are generated even if the water pressure decreases due to water treatment equipment within the pathway.

[0028] Furthermore, by determining the gauge pressure at the desired dissolved hydrogen concentration from Table 2 and adjusting the pressure reducing valve at the tap water inlet of the tap water hydrogen water supply device so that the gauge pressure at or above that gauge pressure becomes the tap water hydrogen water supply gauge pressure, the desired dissolved hydrogen concentration can be easily obtained.

[0029] Embodiments of the present invention will be described below.

[0030] Figure 1 schematically shows the overall configuration of a water hydrogen water supply device 100 according to one embodiment of the present invention. This embodiment is a water hydrogen water supply device that does not have a hydrogen gas storage tank in the hydrogen gas generator portion. The water hydrogen water supply device 100 of this embodiment is directly connected to the water supply and produces hydrogen water by dissolving hydrogen gas in tap water supplied from the water supply, and can be used to produce medical hydrogen water used for hemodialysis, etc.

[0031] As shown in Figure 1, the water hydrogen water supply device 100 of this embodiment comprises a hydrogen gas generator (corresponding to the hydrogen gas generation processing means of the present invention) 10 consisting of an electrolysis device and not having a hydrogen gas storage tank, a water vapor component removal device 11 connected to the hydrogen gas generator 10, a hydrogen gas dissolution device (corresponding to the hydrogen gas dissolution means of the present invention) 15 whose gas inlet 15a is connected to the water vapor component removal device 11 via a manual valve (or solenoid valve) 12 and a flow path 14, and a control circuit 16. The water inlet 100a of the water hydrogen water supply device 100 is connected to the water supply via a flow path 17, and the water inlet 15b of the hydrogen gas dissolution device 15 is connected to this water inlet 100a via a solenoid valve 18, a pressure reducing valve 19, a flow path 20, a flow meter 21, and a flow path 22, which are water supply valves. The hydrogen water outlet 15c of the hydrogen gas dissolution device 15 is connected to the hydrogen water outlet 100b of the water hydrogen water supply device 100 via a flow path 23. The condensation outlet 15d of the hydrogen gas dissolution device 15 is connected to the condensation outlet 100c of the tap water hydrogen water supply device 100 via the flow path 24 and the condensation discharge valve 25. A device (not shown) for measuring the amount of condensation is connected to this condensation outlet 100c.

[0032] A tap water pressure gauge 26 is installed in the water channel 20 through which tap water is supplied, and a water thermometer 27 is installed in the water channel 22 further down the channel to detect the temperature of the tap water supplied to the hydrogen gas dissolution device 15. A supply hydrogen gas pressure gauge 28 is installed in the water channel 14 through which hydrogen gas is supplied to the hydrogen gas dissolution device 15 to detect the pressure of the hydrogen gas supplied to the hydrogen gas dissolution device 15. A tap water hydrogen water pressure gauge 29 is installed in the water channel 23 through which hydrogen water is output from the hydrogen gas dissolution device 15. A hollow fiber membrane hydrogen gas pressure gauge 30 is installed in the water channel 24 through which condensed water is output from the hydrogen gas dissolution device 15.

[0033] The hydrogen water outlet 100b of the tap water hydrogen water supply device 100 is sequentially connected to a hard water softener (corresponding to the ion exchange treatment means of the present invention) 31 that softens water by ion exchange treatment, an activated carbon filter (corresponding to the filtration treatment means of the present invention) 32, a flow path 33, a gas-liquid separator 34 for checking for bubbles, and a tap water hydrogen water extraction valve 35 which is a solenoid valve. The generated tap water hydrogen water is supplied to an RO device (not shown) via this tap water hydrogen water extraction valve 35. A manual valve (or solenoid valve) 36 is connected to the flow path 33 connected to the outlet of the activated carbon filter 32, and the tap water hydrogen water output from the activated carbon filter 32 is supplied to a concentration measuring device (not shown) via this manual valve 36. A manual valve (or solenoid valve) 37 is connected to the outlet of the hard water softener 31, and the tap water hydrogen water output from the hard water softener 31 is supplied to a concentration measuring device via this manual valve 37. Furthermore, a manual valve (or solenoid valve) 38 is connected to the hydrogen water outlet 100b of the tap water hydrogen water supply device 100, and the tap water hydrogen water output from the tap water hydrogen water supply device 100 is supplied to the concentration measuring device via this manual valve 38. In addition, a tap water hydrogen water pressure gauge 39 output from the activated carbon filter 32 is provided in the flow path 33.

[0034] The control circuit 16 (corresponding to the control means of the present invention), although not shown in the figures, is electrically connected to pressure gauges such as a tap water pressure gauge 26, a water thermometer 27, a supply hydrogen gas pressure gauge 28, a tap hydrogen water pressure gauge 29, a hollow fiber membrane hydrogen gas pressure gauge 30, and a tap hydrogen water pressure gauge 39. It is also electrically connected to the hydrogen gas generator 10, a tap water valve 18, a condensation water discharge valve 25, and a tap hydrogen water extraction valve 35.

[0035] The hydrogen gas generator 10 is an electrolysis device configured to produce hydrogen gas by electrolysis of water. This electrolysis device can electrolyze water and generate hydrogen gas only when and as needed, and can supply hydrogen gas safely and conveniently with simple operation. The control circuit 16 controls the start and stop (on / off) of electrolysis by the hydrogen gas generator 10, thereby adjusting the hydrogen gas pressure. Specifically, the start and stop (on / off) of electrolysis is controlled based on the detected pressure of the hydrogen gas pressure gauge 28, which is a digital control pressure gauge, and the hydrogen gas pressure is adjusted accordingly. In this embodiment, the hydrogen gas generator 10 is the DMHG electrolysis device (30 mL / min hydrogen gas, maximum pressure 200 kPa) from the hydrogen water server H2JV3 manufactured by Doctors Man Co., Ltd.

[0036] The water vapor component removal device 11 is configured by combining a first-stage mechanism that separates liquid and gas (water vapor and hydrogen gas) using a commercially available, known gas-liquid separation device, and a second-stage mechanism that removes the water vapor humidity portion from the gas (hydrogen gas and water vapor). The removal of water vapor humidity in the second-stage mechanism uses a dehumidifying tube that utilizes a hygroscopic resin membrane tube, such as the Nafion dehumidifying tube manufactured by Permapure, Inc., the Sunsep dehumidifying membrane module manufactured by AGC Engineering Inc., or the Moisture Control Tube manufactured by SMC Corporation.

[0037] The hydrogen gas dissolution device 15 dissolves supplied hydrogen gas in water via a hollow fiber membrane for gas separation. Tap water from a water supply is supplied to the inside of the gas separation hollow fiber membrane, and the hydrogen gas to be dissolved is supplied from the hydrogen gas generator 10 to the outside of the gas separation hollow fiber membrane. The gas separation hollow fiber membrane is a commercially available membrane that allows only gas to pass through and does not allow water to pass through. An important point in this embodiment is that the pressure of the hydrogen gas outside the gas separation hollow fiber membrane is set lower than the water pressure of the hydrogen water generated after passing through the gas separation hollow fiber membrane. This prevents the dissolved gas in the generated hydrogen water from becoming supersaturated and forming bubbles due to the decrease in water pressure. In other words, by not dissolving under pressure, the generation of bubbles in the hydrogen water path can be suppressed. Thus, in order to dissolve hydrogen gas in the tap water inside the gas separation hollow fiber membrane, the differential pressure of the tap water passing through the inside of the gas separation hollow fiber membrane is increased, and the hydrogen gas is dissolved by utilizing the negative pressure of the tap water passing through. In this embodiment, the hydrogen gas dissolution apparatus 15 uses the "SEPAREL" hollow fiber module membrane manufactured by DIC Corporation and the "Nagasep" hollow fiber gas separation membrane manufactured by Nagayanagi Industries Co., Ltd., but other hollow fiber degassing membranes and hollow fiber gas separation membranes can also be used.

[0038] A water thermometer 27 is connected to the flow path 22 connected to the water inlet of the hydrogen gas dissolution device 15. The water thermometer 27 detects the temperature T of the supplied tap water, that is, the temperature of the water applied to the gas separation hollow fiber membrane of the hydrogen gas dissolution device 15, and outputs a water temperature signal. This water temperature signal detected by the water thermometer 27 is sent to the control circuit 16.

[0039] In this embodiment, the hydrogen gas generator 10 is an electrolysis device controlled on / off by a control circuit 16. This electrolysis device can generate hydrogen gas by electrolyzing water as needed, and can supply hydrogen gas safely and conveniently with simple operation. The hydrogen gas pressure is adjusted by the control circuit 16 controlling the start and stop (on / off) of electrolysis by the hydrogen gas generator 10.

[0040] In this embodiment, a water softener 31 using a water softener cartridge containing 350 mL of Diaion SK-1B is used for ion exchange treatment, but a pure water system may be used instead of the water softener.

[0041] Furthermore, in this embodiment, an activated carbon filter 32 made from a Mariage activated carbon filter cartridge manufactured by Doctors Man Co., Ltd. is used for the filtration process. However, a sand filter for water, other filter filtration devices, or membrane filtration devices may be used instead of the activated carbon filter 32.

[0042] Furthermore, in this embodiment, a transparent PVC gas-liquid separator 34 with a diameter of 25 mm and a height of 110 mm (capacity of 54 mL) is used.

[0043] The tap water hydrogen water extraction valve 35 is a solenoid valve controlled by a control circuit 16 to open when tap water hydrogen water generated by the hydrogen gas dissolution device 15 is extracted, and to remain open when tap water hydrogen water is supplied. As mentioned above, this tap water hydrogen water extraction valve 35 is installed downstream of the tap water hydrogen water pressure gauge 39, and may be configured to be manually controlled when extracting hydrogen water.

[0044] The tap water shut-off valve 18 is a solenoid valve controlled by a control circuit 16 to open when tap water is supplied to the hydrogen gas dissolution device 15 and to remain open when tap hydrogen water is supplied. As mentioned above, this tap water shut-off valve 18 is installed in the flow path 17, which is the tap water inflow path from the water supply.

[0045] The control circuit 16, although not shown in the diagram, includes, for example, a CPU, ROM, RAM, an operation unit, and a display unit. The CPU is configured to control the operation of the tap water hydrogen water supply device 100 according to a control program stored in ROM, using the RAM as a work area. Detection signals from the tap water pressure gauge 26, water temperature gauge 27, supply hydrogen gas pressure gauge 28, tap water hydrogen water pressure gauge 29, hollow fiber membrane hydrogen gas pressure gauge 30, and tap water hydrogen water pressure gauge 39 are input to this control circuit 16, and drive signals are output to the hydrogen gas generator 10, tap water valve 18, condensation water discharge valve 25, and tap water hydrogen water extraction valve 35.

[0046] The operation of the tap water hydrogen water supply device 100 in this embodiment will be described below.

[0047] Figure 2 shows an example of the hydrogen gas pressure control program for the control circuit 16.

[0048] Upon receiving a signal to begin the hydrogen water supply operation, the CPU first opens the tap water supply valve 18 and the hydrogen water extraction valve 35 (step S1), and continues operation in this state until a signal to end the tap water supply operation is received. Prior to this, the condensation water discharge valve 25 and the manual valves (or solenoid valves) 36, 37, and 38 are closed.

[0049] Next, it is determined whether a signal indicating the completion of the hydrogen water supply operation has been received (step S2). If it is determined that the signal has been received (YES), the process proceeds to step S7 to complete the hydrogen water supply operation completion process.

[0050] If it is determined that no signal indicating the completion of the hydrogen water supply operation has been received (in the case of NO), the hydrogen gas pressure detected by the supply hydrogen gas pressure gauge 28 or the hydrogen gas pressure gauge 30 inside the hollow fiber membrane (P G ) is the target hydrogen gas pressure lower limit (P min ) Check if it has reached (Step 3). That is, hydrogen gas pressure P G <Target gas pressure limit P> min Determine whether or not it is true.

[0051] Hydrogen gas pressure (P G ) is lower than the lower limit of the target hydrogen gas pressure (P min ), the electrolysis of the hydrogen gas generator 10 is started to increase the hydrogen gas pressure to the upper limit of the target hydrogen gas pressure (P max ). (Step S4)

[0052] Then, it is determined whether the hydrogen gas pressure (P G ) is lower than the tap water-hydrogen water pressure (P W ) detected by the tap water-hydrogen water pressure gauge 29 or the tap water-hydrogen water pressure gauge 39 (Step S5). That is, it is determined whether the hydrogen gas pressure P G < tap water-hydrogen water pressure P W .

[0053] In Step S5, if it is determined that P G <P W (NO), the dew condensation drain valve 25 is slightly opened to adjust the hydrogen gas pressure (Step S6). That is, in this case, the hydrogen gas pressure (P G ) is decreased.

[0054] After that, while maintaining that the hydrogen gas pressure (P G ) is below the tap water-hydrogen water pressure (P W ), it is confirmed whether a signal indicating the end of the tap water supply operation has been received (Step S2). That is, it returns to Step S2 and repeats the processes of Steps S2 to S6.

[0055] The CPU that has received the signal indicating the end of the tap water-hydrogen water supply operation ends the electrolysis of the hydrogen gas generator 10 in Step S7, opens the dew condensation drain valve 25 to discharge the hydrogen gas in the hollow fiber membrane 15 and then closes it in Step S8, and closes the tap water flow valve 18 and the tap water-hydrogen water extraction valve 35 in Step S9 to end this hydrogen gas pressure control process.

[0056] By this hydrogen gas pressure control operation, the pressure of the hydrogen gas (P G ) on the outside of the gas separation hollow fiber membrane in the hydrogen gas dissolving device 15 becomes the water pressure of the generated tap water-hydrogen water (P WThe pressure is controlled to be lower than the specified value. This prevents the dissolved gas in the generated hydrogen water from becoming supersaturated and forming bubbles due to the decrease in water pressure. In other words, by not dissolving hydrogen gas under pressure, the generation of bubbles in the hydrogen water pathway can be suppressed.

[0057] Furthermore, it is desirable that the control circuit 16 controls the hydrogen gas generator 10 so that the supplied hydrogen gas pressure falls within a predetermined range defined by the tap water temperature T detected by the water thermometer 27, as part of hydrogen gas pressure control. This is because the hydrogen gas permeation state and the hydrogen gas dissolution concentration state change depending on the temperature of the water flowing into the gas separation hollow fiber membrane in the hydrogen gas dissolution device 15. Therefore, the hydrogen gas pressure supplied to the hydrogen gas dissolution device 15 is controlled by switching the electrolysis of the hydrogen gas generator 10 on and off according to the water temperature T of the tap water flowing into the hydrogen gas dissolution device 15. This control is performed to compensate for the fact that the saturated dissolved hydrogen concentration in the water changes with water temperature, and that the amount of gas permeate through the gas separation hollow fiber membrane for hydrogen gas dissolution changes significantly with water temperature. In order to dissolve hydrogen gas in tap water containing dissolved oxygen and nitrogen gas to obtain a desired concentration, it is necessary to consider the pressure of the hydrogen water and the amount of hydrogen gas supplied, as well as the fact that the amount of gas permeate through the gas separation hollow fiber membrane for hydrogen gas dissolution changes with water temperature. In other words, when the water temperature is low, the membrane contracts and the amount of gas permeation decreases, and when the water temperature is high, the membrane swells and the amount of gas permeation increases. Therefore, it is effective to measure the water temperature and adjust the hydrogen gas supply pressure in order to keep the amount of permeation constant.

[0058] As explained above, according to this embodiment, the pressure of hydrogen gas outside the gas separation hollow fiber membrane is lower than the water pressure of the hydrogen-rich tap water generated after passing through the gas separation hollow fiber membrane. Therefore, it is possible to suppress the formation of bubbles due to supersaturation of the dissolved gas in the generated hydrogen-rich water as a result of the drop in water pressure. In other words, by not pressurizing and dissolving the hydrogen gas, the generation of bubbles in the hydrogen water path can be suppressed. In this way, in order to dissolve hydrogen gas in the tap water inside the gas separation hollow fiber membrane, the differential pressure of the tap water passing through the inside of the gas separation hollow fiber membrane is increased, and the hydrogen gas is dissolved by utilizing the negative pressure of the tap water passing through. Furthermore, since hydrogen gas is generated by electrolysis, hydrogen gas cylinders are not required, saving the trouble of replacing them and allowing for a stable supply of hydrogen gas. Moreover, since hydrogen gas cylinders are not used, there is no need to employ a high-pressure gas handling supervisor or be subject to the Safety Act, such as storage facility standards, making application simpler.

[0059] Figure 3 schematically shows the overall configuration of the tap water hydrogen water supply device 100' according to a modified embodiment of the embodiment in Figure 1. This modified embodiment has the same configuration as the hydrogen gas generator 10 in the embodiment of Figure 1, except that the hydrogen gas storage tank is provided in the hydrogen gas generator 10' and the water removal device 11, and the supply hydrogen gas pressure gauge 28' and pressure reducing valve 13 are provided in the flow path from the hydrogen gas generator 10'. However, this modified embodiment uses an electrolytic hydrogen gas generator H2JI1 (hydrogen gas 250 mL / min, maximum pressure 700 kPa, dew point -21.9℃) manufactured by Doctors Man Co., Ltd., which incorporates the electrolysis device 10', water removal device 11, and supply hydrogen gas pressure gauge 28'. A detailed explanation of the other components in this modified embodiment is omitted.

[0060] This modified configuration includes a hydrogen gas storage tank in the hydrogen gas generator 10' and moisture removal device 11. Within the hydrogen gas generator 10' and moisture removal device 11, a hydrogen gas pressure higher than the hydrogen gas pressure used is maintained, and the generated hydrogen gas is kept at a constant pressure by a pressure reducing valve 13 before being supplied to the hydrogen gas dissolution device 15. In other words, the hydrogen gas generator 10' generates hydrogen gas at a relatively high gas pressure through electrolysis, stores the generated hydrogen gas in the hydrogen gas storage tank within the hydrogen gas generator 10' and moisture removal device 11, and reduces the hydrogen gas from this storage tank to a constant pressure by the pressure reducing valve 13 before supplying it to the hydrogen gas dissolution device 15. In this case, the pressure of the hydrogen gas supplied from the pressure reducing valve 13 to the hydrogen gas dissolution device 15 is set to be lower than the water pressure of the hydrogen-rich tap water produced. With this configuration, (on / off) control of electrolysis by a control circuit becomes unnecessary, resulting in a very simple configuration. [Examples]

[0061] (Example 1) Figure 4 schematically shows the overall configuration of the tap water hydrogen water supply system in Example 1.

[0062] As shown in Figure 4, the tap water hydrogen water supply device of Example 1 comprises a hydrogen gas generator 110 consisting of an electrolysis device connected to a pure water tank 140, a water vapor component removal device consisting of a gas-liquid separator 111a and a dehumidifying tube 111b connected to the hydrogen gas generator 110, and a gas separation hollow fiber membrane 115 to which a gas inlet (outside of the gas separation hollow fiber membrane) 115a is connected. A digital control pressure gauge 141 is connected to the outlet of the water vapor component removal device. The hydrogen water outlet 115c of the gas separation hollow fiber membrane 115 is connected to the outlet of the generated hydrogen water via a flow meter 121, a hydrogen water gas-liquid separator 134 for checking bubbles, and a dissolved hydrogen concentration meter 142. The tap water inlet, to which tap water is supplied from the outside, is connected to the tap water inlet (inside of the gas separation hollow fiber membrane) 115b of the gas separation hollow fiber membrane 115.

[0063] In this Example 1 of the tap water hydrogen water supply system, hydrogen gas is generated by electrolyzing pure water in the hydrogen gas generator 110, and the generated hydrogen gas is dehumidified by the gas-liquid separator 111a and the dehumidifying tube 111b. The dehumidified hydrogen gas is dissolved in tap water in the gas separation hollow fiber membrane 115. The formation of bubbles in the tap water after hydrogen gas dissolution was confirmed using the transparent gas-liquid separator 134, which allows observation of bubbles inside.

[0064] The detailed configuration of the tap water hydrogen water supply device in Example 1 is as follows: Hydrogen gas generator 110 : The DMHG electrolysis unit (hydrogen gas 30 mL / min, maximum pressure 200 kPa) of the H2JV3 hydrogen water server manufactured by Doctors Man Co., Ltd. Gas-liquid separator 111a :25mmφ50mmH (capacity 25mL) made of transparent PVC, Dehumidifying tube SWT-3.0-030 / BF tube manufactured by AGC Engineering Co., Ltd. Gas separation hollow fiber membrane 115 : PF-001D film manufactured by DIC Corporation, Hydrogen water-liquid separator 134 :25mmφ110mmH (capacity 54mL) made of transparent PVC, Dissolved hydrogen concentration meter 142 : BIH-50D dissolved hydrogen meter manufactured by Bionics Instruments Co., Ltd.

[0065] The test duration was 1 hour of continuous operation, with the supplied hydrogen gas pressure set to 70-80 kPa. The hydrogen gas pressure was controlled by electrolysis using a hydrogen gas generator 110 based on the detected pressure of a digital pressure gauge 141, with a lower limit of on and an upper limit of off. The tap water flow rate was 0.9 L / min, the shut-off pressure was 220 kPa, and the inlet pressure of the gas separation hollow fiber membrane 115 was adjusted to 200 kPa and the outlet pressure to 130 kPa. For gas chromatography analysis after water sampling, a sensor gas chromatograph SGHA-P3-A manufactured by NISSHA FIS Co., Ltd. was used.

[0066] Table 3 shows the measurement results for each item measured at the cumulative time elapsed since the start of measurement (at the start of measurement and 1 hour after the start). The measured items are tap water flow rate, tap water temperature, tap water shutoff pressure, lower and upper pressure limits for hydrogen gas, hydrogen gas separation volume, inlet pressure, outlet pressure and condensation volume of the gas separation hollow fiber membrane, pressure at measurement points within the system, maximum dissolved hydrogen concentration, minimum dissolved hydrogen concentration, average dissolved hydrogen concentration and bubble accumulation volume, and gas chromatographic analysis values ​​after water sampling. [Table 3]

[0067] As can be seen from Table 3, in Example 1, even when detailed confirmation was performed by gas chromatography analysis after sampling of tap water containing hydrogen, the dissolved hydrogen concentration was 1.59 mg / L, which is approximately equivalent to the theoretical value of 1.62 mg / L for hydrogen gas dissolution mentioned above. The hydrogen gas supply pressure was lower than the water pressure at the outlet of the hollow fiber membrane and lower than the water pressure at the measurement points within the system, which allowed for good results. Moreover, no bubbles were generated at the measurement points within the system. Furthermore, there was no condensation water on the gas separation hollow fiber membrane 115. This is presumed to be because the water portion in the hydrogen gas was removed by the gas-liquid separator 111a, and the water vapor moisture was removed by the dehumidifying tube 111b.

[0068] Figure 5 is a graph showing the change in dissolved hydrogen concentration over time when hydrogen gas pressure control (on / off operation electrolysis control) is performed in Example 1. In Figure 5, the horizontal axis represents elapsed time (sec), and the vertical axis represents the dissolved hydrogen concentration (mg / L) in the gas separation hollow fiber membrane 115 measured by the dissolved hydrogen concentration meter 142. This measurement is performed using the polarographic method, and although there are parts that exceed the theoretical value of 1.62 mg / L, this is within the ultrafine bubble content range, and the gas chromatographic analysis value of 1.59 mg / L represents the dissolved hydrogen gas concentration, enabling a stable supply of tap hydrogen water at the upper limit of dissolution.

[0069] Figure 6 is a graph showing the data from Example 1, specifically the dissolved hydrogen concentration corresponding to the hydrogen gas pressure, the saturated hydrogen concentration corresponding to the tap water pressure, a line for the observation point water pressure of 100 kPa, and a line for the saturated hydrogen concentration (1.6 mg / L dissolved hydrogen) at a tap water pressure of 100 kPa. In Figure 6, the horizontal axis represents hydrogen gas pressure (kPa) and tap water pressure (kPa), and the vertical axis represents dissolved hydrogen concentration (mg / L). From Figure 6, it can be seen that, according to Example 1, a sufficient dissolved hydrogen concentration can be obtained even when the hydrogen gas supply pressure is 80 kPa, which is lower than the observation point water pressure of 100 kPa. Furthermore, as shown in Table 3, the generation of bubbles in the system was also suppressed in Example 1.

[0070] (Comparative Example 1) Since the same hydrogen water supply device as in Example 1 was used, a description of its configuration will be omitted. However, in Comparative Example 1, the gas pressure of the supplied hydrogen gas was set to 90-100 kPa. Also, the measurement items in Comparative Example 1 are the same as in Example 1.

[0071] As can be seen from Table 3, in Comparative Example 1, the water pressure at the measurement point within the system was approximately equal to the water pressure of 100 kPa at the observation point in Example 1, but some bubble accumulation was detected.

[0072] (Comparative Example 2) Since the same hydrogen water supply device as in Example 1 was used, a description of its configuration will be omitted. However, in Comparative Example 2, the gas pressure of the supplied hydrogen gas was set to 110-120 kPa. Also, the measurement items in Comparative Example 2 were the same as in Example 1.

[0073] Figure 7 is a graph showing the change in dissolved hydrogen concentration over time when hydrogen gas pressure control (on / off operation electrolysis control) is performed in Comparative Example 2, the change in dissolved hydrogen concentration over time when hydrogen gas pressure control (on / off operation electrolysis control) is performed in Example 1, and the line representing the saturated hydrogen concentration (1.6 mg / L dissolved hydrogen) at a tap water pressure of 100 kPa.

[0074] As shown in Table 3, in Comparative Example 2, the upper pressure limit is 120 kPa, which is 20 kPa higher than the water pressure at the observation point of 100 kPa. As shown in Table 2, when the water pressure increases from 100 kPa to 120 kPa, the amount of soluble hydrogen gas increases from 1.62 mg / L to 1.94 mg / L, an over-dissolution of 0.32 mg / L, or a 20% increase. As shown in Table 3, it is presumed that this increase was measured as a bubble accumulation at the 100 kPa water pressure point within the water supply hydrogen water system.

[0075] (Comparative Example 3) Since the same tap water hydrogen water supply device as in Example 1 was used, a description of its configuration will be omitted. However, in Comparative Example 3, the tap water supply shut-off pressure was set to 150 kPa. Also, the measurement items in Comparative Example 3 are the same as in Example 1.

[0076] As can be seen from Table 3, as in Comparative Example 3, lowering the water supply pressure resulted in a low water pressure of 35 kPa at the observation point, leading to the generation of a large amount of bubbles.

[0077] (Comparative Example 4) The configuration used in Comparative Example 4 is the same as that of Example 1, but with the water vapor component removal device consisting of the gas-liquid separator 111a and the dehumidifying tube 111b removed. Other configurations are the same, so their explanation is omitted. Furthermore, the measurement items in Comparative Example 4 are the same as those in Example 1.

[0078] Figure 8 is a graph showing the results of Example 1 shown in Figure 6 (saturated hydrogen concentration corresponding to hydrogen gas pressure, saturated hydrogen concentration corresponding to tap water pressure, a line for observation point water pressure of 100 kPa, and a line for saturated hydrogen concentration at tap water pressure of 100 kPa (dissolved hydrogen of 1.62 mg / L)), with the results of Comparative Example 4 added.

[0079] As can be seen from Figure 8 and Table 3, when the generated hydrogen gas was not dehumidified as in Comparative Example 4, no bubbles were generated, but the dissolution efficiency was worse compared to Example 1, where dehumidification was performed. In other words, when the generated hydrogen gas was not dehumidified as in Comparative Example 4, no bubbles were generated, and although the dissolved hydrogen concentration was within the limit of solubility, the dissolution efficiency was more than 15% lower compared to Example 1, where dehumidification was performed. The calculation (1.91-1.54) / 1.91, based on the dissolved hydrogen concentration of 1.91 mg / L in Comparative Example 1 at a water pressure of 100 kPa and the maximum dissolved hydrogen of 1.54 mg / L in Comparative Example 4, shows a decrease of more than 15% (19%). If a water film forms further within the gas separation hollow fiber membrane, the efficiency will decrease further, and the dissolved hydrogen concentration will decrease even more. In other words, from Example 1 and Comparative Example 4, it can be said that using dehumidified hydrogen gas provides a dissolution margin of more than 15%.

[0080] (Example 2) This embodiment uses a hard water softener and an activated carbon filter as pretreatment devices before the RO (reverse osmosis) system in a dialysis water production system, and supplies tap water with hydrogenated water as the raw water for RO treatment. The tap water hydrogenated water supply system in this embodiment 2 is substantially the same as the modified version shown in Figure 3, so a description of the overall configuration is omitted.

[0081] The detailed configuration of the tap water hydrogen water supply device in Example 2 is as follows: Hydrogen gas generator 10, water vapor component removal device 11, and supply hydrogen gas pressure gauge 28′ : Electrolytic hydrogen gas generator H2JI1 manufactured by Doctors Man Co., Ltd. (hydrogen gas 250 mL / min, maximum pressure 700 kPa, dew point -21.9℃) Gas separation hollow fiber membrane 15 : PF-001D film manufactured by DIC Corporation, Hydrogen water-liquid separator 34 :25mmφ110mmH (capacity 54mL) made of transparent PVC, Hard water softener 31 : Diaion SK-1B 350mL hard water softening device cartridge, Activated carbon filter 32 : Activated carbon filter cartridge for Mariage, manufactured by Doctors Man Co., Ltd. Dissolved hydrogen concentration meter: BIH-50D dissolved hydrogen meter manufactured by Bionics Instruments Co., Ltd.

[0082] The test duration was 1 hour of continuous operation, with the supplied hydrogen gas pressure set to 80 kPa. The hydrogen gas pressure was adjusted by controlling the electrolysis of the hydrogen gas generator 10 based on the detected pressure of a digitally controlled pressure gauge, with the lower limit (190 kPa) on and the upper limit (200 kPa) off. The stored hydrogen gas was then supplied at a constant pressure to the hollow fiber membrane gas inlet 15a using a pressure reducing valve 13 from the hydrogen gas storage tank (not shown). The tap water flow rate was 0.9 L / min, the shut-off pressure was 180 kPa, and the inlet pressure of the gas separation hollow fiber membrane 15 was adjusted to 160 kPa and the outlet pressure to 115 kPa.

[0083] Table 4 shows the measurement results for each item measured one hour after the start of measurement in this Example 2. The measured items are tap water flow rate, tap water temperature, tap water inlet pressure, outlet pressure and shutoff pressure, dissolved oxygen concentration of tap water, outlet pressure of the hydrogen gas pressure reducing valve, amount of hydrogen gas condensation, dissolved hydrogen concentration, dissolved oxygen concentration and residual chlorine concentration at the outlet of the gas separation hollow fiber membrane, dissolved hydrogen concentration and dissolved oxygen concentration at the outlet of the hard water softener, outlet pressure, dissolved hydrogen concentration, dissolved oxygen concentration and residual chlorine concentration at the outlet of the activated carbon filter, and the presence or absence of bubble generation. [Table 4]

[0084] As can be seen from Table 4, in Example 2, although the dissolved hydrogen concentration was slightly lower, no bubbles were generated. By controlling the hydrogen gas pressure to a level lower than the tap water hydrogen water outlet pressure, it was found that no bubbles were generated in the tap water hydrogen water path. Furthermore, even when the tap water hydrogen water passed through the ion exchange layer of the hard water softener 31, no significant changes were observed in the dissolved hydrogen concentration, dissolved oxygen concentration, or even the residual chlorine concentration. Similarly, no significant changes were observed in the dissolved hydrogen concentration or dissolved oxygen concentration when passing through the activated carbon filter 32. Naturally, residual chlorine is removed by the activated carbon.

[0085] (Example 3) Since the same tap water hydrogen water supply device as in Example 2 was used, the explanation of its configuration will be omitted. However, in this Example 3, the M60-6000GE manufactured by Nagayanagi Kogyo Co., Ltd. was used as the gas separation hollow fiber membrane, and the outlet pressure of this gas separation hollow fiber membrane was 135 kPa. The measurement items in this Example 3 were the same as in Example 2, and the measurement results for each item are shown in Table 4.

[0086] As can be seen from Table 4, in Example 3, although the dissolved hydrogen concentration was slightly low, no bubbles were generated. By controlling the hydrogen gas pressure to a level lower than the tap water hydrogen water outlet pressure, it was found that no bubbles were generated in the tap water hydrogen water path. Furthermore, even when the tap water hydrogen water passed through the ion exchange layer of the hard water softener 31, no significant changes were observed in the dissolved hydrogen concentration, dissolved oxygen concentration, or even the residual chlorine concentration. Similarly, no significant changes were observed in the dissolved hydrogen concentration or dissolved oxygen concentration when passing through the activated carbon filter 32. Naturally, residual chlorine is removed by the activated carbon.

[0087] (Comparative Example 5) Since the same tap water hydrogen water supply device as in Examples 2 and 3 was used, a description of its configuration will be omitted. However, in Comparative Example 5, a PF-001D membrane manufactured by DIC Corporation was used as the gas separation hollow fiber membrane, and the hydrogen gas pressure was set to 120 kPa. The measurement items in Comparative Example 5 were the same as in Examples 2 and 3, and the measurement results for each item are shown in Table 4.

[0088] As can be seen from Table 4, in Comparative Example 5, bubbles were generated in the tap water hydrogen water pathway. In other words, it was confirmed that bubbles are generated in the tap water hydrogen water pathway when the hydrogen gas pressure is controlled at a higher pressure than the tap water hydrogen water outlet pressure.

[0089] (Comparative Example 6) Since the same tap water hydrogen water supply device as in Examples 2 and 3 and Comparative Example 5 was used, a description of its configuration will be omitted. However, in Comparative Example 6, the M60-6000GE manufactured by Nagayanagi Industries Co., Ltd. was used as the gas separation hollow fiber membrane, and the hydrogen gas pressure was set to 120 kPa. The measurement items in Comparative Example 6 were the same as in Examples 2 and 3 and Comparative Example 5, and the measurement results for each item are shown in Table 4.

[0090] As can be seen from Table 4, bubbles were generated in the tap water hydrogen water pathway in Comparative Example 6. It was confirmed that bubbles are generated in the tap water hydrogen water pathway when the hydrogen gas pressure is controlled at a higher pressure than the tap water hydrogen water outlet pressure.

[0091] (Example 4) Since the same tap water hydrogen water supply device as in Example 2 was used, the explanation of its configuration is omitted. However, in this Example 4, hydrogen gas was supplied at a gas pressure lower than the water pressure at the observation point, and tap water hydrogen water intake (valve not shown) was performed continuously, as well as repeatedly with "30 seconds of intake (valve open) / 30 seconds of closure (valve closed)". The change in concentration over time was observed using a BIH-50D dissolved hydrogen meter (polarographic measuring instrument) manufactured by Bionics Instruments Co., Ltd. The measured items were tap water flow rate, tap water temperature, tap water inlet pressure, outlet pressure and shutoff pressure, outlet pressure of the hydrogen gas pressure reducing valve, outlet pressure at the outlet of the activated carbon filter, and dissolved hydrogen concentration. The measurement results for each measured item are shown in Table 5. [Table 5]

[0092] Figure 9 is a graph showing the change in saturated hydrogen concentration over time when continuous water intake was performed in Example 4. In Figure 9, the horizontal axis represents elapsed time (sec), and the vertical axis represents dissolved hydrogen concentration (mg / L). From Figure 9, it can be seen that the results are consistently stable with continuous water intake.

[0093] Figure 10 is a graph showing the change in saturated hydrogen concentration over time when repeated water intake of "30 seconds water intake / 30 seconds shut-off" was performed in Example 4. In Figure 10, the horizontal axis represents elapsed time (sec), and the vertical axis represents dissolved hydrogen concentration (mg / L). From Figure 10, it can be seen that in repeated water intake, the dissolved hydrogen concentration fluctuates between 0.75 mg / L and 1.55 mg / L. However, considering the electromotive force principle of polarographic methods, which states that "if water is not flowing, the dissolved hydrogen concentration will be consumed, and even after starting water flow, it takes about 30 seconds to stabilize," the result is that the dissolved hydrogen concentration of the hydrogen water that is flowing (taking water) stabilizes at a concentration of 1.54 mg / L.

[0094] From the above-described examples and comparative examples, it is important that the pressure of the hydrogen gas supplied to the gas separation hollow fiber membrane is lower than the water pressure of the generated tap hydrogen water (tap hydrogen water outlet pressure) to prevent the generation of bubbles in the tap hydrogen water path. In this case, it is desirable to set the tap hydrogen water outlet pressure to a minimum of around 100kPa to 120kPa, and to control the dissolved hydrogen concentration of the tap hydrogen water to be 1.6mg / L or less, which is desirable from the viewpoint of ensuring a stable dissolved hydrogen concentration without generating bubbles in the tap hydrogen water path.

[0095] The embodiments, modifications, and examples described above are all illustrative and not limiting to the present invention, and the present invention can be implemented in various other modified forms. Accordingly, the scope of the present invention is defined solely by the claims and their equivalents. [Industrial applicability]

[0096] The hydrogen water supply device of the present invention is directly connected to the water supply and can be used as a hydrogen water supply device to generate medical hydrogen water for use in hemodialysis and the like. In addition, it can be used with household tap water and can be used as hydrogen water for drinking, cooking, washing your face, bathing, etc. [Explanation of symbols]

[0097] 10, 10′, 110 Hydrogen gas generator 11. Water vapor component removal device 12, 36, 37, 38 Manual valves (or solenoid valves) 13 Pressure Reducing Valve 14, 17, 20, 22, 23, 24, 33, Channel 15. Hydrogen gas dissolution apparatus 15a, 115a gas inlet 15b, 115b Tap water inlet 15°C, 115°C Hydrogen water outlet 15d, 100c Condensation water outlet 16 Control circuits 18 Solenoid valve 19 Pressure Reducing Valve 21 Flow meter 25. Condensation water discharge valve 26. Tap water pressure gauge 27 Water temperature gauge 28, 28′ Supply hydrogen gas pressure gauge 29. Tap water hydrogen water pressure gauge 30. Hydrogen gas pressure gauge inside hollow fiber membrane 31 Water softener 32 Activated carbon filter 34, 111a, 134 gas-liquid separator 35. Tap water hydrogen water extraction valve 39. Tap water hydrogen water pressure gauge 100, 100' Hydrogen water supply system 100a Water Inlet 100b Hydrogen water outlet 111b Dehumidifying tube 115 Gas separation hollow fiber membrane 140 Pure water tanks 141 Digital Controlled Pressure Gauge 142 Dissolved Hydrogen Concentration Meter

Claims

1. A water hydrogen water supply device that is directly connected to a water supply and supplies tap water from said water supply in a single pass, A tap water hydrogen water supply device comprising: a hydrogen gas generating means for generating hydrogen gas by electrolysis; and a hydrogen gas dissolving means having a gas separation hollow fiber membrane, wherein tap water is supplied to the inside of the gas separation hollow fiber membrane, and hydrogen gas to be dissolved is supplied from the hydrogen gas generating means to the outside of the gas separation hollow fiber membrane, characterized in that the pressure of the hydrogen gas outside the gas separation hollow fiber membrane is set lower than the water pressure of the hydrogen water generated after passing through the gas separation hollow fiber membrane.

2. The water hydrogen water supply device according to claim 1, further comprising control means for controlling the electrolysis of the hydrogen gas generating means such that the pressure of the hydrogen gas supplied to the hydrogen gas dissolving means is lower than the water pressure of the generated water hydrogen water.

3. The water hydrogen water supply apparatus according to claim 1, further comprising a water vapor component removal means for removing water vapor components from the hydrogen gas generated by the hydrogen gas generating means.

4. The tap water hydrogen water supply device according to claim 3, characterized in that the water vapor component removal means is configured in combination with a gas-water separator and a humidity control tube.

5. The tap water hydrogen water supply device according to claim 2, further comprising a filtration means for filtering the generated tap water hydrogen water, wherein the control means is configured to control the electrolysis of the hydrogen gas generating means so that the pressure of the hydrogen gas supplied to the hydrogen gas dissolution means is lower than the water pressure of the tap water hydrogen water output from the filtration means.

6. The tap water hydrogen water supply device according to claim 2, further comprising an ion exchange processing means for ion exchange processing of the generated tap water hydrogen water, wherein the control means is configured to control the electrolysis of the hydrogen gas generating means so that the pressure of the hydrogen gas supplied to the hydrogen gas dissolution means is lower than the water pressure of the tap water hydrogen water output from the ion exchange processing means.

7. A method for supplying tap water with hydrogen gas, characterized by generating hydrogen gas by electrolyzing water, supplying tap water to the inside of a gas separation hollow fiber membrane, supplying hydrogen gas to be dissolved to the outside of the gas separation hollow fiber membrane, and controlling the pressure of the hydrogen gas outside the gas separation hollow fiber membrane to be lower than the water pressure of the hydrogen water generated after passing through the gas separation hollow fiber membrane.

8. The method for supplying tap water hydrogen water according to claim 7, characterized in that the water vapor component is removed from the hydrogen gas generated.

9. The method for supplying tap water hydrogen water according to claim 7, characterized in that the electrolysis is controlled so that the pressure of the supplied hydrogen gas is lower than the water pressure of the tap water hydrogen water produced.

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