Water purification system

Abstract

We provide a water purification system that can widely adjust the hardness of the treated water processed by the filter. [Solution] A water purification system comprising: a raw water inlet for receiving raw water; a discharge port; a first filter unit that does not have ion separation capabilities and filters the raw water to produce purified water; a second filter unit that has ion separation capabilities and processes the purified water to produce low-hardness water and high-hardness water; a raw water flow path for sending the raw water to the discharge port; a purified water flow path for sending the purified water to the discharge port; a low-hardness water flow path for sending the low-hardness water to the discharge port; a high-hardness water flow path for sending the high-hardness water to the discharge port; and a switching unit that allows switching between discharging from the discharge port one or more of the raw water, purified water, low-hardness water, and high-hardness water, and one or more mixed waters that are combinations of two or more of the raw water, purified water, low-hardness water, and high-hardness water.

Description

【Technical Field】 【0001】 The present invention relates to a water purification system. 【Background Art】 【0002】 Conventionally, a water purifier that removes residual chlorine, bacteria such as bacteria and Escherichia coli, or fine particles such as iron rust in raw water such as tap water by a filter in which a filter medium such as activated carbon or a hollow fiber membrane is housed inside a cartridge is known. In addition, a water purification system that includes a plurality of filters having different filtration performances and selectively switches the filter to be used according to the required quality of purified water is known. 【0003】 For example, in Patent Document 1, a second filter provided with an RO membrane is provided downstream of a first filter provided with a hollow fiber membrane, and the first purified water filtered by the first filter, the second purified water that has passed through the second filter, and a water purification system that can selectively discharge mixed purified water obtained by mixing these are proposed. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2015-123389 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 In recent years, interest in the difference in taste due to the hardness of drinking water has increased, and it is desirable that the hardness of the treated water treated with a filter can be widely changed. The present invention provides a water purification system capable of widely changing the hardness of treated water. 【Means for Solving the Problems】 【0006】 The present invention has the following aspects. <1> A water purification system comprising: a raw water inlet for receiving raw water; a discharge port; a first filter unit that does not have ion separation capabilities and filters the raw water to produce purified water; a second filter unit that has ion separation capabilities and processes the purified water to produce low-hardness water and high-hardness water; a raw water channel for sending the raw water to the discharge port; a purified water channel for sending the purified water to the discharge port; a low-hardness water channel for sending the low-hardness water to the discharge port; a high-hardness water channel for sending the high-hardness water to the discharge port; and a switching unit that allows switching between discharging from the discharge port one or more of the raw water, purified water, low-hardness water, and high-hardness water, and one or more mixed waters combining two or more of the raw water, purified water, low-hardness water, and high-hardness water. <2> The second filter section comprises an RO membrane and activated carbon. <1> The water purification system described above. <3> The first filter section comprises a bundle of hollow fiber membranes and activated carbon. <1> or <2> The water purification system described above. <4> The mixed water is one or more selected from a first mixed water, a first mixed water, a second mixed water, a first mixed water, and a third mixed water, a second mixed water, a first mixed water, a second mixed water, and a third mixed water, a first mixed water, a first mixed water, a second mixed water, and a third mixed water, a first mixed water, a second mixed water, and a third mixed water, a third mixed water, a first mixed water, and a third mixed water, a first mixed water, and a third mixed water, respectively. <1> ~ <3> A water purification system as described in any of the following. <5> The hardness of the first mixed water is less than 60 mg / L. <4> The water purification system described above. <6> The hardness of the second mixed water is 120 mg / L or more. <4> or <5> The water purification system described above. <7> The switching section includes a switching valve that switches the flow path to communicate with the discharge port, and a common flow path connecting the switching valve and the discharge port, and the common flow path has a mixing section in which the flow path cross-sectional area is locally enlarged. <1> ~ <6> A water purification system as described in any of the following. [Effects of the Invention] 【0007】 According to the present invention, a water purification system is obtained that can widely change the hardness of the treated water. [Brief explanation of the drawing] 【0008】 [Figure 1] This is a schematic block diagram showing an example of the configuration of a water purification system according to an embodiment of the present invention. [Figure 2] This is an example of a switching valve according to an embodiment of the present invention, where (A) is a fixed disk and (B) is a movable disk in a plan view. [Figure 3] Figure 2 is a diagram illustrating the switching mechanism of the switching valve, with (A) being a plan view showing the fixed disk and (B) being a plan view showing the movable disk. [Figure 4] Figure 2 is a diagram illustrating the switching mechanism of the switching valve, with (A) being a plan view showing the fixed disk and (B) being a plan view showing the movable disk. [Figure 5] Figure 2 is a diagram illustrating the switching mechanism of the switching valve, with (A) being a plan view showing the fixed disk and (B) being a plan view showing the movable disk. [Figure 6] Figure 2 is a diagram illustrating the switching mechanism of the switching valve, with (A) being a plan view showing the fixed disk and (B) being a plan view showing the movable disk. [Figure 7] Figure 2 is a diagram illustrating the switching mechanism of the switching valve, with (A) being a plan view showing the fixed disk and (B) being a plan view showing the movable disk. [Figure 8] Figure 2 is a diagram illustrating the switching mechanism of the switching valve, with (A) being a plan view showing the fixed disk and (B) being a plan view showing the movable disk. [Figure 9] Figure 2 is a diagram illustrating the switching mechanism of the switching valve, with (A) being a plan view showing the fixed disk and (B) being a plan view showing the movable disk. [Modes for carrying out the invention] 【0009】 Figure 1 is a schematic block diagram showing the configuration of a water purification system 1 according to one embodiment of the present invention. The water purification system described in this embodiment is a so-called Type I (stop-type) water purification system that is used under constant water pressure within the system. 【0010】 As shown in FIG. 1, the water purification system of this embodiment includes a raw water inlet 11, a discharge port 81, a first filter section 21, a second filter section 31, a raw water flow path 12, a purified water flow path 22, a low hardness water flow path 41, a high hardness water flow path 51, and a switching section 60. It is preferable to provide a check valve as needed. In this specification, "upstream" and "downstream" mean the directions in the flow path with the raw water inlet as the most upstream and the discharge port as the most downstream. 【0011】 The raw water flowing into the water purification system 1 from the raw water inlet 11 is sent to the discharge port 81 of the faucet 80 through the raw water flow path 12. Also, the raw water is sent to the first filter section 21 through the raw water branch flow path 13 branched from the raw water flow path 12. Examples of the raw water include tap water and well water. Tap water is preferred. 【0012】 The first filter section 21 includes a first filter that filters the raw water without having ion separation performance to generate purified water. Examples of the first filter include a sheet-shaped flat membrane, a hollow fiber membrane bundle formed by bundling hollow fiber membranes, activated carbon, a non-woven fabric filter, a ceramic filter, a metal filter, etc. The first filter may be one type or a combination of two or more types. 【0013】 Examples of activated carbon include powdered, granular, and fibrous activated carbon. Examples of powdered and granular activated carbon include those obtained by carbonizing plant materials (such as wood, cellulose, sawdust, charcoal, coconut shell charcoal, and plant ash), coal materials (such as peat, lignite, brown coal, bituminous coal, anthracite, and tar), petroleum materials (such as petroleum residues, sulfuric acid sludge, and oil carbon), pulp waste liquor, synthetic resins, etc., and if necessary, activating them with gases (such as steam, carbon dioxide, and air) or chemicals (such as calcium chloride, magnesium chloride, zinc chloride, phosphoric acid, sulfuric acid, sodium hydroxide, and KOH). Examples of fibrous activated carbon include those obtained by carbonizing precursors made from polyacrylonitrile (PAN), cellulose, phenol, and coal-based pitch, and activating them with gases (such as steam, carbon dioxide, and air) or chemicals (such as calcium chloride, magnesium chloride, zinc chloride, phosphoric acid, sulfuric acid, sodium hydroxide, and KOH). Among them, considering the removal performance, granular activated carbon is preferred. The particle size of the granular activated carbon may be in the range of 20 to 200 mesh (75 μm to 850 μm) conforming to JIS Z8801, and preferably in the range of 36 to 150 mesh (106 μm to 425 μm). If the particle size is smaller than this range, the water permeability will deteriorate, and if it is larger than this range, the filtration performance will be low. 【0014】 Examples of the material of the hollow fiber membrane include cellulose-based, polyolefin (such as polyethylene and polypropylene)-based, polyvinyl alcohol-based, ethylene-vinyl alcohol copolymer, polyether-based, polymethyl methacrylate (PMMA)-based, polysulfone-based, polyacrylonitrile-based, polytetrafluoroethylene (Teflon (registered trademark))-based, polycarbonate-based, polyester-based, polyamide-based, aromatic polyamide-based, etc. Among them, a polyethylene-based hollow fiber membrane is preferred in terms of excellent handling properties, processing characteristics, chemical resistance, etc. 【0015】 The first filter section 21 preferably includes a hollow fiber membrane and activated carbon. The activated carbon is preferably arranged upstream of the hollow fiber membrane. As the first filter section 21, a cartridge in which activated carbon and a hollow fiber membrane are housed in a housing may be used. 【0016】 The purified water flowing out from the first filter section 21 passes through the purified water flow path 22 and through the switching section 60 to the outlet 81 of the faucet 80. The purified water is also sent to the second filter section 31 through a purified water branch channel 23 that branches off from the purified water channel 22. It is preferable to have a pressurizing pump 30 in the purified water branch channel 23 so that the RO membrane can be pressurized and the water volume can be secured. 【0017】 The second filter section 31 includes a second filter that has ion separation capabilities and processes purified water to produce low-hardness water and high-hardness water. Low-hardness water has lower hardness than purified water, and high-hardness water has higher hardness than purified water. The second filter section 31 may have a post-filter downstream of the second filter that does not have ion separation capabilities. Examples of the second filter include RO membranes and ion exchange materials (ion exchange resins, ion exchange fibers, etc.). The second filter may be a single type or a combination of two or more types. Examples of post-filters include activated carbon, microfiltration membranes (MF membranes), and ultrafiltration membranes (UF membranes). A single post-filter may be used, or a combination of two or more may be employed. 【0018】 As a second filter, an RO membrane is preferred because it can completely separate hardness components. An RO membrane is an artificial semipermeable membrane with ultrafine pores of 0.0001 to 0.0005 μm, and is used to remove metal ions such as sodium and calcium, anions such as chloride ions and sulfate ions, and low molecular weight organic substances such as pesticides. The permeate water that passes through the RO membrane is low-hardness water from which mineral components have been removed, while the concentrated water that does not pass through the RO membrane is high-hardness water from which mineral components have been concentrated. The sodium chloride removal performance of RO membranes is specified as 93% or higher in the AMST-002 standard for membrane modules used in water supply. The permeate is extremely pure water with very few mineral components, and can produce soft water with a hardness of 0 as low-hardness water. 【0019】 The second filter section 31 preferably includes an RO membrane and activated carbon. Since activated carbon can adsorb organic compounds that cause off-flavors and odors generated in RO membranes, it is preferable that the post-filter downstream of the RO membrane be equipped with activated carbon. Furthermore, since RO membranes remove residual chlorine contained in the raw water, bacteria and microorganisms are likely to proliferate in the permeate from the RO membrane. In this respect, it is preferable to have a microfiltration membrane (MF membrane) as a post-filter. Moreover, since it can remove not only bacteria and microorganisms but also fine activated carbon particles, it is even more preferable to have a microfiltration membrane (MF membrane) downstream of the activated carbon. 【0020】 The low-hardness water flowing out from the low-hardness water outlet 41a of the second filter section 31 passes through the low-hardness water channel 41 and is sent to the outlet 81 of the faucet 80 via the switching section 60. A low-hardness water tank 40 may be provided in the middle of the low-hardness water channel 41. The hard water flowing out from the hard water outlet 51a of the second filter section 31 passes through the hard water channel 51 and is sent to the outlet 81 of the faucet 80 via the switching section 60. A hard water tank 50 may be provided in the middle of the hard water channel 51. Furthermore, an auto-shut-off valve 32 may be provided in the low-hardness water flow path 41 between the second filter section 31 and the low-hardness water tank 40, and in the high-hardness water flow path 51 between the second filter section 31 and the high-hardness water tank 50. 【0021】 The auto-shutoff valve 32 has a valve that shuts off both water channels when the water pressure in at least one of the low-hardness water channel 41 and the high-hardness water channel 51 becomes high. For example, an auto-shutoff valve equipped with a known rubber valve can be used. The auto-shut-off valve 32 is configured to shut off the low-hardness water channel 41 and the high-hardness water channel 51 when the low-hardness water tank 40 is full, by receiving the water pressure from the backflow from the low-hardness water tank 40, and also to shut off the low-hardness water channel 41 and the high-hardness water channel 51 when the high-hardness water tank 50 is full, by receiving the water pressure from the backflow from the high-hardness water tank 50. 【0022】 The post-filter of the second filter section 31 may be provided downstream of the second filter and upstream of the discharge port 81. For example, the post-filter may be provided close to the second filter, or it may be provided between the low-hardness water tank 40 and the switching section 60, and between the high-hardness water tank 50 and the switching section 60. 【0023】 The switching section 60 includes a switching valve 61 and a common flow path 64. In this embodiment, the switching section 60 is connected to a purified water flow path 22, a low-hardness water flow path 41, and a high-hardness water flow path 51. The common flow path 64 connects the switching valve 61 to the discharge port 81. The switching valve 61 switches the flow path connected to the common flow path 64 to one or two selected from the purified water flow path 22, the low-hardness water flow path 41, and the high-hardness water flow path 51. Specifically, it switches between a state where only the purified water flow path 22 is open and the rest are closed, a state where only the low-hardness water flow path 41 is open and the rest are closed, a state where only the high-hardness water flow path 51 is open and the rest are closed, a state where both the purified water flow path 22 and the low-hardness water flow path 41 are open and the rest are closed, a state where both the low-hardness water flow path 41 and the high-hardness water flow path 51 are open and the rest are closed, and a state where all flow paths are closed. In this way, the switching unit 60 supplies purified water, low-hardness water, high-hardness water, a first mixed water (a combination of purified water and low-hardness water), a second mixed water (a combination of purified water and high-hardness water), and a third mixed water (a combination of low-hardness water and high-hardness water) to the discharge port 81 in a switchable manner. 【0024】 Examples of the switching valve 61 include a solenoid valve, a rotary manual switching valve equipped with a fixed disk and a movable disk, and the like. Figures 2-9 show an example in which a rotary manual switching valve is used as the switching valve 61. The rotary manual switching valve in this example comprises a disc-shaped fixed disk 62 and a disc-shaped movable disk 63. The movable disk 63 is superimposed on the fixed disk 62 so as to be rotatable relative to it. 【0025】 The fixed disc 62 has three through holes 72, 74, and 75 formed radially on its outer circumference. The movable disc 63 also has three through holes 70A, 70C, and 70H formed radially on its outer circumference. A water purification channel 22 is connected to the through-hole 72 of the fixed disk 62, a low-hardness water channel 41 is connected to the through-hole 74, and a high-hardness water channel 51 is connected to the through-hole 75. Due to the relative rotation of the fixed disk 62 and the movable disk 63, one or more of the through holes 72, 74, and 75 of the fixed disk 62 and one or more of the through holes 70A, 70C, and 70H of the movable disk 63 are arranged to overlap. 【0026】 If the planar shape of the fixed disk 62 is divided into eight equal sectors in the circumferential direction, these sectors are designated as regions a, b, c, d, e, f, g, and h. The through holes 72, 74, and 75 are located in regions a, d, and g, respectively. Similarly, if the planar shape of the movable disk 63 is divided into eight equal sectors in the circumferential direction, these sectors are designated as regions A, B, C, D, E, F, G, and H. The through holes 70A, 70C, and 70H are located in regions A, C, and H, respectively. 【0027】 As shown in Figure 2, when the area a of the fixed disk 62 and the area A of the movable disk 63 overlap, the through-holes 72 and 70A overlap, and only the purified water flow path 22 opens. The remaining flow paths remain closed. Only purified water flows out into the common flow path 64 and is sent to the discharge port 81. 【0028】 As shown in Figure 3, when the area a of the fixed disk 62 and the area C of the movable disk 63 overlap, the through-holes 72 and 70C, and 75 and 70A overlap, respectively, and the purified water channel 22 and the high-hardness water channel 51 open. The low-hardness water channel 41 closes. The purified water and high-hardness water flow out into the common channel 64, and the second mixed water is sent to the discharge port 81. 【0029】 As shown in Figure 4, when the area a of the fixed disk 62 and the area H of the movable disk 63 overlap, the through-holes 72 and 70H, and 74 and 70C overlap, respectively, and the purified water channel 22 and the low-hardness water channel 41 open. The high-hardness water channel 51 closes. The purified water and low-hardness water flow out into the common channel 64, and the first mixed water is sent to the discharge port 81. 【0030】 As shown in Figure 5, when the area a of the fixed disk 62 and the area B of the movable disk 63 overlap, the through-holes 75 and 70H overlap, and only the high-hardness water channel 51 opens. The remaining channels remain closed. Only the high-hardness water flows out into the common channel 64 and is sent to the discharge port 81. 【0031】 As shown in Figure 6, when the area a of the fixed disk 62 and the area F of the movable disk 63 overlap, the through-hole 74 and the through-hole 70A overlap, and only the low-hardness water channel 41 opens. The remaining channels remain closed. Only the low-hardness water flows out into the common channel 64 and is sent to the discharge port 81. 【0032】 As shown in Figure 7, when the area a of the fixed disk 62 and the area E of the movable disk 63 overlap, the through-holes 74 and 70H, and 75 and 70C overlap, respectively, and the low-hardness water channel 41 and the high-hardness water channel 51 open. The purified water channel 22 closes. The low-hardness water and high-hardness water flow out into the common channel 64, and the third mixed water is sent to the discharge port 81. 【0033】 As shown in Figure 8, when the area a of the fixed disk 62 and the area D of the movable disk 63 overlap, and as shown in Figure 9, when the area a of the fixed disk 62 and the area G of the movable disk 63 overlap, there are no overlapping through holes. The purified water channel 22, the low-hardness water channel 41, and the high-hardness water channel 51 are all closed and the water flow is stopped. 【0034】 It is preferable that the common channel 64 is provided with a mixing section 65, which is formed by locally expanding the cross-sectional area of ​​the channel. In Figure 1, reference numeral 65 indicates that the mixing section 65 is located in the middle of the common channel 64. For example, if the diameter of the flow path adjacent to the upstream side of the mixing section 65 is d1 and the diameter of the mixing section 65 is d2, the ratio of d2 / d1 is preferably 1.1 to 1.5. When the flow path expands, turbulent flow occurs, making the fluid in the flow path easier to mix. If the diameter of the flow path adjacent to the downstream side of the mixing section 65 is d3, it is preferable that d3 < d2, and d3 may be equal to d1. In addition, when the cross-sectional shape of the flow path is not circular, the diameter of a circle (equivalent circle diameter) having an area equal to the cross-sectional area of the flow path is used as the diameter of the flow path. 【0035】 The switching lever 82 attached to the faucet 80 is connected to the movable disk 63 by a mandrel (not shown). When the switching lever 82 is rotated, the movable disk 63 rotates relative to the fixed disk 62. The switching lever 82 is an operating means for selecting the discharge and stopping of the treated water obtained by treating the raw water, and the type of treated water to be discharged. Although not shown in the figure, the faucet 80 includes raw water operating means for switching between a state in which the raw water flow path 12 communicates with the discharge port 81 and a state in which the raw water flow path 12 is closed, separately from the switching lever 82. 【0036】 Next, the operation of the water purification system 1 will be described. During use, raw water is constantly supplied to the first filter section 21 in the water purification system 1. Even when the discharge port 81 is in a water-stopped state, if neither the low hardness water tank 40 nor the high hardness water tank 50 is full, the auto shut-off valve 32 does not operate, and purified water continues to be supplied to the second filter section 31, and the low hardness water in the low hardness water tank 40 and the high hardness water in the high hardness water tank 50 continue to increase. When at least one of the low hardness water tank 40 and the high hardness water tank 50 becomes full and the internal pressure in the auto shut-off valve 32 increases due to water stoppage by the switching lever 82, the rubber valve expands, blocking the low hardness water flow path 41 and the high hardness water flow path 51, and the supply of purified water to the second filter section 31 is stopped. 【0037】 The water purification system 1 can selectively discharge treated water from the outlet 81 by operating the switching lever 82. This treated water can be purified water, low-hardness water, high-hardness water, a first mixed water (purified water and low-hardness water), a second mixed water (purified water and high-hardness water), or a third mixed water (low-hardness water and high-hardness water). The system can also choose to shut off the treated water flow. Furthermore, the water purification system 1 can select to discharge or stop the flow of raw water by operating a raw water handling means (not shown). 【0038】 The shape of the through holes provided in the fixed disk 62 and the movable disk 63 is not limited to a circular shape. The shape and size of the multiple through holes provided in the fixed disk 62 do not need to be uniform. The shape and size of the multiple through holes provided in the movable disk 63 do not need to be uniform. By designing the number and shape of the through-holes so that the area of ​​the overlapping portion between the through-holes of the movable disc 63 and the through-holes of the fixed disc 62 changes as the movable disc 63 rotates, the degree of freedom in the mixing ratio of the mixed water is increased. 【0039】 The water purification system of this embodiment includes a purified water channel 22 that sends purified water to the outlet 81, a low-hardness water channel 41 that sends low-hardness water to the outlet 81, and a high-hardness water channel 51 that sends high-hardness water to the outlet 81, so that the hardness of the water discharged from the outlet 81 can be widely adjusted. For example, the first mixed water can be adjusted to soft water with a hardness of less than 60 mg / L, or to very soft water with a hardness of 20 mg / L or less. The lower limit of the hardness of the first mixed water is preferably greater than 0 mg / L, and may be 10 mg / L or more. For example, the second mixed water can be adjusted to hard water with a hardness of 120 mg / L or more, or to very hard water with a hardness of 180 mg / L or more. The upper limit of the hardness of the second mixed water is preferably 300 mg / L or less, but may be 240 mg / L or less. Low-hardness water is preferably pure water (very soft water) with a hardness of 0 mg / L. The hardness of the high-hardness water is preferably 240 mg / L or higher, and may be 300 mg / L or higher. The hardness of the third mixed water can be adjusted to a range higher than that of low-hardness water and lower than that of high-hardness water. For example, the third mixed water may be moderately hard water with a hardness of 60 mg / L or more and less than 120 mg / L. The hardness of purified water is almost the same as that of the raw water. The hardness of the treated water can be measured using a hardness meter or a TDS meter. The faucet 80 may be equipped with a display that shows the hardness and TDS. 【0040】 The purified water filtered through the first filter preferably has a total dissolved solids (TDS) of 30 ppm to 200 ppm. This range is the target value for water supply management targets in Japan, and ensures that treated water suitable for drinking is obtained. Furthermore, it is possible to obtain treated water with a hardness suitable not only for drinking water and cooking water, but also for showers used in bathrooms, washbasins, barber shops, beauty salons, etc. 【0041】 <Variation> This invention is not limited to this embodiment, and various modifications and variations are possible within the scope of the technical idea described in the claims. 【0042】 The water purification system of this embodiment is configured to produce six types of treated water in addition to raw water: purified water, low-hardness water, high-hardness water, first mixed water, second mixed water, and third mixed water. However, the number of treated water types may be five or fewer depending on the application. At the very least, using both low-hardness water and high-hardness water in a water purification system is preferable because it enables the realization of a water purification system without wastewater. In other words, it is preferable that the multiple types of treated water produced in the water purification system include one or more types of treated water containing low-hardness water and one or more types of treated water containing high-hardness water. For example, the multiple types of treated water produced in the water purification system may be five types: purified water, low-hardness water, high-hardness water, first mixed water, and second mixed water; or five types: purified water, low-hardness water, first mixed water, second mixed water, and third mixed water; or four types: purified water, low-hardness water, first mixed water, and second mixed water. 【0043】 In this embodiment, the purified water channel 22, the low-hardness water channel 41, and the high-hardness water channel 51 are connected to the switching unit 60. However, the raw water channel 12 may also be connected to the switching unit 60, and the switching unit 60 may be designed so that the operation of the switching lever 82 allows for the selection of raw water discharge, treated water discharge, selection of the type of treated water, and shut-off. 【0044】 In this embodiment, there is one discharge port, but two or more discharge ports may be provided. For example, two faucets, each having one discharge port, may be provided, and the raw water flow path 12 and the common flow path 64 may be connected to separate faucets. 【0045】 In this embodiment, the raw water is discharged as raw water only, but it may also be possible to discharge a mixed water by combining raw water with one or more waters selected from purified water, low-hardness water, and high-hardness water. 【0046】 The water purification system of this embodiment is a Type I (stop-stop type), but it may be modified as appropriate so that it can be used as a so-called Type II (end-stop type) water purification system. [Explanation of symbols] 【0047】 1. Water purification system 11 Raw water intake 12 Raw water flow path 13 Raw water branching channel 21 First filter section 22 Purified water flow path 23 Water purification branch channel 30 Pressure pump 31 Second filter section 32 Auto Shut-off Valve 40 Low-hardness water tanks 41 Low hardness water channel 41a Low hardness water outlet 50 High-hardness water tanks 51 High hardness water channel 51a High hardness water outlet 60 Switching section 61 Switching valve 62 Fixed disks 63 movable discs 64 Common Channel 65 Mixing section 70A, 70C, 70H Through-holes in movable discs 72, 74, 75 Through holes in the fixed disk 80 faucets 81 Discharge port 82. Switching lever

Claims

[Claim 1] The raw water inlet that receives the raw water, Outlet and A first filter unit that does not have ion separation capabilities and filters the raw water to produce purified water, A second filter unit having ion separation capabilities and processing the purified water to produce low-hardness water and high-hardness water, A raw water channel that sends the raw water to the discharge port, A purified water channel that sends the purified water to the discharge port, A low-hardness water channel that sends the low-hardness water to the discharge port, A high-hardness water channel that sends the high-hardness water to the discharge port, A water purification system having a switching unit that allows switching between discharging from the outlet one or more of the raw water, purified water, low-hardness water, and high-hardness water, and one or more mixed waters that combine two or more of the raw water, purified water, low-hardness water, and high-hardness water. [Claim 2] The water purification system according to claim 1, wherein the second filter section comprises an RO membrane and activated carbon. [Claim 3] The water purification system according to claim 1 or 2, wherein the first filter section comprises a bundle of hollow fiber membranes and activated carbon. [Claim 4] The water purification system according to claim 1, wherein the mixed water is one or more selected from a first mixed water obtained by combining the purified water and the low-hardness water, a second mixed water obtained by combining the purified water and the high-hardness water, and a third mixed water obtained by combining the low-hardness water and the high-hardness water. [Claim 5] The water purification system according to claim 4, wherein the hardness of the first mixed water is less than 60 mg / L. [Claim 6] The water purification system according to claim 4 or 5, wherein the hardness of the second mixed water is 120 mg / L or more. [Claim 7] The water purification system according to claim 1, wherein the switching section has a switching valve that switches the flow path to communicate with the discharge port, and a common flow path that connects the switching valve and the discharge port, and the common flow path has a mixing section in which the cross-sectional area of ​​the flow path is locally enlarged.

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