Water softening device

Abstract

Provided is a water softening device capable of detecting a decrease in the capacity of ion exchange in a cation exchange resin. A water softening device (1) is provided with: a water softening chamber (3) having a cation exchange resin (4) and generating soft water from raw water containing a hardness component by ion exchange; a measurement unit (5) that measures the conductivity of the softened water that has passed through the softening chamber; and a calculation unit (10) that calculates the hardness of the soft water on the basis of the conductivity of the soft water measured by the measurement unit. The measuring unit is provided with: an upstream measuring unit (6) for measuring the conductivity of the soft water flowing into the measuring unit; an ion exchange unit (7) that has a strongly acidic cation exchange resin (8), adsorbs a hardness component contained in the soft water that has passed through the upstream measurement unit to the strongly acidic cation exchange resin, releases cations from the strongly acidic cation exchange resin, and generates substituted soft water; and a downstream measurement unit (9) that measures the conductivity of the displaced soft water generated by the ion exchange unit.

Description

Technical Field

[0001] The invention relates to a water softening device. Background Art

[0002] In the previous softening device, a cation exchange resin having sodium ions at the end of the functional group was used to exchange the hardness components (e.g., calcium ions, magnesium ions, etc.) in the raw water for sodium ions to soften the raw water. If the cation exchange resin is used continuously, the ion exchange capacity will decrease or disappear. Therefore, in order to be able to perform ion exchange again, it is necessary to regenerate the cation exchange resin. As a regeneration treatment, a treatment such as passing regenerated water such as saturated salt water through the cation exchange resin is performed. (For example, refer to Patent Document 1)

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 8-1155 Summary of the invention

[0006] In such conventional water softening devices, even if there is a possibility that the ion exchange capacity of the cation exchange resin has decreased, the decrease cannot be confirmed. Therefore, there is a problem that the regeneration process cannot be performed at an appropriate timing, and the water obtained from the water softening device contains hardness components.

[0007] The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a water softening device capable of detecting a reduction in the ion exchange capacity of a cation exchange resin.

[0008] The water softening device of the present invention comprises: a softening chamber having a cation exchange resin and generating soft water from raw water containing hardness components by ion exchange; a measuring section measuring the conductivity of the soft water that has passed through the softening chamber; and a calculating section calculating the hardness of the soft water based on the conductivity of the soft water measured by the measuring section. The measuring section comprises: an upstream measuring section measuring the conductivity of the soft water flowing into the measuring section; an ion exchange section having a strong acid cation exchange resin and causing the hardness components contained in the soft water that has passed through the upstream measuring section to be adsorbed on the strong acid cation exchange resin, releasing cations from the strong acid cation exchange resin, thereby generating replacement soft water; and a downstream measuring section measuring the conductivity of the replacement soft water generated by the ion exchange section.

[0009] According to the present invention, it is possible to provide a water softening device capable of detecting a decrease in the ion exchange capacity of a cation exchange resin. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a conceptual diagram showing the structure of the water softening device according to the first embodiment.

[0011] Figure 2 1 is a diagram showing the configuration of a water softening flow path of the water softening device according to the first embodiment.

[0012] Figure 3 This is a conceptual diagram showing the structure of a water softening device according to the second embodiment.

[0013] Figure 4 This is a diagram showing the structure of a water softening flow path of a water softening device according to the second embodiment.

[0014] Figure 5 This is a structural diagram showing the structure of a water softening device according to a modified example of the first embodiment.

[0015] Figure 6 This is a diagram showing the configuration of a water softening flow path of a water softening device according to a modified example of the first embodiment.

[0016] Description of Reference Numerals

[0017] 1.1a,1b Water softening device

[0018] 2 Inlet

[0019] 3 Water softening room

[0020] 4 Cation exchange resin

[0021] 5. Measurement unit

[0022] 6 Upstream measurement unit

[0023] 7 Ion exchange unit

[0024] 8 Strong acid cation exchange resin

[0025] 9 Downstream measurement unit

[0026] 10.10a Calculation Department

[0027] 11 Water intake

[0028] 12 Water pipe

[0029] 13, 13a, 13b Water softening flow path

[0030] 14 Raw Water Measurement Department

[0031] 15 Raw water upstream measurement department

[0032] 16 Raw water ion exchange unit

[0033] 17 Strong acid cation exchange resin

[0034] 18 Raw water downstream measurement department

[0035] 19 Raw water branch pipe

[0036] 20 Soft water branch flow path

[0037] X, V branch point

[0038] Y, W merge point. DETAILED DESCRIPTION

[0039] Hereinafter, the embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the following embodiments are examples of specific implementations of the present invention and do not limit the technical scope of the present invention. In addition, the figures described in the embodiments are schematic figures, and the size and thickness ratios of the constituent elements in the figures may not necessarily reflect the actual size ratios.

[0040] (Implementation method 1)

[0041] Reference Figure 1 The water softening device 1 according to this embodiment will be described.

[0042] Figure 1 1 is a conceptual diagram showing the structure of the water softening device 1 of this embodiment. Figure 1 , each element of the water softening device 1 is conceptually shown.

[0043] (Overall structure)

[0044] The softening device 1 is a device for generating neutral soft water from raw water containing hardness components supplied from the outside. It should be noted that raw water refers to water (treatment target water) introduced into the softening device 1 from the inlet 2, such as tap water or well water. In addition, hardness components refer to calcium ions or magnesium ions, etc. By using the softening device 1 to soften raw water, neutral soft water with reduced hardness can be obtained, and soft water can be used even in areas where the hardness of raw water is high.

[0045] Specifically, if Figure 1 As shown, the water softening device 1 includes an inlet 2 , a water softening chamber 3 , a measuring unit 5 , a calculating unit 10 , and a water intake port 11 .

[0046] In the softening process of the softening device 1 , raw water supplied from the outside flows through the inlet 2 , the softening chamber 3 , the measuring unit 5 , and the water intake 11 in this order, and is discharged as neutral soft water.

[0047] ((Inlet, water intake and water flow pipe))

[0048] The inlet 2 is connected to a raw water supply source. The inlet 2 is an opening for introducing raw water into the water softening device 1.

[0049] The water intake 11 is an opening for supplying softened water flowing through the water softening device 1 to the outside of the water softening device 1. The water softening device 1 can take out softened water from the water intake 11 under the pressure of raw water flowing in from the inlet 2.

[0050] The water flow pipe 12 is a member that connects the inlet 2 to the water intake 11, and the softening chamber 3 and the measuring unit 5 are provided between the inlet 2 and the water intake 11. That is, the water flow pipe 12 is a flow path that guides raw water containing hardness components from the inlet 2 to the water intake 11 via the softening chamber 3 and the measuring unit 5. As the water flow pipe 12, a pipe such as a pipeline is used.

[0051] ((Water Softening Chamber))

[0052] The softening chamber 3 is equipped with a cation exchange resin 4, and softens raw water containing hardness components under the action of the cation exchange resin 4. Specifically, cations (for example, calcium ions, magnesium ions, etc.) as hardness components contained in the circulating water (raw water) are exchanged with sodium ions in the softening chamber 3. As a result, the hardness of the raw water is reduced and the raw water is softened.

[0053] The water softening chamber 3 is formed by filling a cylindrical container with a cation exchange resin 4, for example.

[0054] The cation exchange resin 4 is an ion exchange resin having sodium ions at the ends of functional groups. The cation exchange resin 4 adsorbs cations (e.g., calcium ions, magnesium ions, etc.) as hardness components contained in the raw water passed through, and releases sodium ions. The soft water treated by the cation exchange resin 4 contains a large amount of sodium ions released in exchange with the hardness components.

[0055] As the cation exchange resin 4 , a general-purpose material can be used, and examples thereof include a strongly acidic cation exchange resin having a sulfonic acid group (—SO 3 H) as an exchange group and a weakly acidic cation exchange resin having a carboxyl group (—COOH) as an exchange group.

[0056] In addition, as the cation exchange resin 4, sodium ions (Na ＋ ) into other metal ions or ammonium ions (NH4 ＋ It should be noted that, among the cation exchange resins 4, it is preferred to use a resin having an ion selectivity coefficient lower than that of the strongly acidic cation exchange resin 8 described later.

[0057] (Measurement Department)

[0058] The measuring unit 5 is a device for measuring the conductivity of the soft water produced by the softening chamber 3. Specifically, the measuring unit 5 includes an upstream measuring unit 6, an ion exchange unit 7, and a downstream measuring unit 9.

[0059] The upstream measurement unit 6 is a device for measuring the conductivity of the soft water that has passed through the water softening chamber 3. As the upstream measurement unit 6, for example, a general-purpose bipolar conductivity meter can be used.

[0060] The ion exchange section 7 includes a strongly acidic cation exchange resin 8. The strongly acidic cation exchange resin 8 adsorbs hardness components contained in the soft water that has passed through the upstream measurement section 6 and releases cations to generate substituted soft water.

[0061] The ion exchange unit 7 is constituted by, for example, filling a cylindrical container with a strongly acidic cation exchange resin 8. The replacement soft water refers to soft water obtained by replacing hardness components of the soft water generated in the softening chamber 3 with cations.

[0062] The strong acid cation exchange resin 8 is an ion exchange resin having potassium ions at the ends of the functional groups. The strong acid cation exchange resin 8 adsorbs cations (e.g., calcium ions, magnesium ions, etc.) as hardness components contained in the soft water that has passed through the softening chamber 3 and the upstream measuring section 6, and releases potassium ions. The replacement soft water treated by the strong acid cation exchange resin 8 contains a large amount of potassium ions released in exchange with the hardness components.

[0063] As the strongly acidic cation exchange resin 8, a general-purpose cation exchange resin can be used, and for example, a strongly acidic cation exchange resin having a sulfonic acid group (—SO 3 H) as an exchange group can be mentioned.

[0064] In addition, as the strongly acidic cation exchange resin 8, potassium ions (K ＋ ) into other metal ions or hydrogen ions (H ＋ ) and other cationic resins.

[0065] It should be noted that, among the strongly acidic cation exchange resins 8 , it is preferable to use a resin having a higher ion selectivity than that of the cation exchange resin 4 .

[0066] The downstream measuring unit 9 is a device for measuring the conductivity of the replacement soft water generated by the ion exchange unit 7. As the downstream measuring unit 9, for example, a general-purpose bipolar conductivity meter can be used.

[0067] The measuring unit 5 is wirelessly or wiredly connected to a calculation unit 10 to be described later for communication. The measuring unit 5 transmits the conductivity information of the soft water measured by the upstream measuring unit 6 and the conductivity information of the replacement soft water measured by the downstream measuring unit 9 to the calculation unit 10 .

[0068] (Computing Department)

[0069] The calculation unit 10 is a device for calculating the hardness of the soft water generated in the softening chamber 3 based on the conductivity information of the soft water measured by the upstream measurement unit 6 and the conductivity information of the replacement soft water measured by the downstream measurement unit 9 sent from the measurement unit 5 .

[0070] The calculation method of the soft water hardness in the calculation unit 10 is described below.

[0071] The calculation unit 10 compares the conductivity of the soft water measured by the upstream measurement unit 6 with the conductivity of the replacement soft water measured by the downstream measurement unit 9 , and calculates the hardness of the soft water generated by the softening chamber 3 based on the magnitude of the difference in conductivity.

[0072] That is, the hardness of soft water is calculated by multiplying the difference between the electrical conductivity of soft water and the electrical conductivity of replacement soft water by a specific coefficient.

[0073] The above is the calculation method of soft water hardness.

[0074] It should be noted that the difference between the conductivity of the soft water measured by the upstream measuring unit 6 and the conductivity of the replaced soft water measured by the downstream measuring unit 9 occurs because the hardness components contained in the soft water generated by the softening chamber 3 are exchanged for potassium ions by the ion exchange unit 7 .

[0075] That is, cations (for example, calcium ions, magnesium ions, etc.) as hardness components that cannot be completely removed by the softening chamber 3 are adsorbed on the strongly acidic cation exchange resin 8 of the ion exchange section 7, and potassium ions are released from the strongly acidic cation exchange resin 8 of the ion exchange section 7 instead of the adsorbed cations. The molar ion conductivity of the hardness components is different from the molar ion conductivity of potassium ions, so the conductivity of the soft water measured by the upstream measuring section 6 and the conductivity of the replaced soft water measured by the downstream measuring section 9 vary.

[0076] In order to calculate the hardness of soft water with higher accuracy in the calculation unit 10 , it is preferable that the difference between the electrical conductivity of the soft water and the electrical conductivity of the replacement soft water is large.

[0077] The molar ion conductivity of calcium ions is 59.50[10 －4 S·m 2 ·mol －1 ], the molar ion conductivity of magnesium ions is 53.06[10 －4 S·m 2 ·mol －1 ], the molar ion conductivity of potassium ions is 73.52[10 －4 S·m 2 ·mol －1 ], the molar ion conductivity of sodium ions is 50.11[10 －4 S·m 2 ·mol－1 ].

[0078] As shown in these molar ion conductivity values, the difference in molar ion conductivity with cations (e.g., calcium ions, magnesium ions, etc.) as hardness components is greater for potassium ions than for sodium ions. Therefore, when the ions at the functional group ends of the strongly acidic cation exchange resin 8 included in the ion exchange section 7 are potassium ions, a greater change in conductivity is shown with respect to the hardness components included in soft water, compared to when the ions at the functional group ends of the strongly acidic cation exchange resin 8 included in the ion exchange section 7 are sodium ions.

[0079] Therefore, it is preferable to use a resin in which the ions at the functional group terminals of the strongly acidic cation exchange resin 8 are potassium ions, because this facilitates the measurement of the conductivity by the measuring section 5 .

[0080] It should be noted that the difference between the conductivity of the soft water and the conductivity of the replacement soft water increases as the hardness of the soft water generated by the softening chamber 3 increases. For example, when the hardness of the soft water generated by the softening chamber 3 is 0 ppm, the difference in conductivity is 0 μS / cm, when the hardness of the soft water is 50 ppm, the difference in conductivity is 5 μS / cm, and when the hardness of the soft water is 100 ppm, the difference in conductivity is 10 μS / cm.

[0081] Therefore, as the water softening process progresses and the ion exchange capacity of the cation exchange resin 4 decreases, the difference in conductivity increases, and the conductivity measurement by the measuring unit 5 becomes easier.

[0082] It should be noted that the calculation unit 10 has a computer system, and the computer system has a processor and a memory. And, the computer system functions as the calculation unit 10 by executing the program stored in the memory through the processor. The program executed by the processor is here set to be pre-recorded in the memory of the computer system, but it can also be recorded in a non-temporary recording medium such as a memory card and provided, or it can also be provided through an electrical communication line such as the Internet.

[0083] The above is the structure of the water softening device 1.

[0084] (Operation of the water softening device)

[0085] Next, the operation of the water softening device 1 will be described.

[0086] Softening process

[0087] Reference Figure 2 The operation in the water softening step performed by the water softening device 1 will be described.

[0088] Figure 2 1 is a diagram showing the structure of the water softening flow path 13 of the water softening device 1 .

[0089] During the water softening process, the water pipe 12 serves as the water softening flow path 13 ( Figure 2 slash arrow) to function.

[0090] The softening flow path 13 softens raw water. Raw water flowing through the softening flow path 13 becomes neutral soft water and is discharged from the water intake port 11 to the outside of the softening device 1. The softening flow path 13 includes an inlet 2, a softening chamber 3, a measuring unit 5, and a water intake port 11.

[0091] In the softening process, raw water flows into the softening device 1 from the inlet 2 under the pressure of raw water flowing in from the outside. The raw water flows into the softening chamber 3 through the water flow pipe 12, and flows through the cation exchange resin 4 provided in the softening chamber 3. At this time, the hardness components (for example, calcium ions, magnesium ions, etc.) in the raw water are exchanged with the cations adsorbed on the cation exchange resin 4, and the raw water becomes soft water containing cations.

[0092] In the present embodiment, since sodium ions are adsorbed on the cation exchange resin 4 , the soft water after the ion exchange is soft water containing a large amount of sodium ions.

[0093] The water softened by the water softening chamber 3 flows into the measuring section 5. Specifically, the soft water generated by the water softening chamber 3 first flows into the upstream measuring section 6, and the conductivity of the soft water is measured in the upstream measuring section 6.

[0094] Next, the soft water flows into the ion exchange section 7 and flows through the strongly acidic cation exchange resin 8 provided in the ion exchange section 7. At this time, the hardness components in the soft water are adsorbed by the strongly acidic cation exchange resin 8, and the potassium ions adsorbed by the strongly acidic cation exchange resin 8 are released from the strongly acidic cation exchange resin 8 by ion exchange. Thus, the hardness components are removed from the soft water, and the soft water becomes substituted soft water in which the hardness components are substituted with potassium ions.

[0095] Finally, the replaced soft water flows into the downstream measuring section 9, and the conductivity of the replaced soft water is measured.

[0096] The information on the conductivity of the soft water and the information on the conductivity of the replaced soft water obtained by the measuring unit 5 are sent to the calculating unit 10 , and the calculating unit 10 can calculate the hardness of the soft water.

[0097] The soft water flowing through the measuring unit 5 can be taken out from the water intake port 11 .

[0098] Thus, in the water softening process, the hardness of the soft water is calculated by the calculation unit 10 based on the information of the conductivity of the soft water and the replacement soft water measured by the measurement unit 5. Thus, the performance reduction of the cation exchange resin 4 in the water softening chamber 3 can be detected.

[0099] As described above, according to the water softening device 1 of the first embodiment, the following effects can be obtained.

[0100] (1) A water softening device 1 includes a water softening chamber 3 having a cation exchange resin 4 and generating soft water from raw water containing hardness components by ion exchange; a measuring unit 5 for measuring the conductivity of the soft water having passed through the water softening chamber 3; and a calculating unit 10 for calculating the hardness of the soft water based on the conductivity of the soft water measured by the measuring unit 5. The measuring unit 5 includes an upstream measuring unit 6 for measuring the conductivity of the soft water flowing into the measuring unit 5; an ion exchange unit 7 having a strongly acidic cation exchange resin 8 and causing the hardness components contained in the soft water having passed through the upstream measuring unit 6 to be adsorbed on the strongly acidic cation exchange resin 8 and cations to be released from the strongly acidic cation exchange resin 8, thereby generating replacement soft water; and a downstream measuring unit 9 for measuring the conductivity of the replacement soft water generated by the ion exchange unit 7.

[0101] According to such a configuration, the hardness of the soft water generated in the water softening chamber 3 can be calculated, and a decrease in the water softening performance in the water softening chamber 3 can be detected with high accuracy.

[0102] (2) The strongly acidic cation exchange resin 8 included in the ion exchange section 7 of the water softening device 1 releases potassium ions as cations.

[0103] According to such a configuration, when the hardness components contained in the soft water are adsorbed on the strongly acidic cation exchange resin 8 by the ion exchange section 7, the cations replaced are potassium ions.

[0104] Since the difference between the molar ion conductivity of potassium ions and the molar ion conductivity of hardness components (e.g., calcium ions, magnesium ions, etc.) is large, the difference between the conductivity of soft water measured by the upstream measuring unit 6 and the conductivity of replaced soft water measured by the downstream measuring unit 9 becomes large. As a result, the measurement of the conductivity in the measuring unit 5 and the calculation of the hardness based on the comparison of the conductivity of soft water and the conductivity of replaced soft water in the calculation unit 10 become easy.

[0105] (3) The cation exchange resin 4 included in the water softening chamber 3 of the water softening device 1 releases sodium ions during ion exchange.

[0106] According to this structure, when the cation exchange resin 4 is regenerated, it is possible to pass regenerated water such as saturated salt water through the cation exchange resin 4, which is an inexpensive regeneration process. Saturated salt water can be prepared using sodium chloride and water. Therefore, by using a resin that releases sodium ions during ion exchange as the cation exchange resin 4, regenerated water can be easily obtained and regeneration can be performed inexpensively.

[0107] (Implementation method 2)

[0108] (Overall structure)

[0109] The softening device 1a of the second embodiment of the present invention is different from the first embodiment in that the hardness of the raw water flowing into the softening chamber 3 can be calculated using the raw water measuring unit 14. The other structures are the same as the softening device 1 of the first embodiment. Hereinafter, the contents described in the first embodiment will be appropriately omitted, and the differences from the first embodiment will be mainly described.

[0110] Reference Figure 3 The water softening device 1 a according to this embodiment will be described.

[0111] Figure 3 1 is a conceptual diagram showing the structure of the water softening device 1a of this embodiment. Figure 3 Element of the water softening device 1 a is conceptually shown in FIG.

[0112] ((Raw water branch pipe))

[0113] The raw water branch pipe 19 is a bypass flow passage that branches from the water flow pipe 12 at a branch point X between the inlet 2 and the softening chamber 3 and merges with the water flow pipe 12 at a confluence point Y between the inlet 2 and the softening chamber 3. The raw water branch pipe 19 is a pipe for introducing raw water to the raw water measuring unit 14.

[0114] The branch point X is located downstream of the inlet 2 in the water flow pipe 12 and upstream of the softening chamber 3 and upstream of the confluence point Y. The branch point X is located upstream of the raw water measuring unit 14 in the raw water branch pipe 19 .

[0115] The confluence point Y is located downstream of the inlet 2 in the water flow pipe 12 and upstream of the water softening chamber 3 and downstream of the branch point X. The confluence point Y is located downstream of the raw water measuring unit 14 in the raw water branch pipe 19 .

[0116] The raw water branch pipe 19 has a smaller volume than the water flow pipe 12 , and a smaller amount of raw water than the raw water flowing through the water flow pipe 12 flows through the raw water branch pipe 19 .

[0117] That is, the raw water branch pipe 19 is a flow path that guides a part of the raw water containing hardness components taken in from the inlet 2 to the water flow pipe 12 to the softening chamber 3 via the raw water measuring unit 14 .

[0118] (Raw Water Measurement Department)

[0119] The raw water measuring unit 14 is a device for measuring the conductivity of raw water flowing into the water softening chamber 3. Specifically, the raw water measuring unit 14 includes a raw water upstream measuring unit 15, a raw water ion exchange unit 16, and a raw water downstream measuring unit 18.

[0120] The raw water upstream measuring unit 15 is a device for measuring the conductivity of raw water supplied from the inlet 2 via the raw water branch pipe 19. The raw water upstream measuring unit 15 is not particularly limited, and a general-purpose member can be used, and an example thereof is a bipolar conductivity meter.

[0121] The raw water ion exchange unit 16 is a device that includes a strongly acidic cation exchange resin 17, and causes the hardness components contained in the raw water that has passed through the raw water upstream measuring unit 15 to be adsorbed on the strongly acidic cation exchange resin 17, and releases cations from the strongly acidic cation exchange resin 17, thereby generating replaced raw water. The raw water ion exchange unit 16 is configured by, for example, filling a cylindrical container with the strongly acidic cation exchange resin 17.

[0122] The strong acid cation exchange resin 17 is an ion exchange resin having potassium ions at the ends of the functional groups. The strong acid cation exchange resin 17 adsorbs hardness components (e.g., calcium ions, magnesium ions, etc.) contained in the raw water and releases potassium ions. The replacement raw water treated by the strong acid cation exchange resin 17 contains a large amount of potassium ions released in exchange with the hardness components.

[0123] There is no particular limitation on the strongly acidic cation exchange resin 17, and a general material can be used. For example, a strongly acidic cation exchange resin having a sulfonic acid group (-SO3H) as an exchange group can be used. In addition, as the strongly acidic cation exchange resin 17, potassium ions (K ＋ ) into other metal ions and hydrogen ions (H ＋ ) and other cationic resins.

[0124] The raw water downstream measuring unit 18 is a device for measuring the conductivity of the replaced raw water generated by the raw water ion exchange unit 16. The raw water downstream measuring unit 18 is not particularly limited, and a general-purpose member can be used, and an example thereof is a bipolar conductivity meter.

[0125] The raw water measuring unit 14 is wirelessly or wiredly connected to the calculation unit 10a so as to be communicable, and transmits conductivity information of the raw water and the replacement raw water measured by the raw water upstream measuring unit 15 and the raw water downstream measuring unit 18 to the calculation unit 10a.

[0126] (Computing Department)

[0127] The calculation unit 10a calculates the hardness of the raw water supplied from the inlet 2 based on the information sent from the raw water measuring unit 14, that is, the conductivity information of the raw water measured by the raw water upstream measuring unit 15 and the conductivity information of the replaced raw water measured by the raw water downstream measuring unit 18.

[0128] The method for calculating the hardness of raw water in the calculation unit 10a is described below.

[0129] In the calculation unit 10a, the conductivity of the raw water measured by the raw water upstream measurement unit 15 is compared with the conductivity of the replacement raw water measured by the raw water downstream measurement unit 18, and the hardness of the raw water is calculated based on the magnitude of the difference in the conductivity. Specifically, the hardness of the raw water is calculated by multiplying the difference between the conductivity of the raw water and the conductivity of the replacement raw water by a specific coefficient.

[0130] The difference between the conductivity of the raw water measured by the raw water upstream measuring unit 15 and the conductivity of the replaced raw water measured by the raw water downstream measuring unit 18 is caused by the hardness component contained in the raw water being exchanged for potassium ions by the raw water ion exchange unit 16 .

[0131] That is, cations (for example, calcium ions, magnesium ions, etc.) as hardness components contained in the raw water are adsorbed on the strongly acidic cation exchange resin 17 in the raw water ion exchange section 16, and potassium ions are released from the strongly acidic cation exchange resin 17 instead, so that the conductivity of the raw water measured by the raw water upstream measuring section 15 and the conductivity of the replaced raw water measured by the raw water downstream measuring section 18 change.

[0132] The difference between the conductivity of raw water and that of replacement raw water is based on the difference in molar ion conductivity between cations (eg, calcium ions, magnesium ions, etc.) as hardness components adsorbed by the raw water ion exchange unit 16 and released potassium ions.

[0133] The molar ion conductivity of calcium ions is 59.50[10 －4 S·m 2 ·mol －1 ], the molar ion conductivity of magnesium ions is 53.06[10 －4 S·m 2 ·mol －1 ], the molar ion conductivity of potassium ions is 73.52[10 －4 S·m 2 ·mol －1 ], the molar ion conductivity of sodium ions is 50.11[10 －4 S·m 2 ·mol －1 ].

[0134] According to these molar ion conductivity values, the difference in molar ion conductivity from cations (eg, calcium ions, magnesium ions, etc.) that are hardness components is larger for potassium ions than for sodium ions.

[0135] Therefore, when the ions at the functional group ends of the strongly acidic cation exchange resin 17 included in the raw water ion exchange section 16 are potassium ions, a greater change in conductivity is shown with respect to the hardness component contained in the raw water, compared to when the ions at the functional group ends of the strongly acidic cation exchange resin 17 included in the raw water ion exchange section 16 are sodium ions. Therefore, the measurement of conductivity by the raw water measuring section 14 becomes easy, which is preferable.

[0136] In addition, the difference between the conductivity of the raw water and the conductivity of the replacement raw water increases as the hardness of the raw water increases. For example, when the hardness of the raw water is 100ppm, the difference in conductivity is 10μS / cm, when the hardness of the raw water is 200ppm, the difference in conductivity is 20μS / cm, and when the hardness of the raw water is 500ppm, the difference in conductivity is 50μS / cm.

[0137] It should be noted that the calculation unit 10a has a computer system, and the computer system has a processor and a memory. And, the computer system functions as a control unit by executing the program stored in the memory by the processor. The program executed by the processor is here set to be pre-recorded in the memory of the computer system, but it can also be recorded in a non-temporary recording medium such as a memory card and provided, or it can also be provided through an electrical communication line such as the Internet.

[0138] ((Softening flow path))

[0139] Reference Figure 4 The softening flow path 13a formed during the water softening step of the water softening device 1a will be described.

[0140] Figure 4 1 is a diagram showing the structure of the water softening flow path 13a of the water softening device 1a.

[0141] Softening flow path 13a ( Figure 4 The oblique line arrows ) are the flow path for softening raw water. The raw water that flows in from the inlet 2 and flows through the softening flow path 13 a becomes neutral soft water and is discharged from the water intake port 11 to the outside of the softening device 1 .

[0142] The softening water flow path 13 a is formed by including the inlet 2 , the raw water measuring unit 14 , the softening water chamber 3 , the measuring unit 5 , and the water intake port 11 .

[0143] As described above, according to the water softening device 1 a of the present embodiment, in addition to the effects (1) to (3) obtained in the first embodiment, the following effects can be obtained.

[0144] (4) The softening water device 1a further includes a raw water measuring unit 14 for measuring the conductivity of raw water flowing into the softening water chamber 3. The raw water measuring unit 14 includes: a raw water upstream measuring unit 15 for measuring the conductivity of raw water flowing into the raw water measuring unit 14; a raw water ion exchange unit 16 having a strong acid cation exchange resin 17, and causing hardness components contained in raw water passing through the raw water upstream measuring unit 15 to be adsorbed on the strong acid cation exchange resin 17, and cations are released from the strong acid cation exchange resin 17 to generate replaced raw water; and a raw water downstream measuring unit 18 for measuring the conductivity of replaced raw water generated by the raw water ion exchange unit 16. The calculation unit 10 calculates the hardness of the soft water based on the conductivity of the raw water measured by the raw water measuring unit 14 and the conductivity of the soft water measured by the measuring unit 5.

[0145] According to this configuration, the hardness of the raw water supplied from the inlet 2 can be calculated based on the conductivity information of the raw water measured by the raw water upstream measuring unit 15 and the conductivity information of the replacement raw water measured by the raw water downstream measuring unit 18. Thus, the calculated hardness of the raw water can be compared with the hardness of the soft water calculated based on the conductivity of the soft water measured by the measuring unit 5, and the change amount of the hardness of the soft water generated by the softening chamber 3 can be calculated. Therefore, information on the change amount of the hardness before and after softening, such as to what extent the soft water generated by the softening chamber 3 is the soft water from which the hardness component is removed relative to the raw water, can be provided.

[0146] The present invention has been described above based on the embodiments. It should be understood by those skilled in the art that these embodiments are for illustration only, and various modifications can be implemented in the combination of the above-mentioned components or processing flows, and such modifications also belong to the scope of the present invention.

[0147] (Variation)

[0148] In the water softening device 1 of the first embodiment, the soft water generated by the water softening chamber 3 is set to flow into the measuring part 5, but the present invention is not limited to this. For example, a part of the soft water generated by the water softening chamber 3 flows into the measuring part 5, and the other part does not flow into the measuring part 5 but reaches the water intake port 11 through the branch flow path.

[0149] use Figure 5 as well as Figure 6 A structure in which part of the soft water generated in the softening chamber 3 flows into the measuring unit 5 and the other part does not flow into the measuring unit 5 but reaches the water intake port 11 through the branch flow path and the softening flow path in this case will be described.

[0150] Figure 5 is a conceptual diagram showing the structure of a water softening device 1b according to a modified example of the first embodiment of the present invention. Figure 6This is a diagram showing the configuration of a water softening flow path of a water softening device 1 b according to a modified example of Embodiment 1 of the present invention.

[0151] The softening device 1 b includes a soft water branch flow path 20 that branches from the water flow pipe 12 and connects a branch point V between the softening chamber 3 and the measuring unit 5 and a confluence point W between the measuring unit 5 and the water intake port 11 .

[0152] In the water softening device 1b, by providing the soft water branch flow path 20, a soft water branch flow path 20 is formed during the soft water treatment. Figure 6 The softening flow path 13b shown in FIG. 1 is a softening flow path 13b as shown in FIG. As a result, not all of the soft water generated by the softening chamber 3 flows into the measuring part 5, and the amount of soft water introduced into the strongly acidic cation exchange resin 8 provided in the ion exchange part 7 can be reduced. Therefore, the life of the strongly acidic cation exchange resin 8 can be extended. It should be noted that in the present invention, there is no limitation on the ratio of the amount of soft water generated by the softening chamber 3 flowing into the measuring part 5 via the water flow pipe 12 and the amount not flowing into the measuring part 5 via the soft water branch flow path 20.

[0153] As another variation, in the softening process of the first embodiment, when the hardness of the soft water calculated by the calculation unit 10 exceeds a certain value, the calculation unit 10 may notify the user of the softening device 1 using sound, light, etc. For example, when the hardness of the soft water calculated by the calculation unit 10 exceeds 100 ppm, an alarm sound may be emitted from the calculation unit 10.

[0154] Industrial Applicability

[0155] The water softening device of the present invention can be applied to a water purification device installed at a point of use (POU) or a water purification device installed at a building entrance (POE: Point of Entry), etc.

Claims

1. A water softening device, wherein: The water softening device comprises: a water softening chamber which has a cation exchange resin and generates soft water from raw water containing hardness components by ion exchange; a measuring unit that measures the conductivity of the soft water that has passed through the water softening chamber; and a calculation unit that calculates the hardness of the soft water based on the conductivity of the soft water measured by the measurement unit, The measuring unit comprises: an upstream measuring section for measuring the conductivity of the soft water flowing into the measuring section; an ion exchange section having a strongly acidic cation exchange resin, and causing hardness components contained in the soft water that has passed through the upstream measuring section to be adsorbed on the strongly acidic cation exchange resin, and releasing cations from the strongly acidic cation exchange resin, thereby generating replacement soft water; as well as A downstream measuring section measures the electrical conductivity of the replacement soft water generated by the ion exchange section.

2. The water softening device according to claim 1, wherein: The strongly acidic cation exchange resin included in the ion exchange section releases potassium ions as the cations.

3. The water softening device according to claim 1 or 2, wherein: The cation exchange resin included in the water softening chamber releases sodium ions during the ion exchange.

4. The water softening device according to claim 1, wherein: The water softening device further includes a raw water measuring unit for measuring the electrical conductivity of the raw water flowing into the water softening chamber. The raw water measuring unit comprises: a raw water upstream measuring unit configured to measure the electrical conductivity of the raw water flowing into the raw water measuring unit; a raw water ion exchange section having a strongly acidic cation exchange resin, and causing hardness components contained in the raw water that has passed through the raw water upstream measuring section to be adsorbed on the strongly acidic cation exchange resin, and releasing cations from the strongly acidic cation exchange resin, thereby generating replacement raw water; as well as a raw water downstream measuring unit for measuring the conductivity of the replaced raw water generated by the raw water ion exchange unit, The calculation unit calculates the hardness of the soft water based on the electrical conductivity of the raw water measured by the raw water measurement unit and the electrical conductivity of the soft water measured by the measurement unit.

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