WATER SOFTENER

To provide a water softener which suppresses catalyst degradation and is capable of maintaining an electrolytic performance for an extended period.SOLUTION: A water softener 1 includes: a softening tank 3 for performing water softening treatment on raw water; a neutralization tank 4 for neutralizing pH of soft water passed through the softening tank; an electrolytic tank 9 for generating acidic electrolytic water and alkaline electrolytic water; and a control part 26 for controlling resin regeneration treatment for performing at least one of the regeneration of a weakly acidic cation-exchange resin 7 using acidic electrolytic water or the regeneration of a weakly basic anion-exchange resin 8 using alkaline electrolytic water. Also, the electrolytic tank 9 includes: a first chamber 76 having a first electrode 77; a second chamber 14 having a second electrode 11 and neighboring with the first chamber 76 via a diaphragm; and a third chamber 18 having a third electrode 15, not neighboring with the second chamber 14, and neighboring with the first chamber 76 via a diaphragm. Also, the control part 26, on resin regeneration treatment, allows the first electrode 77 and the second electrode 11 to function as an anode and allows the third electrode 15 to function as a cathode.SELECTED DRAWING: Figure 1 【課題】触媒劣化を抑制し、長期間に亘って電解性能を維持可能な軟水化装置を提供する。【解決手段】軟水化装置１は、原水を軟水化処理する軟水化槽３と、軟水化槽を通過した軟水のｐＨを中和する中和槽４と、酸性電解水とアルカリ性電解水とを生成する電解槽９と、酸性電解水を用いた弱酸性陽イオン交換樹脂７の再生またはアルカリ性電解水を用いた弱塩基性陰イオン交換樹脂８の再生の少なくとも一方を行う樹脂再生処理を制御する制御部２６と、を備える。また、電解槽９は、第一電極７７を有する第一室７６と、第二電極１１を有し第一室７６と隔膜を隔てて隣接する第二室１４と、第三電極１５を有し第二室１４と隣接することなく第一室７６と隔膜を隔てて隣接する第三室１８と、を備える。そして、制御部２６は、樹脂再生処理時には、第一電極７７及び第二電極１１を陽極として機能させ、第三電極１５を陰極として機能させる。【選択図】図１