Water treatment device
Disclosed is a water treatment device such as a water purifier. In particular, a water treatment device capable of producing sterilizing water is disclosed. The device includes a sterilizing water producing module for electrolyzing raw water to produce sterilizing water, wherein the sterilizing water producing module includes a plurality of first electrodes and a plurality of second electrodes arranged alternately with each other and spaced from each other, wherein the first and second electrodes have opposite polarities to each other, wherein a polarity of each of the first electrode and the second electrode is switchable to between a positive potential and a negative potential, such that the sterilizing water producing module operates such that a positive potential operation and a negative potential operation are alternately repeated, wherein a magnitude of voltage or current applied to the sterilizing water producing module under the negative potential operation is smaller than a magnitude of voltage or current applied to the module under the positive potential operation.
1 . A water treatment device having a purified water and a sterilizing water producing function, the device comprising:
a filter assembly that filters foreign materials contained in raw water supplied from a water supply source;
a water supply valve located downstream of the filter assembly;
a sterilizing water producing module connected to and disposed between a first point and a second point and at a downstream of the water supply valve and having a plurality of first electrodes and a plurality of second electrodes having opposite polarities and adjacent to each other for electrolyzing the raw water to produce the sterilizing water;
a bypass path branched at a front end of the sterilizing water producing module, the bypass path bypassing the sterilizing water producing module and discharging the purified water;
a first path located at a rear end of the sterilizing water producing module, branched from the first point, and equipped with a water discharge valve that controls a discharge of the sterilizing water;
a second path located at the rear end of the sterilizing water producing module, branched from the first point, and equipped with a drain valve that controls a discharge of scale generated in the sterilizing water producing module; and
a controller configured to operate by applying voltage or current to each of the first electrodes and the second electrodes of the sterilizing water producing module,
wherein the first electrodes include:
a substrate metal layer forming each of the first electrodes;
a catalyst metal layer formed of oxide material on the substrate metal layer; and
a protective layer disposed between the substrate metal layer and the catalyst metal layer,
wherein the second electrodes are formed with a substrate metal layer for asymmetric potential operation with respect to the first electrodes,
wherein the controller is configured to asymmetrically switch the polarities of each of the first electrodes and the second electrodes between a positive potential and a negative potential, thereby repeatedly driving the sterilizing water producing module in an asymmetrical positive potential operation and a negative potential operation,
wherein the positive potential operation performs a first polarity-based operation for producing the sterilizing water by applying a constant voltage or current to each of the first electrodes and the second electrodes,
wherein the negative potential operation performs a second polarity-based operation to remove scale from the sterilizing water producing module by applying a voltage or current lower than the constant voltage or current in the positive potential operation to each of the first electrodes and the second electrodes in a pulse form for a shorter time than the positive potential operation,
wherein an idle operation is performed for washing each of the first electrodes and the second electrodes between the first polarity-based operation and the second polarity-based operation, or before and after the second polarity-based operation, and
wherein the controller is configured to discharge the sterilizing water through the first path when generating sterilizing water, and discharge the scale through the second path when cleaning the scale.
2 . The device of claim 1 , wherein the sterilizing water is produced under the positive potential operation, wherein at least one of scale removal or washing is performed under the negative potential operation.
3 . The device of claim 1 , wherein washing of each of the first electrode and the second electrode is performed during each idle period.
4 . The device of claim 1 , wherein the catalyst metal layer includes at least one of Ru, Ir, Pt, Pd, or Rh.
5 . The device of claim 1 , wherein the catalyst metal layer includes at least one of Ta, Pt, Sn, or Ti.
6 . The device of claim 1 , wherein the substrate metal layer of the first electrodes and the second electrodes includes at least any of Ti, Ta, or an oxide thereof, or at least one of stainless steel (SUS) or Pt.
7 . The device of claim 1 , wherein a time duration of the idle operation is longer than a time duration of each pulse of the negative potential operation.
8 . The device of claim 1 , wherein a time duration of the idle operation is equal to a time duration of the negative potential operation.
9 . The device of claim 1 , wherein a time duration of the positive potential operation is longer than a time duration of the idle operation.