Water treatment device

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.