Water purifier

A water purifier comprising:

• A reverse osmosis (RO) filter including a non-filtering unit into which raw water flows, a filtering unit for discharging purified water, and a reverse osmosis membrane that partitions the non-filtering unit and the filtering unit and filters the raw water into the purified water;
• A raw water storage unit in which the raw water is stored;
• a purified water storage unit in which the purified water discharged from the filtering unit is stored;
• A water storage tank including a separator membrane made of a non-permeable material to independently partition the raw water storage unit and the purified water storage unit and having elasticity, the water storage tank being configured such that the purified water storage unit contracts when the raw water storage unit expands and the raw water storage unit contracts when the purified water storage unit expands;
• A flow channel providing passages through which the raw water and the purified water flow, the flow channel further including;
• An RO filter inflow passage providing a passage through which any one of the raw water or the purified water flows into the non-filtering unit;
• A first tank passage providing a passage through which the raw water flows into the raw water storage unit;
• A second tank passage providing a passage through which the purified water discharged from the purified water storage unit flows in, the second tank passage being joined to the RO filter inflow passage;
• A purified water storage passage providing a passage through which the purified water discharged from the filtering unit flows in, and the purified water storage passage being joined to the second tank passage;
• and
• A purified water discharge passage providing a passage through which the purified water is discharged from the purified water storage unit and discharged to the outside, and the purified water discharge passage being joined to the purified water storage passage;
• A valve unit including a plurality of valve modules selectively opened/closed to control flow of the raw water and the purified water in the flow channel;
• and
• A control device for controlling opening/closing of the plurality of valve modules based on a plurality of flow modes,
• Wherein the plurality of flow modes includes a purified water storage mode in which the purified water is stored in the purified water storage unit,
• Wherein the plurality of valve modules is opened/closed such that the raw water flows into the non-filtering unit and the purified water discharged from the filtering unit flows into the purified water storage unit in the purified water storage mode.