A water reuse device for reusing waste water discharged from a bathroom or a kitchen as toilet flushing water, comprising:
- a water collecting tank (10) for collecting used water;
- a storage tank (20) receiving the used water stored in the water collecting tank (10) and having a water level sensor (21);
- a toilet water tank (32) located at a lower level than the storage tank (20) and having a first water level sensor (36) and a second water level sensor (35), wherein the first water level sensor (36) senses whether the reused water reaches a given full water level in the toilet water tank (32), wherein the second water level sensor (35) senses whether the reused water reaches a given depletion water level in the toilet water tank (32);
- a first pipe (22) connecting, the storage tank (20) and the toilet water tank (32);
- a first pump (23) provided in the storage tank (20) and supplying the used water in the storage tank (20) to the toilet water tank (32) through the first pipe (22);
- a user detection sensor (37) sensing whether there is a user using a toilet howl (30);
- a first solenoid valve (40) installed in the first pipe (22), wherein the first solenoid valve (40) turns on or shuts off the used water supplied from the storage tank (20) to the toilet water tank (32);
- a second pump (38) installed in the toilet water tank (32) and communicating with a second pipe (33-2), wherein the second pipe (33-2) connects a washing valve piston (33-1) and a water pressure control valve (41-1) with each other;
- a third pipe (33-3) connecting the toilet water tank (32) and the second pipe (33-2) with each other;
- a backflow prevention valve (34) provided between the second pipe (33-2) and the third pipe (33-3);
- and
- a water shutoff valve (41) provided between a water supply pipe (31) and the water pressure control valve (41-1), wherein the water supply pipe (31) supplies water from a water supply pipe (11) to the toilet bowl (30) through the second pipe (33-2),
- wherein, when the second pump (38) turns on when (i) the toilet water tank (32) is in full, and (ii) the user detection sensor (37) senses the user using the toilet bowl (30),
- wherein the used water in the toilet water tank (32) is discharged to the toilet bowl (30) when a water flushing handle (33) is pressed,
- wherein, when the used water in the toilet water tank (32) detected by the second water level sensor (35) is at a first given depletion level, the second pump (38) turns off, and the first solenoid valve (40) is opened to turn on the first pump (23) and supply the used water from the storage tank (20) to the toilet water tank (32),
- wherein, when the used water in the toilet water tank (32) detected by the first water level sensor (36) is at a first given full level, the first pump (23) turns off, and the first solenoid valve (40) is shut off,
- wherein, when (a) the used water in the toilet water tank (32) is detected at the depletion level using the second water level sensor (35) and (b) water level in the storage tank (20) detected by the water level sensor (21) is at a second given depletion level, (i) the second pump (38) turns off even when the user detection sensor 37) detects the user who utilizes the toilet bowl (30),
- (ii) the water shutoff valve (41) remains opened, (iii) water supplied from outside through the water supply pipe (31) is discharged to the toilet bowl (30), and (iv) the backflow prevention valve (34) prevents the water supplied from outside from backflowing to the toilet water tank (32),
- wherein a drain pipe (57) is provided in the toilet water tank (32) and prevents the used water from overflowing over the toilet water tank (32) due to a malfunction of the first pump (23), wherein an upper end of the drain pipe (57) is located at a higher level than the first water level sensor (36), and
- wherein a lower end of the drain pipe (57) is connected to a fourth pipe (39) and discharges the used water overflowing from the toilet water tank (32) to the toilet bowl (32), wherein the fourth pipe (39) is provided between the piston (33-1) and the toilet bowl (30).