A buoyancy flushing apparatus is disclosed which comprises a reservoir for accumulating
liquid, having an inlet for receiving liquid and an outlet chamber recessed in
a bottom wall of the reservoir. The outlet chamber includes an outlet for draining
liquid out of the reservoir. The apparatus further comprises an outlet valve movable
between a down position where liquid accumulates in the reservoir and a raised
position where liquid accumulated in the reservoir is flushed out via the outlet.
The outlet valve comprises a ballast unit sized and shaped to fit loosely in the
outlet chamber when said valve is in the down position; and a float unit topping
the ballast unit to move the valve in the raised position by buoyancy when a sufficient
amount of liquid is accumulated in the reservoir, thereby providing a passageway
for liquid between the bottom wall of the reservoir and the valve leading to the
outlet in the outlet chamber to flush liquid out of the reservoir. Guiding means
are provided for guiding the outlet valve between the down position and the raised
position. The apparatus can be used for applications such as water treatment and
irrigation. It could advantageously be used for directing and spreading waste water
previously treated in a septic tank to different sanitary treating fields.
