The invention relates to the technical field of unpowered drainage devices for
wastewater treatment
sedimentation tanks, in particular to a duckweed isolating type quantitative floating water outlet device. The device comprises an upper slide way fixing frame,
inductance approach switches, float bowls, water distribution weir plates, a drainage tank, float bowl adjusting devices, drainage telescopic pipes, a water collecting
pipe, an electrically-operated valve, a
sedimentation tank, limiters, support slide ways and drainage tank guide sleeves. The device is characterized in that the drainage tank guide sleeves are welded with the drainage tank and are sleeved on the support slide ways, the drainage telescopic pipes are connected on the water collecting
pipe by
welding, the water distribution weir plates are symmetrically mounted on two sides of a drainage tank end plate, the float bowl adjusting devices are welded in the middles of two ends of the float bowls, and the float bowls can move up and down by rotating float bowl adjusting bolts so that quantitative drainage is achieved. The electrically-operated valve is mounted on an outer
pipe portion of the water collecting pipe extending out of the
sedimentation tank, and drainage automatically stops when the sedimentation tank reaches an upper limit
water level and a
lower limit water level by the aid of the upper
limiter, the lower
limiter and the
inductance approach switches. The duckweed isolating type quantitative floating water outlet device is free from powered
energy consumption, low in equipment investment and operating maintenance cost and high in operating stability.