Rectangular sedimentation system having a self-aggregation facility

The present invention relates to the configuration of a sedimentation tank, comprising on the upstream side, a hopper part and a sedimentation part and, on the downstream side, an outflow part, and the inside of the hopper part contains a vertical baffle formed in the side surface where the inflowing water is introduced, and a sludge collector and an outflow weir. The present invention is a rectangular sedimentation system having a self-aggregation facility, which is obtained by providing such a common form of rectangular sedimentation system with: a vertical screening plate which screens theupper part of the water flow in a position corresponding to between 50 and 80% of the horizontal surface area of the hopper part, and the lower part of which has a 60% spacing of the orthocentre to 20 cm from the floor; and a plurality of horizontal baffles which are positioned between the vertical baffle and the vertical screening plate and which are formed with a plurality of water-passing holes in such a way that the i