In sewers, storage sewers and rainwater basins, flushing devices are used to dissolve the pollutants that have accumulated on the bottom by means of a flushing surge and feed them to the treatment plant either via pumping technology or through gravity.
Surge flushing is a remobilisation and transport process of sedimented wastewater constituents consisting of single or multiple surge waves, which is used for the cleaning of storm-water basins and sewers. Surge waves are a transient flow condition with sudden increases in water level, flow velocity, discharge and shear load.
The operation of flushing devices is based on the use of a flushing surge whose energy is large enough to overcome the drag stress required for the detachment and removal of the deposits. This energy is provided in the form of position energy and released abruptly by opening a closure device.
The length of the flushing section, invert slope and width of the flushing path (diameter for sewer flushing) determine the size of the flushing water volume required. The flushing water volume is provided either in separate containers (flushing tilt), separate chambers (flushing flap) or in the sewer space itself (curved flap). We use flush systems because of their low energy consumption, high cleaning and transport performance and low maintenance requirements.