Two-dimensional perforated plate screens achieve a high removal of hairs and fibres, i.e. two to four times the amount of solids are removed than one-dimensional screens are able to separate. The significantly increased separation efficiency is accompanied by a high level of screen surface blinding and requires larger dimensioning of the fine screens compared to other commonly known wedge wire screens. Conventionally, a screen basket with bigger external dimensions is used to achieve larger dimensioning with the result of significantly increased investment costs and even building costs as a bigger channel is required. We have solved this problem with our ROTAMAT® Perforated Plate Screen RPPS-Star: The perforated plate of the screen basket is folded in axial direction like an accordion. The zig-zag folds form the star-shaped screen basket (RPPS-Star). This increases the screen basket surface by about 30 % with still the same nominal diameter.
The filter drum of the ROTAMAT® Perforated Plate Screen RPPS-Star is cleaned by a water jet spraying against wastewater flow direction. This ensures that fibres and screenings are reliable washed from the drum surface and removed by the centrally arranged conveying screw. With this innovation we have made a ’traditional’ machine fit for the future. We are well prepared for higher future requirements related to separation efficiency and hydraulic throughput. The extensive experience gathered from real size installations is reflected in the continuous development and optimisation of our fine screens.
Compared to one-dimensional wedge wire screens, the two-dimensional perforated plate screen achieves a significantly higher separation efficiency. Due to its star-shaped screen drum the ROTAMAT® Perforated Plate Screen RPPS-Star has a by about 30 % larger screening surface, with the same small nominal diameter and with the result of a significantly increased hydraulic throughput capacity.