Abstract
Today, intensive urban development calls for new technologies in the field of environmental engineering. Extensive infrastructure requires more roads and motorways, as well as larger areas covered with concrete, which altogether leads to greater volumes ofwater creating surface run-off. Rotational separators, besides lamella and coalescence units, may provide a highly efficient method for treatment of storm water running off roads and motorways. This paper is focused on two important aspects of the operation of rotational separators: forces acting on a particle in liquid flow, and pressure distribution in the chamber. The resulting relations constitute crucial elements in the future method of designing such devices.