Differences of behavior between filtering hydrocyclones with Bradley and Rietema geometries

Hydrocyclones constitute an important class of devices intended for the solid-liquid suspensions separation.. Those equipments are divided in several families, which differ to each other in the geometric relationships. The filtering hydrocyclone is a device which consists of a cyclone, whose conical section was replaced by a conical filtering wall. The objective of this work is to compare the performance of the filtering hydrocyclones of the Bradley's and Rietema's designs. The experimental apparatus was composed of a well-stirred tank, a centrifugal pump, an agitator, valves and the filtering hydrocyclones with Bradley's and Rietema's geometries. The experimental results obtained with the filtering hydrocyclones in the same operation conditions that their conventional devices, allow to conclude that the performance of the hydrocyclones of the families Bradley and Rietema is significantly influenced by the presence of the filtering medium. The Rietema's filtering hydrocyclones supplied smaller volumetric feed flowrate in relation to the conventional device, the Bradley's filtering hydrocyclones presented increments for this same variable. In both geometry, the overall efficiencies were influenced by the underflow-to-throughput ratio.