Abstract: A system for separating at least one constituent from a liquid suspension such as blood induces high velocity flow by viscous drag about the circumference of a spinner having a filtration membrane with pore sized selected for the desired constituent. The high velocity circumferential flow is bounded by a spaced apart shear wall, with a spacing selected relative to the diameter of the spinner and its rotational velocity, also with respect to the viscosity of the suspension, to establish a flow within the shear gap, as substantial centrifugal forces are exerted upon the suspension. Under these conditions, in contact with the membrane and filtrate passes through the membrane is replenished with minimal adverse effects from deposition and concentration polarization, and with high efficiency because of high shear levels that are maintained. The filtrate is collected within the interior of the spinner in a conduit system and passed to an outlet orifice.