Abstract: A method of separating blood plasma from particles including blood cells, in the blood, includes the steps:(a) providing a membrane with holes therethrough of a size to pass the particulate, and supplying blood to one side of the membrane,(b) moving the membrane at sufficiently high velocity that shear conditions created in the blood adjacent the membrane cause particles in the blood to move or remain away from the surface of the membrane and from the holes,(c) creating a pressure differential across the membrane sufficient to cause plasma to pass through the holes from said one side of the membrane to the opposite side thereof,(d) the holes being allowed to reduce in cross-sectional area as by protein collection on the membrane at the holes, or by expansion of the membrane material, and the holes maintained sufficiently open, by virtue of their original size, to continue to pass the plama therethrough.

Abstract: The present invention provides significant improvements in the design and performance of a specific type of Rotary Membrane Filter (RMF) apparatus which has the capability of separating particles from a fluid having the same and nearly the same density as the particles by utilizing shear to achieve separation, not centrifugal forces. A particular application for the apparatus is in the processing of fluid suspensions in which the suspensions contain fragile particles which are subject to damage due to excessive shear stresses. The prior art describes processing at constant shear rate, whereas the present invention provides the design and optimization of operation of such an apparatus at constant shear stress, which is maintained at a value below that at which significant damage to the fragile particles is encountered.

Abstract: The present invention provides significant improvements in the design and performance of a specific type of Rotary Membrane Filter (RMF) apparatus which has the capability of separating particles from a fluid having the same and nearly the same density as the particles by utilizing shear to achieve separation, not centrifugal forces. A particular application for the apparatus is in the processing of fluid suspensions in which the suspensions contain fragile particles which are subject to damage due to excessive shear stresses. The prior art describes processing at constant shear rate, whereas the present invention provides the design and optimization of operation of such an apparatus at constant shear stress, which is maintained at a value below that at which significant damage to the fragile particles is encountered.