Apparatus for field flow fractionation
AssigneeE. I. Du Pont de Nemours and Company
InventorsJohn W. Grant, Joseph J. Kirkland, Wallace W. Yau
Life of this patent
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Abstract
A long, thin annular belt-like channel is designed for use in sedimentation field flow fractionation. This channel, which may be contained in the rotor of a centrifuge, has a generally rectangular cross-section. It has an inlet positioned to introduce particulates (includes particles and/or macromolecules) approximately at the radial distance from the outer wall that is the equilibrium distance resulting from the average force field exerted on each particulate by the centrifugal force field and by the opposing normal diffusion forces due to Brownian motion. An outlet for the channel is similarly located. A modified design tapers the inlet and outlet.
Claims11
An apparatus for separating particulates suspended in a fluid medium according to their effective masses, said apparatus having an annular cylindrical channel with a cylinder axis, means for rotating said channel about said axis, means for passing said fluid medium circumferentially through said channel, and means for introducing a sample of said particulates into said medium for passage through said channel, the improvement wherein said channel is generally rectangular in cross section, having radially inner and outer walls and inlet and outlet ends, and has an inlet positioned to introduce said particulates approximately at the radial distance 1 inwardly from the outer wall, where 1 is the point of equilibrium between the average force field exerted on each particulate by the rotational centrifugal force and by the normal opposing diffusion forces due to Brownian motion.
Dependencies are inferred from the claim text.