Particle size separation by suspension flow in an unobstructed passageway
AssigneeMicromeritics Instrument Corporation
InventorsDean M. Ball, Robert C. Fincher, Clyde Orr, Jr.
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Abstract
Particles suspended in a fluid medium are separated into isolated fractions by size by passing a suspension of such particles through an unobstructed passageway, the particles emerging from the passageway in decreasing order of size.
Claims18
In a method of separating particles into isolated particle size fractions, the steps of
- dispersing said particles in a liquid dispersing medium to obtain a particle suspension;
- passing said particle suspension through an elongate unrestricted tube by a laminar flow of said particle suspension, said laminar flow being undisturbed by said passageway and external forces and having a cross sectional area in a plane transverse to its direction and a duration sufficient for the majority of particles of a particular size in said particle suspension to become substantially advanced in the direction of said laminar flow beyond the majority of the next successively smaller particles in said suspension.
In a method of separating particles into isolated particle size fractions, the steps of
- dispersing said particles in a liquid dispersing medium to obtain a particle suspension;
- passing said particle suspension through an elongate, unrestricted tube by a laminar flow of said particle suspension, said laminar flow being undisturbed by said tube and external forces and having a cross sectional area in a plane transverse to its direction and a duration selected to cause the largest particles in said particle suspension to respond to said laminar flow with a velocity within said passageway that is greater than that of other particles in said suspension, said duration of said laminar flow being additionally selected to be sufficient for the majority of said largest particles to become substantially separated from the majority of the next successively smaller particles in the suspension.
An apparatus for separating particles by size, comprising an unrestricted tube, means for injecting a suspension of particles in a liquid dispersing medium into said tube, means for eluting the tube with a laminar flow of said suspension to obtain an effluent stream, and means for detecting particles in said effluent stream, said tube having a length sufficient for undisturbed laminar flow of said suspension in said tube to cause a majority of particles in said suspension of a particular size to be separated within said effluent stream from the majority of particles in said suspension of the next successively smaller size.
Dependencies are inferred from the claim text.