Method and apparatus for flow field-flow fractionation
AssigneeUniversity of Utah
InventorJohn C. Giddings
Life of this patent
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Abstract
A method and apparatus for flow field-flow fractionation involving the application of a lateral cross flow superimposed on a channel fluid flow in a field-flow fractionation system. The cross flow is developed by applying a pressure across semipermeable plates which substantially define a narrow channel region carrying a fluid substance to be subjected to the influence of the cross flow. This cross flow causes differential migration of solute material carried by the channel flow, thereby providing application to numerous processes such as separations, fractionation, solute exchange, purification, dialysis and ultrafiltration.
Claims13
A flow field-flow fractionation apparatus, including:
- (a) elongated first and second semipermeable plates substantially parallel in orientation and closely spaced apart to form a partially bounded, narrow, elongate channel therebetween, said first plate being adapted for entry fluid flow therethrough to said channel and said second plate being adapted for exit fluid flow therethrough, thereby establishing a cross-flow fluid path through said elongate channel, said semipermeable plates being permeable to said cross-flow fluid but impermeable to at least one constituent of a channel fluid which flows along an axis defined by said channel;
- (b) nonporous side walls laterally circumscribing said elongate channel and affixed in combination with said first and second plates to define lateral bounds of said elongate channel;
- (c) inlet and outlet means located at respective ends of said elongate channel for permitting flow of channel fluid along said axis;
- and
- (d) crossflow fluid control means in association with said plates for controlling and regulating rate of crossflow;
- the combination being adapted for use with said respective channel and crossflow fluids to establish a crossflow pressure gradient as an influencing force for laterally displacing substances carried in said channel flow toward said second semipermeable plate.
A method of establishing a crossflow across a field-flow fractionation channel having elongated first and second plates substantially defining a narrow flow channel therebetween, said method comprising the steps of:
- (a) selecting a semipermeable material suitable for passage of a crossflow fluid therethrough,
- (b) adapting said semipermeable material with rigid structure to enable use thereof as a semipermeable plate in a field-flow fractionation system,
- (c) constructing a flow field-flow fractionation channel using said semipermeable plates as first and second plates, and
- (d) applying a regulated rate of fluid cross flow at said first plate means, in combination with a channel fluid flow, to establish a cross-flow, substantially perpendicular to said channel flow.
Dependencies are inferred from the claim text.