US 5,296,145 AGranted

Apparatus and method for supercritical fluid extraction

AssigneeIsco, Inc.

InventorsRobert W. Allington, Daniel G. Jameson, Robin R. Winter, Dale L. Clay

Life of this patent

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Abstract

An apparatus for supercritical fluid extraction incorporates a removable extraction cartridge which in operation has insignificant pressure difference between its inside and outside walls. In one embodiment, the extractor includes a fraction collector for extractants, an automatic sample changer and an automatic cartridge transfer mechanism which provide completely automated extractions. To automatically perform extraction, valves for the fluids are automatically opened and closed in synchronism with the insertion and removal of the cartridges. These valves force a hard valve element into a softer valve seat with a valve stem that does not rotate significantly under the control of a rotary motor.

Claims6

Dependent claims

Supercritical fluid extraction cartridge for confining a sample, said cartridge having a tubular body with two ends, having an inside surface and an outside surface, porous means at each end near the said inside surface to retain the said sample and to provide for flow of pressurized supercritical fluid through the said cartridge and past or through the said sample contained therein, at least one of said ends and porous means removable to provide for insertion and removal of said sample into and from the said cartridge;

characterized by:
at least one of the said body or ends being molded of plastic;
the said extraction cartridge being adapted to fit removably within the interior of a pressure vessel heated to a supercritical temperature with respect to the said fluid, said vessel sealed and pressurized to a high and supercritical gauge pressure to allow supercritical fluid extraction of the said sample within the said cartridge, at least one of the said ends incorporating a fluid path from the said porous means to a first low pressure sealing means, said first low pressure sealing means cooperating with a mating low pressure sealing means which is part of the said pressure vessel, the said mating sealing means continuing the said flow path within it and having an outside surface in contact with the said pressure vessel interior, and the two said low pressure sealing means when coupled seal only up to a pressure difference between said inside flow path to said outside surface which is substantially lower than the said gauge pressure.

Dependencies are inferred from the claim text.

Facts

Application: 08/075,314Filed 11 Jun 1993 · division
Priority: 13 Jul 1990
Granted: 22 Mar 1994
Term ends: Not estimatedThe source records don’t support an estimate.

Classification30 codes

B01D 11/0203
Of solids: with a supercritical fluid
B01D 11/0407
With a supercritical fluid: the supercritical fluid acting as solvent for the solute
F04B 9/042
The means being cams, eccentrics or pin-and-slot mechanisms: the means being cams
F04B 15/08
For liquids near their boiling point, e.g. under subnormal pressure: the liquids having low boiling points

Family

Serial553,119Parent of this continuation-in-part · filed 13 Jul 1990
Serial795,987Parent of this continuation-in-part · filed 22 Nov 1991
Serial847,652Parent of this continuation-in-part · filed 5 Mar 1992
Serial966,083Parent of this division · filed 23 Oct 1992
US 5,173,188 AParent of this continuation-in-part
US 5,160,624 AParent of this continuation-in-part
US 5,094,753 AParent of this continuation-in-part
US 5,296,145 AThis patent

From the US filing history. Foreign family members aren’t listed.