US PATENT SUBCLASS 210 / 634
.~ Liquid/liquid solvent or colloidal extraction or diffusing or passing through septum selective as to material of a component of liquid; such diffusing or passing being effected by other than only an ion exchange or sorption process

Current as of: June, 1999
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210 /   HD   LIQUID PURIFICATION OR SEPARATION

600  DF  PROCESSES {14}
634.~ Liquid/liquid solvent or colloidal extraction or diffusing or passing through septum selective as to material of a component of liquid; such diffusing or passing being effected by other than only an ion exchange or sorption process {11}
635  DF  .~.~> Liquid/liquid or gel type (i.e., jellylike) chromatography
636  DF  .~.~> Including cleaning or sterilizing of apparatus
637  DF  .~.~> Including regulating pressure to control constituent gradient at membrane or to prevent rupture of membrane
638  DF  .~.~> Including ion exchange or other chemical reaction
639  DF  .~.~> Including prior use of additive (e.g., changing pH, etc.)
640  DF  .~.~> Passing through membrane in vapor phase
641  DF  .~.~> Utilizing plural diverse membranes
642  DF  .~.~> Extracting water from brine utilizing liquid/liquid solvent or colloidal extraction
643  DF  .~.~> Utilizing liquid membrane (e.g., emulsion) in liquid/liquid solvent or colloidal extraction
644  DF  .~.~> Diffusing or passing through septum selective as to material of a component in liquid/liquid solvent or colloidal extraction {2}
649  DF  .~.~> Diffusing or passing through septum selective as to material of a component of liquid {1}

DEFINITION

Classification: 210/634

Liquid/liquid solvent or colloidal extraction or diffusing or passing through septum selective as to material of a component of liquid; such diffusing or passing being effected by other than only an ion exchange or sorption process:

(under subclass 600) Process in which either (a) a dissolved or suspended constituent of the liquid is preferentially dissolved or dispersed into a second liquid, or (b) a constituent of the liquid is selectively allowed to migrate through a barrier.

(1) Note. The liquid/liquid extraction may be by direct contact of the liquids or through a permeable barrier (dialysis). While in the second situation (b of this definition) the barrier allows selective migration (is semipermeable), in liquid/liquid extraction, the barrier, per se, need not be semipermeable.

(2) Note. The constituent which transfers must be dissolved or colloidally suspended in the second liquid and not merely removed as a floated or precipitated solid.

(3) Note. No distinction is made as to the nature of the constituent which is removed; it may be considered a solute, solvent, or both, or additive, etc.

(4) Note. The mechanism by which the constituent is separated from the liquid through the membrane is more than mere microfiltration, being based on the materials of the liquid and the membrane, and is discussed in Kirk-Othmer Encyclopedia of Chemistry-Dialysis-Vol. 7; and Osmosis, Osmotic Pressure - Vol. 14.

(5) Note. The processes provided for in different subclasses of this class utilize similar functions based on relative attraction or repellancy of materials. See the notes below and the Search This Class, Subclass references for the distinction between the concepts. Processes of other subclasses require solid material as an agent (often granular or in divided form) which tends to trap or capture on its surface or within its cavities, a constituent to be removed from a liquid. See Search This Class, Subclass, below In this subclass (634) and that above it, processes which are directed to extraction utilize a liquid (or a solid which becomes liquid-the solute). In processes which are directed to diffusing through a septum, a constituent appears to become incorporated temporarily into the material of the septum (not merely at the surface or in cavities, but throughout) and is not retained but exudes from the downstream side of the septum. During the diffusion the material passed and the material of the septum appear to form a solid solution with a concentration gradiant along the path of diffusion. See the Search This Class, Subclass notes for provision for liquid/liquid chromatography. Filtration to an extremely fine degree, e.g., ultra- or hyper-filtration, where separation is achieved by using an element with interstices so small that it prevents passage of very small particles (even down to colloidal size) is provided for elsewhere see Search This Class, Subclass, below. Some documents refer to dialysis and osmosis (reverse) as ultrafiltration or hyperfiltration. When there is confusion or doubt whether hyperfiltration or ultrafiltration is due to pore or interstices size or attraction-repulsion due to chemical nature of a membrane or septum, placement of the document should be in the appropriate first appearing subclass.

SEE OR SEARCH THIS CLASS, SUBCLASS: 635, for liquid/liquid chromatography, because a liquid/liquid solvent or colloidal extraction function is performed and this appears before chromatography in the schedule.

656+, 660+ require solid material as an agent (often granular

or in divided form) which tends to trap or capture on its surface or within its cavities, a constituent to be removed from a liquid. The method of subclasses 656+ is a species of the art of subclass 660 and in both situations the agent utilized remains a solid and retains the constituent which is removed.

767, for filtration to an extremely fine degree, e.g., ultra- or hyper-filtration, where separation is achieved by using an element with interstices so small that it prevents passage of very small particles (even down to colloidal size).