Methods for cleaning apparatus using compressed fluids
AssigneeUnion Carbide Chemicals & Plastics Technology Corporation
InventorsKenneth L. Hoy, Kenneth A. Nielsen
Life of this patent
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Abstract
The application contains subject matter related to cleaning mixtures and methods for using such cleaning mixtures to clean apparatus which contain one or more polymeric compounds wherein said cleaning mixture is comprised of at least one compressed fluid and at least one active solvent in which said at least one or more polymeric compounds are at least partially soluble and which is at least partially miscible with the at least one compressed fluid, said compressed fluid being a gas at standard conditions of 0.degree. C. and one atmosphere (STP), which cleaning mixture is in one phase and at a pressure at which the cleaning mixture is substantially near its two phase region.
Claims44
A method of cleaning apparatus containing one or more polymeric compounds which comprises:
- a) forming a one phase, liquid cleaning mixture comprising:
- (i) a compressed fluid fraction containing at least one compressed fluid, said compressed fluid being a gas at standard conditions of 0.degree. C. and one atmosphere (STP);
- and
- (ii) a solvent fraction containing at least one active solvent component in which said at least one or more polymeric compounds are at least partially soluble and which is at least partially miscible with the at least one compressed fluid component;
- and
- b) passing said liquid cleaning mixture through the apparatus at a pressure at which the cleaning mixture and the polymer dissolved therein is substantially near its two fluid phase boundary region.
A method for cleaning spray apparatus in which a liquid composition comprised of at least one or more polymeric compounds, one or more organic solvents in which the polymeric compounds are at least partially soluble, and at least one compressed fluid is sprayed at a pressure P.sub.1 comprising:
- a) spraying said liquid composition at pressure P.sub.1 ;
- b) stopping the spray of the liquid composition in the spray apparatus;
- c) forming a one phase, liquid cleaning mixture comprising:
- (i) a compressed fluid fraction containing at least one compressed fluid, said compressed fluid being a gas at standard conditions of 0.degree. C. and one atmosphere (STP);
- and
- (ii) a solvent fraction containing at least one active solvent component in which said at least one or more polymeric compounds are at least partially soluble and which is at least partially miscible with the at least one compressed fluid component;
- and
- d) passing said liquid cleaning mixture through the spray apparatus at a pressure P.sub.2, where P.sub.2 is greater than P.sub.1 such that polymer is dissolved in said cleaning mixture.
Dependencies are inferred from the claim text.