The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 31, 1994
Filed:
Aug. 10, 1992
Sidney C Chao, Manhattan Beach, CA (US);
Edna M Purer, Los Angeles, CA (US);
Thomas B Stanford, San Pedro, CA (US);
Carl W Townsend, Los Angeles, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
Undesired material is removed from a chosen substrate by a process comprising the steps of (a) placing the substrate containing the undesired material in a cleaning chamber provided with cavitation-producing means; (b) introducing a liquefied gas, such as liquid carbon dioxide, into the cleaning chamber and contacting the substrate containing the undesired material with the liquid carbon dioxide at a temperature below its critical temperature; and (c) exposing the liquid carbon dioxide to the cavitation-producing means for a period of time sufficient to remove the undesired material from the substrate. The substrate containing the undesired material may optionally be contacted with carbon dioxide in the dense phase prior to and/or after the cavitation treatment to aid in removal of the undesired material. Further, spent liquid carbon dioxide may be treated to regenerate fresh liquid carbon dioxide which is recycled to the cleaning chamber. Other gases besides carbon dioxide which may be used include nitrous oxide, sulfur hexafluoride, and xenon.