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:
Jul. 02, 1991
Filed:
Aug. 28, 1990
William R Weltmer, Jr, New Providence, NJ (US);
Satish S Tamhankar, Scotch Plains, NJ (US);
The BOC Group, Inc., New Providence, NJ (US);
Abstract
The present invention provides a method for cleaning articles by removing surface particulate matter from the articles. In accordance with the present invention, the articles are immersed in a bath of liquid cryogen, chemically non-reactive with the articles to be cleaned. Prior to immersion it is necessary to insure that the articles have a sufficiently high temperature above that of the liquid cryogen and during immersion it is also necessary to insure that the articles are immersed at a sufficient rate to insure that the liquid cryogen undergoes film boiling before undergoing nucleate boiling at the surfaces of the articles. The articles are left immersed so that nucleate boiling of the liquid cryogen occurs at the surfaces of the articles. During the nucleate boiling, the surface particulate matter is carried from the articles and into the liquid cryogen bath. After the articles have reached thermal equilibrium with the liquid cryogen, the articles are removed from the bath. The method can be carried out in an atmospheric environment and at room temperature. In accordance with another aspect of the present invention, the articles can be rewarmed to room temperature in a moisture free environment to prevent atmospheric moisture from condensing on the articles.