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:
Aug. 15, 1995
Filed:
Sep. 21, 1993
Sivaramasubramanian Ramachandran, Warrington, PA (US);
Alfred U Boehm, Chalfont, PA (US);
MG Industries, Malvern, PA (US);
Abstract
The interior of a gas cylinder is cleaned using a supercritical fluid. A treating material, such as carbon dioxide, is injected into the cylinder, and the pressure in the cylinder is increased until the pressure of the treating material exceeds its critical pressure. Then, the cylinder is heated until the temperature of the treating material exceeds its critical temperature. The treating material therefore becomes a supercritical fluid. The treating material is maintained in its supercritical state while the cylinder is rolled for a period of time, while the supercritical fluid dissolves contaminants on the interior surface of the cylinder, and on objects within the cylinder. Then, the supercritical fluid is vented from the cylinder, preferably while the fluid in the cylinder is maintained in its supercritical state. This process provides exceptionally thorough cleaning of the interior of the cylinder, and makes it possible to provide a cylinder gas having a level of contaminants of the order of parts per billion or better.