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. 07, 1979
Filed:
Jun. 09, 1977
Robert D MacDonald, Phoenix, AZ (US);
Robert K Rose, Burnt Hills, NY (US);
John W Papsdorf, Lake Orion, MI (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
Fluid-carrying tubes for a heat exchanger are provided with internal longitudinal fins formed separately from the tube itself. One form utilizes individual elongated V-shaped strips biased radially outwardly by an annular sheet metal spring, with the tips of the fins brazed to the inner surface of the tube wall. Second and third embodiments utilize a one-piece corrugated sheet metal cylinder rather than individual strips, but with adjacent fins being almost completely severed from each other to provide sharp edge contact between the tips of the fins and the tube wall for optimum brazing. Either the fins or tube inner wall is clad with a lower-melting point material which permits furnace brazing of the fin tips to the tube wall. All three forms have longitudinally spaced holes and slots to enhance heat exchange by inducing transverse fluid flow through the fins and to allow liquid levels to equalize.