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:
Dec. 21, 1993
Filed:
Apr. 02, 1993
Lin-Tao Lu, Fort Smith, AR (US);
Ali Shenasa, Fort Smith, AR (US);
Diane M Jakobs, Alma, AR (US);
Gallen W Stokes, Fort Smith, AR (US);
Rheem Manufacturing Company, New York, NY (US);
Abstract
A fuel-fired condensing furnace is provided with a specially designed heat exchanger structure having a metal primary section and a plastic secondary or recuperative section. The primary section is defined by a horizontally spaced series of identically sized, vertically serpentined metal combustor tubes adapted to receive a throughflow of a burning fuel-air mixture discharged from the furnace burner section. Each tube has an essentially straight inlet combustion section sized to permit essentially complete combustion therein of the burning fuel-air mixture received by the tube, and a plurality of vertically spaced horizontal heat transfer sections that are horizontally flattened and narrowed to enhance their combustion heat transfer to supply air being forced upwardly through the furnace housing. The heat transfer efficiency of the flattened tube sections is further enhanced by forming spaced series of indentations in their flattened opposite side walls to create combustion gas flow turbulence within their interiors, and air flow turbulence along their exterior surfaces.