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:
Sep. 15, 1992
Filed:
Jul. 18, 1991
Keith M Grahl, Fort Smith, AR (US);
Larry R Mullens, Fort Smith, AR (US);
Rheem Manufacturing Company, New York, NY (US);
Abstract
Elongated metal devices are coaxially inserted into, and closely received within, inlet end portions of the heat exchanger combustor tubes of a fuel-fired heating appliance, representatively a forced air heating furnace. The inserted devices function to substantially reduce the NO.sub.x content of the combustion gases ultimately discharged from the furnace by intercepting, dispersing, and thermally quenching the burner flames drawn through the combustor tubes by a draft inducer fan portion of the furnace. Each device is formed by a pair of elongated, generally rectangular slotted metal plate members which are longitudinally overlapped and transversely secured to one another in a manner providing the device with a generally cross-shaped cross section along its length. Elongated slots are formed in the four outer side edges of the device for operational sound reduction purposes. An alternate embodiment of the device is formed by welding together two elongated metal members each having an L-shaped cross section. Due to the cross-sectional configurations of the devices, they perform their NO.sub.x reducing functions without generating an appreciable amount of noise during operation of their associated furnace. The improved furnace is accordingly suitable for indoor residential installations. The devices may also be incorporated in the combustor tubes of other types of fuel-fired heating appliances such as water heaters and boilers.