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. 18, 1995
Filed:
Aug. 10, 1993
Robert T Brady, Elmhurst, IL (US);
Dean C Townsend, Northbrook, IL (US);
George A Weller, Blainville, CA;
Joseph H Werling, Mundelein, IL (US);
Mark IV Transportation Products Corporation, Niles, IL (US);
Abstract
A method and apparatus for low NOX combustion of natural gas in a compact steam boiler having output steam delivery controlled by predetermined outlet steam pressure. The compact boiler employs a small high heat release combustor discharging into a forced draft convective heat exchange section. In operation, the compact boiler is completely and automatically self-operating, employing flue gas recirculation (FGR) wherein the FGR is admitted into the burner combustion air through a valve controlled by boiler flue gas NOX content. A novel bell mouthed flue gas scoop is utilized in the boiler stack upstream of the NOX sensor. In an alternate combustion chamber design, a cylindrical water wall coil surrounds the combustion process, increasing boiler efficiency through the inherent large temperature difference between the coil and the combustion in process, along with reducing the combustion temperature and further reducing the NOX content of combustion products. A further variation in the combustion system utilizes a ceramic shield surrounding a natural gas burner as it fires into the compact combustion chamber. Primary and secondary combustion air are admitted to the combustion chamber through first stage combustion internal of the shell and second stage combustion occurring internal of the boiler combustion chamber.