Reduced NOx method of combustion

Abstract

The present invention is a method for achieving low NOx single-stage combustion. A high velocity burner is run normally, with combustion occurring within both the burner combustion chamber and furnace chamber, until the gases within the furnace exceed the auto-ignition temperature of the gaseous fuel. The gaseous fuel is then shut off until the temperature within the burner combustion chamber drops below the auto-ignition temperature of the gaseous fuel. The gaseous fuel is then turned back on and the gaseous fuel auto ignites within the furnace chamber. The combustion then occurs only within the furnace chamber and not in the burner combustion chamber.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application No. 60 / 675,975 filed Apr. 29, 2005, which application is hereby incorporated by reference in its entirety.FIELD OF THE INVENTION [0002] The present invention is generally directed to a method of combustion and specifically directed to a low nitrogen oxide method of combustion. BACKGROUND OF THE INVENTION [0003] One of the by-products created by the combustion of hydrocarbon (HC) fuels in burners that use atmospheric air is nitrogen oxide (NOx). A well-known problem in the industry for many years with the use of conventional burner designs utilizing preheated combustion air is higher flame temperatures which in turn contribute to an exponential increase in NOx emissions. Efforts to save fuel and increase combustion efficiency via recuperative and / or regenerative combustion systems combined with increasingly strict governmental regulations to achieve acceptable NOx emissi...

AI Technical Summary

Benefits of technology

"The present invention provides a method for achieving low NOx single-stage combustion using a high velocity gaseous fuel burner that is currently installed without needing to alter it. The method involves mixing gaseous fuel with combustion air in a burner, flowing the mixture into a furnace chamber, and igniting it to form a flame. The flame is then stabilized by a flame stabilizer. The method results in low NOx emissions and can be used with existing burners."

Problems solved by technology

A well-known problem in the industry for many years with the use of conventional burner designs utilizing preheated combustion air is higher flame temperatures which in turn contribute to an exponential increase in NOx emissions.

However, these factors are difficult to predict because burners for different industrial processes must operate at various furnace chamber temperatures, have various oxygen concentrations in the work chambers, may or may not have preheated combustion air, and are required to operate at different heat inputs depending on changing heat load requirements.

However, the added capital expense for piping and controlling the recirculated flue gases are substantial.

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