Experimental Evaluation of NOx Control Using a Glass-Tank Simulator

Abstract

This paper discusses the results of tests conducted on a 1/4-scale glass melter firing port to determine the effects of various burner operating parameters on NO/sub x/ mission levels. The burner port was designed for a firing rate of 3 million Btu/hr in consultation with a container glass manufacturer and was tested on a pilot-scale furnace. The furnace was operated at temperatures generally found in glass melters (2600/sup 0/ to 2850/sup 0/F). The furnace temperature was adjusted using water-cooling tubes as a load. We investigated combustion air preheat temperature (1600/sup 0/F to 2200/sup 0/F), air/fuel ratio (fuel rich to 8% excess oxygen), fuel injection velocity, turndown, and flue-gas recirculation (5% and 10%) and furnace wall temperature. NO/sub x/ levels decreased significantly with decreasing combustion air preheat temperature, decreasing furnace refractory temperature, and decreasing excess oxygen levels below 5% to 6%. Above 5% to 6% oxygen, the NO/sub x/ levels decreased with increasing oxygen levels. Though not as significant, NO/sub x/ levels were also reduced by varying degrees at reduced firing rate, reduced fuel injection velocity, and with flue-gas recirculation.