Primary measures for the ΝΟx reduction on glass melting furnaces

Abstract

On a producing horseshoe furnace fired with natural gas experiments were carried out to reduce the NOx emission by primary measures. After optimizing the combustion conditions flue gas recirculation and air staging were tested as new measures. To ensure a complete combustion the CO content of the flue gases was limited to values of less than 1000 mg/m3, measuring the CO content at the top of the regenerator. The recirculated flue gas was used to replace the primary air. The ΝΟx content obtained by flue gas recirculation in combination with other measures was about half of the original value. The air staging was realized by branching a part of the preheated combustion air from the top of the regenerator and feeding the air over existing sight holes to the combustion space. The preheated air was transported using a jet pump. This measure established ΝΟx contents in the flue gas which were less than 1000 mg/m3.