Simulation on Optimizing the Elevation Angle of Tertiary Air in a 700t/d Glass Furnace for Clean Combustion

The high NO emission is one of the important factors limiting the sustainable development of glass furnaces. This paper uses numerical simulation to improve the combustion characteristics of glass furnaces and reduce NO emissions by changing the upward angle of the tertiary air (0°, 2°, 6° and 6/4/2°). The distribution laws of flow field, temperature field and NO concentration field in glass furnace under different conditions of upward angles for tertiary air are analyzed. And the most appropriate combination of tertiary air rising angles is determined. The results indicated that with the increase of the rising angle of the tertiary air, the high temperature area of the furnace crown was obviously reduced due to the interference of the longitudinal backflow of the furnace crown, which is beneficial to protect and prolong the service life of the furnace crown. Moreover, the NO concentration at the outlet of the furnace dropped significantly, and the higher average temperature was obtained which is beneficial for melting glass when the tertiary air was rose 6/4/2° respectively. Under this angle condition, the NO-emission was reduced by approximately 126 ppm. Thus, adjusting the upward angle of the tertiary air was conducive to facilitating NO-emission reduction and melting glass.