Patent ID: 6289694
Filing Date: 2001-09-18
Classification: C03B,F23C,Y02P

Abstract:
A process for melting glass from charging material, which charging material begins to stick at a predetermined temperature, in U-flame and cross-fired furnaces with burners for fossil fuels and with regenerators for recovery of waste heat from waste gases for preheating combustion air, comprising the steps of:adding controlled quantities of oxygen and primary fuel in an area around flame roots at said burners under slightly sub-stoichiometric conditions to provide an amount of heat required for the melting process,adding secondary fuel and additional air further downstream of the flame to further reduce NO.sub.x, and CO contents of the waste gases by re-burning beyond the flame,such adding occurring in such a way that ultimately approximately stoichiometric combustion takes place using the waste gases to preheat the charging material in at least one raw material pre-heater before the waste gases enter a waste gas stack,measuring a temperature of the waste gases from the regenerators in front of an entry of the at least one raw material pre-heater, andadjusting a quantity of the secondary fuel in accordance with the temperatures measured, so that the temperature of the waste gases in front of the entry into the at least one raw material pre-heater is at least 400.degree. C.