Patent ID: 6519973
Filing Date: 2003-02-18
Classification: C03B,Y02P

Abstract:
In a process for melting glass forming ingredients in a furnace by both air-fuel combustion and oxy-fuel combustion wherein:(a) the furnace has a charging end, a discharge end, a melting zone adjacent the charging end and a fining zone adjacent the discharge end; (b) the glass forming ingredients are introduced into the melting zone, travel along a path from the melting zone to the fining zone and are withdrawn as molten glass from the fining zone; and (c) there is a combustion energy requirement over both the melting zone and the fining zone; and (d) the oxy-fuel combustion is provided by at least one oxy-fuel burner producing an oxy-fuel combustion flame directed toward the glass forming ingredients at an angle between 0Â° and 30Â° to the horizontal; and (e) the air-fuel combustion is provided by at least one air-fuel burner producing an air-fuel combustion flame; the improvement comprising: (i) providing a majority of the combustion energy over the melting zone by oxy-fuel combustion where the oxidant is between 50 and 100% oxygen; and (ii) providing a majority of the combustion energy over the fining zone by air-fuel combustion where the oxidant is between about 21% and 30% oxygen.