Patent ID: 8056366

Claim:
A glassmelting method comprising (A) passing heated glassmaking material into a glassmelting furnace; (B) combusting fuel with oxidant having an overall average oxygen content of at least 35 vol. % oxygen to produce heat for melting said heated glassmaking material in said glassmelting furnace and produce hot combustion products having a temperature greater than 982Â° C. (1800Â° F.); (C) withdrawing said hot combustion products from said glassmelting furnace and feeding said hot combustion products into a first passageway of a heat exchange unit, wherein the temperature of said hot combustion products entering said first passageway is at least 982Â° C. (1800Â° F.); (D) flowing said hot combustion products through and out of said first passageway; (E) feeding glassmaking material into and through a second passageway of said heat exchange unit that is separated from said first passageway by a barrier through which said glassmaking material and said hot combustion products cannot pass and through which heat from said hot combustion products passes to said glassmaking material to form said heated glassmaking material; and (F) maintaining heat flux from hot combustion products in said first passageway to said barrier sufficient that the temperature of the surface of said barrier that is in contact with said glassmaking material does not exceed 871Â° C. (1600Â° F.) and that the temperature of said glassmaking material does not reach or exceed the temperature at which the glassmaking material becomes adherent.