Submerged Combustion Melter

Submerged combustion melting (SCM) is an advanced, high-temperature melting technology in which fuel and oxidant are fired directly into a bath of material being melted. Combustion gases bubble through the melt, providing high heat transfer and turbulence, which leads to high mass transfer and a homogeneous product composition. Raw material requires little or no crushing and can be fed to the top of the bath. Raw material fines can be charged below the melt line to minimize fines carryover. Product melt is drained from a tap near the bottom of the melter. The Gas Institute (GI) developed the submerged combustion melting technology. Two 75-ton/day SCM units are in commercial operation for mineral wool production: one in Ukraine and one in Belarus. Recuperators on the commercial melters preheat combustion air to 575°F. Both melters operate with less than 10% excess air while generating very low CO and NOx (less than 100 vppm at 0% O2) emissions. The Gas Institute is focusing on improving thermal efficiency and production rate through development of a recuperator for 750°F combustion air preheat and a heat recovery batch (charge) preheater for batch preheat to 1650°F. The Institute of Gas Technology (IGT), in partnership with GI, has licensed the technology for world-wide application outside the former Soviet Union. A new, 6-ton/day pilot-scale SCM unit has been constructed and operated at IGT. This unit is serving as a demonstration and development tool for the production of a number of mineral melts and includes a choice between air gas burners and the first oxygen-gas burners. The pilot-scale melter system includes an advanced control system and a fines feeder for charging below the melt surface. This melter is being used to incorporate oxy-gas combustion and to develop the SCM technology for production of a number of mineral melts.