Abstract: A practical 3-dimensional mathematical model of a float glass tank furnace incorporating the batch melting process has been formulated.As for the boundary condition ofheat transfer on the batch and glass surfaces,a semiempirical model of heat transfer betweenflame and batch/glass was suggested.The model equations were solved by using SIMPLECScheme. By computation,the velocity and temperature distribution in a float glass tank werestudied.It was found that a special circulation current existed near charge end.The computation also showed that the upper glass flow under batch moved towards the center line fromboth side walls,just on the contrary of the case near hotspot.