a continuous glass - melting tank furnace includes a melting compartment including a melting tank having a lower part , and a superstructure equipped with heaters for receiving and melting raw batch material . additionally included is a separate refining compartment including a refining tank and a superstructure equipped with a further heater , the refining tank having a lower part and including a transverse sill which divides the refining tank into an upstream refining cell and a downstream refining cell , each of the upstream refining cell and the downstream refining cell having respective upstream ends and downstream ends , and the further heater being arranged to heat melt in the upstream refining cell for creating a spring zone located closer to the downstream end of the upstream refining cell and a circulation of melt in the upstream refining cell which feeds the spring zone . a throat allowing communication between the lower parts of the melting tank and the refining tank , and a conditioning tank for receiving melt from the refining tank are also included .