PURPOSE: To upgrade the efficiency of titled recovery with small-size equipment, by directly turning and driving a blower by a blast furnace gas turbine and using driving equipment depending upon an external power source when the turbine output is deficient.

CONSTITUTION: Blower 10, which is initially started by driving equipment 20 connected with an external power source, supplies high pressure hot air through hot air furnace 12 to blast furnace 14. When blast furnace gas is exhausted from the top owing to a reaction within blast furnace 14, the gas is supplied via dust remover 22 and emergency shut off valve 24 to blast furnace gas turbine 26 to turn and drive the gas turbine. The gas turbine 26 in turn directly turns and drives the blower 10. After blower 10 is drived by gas turbine 26, equipment 20 is used only for making up for a deficiency in the output of gas turbine 26. In the failure of recovering equipment, e.g. turbine 26, emergency shut off valves 24 and 30 are closed, and the pressure of blast furnace gas is reduced through reducing valve 36 to supply the gas into a blast furnace gas reservoir 32, and at the same time, connecter 28 is cut off to shut down turbine 26.