| 摘要 |
The invention mainly relates to a method for recirculating gas from a blast furnace in which at least part of the gases from the blast furnace are subjected to a CO2 purification step so as to create a gas that is rich in CO, which is then reinjected, at a first top injection point located above the base of the blast furnace and at a temperature of between 700 and 1000°C, through a top injection line, and through a second bottom injection point at the base of the blast furnace at a temperature of between 1000°C and 1300°C through a bottom injection line, wherein the gases from the top and bottom injection lines are heated with reheaters from which gases are discharged at a temperature of between 1000°C and 1300°C. The method of the invention is essentially characterized in that part of the CO-rich gas (18) being discharged from the purification step is directly injected into the top injection line (21) via a cold gas injection line (35) so as to result in a temperature of between 700 and 1000°C at the first top injection point (20), and in that the gas flow control in the bottom (22) and top (20) injection points takes place upstream from the reheater system (30,33; 45). The invention also relates to a device for implementing the abovementioned method. |
