| 摘要 |
PURPOSE:To enable control of temp. of exhaust gas with independently control of reduction degree by injecting fine powdered coal just above smelting reduction furnace, passing the exhaust gas through an exhaust gas reaction passage together with the fine powdered coal to reform the exhaust gas and supplying the exhaust gas into a pre-reduction furnace after adjusting the exhaust gas. CONSTITUTION:The fine powdered coal is added from fine powdered coal injecting part 3 arranging just above the smelting reduction furnace 1. The exhaust gas from the reduction furnace 1 is passed through the exhaust gas reaction vessel 4 together with the fine powdered coal. At front stage of the reaction vessel 4, as CO2 and H2O concns. in the exhaust are increased, reaction ratio of the fine powdered coal is improved and the reductibility of the exhaust gas is improved. The temp. of exhaust gas comes to high at front step gas discharging hole 5 and low at rear step gas discharging hole 6. The exhaust gases from both waste gas discharging holes 5, 6 are mixed, to supply into an ore pre-reduction furnace 12. Then, an exhaust gas flow rate and fine powdered coal injecting rate control device adjusts the fine powdered coal injecting rate and exhaust gas flow rate based on detected results of exhaust gas temp..flow rate measuring instruments 17, 18 and exhaust gas temp..flow rate.composition measuring instrument 19. |
