【摘要】 通过冷,热态模拟试验,得到了中央送风冲天炉炉内气流运动、炉气成分分布和炉温分布的规律。在5t/h中央送风冲天炉上进行了现场试验,在焦铁比1∶10～11的情况下,出铁槽处铁水温度达到1440～1480℃,Si、Mn烧损在10—20％以内。对熔炼过程中Si、Mn烧损进行了理论分析,认为对这类冲天炉采用低风速进风熔炼是合理的。更多还原

【Abstract】 Bottom blasting cupolas have been in practical application to iron foundry over twenty years in China. It has been proved in practice and verified by simulating tests that bottom blasting cupolas are preferable to the conventional side blasting cupolas in blasting effect. As shown in Fig. 3, 4, 7 and 8 , the improvement on blast for bottom blasting cupolas is gained by their uniformly peripheral velocity profile and the better CO2 gas distribution in furnace as compared to the side blasting cupolas. The advantage of bottom blast cupola, however, did not give full play to improve the blast condition because of the smaller section area of tuyeres and, espeacially, the higher blast velocity up to 5C~100 m/s. The higher blast velocity has led both to lower the temperature of molten iron at tapping spout to 137C~1410℃ and to raise the melting losses of Si and Mn to so much as 35-45% respectively. With the cold and hot simulation, this paper investigates the rules of air flow movement and the distributions of CO2 gas and temperature in cupola at different blast velocities (cf. Fig. 1, 2, 5, 6, 9-12) . A conclusion is then reached that a lower blast velocity within the range of 28~32 m/s is suitable for keeping the bottom blasting cupola in better operation. Experiments show industrially that at such a blast velocity the bottom blasting cupola may ensure the temperature of molten iron at tapping spout up to 1440~1480℃ and both the melting losses of Si and Mn down to 10~20% on condition that the coke ratio is equal to 1:10~11 with nut cokes. As regards the melting losses of Si and Mn, a study has been made in the view of free energy to quantitatively analyze the oxidations and reductions of Si and Mn at different blast velocities. It is found that the lowerings of melting losses of Si and Mn at lower blast velocity are resulted from the increase in re-ducibjlities of Si and Mn instead of their oxidizabilities as commonly considered. The positions of Si and Mn melting losses are also to be found out.更多还原