Influence of furnace temperature and non-uniform heat flux density on direct reduction process of newly designed carbon containing pellet

炉膛温度和非均匀热流密度对新设计的含碳颗粒直接还原过程的影响

In this study,innovative ellipsoid pellet with craters on its surface was designed,and the direct reduction process was compared with ellipsoid(without craters)and sphere pellets.In addition,furnace temperature and uneven heat flux density effects on the pellet direct reduction process were also studied.The results show that ellipsoid pellet is better than that of spherical pellet on metallization ratio.However,under the condition of non-uniform heat flow,the ellipsoid pellet final metallization rate and zinc removal rate were lower.Although the heat transfer effect of ellipsoid pellet with craters was not improved significantly,the metallization rate and zinc removal rate were found improved,which will have a cumulative effect on the pellets direct reduction process in rotary hearth furnace.Under varying furnace temperature conditions,the pellet temperature was higher than that of the constant furnace temperature.After 1200 s,pellet Fe concentration increased to 123.6%,metallization rate and zinc removal rate increased to 113.7%and 102.2%,respectively.These results can provide references for the carbon-containing pellet design used in rotary hearth furnace.

本文设计了在表面上具有凹坑的新型椭圆形球团,并将其直接还原过程与椭圆形(无凹坑)和球形球团进行比较,进一步研究了炉膛温度和非均匀热流密度对上述球团直接还原过程的影响。结果表明,在还原所得金属化率方面,椭球球团优于球形球团。在非均匀热流密度的条件下,椭球球团的最终金属化率和除锌率较低。尽管具有表面凹坑的椭圆球团的传热效果改善不明显,但其金属化率和除锌率却得到了提高,这将对转底炉中球团的直接还原过程产生累积效应。在变化的炉温条件下,球团的温度高于恒定炉温情况。在还原1200 s后,球团中的铁的浓度增加到123.6%,金属化率和除锌率分别增加到113.7%和102.2%。这些结果可为转底炉中含碳球团的还原过程设计提供参考。