Evaluation and Improvement of Circumferential Uniformity for Blast Furnace Raceway

The bustle pipe model of a running 2 500 m(3) blast furnace was established. The local and overall uniformity indexes of the raceway were defined and constructed. And then the effects of blast flow rate, the diameter and length of all tuyeres or No. 2 tuyere on the circumferential uniformity of raceway were quantitatively evaluated. It was shown that the circumferential uniformity of raceway decreased with the increasing blast flow rate, and when the blast flow rate increased from 4 300 m 3 /min to 4 700 m(3)/min, the circumferential uniformity index of raceway decreased from 0.1715 to 0.0760. The diameter of tuyere had a significant effect on the circumferential uniformity, while the length of tuyere showed little influence. The circumferential uniformity of raceway could be improved by increasing the diameter of all tuyeres or No. 2 tuyere with the minimum blast kinetic energy. When the diameter of all tuyeres increased to 140 mm, the overall uniformity index of raceway increased to 0.207, but the blast kinetic energy was only about 64 kJ/s which couldn't meet the smelting. requirement. While the diameter of No. 2 tuyere near the hot blast main increased to 126 mm, the overall uniformity of the raceway increased to 0.124, and the blast kinetic energy was 120.11 kJ/s which was still within the reasonable range. it was feasible to improve the circumferential uniformity of raceway by adjusting the diameter of one or some off-average tuyeres but not all.