ADMIXTURE EFFECT OF LANCE ARRANGEMENT ON PULVERIZED COAL INJECTION

摘要

The dye injection method is employed to visualize two-dimensional admixture and diffusion of pulverized coal injected into the blowpipe in the blast furnace. Both the single lance and the double lances are studied. Water is used as working fluid. The velocity ratio and the lance inlet are varied. The lance inlet-angle is fixed as 13°. The jet-width growth rates and the trajectories of jets are not obviously influenced by the velocity ratio in the range 0.1 ≤ v/U ≤ 0.18. For the double lances, much faster jet-width growth rates than those for the single lance under the same test conditions were disclosed, but the flows gradually move away from the center of the blowpipe after impinging. In contrast, the eccentric double lances, two lances arranged asymmetrically to avoid impingement of two coal flows and obtain excellent jet-width growth rates, are suggested in the study for pulverized coal injection.