SYSTEM FOR COAL INJECTION IN IRON OXIDE REDUCING KILNS

摘要

IMPROVED SYSTEM FOR COAL INJECTION IN IRONOXIDE REDUCING KILNSAbstractA method and means for improved control of theprocess for directly reducing materials containingiron oxides in a rotary kiln using a solid carbo-naceous reducing agent, such as coal, introducedfrom the charge feed and discharge ends of the kiln,as the source of both fuel and reductant, andoxygen-containing gas introduced along the kilnlength, is disclosed wherein the portion of thereducing agent fed at the discharge end is injectedin the form of two or more streams through thedischarge end of the kiln onto the charge bed insuch manner as to permit close and efficient controlof the process, particularly when carried out inlarger kilns. The important features in creatingand distributing the streams over the bed aredescribed including their longitudinaldistribution and axial spread, as well as theircontact regions with the kiln interior side wallsand the quadrants of the kiln barrel into which theyare directed, to meet the incremental heat demandsalong the successive segments of the charge bed,whereby the bed and gas phase temperatures may becontrolled and heat transfer to the bed enhanced.2.