Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Two Dimensional Cold Model Study on Unstable Solid Descending Motion and Control in Blast Furnace Operation with Low Reducing Agents Rate
Author information

2006 Volume 92 Issue 12 Pages 996-1005


Unsteady behavior with bridging/slipping of solid bed in low reducing agents operation of blast furnace was simulated using a two dimensional cold model. Alumina sphere was used as representative particle of coke/ore packed bed. Two kinds of deadman particles different in gas permeability was examined. To simulate the effect of cohesive zone on unsteady behavior, a sand layer of lower gas-permeability was charged with a certain thickness at the top of the bed, which descended with a form of cohesive zone when it reached at the lower part. Further, a fine coke layer was set at the shaft bottom with a certain size assuming accumulation of fines. Unsteady phenomenon with the fine coke accumulation was also observed with another thin sand layers, charged in the shaft assuming increase of gas-permeability resistance in reducing coke supply operation. It was revealed that the ratio of peripherally flowing rate of tuyere gas had a considerable effect on the discontinuous behavior of both solid descending motion and gas static pressure. The ratio increased with decline in deadman gas-permeability, approach of the simulated cohesive zone to deadman surface and inflow of small particles into raceway. There was a lowest critical position of the simulated cohesive zone for the rapid increase of discontinuity. The bridging/slipping behavior with fines accumulation was significantly affected by the low gas-permeability layers charged in shaft. Setting up the chimney zone of high gas-permeability at the central part was effective to decrease the discontinuous motion.

Information related to the author
© The Iron and Steel Institute of Japan
Previous article Next article