Development of the direct measurement technology of the cohesive zone and the structure of the root of the cohesive zone during the operation of the large blast furnace

A belly probe was newly developed at Oita No. 2 blast furnace. It has the function of observing directly the furnace conditions and measuring the solid temperature by an image fiberscope, identifying and measuring layer structure by a microwave during operation, gas temperature and gas composition measurement and taking burden material samples during scheduled shutdown. The conditions of the lower part of the furnace during operation were observed successfully. Some knowledge relating to the cohesive zone and its surrounding neighborhood were obtained through our measurements. The results are summarized as follows: 1) The burden materials were observed layer by layer and were found to occasionally be inclined. The maximum inclination angle was estimated to be about 20 degrees. 2) The coke between the cohesive zone and the deadman was observed, as an image, to be floating. The gas volume flowing in this region was estimated to be about at least one third of the bosh gas volume and the gas volume distribution at the lower part of the furnace was estimated to be relatively large.