著者

Toshiyuki Hirosawa Akinori Murao Nobuyuki Oyama Shiro Watakabe Michitaka Sato

出版者

The Iron and Steel Institute of Japan

雑誌

ISIJ International (ISSN:09151559)

巻号頁・発行日

vol.55, no.6, pp.1321-1326, 2015-06-15 (Released:2015-06-20)

参考文献数

12

被引用文献数

4 6

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The use of high reactivity coke is a technology that dramatically improves the reaction efficiency in blast furnaces by decreasing the temperature of the thermal reserve zone. In this study, a blast furnace shaft simulator was developed to estimate the temperature of the thermal reserve zone and the distributions of the temperature and gas composition in the blast furnace when using cokes with different reactivity. The shaft simulator combines an experimental reaction furnace and a calculation model. Chemical reaction and mass/heat transfer phenomena in the blast furnace are considered in the calculation model so as to calculate the ore and coke reaction rate and the distribution of temperature and gas composition. Relatively small amounts of packed coke and sinter specimens are reacted with the temperature and gas composition controlled based on the calculation results. The coke gasification rate is fed back to the calculation model, and it is then possible to estimate the temperature of the thermal reserve zone and the distributions of the temperature and gas composition in the blast furnace. Shaft simulator experiments with high reactivity coke, such as CIC (Carbon Iron Composite), showed that the temperature of the thermal reserve zone is 140 K lower with high reactivity coke than with conventional coke.

著者

Kazuhira Ichikawa Yusuke Kashihara Nobuyuki Oyama Toshiyuki Hirosawa Jun Ishii Michitaka Sato Hidetoshi Matsuno

出版者

The Iron and Steel Institute of Japan

雑誌

ISIJ International (ISSN:09151559)

巻号頁・発行日

vol.57, no.2, pp.254-261, 2017-02-15 (Released:2017-02-16)

参考文献数

22

被引用文献数

11 14

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Recently, low coke rate blast furnace operation has been required in response to the rising cost of coking coal. However, the thickness of the coke layer decreases in low coke rate operation. Since it is known that the gas permeability of the blast furnace deteriorates as the coke layer thickness decreases, it is important to determine the minimum coke layer thickness for stable blast furnace operation. On the other hand, the minimum coke layer thickness has not been clarified due to a lack of equipment capable of measuring the effect of the coke layer thickness on permeability.In this study, a new experimental device called the cohesive zone simulator was developed to clarify the minimum coke layer thickness. In the cohesive zone, gas flows horizontally along the coke layer. In order to quantify the effect of the coke layer thickness on permeability, this horizontal gas flow should be simulated. Therefore, this simulator simulates a horizontal gas flow.Next, the effect of the coke layer thickness was quantified by using the cohesive zone simulator. The results showed that melting iron ore penetrated into the coke layer and closed part of the layer. These phenomena caused a deterioration of permeability under thin coke layer thickness conditions.Finally, a pressure drop estimation model considering penetration of the coke layer by melting ore was developed with the aim of quantifying the minimum coke slit thickness.