| ‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘ KAWASAKI STEEL TECHNICAL REPORT No.38 ( April 1998 ) Ironmaking Technology and Tubular Products Technology ‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘ |
| Prediction of Blended Coal Fluidity and Lateral
Contraction of Coal in Coke Ovens -Technology
for Increasing the Charging Ratio of Low
Quality Coal in Cokemaking- Takashi Matsui, Katsutoshi Igawa, Ken-ichi Sorimachi |
| Synopsis: New models for estimating the maximum fluidity (MF) of blended coal and the clearance between the coke oven wall and coke cake were developed to reduce hard pushing rate in coke ovens. In the MF model, heated coal during carbonization is regarded as a suspension composed of melted coal, unmelted coal and solidified coke. The viscosity of the suspension was evaluated by Mori's equation, which included the viscosity of the solvent and volume fractions of solid. The clearance model is based on the balance between the contraction force and coking pressure. A clearance begins to appear when the contraction force exceeds the coking pressure in this model. The contraction force is calculated in consideration of the visco-elastic behavior of the thermal shrinkage of coke. The coking pressure is calculated from the generation and dispersion of gas in the melting layer. Use of these models in the coal blending design system has successfully reduced the hard pushing rate. Moreover, precise control of coke strength with the new system has make it possible to increase the use of low-grade coal. |
| TextiPDF: 6p./287kbj |