A Quantitative Description of Void Distributions in Blast Furnace Raceway

A void distribution in a blast furnace raceway significantly affects the results of numerical simulations for the raceway combustion zone. Despite its importance, technical difficulty in measuring this physical property had left a quantitative description out of reach.In the present paper, the direct measurement of raceway void distributions was attained in a three-dimensional cold model with the aid of laser sensors. Measured void fractions clarified the typical distribution pattern in a raceway, showing the inlet region with relatively high and constant void fractions(the gas core region) from the tuyere tip to the middle part of the raceway, followed by the linear decrease of voidage toward the raceway boundary. The extent of the gas core region was used to achieve the non-dimensional representaion for the axial void distribution, and was successfully estimated by the newly established correlation between a gas core length(DM), a tuyere diameter(DT) and a raceway factor (Rf), expressed by DM/DT=0.0963Rf0.546.