A mathematical and physical representation of the raceway region in the iron blast furnace

Abstract

Through the establishment of a macroscopic momentum balance a mathematical representation has been developed for predicting the size of the raceway region in blast furnaces. The formulation involved the establishment of a force balance where the radial momentum transfer from the incoming gas was balanced against the weight of the bed. The predictions based on the analysis were compared to experimental measurements on both two and three dimensional systems using solid particles of varying shape, size and density. Reasonable agreement was obtained between measurements and predictions and it was found that for small and light particles and for high blast rates the size of the raceway could be predicted from first principles without recourse to empirical correction factors. The predictions based on the analysis were also consistent with previous measurements of Elliott and Wagstaff on both laboratory scale models and operating blast furnaces. It was thus shown that the analysis developed in the paper may be used for estimating the size of the raceway in blast furnaces from first principles without recourse to empirical correlations.