Improvement of gas flow through analyzing discharge behavior in the bunker used in blast furnace

Abstract

According to the analysis of solid flow behavior in center feed/parallel bunker through videotaping, the flow pattern was changed from plug flow at the initial stage to funnel flow after the middle stage irrespective of the bunker type. As there were some structural parts such as stone box in the bunker, which changes the direction of solid flow, it resulted in the shape change of burden layer, and brought about the particle size distribution in the bunker. Consequently, it was found that the flow pattern and the shape of burden layer in the bunker determined the particle size distribution in the radial direction of the blast furnace. By attaching a central chute around the stone box in the lower bunker, the shape of burden layer was modified to obtain the central gas flow in the blast furnace without removing the stone box. The mechanism of flow region formation at the initial discharge stage was analyzed by an approximate stress analysis based on the method of differential slice.