Two dimensional analysis of burden flow in blast furnace based on plasticity theory.

Abstract

Using a two-dimensional cold model, the dynamic behavior of particles in blast furnace was studied on a detailed analysis of the flow pattern. The field of the flow was characterized with the stagnant region formed in the central lower part of the apparatus and the flow channels consisting of two regions, i.e., slow moving and fast moving regions. On crossing the boundary between the slow and fast moving regions, the particles experienced a discontinuous, sudden change in the velocity as well as the direction of flow. An approximate method of predicting the flow pattern is described on the basis of plasticity theory. The velocity discontinuous boundary could be theoretically represented by the characteristic curve of the velocity. The boundary of the stagnant region corresponded to the characteristic curve of the stress, so-called slip line. Finally, the flow patern of burden material in a practical blast furnace was simulated, based on the calculas presented.