Disintegration of Pseudo-particles in the Moving Bed

Abstract

Material disintegration in the blast furnace should be relative not only to the material strength but also to the stresses in the furnace. However, there are only few papers on the particle disintegration related to stresses.
Disintegration of pseudo-particles in the moving bed was investigated by using the reduced scale model of Hirohata No. 4 blast furnace. Normal stresses in the model were also measured and analyzed in relation to the particle disintegration.
As a result, the followings were clarified. Most of the particle disintegration occured at the periphery of the model. The generation rate of fine particle in the lower part was higher than that in the upper part. Particles were highly disintegrated when a large dead zone was temporarily formed at the wall. Through the comparison of the stresses with the particle strength, it was suggested that the shear stress causes the particle disintegration. Maximum shear stress possibly acts on the particles at the boundary of the temporary dead zone. The shear stress possibly varies in accordance with the temporary dead zone growth.
When the strength of the materials charged into the blast furnace is lower than the shear stress, the materials will enormously be disintegrated.