Effects of granulator structure and cooperating mode with slag tube on the centrifugal granulation characteristics of molten slag

Abstract

Molten slag flows to the edge of the rotating cup and is rapidly broken into droplets under the centrifugal force provided by the high-speed rotating cup. The diameter of the droplets is closely related to subsequent waste heat recovery and resource utilization. To clarify the law of centrifugal granulation of molten slag, the effects of the structure parameters of the rotating cup, the way the slag tube and the rotating cup are matched, and the eccentricity on characteristics of molten slag are investigated in the paper. In the present work, an unsteady, three dimensional, and two-phase model is established to analyze the influence of the above factors on the particle size distribution, average particle size, and maximum and minimum particle size of the granulated slags. As a result, in the range of 0–45°, the increase of the inclination of the inner wall surface of the rotating cup can strengthen the granulation effect. To ensure the granulation effect, the ratio of the diameter of the slag tube to the rotating cup should not exceed 0.44, and the installation height of the slag tube should be as close as possible to the granulator. Moreover, to make the particle size uniform after granulation, the slag eccentricity is kept within 5%. Finally, the dimensionless correlation of the diameter of droplets was obtained to guide industrial practice to control the particle size of the granulated slag particles in the paper.