The Effect of the Speed of Rotation on Segregation of Particles in a Horizontal Rotary Conical Vessel

Abstract

In order to discuss the axial segregation of solid mixture in a horizontal rotary vessel, the experiments were carried out by using a horizontal conical vessel of 12.5cm inside diameter of one end, where the diameter of the vessel is a minimum, 24.5cm in i. d. of the other end, where the diameter is the maximum, and 30cm in length. As materials, three kinds of mixtures were prepared.As the result of the experiments, the larger particles of silica sand mixture having size distribution move to the point of the maximum inside diameter, and the smaller particles segregate near the end of the maximum diameter of the conical vessel at lower speed of rotation (at 20≤n<80 r.p.m.). The smaller particles migrate toward the point of smaller diameter at 80<n≤100 r.p.m., and this tendency of the segregation is contrary to the result of the segregation at n<80 r.p.m.. Most of spherical silicagel particles of the binary solid mixture which consists of spherical and irregular silica gel of nearly the same size are segregated near the end of the minimum diameter at 15≤n<80 r.p.m. and the irregular particles are collected at the point of smaller diameter at 80<n≤100 r.p.m.. The irregular particles of the binary solid mixture, whose diameter is larger than that of the spherical particles in Weigels diameter, are segregated near the end of the minimum diameter of the vessel at n=15 r.p.m.. At about 80 r.p.m., the degree of these axial segregations decreases.These experimental results are discussed on the basis of a few characteristics of cascading particles in a rotary cylinder and the shape of the conical vessel.