Mixing of Solid Particles in a Vertical Cylindrical Vessel

Abstract

To investigate the influence of operational condition affecting the mixing performance in a continuous mixer, we have made some experiments using a simple mixer with multiple blades.In this study, the experiments were carried out by sampling and inpulse response method using Toyoura Standard Sand, with coloured sand and salts as tracer, and we investigated chiefly the mixing state of particles in the vessel when the depth of the particle layer was many times larger than the diameter. The results obtained are as follows:1) The mass of particles fed from the upper part of the agitator, is pushed out toward the wall side of the vessel as the blade moves, and then it flows down to the bottom with spiral rotation. Near the axis of the agitator, the separate zone is formed, in which particles moves slowly than other.2) It may be applied “The Distributed Side Capasity Model” to the experimental response curves.3) In order to find better mixing state, the flow pattern in the vessel and the relation between the parameters of the model and the experimental conditions have been observed. We have obtained the fllowing results:3-1) There was no influence of depth of the particles layer on the mixing rate per unit height of vessel.3-2) Better mixing state could be expected, with increase of rate of agitation and with decrease of the feed of particls.