CFD simulation of solid suspension in a stirred tank

Particle concentration distribution in seven phases in stirred tank is simu lated on the basis of information in three dimensional flow field, as obtai ned by numerical solution of the flow equations (CFD), using the well known k-epsilon model. A model for simulation of multi-phase flow field was deve loped based on the commercial CFD program of CFX4.2. The volume fraction di stribution of different sizes of particle was studied by the simulation res ults, Local particle size distributions in suspension are studied as a func tion of agitation intensity and distance from the bottom of the tank by the use of CFD, For this purpose a multiple phase approach was used. There, th e different particle size classes are taken as separate computational phase s. Six classes of particle sizes were used in the simulation, The continuou s phase was water. The six solid phases were composed of particle sizes of 50, 100, 300, 500, 700 and 900 mum. The particle density was 2600 kg/m(3), different stirrer speeds were used with multiple phase flow. Further, expre ssions were developed and added in the program which enable the local parti cle size distributions to be calculated. Computed suspension densities were verified with existing experimental data in the literature.