ANALYSIS OF MIXING PROCESS FOR WET PARTICLE SYSTEM IN A DOUBLE BLADE BATCH KNEADER MIXER

Kneading with a double-blade batch kneader mixer for wet particle syst ems combines both the convective and dispersive mixing processes. In t his paper, we show that the mixing phenomena in the kneader can be ana lyzed by a mathematical model. Namely, for analysis of this mixing pro cess, we derived an analytical equation considering both convective an d dispersive mixing with the following three dimensionless numbers. Th e first dimensionless number represents the convective mixing of wet p article systems, which is the dimensionless interchange amount between two kneading vessels. The second dimensionless number represents disp ersive mixing, which is advanced by compression and the rolling effect between the wall and the rotating blades. The last dimensionless numb er indicates the contribution of dispersive mixing to the total mixing . To determine each dimensionless number value, we also derived an emp irical equation using only the rheological properties of the wet parti cle systems, namely, plastic viscosity, mu(0), and yield stress, tau(0 ). We ascertained that the analytical equation proposed in this study can estimate the mixing phenomena with high precision by verifying the estimated values with experimental results for various kinds of wet p article systems in a batch kneader with sigma blades.