STUDY OF MIXING EFFICIENCY IN ROLL-MILLS

A fluid dynamics analysis package (FIDAP) based on the finite element method was used to simulate the 2-D, isothermal flow of a power law mo del fluid in the bank and nip area of a two roll-mill geometry, includ ing the determination of the free surface. Dispersive mixing efficienc y was analyzed in terms of the shear stresses generated and the elonga tional flow characteristics. The latter were quantified using a frame invariant flow strength parameter. We found that the converging region rather than the nip region provides better mixing now characteristics . We also found that the presence of vortices in the bank region is no t beneficial for dispersive mixing.