Abstract:

A geometric simulation and scaling-up model of mixer is established based on the geometric similarity, the constancy of maximum shear stress and the approximation of compound viscosity. By taking the similarity of compound quality as the design goal, four geometric scaling-up factors are then chosen and the similarity conditions between the model mixer and the actual one are presented in the form of similarity criteria. According to the simi- larity criteria and the rheology theory, a scaling-up model to simulate the mixer is proposed. Moreover, with the simi]arity scaling-up theory as a design platform, a model of 370L mixer is designed, which is finally compared with the prototype mixer （BB270） and the practical one （BB370）. The results show that the modeled 370L mixer with a single-parameter error of less than 10.7% and a geometric parameter-group A error of less than 8% meets the requirements of engineering design well, and that the mixing quality of the modeled mixer is similar to that of the pro- totype one. Thus, the similarity scaling-up of mixer is successfully implemented.

Key words: mixer, geometric scaling-up, similarity criterion, mixing