Experimental and computational investigation of segregation during tumblers unloading
2018
Volpato, S. | Scanferla, L. | Santomaso, A.C.
Dry mixing is a common operation in many industrial processes. The unloading of the mixer is an essential aspect of the process which actively contributes to the final quality of the mixture. Its effect however is often underestimate or even ignored. In the present work the consequences of the unloading process on mixture quality were investigated in three different types of tumbling mixers: a symmetric double cone, an asymmetric double cone and a conic mixer were considered. The symmetric double cone mixer is a standard geometry in the pharmaceutical industry, while the other two geometries are unconventional. The effects of mixer geometry on the mixture quality were studied and related to differences in the unloading flow patterns. A segregating polydispersed mixture was used during the experiments in order to emphasize the different performances of the three tumblers. Additional quasi-2D experiments and FEM simulation of the unloading process clearly showed the ability of the unconventional geometries to mitigate the effect of segregation improving the mixture quality evaluated at the outlet of the mixer.
显示更多 [+] 显示较少 [-]