Investigation of the effect of impeller rotation rate, powder flow rate, and cohesion on powder flow behavior in a continuous blender using PEPT
Portillo, Patricia M., Vanarase, Aditya U., Ingram, Andrew, Seville, Jonathan P. K., Ierapetritou, Marianthi G. and Muzzio, Fernando J.. (2010) Investigation of the effect of impeller rotation rate, powder flow rate, and cohesion on powder flow behavior in a continuous blender using PEPT. Chemical Engineering Science, Vol.65 (No.21). pp. 5658-5668. ISSN 0009-2509Full text not available from this repository.
Official URL: http://dx.doi.org/10.1016/j.ces.2010.06.036
In this paper, we examine the movement of particles within a continuous powder mixer using PEPT (Positron Emission Particle Tracking). The benefit of the approach is that the particle movement along the vessel can be measured non-invasively. The effect of impeller rotation rate, powder flow rate, and powder cohesion on the particle trajectory, dispersive axial transport coefficient, and residence time is examined. Increase in the impeller rotation rate decreased the residence time, increased the axial dispersion coefficient, and resulted in longer total path length. Effect of flow rate was different at two different rotation rates. At lower rotation rate, increase in flow rate increased the residence time, decreased the axial dispersion, and resulted in longer total path length. At higher rotation rate, increase in flow rate decreased the residence time, increased the total path length and showed a complex dependence on the axial dispersion coefficient. Increasing cohesion (measured using the flow index, dilation, and the Hausner ratio) did not affect the axial dispersion coefficient significantly, but had significant effects on the total particle path length traveled and the residence time. These results, relevant to pharmaceutical powders, provide better physical understanding of the influence of operating parameters on the flow behavior in the continuous mixer. In addition, one of the main obstacles of modeling continuous mixing of particles is to know the appropriate values for the modeling parameters as well as validate modeling approaches. One example is the dispersion coefficient which leads to ananalytical solution for the axial dispersion model of a continuous blending process. (C) 2010 ElsevierLtd. All rights reserved.
|Item Type:||Journal Article|
|Subjects:||T Technology > TP Chemical technology|
|Divisions:||Faculty of Science > Engineering|
|Journal or Publication Title:||Chemical Engineering Science|
|Official Date:||1 November 2010|
|Number of Pages:||11|
|Page Range:||pp. 5658-5668|
|Access rights to Published version:||Restricted or Subscription Access|
|Funder:||National Science Foundation|
|Grant number:||NSF-0504497, NSF-ECC 0540855|
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