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A new technique to determine rate constants for growth and agglomeration with size and time dependent nuclei formation

by Peglow, M., Kumar, J., Warnecke, G., Heinrich, S., Mörl, L..

Series: 2005-11, Preprints

65M99 None of the above, but in this section
82C80 Numerical methods (Monte Carlo, series resummation, etc.)
45K05 Integro-partial differential equations

Fluidized bed spray agglomeration is a particle size enlargement process where particles stick together with the help of spraying binder. High impact forces between particles lead to attrition. Attrition may be modeled as poly-disperse nucleation. Furthermore, particulate event like over-spray leads to the formation particles in a wide range of volume. A new technique for the determination of agglomeration, growth and nucleation parameters is presented in this work. The model is based on a previous approach which takes mono disperse nuclei formation in the smallest class in to account. Frequently in crystallization processes, nucleation is assumed to be mono-disperse. The technique presented here incorporates nuclei formation in a certain range of volume. It is quite general and applicable to consider size and and time dependent nuclei formation. For two particularcases of growth and agglomeration including size dependent nuclei formation, simulation data was generated by continuous feeding of nuclei in a certain range to demonstrate the capability of parameter extraction of the model. Further, the new technique is applied to extract rate constants from experimental data measured during fluidized bed spray agglomeration. This technique is also useful for the prediction of bimodal behavior of particle size distributions (PDS).

population balance; agglomeration; growth; kinetics