Granulation modeling

Fig. 3.5. Representation of dry granule surface in granulation model of Sherrington [8].

Chromaffin granules model neurosecretory vesicles for proneuropeptide processing proteases... 

Gantt, J. A. Gatzke, E. P. 2006 A stochastic technique for multidimensional granulation modeling. AIChE Journal 52, 3067-3077. 

Fig. 7.87 Photograph of a pressure swing granulator, Model DQ-350 (courtesy Fuji Paudal, Osaka, japan).

The conservation of mass, energy, momentum, and particle number can be important aspects of granulation modeling. 

Sanders CFW, Willemse AW, Salman AD, Hounslow MJ. Development of a predictive high-shear granulation model. Powder Technology 2003 138 18-24. 

Consider the granulation model that was given in Example 23.2. 

The Andritz-Sprout-Bauer attrition miU (Fig. 20-51) is available in single- and double-runner models with 30- to 91-cm- (12- to 36-in.-) diameter disks and with power ranging up to 750 kW (1000 hp). By the use of a variety of plates and sheirconstruciions these units are represented in such applications as coarse granulating, piilveriz-ing, and shredding. 

Extent of Noninertial Growth Growth by coalescence in granulation processes may be modeled by the population balance. (See the... 

The last approach is to measure the deviation in the growth-rate curve from random exponential growth [Adetayo Ennis, AfChE J., (1997)]. The deviation from random growth indicates a value of t/ , or the critical granule diameter at which noninertial growth ends. This value is related to D. (See the Modeling and Simulation subsection for further discussion.)... 

The use of PB modeling by practitioners has been hmited for two reasons. First, in many cases the kinetic parameters for the models have been difficult to predict and are veiy sensitive to operating conditions. Second, the PB equations are complex and difficult to solve. However, recent advances in understanding of granulation micromechanics, as well as better numerical solution techniques and faster computers, means that the use of PB models by practitioners should expand. 

Coalescence Coalescence is the most difficult mechanism to model. It is easiest to write the population balance (Eq. 20-71) in terms of number distribution by volume n v) because granule volume is conserved in a coalescence event. The key parameter is the coalescence kernel or rate constant P(ti,i ). The kernel dictates the overall rate of coalescence, as well as the effect of granule size on coalescence... 

Tablet Formulations (Immediate Release). Two papers in the mid-1990s reported the earliest studies on immediate release tablets. In the first, tablet formulations of hydrochlorothiazide [33] were modeled in an attempt to maximize tablet strength and select the best lubricant. In the other, a tablet formulation of caffeine was modeled [34] to relate both formulation and processing variables with granule and tablet properties.

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