Growth and Consolidation

TABLE 20-40 Controlling Growth and Consolidation in Granulation Processes ... 

FIG. 21-108 Granule porosity and mean (pellet) size. Typical regimes of granule growth and consolidation. [After Kapur, Adv. Chem. Eng., 10, 55 (1978) Chem. Eng. Sci., 26,1093 (1971).]... 

Typical changes in material or operating variables that maximize growth and consolidation Appropriate routes to alter variable through formulation changes Appropriate routes to alter variable through process changes... 

The impact of scale on growth and consolidation depends upon the choice of collisional velocity (Table 21-22). Granule consolidation and density likely increase with the maximum peripheral speed, or scale-up by For growth, on the basis of a critical viscous Stokes number... 

For deformable growth and consolidation where a limit of growth is not achieved, a constant deformation Stokes number Stjef [Eq. (21-118)] should be maintained with scale-up. Depending upon the choice of impact velocity Uq (Table 21-22) and assuming a constant profile of developing yield stress Y, this leads to different scaling criteria as follows ... 

FIG. 21-165 Two-stage continuous granulation process, consisting of high-shear nucleation (pin mixer) and moderate shear growth and consolidation (plough shear). [Mart et al.. Powder Technoh, 117,173 (2003).]... 

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