Growth regime map for liquid‐bound granules

Abstract

A regime map of granule growth behavior is proposed based on granule deformation during collision and the granule liquid content measured as the maximum pore saturation. The granule deformability on collision is represented by a deformation number, which is a ratio of granule impact energy to the plastic energy absorbed per unit strain. Granule growth regimes such as steady growth, induction, nucleation, crumb, and sluny are defined. This regime map qualitatively explains the uariatiom in granulation behauior. Laboratoly drum granulation experiments were used to test the regime map. Experiments were peqformed in a 0.3-m-dia. drum using three sizes of glass ballotini (19, 31, and 60 pm) with water and glycerol as liquid binders. Increasing granule yield stress by decreasing particle size and increasing binder uiscosity caused the system to move from steady growth to induction behauior as predicted by the regime map. Preliminary ualidation with literature data was also encouraging. More work, howeuer, is required to better quantify the boundaries between different growth regimes and to investigate the effect of process agitation intensiq. This regime map has great potential to help design and control granulation systems, because it is based on properties of the powder/binder qstem that can be measured or estimated without peqforming any granulation tests.

A Kinetic Study of the Polymorphic Transformation of Nimodipine and Indomethacin during High Shear Granulation

“…Former researchers described that the high shear granulation process could be divided into three phases, namely, nucleation, growth, and breakage (27,28). As shown in Fig.…”

Wet granulation: the effect of shear on granule properties

“…This can be explained, firstly, by the existence of a critical speed N c (see Section 3.2.1) for optimal granulation and growth regimes. In granulation processes, two main growth regimes have been identified [17]: steady growth and induction type behaviour. Steady growth occurs when the deformability is high.…”

Estimation of granule size distribution for batch fluidized bed granulation process using acoustic emission and N‐way PLS

“…Iveson et al [22,23] proposed a granule growth regime map, shown in Figure 1, in which the granule growth behavior is expressed as the granule pore saturation in comparison to granule deformation during impact. In general, the growth regime map is divided into two categories: the steady growth and induction growth.…”

“…The nucleation phase is fundamentally directed by wetting thermodynamics and kinetics, whereas granule-granule collisions during the steady growth phase are more dependent on the visco-elastic properties of the granules. In order to achieve a successful granule-granule coalescence in fluidized bed systems, the kinetic energy of the colliding granules must be dissipated in the viscous liquid layer on the granule surface [20][21][22][23]. The granule's liquid layer thickness, liquid ratio and mass strongly affect the Young's modulus of elasticity [24], which further influences the AE produced by particle impact [25].…”