Computer simulation of agglomerate

Fukumori, Y. Ichikawa, H. Jono, K. Takeuchi, Y. Fukuda, T. Computer simulation of agglomeration in the Wurster process. Chem. Pharm. Bull. 1992, 40 (8), 2159-2163. 

Moreno-Atanasio, R. Ghadiri, M. 2006 Mechanistic analysis and computer simulation of impact breakage of agglomerates effect of surface energy. Chemical Engineering Science 61, 2476-2481. 

As the fundamental understanding of agglomeration circuits improves and suitable monitoring instrumentation is developed, simulation and automatic computer control [28] of these operations becomes possible. 

An alternative to stochastic reconstruction of multiphase media is the reconstruction based on the direct simulation of processes by which the medium is physically formed, e.g., phase separation or agglomeration and sintering of particles to form a porous matrix. An advantage of this approach is that apart from generating a medium for the purpose of further computational experiments, the reconstruction procedure also yields information about the sequence of transformation steps and the processing conditions required in order to form the medium physically. It is thereby ensured that only physically realizable structures are generated, which is not necessarily the case when a stochastic reconstruction method such as simulated annealing is employed. 

Computational algorithms have been developed to simulate the agglomeration process (Meakin, 1986). Calculations based on these algorithms produce structures whose Df values tend to approach an asymptotic limit that depends on the algorithm. (There appears to be no proof that such limits exist.) We consider three different types of algorithms, each of which has two subca.ses. The six examples are illustrated in Fig. 8.3. 

Agglomerate size distributions can also be calculated by. solving the Smol uchowski equation using an appropriate expression for the collision kernel. There is a fundamental dilfercncc between this approach and direct numerical simulation of the coagulation process. In computer. simulation, the value of Df is determined by the collision algorithm analyses based on the Smoluchowski equation require an assumption in advance of the value of... 

Die compaction of agglomerates has been simulated in a computer sphere model by Thornton et When the particles are in a liquid paste, the liquid is usually expelled through pores in the mold, and the partieles form a filter cake. The mechanism by which this occurs has been modeled by Woodcock et The application of forces to powder beds, sometimes immersed in liquids, is the subject of soil mechanics. " This considers particles to interact via Coulomb s law, Equation (11.16), but also takes into account the hydrodynamic forces acting on the individual particles. Unfortunately, as we have seen. Coulomb s law is not correct for particles which experience molecular adhesion, so the friction coefficients found in soil mechanics theories seem to vary. Friction seems to increase as the particles get smaller because smaller particles adhere more strongly. Soil mechanics is therefore a difficult science. 

---