Agglomerate Size Distribution

Various studies [1,2,4] have shown that the agglomeration of moist powders by tumbling can lead to self-preserving size distributions. That is, the ratio of the spread of granule sizes to the mean size at any given time is approximately constant during batch balling. 

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Clarke,. 1. and Freakley, P.K., 1995. Modes of dispersive mixing and filler agglomerate size distributions in rubber compounds, Plast. Rubber Compos. Process. Appl. 24, 261-266. 

Figure 6.15 Predicted and experimental calcium oxalate agglomerate size distributions (Hartel and Randolph, 1986)...

At the simplest level, the rate of flow-induced aggregation of compact spherical particles is described by Smoluchowski s theory [Eq. (32)]. Such expressions may then be incorporated into population balance equations to determine the evolution of the agglomerate size distribution with time. However with increase in agglomerate size, complex (fractal) structures may be generated that preclude analysis by simple methods as above. 

Analytical approaches to obtain the agglomerate size distribution are possible for well-mixed systems and when the rate of aggregation of clusters is defined by simple functions. In general, irreversible aggregation in well-mixed systems is described by Smoluchowski s coagulation equation, which... 

Two-roll mills have been analyzed in terms of the pressure distribution and velocity profiles created between the rolls [95], the shear imposed on fluid elements exposed to these conditions in the nip region [129] and their resulting efficiency as dispersive mixing devices [130,131]. An earlier mathematical model was proposed to describe the dispersive mixing process of carbon black in rubber on roll mills, through consideration of agglomerate size distribution and... 

From the preceding equations, we can also calculate the discreet agglomerate size distribution at any mixing time. The total initial number of agglomerates is... 

Fig. 34. Top Schematic view of a Ban ry Offo/n Evolution of the agglomerate size distribution with time predicted by the two-zone model with parameter values corresponding to the dispersion of carbon black in rubber in a Banbury muter. The size of an agglomerate after j ruptures is given by Dj — DQl2 i, where Do is the initial size of the agglomerates. The size of the aggregate (primary particle) corresponds to j = 28 (Manas-Zloczower, Nir, and Tadmor, 1982).

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... 

Fig. 7.4 Agglomerate size distribution after different times, n = number of drum revolutions.

In the measurement of particle or agglomerate size distribution, the major distinction is that agglomerates are made of primary particles. Hence, often there is a need to determine the true size of the underlying primary particles. In such cases, the size distribution of particles may be determined by a number of techniques, as shown in Table 2, which lists the commonly used methods [3]. With... 

Keywords Nickel Laterite, Crushed Ore Agglomeration, Agglomerate Size Distribution, Electrical Conductivity, Permeability... 

The agglomerate size distribution, permeability of agglomerate beds, and electrical conductivity of agglomerates were investigated in this study. It is believed that this is the first report of these... 

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