Agglomeration processes

Table 6. Important Agglomeration Processes Carried Out in Liquid Systems...

FIG. 20-71 Classification of agglomeration processes by agitation intensity and compaction pressure. Relative density is with respect to primary particle density and equals (1 — e) where e is the solid volume fraction. Reprinted from Granulation and Coating Technologies for High-Value-Added Industties, Ennis and Litster (1996) with permission of E G Associates. All rights reserved. 

Pai+icle size enlargement equipment can be classified into several groups, with advantages, disadvantages, and applications summarized in Table 20-36. Comparisons of bed-agitation intensity, compaction pressures, and product bulk density for selected agglomeration processes are highlighted above in Fig. 20-71. 

It was established that at direct AAS analysis of based materials with SoST on account of agglomeration process and low rate evaporation trace amounts of As, Bi, Sb and Sn into zone of analytical signal formation the range of so-called effective temperature heating T ) has arranged by not... 

Mechanical compatibilization is accomplished by reducing the size of the dispersed phase. The latter is determined by the balance between drop breakup and coalescence process, which in turn is governed by the type and severity of the stress, interfacial tension between the two phases, and the rheological characteristics of the components [9]. The need to reduce potential energy initiates the agglomeration process, which is less severe if the interfacial tension is small. Addition... 

Zeolites. In heterogeneous catalysis porosity is nearly always of essential importance. In most cases porous materials are synthesized using the above de.scribed sol-gel techniques resulting in so-called amorphous catalysts. Porosity is introduced in the agglomeration process in which the sol is transformed into a gel. From X-ray Diffraction patterns it is clear that the material shows only weak broad lines, characteristic of non-crystalline materials. Silica and alumina are typical examples. Zeolites are an exception they are crystalline materials but nevertheless exhibit high (micro) porosity. Zeolites belong to the class of molecular sieves, which are porous solids with pores of molecular dimensions, i.e., typically the pore diameter ranges from 0.3 to 10 nm. Examples of molecular sieves are carbons, oxides and zeolites. 

Kapur and Fuerstenau (K5) have presented a unified description of the agglomeration process in which the phenomena of the compaction of the agglomerates and their passage through the various capillary regimes have... 

Fig. 10. Results of LES-based simulations of an agglomeration process in two vessels one agitated by a Rushton turbine (left) and one agitated by a Pitched Blade Turbine (right). The two plots show the agglomeration rate constant fl0 normalized by the maximum value, in a vertical cross-sectional plane midway between two baffles and through the center of the vessel. Each of the two plots consists of two parts the right-hand parts present instantaneous snapshots the left-hand parts present spatial distributions of time-averaged values after 50 impeller revolutions. Reproduced with permission from Hollander et al. (2003).

As discussed in Chapter 15, the size distribution of particles in an agglomeration process is essentially determined by a population balance that depends on the kinetics of the various processes taking place simultaneously, some of which result in particle growth and some in particle degradation. In a batch process, an equilibrium condition will eventually be established with the net rates of formation and destruction of particles of each size reaching an equilibrium condition. In a continuous process, there is the additional complication that the residence time distribution of particles of each size has an important influence. 

Mechanistic Understanding of the Wet Agglomeration Process and the Power Consumption Profile... 

Some Hints Concerning the Wet Agglomeration Process in a High-Shear Mixer to Avoid Problems... 

Betz G, Junker Biirgin P, Leuenberger H. Power consumption profile analysis and tensile strength measurements during moist agglomeration process. Int J Pharm 2003 252 11-25. 

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