Mixing and Segregation

Many mixing models which utilize the simplified concepts of micro-mixing and segregation have been introduced. Most notable of these are the two-environment models of Chen and Fan (19), Kearns and Manning (20), and others (21, 22), and the dispersion models of Spielman and Levenspiel (23), and Kattan and Adler (24). 

BATSEG, SEMISEG, COMPSEG - Mixing and Segregation in Chemical Reactors... 

Data of tracer concentration in effluent of impulse input to a reactor are given in the first two columns (Fogler, 1992). A second order reaction with C0 = 8 and several values of specific rate is to be carried out here. Find conversion under max mixed and segregated flow conditions. 

A second order reaction is to be checked under plug flow, max mixed and segregated flow conditions when E(tr) of the reactor is Erlang with n = 3.(a) When conversion in a PFR is 90%, what are the other conversions (b) Find the relative reactor volumes when all three conversions are 90%. 

Dynamics of an Equalisation Basin 560 Dimensionless Kinetics in a Batch Reactor 235 Batch Reactor with Complex Reaction Sequence 240 Single Solute Batch Extraction 442 Mixing and Segregation 394... 

Rowe, RN. and Nienow, A.W., Particle mixing and segregation in gas fluidised beds a review, Powder Tech., 15 (1976) 141-147. 

Effect of conversion level. At low conversion levels is insensitive to RTD, earliness of mixing, and segregation. At intermediate conversion levels, the RTD begins to influence Xp however, earliness and segregation still have little effect. This is the case of Example 16.1. Finally, at high conversion levels all these factors may play important roles. 

Hu J, Lui G. Chain mixing and segregation in B-C and C-D diblock copolymer micelles. Macromolecules 2005 38 8058-8065. 

Figure 17.2. Relative volumes of maximum-mixed and segregated flow reactors with the same RTDs identified by n = 1 /< , as a function of conversion for second- and half-order reactions. For first-order reactions the ratio is unity throughout.

Staniforth JN. 1982. Advances in powder mixing and segregation in relation to pharmaceutical processing. Int. J. Pharm. Tech. Prod. Manuf. 3(suppl.) 1-12. 

Mixing and Segregation of Solid Particles (J.C. Williams and N. Hamby)... 

Complex as this joint process of mixing and segregation is, the mechanism is best understood by studying the simplest case of a binary mixture of two kinds of solid particles having dissimilar properties, e.g., density and/or particle size. 

The general problem of solids mixing and segregation can thus be resolved into three aspects ... 

Nienow, A. W., and Chiba, T., Solids Mixing and Segregation in Gas-Fluidized Beds, POWTECH 81, Mixing, paper S2/F (1981). 

This Structural feature has been shown to be a necessary condition for electrical conductivity in these materials, although the mixed mode of stacking is generally considered to be the thermodynamically preferred one (Shaik 1982). Proof of the relative stability of the mixed and segregated stack motifs, and a recipe for obtaining crystals of the latter, came with the discovery of a pair of polymorphic 1 1 complexes of 6-II with 6-III (Bechgaard etal. 1977 Kistenmacher etal. 1982). The red, transparent, mixed-stack form of the complex is a semiconductor, while the black, opaque structure with segregated stacks is a conductor (Fig. 6.2). 

The most significant differences between perfectly mixed and segregated flow in a CSTR occur in copoly merizalions. In a batch reaction, the copolymer composition varies with conversion, depending on the reactivity ratios and initial monomer feed composition. In a perfectly mixed CSTR, there will be no composition drifts but the distribution of product compositions will broaden as mixing in the reactor approaches segregated flow. 

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