Scale of segregation

Scale of segregation A measure of the average distance between clumps of the same component in a mixture. 

An important parameter characterizing the laminar regime is the intersegment spacing over which the species must diffuse to be able to react. For kinetic control, as opposed to diffusion control of the reaction, this spacing must not exceed a certain scale of segregation given by [53J ... 

The scale of segregation is the integral of the coefficient of correlation from distance zero, where R(0) = 1, to distance C at which there is no correlation [R(C) = 0]... 

In this particular example it should be noted that there are two clearly visible characteristic scales of segregation values, about 6 cm and 0.5 cm. These represent... 

Fig. 7.39 The scale of segregation profile for the PE Him in Fig. 7.32(c). [Reprinted by permission from N. Nadav and Z. Tadmor, Quantitative Characterization of Extruded Film Textures Chem. Eng. Sci., 28, 2175 (1973).]...

The Scale of Segregation of a Striped Texture Using the coefficient of correlation from the previous problem, show that the linear scale of segregation (perpendicular to the stripes) of the texture of the figure in Problem 7.21 is given by... 

Danckwerts [1] gave a set of criteria to provide a measure of the level of mixing. The scale of segregation measures the size of the... 

Heterogeneous blends with very line scales of segregation may have very broad glass transition regions and good optical clarity. It is a moot point, then, whether such mixtures are compatible. If the components are not truly miscible, the blend is not at equilibrium but the user may not be able to distinguish between a persistent metastable state and true miscibility. 

The three primary mechanisms responsible for mixing are convective movement of relatively large portions of the bed, shear failure that primarily reduces the scale of segregation, and diffusive movement of individual particles. 

Convective mixing predominates in machines utilizing a mixing element moving in a stationary container, for example, the horizontal ribbon mixer. Groups of adjacent particles are moved from one position to another, steadily decreasing the scale of segregation. 

Danckwerts mentions two measures of scale of segregation, (1) the linear scale, S, defined as the area under the correlogram ... 

A familiar experimental technique used in solids mixing is method 4, which involves analysis of a number of samples of size v. Danckwerts Computes the volume scale of segregation F, from this analysis as follows ... 

The scale of segregation effectively measures the size of unmixed regions. As mixing proceeds, the scale of segregation is reduced, due to liquid motion. 

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