Intensity of segregation

Intensity of segregation A measure of the difference in concentration between neighboring clumps of fluid, = C /C (l - C ), where C is the time-averaged concentration and C a is the fluctuating component of concentration A. 

The intensity of segregation, I, can be described in terms of concentration fluctuations, as shown in Fig. 5.135. Here the time-varying fluctuations above and below an average value are shown. 

To compare the "state of unmixedness", Danckwerts introduced the intensity of segregation, which is calculated in terms of the mean square of the fluctuations, as... 

This equation predicts the intensity of segregation to decay with time in the batch reactor. It is also applicable to a steady-state plug flow system, where t is the residence time. 

The kinetics in terms of the intensities of segregation and the mean concentrations can be shown to be... 

Simulation Tools and Examples of Chemical Engineering Processes Intensities of Segregation in a Semi-Continuous Reactor... 

At intermediate times, the scalar variance will be a decreasing function of time. We can thus define the intensity of segregation - a measure of the departure of the scalar field... 

If the scalar mixing time is constant, then the classical exponential-decay result is recovered for the intensity of segregation defined by (3.23), p. 66 ... 

This latter formula, which is commonly used in the industrial practice, also holds for the case of an estimation of the mixture quality using random sampling. However, the main problem in this global analysis lays in the well-known (since the famous Danckwert s example in chemical reactors [23]) fact that two different structures can correspond to the same intensity of segregation criteria. Fig. 1 illustrates this idea, which has a very practical sense in the context of pharmaceutical blending. 

The mixing efficiency was characterized by a dimensionless parameter, called the intensity of segregation, for the six scenarios [68], This parameter is based on the distribution of the mass fractions of the species. The results given in Table 1.4 show the importance of the z-component of the flow velocity to induce penetration of species and thus to promote mixing. 

Pressure drop plots - intensity of segregation and velocity vector plots... 

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