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Global mixing effects

A useful description of mixing in bubble columns is provided by the dispersion model. The global mixing effects are generally characterized by the dispersion coefficients El and Eq of the two phases which are defined in analogy to Fick s law for diffusive transport. Dispersion in bubble columns has been the subject of many investigations which have recently been reviewed by Shah et al. (45). Particularly, plenty of data are available for liquid-phase dispersion. [Pg.228]

The global mixing effects in tower bioreactors can conveniently be described by the dispersion coefficients of both phases which are defined in analogy to Fick s law for diffusive transport. [Pg.483]

In fermentation technology it is the mixing time rather than the dispersion coefficient El which is used to characterize the global mixing effects. The mixing time can be obtained from the transient solution of the dispersion model and is usually defined for 90 % homogeneity. [Pg.486]

Mixing effects in heterogeneous reactions are often complex because of local effects in dispersed phase films and global mixing effects when competitive reaction(s) occur in the continuous phase. [Pg.1428]

Mixing effects in chemical reactions must be formulated in terms of local mixing rates or local mixing times. The easily formulated global blend time seldom has an effect, while the time constants based on local conditions in the reactor, such as local mixing time or local mass transfer rate can be very important. [Pg.1699]

Thus in the neighborhood of hyperbolic points the distance between fluid particles, or the length of material lines, grows exponentially in time that would lead to efficient mixing. However, since the fluid elements are quickly ejected from the vicinity of these isolated points they only have a short term transient effect with little influence on the global mixing properties of the flow. [Pg.35]

Levels of Cl from these anthropogenic sources now heavily outweigh natural sources (the most abundant of which is biogenic CH3CI, with a global mixing ratio at 550 ppt [8]). Their overall effect therefore is to remove ozone the chemistry involved is, however, highly complex, since all these species react with many other species present, which may themselves react with ozone or even promote its formation. Of particular note is the formation of reservoir species. For the X = Cl reactions, an important example is HCl. It forms via the sequence ... [Pg.230]

On the reverse, how does the presence of particles affect local and global flow features in the vessel such as the vortex structure in the vicinity of the impeller, power consumption, circulation and mixing times, and the spatial distribution of turbulence quantities more specifically colliding particles have an impact on the liquid s turbulence (Ten Cate et al., 2004) while local particle concentrations affect the effective (slurry) viscosity which may be useful in the macroflow simulations ... [Pg.193]

Under global charge neutrality condition, assuming that the effect of Coulomb forces and the surface tension is small, one can construct a mixed phase composed of positive charged 2SC phase and negative charged normal quark matter. [Pg.238]


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See also in sourсe #XX -- [ Pg.229 , Pg.230 ]




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Global Effects

Mixed effect

Mixing effect

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