Reactive mixing dispersions

The statistical description of multiphase flow is developed based on the Boltzmann theory of gases [37, 121, 93, 11, 94, 58, 61]. The fundamental variable is the particle distribution function with an appropriate choice of internal coordinates relevant for the particular problem in question. Most of the multiphase flow modeling work performed so far has focused on isothermal, non-reactive mono-disperse mixtures. However, in chemical reactor engineering the industrial interest lies in multiphase systems that include multiple particle t3q)es and reactive flow mixtures, with their associated effects of mixing, segregation and heat transfer. 

There is also axial dispersion. Again this is not mixing but a mechanism that introduces a residence time distribution. If a pulse is added to a turbulent pipeline, it will gradually lengthen with time. The best discussion of this is in Levenspiel s book (1967), where the work of Levenspiel and Bischoff is discussed. Mixing time, an important concept for reactive mixing, is given by... 

Jerome et al. reported on the influence of the mixing sequence on the phase morphology of the previously discussed (SAN-X/SAN)/(EP-g-MA/EPDM) reactive blends. The particle-in-particle phase morphology, could be forced by melt blending the reactive SAN diluted by a small part of neat SAN with the pre-mixture of EPDM and EP-g-MA. This reactive pre-dispersion of SAN in the polyolefinic rubber was then added by the rest of neat SAN, so that the phase inversion occurred, although incompletely, with part of SAN remaining occluded in the dispersed mbber phase. The faster NH2/MA interfacial reaction (compared to the slow carbamate/MA reaction) was more favorable to the retention of the occluded SAN, as a result of more efficient stabilization of the interface between these occlusions and the host phase [119]. 

The physical mass-transfer rate of o2one into water is affected by the gaseous o2one concentration, temperature, pressure, gas dispersion, turbulence, mixing, and composition of the solution, ie, pH, ionic strength, and the presence of reactive substances. Mass transfer of gaseous o2one into... 

The additives can be added during the polymerisation (either in the form of a reactive monomer or as an inert material — advantages include better dispersion and increased retention), but they are usually added immediately postpolymerisation of the polymer and extruded with the polymer. Often a concentrated mix with the plastic (master-batch) is prepared by the plastic manufacturer and this can be sold to the fabricators to be added during subsequent processing. 

Disperse liquid brands of sulphur, vat or disperse dyes, including mixed formulations of disperse and vat dyes in matching hues for the dyeing of polyester/cellulosic blends, have been commercially available for many years. The proportion of reactive dyes marketed as aqueous solutions is expected to increase markedly [10] because of ... 

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