An updated review on suspension polymerization is presented. The time period from 1991 to 1995 is stressed, as well as research articles or reports not considered in previous reviews. Our review is aimed at providing a sound basis for the theoretical background required to build an effective model for the particle size distribution (PSD) in suspension polymerization. All major phenomena that affect the PSD are considered, and a proposed approach to develop an accurate, yet simple, model is included. Most of the experimental information in this review is related to the styrene/divinylbenzene copolymerization system, although the ideas and models are not exclusive to this system.

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Efforts to model the turbulent flow in stirred tanks Kolar's (1982)

The impeller discharge stream and bulk circulation flow produced by a pitched blade turbine (PBT) in a fully baffled stirred tank have been defined, using a combination of flow visualization and laser Doppler anemonietry measurement techniques. Two distinct bulk circulation patterns have been identified, one for higher off bottom clearances, and one for lower clearances. The circulation patterns are shown to have a substantial impact on the discharge stream, even very close to the edge of the impeller blades. These findings indicate that the action of the impeller is not independent of the tank geometry, but contains a substantial feedback component from the bulk flow. This conclusion has substantial implications for the modelling and prediction of stirred tank flow fields. ~ On a analysC le courant de dCcharge et I'kcoulement principal produits par une turbine a aubes inclinee dans un rCacteur agitC chicanes, en combinant des techniques de visualisation de I'Ccoulement et de mesure anCmomCtrique laser Doppler. Deux profils de circulation globale distincts ont CtC observCs, I'un pour des dCgagements dans le fond du reservoir importants, l'autre pour des petits dkgagements aux parois. On montre que les profils de circulation ont un effet marquC sur le courant de dCcharge, mime i proximiti des aubes de la turbine. Ces dkcouvertes indiquent que I'action de la turbine n'est pas indkpendante de la gComCtrie du rkservoir et qu'elle subit une influence non nkgligeable de l'kcoulement global. Cette conclusion a des implications importantes pour la modklisation et la prkdiction des champs d'kcoulement dans les rkservoirs agitks.Keywords: stirred tank, pitched blade impeller, LDA, flow visualization, refractive index correction. lthough stirred tanks in their various forms comprise 42