Aggregation and breakup of acrylic latex particles inside millimetric scale reactors

Abstract

OATAO is an open access repository that collects the work of some Toulouse researchers and makes it freely available over the web where possible. a b s t r a c tAggregation of acrylic latex is investigated inside tubular millireactors working under laminar hydrodynamic conditions. The size distribution and fractal dimension of aggregates are measured using light scattering. Results show that the equilibrium between rupture and aggregation is achieved quickly, allowing the study of cluster size distribution and shape at the aggregation/rupture steady state. Both laminar hydrodynamic conditions and high shear rate are suspected to promote the formation of aggregates with a high fractal dimension, which means that the particles are almost spherical, thereby offering an interesting alternative to conventional batch processes. These results can provide useful information for industries aiming at producing aggregates at specified size and quality.

Inverse Population Balance Problems: Heuristics for Aggregation/Breakage of Solid Clusters in Liquid Metals

“…Reversibility accounts for some unusual aspects of this work, as pure aggregation or breakage have been studied separately in several instances (refs − , for example) but much more rarely together. This hypothesis implies the existence of at least one reversible aggregation reaction in the system but does not assume reversibility for each. …”

Estimation of characteristic coagulation time based on Brownian coagulation theory and stability ratio modeling using electrokinetic measurements

“…Mixing times observed in Taylor flow devices range from 2 to 60 s [54]. Tubular reactors in the laminar flow regime, which favors the formation of spherical aggregates, are also used [55][56][57][58][59][60]. However, the laminar flow regime typically does not provide effective mixing and a mixing device should be used before the coagulator to mix the colloidal suspension and the coagulant.…”

Towards the design of an intensified coagulator

“…Three geometriesa straight tube with square section, a coiled tube with circular section and a wavy geometry with square section, called "Dean-Hex" -of equal volume (V = 6.59 × 10 −7 m 3 ) and equal crosssection area (S = 3.14 × 10 −6 m 2 ) have been considered for this study. The cross-section corresponds to the section of a coiled tubular reactor considered in a previous experimental coagulation study [27].…”

“…The internal diameter (d tube = 2 mm) and the radius of curvature are chosen to correspond to realistic experimental conditions, where these tubular reactors are conventionally wound around small cylindrical guides to avoid space loss. As a consequence, the curvature radius of the tube R curv is chosen equal to 37 mm, which corresponds to the radius of the cylindrical guide that has been used to carry out latex coagulation experiments [27].…”