Drying particle creation

Agglomeration (UNIT OPERATION) generic term in process engineering for all unit operations which enlarge the particle size of a dispersed system by the creation of particle — agglomerates—e.g. spray drying, granulation in dmms, and compaction of powders. 

The creation of this accumulation region seems to be strongly dependent on the evaporation of the solvent and thus can be directly controlled by an appropriate tuning of the temperature close to the contact line. Indeed, as it was observed for convective assembly, evaporation induces a particle flow Ji from the suspension to the drying region. Accumulation of particles occurs when particle consumption through deposition does not compensate for particle income. This mechanism is illustrated in Fig 15.11 in the case of 500 nm PS particles. 

The result of the polycondensation reactions is the creation of inorganic three dimensional crosslinked polymer, leading to formation of sol particles. Farther condensation reactions link between the sol particles forming wet gel. Evaporation of the liquids leads to dry gel (xerogel). 

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