INFLUENCE OF THE INTERNAL CRYSTALLIZER GEOMETRY AND THE OPERATIONAL CONDITIONS ON THE SOLID PRODUCT QUALITY

From an industrial point of view control of precipitated particles: qu ality turns out to be crucial. Experiments carried out in a pilot-scal e baffled stirred tank with and without draft tube of two different di ameters under different process conditions show a great influence of i nternal geometry and feed point locations on crystal size distribution and morphology of precipitated particles. Several results in contradi ction with those expected by intuition show that much more work is nee ded to elucidate the interaction between mixing and precipitation phen omena in stirred tanks. In this context, the paper provides a frame of reference and some rules of thumb useful to industrial manufacturers for controlling the product quality.