RHEOLOGICAL CHARACTERIZATION of SUSPENSIONS of SUCROSE CRYSTALS IN SATURATED SUCROSE SOLUTIONS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Processo FAPESP: 02/06838-1

Processo FAPESP: 03/05802-6

Processo FAPESP: 04/12620-4

Suspensions formed by saturated sucrose solutions were analyzed at different temperatures (0 <= T <= 65C) and with different added fractions (0.005 <= phi <= 0.40) of known size sucrose crystals (0.163 <= d(p) <= 1.26 mm). Saturated sucrose solutions, taken as the suspension dispersant mean, were rheologically characterized using a concentric-cylinder rheometer and showed Newtonian behavior. The crystal suspensions were rheologically evaluated by using a mixer-type rheometer constituting an anchor impeller coupled to a rotational rheometer, also known as a mixer-type rheometer. The studied crystal suspensions also showed Newtonian behavior. Theoretical and semiempirical models were used to describe the correlation between suspension relative viscosity and crystal volumetric fraction. The best results were obtained using the Krieger and Dougherty, and the Mooney model, resulting in values of intrinsic viscosity, (eta), and maximum packing fraction, phi(m), compatible with data reported for coarse concentrated suspensions of nonspherical particles.