Brookfield R.V.T. apparent viscosity measurements of 31.1 to 73º Brix vinasses, with and without nondissolved solids (N.D.S.), were carried out at varying rotation speeds (N) and temperatures (T). A regression analysis of this data was carried out to select the corresponding mathematical models. It was concluded that apparent Brookfield viscosity for low concentration vinasses (up to 52.4º Brix) depends only on linear and quadratic temperature terms. At higher concentrations (66º and 73º Brix) regression models for apparent viscosity, must also include quadratic as well as rotation speed-temperature interaction terms. This behavior is discussed, identifying two types of rheological behaviors and advancing a preliminary hypothesis about the role of solutes, N.D.S. and temperature.
vinasse; Brookfield viscosity; regression analysis
