Viscosity of Black Liquor Up to 130 Degrees Celsius and 84% Solids, 1991 Forest Products Symposium Proceedings
The viscosities of two kraft pulping black liquors were determined for solids content from 10 to 84%, temperatures from 25 to 130°C, and shear rates up to 10,000 sec(-l). Glass capillary methods were used to determine the viscosities of the liquors at low solids. An Instron capillary Rheometer, a Haake coaxial cylinder viscometer and a parallel plate viscometer were used to study the effect of temperature and shear rate on liquor viscosity at different solids concentrations. At high solids, there are two distinguishable regions of viscosity behavior. shear rate independent and shear thinning regions. Reduced variables methods were used to correlate the viscosity with temperature, shear rate and solid contents. An empirical method is suggested to correlate the zero shear rate viscosities to temperature and solids concentrations.
Viscosity of Black Liquor Up to 130 Degrees Celsius and 84% Solids, 1991 Forest Products Symposium P