Temperature Effect on Rheological Properties of Cattle Manure Slurry

Abstract

A constant temperature rotational viscometer was fabricated for studying temperature effect on rheological properties of beef cattle manure slurries having total solids concentrations (TS) ranging from 2.5 to 19.3%. The rheological properties of the slurries had shear rates ranging from ∼ 20 to 200 s−1 and temperatures ranging from 14 to 64°C. In this shear rate range, it was found that the power-law equation could be used to describe the slurry's shear stress and shear rate relationship. Apparent viscosity of the slurry was found to decrease as temperature increased, and increase as TS increased. Equations to express the apparent viscosity as a function of TS and absolute temperature were given. The activation energy (Andrade's equation) of the beef cattle manure slurries was found to be 13.8 kJ/mol.