Ribbon viscometer

For the impeller ribbon viscometer technique, the power number of an impeller is inversely proportional to the impeller Reynolds number (Eq. 1). As the impeller rotational speed increases, the flow will gradually change from laminar to turbulent, passing through a transition region. Parameter c can be obtained from the calibration fluids. If the same value for c is assumed to apply to a non-Newtonian fluid, then Eq. 4 can be used to calculate the apparent viscosity of that fluid. The range of the impeller method is determined by the minimum and maximum torques that can be measured (5). 

Because of the problem of sealing at both ends, this so-called ribbon viscometer can only be realized for materials of extremely high viscosity. The properties of a ribbon viscometer are shown to a good approximation by a rotation viscometer of the Couette type (see Section 9.5.2). In Couette viscometers, a rotor revolves around a stator (or vice versa). The viscous... 

Two Brookfield viscometers were used to collect the data necessary for rheologic property studies of wet grains a Brookfield RVDV III viscometer with a cone-and-plate spindle and a Brookfield HBDV III viscometer with a double helical ribbon impeller attachment. The Brookfield RVDV III had a full-scale torque of 7187 dyn-cm, and the HBDV III had a full-scale torque of 57,496 dyn-cm. Each viscometer had a maximum rotational speed of 250 rpm. Both viscometers had accuracy limits of 5% full-scale torque. 

---