PROCESS VISCOMETRY OF COMPLEX FLUIDS AND SUSPENSIONS WITH HELICAL RIBBON AGITATORS

The viscosity of highly inelastic shear thinning fluids and aqueous su spensions of kaolin clay particles has been investigated using a helic al ribbon impeller fitted to a rheometer. Viscosity data for the singl e phase non-Newtonian fluids adequately processed with a generalized R eynolds number based on the impeller tip speed are shown to superimpos e very well to the results obtained with a cone and plate rheometer. I n the case of the two-phase system, it is shown that the data treatmen t for single phase system can be extended. The helical ribbon impeller yields more stable viscosity values than with the traditional geometr ies and no spurious flow phenomena (i.e., sedimentation, slip at the w all, etc.) was observed, making this system a superior device for susp ension rheology over cone and plate and Couette flow rheometers.