Development and Application of the PRL Single-Pass Capillary Viscometer

The design and construction of a versatile capillary high-shear viscometer is described. Use of nitrogen pressure as the driving force and of a single pass through the capillary completely eliminate all areas of nonstreamline flow from the viscometer. By using interchangeable capillaries and efflux bulbs, the viscometer has a temperature range of -65 to 300 F, a viscosity range of S to 1 million centipoises, and a rate-of-shear range of 1 to 1 million reciprocal seconds. The maximum shearing stress for the three capillaries described varies from 92,000 to 300,000 dynes per sq cm.

Calibration techniques with Newtonian hydrocarbon fluids are described. Temperature and pressure effects of both Newtonian hydrocarbons and non-Newtonian polymer solutions are evaluated in capillary instruments.

Non-Newtonian data for the PRL (Petroleum Refining Laboratory) single-pass viscometer, using ASTM oils 103 and 104, are compared with similar data for the Kingsbury tapered plug viscometer and for the PRL high-shear viscometer.

High-shear-rate viscosity measurement of polymer solutions without permanent viscosity change is demonstrated. The effects of polymer type, polymer molecular weight, and solvent type are illustrated, using the PRL single-pass viscometer.