Patent ID: 7730769
Filing Date: 2010-06-08
Classification: G01N

Abstract:
1. A capillary viscometer for the determination of a viscosity value of a Newtonian test fluid or at least one rheological parameter of a non-Newtonian test fluid, said viscometer comprising: a. a storage reservoir for holding said test fluid; b. at least one drain tube assembly, each drain tube assembly having an inner capillary drain tube, each of said inner capillary drain tubes having a first end with a first opening and a second end with a second opening, said first end opening being in fluid communication with said storage reservoir and said second end being open to the atmosphere; c. a collector for collecting said test fluid, said collector positioned under said second opening of each of said inner capillary drain tube; d. a detector in communication with said collector; and e. a processor in communication with said detector, said processor comprising a data acquisition software; where g=acceleration of gravity; H=initial level of the test fluid in said reservoir tank or height of said reservoir tank, when the reservoir tank is filled up; L=length of the inner capillary drain tube of the drain tube assembly; m=accumulated amount of said test fluid drained at drain duration time, t; P R=inside equivalent radius of said storage reservoir; R t=drain duration time; ρ=density of said test fluid; and μ=dynamic viscosity of said Newtonian fluid π=3.1416; and where said experimental data sets for a non-Newtonian fluid are used to determine said set of rheological parameters of said non-Newtonian fluid, said set of rheological parameters selected from the group consisting of a flow behavior index and a consistency index, said flow behavior index and said consistency index being determined using a slope value and an intercept value, respectively, said slope value and said intercept value determined from a linear least squares fit of a straight line obtained by applying said experimental data to the following non-Newtonian viscosity equation (NNVE): where k=consistency index of the power law equation; n=flow behavior index of the power law equation; and g, H, L, m, Pg, π, Ro, t, Pg, and ρ are as defined above.