Device and method for determining rheological quality of non-newtonian liquids

An apparatus for evaluating the rheological properties of a liquid, the apparatus comprising:

• a closable barrel adapted to receive a quantity of a liquid to be evaluated, the barrel having a first end and a second distal end,
• a piston slidable in said barrel between said first end and said second end, thus defining a first and a second chamber between said piston and the respective ends of the barrel,
• drive means for moving said piston between the first and the second end,
• control means associated with the drive means for controlling the speed and timing of the piston movement,
• an orifice associated with the piston and adapted for the liquid to pass therethrough from said first chamber to the second chamber when said liquid is pressured by the movement of the piston against it,
• a separate return flow means for enabling the flow of the liquid back to the first chamber when the stroke of the piston is reversed,
• differential pressure measurement means for measuring the pressure drop across the orifice during the flow of the liquid through the orifice, and
• data acquisition and processing means for determining a relationship between the differential pressure and the at least one of the timing and the speed of the piston strokes, the relationship being indicative of rheological properties of the liquid.

A method for evaluating the rheological properties of a liquid utilizing an apparatus having a chamber for accommodating a quantity of a liquid to be evaluated, a piston slidably movable within the chamber, and an orifice in fluid communication with the chamber such that the liquid can pass through the orifice when the liquid is forced against it by a movement of the piston, the method comprising

• a) placing a sample of the liquid to be evaluated in the chamber,
• b) forcing the sample to flow from the chamber through the orifice by way of a movement of said piston,
• c) causing the sample to flow back into the chamber through a separate retrn flow passage,
• d) repeating steps b) and c) while
• e) controlling at least one parameter of the piston movement and measuring a parameter of flow of the liquid through the orifice, and then
• f) determining a relationship between the flow parameter and the piston movement parameter, the relationship being indicative of the rheological properties of the liquid.

A method for evaluating the rheological properties of a liquid utilizing an apparatus having a chamber for accommodating a quantity of a liquid to be evaluated, a piston slidably movable within the chamber, and an orifice in fluid communication with the chamber such that the liquid can pass through the orifice when the liquid is forced against it by a movement of the piston, the method comprising

• a) placing a sample of the liquid to be evaluated in the chamber,
• b) forcing the sample to flow from the chamber through the orifice and back to the chamber through a separate return flow passage,
• c) repeating step b) a number of times while
• d) controlling at least one parameter of the piston movement and measuring a parameter of flow of the liquid through the orifice, and then
• e) determining a relationship between the flow parameter and the piston movement parameter, the relationship being indicative of the rheological properties of the liquid.