US 6,484,565 B2Granted

Single riser/single capillary viscometer using mass detection or column height detection

AssigneeDrexel University

InventorsSehyun Shin, Young Cho, Kenneth Kensey, William N. Hogenauer, Sangho Kim

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Abstract

An apparatus and method for determining the viscosity of a fluid over plural shear rates caused by a decreasing pressure differential by monitoring the movement of the fluid through a riser tube and a capillary tube. The movement can be monitored by detecting the changing weight of the fluid, using a precision balance or load cell, as it moves through the riser tube and capillary tube into a fluid collector; or, alternatively, the movement can be monitored by detecting the changing level of a fluid column in the riser tube using a column level detector. A processor then uses the changing weight or height data, along with the dimensions of the capillary tube and a dimension of the riser tube, to determine the viscosity of the fluid. In addition, apparatus and methods for determining fluid viscosity online and fluid mixture homogeneity online are also described.

Claims30

Dependent claims

An apparatus for determining the viscosity of a fluid over plural shear rates using a decreasing pressure differential, said apparatus comprising:

a lumen having a first end and a second end and being positioned at an angle to a horizontal reference greater than zero degrees, said lumen having a first known dimension;
a flow restrictor having an inlet and an outlet, said inlet being in fluid communication with said second end and wherein said outlet is arranged to deliver any fluid that passes therethrough to a collector, said flow restrictor including some known dimensions;
said lumen and said flow restrictor being initially occupied by a continuous, non-moving sample of fluid therein;
a sensor for detecting the movement of the fluid over time once the sample of fluid begins moving and passes from said outlet into said collector, said sensor generating data relating to the movement of the fluid over time;
said first end being exposed to atmospheric pressure creating a pressure differential between said first end and said outlet, said sample of fluid moving through said lumen and said flow restrictor at a first shear rate caused by said pressure differential, said movement of fluid causing said pressure differential to decrease from said first shear rate for generating said plural shear rates;
and
a computer, coupled to said sensor, for calculating the viscosity of the fluid based on said data relating to the movement of the fluid over time, said first known dimension of said lumen and said some known dimensions of said flow restrictor.

4 more elements

A method for detecting the viscosity of a fluid at plural shear rates caused by a decreasing pressure differential, said method comprising the steps of:

(a) providing a lumen having a first end and a second end and positioned at an angle to a horizontal reference greater than zero degrees, said lumen having known dimension;
(b) coupling an inlet of a flow restrictor, having an outlet, to said second end of said lumen, said flow restrictor having some known dimensions;
(c) submerging said outlet in a collector containing the fluid;
(d) coupling a suction source to said first end and activating said source to draw up a sample of the fluid from said collector to form a continuous sample of fluid that occupies said lumen and said flow restrictor, thereby establishing a pressure differential between said first end and said outlet;
(e) adding additional fluid to said collector to maintain said outlet submerged in the fluid in said collector;
(f) exposing said first end to atmospheric pressure to cause said sample of fluid to move through said lumen and said flow restrictor at a first shear rate caused by said pressure differential, said movement of fluid causing said pressure differential to decrease from said first shear rate for generating said plural shear rates;
and
(g) providing a sensor for detecting the movement of the fluid over time as the sample of fluid moves and passes from said outlet into said collector while maintaining said outlet being submerged in the fluid in said collector, said generating data regarding said movement;
and
(h) calculating the viscosity of the fluid based on the generated data, said first known dimension and said some known dimensions.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/897,164Filed 2 Jul 2001 · continuation in part
Priority: 12 Nov 1999
Published: US 2002/0007664 A124 Jan 2002
Granted: 26 Nov 2002
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

A61B 5/02035
Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction: determining…
G01N 11/04
By measuring flow of the material: through a restricted passage, e.g. tube, aperture
G01N 11/06
Through a restricted passage, e.g. tube, aperture: by timing the outflow of a known quantity
G01N 5/00
Analysing materials by weighing

Family

Application09/439,795Parent of this continuation-in-part · filed 12 Nov 1999
Application60/228,612Us provisional application · filed 29 Aug 2000
Application09/789,350Parent of this continuation-in-part · filed 21 Feb 2001
US 2002/0007664 A1Pre-grant publication · published 24 Jan 2002
US 6,322,524 B1Parent of this continuation-in-part
US 2001/0039828 A1Published application
US 6,484,565 B2This patent

From the US filing history. Foreign family members aren’t listed.