System for measuring the flow rate of liquid in a microfluidic pipe
AssigneeElvesys
InventorsAdrien Plecis, Alexander McMillan, Guilhem Velve-Casquillas, Eric Farin
Life of this patent
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Abstract
A system for measuring the flow rate in a microfluidic pipe having n pressure sensors arranged in series on a pipe and measuring the pressure Pi of the liquid passing through same. These sensors being separated from one another by pipe portions Ri. Each pipe portion having a hydraulic resistance Rhi, thus making it possible to measure the pressure variations or head loss ΔPi between two consecutive sensors of the liquid flowing successively through these hydraulic resistances. The comparison between the estimated flow rates Di=ΔPi/Ri, making it possible to determine the fouling of the microfluidic pipe.
Claims8
A flow rate measurement system in a microfluidic pipe, comprising:
- n pressure sensors, with n greater than or equal to 3, arranged in series on the microfluidic pipe to measure a pressure of a liquid through the n pressure sensors, the n pressure sensors being separated from each other by n−1 pipe portions of the microfluidic pipe, each pipe portion having a calibrated hydraulic resistance Rhi, respectively, each pressure sensor measures the pressure of the liquid through said each pressure sensor, a pressure sensor is arranged respectively at the two ends of said each pipe portion of the microfluidic pipe configured in series to measure pressure variations ΔPi between two pressure sensors at both ends of an i-th portion of the microfluidic pipe;
- and
- a processor-based computer specially configured to:
- measure pressure variations or pressure losses between two successive pressure sensors;
- calculate an apparent liquid flow rate Di in said each pipe portion according to the following relationship:
- Di
- =
- Δ
-
- Pi
- /
- Rhi
- ;
- calculate a proportional difference ΔDk,j in the apparent liquid flow rates between two pipe portions according to the following relationship:
- Δ
-
- Dk
- ,
- j
- =
- ❘
- "\[LeftBracketingBar]"
- Dk
- -
- Dj
- ❘
- "\[RightBracketingBar]"
- /
- (
- (
- Dk
- +
- Dj
- )
- /
- 2
- )
- ;
- comparing the proportional difference in the apparent liquid flow rates between any two pipe portions to a threshold value;
- and
- wherein the processor-based computer further comprises a blockage detector configured to generate an alert signal when the proportional difference in the apparent liquid flow rates between any two pipe portions is greater than a threshold value, the alert signal indicating at least one of a partial blockage and a clogging of the microfluidic pipe.
A method for measuring a blockage of a microfluidic pipe, comprising:
- circulating a fluid through n−1 pipe portions of the microfluidic pipe, n being greater than or equal to 3, arranged in series and each pipe portion having a calibrated hydraulic resistance Rhi, respectively, a pressure sensor among n pressure sensors being arranged respectively at the two ends of said each pipe portion of the microfluidic pipe configured in series to measure pressure variations ΔPi between two pressure sensors at both ends of an i-th portion of the microfluidic pipe;
- calibrating by injecting a clean liquid at a predetermined flow rate and measuring responses of the n pressure sensors with a processor-based computer to determine a pressure drop and to determine the calibrated hydraulic resistance Rhi of each of the n−1 pipe portions;
- calculating an apparent liquid flow rate Di in said each pipe portion according to the following relationship:
- Di
- =
- Δ
-
- Pi
- /
- Rhi
- ;
- calculating a proportional difference ΔDk,j in the apparent liquid flow rates, according to the following relationship:
- Δ
-
- Dk
- ,
- j
- =
- ❘
- "\[LeftBracketingBar]"
- Dk
- -
- Dj
- ❘
- "\[RightBracketingBar]"
- /
- (
- (
- Dk
- +
- Dj
- )
- /
- 2
- )
- ;
- calculating an average of the apparent liquid flow rates Dmean according to the following relationship:
- Dmean
- =
- ∑
- (
- Di
- )
- /
- (
- n
- -
- 1
- )
- ;
- and
- comparing the proportional difference in the apparent liquid flow rates between any two pipe portions to a threshold value;
- and generating alert signal when at least one proportional difference is greater than the threshold value indicating a blockage of one of the two portions of microfluidic pipe.
Dependencies are inferred from the claim text.