FLUID MIXTURE ANALYZER USING A CAPACITIVE PROBE AND VOLTAGE DIVIDER

• US 3,816,811 A
• Filed: 01/12/1973
• Issued: 06/11/1974
• Est. Priority Date: 01/12/1973
• Status: Expired due to Term

• Current Assignee: Cmelik K., Rudolf Max Helmut
• Original Assignee: Cmelik K., Rudolf Max Helmut
• Inventors: Cmelik K., Rudolf Max Helmut
• Primary Examiner(s): Krawczewicz, Stanley T.
• Application Number:
  US05/323,026
• Time in Patent Office: 515 Days
• Field of Search: 324/61P,61R 73/53,61R,153,194E 317/246
• US Class Current: 324/667
• CPC Class Codes: G01N 27/223 for determining moisture content, e.g. humidity rain detectors on vehicle windows B60S1/0825

Abstract

A sensor device for ascertaining water content of a petroleum flow in a well-pipeline including a capacitive sensing head between the plates of which the petroleum flows and an electrical assembly to measure the dielectric constant of the petroleum flow between the plates and to provide an output representing said dielectric constant which is indicative of the water content of the petroleum.

Claims

1. A sensor device comprising a housing having an electrically insulative plate support, a pair of electrically conductive plates mounted to said support in fixed spaced electrically insulated relationship and adapted for the passage of a fluid, the dielectric constant of which is to be sensed, therebetween, and electrical means housed in said housing and electrically connected to said plates to measure said dielectric constant of said fluid between said plates and to provide an output signal representing said dielectric constant, said electrical means including a capacitor voltage divider, one of the capacitors of which is said pair of plates.

2. A sensor device according to claim 1 wherein said housing is in the form of an elongate hermetically sealed cylinder at one end of which is said support and in which the electrical means is housed, and said plates are mounted to extend coaxially with the longitudinal axis of the housing, one said plate being an elongate hollow cylindrical plate and the other said plate being an elongate rod mounted within the hollow center of said hollow plate and defining therewith an annular space longitudinally through which said fluid can flow.

3. A sensor device according to claim 2 wherein said housing and hollow plate together form an elongate cylindrical shape of substantially constant diameter adapted for use in a well-pipeline to measure the dielectric constant of fluid flowing through said pipeline.

4. A sensor device according to claim 3 wherein said hollow plate has a plurality of openings adjacent the housing to facilitate flow of said fluid from the end of the plates remote from said housing through said annular space.

5. A sensor device according to claim 4 wherein the ends of said plates remote from said housing are shaped to minimize the resistance of said device to flow of said fluid through the annular space and by the device.

6. A sensor device according to claim 1 wherein the electrical means comprise an oscillator, to generate an alternating electric current, said capacitor voltage divider, to receive the output from said oscillator, the capacitance of said pair of plates of which will vary with variation of the dielectric constant of said fluid between said plates to produce a divider output which is an alternating electric signal the amplitude of which represents said dielectric constant of said fluid, a diode detector to convert the alternating signal from said divider into a direct current electric signal the amplitude of which represents said dielectric constant of said fluid, a voltage to frequency converter arranged to generate an alternating current electric signal, in response to the direct current electric signal, the frequency of which represents said dielectric constant of said fluid and a signal transmitter arranged to adapt the signal from the converter for transmission to a remote receiving means.

7. A sensor device according to claim 6 wherein an electric cable connects the sensor device with the receiving means.

8. A sensor device for measuring water content of fluid in a petroleum well-pipeline having an electrically conductive well liner, comprising an elongate hermetically sealed cylindrical housing having an electrically insulative plate support, an electrically conductive elongate rod mounted to said support and extending coaxially with and from said housing, at least three resilient spacers electrically insulated from said rod and adapted to engage said liner to maintain said rod in substantially fixed spaced concentric relationship with said liner so that said liner and said rod define an annular space through which said fluid can flow, and electrical means housed in said housing and electrically connected to said rod and by, way of electRical ground, to said liner to measure the dielectric constant of fluid between said rod and said liner in said annular space and to provide an output signal representing said dielectric constant and consequently the water content of said fluid, said electrical means including a capacitor voltage divider, one of the capacitors of which is said rod and said liner.

9. A sensor device according to claim 8 wherein the electrical means comprises an oscillator, to generate an alternating electric current, said capacitor voltage divider, to receive the output from said oscillator, the capacitance of said rod and said liner of which will vary with variation of the dielectric constant of said fluid between said rod and said liner to produce a divider output which is an alternating electric signal the amplitude of which represents said dielectric constant of said fluid, a diode detector to convert the alternating signal from said divider into a direct current electric signal the amplitude of which represents said dielectric constant of said fluid, a voltage to frequency converter arranged to generate an alternating current electric signal in response to the direct current electrical signal the frequency of which represents said dielectric constant of said fluid and a signal transmitter arranged to adapt the signal from the converter for transmission to a remote receiving means.