Extreme temperature flow meter
AssigneeEngineering Measurements Company
InventorsGerald L. Schlatter, Robert L. Poland
Life of this patent
Estimating the term…
Abstract
A flowmeter has an elongated probe with a rotor positioned at the distal end of the probe for insertion into a fluid flow and an elongated conductor in the probe that terminates adjacent the rotor. A signal generator induces a standing wave on the conductor, and rotation of the rotor, which acts as a capacitor, induces a reciprocating phase shift in the standing wave. The rate of reciprocation of the phase shift, as well as the change in amplitude at a point on the conductor, is proportional to, and indicative of, the flow rate of the fluid and is detected and measured as an instrumentation signal. The probe, rotor, circuit insulation, and seal components are all fabricated of materials that withstand extreme temperatures.
Claims50
Apparatus for determining the flow rate of a fluid flowing in a pipeline, comprising:
- probe means for insertion into said pipeline for detecting the flow of said fluid;
- electronic generator means connected to said probe means for generating a standing wave in said probe means;
- impedance means connected to said probe means for causing variations of phase angle and amplitude in said standing wave in relation to the flow of said fluid;
- and
- sensing means connected to said probe means for detecting said variations in said standing wave.
The apparatus of claim 2, wherein said probe means includes a transmission line comprised of a first electrical conductor and a second electrical conductor, both of which are connected to said generator means and both of which terminate in an essentially open circuit.
Apparatus for determining the flow rate of fluid flowing in a pipeline, comprising:
- a probe with a tube portion having a proximal end and a distal end with a rotor rotatably mounted at said distal end adapted for insertion into the fluid in the pipeline, said proximal end being adapted for mounting on the pipeline, and said rotor having a plurality of blades adapted to interact with the flowing fluid to cause rotation of said rotor, said probe also having an elongated conductor extending coaxially through, but electrically insulated from, said tube portion and terminating in a capacitive element forming a first plate adjacent said rotor, said tube portion being electrically conductive, said blades of said rotor forming a part of a capacitor in combination with said capacitive element, and said rotor being positioned in such a manner that said blades pass into and out of close proximity to said capacitive element to cause variations in capacitance as said rotor rotates;
- electronic generator means connected to said elongated conductor and to said probe for inducing an alternating emf and a standing wave on said elongated conductor;
- and
- sensing means connected to said probe for detecting variations in the standing wave induced by said variations in capacitance at said first plate.
The method of determining the flow rate of a fluid flowing in a pipeline, comprising the steps of:
- flowing the fluid through a chamber past a probe;
- inducing a standing wave to exist within an electrical circuit that includes the probe;
- causing changes in electrical impedance to occur in the electrical circuit in relation to the fluid flow past the probe;
- causing the changes in electrical impedance to effect changes including the amplitude and phase angle, in said standing wave;
- measuring any of the changes in said standing wave caused by the changes in electrical impedance and correlating said changes to the flow rate of said fluid flowing through said chamber.
Dependencies are inferred from the claim text.