US4914959A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultrasonic flow meter using obliquely directed transducers
Assignee: Equinor ASA
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Filing: 1988-04-20
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Granted: 1990-04-10
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Expires: 2008-04-20
Abstract
Abstract A transducer system and method is provided for ultrasonic measurement of the flow velocity of a fluid in a pipe. Two transducers are mounted on opposite sides of a pipe, the second transducer being downstream from the first. The two transducers alternately transmit and receive ultrasonic pulses along respective center axes which are deviated upstream from an imaginary line connecting the transducers.
Inventors
- 👤 Kanagasaba Mylvaganam
- 👤 Erling Hammer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:00
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/66; G01F1/667; G01F1/662; G01P; G01P5/00; G01P5/24; G01P5/245
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
65 words
A transducer device for ultrasonic measurement of flow velocity of fluid in a pipe, comprising: at least a first and second transducer each disposed on opposite sides of said pipe; said second transducer being located downstream from said first transducer; said transducer transmitting and receiving sonic pulses about center axes thereof, wherein the center axes are deviated upstream from an imaginary line connecting said transducers.
Claim 2
Dependent Claim
65 words
A transducer device for ultrasonic measurement of flow velocity of fluid in a pipe, comprising: at least a first and second transducer each disposed on opposite sides of said pipe; said second transducer being located downstream from said first transducer; said transducer transmitting and receiving sonic pulses about center axes thereof, wherein the center axes are deviated upstream from an imaginary line connecting said transducers.
Claim 3
Dependent Claim
36 words
Transducer device according to claim 1, wherein the imaginary connecting line forms an angle of approximately 55° to the flow direction, and the deviation for the respective transducer from said imaginary connecting line is approximately 10°.
Claim 4
Dependent Claim
53 words
Transducer device according to claim 1, wherein in a range of flow velocity from about 0-7 meters/second, a CW-signal in combination with a CHIRP-signal is used, while in the case of ranges of flow velocity over about 7 meters second and up to about 77-100 meters/second, a CHIRP-signal with correlation detection is used.
Claim 5
Dependent Claim
50 words
Transducer device according to claim 1, wherein each said transducer comprises, a cup-shaped metal body whose base forms a membrane having a piezo-electric element on an inside surface thereof, which is sealed off from the flow, and whose cup-wall is designed with an annulus filled with a powerful damping material.
Claim 6
Dependent Claim
18 words
Transducer device according to claim 4, wherein the annulus is open towards an outside of the cup base.
Claim 7
Dependent Claim
17 words
Transducer device according to claim 4, wherein the annulus is open towards the top of the cup.
Claim 8
Dependent Claim
15 words
Transducer device according to claim 4, wherein the cup-formed metal body is made of titanium.
Claim 9
Dependent Claim
105 words
Transducer device according to claim 1, wherein each transducer is connected to a transmitter and a receiver with an optic receiver part and an optic transmitter part, a first multiplexer is connected to the two transmitter through optical fibres, a second multiplexer is connected to the two receivers through optical fibres, a CHIRP-generator and a CW-generator are connected to the first multiplexer, a CW-detector and CHIRP-correlator are connected to the second multiplexer, a clock and sequence generator is connected to the multiplexers, the CHIRP-generator, the CW-generator, the CW-detector and the CHIRP-correlator, and a computer are connected to the sequence generator, the CW-detector and the CHIRP-correlator.
Claim 10
Independent Claim
129 words
A method of ultrasonic measurement of flow velocity of a fluid along a flow axis in a pipe, comprising the steps of: mounting at least a first and second transducer on opposite sides of said pipe, said second transducer being mounted downstream from said first transducer; alternately transmitting and receiving sonic pulses about center axes of said transducers, said center axes being deviated upstream from an imaginary line connecting said transducers; and calculating the velocity of the fluid using the formula: ##EQU2## where: U is the mean flow velocity along the flow axis of the pipe, D is the pipe diameter, θ is the angle between the imaginary connecting line and the flow axis, t 23 is the downstream transit time, and t 32 is the upstream transit time.
Claim 11
Independent Claim
129 words
A method of ultrasonic measurement of flow velocity of a fluid along a flow axis in a pipe, comprising the steps of: mounting at least a first and second transducer on opposite sides of said pipe, said second transducer being mounted downstream from said first transducer; alternately transmitting and receiving sonic pulses about center axes of said transducers, said center axes being deviated upstream from an imaginary line connecting said transducers; and calculating the velocity of the fluid using the formula: ##EQU2## where: U is the mean flow velocity along the flow axis of the pipe, D is the pipe diameter, θ is the angle between the imaginary connecting line and the flow axis, t 23 is the downstream transit time, and t 32 is the upstream transit time.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-09 | 1993-10-09 | 1994-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-09 | 1997-10-09 | 1998-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-09 | 2001-10-09 | 2002-04-10 | $7700.00 | Window Closed / Lapsed |