US3719080A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sensor probe and shield assembly for swirl-type flowmeter
Assignee: Fischer and Porter Co
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Filing: 1971-06-07
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Granted: 1973-03-06
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Expires: 1991-06-07
Abstract
Abstract A swirl-type flowmeter whose output frequency is a function of fluid-flow rate. The inlet section of the meter flow tube is provided with a set of fixed swirl blades which impart a swirling motion to incoming fluid, the swirling fluid being caused to precess in an enlarged section of the tube. The precessional motion is detected by a thermistor probe and shield assembly to produce voltage pulses whose frequency depends on flow rate. This assembly is constituted by a probe extending transversely into the tube and supporting a bead-type thermistor at a point adjacent to the inner wall of the tube. Surrounding the probe and the thermistor is the upper end portion of an elongated tubular shield whose lower end portion has an access port therein which is oriented to capture a small sample of the precessing fluid and to conduct it in the direction of the thermistor to a discharge port beyond the thermistor, whereby the thermistor is responsive to the precessional motion but is otherwise effectively isolated from the mass of fluid flowing through the tube and from destructive particles borne by the fluid.
Inventors
- 👤 T Burgess
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:13
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/05; G01F1/20; G01F1/32; G01F1/3236
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
123 words
In a swirl-type flowmeter provided with a flow conduit having means disposed in the inlet section thereof to impart a swirling motion to fluid admitted therein, the swirling fluid being caused to precess in an enlarged section of the conduit to create cyclic variations in local transport properties, such as variations in velocity or pressure, a tube disposed in said conduit to define a relatively narrow passage extending transversely with respect to the longitudinal axis of the conduit, said tube communicating with points in said conduit located on opposite sides of said axis at which cyclic variations are alternately present, and a sensor disposed within said tube at a position intermediate said points, said sensor being adapted to amplify or transduce said variations.
Claim 2
Dependent Claim
123 words
In a swirl-type flowmeter provided with a flow conduit having means disposed in the inlet section thereof to impart a swirling motion to fluid admitted therein, the swirling fluid being caused to precess in an enlarged section of the conduit to create cyclic variations in local transport properties, such as variations in velocity or pressure, a tube disposed in said conduit to define a relatively narrow passage extending transversely with respect to the longitudinal axis of the conduit, said tube communicating with points in said conduit located on opposite sides of said axis at which cyclic variations are alternately present, and a sensor disposed within said tube at a position intermediate said points, said sensor being adapted to amplify or transduce said variations.
Claim 3
Dependent Claim
123 words
In a swirl-type flowmeter provided with a flow conduit having means disposed in the inlet section thereof to impart a swirling motion to fluid admitted therein, the swirling fluid being caused to precess in an enlarged section of the conduit to create cyclic variations in local transport properties, such as variations in velocity or pressure, a tube disposed in said conduit to define a relatively narrow passage extending transversely with respect to the longitudinal axis of the conduit, said tube communicating with points in said conduit located on opposite sides of said axis at which cyclic variations are alternately present, and a sensor disposed within said tube at a position intermediate said points, said sensor being adapted to amplify or transduce said variations.
Claim 4
Dependent Claim
123 words
In a swirl-type flowmeter provided with a flow conduit having means disposed in the inlet section thereof to impart a swirling motion to fluid admitted therein, the swirling fluid being caused to precess in an enlarged section of the conduit to create cyclic variations in local transport properties, such as variations in velocity or pressure, a tube disposed in said conduit to define a relatively narrow passage extending transversely with respect to the longitudinal axis of the conduit, said tube communicating with points in said conduit located on opposite sides of said axis at which cyclic variations are alternately present, and a sensor disposed within said tube at a position intermediate said points, said sensor being adapted to amplify or transduce said variations.
Claim 5
Dependent Claim
168 words
In a swirl-type flowmeter provided with a flow tube having swirl blades disposed in the inlet section thereof to impart a swirling motion to fluid admitted thereto, the swirling fluid being caused to precess in an enlarged section of the tube to create cyclic variations in local fluid velocity, temperature and pressure; a sensor assembly disposed in said tube to amplify the fluidic variations or convert them into electrical variations, said assembly comprising: A. a probe mounted on the wall of said tube and projecting transversely therein, B. a sensor mounted on the free end of the probe, and C. an elongated tubular shield, transversely disposed in said tube, the upper end portion of said shield enclosing both said probe and said sensor, said shield having ports both above and below the sensor located so that the passage of the vortex core around the circumference of the tube creates an alternating pressure at said ports and a corresponding oscillating flow in said shield, whereby said sensor is actuated.
Claim 6
Dependent Claim
168 words
In a swirl-type flowmeter provided with a flow tube having swirl blades disposed in the inlet section thereof to impart a swirling motion to fluid admitted thereto, the swirling fluid being caused to precess in an enlarged section of the tube to create cyclic variations in local fluid velocity, temperature and pressure; a sensor assembly disposed in said tube to amplify the fluidic variations or convert them into electrical variations, said assembly comprising: A. a probe mounted on the wall of said tube and projecting transversely therein, B. a sensor mounted on the free end of the probe, and C. an elongated tubular shield, transversely disposed in said tube, the upper end portion of said shield enclosing both said probe and said sensor, said shield having ports both above and below the sensor located so that the passage of the vortex core around the circumference of the tube creates an alternating pressure at said ports and a corresponding oscillating flow in said shield, whereby said sensor is actuated.
Claim 7
Dependent Claim
16 words
An assembly as set forth in claim 2, wherein said sensor is a glass-coated, bead-type thermistor.
Claim 8
Dependent Claim
24 words
An assembly as set forth in claim 3, further including a baffle disposed in said shield to focus the sample stream on the thermistor.
Claim 9
Dependent Claim
26 words
An assembly as set forth in claim 2, wherein the axes of said ports are at 90* to 270* with respect to the mean velocity direction.
Claim 10
Dependent Claim
22 words
An assembly as set forth in claim 2, further including means attachable to the lower end of said shield to stabilize same.
References Cited (Backward Citations)
US3246515A
Cited
US3279251A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-05 | 1976-09-04 | 1977-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-05 | 1980-09-04 | 1981-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-05 | 1984-09-04 | 1985-03-06 | $7700.00 | Window Closed / Lapsed |