US3863500A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flow velocity measuring device
Assignee: Yokogawa Electric Corp
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Filing: 1973-04-05
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Granted: 1975-02-04
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Expires: 1993-04-05
Abstract
Abstract Flow metering apparatus of the type wherein a vortex generating element having a generally elongate cylindrical shape is placed transversely in the stream of flowing fluid to produce on opposite sides of the element vortices which are shed in alternating fashion, and of the type wherein the element is formed with openings at said opposite sides which are connected together through the interior of said element to produce therethrough an alternating fluid flow corresponding to the alternating shedding of vortices. To improve the correspondence of vortex production rate with flow velocity over conditions of turbulent flow, the element has the openings on opposite sides thereof arranged both in an upstream region, and in a downstream region circumferentially spaced from the upstream region. Fluid flowing into the openings on one side of the element serves to maintain the boundary layer attached to the element to the vicinity of the downstream region to aid vortex formation. Fluid flowing outwardly from the openings on the opposite side of the element assists in separating the boundary layer and in preventing it from reattaching to the element in the vicinity of the downstream region.
Inventors
- 👤 Hiroo Yamasaki
- 👤 Ichizo Ito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:04
CPC Classifications
G; G01; G01P; G01P5/00; G01P5/14; G01F; G01F1/00; G01F1/05; G01F1/20; G01F1/32; G01F1/3209; G01F1/3218; G01F1/325; G01F1/3259; G01P5/01
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
176 words
Flow metering apparatus of the type wherein a vortex generating element is placed transversely in a stream of fluid to produce on opposite sides of the element vortices which are shed in alternating fashion, and wherein the element is formed with openings along said opposite sides which are connected together through the interior of the element to produce therethrough an alternating fluid flow corresponding to the alternating shedding of vortices, such apparatus being characterized in that: the openings on each of the opposite sides of the element are arranged relative to the stream of fluid both in an upstream region and in a downstream region spaced circumferentially from the upstream region such that the fluid flow inwardly through the spaced openings on one side of the element serves to maintain the boundary layer of the stream of fluid attached to the element to the vicinity of said downstream region, said fluid flowing outwardly through the spaced openings on the other side of the element serves to prevent reattachment of the spearated boundary layer to the element.
Claim 2
Dependent Claim
176 words
Flow metering apparatus of the type wherein a vortex generating element is placed transversely in a stream of fluid to produce on opposite sides of the element vortices which are shed in alternating fashion, and wherein the element is formed with openings along said opposite sides which are connected together through the interior of the element to produce therethrough an alternating fluid flow corresponding to the alternating shedding of vortices, such apparatus being characterized in that: the openings on each of the opposite sides of the element are arranged relative to the stream of fluid both in an upstream region and in a downstream region spaced circumferentially from the upstream region such that the fluid flow inwardly through the spaced openings on one side of the element serves to maintain the boundary layer of the stream of fluid attached to the element to the vicinity of said downstream region, said fluid flowing outwardly through the spaced openings on the other side of the element serves to prevent reattachment of the spearated boundary layer to the element.
Claim 3
Dependent Claim
38 words
Flow metering apparatus as claimed in claim 1 wherein the opening on each of the opposite sides of the element comprise a row of ports in said upstream region and a row of ports in said downstream region.
Claim 4
Dependent Claim
18 words
Flow metering apparatus as claimed in claim 2 wherein said downstream ports are smaller than the upstream ports.
Claim 5
Dependent Claim
20 words
Flow metering apparatus as claimed in claim 2 wherein said downstream ports are staggered in relation to the upstream ports.
Claim 6
Dependent Claim
19 words
Flow metering apparatus as claimed in claim 1 wherein said openings comprise elongate slots extending lengthwise of the element.
Claim 7
Dependent Claim
40 words
Flow metering apparatus as claimed in claim 5 wherein said openings on each of the opposite sides of the element comprise a row of elongate slots in said upstream region and a row of elongate slots in said downstream region.
Claim 8
Dependent Claim
28 words
Flow metering apparatus as claimed in claim 1 wherein the opening on each of the opposite sides of the element comprise elongate slots extending circumferentially of the element.
Claim 9
Dependent Claim
40 words
Flow metering apparatus as claimed in claim 7 wherein the openings on each of the opposite sides of the element comprise a row of ports in said upstream region and a row of circumferentially extending slots in said downstream region.
Claim 10
Dependent Claim
21 words
Flow meteRing apparatus as claimed in claim 1 wherein the openings arranged in said downstream region comprise adjacent rows of ports.
Claim 11
Dependent Claim
63 words
Flow metering apparatus as claimed in claim 1 wherein the openings arranged in said upstream region are located at an angle, measured from the openings to the element center to the element stagnation point, lying within the range of 70* to 100*, and the opening arranged in the downstream region are a similarly measured angle lying within the range of 100* to 140*.
Claim 12
Dependent Claim
38 words
Flow metering apparatus as claimed in claim 10 wherein the openings arranged in said upstream region are at an angle of approximately 85*, and the openings arranged in said downstream region are at an angle of approximately 115*.
Claim 13
Dependent Claim
16 words
Flow metering apparatus as claimed in claim 1 wherein said element is a right circular cylinder.
Claim 14
Dependent Claim
34 words
Flow metering apparatus as claimed in claim 1 wherein said element is formed with an interior chamber communicating with the fluid in said flowing stream through said openings in said upstream and downstream regions.
References Cited (Backward Citations)
US3564915A
Cited
US3722273A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |