Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
  • G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
  • G01F1/20—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow
  • G01F1/32—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow using swirl flowmeters
  • G01F1/3209—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow using swirl flowmeters using Karman vortices
  • G01F1/3218—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow using swirl flowmeters using Karman vortices bluff body design
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
  • G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
  • G01F1/20—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow
  • G01F1/32—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow using swirl flowmeters
  • G01F1/325—Means for detecting quantities used as proxy variables for swirl
  • G01F1/3259—Means for detecting quantities used as proxy variables for swirl for detecting fluid pressure oscillations
  • G01F1/3266—Means for detecting quantities used as proxy variables for swirl for detecting fluid pressure oscillations by sensing mechanical vibrations

Definitions

• the present invention relates to a vortex flow meter for measuring fluid flow, and more particularly, a flow meter for use with high pressure process fluid.
• Various differential pressure sensitive vortex flow meters have been advanced, which operate on a principle that a buff body or shedding bar placed in a fluid flow causes or generates vortices alternately on opposite sides of the shedding bar, causing variations in pressure on either side of the bar.
• the frequency of vortex shedding for an individual bar configuration characteristic is directly proportional to the velocity of flow in the stream.
• Vortex flow meters are known in the prior art, and examples of vortex flow meter implementations can be found in U.S. Patent No.
• a vortex flow meter for measuring fluid flow includes a conduit having a wall surrounding a bore for carrying the fluid.
• the wall has a wall region of reduced thickness formed therein.
• the wall region of reduced thickness is sometimes referred to as a "region of reduced stiffness" or a "flexure”.
• a shedding bar is disposed in the bore.
• the shedding bar includes an upstream extremity, a downstream extremity and an intermediate portion connecting the upstream and downstream extremities.
• FIG. 1 is a partial cut away view of a flow meter in situ according to an embodiment of the present invention.
• FIG. 2 is an enlarged view of the flexure portion of the flow meter of FIG. 1.
• the center rib 26 is approximately the same width as the post 30 and extends the entire diameter of the flexure 28. In an alternative embodiment, the center rib 26 is a fraction of an inch wider than the post 30 and extends the full diameter of the flexure.
• the reinforcing ribs are approximately the same relative height and width. In one embodiment, the reinforcing ribs have a height and a width that are approximately the same as the thickness of the flexure. It will be understood by a worker skilled in the art that the flexure 28 is curved so as to match the wall of the pipe.
• the height of the reinforcing ribs 42 is relative to the surface of the flexure 28, but varies relative to a fixed point according to a radius of curvature of the pipe.
• the rib size may be adjusted to account for different pressures and different flexure sizes.
• the location of the reinforcing ribs 42 may be adjusted toward or away from the center line.
• the reinforcing ribs 42 are substantially centered between the center line of the flexure 28 and the outer edge of the flexure 28. It is appreciated that these reinforcing ribs 42 add to the burst pressure strength of the meter.
• FIG. 2 shows an expanded view of the flexure 28 of FIG. 1.
• the conduit 12 has an opening 24 in which a flexure 28 is disposed.
• Center rib 26 extends a full diameter of the flexure, and is positioned on a center line 44 of the flexure 28.
• FIG. 4 illustrates an expanded cross- sectional view of the flexure 28. Flexure 28 is disposed in opening 24 within conduit 12. Center rib 26 is centered on the flexure 28, and reinforcing ribs 42 are approximately centered between the center rib 42 and the outer circumferential edge of the flexure 28.
• the flexure 28 has a diameter D, which can be measured from edge to edge along the outer (non-wetted) surface of the flexure 28.
• the position of the reinforcing ribs 42 may be determined relative to the centerline (pivot line) 27 of the flexure 28, such that the reinforcing ribs 42 are centered at approximately 0.25D.
• the primary method of determining the pressure rating for a meter is a burst pressure test. In these tests, the flow meter is connected to a testing device and then pressurized until the meter fails because it can no longer retain the pressure.
• the reinforcing ribs were approximately 0.035 inches wide and 0.070 inches tall and extended parallel to the center rib 26.
• the reinforcing ribs 42 were positioned at the area where the maximum total displacement occurred in the prior art design. Calculations predicted a greater than 30 percent increase in burst pressure. The tested device showed improvement in burst pressure of 50 percent. Further analysis of the reinforced flexure design showed improved sensitivity over conventional flexure designs . Calculations predicted an increase in sensitivity of approximately 6 percent.
• the reinforcing ribs 42 increased sensitivity of the meter up to 20 percent in some embodiments . It is also important to note that the center rib contributes to a restorative force tending to restore pivoting member 22 to its equilibrium position.
• the position of the reinforcing rib relative to the pivot line or the circumferential edge would vary depending on where the measurement was taken.
• the angle By changing the angle, it may be possible to adjust the sensitivity of the meter while maintaining the improved pressure retention advantages.

Landscapes

• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• General Physics & Mathematics (AREA)
• Measuring Volume Flow (AREA)

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Cited By (1)

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Citations (2)

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• 2004
  • 2004-04-16 US US10/826,510 patent/US6973841B2/en not_active Expired - Lifetime
• 2005
  • 2005-03-28 CN CNB2005800113973A patent/CN100510652C/zh not_active Expired - Fee Related
  • 2005-03-28 WO PCT/US2005/010338 patent/WO2005106399A1/en not_active Ceased
  • 2005-03-28 JP JP2007508368A patent/JP4740230B2/ja not_active Expired - Fee Related
  • 2005-03-28 EP EP05733073.0A patent/EP1738141B1/en not_active Ceased

Patent Citations (2)

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