FLUID FLOW METER

• US 20120160034A1
• Filed: 04/23/2010
• Published: 06/28/2012
• Est. Priority Date: 04/23/2009
• Status: Active Grant

• Current Assignee: Elster Water Metering Limited (Honeywell International Inc.)
• Original Assignee: Elster Metering Limited (Honeywell International Inc.)
• Inventors: Bardon, Ross James, Claridge, Ronald Desmond, Rashid, Alam, Rogers, Ivor Thomas, Stockill, William David, Wright, Douglas Richard
• Granted Patent: US 9,109,931 B2
• Time in Patent Office: Days
• US Class Current: 73/861.79
• CPC Class Codes: G01F 1/115 with magnetic or electromagnetic coupling to the indicating device
• CPC Class Codes: G01F 1/12 Adjusting, correcting, or compensating means therefor

Abstract

The present invention relates to a fluid flow meter, comprising: means for defining a fluid flow path; a rotor, with at least one blade, positioned in said fluid flow path; and a ring positioned upstream from, and adjacent to, said rotor; wherein the ring is adapted to conditions the flow at the leading edge of the rotor blade over a range of operating conditions. By providing a ring the accuracy and flow measuring range may be improved.

Claims

1-56. -56. (canceled)

57. A fluid flow meter, comprising:

means for defining a fluid flow path;

a rotor, with at least one blade, positioned in said fluid flow path; and

a ring positioned upstream from, and adjacent to, said rotor, wherein the ring is adapted to condition the fluid flow at the leading edge of the rotor blade over a range of operating conditions.

58. A fluid flow meter according to claim 57, wherein the ring is adapted to improve flow conditions at the leading edge of the rotor blade over a range of operating conditions.

59. A fluid flow meter according to claim 57, wherein said range of operating conditions is a range of flow rates.

60. A fluid flow meter according to claim 59, wherein said range of flow rate is less than the rated range of flow rate of the fluid flow meter, but preferably, more than 25% or 33% or 50% or 75% of said rated range.

61. A fluid flow meter according to claim 58 wherein, under said range of operating conditions, the flow conditions are improved in comparison with not providing a ring upstream of the rotor blade.

62. A fluid flow meter according to claim 57, wherein, under said range of operating conditions, the ring is adapted to smooth flow.

63. A fluid flow meter according to claim 57, wherein, under at least part of said range of operating conditions, the ring is adapted to induce substantially turbulent flow at the leading edge of the rotor blade.

64. A fluid flow meter according to claim 57, wherein the radius of the ring is optimised in order to maximise the improvement in flow conditions at the leading edge of the rotor blade.

65. A fluid flow meter according to claim 57, wherein the radius of the ring is greater than the radius of the rotor hub.

66. A fluid flow meter according to claim 65, wherein the radius of said ring is greater than the radius of the rotor hub by between 40% and 60% of the distance from the hub of the rotor to the tip of the blades, preferably between 45% and 55%, more preferably 53%.

67. A fluid flow meter according to claim 57, wherein the radius of the ring is greater than the radius of the rotor hub by between 35% and 55% of the distance from the hub of the rotor to the means defining the flow path, preferably between 40% and 50%, more preferably 45%.

68. A fluid flow meter according to claim 67, wherein the means defining the flow path is substantially cylindrical in shape.

69. A fluid flow meter according to claim 68, wherein the radius of the ring is between 65% and 85% of the radius of the cylindrical means defining the flow path, preferably between 70% and 80%, more preferably 75%.

70. A fluid flow meter according to claim 57, wherein the ring is positioned centrally within said fluid flow path.

71. A fluid flow meter according to claim 57, wherein the axial distance of the ring from the rotor hub is optimised to maximise the improvement in flow conditions at the leading edge of the rotor blade.

72. A fluid flow meter according to claim 71, wherein the axial distance of the ring from the rotor hub is between 10% and 30% of the chord length of the ring, more preferably between 15% and 25%, yet more preferably 20%.

73. A fluid flow meter according to claim 71, wherein the axial distance of said ring from said rotor hub is between 1.0 mm and 3.0 mm, more preferably between 1.5 mm and 2.5 mm, yet more preferably 2.0 mm.

74. A fluid flow meter according to claim 57, wherein the leading edge of the ring is thinner than the trailing edge of the ring.

75. A fluid flow meter according to claim 74, wherein the leading edge of the ring is tapered.

76. A fluid flow meter according to claim 74, wherein the leading edge of the ring is sharp.

77. A fluid flow meter according to claim 57, wherein the trailing edge of the ring is blunt.

78. A fluid flow meter according to claim 77, wherein the trailing edge of the ring is square.

79. A fluid flow meter according to claim 57, wherein the shape of the ring is mouldable.

80. A fluid flow meter according to claim 57, wherein the ring is further adapted to throttle the fluid flow at the rotor blade.

81. A fluid flow meter according to claim 57, wherein the ring is further adapted to induce turbulent flow downstream of the rotor.

82. A fluid flow meter according to claim 81, wherein turbulent flow is induced at the exit of the flow meter.

83. A fluid flow meter according to claim 57, wherein the ring is further adapted to at least partially relieve the thrust loading on said rotor.

84. A method of substantially optimising the accuracy and flow range of a fluid flow meter, comprising:

positioning a ring upstream from, and adjacent to, a rotor within a fluid flow path; and

adjusting the characteristics and position of said ring to substantially optimise the accuracy and flow range.

85. The method according to claim 84, wherein the characteristics comprise at least one of:

the ring radius, the ring thickness, the ring chord length; and

the ring'"'"'s cross-sectional shape.

86. The method according to claim 84, wherein the position comprises at least the axial distance from the rotor.

87. A fluid flow meter, comprising:

means for defining a fluid flow path;

a rotor positioned in said fluid flow path;

at least one inductive target on the shaft of said rotor; and

at least one inductive sensor;

wherein said at least one sensor is positioned adjacent said at least one inductive target.