Device and method for measuring fluid flow in a conduit having a gradual bend

• US 5,834,659 A
• Filed: 10/03/1996
• Issued: 11/10/1998
• Est. Priority Date: 02/03/1995
• Status: Expired due to Fees

• Current Assignee: Battelle Energy Alliance LLC (Battelle Memorial Institute)
• Original Assignee: Lockheed Martin Postal Technologies Inc (Opex Corporation)
• Inventors: Boucher, Timothy J, Ortiz, Marcos German
• Primary Examiner(s): CLARK, ROBIN C
• Assistant Examiner(s): Amrozowicz, Paul D.
• Application Number:
  US08/725,526
• Time in Patent Office: 768 Days
• Field of Search: 73/861.42, 73/861.69, 73/861.72
• US Class Current: 73/861.69
• CPC Class Codes: G01F 1/206 Measuring pressure, force or momentum of a fluid flow which is forced to change its direction
• CPC Class Codes: G01F 1/34 by measuring pressure or differential pressure
• CPC Class Codes: G01F 1/363 with electrical or electro-mechanical indication G01F1/37 and G01F1/38 take precedence
• CPC Class Codes: G01F 1/72 Devices for measuring pulsing fluid flows
• CPC Class Codes: G01F 1/74 Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid
• CPC Class Codes: G01F 1/80 operating by measuring pressure, force, momentum, or frequency of a fluid flow to which a rotational movement has been imparted
• CPC Class Codes: G01F 1/88 with differential-pressure measurement to determine the volume flow

Abstract

A system for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow.

Claims

1. A system for measuring fluid mass flow in a conduit having a gradual arc and straight sections either before or after the arc or both, comprising:

a first or more pressure sensor means disposed in the side of the conduit at a location on the outside of the arc for measuring pressure of fluid in the conduit at that location,

a second pressure sensor means disposed on a side of the conduit at a location on a straight section of the conduit, for measuring pressure of fluid in the conduit at that location; and

computation means for computing flow rate of fluid in the conduit from the fluid pressure measurements by the first and second pressure sensor means.

2. A system as in claim 1 wherein said second pressure sensor means is located upstream from the arc, of the direction of flow of fluid in the conduit.

3. A system as in claim 1 wherein said second pressure sensor means is located downstream from the arc, of the direction of flow of fluid in the conduit.

4. A system as in claims 2 or 3 wherein said second pressure sensor means is located in line, on the same side of the conduit, and generally at the same elevational level, as the first or more pressure sensor means.

5. A method for measuring fluid flow in a conduit having a gradual arc and a straight section, the method comprising the steps of:

positioning a first or more pressure transducers in the side of the conduit on the outside the arc, to measure pressure of fluid in the conduit;

positioning a second pressure transducer on a side of the conduit at a location in a straight section of the conduit, to measure pressure of fluid in the conduit; and

a computer computing flow rate of fluid in the conduit in accordance with the formula, ##EQU3## where mf is the flow rate in kilograms per second, R is the radius of curvature of the arc in the conduit, D is the diameter of the conduit in meters, ρ

is the fluid density in kilograms per cubic meter, and Δ

P₁ is the pressure difference between the first or more pressure transducers and the second pressure transducer.