Patent EA-001256-B1 (EA)
Title: Fluid flow apparatus
Inventor: PINKERTON ROBERT N
IPC: G01F1/42
Filed: 1998-04-16
Abstract: 1. Fluid flow apparatus comprising, in combination, a conduit including a removable and replaceable conduit section having a peripheral wall with an interior surface for conveying fluid therethrough in a given direction, said conduit section having relative to the direction of fluid flow an upstream end and a downstream end, a fluid flow displacement member in said conduit section having in relation to the direction of fluid flow an upstream end and a downstream end, said displacement member being of smaller size than said section and having between the ends thereof sloped wall means forming a periphery on said member for deflecting the fluid to flow through a region defined between the periphery of said displacement member and the interior surface of said section, said sloped wall means being effective to substantially linearize the velocity profile of the fluid in at least said region over a predetermined range of flows through said section, said displacement member and said section having at one end thereof cooperative means for removably and replaceably mounting said displacement member in said section, whereby said displacement member may be removed and replaced by a different displacement member to accommodate a different range of flows through said section. 2. Fluid flow apparatus as set forth in claim 1 wherein said cooperative means comprises a tongue on one and a groove in the other of said displacement member and said conduit section, said groove removably receiving said tongue for removably mounting said displacement member in said section. 3. Fluid flow apparatus as set forth in claim 1 wherein said cooperative means is located at the downstream end of said displacement member and said section. 4. Fluid flow apparatus as set forth in claim 1 wherein said conduit section has a plurality of grooves in the interior surface of said section at the downstream end thereof, said displacement member has a plurality of outwardly extending tongues on its downstream end, said tongues mating with and being removably received in said grooves for mounting said displacement member in said section at the downstream end thereof. 5. Fluid flow apparatus as set forth in claim 1 including flow sensing means associated with said conduit section and constituting therewith a meter body, said displacement member being replaceable by a different displacement member whereby different fluids and different ranges of flows may be measured using a single meter body. 6. Fluid flow apparatus comprising, in combination, a conduit for conveying fluid therethrough in a given direction, said conduit having a peripheral wall with an interior surface, a fluid flow displacement member in said conduit having in relation to the direction of fluid flow an upstream end and a downstream end, said member being of smaller size than said conduit and having sloped wall means forming a periphery on said member for deflecting the fluid to flow through a region defined by the periphery of said displacement member and the interior surface of said conduit, said conduit having relative to the direction of fluid flow an area upstream from said member and an area downstream from said member, said sloped wall means being effective to substantially linearize fluid flow in at least said region over a predetermined range of flows through said conduit and to flatten the velocity profile of the fluid flow in said conduit in areas both upstream and downstream from said displacement member, said displacement member comprising a unitary member having no areas of physical joinder, said displacement member and said conduit having cooperative means for mounting said displacement member in said conduit without permanently joining said displacement member to said conduit, the apparatus being constructed and assembled without material joining. 7. Fluid flow apparatus as set forth in claim 6 including flow measurement taps extending through the wall of said conduit and communicating respectively with the upstream and downstream areas where the velocity profile is relatively flat. 8. Fluid flow apparatus as set forth in claim 7 including diaphragm pressure sensors in said measurement taps. 9. Fluid flow apparatus as set forth in claim 7 wherein said displacement member is mounted at its downstream end within said conduit downstream of said measurement taps, whereby measurements are taken upstream of said cooperative mounting means and prior to any disturbance of fluid flow that may be caused by said cooperative mounting means. 10. Fluid flow apparatus comprising, in combination, a conduit for conveying fluid therethrough in a given direction, said conduit having a peripheral wall with an interior surface, a fluid flow displacement member in said conduit having in relation to the direction of fluid flow an upstream end and a downstream end, said member being of smaller size than said conduit and having sloped wall means forming a periphery on said member for deflecting the fluid to flow through a region defined by the periphery of said displacement member and the interior surface of said conduit, said conduit having relative to the direction of fluid flow an area upstream from said member and an area downstream from said member, said sloped wall means being effective to substantially linearize fluid flow in at least said region over a predetermined range of flows through said conduit and to flatten the velocity profile of fluid flow in said conduit in areas both upstream and downstream from said displacement member, and means mounting said displacement member solely adjacent its downstream end within said conduit at a location downstream from said member whereby fluid flow may be measured upstream from said mounting means prior to the occurrence of any disturbance of fluid flow that may be caused by said mounting means. 11. Fluid flow apparatus as set forth in claim 10 including a pair of measurement taps extending through the wall of said conduit, one of said taps communicating with the area in the upstream area in the conduit where the velocity profile of fluid flow is relatively flat and the other communicating with the area in the downstream area in the conduit where the velocity profile of fluid flow is relatively flat, and flow measurement means external to said conduit communicating with the interior of said conduit via said measurement taps. 12. Fluid flow apparatus set forth in claim 10 wherein said mounting means comprises cooperative means in said conduit and on the downstream end of said displacement member for removably and replaceably mounting said displacement member in said conduit, whereby said displacement member may be removed and replaced by a different displacement member to accommodate different fluids and different ranges of flows through said conduit. 13. Fluid flow apparatus as set forth in claim 10 wherein said conduit includes a removable section having an upstream end and a downstream end and a plurality of circumferentially spaced grooves in the interior surface of said section at the downstream end thereof, said displacement member has a plurality of outwardly extending tongues of equal number and spacing on its downstream end, said tongues mating with and being removably received in said grooves for removably and replaceably mounting said displacement member in said section at the downstream end thereof. 14. Fluid flow apparatus as set forth in claim 12 wherein said displacement member comprises a unitary member having no areas of physical joinder and said cooperative means detachably mounts said displacement member in said conduit without permanently joining said displacement member to said conduit, whereby the apparatus is constructed and assembled without material joining. 15. A fluid flowmeter comprising, in combination, a conduit for conveying fluid therethrough in a given direction, said conduit having a peripheral wall with an interior surface and having in relation to the direction of fluid flow an upstream direction and a downstream direction, a fluid displacement member in said conduit including a first sloped wall portion facing in the upstream direction and tapering inwardly toward the axis of said conduit and a contiguous second sloped wall portion facing in the downstream direction and tapering inwardly toward the axis of said conduit, said sloped wall portions forming a periphery on said member and defining a peripheral edge at the juncture of their larger ends, the second sloped wall portion being of shorter axial extent and greater slope than the first sloped wall portion, said displacement member being mounted coaxially in said conduit with the plane of said peripheral edge substantially normal to the direction of fluid flow and with said sloped wall portions and peripheral edge spaced symmetrically inward from the interior surface of said conduit, said displacement member deflecting the fluid to flow through a region between the periphery of the displacement member and the interior surface of the conduit and being effective to linearize fluid flow in said region and to flatten the velocity profile of fluid flow in areas within the conduit both upstream and downstream from the displacement member, a first pressure tap extending through the wall of the conduit in the area upstream from said edge where the velocity profile of the fluid is relatively flat, and a second pressure tap extending through the wall of the conduit in the area downstream from said edge where the velocity profile of the fluid is relatively flat, said first and second pressure taps facilitating determination of the fluid pressure differential between the upstream and downstream sides of said edge for the purposes of measuring fluid flow through the conduit without requiring a pressure tap within said displacement member. 16. A fluid flowmeter as set forth in claim 15 wherein the first pressure tap is located within an area between said edge and a locat