EP1226406A1 - Flow meter - Google Patents

Flow meter

Info

Publication number
EP1226406A1
EP1226406A1 EP00962698A EP00962698A EP1226406A1 EP 1226406 A1 EP1226406 A1 EP 1226406A1 EP 00962698 A EP00962698 A EP 00962698A EP 00962698 A EP00962698 A EP 00962698A EP 1226406 A1 EP1226406 A1 EP 1226406A1
Authority
EP
European Patent Office
Prior art keywords
aperture
pressure
section
nose
fish
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP00962698A
Other languages
German (de)
French (fr)
Inventor
Angus Jamieson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
IPR Co 21 Ltd
Original Assignee
IPR Co 21 Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GBGB9922983.3A external-priority patent/GB9922983D0/en
Priority claimed from GBGB9925715.6A external-priority patent/GB9925715D0/en
Application filed by IPR Co 21 Ltd filed Critical IPR Co 21 Ltd
Publication of EP1226406A1 publication Critical patent/EP1226406A1/en
Withdrawn legal-status Critical Current

Links

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
    • G01F1/34—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 measuring pressure or differential pressure
    • G01F1/36—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 measuring pressure or differential pressure the pressure or differential pressure being created by the use of flow constriction
    • G01F1/40—Details of construction of the flow constriction devices
    • 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
    • G01F1/34—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 measuring pressure or differential pressure
    • 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
    • G01F1/34—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 measuring pressure or differential pressure
    • G01F1/36—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 measuring pressure or differential pressure the pressure or differential pressure being created by the use of flow constriction
    • G01F1/38—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 measuring pressure or differential pressure the pressure or differential pressure being created by the use of flow constriction the pressure or differential pressure being measured by means of a movable element, e.g. diaphragm, piston, Bourdon tube or flexible capsule
    • G01F1/383—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 measuring pressure or differential pressure the pressure or differential pressure being created by the use of flow constriction the pressure or differential pressure being measured by means of a movable element, e.g. diaphragm, piston, Bourdon tube or flexible capsule with electrical or electro-mechanical indication

Definitions

  • This invention relates to a flow meter which can be inserted into the flow to measure the differential pressure between the fluid at its upstream end and the fluid flowing past its sides.
  • the present invention provides a device for measuring pressure or flow in a conduit, the device comprising a body having a first pressure chamber within the body communicating with a first aperture in the body; a second pressure chamber within the body communicating with a second aperture in the body spaced from the first aperture; and means for sensing pressure difference between said first and second pressure chambers.
  • the body has a nose, a centre section, and a tail; the nose is typically curved or tapered.
  • the centre section can have generally parallel sides, and the tail can be generally tapered.
  • a single forward facing aperture can be provided in the nose, and a set of e.g. 2-6 or more second apertures can be provided, typically in the centre section of the body spaced backwards from the nose .
  • the second apertures could instead be in the tail .
  • More than one (e.g. 2-6) first apertures could be provided.
  • the first chamber is typically provided in the nose section, and the second chamber is preferably provided in the centre section, but this is only exemplary, and the two chambers can be located at any convenient place on the body; all that is required is that the second aperture is spaced from the first, and is preferably located at a position that is behind the first with respect to the flow of fluid past the device, i.e. downstream of the first aperture.
  • the means for sensing pressure difference can be any conventional pressure sensor such as a diaphragm differential pressure sensor.
  • Fig. 1 is a perspective view of a first device
  • Fig. 2 is a schematic cross-section of the device of Fig. 1;
  • Fig. 3 is a side view, partly in section, of a modified form of the foregoing embodiment;
  • Fig. 4 is a perspective view of a sock used in Fig. 3.
  • the device consists of a shaped "fish" 10 which is inserted into a conduit.
  • the fish 10 has a nose cap 17, a centre section 18 and a tail section 19.
  • the centre section has an optional mounting bar 12 that connects it to a pipe (not shown) .
  • the mounting bar 12 could optionally be hinged at 13 into the fish 10 in such a way that the fish can be inserted nose first if necessary and the centre of gravity will be slightly upstream of the pivot ensuring that the fish will level out if a minimum flow is experienced and will return to vertical if the flow is switched off. This helps to insert the fish 10 through narrow standpipes, but is not essential.
  • the fish need not be hinged and could simply be permanently mounted in its own housing plumbed into the flow pipe.
  • a small aperture 14 at the front of the fish 10 in the nose cap 17 leads to a reservoir 16 of 'High Pressure' inside the nose cap 17.
  • Apertures 20 around the sides of the central section 18 of the fish 10 lead to a reservoir 22 of 'Low Pressure' in the central section 18 of the fish.
  • the pressures within these two reservoirs 16, 22 are compared by a small differential pressure sensor 24 and their difference is optionally pre-calibrated for a given flow rate for the appropriate size of pipe, or could be calibrated in situ.
  • the analogue signal from the pressure sensor 24 is carried on two wires 26 up through the mounting bar to the surface where electronics and firmware of conventional design can convert it to a stabilised digital reading for display or recording.
  • the signal can optionally be transmitted electronically (and optionally automatically in real time) by any suitable means to a remote monitoring or control station, where data from numerous meters throughout a water supply system can be co-ordinated and analysed to provide a real time report of the water flow rates and/or pressures at different points in the system, from which leak causes and locations can be derived.
  • the differential pressure signals can be used as an indicator of the flow rate of the fluid flowing past the fish 10, and can be used as an indicator for leaks in a pipe.
  • High-pressure differentials can mean high flow rates, and vice versa .
  • the pressure sensor 24 may suitably be a silicon diaphragm differential pressure sensor by Honeywell, which comprises a silicon diaphragm having opposite faces exposed to the respective high and low pressure already.
  • Figs 3 and 4 illustrate a modified embodiment in which a fish 100 is used which is similar to the fish 10 but, instead of being hinged to a mounting bar, is tethered by flexible lines (or a rigid mounting bar) to a sock assembly 102.
  • the sock assembly 102 provides a known flow cross section, within which the fish 100 operates.
  • the sock assembly 102 comprises a hinged perimeter 104 connected to a mounting rod 106 and attached to the upstream end of a fine woven bag 108 which is slightly larger than the pipe diameter at first, and then tapers to a long cylindrical section, smaller than the pipe, in which the fish 100 is located.
  • the sock assembly 102 could be flexible or rigid.
  • the perimeter 104 is formed of hinged sections with hinges whose rotation is limited by stops.
  • the member 104 can be inserted in a collapsed condition through a standpipe 110; when the bottom of the member 104 engages the bottom of the pipe, the hinges open to fill the inside of the pipe. This ensures that the flow sensor is located in an accurately known flow cross- section.

Landscapes

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

Abstract

A device for use as a flow meter in fluid-carrying pipes, having a pair of pressure chambers (16, 22) each linked to a respective aperture (14, 20) in the body, and a pressure-sensing means (24) to determine the pressure differential between the two chambers.

Description

"FLOW METER"
This invention relates to a flow meter which can be inserted into the flow to measure the differential pressure between the fluid at its upstream end and the fluid flowing past its sides.
The present invention provides a device for measuring pressure or flow in a conduit, the device comprising a body having a first pressure chamber within the body communicating with a first aperture in the body; a second pressure chamber within the body communicating with a second aperture in the body spaced from the first aperture; and means for sensing pressure difference between said first and second pressure chambers.
Preferably the body has a nose, a centre section, and a tail; the nose is typically curved or tapered. The centre section can have generally parallel sides, and the tail can be generally tapered.
There can be more than one aperture, for example, a single forward facing aperture can be provided in the nose, and a set of e.g. 2-6 or more second apertures can be provided, typically in the centre section of the body spaced backwards from the nose . The second apertures could instead be in the tail . More than one (e.g. 2-6) first apertures could be provided.
The first chamber is typically provided in the nose section, and the second chamber is preferably provided in the centre section, but this is only exemplary, and the two chambers can be located at any convenient place on the body; all that is required is that the second aperture is spaced from the first, and is preferably located at a position that is behind the first with respect to the flow of fluid past the device, i.e. downstream of the first aperture.
The means for sensing pressure difference can be any conventional pressure sensor such as a diaphragm differential pressure sensor.
Preferred embodiments of the invention will now be described, referring to the drawings, in which:
Fig. 1 is a perspective view of a first device;
Fig. 2 is a schematic cross-section of the device of Fig. 1; Fig. 3 is a side view, partly in section, of a modified form of the foregoing embodiment; and
Fig. 4 is a perspective view of a sock used in Fig. 3.
Referring to Figs. 1 and 2, the device consists of a shaped "fish" 10 which is inserted into a conduit. The fish 10 has a nose cap 17, a centre section 18 and a tail section 19. The centre section has an optional mounting bar 12 that connects it to a pipe (not shown) .
The mounting bar 12 could optionally be hinged at 13 into the fish 10 in such a way that the fish can be inserted nose first if necessary and the centre of gravity will be slightly upstream of the pivot ensuring that the fish will level out if a minimum flow is experienced and will return to vertical if the flow is switched off. This helps to insert the fish 10 through narrow standpipes, but is not essential.
For very small pipes the fish need not be hinged and could simply be permanently mounted in its own housing plumbed into the flow pipe.
A small aperture 14 at the front of the fish 10 in the nose cap 17 leads to a reservoir 16 of 'High Pressure' inside the nose cap 17. Apertures 20 around the sides of the central section 18 of the fish 10 lead to a reservoir 22 of 'Low Pressure' in the central section 18 of the fish. The pressures within these two reservoirs 16, 22 are compared by a small differential pressure sensor 24 and their difference is optionally pre-calibrated for a given flow rate for the appropriate size of pipe, or could be calibrated in situ.
The analogue signal from the pressure sensor 24 is carried on two wires 26 up through the mounting bar to the surface where electronics and firmware of conventional design can convert it to a stabilised digital reading for display or recording. The signal can optionally be transmitted electronically (and optionally automatically in real time) by any suitable means to a remote monitoring or control station, where data from numerous meters throughout a water supply system can be co-ordinated and analysed to provide a real time report of the water flow rates and/or pressures at different points in the system, from which leak causes and locations can be derived.
The differential pressure signals can be used as an indicator of the flow rate of the fluid flowing past the fish 10, and can be used as an indicator for leaks in a pipe. High-pressure differentials can mean high flow rates, and vice versa .
The pressure sensor 24 may suitably be a silicon diaphragm differential pressure sensor by Honeywell, which comprises a silicon diaphragm having opposite faces exposed to the respective high and low pressure already. Figs 3 and 4 illustrate a modified embodiment in which a fish 100 is used which is similar to the fish 10 but, instead of being hinged to a mounting bar, is tethered by flexible lines (or a rigid mounting bar) to a sock assembly 102.
For maximum accuracy of volumetric flow, the cross sectional area of the flow requires to be accurately known. Many pipes are heavily scaled on the inside, making the cross sectional area uncertain. The sock assembly 102 provides a known flow cross section, within which the fish 100 operates.
The sock assembly 102 comprises a hinged perimeter 104 connected to a mounting rod 106 and attached to the upstream end of a fine woven bag 108 which is slightly larger than the pipe diameter at first, and then tapers to a long cylindrical section, smaller than the pipe, in which the fish 100 is located. The sock assembly 102 could be flexible or rigid.
The perimeter 104 is formed of hinged sections with hinges whose rotation is limited by stops. The member 104 can be inserted in a collapsed condition through a standpipe 110; when the bottom of the member 104 engages the bottom of the pipe, the hinges open to fill the inside of the pipe. This ensures that the flow sensor is located in an accurately known flow cross- section.
Modifications and improvements can be incorporated without departing from the scope of the invention.

Claims

Claims
1. A device for measuring pressure or flow in a conduit, the device comprising a body having a first pressure chamber within the body communicating with a first aperture in the body; a second pressure chamber within the body communicating with a second aperture in the body spaced from the first aperture; and means for sensing pressure difference between said first and second pressure chambers.
2. A device as claimed in claim 1, where the body has a nose, a centre section, and a tail.
3. A device as claimed in claim 2, wherein the first chamber is provided in the nose section, and the second chamber is provided in the centre section.
4. A device as clamed in claim 2 or claim 3, wherein the nose is curved or tapered.
5. A device as claimed in claim 2, 3 or 4 wherein the centre section has generally parallel sides
6. A device as claimed in any one of claims 2-5, wherein the tail is tapered.
7. A device as claimed in any preceding claim, having more than one first and/or second aperture.
8. A device as claimed in any preceding claim, wherein the first aperture is a forward-facing aperture.
9. A device as claimed in any preceding claim, wherein the second aperture is a side-facing aperture.
10. A device as claimed in any preceding claim, wherein the second aperture is positioned downstream of the first aperture.
11. A device as claimed in any preceding claim, wherein the means for sensing pressure difference comprises a diaphragm differential pressure sensor.
12. A device according to any one of the preceding claims, having a hinge to facilitate insertion of the device into a narrow pipe.
13. A device according to any one of the preceding claims, having a funnel in which the device can be located in use, the funnel having a pre-determined cross-section and being adapted to fit within the conduit.
14. A device as claimed in claim 13, in which the funnel is foldable to facilitate insertion into a narrow pipe.
EP00962698A 1999-09-29 2000-09-22 Flow meter Withdrawn EP1226406A1 (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
GBGB9922983.3A GB9922983D0 (en) 1999-09-29 1999-09-29 Fow sensor
GB9922983 1999-09-29
GB9925715 1999-10-30
GBGB9925715.6A GB9925715D0 (en) 1999-10-30 1999-10-30 Flow sensor
PCT/GB2000/003621 WO2001023844A1 (en) 1999-09-29 2000-09-22 Flow meter

Publications (1)

Publication Number Publication Date
EP1226406A1 true EP1226406A1 (en) 2002-07-31

Family

ID=26315965

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00962698A Withdrawn EP1226406A1 (en) 1999-09-29 2000-09-22 Flow meter

Country Status (3)

Country Link
EP (1) EP1226406A1 (en)
AU (1) AU7434500A (en)
WO (1) WO2001023844A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102014000241B4 (en) * 2014-01-10 2015-04-16 Testo Ag Flow Meter
FR3086752B1 (en) * 2018-10-01 2021-11-12 Kimo FOLDING FRAME FOR FLOWMETER AND CORRESPONDING FLOWMETER

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4304137A (en) * 1979-05-31 1981-12-08 Honeywell Inc. Air direction insensitive static pressure sensor
US5029479A (en) * 1988-08-15 1991-07-09 Imo Industries, Inc. Differential pressure transducers
US5597963A (en) * 1991-12-23 1997-01-28 National Institute Of Water And Atmospheric Research Submersible streamlined meter with a pitot tube for measuring water flow in an open channel
DE4225696A1 (en) * 1992-08-04 1994-02-10 Wiesheu Gmbh Device for the heat treatment of food
FI102783B1 (en) * 1994-12-22 1999-02-15 Vaisala Oyj A method for linearizing a flow rate sensor and a linearized flow rate measuring apparatus

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0123844A1 *

Also Published As

Publication number Publication date
AU7434500A (en) 2001-04-30
WO2001023844A1 (en) 2001-04-05

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