GB2162647A - Apparatus for measuring total flow in pipes - Google Patents

Apparatus for measuring total flow in pipes Download PDF

Info

Publication number
GB2162647A
GB2162647A GB08419721A GB8419721A GB2162647A GB 2162647 A GB2162647 A GB 2162647A GB 08419721 A GB08419721 A GB 08419721A GB 8419721 A GB8419721 A GB 8419721A GB 2162647 A GB2162647 A GB 2162647A
Authority
GB
United Kingdom
Prior art keywords
pipe
trap
flow
sample
fluid
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.)
Granted
Application number
GB08419721A
Other versions
GB2162647B (en
GB8419721D0 (en
Inventor
Harry Matthews
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.)
Sellafield Ltd
Original Assignee
British Nuclear Fuels PLC
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
Application filed by British Nuclear Fuels PLC filed Critical British Nuclear Fuels PLC
Priority to GB08419721A priority Critical patent/GB2162647B/en
Publication of GB8419721D0 publication Critical patent/GB8419721D0/en
Publication of GB2162647A publication Critical patent/GB2162647A/en
Application granted granted Critical
Publication of GB2162647B publication Critical patent/GB2162647B/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/02—Devices for withdrawing samples
    • G01N1/10—Devices for withdrawing samples in the liquid or fluent state
    • G01N1/20—Devices for withdrawing samples in the liquid or fluent state for flowing or falling materials
    • G01N1/2035—Devices for withdrawing samples in the liquid or fluent state for flowing or falling materials by deviating part of a fluid stream, e.g. by drawing-off or tapping

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Sampling And Sample Adjustment (AREA)

Abstract

To obtain a sample representative of the total flow in a pipe (1) over a given period a Pitot tube (2) is located in the pipe and connected to a collector (4) outside the pipe. The collector is pressurised to a pressure substantially equal to the static head of the flow in the pipe via line 7. Liquid is discharged from collector (4) to a container (6) which is vented to atmosphere. <IMAGE>

Description

SPECIFICATION Method and apparatus for sampling flows in pipes The present invention concerns a method and apparatus for obtaining a sample representative of the total flow in a pipe over a given period.
According to the present invention a method of obtaining a sample representative of the total flow of a fluid in a pipe over a given period comprises locating a Pitot tube within the pipe, connecting the Pitot tube to a collector outside the pipe and pressurising the collector to a pressure substantially equal to the static head of the fluid in the pipe.
According to another aspect of the present invention an apparatus for obtaining a sample representative of the total flow of a fluid in a pipe over a given period comprises a Pitot tube within the pipe, a collector outside the pipe connected to the Pitot tube and means for pressurising the collector to a pressure substantially equal to the static head of the fluid in the pipe.
Conveniently the collector comprises a trap for the sample, the trap having an outlet leading to a vented tank. The outlet in the trap is normally closed by a float valve operable to open the outlet when the sample flows into the trap.
The invention will be described further, by way of example, with reference to the accompanying diagrammatic drawing.
A pipe 1 carries a pumped flow of a liquid to be sampled, the flow direction being from left to right as indicated by the arrow. A Pitot tube 2 is located within the pipe 1 and is connected through an extension tube 3 to a trap 4. An exit tube 5 from the trap 4 communicates with a vented tank 6. An air or gas line 7 communicates with the trap 4. The outlet from the trap 4 to the exit tube 5 is controlled by a float valve. In the absence of liquid in the trap 4 the valve is closed. As liquid enters the trap the valve is lifted off its seat to allow the liquid to flow into the tank 6.
The Pitot tube 2 is positioned within the pipe 1 at a region of high turbulence, that is at a region at which the flow is thoroughly mixed.
The total head HT of liquid in the pipe 1 is the sum of the static head H5 and the friction head H,.
The static head H5 results from the elevation of the pipe 1 relative to a datum and the friction head Hf is determined by the pressure and velocity of the flow QT through the pipe 1. Air or gas at a constant pressure equal to the static head H5 in the pipe 1 is supplied to the trap 4 through the line 7. As a result, when OT, the flow in the pipe 1, is zero and therefore Hf is zero the pressure within the trap 4 is equal to the static head H5 and accordingly there is no sample flow Os from the pipe 1 into the trap 4.
As QT and hence Hf increases there is a proportional increase in the sample flow Q5.
Sample flow Q5 collecting in the trap 4 is discharged into the tank 6 when the amount of sample in the trap is sufficient to operate the float valve.
The proportion of the sample flow Q5 to the main flow 0T is determined by the diameter and length of the Pitot tube 2 and the extension tube 3.
An increase in the diameter and a decrease in the length has the effect of increasing the proportions Q5 to 0T Conversely, a decrease in diameter and an increase in the length results in a decrease in the proportion of flow taken from the pipe 1.
1. A method of obtaining a sample representative of the total flow of a fluid in a pipe over a given period comprising locating a Pitot tube within the pipe, connecting the Pitot tube to a collector outside the pipe and pressurising the collector to a pressure substantially equal to the static head of the fluid in the pipe.
2. An apparatus for obtaining a sample representative of the total flow of a fluid in a pipe over a given period comprising a Pitot tube within the pipe, a collector outside the pipe connected to the Pitot tube and means for pressurising the collector to a pressure substantially equal to the static head of the fluid in the pipe.
3. An apparatus as claimed in claim 2 in which the collector comprises a trap for the sample, the trap having an outlet in communication with a vented tank.
4. An apparatus as claimed in claim 3 in which the outlet in the trap is normally closed by a float valve operable to open the outlet when the sample flows into the trap.
5. A method of obtaining a sample representative of the total flow of a fluid in a pipe over a given period substantially as herein described with reference to the accompanying drawings.
6. An apparatus for obtaining a sample representative of the total flow of a fluid in a pipe over a given period substantially as herein described with reference to and as illustrated in the accompanying drawing.
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Method and apparatus for sampling flows in pipes The present invention concerns a method and apparatus for obtaining a sample representative of the total flow in a pipe over a given period. According to the present invention a method of obtaining a sample representative of the total flow of a fluid in a pipe over a given period comprises locating a Pitot tube within the pipe, connecting the Pitot tube to a collector outside the pipe and pressurising the collector to a pressure substantially equal to the static head of the fluid in the pipe. According to another aspect of the present invention an apparatus for obtaining a sample representative of the total flow of a fluid in a pipe over a given period comprises a Pitot tube within the pipe, a collector outside the pipe connected to the Pitot tube and means for pressurising the collector to a pressure substantially equal to the static head of the fluid in the pipe. Conveniently the collector comprises a trap for the sample, the trap having an outlet leading to a vented tank. The outlet in the trap is normally closed by a float valve operable to open the outlet when the sample flows into the trap. The invention will be described further, by way of example, with reference to the accompanying diagrammatic drawing. A pipe 1 carries a pumped flow of a liquid to be sampled, the flow direction being from left to right as indicated by the arrow. A Pitot tube 2 is located within the pipe 1 and is connected through an extension tube 3 to a trap 4. An exit tube 5 from the trap 4 communicates with a vented tank 6. An air or gas line 7 communicates with the trap 4. The outlet from the trap 4 to the exit tube 5 is controlled by a float valve. In the absence of liquid in the trap 4 the valve is closed. As liquid enters the trap the valve is lifted off its seat to allow the liquid to flow into the tank 6. The Pitot tube 2 is positioned within the pipe 1 at a region of high turbulence, that is at a region at which the flow is thoroughly mixed. The total head HT of liquid in the pipe 1 is the sum of the static head H5 and the friction head H,. The static head H5 results from the elevation of the pipe 1 relative to a datum and the friction head Hf is determined by the pressure and velocity of the flow QT through the pipe 1. Air or gas at a constant pressure equal to the static head H5 in the pipe 1 is supplied to the trap 4 through the line 7. As a result, when OT, the flow in the pipe 1, is zero and therefore Hf is zero the pressure within the trap 4 is equal to the static head H5 and accordingly there is no sample flow Os from the pipe 1 into the trap 4. As QT and hence Hf increases there is a proportional increase in the sample flow Q5. Sample flow Q5 collecting in the trap 4 is discharged into the tank 6 when the amount of sample in the trap is sufficient to operate the float valve. The proportion of the sample flow Q5 to the main flow 0T is determined by the diameter and length of the Pitot tube 2 and the extension tube 3. An increase in the diameter and a decrease in the length has the effect of increasing the proportions Q5 to 0T Conversely, a decrease in diameter and an increase in the length results in a decrease in the proportion of flow taken from the pipe 1. CLAIMS
1. A method of obtaining a sample representative of the total flow of a fluid in a pipe over a given period comprising locating a Pitot tube within the pipe, connecting the Pitot tube to a collector outside the pipe and pressurising the collector to a pressure substantially equal to the static head of the fluid in the pipe.
2. An apparatus for obtaining a sample representative of the total flow of a fluid in a pipe over a given period comprising a Pitot tube within the pipe, a collector outside the pipe connected to the Pitot tube and means for pressurising the collector to a pressure substantially equal to the static head of the fluid in the pipe.
3. An apparatus as claimed in claim 2 in which the collector comprises a trap for the sample, the trap having an outlet in communication with a vented tank.
4. An apparatus as claimed in claim 3 in which the outlet in the trap is normally closed by a float valve operable to open the outlet when the sample flows into the trap.
5. A method of obtaining a sample representative of the total flow of a fluid in a pipe over a given period substantially as herein described with reference to the accompanying drawings.
6. An apparatus for obtaining a sample representative of the total flow of a fluid in a pipe over a given period substantially as herein described with reference to and as illustrated in the accompanying drawing.
GB08419721A 1984-08-02 1984-08-02 Apparatus for measuring total flow in pipes Expired GB2162647B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08419721A GB2162647B (en) 1984-08-02 1984-08-02 Apparatus for measuring total flow in pipes

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08419721A GB2162647B (en) 1984-08-02 1984-08-02 Apparatus for measuring total flow in pipes

Publications (3)

Publication Number Publication Date
GB8419721D0 GB8419721D0 (en) 1984-09-05
GB2162647A true GB2162647A (en) 1986-02-05
GB2162647B GB2162647B (en) 1988-04-13

Family

ID=10564838

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08419721A Expired GB2162647B (en) 1984-08-02 1984-08-02 Apparatus for measuring total flow in pipes

Country Status (1)

Country Link
GB (1) GB2162647B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3837598A1 (en) * 1988-07-01 1990-02-08 Schwarte Werk Gmbh Method and device for obtaining milk samples from a flow conduit
EP0367899A1 (en) * 1988-11-05 1990-05-16 SCHWARTE-WERK GmbH Method and apparatus for extracting liquid-samples from a liquid-flow pipe
DE4030729A1 (en) * 1990-09-28 1992-04-02 Tuchenhagen Otto Gmbh METHOD AND DEVICE FOR SAMPLING AND SAMPLE HANDLING BY MEANS OF A SAMPLE BOTTLE
US6287456B1 (en) 1998-10-30 2001-09-11 Kimberly-Clark Worldwide, Inc. Filtration system with filtrate volume indicator

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3837598A1 (en) * 1988-07-01 1990-02-08 Schwarte Werk Gmbh Method and device for obtaining milk samples from a flow conduit
EP0367899A1 (en) * 1988-11-05 1990-05-16 SCHWARTE-WERK GmbH Method and apparatus for extracting liquid-samples from a liquid-flow pipe
WO1990005291A1 (en) * 1988-11-05 1990-05-17 Schwarte-Werk Gmbh Process and device for withdrawing liquid samples from a flow line
DE4030729A1 (en) * 1990-09-28 1992-04-02 Tuchenhagen Otto Gmbh METHOD AND DEVICE FOR SAMPLING AND SAMPLE HANDLING BY MEANS OF A SAMPLE BOTTLE
WO1992006363A1 (en) * 1990-09-28 1992-04-16 Otto Tuchenhagen Gmbh & Co. Kg Process and device for obtaining and handling samples
US6287456B1 (en) 1998-10-30 2001-09-11 Kimberly-Clark Worldwide, Inc. Filtration system with filtrate volume indicator

Also Published As

Publication number Publication date
GB2162647B (en) 1988-04-13
GB8419721D0 (en) 1984-09-05

Similar Documents

Publication Publication Date Title
EP0547050B1 (en) Gas sampling device and dilution tunnel used therewith
US3869068A (en) Diluter probe assembly
US3765226A (en) Self-powered sample probe
US5811696A (en) Isokinetic fluid sampling method
US4060001A (en) Sampling probe and method of use
GB2162647A (en) Apparatus for measuring total flow in pipes
US4366700A (en) Apparatus for measuring the differential pressure of dissolved gases in a fluid medium
US3262313A (en) Pressure chamber level gauge with bubble supply
GB1564857A (en) Device for continuously determining the carbon dioxide content of a liquid flowing through a pipe particularly a liquid beverage
JPS5716333A (en) Sampling device for solid-gas mixture phase fluid
EP0122975A1 (en) Device and method for detecting leaks in the combustion system of a water-cooled internal-combustion engine
GB2030963A (en) Liquid Sampling System
FR2250111A1 (en) Presampling device for liquids - removes samples required for quality control analysis from continuously flowing liquid
CA2153286A1 (en) Apparatus for measuring surface tension
GB2101310A (en) Gas detection apparatus
US2986939A (en) Fluid sampling apparatus
US2934958A (en) Gas sampling device
DE59500440D1 (en) Device for measuring the surface tension
US3283585A (en) Gas sampling system
GB2129696A (en) Mixing device
SU894418A1 (en) Device for automatic liquid sampling
SU1704010A1 (en) Liquid sampling device for pipe lines
GB1477199A (en) Sample supply apparatus for automatic analysis systems
GB2259982A (en) Sampling a fluid to determine its contaminant content
US3908696A (en) Metering of trace amounts of fluids for producing low concentrations thereof in carrier fluids

Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee