Product category:
Flowmeters and Flow Sensors
News Release from: Flowline | Subject: Ultraflux ultrasonic measurement
Edited by the Engineeringtalk Editorial
Team on 06 September 2007
Flow technology helps prevent pollution
Cemex asked Flowline to provide a metering station which would measure the river flows to provide data for use in calibrating a hydraulic model of the Erewash and Attenborough lake system.
Flowline was involved in minimising the risk of river pollution and protecting a site of special scientific interest (SSSI) The project was on the River Erewash, a tributary of the River Trent at the Attenborough Lakes Nature Reserve in Nottingham, at a point where the river is around 10m wide with a depth ranging from 0.5 to 2m Cemex had to overcome the problems of various sewage works and other sites discharging into the river and causing contamination
This article was originally published on Engineeringtalk on 2 Feb 2001 at 8.00am (UK)
Related stories
Level switch ideal for medium-scaling liquids
A unique guard circuit rejects the negative effects of coating build-up on the probe of Flowline's new capacitance level switch by eliminating the coating signal path between the electrodes
Non-intrusive level switch for tanks to 1in thick
A new, non-intrusive capacitance level switch detects liquids through non-metallic tanks up to 1" thick and mounts in a bracket on the exterior wall of the tank
The critical point was where the river passed through the site of a former aggregate quarry shortly before meeting the river Trent, an area designated as being of special scientific interest and home to a wildlife sanctuary.
Therefore, a key requirement was to move the discharge point of the river to ensure that Cemex asked Flowline to provide a metering station which would continuously measure the river flows to provide data for use in calibrating a hydraulic model of the Erewash and Attenborough lake system.
Another important consideration was that the site was open and accessible to the public and incidents of vandalism had occurred, so any equipment installed had to be as robust as possible, without being too intrusive.
Following an initial survey and taking all the dynamics of the site into account, Flowline supplied a four-path ultrasonic flowmeter incorporating an Ultraflux Time of Flight sound pulse measurement device with GSM telemetry.
The complete supply package included an initial site survey, the selection of a suitable metering point, the installation of the system including support columns and cable runs and commissioning the system.
Further reading
Miniature transducer ideal for small tank use
CFlowline's new LA15 and LA20 Ricochet level transmitters are the non-contact, low-cost solutions for applications involving general-purpose IBCs.
Low-cost, two-wire, level transmitter
Flowline's new low-cost, two-wire, LA12 Cricket level transmitter is mounted through the top wall of the tank and provides continuous liquid measurement up to 10 feet.
Tuning Fork level switch tackles harder tasks
Flowline's new LZ10 Tuning Fork Level Switch is an excellent choice for such challenging liquid applications as those with light to medium coating or scaling-type characteristics
The application of the Ultraflux ultrasonic measurement principle at this site involved the use of a number of ultrasonic paths located at approximately 45 degrees to the river axis.
The requirement for real-time monitoring and continuous recording of flows was satisfied by the use of a GSM modem which was connected directly to the flowmeter control unit.
This ensured that flow could be read at any time and also meant that the built-in data logger could be downloaded when required.
Latest job opportunities
Multi Skilled Maintenance Engineer, Maintenance Engineer
Maintenance Engineer (FOOD/FMCG)
Job Title: Multi Skilled Maintenance Engineer, Maintenance Engineer
Area: Buckinghamshire, Bedfordshire, London, Middlesex, Hertfordshire, Buckinghamshire, Berkshire, Essex, Kent, Surrey, South East
Salary: ...
Electrical, Multi-skilled, Mechanical, Maintenance Engineer
Maintenance Engineer x 2, Multi-skilled Maintenance Engineer, Electrical Maintenance
Job Title: Electrical, Multi-skilled, Mechanical, Maintenance Engineer
Area: London, Hertfordshire, Middlesex, Bedfordshire, Essex, Buckinghamshire, South...
Field Service Engineer, Service Engineer
Field Service Engineer (Medical)
Job Title: Field Service Engineer, Service Engineer
Area: London, Hampshire, Surrey, Hertfordshire, Middlesex, Bedfordshire, Buckinghamshire, Berkshire, Essex, South East.
Salary: £21,500 - £28,000 + OTE +...
This measurement principle and its configuration at the River Erewash site provided accurate flow measurement data, despite significant variations in velocity and turbidity.
These factors often render other types of sensing technology ineffective.
The installation at the River Erewash site involves ultrasonic sound pulses being sent alternately between probes mounted on opposite sides of the channel / river.
The pulses that travel with the flow are speeded up, while the pulses that travel against the flow are slowed down.
The time between each pulse being transmitted and received is measured very accurately and the greater the time difference between transmission and reception, the higher the flow velocity.
Commenting on the Flowline installation, Chris Pointer, Senior Hydrogeologist within the Geological Services Department at Cemex UK, said, "The Flowline system has enabled hydraulic modelling work that ultimately led to the granting of planning permission for an extension to our sand and gravel operations at the Attenborough Quarry".
"In the past we have used ultrasonic doppler flow meters and these gave very noisy data due to low suspended solids content, so the data was virtually unusable and we also experienced difficulties with a fixed weir gauge".
"Overall we are pleased with the system which has been operating successfully, the problems associated with the doppler flow meter have not occurred with the Flowline Ultraflux system".
"Also, we particularly appreciate the instantaneous direct flow measurement data without the need to use a rating curve, while the telemetry enables real-time monitoring of flows and allows us to check on the system performance".
The general specification of the key components of the Flowline system included; for the volumetric flow measurement, partially filled round and rectangular and other shaped conduits using from two to six velocity chords, for velocity measurement, time-of-flight ultrasonic providing accuracy of +/- 0.5% of reading with a range of 0.002m/s to +5m/s and with a probe frequency from 0.5 MHz (dependent on the application).
Level measurement was provided by 4-20 mA signal from the transmitter while the flow calculation method was conversion of water level and pipe size to fluid area with multiplication of fluid area by mean velocity to equal flowrate.
Flow measurement accuracy was typically +/- 2 to 5%.
The sensor probe units were field interchangeable with control units, the sensor housings were rated to IP68 and constructed using stainless steel casing, with twinax type sensor cables.
The controller / display unit was field interchangeable with the sensor units and rated to IP67.
The enclosure housed a built-in data logger providing up to 32,400 flow readings while the control unit was programmable via the supplied software or key pad, with report generating software included as standard.
The display provides flowrate / total, diagnostics, three off programmable relays, with a 4-20mA output for flowrate.
The Flowline system at the River Erewash site, which is also being considered for use by the Environment Agency, exceeds the requirements of ISO6416 and is also CE marked, although certification to ATEX standards is possible for hazardous areas, if required.
• Flowline: contact details and other news
• Email this article to a colleague
• Register for the free Engineeringtalk email newsletter
• Engineeringtalk Home Page
Search the Pro-Talk network of sites
