This page contains a Flash digital edition of a book.
TECHNOLOGY ROUNDUP

Two very different flow measurement applications have been found for Pulsar’s MCERT-ified flow measurement system. Keith Flint of Pulsar explains how its DUET transducer is helping at Manchester Airport and Premier Foods

control unit to a Premier Foods processing plant in Newport as part of an open channel measurement project for the MCERTS certification scheme. The accuracy achieved by Premier Foods has allowed the company to make a substantial saving on effluent charges. Siris led the project, supplying and installing the primary measurement device together with the flow and sampling equipment. Pulsar’s DUET non-contacting ultrasonic transducer array was chosen for the extraordinary accuracy achievable. Siris’ sales manager, Simon Richardson, explained the process: “To achieve the most accurate flow measurement system, both the design and the installation of the weir tank and associated equipment was undertaken to the highest possible standards. It is vital that upstream flow conditions are controlled, the weir tank was constructed to be very rigid, the weir

Contrasts and connections

S

iris Environmental of Durham has installed Pulsar Process Measurement’s DUET transducer array and its associated

Substantial savings: Premier Foods’ processing plant in Newport

plate was reinforced and the chamfering of the edges of the weir plate was closely controlled.” Ultrasonic systems work by bouncing a sound

pulse from the surface being measured and calculating the distance from the time taken for

the pulse to return to a transducer. The accuracy of the measurement depends on the speed of sound, which can vary with temperature. Temperature changes can be compensated

for, but a temperature compensation circuit cannot respond immediately and there may be temperature variations in the column of air below the transducer face. DUET uses two transducers a known distance apart, and by comparing the returning signal from both transducers, variations in the speed of sound are dynamically compensated for. This was critical to the success of the project. A 2mm variation in measurement accuracy would result in an error of 40m3/d. Richardson explained the advantage of MCERTS: “Many companies see the MCERTS Certification Scheme as another additional expense, they often don’t appreciate that the scheme ensures accurate measurement of their effluent discharge and in this case we have proved that a well implemented installation can save real money.”■■■

Up and away: take-off for run-off monitoring

Like any other airport, surface water runoff at Manchester Airport is considerable, and in certain areas may be mixed with aviation fuel, oil and other contaminants. For this reason it has to be treated like any other industrial effluent before it can be discharged. To assist with separation, treatment and measurement of the final effluent flow, Pulsar supplied a non- contacting, ultrasonic, open channel flow measurement system, featuring the company’s DUET transducer array. The DUET is used in

Editor

Natasha Wiseman – 01204 698951 natasha.wiseman@fav-house.com

Sub-editor

Richard Sharpe

Group advertisement manager

Ella Westaway – 020 8651 7077

Advertisement manager (south)

Adam Jeffery – 020 8651 7147 adamj@fav-house.com

14 Sampling & Monitoring May 2010

the airport’s critical API hydrocarbon separation unit. Pulsar supplied a V-notch

weir plate and a DUET transducer array and FlowCERT control unit to measure effluent flow through an open channel. The channel was in an exposed position, where solar radiation can be a significant factor affecting the accuracy of the measurement. The V-notch weir plate was

sized for a maximum flow rate of 25l/s. Although the flow can be low in dry periods of the year, it is vital that the measurement remains reliable

Sales executive (north)

Matthew Byron – 0161 903 1515 matthew.byron@fav-house.com

Design & production manager

Luana Marca

Classified sales

Vernon Ward – 020 8651 7058 vernon.ward@fav-house.com

Team administrator

Clare Klos – 020 8651 7121

and accurate. In this case, because the head varies by around 200mm between high flow and zero, it is crucial that the measurement is accurate, repeatable and records a genuine zero when there is no flow. DUET is perfect for this type of application, consisting of two transducers that fire simultaneous ultrasonic pulses which are then received at the lower transducer only. Mark Stewart, the airport

water services engineer in charge of the project, said: “We have been delighted with the performance of the DUET.”

clare.klos@fav-house.com

Editorial co-ordinator

Sarah Owens – 020 8651 7108 sarah.owens@fav-house.com

Production controller

Mike Smith – 020 8651 7105 mike.smith@fav-house.com

Publisher

Angela Himus – 020 8651 7164 angela.himus@fav-house.com Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64