32 May/June 2012 Plant Engineer

ENGINEER TO ENGINEER

GKN Wheels plant in Telford believes itwill save some £25,000 per year,following the installation of an ABB lowvoltage ac drive.

One of the plant’s lines, which makeswheels for the likes of Caterpillar andJCB, includes a walking beam withreciprocating parallel bars to pass rolledand welded wheel rims from an oil dipto a flare press.

Production manager Kevin Evansexplains that a problem has been that,as the beam reaches top dead centre,the larger wheel rims can cause it toover-speed, with the momentum thencarrying them too quickly towards thepress, which can, in turn, jam.

“This type of stoppage can take anaverage of two hours to remedy,resulting in lost production time andassociated costs,” he says. So, tomaintain schedules, the plant had torun overtime following such incidents,leading to the £25,000 estimate.

With Estil, a systems integrationcompany, and ABB already on site,investigating potential energy savings,Evans asked them to come up with abetter control system as well.

Phil Lampitt of Estil, which designedthe system, explains that it uses a1.5kW ABB standard drive. At thebeginning of the walking beam’s cycle,the drive starts and the internal timerruns it for one second at full speed.Then the drive is switched to two-thirdsspeed and gradually decelerated.Hence the beam, carrying the wheel

rim, slows as it approaches the press.As the wheel rim reaches the press, thebeam triggers a limit switch that stopsthe drive to complete the cycle.

“We worked closely with ABB tofine-tune the application to get a steadypositioning of the wheel rims,” saysLampitt. “ABB also helped us size thedrive – particularly critical in view of theneed to cater for the heavier rims in therange,” he continues.

“As there is limited space, we had tomount the drive externally. This led tochallenges from the harsh environmentof the production building and weneeded to specify an IP54 rated drivecasing to resist the ingress of oil.”

Evans confirms that, since itsinstallation, the plant has notexperienced a single stoppage on thispart of the process. “This is a significantsaving for us and we are also looking tostandardise on ABB drives throughoutthe plant to save further costs.”

Drive saves £25,000 of downtime at GKN

CompAir puts energysavings on the menu

Allessa Chemie goes mobilefor plant SCADA monitoring

Since installing fixed and regulated speed compressors, fromCompAir, at its plant in Sablé sur Sarthe, France, foodprocessor Société Marie says it has achieved annual electricitysavings of €10,500. Maintenance manager Stéphane Lemialesays payback on this investment will be less than two years.

Compressed air is used throughout manufacturing, fromcontrolling hot water valves to packaging the finished product– 10,000 tonnes of fresh and frozen ready meals per annum.However, its previous compressors were 20 years old and anair audit out by CompAir promised huge savings by installingtwo new compressors, as well as a heat recovery system.

“Based on the air audit, we opted to install a fixed speedCompAir L50 and regulated speed L55RS compressor, inaddition to heat exchangers,” explains Lemiale. “Theregulated speed technology in the L55RS means that thecorrect volume of air is produced at all times, [which] reducesoffload running.”

And he adds: “Using heat exchangers, we can recover andtransfer the heat generated duringcompression to our water supply.”

Since installing the new compressors,Société Marie has reduced electricityconsumption for compressed air by 25%. Inaddition, the new heat recovery system hasreduced natural gas consumption by 15%.

Speciality chemicals manufacturerAllessa Chemie has implementedSchad’s Extend7000 Mobile SCADAsystem to get instant notification ofpower plant problems.

The company, which runs twoproduction plants in the Rheinland areaof Germany, selected the system for itsFrankfurt-Fechenheim plant to improvethe consistency of energy distributionmonitoring within its 400V plant power supply.

Klaus Knahl, head of EMR operations at Allessa Chemie,explains that changes to power distribution can cause lossesin production, as well as compromising health and safety.“We needed to identify a way to improve the existing fixedmonitoring capabilities,” says Knahl.

“Extend7000 was the perfect solution. It allowed us tocontinue using our existing SCADA system and enhance it[for] mobile working,” he adds.

Immediate notifications delivered directly to plantengineers through Extend7000 will, he says, significantlyreduce downtime. He also explains that the system has beenconfigured to trigger switching devices and monitor bus bars– both of which actions previously needed manualintervention from the control room.

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