“By using the low-temperature Oxyfuel method, we can melt 50 percent more cold aluminum in the same amount of time as we did previously. In addition the propane consumption and carbon dioxide emissions have been cut in half which also is very positive.”

Wenche EldegardCast House Manager

Invensys Helps Hydro to Significantly Increase its Aluminum Cold Melting Capacity as well as Reduce Waste and Emissions

Goals• Thecompanyrequiredasolutionthatwould

enableittoachieveincreasedmeltingcapacityandreducewaste

• Thetechnologyneededtonotonlyincreaseproductionefficiencybutalsoreduceproductioncostsandincreaseenergysavings

Challenges• Thealuminummanufacturerneededto

accuratelycontrolcombustionoperationsandenablethesmoothtransitionofvariousmetallurgicalprocesses

• Optimizingenergyoutputduringthealuminummeltingcyclewasvitaltoachievingoverallproductionefficiency

• Tomaintainprofitability,thetechnologyneededtoprovidebothcostsavingsinproductionaswellasassistinminimizingthecompany’senvironmentalimpact

Solutions and Products• FoxboroProgrammableAutomationController

(PAC)System

Results• ByutilizingthekeyfeaturesofthetheFoxboro

PACSystem,LindeGashasenabledHydrotoincreaseitsaluminumcoldmetalmeltingcapacitybymorethan50percent

• Thecompanywasabletoreducedrosstolessthan2%andfuelconsumptionby50%

• Asignificantreductionincarbondioxideandnitrogenoxideemissionsalsowasachievedtomaintainthecompany’scommitmenttoreducingitsimpactontheenvironment

• TheLindeGasLowTemperatureOxyfueltechnology,usingTheFoxboroPACSystem,nowenablesthecontinuousproductionof125,000tonsoffoundryalloysannually

INDUSTRY:METALS,MINERALS&MINING

Hydrowww.hydro.com

©NorskHydro

Ardal, Norway–In1957thetincanmadeasignificantleapindesignandfunctionalitybyincorporatingthemostabundantmetalintheEarth’scrust--aluminum.Thoughthenewaluminumcontainerstillhadtobeopenedwithaknife,itbecamecheapertoproduceandreducedthepossibilityofleadpoisoningassociatedwithsolderusedtosealtincontainers.Thelowdensity,corrosion-resistantmetalalsoofferedgreatermalleability,enablingittobemanufacturedinawiderarrayofshapesandsizes.

Duringthelastdecade,aluminummanufacturinghasmadevariousevolutionaryleapsinprocessesandmaterialsthankstothedevelopmentofnewproductiontechnologies.Hydroisoneoftheworld’sleadingproducersofaluminumandisasuppliertoawiderangeofindustriesspanningautomotiveandtransportationtobuildingsupplies,packagingandconsumergoods.

Toprovidetop-qualityandcost-effectivealuminumproducts,Hydroemploysintelligentburnercontrolsolutionsforlow-temperatureOxyfuelcontrol.TheuseofOxyfuelcombustionsubstantiallyincreasesthethermalefficiencyoftheproductionfacility’sfurnaceoperationsbecausetheradiantheattransferoffurnacegasesproducedaresignificantlymoreefficientthanthosecreatedfromair-fuelprocesses.

UsingtheFoxboroProcessAutomationController(PAC)System,inconjunctionwithLindeGasOxyfuelburnershasresultedinsignificanteconomicsavingsandsupportsHydro’scommitmenttoreducinggreenhouseemissionsanddross,whichisamassofsolidimpuritiesfoundfloatingonmoltenmetalsuchasaluminum.

More Than Just Aluminum Foil

WorkinginconjunctionwithLindeGas,aleadinggasesandengineeringcompany,InvensysOperationsManagementinstalledtheFoxboroPACSystemforprocesscontrol,dataacquisition,remoteequipmentmonitoring,machinevisionandmotioncontrol.ThewholeSystemreducesHydro’sengineeringcostsandprovideshighavailabilityofdata,maximizingthecompany’sprocessuptime.

ThechallengeatHydrowastooptimizetheamountofenergyrequiredinthemanufacturingprocesswhenproducingitsmorethan125,000tonsoffoundryalloyseachyear.Combinedwiththelow-temperatureOxyfueltechnology,theFoxboroPACSystemdelivershighermeltrateswithreducedoxidation,lowerfuelconsumptionandultra-lownitrogenoxideemissions.There-meltcapacityhasnowbeenincreased,withcapacityup50%whiledrossislessthan2%.

AlthoughOxyfuelisacceptedasstate-of-the-artforrotaryfurnaces,thealuminumindustryhasbeenmorecautioustoadoptthetechnologyinreverberatoryfurnaces.Withtheriskofcreatinghotspotsduetooverheatingthealuminumsurface,amoreeffectiveprocesshadtobefound.Hydronoweffectivelymanagestheserisksbyemployinglow-temperatureOxyfueltechnologycombinedwiththeFoxboroPACSystemintelligentburnercontrolsolution.

TheFoxboroPACSystemisahigh-performancehybridautomationcontrollerwhichoffershighperformance,reliabilityandhighI/Odensitieswithcost-effectiveredundancyoptions.ItscontrolunitandI/Osystemformthebasisofacompletedistributedcontrolandrecordingenvironmentcapableofcontinuousanalog,logicandsequentialcontrol.Combinedwithsecuredatarecordingforaccuratemanufacturingmeasurementparameters,theFoxboroPACSystem’scollectionoffeaturesisdesignedtomaximizeHydro’sreturnoninvestment.

©NorskHydro

Oxyfuel and Foxboro PAC Technology

ByusingthelowtemperatureOxyfueltechnology,Hydrocanreplace20,000tonsofliquidaluminumbyre-meltingcoldmetal.Previously,theprocessincludedthemixingof8tonsofcoldmetaland22tonsofliquidmetalwhichhadahighproductioncostfactor.Nowthemixis13tonscoldand17tonsliquidmetal,reducingoveralloperationscosts.TheOxyfuelprocessandFoxboroPACSystemtechnologyhasenabledthecompanytoincreaseitsoverallaveragere-meltingcapacitybymorethan50%forthefourfurnacesatthecasthouse.

“ThekeyelementHydroneededwasincreasedcapacityonmeltingcoldmetal,thesolutiongivesthemthatalongsidelargeenergysavings.Itwasvitaltoprovideaccuratecombustioncontrolandasmoothtransitionbetweenallaspectsofthecyclewhileoptimizingthemeltingcycleandapplyingthemaximumenergywhenthethermalefficiencyishighest,”saidLarsGoranElfgren,ProjectManageratInvensysOperationsManagement.

Thankstoimprovedthermalefficiencyandincreasedheating/meltingrates,overallproductivityisincreasedwhileatthesametimesavingonfuelcostsandreducingcarbondioxideandnitrogenoxideemissions.ThetwoproductionlinesforprimaryfoundryalloyswereconvertedtothelowtemperatureOxyfuelandFoxboroPACSystemprocessresultingina50%increaseinre-meltingcapacity.

Combiningthelow-temperatureOxyfuelburnerforaluminummeltingwiththeFoxboroPACSystem,Hydrohastakenasignificantsteptowardenablingmoreefficientre-meltingofaluminuminreverberatoryfurnaces.

IntegratingtheFoxboroPACSystemwiththeplant’sPLCsenableHydrotomaximizeROIbyofferingautomaticdual-redundancyoptionstoguaranteeprocessefficienciesandprotectagainstcontrollerorcommunicationsfailures.Thispowerful,cost-effectiveprocessautomationcontrolleralsouniquelyprovidessecuredatarecordingwithdual-redundancyatpointofmeasurement.

“TheFoxboroPACSystemallowslow-cost,multi-loopprocesscontrolcapabilitytobedeployedrightataprocessunitandcanbeeasilyconfiguredusingInvensystechnology,”saidConstantineLau,DirectorofProductMarketingforControlandSafetyProductsatInvensysOperationsManagement.“WhiletheFoxboroPACSystemcanbeeasilyintegratedintoacontrolorplantnetwork,itwillcontinuetocontroltheprocessevenifanetworklinkislost.Combinedwithoptionalcontrollerredundancy,thisprovidesahighdegreeoffault-toleranceataverylowcost.”

Foxboro Combines PLC Architecture and DCS Functionality

Inaddition,theFoxboroPACSystemenablesredundancyofprocessors,powersupplies,recordingandnetworks.Thecontroller/recorderredundancyisautomaticallycommissionedbysimplypluggingtheadditionalprocessormoduleintotheredundantbaseandinitiatingtheE-Synctechnologywithasinglebuttonpressonthefrontoftheunit.DuringtheE-Syncprocess,allfilesfromtheprimaryprocessorarecopiedtoallowasecondaryprocessortomirrorandmonitortheprimaryprocessor.Nospecialcablingorengineeringisrequiredtoconfigureasecondaryprocessor.

WiththeE-Synctechnology,theFoxboroPACSystemprovidesahigh-performancesolutionthatoffersextremelycost-effectiveredundancyoptions.ThecontrolunitandI/Osystemformthebasisofacompletedistributedcontrolandrecordingenvironmentcapableofcontinuousanalog,logicandsequentialcontrolallcombinedwithsecuredatarecordingatpointofmeasurementtomaximizeROI.

Asaluminumhasdemonstrateditsabilitytobeusedinamultiplicityofproductswithmyriadbusinessandconsumerapplications,Hydrohasbeenaleaderinadvancingimprovementstothemetallurgicalprocessingofthisextremelyabundantmetal.WiththehelpofInvensys,Hydrohasimplementedredundantcapabilitiesthatmaximizeprocessuptimeinitsaluminummeltingprocess,resultinginlowerengineeringcostsandareducedimpactontheenvironment.

Invensys,theInvensyslogo,ArchestrA,Avantis,Eurotherm,Foxboro,IMServ,InFusion,SimSci-Esscor,Skelta,Triconex,andWonderwarearetrademarksofInvensysplc,itssubsidiariesoraffiliates.Allotherbrandsandproductnamesmaybethetrademarksorservicemarksoftheirrepresentativeowners.

©2011InvensysSystems,Inc.Allrightsreserved.Nopartofthematerialprotectedbythiscopyrightmaybereproducedorutilizedinanyformorbyanymeans,electronicormechanical,includingphotocopying,recording,broadcasting,orbyanyinformationstorageandretrievalsystem,withoutpermissioninwritingfromInvensysSystems,Inc.

Invensys Operations Management • 5601 Granite Parkway III, #1000, Plano, TX 75024 • Tel: (469) 365-6400 • Fax: (469) 365-6401 • iom.invensys.com

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