Compressed Air and Gas Handbook Chapter One

CompressedAir&GasInstitute•1300SumnerAvenue•Cleveland,OH44115Phone:[phone]•Fax:[phone]•E-mail:[e-mail]&GasInstitute•1300SumnerAvenue•Cleveland,OH44115Phone:[phone]•Fax:[phone]•E-mail:[e-mail]™™xii1CompressedAirUsesCompressedAirUsesChAPtEr11CompressedAirUsesINTRODUCTIONThemanufactureofcompressorsandofdevicesandmachinestoapplycompressedairandutilizecompressedgasesisalargeandessentialindustrythatcontributesgreatlytotheeconomyofallnations.Compressedairprovidespowerforamulti-tudeofmanufacturingoperations,someofwhicharelistedinFigure1.1.Carbondioxide,compressedandaddedtothestagecondensersofmulti-stageflashevapo-rators,likethatinFigure1.2,helpspreventscalebuildupandimproveseconomyofoperation.Thisisaprocessapplication,atypediscussedatlengthinChapter7.Therearemanydifferenttypesofcompressors,andtheirapplicationsarenumerous.Bygroupingthemaccordingtodesignobjectivesanddifferences,thereadermayobtainacertainperceptionoftheequipmentanditsapplications.The80-125psigaircompressoristhefirstgroup.Perhapsthisgroupisrespon-sibleforaslighttechnicalerrorinthetitleofthebook.Airisagas.Butaircom-pressedto100psigisessentiallyautility,anditscompressorsaresolargeaclassthataircompressorsareconsideredseparatelyfromcompressorsforothergases.Mostplantairsystemsoperateatornearthispressure,andmanyairtoolsmaybepluggedintothesystemusingquick-disconnectfittings,inmuchthesamewaythehouseholderplugsinatoasterorfoodprocessor.Inthetextofthisbook,everyapplicationof100psigaircannotpossiblybetakenup,sincetheyaresonumerous.Asanexample,considerthesyntheticfibersthatarenowthemainingredientofclothingandrugs.Whenthismaterialwasfirstintroducedintothemarketplace,ithadasmoothsilkytexture.Theclothingitemswereconsidereduncomfortable,especiallytomen.Toovercomethisobjection,thesmoothsyntheticstrandswerecutinlengthsandwovenintoacombinedthreadofCompressedAir&GasInstitute•1300SumnerAvenue•Cleveland,OH44115Phone:[phone]•Fax:[phone]•E-mail:[e-mail]&GasInstitute•1300SumnerAvenue•Cleveland,OH44115Phone:[phone]•Fax:[phone]•E-mail:[e-mail]™™23CompressedAirUsesCompressedAirUsesChAPtEr1AirBrakeAirChuckAirCylinderAirEjectionAirJetAirMotorAirViseAtomizingBoilerTubeCleaningBuffingChippingConveyingCoreBlowingDieCastingDrillingElevatingFormingGasCompressionGrindingHoistingMixingNutSettingPaintSprayingPavementBreakingPileDrivingPressurizingProcessControlReamingRivetingSandingSandBlastingSandRammingScrapBalingScrewDrivingStaplingThreadTappingTransferringWireBrushingWorkPositioningFigure1.1Typicalmajorapplicationsofcompressedairinmanufacturing.CompressedAir&GasInstitute•1300SumnerAvenue•Cleveland,OH44115Phone:[phone]•Fax:[phone]•E-mail:[e-mail]&GasInstitute•1300SumnerAvenue•Cleveland,OH44115Phone:[phone]•Fax:[phone]•E-mail:[e-mail]™™23CompressedAirUsesCompressedAirUsesChAPtEr1syntheticandnaturalfiber,suchaswoolorcotton.Theprocessproducedafinalproducthavingthetextureofthenaturalfibercomponent.However,thesyntheticcomponentswouldcurlandformballsoftheseparatedsynthetic.Thefinalsolutionwastotangleandloopthesyntheticfiberbyusingnonlubricatedairinaturbulentflowofairandfiberpassingthroughaventuri.Figure1.2Desalinationplantextractingfreshwaterfromseawatercanhaveaprofoundeffectonaridandsemi-aridareas.Carbondioxide,compressedandaddedtothestagecon-densersofsuchmulti-stageflashevaporators,helpspreventscalebuildupandimproveseconomyofoperation.Thedesignofthe100psigaircompressorpermitsawiderangeofstandardmodels,fromthesmallhomeaircompressortothelarge-flow-capacitycentrifugalcompressor.Themachineisself-containedinthatallcomponentsrequiredinthecompressordesignarefurnishedinaneat,compactpackage.Theaircompressorpackageshouldrequiretheminimumamountofpowerperunitofflow.Itmayhaveoneortwostages,ormore,dependingonthetypeofcompressorused.Thesecondgroupismadeupofgascompressors.Inthisgroup,specialcom-pressorsaredesignedtomeetachemicalprocessrequirementonpressureorflow,andarecapableofhandlingwhatevergasorgasmixtureistobeused.Thegascompressoristheconveyoroftherawmaterialsneededbytheprocess.Withintheprocess,thegasischemicallycombinedtoproducethedesiredproduct.Severalpressurelevelsareoftenrequiredbytheprocess.Whilethegascompressormaybesimilarinappearancetothe100psigaircompressor,muchmoreengineeringisCompressedAir&GasInstitute•1300SumnerAvenue•Cleveland,OH44115Phone:[phone]•Fax:[phone]•E-mail:[e-mail]&GasInstitute•1300SumnerAvenue•Cleveland,OH44115Phone:[phone]•Fax:[phone]•E-mail:[e-mail]™™45CompressedAirUsesCompressedAirUsesChAPtEr1generallyinvolved.SuchcompressorswillbediscussedinChapter7.Thethirddivisionismadeupofoilandgasfieldcompressors.Theseareseparatedfromthegascompressorgroupforseveralreasons.First,theyareunitsthatcanbemovedfromoneoilfieldtoanotherbytruck.Theyareusuallydesignedtooperateat100rpmtomatchthegas-engine-driverotationspeed.Thecompressoranddriverareonacombinedsupportskid.Thisrequirementimposesrestrictionsonthesizeoftheunitandnecess