Rotameters in an Olefins Pyrolysis Furnace Replaced with Micro ...
Transcript of Rotameters in an Olefins Pyrolysis Furnace Replaced with Micro ...
Rotameters in an Olefins Pyrolysis FurnaceReplaced with Micro Motion R-Series Meters
CHEMICAL
RESULTS•$384,000peryearinproductionsavings
•$92,000peryearinmaintenancesavings
•Paybackinlessthansixmonths
APPLICATIONInanolefinspyrolysisfurnace,ahydrocarbonfeedstock/steammixtureispumpedthroughamazeof4to6-inch((DN800toDN1000)diametertubeswhereitisheatedto815-885°C(1500-1600°F).Duringthecrackingprocess,undesirableby-products,includingmethaneandcoke(carbondeposits),areproduced.TheobjectiveoftheprocessistobeasselectiveaspossibletowardsEthylene,makingasmuchofthatmoleculeaspossible,whileminimizingtheproductionofby-products.Evenwiththebestcontrolschemes,cokeisstillproducedanddepositedontheinsideofthetubes.Thiscokeactsasaninsulator,preventingthefeedstock/steammixturefrombeingheatedenoughforthecrackingprocesstoworkandtheunithastobefrequentlyshutdownforde-coking.Toadequatelyde-cokeafurnace,thehydrocarbonfeedisreplacedwithairandmixedwithsteam,thenfedthroughthetubes.Bothsteamandairflowsshouldbemeasuredtoproperlyratiothecomponentsforefficientde-coking.
CHALLENGEAlargepetrochemicalcompanylocatedinsouthTexashasmultipleolefinsfurnacesthatusedrotameterstomeasuredecokingairfeed.Thecompanyneededtokeepthetubesfromcokinguptooquickly,preventfurnacetuberupture,andtominimizethedowntimerequiredtode-coketheunit.Thechallengewiththerotameterswasthatthemagnetusedtogeneratetheflowsignalwouldbecomecoveredwithdebrisfromtheairlinewhichnolongerprovidedanaccurateenoughflowsignaltoadequatelycontrolthedecokingprocess.
SOLUTIONThecompanychosetopurchaseMicroMotion®R-Seriesmeterswith1700transmitterstoreplaceeachrotameter.Thiswasacost-
AN-001863RevB/©2015MicroMotion,Inc.Allrightsreserved.
Formoreinformation:www.MicroMotion.com/chemicalwww.MicroMotion.com
EthylenePlant
CHEMICAL
effectivesolutionbecausetheMicroMotionmetersprovidedamaintenance-freeoptionwithamoreaccurateandreliableflowreading.Inoneyear,thecompanysaved$92,160inmaintenanceand$384,000inproductioncosts.
AN-001863RevB/©2015MicroMotion,Inc.Allrightsreserved.
BEFORE:RotameterInstallation AFTER:R-SeriesCoriolisMeter-ReducedMaintenanceandImprovedDecokeProcess
Coriolis Installation Costs
PipingMaterials&Modification
$30,000
Wire&Conduit $40,300
R-SeriesMeter $153,633
Total Installed $223,933
Coriolis Installation Savings
IncreasedProduction $384,000
DecreasedMaintenance $92,160
Total $476,160
Payback on Coriolis Meters
InstallationCost $223,933
AnnualSavings $476,160
Payback=Cost/Savings(Years)
0.46
Payback=Cost/Savings(Months)
5.64