HeatTransferinaRotaryDrumviaConduc6on,Convec6on,andRadia6onBrandonBoepple,ChemicalEngineering

Mentor:Dr.HeatherEmady,AssistantProfessorSchoolforEngineeringofMaDer,Transport,&Energy

Howisheattransferinarotarydrumaffectedbyopera6ngparameterssuchasgranularfilllevelanddrumrota6onrate?

Heattransferoccursvia3modes:conduc6on,convec6on,andradia6on.Ageneralequa6onfortotalheattransferis:In this applica6on, heat is transferred through wall-par6cle, par6cle-par6cle, wall-air, and par6cle-air contacts. First, we will completeexperiments for conduc6on hea6ng through wall-par6cle, wall-air, andpar6cle-par6cle contacts. The drum will be heated externally and isassumed to be sealed so that convec6on effects can be neglected. Byopera6ngbelowroughly600K,effects fromradia6onarealsoneglected.Fromthisfirstroundofexperiments,wecancalculateQcond.Next, we will perform experiments to study convec6on hea6ng byinser6nghotairintothedrumviaaholeintheviewingwindow.Fromthisroundofexperiments,wecancalculateQconvfromQtot-Qcond.Lastly,wewillconsiderhea6ngviaradia6onbyopera6ngattemperaturesabove600K.Fromthisroundofexperiments,wecancalculateQradfromQtot– Qcond– Qconv.These values of heat transfer coefficients will be calculated from heatbalance equa6ons; the following example equa6on is a heat balancebetween thedrumwall andgranularbed.Valuesofαs canbecalculatedfromtheslopeofthebest-fitlinefromthegraphofln(T)vs.6me.

Qtot=Qcond+Qconv+Qrad

Methodology

FutureWorkExperimentalSetup

AcknowledgementsChaudhurietal.,Experimentallyvalidatedcomputa6onsofheattransferingranularmaterialsinrotarycalciners,PowderTechnology198(2010).ManognaAdepu,GraduateResearchAssociate

•  Thedrumis3in.longwithaninnerdiameterof6in.•  Stainlesssteel(commoninindustry).•  Thebluecircleistheairinlethole.•  Thegreencirclesaretheexhaustholes.•  Theredsurroundsthe10thermocoupleinletholes.•  Thefrontwindowisasapphirematerialthatcan

withstand600+Kforinfraredviewingpurposes.

Rollers for rota6ng thedrum.

2heatgunswillbeusedto heat the drum. Theycan reach temperaturesupto900K.

Thermocouple (boDom),wi re less t ransmiDer(led),andreceiver(right)will be used to collecttemperaturedata.

3mm silica beads, acommon catalyst inmanyindustries.

•  Conductexperimentstoquan6fyall3heattransfermechanisms.

•  Inves6gatetheeffectsoffilllevelandrota6onrate.•  ADOEchartfortheconduc6onexperimentsisshown

below,includingatotalof48experiments.

Themassrequiredforeachfilllevelwascalculatedusingthefollowingequa6on:Mass=(Filllevel)*Φ*ρ*π*R2*LwhereΦissolidsfrac6on,ρisdensityofpar6cles,Risradiusof drum, and L is length ofdrum.

FillLevel Mass(g)10% 213.615% 320.420% 427.225% 534.0

S.No FilllevelRotaConspeed Trial

(%) (rpm) 1 2 31 10 1 1101 2101 31012 10 5 1105 2105 31053 10 10 11010 21010 310104 10 20 11020 21020 310205 15 1 1151 2151 31516 15 5 1155 2155 31557 15 10 11510 21510 315108 15 20 11520 21520 315209 20 1 1201 2201 320110 20 5 1205 2205 320511 20 10 12010 22010 3201012 20 20 12020 22020 3202013 25 1 1251 2251 325114 25 5 1255 2255 325515 25 10 12510 22510 3251016 25 20 12520 22520 32520

Futureexperimentsmayalsoincludetheuseofaninfraredcamera to gather temperature data while the process isrunning.Thiswouldenhancetheaccuracyoftheresults.

IntroducConRotary drums have many industrial applica6ons with granules, butgranules don’t behave like conven6onal solids, liquids, or gases whichmakestheseprocessesdifficulttomodelandop6mize.Thepurposeofthisresearchistoquan6fyallthreemodesofheattransferinthegranularbedandstudywhichmodesdominateundervaryingopera6ngcondi6ons.