kka-hidry
DESCRIPTION
KKA DryTRANSCRIPT
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HighEfficientDrying
HeattransferperformanceDryingprocessparameterOvendesign
St.PetersburgJune3rd
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Dryingprocessrequirements
HighsolventevaporationrateacrosscoatinglayerLowsolventdiffusionintosubstrateLowthermalstresstowebLowmechanicalstresstowebMaximumsolventconcentrationinexhaustair
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HeattransferbyconvectionyAirimpingementprinciple Heattransfercoefficientdependson
geometric data
geometricdata .- relativejetarea(f=V/(wD)- jetdiameter(D)- jetarrangment- distancejetsubstrate(H): 100 160W/m K:100 160W/m KHeattransferrate.Q A TQ= AT
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Heattransferbyradiationy
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Wellenlnge [m]
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Heattransferbyconvection/radiationy /Convectiveheattransfer
Combinedheattransfer .
Air Air
Shortwaveinfrared
radiation Air solvent Absorption .
Q
solvent
Q Substrate
Substrate
- Energyconsumptiononsurfaceonly- Solventevaporationonsurfaceinterferes
withsolventdiffusionHeat transfer rate limited
- Transmissionofinfraredradiationincoatinglayer- Energyconsumptioninsidelayerinaddtion- Energyconsumptiononsubstratesupportsevaporation- Highest rate of heattransfer- Heattransferratelimited Highestrateofheat transfer
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Calculation/simulationofdryingprocessesSpecificsolventevaporationrateat
Design Calc. No.: 08100911 Rev02 Date: 16.04.2010
Costumer : KKA SheetProduct : coating 24 m/min 1/1Product Properties web temperatureWeb Width : AB 4.300 mm infeed outfeedMachine Speed : v 24 m / min 30 0C 65 5C
34m/sairspeedthroughjet140CairtemperatureWaterbasedcoating
160 W/ K
Machine Speed : v 24 m / min 30,0 C 65,5 C
Web Weight : GT2000,0
g / m2Specific Heat Cap. :
Web Material : PVC 0,98 kJ/kg,KCoating Weight, Solids : At 10,00 g / m2Coverage : BG 100,0 %Solid Content : Fg 12,5 %Solvent Weight : AL 70,00 g / m2 WaterSolvent Evaporation Rate : LA 433,3 kg / h Retaining : 25 mg/mLower Explosion Limit
160W/mK
Airimpingementeffect11 kg/m h
(LEL) at 20C : UEG -- g / m3Ignition Temperature : ZT -- C Ex-Protect.: noBoiling Point : TS 100 C Ex-Venting: noLatent Heat : VE 2445,0 kJ/kg LEL-Control:noHeated by : In 240,0 C
Thermal OilOut 220,0 C Drying Data
Drying Temperature : TT 140 C(bulk mean temp.)
W t B lb T t Tk 49 7 C 11kg/mh
Combinedairimpingement/infraredradiation application
Wet Bulb Temperature : Tkg 49,7 C
Drying Rate : GD 11,01kg/m2,h(mean value)
Theoretical Drying Length : TLT 9,16m without IR
No. of Zones Z - Length
Tunnel Length Installed : TL 5,00 m with IR 2 2,50 mCooling Section Length : TRL 0,00 m 0 2,50 mTotal Length GL 5,00 mModule (Zone) Data : Type = AT - U -43.25 Transfer Coeff.Module Length : ZL 2,50 m Heat :single sided radiationapplication
21kg/mhModule Length : ZL 2,50 m Heat :single sidedCirculation Air per Module : UM 17.494 m3/h h = 163W/m2,KSlot (web) Air per Module : FM ca. 2.200 m3/h Mass :single sidedNozzle Velocity : vD max 34 m/sekMotor Capacity needed : NW 14,8 KW Ex-Protect.: --Fresh / Exhaust Air Data
Fresh Air Temperature : FLT 20 Crel.
Humidity:50% rFConcentration Limit Allowed : AAZ -- % of LELSolvent Load Exhaust Air : AA 47,00 g / m3Exhaust Air needed : ABL 10.625 m3 / h lower limitExhaust Air Bulk Mean Temp. : ATM 109 C approx.
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Calculation/simulationofdryingprocesses
80160
Drying process simulationwater based coating: 80g/m wet, 12,5% solids at 24 m/min
140,0
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drying air temp.web temp IR on
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Dryer Length mDryer Length, m
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Ovendesign
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Ovendesign
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Ovendesignvs.dryingprocess
80160140,0
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80100120140160
drying air temp.web temp IR onweb temp off
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OvendesignIncreaseofthesolventevaporationrateuntil100%
Significantshorteningofthenecessarydryerlength
Significantenergysavingsduetoreducedexhaustairrates
Radiatordesignapplicableforwaterandsolventbasedcoatings(EXX)
Combinationofdryingandcrosslinkingprocessesinonestep