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Transcript of Particle Drying Ressel Komp
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html
Center for Wood Sciences
CAS Wood Based Panels
Module 1: Process Technology
Particle drying
Prof. Dr. Joerg B. Ressel
September 7 12, 2015 – Biel, CH
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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ContentWood Based Panels
ContentParticle drying - fundamentalsParticle drying – dryer typesDrying plant components
Flash tube pre-dryerDrum dryerSingle pass drum dryerDrum dryer for OSB strandsIndirect heated tube bundle dryerIndirect heated rotary tube bundle dryerFibre dryerSuperheated steam dryer for wood fibres
Additional InformationMOLLIER-h,x-Diagram for humid airemc of wood – KEYLWERTH-Diagram
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Particle dryingWood Based Panels
Particle drying process - fundamentals• Continuous drying process • Combined heat transfer to particles by convection
(fluid = hot gas / air, steam) and conduction (contact …)• Drying phases (simplified)
1. Particle mc FSP evaporation of free water, fast increase of particle temperature up to constant level (cooling limit temp.) below the boiling point of water
2. Particle mc < FSP desorption and evaporation of capillary and bound water, increasing particle tempe-rature up to gas temperature; fire hazard ! (self ignitionat approx. 240ºC)!
• Drying parameters (… process parameters)• Material related …: wood species, density, particle di-
mensions (thickness, width, length), mc (initial, final) ...• Process related …: gas/air/steam temperature, partial
pressure of water vapour, gas velocity, retention time …
t
FSP
mc
mcfin
mcinDrying curve
const. evaporation( free water)
decreas. evaporation( bound water)
FSP … fibre saturation (point); upper limit of hygroscopic mc-range (0 emc approx. 28% mc … FSP)
dmc/dt
t
Drying rate
2. Phase1.
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Particle dryingWood Based Panels
Particle drying process - fundamentalsEnergy required for … heating up wood particles ( wood substance & water!)(heat and electricity) evaporation and desorption of free and bound water from wood
covering exhaust heat lossescovering transmission heat losses (drying plant)electric power for fans, drum drive, servo-motors …
Specific energy consumption is related to 1 kg water removed from wood particles
0,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5
4,0
0 5 10 15 20 25
Spec
. ene
rgy
cons
umpt
. [M
J/kg
wat
er]
Initial moisture content [%]
2,50
2,55
2,60
2,65
2,70
25 50 75 100 125
Spec
. ene
rgy
cons
umpt
. [M
J/kg
wat
er]
Initial moisture content [%]
Heat ofevaporationhv = 2,5 MJ/kg
Heat of adsorption(hv+hb)max = 3,6 MJ/kg
Left:Heat of evaporation and heat of adsorp-tion for flake drying depending on mc (May 1979)
Right:Average specific ener-gy consumption of fla-ke drying depending on initial mc (May 1979)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Particle dryingWood Based Panels
Ressel J B Energieanalyse der Holzindustrie der Bundesrepublik Deutschland. BMFT-PS T 86-184. 1986. 161 pages
(http://sankeymatic.com/build/ 26.08.2015)
all figures in % of the total energy consumption
Particle drying process - fundamentalsTotal energy consumption
o PB production 140.000 m³/a
o PB coating 40.0000 m³/a
Heat 2,69 GJ/m³ 84,6 %
Electricity 0,49 GJ/m³ 15,4 %
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Particle dryingWood Based Panels
Particle drying process - fundamentalsEnergy consumption
entire PB production
Heat 2,95 GJ/m³ 82 %
Electricity 0,65 GJ/m³ 18 %
FAO Energy conservation in the mechanical forest industries. FORESTRY PAPER 93. Rome, 1990
(http://sankeymatic.com/build/ 26.08.2015)
all figures in % of the total energy consumtion
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
7
Particle dryingWood Based Panels
Particle drying process - basic dryer types
acc.
Dep
pe, E
rnst
200
0 / F
ig. 3
.2-5
40 t/h20 - 30 minup to450ºC
Single-pass drum dryer
10 … 18 t/hn.a.up to160ºC
Tube bundle dryer( spinning drum)
1 … 9 t/h20 minup to200ºC
Rotary bundle dryer( spinning tubes)
10 t/h 0,5 - 3 minapprox.500ºCJet tube dryer
2 … 14 t/h 20 sup to500ºC
Flash tube pre-dryer
25 t/h5 - 7 minup to400ºC
Triple-pass drum dryer
CapacityDrying timeTemp. rangeSchemeDryer type
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Particle dryingWood Based Panels
Basic drying plant componentsHeating system for drying medium (fluid = flue gas, hot air, superheated steam) boilerDryer - one or two stages – pre-dryer optionalMaterial infeed systems – material sluice/airlock … cellular wheelMaterial separators – cyclonesHeating gas re-circulating system and fan(s) – feed-back of flue gas etc.Exhaust gas cleaning system – filter systems reduction of VOC emissions !Chimney stack
Heating systems – direct heating indirect heating
Burner for natural gas, oil, dust Flue gas from energy system (e.g., grate firing systems)Turbine exhaust gasCombination of heating systems mentioned above
Particle movement / particle transport through the dryerPneumatic transport, particles carried by fluid (gas velocity approx. 5…25 m/s)Mechanical transport by built-in devices (“paddles”), e.g., rotating with the drumCombined transport (fines pneumatic transport, coarse particles mechanical transport)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Particle dryingWood Based Panels
Flash tube pre-dryer Type VT (Buettner 2015)Used for material with high initial moisture content
Separate pre-dryer or combined a downstream drum dryerIncrease capacity of existing dryerWater evaporation from 1…15 t/hMaterial throughput: 1…70 t/h (dry) resp. 1…85 t/h (wet material)Fresh air or re-circulating air operationHeating systems
Direct heating flue gases from gas, dust, oil burner or grate firing, exhaust gas from turbineIndirect heating heat exchangers with steam, thermal oil
Infeed of material with different moisture content and bulk densities at the same timePower and control switch plant including PLC and visualization Flash tube pre-dryer (Buettner 2015)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Particle dryingWood Based Panels
Flash tube pre-dryer Type VT (Buettner 2013)
Stack / to exhaust gas cleaning system
Fan
Dry material to production
Emergency material
discharge
Oversized material
Rotary valveRotary valve
(Buettner 2013)
Heating system
• Direct heating flue gases
• Indirekt heating heat exchanger
Cyclone / separator
Optional re-circulation gasapprox. 25% of thermal
energy savingWet material
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
11
Particle / Flake dryingWood Based Panels
Drum dryer Type NH (Buettner 2013)Water evaporation from 5…50 t/hMaterial throughput: 5…70 t/h (dry) resp.
10…120 t/h (wet material)Fresh air or re-circulating air operationHeating systems:
Burner for natural gas, oil, dust ( heat exchanger)Flue gas from energy plant (e.g., grate firing systems)Turbine exhaust gas ( heat exchanger)Combination of above mentioned heating systems
Possible combination with flash tube pre-dryer and discharge of coarse particlesDrum diameter 3000…6200 mmMaterial discharge via cyclonesIndividual exhaust gas cleaning system (e.g., high efficiency cyclones, filter systems (EFB, WESP, RTO)Power and control switch plant including PLC and visualization, also for conveyors in front and behind the dryer
Drum dryer Type NH with material discharge box (Buettner 2013)Drum dryer Type NH without material discharge box (Buettner 2013)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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(http://www.wbpionline.com/uploads/newsarticle/853739/images/210594/large/vanachai1.jpg / 24.08.2015)
Particle / Flake dryingWood Based Panels
(Flash-Dryer) Pre-dryer and Drum dryer
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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(http://www.instalmec.it/images/stories/settori/orig/01.jpg / 24.08.2015)
Particle / Flake dryingWood Based Panels
(Flash-Dryer) Pre-dryer and Drum dryer
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Particle / Flake dryingWood Based Panels
Stack / to exhaust gas cleaning system
Wet material
Pre-dried material
Oversized materialDry material to production
Emergency material
discharge
Material separators or high efficiency cyclones
FanRecirculation duct
Swivel damper
Pre-dryer
Drum dryerHeating system
Drum dryer Type NH … without discharge box (Buettner 2013)• Material discharge directly via cyclone
(Buettner 2013)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Particle / Flake dryingWood Based Panels
Stack / to exhaust gas cleaning system
Wet material
Pre-dried material
Oversized material
Dry material to production
Emergency material
discharge
High efficiency cyclones
Fan
Recirculation duct
Swivel damper
Pre-dryer
Drum dryer
Heating system
Dry material to production
Emergency material
discharge
Reversible srew feeder
Discharge box
Mixing chamber
Drum dryer Type K (Buettner 2013)• Material discharge via outlet box• Fine material discharge via cyclone
(Buettner 2013)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Particle / Flake dryingWood Based Panels
Flash tube pre-dryer and single pass drum dryer (Ø 5200 mm, length 28 m, 30 t h-1; Buettner 2005)
Pre-dryer and single pass drum dryer (SPE 2005)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
17
Particle / Flake dryingWood Based Panels
Single pass drum dryer (SPE – Dieffenbacher Group 2007)Standard installation
Options• Direct discharge to
cyclons• Discharge via drop-
out box
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Particle / Flake dryingWood Based Panels
Bison ( o. J.)
Pre-dryer and single pass drum dryer (Binos 2011)Single-pass drum dryers are either direct or indirect heated. The dimen-sions of the dryer drum are similar to the three-pass drum dryer; gas inlet temperature is lower (< 500°C).The moisture is removed more gent-ly, retention time is longer (> 20 min).The system is suitable for drying ma-terial with various mc and dimen-sions.
Combustionchamber
Mixing chamber
Pre-dryer
Wet material inlet
Drum dryerDischargebox
Cyclone battery
Dry mat. discharge
Stack
Emergency stack
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
19
Particle / Flake dryingWood Based Panels
Drum dryer datails (SPE 2007)
Single pass drum dryer (SPE 2007)Particle discharge
Dust se-paration
Sand / ash separation
Particles
Dischargebox
Dust se-paration
Particles
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Particle / Flake dryingWood Based Panels
Single pass drum dryer (SPE 2007)Design details for the flake dryer
Drum (Ø 2…7 m, thick drum shell, rigid concept) Trunnion assemblyVariable speed drive with friction, chain or rack ring
Drum dryer datails (SPE 2007)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Flake / Strand dryingWood Based Panels
Single pass drum dryer (SPE 2007)Specific drum internals for PB (left) and OSB (right)
Omega supports
Support discs
Cross internals
Drum dryer datails(SPE 2007)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Strand dryingWood Based Panels
Drum dryer Type NH for OSB strandsParticularly developed for strand drying requirements
Water evaporation from 5…40 t/hMaterial throughput: 5…40 t/h (dry) resp.
10…80 t/h (wet material)Fresh air or re-circulating air operationHeating systems:
Burner for natural gas, oil, dust ( heat exchanger)Flue gas from energy plant (e.g., grate firing systems)Turbine exhaust gas ( heat exchanger)Combination of above mentioned heating systems
Drum diameter 4000…6200 mmParticularly designed internal strand transport system inside the drumMaterial discharge via cyclonesIndividual exhaust gas cleaning system (e.g., high efficiency cyclones, filter systems (EFB, WESP, RTO)Power and control switch plant including PLC and visua-lization, also for conveyors in front and behind the dryer
Drum dryer for OSB strands (Buettner 2013)
Single-pass drum dryer for OSB strands (Metso panelboard 2004)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
23
Particle dryingWood Based Panels
(Buettner 2013)
Wet material
Dry material to production
Emergency material
discharge
Material separator
FanRecirculation duct
Swivel damper
Drum dryer
Heating system
Mixing chamber
Grate firing system
Drum dryer Type NH for OSB strands (Buettner 2013)
Stack / to exhaust gas cleaning system
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
24
Particle dryingWood Based Panels
Wet
material
Dry material to production
Emergency material discharge
Material separator
FanRecirculation duct
Drum dryerDirect heating system
Drum dryer Type LS (Buettner 2013)
Stack / to exhaust gas cleaning system
(Buettner 2013)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
25
Particle dryingWood Based Panels
Triple pass drum dryer for flakes (Binos 2011)Pre-drying in the centre tube of the dryer drumFinal drying during the second and third pass of the drum after turning back of flow direction with decreasing temperature and flake mc
(Binos 2011)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
26
Particle dryingWood Based Panels
Triple pass drum dryer (Binos 2011)Pre-drying in an upstream flash tube dryerFinal drying during the passage of the nested tubes within the drum: Particles are carried through the dryer by the flowing hot gas; temperature and flake mc decrease with transport distance
(Binos 2011)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
27
(Buettner 2013)
Particle dryingWood Based Panels
Indirectly heated tube bundle dryer
Water evaporation from 8…25 t/hMaterial throughput: 8…>30 t/h (dry) respectively
16…> 55 t/h (wet material)Heating systems:
Steam - combination with flue gas optionalDrum diameter 3000…5600 mmRotating drum, stationary tube bundlesMaterial discharge via outlet boxExhaust gas cleaning by filter system – no cyclonesPower and control switch plant including PLC and visualization, also for conveyors in front and behind the dryerPreferred in combination with cogeneration ( coupled heat & electricity generation)
Indirect heated tube bundle dryer (Buettner 2013)
Tube bundle (Buettner 2013)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
28
Particle dryingWood Based Panels
Indirectly heated tube bundle dryer (Buettner 2013)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
29
Particle dryingWood Based Panels
Indirectly heated rotary bundle dryer
Stationary dryer case (drum or trough) – rota-ting tube bundle (designed as single or doub-le rotary bundle dryer), tube bundle size up to 3.600 mmWater evaporation from 2… 10 t/hMaterial throughput: 2 …10 t/h (dry)
respectively 4…20 t/h (wet material)Heating systems:
Steam – thermal oil – hot waterMaterial discharge via outlet boxDust cleaning by cyclonesIndividual exhaust gas cleaning systems, e.g., cyclones, EFB, WESP, RTOPower and control switch plant including PLC and visualization, also for up- and downstream conveyorsPreferred in combination with cogeneration
Indirectly heated rotary bundle dryer (Buettner 2015)
(Buettner 2015)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
30
http://www.buettner-energy-dryer.com/en/drying-systems/drying-systems-indirectly-heated-tube-bundle-dryers/ / 24.08.2015
Particle dryingWood Based Panels
Indirectly heated rotary bundle dryer (Buettner 2015)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
31
Particle dryingWood Based Panels
Indirectly heated rotary tube bundle dryer (Bison o.J.)
Fully insulated rotary bundle dryer
(Ponndorf 2005)
Heat pipe arran-gement in rotary tube bundle dryers
• type RK (top)
• type RS (bottom) (Ponndorf 2005)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
32
Particle dryingWood Based Panels
Indirectly heated rotary tube bundle dryer (Buettner 2013)
(Buettner 2013)
Wet material
Dry mate-rial to pro-duction
Heat exchanger
Fresh air
Combus-tion air
Fuel
Ash
Fresh air
Fan
Pump
Rotary tube bundle dryer
Thermal oil heater
Wet electrosta-tic precipitator
WESPCyc-lone
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
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Dryer for fibrous materials – heating system (Buettner2013)
Fibre dryingWood Based Panels
Fibre dryer (Buettner 2013)Particularly designed for drying fibrous materials
Water evaporation from 5…> 60 t/hMaterial throughput: 5…> 60 t/h (dry) respectively
10…> 90 t/h (wet material)Fresh air or re-circulating airHeating systems:
Indirect heating via heat exchanger steam, hot water or thermal oilDirect heating burner for natural gas, LPG, oil, dust, flue gas from energy plants (grate firing systems) or turbine exhaust gas
High efficiency radial fansDryer duct diameter 800…> 3.000 mmCyclone (diameter 3.000…6.500 mm) for material discharge and dust removalPower and control switch plant including PLC and visualization, also for subsequent fibre sifter
Dryer for fibrous materials (Buettner 2013)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
34
Fibre dryingWood Based Panels
Flash dryer types for fibrous material
(Deppe / Ernst 1996)
Fibre inlet
Steam recovery
Fibre inlet
Single stageflash dryer
Fibre inlet
Two stageflash dryer
Single stage flash dryer
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
35
Fibre dryingWood Based Panels
One stage fibre dryer
Simple process solution and controlLow capital costHigh level of temperature and therefore over-drying or fire hazardHigh pre-curing rates of resinsDirect flue gas from energy plantLow electrical energy consumption
(SPE 2005)
Wet material from refiner
Fresh air
dry mate-
rial
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
36
Fibre dryingWood Based Panels
(Buettner 2013) Wet material from refiner
Heating system
Fresh air
Stack / to exhaust gas cleaning system
High efficiency cyclone Flue gas
Dryer duct
Dry material to production
Emergency material discharge
Fan
Dryer for fibrous material (Buettner 2013)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
37
Fibre dryingWood Based Panels
Two stage fibre dryer
Advanced process controlHigh capital cost (more construction space)Higher electric power consumption
(SPE 2005)
Fresh air
dry material
Lower gas temperature levelGood control of final mc, less overdryinglow pre-curing of resins
1. stage
2. stage
Fibre bin Sifter
Wet material from refiner
Fresh air
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
38
Fibre dryingWood Based Panels
(Metso panelboard 2002)
Wet material from refinerFresh
air
1. stage
2. stage
Return air system (RAS)
Fibre bin Sifter
Two stage fibre dryer Advantages compared to single-stage fibre drying
Increased fibre quality and more uniform final mcReduced resin consumption with blow-line blendingReduced energy consumption; 15 % compared to one-stage drying, 25 % with RASSmaller ducts and cyclones, particularly at high capacities
Advantages of RASlower energy consumptiondecreased emission of par-ticleslower exhaust gas flow and lower investment costs for environmental control tech-nology
(Metso panelboard 2002)
020406080
100120140160180
0,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4
Relative drying time [-]
Tem
pera
ture
[°C
]
020406080
100120140160180
0,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4
Relative drying time [-]
Tem
pera
ture
[°C
]
Two-stage dryer
One-stage dryer
Fresh air
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
39
Fibre dryingWood Based Panels
Superheated steam dryer for wood fibres (SPE – Dieffenbacher 2005)
Superheated steam as drying medium offers considerable advantages compared to humid air in conventional drying processes:
less energy consumption (heat & electric power)heat recovery up to 60…80 %closed loop system no exhaust gas, no dust and other emissions (VOC); all emis-sions removed by condensate waste water treatment requiredalmost oxygen-free gas circulation no fire and explosion hazard reduced drying time due to better heat transfer less mass flow (fluid = steam), less fan powershorter drying duct
(SPE 2005)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
40
Fibre dryingWood Based Panels
Superheated steam dryer for wood fibres (SPE – Dieffenbacher 2005)Comparison of mass flow
Conventional fibre drying process
Superheated steam fibre drying process
SPE 2005
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
41
Fibre dryingWood Based Panels
Superheated steam dryer for wood fibres (SPE – Dieffenbacher 2005)Comparison of energy consumption
Superheated steam fibre drying process
SPE 2005
Conventional fibre drying process
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html
Overview
emc & humid air
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html
Fibre dryingWood Based Panels
MOLLIER-h,x-Diagramme
... changes of humid air con-ditions, e.g., with convective drying processes. recommended literature
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html (http://public.beuth-hochschule.de/~wseifert/lmr/thermo/BilderThermo/Theorie/HX_Diagramm4.jpg / 27.08.2013)
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html
Keylwerth-DiagrammeWood Based Panels
The KEYLWERTH-Diagram… how to determine emc …
• Psychrometertemperatures TDB
and TWB EMC und r.h.
• Dry bulb Temperature TDB and
relative humidity r.h. EMC und
WBT
Note: use of the psychrometer for determination of r.h. and emc res-pectively requires an air flow of at least vL 2 m/s at the wet bulb thermometer to met the adiabatic evaporation temperature !
TDB = 60 °C EMC = 8,7 %TWB = 50 °C r.h. = 58 %
TDB = 25 °C EMC = 6,1 %r.h. = 30 % TWB = 15 °C
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html07.05.2008 46
EMC-ChartTDB = 25°C
WBD = (TDB-TWB)
= 5°C
EMC 11,1 %
r.h. 63 %
TDB = 60°C
WBD = 10°C
EMC 8,7 %
r.h. 58 %
Wood Based Panels Wood mc-determination EMC-Chart
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html07.05.2008 47
Prof. Dr. Joerg B. Resselwww.biologie.uni hamburg.de/zentrum holzwirtschaft.html 2015 08 05
48
Overview / Intro