Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13....
-
Upload
agnes-thompson -
Category
Documents
-
view
216 -
download
0
Transcript of Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13....
![Page 1: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/1.jpg)
Quality Drying of Hardwood
11.-13. September 2000
Sopron Hungary
Quality Drying of Hardwood
11.-13. September 2000
Sopron Hungary
2nd. Workshop of COST Action E15
2nd. Workshop of COST Action E15
![Page 2: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/2.jpg)
Drying of Black LocustWood
Marian Babiak
Technical University in Zvolen
Slovak Republic
![Page 3: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/3.jpg)
Zvolen - location
![Page 4: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/4.jpg)
Zvolen castle
Zvolen castleZvolen castle
![Page 5: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/5.jpg)
Main squareMain square
![Page 6: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/6.jpg)
University campusUniversity campus
![Page 7: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/7.jpg)
Main building – ceremony hallMain building – ceremony hall
![Page 8: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/8.jpg)
Another view of the University Another view of the University
![Page 9: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/9.jpg)
Why Black Locust wood?
Weedy species?
Low quality?
Small dimensions?
Difficult to process (tool blunting)?
Toxic???
Why Black Locust wood?
Weedy species?
Low quality?
Small dimensions?
Difficult to process (tool blunting)?
Toxic???
![Page 10: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/10.jpg)
One of the traditional produtsOne of the traditional produts
![Page 11: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/11.jpg)
•Ecological species – long natural durability
•Good mechanical properties
•Possibility to change the color by steaming
•Fast growing species
•Ecological species – long natural durability
•Good mechanical properties
•Possibility to change the color by steaming
•Fast growing species
![Page 12: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/12.jpg)
INCO-COPERNICUS Project No. PL 96-4114; Contract No.ERB IC15 - CT
960713Technology for High Quality Products
from Black Locust Robinia pseudoacacia „TEQUBLOC“
![Page 13: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/13.jpg)
Partners
Institute for Wood Biology, University of Hamburg (coordinator)
Department of Wood Science, West Hungarian University, Sopron
Department of Wood Science, Technical University, Zvolen
TNO Building and Construction Research, Delft
Robinia Kft, Budapest
![Page 14: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/14.jpg)
What we know?
Czech,H.-Tamásy-Banó,M: Holz Zentralblatt
above FSP max.temp.60°C < 30mm,
55°C > 30mm
below FSP 65°C
high thylosis – low permeability
requires soft drying schedule
tendency to form drying checks
![Page 15: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/15.jpg)
Dry Kiln Operator's Manual, USDA, 1991
For thicknesses of 25 to 38 mm: recommended drying schedule: T6-A3 :
For a thickness of 50 mm: recommended drying schedule is T3-A2
Slovak ON 49 0651
15-28 mm, 32-60mm, 75-100mm
soft, hard
![Page 16: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/16.jpg)
Drying steps
10-final8
15-107
20-156
25-205
30-254
40-303
60-402
Over 601
MC [%](T6-A3)+(T3-A2)
Steps 4-8
ON 49 0651
Steps 1-8
![Page 17: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/17.jpg)
Dry bulb temperature - softDry bulb temperature - soft
![Page 18: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/18.jpg)
Dry bulb temperature - hardDry bulb temperature - hard
![Page 19: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/19.jpg)
Equilibrium MC - softEquilibrium MC - soft
![Page 20: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/20.jpg)
Drying schedules: Hamburg – ON softDrying schedules: Hamburg – ON soft
![Page 21: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/21.jpg)
Equilibrium MC - hardEquilibrium MC - hard
![Page 22: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/22.jpg)
Drying schedules: Hamburg – ON hardDrying schedules: Hamburg – ON hard
![Page 23: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/23.jpg)
Klement,I. – Trebula,P.:
Comparison of classic and MW drying
Black Locust 50x150x3000 mm
Schedule 15min…………P
105min…………P/2
180min…………0
MC 33% 10% MW 145 hours
classic 408 hours
![Page 24: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/24.jpg)
Microwave kiln DIES 3-V
f=2,42 GHz, P=2kW
Microwave kiln DIES 3-V
f=2,42 GHz, P=2kW
![Page 25: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/25.jpg)
Our experiments
Semivacuum kiln 30-40kPa
MW resonator – normal pressure
MW resonator – normal pressure
lowered pressure
HF heating
![Page 26: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/26.jpg)
“Vacuum” kiln“Vacuum” kiln
![Page 27: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/27.jpg)
![Page 28: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/28.jpg)
Microwave “oven”Microwave “oven”
magnetron power 800 W, frequency 2450 MHz magnetron power 800 W, frequency 2450 MHz
![Page 29: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/29.jpg)
MW in kilnMW in kiln
![Page 30: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/30.jpg)
HF heatingHF heating
frequency 23 MHz, power 3,7 kW frequency 23 MHz, power 3,7 kW
![Page 31: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/31.jpg)
MaterialMaterial
Specimen dimensions for drying
(h = 30 w = 100-150mm ;
h = 60 w = 150 - 200mm)
Specimen dimensions for drying
(h = 30 w = 100-150mm ;
h = 60 w = 150 - 200mm)
![Page 32: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/32.jpg)
Board for experimental evaluationBoard for experimental evaluation
![Page 33: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/33.jpg)
Steaming diagram - 3x each cycle
pressure 0,35 MPa
![Page 34: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/34.jpg)
Drying parameters for conventional
heating
Slow Standard
Init. temp. 40 °C 50 °C
Final temp. 50 °C 60 °C
Init.RH 77,5% 72,5%
Final RH 30% 30%
Min. dr.rate 0,05 %/hour 0,1 %/hour
![Page 35: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/35.jpg)
Results
![Page 36: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/36.jpg)
Drying curves 30mm: MC[%]vs time[h]Drying curves 30mm: MC[%]vs time[h]
![Page 37: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/37.jpg)
MC[%] distribution in layers (1-6) 30 mmMC[%] distribution in layers (1-6) 30 mm
![Page 38: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/38.jpg)
Quality testing “vacuum” 30 mm
1 2 3 4 5 6 7 8 930 U SL 2,7 S L L S 0,07 285 31 1330 U ST 1,6 O M L U 0,11 281 38 10
30 S SL 1,8 S L L U 0,09 180 28 13
30 S ST 2,8 S L L U 0,13 137 28 12
1 MC SD [%]; 2 Target MC; 3 End checking; 4 Internal checking; 5 Casehardening; 6 Average drying rate [%/h] 7 Drying time 8 Starting MC 9Final MC
1 MC SD [%]; 2 Target MC; 3 End checking; 4 Internal checking; 5 Casehardening; 6 Average drying rate [%/h] 7 Drying time 8 Starting MC 9Final MC
![Page 39: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/39.jpg)
Drying curves 60mm: MC[%]vs time[h]Drying curves 60mm: MC[%]vs time[h]
![Page 40: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/40.jpg)
MC[%] distribution in layers (1-6) 60 mmMC[%] distribution in layers (1-6) 60 mm
![Page 41: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/41.jpg)
Quality testing “vacuum” 60 mm
1 2 3 4 5 6 7 8 960 U SL 2,2 O L L S 0,04 871 47 1060 U ST 3 S M L U 0,07 290 31 1460 S SL 3 Q L L S 0,03 575 30 1260 S ST 4,2 Q M L U 0,07 249 30 15
1 MC SD [%]; 2 Target MC; 3 End checking; 4 Internal checking; 5 Casehardening; 6 Average drying rate [%/h] 7 Drying time 8 Starting MC 9Final MC
1 MC SD [%]; 2 Target MC; 3 End checking; 4 Internal checking; 5 Casehardening; 6 Average drying rate [%/h] 7 Drying time 8 Starting MC 9Final MC
![Page 42: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/42.jpg)
Drying curves(MW) MC[%] vs time[h]Drying curves(MW) MC[%] vs time[h]
![Page 43: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/43.jpg)
MC[%] distribution in layers (1-6; 1-7) - MWMC[%] distribution in layers (1-6; 1-7) - MW
![Page 44: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/44.jpg)
1 2 3 4 5 6 7 8 930_1M 1,9 Q L S U 3,26 6 36 1630_2M 1,7 Q L L U 1,86 11 35 1430_3M 0,2 O L S Q 1,58 15 31 860_1M 1,2 E L S Q 0,61 28 29 1260_2M 0,5 E L S Q 0,62 30 30 1160_3M 0,9 E L L Q 0,27 65 28 11
1 MC SD [%]; 2 Target MC; 3 End checking; 4 Internal checking; 5 Casehardening; 6 Average drying rate [%/h] 7 Drying time 8 Starting MC 9Final MC
1 MC SD [%]; 2 Target MC; 3 End checking; 4 Internal checking; 5 Casehardening; 6 Average drying rate [%/h] 7 Drying time 8 Starting MC 9Final MC
Quality testing microwaves 30, 60 mmQuality testing microwaves 30, 60 mm
![Page 45: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/45.jpg)
Drying curves(MWV) MC[%] vs time[h]Drying curves(MWV) MC[%] vs time[h]
![Page 46: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/46.jpg)
MC[%] distribution in layers (1-6; 1-7) - MWVMC[%] distribution in layers (1-6; 1-7) - MWV
![Page 47: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/47.jpg)
Drying curves(MWV,HF)
MC[%] vs time[h]
Drying curves(MWV,HF)
MC[%] vs time[h]
![Page 48: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/48.jpg)
MC[%] distribution in layers - MWV-HFMC[%] distribution in layers - MWV-HF
![Page 49: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/49.jpg)
1 2 3 4 5 6 7 8 9
30_1 MV 1,2 E L S - 3,4 8 39 1230_2MV 0,4 O L M S 2,5 16 45 6,630_3MV 1,8 Q S S U 3,7 8,3 45 1330_3M 0,8 Q L L Q 2,4 11,3 41 13
60_1MV 2,1 Q L S U 0,88 21,2 36 1860_1M 1,5 Q L S U 0,69 26,2 37 18
60_2MV 1,2 S L S S 0,55 37 36 1560_2M 1,2 Q L M S 0,48 45,3 34 1430_1HF 1,7 Q L L S 1,26 24 44 1730_2HF 1,6 S L L S 1,04 31 47 1530_3HF 1,4 E L L U 0,89 26 36 12
Quality testing microwaves + vacuum 30, 60 mm; high frequency 30mmQuality testing microwaves + vacuum 30, 60 mm; high frequency 30mm
![Page 50: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/50.jpg)
Diffusion coefficient D[m2.s-1] “vacuum”Diffusion coefficient D[m2.s-1] “vacuum”
![Page 51: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/51.jpg)
D[m2.s-1] MW (+V); HF D[m2.s-1] MW (+V); HF
![Page 52: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/52.jpg)
Diffusion coefficient [m2.s-1] vs drying rate [%/h]
Diffusion coefficient [m2.s-1] vs drying rate [%/h]
y = 1E-09x - 4E-11 R2 = 0,9993 y = 1E-09x - 4E-11 R2 = 0,9993
![Page 53: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/53.jpg)
Conclusions“Vacuum drying”
30 mm material - classification "standard" both standard and slow schedules
60 mm - slow schedule - lumber classified as "quality"
frequently severe case hardening ("unacceptable") can be compensated by appropriate conditioning after drying
![Page 54: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/54.jpg)
Conclusions“Vacuum drying”
average drying rate 0,097%/h 30 mm
0,053%/h 60 mm
diffusion coefficients 0,93.10-10 to 3,64.10-10 m2.s-1
![Page 55: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/55.jpg)
ConclusionsMicrowave drying
substantially faster drying rate 20-fold for 30 mm and about 10-fold for 60 mm
quality of dry material is good
diffusion coefficients 5,2.10 –9 to 18,4.10 –9 m2.s-1
drawback - non-uniform distribution of energy
![Page 56: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/56.jpg)
ConclusionsMicrowave+”vacuum” drying
drying rate under vacuum is higher than at atmospheric pressure
for the 30 mm material this effect is more pronounced than for the 60mm material
diffusion coefficients 6,4.10-9 to 8,4.10-9 m2.s-1
![Page 57: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/57.jpg)
ConclusionsHigh frequency drying
drying rate slightly lower than microwaves
diffusion coefficients 1,4.10-9 to 2,5.10-9 m2.s-1
lesser risk to exceed temperature than microwaves
more uniform temperature distribution
![Page 58: Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary Quality Drying of Hardwood 11.-13. September 2000 Sopron Hungary 2nd. Workshop of COST.](https://reader035.fdocuments.net/reader035/viewer/2022062802/56649e915503460f94b96ba7/html5/thumbnails/58.jpg)
Thank you for your attentionThank you for your attention
Zvolen 2000