2011 International Conference on Alternative Energy in Developing Countries and Emerging Economies
- 172 -
P
HYSICAL DRYING CHARACTERISTICS AND SPECIFIC ENERGY CONSUMPTION
(SEC)
IN EXPERIMENT
Drying temp. (°C)
& RH (%)
Drying
time
(h)
Drying
rate
(kg/h)
Physical drying characteristics
SEC
(kJ/kg H
2
O
evap.)
Shrinkage
(%)
Brightness and color
Bubble
Initial
Final
Infrared Radiation Drying
39.2
127
0.2631
7.16
Dense/white
color
Bright gel/
yellow color
No
131.63
44.0
111
0.4171
11.17
Bright gel/
yellow color
No
193.05
51.2
89
0.3025
4.93
Bright gel/ yellow color
No
149.12
54.2
46
0.6103
4.57
Bright gel/ dark yellow color
Little
139.70
62.9
44
0.7205
8.74
Sticky/ yellow color
Much
170.31
64.1
39
0.9116
5.62
Bright gel/ dark yellow color
Much
141.05
Green House Drying
36.1,65.6
190.3
0.2805
3.31
Dense/white
color
Sticky/ yellow color
No
-
32.8, 68
212.4
0.2438
3.34
Dense/white
color
Sticky/ yellow color
No
-
Green House + Conventional Drying
(31.5, 60),
(28.7, 55)
278.4
0.2010
2.73
Dense/white
color
Bright gel/
yellow color
No
-
(35, 67),
(29.3,51.5)
190.3
0.2517
2.95
Dense/white
color
Bright gel/
yellow color
No
-
Open Sun + Conventional Drying
12hr (26.8, 58),
(28.1,60)
286.1
0.1118
2.98
Dense/white
color
Bright gel/
yellow color
No
-
24hr (27.4, 55),
(28.9, 55)
232
0.1250
2.91
Bright gel/
yellow color
No
-
48hr (27.8, 55),
(29.5, 53)
211.2
0.1576
6.71
Bright gel/
yellow color
-
Hot- Air Drying
24hr (60.5),
Convectional (29,
55)
159.1
0.1905
3.05
Dense/white
color
Bright gel/ dark yellow color
Much
49.1
62.1
87.4
0.4130
3.07
Bright gel/ dark yellow color
Much
153.6
V.
C
ONCLUSION
The results can be concluded as the follows:
1.
Equilibrium moisture content (EMC) of the
unsmoke sheet rubber increase when the relative
humidity increases. The appropriate mathematical
model equation for well describing experimental
results was the Modified Halsay EMC model.
2.
The drying rate increased with increase of inlet
drying temperature.
3.
Effective moisture diffusion coefficient exponential
related to drying temperature and can be written as
Arrhenius equation.
4.
The drying time of rubber sheet was affected by
sheet thickness, drying temperature and IR intensity
level.
5.
The standards confirm high quality of unsmoke
sheet rubber can be used as the same standardized
level as STR5L quality.
A
CKNOWLEDGEMENT
The authors wish to express their sincere thank to the
National Research University Project of Thailand's Office
of the Higher Education Commission, the Graduate
school scholarship, Department of Physics, Department of
Biochemistry under Faculty of Science, Department of
Chemical Engineering under Faculty of Engineering
Prince of Songkla University Thailand for their grant and
financial support.
R
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