Effects of Discharge Fan on the Drying Efficiency in Flat-bed type Dryer
The study of interaction among the grain, moisture,
and the surrounding space (air) is key to understanding the graindrying
process. In Iran, rice (mostly Indica type) is dried by flat
bed type dryer until the final MC reaches to 6 to 8%. The
experiments were conducted to examine the effect of application of
discharge fan with different heights of paddy on the drying
efficiency. Experiments were designed based on two different
configurations of the drying methods; with and without discharge
fan with three different heights of paddy including; 5, 10, and 15
cm. The humid heated air will be going out immediately by the
suction of discharge fan. The drying time is established upon the
average final MC to achieve about 8%. To save energy and reduce
the drying time, the distribution of temperature between layers
should be fast and uniform with minimum difference; otherwise
the difference of MC gradient between layers will be high and will
induce grain breakage. The difference of final MC between layers
in the two methods was 48-73%. The steady state of temperature
between the two methods has saved time in the range of 10-20%,
and the efficiency of temperature distribution increased 17-26% by
the use of discharge fan.
[1] J. Hashemi, A. Borghei, N. Shimizu, &T. Kimura, "Optimization of
Final Moisture Content of Paddy in Flat Bed Dryer with
Consideration of Minimum Losses and Marketability in Iran," Journal
of Agricultural Sciences and Natural Resources of Khazar, 2005,
3(2), 72-82.
[2] L. Velupilla, &J. P. Pandey, "The impact of fissured rice on milled
yields," Cereal Chem., 1990, 67(2), 118-124.
[3] B. K. Bala, "Drying and storage of cereal grains (Book style).,"
Oxford & IBH publishing Co. PVT. LTD. New Dehli, 1997.
[4] M. A. Basunia, & T. Abe, "Thin-layer solar drying characteristics of
rough rice under natural convection," Journal of Food Engineering,
2001, 47, pp. 295-301.
[5] V. K. Arora, S. M. Henderson, & T. H. Burkhardt, "Rice drying
cracking versus thermal and mechanical properties," Transactions of
the ASAE, 1973, 16, 320-327.
[6] C. Chiachung, "Evaluation of air oven moisture content determination
methods for rough rice," Biosystems Engineering, 2003, 86 (4), 447-
457.
[7] R. Aguerre, C. Suarez, & P. E. Viollaz, "Effect of drying on the
quality of milled rice," Journal of Food Technology, 1986, 21, 75-80.
[8] W. Yang, C. Jia, T. G. Siebenmorgen, & A. Cnossen, "Intra kernel
moisture gradients and glass transition temperature in relation to head
rice yield variation during heated air drying of rough rice (Published
Conference Proceedings style)," Paper No. 069. In proceedings of the
twelve-s International Drying Symposium. Netherland, 2000.
[9] P. Somkiat, N. Poomsa-ad, & S. Somchart, "Quality maintenance and
economy with high-temperature paddy-drying processes," Journal of
Stored Products Research, 2004.
[10] S. Zhenhua, W. Yang, T. Siebenmorgen, A. Stelwagen, & A.
Cnossen, "Thermo mechanical transition of rice kernels," Cereal
Chem., 2002, 79(3), 349-353.
[11] O. R. Kunze, "Moisture adsorption in cereal grain technology.
Areview with emphesis on rice," Applied Eng. In Agric, 1991, 7, 717-
723.
[12] R. C. Bautista, T. J. Siebmorgen, & A. G. Cnossen, "Fissure
formation characterization in rice kernels using video microscopy
(Published Conference Proceedings style)," Proceedings of the 12th
international drying symposium. IDS2000, paper no. 419. Elsevier
science, Amsterdam, 2000.
[13] A. P. Mossman, "A review of basic concepts in Rice-drying research,"
Critical Rev. in Food Science and Nutrition, 1986, 25(1), 49-70.
[1] J. Hashemi, A. Borghei, N. Shimizu, &T. Kimura, "Optimization of
Final Moisture Content of Paddy in Flat Bed Dryer with
Consideration of Minimum Losses and Marketability in Iran," Journal
of Agricultural Sciences and Natural Resources of Khazar, 2005,
3(2), 72-82.
[2] L. Velupilla, &J. P. Pandey, "The impact of fissured rice on milled
yields," Cereal Chem., 1990, 67(2), 118-124.
[3] B. K. Bala, "Drying and storage of cereal grains (Book style).,"
Oxford & IBH publishing Co. PVT. LTD. New Dehli, 1997.
[4] M. A. Basunia, & T. Abe, "Thin-layer solar drying characteristics of
rough rice under natural convection," Journal of Food Engineering,
2001, 47, pp. 295-301.
[5] V. K. Arora, S. M. Henderson, & T. H. Burkhardt, "Rice drying
cracking versus thermal and mechanical properties," Transactions of
the ASAE, 1973, 16, 320-327.
[6] C. Chiachung, "Evaluation of air oven moisture content determination
methods for rough rice," Biosystems Engineering, 2003, 86 (4), 447-
457.
[7] R. Aguerre, C. Suarez, & P. E. Viollaz, "Effect of drying on the
quality of milled rice," Journal of Food Technology, 1986, 21, 75-80.
[8] W. Yang, C. Jia, T. G. Siebenmorgen, & A. Cnossen, "Intra kernel
moisture gradients and glass transition temperature in relation to head
rice yield variation during heated air drying of rough rice (Published
Conference Proceedings style)," Paper No. 069. In proceedings of the
twelve-s International Drying Symposium. Netherland, 2000.
[9] P. Somkiat, N. Poomsa-ad, & S. Somchart, "Quality maintenance and
economy with high-temperature paddy-drying processes," Journal of
Stored Products Research, 2004.
[10] S. Zhenhua, W. Yang, T. Siebenmorgen, A. Stelwagen, & A.
Cnossen, "Thermo mechanical transition of rice kernels," Cereal
Chem., 2002, 79(3), 349-353.
[11] O. R. Kunze, "Moisture adsorption in cereal grain technology.
Areview with emphesis on rice," Applied Eng. In Agric, 1991, 7, 717-
723.
[12] R. C. Bautista, T. J. Siebmorgen, & A. G. Cnossen, "Fissure
formation characterization in rice kernels using video microscopy
(Published Conference Proceedings style)," Proceedings of the 12th
international drying symposium. IDS2000, paper no. 419. Elsevier
science, Amsterdam, 2000.
[13] A. P. Mossman, "A review of basic concepts in Rice-drying research,"
Critical Rev. in Food Science and Nutrition, 1986, 25(1), 49-70.
@article{"International Journal of Biological, Life and Agricultural Sciences:51606", author = "Jafar Hashemi and Reza Tabatabaekoloor and Toshinori Kimura", title = "Effects of Discharge Fan on the Drying Efficiency in Flat-bed type Dryer", abstract = "The study of interaction among the grain, moisture,
and the surrounding space (air) is key to understanding the graindrying
process. In Iran, rice (mostly Indica type) is dried by flat
bed type dryer until the final MC reaches to 6 to 8%. The
experiments were conducted to examine the effect of application of
discharge fan with different heights of paddy on the drying
efficiency. Experiments were designed based on two different
configurations of the drying methods; with and without discharge
fan with three different heights of paddy including; 5, 10, and 15
cm. The humid heated air will be going out immediately by the
suction of discharge fan. The drying time is established upon the
average final MC to achieve about 8%. To save energy and reduce
the drying time, the distribution of temperature between layers
should be fast and uniform with minimum difference; otherwise
the difference of MC gradient between layers will be high and will
induce grain breakage. The difference of final MC between layers
in the two methods was 48-73%. The steady state of temperature
between the two methods has saved time in the range of 10-20%,
and the efficiency of temperature distribution increased 17-26% by
the use of discharge fan.", keywords = "FBT Dryer, Final MC, Discharge Fan.", volume = "3", number = "1", pages = "26-5", }