7/21/2019 Fluidized Bed Dryer Technical Poster
http://slidepdf.com/reader/full/fluidized-bed-dryer-technical-poster 1/6
Fluidized bed drying system offers better solution when dryinghigh moisture paddy. The grains are semi-suspended in highair flow and experience vigorous mixing.To this date, there is no commercial paddy drying system thatentirely uses fluidized bed dryers for both first stage andsecond stage drying.
Thus, in 2013 PHilMech developed a laboratory-scalemodel with 5 kg/batch capacity (Pontawe, et.al., 2013).Therefore, the established technical parameters needs toalidate for larger Fluidized Bed Dryer capacity.
The developed laboratory-scale fluidized bed dryer
To develop a pilot-scale model fluidized bed dryer for highmoisture paddy with full-automatic control system.Specific Objectives: To evaluate a pilot-scale (500 kg/h grain flow rate) fully
automated fluidized bed dryer for drying high moisturepaddy.
To validate the technical operating conditions for full dryingof high moisture paddy.
To evaluate the grain quality and energy consumption of thedeveloped pilot-scale model fluidized bed dryer system.
Material flow diagram of the pilot-scale model during dryingexperiments
1. Loading Bin2. Venturi-type Conveyor3-4 Drying Chamber5-6 Tempering Bin7. Screw Conveyor
Complete drying of high moisture paddy can be attained using fluidized bed dryingsystem with the following technical parameters:70°C drying temperature 2 minutes fluidization time10.16 cm grain depth 6 in H2O static pressure4.9 m/s superficial air velocity60 minutes tempering (ambient air & forced air)
The developed fluidized bed dryer system offers low energy requirement (2.84MJ/kg with substantial reduction on the drying time (82%).
Milled products dried using the technical parameters passed the PAES limits forHRY recovery.
Major parameters that influenced consumer’s preferences in buying milled rice likecolor, aroma, taste and mouth-feel have no significant differences between thefluidized bed and air dried sample.
Drying could be
done in severalways
Sun drying is the cheapestmethod, but it is not feasibleduring rainy seasons.
Mechanical dryerslike flatbed islabor intensive
Recirculating batch-typeis not ideal for handlinghigh moisture paddy.
The developed automated pilot-scale modelfluidized bed dryer
Particulars Parameters
Drying temperature (oC) 70
Airflow rate (m3/s) 1.47 (4.9 m/s)
Static pressure (inch H2O) 6
Grain depth (cm) 10.16
Fluidization time (minute) 2
Ambient tempering (minute) 30
Forced air tempering
(minute)
30
Table 1. Technical parameters established
Table 2. Mean scores on the color, aroma, tasteand mouth-feel of paddy dried
Attributes Product Mean Mean Std. Error
Over-allliking
A 6.7292a
0.19465B 6.9167a 0.18792
Color A 6.9800a 0.19057
B 7.3400a 0.17982
Aroma A 6.5510a 0.17990
B 6.2449a 0.28050
Taste A 6.9800a 0.19270
B 6.8800a 0.24014
Mouth-
Feel
A 6.2245a 0.26609
B 6.4286ab 0.24046
10.00
14.00
18.00
22.00
26.00
30.00
34.00
0 20 40 60 80 100 120 140
M o i s t u r e c o n t e n t ( % w
e t b a s i s )
Drying Time (min)
Figure 1. Moisture reduction of paddy dried at70˚C and 2 min fluidization time with 30.95%(wet basis) initial MC
0
0.08
0.16
0.24
0.32
0.4
0.48
0.56
0.64
0.72
0.8
0.88
0.96
0 20 40 60 80 100 120 140
( M - M e ) / ( M o - M e )
Drying time (min)
70 80
90 100
Figure 3. Normalized MC of paddy dried at
different drying temperatures with 2 min.fluidization
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80 100 120 140
( M -
M e ) / ( M o - M e )
Drying time (min)
2 min fluidization
3 min fluidization
Figure 2. Normalized MC of paddy dried at 70̊ Ctemperature
2.2
2.7
3.2
3.7
4.2
4.7
5.2
5.7
65 70 75 80 85 90 95 100 105
S p e c i f i c H e a t E n e r g y C o n s u m p t i o n
( M J / k g )
Drying temperature, oC
25-30% (w.b.) IMC
31-35% (w.b.) IMC
a
b
a
b
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
60 70 80 90 100 110
H R Y R
Drying temperature, oC
2 minutes fluidization
3 minutes fluidization
Figure 4. Specific heat energy requirement(MJ/kg) of paddy dried at different dryingtemperature with 2 min. fluidization time and 60min. tempering period
Figure 5. Head rice yield reduction ratio ofsamples dried in relation to the different drying
temperatures (HRYR with the same script is notsignificantly different at a=0.05)
Engr. Reagan J. Pontawe1, Engr. Nestor T. Asuncion1, Engr. Roselyn B. Villacorte2 and Dr. Romualdo C. Martinez3
1Science Research Specialist, 2Science Research Analyst, 3Chief Science Research Specialist
7/21/2019 Fluidized Bed Dryer Technical Poster
http://slidepdf.com/reader/full/fluidized-bed-dryer-technical-poster 2/6
7/21/2019 Fluidized Bed Dryer Technical Poster
http://slidepdf.com/reader/full/fluidized-bed-dryer-technical-poster 3/6
7/21/2019 Fluidized Bed Dryer Technical Poster
http://slidepdf.com/reader/full/fluidized-bed-dryer-technical-poster 4/6
7/21/2019 Fluidized Bed Dryer Technical Poster
http://slidepdf.com/reader/full/fluidized-bed-dryer-technical-poster 5/6
7/21/2019 Fluidized Bed Dryer Technical Poster
http://slidepdf.com/reader/full/fluidized-bed-dryer-technical-poster 6/6
Top Related