The document describes experiments to determine the pressure drop and airflow rate through a storage bin filled with different commodities. Equations were fitted to resistance curves for maize using data points from manufacturers. The coefficients were determined through iteration to achieve an airflow rate of 1.5 m3/s at a pressure of 750 Pa, making maize suitable for the storage application.

1. Dimensions of Values for all the
Bin the storage constants were given in
Diameter, m (2r) 4 structure the adjacent tabel.
Bulk depth, m 4 (cylinder) Which were used in the
given equation
Physical properties
Commodity barley rye wheat rice maize
epsilon, poured 0.44 0.39 0.39 0.46 0.38
epsilon, shaken 0.4 0.35 0.36 0.42 0.36
c_1 Volume of 270 223 168 267 76
n Air/sec 0.7 0.7 0.7 0.7 0.6
(πr2 *vair )
Air flow resistance in bulk
Air velocity, m/ Airflow rate, (Pa)
s m3/s Barley (Pa) Rye (Pa) Wheat (Pa) Rice (Pa) Maize
0.0000 0.00 0 0 0 0 0
0.0100 0.13 72 97 73 60 23
0.0200 0.25 178 238 180 148 61
0.0300 0.38 302 404 304 250 108
0.0400 0.50 439 587 442 363 161
0.0500 0.63 587 785 591 486 220
0.0600 0.75 743 995 749 615 284
0.0700 0.88 908 1215 916 752 352
0.0800 1.00 1081 1446 1089 894 425
0.0900 1.13 1259 1685 1269 1042 501
0.1000 1.26 1444 1932 1456 1195 580
0.1100 1.38 1635 2187 1648 1353 663
0.1200 1.51 1830 2449 1845 1515 749
0.1300 1.63 2031 2718 2048 1681 838
0.1400 1.76 2237 2993 2255 1851 930
0.1500 1.88 2446 3274 2466 2025 1024
0.1600 2.01 2661 3560 2682 2202 1121
0.1700 2.14 2879 3852 2902 2383 1220
0.1800 2.26 3101 4149 3126 2567 1322
0.1900 2.39 3327 4451 3353 2754 1426
0.2000 2.51 3556 4758 3585 2944 1532

2. r all the Commodity Coefficient Rel. pore volume Coeficient
were given in n epsilon c1
ent tabel. poured shaken m^n-4 kg s^-n
ere used in the
ation
Barley 0.7 0.44 0.4 270
Rye 0.7 0.39 0.35 223
Wheat 0.7 0.39 0.36 168
Rice 0.7 0.46 0.42 267
Maize 0.6 0.38 0.36 76 1 2− n
∆ pbulk = c1 ⋅ h ⋅ ⋅v
ε 4
Resistance curves were
5000 plotted using the equation
above for all the crops, Maize
4500
is the crop which was
4000 choosen for the final step.
3500
3000 Air velocity, m/s
(Pa) Barley
2500 (Pa) Rye
2000 (Pa) Wheat
(Pa) Rice
1500 (Pa) Maize
1000
500
0
Row 20 Row 22 Row 24 Row 26 Row 28 Row 30 Row 32 Row 34 Row 36 Row 38
Row 19 Row 21 Row 23 Row 25 Row 27 Row 29 Row 31 Row 33 Row 35 Row 37 Row 39

3. icient
-4 kg s^-n
1 2− n
∆ pbulk = c1 ⋅ h ⋅ ⋅v
ε 4
Air velocity, m/s
(Pa) Barley
(Pa) Rye
(Pa) Wheat
(Pa) Rice
(Pa) Maize
34 Row 36 Row 38
Row 35 Row 37 Row 39

4. 1. Reading points from manufacturers chart
n, rpm V_L p stat Referance points
4000 1.11 3000 at 4000rpm were
4000 1.81 2800 taken for 3500
3300
4000 2.78 1800 Pressure and Air 3150
4000 3.8 400 Flow volume. 3000 3000
2. Finding an equation via iteration 2500 2526.56
2372.5
2000
p_0 3300
Pressure
Value of the
c 150 cofficients are as
1500
m 2.20 follows, the red line
was fitted to the
n1 n2 blue points by 1000
n, rpm 4000 3500 constantly changing
these variables
V_L, m³/s p1, Pa p2, Pa 500
0 3300 2526.56
1 3150 2372.5 0
0 0.5 1 1.
2 2610.78 1818.69
3 1618.26 799.31
Value of the p1 has been fitted to the
4 133.18 -725.97
reference points , using the given equation
for p1. Then the transformation step was
taken by using the second equation which
is for p2. The values of all the cofficients
( p_0, c, m) has been obtained by hit and
trail method.

5. Fanlines
3300
3150
3000
2800
2610.78
2526.56
2372.5
1818.69 1800
1618.26
799.31
400
133.18
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Air Volume
ted to the
given equation
tion step was
quation which
he cofficients
ned by hit and

6. 2 2 −m
n  n 
4.5 5
p2 =  2
n  ⋅ p0 − c ⋅  2
 n 


V m p = p − c ⋅V m

 1   1  1 0

7. 
− c ⋅V m

8. Airflow requirement Given Preconditions 3500
Airflow rate, m3/s 1.50 ( Target Line)
1.50 0 3000
1.50 3500
p_0 was constantly 2500
Reacting fan lines reduced to get the
p_0 1100 required intersection of all
c 150 the three lines, 2000
m 2.20 Final value of our
coffecients, p_0,c and m
n1 n2 are as follows. 1500
n, rpm 4000 3500
V_L, m³/s p1, Pa p2, Pa 750 Pascals is the operationing 1000
0 1100 2526.56 pressure at 1.5mcu./sec Airflow
1 950 2372.5 will be achieved for Maize.
2 410.78 1818.69 500
3 -581.74 799.31
4 -2066.82 -725.97
0
0 0.5
Resistance line
Barley Rye Wheat Rice
Air flow resistance in bulk
Airflow rate,
m3/s Pa Pa Pa Pa
0.00 0 0 0 0
0.13 72 97 73 60
0.25 178 238 180 148
0.38 302 404 304 250
0.50 439 587 442 363
0.63 587 785 591 486
0.75 743 995 749 615
0.88 908 1215 916 752
1.00 1081 1446 1089 894
1.13 1259 1685 1269 1042
1.26 1444 1932 1456 1195
1.38 1635 2187 1648 1353
1.51 1830 2449 1845 1515
1.63 2031 2718 2048 1681
1.76 2237 2993 2255 1851
1.88 2446 3274 2466 2025
2.01 2661 3560 2682 2202
2.14 2879 3852 2902 2383
2.26 3101 4149 3126 2567
2.39 3327 4451 3353 2754
2.51 3556 4758 3585 2944

9. 3500
3000
2500
2000
Column D
Column C
Column G
1500
Column B
oning 1000
irflow
e. optimum
500
0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Maize
Pa
0
23
61
108
161
220
284
352
425
501
580
663
749
838
930
1024
1121
1220
1322
1426
1532

10. Column D
Column C
Column G
Column B
4 4.5 5