Fan operation – Grain Systems PNEG-119 User Manual
Page 16
6. Fan Operation
16
PNEG-119 Inline Centrifugal Fan
Approximate Allowable Holding Time for Field-Shelled Corn, to Maintain Grade*
Drying fronts and/or temperature fronts move through grain at different rates depending on bin and fan
size and different moistures and temperatures.
lists the approximate time required to completely change the temperature of a bin.
Current conditions can cause this time to vary greatly. Therefore, this should only be used as a guide.
It may be necessary to run the fan only part of a day because of changing weather conditions. It would be
necessary to run it a few hours each day on several days to complete the temperature change.
Approximate Hours of Fan Time to Change Bin Temperature
1. Bushels are rounded and approximate.
2. The hours required are based on clean grain. High moisture grain and grain containing fines or foreign material will
require more time to complete the air change.
3. Not Recommended: Bins in the NR range, may require fan(s) of a different size to get the cool time into the
accepted range.
4. Bins requiring more than 100 hours of aeration to totally change the temperature may require continuous aeration at
about 1/10
th
CFM per bushel or some other acceptable method.
Grain
Temperature
15%
Days
18%
Days
20%
Days
22%
Days
24%
Days
26%
Days
28%
Days
30%
Days
40°F
898
195
85
54
38
28
24
20
50°F
451
102
46
28
19
16
13
11
60°F
242
63
26
16
10
8
6.5
5.5
70°F
147
37
13 8
5
4
3.5
3
80°F
109
27
10
6
4
3
2.5
2
*Allowable holding time for field-shelled corn at various grain temperatures and moisture.
Fan Size
HP
Bin Diameter Approximate 22' to Eave-Approximate Hours
of Fan Time Required
Approximate 32' to Eave
18
21
24
27
30
33
36
42
48
36
42
48
1
73
79
90
NR
NR
NR
NR
NR
NR
NR
NR
NR
1.5
56
61
65
66
76
82
92
NR
NR
NR
NR
NR
3
44
51
52
57
63
69
78
93
NR
NR
NR
NR
7
38
42
44
47
52
56
61
71
81
79
93
NR
10
35
37
41
42
45
49
53
62
71
72
82
92
15
30
32
35
39
40
42
45
54
63
62
70
80
Approximate BU
4500
6500
8500
11000
13500
16500
19500
27000
35500
28000
38500
50500
NR