Fan operation, Chapter 6 fan operation, Start-up maintaining grain quality grain storage – Grain Systems PNEG-119 User Manual
Page 15: Start-up, Maintaining grain quality, Grain storage, Equilibrium moisture chart
PNEG-119 Inline Centrifugal Fan
15
6. Fan Operation
Start-Up
On initial start-up of the fan, run it momentarily to make sure that the fan blade is rotating in the proper
direction and airflow is correct. If not, change motor direction using instructions on the motor.
Proper installation and start-up ensures many years of trouble-free operation.
Maintaining Grain Quality
To properly maintain the quality of stored grain, it is necessary to keep the grain dry, cool and insect free.
Any one of these problems can contribute to spoilage. Wet, warm grain promotes insect growth as well as
grain spoilage. Cool, dry grain can keep for long periods of time.
It is recommended that the grain be kept cool (avoid freezing as freezing can reduce quality). Grain should
be cooled through the fall and winter, warmed in the spring and summer.
Grain Storage
Average grain temperature should be above 35°F in the winter and below 65°F in the summer. Always try
to keep the grain within 10°F-15°F of the average monthly outside temperature. This means grain may
need to be aerated on warm days during the winter to stay above 35°F when freezing temperatures
are predominate.
During the summer it may be necessary to aerate the grain on cool nights, so the 65°F temperature is not
exceeded during the hot days of summer.
Conditions and requirements may vary from area to area. We suggest that you contact the local
Agriculture Extension Office or State Agriculture University for more exact guidelines.
If the grain is to be stored more than 1 year, it has to be recooled the following fall and winter, repeating
the process as long as the grain is in storage. Frequent and regular inspection (at least weekly during
fall and spring) is the best prevention against grain spoilage).
Equilibrium Moisture Chart
Air
Temperature
Percentage Relative Humidity
35
40
45
50
55
60
65
70
75
80
85
90
95
100
20°F
11.2
11.7
12.7
13.7
14.5
15.1
16.2
17.1
18.0
19.6
21.2
23.5
25.8
29.1
30°F
10.8
11.3
12.2
13.1
13.9
14.6
15.5
16.4
17.4
18.7
20.2
22.5
25.0
28.3
40°F
10.5
11.0
11.7
12.5
13.3
14.0
14.8
15.5
16.6
17.8
19.4
21.5
24.2
27.5
50°F
10.1
10.6
11.3
12.0
12.7
13.3
14.1
14.8
15.8
16.9
18.6
20.5
23.4
26.7
60°F
9.7
10.2
10.9
11.6
12.1
12.7
13.4
14.2
15.0
16.0
17.8
19.5
22.6
25.9
70°F
9.0
9.7
10.4
11.1
11.5
12.0
12.8
13.5
14.5
15.4
16.8
18.5
21.3
24.5
80°F
8.3
9.1
9.8
10.5
10.8
11.2
12.1
13.0
13.9
14.8
15.8
17.4
20.0
22.8
Safe moisture for normal winter storage of shelled corn is about 15%. Grain to be stored through the
summer or long term, needs to be 1 to 3 points dryer.