7. A
PPENDIX
W
ESTEEL
- A
XIAL
F
LOW
A
ERATION
F
AN
7.3. G
RAIN
D
RYING
& A
ERATION
T
IPS
3HP, 5HP, 7HP, 10HP, & 15HP
28
198941
•
AT WHAT TEMPERATURE DOES NATURAL AIR DRYING BEGIN?
Grain
drying begins at 10°C (50°F). Anything less than 10°C means the air is too
cold and can only hold a small amount of moisture; therefore, moisture
removal from grain will be very slow.
•
WHEN SHOULD I START MY FAN FOR NATURAL AIR DRYING?
In order
to create a uniform drying front, the bin must be filled to the height of at least
half of the bin's diameter above the system.
(Example: A 14' diameter bin
needs to have a minimum of 7' of grain above the system). The best uniform
drying front can be produced by filling your bin and then turning on the fan.
Turning your fan on too soon can cause uneven drying and negative results.
•
WHEN SHOULD I START MY FAN FOR AERATION?
The aeration fan
should be started as soon as the aeration ducts are covered with grain when
filling. Once started, to prevent crusted grain, air flow through the grain bin
must be maintained until the bin reaches the desired temperature.
•
SHOULD I SHUT MY FAN OFF AT NIGHT OR WHEN IT RAINS?
NO! High
moisture grain drying (16% - 20%) requires continuous air flow to prevent the
drying front from crusting over and restricting airflow.
•
DOES FAN OPERATION AT NIGHT OR IN HIGH HUMIDITY CONDITIONS
REVERSE THE DRYING PROCESS?
We tend to think that a fan will force
moisture back into a bin in high humidity conditions. However, it is much more
difficult to put moisture back into the grain than it is to take it out. In fact, grain
in the bottom of the bin that may be a little over-dried would benefit from tak-
ing on a little moisture. At 19% moisture and 10°C, corn that hasn't been dried
will remain constant as the 86% relative humidity moisture level in the air
equals the moisture in the grain, refer to Table 7.1.
•
IF I ADD SUPPLEMENTAL HEAT, CAN I DRY IN HIGH HUMIDITY CONDI-
TIONS?
Adding supplemental heat (when available) to the natural air drying
process will reduce relative humidity and increase the rate of moisture move-
ment. Therefore, a low temperature supplemental heater will increase the
drying rate and reduce the drying time.
Table 7.1
Relative
Humidity
of Air %
Wheat Equilibrium
Moisture Content %
Canola Equilibrium
Moisture Content %
Corn Equilibrium Moisture
Content %
at 25ºC
(77ºF)
at 10ºC
(50ºF)
at 25ºC
(77ºF)
at 10ºC
(50ºF)
at 25ºC
(77ºF)
at 10ºC
(50ºF)
58
12
13
7.5
8.6
12.2
13.5
64
13
14
8.2
9.4
13.0
14.4
70
14
15
9.0
10.3
14.0
15.4
75
15
16
9.8
11.1
15.0
16.4
79
16
17
10.8
12.0
15.8
17.1
83
17
18
12.0
13.2
16.9
18.2
86
18
19
13.4
14.5
17.8
19.0
Содержание 10HP
Страница 4: ...WESTEEL AXIAL FLOW AERATION FAN 3HP 5HP 7HP 10HP 15HP 4 198941 ...
Страница 6: ...1 INTRODUCTION WESTEEL AXIAL FLOW AERATION FAN 3HP 5HP 7HP 10HP 15HP 6 198941 ...
Страница 18: ...4 OPERATION WESTEEL AXIAL FLOW AERATION FAN 4 4 EMERGENCY STOP 3HP 5HP 7HP 10HP 15HP 18 198941 ...
Страница 22: ...6 TROUBLESHOOTING WESTEEL AXIAL FLOW AERATION FAN 3HP 5HP 7HP 10HP 15HP 22 198941 ...
Страница 32: ...450 Desautels Street P O Box 792 Winnipeg Manitoba CANADA R3C 2N5 Phone 204 233 7133 Fax 204 235 0796 ...
