GNA-2538 R0
39
Important
Do not exceed the plenum temperatures listed in
below.
is not intended as a drying
guide. It should be used as a reference for setting maximum plenum temperature for safe operation
and minimizing damage to the commodity being dried.
Table 6.
Recommended Temperature
Crop
In-Bin
Continuous
Stir Drying
In-Bin Batch
Corn
160 °F (71 °C)
140 °F (60 °C)
120 °F (49 °C)
Grain Sorghum
160 °F (71 °C)
140 °F (60 °C)
120 °F (49 °C)
Wheat
140 °F (60 °C)
120 °F (49 °C)
110 °F (43 °C)
Rice
105 °F (40 °C)
100 °F (38 °C)
90 °F (32 °C)
Oats
140 °F (60 °C)
120 °F (49 °C)
110 °F (43 °C)
Sunflowers
110 °F (43 °C)
110 °F (43 °C)
100 °F (38 °C)
Soybeans
120 °F (49 °C)
120 °F (49 °C)
110 °F (43 °C)
Pinto Beans
100 °F (38 °C)
100 °F (38 °C)
100 °F (38 °C)
• Grain quality is enhanced when drying is accomplished at lower temperatures AND for optimal results,
monitor the temperatures in the bin at all times.
• The drying front moves upward from the base of the bin. Therefore, significant overdrying can occur at the
base of the bin in the area where the grain isn’t being stirred.
• As long as moisture is evaporating from the grain, the kernels remain relatively cool; but as the kernels
become dry they warm to the drying temperature. Therefore, higher temperatures increase not only the
drying rate but also the likelihood of damage to the grain.
• Reduce the drying temperature as grain reaches the target moisture content. Doing so will prevent cracked
grain and reduce fire hazard.
• Be very careful when drying sunflowers as they are highly flammable, especially the chaff. Do not exceed
temperature recommendations. Do not let the area around the dryer become cluttered with sunflower
residue or chaff.
• Do not automatically set the plenum temperature to the maximum recommended temperature.
Temperature Control
• The burner control, whether thermostat, humidistat, or modulating valve, determines the temperature
under the bin.
• Though you can operate the heater without a burner control mounted in the bin plenum, this practice is
NOT recommended. Excessive temperatures can lead to uneven drying, scorched product, or fire.
• AGI also recommends that a thermometer be mounted near the burner control probe under the bin to help
ensure that burner controls are operating at the desired setting.
• Standard heaters control the plenum temperature by cycling on and off:
–
The ideal cycle time should last between 1-½ and 3 minutes.
–
Avoid temperature settings that allow the heater to cycle on and off too frequently.
–
Cycle times will vary somewhat with each installation depending on factors such as bin size, grain depth,
fan size, and type of grain being dried.
AXIAL FAN HEATER – LP AND NG-FIRED HEATER
