Do you know what the maximum moisture content is for drying wheat with natural air? How long you can shut off the fan when air drying wheat if the humidity is high? What temperature settings are recommended for crossover and plenum-type high temperature dryers when drying wheat?

Ken Hellevang, North Dakota State University Extension agricultural engineer, has the answers to those and other questions about drying wheat.

Eight things that he says every wheat grower should know about drying wheat include:

1. Max moisture content. The maximum recommended moisture content for natural-air drying wheat is 17%, which requires a minimum airflow rate of .75 cubic feet per minute per bushel (cfm/bu) to dry the wheat before it begins to spoil.

2. More heat. Supplemental heat is needed when the average relative the relative humidity exceeds 70%. The air only needs to be heated 2-3 degrees F.

3. Fairweather fans. When the weather is foggy or it’s raining, fans can be shut off. But don’t leave the fans off too long.  Wheat up to 16% moisture can hold without airflow for a few days, but wheat at 18% moisture should not be without airflow for more than a day or two due to the potential for heating and spoilage.

4. Max depth. The maximum recommended depth for natural air drying of wheat in a bin is about 18 feet.

5. Required horsepower. 1 horsepower of fan is needed for each 1,000 bushels of wheat to obtain an airflow rate of 0.75 cfm/bu.

6. Centrifugal fan. A centrifugal fan is required in a natural air system to dry wheat. The NDSU Grain Drying and Storage page has a link to a fan selection program. It can be used to determine the fan size needed to obtain the desired airflow or to estimate the airflow provided by an existing fan.

7. High temp. High-temperature drying is recommended if the wheat moisture content exceeds 17%.

8. Max temp.150 degrees F is the general recommended maximum drying air temperature for 16% moisture milling wheat in a cross-flow dryer. It is 130 degrees F for 20% moisture content wheat.

Generally, the recommended maximum temperature for a plenum type dryer where the kernel temperature remains below plenum temperature is a 30 degree higher than a cross-over type dryer. Allowable dryer temperatures will vary with dryer type and design. Refer to the manufacturer’s recommendation for guidance.

Source: NDSU, which is solely responsible for the information provided and is wholly owned by the source. Informa Business Media and all its subsidiaries are not responsible for any of the content contained in this information asset.