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Consider options when selecting on-farm grain dryer
Farmers are increasingly
building their own grain handling systems and by-passing local elevators.
Grain dryer systems are an integral part of farm grain storage, and there are
many choices, according to Dr. Kenneth J. Hellevang, PE, Extension Agricultural
Engineer of North Dakota State University.
Natural drying has no
restrictions on the amount of grain dried but has a limit on the initial
moisture and can take several weeks to accomplish. Layer drying is
similar but grain with higher moisture can be dried as long as the amount is
limited in depth to what the fan can move air through. A layer that is
too deep will spoil because the air cannot penetrate the grain. Both of
these systems are common to smaller, older grain storage bins
Many farmers use bin batch
dryers, some with a stirring device to reduce moisture variation throughout the
bin. Some batch bins have a sweep auger that removes dry grain and
transfers it to another cooling bin for storage.
Column dryers can be
portable and the drying action takes place outside the storage bin. 2-3
hours per batch of up to 1,000 bushels may be possible with a column batch
dryer. The normal cycle is fill-head-cool-unload. Some column dyers
are continuous fill.
To increase efficiency, you
can partially dry a batch using the high-temperature method and finish with a
natural air system. Another way to attain efficiency is to use
dryeration. Hot grain is removed from the drying bin about 1-2% wetter
than desired allowed to temper without airflow for up to 6 hours. After
the temperature equalizes in the kernel, the cooling fan is turned on and the
temperature is taken down to the desired level.
publication is a good introduction to grain drying.