Grain Systems PNEG-1851 - Manual (Page 83)

Appendix A: Grain Drying Operations
Table A-6 Description of common grain cooling processes
Cooling process Description Advantages Disadvantages
Dryeration Hot grain is discharged
from the dryer with a
slight amount (2% to
3%) of excess moisture
and heat, tempered for
several hours in a dry-
eration bin, and then
slowly cooled to attain
the desired moisture
content before it can
be stored.
• Hot grain is
allowed to
temper (steep in
its own vapor),
thus reducing the
risk of stress
cracks.
• Produces grain
of high quality.
• Increases drying
capacity because
the grain is dis-
charged hot and
not cooled.
• Increases energy
efficiency
because the
grain spends less
time in the dryer.
• Process is slower
than with in-stor-
age cooling,
because the
grain is trans-
ferred from the
dryer to the dry-
eration bin to the
storage bin.
• Requires careful
planning, addi-
tional manage-
ment time, more
grain handling
equipment, and
the extra costs
associated with
aforementioned.
• Requires you to
move the grain to
a final storage
bin because of
the excess mois-
ture in the dryera-
tion bin.
In-storage cooling Hot grain is discharged
from the dryer at a
moisture content that is
1.5% to 2% above its
target, placed in a stor-
age bin where it is
immediately cooled,
and left there to store.
In-storage cooling is
GSI’s recommended
cooling method.
• Process is faster
than dryeration
because the tem-
pering phase is
eliminated.
• Grain can be
cooled and
stored in the
same bin.
• If cooling is
delayed upon
transferring the
hot grain to the
storage bin, con-
densation might
form inside the
bin and affect the
grain quality.
• Cooling fans
inside storage
bin must be able
to keep up with
the dryer; there-
fore the fans’ air-
flow is dictated
by the dryer’s
capacity, not the
bin’s capacity.
PNEG-1851 Vision N2 83