On-farm Bin Storage
Sandra M. Frost
UW Cooperative Extension Service
Crops
• Small grains, barley, wheat, oats
• Corn
Bin Types
• Low profile bins 12-13 ft depth
• Deep bins 17-18 ft depth
• Hopper-bottom bins
Bin Systems
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Safety equipment
Loaders/augers
Power sweep
Perforated Floor
Fans
Dryers & heat recyclers
Aerators
Ventilators
Storage Goals
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Avoid crop loss at harvest
Prolong crop storage life
Maintain crop quality
Increase value of crop
National/international availability
Storage Principles
• Proper crop condition going into storage
• Control moisture
• Control temperature
• Control insects
Grain Conditioning Technology
• We dry a crop because we choose to
harvest a slightly “wet” crop to avoid
harvest losses
Management
• Moisture content for crops:
– Shelled corn at 13% to 15.5%
– Wheat, barley, oats at 13%
– Sunflowers at 8% to 10%
• No advantage to frozen grain
• Clean grain has uniform air spaces
• Distribute/eliminate fines in bin
S.L.A.M.
• Sanitation
• Loading
• Aeration
• Monitoring
Bin Sanitation
• Clean and sanitize aeration ducts, augers,
floors
• Remove weeds, trash, moldy crop
• Spray insecticides while bin is empty
• Clean/inspect/replace aeration equipment
and dryers
Loading
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Optimize handling & storage operations
Operate augers at capacity, slow speed
Use a spreader to fill bin
Core the fines from center of grain
level peaked grain ASAP
Record grain moistures going into storage
Screen for mycotoxins
Aeration Goals
• To cool dried grain uniformly to 30-35oF.
• Move cooling front completely through and
out of grain mass
• Avoid condensation on inside walls/roof
• Maintain low grain temps as long as
possible
Aeration
• Aeration rates depend upon 4 factors.
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Bin type
Air distribution system
Desired grain moisture content
Management practices
Spring
Fall
Aeration
• Air flow either positive pressure (flow up) or
negative (flow down)
• Ventilation required during fan operation
• Fan operation times depend upon airflow rate
Monitoring
• Check for insects while grain temperature is
above 50 F. If found then fumigate. Fumigation
will not be effective below 50 F.
• Temperatures below 50 F will control insects
• Inspect grain surface at least every other week
• Walk on grain, poke into it, check for hot spots or
insect infestations.
From Warm to Cool
From Wet to Dry
Drying
• Warms the kernel – water leaves kernel
through osmosis
• Evaporates water from the kernel surface
• For grain, to remove 1 lb water takes 1300
BTU’s at 60oF.
Drying Methods
• Equilibrium
– Natural air and fans
– Relative vapor pressure
– Charts
– Drying front moves through grain
Drying Methods
• Non-equilibrium
– Heated air in a bin or column dryer
Quantity of Grain
Drying
• Calculations to get the amount of grain stored
• You can calculate the size of the job
• You can relate it all to the speed of harvest for
bin management
Safety
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Safety equipment
Loaders/augers
Power sweep
Perforated Floor
Fans
Dryers & heat recyclers
Aerators
Ventilators
Bin Safety
• Enter a bin only if you know its history and if you
are not alone
• If grain has not been removed you should see a
cone in the middle of the bin.
• If grain has been removed you should see a flat
area or inverted cone, and a shiny surface on
the side of the bin. If you do not see these signs,
surface may be crusted and unsafe to enter.
Bin Safety
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Label bins to warn of entrapment hazard
Lock entrances
Install ladders inside bins
Do not enter while loading/unloading
Bin Safety
• Shut off and lock out power when entering
• Wear NIOSH-approved dust filter
respirators
• Be cautious of grain that is out of condition
• Do not work alone in bins
Bin Safety
• 3 kinds of entrapment
– Flowing grain: auger creates funnel effect
– Grain bridge over hollow cavity
– Avalanche of vertical grain wall
Bin Safety
• Prevention
– Lock out power sources before entering
– Work from the top down
– Wear body harness, have inside ladder
Precaution !
• The maximum temperature for drying
barley is 100 F. Higher temperatures will
kill the embryo in the barley kernel.
• A dead embryo
will NOT make beer!