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 • • • • • • • • Safety equipment Loaders/augers Power sweep Perforated Floor Fans Dryers & heat recyclers Aerators Ventilators Storage Goals • • • • • 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 • • • • • • • 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. – – – – 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 • • • • • • • • 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 • • • • 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!