Drying Guide

Use the below drying guide to assist you with setting up and running a store using on-floor drying equipment. To use the High-Temperature drying method, you will need a Maxi-Stirrer to avoid capping the surface.

Relative Humidity Drying Guide

With a Maxi-Stirrer

  1. Tip the first loads around the bases of the stirrer flights to a minimum depth of 0.5m.
  2. Start the auger drive motors on the stirrer.
  3. Start to fill the store, keeping the top of the crop as level as possible.
  4. Once the first bay of the store is filled, the stirrer can be switched to travel.
  5. Place the stop on the track just before the crop slope.
  6. Continue to load the store, repositioning the stop as you go to include the additional crop.
  7. Leave the stirrer running in Auto overnight to thoroughly mix the crop.
  8. Turn on the drying fans and burners, following the equilibrium chart on the CHC, to set a target RH 2% below the grain moisture.
  9. Back pressure on the manometer should be maintained at a minimum of 2.5” – 3.0″ wg, or using our Air Flow Meter, target 16-20 ft/m on top of the crop
  10. It is vital that fans and burners are left running 24 hours a day. Your CHC will be sized to cope with any weather.
  11. Ventilate for 3 days before running the stirrer overnight to mix the crop.
  12. Check the moisture levels to determine if further drying is required.
  13. Reset the target RH on the CHC as crop moisture decreases. Stepping the RH down rather than making large-scale changes will avoid capping issues.
  14. Ventilate for 3 days between any stirring, as over-stirring WILL NOT improve drying time.
  15. It may be necessary to set the target RH 2 or 3 points below the value shown on the equilibrium chart to drive the remaining moisture from the crop.
  16. Once the crop has reached your required moisture level, stir it overnight again to ensure the best possible sample.

In terms of expected moisture reduction rates, 0.5% moisture should be removed for every 24 hours of running the drying fans and burners.

Without a Maxi-Stirrer

  1. Start to fill the store, keeping the top of the crop as level as possible.
  2. Turn on the drying fans and burners, following the equilibrium chart on the CHC, to set a target RH 2% below the grain moisture.
  3. Back pressure on the manometer should be maintained at a minimum of 3.5” wg, or using our Air Flow Meter, target 16-20 ft/m on top of the crop.
  4. It is vital that fans and burners are left running 24 hours a day. Your CHC will be sized to cope with any weather.
  5. Check the moisture levels to determine if further drying is required.
  6. Reset the target RH on the CHC as crop moisture decreases.
  7. Stepping the RH down rather than making large-scale changes will avoid capping issues.
  8. It may be necessary to set the target RH 2 or 3 points below the value shown on the equilibrium chart to drive the remaining moisture from the crop.
  9. Once the crop has reached your desired moisture level, proceed to cooling and conditioning.

In terms of expected moisture reduction rates, 0.5% moisture should be removed for every 24 hours of running the drying fans and burners.

High Temperature Drying Guide

With a Maxi-Stirrer

  1. Tip the first loads around the bases of the stirrer flights to a minimum depth of 0.5m.
  2. Start the auger drive motors on the stirrer.
  3. Start to fill the store, keeping the top of the crop as level as possible.
  4. Once the first bay of the store is filled, the stirrer can be switched to travel.
  5. Place the stop on the track just before the crop slope.
  6. Continue to load the store, repositioning the stop as you go to include the additional crop.
  7. Leave the stirrer running in Auto overnight to thoroughly mix the crop.
  8. In the morning, stop the stirrer and turn on the drying fans and burners, setting the set point to 45°C. Ventilate the stack for 12 hours; this will raise the crop temperature to 27°C-29°C. Back pressure on the manometer should be maintained at no more than 2.5” wg or using our Air Flow Meter, target 6-10 ft/m on top of the crop.
  9. Turn the drying fans and burners off overnight; this will cause the crop to sweat.
  10. Restart the fans and burners in the morning, and continue ventilating.
  11. Do not run the stirrers whilst ventilating the crop. Stir the crop fully overnight after the third day of ventilating.
  12. Restart the fans and burners in the morning, and ventilate for at least 2 hours to ensure an even sample.
  13. Decide if further drying is required, or if the crop can be cooled.
  14. In terms of moisture reduction rates, just heating the stack alone will remove 1.0% but with 12 hours of overnight sweating, an additional 0.5% will be removed, yielding approx. 1.5% in 24 hours.
  15. Repeat the ventilation/stirring cycle until the required moisture content is reached.

NOTE: This drying method is the most cost-effective way to dry bulk grain. However, it requires the highest level of store management to get the best results and avoid over-drying; we suggest you follow this drying guide to avoid this.

Without a Maxi-Stirrer

It is essential that you use a Maxi-Stirrer for the high-temperature drying process; otherwise, you will cause capping on the crop surface.

Cooling & Conditioning

  1. Whether Temperature Drying or using Relative Humidity, final cooling is an essential part of the storage process and one of the most important sections of this drying guide.
  2. Temperature-dried crops require high ventilation to reduce their temperature to ambient levels as quickly as possible.
  3. Further cooling can be planned for either drying type once ambient temperatures in the heap are established.
  4. As post-harvest temperatures drop, take every advantage of cooler nights to ventilate crops with high amounts of air.
  5. Ideally, use our Advanced Controller, which monitors air temperature, to maximise cooling time.
  6. A target of 9°C will ensure the crop remains in the best condition and provides pest control benefits.
  7. The CHC burner can be used in RH mode with a set point of 70% to safeguard against sudden increases in ambient air moisture. The burner will add only few degrees to the incoming air temperature, but will prevent the potential for damp air to be blown into the store for long periods.
  8. Once cooled, ventilate periodically throughout storage with cooler overnight air or cold winter-frosted air.
  9. Good store monitoring is essential for both temperature and moisture levels. It allows early action to be taken to control small pockets of grain that require extra ventilation or conditioning.
Advanced Controller
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