A covered stockpile dryer in action with a 11kW fan heated fan .
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This is still a work in progress ... but if people are lookign for an immediate solution , this is something that can be constructed on site and used immediately
wide 10mm square aviary mesh . They were hinged at the top so they could collapse when lifted out by a front-end loader .
Creating your dryer
Get the largest motor / fan combo that you can - the largest we observed was 11kW pushing about 12 m3 / s of 40 ° C air . That could dry a covered stockpile about 20m long with a 4m peak in about 2-3 days with a kernel moisture around 16 %. The air has to be dry - ambient air is no good . If you can ’ t create dry air , it would be better find a place outside the orchard rows to windrow . Diesel heaters were used ; in some cases connected to the fan , in others we used a diesel torpedo heater ( pictured right ) blowing at the fan inlet .
Covering stockpiles
The air saturates quickly so some air is wasted pushing it quickly through the fruit . As the air picks up moisture it will cool down ( just like an evaporative cooler ) and the temperature can drop 10-20 ° C within a metre of the air inlet .
A diesel torpedo heater .
The slower the airflow , the cooler the air will be , there is no getting away from the evaporative cooling effect . Nuts do not behave like grains , they are more porous when contained in bulk and hold a lot more moisture . Grains tend to disperse the air more evenly while nuts do not . Air will take the path of least resistance so we had to cover the stockpile to force a bit of back pressure into the stockpile ( pictured above ) and direct the air to exit along the ground through the thickest part of the stockpile .
A work in progress
This is still a work in progress as the nuts at the far end of the fan will dry faster than the nuts near the fan , but if people are looking for an immediate solution , this is something that can be constructed on site and used immediately . Want to know more ? Get in touch with me at Michael . coates @ plantandfood . com . au
industry . australianalmonds . com . au
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