With ever increasing fuel costs it is even more important to dry grain as efficiently as possible. For many years now the proven system of humidity control in bulk stores has seen drying change from a lengthy hit and miss system completely dependant on weather conditions during the drying period, to a controlled continuous system with gas burners delivering drying air at a controlled humidity level, while this has dramatically reduced drying times and running costs in many cases there is still room for further reduction in expenditure.
It is a well proven fact that a continuous 24 hour drying regime gives the lowest drying cost per tonne although there are many growers who are tempted to suspend drying during periods of bad weather. The drying process in static bulk stores moves from floor level up through the crop and this needs to be a continuous process any break in ventilation will allow the “drying front” to drop back and when restarting considerable energy will be consumed just to get back to where the “drying front” was previously.
With continuous drying the crop ventilation fan will run for a shorter length of time overall, obviously during night time running and periods of high humidity gas will be consumed to control the quality of the air but the reduction in fan running time will more than compensate for this.
When starting to dry grain down from high moisture levels there is no point in switching on humidity controllers as ambient air with humidity as high as 85-90% will bring down moisture content to 19-20%, then the burners can be employed to continue to reduce grain moisture to the required level. Obviously an accurate indication of ambient humidity levels are required and the Harvest Humidity Controller will give a continuous readout even when not actually inducing heat.
Other factors which can reduce energy bills are starting the drying regime as soon as possible to get maximum benefit from ambient weather conditions early in the season. Also remember that any temperature build up in the store during the drying process can be utilised to give a drop in moisture content when cooling dependent on the amount of heat to be removed and this should be taken into account when calculating the final moisture content required.
Bulk stores fitted with stirring systems will dry faster than static stores, but the same guidelines apply to keep energy costs to a minimum.
For further information please contact HARVEST INSTALLATIONS.
Unit E, North Yard, The Brents, Faversham, Kent. ME13 7DZ
Tel: 01795 533903 Fax: 01795 538524