A survey of bulk grain stores that Harvest Installations have been involved in over the last three seasons has shown that the average capacity of new stores is now in excess of 2000 tonnes.
Storage depth is invariably 12’ (3.6m) or 14’ (4.2m) with the use of stirring systems there is no longer any problem with storage depths over 10’(3m) but consideration must be given to the provision of an adequate “pusher” to be able to achieve these greater depths when filling to maximum capacity.
Although store capacity has been increasing over the years fan size has not increased proportionately it appears that a fan capacity to dry approximately 500tonnes per batch fulfils most growers requirements this keeps energy requirements both electrical and gas at reasonable level for either humidity of temperature drying.
Increasing number of stores are being fitted with a second stirrer unit enabling two batches to be treated at the same time this means conditioning, cooling or drying can take place at the same time when batches need to be moved on quickly. Although some stores are initially supplied with two stirrers most second units are fitted retrospectively.
Without exception ventilation and extraction fan units are fitted as standard to avoid excessive condensation problems that can occur with the enhanced rate of drying now available. Fans can either be roof mounted, positioned at the eaves or gable end these units also greatly improve the working environment within the store, current installation techniques avoid any ingress of rain making these fans completely waterproof. All extraction and air inlet areas can be fitted with acoustic cowls which have been used in noise sensitive areas.
Building structures now have further increased eaves height to allow for greater storage depths and to give clearance for ever increasing trailer size. Concrete retaining walling has now become almost universally used giving a durable and easy cleaning structure.
There is also an increasing trend to design buildings with side entry doors this give the advantage of segregating the storage area into four units if required.
Although various patterns have evolved over the last few years with the incorporation of stirrers into floor stores and drying units it is still imperative that each customers individual requirements are discussed in depth before a final specification is decided on.