A bespoke drying floor constructed for efficient bulk grain drying that can also cope with the added rigours of preparing woodchip for fuel is a feature of a 1,000t store in Aberdeenshire.
Among its other novelties is a remotely controlled stirring system with built in moisture sensors to “map” moisture distribution in the bulk and help get the grain dried evenly.
Grower Andrew Booth points out also that the store at Savoch Farm, Foveran, can easily be extended relatively easily in future to cope with increase tonnage.
As it is, the 36m x 24m structure designed and erected by Inverurie-based Rapid Project Development is laid out with two storage bunkers occupying four of the six bays with a concrete air tunnel between them.
The large clear area in front of them provides allows trailers to sweep in and out using the two roller shutter doors and there is sufficient room to load a lorry under cover.
Original plans to lay a proprietary heavy-duty ventilated floor were abandoned when the contractor’s quote for laying it came in.
“The concrete moulding system we planned to use could be laid only a section at a time, which meant it could have taken three weeks to install,” explains John-Paul Duxbury of RPD. “Using a system we had already installed at a woodchip drying facility, we were able to pour concrete for the drying floor in just three days.”
The floor is constructed by forming 2mm galvanised steel into U-shaped laterals with sufficient rigidity to also act as concrete shuttering. Being able to lay the concrete in less time made it a more affordable solution while still providing the long-term durability needed for drying woodchip.
Apart from being a more abrasive material, repeatedly drying batches of woodchip involves a lot more traffic from the farm loader and from trailers ferrying the fuel in and out of store.
Woodchip and a 750kW Kalvis automatic boiler were chosen as a cost-effective means of drying grain in a part of the country where it is pretty much assured that drying is needed most years.
“Drying costs are an important factor because we’re often cutting wet grain at 26-27% moisture in Aberdeenshire just to get the crop in store,” points out Mr Booth.
“You can try to reduce costs by investing in a bigger combine and be choosier about when to cut. But saving 6p/kWh and getting RHI payments of almost £8,500 a year means cutting wet and drying is the better option.”
Electronics specialist Kenny Addison prepared the control system, which includes wireless moisture sensing on the stirring augers and automatic fan control – both of also make a contribution to the cost-efficiency of the store.
The former allows targeted use of the augers to tackle wetter areas within the bulk, while the latter adjusts fan speed and power requirement as the grain dries and presents less air resistance.